KR101776447B1 - Polyimide precursor and resin composition containing same - Google Patents

Abstract

로 나타내는 디아민을 포함하는 모노머 성분으로부터 얻어지고, 또한 하기 일반식 (B) :

{식 중, 복수 있는 R₃ 과 R₄ 는 각각 독립적으로 탄소수 1 ∼ 20 의 1 가의 유기기이고, 그리고 h 는 3 ∼ 200 의 정수이다} 로 나타내는 구조 단위를 갖는 폴리이미드 전구체로서, 이것을 가열 경화시킨 경우, 150 ℃ ∼ 380 ℃ 의 온도 영역에 적어도 1 개의 유리 전이 온도를 갖고, 0 ℃ ∼ 150 ℃ 의 온도 영역 (양단을 포함하지 않는다) 에 유리 전이 온도를 갖지 않고, 그리고 그 이미드기 농도가 2.00 ∼ 3.70 m㏖/g 인, 용매를 포함하고 있어도 되는 폴리이미드 수지가 얻어지는 것을 특징으로 한다.A polyimide precursor useful for the production of a polyimide film which is colorless and transparent and has low residual stress generated between the film and the inorganic film and which is excellent in mechanical properties and thermal properties.
The polyimide precursor is represented by the following formula (A):

(B): < EMI ID = 1.0 >

(Wherein plural R ₃ and R ₄ are each independently a monovalent organic group having 1 to 20 carbon atoms and h is an integer of 3 to 200), which is heat-cured , It has at least one glass transition temperature in a temperature range of 150 ° C to 380 ° C and does not have a glass transition temperature in a temperature range of 0 ° C to 150 ° C (not including both ends) A polyimide resin which may contain 2.00 to 3.70 mmol / g of a solvent may be obtained.

Description

TECHNICAL FIELD [0001] The present invention relates to a polyimide precursor and a resin composition containing the polyimide precursor,

The present invention relates to a polyimide precursor and a resin composition containing the polyimide precursor, a polyimide film and a process for producing the polyimide precursor, a laminate and a process for producing the same, which are used for a substrate for a flexible device, for example.

Generally, a polyimide (PI) film is a film of a polyimide resin. A typical polyimide resin is a polyimide resin obtained by solution polymerization of an aromatic dianhydride and an aromatic diamine to prepare a polyimide precursor, followed by ring-closing dehydration at a high temperature, thermal imidization, or chemical imidization using a catalyst, Resin.

The polyimide resin is an insoluble or refractory super heat resistant resin and has excellent properties such as heat oxidation resistance, heat resistance, radiation resistance, low temperature resistance, and chemical resistance. The polyimide resin is used in a wide range of fields including an insulating coating, an insulating film, a semiconductor, and an electrode protective film of a TFT-LCD. In recent years, instead of a glass substrate conventionally used in the field of display materials such as a liquid crystal alignment film, , And a colorless transparent flexible substrate using flexibility.

However, a general polyimide resin is colored in brown or yellow by a high directional ring density, has a low transmittance in a visible light region, and is difficult to be used in fields requiring transparency.

In order to improve the transparency of such a polyimide, non-patent reference 1 below discloses a method for producing a polyimide film, which comprises reacting 2,2-bis (trifluoromethyl) benzidine (hereinafter also referred to as TFMB) Discloses a polyimide having improved transmittance and transparency of color.

On the other hand, Patent Document 1 below discloses introducing a flexible skeleton such as silicon diamine into a polyimide by random copolymerization in order to lower the glass transition temperature or the Young's modulus of the polyimide film.

In the following Patent Document 2, a flexible silicon-containing diamine is introduced by block copolymerization for the purpose of reducing residual stress while maintaining the glass transition temperature or Young's modulus of the polyimide.

In Example 11 of the following Patent Document 3, a polyimide that exhibits high Tg, transparency, high adhesion, and low warpage is produced by copolymerizing a specific alicyclic tetracarboxylic acid dianhydride with a fluorine-based diamine or a silicon- Polyimide precursors are disclosed.

Japanese Patent Application Laid-Open No. 2007-246920 International publication number 2012/118020 pamphlet International publication number 2011/122198 pamphlet

 The latest polyimide (foundation and application) Japanese polyimide research meeting compilation manual P152

In the polyimide resin described in Non-Patent Document 1 in which transparency and color transparency are improved by using the above-mentioned 2,2-bis (trifluoromethyl) benzidine and acid dianhydride having a specific structure, its mechanical and thermal properties For example, a semiconductor insulating film, a TFT-LCD insulating film, an electrode protecting film, and a heat-resistant colorless transparent substrate for a flexible display.

When a polyimide resin is used for a colorless transparent substrate for a flexible display, a polyimide film is usually formed on a support such as a support glass, and on top of the polyimide film, an inorganic material such as silicon nitride or silicon dioxide Or a film is formed. When the coefficient of linear expansion of polyimide (hereinafter also referred to as CTE) is high, residual stress is generated between the inorganic film and the support glass due to mismatch of CTE between the inorganic film and the support glass and the polyimide film, A problem arises that the support glass substrate is bent and the performance of the TFT element is deteriorated. Therefore, there is a problem that the residual stress of the polyimide is lowered.

Further, when the polyimide is stained, cloudy or turbid, there is a problem that the image quality of the display is lowered, and it is necessary to lower the yellowness (hereinafter also referred to as YI value) as much as possible and to increase the total light transmittance in visible light There is also.

Generally, in order to reduce the residual stress, a method of lowering the CTE of the polyimide film, lowering the glass transition temperature (hereinafter also referred to as Tg), or lowering the Young's modulus is known.

Generally, it is known to employ a rigid polyimide structure in order to lower the CTE. However, if the molecule is rigid, formation of a charge transfer complex in the molecule and between molecules proceeds to increase the degree of yellowing, thereby hindering the colorless transparency .

As described above, as disclosed in Patent Document 1, it is known to introduce a flexible skeleton such as silicon diamine into polyimide by random copolymerization in order to lower the glass transition temperature or Young's modulus of the polyimide film. In this case, the optical transparency is not hindered. However, since there is a problem that the polyimide film is softened in the TFT element fabricating step performed at 280 DEG C or higher, adversely affecting the performance of the TFT element, the glass transition temperature Or more. In addition, if the Young's modulus is low, the mechanical strength of the flexible display is lowered, and the rigidity of the display itself is lost, so that the Young's modulus is required to be high. Also, polyimide materials having high tensile strength and high tensile strength are preferable from the viewpoint of the sticking strength of the display.

As described above, Patent Document 2 discloses that flexible silicon-containing diamines are introduced by block copolymerization for the purpose of reducing residual stress while maintaining the glass transition temperature or Young's modulus of polyimide. However, as described in Comparative Example 4 of Patent Document 2, unless a specific combination of solvents is used, the phase separation of the silicon portion proceeds usually when the silicon-containing diamine is copolymerized, and the degree of the refractive index of the sea- The larger the structure of the portion is, the more the optical transmittance is lowered optically. When a combination of a special solvent having a low boiling point is used, if a polyimide precursor is applied to a substrate by bar coating or the like and then left at room temperature for several hours, haze may be generated and the coating film may become cloudy, .

Further, as described in the example of Patent Document 2, there is a problem that when the glass transition temperature is 450 캜 or higher, the effect of reducing the residual stress can not be sufficiently obtained. In addition, in order to obtain an effect of lowering the residual stress to be aimed, increasing the amount of silicon to be introduced increases the phase separation of the silicon portion, resulting in a decrease in the total light transmittance.

Further, as described above, in Example 11 of Patent Document 3, a polyisocyanate compound having high Tg, transparency, high adhesion, and low warpability can be obtained by copolymerizing a specific alicyclic tetracarboxylic acid dianhydride with a fluorine- ≪ / RTI > and polyimide precursors capable of forming a polyimide precursor. When polyimide is used as a base material of a flexible device, the device including the polyimide film and an inorganic film such as silicon nitride or silicon dioxide is required to have bending resistance. The inventors of the present invention have found that the polyimide obtained from the polyimide precursor has a problem of insufficient bending resistance (see Comparative Example 8 in this specification).

SUMMARY OF THE INVENTION In view of the above-described problems, it is an object of the present invention to provide a polyimide film which is colorless and transparent, has a low residual stress occurring with an inorganic film, has excellent mechanical and thermal properties, A polyimide precursor capable of producing a polyimide film and a resin composition containing the polyimide film, a polyimide film and a process for producing the polyimide film, a laminate, and a process for producing the polyimide film, wherein the flexible device including the polyimide film can have excellent bending resistance will be.

The inventors of the present invention have conducted intensive studies and experiments to solve these problems. As a result, it has been found that polyimides obtained by imidizing polyimide precursors having a specific structure are colorless and transparent, and residual stress generated between the polyimide precursor and the inorganic film is low, Further, it has been found that a flexible device including the polyimide film has excellent mechanical properties and thermal properties, and has excellent bending resistance. Based on such findings, the present invention has been completed.

That is, the present invention is as follows.

[1] A compound represented by the following formula (A):

[Chemical Formula 1]

(B): < EMI ID = 1.0 >

(2)

(Wherein plural R ₃ and R ₄ are each independently a monovalent organic group having 1 to 20 carbon atoms and h is an integer of 3 to 200), which is heat-cured , It has at least one glass transition temperature in a temperature range of 150 ° C to 380 ° C and does not have a glass transition temperature in a temperature range of 0 ° C to 150 ° C (not including both ends) 2.00 to 3.70 mmol / g of a polyimide precursor which may contain a solvent.

[2] The polyimide precursor according to [2]

(3)

(Wherein R ₂ is a single bond or a divalent organic group having 1 to 20 carbon atoms, and R ₃ , R ₄ , and R _{5, which} are plural, each independently represent a monovalent organic group having 1 to 20 carbon atoms and, L _1, L _2, and L ₃ is the one group each independently selected from an amino group, acid anhydride group, a carboxyl group, selected from a hydroxyl group, an epoxy group, a mercapto group, and the group consisting of R _6, R ₆ is Is a monovalent organic group having 1 to 20 carbon atoms, j is an integer of 3 to 200, and k is an integer of 0 to 197. The polyimide according to the above [1], which is obtained by using a silicone compound as a monomer component, Precursor.

[3] The polyimide precursor according to [1] or [2], wherein L ₁ and L ₂ in the general formula (C) are each independently an amino group or an acid anhydride group, and L ₃ is R ₆ .

[4] The polyimide precursor according to [3], wherein both of L ₁ and L ₂ in the general formula (C) are amino groups.

[5] The polyimide precursor according to any one of [1] to [5]

[Chemical Formula 4]

A plurality of R _{1 s} are each independently a hydrogen atom, a monovalent aliphatic hydrocarbon having 1 to 20 carbon atoms, or an aromatic group; X ₁ is a tetravalent organic group having 4 to 32 carbon atoms, And n is an integer of 1 to 100, and a unit represented by the following general formula (2):

[Chemical Formula 5]

Wherein the plurality of R _{1 s} are each independently a hydrogen atom, a monovalent aliphatic hydrocarbon having 1 to 20 carbon atoms, or an aromatic group, and the plurality of R _{2 s} are each independently a divalent aliphatic hydrocarbon having 3 to 20 carbon atoms, R ₃ and R ₄ are each independently a monovalent aliphatic hydrocarbon having 1 to 3 carbon atoms or an aromatic group having 6 to 10 carbon atoms and X ₂ is an aromatic group having 4 to 32 carbon atoms, The polyimide precursor according to any one of the above [1] to [4], wherein the polyimide precursor contains unit 2 represented by the following formula (1), wherein l is an integer of 3 to 50 and m is an integer of 1 to 100.

[6] The method according to any one of the above [1] to [4], wherein the polyimide precursor is a polyimide precursor having, in place of or in addition to the unit 1 represented by the general formula (1)

[Chemical Formula 6]

Wherein R ₈ is a trivalent aliphatic hydrocarbon having 3 to 20 carbon atoms or an aromatic group and each of R _{1 s} is independently a hydrogen atom, a monovalent aliphatic hydrocarbon having 1 to 20 carbon atoms, , Q is an integer of 3 to 50, and p is an integer of 1 to 100, and R < ₃ > and R < ₄ > each independently represent a monovalent aliphatic hydrocarbon having 1 to 3 carbon atoms or an aromatic group having 6 to 10 carbon atoms, Wherein the unit 3 is represented by the following formula (1).

[7] A polyimide precursor composition comprising the polyimide precursor according to any one of [1] to [6], a polyimide precursor represented by the following general formula (D)

(7)

Wherein X ₃ is a tetravalent organic group having 4 to 32 carbon atoms, and each of R _{1 s} is independently a hydrogen atom, a monovalent aliphatic hydrocarbon having 1 to 20 carbon atoms, or an aromatic group, And r is an integer from 1 to 100.

[8] The polyimide precursor or mixture thereof according to any one of [1] to [7], wherein a polyimide resin having a degree of yellowness of 10 or less at a film thickness of 20 μm is obtained when cured by heating.

[9] The method according to any one of [1] to [4], wherein the component derived from the acid anhydride of the unit 1 and the unit 2 comprises the component derived from pyromellitic dianhydride (PMDA) and the component derived from biphenyltetracarboxylic acid (ODPA), a component derived from 4,4 '- (hexafluoroisopropylidene) diphthalic anhydride (6FDA), a component derived from cyclohexane-1,2,4,5-tetracarboxylic acid (CHDA), a component derived from 3,3 ', 4,4'-diphenylsulfone tetracarboxylic acid dianhydride (DSDA), a component derived from 4,4'-biphenylbis (trimellitic acid mono (TAHQ) and a component derived from 9,9'-bis (3,4-dicarboxyphenyl) fluorene dianhydride (FLDA), and a combination of at least one selected from the group consisting of , And the combination thereof is contained in an amount of not less than 60 mol% based on the total amount of the acid dianhydride-derived components of the unit 1 and the unit 2. [ A polyimide precursor or a mixture according to any one.

[10] The acid-derived dianhydride-derived component of the unit 1 and the unit 2 is a combination of a component derived from pyromellitic dianhydride (PMDA) and a component derived from 4,4'-oxydiphthalic acid dianhydride (ODPA) , The number of moles of the ODPA-derived component / (the number of moles of the PMDA-derived component + the number of mols of the ODPA-derived component) in the polyimide precursor or mixture thereof is in the range of 0.2 to 0.8.

[11] The polyimide precursor according to any one of [1] to [10], or a mixture thereof, wherein a part of the polyimide precursor is imidized.

[12] After developing on the surface of the support after being dissolved in a solvent and imidizing at 350 ° C under a nitrogen atmosphere, the degree of yellowness at a film thickness of 20 μm is 10 or less, the breaking strength is 200 MPa or more, The polyimide precursor according to any one of [1] to [11] or a mixture thereof, wherein a polyimide resin having a residual stress of 20 mPa or less in thickness is obtained.

[13] The polyimide precursor according to any one of [1] to [12], or a mixture thereof, used in the production of a flexible device.

[14] A resin composition containing the polyimide precursor or mixture thereof according to any one of [1] to [13], and a solvent.

[15] The polyimide precursor or the mixture thereof is imidized by developing the resin composition according to [14] above on the surface of a support, and then heating the support and the resin composition. film.

[16] A compound represented by the following formula (A):

[Chemical Formula 8]

Derived structural unit represented by the following general formula (B):

[Chemical Formula 9]

(Wherein plural R ₃ and R ₄ are each independently a monovalent organic group having 1 to 20 carbon atoms and h is an integer of 3 to 200) is preferably a polyimide film having a structural unit represented by the formula: Wherein the glass transition temperature is in the range of 0 to 150 DEG C and the glass transition temperature is not more than 2.00 to 3.70 mmol / lt; / RTI >

[17] A method for producing a resin composition, comprising the steps of: developing the resin composition according to [14]

Heating the support and the resin composition to imide the polyimide precursor to form a polyimide film;

A step of peeling the polyimide film from the support to obtain the polyimide film

Wherein the polyimide film is a polyimide film.

[18] A resin composition as described in [14] above is provided on a support having a support and a polyimide film, and the support and the resin composition are heated to imidize the polyimide precursor to form a polyimide film By weight.

[19] A method for producing a resin composition, comprising the steps of: developing a resin composition according to [14]

Heating the support and the resin composition to imidize the polyimide precursor to form a polyimide film and obtaining a laminate composed of the support and the polyimide film

And a step of forming a laminate.

[20] A flexible substrate comprising a polyimide film and an inorganic film obtained by heating the resin composition according to [14] to imidize the polyimide precursor.

When the polyimide precursor according to the present invention is used, it is colorless and transparent, has low residual stress generated with the inorganic film, has excellent mechanical properties and thermal stability, and is excellent in the flexible device including the polyimide film It becomes possible to produce a polyimide film which can have bending resistance.

Hereinafter, one embodiment of the present invention (hereinafter abbreviated as " embodiment ") will be described in detail. The present invention is not limited to the following embodiments, and various modifications may be made within the scope of the present invention.

The polyimide precursor according to the embodiment of the present invention has the following formula (A):

[Chemical formula 10]

(B): < EMI ID = 1.0 >

(11)

(Wherein plural R ₃ and R ₄ are each independently a monovalent organic group having 1 to 20 carbon atoms and h is an integer of 3 to 200), which is heat-cured , It has at least one glass transition temperature in a temperature range of 150 ° C to 380 ° C and does not have a glass transition temperature in a temperature range of 0 ° C to 150 ° C (not including both ends) A polyimide resin which may contain 2.00 to 3.70 mmol / g of a solvent may be obtained.

The polyimide precursor obtained from the monomer component containing the diamine of the formula (A) and having the structural unit represented by the general formula (B) is obtained by reacting a diamine represented by the formula (A) with a tetracarboxylic acid dianhydride, And a reactive derivative thereof, which is a polyimide precursor having a structural unit of the general formula (B). Examples of the reactive derivative include an acid esterified product of the carboxylic acid, acid chloride of the carboxyl group, and the like.

Examples of the compound represented by the above formula (A) include 2,2'-bis (trifluoromethyl) benzidine and 3,3'-bis (trifluoromethyl) benzidine. Bis (trifluoromethyl) benzidine is preferable in view of the YI value and transparency of the obtained polyimide.

In the general formula (B), R ₃ and R ₄ each independently represent a monovalent organic group having 1 to 20 carbon atoms, and h represents an integer of 3 to 200.

Examples of the monovalent organic group having 1 to 20 carbon atoms in R ₃ and R ₄ include a monovalent hydrocarbon group having 1 to 20 carbon atoms, a monovalent amino group having 1 to 20 carbon atoms, an alkoxy group, and an epoxy group. Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms in R ₃ and R ₄ include an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, and an aryl group having 6 to 20 carbon atoms. The alkyl group having 1 to 20 carbon atoms is preferably an alkyl group having 1 to 10 carbon atoms. Specific examples thereof include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, And the like. The cycloalkyl group having 3 to 20 carbon atoms is preferably a cycloalkyl group having 3 to 10 carbon atoms, and specific examples thereof include a cyclopentyl group and a cyclohexyl group. The aryl group having 6 to 20 carbon atoms is preferably an aryl group having 6 to 12 carbon atoms, and specific examples thereof include a phenyl group, a tolyl group and a naphthyl group. Examples of the monovalent alkoxy group having 1 to 20 carbon atoms for R ₃ and R ₄ include a methoxy group, an ethoxy group, a propoxy group, an isopropyloxy group, a butoxy group, a phenoxy group, a propenyloxy group and a cyclohexyloxy group And the like.

The plurality of R ₃ and R ₄ in the general formula (B) are preferably monovalent aliphatic hydrocarbons having 1 to 3 carbon atoms or polyimide membranes having an aromatic group having 6 to 10 carbon atoms, both having high heat resistance and low residual stress . Here, the monovalent aliphatic hydrocarbon having 1 to 3 carbon atoms is preferably a methyl group, and the aromatic group having 6 to 10 carbon atoms is preferably a phenyl group.

H in the general formula (B) is an integer of 3 to 200, preferably 10 to 200, more preferably 20 to 150, still more preferably 30 to 100, still more preferably 35 to 80. When h is 2 or less, the residual stress of the polyimide obtained from the polyimide precursor may deteriorate (become large). When h exceeds 200, the varnish comprising the polyimide precursor and the solvent may be cloudy or the mechanical strength of the polyimide There may be a problem that the temperature of the catalyst is lowered.

The polyimide precursor having the structural unit represented by the general formula (B) is represented by the following general formula (C):

[Chemical Formula 12]

(Wherein R ₂ is a single bond or a divalent organic group having 1 to 20 carbon atoms, and R ₃ , R ₄ , and R _{5, which} are plural, each independently represent a monovalent organic group having 1 to 20 carbon atoms and, L _1, L _2, and L ₃ is the one group each independently selected from an amino group, acid anhydride group, a carboxyl group, selected from a hydroxyl group, an epoxy group, a mercapto group, and the group consisting of R _6, R ₆ is Is a monovalent organic group having 1 to 20 carbon atoms, j is an integer of 3 to 200, and k is an integer of 0 to 197. The polyimide precursor is a polyimide precursor obtained by using a silicone compound as a monomer component.

In the general formula (C), a plurality of R _{2 s} each independently represent a single bond or a divalent organic group having 1 to 20 carbon atoms. Examples of the divalent organic group having 1 to 20 carbon atoms in R ₂ include a methylene group, an alkylene group having 2 to 20 carbon atoms, a cycloalkylene group having 3 to 20 carbon atoms, and an arylene group having 6 to 20 carbon atoms. The alkylene group having 2 to 20 carbon atoms is preferably an alkylene group having 2 to 10 carbon atoms, and examples thereof include a dimethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group and a hexamethylene group. The cycloalkylene group having 3 to 20 carbon atoms is preferably a cycloalkylene group having 3 to 10 carbon atoms, and examples thereof include a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, and a cycloheptylene group. Among them, bivalent aliphatic hydrocarbons having 3 to 20 carbon atoms are preferable. The arylene group having 6 to 20 carbon atoms is preferably an aromatic group having 3 to 20 carbon atoms, and examples thereof include a phenylene group and a naphthylene group.

R ₅ is the same as R ₃ and R ₄ in the general formula (B), j represents an integer of 3 to 200, and k represents an integer of 0 to 197.

L ₁ , L ₂ and L ₃ are each independently one group selected from the group consisting of an amino group, an acid anhydride group, a carboxyl group, a hydroxyl group, an epoxy group, a mercapto group and R ₆ . R ₆ is a monovalent organic group having 1 to 20 carbon atoms.

The amino group includes an amino group and a reactive derivative thereof. Examples of the reactive derivative include an isocyanate compound and bis (trialkylsilyl) amino. Specific examples of the compound in which L ₁ , L ₂ and L ₃ are amino groups include amino-terminated methylphenyl silicone at both ends (X22-1660B-3 (number average molecular weight 4,400) and X22-9409 (number average molecular weight 1,300 (Number average molecular weight: 4,400), manufactured by Toray Dow Corning; BY16-61B (number average molecular weight: 3,000), amino-modified dimethyl silicone at both ends (manufactured by Shinetsu Chemical Co., 835U (number average molecular weight: 900)) and SILLA PLAIN FM3311 (number average molecular weight: 1,000) manufactured by Chisso Corporation.

The acid anhydride group includes an acid anhydride group and a reactive derivative thereof. Examples of the reactive derivative include an acid esterified product of the carboxyl group, acid chloride of the carboxyl group, and the like. Specific examples in which L ₁ , L ₂ , and L ₃ of the acid anhydride group are acid anhydride groups include those represented by the following formulas:

[Chemical Formula 13]

And at least one acyl compound represented by the following formula (1).

Specific examples of the compound in which L ₁ , L ₂ and L ₃ are acid anhydride groups include X22-168 AS (Shin-Etsu Chemical Co., number average molecular weight 1,000), X22-168A (Number average molecular weight: 3,200), X22-168-P5-8 (manufactured by Shin-Etsu Chemical Co., Ltd., number average molecular weight: 4,200), DMS-Z21 (manufactured by Gelest Co., number average molecular weight: 600 to 800) have.

Specific examples of the compound in which L ₁ , L ₂ and L ₃ are hydroxyl groups include KF-6000 (manufactured by Shin-Etsu Chemical Co., Ltd., number average molecular weight: 900), KF-6001 -6002 (manufactured by Shin-Etsu Chemical Co., number average molecular weight: 3,200) and KF-6003 (manufactured by Shin-Etsu Chemical Co., number average molecular weight: 5,000). It is considered that the compound having the hydroxyl group reacts with other tetracarboxylic acid dianhydride monomers.

Specific examples of the compound in which L ₁ , L ₂ and L ₃ are epoxy groups include X22-163 (Shin-Etsu Chemical Co., Ltd., number average molecular weight: 400) and KF-105 980), X22-163A (number average molecular weight: 2,000, manufactured by Shin-Etsu Chemical Co., Ltd.), X22-163B (number average molecular weight: 3,500, X22-169AS (manufactured by Shin-Etsu Chemical Co., Ltd., number average molecular weight 1,000) and X22-169B (manufactured by Shin-Etsu Chemical Co., number average molecular weight 3,400). It is considered that the compound having the epoxy group reacts with other diamine monomers.

Specific examples of the compound in which L ₁ , L ₂ and L ₃ are mercapto groups include X22-167B (Shin-Etsu Chemical Co., number average molecular weight: 3,400), X22-167C . It is considered that the compound having a mercapto group reacts with other tetracarboxylic acid dianhydride monomers.

Each of L ₁ , L ₂ and L ₃ is independently one group selected from the group consisting of an amino group, an acid anhydride group, a carboxyl group, a hydroxyl group, an epoxy group, a mercapto group and R ₆ , From the viewpoint of improvement, or from the viewpoint of the heat resistance of the obtained polyimide, it is preferable that each of them is independently one group selected from the group consisting of an amino group, an acid anhydride group and R < ₆ >, and the group consisting of a polyimide precursor and a solvent From the viewpoint of avoidance or cost, it is more preferable that each of them is independently an amino group.

J and k in the general formula (C) are the same as h in the general formula (B).

The polyimide precursor according to the embodiment of the present invention is preferably a polyimide precursor containing a unit 1 represented by the following general formula (1) and a unit 2 represented by the following general formula (2) or (4) Do.

[Chemical Formula 14]

A plurality of R _{1 s} are each independently a hydrogen atom, a monovalent aliphatic hydrocarbon having 1 to 20 carbon atoms, or an aromatic group; X ₁ is a tetravalent organic group having 4 to 32 carbon atoms, And n is an integer from 1 to 100}.

[Chemical Formula 15]

Wherein the plurality of R _{1 s} are each independently a hydrogen atom, a monovalent aliphatic hydrocarbon having 1 to 20 carbon atoms, or an aromatic group, and the plurality of R _{2 s} are each independently a divalent aliphatic hydrocarbon having 3 to 20 carbon atoms, R ₃ and R ₄ are each independently a monovalent aliphatic hydrocarbon having 1 to 3 carbon atoms or an aromatic group having 6 to 10 carbon atoms and X ₂ is an aromatic group having 4 to 32 carbon atoms, L is an integer from 3 to 50, and m is an integer from 1 to 100}.

[Chemical Formula 16]

Wherein R ₈ is a trivalent aliphatic hydrocarbon having 3 to 20 carbon atoms or an aromatic group and each of R _{1 s} is independently a hydrogen atom, a monovalent aliphatic hydrocarbon having 1 to 20 carbon atoms, , Q is an integer of 3 to 50, and p is an integer of 1 to 100, and R < ₃ > and R < ₄ > each independently represent a monovalent aliphatic hydrocarbon having 1 to 3 carbon atoms or an aromatic group having 6 to 10 carbon atoms, Integer}.

In the polyimide precursor according to the present embodiment, the unit 1 represented by the above general formula (1) is a unit derived from 2,2'-bis (trifluoromethyl) benzidine (hereinafter also referred to as TFMB) And an acid dianhydride-derived component having an organic group X < _{1 &} gt ;. On the other hand, the unit 2 represented by the general formula (2) or the general formula (4) is a component derived from a diamine having a silicon group as a diamine-derived component, a component derived from an acid anhydride having an organic group X ₂ , A component derived from 2,2'-bis (trifluoromethyl) benzidine (hereinafter also referred to as TFMB), and a silicon group-containing acid dianhydride as a component derived from an acid dianhydride.

The unit 1 described above is a polyimide resin film formed by thermally curing a polyamic acid derivative, and is a portion for expressing Tg in the range of 150 to 380 ° C. When repeating unit 1 and unit 2 become a random structure, Tg may be expressed between 0 deg. C and 150 deg. C, so unit 1 and unit 2 are preferably block copolymers. However, it is not excluded that the repetition of unit 1 and unit 2 includes a small amount of the random structure in the range capable of expressing the target Tg.

The imide concentration (m mol / g) means an imide group number per unit weight of polyimide when the imidization rate is assumed to be 100 mol%. In the present embodiment, the imide group concentration of the polyimide is 2.00 to 3.70 mmol / g, preferably 2.34 to 3.70 mmol / g, and more preferably 2.78 to 3.39 mmol / g from the viewpoint of bending resistance.

It is unclear why the range of the imide concentration with good bending resistance is in the above range, but it is considered that the toughness of the polyimide film is involved.

≪ Component derived from acid anhydride >

Hereinafter, the acid-derived dianhydride-derived component having the organic group X ₁ contained in the unit ₁ and the acid-derived dianhydride-containing component having the organic group X ₂ contained in the unit 2 will be described.

X ₁ and X ₂ of the polyimide precursor represented by the general formula (1) and the general formula (2) may be the same or different. The acid-derived anhydride-derived component is preferably a compound selected from an aromatic tetracarboxylic acid dianhydride having 8 to 36 carbon atoms and an alicyclic tetracarboxylic acid dianhydride having 6 to 36 carbon atoms.

Specific examples thereof include 4,4 '- (hexafluoroisopropylidene) diphthalic anhydride (hereinafter also referred to as 6FDA), 5- (2,5-dioxotetrahydro-3-furanyl) -3- Methyl-cyclohexene-1,2-dicarboxylic acid anhydride, pyromellitic acid dianhydride (hereinafter also referred to as PMDA), 1,2,3,4-benzenetetracarboxylic acid dianhydride, 3,3 ', 4 , 4'-benzophenonetetracarboxylic acid dianhydride, 2,2 ', 3,3'-benzophenonetetracarboxylic acid dianhydride, 3,3', 4,4'-biphenyltetracarboxylic acid dianhydride (Hereinafter also referred to as BPDA), 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride, methylene-4,4'-diphthalic dianhydride, 1,1-ethylidene-4,4 Diphthalic dianhydride, 2,2-propylidene-4,4'-diphthalic dianhydride, 1,2-ethylene-4,4'-diphthalic dianhydride, 1,3-trimethylene- Diphthalic dianhydride, 1,4-tetramethylene-4,4'-diphthalic dianhydride, 1,5-pentamethylene-4,4'-diphthalic dianhydride, 4,4'- 2-anhydride (hereinafter also referred to as ODPA), thio-4,4'-diphthalic acid dianhydride, sulfonyl-4,4'-diphthalic dianhydride, 1,3-bis (3,4-dicarboxyphenyl) Benzene dianhydride, 1,3-bis (3,4-dicarboxyphenoxy) benzene dianhydride, 1,4-bis (3,4-dicarboxyphenoxy) benzene dianhydride, 1,3- (3,4-dicarboxyphenyl) -2-propyl] benzene dianhydride, bis [3- (3,3- , 4-dicarboxyphenoxy) phenyl] methane dianhydride, bis [4- (3,4-dicarboxyphenoxy) phenyl] methane dianhydride, 2,2- Bis (3,4-dicarboxyphenoxy) phenyl] propane dianhydride, bis (3,4-dicarboxyphenoxy) dimethylsilane dianhydride, 1,1- 3-bis (3,4-dicarboxyphenyl) -1,1,3,3-tetramethyldisiloxane dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 1,4,5- 8-naphthalene tetracarboxylic acid dianhydride , 1,2,5,6-naphthalenetetracarboxylic acid dianhydride, 3,4,9,10-perylenetetracarboxylic acid dianhydride, 2,3,6,7-anthracenetetracarboxylic acid dianhydride, 1,2,7,8-phenanthrenetetracarboxylic acid dianhydride, ethylene tetracarboxylic acid dianhydride, 1,2,3,4-butanetetracarboxylic acid dianhydride, 1,2,3,4-cyclo Butane tetracarboxylic acid dianhydride (hereinafter also referred to as CBDA), cyclopentanetetracarboxylic acid dianhydride, cyclohexane-1,2,3,4-tetracarboxylic acid dianhydride, cyclohexane-1,2, Tetracarboxylic acid dianhydride (hereinafter referred to as CHDA), 3,3 ', 4,4'-bicyclohexyltetracarboxylic acid dianhydride, carbonyl-4,4'-bis (cyclo 1,2-dicarboxylic acid dianhydride, methylene-4,4'-bis (cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,2-ethylene-4,4'-bis (Cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,1-ethylidene-4,4'-bis (cyclohexane-1,2-dicar (Cyclohexane-1,2-dicarboxylic acid) dianhydride, oxy-4,4'-bis (cyclohexane-1,2-dicarboxylic acid) dianhydride, 2,2- (Cyclohexane-1,2-dicarboxylic acid) dianhydride, sulfonyl-4,4'-bis (cyclohexane-1,2-dicarboxylic acid) dicarboxylic acid dianhydride, thio-4,4'- [1S, 5R, 6R] -3-oxa-2, 3,3,5,6-tetracarboxylic acid dianhydride, (Tetrahydrofuran-2 ', 5'-dione), 4- (2,5-dioxotetrahydrofuran -3,4-tetrahydronaphthalene-1,2-dicarboxylic acid anhydride, ethylene glycol-bis- (3,4-dicarboxylic acid anhydride phenyl) ether, 3,3 4,4'-biphenylbis (trimellitic acid monoester acid anhydride) (hereinafter also referred to as TAHQ), a component derived from 4,4'-diphenylsulfone tetracarboxylic acid dianhydride (hereinafter also referred to as DSDA) Derived component, 9,9'-bis (3,4-dicarboxyphenyl) Lu (hereinafter also referred to as FLDA) fluorene dianhydride, and the like.

Among them, PMDA is preferable from the viewpoint of reduction of CTE, improvement of chemical resistance, improvement of glass transition temperature (Tg), and improvement of machine elongation. Further, 6FDA and ODPA are preferable from the viewpoint of reduction in yellowness and improvement in machine elongation. Further, BPDA is preferable from the viewpoints of reduction of residual stress, improvement of chemical resistance, improvement of Tg, and improvement of machine elongation. Also, CHDA is preferable from the viewpoint of reducing residual stress and decreasing yellow color. Of these, tetracarboxylic acid dianhydrides selected from the group consisting of high Tg, PMDA and BPDA having a rigid structure expressing a low CTE, and a group consisting of 6FDA, ODPA, DSDA, TAHQ, FLDA and CHDA Is preferably used in combination with the tetracarboxylic acid dianhydride selected from the viewpoint of lowering the residual stress, lowering the yellowing degree, and improving the total light transmittance.

Among them, it is preferable to use PMDA or BPDA in an amount of 60 mol% or more based on the total acid anhydride-derived component in combination with PMDA or BPDA and ODPA from the viewpoints of high shininess, chemical resistance, More preferably 70% or more, further preferably 80% or more, or 100%.

A preferable combination is a combination of PMDA and ODPA, and it is preferable that the ratio of moles of ODPA / (moles of PMDA + mols of ODPA) is in the range of 0.2 to 0.8, more preferably 0.4 to 0.6 in the range of yellow Is most preferable in terms of reduction in the total light transmittance and reduction in residual stress.

<Ingredients derived from diamine>

The polyimide precursor according to the present embodiment contains a component derived from 2,2'-bis (trifluoromethyl) benzidine (hereinafter also referred to as TFMB) as a diamine component in the unit 1. From the viewpoint of obtaining a desirable yellow color of the polyimide film, an improvement in the total light transmittance, a reduction in the residual stress occurring between the film and the inorganic film, and a high Tg and a breaking strength, the component derived from the TFMB contains 60 moles , More preferably 70 mol% or more, and still more preferably 80 mol% or more.

The polyimide precursor according to the present embodiment includes a diamine component other than TFMB in the unit 2 (hereinafter, simply referred to as a silicon-containing diamine) having a bivalent silicon-containing group of 2 to 50 silicon atoms do. Examples of the silicon-containing diamines include compounds represented by the following general formula (3): wherein L ₁ and L ₂ in the general formula (C)

[Chemical Formula 17]

{Wherein, R ₂ may be the divalent hydrocarbon group, each may be the same or different, a plurality of R ₃ and R ₄ may be the represents a monovalent hydrocarbon group, each may be the same or different, and l is from 3 to 200 (Integer) represents a diamino (poly) siloxane.

Preferred structures of R ₂ in the general formula (3) include a methylene group, an ethylene group, a propylene group, a butylene group, and a phenylene group. Preferable examples of R ₃ and R ₄ include a methyl group, an ethyl group, a propyl group, a butyl group, and a phenyl group.

Specific examples of the compound represented by the general formula (3) include both terminal amine-modified methylphenyl silicone oil (X22-1660B-3 (number average molecular weight 4400) and X22-9409 (number average molecular weight 1300) (Number average molecular weight: 1,600), X22-161B (number average molecular weight: 10,000), KF8021 (number average molecular weight: 4,400), Tereida Dow Corning: BY16-835U Molecular weight 900) SILLA PLAIN FM3311 (number average molecular weight 1000) manufactured by Chisso Corporation) and the like. Of these, both terminal amine-modified methylphenyl silicone oils are preferable from the viewpoints of improving chemical resistance and improving Tg.

The copolymerization ratio of the silicon-containing diamines is preferably in the range of 2 to 30 mass% with respect to the mass of the entire polyimide precursor. When the content is 2% by mass or less, the effect of lowering the stress caused by the inorganic film and the effect of lowering the yellowiness is small, and consequently, the residual stress and yellowing degree are increased. When the amount is 30% by mass or more, the chemical resistance is remarkably lowered, and the total light transmittance is decreased and the Tg is also lowered. The copolymerization ratio of the silicon-containing diamines is preferably 5% by mass to 25% by mass, and 10% by mass to 20% by mass is most preferable in view of chemical resistance, total light transmittance, yellowness, Tg and residual stress .

The polyimide precursor according to the present embodiment may contain a diamine-derived component other than TFMB and silicon-containing diamines within the range that does not impair its performance. For example, an aromatic diamine having 6 to 30 carbon atoms is a preferred embodiment.

Specific examples thereof include 4,4'- (or 3,4'-, 3,3'-, 2,4'-) diaminodiphenyl ether, 4,4 '- (or 3,3'-) diamino Diphenyl sulfone, 4,4'- (or 3,3'-) diaminodiphenyl sulfide, 4,4'-benzophenone diamine, 3,3'-benzophenone diamine, 4,4'-di (Aminophenoxy) phenylsulfone, 4,4'-di (3-aminophenoxy) phenylsulfone, 4,4'-bis Bis (4-aminophenoxy) phenyl} propane, 3,3 ', 5,5'-tetramethyl-benzene, Diaminodiphenylmethane, 2,2'-bis (4-aminophenyl) propane, 2,2 ', 6,6'-tetramethyl-4,4'- Bis (4-aminophenyl) -2-propyl} 1,4-benzene, 9,9-bis -Aminophenyl) fluorene, 9,9-bis (4-aminophenoxyphenyl) fluorene, 3,3'-dimethylbenzidine, 3,3'-dimethoxybenzidine and 3,5- Diamine, 2,6-di Aminophenyl-2-propyl) -1,4-benzene, 3,3'-bis (trifluoromethyl) -4,4'-diaminobiphenyl, Phenyl (3,3'-TFDB), 2,2'-bis [3 (3-aminophenoxy) phenyl] hexafluoropropane (3-BDAF), 2,2'- (4-aminophenyl) hexafluoropropane (3,3'-6F), 2,2'-bis (4-aminophenyl) hexafluoropropane ), And hexafluoropropane (4,4'-6F).

In the polyimide precursor represented by the general formulas (1) and (2) according to the present embodiment, the number of repeating units 1 is preferably 2 to 500, more preferably 5 to 300, 200 is most preferable. The repeating number of the unit 2 is preferably from 1 to 300, more preferably from 1 to 200, and most preferably from 1 to 100 per molecule. When the number of repeats of the unit 1 exceeds 500 and the number of repeats of the unit 2 exceeds 300, the solubility of the polyimide precursor in a solvent deteriorates, which is not preferable.

The ratio defined as a value obtained by dividing the number of repetitions of the unit 1 by the number of repetitions of the unit 2 (hereinafter referred to as the unit ratio) varies depending on the type and the molecular weight of the raw material to be used, but is preferably 0.5 to 300, Is more preferable.

The polyimide resin according to the present embodiment has a glass transition temperature derived from the structure of the unit 1 in the region A of 150 ° C to 380 ° C and a glass transition temperature derived from the siloxane structure contained in the unit 2 in the range of -150 ° C to 0 ° C ° C., and the region C between 0 ° C. and 150 ° C. (not including both ends) between the region A and the region B does not have a glass transition temperature. When the unit ratio is 0.5 or more, the heat resistance of the polyimide resin after curing becomes sufficient. On the other hand, when the unit ratio is 300 or less, the residual stress can be lowered.

Further, from the viewpoint of heat resistance, it is more preferable that the glass transition temperature derived from the structure of the unit 1 is in the region A1 of 200 to 380 占 폚, more preferably in the region A2 'of 250 to 380 占 폚. The glass transition temperature derived from the structure of the unit 1 is preferably 380 占 폚 or lower, and is preferable from the viewpoint of improving the residual stress. From the viewpoint that the inorganic film such as silicon nitride or silicon dioxide is formed on the polyimide film by using the CVD method or the sputtering method, the annealing temperature of the inorganic film can be improved and the performance such as the gas barrier property of the inorganic film can be improved , The glass transition temperature of the polyimide is preferably 150 占 폚 or higher, more preferably 250 占 폚 or higher, and still more preferably 300 占 폚 or higher.

On the other hand, when the silicone diamine has a high molecular weight (specifically, an average molecular weight of 3000 or more), even if the block copolymer is not formed, the resulting polyimide has a high residual glass transition temperature Can be expressed. In the case of a high molecular weight, the silicone unit itself has a long-chain siloxane structure, which is considered to have the same function as the above-mentioned block structure.

In the case where the silicone diamine has a high molecular weight, since the functional group concentration is lowered, the injection molar number can exhibit at least the high glass transition temperature and the low residual stress. At this time, in addition to the copolymer of the unit 1 of the general formula (1) derived from TFMB and the unit 2 of the general formula (2) derived from silicone diamine, the polyimide precursor (B) May be present as a polyimide precursor mixture, i.e., in a blended state. Specific examples of the polyimide precursor of the unit 1 of the present invention include the following general formula (D):

[Chemical Formula 18]

Wherein X ₃ is a tetravalent organic group having 4 to 32 carbon atoms, and each of R _{1 s} is independently a hydrogen atom, a monovalent aliphatic hydrocarbon having 1 to 20 carbon atoms, or an aromatic group, And r is an integer of 1 to 100}.

The reason why the polyimide resin according to the present embodiment can remarkably reduce the residual stress with the inorganic film while maintaining the glass transition temperature at a high level is not limited to the silicone diamine described above, ₁ , L ₂ and L ₃ are each independently a group selected from the group consisting of an acid anhydride group, a carboxyl group, a hydroxyl group, an epoxy group, a mercapto group and R ₆ I think.

The number average molecular weight of the polyimide precursor according to the present embodiment is preferably from 3,000 to 1,000,000, more preferably from 10,000 to 300,000. It is preferable that the molecular weight is 3000 or more from the viewpoint of sufficient heat resistance and strength. Is preferably 1000000 or less from the viewpoint of satisfactory solubility in a solvent.

The polyimide resin according to the present embodiment can be achieved with a polyimide resin randomly incorporating a siloxane structure in which the residual stress with the inorganic film can be remarkably reduced while the glass transition temperature in the region A is kept high It is possible to achieve a property that can not be achieved.

That is, with the polyimide resin according to the present embodiment, the glass transition temperature on the high-temperature side is 150 ° C. to 380 ° C., which is resistant to a display manufacturing process including a TFT element device on a colorless transparent polyimide substrate, A polyimide resin having a residual stress with the inorganic film of 20 MPa or less can be obtained. In a more preferred embodiment, a polyimide resin having a residual stress of 15 MPa or less with respect to the inorganic film at a glass transition temperature of 240 to 380 DEG C can be obtained. In the polyimide resin according to the present embodiment, the glass transition temperature on the low temperature side at -150 to 0 캜 does not affect the heat resistance required in an actual display manufacturing process since it is lower than the room temperature.

As described above, the reason why the polyimide resin according to the present embodiment exhibits a low residual stress with the inorganic film while maintaining a high glass transition temperature in the region A is not clear. However, in the polyimide resin, And the portion derived from the siloxane structure is micro-phase-separated, and it is presumed that the functional separation of each block is highly achieved. This is suggested from the fact that the resin is composed of two block structures and the glass transition temperature defined by the measurement method described later is observed in each of the region A and the region B from the single structure of each block.

That is, in the portion derived from the siloxane structure having a glass transition temperature of -150 ° C. to 0 ° C., the glass transition temperature is in the range of 150 to 380 ° C., Since the polymer does not flow as a whole for the chemical bonding with the portion and forms a micro-phase separation structure between the blocks, the micro-plastic deformation of the portion derived from the siloxane structure causes the residual It is considered that the stress is relaxed and the residual stress with the inorganic film at room temperature is reduced.

Next, a method of synthesizing the polyimide precursor according to the present embodiment will be described. When the molecular weight of the starting siloxane-containing raw material is 3000 or less, it is preferable that the polyimide precursor is composed of a block containing a siloxane structure and two blocks containing no siloxane structure. In this case, the polyimide precursor corresponding to each block may be prepared separately, and then the two may be mixed and provided to the condensation reaction to obtain the polyimide precursor according to the present embodiment. In the case where the terminal block of one block polyimide precursor is a carboxylic acid anhydride group so that both blocks can be provided in the condensation reaction, the terminal block of the other block polyimide precursor may be a tetra It is necessary to adjust the molar ratio of carboxylic acid dianhydride and diamine. With this method, a polyimide precursor having a complete block property can be synthesized.

On the other hand, when an aromatic diamine of TFMB as a constituent material and a silicon-containing diamine having high reactivity as a raw material of the unit 2 are used, a synthesis method using the difference in reactivity of both diamines may be possible. For example, a polyimide precursor having a certain degree of blockiness can be prepared by adding TFMB and a silicon-containing diamine to a tetracarboxylic acid dianhydride which has been previously prepared at the same time to provide a condensation reaction. In this method, it is not possible to synthesize a block polyimide precursor having a complete block property, but a polyimide precursor having a block property can be synthesized. Here, having a block property means that the polyimide resin after heat curing has a glass transition temperature derived from a polycondensation product of TFMB and tetracarboxylic anhydride and a glass transition temperature derived from a silicon-containing diamine and tetracarboxylic acid Quot; refers to each of the glass transition temperatures derived from the block 2 derived from the polycondensation of the carboxylic acid anhydride.

As described above, the polyimide precursor according to the present embodiment is a polyimide resin formed by heat curing. When the polyimide resin has a blocking property to the extent that the glass transition temperature is visible in the region A on the high temperature side and the region B on the low temperature side And does not necessarily have a complete block property. If the glass transition temperature is not visible in the region C between the region A and the region B, it may contain units other than the block 1 and the block 2.

On the other hand, in the case where the raw material containing silicon has a high molecular weight (specifically, an average molecular weight of 3000 or more), the silicone unit itself has a long-chain siloxane structure without forming such a block copolymer, It has the same function. Further, if the synthesis method for forming the block structure as described above is employed, the domain of the silicon portion in the polyimide film becomes large, and the polyimide film may become cloudy. In this case, the amount of the silicon-containing raw material is reduced so that the raw material containing silicon is random in the polymer, or the number of repetitions of the unit 2 is adjusted to be 1. Specifically, when silicon diamine is used, a small amount of silicon diamine is added to a large amount of acid dianhydride, and the remaining TFMB is added after completion of the reaction, or a large amount of acid dianhydride is added to a small amount of silicon diamine, A method of adding remaining TFMB is preferable. In the case of using a silicon acid dianhydride, it is preferable to dissolve a large amount of TFMB in a solvent, and then suitably add a silicone acid dianhydride and another acid dianhydride to obtain a polymer.

Further, by adding N, N-dimethylformamide dimethylacetal or N, N-dimethylformamide diethyl acetal to the above-mentioned polyamic acid and heating the mixture, a part or all of the carboxylic acid is esterified, The viscosity stability during storage at room temperature in a solution may be improved. These ester-modified polyamic acid may be prepared by reacting the above-described tetracarboxylic acid anhydride with one equivalent of an alcohol in advance of the acid anhydride group and then reacting with a dehydrating condensing agent such as thionyl chloride or dicyclohexylcarbodiimide , Followed by condensation reaction with diamines.

<Resin composition>

The polyimide precursor according to this embodiment as described above is used as a resin composition (varnish) in which the polyimide precursor is dissolved in a solvent.

In a more preferred embodiment, the resin composition is prepared by dissolving an acid anhydride component and a diamine component in a solvent, for example, an organic solvent and reacting them to prepare a polyamic acid solution containing a polyamic acid as an embodiment of the polyimide precursor and a solvent Can be manufactured. The conditions for the reaction are not particularly limited. For example, the reaction temperature is -20 to 150 ° C and the reaction time is 2 to 48 hours. It is preferable to heat it at 120 DEG C for about 30 minutes in order to sufficiently proceed the reaction with the diamine group containing a silicon group. At the time of the reaction, it is preferable to be an inert atmosphere such as argon or nitrogen.

The solvent is not particularly limited as long as it is a solvent dissolving the polyamic acid. (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethylsulfoxide (DMSO), acetone, and diethyl acetate as known reaction solvents. One or more polar solvents selected are useful. Of these, NMP and DMAc are preferable. In addition, a low boiling point solution such as tetrahydrofuran (THF), chloroform, or a low-absorbency solvent such as? -Butyrolactone may be used.

The polyimide precursor preferably has a weight average molecular weight (Mw) of 5,000 or more and 1,000,000 or less, more preferably 50000 or more and 500,000 or less, still more preferably 70000 or more and 250,000 or less. When the weight average molecular weight is 5,000 or more, the strength of the resin layer obtained by using the resin composition is improved and mechanical properties are excellent. When the weight average molecular weight is 1000000 or less, it can be applied to the desired film thickness without any smoothing at the time of processing such as coating. In particular, from the viewpoint of obtaining a high mechanical elongation, the molecular weight is preferably 50,000 or more. Here, the weight average molecular weight refers to the molecular weight measured by gel permeation chromatography using polystyrene having a known number average molecular weight as a standard.

After the polyamic acid varnish described above is prepared, the solution may be heated at 130 to 200 ° C for 5 minutes to 2 hours to dehydrate a part of the polymer to such an extent that the polymer does not precipitate. By controlling temperature and time, the imidization rate can be controlled. By performing partial imidization, the viscosity stability of the resin solution at room temperature can be improved. The imidization rate ranges from 5% to 70% in view of solubility in a solution and storage stability.

<Polyimide Film>

The polyimide film according to the present embodiment is formed by developing the polyimide precursor and the solvent-containing resin composition according to the present embodiment on the surface of the support, then heating the support and the resin composition to imidize the polyimide precursor . More specifically, as described above, a polyamic acid solution obtained by dissolving and reacting an acid anhydride component and a diamine component in an organic solvent can be used.

Here, the support is, for example, an inorganic substrate such as a glass substrate such as a non-alkali glass substrate, but is not particularly limited.

More specifically, the above-described polyimide precursor solution is developed and dried on an adhesive layer formed on a main surface of an inorganic substrate and cured at 230 to 500 ° C under an inert atmosphere to form a polyimide film .

Here, as a developing method, for example, a known coating method of a spin coat, a slit coat and a blade coat can be mentioned. After the polyamic acid solution is developed on the adhesive layer, the heat treatment is performed for a period of 1 minute to 300 minutes at a temperature of 300 DEG C or lower for the purpose of mainly removing the solvent, and further annealed at 230 DEG C to 550 DEG C At a temperature of 1 to 300 minutes to polyimide the polyamic acid.

The thickness of the polyimide film according to the present embodiment is not particularly limited and is preferably in the range of 10 to 200 占 퐉, more preferably 10 to 50 占 퐉.

<Laminate>

The laminate related to this embodiment includes a support and a polyimide film. The resin composition according to this embodiment is developed on the surface of the support, and the support and the resin composition are heated to imidize the polyimide precursor to form a polyimide film .

This laminate is used, for example, in the manufacture of a flexible device. More specifically, a flexible device having a flexible transparent substrate made of a polyimide film can be obtained by forming a semiconductor device on a polyimide film and thereafter peeling the support.

<Flexible Substrate>

The flexible substrate according to this embodiment includes a polyimide film and an inorganic film. Specific examples of the inorganic film include films containing SiO ₂ , SiN, and the like.

The flexible substrate can be obtained by forming a polyimide film by imidizing a polyimide precursor by heating the support and the resin composition on the surface of a support, developing the polyimide film by a plasma CVD method A film containing SiO ₂ , SiN or the like is formed by a sputtering method, and then a semiconductor device for a purpose such as a TFT is provided, and thereafter laser irradiation or the like is performed to peel off the polyimide film and the inorganic film from the support.

As described above, the polyimide film produced from the polyimide precursor according to the present embodiment is colorless and transparent, has low yellowing degree, and the phase separation of the silicon portion is appropriately controlled. Therefore, the total light transmittance is high, Is low due to the relaxation of the phase-separated silicon portion to such an extent that the residual stress does not interfere optically, has a practical glass transition temperature capable of withstanding the TFT fabrication process, and has excellent mechanical properties. Therefore, the transparent substrate of the flexible display It is suitable for use in.

More specifically, in the case of forming a flexible display, a flexible substrate is formed thereon using a glass substrate as a support, and a TFT or the like is formed thereon. The step of forming the TFT on the substrate is typically carried out at a temperature in a wide range of 150 to 650 DEG C, but in order to actually achieve the desired performance, a TFT-IGZO (InGaZnO ) Oxide semiconductor or TFT (a-Si-TFT, poly-Si-TFT).

At this time, when the residual stress generated in the flexible substrate and the polyimide film is high, when the glass substrate is expanded at the high temperature TFT process and then shrunk at the room temperature cooling, problems such as warpage and breakage of the glass substrate and peeling of the flexible substrate from the glass substrate . Generally, since the thermal expansion coefficient of the glass substrate is smaller than that of the resin, residual stress is generated between the glass substrate and the flexible substrate. In consideration of this point, the polyimide film according to the present embodiment preferably has a residual stress of 20 MPa or less between the polyimide film and the glass based on the thickness of 10 mu m of the film.

When the transmittance of the polyimide film according to the present embodiment is measured with an ultraviolet spectrophotometer on the basis of a film thickness of 20 占 퐉 and a yellowness degree of 10 or less and a film thickness of 20 占 퐉, Is preferably 85% or more.

From the standpoint of improving the production rate, the polyimide film according to the present embodiment is more preferable to have a breaking strength of 200 MPa or more from the viewpoint of improving the production rate in view of the excellent breaking strength when handling the flexible substrate .

The polyimide film according to the present embodiment satisfying the physical properties described above is used as a colorless transparent substrate for use in a limited use of the conventional polyimide film due to its yellow color, particularly for a flexible display. Further, it can be used in a field where colorless transparency is required such as a protective film or a light-diffusing sheet made of a TFT-LCD or the like and a coating film (for example, an interlayer of a TFT-LCD, a gate insulating film, a liquid crystal alignment film). When a polyimide according to the present embodiment is applied as a liquid crystal alignment film, a TFT-LCD having a high contrast ratio can be produced, contributing to an increase in the aperture ratio.

The polyimide film and the laminate produced using the polyimide precursor according to the present embodiment can be suitably used as a substrate, for example, in the production of a semiconductor insulating film, a TFT-LCD insulating film, an electrode protecting film, and a flexible device . Here, the flexible device includes, for example, a flexible display, a flexible solar cell, a flexible light, and a flexible battery.

Example

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but these are described for the purpose of explanation, and the scope of the present invention is not limited to the following examples.

Various evaluations in Examples and Comparative Examples were carried out as follows.

(Measurement of weight average molecular weight)

The weight average molecular weight (Mw) was determined by gel permeation chromatography (GPC) under the following conditions. As the solvent, 24.8 mmol / l of lithium bromide monohydrate (manufactured by Wako Pure Chemical Industries, Ltd., purity: 99.5%) was dissolved in N, N-dimethylformamide (manufactured by Wako Pure Chemical Industries, ) And 63.2 mmol / l phosphoric acid (for high-performance liquid chromatography, manufactured by Wako Pure Chemical Industries, Ltd.) were added. In addition, a calibration curve for calculating the weight average molecular weight was prepared using standard polystyrene (manufactured by Tosoh Corporation).

Column: Shodex KD-806M (manufactured by Showa Denko KK)

Flow rate: 1.0 ml / min

Column temperature: 40 DEG C

Pump: PU-2080Plus (manufactured by JASCO)

Detector: RI-2031Plus (RI: differential refractometer, manufactured by JASCO)

         UV-2075Plus (UV-VIS: ultraviolet visible light absorber, manufactured by JASCO)

(Preparation of laminate and insulating film)

The polyamide acid was applied to an alkali-free glass substrate (0.7 mm thick) with a bar coater and leveling was carried out at room temperature for 5 minutes to 10 minutes and then heated in a hot air oven at 140 占 폚 for 60 minutes. For 60 minutes to prepare a laminate. The film thickness of the resin composition of the laminate was 20 占 퐉. After curing at 350 DEG C (curing treatment), the laminate was allowed to stand at room temperature for 24 hours, and the polyimide film was peeled from the glass and the film was isolated. In evaluating the breaking strength, yellowness degree, total light transmittance, glass transition temperature and linear expansion coefficient, the polyimide film cured at 350 DEG C was used as a sample. The oxygen concentration in the cure (measured by Oxygen analyzer LC700L, manufactured by Toray Engineering Co., Ltd.) was in the range of 20 to 120 ppm.

(Evaluation of tensile elongation and breaking strength)

A polyimide film having a sample length of 5 x 50 mm and a thickness of 20 占 퐉, which was cured at 350 占 폚, was stretched at a speed of 100 mm / min using a tensile tester (RTG-1210, manufactured by A and D Co., And the fracture strength was measured.

(Yellow degree, evaluation of total light transmittance)

(YI value) and total light transmittance were measured using a D65 light source with a spectrophotometer (SE600) manufactured by Nippon Denshoku Industries Co., Ltd., and cured at 350 占 폚 and having a thickness of 20 占 퐉.

(Evaluation of glass transition temperature, linear expansion coefficient)

With respect to the measurement of the glass transition temperature (hereinafter referred to as Tg (1)) and the linear expansion coefficient (CTE) at room temperature or higher, the polyimide tape was measured using a thermomechanical analyzer (TMA-50 manufactured by Shimadzu Corporation) The test piece elongation was measured by thermomechanical analysis in a range of a load of 5 g, a temperature raising rate of 10 캜 / min, a nitrogen atmosphere (flow rate of 20 ml / min) and a temperature of 50 to 450 캜, Was determined as the glass transition temperature, and the CTE of the polyimide film at 100 to 250 ° C was determined.

Since the above method can not measure the glass transition temperature (hereinafter referred to as Tg (2)) in the room temperature region or below, the obtained polyimide tape is subjected to a dynamic viscoelasticity measurement at -150 캜 to 400 캜 (RHEOVIBRON MODEL RHEO-1021, manufactured by ORIENTECH CORPORATION), the inflection point of the E-prime in the temperature region below the room temperature was measured, and the inflection point was determined as the glass transition temperature at low temperature.

(Evaluation of Residual Stress)

On a 6-inch silicon wafer having a thickness of 625 占 퐉 占 25 占 퐉, which had been previously measured for "bending amount" using a residual stress measuring apparatus (manufactured by Tencor Corporation, model name FLX-2320), polyamic acid was applied using a bar coater , Pre-baked, and then subjected to a heat curing treatment at 350 DEG C for 1 hour in a nitrogen atmosphere using a vertical cure furnace (model name VF-2000B, manufactured by Koyo Lindberg), and a polyimide film Thereby forming a silicon wafer. The amount of warpage of the wafer was measured using the residual stress measuring apparatus described above to evaluate the residual stress generated between the silicon wafer and the polyimide film.

(Calculation of the imide concentration)

It is assumed that the imidization ratio is 100 mol% and two imide groups per one mole of the monomer are used. Therefore, the imide groups in the examples and comparative examples (theoretical value when the imidization ratio is assumed to be 100 mol% ). The results are shown in Table 5 below.

Number of moles of imide (mol): number of moles of acid anhydride monomer or amine monomer (when the number of moles is small, number of moles thereof) x 2

Weight of polyimide (g) = total weight of acid anhydride monomer or amine monomer - number of moles of imide group x molecular weight of water

Imide concentration (m mol / g) = number of moles of imide moiety 占 1000 / polyimide weight

(Bending test)

When polyimide is used as a base material of a flexible device (for example, a flexible display), it is required to have a bending resistance after forming a TFT element or the like on the polyimide film. Thus, as a simple test, a SiN film was formed on a polyimide film, and a bending test of the laminated film was carried out.

Specifically, a polyimide film was formed on a glass wafer so as to have a film thickness of 5 占 퐉 after curing (cure condition: 350 占 폚, 2 hours) on the polyimide precursors of Examples and Comparative Examples, A SiN film having a thickness of 100 nm was formed. Thereafter, the polyimide film on which the SiN film was formed was peeled off from the glass wafer. The bending test was conducted using the polyimide film on which the obtained SiN film was formed. The test conditions were an inscribed circle diameter of 15 mm and a bending angle of 180 °. The bending operation was performed by bending the SiN film to the inner side and bending to be the outer side, and repeating the operation ten times. After the bending operation, the polyimide film on which the SiN film was formed was observed with an optical microscope. Evaluation was carried out according to the following criteria:

&Amp; cir &amp;: Crack peeling was not observed after the bending test

C: Crack was observed after the bending test

X: After the bending test, peeling was observed in the crack, the polyimide film and the SiN film

Xx: Peeling is observed in cracks, polyimide film and SiN film by bending operation not more than 5 times.

The evaluation results are shown in Table 5 below.

[Example 1]

12.25 g of both terminal amine-modified methylphenyl silicone oil (X22-1660B-3 (number average molecular weight: 4400), manufactured by Shin-Etsu Chemical Co., Ltd.) and 12.25 g of NMP (ODPA) was added in an amount of 124.1 g (0.4 mole), followed by stirring at room temperature for 30 minutes. Thereafter, 152.99 g (0.478 mol) of 2,2'-bis (trifluoromethyl) benzidine (TFMB) was added to the solution to confirm that it was dissolved. Then, 21.8 g (0.1 mol) of pyromellitic dianhydride The mixture was stirred at room temperature for 3 hours, then heated to 80 ° C, stirred for 4 hours, and then the oil bath was removed and returned to room temperature to obtain an NMP solution of polyamic acid (hereinafter, also referred to as varnish). The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Example 2]

A varnish was obtained in the same manner as in Example 1 except that 93.06 g (0.3 mol) of ODPA, 2749 g of NMP and 43.62 g (0.2 mol) of PMDA were used. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Example 3]

A varnish was obtained in the same manner as in Example 1 except that 77.55 g (0.25 mol) of ODPA, 2711 g of NMP and 54.33 g (0.25 mol) of PMDA were used. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Example 4]

A varnish was obtained in the same manner as in Example 1 except that 62.04 g (0.2 mol) of ODPA, 2675 g of NMP and 65.44 g (0.3 mol) of PMDA were used. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Example 5]

A varnish was obtained in the same manner as in Example 1 except that 31.02 g (0.1 mole) of ODPA, 2601 g of NMP, and 87.25 g (0.4 mole) of PMDA were changed. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Example 6]

Terminal amine-modified dimethyl silicone oil (SILLA PLAIN FM3311 (number average molecular weight 1000) manufactured by Chisso Co., Ltd.) was mixed with 12.25 g of both terminal amine-modified methylphenyl silicone oil (X22-1660B-3 (number average molecular weight: 4400) g, 2578 g of NMP, and 141.23 g (0.449 mol) of TFMB, respectively. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Example 7]

A varnish was obtained in the same manner as in Example 3 except that PMDA was changed to 73.56 g (0.25 mol) of BPDA and NMP was changed to 2864 g. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Example 8]

A varnish was obtained in the same manner as in Example 3 except that ODPA was changed to 56.04 g (0.25 mol) of CHDA, 73.56 g (0.25 mol) of BPDA and 2540 g of NMP were used. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Referential Example 9]

A varnish was obtained in the same manner as in Example 3 except that ODPA was changed to 56.04 g (0.25 mol) of CHDA and to 2692 g of NMP. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Example 10]

A varnish was obtained in the same manner as in Example 3 except that ODPA was changed to 49.03 g (0.25 mol) of CBDA, 73.56 g (0.25 mol) of BPDA and 2484 g of NMP were changed. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Referential Example 11]

A varnish was obtained in the same manner as in Example 3 except that ODPA was changed to 49.03 g (0.25 mol) of CBDA and 2636 g of NMP. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Example 12]

A varnish was obtained in the same manner as in Example 3 except that ODPA was changed to 111.06 g (0.25 mole) of 6FDA, PMDA was changed to 73.56 g (0.25 mole) of BPDA and 3132 g of NMP. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Example 13]

A varnish was obtained in the same manner as in Example 3 except that ODPA was changed to 111.06 g (0.25 mol) of 6FDA and NMP was changed to 2980 g. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 2 below.

[Example 14]

A varnish was obtained in the same manner as in Example 3 except that OMPA was changed to 155.11 g (0.5 mol) and PMDA was not added and NMP was changed to 2896 g. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Example 15]

A varnish was obtained in the same manner as in Example 14 except that ODPA was changed to 222.12 g (0.5 mol) of 6FDA and NMP was changed to 3432 g. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Referential Example 16]

A varnish was obtained in the same manner as in Example 14 except that ODPA was changed to 98.06 g (0.5 mol) of CBDA and 2440 g of NMP. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Example 17]

A varnish was obtained in the same manner as in Example 14 except that ODPA was changed to 112.08 g (0.5 mol) of CHDA and NMP was changed to 2552 g. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Comparative Example 1]

A varnish was obtained in the same manner as in Example 1 except that ODPA was not added, NMP was changed to 2528 g, and PMDA to be added was changed to 109.06 g (0.5 mol). The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Comparative Example 2]

A varnish was obtained in the same manner as in Comparative Example 1 except that the PMDA was changed to 147.11 g (0.5 mole) of BPDA and the NMP was changed to 2832 g. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Comparative Example 3]

2486 g of NMP was added while nitrogen gas was introduced into a 3 L separable flask equipped with a stirrer bar equipped with an oil bath and 156.92 g (0.49 g) of 2,2'-bis (trifluoromethyl) benzidine (TFMB) Mol) was added thereto. After confirming the dissolution, 155.11 g (0.5 mol) of 4,4'-oxydiphthalic dianhydride (ODPA) was added and the mixture was stirred at room temperature for 30 minutes. Thereafter, the mixture was heated to 80 DEG C and stirred for 4 hours, then the oil bath was removed, and the temperature was returned to room temperature to obtain an NMP solution of polyamic acid (hereinafter, also referred to as a varnish). The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Comparative Example 4]

A varnish was obtained in the same manner as in Comparative Example 3 except that ODPA was changed to 222.12 g (0.5 mole) of 6FDA and NMP was changed to 3032 g. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Comparative Example 5]

A varnish was obtained in the same manner as in Comparative Example 3, except that 77.55 g (0.25 mole) of ODPA and 54.53 g (0.25 mole) of PMDA were added simultaneously with ODPA, and NMP was changed to 2312 g. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Comparative Example 6]

A varnish was obtained in the same manner as in Comparative Example 5, except that 124.1 g (0.4 mole) of ODPA, 21.8 g (0.1 mole) of PMDA and 2452 g of NMP were changed. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Comparative Example 7]

A varnish was obtained in the same manner as in Comparative Example 5 except that PMDA was changed to 73.56 g (0.25 mole) of BPDA and 2464 g of NMP. The composition is shown in Table 1 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the film cured at 350 占 폚 are shown in Table 2 below.

[Example 18]

A varnish was obtained in the same manner as in Example 1 except that 55.00 g of the amine-modified methylphenyl silicone oil (Shin-Etsu Chemical Co., Ltd.: X22-1660B-3 (number average molecular weight: 4400)) and NMP were changed to 3206 g. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 19]

A varnish was obtained in the same manner as in Example 2 except that 55.00 g of the both-end amine-modified methylphenyl silicone oil (X22-1660B-3 manufactured by Shin-Etsu Chemical Co., Ltd. (number average molecular weight: 4400)) and NMP were changed to 3123 g. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 20]

Varnish was obtained in the same manner as in Example 3 except that 55.00 g of the amine-modified methylphenyl silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd .: X22-1660B-3 (number average molecular weight: 4400)) and NMP were changed to 3079 g. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 21]

A varnish was obtained in the same manner as in Example 4 except that 55.00 g of the amine-modified methylphenyl silicone oil (Shin-etsu Chemical Co., Ltd.: X22-1660B-3 (number average molecular weight: 4400)) and NMP were changed to 3039 g. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 22]

A varnish was obtained in the same manner as in Example 5 except that 55.00 g of the both-end amine-modified methylphenyl silicone oil (X22-1660B-3 manufactured by Shin-Etsu Chemical Co., Ltd. (number average molecular weight: 4400)) and NMP were changed to 2956 g. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 23]

A varnish was obtained in the same manner as in Example 7 except that 55.00 g of the both-end amine-modified methylphenyl silicone oil (X22-1660B-3, manufactured by Shin-Etsu Chemical Co., Ltd., number average molecular weight: 4400) was changed to 3254 g. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 24]

A varnish was obtained in the same manner as in Example 8 except that the both-end amine-modified methylphenyl silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd.: X22-1660B-3 (number average molecular weight: 4400)) was changed to 55.00 g and NMP was changed to 3059 g. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test result of the film cured at 350 占 폚 are shown in Table 4 below.

[Example 25]

A varnish was obtained in the same manner as in Reference Example 9 except that 55.00 g of the amine-modified methylphenyl silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd .: X22-1660B-3 (number average molecular weight: 4400)) and NMP were changed to 2884 g. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 26]

A varnish was obtained in the same manner as in Example 12 except that 55.00 g of the both-end amine-modified methylphenyl silicone oil (X22-1660B-3, manufactured by Shin-Etsu Chemical Co., Ltd. (number average molecular weight: 4400)) was changed to 3557 g. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 27]

A varnish was obtained in the same manner as in Example 13 except that 55.00 g of the both-end amine-modified methylphenyl silicone oil (X22-1660B-3, manufactured by Shin-Etsu Chemical Co., Ltd., number average molecular weight: 4400) and 3383 g of NMP were used. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 28]

A varnish was obtained in the same manner as in Example 14 except that 55.00 g of the amine-modified methylphenyl silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd .: X22-1660B-3 (number average molecular weight: 4400)) and NMP were changed to 3290 g. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 29]

A varnish was obtained in the same manner as in Example 15 except that 55.00 g of the amine-modified methylphenyl silicone oil (Shin-Etsu Chemical Co., Ltd.: X22-1660B-3 (number average molecular weight: 4400)) and NMP were changed to 3897 g. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 30]

A varnish was obtained in the same manner as in Example 17 except that 55.00 g of the amine-modified methylphenyl silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd .: X22-1660B-3 (number average molecular weight: 4400)) and NMP were changed to 2900 g. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 31]

A varnish was obtained in the same manner as in Example 17 except that 94.96 g of the amine-modified methylphenyl silicone oil (Shin-etsu Chemical: X22-1660B-3 (number average molecular weight: 4400)) and NMP were changed to 3441 g. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 32]

Except that ODPA was changed to 55.00 g and NMP was changed to 3188 g and 89.57 g (0.25 mole) of DSDA, respectively, with both terminal amine-modified methylphenyl silicone oil (X22-1660B-3 (number average molecular weight: 4400) A varnish was obtained in the same manner as in Example 3. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 33]

55.00 g of ODPA as DSDA and 89.57 g (0.25 mol) of PMDA as PMDA and 73.56 g (0.25 mole) of BPDA as the end-amine amine-modified methylphenyl silicone oil (X22-1660B-3 (number average molecular weight: 4400) , And NMP was changed to 3362 g, to obtain a varnish. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 34]

Except that ODSA was changed to 55.00 g and NMP was changed to 3507 g and 179.14 g (0.5 mol), respectively, with both terminal amine-modified methylphenyl silicone oil (X22-1660B-3 (number average molecular weight: 4400) A varnish was obtained in the same manner as in Example 14. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 35]

Except that the ODPA was changed to 55.00 g and the NMP was changed to 3415 g and 114.58 g (0.25 mol) of TAHQ and both end amine-modified methylphenyl silicone oils (X22-1660B-3 (number average molecular weight: 4400) A varnish was obtained in the same manner as in Example 3. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 36]

55.00 g of both terminal amine-modified methylphenyl silicone oil (X22-1660B-3 (number average molecular weight: 4400) manufactured by Shin-Etsu Chemical Co., Ltd.) was mixed with 114.58 g (0.25 mol) of TAHQ and 73.56 g , And NMP was changed to 3589 g, to obtain a varnish. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 37]

Except that the ODPA was changed to 55.00 g and the NMP was changed to 3961 g and 229.17 g (0.5 mole) of TAHQ, respectively, with both terminal amine-modified methylphenyl silicone oil (X22-1660B-3 (number average molecular weight: 4400) A varnish was obtained in the same manner as in Example 14. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 38]

Except that the ODPA was changed to 55.00 g and the NMP was changed to 3415 g with 114.61 g (0.25 mol) of FLDA and with both terminal amine-modified methylphenyl silicone oil (X22-1660B-3 (number average molecular weight: 4400) A varnish was obtained in the same manner as in Example 3. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 39]

55.00 g of ODPA was added to 114.61 g (0.25 mol) of FLDA and 73.96 g (0.25 mol) of PMDA was added to BPDA to obtain an amine amine-modified methylphenyl silicone oil (X22-1660B-3 manufactured by Shin-Etsu Chemical Co., , And NMP was changed to 3589 g, to obtain a varnish. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 40]

Except that the ODPA was changed to 55.00 g and the NMP was changed to 3961 g and 229.21 g (0.5 mole) of FLDA and the both end amine-modified methylphenyl silicone oil (X22-1660B-3 (number average molecular weight: 4400) A varnish was obtained in the same manner as in Example 14. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 41]

157.1 g (0.493 mol) of TFMB and 3101 g of NMP were added to a 3-liter separable flask equipped with a stirrer bar equipped with an oil bath while introducing nitrogen gas. Subsequently, methylphenyl silicone oil modified with both terminal anhydrides Manufactured by X22-168-P5-B (number average molecular weight: 4200)) was added, and the mixture was stirred at room temperature for 30 minutes. Thereafter, 77.55 g (0.25 mol) of ODPA and 54.35 g (0.25 mol) of PMDA were added and stirred. After confirming that the mixture was dissolved, the mixture was stirred at room temperature for 3 hours and then heated to 80 DEG C and stirred for 4 hours. The bath was removed and returned to room temperature to obtain a varnish of polyamic acid. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 42]

Except that 77.55 g (0.25 mole) of ODPA and 54.35 g (0.25 mole) of PMDA were changed to 77.55 g (0.25 mole) of ODPA and 73.56 g (0.25 mole) of BPDA by changing NMP to 3275 g, To obtain a varnish. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 43]

A varnish was obtained in the same manner as in Example 41 except that NMP was changed to 3311 g, OPSA (77.55 g, 0.25 mole) and PMDA (54.35 g, 0.25 mole) were changed to ODSA (155.11 g, 0.5 mole). The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 44]

12.25 g of both terminal amine-modified methylphenyl silicone oil (X22-1660B-3, manufactured by Shin-Etsu Chemical Co., Ltd., number average molecular weight: 4400) ), And NMP was changed to 3193 g, to obtain a varnish. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 45]

12.25 g of both terminal amine-modified methylphenyl silicone oil (X22-1660B-3, manufactured by Shin-Etsu Chemical Co., Ltd., number average molecular weight: 4400) ), And NMP was changed to 3367 g, to obtain a varnish. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 46]

12.25 g of both terminal amine-modified methylphenyl silicone oil (X22-1660B-3, manufactured by Shin-Etsu Chemical Co., Ltd., number average molecular weight: 4400) ), And NMP was changed to 3403 g. The varnish was obtained in the same manner as in Example 14. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 47]

Terminal hydroxy-modified dimethyl silicone oil (KF-6003 (number average molecular weight 5100)) of both ends was modified with 12.25 g of an amine-modified methylphenyl silicone oil (Shin-Etsu Chemical Co.: X22-1660B- And varnish was obtained in the same manner as in Example 3 except that NMP was changed to 3158 g. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 48]

Terminal hydroxy-modified dimethyl silicone oil (KF-6003 (number average molecular weight 5100)) of both ends was modified with 12.25 g of an amine-modified methylphenyl silicone oil (Shin-Etsu Chemical Co.: X22-1660B- 63.66 g, and NMP was changed to 3332 g, and varnish was obtained in the same manner as in Example 7. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 49]

Terminal hydroxy-modified dimethyl silicone oil (KF-6003 (number average molecular weight 5100)) of both ends was modified with 12.25 g of an amine-modified methylphenyl silicone oil (Shin-Etsu Chemical Co.: X22-1660B- 63.66 g, and NMP was changed to 3368 g, to obtain a varnish. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 50]

12.25 g of both terminal amine-modified methylphenyl silicone oil (X22-1660B-3, manufactured by Shin-Etsu Chemical Co., Ltd., number average molecular weight: 4400) was added to a two-terminal mercapto-modified dimethyl silicone oil (X22-167- )), And the amount of NMP was changed to 3102 g, to obtain a varnish. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 51]

12.25 g of both terminal amine-modified methylphenyl silicone oil (X22-1660B-3, manufactured by Shin-Etsu Chemical Co., Ltd., number average molecular weight: 4400) was added to a two-terminal mercapto-modified dimethyl silicone oil (X22-167- )), And NMP was changed to 3276 g, to obtain a varnish. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 52]

12.25 g of both terminal amine-modified methylphenyl silicone oil (X22-1660B-3, manufactured by Shin-Etsu Chemical Co., Ltd., number average molecular weight: 4400) was added to a two-terminal mercapto-modified dimethyl silicone oil (X22-167- )), And NMP was changed to 3312 g, to obtain a varnish. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Example 53]

The polyimide precursor was synthesized in the same manner as in Example 20. Subsequently, the NMP solution of the polyamic acid was heated to 150 DEG C, stirred for 10 minutes, the oil bath was removed, and the temperature was returned to room temperature. An NMP solution of an acid was obtained. From the peak of the imide (1780 cm ^-1 ) determined by IR measurement, it was confirmed that the imidization ratio was 10%. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid imidized in some of the obtained varnishes and the test result of the cured film at 350 占 폚 are shown in Table 4 below.

[Comparative Example 8]

OMPA was changed to 2.03 g with 5.12 g (0.0261 mol) of CBDA and 7.9 g (0.0245 mol) of TFMB with 2.032 g of both terminal amine-modified methylphenyl silicone oil (Shin-Etsu Chemical Co., Ltd .: X22-9409, number average molecular weight 1300) The varnish was obtained in the same manner as in Comparative Example 3 except that the weight of the varnish was changed to 136 g. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below. Comparative Example 8 corresponds to Example 11 of Patent Document 3 described in the column of the prior art document.

[Comparative Example 9]

A varnish was obtained in the same manner as in Comparative Example 1 except that 55.00 g of the both-end amine-modified methylphenyl silicone oil (X22-1660B-3, manufactured by Shin-Etsu Chemical Co., Ltd., number average molecular weight: 4400) and NMP were changed to 2873 g. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Comparative Example 10]

A varnish was obtained in the same manner as in Comparative Example 2 except that 55.00 g of the amine-modified methylphenyl silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd .: X22-1660B-3 (number average molecular weight: 4400)) and NMP were changed to 3217 g. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Comparative Example 11]

A varnish was obtained in the same manner as in Comparative Example 3 except that ODA was changed to 179.14 g (0.5 mol) of DSDA and 3045 g of NMP. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Comparative Example 12]

A varnish was obtained in the same manner as in Comparative Example 3 except that ODPA was changed to 229.17 g (0.5 mol) of TAHQ and 3498 g of NMP. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

[Comparative Example 13]

A varnish was obtained in the same manner as in Comparative Example 3 except that ODA was changed to 229.21 g (0.5 mole) of FLDA and 3498 g of NMP. The composition is shown in Table 3 below. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish and the test results of the cured film at 350 占 폚 are shown in Table 4 below.

As shown in Tables 2 and 4, it was confirmed that the examples satisfied the following conditions simultaneously in film properties.

(1) The residual stress is 20 MPa or less

(2) Yellowness is 10 or less

(3) a glass transition temperature in the temperature range of the room temperature or higher is 250 DEG C or more and 380 DEG C or less

(4) The total light transmittance is 85% or more

(5) a breaking strength of 200 MPa or more, a tensile elongation of 20% or more

On the other hand, in Comparative Example 1, the yellowness increases due to the increase of the PMDA component, and the total light transmittance also becomes cloudy and low. Comparative Example 2 also has the same tendency. In Comparative Examples 3 to 7 and 9 to 11, although yellow tint and total light transmittance were high, residual stress was high.

Further, as shown in Table 5, a SiN film was formed on the polyimide film and the bending test of the laminated film was carried out. However, it was confirmed that the examples had sufficient bending resistance in the test.

On the other hand, in Comparative Examples 1 to 8 and 11 to 13, peeling was observed in cracks or in the polyimide film and the SiN film, and the bending resistance was insufficient.

From these results, it is found that the polyimide obtained from the polyimide precursor according to the present invention is colorless and transparent, has a low residual stress with the inorganic film, has excellent mechanical and thermal properties, It is possible to produce a polyimide film which can have excellent bending resistance.

The present invention is not limited to the above-described embodiment, but can be modified in various ways.

Industrial availability

 The polyimide film obtained by imidizing a polyimide resin using the polyimide precursor according to the present invention can be preferably used as a substrate material in the production of, for example, a semiconductor insulating film, a TFT-LCD insulating film, an electrode protecting film, and a flexible display.

Claims (20)

(A):

(B): &lt; EMI ID = 1.0 &gt;

(Wherein plural R ₃ and R ₄ are each independently a monovalent organic group having 1 to 20 carbon atoms and h is an integer of 3 to 200), which is heat-cured , It has at least one glass transition temperature in the temperature range of 150 ° C to 380 ° C and does not have a glass transition temperature in the temperature range of 0 ° C to 150 ° C (not including both ends) and its imide concentration is 2.00 To 3.70 mmol / g of a polyimide precursor, which may contain a solvent. The method according to claim 1,
Wherein the polyimide precursor is represented by the following general formula (C):

(Wherein R ₂ is a single bond or a divalent organic group having 1 to 20 carbon atoms, and R ₃ , R ₄ , and R _{5, which} are plural, each independently represent a monovalent organic group having 1 to 20 carbon atoms and, L _1, L _2, and L ₃ is the one group each independently selected from an amino group, acid anhydride group, a carboxyl group, selected from a hydroxyl group, an epoxy group, a mercapto group, and the group consisting of R _6, R ₆ is A monovalent organic group having 1 to 20 carbon atoms, j is an integer of 3 to 200, and k is an integer of 0 to 197. The polyimide precursor is obtained by using a silicone compound as a monomer component. 3. The method of claim 2,
Wherein L ₁ and L ₂ in formula (C) are each independently an amino group or an acid anhydride group, and L ₃ is R ₆ . The method of claim 3,
Wherein all of L ₁ and L ₂ in the general formula (C) are amino groups. 3. The method according to claim 1 or 2,
Wherein the polyimide precursor is at least a compound represented by the following general formula (1):

A plurality of R _{1 s} are each independently a hydrogen atom, a monovalent aliphatic hydrocarbon having 1 to 20 carbon atoms, or an aromatic group; X ₁ is a tetravalent organic group having 4 to 32 carbon atoms, And n is an integer of 1 to 100, and a unit represented by the following general formula (2):

Wherein the plurality of R _{1 s} are each independently a hydrogen atom, a monovalent aliphatic hydrocarbon having 1 to 20 carbon atoms, or an aromatic group, and the plurality of R _{2 s} are each independently a divalent aliphatic hydrocarbon having 3 to 20 carbon atoms, R ₃ and R ₄ are each independently a monovalent aliphatic hydrocarbon having 1 to 3 carbon atoms or an aromatic group having 6 to 10 carbon atoms and X ₂ is an aromatic group having 4 to 32 carbon atoms, Wherein m is an integer of 1 to 100. 2. A polyimide precursor according to claim 1, 6. The method of claim 5,
Wherein the polyimide precursor is used in place of or in addition to the unit 1 represented by the general formula (1) and the unit represented by the general formula (2)

Wherein R ₈ is a trivalent aliphatic hydrocarbon having 3 to 20 carbon atoms or an aromatic group and each of R _{1 s} is independently a hydrogen atom, a monovalent aliphatic hydrocarbon having 1 to 20 carbon atoms, , Q is an integer of 3 to 50, and p is an integer of 1 to 100, and R &lt; ₃ &gt; and R &lt; ₄ &gt; each independently represent a monovalent aliphatic hydrocarbon having 1 to 3 carbon atoms or an aromatic group having 6 to 10 carbon atoms, Lt; RTI ID = 0.0 &gt; 3. &Lt; / RTI &gt; A polyimide precursor composition comprising the polyimide precursor according to claim 1 or 2 and a polyimide precursor represented by the following formula (D):

Wherein X ₃ is a tetravalent organic group having 4 to 32 carbon atoms, and each of R _{1 s} is independently a hydrogen atom, a monovalent aliphatic hydrocarbon having 1 to 20 carbon atoms, or an aromatic group, And r is an integer from 1 to 100. 3. The method according to claim 1 or 2,
A polyimide precursor having a degree of yellowing of 10 or less at a film thickness of 20 탆 when heated and cured is obtained. 6. The method of claim 5,
Wherein the component derived from the acid anhydride of the unit 1 and the unit 2 comprises the component derived from pyromellitic dianhydride (PMDA) and the component derived from biphenyltetracarboxylic acid (BPDA) (ODPA), a component derived from 4,4 '- (hexafluoroisopropylidene) diphthalic anhydride (6FDA), a component derived from cyclohexane-1,2,4,5-tetracarboxylic acid 2 A component derived from an anhydride (CHDA), a component derived from 3,3 ', 4,4'-diphenylsulfone tetracarboxylic acid dianhydride (DSDA), a component derived from 4,4'-biphenylbis (trimellitic acid monoester acid anhydride (TAHQ), and a component derived from 9,9'-bis (3,4-dicarboxyphenyl) fluorene dianhydride (FLDA) And the combination is contained in an amount of 60 mol% or more based on the total amount of the acid dianhydride-derived components of the unit 1 and the unit 2, . 10. The method of claim 9,
The acid-derived anhydride-derived component of the unit 1 and the unit 2 is a combination of a component derived from pyromellitic dianhydride (PMDA) and a component derived from 4,4'-oxydiphthalic acid dianhydride (ODPA) Component / (the number of moles of the PMDA-derived component + the number of moles of the ODPA-derived component) is in the range of 0.2 to 0.8. 3. The method according to claim 1 or 2,
Wherein the polyimide precursor is partially imidated. 3. The method according to claim 1 or 2,
Dissolved in a solvent and developed on the surface of a support and then imidized at 350 ° C in a nitrogen atmosphere, the degree of yellowness at a film thickness of 20 μm was 10 or less, the breaking strength was 200 MPa or more, A polyimide precursor having a stress of 20 MPa or less is obtained. 3. The method according to claim 1 or 2,
A polyimide precursor for use in the manufacture of flexible devices. A resin composition containing the polyimide precursor according to claim 1 or 2 and a solvent. A polyimide film characterized in that the resin composition according to claim 14 is developed on the surface of a support, and then the support and the resin composition are heated to imidize the polyimide precursor or a mixture thereof. (A):

Derived structural unit represented by the following general formula (B):

A polyimide film having a structural unit represented by {wherein plural R ₃ in the R ₄ are each independently ^a monovalent group having 1 to 20 carbon atoms and an organic group, and h is from 3 to 200 integer}, 150 ℃ And has at least one glass transition temperature in the temperature range of ~ 380 占 폚, does not have a glass transition temperature in the temperature range of 0 占 폚 to 150 占 폚 (not including both ends), and the imidization concentration is 2.00 to 3.70 mmol / g. &lt; / RTI &gt; A method for producing a resin composition, comprising the steps of: developing the resin composition according to claim 14 on a surface of a support;
Heating the support and the resin composition to imide the polyimide precursor to form a polyimide film;
A step of peeling the polyimide film from the support to obtain the polyimide film
Wherein the polyimide film is a polyimide film. Characterized in that it is obtained by expanding the resin composition according to claim 14 on a surface of a support and a polyimide film and heating the support and the resin composition to imide the polyimide precursor to form a polyimide film . A step of developing the resin composition according to claim 14 on the surface of a support,
Heating the support and the resin composition to imidize the polyimide precursor to form a polyimide film and obtaining a laminate composed of the support and the polyimide film
And a step of forming a laminate. A flexible substrate comprising a polyimide film and an inorganic film obtained by heating the resin composition according to claim 14 to imidize the polyimide precursor.