TW201813993A - Polyimide precursor, resin composition, resin film and manufacturing method thereof with the polyimide precursor having low residual stress, low warpage, low yellowing index in high temperature region and high elongation - Google Patents

Abstract

The present invention provides a polyimide precursor having relatively low residual stress, relatively low warpage, relatively low yellowing index (YI value) in high temperature region and relatively high elongation, and a polyimide resin film and a manufacturing method thereof. The present invention also provides a resin composition for a substrate of low-temperature polysilicon thin film transistor (TFT) element, which comprises a polyimide precursor obtained by polymerizing a diamine component and an acid di-anhydride component, and a solvent, wherein the polyimide precursor (a) is a structure represented by the following general formula (1).

Description

Polyfluorene imide precursor, resin composition, resin film and manufacturing method thereof

The present invention relates, for example, to a polyimide precursor, a resin composition, a resin film, and a manufacturing method thereof for manufacturing a substrate for a flexible device.

Generally, a film of a polyimide resin is used as a resin film in applications requiring high heat resistance. General polyfluorene imide resins are produced by solution polymerization of an aromatic carboxylic dianhydride and an aromatic diamine to produce a polyfluorene imide precursor, and then thermally fluorinated at high temperatures, or using a catalyst. A highly heat-resistant resin produced by chemical sulfonation. Polyimide resins are insoluble and insoluble super heat-resistant resins. They have excellent properties such as thermal oxidation resistance, heat resistance, radiation resistance, low temperature resistance, and chemical resistance. Therefore, polyimide resins are used in a wide range of fields including electronic materials. Examples of application of polyimide resins in the field of electronic materials include insulating coating agents, insulating films, semiconductor protective films, and TFT-LCD (Thin Film Transistor-Liquid Crystal Display) ) Electrode protection film. Recently, the industry is researching to replace the glass substrate previously used in the field of display materials with a colorless and transparent flexible substrate that uses its light weight and flexibility. In the case of manufacturing a polyimide resin film as a flexible substrate, a composition containing a polyimide precursor is coated on an appropriate support to form a coating film, and then heat-treated to make the polyimide, Thus, a polyfluorene imide resin film was obtained. Examples of the support include glass, silicon, silicon nitride, silicon oxide, and metal. When manufacturing a laminate having a polyimide film on such a support, in order to dry and polyimide the polyimide precursor, heat treatment at a high temperature of 250 ° C or higher is required. Residual stress is generated in the laminated body by the heat treatment, which causes deep problems such as warping and peeling. The reason is that the linear thermal expansion coefficient of polyimide is larger than that of the material constituting the support. As a polyimide material having a small thermal expansion coefficient, polyimide formed from 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and p-phenylenediamine is most widely known. Although it has been reported that this polyimide film depends on the film thickness and production conditions, this polyimide film exhibits a very low coefficient of linear thermal expansion (Non-Patent Document 1). In addition, it has been reported that polyfluorene imide having an ester structure in the molecular chain has a moderate linearity and rigidity, and therefore exhibits a low linear thermal expansion coefficient (Patent Document 1). However, the general polyimide resin containing the polyimide described in the above-mentioned document is colored brown or yellow due to a higher aromatic ring density, and therefore the light transmittance in the visible light region is low, and therefore it is difficult to use it. Areas that require colorless transparency. For example, the yellowness (YI value) of the polyimide-based polyimide film of the above-mentioned non-patent document 1 obtained from 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and p-phenylenediamine at a thickness of 10 μm ) Is as high as 40 or more, which is insufficient in terms of colorless transparency. Regarding the yellowness of the film, for example, polyimide using a monomer having a fluorine atom is known to exhibit extremely low yellowness (Patent Document 2). In addition, a polyimide precursor having both a lower yellowness and a lower Rth is disclosed (Patent Document 3). [Prior Art Literature] [Patent Literature] [Patent Literature 1] Japanese Patent No. 4627297 [Patent Literature 2] Japanese Patent Publication No. 2010-538103 [Patent Literature 3] International Publication No. 2014/148441 [Non-Patent Literature [Non-Patent Document 1] The latest polyimide Japan Polyimide Research Society NTS

[Problems to be Solved by the Invention] In addition, in order to apply a polyimide resin as a colorless transparent flexible substrate, in addition to transparency, the residual stress with the substrate is also required to be small, the glass transition temperature is high, and Rth (delay ) Lower. Previously, the device type of a TFT manufactured for the purpose of display driving of a display was amorphous silicon or IGZO (Indium Gallium Zinc Oxide, Indium Gallium Zinc Oxide), so the process temperature was below 350 ° C. On the other hand, as the device type of TFTs has recently changed to low-temperature polycrystalline silicon (hereinafter referred to as LTPS), the process temperature has reached 400 ° C or higher, and it is expected that the film exhibiting the above-mentioned physical properties even after such a high-temperature thermal history. However, the known physical properties of the transparent polyimide are insufficient to be used as a heat-resistant colorless transparent substrate for a display. Furthermore, the present inventors confirmed that the polyimide resin described in Patent Document 1 shows a low linear thermal expansion coefficient, but has the following problems: yellowness of the polyimide resin film after peeling (YI value) is large, and the residual stress is high. Regarding the yellowness, it is known that although the polyimide films described in Patent Documents 2 and 3 show low yellowness in a temperature range of about 300 ° C, the yellowness after a high-temperature thermal history above 400 ° C (YI value) is significantly deteriorated. The present invention has been made in view of the problems described above. Therefore, an object of the present invention is to provide a yellowness (YI value) after high-temperature thermal history that can be suitably used when a TFT device type is LTPS, a small residual stress with a glass substrate, and glass transfer. Polyimide resin film having a higher temperature and a lower Rth (retardation), a method for producing the same, and a laminate. [Technical Means for Solving the Problem] The present inventors and the like have made intensive studies in order to solve the above problems. As a result, it was found that the yellowness (YI value) of the polyimide resin film obtained by curing a resin composition containing a polyimide precursor having a specific structure is small, and the residual stress of the substrate is small. In addition, it was also found that the laminated body containing a polyimide film and a LTPS layer with a specific structure did not warp when it was made into an organic EL (Electroluminescence, electroluminescence) device, and the lighting test was also good. Less, the present invention has been completed based on such knowledge and insights. That is, the present invention is as described below. [1] A resin composition for a substrate of a low-temperature polycrystalline silicon TFT device, which comprises a polyimide precursor obtained by polymerizing a diamine component and an acid dianhydride component, and a solvent, and the polyfluorene The amine precursor contains (a) the following general formula (1): The structure represented. [2] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to [1], wherein the polyfluorene imide precursor includes the following general formula (2): [化 2] The structure represented. [3] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to [1] or [2], wherein the weight average molecular weight of the polyimide precursor is 40,000 or more and 300,000 or less. [4] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to any one of [1] to [3], wherein the total weight of the solid components contained in the resin composition is 100 At mass%, the amount of molecules having a molecular weight of less than 1,000 contained in the solid component is less than 5 mass%. [5] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to [4], wherein the amount of the molecules having a molecular weight of less than 1,000 contained in the solid component is 1% by mass or less. [6] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to any one of [1] to [5], wherein the polyfluorene imide precursor is a mixture of the diamine component and the acid dianhydride component. When the total mass is 100% by mass, the following formula (3) is included: [化 3] (In the formula, there are a plurality of R ₃ and R ₄ each independently being a monovalent organic group having a carbon number of 1 to 20, and h is an integer of 3 to 200.) Less than 6% by mass. [7] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to [6], wherein the content of the silicone diamine component is 5.9% by mass or less. [8] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to [7], wherein the content of the silicone diamine component is 3% by mass or less. [9] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT element according to any one of [1] to [8], wherein the polyfluorene imide precursor is set to a total mole number of the diamine component. When it is 100 mol%, the following polyimide precursor contains the following general formula (4): (Wherein R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having 1 to 20 carbon atoms. N represents 0 or 1. and a, b, and c are integers of 0 to 4) The amount of diamine is 48 mol% or less. [10] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to [9], wherein the amount of the diamine represented by the general formula (4) contained in the polyfluorene imide precursor is less than 1 mole. ear%. [11] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to [10], wherein the amount of the diamine represented by the general formula (4) contained in the polyimide precursor is 0.9 mol% or less . [12] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to [9], wherein the polyfluorene imide precursor includes 4-aminophenyl-4-aminobenzoate as the general formula (4) The diamine component shown. [13] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to any one of [1] to [12], wherein the polyfluorene imide precursor is set to a total mole number of the diamine component. When it is 100 mol%, the content of the 4-aminophenyl-4-aminobenzoate is 48 mol% or less. [14] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to [13], wherein the content of the 4-aminophenyl-4-aminobenzoate of the polyfluorene imide precursor is not Up to 1 mole%. [15] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to [14], wherein the content of the 4-aminophenyl-4-aminobenzoate of the polyfluorene imide precursor is not Up to 0.9 mol%. [16] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT element according to any one of [1] to [15], wherein the polyfluorene imide precursor includes diaminodiphenylphosphonium as the diamine ingredient. [17] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to [16], wherein when the polyfluorene imide precursor is 100 mol% in total mole number of the diamine component, the above The content of diaminodiphenylphosphonium is above 90 mole%. [18] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to any one of [1] to [17], wherein the polyfluorene imide precursor includes pyromellitic dianhydride as the acid dianhydride ingredient. [19] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to [18], wherein when the polyfluorene imide precursor is 100 mol% in total mol number of the acid dianhydride component, The content of the pyromellitic dianhydride is more than 90 mol%. [20] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to any one of [1] to [19], wherein the polyimide obtained by heating the resin composition at 430 ° C for 1 hour The yellowness of the film was 20 or less at a film thickness of 10 μm. [21] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to [20], wherein the yellowness of the polyimide film obtained by heating the resin composition at 430 ° C for 1 hour is at a film thickness of 10 13 μm or less. [22] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT element according to any one of [1] to [21], wherein the polyimide obtained by heating the resin composition at 430 ° C for 1 hour The glass transition temperature of the film is above 360 ° C. [23] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to [22], wherein the glass transition temperature of the polyimide film obtained by heating the resin composition at 430 ° C for 1 hour is 470 ° C the above. [24] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT element according to any one of [1] to [23], wherein the polyimide obtained by heating the resin composition at 430 ° C for 1 hour The retardation of the film is 1000 nm or less at a film thickness of 10 μm. [25] The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to [24], wherein the polyimide film obtained by heating the resin composition at 430 ° C for 1 hour has a retardation of a film thickness of 10 μm At 140 nm. [26] A method for manufacturing a resin film, comprising the following steps: a step of applying the resin composition according to any one of [1] to [25] on a surface of a support; and combining the resin Forming a polyimide resin film; and a step of peeling the polyimide resin film from the support. [27] The method for producing a resin film according to claim 26, wherein the step of irradiating laser light from the support side is performed before the step of peeling the polyfluorene imide resin film from the support. [28] A method for manufacturing a display, including a method for manufacturing a resin film by the method described in [26] or [27]. [29] A method for producing a laminated body, comprising the steps of: coating a surface of a support with the resin composition according to any one of [1] to [25]; and forming the resin composition from the resin composition A step of polyimide resin film; and a step of forming a low-temperature polycrystalline silicon TFT on the polyimide resin film. [30] The method for producing a laminated body according to [29], further comprising a step of peeling the polyimide resin film from the support. [31] A method for manufacturing a flexible device, including the method for manufacturing a laminated body according to [29] or [30]. [32] A laminated body, comprising: containing the following general formula (5): [化 5] The polyimide layer of the polyimide and the low-temperature polycrystalline silicon TFT layer shown. [33] The laminated body according to [32], wherein the amount of molecules having a molecular weight of less than 1,000 contained in the polyimide layer is not more than 5% by mass. [34] A polyimide film characterized by a yellowness of 20 or less at a film thickness of 10 μm when heated at 430 ° C, a residual stress of 25 MPa or less, and an elongation of 15% or more. [Effect of the invention] The polyimide film obtained from the resin composition of the present invention has a small yellowness (YI value) in a high temperature region, a small residual stress with a substrate, a high glass transition temperature, and a Rth (delay) ) Low. In addition, the laminate system comprising the polyimide film and the low-temperature polycrystalline silicon TFT obtained from the resin composition of the present invention has less warpage, lower haze, and a good result of the thermal cycle test.

Hereinafter, exemplary embodiments (hereinafter referred to simply as "embodiments") of the present invention will be described in detail. The present invention is not limited to the following embodiments, and can be implemented with various changes within the scope of the gist thereof. In addition, as long as the characteristic value described in this invention is not specifically mentioned, it means the value measured using the method described in the item of [Example], or a method which a supplier understands equivalent. <Resin Composition> The resin composition according to one aspect of the present invention contains (a) a polyimide precursor, and (b) an organic solvent. Hereinafter, each component is demonstrated in order. [Polyimide precursor] The polyimide precursor system (a) in the present embodiment (a) has the following general formula (1): [Chem. 6] Represented polyfluorene imide precursor. Examples of the acid dianhydride used in the general formula (1) of this embodiment include pyromellitic dianhydride (hereinafter also referred to as PMDA). Examples of the diamine used in the general formula (1) in this embodiment include 4,4'-diaminodiphenylphosphonium and 3,3'-diaminodiphenylphosphonium. Among them, from the viewpoints of residual stress, YI, glass transition temperature, retardation Rth, elongation, and haze of the obtained polyimide film, the use represented by the following general formula (2) is more preferable. Structure of 4'-diaminodiphenylphosphonium. [Chemical 7] The weight average molecular weight (Mw) of the polyfluorene imide precursor in this embodiment is preferably 10,000 to 300,000, and particularly preferably 40,000 to 300,000. When the weight average molecular weight is 40,000 or more, especially mechanical properties such as elongation and breaking strength are excellent, residual stress becomes low, and YI becomes low. When the weight average molecular weight is less than 300,000, it becomes easy to control the weight average molecular weight during the synthesis of the polyamic acid, and a resin composition having a moderate viscosity can be obtained, and the coating property of the resin composition becomes good. In the present invention, the weight average molecular weight is a value obtained in the form of a standard polystyrene conversion value using a gel permeation chromatography (hereinafter also referred to as GPC). When the total weight of the solid components contained in the resin composition of this embodiment is 100% by mass, the smaller the content of molecules having a molecular weight of less than 1,000, the better. Specifically, it is preferably less than 5 mass%, more preferably 4 mass% or less, more preferably 3 mass% or less, more preferably 2 mass% or less, and more preferably 1 with respect to the total weight of the solid components. Mass% or less, preferably 0.5 mass% or less, preferably 0.1 mass% or less, preferably 0.05 mass% or less, and more preferably 0.02 mass% or less. This composition is excellent in viscosity stability and varnish coatability. In addition, the polyimide film obtained from such a composition has a low residual stress, a small YI, a high glass transition temperature (Tg), a low retardation Rth, and a high elongation, which is preferable. In addition, a laminate system including such a polyfluorene film and a low-temperature polycrystalline silicon TFT has less warpage and lower haze, and the results of the thermal cycle test are good. The content of molecules having a molecular weight of less than 1,000 can be calculated from the peak area obtained by GPC measurement of the resin composition. In the polyimide precursor in this embodiment, in addition to pyromellitic dianhydride, other acid dianhydrides can be used within a range that does not impair elongation, strength, stress, and yellowness. Examples of such acid dianhydride include 4,4 '-(hexafluoroisopropylidene) diphthalic anhydride, 5- (2,5-dioxotetrahydro-3-furanyl) -3 -Methyl-cyclohexene-1,2 dicarboxylic anhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride, 2,2 ', 3,3'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 3,3 ', 4,4'-diphenyl Tetracarboxylic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride, methylene-4,4'-diphthalic dianhydride, 1,1-ethylene -4,4'-diphthalic dianhydride, 2,2-propylene-4,4'-diphthalic dianhydride, 1,2-ethyl-4,4'-diphthalic acid Phthalic acid dianhydride, 1,3-trimethylene-4,4'-diphthalic acid dianhydride, 1,4-tetramethylene-4,4'-diphthalic acid dianhydride, 1 , 5-pentamethylene-4,4'-diphthalic dianhydride, 4,4'-oxydiphthalic dianhydride, p-phenylene bis (anhydrotrimellitic acid ester), sulfur -4,4'-diphthalic dianhydride, sulfo-4,4'-diphthalic dianhydride, 1,3-bis (3,4-dicarboxyphenyl) phthalic anhydride , 1,3-bis (3,4-dicarboxyphenoxy) phthalic anhydride, 1,4-bis (3,4-dicarboxyphenoxy) phthalic anhydride, 1,3-bis [2- ( 3,4- Dicarboxyphenyl) -2-propyl] phthalic anhydride, 1,4-bis [2- (3,4-dicarboxyphenyl) -2-propyl] phthalic anhydride, bis [3- (3, 4-dicarboxyphenoxy) phenyl] methane dianhydride, bis [4- (3,4-dicarboxyphenoxy) phenyl] methane dianhydride, 2,2-bis [3- (3,4- Dicarboxyphenoxy) phenyl] propane dianhydride, 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride, bis (3,4-dicarboxyphenoxy ) Dimethylsilane dianhydride, 1,3-bis (3,4-dicarboxyphenyl) -1,1,3,3-tetramethyldisiladian dianhydride, 2,3,6,7- Naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 3,4,9,10-fluorenetetracarboxylic dianhydride Anhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, etc. The content of the other acid dianhydrides in the total acid dianhydride is preferably 20 mol% or less, more preferably 10 mol% or less, and even more preferably 0 mol%. The content of pyromellitic dianhydride in the total acid dianhydride is preferably 90 mol% or more, more preferably 95 mol% or more, more preferably 98 mol% or more, and more preferably 99 mol% or less, It is preferably 99.5 mol% or more. The larger the amount of pyromellitic dianhydride in the total acid dianhydride, the better it is from the viewpoints of YI, glass transition temperature Tg, and elongation. In the polyfluorene imide precursor in this embodiment, in addition to 4,4'-diaminodiphenylphosphonium and 3,3'-diaminodiphenylphosphonium, the elongation can be maintained without compromising elongation, Use other diamines within the range of strength, stress, and yellowness. Examples of other diamines include p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylsulfide, 3,4'-diaminodiphenylsulfide, and 3,3'- Diaminodiphenyl sulfide, 4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 4,4'-diaminodiphenyl Benzophenone, 3,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 4,4'-diaminodiphenylmethane, 3,4'-diamine Diphenylmethane, 3,3'-diaminodiphenylmethane, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, bis [4- (4-aminophenoxy) phenyl] fluorene, 4,4-bis (4-aminophenoxy) biphenyl , 4,4-bis (3-aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl] ether, bis [4- (3-aminophenoxy) benzene Group] ether, 1,4-bis (4-aminophenyl) benzene, 1,3-bis (4-aminophenyl) benzene, 9,10-bis (4-aminophenyl) anthracene, 2 2,2-bis (4-aminophenyl) propane, 2,2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl ] Propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 1,4-bis (3-aminopropyldimethylsilyl) benzene, etc. are preferred for Selected from one or more of these in. The content of the other diamines in the total diamine is preferably 20 mol% or less, more preferably 10 mol% or less, and even more preferably 0 mol%. The content of diaminodiphenylphosphonium in the total diamine is preferably 90 mol% or more, more preferably 95 mol% or more, more preferably 98 mol% or more, and more preferably 99 mol% or more, It is preferably 99.5 mol% or more. The larger the amount of diaminodiphenylphosphonium, the better it is from the viewpoints of residual stress, YI, glass transition temperature Tg, retardation Rth, and elongation. The diaminodiphenylphosphonium is preferably 4,4'-diaminodiphenylphosphonium. The polyimide precursor is preferably the amount of the diamine represented by the following general formula (4) contained in the polyimide precursor when the total mole number of the diamine component is 100 mol%. It is 48 mol% or less. [Chemical 8] (Where, R ₁ , R ₂ , R ₃ Each independently represents a monovalent organic group having 1 to 20 carbon atoms. n represents 0 or 1. (A, b, and c are integers of 0 to 4) As the diamine represented by the general formula (4), for example, when n is 0, 4-aminophenyl-4-aminobenzoic acid may be exemplified. Ester (APAB), 2-methyl-4-aminophenyl-4-aminobenzoate (ATAB), 4-aminophenyl-3-aminobenzoate (4,3-APAB )Wait. When n is 1, [4- (4-aminobenzyl) phenoxy] 4-aminobenzoate and the like can be exemplified. In particular, when the polyfluorene imide precursor is 100 mol% of the total moles of the diamine component, the polyamine imide precursor contains the diamine component represented by the general formula (4). The content of 4-aminophenyl-4-aminobenzoate is 48 mol% or less. The effects of smaller YI, higher Tg, lower delay, and higher elongation are obtained. It may or may not contain 4-aminophenyl-4-aminobenzoate. The smaller the amount of the diamine represented by the general formula (4), the better it is from the viewpoints of YI, glass transition temperature Tg, retardation Rth, and elongation. The amount of the diamine represented by the general formula (4) contained in the polyfluorene imide precursor is preferably 30 mol% or less, preferably 20 mol% or less, and more preferably 10 mol% or less. It is preferably 5 mol% or less. The amount of the diamine represented by the general formula (4), particularly, for example, 4-aminophenyl-4-aminobenzoate is preferably less than 1 mole%, and more preferably 0.9 mole%. Hereinafter, it is preferably 0.8 mol% or less, preferably 0.6 mol% or less, preferably 0.4 mol% or less, more preferably 0.2 mol% or less, and preferably 0.1 mol% or less. The polyfluorene imide precursor preferably includes the following formula (3) when the total mass of the diamine component and the acid dianhydride component is 100% by mass: (Where, there is a plurality of R ₃ And R ₄ Each is independently a monovalent organic group having a carbon number of 1 to 20, and the content of the silicone diamine component of the structure represented by h is an integer of 3 to 200) is less than 6 mass%. The smaller the silicone diamine component including the structure represented by the formula (3), the smaller the YI, the larger the glass transition temperature Tg, and the smaller the retardation Rth, which is preferable. The content of the silicone diamine component including the structure represented by the formula (3) is preferably 5.9% by mass or less, 5.5% by mass or less, 5.0% by mass or less, 4.0% by mass or less, 3.0% by mass or less, and 2.0% by mass or less. 1.0% by mass, 0.5% by mass, 0.4% by mass, 0.3% by mass, 0.2% by mass, 0.1% by mass, 0.08% by mass, 0.06% by mass, 0.04% by mass, 0.02% by mass . The polyfluorene imine precursor in the embodiment can also be made into a polyfluorene imine precursor by using a dicarboxylic acid in addition to the above-mentioned tetracarboxylic dianhydride within a range that does not impair its performance. By using such a precursor, various properties such as an increase in mechanical elongation, an increase in glass transition temperature, and a decrease in yellowness of the obtained film can be adjusted. Examples of such a dicarboxylic acid include a dicarboxylic acid having an aromatic ring and an alicyclic dicarboxylic acid. Particularly preferred is at least one compound selected from the group consisting of an aromatic dicarboxylic acid having 8 to 36 carbon atoms and an alicyclic dicarboxylic acid having 6 to 34 carbon atoms. The number of carbons mentioned here also includes the number of carbons contained in a carboxyl group. Among these, dicarboxylic acids having an aromatic ring are preferred. Specific examples include isophthalic acid, terephthalic acid, 4,4'-biphenyldicarboxylic acid, 3,4'-biphenyldicarboxylic acid, and 3,3'-biphenyldicarboxylic acid. , 1,4-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-sulfofluorenylbisbenzoic acid, 3,4'- Sulfobibenzoic acid, 3,3'-sulfobibenzoic acid, 4,4'-oxybisbenzoic acid, 3,4'-oxybisbenzoic acid, 3,3'-oxybisbenzene Formic acid, 2,2-bis (4-carboxyphenyl) propane, 2,2-bis (3-carboxyphenyl) propane, 2,2'-dimethyl-4,4'-biphenyldicarboxylic acid, 3,3'-dimethyl-4,4'-biphenyldicarboxylic acid, 2,2'-dimethyl-3,3'-biphenyldicarboxylic acid, 9,9-bis (4- (4 -Carboxyphenoxy) phenyl) fluorene, 9,9-bis (4- (3-carboxyphenoxy) phenyl) fluorene, 4,4'-bis (4-carboxyphenoxy) biphenyl, 4 , 4'-bis (3-carboxyphenoxy) biphenyl, 3,4'-bis (4-carboxyphenoxy) biphenyl, 3,4'-bis (3-carboxyphenoxy) biphenyl, 3,3'-bis (4-carboxyphenoxy) biphenyl, 3,3'-bis (3-carboxyphenoxy) biphenyl, 4,4'-bis (4-carboxyphenoxy) -pair Triphenyl, 4,4'-bis (4-carboxyphenoxy) -m-terphenyl, 3,4'-bis (4-carboxyphenoxy) -p-terphenyl, 3,3'-bis (4 -Carboxy Phenylphenoxy) -p-terphenyl, 3,4'-bis (4-carboxyphenoxy) -m-terphenyl, 3,3'-bis (4-carboxyphenoxy) -m-terphenyl, 4,4'-bis (3-carboxyphenoxy) -p-terphenyl, 4,4'-bis (3-carboxyphenoxy) -m-terphenyl, 3,4'-bis (3-carboxybenzene (Oxy) -p-terphenyl, 3,3'-bis (3-carboxyphenoxy) -p-terphenyl, 3,4'-bis (3-carboxyphenoxy) -m-terphenyl, 3,3 '-Bis (3-carboxyphenoxy) -m-terphenyl, 1,1-cyclobutanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 4,4'-benzophenone dicarboxylic acid, 1,3-phenylene diacetic acid, 1,4-phenylene diacetic acid, etc .; and 5-amines described in International Publication No. 2005/068535 Isophthalic acid derivatives and the like. In the case of actually copolymerizing these dicarboxylic acids and polymers, they can also be used in the form of chloroforms, active esters, etc. derived from thionylchloride and the like. [Production of polyimide precursor] The polyimide precursor (polyamidic acid) of the present invention can be used by using pyromellitic dianhydride and the structural unit represented by the general formula (1). Diamine (for example, 4,4'-diaminodiphenylphosphonium) is synthesized by polycondensation. This reaction is preferably performed in a suitable solvent. Specifically, for example, a method in which a specific amount of 4,4′-DAS is dissolved in a solvent, and a specific amount of pyromellitic dianhydride is added to the obtained diamine solution and stirred is mentioned. Regarding the ratio (mole ratio) of the tetracarboxylic dianhydride component to the diamine component when synthesizing the above polyfluorene imide precursor, the thermal linear expansion ratio, residual stress, elongation, and yellowness of the obtained resin film were determined. (Hereinafter also referred to as YI) from the viewpoint of controlling the desired range, it is preferable to use tetracarboxylic dianhydride: diamine = 100: 90 ~ 100: 110 (1 mole part relative to tetracarboxylic dianhydride) The diamine is in the range of 0.90 to 1.10 moles), and is more preferably set to the range of 100: 95 to 100: 105 (1 mole of acid dianhydride and 0.95 to 1.05 moles of diamine). . In this embodiment, when synthesizing polyamic acid as a preferred polyimide precursor, it can be adjusted by the ratio of the tetracarboxylic dianhydride component to the diamine component and the addition of a blocking agent. Control molecular weight. The closer the ratio of the acid dianhydride component to the diamine component is 1: 1, and the smaller the amount of end-capping agent used, the larger the molecular weight of the polyamine acid can be increased. As the tetracarboxylic dianhydride component and the diamine component, high-purity products are recommended. The purity is preferably 98% by mass or more, more preferably 99% by mass or more, and even more preferably 99.5% by mass or more. When a plurality of acid dianhydride components or diamine components are used in combination, as long as the acid dianhydride component or diamine component has the above-mentioned purity, it is sufficient. It is preferable that all kinds of acid dianhydride components and diamine components are used Each has the aforementioned purity. The solvent used for the reaction is not particularly limited as long as it is a solvent capable of dissolving a tetracarboxylic dianhydride component and a diamine component, and a produced polyamic acid to obtain a polymer having a high molecular weight. Specific examples of such a solvent include aprotic solvents, phenol-based solvents, ethers, and glycol-based solvents. As these specific examples, examples of the aprotic solvent include N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), and N-methyl 2-Pyrrolidone (NMP), N-methylcaprolactam, 1,3-dimethylimidazolidinone, tetramethylurea, the following general formula (7): [Chem. 10] Where R ₁₂ = Equamide M100 (trade name: manufactured by Idemitsu Kosan Co., Ltd.) represented by methyl, and R ₁₂ = Ethylamine-based solvents such as Equamide B100 (trade name: manufactured by Idemitsu Kosan Co., Ltd.) represented by n-butyl; lactone-based solvents such as γ-butyrolactone and γ-valerolactone; hexamethylphosphonium amine, hexamethylene Phosphonium-containing amine-based solvents such as methylphosphine-triamine; Sulfur-based solvents such as dimethylfluorene, dimethylsulfinium, and cyclobutane; Ketone solvents such as cyclohexanone and methylcyclohexanone; A Tertiary amine-based solvents such as pyridine and pyridine; ester-based solvents such as (2-methoxy-1-methylethyl) acetate; and the like as the phenol-based solvents, for example, phenol, o-cresol, and m-phenol Cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5 -Xylenol, etc .; Examples of the ether and glycol solvents include 1,2-dimethoxyethane, bis (2-methoxyethyl) ether, and 1,2-bis (2- Methoxyethoxy) ethane, bis [2- (2-methoxyethoxy) ethyl] ether, tetrahydrofuran, 1,4-dioxane, and the like. The boiling point under normal pressure of the solvent used in the synthesis of the polyamic acid is preferably 60 to 300 ° C, more preferably 140 to 280 ° C, and even more preferably 170 to 270 ° C. If the boiling point of the solvent is higher than 300 ° C, the drying step may take a long time. On the other hand, if the boiling point of the solvent is lower than 60 ° C., the surface of the resin film may be roughened during the drying step, bubbles may be mixed in the resin film, and a uniform film may not be obtained. Thus, from the viewpoints of solubility and edge shrinkage during coating, it is preferable to use a solvent having a boiling point of 170 to 270 ° C, more preferably 20 ° C and a vapor pressure of 250 Pa or less. More specifically, it is preferable to use one or more members selected from the group consisting of N-methyl-2-pyrrolidone, γ-butyrolactone, and the compound represented by the general formula (5). The moisture content in the solvent is preferably 3,000 mass ppm or less. These solvents may be used alone or in combination of two or more. In the resin composition in this aspect, the content of molecules having a molecular weight of less than 1,000 is preferably not more than 5% by mass. It is considered that the reason why the molecular weight of less than 1,000 exists in the resin composition is due to the influence of the water content of the solvent or raw materials (acid dianhydride, diamine) used in the synthesis. That is, it is considered that the reason is that a part of the acid anhydride gene of the acid dianhydride monomer was hydrolyzed to a carboxyl group, and remained in a low molecular state without being polymerized. Therefore, it is preferable that the water content of the solvent used in the above polymerization reaction is as small as possible. The water content of this solvent is preferably 3,000 mass ppm or less, and more preferably 1,000 mass ppm or less. Regarding the amount of water contained in the raw material, it is also preferably 3,000 mass ppm or less, and more preferably 1,000 mass ppm or less. It can be considered that the water content of the solvent is affected by the grade of the solvent used (dehydration grade, general grade, etc.), the solvent container (bottle, 18 L bucket, storage tank, etc.), the storage state of the solvent (the presence or absence of rare gas sealing, etc.), The time from opening to use (immediately after opening, or after a period of time after opening, etc.). In addition, it can be considered that it is also affected by the replacement of the rare gas in the reactor before the synthesis, and the presence or absence of the circulation of the rare gas in the synthesis. Therefore, it is recommended to take the following measures in the synthesis of (a) polyfluorene imide precursors: use high purity products as raw materials, use solvents with less water content, and do not mix in the system from the environment before and during the reaction Of moisture. When dissolving each monomer component in a solvent, you may heat as needed. (a) The reaction temperature during the synthesis of the polyimide precursor is preferably set to 0 ° C to 120 ° C, more preferably 40 ° C to 100 ° C, and even more preferably 60 to 100 ° C. By carrying out the polymerization reaction at this temperature, a polyimide precursor having a high degree of polymerization can be obtained. The polymerization time is preferably 1 to 100 hours, and more preferably 2 to 10 hours. A polyimide precursor having a uniform polymerization degree can be obtained by setting the polymerization time to 1 hour or more, and a polyimide precursor having a high polymerization degree can be obtained by setting the polymerization time to 100 hours or less. The polyimide precursor according to this embodiment may optionally contain other polyimide precursors within a range that does not impair the required performance of the present invention. As such a polyfluorene imide precursor, for example, a polyfluorene imide precursor obtained by polycondensing the other acid dianhydride and another diamine is exemplified. The mass ratio of the other polyimide precursors in this embodiment is preferably 30% by mass or less with respect to the entire (a) polyimide precursors, and the oxygen dependence of the YI value and total light transmittance is reduced. From a viewpoint, it is more preferably 10% by mass or less. In a preferred aspect of this embodiment, (a) the polyfluorene imide precursor may also be partially imidized. In this case, the imidization ratio of fluorene is preferably 80% or less, and more preferably 50% or less. The partial fluorene imidization is obtained by heating and dehydrating the polyalimine precursor (a) to perform ring closure. The heating may be performed at a temperature of preferably 120 to 200 ° C, more preferably 150 to 180 ° C, preferably 15 minutes to 20 hours, and more preferably 30 minutes to 10 hours. Further, N, N-dimethylformamide dimethyl acetal or N, N-dimethylformamide diethyl acetal is added to the polyamidic acid obtained by the above reaction, and the mixture is heated. After a part or all of the carboxylic acid is esterified, it is used as the (a) polyimide precursor in this embodiment, thereby obtaining a resin composition with improved viscosity stability during storage at room temperature. In addition, these ester-modified polyfluorenic acids can also be obtained by making the acid dianhydride component and 1 equivalent of a monohydric alcohol with respect to the acid anhydride group, and thionyl chloride and dicyclohexylcarbodifluoride. After a dehydration condensation agent such as imine reacts sequentially, it undergoes a condensation reaction with a diamine component. The ratio of the (a) polyfluorene imine precursor (preferably polyamic acid) in the resin composition of this embodiment is preferably 3 to 50% by mass from the viewpoint of coating film formability, and more preferably It is preferably 5 to 40% by mass, and particularly preferably 10 to 30% by mass. As a second aspect of this embodiment, a weight-average molecular weight of 40,000 to 300,000 and a molecular weight of less than 1,000 with a weight-average molecular weight of less than 5 can be provided. % Polyimide precursor. [Chemical 11] The polyfluorene imide precursor in the embodiment is not limited as long as the weight average molecular weight is 40,000 or more and 300,000 or less, and the content of molecules having a weight average molecular weight of less than 1,000 is not more than 5% by mass. In order to obtain such a polyfluorene imide precursor, the molar ratio of the acid dianhydride to the diamine can be set to a specific range by setting the water content in the solvent or the raw material to a specific range or less. Achieved within range. Specifically, the water content in the solvent is preferably 3,000 ppm or less, more preferably 1500 ppm or less, and even more preferably 500 ppm or less. The purity of the raw material is preferably 98% by mass or more, more preferably 99% by mass or more, and even more preferably 99.5% by mass or more. Tetracarboxylic dianhydride: diamine = 100: 90 ~ 100: 110 (Diamine is preferably 0.90 to 1.10 mol parts relative to 1 mol part of tetracarboxylic dianhydride), and more preferably The range is 100: 95 to 100: 105 (the diamine is 0.95 to 1.05 mol parts with respect to 1 mol part of the acid dianhydride). From the viewpoints of the haze and elongation of the obtained polyimide film, the polyimide precursor is preferably a structure represented by the following general formula (2). [Chemical 12] When the polyimide precursor has only the structure represented by the general formula (1) (preferably the general formula (2)), even if the yellowness is 20 or less and the residual stress is 25 MPa or less, it cannot be provided. Satisfy polyimide film with an elongation of 15% or more. In this embodiment, in addition to having a structure represented by the general formula (1), the weight average molecular weight is 40,000 or more and 300,000 or less, and the content of molecules having a weight average molecular weight of less than 1,000 is less than 5% by mass. Polyimide precursors can provide polyimide films that further satisfy elongation. Specifically, a polyimide film having a yellowness of 20 μm or less, a residual stress of 25 MPa or less, and an elongation of 15% or more at a film thickness of 10 μm after heating at 430 ° C. can be provided. <Resin Composition> Another aspect of the present invention provides a resin composition containing the above (a) polyfluorene imide precursor and (b) an organic solvent. This resin composition is typically a varnish. [(b) Organic solvent] The (b) organic solvent in this embodiment is not particularly limited as long as it can dissolve the (a) polyfluorene imide precursor and any other components used arbitrarily. As such (b) organic solvents, those described above as solvents that can be used in the synthesis of the (a) polyfluorene imide precursor can be used. Preferred organic solvents are also the same as described above. (B) The organic solvent in the resin composition of this embodiment may be the same as or different from the solvent used in the synthesis of the (a) polyfluorene imide precursor. (b) The organic solvent is preferably an amount such that the solid component concentration of the resin composition becomes 3 to 50% by mass. In addition, it is preferable to adjust the composition and amount of (b) the organic solvent so that the viscosity (25 ° C) of the resin composition becomes 500 mPa · s to 100,000 mPa · s. [Other Components] The resin composition according to this embodiment may contain (c) a surfactant, (d) an alkoxysilane compound, and the like in addition to the components (a) and (b). ((c) Surfactant) By adding a surfactant to the resin composition of this embodiment, the coating property of the resin composition can be improved. Specifically, the occurrence of fine lines in the coating film can be prevented. Examples of such a surfactant include a silicone-based surfactant, a fluorine-based surfactant, and a nonionic surfactant other than these. Regarding these examples, examples of the silicone-based surfactants include organic silicone polymers KF-640, 642, 643, KP341, X-70-092, and X-70-093 (the above are trade names) , Manufactured by Shin-Etsu Chemical Industry Co., Ltd.), SH-28PA, SH-190, SH-193, SZ-6032, SF-8428, DC-57, DC-190 (the above are trade names, manufactured by Toray Dow Corning Silicone Corporation), SILWET L-77, L-7001, FZ-2105, FZ-2120, FZ-2154, FZ-2164, FZ-2166, L-7604 (the above are the trade names, manufactured by Nippon Unicar), DBE-814, DBE- 224, DBE-621, CMS-626, CMS-222, KF-352A, KF-354L, KF-355A, KF-6020, DBE-821, DBE-712 (Gelest), BYK-307, BYK-310, BYK -378, BYK-333 (the above are trade names, manufactured by BYK-Chemie Japan), Glano (trade name, manufactured by Kyoeisha Chemical Co., Ltd.), etc .; Examples of fluorine-based surfactants include: MEGAFAC F171, F173, R -08 (manufactured by Dainippon Ink Chemical Industry Co., Ltd., trade name), Fluorad FC4430, FC4432 (Sumitomo 3M Co., Ltd., trade name), etc .; Non-ionic surfactants other than these include, for example, polyoxygen B Lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl phenol ether and the like. Among these surfactants, from the viewpoint of coating properties of the resin composition (inhibiting fine lines), silicone surfactants and fluorine surfactants are preferred, and the oxygen concentration in the curing step is preferred. From the viewpoint of the influence of the YI value and total light transmittance, a silicone-based surfactant is preferred. In the case of using (c) a surfactant, the blending amount is preferably 0.001 to 5 parts by mass, more preferably 0.01 to 3 parts, relative to 100 parts by mass of the (a) polyfluorene imide precursor in the resin composition. Parts by mass. (d) Alkoxysilane compound In order that the resin film obtained from the resin composition of this embodiment exhibits sufficient adhesion to a support during the manufacturing process of a flexible device, the resin composition can be relatively (A) 100% by mass of the polyfluorene imide precursor and 0.01 to 20% by mass of an alkoxysilane compound. When the content of the alkoxysilane compound relative to 100% by mass of the polyfluorene imide precursor is 0.01% by mass or more, good adhesion with the support can be obtained. The content of the alkoxysilane compound is preferably 20% by mass or less from the viewpoint of storage stability of the resin composition. The content of the alkoxysilane compound is more preferably 0.02 to 15% by mass, more preferably 0.05 to 10% by mass, and even more preferably 0.1 to 8% by mass relative to 100 parts by mass of the polyimide precursor. By using an alkoxysilane compound as an additive of the resin composition of the present embodiment, in addition to the above-mentioned improvement in adhesion, the coating property of the resin composition can be further improved (fine unevenness of fine lines can be suppressed), and the obtained When the YI value of the cured film is cured, the oxygen concentration dependency decreases. Examples of the alkoxysilane compound include 3-ureidopropyltriethoxysilane, bis (2-hydroxyethyl) -3-aminopropyltriethoxysilane, and 3-glycidyloxy Propyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltripropoxysilane, γ-aminopropyltributoxysilane, γ-aminoethyltriethyl Oxysilane, γ-aminoethyltripropoxysilane, γ-aminoethyltributoxysilane, γ-aminobutyltriethoxysilane, γ-aminobutyltrimethoxysilane , Γ-aminobutyltripropoxysilane, γ-aminobutyltributoxysilane, phenylsilanetriol, trimethoxyphenylsilane, trimethoxy (p-tolyl) silane, diphenyl Silyl diol, dimethoxydiphenylsilane, diethoxydiphenylsilane, dimethoxydi-p-tolylsilane, triphenylsilanol, and alkoxy represented by each of the following structures It is preferable to use one or more selected from these silyl compounds and the like. [Chemical 13] The manufacturing method of the resin composition of this embodiment is not specifically limited. For example, the following method can be adopted. When the solvent used in synthesizing (a) the polyfluorene imide precursor is the same as (b) the organic solvent, the synthesized polyfluorene imide precursor solution can be directly used as the resin composition. It is also possible to add (b) one or more organic solvents and other components to the polyimide precursor in a temperature range from room temperature (25 ° C) to 80 ° C, and use them as a resin composition after stirring and mixing. Thing. For the stirring and mixing, a suitable device such as a Trinity Motor (manufactured by Shinto Chemical Co., Ltd.) having a stirring blade, a revolution-revolving mixer, and the like can be used. Also, if necessary, heat of 40 to 100 ° C may be applied. On the other hand, when the solvent used in the synthesis of (a) the polyimide precursor is different from (b) the organic solvent, the synthesized compound can also be synthesized by suitable methods such as reprecipitation and solvent distillation. After the solvent in the polyimide precursor solution is removed and (a) the polyimide precursor is isolated, (b) an organic solvent and other components as needed are added within a temperature range of room temperature to 80 ° C, and The resin composition is prepared by stirring and mixing. After the resin composition is prepared as described above, the composition solution may be heated at, for example, 130 to 200 ° C, for example, for 5 minutes to 2 hours, so that the polyimide precursor can be made to the extent that the polymer does not precipitate. A part is subjected to dehydration. Here, by controlling the heating temperature and the heating time, it is possible to control the amidation ratio. Partial fluorene imidization of the polyfluorene imide precursor can improve the viscosity stability of the resin composition when stored at room temperature. The range of the fluorene imidization ratio is preferably 5% to 70% from the viewpoint of achieving a balance between the solubility of the polyfluorene imide precursor in the resin composition solution and the storage stability of the solution. The resin composition of this embodiment preferably has a water content of 3,000 mass ppm or less. The moisture content of the resin composition is preferably 2500 mass ppm or less, more preferably 2000 mass ppm or less, more preferably 1500 mass ppm or less, and more preferably 1,000 in terms of viscosity stability when the resin composition is stored. Mass ppm or less, more preferably 500 mass ppm or less, preferably 300 mass ppm or less, and more preferably 100 mass ppm or less. The solution viscosity of the resin composition according to this embodiment is preferably 500 to 200,000 mPa · s, more preferably 2,000 to 100,000 mPa · s, and even more preferably 3,000 to 30,000 mPa · s at 25 ° C. The viscosity of this solution can be measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., VISCONICEHD). If the viscosity of the solution is lower than 300 mPa · s, there is a possibility that coating may be difficult to perform during film formation, and if it is higher than 200,000 mPa · s, there may be a problem that agitation during synthesis may become difficult. That is, it is convenient to synthesize the (a) polyfluorene imide precursor, and the solution has a high viscosity, and a resin composition with good viscosity can be obtained by adding a solvent and stirring after the reaction is completed. The resin composition of this embodiment has the following characteristics in a preferable aspect. After the resin composition is applied to the surface of the support to form a coating film, the coating film is heated at 430 ° C for one hour under a nitrogen atmosphere (in a nitrogen gas having an oxygen concentration of 2,000 ppm or less), thereby allowing the polyimide to be formed. The polyimide film obtained by the precursor imidization is preferably 10 μm in film thickness and has a yellowness of 20 or less. The yellowness at a film thickness of 10 μm is preferably 18 or less, preferably 16 or less, preferably 14 or less, preferably 13 or less, preferably 10 or less, and preferably 7 or less. The residual stress of the polyfluoreneimide film thus obtained is preferably 25 MPa or less. The preferred residual stress is 23 MPa or less, 20 MPa or less, 18 MPa or less, and 16 MPa or less. The glass transition temperature Tg of the polyfluoreneimide film thus obtained is preferably 360 ° C or higher. The preferred glass transition temperature Tg is 470 ° C or higher. The retardation Rth of the polyimide film thus obtained at a thickness of 10 μm is preferably 1000 nm or less. The preferable retardation Rth is 800 nm or less, 700 nm or less, 500 nm or less, 300 nm or less, 200 nm or less, 140 nm or less, and 100 nm or less. In addition, the tensile elongation at a thickness of 10 μm of the polyimide film thus obtained is preferably 15% or more. The preferable tensile elongation is 20% or more, 25% or more, 30% or more, 35% or more, and 40% or more. The resin composition of this embodiment can be suitably used, for example, to form a transparent substrate of a display device such as a liquid crystal display, an organic electroluminescence display, a field emission display, or an electronic paper. Specifically, it can be used to form a substrate of a thin film transistor (TFT), a substrate of a color filter, a substrate of a transparent conductive film (ITO, Indium Thin Oxide), and the like. Since the resin precursor of this embodiment can form a polyimide film having a residual stress of 25 MPa or less, it can be easily applied to a manufacturing step of a display having a TFT element device on a colorless and transparent polyimide substrate. <Resin film> Another aspect of the present invention provides a resin film formed from the resin precursor described above. Moreover, another aspect of this invention provides the method of manufacturing a resin film from the said resin composition. The resin film in this embodiment is characterized by including the following steps: a step of forming a coating film by coating the resin composition on the surface of the support (coating step); and heating the support and the coating film The step of heating the polyimide resin precursor contained in the coating film to form a polyimide resin film (heating step); and peeling the polyimide resin film from the support. Step (peeling step). Here, the support is not particularly limited as long as it has heat resistance at the heating temperature of the subsequent step and good peelability. For example: glass (such as alkali-free glass) substrates; silicon wafers; PET (polyethylene terephthalate), OPP (extended polypropylene), polyethylene terephthalate, polyethylene naphthalate Resin substrates such as diester, polycarbonate, polyimide, polyimide, imine, polyetherimide, polyetheretherketone, polyether, polyphenylene, polyphenylene sulfide; stainless steel, alumina , Copper, nickel and other metal substrates. In the case of forming a film-shaped polyimide formed body, for example, a glass substrate or a silicon wafer is preferred. In the case of forming a film-shaped or sheet-shaped polyimide formed body, for example, it is preferable to include Supports for PET (polyethylene terephthalate), OPP (extended polypropylene), etc. As the coating method, for example, coating by a knife coater, an air knife coater, a roll coater, a spin coater, a flow coater, a die coater, a bar coater, or the like can be applied. Methods; coating methods such as spin coating, spray coating, dip coating, etc .; printing technologies represented by screen printing and gravure printing, etc. The coating thickness should be appropriately adjusted according to the required thickness of the resin film and the content of the polyimide precursor in the resin composition, and is preferably about 1 to 1,000 μm. The application step is sufficient at room temperature. However, in order to reduce the viscosity and improve workability, the resin composition may be heated at a temperature in the range of 40 to 80 ° C. to be implemented. After the coating step, a drying step may be performed, or the drying step may be omitted and the heating step may be directly performed. This drying step is performed in order to remove the organic solvent. In the case of performing the drying step, for example, a suitable device such as a hot plate, a box dryer, and a conveyor-type dryer can be used. The drying step is preferably performed at 80 to 200 ° C, and more preferably 100 to 150 ° C. The implementation time of the drying step is preferably 1 minute to 10 hours, and more preferably 3 minutes to 1 hour. A coating film containing a polyfluorene imide precursor was formed on the support as described above. This is followed by a heating step. The heating step is a step of removing the organic solvent remaining in the coating film in the above-mentioned drying step, and subjecting the polyimide precursor in the coating film to a fluorimidation reaction to obtain a film containing polyimide. This heating step can be performed using, for example, an inert gas oven, a hot plate, a box dryer, a conveyor-type dryer, or the like. This step may be performed simultaneously with the above-mentioned drying step, or two steps may be performed sequentially. The heating step may also be performed in an air atmosphere, but from the viewpoints of safety and transparency and YI value of the obtained polyimide film, it is recommended to perform it in an inert gas atmosphere. Examples of the inert gas include nitrogen and argon. The heating temperature can also be appropriately set according to the type of the organic solvent (b), preferably 250 ° C to 550 ° C, and more preferably 300 to 450 ° C. If the temperature is 250 ° C or higher, the fluorene imidization is sufficient. If the temperature is 550 ° C or lower, the resulting polyimide film does not suffer from deterioration in transparency and heat resistance. The heating time is preferably about 0.5 to 3 hours. In this embodiment, the oxygen concentration in the surrounding atmosphere in the heating step is preferably 2,000 mass ppm or less, and more preferably 100 mass ppm from the viewpoint of the transparency and YI value of the obtained polyimide film. Hereinafter, it is more preferably 10 ppm by mass or less. By heating in an atmosphere having an oxygen concentration of 2,000 mass ppm or less, the YI value of the obtained polyimide film can be made 30 or less. Depending on the purpose and purpose of the polyimide resin film, a peeling step of peeling the resin film from the support may be required after the above heating step. This peeling step is preferably carried out after cooling the resin film on the support to about room temperature to about 50 ° C. Examples of the peeling step include the following aspects (1) to (4). (1) After a structure including a polyimide resin film / support is produced by the above method, a laser is irradiated from the support side of the structure to ablate the interface between the support and the polyimide resin film. Processing to remove the polyimide resin. Examples of the type of laser include a solid (YAG) laser and a gas (UV excimer) laser. It is preferable to use a spectrum having a wavelength of 308 nm or the like (refer to Japanese Patent Publication No. 2007-512568, Japanese Patent Publication No. 2012-511173, etc.). (2) Before coating a resin composition on a support, a release layer is formed on the support, and thereafter a structure including a polyimide resin film / release layer / support is obtained, and the polyimide resin film is peeled off Method. Examples include: a method using Parylene (registered trademark, manufactured by Japan Parylene Co., Ltd.) and tungsten oxide as a release layer; a method using a release agent such as vegetable oil, silicone, fluorine, alkyd, etc. (Refer to Japanese Patent Laid-Open No. 2010-67957, Japanese Patent Laid-Open No. 2013-179306, etc.). This method (2) may be used in combination with the laser irradiation of the above (1). (3) A method of obtaining a polyimide resin film by using an etchable metal substrate as a support and obtaining a structure including a polyimide resin film / support, and then etching the metal with an etchant. As the metal, for example, copper (as a specific example, electrolytic copper foil "DFF" manufactured by Mitsui Metals Mining Co., Ltd.), aluminum, and the like can be used. As the etchant, ferric chloride or the like can be used for copper, and dilute hydrochloric acid or the like can be used for aluminum. (4) After obtaining a structure comprising a polyimide resin film / support by the above method, attach an adhesive film on the surface of the polyimide resin film, and separate the adhesive film / polyimide resin from the support. A method of separating a polyimide resin film from an adhesive film thereafter. Among these peeling methods, from the viewpoints of the refractive index difference, the YI value, and the elongation of the front and back surfaces of the obtained polyimide resin film, the method (1) or (2) is appropriate. The method (1) is more appropriate from the viewpoint of the refractive index difference between the front and back sides of the obtained polyimide resin film. Further, in the method (3), when copper is used as a support, it can be seen that the YI value of the obtained polyimide resin film becomes larger and the elongation tends to be smaller. It can be considered as the effect of copper ions. The thickness of the resin film obtained by the above method is not particularly limited, but is preferably in the range of 1 to 200 μm, and more preferably 5 to 100 μm. The resin film of this embodiment may have a yellowness YI of 20 or less when the film thickness is 10 μm. Such characteristics can be performed, for example, in a nitrogen atmosphere (for example, in a nitrogen gas having an oxygen concentration of 2,000 ppm or less) at a temperature of preferably 400 ° C to 550 ° C, more preferably 400 ° C to 450 ° C. The amidation is well achieved. The resin film of this embodiment may further have a tensile elongation of 15% or more. The tensile elongation of the resin film may be 20% or more, and particularly 30% or more. Thereby, the resin film of this embodiment is excellent in breaking strength when a flexible substrate is handled, and therefore, it is possible to improve the yield when manufacturing a flexible display. This tensile elongation can be measured using a resin film having a film thickness of 10 μm as a sample using a commercially available tensile tester. <Laminate> Another aspect of the present invention provides a laminate comprising a support and a polyimide resin film formed from the resin composition on a surface of the support. Moreover, another aspect of this invention provides the manufacturing method of the said laminated body. The laminated body in this embodiment can be obtained by a method for producing a laminated body including the following steps: a step (coating step) of forming a coating film by applying the resin composition on the surface of a support; and A step (heating step) of heating the support and the coating film to subject the polyimide precursor contained in the coating film to imidization to form a polyimide resin film. The manufacturing method of the said laminated body can be implemented similarly to the manufacturing method of the said resin film, for example, except not performing a peeling process. This laminated body can be used suitably for manufacture of a flexible device, for example. This will be described in more detail as follows. When forming a flexible display, a glass substrate is used as a support, a flexible substrate is formed thereon, and a TFT or the like is formed thereon. The step of forming a TFT or the like on a flexible substrate is typically performed at a wide range of temperatures from 150 to 650 ° C. However, in the case of forming LTPS as a TFT, compared with amorphous silicon (250 ° C) or IGZO (350 ° C), an extremely high temperature is required, and heating of about 400 ° C to 550 ° C is required. On the other hand, due to these thermal history, the physical properties (especially yellowness or elongation) of the polyimide film tend to decrease, and if it exceeds 400 ° C, the yellowness or elongation particularly decreases. However, even if the polyimide film obtained from the polyimide precursor of the present invention is in a high-temperature region of 400 ° C. or higher, there is little decrease in yellowness or elongation, and it can be used well in this region. With respect to the polyimide film of this embodiment, a better thermal cycle test result can be obtained when it is formed on LTPS than when it is formed on IGZO. Therefore, the polyfluorene imide film of this embodiment can be suitably used when the device type of the TFT is LTPS. Furthermore, in this embodiment, it is possible to provide a laminated body including a polyimide film layer containing a polyimide represented by the following general formula (5) and an LTPS layer. [Chemical 14] As a method for manufacturing the laminated body, an amorphous silicon layer is formed after manufacturing a laminated body including the support and a polyimide resin film formed from the resin composition on the surface of the support, at 400 ~ After performing dehydrogenation annealing at 450 ° C for about 0.5 to 3 hours, crystallization is performed by an excimer laser or the like, thereby forming a low-temperature polycrystalline silicon layer. Thereafter, the glass and the polyimide film are peeled by laser peeling or the like, whereby the above-mentioned laminated body can be obtained. In addition, SiO can be formed on the polyfluorene imine film if necessary. ₂ Or an inorganic film such as SiN to form an LTPS layer. As said polyimide film layer, the following general formula (6) is more preferable from a viewpoint of haze and elongation. [Chemical 15] At this time, the higher the residual stress generated in the glass substrate and the polyimide resin film, the more likely it is that glass will be generated when the laminated body including the two expands in a high-temperature TFT formation step and shrinks when cooled at room temperature. Problems such as warpage and breakage of the substrate, and peeling of the flexible substrate from the glass substrate. Generally, the thermal expansion coefficient of a glass substrate is smaller than that of a resin, so a residual stress is generated between the glass substrate and the flexible substrate. As described above, the resin film of this embodiment can be used for forming a flexible display because the residual stress between the resin film and the glass substrate can be 25 MPa or less. Furthermore, the polyimide film of this embodiment can have a yellowness YI of 10 or less when the polyimide film is heated at 430 ° C and a tensile elongation of 15 %the above. Thereby, the resin film of this embodiment is excellent in breaking strength when a flexible substrate is handled, and therefore, it is possible to improve the yield when manufacturing a flexible display. The above-mentioned aspect is a description of an embodiment in which an LTPS-TFT substrate for a flexible display is produced, and an embodiment of the display device will be described below. Examples of the flexible display include an organic EL display. The organic EL display is a so-called flexible display in which a display portion can be flexibly deformed (flexible). FIG. 1 is a diagram showing a part of the configuration of the organic EL structure section 25. The organic EL structure portion 25 is formed on the lower substrate 2a including the glass substrate 21, the light and heat exchange film 22, the transparent resin layer 23, and the undercoat layer 24. The organic EL structure portion 25 includes the same constituent members as those constituting a general organic EL display. The organic EL element 250a that emits red light, the organic EL element 250b that emits green light, and the organic EL element 250c that emits blue light are arranged in a matrix as a unit, and the partitions (banks) 251 divide the organic EL elements. Glowing area. Each organic EL element includes a lower electrode (anode) 252, a hole transport layer 253, a light emitting layer 254, and an upper electrode (cathode) 255. Further, a plurality of TFTs 256 (a-Si, p-Si, oxide semiconductor) for driving the organic EL element are provided on the lower substrate 2a. (Manufacturing Method of Organic EL Display) The manufacturing steps of the organic EL display 20 include an organic EL substrate manufacturing step, a sealing substrate manufacturing step, an assembly step of bonding two substrates, and a peeling step of peeling the glass substrates 21 and 29. The organic EL substrate manufacturing step, the sealing substrate manufacturing step, and the assembly step can be performed using well-known manufacturing steps. An example is given below, but it is not limited to this. The peeling step is the same as the peeling step of the polyfluoreneimide film. For example, after an LTPS-TFT substrate for a flexible display is produced by the above method, an interlayer insulating film having a contact hole is formed using a photosensitive acrylic resin or the like. An ITO film is formed by a sputtering method or the like, and a lower electrode is formed so as to form a pair with the TFT. Next, after forming a partition wall using a photosensitive polyimide or the like, a hole transport layer and a light emitting layer are formed in each space divided by the partition wall. The upper electrode is formed so as to cover the light emitting layer and the partition wall. An organic EL substrate is produced by the above steps, and sealed with a sealing film or the like, thereby producing a top-emission type flexible organic EL display. A bottom-emission type flexible organic EL display can also be manufactured by a known method. In addition, after producing the LTPS-TFT substrate, a color filter glass substrate having a colorless transparent polyimide is produced. On one of the TFT substrate and the CF substrate, a thermosetting epoxy resin is included by screen printing. The sealing material is coated as a frame-like pattern lacking a liquid crystal injection port, and a spherical spacer including a plastic or silicon dioxide having a diameter equivalent to the thickness of the liquid crystal layer is dispersed on another substrate. Then, the TFT substrate and the CF substrate were bonded together to harden the sealing material. Finally, in a space surrounded by the TFT substrate, the CF substrate, and the sealing material, the liquid crystal material is injected by the decompression method, and then a thermosetting resin is applied to the liquid crystal injection port, and the liquid crystal material is sealed by heating to form a liquid crystal. Floor. Finally, the glass substrate on the CF side and the glass substrate on the TFT side are peeled by a laser peeling method or the like, whereby a flexible liquid crystal display can be manufactured. Therefore, another aspect of the present invention provides a display substrate. Furthermore, another aspect of the present invention provides a method for manufacturing the above display substrate. The method for manufacturing a display substrate in this embodiment is characterized by including the following steps: a step (coating step) of forming a coating film by coating the resin composition on the surface of a support; and applying the support and The step of heating the coating film to subject the polyimide precursor contained in the coating film to imidization to form a polyimide resin film (heating step); forming an element on the polyimide resin film Or a circuit (element, circuit forming step); and a step (peeling step) of peeling the polyimide resin film on which the above-mentioned element or circuit is formed from the support. In the above method, the coating step, the heating step, and the peeling step can be performed in the same manner as in the method for producing the resin film, respectively. The element and circuit formation steps can be carried out by a method known to those skilled in the art. The resin film of this embodiment which satisfies the above-mentioned physical properties can be suitably used for applications where use is restricted due to the yellow color of the existing polyimide film, and can be suitably used in particular for colorless transparent substrates for flexible displays and color filters. Protective film for light sheet, etc. Furthermore, for example, it can be used in protective films, diffusing sheets and coating films in TFT-LCD (such as the intermediate layer of TFT-LCD, gate insulating film, liquid crystal alignment film, etc.), ITO substrates for touch panels, and smartphone Cover glass replaces resin substrates and other fields that require colorless transparency and low birefringence. The polyimide precursor of this embodiment, the resin film produced by using the resin precursor, and the laminated body can be used, for example, as a semiconductor insulating film, a TFT-LCD insulating film, an electrode protection film, etc. It is particularly suitably used as a substrate in manufacturing. Here, as a flexible device to which the resin film and the laminated body of this embodiment can be applied, for example, a flexible display, a flexible solar cell, a flexible touch panel electrode substrate, flexible lighting, a flexible battery, and the like can be cited. [Examples] Hereinafter, the present invention will be described in more detail based on examples, but these are described for explanation, and the scope of the present invention is not limited to the following examples. Various evaluations in the examples and comparative examples were performed as follows. <Measurement of weight average molecular weight> The weight average molecular weight (Mw) and the number average molecular weight (Mn) were measured using a gel permeation chromatography (GPC) under the following conditions. As a solvent, NMP (manufactured by Wako Pure Chemical Industries, Ltd., for high-performance liquid chromatography, 24.8 mmol / L lithium bromide monohydrate (manufactured by Wako Pure Chemical Industries, Ltd., purity 99.5%) and 63.2 mmol / L of phosphoric acid (made by Wako Pure Chemical Industries, Ltd., for high performance liquid chromatography) and dissolved). 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) Flow rate: 1.0 mL / min Column temperature: 40 ° C Pump: PU-2080Plus (manufactured by JASCO) Detector: RI-2031Plus (RI: differential refractometer, JASCO) (Manufactured) and UV-2075Plus (UV-VIS: UV-VIS absorptometer, manufactured by JASCO) <Evaluation of the content of molecules having a molecular weight of less than 1,000 (low-molecular polymer content)> The content of molecules having a molecular weight of less than 1,000 in the resin The measurement results using the GPC obtained above are calculated as the ratio (percentage) of the peak area occupied by the component having a molecular weight of less than 1,000 to the peak area of the overall molecular weight distribution. <Evaluation of Moisture Content> The moisture content of the synthetic solvent and the resin composition (varnish) was measured using a Karl Fischer moisture measuring device (a trace moisture measuring device AQ-300, manufactured by Hiranuma Sangyo Co., Ltd.). <Evaluation of Viscosity Stability of Resin Compositions> For the resin compositions prepared in each of the Examples and Comparative Examples, a sample that was left at room temperature for 3 days after preparation was used as a sample after preparation to measure the viscosity at 23 ° C. ; After that, a sample left still at room temperature for 2 weeks was taken as a sample after 2 weeks, and the viscosity measurement at 23 ° C. was performed again. These viscosity measurements were performed using a viscometer (TV-22 manufactured by Toki Sangyo Co., Ltd.) with a temperature regulator. Using the measured values, the viscosity change rate at room temperature over two weeks was calculated by the following equation. Viscosity change rate at room temperature for 2 weeks (%) = [(viscosity of sample after 2 weeks)-(viscosity of sample after preparation)] / (viscosity of sample after preparation) x 100 Evaluation was performed based on the following criteria. ◎: Viscosity change rate is 5% or less (storage stability "excellent") ○: Viscosity change rate is more than 5 and 10% or less (storage stability "good") ×: Viscosity change rate is more than 10% (storage stability " Defective ") <Evaluation of varnish coatability> The resin composition prepared in each Example and Comparative Example was coated on an alkali-free glass substrate (size 37 using a bar coater so that the film thickness after curing became 15 μm). × 47 mm, thickness 0.7 mm), and pre-baked at 140 ° C for 60 minutes. The profile of the surface of the coating film was measured using a profiler (manufactured by Tencor, model name P-15) to evaluate the applicability of the varnish. ：: The step of the surface is 0.1 μm or less (the coating property is “excellent”) ○: The step of the surface is more than 0.1 and 0.5 μm or less (the coating property is “good”) ×: The step of the surface is more than 0.5 μm (coating "Fabric" poor ") <Evaluation of Residual Stress> Each resin composition was coated on a 6-inch silicon wafer having a thickness of 625 μm ± 25 μm having a“ warpage amount ”measured in advance by a spin coater, and Pre-bake at 100 ° C for 7 minutes. Thereafter, the temperature was adjusted using a vertical curing furnace (manufactured by Koyo Lindberg, model name VF-2000B) so that the oxygen concentration in the chamber became 10 mass ppm or less, and a heat curing treatment (curing treatment) was performed at 430 ° C for 1 hour. ), And a silicon wafer with a polyimide resin film with a film thickness of 10 μm after hardening was produced. The residual stress measurement device (manufactured by Tencor, model name FLX-2320) was used to measure the amount of warpage of the wafer, and the residual stress generated between the silicon wafer and the resin film was evaluated. <Evaluation of yellowness (YI value)> The resin composition prepared in each Example and Comparative Example was spin-coated on a 6-inch silicon wafer provided with an aluminum vapor-deposited layer so that the film thickness after curing became 10 μm. Pre-bake at 100 ° C for 7 minutes on the substrate. Thereafter, it was adjusted by using a vertical curing furnace (manufactured by Koyo Lindberg, model name VF-2000B) so that the oxygen concentration in the chamber became 10 mass ppm or less, and then subjected to heat-hardening treatment at 430 ° C for one hour to produce A wafer having a polyimide resin film formed. The laminated body wafer obtained above was immersed in a dilute aqueous hydrochloric acid solution, and the polyimide film was peeled from the wafer, thereby obtaining a sample of a polyimide film having an inorganic film formed on the surface. About the obtained polyimide resin film, the YI value (film thickness conversion of 10 μm) was measured using a D65 light source (Spectrophotometer: SE600) manufactured by Nippon Denshoku Industries Co., Ltd. <Evaluation of Elongation and Breaking Strength> A wafer was produced in the same manner as in the above-mentioned <Evaluation of Yellowness>. A wafer dicing machine (DAD 3350 manufactured by DISCO Co., Ltd.) was used to cut a 3 mm wide cut into the polyimide resin film of the wafer, and then immersed in a dilute hydrochloric acid aqueous solution overnight to peel off the resin film. dry. It was cut to a length of 50 mm to make a sample. For the above samples, elongation and breaking strength were measured using TENSILON (UTM-II-20 manufactured by Orientec) at a test speed of 40 mm / min and an initial load of 0.5 fs. [Synthesis Example 1] In a 3 L separable flask equipped with an oil bath and a stirring rod, NMP1 (1065 g) was added while introducing nitrogen gas, and 4,4'-diaminodiphenylphosphonium (4,4-diaminodiphenylphosphonium) was added while stirring. 248.3 g) was used as a diamine, and then PMDA (218.12 g) was added as an acid dianhydride and stirred at room temperature for 30 minutes. After raising the temperature to 50 ° C. and stirring for 12 hours, the oil bath was removed and the temperature was returned to room temperature to obtain a transparent polyamic acid NMP solution (hereinafter also referred to as varnish) (varnish P-1). The composition here and the weight average molecular weight (Mw) of the obtained polyamic acid are shown in Table 1, respectively. The test results of the film cured at 430 ° C are shown in Table 2. [Example 1] In a 3 L separable flask equipped with a stirring rod with an oil bath, NMP2 (1065 g) was added while introducing nitrogen gas, and 4,4'-diaminodiphenylphosphonium (4,4-diaminodiphenylphosphonium) was added while stirring. 248.3 g) was used as a diamine, and then PMDA (218.12 g) was added as an acid dianhydride and stirred at room temperature for 30 minutes. After the temperature was raised to 80 ° C. and stirred for 3 hours, the oil bath was removed and the temperature was returned to room temperature to obtain a transparent polyamic acid NMP solution (hereinafter also referred to as varnish) (varnish P-2). The composition here and the weight average molecular weight (Mw) of the obtained polyamic acid are shown in Table 1, respectively. The test results of the film cured at 430 ° C are shown in Table 2. [Example 2] Synthesis was performed in the same manner as in Example 1 except that NMP2 was changed to NMP3 (varnish P-3). The results are shown in Tables 1 and 2. [Example 3] In addition to the addition of 4,4'-diaminodiphenylphosphonium as the first diamine so that the molar ratio becomes 99.33: 0.67 in the amine, it was modified with the two terminal amines as the second diamine. Except for the methyl phenyl silicone oil, it was synthesized in the same manner as in Example 2 (varnish P-4). The results are shown in Tables 1 and 2. [Example 4 to Example 13] Synthesis was performed in the same manner as in Example 3 except that the types and molar ratios of the first diamine and the second diamine were changed as shown in Table 1 in the amine (varnish P -5 ~ P-14). The results are shown in Tables 1 and 2. [Example 14] Except that pyromellitic dianhydride as the first acid dianhydride and biphenyltetracarboxylic acid dianhydride as the second acid dianhydride were added to the acid dianhydride so that the molar ratio became 80:20. Synthesis was carried out in the same manner as in Example 2 except for the anhydride (varnish P-15). The results are shown in Tables 1 and 2. [Example 15 to Example 17] Synthesis was performed in the same manner as in Example 2 except that the molar ratio of the first acid dianhydride to the second acid dianhydride was changed in the acid dianhydride as shown in Table 1. Varnish P-16 ~ P-18). The results are shown in Tables 1 and 2. [Example 18] Synthesis was performed in the same manner as in Example 2 except that 4,4'-diaminodiphenylphosphonium was changed to 3,3'-diaminodiphenylphosphonium in diamine ( Varnish P-19). [Comparative Example 1 to Comparative Example 6] Synthesis was performed in the same manner as in Example 2 except that the acid dianhydride and diamine were changed as shown in Table 1 (varnish P-20 to varnish P-25). The composition in each of the above Examples and Comparative Examples and the weight average molecular weight (Mw) of the obtained polyamic acid are shown in Table 1, respectively. The test results of the film cured at 430 ° C are shown in Table 2. [Table 1] The abbreviations of the components in the table have the following meanings. PMDA: pyromellitic dianhydride BPDA: biphenyltetracarboxylic dianhydride 4,4'-DAS: 4,4'-diaminodiphenylphosphonium 3,3'-DAS: 3,3'-diamine APAB: 4-aminophenyl-4-aminobenzoate p-PD: p-phenylenediamine 6FDA: 4,4 '-(hexafluoroisopropylidene) diphthalate Anhydride CHDA: 1,4-cyclohexanediamine DSDA: 3,3 ', 4,4'-diphenylphosphonium tetracarboxylic dianhydride HPMDA: 1,2,4,5-cyclohexanetetracarboxylic dicarboxylic acid Anhydride TFMB: 2,2'-bis (trifluoromethyl) benzidine X-22-1660B-3: Both terminal amine modified methylphenyl silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd.) NMP1: 500 ml bottle One month after opening, the moisture content is 3,070 ppm NMP2: 500 ml bottle, one week after opening, the water content is 1500 ppm NMP3: The 18 L bucket has just opened the latter, the water content is 250 ppm [Table 2] As shown in Tables 1 and 2, it can be seen that the resin compositions of Synthesis Example 1 and Examples 1 to 18 having the structure represented by the general formula (1) have residual stress compared with the resin compositions of Comparative Examples 1 to 6 Smaller, lower yellowness and higher elongation. In particular, in Examples 1 to 18, the weight average molecular weight of the polyimide precursor is 40,000 to 300,000, and the content of molecules having a weight average molecular weight of less than 1,000 is less than 5% by mass, which is the same as that of Synthesis Example 1. The specific elongation is large, and particularly good results can be obtained. Specifically, a resin film having a residual stress of 25 MPa or less, a yellowness YI of 20 or less, and an elongation of 15% or more can be obtained. In addition, comparing Synthesis Example 1 with Examples 1 and 2 shows that the smaller the water content of the solvent used in the polymerization reaction, the smaller the content of molecules having a molecular weight of less than 1,000. [Synthesis Example, Examples 1 to 18, Comparative Examples 1 to 6] An organic EL substrate as shown in FIG. 1 was produced. A polyimide precursor varnish of Synthesis Example 1, and Examples and Comparative Examples was applied on a plain glass substrate (thickness 0.7 mm) using a bar coater so that the film thickness became 10 μm after curing. Pre-bake at 140 ° C for 60 minutes. Next, it was adjusted by using a vertical curing furnace (manufactured by Koyo Lindberg, model name VF-2000B) so that the oxygen concentration in the warehouse became 10 mass ppm or less, followed by heating and hardening treatment at 430 ° C for 1 hour to form a polymer Glass substrate of fluorene imide resin film. Then, a SiN layer was formed into a thickness of 100 nm by a CVD (Chemical Vapor Deposition) method. Then, titanium is formed into a film by a sputtering method, and then patterned by a photolithography method to form a scanning signal line. Next, a SiN layer was formed on the entire glass substrate on which the scanning signal lines were formed by a CVD method to a thickness of 100 nm. (It has been referred to as the lower substrate 2a so far.) Next, an amorphous silicon layer 256 is formed on the lower substrate 2a, and dehydrogenation annealing is performed at 430 ° C for one hour, followed by irradiation with an excimer laser, thereby forming an LTPS layer. Thereafter, a photosensitive acrylic resin is coated on the entire surface of the lower substrate 2a by a spin coating method, and exposed and developed by a photolithography method to form an interlayer insulating film 258 having a plurality of contact holes 257. A part of each LTPS 256 is exposed through the contact hole 257. Next, an ITO film is formed on the entire surface of the lower substrate 2a on which the interlayer insulating film 258 is formed by a sputtering method, exposure and development are performed by a photolithography method, and patterning is performed by an etching method to correspond to each LTPS The lower electrodes 259 are formed in pairs. Furthermore, in each contact hole 257, the lower electrode 252 penetrating the interlayer insulating film 258 is electrically connected to the LTPS 256. Secondly, after the partition wall 251 is formed, a hole transmission layer 253 and a light emitting layer 254 are formed in each space divided by the partition wall 251. The upper electrode 255 is formed so as to cover the light emitting layer 254 and the partition wall 251. An organic EL substrate is produced by the above steps. Next, an ultraviolet curable resin is applied to the periphery of the sealing substrate 2b in which a glass substrate, a polyimide film and a SiN layer are sequentially formed, and the sealing substrate 2b and the organic EL substrate are bonded in an argon atmosphere. This is enclosed in an organic EL element. Thereby, a hollow portion 261 is formed between each organic EL element and the sealing substrate 2b. An excimer laser (wavelength 308 nm, repetition frequency 300 Hz) was irradiated from the lower substrate 2a side and the sealing substrate 2b side of the laminated body thus formed, and peeled with the minimum energy required to peel the entire surface. Evaluation of the presence or absence of a substrate warpage, lighting test, and evaluation of white turbidity of the laminate after peeling the laminate. A thermal cycle test was also performed. The results are shown in Table 3. <Substrate warpage> ◎: No warpage ○: Slight warpage only Δ: Rolled up due to warpage <Lighting test> ○: Lightened ×: Not lighted <Laminated body turbidity evaluation> After forming a laminated body By visual observation, the device as a whole is considered to be ○, slightly white turbid as Δ, white turbid as X. <Thermal cycle test> The thermal cycle tester manufactured by Espek was used to perform a cycle test at -5 ° C and 60 ° C for 30 minutes (the movement time of the tank was 1 minute), and then the appearance was observed. Those with no peeling or bulging were regarded as ○, those with a few peeling or bulging observed after the test were regarded as Δ, and those with peeling or bulging observed on the entire surface after the test were regarded as ×. [table 3] As shown in Table 3, in Examples 1 to 18 using varnishes P-2 to P-19, a laminate having no warpage of the substrate, a good lighting test, no white turbidity, and good thermal cycle characteristics was obtained. body. Such a laminate can be suitably used as a low-temperature polycrystalline silicon TFT element substrate, such as a transparent flexible substrate for an organic EL display. The present invention is not limited to the embodiments described above, and can be implemented with various changes without departing from the spirit of the invention. [Industrial Applicability] By using the polyimide precursor and the resin composition of the present invention, a resin having a residual stress of 25 MPa or less, a yellowness YI of 20 or less, and an elongation of 15% or more can be obtained. membrane. Such a resin film can be applied to, for example, a semiconductor insulating film, a TFT-LCD insulating film, an electrode protective film, and the like, and is particularly suitably used as a substrate in the manufacture of a flexible display and a substrate for a touch panel ITO electrode.

2a‧‧‧ lower substrate

2b‧‧‧Sealed substrate

20‧‧‧Organic EL Display

21‧‧‧ glass substrate

22‧‧‧Light and heat exchange film

23‧‧‧ transparent resin layer

24‧‧‧ Undercoat

25‧‧‧Organic EL Structure Department

29‧‧‧ glass substrate

250a‧‧‧ Organic EL element emitting red light

250b‧‧‧ Organic EL element emitting green light

250c‧‧‧Organic EL element emitting blue light

251‧‧‧wall (dikes)

252‧‧‧Lower electrode (anode)

253‧‧‧ Hole Transmission Layer

254‧‧‧Light-emitting layer

255‧‧‧upper electrode (cathode)

256‧‧‧LTPS

257‧‧‧contact hole

258‧‧‧Interlayer insulation film

259‧‧‧Lower electrode

261‧‧‧Hollow Department

FIG. 1 is a diagram showing an organic EL structure in which the present invention is applied to an organic EL substrate.

Claims (34)

A resin composition for a substrate of a low-temperature polycrystalline silicon TFT device, comprising a polyimide precursor obtained by polymerizing a diamine component and an acid dianhydride component, and a solvent, and the polyimide precursor described above. Containing (a) the following general formula (1): The structure represented. The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to claim 1, wherein the polyfluorene imide precursor includes the following general formula (2): [化 2] The structure represented. For example, the resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to claim 1 or 2, wherein the weight average molecular weight of the polyimide precursor is 40,000 or more and 300,000 or less. The resin composition for a substrate of a low-temperature polycrystalline silicon TFT element according to any one of claims 1 to 3, wherein when the total weight of the solid component contained in the resin composition is 100% by mass, the solid The amount of molecules having a molecular weight of less than 1,000 contained in the component is less than 5% by mass. For example, the resin composition for a substrate of a low-temperature polycrystalline silicon TFT element according to claim 4, wherein the amount of the molecule having a molecular weight of less than 1,000 contained in the solid component is 1% by mass or less. The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to any one of claims 1 to 5, wherein the polyfluorene imide precursor has a total mass of the diamine component and the acid dianhydride component of 100 mass. %% contains the following formula (3): [化 3] (In the formula, there are a plurality of R ₃ and R ₄ each independently being a monovalent organic group having a carbon number of 1 to 20, and h is an integer of 3 to 200.) Less than 6% by mass. The resin composition for a substrate of a low-temperature polycrystalline silicon TFT element according to claim 6, wherein the content of the silicone diamine component is 5.9% by mass or less. For example, the resin composition for a substrate of a low-temperature polycrystalline silicon TFT element according to claim 7, wherein the content of the silicone diamine component is 3% by mass or less. The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to any one of claims 1 to 8, wherein when the polyfluorene imide precursor is set to a total mole number of the diamine component to 100 mole%, The following general formula (4) contained in the aforementioned polyfluorene imide precursor: (Wherein R ₁ , R ₂ , and R ₃ each independently represent a monovalent organic group having a carbon number of 1 to 20; n represents 0 or 1; and a, b, and c are integers of 0 to 4) The amount of diamine is 48 mol% or less. For example, the resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to claim 9, wherein the amount of the diamine represented by the general formula (4) contained in the polyfluorene imide precursor is less than 1 mole%. The resin composition for a substrate of a low-temperature polycrystalline silicon TFT element according to claim 10, wherein the amount of the diamine represented by the general formula (4) contained in the polyfluorene imide precursor is 0.9 mol% or less. The resin composition for a substrate of a low-temperature polycrystalline silicon TFT element according to claim 9, wherein the polyfluorene imide precursor includes 4-aminophenyl-4-aminobenzoate as the general formula (4) The diamine component. The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to any one of claims 1 to 12, wherein when the polyfluorene imide precursor is set to a total mole number of the diamine component to 100 mole%, The content of the 4-aminophenyl-4-aminobenzoate is 48 mol% or less. For example, the resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to claim 13, wherein the content of the 4-aminophenyl-4-aminobenzoate in the polyimide precursor is less than 1 mole%. . For example, the resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to claim 14, wherein the content of the 4-aminophenyl-4-aminobenzoate in the polyimide precursor is less than 0.9 mol%. . The resin composition for a substrate of a low-temperature polycrystalline silicon TFT element according to any one of claims 1 to 15, wherein the polyfluorene imide precursor includes diaminodiphenylphosphonium as the diamine component. For example, the resin composition for a substrate of a low-temperature polycrystalline silicon TFT element according to claim 16, wherein when the polyfluorene imide precursor is set to 100 mole% of the diamine component, the diamine dibenzene is The content of the base is more than 90 mol%. The resin composition for a substrate of a low-temperature polycrystalline silicon TFT element according to any one of claims 1 to 17, wherein the polyfluorene imide precursor includes pyromellitic dianhydride as the acid dianhydride component. For example, the resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to claim 18, wherein when the polyfluorene imide precursor is 100 mol% in the total mole number of the acid dianhydride component, the above pyromellitic acid The dianhydride content is above 90 mol%. The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to any one of claims 1 to 19, wherein the yellowness of the polyimide film obtained by heating the resin composition at 430 ° C for 1 hour is at a film thickness It is 20 or less at 10 μm. For example, the resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to claim 20, wherein the yellowness of the polyimide film obtained by heating the resin composition at 430 ° C for 1 hour is 13 or less at a film thickness of 10 μm . The resin composition for a substrate of a low-temperature polycrystalline silicon TFT element according to any one of claims 1 to 21, wherein the glass transition temperature of the polyimide film obtained by heating the resin composition at 430 ° C for 1 hour is 360. Above ℃. For example, the resin composition for a substrate of a low-temperature polycrystalline silicon TFT element according to claim 22, wherein the glass transition temperature of the polyimide film obtained by heating the resin composition at 430 ° C for 1 hour is 470 ° C or higher. The resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to any one of claims 1 to 23, wherein the polyimide film obtained by heating the resin composition at 430 ° C for 1 hour has a retardation of a film thickness of 10 1000 μm or less. For example, the resin composition for a substrate of a low-temperature polycrystalline silicon TFT device according to claim 24, wherein the retardation of the polyimide film obtained by heating the resin composition at 430 ° C for 1 hour is 140 nm or less at a film thickness of 10 μm . A method for producing a resin film, comprising the steps of: applying a resin composition according to any one of claims 1 to 25 on a surface of a support; and forming a polyimide resin from the resin composition. A step of filming; and a step of peeling the polyimide resin film from the support. The method for manufacturing a resin film according to claim 26, wherein the step of irradiating a laser from the support side is performed before the step of peeling the polyimide resin film from the support. A method for manufacturing a display device, which includes a method for manufacturing a resin film by a method as claimed in claim 26 or 27. A method for manufacturing a laminated body, comprising the steps of: coating a surface of a support with the resin composition according to any one of claims 1 to 25; and forming a polyimide resin film from the resin composition. Step; and a step of forming a low-temperature polycrystalline silicon TFT on the polyimide resin film. The method for producing a laminated body according to claim 29, further comprising a step of peeling the polyimide resin film from the support. A method for manufacturing a flexible device, comprising the method for manufacturing a multilayer body as claimed in claim 29 or 30. A laminated body comprising the following general formula (5): The polyimide layer of the polyimide and the low-temperature polycrystalline silicon TFT layer shown. For example, the laminated body of claim 32, wherein the amount of molecules having a molecular weight of less than 1,000 contained in the polyimide layer is less than 5% by mass. A polyimide film characterized by a yellowness of 20 or less at a film thickness of 10 μm when heated at 430 ° C, a residual stress of 25 MPa or less, and an elongation of 15% or more.