JP2016132686A - Polyimide, method for producing polyimide, polyimide solution and polyimide film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyimide which has high heat resistance and transparency excellent solubility in a casting solvent and high workability, can be stored in a polyimide state and can sufficiently prevent degradation in quality after long term storage.SOLUTION: There is provided a polyimide which comprises 50 mol% or more of a repeating unit represented by the formula (1) based on the total repeating units and dissolves in a casting solvent. [Rto Reach independently represents H, F or an alkyl; Rrepresents a specific group; and n represents an integer of 0 to 12.]SELECTED DRAWING: None

Description

  The present invention relates to polyimide, a method for producing polyimide, a polyimide solution, and a polyimide film, and more specifically, a polyimide that can be dissolved in a so-called cast solvent such as dichloromethane and trichloromethane, a method for producing the polyimide, and the polyimide being dissolved. And a film made of the polyimide.

  In recent years, in the field of mobile devices such as smartphones and tablet terminals, due to the problem that the glass substrate used for the display etc. breaks due to impact or dropping, it has a high light transmission and sufficiently high heat resistance like glass. The appearance of light and flexible materials has been demanded. As a material used for such glass substitute applications, attention has been paid to a light and flexible polyimide having high heat resistance.

  As such a polyimide, for example, an aromatic polyimide (for example, trade name “Kapton” manufactured by DuPont) is known. However, although such aromatic polyimide is a polyimide having sufficient flexibility and high heat resistance, it exhibits a brown color and can be used for glass replacement applications and optical applications that require light transmission. It wasn't.

  Therefore, in recent years, development of an alicyclic polyimide having sufficient light transmissibility that can be used for glass substitute applications and the like has been promoted. For example, in International Publication No. 2011/099518 (Patent Document 1) A polyimide having a repeating unit represented by the general formula is disclosed. Such a polyimide as described in Patent Document 1 has sufficient light transmittance and high heat resistance.

International Publication No. 2011/099518

  However, the alicyclic polyimide as described in Patent Document 1 is not always sufficient in terms of solubility in a so-called casting solvent. Therefore, the alicyclic polyimide described in Patent Document 1 is not always easy to process by imidizing and storing once by film formation or the like and then dissolving in the casting solvent again, and has higher processability. The appearance of polyimide is desired.

  In addition, since the polyamic acid (polyamic acid) formed at the time of manufacture of such a polyimide as described in Patent Document 1 does not necessarily have sufficient storage stability of the resin solution (varnish), It has not always been easy to store for a long time in a state before processing of a film or the like (a state of a resin solution in which a polyamic acid is soluble in a good solvent: a state of a varnish). Actually, such a polyamic acid (polyamic acid) may need to be used before quality deterioration, or may need to be refrigerated and frozen for temporary storage. It should be noted that it is not always easy to obtain a polyimide having excellent processability, transparency and heat resistance from a varnish whose quality has deteriorated due to storage.

  Here, if the polyamic acid is to be stored as formed in the production of the polyimide described in Patent Document 1, the polyamic acid resin solution (varnish) is used in a large amount of solvent (for example, methanol, hexane). It is not impossible to store after solidification by performing a reprecipitation operation to solidify the resin by adding it to a poor solvent insoluble in polyamic acid such as water. The reprecipitation operation used was a method that was difficult to industrialize. As described above, the conventional polyimide is not always sufficient in that it is stored for a long time in a state before the production of the final product to sufficiently prevent the deterioration of the quality.

  In addition, as a general method for producing polyimide, after varnish (polyamic acid solution) obtained by solution polymerization of acid dianhydride and diamine is cast on a glass plate or the like and the solvent is removed (dried) A processing method is known in which a polyimide film is formed by thermal imidization at a high temperature of about 250 ° C. or higher. However, in the processing method using such general thermal imidization, a heating step at a high temperature is necessary when producing a final product (film for a substrate or the like). Therefore, it is not always necessary to use a heating process at a high temperature, and sufficiently high processability so that the final product (such as a polyimide film for a substrate) can be processed more efficiently by a simpler process. The emergence of polyimides having the following is also desired.

  The present invention has been made in view of the above-mentioned problems of the prior art, has a sufficiently high heat resistance and transparency, sufficiently excellent in solubility in a casting solvent, and dissolved in the casting solvent in various shapes. Can be processed to a high degree, has a sufficiently high workability, can be stored in the state of polyimide, and can sufficiently prevent deterioration of quality after long-term storage, and the polyimide can be efficiently used It is another object of the present invention to provide a method for producing polyimide that can be reliably produced. Another object of the present invention is to provide a polyimide solution and a polyimide film obtained using the polyimide.

  As a result of intensive studies to achieve the above object, the present inventors have found that a specific tetracarboxylic dianhydride represented by the following general formula (2) and the following general formula (301) are present in the presence of a polymerization solvent. ) To (311) to react with the specific aromatic diamine to obtain a specific polyamic acid, and then sufficiently imidize the polyamic acid with a condensing agent in the polymerization solvent. It is also possible to imidize at low temperature, and it is found that polyimide can be produced efficiently and reliably, and such polyimide has sufficiently high heat resistance and transparency, and is soluble in cast solvents. It is sufficiently excellent in that it can be dissolved in a casting solvent and processed into various shapes. It has sufficiently high processability and can be stored in a polyimide state. As compared with the case of storing it found that becomes capable also to sufficiently prevent deterioration of quality after long-term storage, and have completed the present invention.

  That is, the polyimide of the present invention has the following general formula (1):

In Expression ^{(1), R 1, R} 2, R 3 are each independently a hydrogen atom, represents one selected from the group consisting of alkyl groups and fluorine atom having 1 to 10 carbon ^{atoms, R 10} is The following general formulas (101) to (111):

1 is selected from the groups represented by the formula: n represents an integer of 0-12. ]
Is contained in an amount of 50 mol% or more based on the total number of repeating units, and is soluble in a casting solvent.

  As the polyimide of the present invention, the cast solvent is preferably a halogen solvent having a boiling point of 200 ° C. or less, dichloromethane (boiling point 40 ° C.), trichloromethane (boiling point 62 ° C.), carbon tetrachloride (boiling point 77 ° C.). ), Dichloroethane (boiling point 84 ° C.), trichloroethylene (boiling point 87 ° C.), tetrachloroethylene (boiling point 121 ° C.), tetrachloroethane (boiling point 147 ° C.), chlorobenzene (boiling point 131 ° C.) and o-dichlorobenzene (boiling point 180 ° C.). More preferably, it is at least one selected.

  As the polyimide of the present invention, the polyimide preferably has an imidization ratio of 90% or more.

  Moreover, the manufacturing method of the polyimide of this invention is the presence of a polymerization solvent, and the following general formula (2):

[In the formula (2), R ¹ , R ² and R ³ each independently represents one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms and a fluorine atom, and n is 0. An integer of ~ 12 is shown. ]
And the following general formulas (301) to (311):

Is reacted with at least one aromatic diamine selected from the compounds represented by formula (4):

Wherein ^{(4), R 1, R} 2, R 3 are each independently a hydrogen atom, it represents one selected from the group consisting of alkyl groups and fluorine atom having 1 to 10 carbon ^{atoms, R 10} is The following general formulas (101) to (111):

1 is selected from the groups represented by the formula: n represents an integer of 0-12. ]
A step of obtaining a polyamic acid containing 50 mol% or more of the repeating units represented by
In the polymerization solvent, the polyamic acid is chemically imidized using a condensing agent, whereby the following general formula (1) is contained in the polymerization solvent:

In Expression ^{(1), R 1, R} 2, R 3, R 10 and n are respectively the same as ^{R 1, R 2, R 3} , R 10 and n in the general formula (4). ]
A step of precipitating polyimide containing 50 mol% or more of the repeating units represented by the following formula to obtain the polyimide;
It is the method characterized by including.

  In the polyimide production method of the present invention, the polymerization solvent is N, N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), 1,3-dimethyl-2-imidazolidinone (DMI). It is preferably at least one organic solvent selected from dimethyl sulfoxide (DMSO), pyridine, m-cresol, γ-butyrolactone, cyclopentanone, cyclohexanone and tetrahydrofuran (THF).

  In the polyimide production method of the present invention, the condensing agent is a carboxylic acid anhydride such as acetic anhydride, propionic anhydride or trifluoroacetic anhydride, a carbodiimide such as N, N′-dicyclohexylcarbodiimide (DCC), or diphenyl. It is at least one compound selected from acid azides such as phosphoric acid azide (DPPA), active esterifying agents such as Castro reagent, and dehydrating condensing agents such as 2-chloro-4,6-dimethoxytriazine (CDMT). And is more preferably at least one compound selected from acetic anhydride, propionic anhydride, and trifluoroacetic anhydride.

In the polyimide production method of the present invention, the reaction accelerator is triethylamine, diisopropylethylamine, N-methylpiperidine, pyridine, collidine, lutidine, 2-hydroxypyridine, 4-dimethylaminopyridine (DMAP), 1 , 4-diazabicyclo [2.2.2] octane (DABCO), diazabicyclononene (DBN), diazabicycloundecene (DBU), or other tertiary amines. Preferably, it is at least one compound selected from triethylamine, diisopropylethylamine, N-methylpiperidine and pyridine.

  Furthermore, in the manufacturing method of the said polyimide of this invention, it is preferable that the temperature conditions in the case of the said chemical imidation are -20 degreeC-150 degreeC.

  Moreover, in the manufacturing method of the polyimide of the said invention, it is preferable that the said polyimide is a polyimide whose imidation ratio is 90% or more.

  Furthermore, in the polyimide production method of the present invention, in the step of obtaining the polyimide, it is preferable to collect the polyimide deposited in the polymerization solvent by filtration. In the present invention, the polyimide precipitated by chemical imidization in the polymerization solvent is in a solid state such as powder and can be easily recovered by filtration.

  The polyimide solution of the present invention is obtained by dissolving the polyimide of the present invention in a casting solvent.

  The polyimide film of the present invention is a film made of the polyimide of the present invention. Further, the polyimide film of the present invention is preferably obtained using the polyimide solution of the present invention.

  In addition, since the polyimide obtained by the present invention is already in the state of polyimide (preferably in the form of powder), it can be stored (stored) stably and sufficiently for a long period of time. In addition, since the polyimide obtained by the present invention is sufficiently excellent in solubility in a casting solvent, it can be easily processed into various shapes and the like by appropriately producing a coating solution using a casting solvent after storage. In addition to being possible, it is possible to easily produce the final product by a simple process of removing the casting solvent from the coating liquid during the production of the final product, and a heating process at a high temperature during the production of the final product. Since it is not always necessary to carry out the process, it is very excellent in terms of workability after storage. As described above, when the polyamic acid is stored, it is necessary to perform a reprecipitation operation with a large amount of solvent (for example, methanol). According to the present invention, the polyimide state (preferably in the form of powder) ) And can be processed after storage, and it is not necessary to carry out a reprecipitation step. Therefore, industrialization is also easy as a method for producing materials for producing polyimide products (final processed products) for various uses. Furthermore, since the polyimide obtained by the present invention is sufficiently excellent in solubility in a cast solvent, dehydration and foaming occur in thermal imidization by preparing a coating liquid (polyimide solution) using a cast solvent. Thick film films, block bodies and the like that are difficult to manufacture can be more efficiently molded and obtained. Thus, although the polyimide of the present invention can be stored in the state of a polyimide having a sufficiently high storage stability, it is sufficiently excellent in solubility in the cast solvent, so that it can be used for various applications. As particularly useful.

  In addition, in the manufacturing method of the polyimide of this invention as mentioned above, when obtaining a polyimide, a polyimide is deposited from the said polymerization solvent. The reason why such precipitation occurs is not necessarily clear, but the present inventors infer as follows for one reason why precipitation occurs. That is, first, in the field of polymers, it is generally known that the higher the linearity of a polymer, the lower the solvent solubility. Therefore, polyamic acid, which cannot be said to have very high linearity, dissolves sufficiently in the polymerization solvent. However, the chemical imidization of the polyamic acid proceeds and the polymer becomes linear. The inventors infer that the higher state results in insolubility in the solvent and the polyimide is precipitated. Therefore, if the chemical imidization of the polyamic acid is sufficiently advanced until the polyimide is precipitated in the polymerization solvent, the imidization rate is sufficiently improved and the polyimide is precipitated from the polymerization solvent. For the same reason as above, even when thermal imidization is adopted, depending on the degree of imidization of the polymer achieved depending on the heating conditions, the resulting polyimide is soluble in the polymerization solvent. Can be. In addition, even when thermal imidization is employed, when imidization proceeds under higher conditions (for example, when thermal imidization is performed at a heat treatment temperature of about 350 ° C.), the imidization is performed. Since the polymer molecules can move and post-polymerization proceeds to improve the imidization rate and the molecular weight, the linearity of the polymer is improved, and the polymerization solvent (for example, DMAc, NMP, DMI, DMSO) is improved. Etc.). Thus, the present inventors speculate that the solubility in the polymerization solvent largely depends on the imidization rate and molecular weight achieved during imidization. Thus, the present inventors speculate that when the imidization rate and molecular weight exceed a certain range, the linearity of the polymer molecules is improved and the polyimide is precipitated from the polymerization solvent. That is, during the production of polyimide, the polyimide formed in the middle stage of the reaction (in the middle stage of the reaction) has a low imidation rate and the like, and is basically strongly influenced by the properties of the polyamic acid. It is considered that it dissolves in the polymerization solvent in the same manner as the acid. On the other hand, when the chemical imidization is sufficiently advanced, the imidization rate and the like are improved, the influence of the properties of the polyamic acid is reduced, and the properties inherent to the polyimide are stronger, so the type of polyimide and the above The present inventors infer that the polyimide is appropriately deposited according to the combination with the polymerization solvent. Further, from the viewpoint of solubility, the present inventors infer that the polyimide tends to precipitate from the polymerization solvent due to imidization when the molecular weight is increased. Thus, in the present invention, it is possible to obtain polyimide by precipitating polyimide from the polymerization solvent, so it is also possible to obtain polyimide in the form of powder, etc. It is also possible to obtain polyimide.

  According to the present invention, it has sufficiently high heat resistance and transparency, is sufficiently excellent in solubility in a casting solvent, can be dissolved in a casting solvent and processed into various shapes, and is sufficiently high in processing. And polyimide that can be stored in the state of polyimide, can sufficiently prevent deterioration of quality after long-term storage, and a method for producing polyimide that can efficiently and reliably produce the polyimide Can be provided. Moreover, according to this invention, it becomes possible to provide the polyimide film which consists of a polyimide solution obtained using the said polyimide, and the said polyimide.

2 is a graph showing an IR spectrum of polyimide obtained in Example 1. FIG. 2 is a graph showing the NMR spectrum of the polyimide obtained in Example 1. FIG. 2 is a graph showing the NMR spectrum of the polyimide obtained in Example 1. FIG.

  Hereinafter, the present invention will be described in detail with reference to preferred embodiments thereof.

[Polyimide of the present invention]
The polyimide of the present invention has the following general formula (1):

In Expression ^{(1), R 1, R} 2, R 3 are each independently a hydrogen atom, represents one selected from the group consisting of alkyl groups and fluorine atom having 1 to 10 carbon ^{atoms, R 10} is The following general formulas (101) to (111):

1 is selected from the groups represented by the formula: n represents an integer of 0-12. ]
Is contained in an amount of 50 mol% or more based on the total number of repeating units, and is soluble in a casting solvent.

The alkyl group that can be selected as R ¹ , R ² , or R ^{3 in the} general formula (1) is an alkyl group having 1 to 10 carbon atoms. When the number of carbon atoms exceeds 10, the glass transition temperature is lowered and a sufficiently high heat resistance cannot be achieved. Moreover, as carbon number of the alkyl group which can be selected as such R < ¹ >, R < ² >, R < ³ >, it is preferable that it is 1-6 from a viewpoint that refinement | purification becomes easier, and it is 1-5. Is more preferable, it is still more preferable that it is 1-4, and it is especially preferable that it is 1-3. Further, such an alkyl group that can be selected as R ¹ , R ² , or R ³ may be linear or branched. Further, such an alkyl group is more preferably a methyl group or an ethyl group from the viewpoint of ease of purification.

As R < ¹ >, R < ² >, R < ³ > in the said General formula (1), when manufacturing a polyimide, from a viewpoint that higher heat resistance is acquired, it is each independently a hydrogen atom or C1-C10. In particular, from the viewpoint of easy availability of raw materials and easier purification, each independently represents a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group. It is more preferably a group, and particularly preferably a hydrogen atom or a methyl group. Moreover, it is especially preferable that several R < ¹ >, R < ² >, R < ³ > in such a formula is the same from viewpoints, such as the ease of refinement | purification.

In addition, the group that can be selected as R ¹⁰ in the general formula (1) is at least one of the groups represented by the above general formulas (101) to (111). By using R ¹⁰ in the general formula (1) as a group represented by the above general formulas (101) to (111), it is possible to obtain a polyimide that can be dissolved in a casting solvent. Among such R ¹⁰ , from the viewpoint of solubility in cast solvent and heat resistance, groups represented by the above general formulas (101), (102), (105), (108), and (109) (more Preferably, the groups represented by the above general formulas (102) and (109) are preferable. From the viewpoints of solubility and transparency of polyimide in a casting solvent, the above general formulas (103), (106), (107 ) And (109) (more preferably, groups represented by the general formulas (106), (107) and (109)) are preferable.

  Moreover, n in the said General formula (1) shows the integer of 0-12. When such a value of n exceeds the upper limit, purification becomes difficult. Further, the upper limit value of the numerical value range of n in the general formula (1) is more preferably 5 and particularly preferably 3 from the viewpoint of easier purification. Further, the lower limit of the numerical range of n in the general formula (1) is more stable from the viewpoint of the stability of the raw material compound used when forming the repeating unit represented by the general formula (1). From the viewpoint of producing a polyimide, it is more preferably 1 and particularly preferably 2. Thus, as n in General formula (1), it is especially preferable that it is an integer of 2-3.

  Furthermore, the polyimide of this invention contains 50 mol% or more of the repeating unit represented by the said General formula (1) with respect to all the repeating units. When the content ratio of the repeating unit represented by the general formula (1) is less than the lower limit, properties and physical properties when used as a film for glass replacement use or optical use are deteriorated. Further, the content ratio of the repeating unit represented by the general formula (1) may be 50 mol% or more based on the total repeating units, but to the casting solvent (halogen solvents such as dichloromethane and trichloromethane). From the viewpoint of solubility, the content ratio of the repeating unit represented by the general formula (1) is more preferably 90 to 100 mol%, and particularly preferably 100 mol%.

  Moreover, such a polyimide is dissolved in a casting solvent. The term “cast solvent” as used herein refers to a solvent used as a solvent when a polymer solution is prepared and applied to a substrate to form a polymer coating or molded article. , Refers to a solvent that can be removed by evaporation. As such a “cast solvent”, a solvent different from the polymerization solvent is used in terms of dissolving the polymer or evaporating and removing after casting. Such cast solvent is not particularly limited, but is soluble, volatile, transpiration, removability, film formability, productivity, industrial availability, recyclability, presence / absence of existing equipment, price From the above viewpoint, a halogen-based solvent having a boiling point of 200 ° C. or lower is preferable, and dichloromethane (methylene chloride), trichloromethane (chloroform), carbon tetrachloride, dichloroethane, trichloroethylene, tetrachloroethylene, tetrachloroethane, chlorobenzene, and o-dichlorobenzene are more preferable. More preferred are dichloromethane (methylene chloride) and trichloromethane (chloroform). In addition, you may utilize such a casting solvent individually by 1 type or in combination of 2 or more types.

  Since the polyimide of the present invention is sufficiently dissolved in the casting solvent as described above, it can be stored in the state of polyimide for a long time and then dissolved in the casting solvent and processed separately. And the workability is sufficiently high. In the present invention, the case where the polyimide is dissolved in the cast solvent at a ratio of 0.01% by mass (more preferably 0.1% by mass) or more under the condition of 25 ° C. is determined to be dissolved in the cast solvent. To do. The amount of dissolution (mass%) of such a polyimide in the casting solvent can be calculated based on the amount of addition and the remaining amount by adding a small piece or powder of polyimide to the casting solvent.

  Moreover, as such a cast solvent, it is preferable that a boiling point is 200 degrees C or less, It is more preferable that it is 20-150 degreeC, It is further more preferable that it is 30-120 degreeC, 40-100 It is particularly preferable that the temperature is 60 ° C, and most preferable is 60 ° C to 100 ° C. When such boiling point exceeds the upper limit, it becomes difficult to remove the solvent at the time of film production (drying after casting), and the solvent tends to remain in the film. It becomes difficult to produce a film under atmospheric pressure and at room temperature, and it tends to be carried out under special conditions such as under pressure and low temperature.

  Thus, the polyimide of the present invention can be dissolved in a low boiling cast solvent. Therefore, the polyimide of the present invention can be dissolved in a low boiling point casting solvent and processed (film formation etc.) using the resulting solution (processing such as film formation from a low boiling point casting solvent). Can be done). In addition, when processing (film formation, etc.) using the resulting solution after dissolving in a low-boiling cast solvent, heating at high temperature is not required during processing, reducing the environmental burden and making the final product It is also possible to make the manufacturing process advantageous. In addition, after dissolving in the casting solvent, it can be processed into various shapes by a simple method such as removing the casting solvent from the solution, and since heating at a high temperature is not necessary, such as a thick film or block body Even when processed into a thick shape, it is possible to sufficiently suppress the occurrence of foaming due to dehydration, and it is also possible to process into various shapes more easily. In addition, even after it has already been processed, it can be dissolved again in the casting solvent, so it can be reused after being made into various forms, and can be processed into various forms and stored (stored). .

Further, the polyimide of the present invention preferably has an imidization ratio of 90% or more, more preferably 95% or more, and particularly preferably 96 to 100%. When such an imidation ratio is less than the lower limit, it does not sufficiently precipitate from the polymerization solvent at the time of production and is partially dissolved, and it tends to be difficult to efficiently recover the polyimide. Such an imidation ratio is obtained by dissolving the polyimide to be measured in a heavy solvent such as deuterated chloroform (preferably deuterated chloroform), performing ¹ H-NMR measurement, and measuring the vicinity of 10 ppm (10 ppm ± from the ¹ H-NMR graph). It is possible to calculate the integral value of N—H of 1 ppm) and H of COOH around 12 ppm (12 ppm ± 1 ppm). In this case, the integral ratio (imidation ratio) is prepared by first preparing a sample in which the acid dianhydride and diamine of the raw material compound are dissolved in a heavy solvent in which they are soluble (such as DMSO-d ₆ ). ¹ H-NMR spectra were measured, and in the ¹ H-NMR graphs, the position of H (chemical shift) and integrated value of acid dianhydride and the position of H (chemical shift) and integrated value of diamine. , And using the position and integral value of H of the acid dianhydride and the position and integral value of H of the diamine as a reference, the NH of about 10 ppm in the ¹ H-NMR graph of the polyimide to be measured A value calculated by relative comparison is adopted for the integrated value of H and H of COOH near 12 ppm. In such a measurement, the amount of the polyimide for measuring the ¹ H-NMR spectrum is 0.01 to 5.0 mass% with respect to the heavy solvent (preferably deuterated chloroform), and the starting compound is acid diacid. The amount of anhydride and the amount of diamine are used so that they are 0.01 to 5.0 mass% with respect to the soluble heavy solvent (DMSO-d ₆ or the like), respectively. In measuring the imidation rate, the amount of polyimide, the amount of acid dianhydride of the raw material compound, and the amount of diamine (the above concentration) are measured at the same concentration. Moreover, for the ¹ H-NMR measurement, an NMR measuring instrument (manufactured by JEOL Ltd., trade name: JNM-Lambda500) is employed as a measuring device.

  Furthermore, the polyimide of the present invention preferably has a 5% weight loss temperature of 400 ° C. or higher, more preferably 450 to 550 ° C. If such a 5% weight loss temperature is less than the lower limit, sufficient heat resistance tends to be difficult to achieve, and if it exceeds the upper limit, it tends to be difficult to produce a polyimide having such characteristics. It is in. Such 5% weight reduction temperature is obtained by gradually heating from room temperature (25 ° C.) while flowing nitrogen gas in a nitrogen gas atmosphere and measuring the temperature at which the weight of the used sample is reduced by 5%. Can be sought.

  Moreover, as such a polyimide, that whose glass transition temperature (Tg) is 250 degreeC or more is preferable, and the thing of 300-500 degreeC is more preferable. If the glass transition temperature (Tg) is less than the lower limit, sufficient heat resistance tends to be difficult to achieve, and if it exceeds the upper limit, it tends to be difficult to produce a polyimide having such characteristics. It is in. In addition, such a glass transition temperature (Tg) can be measured using a differential scanning calorimeter (trade name “DSC220” manufactured by SII Nano Technology Co., Ltd.).

  Moreover, as such a polyimide, a thing with a thermal decomposition temperature (Td) of 450 degreeC or more is preferable, and a 480-600 degreeC thing is more preferable. If such a thermal decomposition temperature (Td) is less than the lower limit, sufficient heat resistance tends to be difficult to achieve, and if it exceeds the upper limit, it is difficult to produce a polyimide having such characteristics. There is a tendency. In addition, such a thermal decomposition temperature (Td) was measured using a TG / DTA220 thermogravimetric analyzer (manufactured by SII Nanotechnology Co., Ltd.) in a nitrogen atmosphere under a heating rate of 10 ° C./min. It can be determined by measuring the temperature at the intersection of the tangent lines drawn on the decomposition curve before and after thermal decomposition under the conditions of

  Furthermore, as a number average molecular weight (Mn) of such a polyimide, it is preferable that it is 1000-1 million in polystyrene conversion, and it is more preferable that it is 10000-500000. If such a number average molecular weight is less than the lower limit, it is difficult to achieve sufficient heat resistance, it does not sufficiently precipitate from the polymerization solvent during production, and it tends to be difficult to obtain polyimide efficiently, When the upper limit is exceeded, the viscosity increases, and it takes a long time to dissolve or requires a large amount of solvent, which tends to make processing difficult.

  Moreover, as a weight average molecular weight (Mw) of such a polyimide, it is preferable that it is 1000-5 million in polystyrene conversion. Moreover, as a lower limit of the numerical range of such a weight average molecular weight (Mw), it is more preferable that it is 5000, It is further more preferable that it is 10,000, It is especially preferable that it is 20000. Moreover, as an upper limit of the numerical range of a weight average molecular weight (Mw), it is more preferable that it is 5000000, It is further more preferable that it is 500,000, It is especially preferable that it is 100,000. If such a weight average molecular weight is less than the lower limit, it is difficult to achieve sufficient heat resistance, and does not sufficiently precipitate from the polymerization solvent during production, and it tends to be difficult to obtain polyimide efficiently, When the upper limit is exceeded, the viscosity increases, so that it takes a long time to dissolve or a large amount of solvent is required, which tends to make processing difficult.

  Furthermore, the molecular weight distribution (Mw / Mn) of such a polyimide is preferably 1.1 to 5.0, and more preferably 1.5 to 3.0. If the molecular weight distribution is less than the lower limit, it tends to be difficult to produce, while if it exceeds the upper limit, it tends to be difficult to obtain a uniform film. In addition, the molecular weight (Mw or Mn) and molecular weight distribution (Mw / Mn) of such polyimide are measured by a gel permeation chromatography (GPC) measuring device (Degasser: DG-2080-54 manufactured by JASCO, Liquid pump: JASCO PU-2080, interface: JASCO LC-NetII / ADC, column: Shodex GPC column KF-806M (× 2), column oven: JASCO 860-CO, RI detector : RI-2031 manufactured by JASCO, column temperature of 40 ° C., and data measured using a chloroform solvent (flow rate: 1 mL / min.) Can be obtained by conversion with polystyrene.

  In such a polyimide, as long as the content ratio of the repeating unit represented by the general formula (1) is 50 mol% or more (more preferably 90 to 100 mol%, still more preferably 100 mol%), other The repeating unit may be included. Such other repeating units are not particularly limited as long as they can be used for polyimide, for example.

  Moreover, such a polyimide preferably has a linear expansion coefficient of 0 to 100 ppm / K, and more preferably 10 to 70 ppm / K. When such a linear expansion coefficient exceeds the upper limit, peeling tends to occur due to thermal history when combined with a metal or inorganic material having a linear expansion coefficient range of 5 to 20 ppm / K. Moreover, when the linear expansion coefficient is less than the lower limit, the solubility and the film characteristics tend to be lowered.

  As a method for measuring the linear expansion coefficient of such a polyimide, after forming a polyimide film having a size of 75 mm in length, 50 mm in width, and 13 μm in thickness, the film is vacuum-dried (at 120 ° C. for 1 hour) to form a nitrogen atmosphere. Using a dry film obtained by heat treatment at 200 ° C. for 1 hour as a measurement sample and using a thermomechanical analyzer (trade name “TMA8310” manufactured by Rigaku) as a measuring device, the sample is pulled in a nitrogen atmosphere. Adopting the mode (49 mN) and the temperature rising rate of 5 ° C./min, measuring the change in the length of the sample in the longitudinal direction from 50 ° C. to 200 ° C., and measuring 1 in the temperature range of 50 ° C. to 200 ° C. The value obtained by calculating the average value of the length change per ° C is adopted.

  Moreover, as such a polyimide, it is preferable that transparency is sufficiently high when a film is formed, and the total light transmittance is 80% or more (more preferably 85% or more, particularly preferably 87% or more). ) Is more preferable. Such total light transmittance can be easily achieved by appropriately selecting the type of polyimide or the like. In addition, as such a total light transmittance, the polyimide film of this invention is used, the polyimide film of a length: 75mm, width 50mm, and thickness 13micrometer is formed, it is set as a sample, and Nippon Denshoku Industries stock is used as a measuring device. A value measured using a trade name “Haze Meter NDH-5000” manufactured by the company can be adopted.

  Moreover, it is preferable that such a polyimide is a powder form from a viewpoint on storage. Such a powdery polyimide preferably has an average particle diameter of 1 to 1000 μm, more preferably 10 to 500 μm. If the average particle size is less than the lower limit, it becomes difficult to separate the powdered polyimide obtained by chemical imidization (centrifugation, filtration separation, sedimentation separation), resulting in deterioration of filterability or filter material. Clogging, prolonged filtration time, further reduction in washing efficiency due to rinsing liquid, and longer time required for drying rinsing liquid, etc. There is a tendency that problems such as deterioration of filterability and agitation, difficulty in removing the solvent and by-products remaining in the powder, reduction of bulk density, and long time for solvent drying. In addition, such an average particle diameter employs a value measured by a method such as direct observation with an optical microscope, a dynamic light scattering method, a laser diffraction method, or the like. In addition, the particle diameter here refers to the diameter of the maximum circumscribed circle of a particle when the particle is not spherical.

  In addition, since such a polyimide is sufficiently dissolved in the casting solvent as described above, after being stored in a polyimide state for a long period of time, it is dissolved in the casting solvent and processed appropriately according to the intended use. It is possible. Thus, the polyimide of the present invention has sufficiently high long-term storage and workability. In addition, since such a polyimide is easily dissolved in a low-boiling cast solvent such as methylene chloride (boiling point: 40 ° C.) or chloroform (boiling point: 62 ° C.), the coating solution obtained by dissolving in such a solvent, It is possible to obtain a polyimide film by applying it on a substrate such as glass and drying the solvent at a low temperature (for example, room temperature). In this case, the heating at about 400 ° C. may be employed.), So that the workability is sufficiently high from this point of view. Therefore, the polyimide of the present invention is a flexible wiring board film, heat-resistant insulating tape, electric wire enamel, semiconductor protective coating agent, liquid crystal alignment film, organic EL transparent conductive film, organic EL lighting film, flexible board film, flexible Organic EL substrate film, flexible transparent conductive film, organic thin film solar cell transparent conductive film, dye-sensitized solar cell transparent conductive film, flexible gas barrier film, touch panel film, flexible display front film, flexible It is particularly useful as a material for producing a back film for display.

  Moreover, such a polyimide can be suitably manufactured by the manufacturing method of the polyimide of this invention mentioned later. Therefore, as such a polyimide, it is preferable that it is obtained by the manufacturing method of the polyimide of this invention mentioned later.

[Polyimide solution]
The polyimide solution of the present invention is obtained by dissolving the polyimide of the present invention in a casting solvent.

  The “cast solvent” used in the polyimide solution of the present invention is the same as the “cast solvent” described in the polyimide of the present invention. In the present invention, a case where the polyimide is dissolved in the cast solvent at a rate of 0.1% by mass or more under the condition of 25 ° C. is determined as being dissolved in the cast solvent. The amount of polyimide dissolved (% by mass) can be calculated from the amount and the remaining amount of polyimide cast or powder charged into the casting solvent.

  Moreover, in the polyimide solution of this invention, it is preferable that content (dissolution amount) of the said polyimide is 1-50 mass%, and it is more preferable that it is 10-20 mass%. When such a content is less than the lower limit, the film thickness after film formation tends to be thin when used for film formation or the like, and when it exceeds the upper limit, it tends to be insoluble in a casting solvent.

  Furthermore, in the polyimide solution of the present invention, antioxidants (phenolic, phosphite-based, thioether-based, etc.), ultraviolet absorbers, hindered amine light stabilizers, nucleating agents, resins, as long as the effects of the present invention are not impaired. Additives such as additives (filler, talc, glass fiber, etc.), flame retardants, processability improvers and lubricants may be further added. In addition, it does not restrict | limit especially as these additives, A well-known thing can be utilized suitably, and a commercially available thing may be utilized.

[Polyimide film]
The polyimide film of the present invention is a film made of the polyimide of the present invention.

  Such a polyimide film is not particularly limited as long as it is a film made of polyimide described as the polyimide of the present invention, but is more preferably obtained using the polyimide solution of the present invention. In addition, since the polyimide film of the present invention is composed of the polyimide of the present invention dissolved in a casting solvent, it can be easily manufactured by processing into a film using the polyimide solution of the present invention. is there. Therefore, it is more preferable that the polyimide film of the present invention is obtained using the polyimide solution of the present invention. Moreover, since the film obtained using the polyimide solution of the present invention can be produced by a simple method such as removing the cast solvent from the coating film after appropriately applying the polyimide solution on the substrate, the process In addition to being advantageous, heating at a high temperature is not required at the time of film formation, and uniform film formation can be carried out more efficiently by suppressing the occurrence of foaming and the like. In particular, when a casting solvent having a low boiling point is used, the environmental burden can be further reduced because a film can be formed more easily.

  Moreover, the form of such a polyimide film should just be a film form, and is not restrict | limited in particular, It can design suitably in various shapes (a disk shape, cylindrical shape (what processed the film into the cylinder shape) etc.). When manufactured using the polyimide solution of the present invention, the design can be changed more easily.

  Furthermore, the thickness of the polyimide film of the present invention is not particularly limited, but is preferably 1 to 500 μm, and more preferably 10 to 200 μm. If the thickness is less than the lower limit, the strength tends to be reduced and handling tends to be difficult.On the other hand, if the upper limit is exceeded, multiple coatings may be required or processing may be complicated. Tend to occur.

  Since such a polyimide film of the present invention is composed of the polyimide of the present invention, it can be excellent in film properties such as transparency, heat resistance, mechanical properties, mechanical properties, durability, and toughness. .

  Moreover, since the polyimide film of the present invention has sufficiently high transparency and heat resistance, for example, a film for a flexible wiring board, a film used for a liquid crystal alignment film, a transparent conductive film for organic EL, an organic EL lighting film, flexible substrate film, flexible organic EL substrate film, flexible transparent conductive film, organic thin film solar cell transparent conductive film, dye-sensitized solar cell transparent conductive film, flexible gas barrier film, touch panel Film, front film for flexible display, back film for flexible display, polyimide belt, coating agent, barrier film, sealing material, interlayer insulating material, passivation film, TAB tape, FPC, COF, optical waveguide, color fill Over the substrate, a semiconductor coating agent, can be appropriately utilized heat insulating tape, for applications such as wire enamels.

[Production Method of Polyimide of the Present Invention]
The method for producing the polyimide of the present invention comprises the following general formula (2) in the presence of a polymerization solvent:

[In the formula (2), R ¹ , R ² and R ³ each independently represents one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms and a fluorine atom, and n is 0. An integer of ~ 12 is shown. ]
And the following general formulas (301) to (311):

Is reacted with at least one aromatic diamine selected from the compounds represented by formula (4):

Wherein ^{(4), R 1, R} 2, R 3 are each independently a hydrogen atom, it represents one selected from the group consisting of alkyl groups and fluorine atom having 1 to 10 carbon ^{atoms, R 10} is The following general formulas (101) to (111):

1 is selected from the groups represented by the formula: n represents an integer of 0-12. ]
A step of obtaining a polyamic acid containing 50 mol% or more of the repeating units represented by the following formula (step (I));
In the polymerization solvent, the polyamic acid is chemically imidized using a condensing agent and a reaction accelerator, whereby the following general formula (1):

In Expression ^{(1), R 1, R} 2, R 3, R 10 and n are respectively the same as ^{R 1, R 2, R 3} , R 10 and n in the general formula (4). ]
A step of depositing a polyimide containing 50 mol% or more of the repeating units represented by the following formula (step (II)),
It is the method characterized by including. Hereinafter, steps (I) to (II) will be described separately.

(Step (I): Step of obtaining polyamic acid)
Step (I) is selected from the tetracarboxylic dianhydride represented by the above general formula (2) and the compounds represented by the above general formulas (301) to (311) in the presence of a polymerization solvent. And a polyamic acid containing 50 mol% or more of the repeating unit represented by the general formula (4) with respect to all repeating units by reacting with at least one kind of aromatic diamine.

Regarding the tetracarboxylic dianhydride represented by the general formula (2), R ¹ , R ² and R ³ in the formula (2) are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, and It is 1 type selected from the group which consists of a fluorine atom, and n is an integer of 0-12. ^{R 1,} R ^{2, R} 3, n in the general formula (2) is, ^R 1 in the general formula (1) described in the polyimide of the present invention described ^above, R ^{2, R} 3, n and The preferred ones are the same as the preferred ones for R ¹ , R ² , R ³ and n in the general formula (1).

  Moreover, it does not restrict | limit especially as a method for manufacturing the tetracarboxylic dianhydride represented by General formula (2) used for such a process (I), A well-known method is employ | adopted suitably. For example, by adopting the method described in International Publication No. 2011/099517, the method described in International Publication No. 2011/099518, etc., the following general formula (5):

Wherein ^{(5), R 1, R} 2, R 3, n are as defined ^{R 1, R 2, R 3} , n in the general formula (1). ]
(Hereinafter simply referred to as “compound represented by the general formula (5)”), and then the compound represented by the general formula (5) is converted into a tetracarboxylic dianhydride. The manufacturing method may be adopted. Thus, the tetracarboxylic dianhydride represented by the general formula (2) can be obtained by a known method (for example, the method described in Example 2 or Example 4 of International Publication No. 2011/099518). It can be adopted as appropriate.

  In addition, as the tetracarboxylic dianhydride represented by the above general formula (2), from the viewpoint of adjusting film properties, thermophysical properties, mechanical properties, optical properties, and electrical properties, the following general formula ( 6):

Wherein ^{(6), R 1, R} 2, R 3, n has the same definition as ^{R 1, R 2, R 3} , n in the general formula (2). ]
Compound (A) represented by the following general formula (7):

Wherein ^{(7), R 1, R} 2, R 3, n are as defined ^{R 1, R 2, R 3} , n in the general formula (2). ]
The compound (B) containing at least one of the compounds (B) and the total amount of the compounds (A) and (B) is preferably 90 mol% or more. In the compound (A) represented by the general formula (6), two norbornane groups are trans-configured, and the carbonyl group of cycloalkanone has an endo configuration with respect to each of the two norbornane groups. It is an isomer of tetracarboxylic dianhydride represented by the general formula (2). Further, the compound (B) represented by the general formula (7) has a configuration in which two norbornane groups are in cis configuration and the carbonyl group of cycloalkanone is endo in each of the two norbornane groups. It is an isomer of tetracarboxylic dianhydride represented by the above general formula (2). In addition, the manufacturing method of the tetracarboxylic dianhydride containing such an isomer in the above ratio is not particularly limited, and a known method can be appropriately employed. For example, it is described in International Publication No. 2014/034760. These methods may be appropriately adopted.

  In addition, the aromatic diamine used in the step (I) is at least one selected from the compounds represented by the above general formulas (301) to (311). By using such an aromatic diamine, it is possible to produce a polyimide that can be dissolved in a casting solvent.

  The aromatic diamines represented by the general formulas (301) to (311) include 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [ 4- (4-aminophenoxy) phenyl] hexafluoropropane, 4,4′-diamino-2,2-bis (trifluoromethyl) biphenyl, m-tolidine, bis [4- (4-aminophenoxy) phenyl] sulfone Bis [4- (3-aminophenoxy) phenyl] sulfone. Among such aromatic diamines, from the viewpoints of solubility and heat resistance, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 1,4-bis (4-aminophenoxy) benzene, 4, 4'-diamino-2,2-bis (trifluoromethyl) biphenyl, m-tolidine (more preferably 4,4'-diaminodiphenyl ether, 4,4'-diamino-2,2-bis (trifluoromethyl) biphenyl In addition, from the viewpoint of solubility and transparency, 1,3-bis (3-aminophenoxy) benzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2, 2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 4,4′-diamino-2,2-bis (trifluoromethyl) Biphenyl (more preferably 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 4,4′-diamino- 2,2-bis (trifluoromethyl) biphenyl) is preferred. Such aromatic diamines can be used singly or in combination of two or more.

  It does not restrict | limit especially as a method for manufacturing such an aromatic diamine, A well-known method is employable suitably. Moreover, you may use a commercially available thing suitably as such aromatic diamine.

  Moreover, as a polymerization solvent used for process (I), both the tetracarboxylic dianhydride represented by the said General formula (2) and the aromatic diamine represented by the said General formula (301)-(311) And an organic solvent capable of precipitating polyimide when the chemical imidization sufficiently proceeds in the polymerization solvent (in addition, the polyimide has an imidization rate and The solubility is different depending on the molecular weight, the type of repeating unit, etc., and therefore it is preferable to select appropriately according to the type of polyimide.

  Examples of such an organic solvent include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, γ-butyrolactone, propylene carbonate, tetramethylurea, 1,3- Aprotic polar solvents such as dimethyl-2-imidazolidinone, hexamethylphosphoric triamide, pyridine; phenolic solvents such as m-cresol, xylenol, phenol, halogenated phenol; tetrahydrofuran, dioxane, cellosolve, glyme And ether solvents such as diglyme; aromatic solvents such as benzene, toluene and xylene; ketone solvents such as cyclopentanone and cyclohexanone; and nitrile solvents such as acetonitrile and benzonitrile.

  In addition, as such a polymerization solvent (organic solvent), it is possible to efficiently precipitate polyimide when chemical imidization is sufficiently advanced, so that N, N-dimethylacetamide, N-methyl- 2-pyrrolidone, N, N-dimethylformamide, 1,3-dimethyl-2-imidazolidinone, dimethyl sulfoxide and the like are preferable, and N, N-dimethylacetamide is more preferable. Such polymerization solvents (organic solvents) may be used alone or in combination of two or more.

  Moreover, as such a polymerization solvent (organic solvent), it is preferable that a boiling point is 20 degreeC or more, and it is preferable that it is a 50-250 degreeC thing. If the boiling point is less than the above lower limit, polymerization at atmospheric pressure and room temperature becomes difficult, and there is a tendency to be carried out under special conditions such as under pressure and low temperature. When a body-like polyimide is obtained, it is difficult to remove the solvent in the step of drying after washing, and the solvent tends to remain in the powdered polyimide.

  In the step (I), the ratio of the tetracarboxylic dianhydride represented by the general formula (2) and the aromatic diamine represented by the general formulas (301) to (311) is as described above. The acid anhydride group of the tetracarboxylic dianhydride represented by the above general formula (2) is reduced to 0.1 equivalent with respect to 1 equivalent of the amino group of the aromatic diamine represented by the general formula (301) to (311). It is preferably 2 to 2 equivalents, more preferably 0.3 to 1.2 equivalents. If the use ratio is less than the lower limit, the polymerization reaction does not proceed efficiently, and a high molecular weight polyamic acid tends not to be obtained. On the other hand, if the upper limit is exceeded, a high molecular weight polyamic acid is obtained as described above. There is no tendency.

  Furthermore, the amount of the polymerization solvent (organic solvent) used in the step (I) is represented by the tetracarboxylic dianhydride represented by the general formula (2) and the general formulas (301) to (311). It is preferable that the total amount of the aromatic diamine is 0.1 to 50% by mass (more preferably 10 to 30% by mass) with respect to the total amount of the reaction solution. If the amount of the organic solvent used is less than the lower limit, the polyamic acid tends not to be obtained efficiently. On the other hand, if it exceeds the upper limit, stirring tends to be difficult due to the increase in viscosity.

  In the step (I), when the tetracarboxylic dianhydride represented by the general formula (2) is reacted with the aromatic diamine represented by the general formulas (301) to (311), From the viewpoint of improving the reaction rate and obtaining a polyamic acid having a high degree of polymerization, a base compound may be further added to the organic solvent. Examples of such basic compounds include, but are not limited to, triethylamine, tetrabutylamine, tetrahexylamine, 1,8-diazabicyclo [5.4.0] -undecene-7, pyridine, isoquinoline, α-picoline, and the like. Can be mentioned. Moreover, it is preferable that the usage-amount of such a basic compound shall be 0.001-10 equivalent with respect to 1 equivalent of tetracarboxylic dianhydrides represented by the said General formula (2), 0.01- More preferably, it is 0.1 equivalent. If the amount of such a basic compound used is less than the lower limit, the effect of addition tends to be lost. On the other hand, if it exceeds the upper limit, it tends to cause coloring or the like.

  Moreover, reaction temperature at the time of making the tetracarboxylic dianhydride represented by the said General formula (2) and the aromatic diamine represented by the said General formula (301)-(311) react in process (I). May be appropriately adjusted to a temperature at which these compounds can be reacted, and is not particularly limited, but is preferably 0 to 100 ° C. Moreover, the tetracarboxylic dianhydride represented by the general formula (2) that can be employed in the step (I) is reacted with the aromatic diamine represented by the general formulas (301) to (311). As a method for the above, a method capable of performing a polymerization reaction of tetracarboxylic dianhydride and an aromatic diamine can be used as appropriate, and is not particularly limited. For example, inactive at atmospheric pressure, such as nitrogen, helium, and argon A method in which an aromatic diamine is dissolved in a solvent under an atmosphere, and then the tetracarboxylic dianhydride represented by the general formula (2) is added at the reaction temperature, followed by a reaction for 10 to 48 hours. It may be adopted. If the reaction temperature or reaction time is less than the lower limit, it tends to be difficult to cause sufficient reaction. On the other hand, if the upper limit is exceeded, the probability of mixing a substance (such as oxygen) that degrades the polymer increases and the molecular weight increases. It tends to decrease.

  Moreover, in such a process (I), the tetracarboxylic dianhydride represented by the said General formula (2) and the aromatic diamine represented by the said General formula (301)-(311) are made to react. Thus, a polyamic acid containing 50 mol% or more of the repeating unit represented by the general formula (4) with respect to all repeating units is obtained.

R ¹ , R ² and R ³ in the general formula (4) are each independently one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms and a fluorine atom, R ¹⁰ is one selected from the groups represented by the following general formulas (101) to (111), and n is an integer of 0 to 12. ^R 1 in the general formula ^(4), R ^2, R ^{3, R 10} and n, ^R 1 in the general formula (1) described in the polyimide of the present invention described ^above, R 2, ^{R 3} , R ¹⁰ and n are the same as those of R ¹ , R ² , R ³ , R ¹⁰ and n in the general formula (1). In addition, R < ¹⁰ > in General formula (4) is group derived from the aromatic diamine represented by the said General Formula (301)-(311).

  Moreover, in such a polyamic acid, the content rate of the repeating unit represented by the said General formula (4) is 50 mol% or more with respect to all the repeating units. The content ratio of the repeating unit represented by the general formula (4) is more preferably 70 mol% or more, more preferably 90 to 100 mol%, and particularly preferably 100 mol%. preferable. When the content ratio of such a repeating unit is less than the lower limit, the solubility in the casting solvent is lowered when the polyamide is used, and it cannot be sufficiently dissolved in the casting solvent. In addition, the content rate of such a repeating unit is represented by the tetracarboxylic dianhydride represented by the said General formula (2) and the said General Formula (301)-(311) in the case of manufacture of a polyimide. By appropriately adjusting the amount of the aromatic diamine used, it can be easily within the above range.

  Moreover, as such a polyamic acid, it is preferable that intrinsic viscosity [(eta)] is 0.05-3.0 dL / g, and it is more preferable that it is 0.1-2.0 dL / g. When the intrinsic viscosity [η] is smaller than 0.05 dL / g, when a film-like polyimide is produced using the intrinsic viscosity [η], the resulting film tends to be brittle, while 3.0 dL / g is reduced. When it exceeds, the viscosity is too high and the processability is lowered, and for example, when a film is produced, it is difficult to obtain a uniform film. Such intrinsic viscosity [η] can be measured as follows. That is, first, N, N-dimethylacetamide is used as a solvent, and the polyamic acid is dissolved in the N, N-dimethylacetamide so as to have a concentration of 0.5 g / dL, and a measurement sample (solution) is obtained. obtain. Next, using the measurement sample, the viscosity of the measurement sample is measured using a kinematic viscometer under a temperature condition of 30 ° C., and the obtained value is adopted as the intrinsic viscosity [η]. As such a kinematic viscometer, THOMAS SCIENTIFIC CO. The brand name “KINEMATIC VISCOMETER TV-5S” manufactured by the company is used.

  In addition, when the polyimide obtained by this invention shall contain another repeating unit with the repeating unit represented by the said General formula (1), for example in process (I), the said General formula ( Using other tetracarboxylic dianhydrides together with the tetracarboxylic dianhydrides represented by 2), these may be reacted with the aromatic diamines represented by the above general formulas (301) to (311), Even if other aromatic diamines are used together with the aromatic diamines represented by the general formulas (301) to (311), these may be reacted with the tetracarboxylic dianhydride represented by the general formula (2). Furthermore, it is also possible to use a polyimide by appropriately utilizing both such other tetracarboxylic dianhydrides and other aromatic diamines. As such other tetracarboxylic dianhydrides and other aromatic diamines, known ones used for the production of polyimide can be used as appropriate.

(Step (II): Step of obtaining polyimide)
In step (II), the polyamic acid is chemically imidized using a condensing agent in the polymerization solvent, whereby the repeating unit represented by the general formula (1) in the polymerization solvent is based on all repeating units. This is a step of precipitating a polyimide containing 50 mol% or more to obtain the polyimide.

  “Chemical imidation” as used herein refers to dehydration of polyamic acid using a dehydration condensing agent (carboxylic anhydride, carbodiimide, acid azide, active esterifying agent, etc.) and a reaction accelerator (tertiary amine, etc.). Ring closure means imidization. By utilizing such chemical imidation, it is not always necessary to heat to high temperature during imidation, and imidization is performed under low temperature conditions (more preferably, about 100 ° C. or less) to obtain polyimide. It becomes possible.

  The polymerization solvent used in the step (II) is the same as that described in the step (I). Therefore, after carrying out the step (I), the polyamic acid having the repeating unit represented by the general formula (4) is not isolated and is represented by the general formula (2) in a polymerization solvent (organic solvent). The reaction liquid obtained by reacting the tetracarboxylic dianhydride produced with the aromatic diamine represented by the general formulas (301) to (311) (repeating the repeating unit represented by the general formula (4) above) You may use the reaction liquid containing the polyamic acid which has it for process (II) as it is. In addition, after carrying out the step (I), the polyamic acid having the repeating unit represented by the general formula (4) is isolated, and separately the repeating unit represented by the general formula (4) in the polymerization solution. It may be used by adding a polyamic acid having.

  In addition, the condensing agent used in the step (II) may be any condensing agent that can be used when the polyamic acid is condensed to form a polyimide, and in combination with a reaction accelerator described later, A known compound used as an “imidating agent” can be appropriately used. Such a condensing agent is not particularly limited, and examples thereof include carboxylic anhydrides such as acetic anhydride, propionic anhydride and trifluoroacetic anhydride, carbodiimides such as N, N′-dicyclohexylcarbodiimide (DCC), and diphenyl phosphoric acid. Examples thereof include acid azides such as azide (DPPA), active esterifying agents such as Castro reagent, and dehydrating condensation agents such as 2-chloro-4,6-dimethoxytriazine (CDMT). Among such condensing agents, acetic anhydride, propionic anhydride, and trifluoroacetic anhydride are preferable, acetic anhydride and propionic anhydride are more preferable, and acetic anhydride is still more preferable from the viewpoint of reactivity, availability, and practicality. Such condensing agents may be used alone or in combination of two or more.

  The reaction accelerator is not particularly limited as long as it can be used when the polyamic acid is condensed to form a polyimide, and a known compound can be appropriately used. Such a reaction accelerator can also function as an acid scavenger that supplements the acid by-produced during the reaction. Therefore, by using such a reaction accelerator, acceleration of the reaction and the reverse reaction due to the by-product acid are suppressed, and the reaction can proceed efficiently. Such a reaction accelerator is not particularly limited, but more preferably also serves as an acid scavenger, such as triethylamine, diisopropylethylamine, N-methylpiperidine, pyridine, collidine, lutidine, 2-hydroxypyridine, Tertiary amines such as 4-dimethylaminopyridine (DMAP), 1,4-diazabicyclo [2.2.2] octane (DABCO), diazabicyclononene (DBN), diazabicycloundecene (DBU) be able to. Among such reaction accelerators, triethylamine, diisopropylethylamine, N-methylpiperidine, and pyridine are preferable from the viewpoint of reactivity, availability, and practicality, triethylamine, pyridine, and N-methylpiperidine are more preferable, and triethylamine, N -More preferred is methylpiperidine. Such reaction accelerators may be used alone or in combination of two or more.

  Also, for example, by adding a catalytic amount of a reaction accelerator (DMAP, etc.) and an azeotropic dehydrating agent (benzene, toluene, xylene, etc.), water generated when the polyamic acid becomes an imide is removed by azeotropic dehydration. It may be imidized. Thus, in the chemical imidization, an azeotropic dehydrating agent may be appropriately used together with the reaction accelerator. Such an azeotropic dehydrating agent is not particularly limited, and may be appropriately selected from known azeotropic dehydrating agents according to the type of material used in the reaction.

  Moreover, when performing chemical imidization using such a condensing agent and a reaction accelerator, from the viewpoint of more efficiently producing polyimide, after carrying out step (I), the above general formula (4) The tetracarboxylic dianhydride represented by the above general formula (2) and the above general formulas (301) to (311) in a polymerization solvent (organic solvent) without isolating the polyamic acid having a repeating unit represented. The reaction solution obtained by reacting with the aromatic diamine represented by formula (4) is used as it is and condensed to the reaction solution. It is more preferable to employ a method of imidizing by adding an agent (imidizing agent).

  Further, the temperature condition during such chemical imidation is preferably −40 ° C. to 200 ° C., more preferably −20 ° C. to 150 ° C., and further preferably 0 to 150 ° C. 50 to 100 ° C. is particularly preferable. If such a temperature exceeds the upper limit, an undesirable side reaction tends to proceed and polyimide cannot be obtained. On the other hand, if the temperature is lower than the lower limit, the reaction rate of chemical imidation decreases or the reaction itself does not proceed. Tend not to be obtained. As described above, in the present invention, since imidization can be performed in a relatively low temperature range of −40 ° C. to 200 ° C., it is possible to reduce the environmental load, and in the manufacturing process. Can also be advantageous.

  The reaction time for such chemical imidation is preferably 0.1 to 48 hours. If the reaction temperature or time is less than the lower limit, it is difficult to sufficiently imidize, and it tends to be difficult to deposit polyimide in the polymerization solvent. On the other hand, if the upper limit is exceeded, the polymer is deteriorated. There is a tendency that the mixing probability of the substance (oxygen, etc.) to be increased increases and the molecular weight decreases.

  The amount of such a condensing agent is not particularly limited, but is preferably 0.05 to 4.0 mol, preferably 1 to 2 mol, based on 1 mol of the repeating unit in the polyamic acid. Is more preferable. If the amount of such a condensing agent (imidizing agent) is less than the lower limit, the reaction rate of chemical imidization tends to decrease, or the reaction itself does not proceed sufficiently and polyimide cannot be obtained sufficiently, When the upper limit is exceeded, an undesirable side reaction proceeds, and thus polyimide cannot be obtained efficiently.

  The amount of the reaction accelerator used is not particularly limited, but is preferably 0.05 to 4.0 mol, preferably 1 to 2 mol, per 1 mol of the repeating unit in the polyamic acid. Further preferred. If the amount of the reaction accelerator used is less than the lower limit, the reaction rate of chemical imidization decreases, or the reaction itself does not proceed sufficiently and polyimide cannot be obtained sufficiently. On the other hand, it exceeds the upper limit. As a result, an undesirable side reaction proceeds, and thus polyimide cannot be obtained efficiently.

  In addition, as atmospheric conditions for performing such chemical imidization, from the viewpoint of preventing coloring due to oxygen in the air and molecular weight reduction due to water vapor in the air, an inert gas atmosphere such as nitrogen gas or under vacuum It is preferable that Moreover, it does not restrict | limit especially as pressure conditions at the time of performing such chemical imidation, However, It is preferable that it is 0.01 hPa-1 MPa, and it is more preferable that it is 0.1 hPa-0.3 MPa. If such pressure is less than the lower limit, the solvent, the condensing agent, and the reaction accelerator are gasified, the stoichiometry is lost, the reaction is adversely affected, and the reaction tends to be difficult to proceed sufficiently. On the other hand, when the above upper limit is exceeded, undesirable side reactions proceed or the solubility of the polyamic acid is lowered and tends to precipitate before imidization.

  In this way, polyamic acid containing 50 mol% or more of the repeating unit represented by the general formula (4) with respect to all repeating units is chemically imidized using a condensing agent in the polymerization solvent. By this, the polyimide which contains 50 mol% or more of repeating units represented by the said General formula (1) with respect to all the repeating units in the said polymerization solvent is deposited. Thus, in this invention, chemical imidation is fully advanced so that a polyimide precipitates in the said polymerization solvent.

  In addition, the polyimide which contains 50 mol% or more of repeating units represented by the general formula (1) with respect to all repeating units basically allows the above-mentioned polymerization solvent (organic) to sufficiently proceed through chemical imidization. The solubility in the solvent is changed and becomes insoluble. The present inventors presume that this is a phenomenon caused by the change in solubility in the polymerization solvent depending on the degree of imidization, molecular weight, and the like. That is, although the reason why polyimide precipitates from the polymerization solvent is not necessarily clear, the present inventors infer one reason why precipitation occurs as follows. In general, it is known that the higher the linearity of the polymer, the lower the solvent solubility. Therefore, the polyamic acid having low linearity basically dissolves in the polymerization solvent. However, when the polyamic acid is chemically imidized, as the polyamic acid is chemically imidized, the polymer formed has linearity, resulting in high linearity that is insoluble in the solvent and precipitation. We speculate that this will happen. Therefore, the polyimide formed in the middle stage of the reaction (one that is in the middle of the reaction and imidation has not progressed sufficiently) has a low imidation ratio, etc., and its characteristics are mainly those of polyamic acid. Therefore, it is considered that it dissolves in the polymerization solvent in the same manner as the polyamic acid. However, when the chemical imidization is sufficiently advanced, the imidization rate is improved, and the The present inventors infer that the polyimide is deposited. Moreover, since the solubility to the polymerization solvent of a polyimide will fall when molecular weight becomes large, the present inventors guess that a polyimide precipitates more easily from the said polymerization solvent. Thus, since polyimide is dissolved or insoluble in the polymerization solvent depending on the degree of molecular weight and imidization rate, it is preferable that chemical imidation proceeds sufficiently until the polyimide is sufficiently precipitated. . In the present specification, “polyimide is insoluble in the polymerization solvent” means that the amount of polyimide dissolved in the polymerization solvent under the temperature condition of 25 ° C. is less than 0.01% by mass. Say. That is, in the present invention, the term “polyimide is insoluble in the polymerization solvent” means a state in which dissolution of 0.01% by mass or more of polyimide cannot be confirmed under a temperature condition of 25 ° C. The amount of polyimide dissolved can be calculated from the amount charged and the amount remaining after charging a small piece of polyimide or powder into the polymerization solvent. In addition, since the polyimide insoluble in the polymerization solvent can be deposited using such chemical imidization, for example, the polyimide can be separated and stored only by a simple method such as filtration, so that the polyamic acid is stored. There is no need to employ a reprecipitation operation as sometimes.

Further, with respect to polyimide obtained by chemical imidization in this manner, ^R 1 in the formula ^{(1), R 2, R 3, R} 10 and n, ^{R 1} of each of the above general formula (4) , R ² , R ³ , R ¹⁰ and n. Thus, the repeating unit represented by the general formula (1) in the polyimide obtained by chemical imidization in the present invention is represented by the general formula (1) described in the polyimide of the present invention. The same as the repeating unit.

  Further, the polyimide obtained by chemical imidization in this manner is a polyimide containing 50 mol% or more of the repeating unit represented by the general formula (1) with respect to all repeating units. When the content ratio of the repeating unit represented by the general formula (1) is less than the lower limit, the solubility in the casting solvent tends to be lowered. Further, from the viewpoint of solubility in the casting solvent, the content ratio of the repeating unit represented by the general formula (1) is more preferably 70 mol% or more with respect to all the repeating units, and 90 to 100 More preferably, it is mol%, and particularly preferably 100 mol%. In addition, the content rate of such a repeating unit is represented by the tetracarboxylic dianhydride represented by the said General formula (2) and the said General Formula (301)-(311) in the case of manufacture of a polyimide. By appropriately adjusting the amount of the aromatic diamine used, it can be easily within the above range.

  Furthermore, in this invention, the polyimide to deposit can also be made into a powder form by chemically imidating the said polyamic acid in the said polymerization solvent using the said condensing agent and the said reaction accelerator. Therefore, in the step of obtaining the polyimide (step (II)), the polyimide can be efficiently recovered by a simple method such as filtration. And from a viewpoint of obtaining a polyimide more efficiently, it is preferable to collect | recover the said polyimide precipitated in the said polymerization solvent by filtration in the process (process (II)) of obtaining the said polyimide. In addition, the polyimide thus obtained can be used as necessary with a solvent (for example, DMAc, NMP, DMF, DMSO, water, methanol, ethanol, propanol, isopropanol, acetone, hexane, ethyl acetate, toluene, acetic acid, etc. May be appropriately washed using a solvent. By such a washing step, it is possible to remove amine salts generated by chemical imidization and low molecular weight polymers. Moreover, you may perform a drying process suitably for the polyimide obtained in this way as needed. Specific conditions and methods for such a drying step are not particularly limited, and known conditions and methods can be appropriately employed.

  The powdery polyimide thus obtained (polyimide powder) preferably has an average particle diameter of 1 to 1000 μm, more preferably 10 to 500 μm. The polyimide thus obtained is preferably a polyimide having an imidization ratio of 90% or more, more preferably 95% or more, and particularly preferably 96 to 100%.

  In addition, when the polyamic acid is chemically imidized using the condensing agent and the reaction accelerator in the polymerization solvent to obtain a powdered polyimide, it should be stored in the form of powder or pellets. It is also possible to make the storage stability higher. When chemical imidization is used, it is possible to obtain a powdery polyimide more efficiently than when thermal imidization is employed. That is, using a varnish (polyamic acid solution) obtained by solution polymerization of acid dianhydride and diamine, removing (drying) the solvent and then thermally imidizing at high temperature to produce polyimide, so-called thermal imidization When it is used, it is not always easy to obtain a powdery polyimide directly from the production process, but when chemical imidization is used, a powdery polyimide is produced more efficiently. It is possible. From this point of view, the present invention can also be used as a method for producing a polyimide that is superior in storage stability (storage property).

  Moreover, the above-mentioned polyimide of the present invention can be produced by the polyimide production method of the present invention. Therefore, the manufacturing method of the polyimide of this invention can be utilized suitably as a method for manufacturing the said polyimide of this invention.

  In addition, by the production method of the polyimide of the present invention, the resulting polyimide can be dissolved in the cast solvent, and since it exists as a stable polyimide before dissolution in the cast solvent, It can be stored (stored) for a long period of time. In addition, since such polyimide is dissolved in a cast solvent such as methylene chloride (boiling point: 40 ° C.) or chloroform (boiling point: 62 ° C.), it is dissolved in those solvents and applied to a substrate such as glass, and is about room temperature. A polyimide film can be easily obtained by removing (drying) the solvent even at a low temperature. In the process of producing the final product, heat treatment at a high temperature of about 250 ° C. or higher (for example, in the case of thermal imidization) In some cases, heating at about 400 ° C. may be employed. Therefore, for example, the polyimide is a polyimide film used for various applications (for example, flexible wiring board film, heat-resistant insulating tape, electric wire enamel, semiconductor protective coating agent, liquid crystal alignment film, transparent conductive film for organic EL, organic EL lighting film, flexible substrate film, flexible organic EL substrate film, flexible transparent conductive film, organic thin film solar cell transparent conductive film, dye-sensitized solar cell transparent conductive film, flexible gas barrier film, touch panel Film, a flexible display front film, a flexible display back film, etc.).

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example.

  First, the evaluation method of the characteristics (linear expansion coefficient etc.) of the polyimide which forms the film obtained by each Example and each comparative example is demonstrated.

<Identification of molecular structure>
Identification of the molecular structure of the compound obtained in each Example etc. is carried out by IR measuring machine (manufactured by JASCO Corporation, trade names: FT / IR-460, FT / IR-4100) and NMR measuring machine (JEOL Ltd.). (Trade name: JNM-Lambda500), and IR and NMR spectra were measured.

<Measurement of imidization ratio>
The imidation ratio in the compounds obtained in each example was measured as follows. That is, first, using a sample obtained by dissolving 2 mg of the compound obtained in each example or the like in 2 g of deuterated chloroform, an NMR spectrum was measured with an NMR measuring instrument (trade name: JNM-Lambda500, manufactured by JEOL Ltd.). Then, an integrated value of H of NH in the vicinity of 10 ppm (10 ppm ± 1 ppm) and H of COOH in the vicinity of 12 ppm (12 ppm ± 1 ppm) was determined by ¹ H-NMR graph. Next, 2 mg of acid dianhydride of the raw material compound of the polyimide to be measured and 2 mg of diamine (aromatic diamine) of the raw material compound of the polyimide to be measured were respectively added to 1 g of heavy DMSO (DMSO-d ₆ ) (acid dianhydride). Samples dissolved in 1 g (amount used relative to diamine) were prepared, respectively, and were measured using an NMR measuring instrument (trade name: JNM-Lambda500, manufactured by JEOL Ltd.). The NMR spectra of the anhydride and the starting compound diamine were respectively measured, and from the obtained ¹ H-NMR graph, the position of H of the acid dianhydride (chemical shift) and the integrated value, and the position of H of the diamine (chemical shift) ) And the integral value, respectively, and the position of H of the acid dianhydride (chemical shift), the integral value, and the position of H of the diamine (chemical G) and using an integral value as a reference, the integral value of H of COOH integral value and around 12ppm of N-H of the H of 10ppm vicinity of the graph of ¹ H-NMR of Compound obtained in each Example or the like Using these ratios, the imidation ratio was calculated by comparing them relative to each other.

<Measurement of intrinsic viscosity [η]>
As described above, the intrinsic viscosity [η] of the polyamic acid obtained as an intermediate when producing the compound obtained in each example or the like was measured using the THOMAS SCIENTIFIC CO. Using “KINEMATIC VISCOMETER TV-5S” manufactured by the company, measurement was performed at a temperature of 30 ° C. using a measurement sample having a concentration of 0.5 g / dL using N, N-dimethylacetamide as a solvent.

<Measurement of molecular weight and molecular weight distribution of polyimide>
The molecular weights (Mw and Mn) and molecular weight distributions (Mw / Mn) of the compounds obtained in each example and the like are measured by gel permeation chromatography (GPC) measuring device (Degasser: DG-2080-54 manufactured by JASCO, liquid feeding Pump: JASCO PU-2080, Interface: JASCO LC-Net II / ADC, Column: Shodex GPC column KF-806M (× 2), Column oven: JASCO 860-CO, RI detector : RI-2031 manufactured by JASCO, column temperature of 40 ° C., and data obtained by using chloroform solvent (flow rate 1 mL / min.) Were converted to polystyrene, and a calibration curve was prepared by GPC measurement using a standard polystyrene sample. Is dissolved in chloroform and adjusted to 0.25 wt% After filtration through a membrane filter (ADVANTEC, PTFE), measurement was performed to prepare a calibration curve.Sample measurement was performed by dissolving a polyimide film in chloroform, preparing a 0.5 wt% solution, filtering through a membrane filter, and then measuring. Went.

<Measurement of linear expansion coefficient>
For the linear expansion coefficient of the compound obtained in each example, first, a film similar to the polyimide film (length: 75 mm, width 50 mm, thickness 13 μm) produced in each example was prepared. A dry film obtained by vacuum drying (120 ° C., 1 hour (Hr)) and then heat-treated at 200 ° C. for 1 hour (Hr) in a nitrogen atmosphere is used as a measurement sample, and heat is used as a measurement device. Using a mechanical analysis device (trade name “TMA8310” manufactured by Rigaku), employing a tension mode (49 mN) under a nitrogen atmosphere and a temperature rising rate of 5 ° C./min, the temperature at 50 ° C. to 200 ° C. It measured by measuring the change of the length of a sample and calculating | requiring the average value of the change of the length per 1 degreeC in the temperature range of 50 to 200 degreeC.

<Measurement of 5% weight loss temperature>
The 5% weight loss temperature of the compound obtained in each example, etc., was measured using a thermogravimetric analyzer (“TG / DTA220” manufactured by SII Nanotechnology Co., Ltd.) using the polyimide film produced in each example. And from room temperature (25 ° C.) to 10 ° C./min. The temperature was determined by measuring the temperature at which the weight of the sample used was reduced by 5%.

<Measurement of glass transition temperature (Tg)>
As for the glass transition temperature (Tg) of the compound obtained in each example etc., a differential scanning calorimeter (“DSC220” manufactured by SII Nano Technology Co., Ltd.) is used using the polyimide film produced in each example. Then, while flowing nitrogen gas (in a nitrogen atmosphere), the temperature rising rate was 10 ° C./min. From room temperature (25 ° C.). , Temperature drop rate 30 ° C / min. It measured on condition of this.

<Measurement of total light transmittance>
The total light transmittance is measured in accordance with JIS K7361-1 using the polyimide film produced in each example and using a trade name “Haze Meter NDH-5000” manufactured by Nippon Denshoku Industries Co., Ltd. as a measuring device. Determined by doing.

<Evaluation of solubility in casting solvent>
The compound (2 mg) obtained in each Example etc. was put into a 5 cc glass vial with a lid, and methylene chloride (1 g) was added thereto, and the lid was capped. The mixture was allowed to stand for about 1 hour, and the solubility in methylene chloride was judged under a temperature condition of 25 ° C. Further, the same method was employed except that chloroform (1 g) was used instead of methylene chloride (1 g), and the solubility of the compound (2 mg) obtained in each Example etc. in chloroform (1 g) was 25 ° C. The temperature was determined under the following conditions. Further, the degree of solubility was determined based on the following criteria A to C.
A: All are dissolved, solid cannot be confirmed in the polyimide solution, and has a sufficiently high solubility.
B: Although a solid remains in the polyimide solution, the concentration of the polyimide solution (dissolved amount of the polyimide) is 0.1% by mass or more (about half of the pre-test is dissolved) from the remaining amount, and is sufficiently dissolved. Have sex.
C: Solid remains in the polyimide solution, and from the remaining amount, the concentration of the polyimide solution (polyimide dissolution amount) is less than 0.01% by mass, and there is no solubility (no change from the shape before the test).

Example 1
<Preparation process of tetracarboxylic dianhydride>
In accordance with the method described in Synthesis Example 1, Example 1 and Example 2 of International Publication No. 2011/099518, the following general formula (8):

Tetracarboxylic dianhydride represented by the formula (norbornane-2-spiro-α-cyclopentanone-α′-spiro-2 ″ -norbornane-5,5 ″, 6,6 ″ -tetracarboxylic acid dianhydride Anhydride) was prepared.

<Preparation process of polyamic acid>
First, a 30 ml three-necked flask was heated with a heat gun and sufficiently dried. Next, the atmosphere gas in the three-necked flask that was sufficiently dried was replaced with nitrogen, and the inside of the three-necked flask was changed to a nitrogen atmosphere. Next, 0.1802 g of 3,4'-diaminodiphenyl ether as an aromatic diamine (0.90 mmol: manufactured by Nichijun Chemical Co., Ltd .: 3,4'-DDE, represented by the above general formula (301) in the three-necked flask. After adding 2.7 g of N, N-dimethylacetamide as a polymerization solvent and stirring, the aromatic diamine compound (3,4) is added to the N, N-dimethylacetamide. A solution in which '-DDE) was dissolved was obtained.

  Next, 0.3359 g (0.90 mmol) of the compound represented by the general formula (8) was added to the three-necked flask containing the solution under a nitrogen atmosphere, and then the room temperature (25 ° C. under a nitrogen atmosphere) was added. ) For 12 hours to obtain a reaction solution. In this way, polyamic acid was formed in the reaction solution.

  A dimethylacetamide solution with a polyamic acid concentration of 0.5 g / dL was prepared using a part of the reaction solution (polyamic acid dimethylacetamide solution), and the reaction intermediate was prepared as described above. When the intrinsic viscosity [η] of a certain polyamic acid was measured, the intrinsic viscosity [η] of the polyamic acid was 0.54.

<Polyimide preparation process>
Using half (half amount) of the reaction solution obtained in the preparation step of the polyamic acid, N-methylpiperidine (0.90 mmol) as a reaction accelerator and acetic anhydride (2.70 mmol) as a condensing agent were used. ) And the resulting mixture was stirred at a temperature of 70 ° C. for 30 minutes. By such stirring for 30 minutes, a white precipitate (powder) was formed in the mixed solution. Thereafter, a white precipitate (powder) was recovered from the mixture by filtration, and the obtained white precipitate was first washed with N, N-dimethylacetamide (2 ml), and then methanol (2 ml × 2). Washed twice). After washing in this manner, the resulting precipitate was placed in a vacuum dryer and dried overnight (12 hours) under the conditions of 60 ° C. and 1 hPa to obtain a white powder (average particle size 10 μm).

In order to identify the molecular structure of the compound thus obtained as a white powder, an IR spectrum was measured. The obtained IR spectrum is shown in FIG. As is apparent from the results shown in FIG. 1, since the C═O stretching vibration of imide was observed at 1711.5 cm ⁻¹ , it was confirmed that the obtained compound was polyimide.

  Moreover, as a result of measuring the yield of the obtained white powder (polyimide), it was confirmed that the yield was 0.242 g (98% yield). In addition, when the white powder (polyimide) was dissolved in deuterated chloroform and the imidization rate was measured by NMR, the imidation rate of the obtained polyimide was 96%. As a result of such NMR measurement, NMR spectra are shown in FIGS. In addition, the number average molecular weight (Mn) of the obtained polyimide was 16000, the weight average molecular weight (Mw) was 28000, and molecular weight distribution (Mw / Mn) was 1.79.

In addition, the obtained polyimide is a repeating unit represented by the above general formula (1) (R ¹ , R ² , R ³ in the formula are all hydrogen atoms, and n is 2 from the type of monomer used). And the content of R ¹⁰ is a repeating unit which is a group represented by the above general formula (101) was 100 mol% of polyimide with respect to all repeating units. The amount of polyimide remaining in the mixed solution (filtrate after filtration) after collecting white precipitate (powder) was confirmed by GPC. The amount of polyimide remaining under the temperature condition of 25 ° C. Since (dissolution amount) was below the detection limit and the dissolution amount was less than 0.01% by mass, the obtained polyimide was insoluble in N, N-dimethylacetamide (DMAc). (It has fully precipitated). Table 1 shows the evaluation results of the imidization ratio of the obtained polyimide and the solubility in the cast solvent.

<Preparation process of polyimide film>
The compound (polyimide: white powder) obtained as described above was dissolved in methylene chloride to a concentration of 10% by mass to obtain a polyimide solution (coating solution). Next, the polyimide solution is spin-coated on a glass plate (length: 75 mm, width 50 mm, thickness 1.3 mm) so that the thickness of the coating film after drying is 13 μm, and the coating film is formed on the glass plate. Formed. Thereafter, the glass plate on which the coating film was formed was placed on a hot plate at 40 ° C. and allowed to stand for 2 hours to remove the solvent from the coating film. Next, the glass plate with the coating film was immersed in hot water at 90 ° C., and the polyimide film (length: 75 mm, width 50 mm, thickness 13 μm) was peeled from the glass plate and recovered. Thus, a polyimide film (length: 75 mm, width 50 mm, thickness 13 μm) was obtained. Subsequently, the characteristics (glass transition temperature (Tg) etc.) of polyimide were evaluated using the obtained polyimide film. The obtained results are shown in Table 1. The polyimide was soluble in dichloroethane.

(Example 2)
In the polyamic acid preparation step, as an aromatic diamine, instead of using 3,4′-diaminodiphenyl ether, 0.1802 g of 4,4′-diaminodiphenyl ether (0.90 mmol: manufactured by Tokyo Chemical Industry Co., Ltd .: 4,4′-DDE) A polyimide (white powder: average particle diameter of 11 μm) was obtained by employing the same method as in Example 1 except that the aromatic diamine represented by the general formula (302) was used. In addition, the molecular structure of the solid content (powder) obtained in the same manner as in Example 1 was identified and confirmed to be polyimide. It was also found that such polyimide was insoluble in N, N-dimethylacetamide (DMAc) as in Example 1. Table 1 shows the evaluation results of the solubility of the obtained polyimide in the casting solvent and the imidization ratio. In addition, when the molecular weight of the obtained polyimide was measured, the number average molecular weight (Mn) was 28000, the weight average molecular weight (Mw) was 55000, and molecular weight distribution (Mw / Mn) was 1.96.

  In addition, as the obtained compound (white powder), the same process as the polyimide film preparation process employed in Example 1 was adopted except that the polyimide (white powder) obtained in this example was used. A polyimide film (length: 75 mm, width 50 mm, thickness 13 μm) was prepared. Using such a polyimide film, the characteristics of the polyimide (such as glass transition temperature (Tg)) were evaluated, and the obtained results are shown in Table 1.

Example 3
In the preparation process of polyamic acid, instead of using 3,4'-diaminodiphenyl ether as an aromatic diamine, 0.2631 g (0.90 mmol: manufactured by Tokyo Chemical Industry Co., Ltd .: 1) instead of using 3,4′-diaminodiphenyl ether , 3,3-BAB, an aromatic diamine represented by the above general formula (303)), a polyimide (white powder: average particle size 13 μm) was adopted in the same manner as in Example 1. Obtained. In addition, the molecular structure of the solid content (powder) obtained in the same manner as in Example 1 was identified and confirmed to be polyimide. It was also found that such polyimide was insoluble in N, N-dimethylacetamide (DMAc) as in Example 1. Table 1 shows the evaluation results of the solubility of the obtained polyimide in the casting solvent and the imidization ratio. In addition, when the molecular weight of the obtained polyimide was measured, the number average molecular weight (Mn) was 22000, the weight average molecular weight (Mw) was 37000, and molecular weight distribution (Mw / Mn) was 1.68.

  In addition, as the obtained compound (white powder), the same process as the polyimide film preparation process employed in Example 1 was adopted except that the polyimide (white powder) obtained in this example was used. A polyimide film (length: 75 mm, width 50 mm, thickness 13 μm) was prepared. Using such a polyimide film, the characteristics of the polyimide (such as glass transition temperature (Tg)) were evaluated, and the obtained results are shown in Table 1.

Example 4
In the preparation process of polyamic acid, instead of using 3,4′-diaminodiphenyl ether as an aromatic diamine, 0.2631 g (0.90 mmol: Wakayama Seika Kogyo Co., Ltd.) is used instead of 3,4′-diaminodiphenyl ether. : 1,3,4-BAB, except that the aromatic diamine represented by the above general formula (304) was used, a polyimide (white powder: average particle size of 12 μm) was adopted in the same manner as in Example 1. ) In addition, the molecular structure of the solid content (powder) obtained in the same manner as in Example 1 was identified and confirmed to be polyimide. It was also found that such polyimide was insoluble in N, N-dimethylacetamide (DMAc) as in Example 1. Table 1 shows the evaluation results of the solubility of the obtained polyimide in the casting solvent and the imidization ratio. In addition, when the molecular weight of the obtained polyimide was measured, the number average molecular weight (Mn) was 20000, the weight average molecular weight (Mw) was 36000, and the molecular weight distribution (Mw / Mn) was 1.80.

  In addition, as the obtained compound (white powder), the same process as the polyimide film preparation process employed in Example 1 was adopted except that the polyimide (white powder) obtained in this example was used. A polyimide film (length: 75 mm, width 50 mm, thickness 13 μm) was prepared. Using such a polyimide film, the characteristics of the polyimide (such as glass transition temperature (Tg)) were evaluated, and the obtained results are shown in Table 1.

(Example 5)
In the polyamic acid preparation step, instead of using 3,4′-diaminodiphenyl ether as an aromatic diamine, 0.2631 g (0.90 mmol: manufactured by Tokyo Chemical Industry Co., Ltd .: 1) instead of using 3,4′-diaminodiphenyl ether , 4, 4-BAB, except that the aromatic diamine represented by the above general formula (305) is used, a polyimide (white powder: average particle size of 14 μm) is adopted in the same manner as in Example 1. Obtained. In addition, the molecular structure of the solid content (powder) obtained in the same manner as in Example 1 was identified and confirmed to be polyimide. It was also found that such polyimide was insoluble in N, N-dimethylacetamide (DMAc) as in Example 1. Table 1 shows the evaluation results of the solubility of the obtained polyimide in the casting solvent and the imidization ratio. In addition, when the molecular weight of the obtained polyimide was measured, the number average molecular weight (Mn) was 30000, the weight average molecular weight (Mw) was 60000, and molecular weight distribution (Mw / Mn) was 2.00.

  In addition, as the obtained compound (white powder), the same process as the polyimide film preparation process employed in Example 1 was adopted except that the polyimide (white powder) obtained in this example was used. A polyimide film (length: 75 mm, width 50 mm, thickness 13 μm) was prepared. Using such a polyimide film, the characteristics of the polyimide (such as glass transition temperature (Tg)) were evaluated, and the obtained results are shown in Table 1.

(Example 6)
In the preparation process of polyamic acid, instead of using 3,4′-diaminodiphenyl ether as an aromatic diamine, 0.3695 g (0.90 mmol: Tokyo Kasei) of 2,2-bis [4- (4-aminophenoxy) phenyl] propane was used. A polyimide (white powder: average particle diameter of 11 μm) is obtained by adopting the same method as in Example 1 except that: manufactured by BAPP Co., Ltd., BAPP, the aromatic diamine represented by the above general formula (306) is used. It was. In addition, the molecular structure of the solid content (powder) obtained in the same manner as in Example 1 was identified and confirmed to be polyimide. It was also found that such polyimide was insoluble in N, N-dimethylacetamide (DMAc) as in Example 1. Table 1 shows the evaluation results of the solubility of the obtained polyimide in the casting solvent and the imidization ratio. In addition, when the molecular weight of the obtained polyimide was measured, the number average molecular weight (Mn) was 24000, the weight average molecular weight (Mw) was 46000, and the molecular weight distribution (Mw / Mn) was 1.92.

  In addition, as the obtained compound (white powder), the same process as the polyimide film preparation process employed in Example 1 was adopted except that the polyimide (white powder) obtained in this example was used. A polyimide film (length: 75 mm, width 50 mm, thickness 13 μm) was prepared. Using such a polyimide film, the characteristics of the polyimide (such as glass transition temperature (Tg)) were evaluated, and the obtained results are shown in Table 1.

(Example 7)
In the preparation process of polyamic acid, instead of using 3,4'-diaminodiphenyl ether as an aromatic diamine, 0.4666 g (0.90 mmol: 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane was used. Made by Tokyo Chemical Industry Co., Ltd .: BAPF, except that the aromatic diamine represented by the above general formula (307) was used, a polyimide (white powder: average particle size of 12 μm) was adopted in the same manner as in Example 1. Got. In addition, the molecular structure of the solid content (powder) obtained in the same manner as in Example 1 was identified and confirmed to be polyimide. It was also found that such polyimide was insoluble in N, N-dimethylacetamide (DMAc) as in Example 1. Table 1 shows the evaluation results of the solubility of the obtained polyimide in the casting solvent and the imidization ratio. In addition, when the molecular weight of the obtained polyimide was measured, the number average molecular weight (Mn) was 15000, the weight average molecular weight (Mw) was 27000, and the molecular weight distribution (Mw / Mn) was 1.80.

  In addition, as the obtained compound (white powder), the same process as the polyimide film preparation process employed in Example 1 was adopted except that the polyimide (white powder) obtained in this example was used. A polyimide film (length: 75 mm, width 50 mm, thickness 13 μm) was prepared. Using such a polyimide film, the characteristics of the polyimide (such as glass transition temperature (Tg)) were evaluated, and the obtained results are shown in Table 1.

(Example 8)
In the polyamic acid preparation step, instead of using 3,4′-diaminodiphenyl ether as the aromatic diamine, 0.2882 g (0.90 mmol: 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl is used. Made by Tokyo Chemical Industry Co., Ltd .: Polyimide (white powder: average particle size 13 μm) using the same method as in Example 1 except that 6FDA, the aromatic diamine represented by the above general formula (309) was used. Got. In addition, the molecular structure of the solid content (powder) obtained in the same manner as in Example 1 was identified and confirmed to be polyimide. It was also found that such polyimide was insoluble in N, N-dimethylacetamide (DMAc) as in Example 1. Table 1 shows the evaluation results of the solubility of the obtained polyimide in the casting solvent and the imidization ratio. In addition, when the molecular weight of the obtained polyimide was measured, the number average molecular weight (Mn) was 28000, the weight average molecular weight (Mw) was 55000, and molecular weight distribution (Mw / Mn) was 1.96.

  In addition, as the obtained compound (white powder), the same process as the polyimide film preparation process employed in Example 1 was adopted except that the polyimide (white powder) obtained in this example was used. A polyimide film (length: 75 mm, width 50 mm, thickness 13 μm) was prepared. Using such a polyimide film, the characteristics of the polyimide (such as glass transition temperature (Tg)) were evaluated, and the obtained results are shown in Table 1.

Example 9
In the polyamic acid preparation step, as an aromatic diamine, instead of using 3,4'-diaminodiphenyl ether, 0.1911 g of m-tolidine (0.90 mmol: manufactured by Tokyo Chemical Industry Co., Ltd .: m-Tol, the above general formula (308) A polyimide (white powder: average particle diameter of 15 μm) was obtained by employing the same method as in Example 1 except that the aromatic diamine represented by the formula (1) was used. In addition, the molecular structure of the solid content (powder) obtained in the same manner as in Example 1 was identified and confirmed to be polyimide. It was also found that such polyimide was insoluble in N, N-dimethylacetamide (DMAc) as in Example 1. Table 1 shows the evaluation results of the solubility of the obtained polyimide in the casting solvent and the imidization ratio. In addition, when the molecular weight of the obtained polyimide was measured, the number average molecular weight (Mn) was 32000, the weight average molecular weight (Mw) was 53000, and molecular weight distribution (Mw / Mn) was 1.68.

  In addition, as the obtained compound (white powder), the same process as the polyimide film preparation process employed in Example 1 was adopted except that the polyimide (white powder) obtained in this example was used. A polyimide film (length: 75 mm, width 50 mm, thickness 13 μm) was prepared. Using such a polyimide film, the characteristics of the polyimide (such as glass transition temperature (Tg)) were evaluated, and the obtained results are shown in Table 1.

(Example 10)
In the polyamic acid preparation step, bis [4- (4-aminophenoxy) phenyl] sulfone 0.3892 g (0.90 mmol: Wakayama Seika Kogyo Co., Ltd.) is used instead of 3,4'-diaminodiphenyl ether as the aromatic diamine. Manufactured by: BAPS, except that the aromatic diamine represented by the above general formula (310) was used, the same method as in Example 1 was adopted to obtain polyimide (white powder: average particle size 12 μm). In addition, the molecular structure of the solid content (powder) obtained in the same manner as in Example 1 was identified and confirmed to be polyimide. It was also found that such polyimide was insoluble in N, N-dimethylacetamide (DMAc) as in Example 1. Table 1 shows the evaluation results of the solubility of the obtained polyimide in the casting solvent and the imidization ratio. In addition, when the molecular weight of the obtained polyimide was measured, the number average molecular weight (Mn) was 19000, the weight average molecular weight (Mw) was 33000, and molecular weight distribution (Mw / Mn) was 1.74.

  In addition, as the obtained compound (white powder), the same process as the polyimide film preparation process employed in Example 1 was adopted except that the polyimide (white powder) obtained in this example was used. A polyimide film (length: 75 mm, width 50 mm, thickness 13 μm) was prepared. Using such a polyimide film, the characteristics of the polyimide (such as glass transition temperature (Tg)) were evaluated, and the obtained results are shown in Table 1.

(Example 11)
In the preparation process of polyamic acid, instead of using 3,4'-diaminodiphenyl ether as an aromatic diamine, 0.3892 g (0.90 mmol: Wakayama Seika Kogyo Co., Ltd.) bis [4- (3-aminophenoxy) phenyl] sulfone Manufactured by: BAPS-M, except that the aromatic diamine represented by the above general formula (311) was used, the same method as in Example 1 was adopted to obtain polyimide (white powder: average particle size 14 μm). It was. In addition, the molecular structure of the solid content (powder) obtained in the same manner as in Example 1 was identified and confirmed to be polyimide. It was also found that such polyimide was insoluble in N, N-dimethylacetamide (DMAc) as in Example 1. Table 1 shows the evaluation results of the solubility of the obtained polyimide in the casting solvent and the imidization ratio. In addition, when the molecular weight of the obtained polyimide was measured, the number average molecular weight (Mn) was 17000, the weight average molecular weight (Mw) was 29000, and the molecular weight distribution (Mw / Mn) was 1.71.

  In addition, as the obtained compound (white powder), the same process as the polyimide film preparation process employed in Example 1 was adopted except that the polyimide (white powder) obtained in this example was used. A polyimide film (length: 75 mm, width 50 mm, thickness 13 μm) was prepared. Using such a polyimide film, the characteristics of the polyimide (such as glass transition temperature (Tg)) were evaluated, and the obtained results are shown in Table 1.

(Comparative Example 1)
In the preparation process of polyamic acid, instead of using 3,4′-diaminodiphenyl ether as the aromatic diamine, the following general formula (9):

A polyimide was obtained by employing the same method as in Example 1 except that 0.2045 g (0.90 mmol: manufactured by Nippon Pure Chemicals Co., Ltd .: DABAN) represented by formula (4) was used. . In addition, the molecular structure of the solid content (powder) obtained in the same manner as in Example 1 was identified and confirmed to be polyimide. It was also found that such polyimide was insoluble in N, N-dimethylacetamide (DMAc) as in Example 1. The evaluation results of the properties of the obtained polyimide are shown in Table 1.

(Comparative Example 2)
In the preparation process of the polyamic acid, instead of using 3,4'-diaminodiphenyl ether as the aromatic diamine, the following general formula (10):

The same method as in Example 1 was adopted except that 0.3316 g (0.90 mmol: manufactured by Nippon Pure Chemicals Co., Ltd .: APBP) represented by the formula 4,4′-bis (4-aminophenoxy) biphenyl was used. The polyimide was obtained. In addition, the molecular structure of the solid content (powder) obtained in the same manner as in Example 1 was identified and confirmed to be polyimide. It was also found that such polyimide was insoluble in N, N-dimethylacetamide (DMAc) as in Example 1. The evaluation results of the properties of the obtained polyimide are shown in Table 1.

(Comparative Example 3)
In the preparation process of polyamic acid, instead of using 3,4′-diaminodiphenyl ether as the aromatic diamine, the following general formula (11):

The same method as in Example 1 was used except that 0.2343 g (0.90 mmol: manufactured by Tokyo Chemical Industry Co., Ltd .: DATP) represented by Got. In addition, the molecular structure of the solid content (powder) obtained in the same manner as in Example 1 was identified and confirmed to be polyimide. It was also found that such polyimide was insoluble in N, N-dimethylacetamide (DMAc) as in Example 1. The evaluation results of the properties of the obtained polyimide are shown in Table 1.

(Comparative Example 4)
In the preparation process of polyamic acid, instead of using 3,4′-diaminodiphenyl ether as the aromatic diamine, the following general formula (12):

O-Toridine 0.1529 g (0.72 mmol: manufactured by Tokyo Chemical Industry Co., Ltd .: o-Tol) and 0.0360 g of 4,4′-diaminodiphenyl ether (0.18 mmol: manufactured by Tokyo Chemical Industry Co., Ltd .: 4, 4) A polyimide was obtained by employing the same method as in Example 1 except that a mixture with '-DDE) was used. In addition, the molecular structure of the solid content (powder) obtained in the same manner as in Example 1 was identified and confirmed to be polyimide. It was also found that such polyimide was insoluble in N, N-dimethylacetamide (DMAc) as in Example 1. Further, from the type of monomer used, the repeating unit represented by the general formula (1) (wherein R ¹ , R ² and R ³ are all hydrogen atoms, n is 2, R ¹⁰ is It turns out that the content rate of the repeating unit which is group represented by the said General formula (102) is a 20 mol% polyimide with respect to all the repeating units. The evaluation results of the properties of the obtained polyimide are shown in Table 1.

(Comparative Example 5)
In the preparation process of polyamic acid, instead of using 3,4′-diaminodiphenyl ether as the aromatic diamine, the following general formula (13):

P-phenylenediamine 0.0876 g (0.81 mmol: manufactured by Aldrich: PDA) and 0.0180 g (0.09 mmol: manufactured by Tokyo Chemical Industry Co., Ltd .: 4,4′-DDE) The polyimide was obtained by adopting the same method as in Example 1 except that the mixture was used. In addition, the molecular structure of the solid content (powder) obtained in the same manner as in Example 1 was identified and confirmed to be polyimide. It was also found that such polyimide was insoluble in N, N-dimethylacetamide (DMAc) as in Example 1. Further, from the type of monomer used, the repeating unit represented by the general formula (1) (wherein R ¹ , R ² and R ³ are all hydrogen atoms, n is 2, R ¹⁰ is It turns out that the content rate of the repeating unit which is group represented by the said General formula (102) is a 10 mol% polyimide with respect to all the repeating units. The evaluation results of the properties of the obtained polyimide are shown in Table 1.

  In Comparative Examples 1 to 5, since the obtained polyimide was not dissolved in methylene chloride, a polyimide film (measuring film) could not be prepared by the same method as used in Example 1. Therefore, in Comparative Examples 1 to 5, the 5% weight loss concentration, the glass transition temperature, the linear expansion coefficient, and the total light transmittance of the polyimide were prepared as follows. It was measured. That is, first, each of the reaction solutions obtained in the preparation steps of the polyamic acid in Comparative Examples 1 to 5 was used, and the reaction solution was dried on a glass plate (length: 75 mm, width 50 mm, thickness 1.3 mm). A coating film was formed by spin coating so that the thickness of the coating film was 13 μm. Then, after drying the glass plate on which the coating film was formed on a hot plate heated to 60 ° C. for about 2 hours, the glass plate was put into an inert oven, and in a nitrogen atmosphere (nitrogen flow rate 3 L / min.) At 140 ° C. After drying for 30 minutes, the coating film was cured by heating at 350 ° C. for 1 hour to form a polyimide film (thermally imidized film) on the glass plate. And the glass plate in which the said film was formed was taken out from inert oven, immersed in 90 degreeC hot water, the film was collect | recovered from the glass plate, and the polyimide film for a comparison was manufactured.

  Moreover, since the polyimide was insoluble in deuterated chloroform and chloroform, the imidation ratio, molecular weight, and molecular weight distribution of the polyimides obtained in Comparative Examples 1 to 5 could not be measured.

  In Table 1, “insoluble in DMAc (N, N-dimethylacetamide)” means that white precipitate (powder) remains (dissolves) in the mixed solution after filtration (filtrate after filtration). When the amount of polyimide is confirmed by GPC analysis at a temperature of 25 ° C., the polyimide concentration is less than 0.01% by mass.

  As is clear from the results shown in Table 1, in the polyimides (Examples 1 to 11) obtained by employing the polyimide production method of the present invention, low boiling point methylene chloride (dichloromethane), chloroform (trichloromethane). It was confirmed that it was dissolved in a sufficient concentration in a solvent such as) (a solvent used as a so-called casting solvent). Moreover, the polyimide (Examples 1-11) obtained by employ | adopting the manufacturing method of the polyimide of this invention melt | dissolves this in a methylene chloride (dichloromethane), makes a film, and can measure various characteristics. Since it was possible, it was confirmed that there was a sufficiently high workability after polyimide. In addition, since it can preserve | save in the state of the compound (polyimide) fully stabilized before processing compared with the varnish etc. of a polyamic acid, the polyimide (Example 1- 1) obtained by employ | adopting the polyimide manufacturing method of this invention 11) was found to be able to sufficiently prevent deterioration in quality even after long-term storage.

  On the other hand, none of the polyimides obtained in Comparative Examples 1 to 5 were soluble in methylene chloride (dichloromethane) and chloroform (trichloromethane), and could not be cast after being made into polyimide. . In Comparative Examples 4 to 5, although 4,4′-diaminodiphenyl ether (4,4′-DDE) was used as in Example 2, the amount used was 20 mol of the total amount of aromatic diamine. % (Comparative Example 4) and 10 mol% (Comparative Example 5), and the content of the repeating unit represented by the general formula (1) is 20 mol% with respect to all repeating units (Comparative Example 4). The present inventors infer that the solubility in methylene chloride (dichloromethane) and chloroform (trichloromethane) has not been sufficient due to the fact that it becomes 10 mol% (Comparative Example 5).

  Moreover, in the polyimide (Examples 1-11) obtained by employ | adopting the manufacturing method of the polyimide of this invention, the glass transition temperature is 250 degreeC or more and 5% weight reduction temperature becomes 459 degreeC or more. It was confirmed that it has sufficiently high heat resistance. Moreover, in the polyimide (Examples 1-11) obtained by employ | adopting the manufacturing method of the polyimide of this invention, the total light transmittance after film-forming is 87% or more, and it has sufficiently high transparency. It was also confirmed that it had. From these results, the polyimide film obtained in each example (polyimide film of the present invention: a film made of polyimide obtained by adopting the method for producing polyimide of the present invention) has high heat resistance and sufficient It turned out that it has transparency.

  From these results, the polyimides (Examples 1 to 11) obtained by adopting the method for producing polyimide according to the present invention have sufficiently high heat resistance and transparency and can be stored in the state of polyimide. In addition, it can be stored and used for a long period of time while maintaining sufficient quality, and further, since it has excellent solubility in cast solvents, it may have sufficiently high processability after long-term storage. I understood.

  Moreover, the polyimides (Examples 1 to 11) obtained by adopting the polyimide production method of the present invention have excellent solubility in cast solvents, and the solvent is removed from the coating film as described above. Since it was also possible to easily form a film, various shapes (for example, the shape of a thicker film (thick film), a block body, etc., in addition to the above-mentioned film, etc.) can be obtained by a simple process of removing the solvent. It can also be seen that it can be easily processed.

  As described above, according to the present invention, it has sufficiently high heat resistance and transparency, is sufficiently excellent in solubility in a casting solvent, and can be dissolved in a casting solvent and processed into various shapes. Yes, it has a sufficiently high processability, can be stored in the state of polyimide, can sufficiently prevent deterioration of quality after long-term storage, and can efficiently and reliably produce the polyimide It is possible to provide a method for producing a possible polyimide. Moreover, according to this invention, it also becomes possible to provide the polyimide film which consists of a polyimide solution obtained using the said polyimide, and the said polyimide.

  Therefore, the polyimide of the present invention is, for example, a flexible wiring board requiring high heat resistance, a heat-resistant insulating tape, a wire enamel, a semiconductor protective coating, a liquid crystal alignment film, an organic EL substrate, an organic EL transparent electrode substrate, Manufactures organic EL lighting films, organic EL TFT substrates, transparent electrode substrates for solar cells, transparent electrode substrates for electronic paper, various gas barrier film substrates, touch panel films, front films for flexible displays, back films for flexible displays, etc. It is particularly useful as a raw material for the purpose.

Claims (13)

The following general formula (1):
In Expression ^{(1), R 1, R} 2, R 3 are each independently a hydrogen atom, represents one selected from the group consisting of alkyl groups and fluorine atom having 1 to 10 carbon ^{atoms, R 10} is The following general formulas (101) to (111):
1 is selected from the groups represented by the formula: n represents an integer of 0-12. ]
The polyimide characterized by containing 50 mol% or more of the repeating unit represented by the above, and being soluble in the casting solvent.   2. The cast solvent according to claim 1, wherein the cast solvent is at least one selected from dichloromethane, trichloromethane, carbon tetrachloride, dichloroethane, trichloroethylene, tetrachloroethylene, tetrachloroethane, chlorobenzene, and o-dichlorobenzene. Polyimide.   The polyimide according to claim 1, wherein the polyimide has an imidization ratio of 90% or more. In the presence of a polymerization solvent, the following general formula (2):
[In the formula (2), R ¹ , R ² and R ³ each independently represents one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms and a fluorine atom, and n is 0. An integer of ~ 12 is shown. ]
And the following general formulas (301) to (311):
Is reacted with at least one aromatic diamine selected from the compounds represented by formula (4):
Wherein ^{(4), R 1, R} 2, R 3 are each independently a hydrogen atom, it represents one selected from the group consisting of alkyl groups and fluorine atom having 1 to 10 carbon ^{atoms, R 10} is The following general formulas (101) to (111):
1 is selected from the groups represented by the formula: n represents an integer of 0-12. ]
A step of obtaining a polyamic acid containing 50 mol% or more of the repeating units represented by
In the polymerization solvent, the polyamic acid is chemically imidized using a condensing agent and a reaction accelerator, whereby the following general formula (1):
In Expression ^{(1), R 1, R} 2, R 3, R 10 and n are respectively the same as ^{R 1, R 2, R 3} , R 10 and n in the general formula (4). ]
A step of precipitating polyimide containing 50 mol% or more of the repeating units represented by the following formula to obtain the polyimide;
The manufacturing method of the polyimide characterized by including.   The polymerization solvent is N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, dimethyl sulfoxide, pyridine, m-cresol, γ-butyrolactone, cyclopentanone, cyclohexanone and The method for producing a polyimide according to claim 4, wherein the polyimide is at least one organic solvent selected from tetrahydrofuran.   The method for producing a polyimide according to claim 4 or 5, wherein the condensing agent is at least one compound selected from acetic anhydride, propionic anhydride, and trifluoroacetic anhydride.   The reaction accelerator is at least one compound selected from triethylamine, diisopropylethylamine, N-methylpiperidine, and pyridine, according to any one of claims 4 to 6. Production method.   The method for producing a polyimide according to any one of claims 4 to 7, wherein a temperature condition in the chemical imidization is -20 ° C to 150 ° C.   The said polyimide is a polyimide whose imidation ratio is 90% or more, The manufacturing method of the polyimide as described in any one of Claims 4-8 characterized by the above-mentioned.   The method for producing a polyimide according to any one of claims 4 to 9, wherein, in the step of obtaining the polyimide, the polyimide deposited in the polymerization solvent is recovered by filtration.   A polyimide solution obtained by dissolving the polyimide according to any one of claims 1 to 3 in a casting solvent.   It is a film which consists of a polyimide as described in any one of Claims 1-3, The polyimide film characterized by the above-mentioned.   The polyimide film according to claim 12, wherein the film is obtained using the polyimide solution according to claim 11.