JP2016166336A - Dihydrofuran derivative composition, polyimide precursor composition and method for producing polyimide resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous composition of a polyimide precursor that is excellent in coatability and storage stability and also excellent in solvent resistance and water resistance of a cured product, and a method for producing a polyimide resin (cured product).SOLUTION: The present invention provides a polyimide precursor composition that comprises a dihydrofuran derivative represented by the formula (1), a polyamine represented by the formula (C), and an aqueous medium, and a method for producing polyimide resin characterized by heating the polyimide precursor composition for curing it.SELECTED DRAWING: None

Description

  The present invention relates to a dihydrofuran derivative composition, a polyimide precursor composition, and a method for producing a polyimide resin.

  Polyimide is one of the super engineering plastics. It boasts higher heat resistance than other polymer materials, and has extremely excellent performance in terms of mechanical strength and chemical resistance. In addition, since it has a low dielectric constant, excellent electrical insulation, excellent elongation characteristics, and a low thermal expansion coefficient, it has been widely used in industrial products such as an insulating layer of an electronic circuit and a binder carrying a conductive material.

  In general, polyimide has poor solubility in a solvent and is difficult to process, so it may be used in a composition containing a precursor and molded into a desired shape, and then heated to form a polyimide. Many.

  Such a composition is usually often handled through coating, and in order to avoid viscosity modification and precipitation that hinder the film-forming property during coating over time, a solvent with high polarity and high dissolving power is used. N-methyl-2-pyrrolidone, dimethyl sulfoxide, dimethylformamide, dimethylacetamide and the like are widely used. On the other hand, these solvents are pointed out as having large environmental burdens such as reproductive toxicity and generation of nitrogen oxides and sulfur oxides during incineration, and the problem is that they cannot be handled without special equipment and protective equipment.

  Since polyimide precursors are often unstable to water, it is difficult to maintain properties suitable for coating without causing gelation or precipitation when water-based compositions using water as a solvent or dispersion medium are used. Problems arise in processability and storage stability when the composition is applied and dried.

  However, aprotic polar solvents such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide and the like used as a medium for a composition containing a polyimide precursor are polar groups. It is a solvent with high environmental load, such as high skin permeability derived from, having biotoxicity, and generating nitrogen oxides upon combustion. Moreover, since these organic solvents are relatively expensive solvents, they also cause an increase in production cost.

  Therefore, it has been studied to dissolve or disperse a polyimide precursor in an aqueous medium to obtain an aqueous composition. For example, Patent Documents 1 to 3 disclose means for producing an aqueous resin composition of a polyimide precursor by forming a salt of a polyimide precursor (polyamic acid) and a specific amine. If left for a long period of time, aggregates, precipitates, and gels are formed, and satisfactory coating stability cannot be obtained, such as inability to perform good coating.

  On the other hand, Patent Document 4 discloses that a protective group is introduced via a hemiacetal ester bond by a reaction between a carboxy group of a polyamic acid that is a polyimide precursor and a secondary vinyl ether compound. In the presence of water molecules, the acetal ester bond is easily decomposed even at room temperature, and changes to acetaldehyde and alcohol, so that storage stability at a practical level cannot be obtained.

Japanese Patent Publication No.43-13387 JP 58-162658 A JP 2003-13351 A JP 2009-242539 A

Therefore, the present invention provides an aqueous composition of a polyimide precursor that is excellent in coating property and storage stability, and also excellent in solvent resistance and water resistance of a cured product, and a method for producing a polyimide resin (cured product). This is the issue.
Another object of the present invention is to provide a dihydrofuran derivative composition.

The present inventor has made extensive studies to solve the above problems, and as a result, dihydrofuran derivatives obtained by adding a specific tetracarboxylic acid to a double bond of a five-membered ring of a specific dihydrofuran compound (the above five-membered). The ring is a tetrahydrofuran skeleton.) And a polyimide precursor aqueous composition (polyimide precursor composition) obtained by mixing a specific polyamine in an aqueous medium has excellent coating properties and storage stability. It has been found that the polyimide resin obtained by curing is excellent in solvent resistance and water resistance, and has completed the present invention.
That is, this invention is the following (1)-(4).

(1) A dihydrofuran derivative composition containing a dihydrofuran derivative represented by the following formula (1) and an aqueous medium.
[In the formula (1), X is a tetravalent organic group (excluding those having a group reactive with an amino group), and R ¹ , R ² , R ³ and R ⁴ are each independently A hydrogen atom, a halogen atom or a monovalent organic group (excluding those containing a group reactive with an amino group or a carboxy group). R ² , R ³ and R ⁴ may be bonded to each other to show a cyclic structure. ]
(2) A polyimide precursor composition containing a dihydrofuran derivative represented by the following formula (1), a polyamine represented by the following formula (C), and an aqueous medium.
[In the formula (1), X is a tetravalent organic group (excluding those having a group reactive with an amino group), and R ¹ , R ² , R ³ and R ⁴ are each independently A hydrogen atom, a halogen atom or a monovalent organic group (excluding those containing a group reactive with an amino group or a carboxy group). R ² , R ³ and R ⁴ may be bonded to each other to show a cyclic structure. In formula (C), Y is an m-valent organic group (excluding those containing a group reactive with a carboxy group), and m is an integer of 2 or more. ]
(3) A dihydrofuran derivative composition manufacturing process in which a dihydrofuran compound represented by the following formula (A), a tetracarboxylic acid represented by the following formula (B), and an aqueous medium are mixed and stirred.
A polyimide precursor composition manufacturing step in which the dihydrofuran derivative obtained in the dihydrofuran derivative composition manufacturing step, a polyamine represented by the following formula (C), and an aqueous medium are mixed and stirred, and the polyimide precursor The manufacturing method of a polyimide resin provided with the polyimide resin manufacturing process which heat-processes and cures the polyimide precursor composition containing the polyimide precursor and aqueous medium which were obtained at the body composition manufacturing process.
[In Formula (A), R ¹ , R ² , R ³ and R ⁴ each independently include a hydrogen atom, a halogen atom or a monovalent organic group (a group having reactivity with an amino group or a carboxy group) R ² , R ³ and R ⁴ may be bonded to each other to show a cyclic structure. In the formula (B), X is a tetravalent organic group (excluding those containing a group reactive with an amino group). In formula (C), Y is an m-valent organic group (excluding those containing a group reactive with a carboxy group), and m is an integer of 2 or more. ]
(4) A polyimide resin obtained by the production method of (3) above.

  ADVANTAGE OF THE INVENTION According to this invention, while being excellent in coating property and storage stability, the polyimide resin aqueous composition excellent in the solvent resistance and water resistance of a polyimide resin, and the manufacturing method of a polyimide resin can be provided. . The present invention can also provide a dihydrofuran derivative composition.

  One of the characteristics of the present invention is that in the polyimide precursor, a carboxy group derived from tetracarboxylic acid has a hemiacetal ester bond formed by an addition reaction with a dihydrofuran compound.

  The hemiacetal ester bond formed by the reaction between a dihydrofuran compound and a carboxy group has resistance to hydrolysis, and deprotection due to elimination of the protective group of the carboxy group hardly occurs. The stability of the polyimide precursor is high, and the storage stability of the polyimide precursor composition is excellent. The inventor has found that the hemiacetal ester bond formed by the reaction of a vinyl ether compound and a carboxy group as described in Patent Document 4 can have a planar structure for resistance to hydrolysis. Is less resistant to hydrolysis, but the hemiacetal ester bond formed by the reaction of the dihydrofuran compound with the carboxy group is a hemiacetal ester due to steric hindrance due to the five-membered ring of the dihydrofuran compound. It is presumed that the bond cannot take a planar structure and the resistance to hydrolysis is increased due to the difficulty of adding water. Furthermore, it is considered that not only the stability in an aqueous medium is high, but also the stability in an organic solvent is high.

  In addition, the hemiacetal ester bond formed by the reaction between the dihydrofuran compound and the carboxy group is rapidly decomposed by heating to 170 ° C. or higher, and the dihydrofuran compound is eliminated, so that the imide is heated at 200 ° C. or higher. The carboxy group can be protected until immediately before the conversion treatment. Furthermore, since the detached dihydrofuran compound is vaporized during heating, the polyimide after imidation has very little residual dihydrofuran compound, and does not impair the solvent resistance and water resistance of the polyimide resin.

As a result, it is possible to obtain a polyimide precursor that becomes a substantially pure polyimide resin after imidization even though the carboxy group is protected and in a stable state during storage.
The present invention will be described in detail below.

The manufacturing method of the polyimide resin of this invention is equipped with the dihydrofuran derivative composition manufacturing process, the polyimide precursor composition manufacturing process, and the polyimide resin manufacturing process.
In the dihydrofuran derivative composition production process, a dihydrofuran derivative composition containing a dihydrofuran derivative and an aqueous medium is produced. In the polyimide precursor composition production process, the dihydrofuran derivative composition, polyamine and an aqueous medium are contained. A polyimide precursor composition is produced.

1. Dihydrofuran derivative composition production process The dihydrofuran derivative composition production process comprises mixing an adihydrofuran compound, a tetracarboxylic acid, and an aqueous medium, stirring them, and stirring the aqueous composition of the dihydrofuran derivative (dihydrofuran derivative composition). Is a process of manufacturing. The dihydrofuran derivative composition of the present invention can be produced by the above process.

<Dihydrofuran compound and tetracarboxylic acid>
The dihydrofuran compound used in the dihydrofuran derivative composition production process is represented by the following formula (A), and the tetracarboxylic acid is represented by the following formula (B).

In formula (A), R ¹ , R ² , R ³ and R ⁴ are each independently a hydrogen atom, a halogen atom or a monovalent organic group, and R ² , R ³ and R ⁴ are each bonded to each other Thus, a ring structure may be shown. R ¹ , R ² , R ³ and R ⁴ are determined depending on the dihydrofuran compound.

Examples of the monovalent organic group include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, and an aryl group. Among these, an alkyl group is preferable, a C _1-3 alkyl group selected from a methyl group, an ethyl group, a propyl group, and an isopropyl group is more preferable, and a methyl group is more preferable. In these monovalent organic groups, an arbitrary hydrogen atom may be substituted with a halogen atom or a hydroxyl group. As the halogen atom, a fluorine atom is preferable. However, it is not limited to these.
In formula (A), R ² , R ³ and R ⁴ may be bonded to each other to represent a cyclic structure. The ring structure is not particularly limited. In addition, when R < ³ >, R < ⁴ > mutually couple | bonds and forms a cyclic structure, it is mentioned as one of the preferable aspects that the said cyclic structure does not contain a benzene ring (hereinafter the same). That is, the present invention includes one preferred embodiment that does not include a benzofuran skeleton in which a tetrahydrofuran skeleton represented by the formula (1) and a benzene ring are condensed. When R ³ and R ⁴ are bonded to each other to form a cyclic structure, examples of the formed cyclic structure include alicyclic hydrocarbons.

  From the monovalent organic group, those containing a group reactive with an amino group or a carboxy group are excluded. Examples of the group having reactivity with an amino group include, but are not limited to, a carboxy group, a carboxylic anhydride group, a carbonyl group, an aldehyde group, and a halogenocarbonyl group. Examples of the group having reactivity with a carboxy group include, but are not limited to, an amino group, a hydroxy group, a carboxy group, and a vinyloxy group.

  Specific examples of the dihydrofuran compound include 2,3-dihydrofuran and 2,3-dihydro-5-methylfuran. Among these, 2,3-dihydrofuran is preferable.

  A dihydrofuran compound can be used individually by 1 type or in combination of 2 or more types.

  In formula (B), X is a tetravalent organic group. X is determined depending on the tetracarboxylic acid.

  Examples of the tetravalent organic group include a compound having a chain hydrocarbon such as ethylene and propane in the basic skeleton, a compound having a cyclic hydrocarbon such as cyclohexane in the basic skeleton, and an aromatic hydrocarbon such as benzene and naphthalene. Any four compounds from a compound having a basic skeleton, a compound having a benzophenone skeleton such as benzophenone, a compound having a diphenyl ether skeleton such as diphenyl ether, a compound having a diphenyl sulfone skeleton such as diphenyl sulfone, a compound having a biphenyl skeleton such as biphenyl, etc. Examples include a group from which a hydrogen atom has been removed. However, it is not limited to these.

  From the tetravalent organic group, those containing a group reactive with an amino group are excluded. Examples of the group having reactivity with an amino group include, but are not limited to, a carboxy group, a carboxylic anhydride group, a carbonyl group, an aldehyde group, and a halogenocarbonyl group.

  Specific examples of the tetracarboxylic acid include 1,2,4,5-benzenetetracarboxylic acid (pyromellitic acid), 1,2,3,4-benzenetetracarboxylic acid (merophanoic acid), 2, 3,6,7-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 3,4,9,10-perylenetetracarboxylic acid 2,3,6,7-anthracenetetracarboxylic acid, 1,2,7,8-phenanthrenetetracarboxylic acid, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, 2,2 ′, 3,3 '-Benzophenone tetracarboxylic acid, bis {4- [4- (1,2-dicarboxy) phenoxy] phenyl} ketone, bis {4- [3- (1,2-dicarboxy) phenoxy] pheny } Ketone, bis {4- [4- (1,2-dicarboxy) phenoxy] phenyl} ketone, bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} ketone, 2,3,3 ', 4'-biphenyltetracarboxylic acid, 3,3', 4,4'-biphenyltetracarboxylic acid, 2,2 ', 3,3'-biphenyltetracarboxylic acid, 2,2', 6,6'- Biphenyltetracarboxylic acid, bis (3,4-dicarboxyphenyl) ether, 4,4′-bis [4- (1,2-dicarboxy) phenoxy] biphenyl, 4,4′-bis [3- (1, 2-dicarboxy) phenoxy] biphenyl, bis (2,3-dicarboxyphenyl) methane, bis (3,4-dicarboxyphenyl) methane, 1,1-bis (2,3-dicarboxyphenyl) ethane, , 2-bis (3,4-dicarboxyphenyl) propane, 2,2-bis (2,3-dicarboxyphenyl) propane, 2,2-bis {4- [4- (1,2-dicarboxy) Phenoxy] phenyl} propane, 2,2-bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} propane, 2,2-bis (3,4-dicarboxyphenyl) -1,1, 1,3,3,3-hexafluoropropane, 2,2-bis (2,3-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane, 2,2-bis {4 -[4- (1,2-dicarboxy) phenoxy] phenyl} -1,1,1,3,3,3-hexafluoropropane, 2,2-bis {4- [3- (1,2-di Carboxy) phenoxy] phenyl} -1,1,1,3,3 3-hexafluoropropane, 1,3-bis [(3,4-dicarboxy) benzoyl] benzene, 1,4-bis [(3,4-dicarboxy) benzoyl] benzene, bis (3,4-dicarboxy Phenyl) sulfone, bis {4- [4- (1,2-dicarboxy) phenoxy] phenyl} sulfone, bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} sulfone, bis {4- [4- (1,2-dicarboxy) phenoxy] phenyl} sulfide, bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} sulfide, and the like.

  The tetracarboxylic acid is preferably an aromatic tetracarboxylic acid from the viewpoint of the heat resistance and linear thermal expansion coefficient of a polyimide resin obtained by drying and curing the polyimide precursor composition, and 1,2,4,5- Benzenetetracarboxylic acid (pyromellitic acid), 1,2,3,4-benzenetetracarboxylic acid (melophanoic acid), 2,3,6,7-naphthalenetetracarboxylic acid, 3,3 ′, 4,4′- Benzophenone tetracarboxylic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 2,3,3 ′, 4′-biphenyltetracarboxylic acid, 2,3,2 ′, 3′-biphenyltetracarboxylic acid, 2,2 ′, 6,6′-biphenyltetracarboxylic acid, bis (3,4-dicarboxyphenyl) ether, 2,2-bis (3,4-dicarboxyphenyl) -1,1, , 3,3,3 hexafluoropropane or bis (3,4-carboxyphenyl) ether, are preferred.

  As the tetracarboxylic acid, from the viewpoint of stability of the hemiacetal ester bond, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 2,3,3 ′, 4′-biphenyltetracarboxylic acid, 2,3 2,2 ′, 3′-biphenyltetracarboxylic acid or bis (3,4-dicarboxyphenyl) ether is preferred.

  Tetracarboxylic acid can be used individually by 1 type or in combination of 2 or more types.

<Aqueous medium>
The aqueous medium is a medium mainly composed of water. As the water, ion-exchanged water, distilled water, deionized distilled water, RO water (water treated with a reverse osmosis membrane) or the like can be used. Here, “having water as a main component” means containing 60 mass% or more, preferably 75 mass% or more, more preferably 90 mass% or more of water.
By using an aqueous medium, environmental load can be reduced.

The aqueous medium may contain a known alcohol or ether that has a small environmental load and does not adversely affect the volatility and drying of water for the purpose of imparting wettability to the substrate and preserving effect. For example, methanol, ethanol, n-propanol, 2-propanol (isopropyl alcohol), n-butanol, isobutanol, t-butanol, butyl cellosolve, propylene glycol monomethyl ether, 1- (2-hydroxyethyl) -2-pyrrolidone, etc. Can be mentioned.
These alcohols or ethers can be used singly or in combination of two or more.

  When the alcohol is added to the aqueous medium, the ratio of the alcohol in the aqueous medium is preferably 1% by mass or more and 40% by mass or less, and more preferably 5% by mass or more and 25% by mass or less. When the alcohol ratio is 1% by mass or more, the effect of improving the wettability of the coating composition with respect to the substrate is exhibited, and the repellency of the coating composition on the substrate is suppressed. Further, when the alcohol ratio is 40% by mass or less, crystals do not precipitate on the polyimide precursor composition, and it becomes easy to dispose the coating composition on the substrate in the form of a film. If the ratio of alcohol is less than 1% by mass, the improvement effect by adding alcohol may be insufficient. In addition, if the alcohol ratio is more than 40% by mass, crystals may be deposited on the polyimide precursor composition, which may make it difficult to dispose the coating composition on the substrate. .

<Method for producing dihydrofuran derivative composition>
An aqueous composition of a dihydrofuran derivative can be produced by mixing and stirring a dihydrofuran compound, a tetracarboxylic acid, and an aqueous medium.
According to this method, it is not necessary to use an organic solvent with a high environmental load, and an aqueous composition of a dihydrofuran derivative can be obtained by reacting a dihydrofuran compound and a tetracarboxylic acid in an aqueous medium. The reaction product dihydrofuran derivative need not be recovered and mixed in an aqueous medium, and the number of steps can be reduced.
In general, the number of moles of the dihydrofuran compound is preferably 0.5 to 4 times, more preferably 1 to 2 times the number of moles of tetracarboxylic acid.
The method for mixing the dihydrofuran compound, the tetracarboxylic acid, and the aqueous medium is not particularly limited, and includes, for example, an aqueous composition containing the dihydrofuran compound and the aqueous medium, and containing the tetracarboxylic acid and the aqueous medium. A method of mixing and stirring an aqueous composition, a method of adding and stirring a dihydrofuran compound to an aqueous composition containing a tetracarboxylic acid and an aqueous medium, and an aqueous composition containing a dihydrofuran compound and an aqueous medium Examples of the method include adding tetracarboxylic acid to the mixture and stirring.
The temperature at the time of mixing and stirring (reaction temperature) is not particularly limited as long as it is a temperature at which an addition reaction can be performed, preferably 5 to 45 ° C, more preferably 20 to 30 ° C, and further about 25 ° C. preferable.
The stirring time is not particularly limited as long as the addition reaction is sufficiently performed, but is preferably 30 minutes to 6 hours, more preferably 1 hour to 3 hours, and further preferably about 2 hours.
The atmosphere during the production of the dihydrofuran derivative composition is not particularly limited, and an atmosphere such as an air atmosphere, a nitrogen atmosphere, an inert gas atmosphere, or the like can be used.
Moreover, the continuous type may be sufficient as the format for manufacturing a dihydrofuran derivative composition, and a batch type may be sufficient as it.

<catalyst>
A catalyst for promoting the reaction between the dihydrofuran compound and the tetracarboxylic acid may be further contained in the mixed liquid obtained by mixing the dihydrofuran compound, the tetracarboxylic acid, and the aqueous medium.
Examples of the catalyst for promoting the reaction between the dihydrofuran compound and the tetracarboxylic acid include a catalyst for promoting the addition reaction between the double bond of the five-membered ring of the dihydrofuran compound and the carboxy group of the tetracarboxylic acid. Can be mentioned. Such a catalyst is not particularly limited, and specific examples include those that promote enol formation such as titanium tetrachloride and tin tetrachloride, which have higher acidity than carboxylic acid.
A catalyst can be used individually by 1 type or in combination of 2 or more types.

<Dihydrofuran derivative composition>
The dihydrofuran derivative composition of the present invention is a composition containing a dihydrofuran derivative represented by the following formula (1) and an aqueous medium. The dihydrofuran derivative composition of the present invention can further contain a catalyst. The catalyst is as defined above.
Production of a dihydrofuran derivative composition (dihydrofuran derivative composition of the present invention) containing a dihydrofuran derivative represented by the following formula (1) and an aqueous medium by the method for producing a dihydrofuran derivative composition described above. Can do.

Wherein ^(1), R ^1, R 2, ^{R 3} and ^{R 4} are each the same meaning as ^{R 1,} R 2, ^{R 3} and R4 in formula (A), X is X in formula (B) It is synonymous with.
In addition to the dihydrofuran derivative represented by the formula (1) and the aqueous medium, the dihydrofuran derivative composition further contains an unreacted dihydrofuran compound, tetracarboxylic acid, and one molecule of tetracarboxylic acid. A dihydrofuran derivative added with 2 to 4 molecules may be contained.

2. Polyimide precursor composition manufacturing process A polyimide precursor composition manufacturing process mixes a dihydrofuran derivative, a polyamine, and an aqueous medium, and stirs to manufacture an aqueous composition (polyimide precursor composition) of a polyimide precursor. It is a process to do. The polyimide precursor composition of this invention can be manufactured according to the said process.

<Dihydrofuran derivative / aqueous medium>
The dihydrofuran derivative is synthesized in the dihydrofuran derivative composition manufacturing process, and is an aqueous composition when the reaction is performed in an aqueous medium.
The aqueous medium is as described above.
The aqueous composition (dihydrofuran derivative composition) of the dihydrofuran derivative produced in the dihydrofuran derivative composition production process may be used as a dihydrofuran derivative and an aqueous medium used in the polyimide precursor composition production process. it can.

<Polyamine>
The polyamine used in the polyimide precursor composition manufacturing process is represented by the following formula (C).

  In formula (C), Y is an m-valent organic group, and m is an integer of 2 or more. The upper limit of m is not particularly limited, but is preferably 2000 or less, more preferably 600 or less. Y and m are determined depending on the polyamine.

  Examples of m-valent organic groups include compounds having a chain hydrocarbon such as ethylene and propane in the basic skeleton, compounds having a cyclic hydrocarbon such as cyclohexane in the basic skeleton, and aromatic hydrocarbons such as benzene and naphthalene. Any m from a compound having a basic skeleton, a compound having a benzophenone skeleton such as benzophenone, a compound having a diphenyl ether skeleton such as diphenyl ether, a compound having a diphenyl sulfone skeleton such as diphenyl sulfone, or a compound having a biphenyl skeleton such as biphenyl Examples include groups from which a single hydrogen atom has been removed. However, it is not limited to these.

  From the m-valent organic group, those containing a group reactive with a carboxy group are excluded. Examples of the group having reactivity with a carboxy group include, but are not limited to, an amino group, a hydroxy group, a carboxy group, and a vinyloxy group.

  Specific examples of the polyamine include p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenylsulfide, 3,4′-diaminodiphenylsulfide, 4,4′-diaminodiphenylsulfide, 3,3′-diaminodiphenylsulfone, 3,4′-diaminodiphenylsulfone, 4,4′- Diaminodiphenyl sulfone, 3,3′-diaminobenzophenone, 4,4′-diaminobenzophenone, 3,4′-diaminobenzophenone, 3,3′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, 3,4′-diamino Diphenyl meta 2,2-di (3-aminophenyl) propane, 2,2-di (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 2,2- Di (3-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 2,2-di (4-aminophenyl) -1,1,1,3,3,3-hexafluoro Propane, 2- (3-aminophenyl) -2- (4-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 1,1-di (3-aminophenyl) -1- Phenylethane, 1,1-di (4-aminophenyl) -1-phenylethane, 1- (3-aminophenyl) -1- (4-aminophenyl) -1-phenylethane, 1,3-bis (3 -Aminophenoxy) benzene, 1,3-bis (4 Aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminobenzoyl) benzene, 1,3-bis ( 4-aminobenzoyl) benzene, 1,4-bis (3-aminobenzoyl) benzene, 1,4-bis (4-aminobenzoyl) benzene, 1,3-bis (3-amino-α, α-dimethylbenzyl) Benzene, 1,3-bis (4-amino-α, α-dimethylbenzyl) benzene, 1,4-bis (3-amino-α, α-dimethylbenzyl) benzene, 1,4-bis (4-amino-) α, α-dimethylbenzyl) benzene, 1,3-bis (3-amino-α, α-ditrifluoromethylbenzyl) benzene, 1,3-bis (4-amino-α, α-ditrifluoro) Methylbenzyl) benzene, 1,4-bis (3-amino-α, α-ditrifluoromethylbenzyl) benzene, 1,4-bis (4-amino-α, α-ditrifluoromethylbenzyl) benzene, 2,6 -Bis (3-aminophenoxy) benzonitrile, 2,6-bis (3-aminophenoxy) pyridine, 4,4'-bis (3-aminophenoxy) biphenyl, 4,4'-bis (4-aminophenoxy) Biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (4 -Aminophenoxy) phenyl] sulfide, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophen Xyl) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, 2,2-bis [4- (3-aminophenoxy) phenyl] Propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [3- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexa Fluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 1,3-bis [4- (3-aminophenoxy) Benzoyl] benzene, 1,3-bis [4- (4-aminophenoxy) benzoyl] benzene, 1,4-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,4-bis [4- (4-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-aminophenoxy) ) -Α, α-dimethylbenzyl] benzene, 1,4-bis [4- (3-aminophenoxy) -α, α-dimethylbenzyl] benzene, 1,4-bis [4- (4-aminophenoxy)- α, α-dimethylbenzyl] benzene, 4,4′-bis [4- (4-aminophenoxy) benzoyl] diphenyl ether, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy Benzophenone, 4,4′-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] diphenylsulfone, 4,4′-bis [4- (4-aminophenoxy) f Noxy] diphenylsulfone, 3,3′-diamino-4,4′-diphenoxybenzophenone, 3,3′-diamino-4,4′-dibiphenoxybenzophenone, 3,3′-diamino-4-phenoxybenzophenone, 3, , 3′-Diamino-4-biphenoxybenzophenone, 6,6′-bis (3-aminophenoxy) -3,3,3 ′, 3′-tetramethyl-1,1′-spirobiindane, 6,6′- Bis (4-aminophenoxy) -3,3,3 ′, 3′-tetramethyl-1,1′-spirobiindane, 1,3-bis (3-aminopropyl) tetramethyldisiloxane, 1,3-bis ( 4-aminobutyl) tetramethyldisiloxane, α, ω-bis (3-aminopropyl) polydimethylsiloxane, α, ω-bis (3-aminobutyl) polydimethyl Tylsiloxane, bis (aminomethyl) ether, bis (2-aminoethyl) ether, bis (3-aminopropyl) ether, bis [2- (aminomethoxy) ethyl] ether, bis [2- (2-aminoethoxy) Ethyl] ether, bis [2- (3-aminopropoxy) ethyl] ether, 1,2-bis (aminomethoxy) ethane, 1,2-bis (2-aminoethoxy) ethane, 1,2-bis [2- (Aminomethoxy) ethoxy] ethane, 1,2-bis [2- (2-aminoethoxy) ethoxy] ethane, ethylene glycol bis (3-aminopropyl) ether, diethylene glycol bis (3-aminopropyl) ether, triethylene glycol Bis (3-aminopropyl) ether, ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1, 11-diaminoundecane, 1,12-diaminododecane, 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, 1,2-di (2-aminoethyl) cyclohexane, 1,3- Di (2-aminoethyl) cyclohexane, 1,4-di (2-aminoethyl) cyclohexane, bis (4-aminocyclohexyl) methane, 2,6-bis (aminomethyl) bicyclo [2.2.1] And heptane, 2,5-bis (aminomethyl) bicyclo [2.2.1] heptane, and the like.

  As the polyamine, at least one selected from the group consisting of a fluorine atom, a methyl group, a methoxy group, a trifluoromethyl group, and a trifluoromethoxy group is used as a part or all of the hydrogen atoms on the aromatic ring of the polyamine. Polyamines substituted with the above substituents can also be used.

As the polyamine, in addition to the above-described polyamine, a polymer having two or more primary amino groups (—NH ₂ ) in one molecule (a primary amino group containing a group reactive with a carboxy group) May be used. Examples of such polyamines include those in which the main chain or side chain of polystyrene, polyacrylic acid, polyurethane, polyamide, polyimide or the like is modified with two or more primary amino groups. More specifically, a primary amino group-containing acrylic polymer or tetracarboxylic acid obtained by grafting polyethyleneimine to the side chain of an acrylic acid copolymer by utilizing the reactivity of the carboxy group of the polymer side chain with ethyleneimine. Polyamic acid resin with dianhydride extended with excess diamine or triamine, polyurethane urea resin with urethane prepolymer extended with excess diamine or triamine, modified epoxy resin with epoxy resin extended with excess diamine or triamine, etc. Is mentioned.

  From the polymer having two or more primary amino groups in one molecule, those containing a group having reactivity with a carboxy group in addition to the primary amino group are excluded. Examples of the group having reactivity with a carboxy group include, but are not limited to, a hydroxy group, a carboxy group, and a vinyloxy group.

  Depending on the purpose, the polyamine may be any of ethynyl group, benzocyclobuten-4′-yl group, vinyl group, allyl group, cyano group, and isopropenyl group that serve as a crosslinking point when a crosslinking reaction is performed after polyimide formation. One kind or two or more kinds can be used even if they are introduced as a substituent into some or all of the hydrogen atoms on the aromatic ring of the polyamine.

The polyamine can be appropriately selected depending on the desired physical properties.
When a rigid diamine such as p-phenylenediamine is used as the polyamine, the finally obtained polyimide can have a low expansion coefficient. As rigid diamines, p-phenylenediamine, m-phenylenediamine, 1,4-diaminonaphthalene, 1,5-diamino are diamines (aromatic diamines) in which two amino groups are bonded to the same aromatic ring. Naphthalene, 2,6-diaminonaphthalene, 2,7-diaminonaphthalene, 1,4-diaminoanthracene and the like can be mentioned. Polyamine dendrimers may also be used.

  Further, polyamines include polyamines in which two or more aromatic rings are bonded by a single bond, and two or more amino groups are each bonded directly or as part of a substituent on a separate aromatic ring. Specific examples include benzidine and toluidine.

  Furthermore, a polyamine having a substituent on the benzene ring can also be used as the polyamine. These substituents are monovalent organic groups, but they may be bonded to each other. Specific examples include 2,2′-dimethyl-4,4′-diaminobiphenyl, 2,2′-ditrifluoromethyl-4,4′-diaminobiphenyl, 3,3′-dichloro-4,4′-diamino. Biphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl and the like can be mentioned.

  On the other hand, when a compound having a siloxane skeleton such as 1,3-bis (3-aminopropyl) tetramethyldisiloxane (siloxane polyamine) is used as the polyamine, the elastic modulus of the finally obtained resin composition is lowered. The glass transition temperature can be lowered.

Here, the selected polyamine is preferably an aromatic polyamine from the viewpoint of heat resistance, and more preferably an aromatic diamine.
Depending on the desired physical properties, an aromatic diamine and at least one non-aromatic diamine selected from the group consisting of an aliphatic diamine such as ethylene diamine and a siloxane diamine can be used in combination as the polyamine.
In such a case, the amount of the diamine other than the aromatic is preferably within a range not exceeding 60 mol% of the whole polyamine, and more preferably within a range not exceeding 40 mol%.

  As the polyamine, for example, an aminoethylated acrylic polymer can be used.

  A polyamine can be used individually by 1 type or in combination of 2 or more types.

<Method for producing polyimide precursor composition>
By mixing and stirring the dihydrofuran derivative, the polyamine, and the aqueous medium, an aqueous composition of the polyimide precursor can be produced.
According to this method, similarly to the method for producing a dihydrofuran derivative composition, it is not necessary to use an organic solvent having a high environmental load, and the number of steps can be reduced.
A method for mixing the dihydrofuran derivative, the polyamine, and the aqueous medium is not particularly limited. For example, an aqueous composition containing the dihydrofuran derivative and the aqueous medium, and an aqueous composition containing the polyamine and the aqueous medium And a method of mixing and stirring, a method of adding a polyamine to an aqueous composition containing a dihydrofuran derivative and an aqueous medium, and stirring.
When the polyimide precursor composition further contains an optional component described later, the optional component can be appropriately used.
Although the temperature at the time of mixing and stirring is not specifically limited, 5-45 degreeC is preferable, 20-30 degreeC is more preferable, About 25 degreeC is further more preferable.
The stirring time is not particularly limited, but is preferably 30 minutes to 6 hours, more preferably 1 hour to 3 hours, and further preferably about 2 hours.
The atmosphere at the time of manufacturing the polyimide precursor composition is not particularly limited, and an atmosphere such as an air atmosphere, a nitrogen atmosphere, an inert gas atmosphere, or the like can be used.
The form for producing the polyimide precursor composition may be a continuous type or a batch type.

<Polyimide precursor composition>
The polyimide precursor composition of the present invention contains a dihydrofuran derivative represented by the above formula (1), a polyamine represented by the above formula (C), and an aqueous medium. The polyimide precursor composition of this invention should just be a mixture of these. In the polyimide precursor composition of the present invention, the dihydrofuran derivative and the polyamine may form, for example, a salt structure represented by the following formula (2) in which carboxylate and ammonium are paired.

(Volatile amine)
The polyimide precursor composition may further contain a volatile amine for the purpose of supplementing the stability of the composition in water.
As the volatile amine, for example, ammonia, trimethylamine, triethylamine, tributylamine, N-methylmorpholine and the like are preferable.
A volatile amine can be used individually by 1 type or in combination of 2 or more types.
Such a volatile amine is desirably an amount that does not exceed the number of moles of carboxy groups that are not used in the addition reaction between the dihydrofuran compound and the tetracarboxylic acid.

(Other components that may be included)
The polyimide precursor composition may further comprise reinforcing materials, fillers, anti-aging agents, antioxidants, light stabilizers, anti-scorch agents, other cross-linking retarders, plasticizers, processing aids, lubricants, adhesives as necessary. Additives such as an agent, a lubricant, a flame retardant, an antifungal agent, an antistatic agent, a colorant, and a surfactant can be blended.
Furthermore, as long as the characteristics of the polyimide precursor composition are not impaired, polymer components such as a polymer other than polyimide and an elastomer can be blended as necessary.
In the polyimide precursor composition of this invention, it can prepare by mix | blending each said component with appropriate | suitable mixing methods, such as roll mixing, Banbury mixing, screw mixing, stirring mixing.

(Organic solvent)
The polyimide precursor composition is substantially free of organic solvents except for organic solvents such as alcohols and ethers contained in aqueous media, organic solvents contained in volatile amines, and trace amounts of organic solvents inevitably mixed in. It is mentioned as one of the preferable embodiments. Examples of such organic solvent include N-methyl-2-pyrrolidone, 1- (2-hydroxyethyl) -2-pyrrolidone, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, N- Examples include organic solvents with high environmental loads such as methyl caprolactam, acetone, γ-butyrolactone, methyl ethyl ketone, and methyl isobutyl ketone.
In the present invention, substantially not containing an organic solvent means that the content of the organic solvent is 0 to 0.1% by mass with respect to the entire polyimide precursor composition.

(Viscosity of polyimide precursor composition)
The viscosity of the polyimide precursor composition according to the present invention is not particularly limited as long as the coating property is not impaired, but the viscosity at 20 ° C. is in the range of 50 mPa · s to 200 Pa · s, It is practically preferable to adjust the viscosity at 22 ° C. to a range of 10 mPa · s to 200 Pa · s.

3. Polyimide resin production process The polyimide resin production process is a process of producing a polyimide resin by heat-treating and curing a polyimide precursor composition containing a polyimide precursor and an aqueous medium.

<Polyimide precursor / aqueous medium>
The polyimide precursor is obtained in the polyimide precursor composition manufacturing process, and becomes an aqueous composition when mixed and stirred in an aqueous medium.
The aqueous medium is as described above. The aqueous medium may be an aqueous medium contained in the polyimide precursor composition produced in the polyimide precursor composition production process.
The polyimide precursor aqueous composition (polyimide precursor composition) produced in the polyimide precursor composition production process can be used as a polyimide precursor and an aqueous medium used in the polyimide resin production process.

<Heat treatment / curing>
By heat treatment, drying of the polyimide precursor composition, deprotection of the carboxy group of the dihydrofuran derivative (that is, elimination of the dihydrofuran compound from the dihydrofuran derivative) and imidation of tetracarboxylic acid and polyamine (polyamide acid formation and Curing by polyimide formation by dehydration ring closure).
The heat treatment is performed by drying the polyimide precursor composition, deprotecting the carboxy group of the dihydrofuran derivative, and curing by imidation of tetracarboxylic acid and polyamine (polyamide acid generation and polyimide generation by dehydration ring closure). A step of drying the polyimide precursor composition, a step of deprotecting the carboxy group of the dihydrofuran derivative, and a step of curing by imidization (dehydration ring closure) of a tetracarboxylic acid and a polyamine. It is preferable to use three stages.
In the stage of drying the polyimide precursor composition, the heating temperature is usually 80 ° C. or higher, and preferably 80 to 100 ° C. The heating time is preferably several minutes to 1 hour, more preferably 15 minutes to 45 minutes. By performing drying, the moldability of the composition can be enhanced.
In the stage of deprotecting the carboxy group of the dihydrofuran derivative, the heating temperature is preferably 170 ° C. or higher and lower than 200 ° C. The heating time is preferably several minutes to 1 hour, more preferably 15 minutes to 45 minutes.
In the stage of deprotecting the carboxy group of the dihydrofuran derivative and curing by imidization (dehydration ring closure) of a tetracarboxylic acid and a polyamine, or the stage of curing by imidization (dehydration ring closure) of a tetracarboxylic acid and a polyamine, -400 degreeC is preferable. The heating time is preferably several minutes to several hours, more preferably 10 to 50 minutes.
As a heating method, an appropriate method such as press heating, steam heating, oven heating, hot air heating and the like can be adopted. Usually, after heating and reacting in a predetermined shape, steam heating, oven heating, hot air is performed. Further reaction by heating or the like.

  The present invention improves storage stability by using, as a polyimide raw material, a dihydrofuran derivative in which a protecting group is introduced via a hemiacetal ester bond formed by a reaction between a dihydrofuran compound and a carboxy group, and a polyamine. And by heating them, deprotection of the carboxy group of the dihydrofuran derivative (ie elimination of the dihydrofuran compound from the dihydrofuran derivative) and imidation of the tetracarboxylic acid and the polyamine (dehydration ring closure: ie polyamide) It is characterized in that a polyimide resin from which the dihydrofuran compound is eliminated is finally obtained by curing by polyimide generation after acid generation).

  Polyimide resin produced by the production method of the present invention is used in a wide range of fields such as transportation equipment such as automobiles, general equipment / devices, electronics / electricity, and architecture, sealing materials, buffering / protecting materials, wire coating materials, industrial use. Useful as belts, hoses, sheets and the like.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

[Example 1]
(1) Production of polyimide precursor composition In a separable flask (200 mL; cylinder type) equipped with a stirrer, 1,2,4,5-benzenetetracarboxylic acid (11.1 g) and water (45.9 g) After stirring for 10 minutes at 25 ° C., 2,3-dihydrofuran (3.8 g) was added, and further stirred and mixed at 25 ° C. for 30 minutes to obtain an aqueous dispersion of a dihydrofuran derivative.
To an aqueous dispersion of the obtained dihydrofuran derivative, styrene acrylic polyamine (manufactured by Nippon Shokubai Co., Ltd., Poliment ^(R) NK-200PM; non-volatile residue 56% by mass, amine value 2.55 mmol / g-solid; m = 60 ) (71.6 g) was added, and the mixture was stirred and mixed at 25 ° C. for 2 hours to obtain a polyimide precursor aqueous dispersion (polyimide precursor composition). The amine value is the number of mmols of amine contained in 1 g of the solid content of the product, and m represents m in the formula (C) (the same applies hereinafter).

(2) Viscosity measurement The viscosity at 22 degreeC immediately after manufacture of the obtained polyimide precursor composition was measured using the E-type viscosity meter (the Toki Sangyo Co., Ltd. make, model number TV-22).
The measurement results are shown in the column of “Initial viscosity (22 ° C.)” in Table 1.

(3) Storage stability test The polyimide precursor composition (30.0 g) immediately after manufacture was extract | collected to the glass bottle, and was left still in a 25 degreeC thermostat. The viscosity at 22 ° C. was measured after 1 day, 3 days, and 7 days from the day of standing, and the appearance was visually observed.
The measurement results of the viscosity are shown in the column of “Viscosity (22 ° C.)” of “Storage stability (25 ° C.)” in Table 2, and the observation results of the appearance are “Appearance ( It is shown in the column of “Visual”).

(4) Solvent resistance test Immediately after production, the polyimide precursor composition was collected in a glass bottle and immediately placed in a thermostatic chamber at 25 ° C. A glass substrate with a cured film was prepared by the following procedure using the polyimide precursor composition 1 day, 3 days, and 7 days after the standing day, and a solvent resistance test was performed.
On one surface of the glass substrate, the polyimide precursor composition was applied so that the dry coating film had a thickness of 40 μm. After coating, heat treatment is performed at 90 ° C. for 30 minutes using a hot plate, and then heat treatment is performed at 250 ° C. for 30 minutes using a constant temperature drying oven, on one surface of the glass substrate. A cured film made of polyimide resin was formed.
The surface of the cured film was rubbed with a cloth containing NMP (N-methyl-2-pyrrolidone), and the solvent resistance of the cured film was evaluated based on the following evaluation criteria. The evaluation results are shown in the column of “Solvent resistance test” in Table 3.
(Evaluation criteria)
A: No change B: Swelling or erosion occurs in the cured film C: At least a part of the glass substrate is exposed or the coating is poor

(5) Water resistance test (hot water impregnation test)
Immediately after production, the polyimide precursor composition was collected in a glass bottle and immediately left in a thermostatic chamber at 25 ° C. A glass substrate with a cured film was prepared according to the following procedure using the polyimide precursor composition after 1 day, 3 days, and 7 days from the day of standing, and a water resistance test was performed.
On one surface of the glass substrate, the polyimide precursor composition was applied so that the dry coating film had a thickness of 40 μm. After coating, heat treatment is performed at 90 ° C. for 30 minutes using a hot plate, and then heat treatment is performed at 250 ° C. for 30 minutes using a constant temperature drying oven, on one surface of the glass substrate. A cured film made of polyimide resin was formed.
The glass substrate on which the cured film was formed was immersed in hot water at 90 ° C. and allowed to stand for 10 minutes, then the cured film was visually observed, and the water resistance of the cured film was evaluated based on the following evaluation criteria. The evaluation results are shown in the column of “Water resistance test” in Table 3.
(Evaluation criteria)
A: No change B: Whitening or swelling occurs in the cured film C: At least a part of the glass substrate is exposed or coating is poor

[Example 2]
(1) 2,3,3 ′, 4′-biphenyltetracarboxylic acid (10.5 g) and water (36.6 g) were added to a separable flask (200 mL; cylinder type) equipped with a stirrer, and 25 ° C. After stirring for 10 minutes, 2,3-dihydrofuran (2.7 g) was added, and further stirred and mixed at 25 ° C. for 30 minutes to obtain an aqueous dispersion of a dihydrofuran derivative.
To an aqueous dispersion of the obtained dihydrofuran derivative, styrene acrylic polyamine (manufactured by Nippon Shokubai Co., Ltd., Poliment ^(R) NK-200PM; non-volatile residue 56% by mass, amine value 2.55 mmol / g-solid; m = 60 ) (50.2 g) was added and stirred and mixed at 25 ° C. for 2 hours to obtain an aqueous dispersion of polyimide precursor (polyimide precursor composition).
(2) Viscosity measurement, storage stability test, solvent resistance test, water resistance test Using the obtained polyimide precursor composition, in the same manner as in Example 1, viscosity measurement, storage stability test, solvent resistance A test and a water resistance test were conducted. The results are shown in Table 1, Table 2, and Table 3.

[Example 3]
(1) In a separable flask (200 mL; cylindrical shape) equipped with a stirrer, 2,3,3 ′, 4′-biphenyltetracarboxylic acid (5.3 g), 2,3,6,7-naphthalenetetracarboxylic Add acid (4.9 g) and water (36.2 g), stir and mix at 25 ° C. for 10 minutes, add 2,3-dihydrofuran (2.7 g), and stir and mix at 25 ° C. for 30 minutes. An aqueous dispersion of a dihydrofuran derivative was obtained.
To an aqueous dispersion of the obtained dihydrofuran derivative, styrene acrylic polyamine (manufactured by Nippon Shokubai Co., Ltd., Poliment ^(R) NK-200PM; non-volatile residue 56% by mass, amine value 2.55 mmol / g-solid; m = 60 ) (50.8 g) was added and mixed with stirring at 25 ° C. for 2 hours to obtain an aqueous dispersion of polyimide precursor (polyimide precursor composition).
(2) Viscosity measurement, storage stability test, solvent resistance test, water resistance test Using the obtained polyimide precursor composition, in the same manner as in Example 1, viscosity measurement, storage stability test, solvent resistance A test and a water resistance test were conducted. The results are shown in Table 1, Table 2, and Table 3.

[Comparative Example 1]
(1) 1,2,4,5-Benzenetetracarboxylic acid (11.1 g) and water (50.0 g) were added to a separable flask (200 mL; cylindrical shape) equipped with a stirrer at 25 ° C. After stirring and mixing for 10 minutes, a styrene acrylic polyamine (Nippon Shokubai Co., Ltd., Poliment ^(R) NK-200PM; nonvolatile residue 56%, amine value 2.55 mmol / g-solid; m = 60) (71.6 g) And stirred and mixed at 25 ° C. for 2 hours to obtain an aqueous polyimide precursor dispersion (polyimide precursor composition).

(2) Viscosity measurement, storage stability test, solvent resistance test, water resistance test Since the obtained polyimide precursor composition had lost fluidity, viscosity measurement, storage stability test, solvent resistance test, and water resistance None of the sex tests were performed.

[Comparative Example 2]
(1) Polyimide precursor composition 1,2,4,5-benzenetetracarboxylic acid (11.1 g) and water (45.9 g) were added to a separable flask (200 mL; cylindrical type) equipped with a stirrer. After stirring and mixing at 25 ° C. for 10 minutes, butyl vinyl ether (4.1 g) was added, and stirring and mixing was further performed at 25 ° C. for 30 minutes to obtain an aqueous dispersion of a butyl vinyl ether derivative.
To an aqueous dispersion of the obtained butyl vinyl ether derivative, a styrene acrylic polyamine (manufactured by Nippon Shokubai Co., Ltd., Poliment ^(R) NK-200PM; non-volatile residue 56% by mass, amine value 2.55 mmol / g-solid; m = 60 ) (71.6 g) was added, and the mixture was stirred and mixed at 25 ° C. for 2 hours to obtain a polyimide precursor aqueous dispersion (polyimide precursor composition).

(2) Viscosity measurement and storage stability test Viscosity measurement and storage stability test were conducted in the same manner as in Example 1 using the obtained polyimide precursor composition. However, since the polyimide precursor composition gelled on the seventh day after standing in a temperature-controlled room in the storage stability test, the viscosity measurement could not be performed.
The viscosity measurement results immediately after production of the obtained polyimide precursor composition are shown in the column of “Initial viscosity (22 ° C.)” in Table 1, and the viscosity measurement results in the storage stability test are shown in “Storage stability (25 In the column of “Viscosity (22 ° C.)” of “° C.)”, the observation results of the appearance are shown in the “Appearance (visual)” column of “Storage stability (25 ° C.)” of Table 2.

(3) Solvent Resistance Test and Water Resistance Test A solvent resistance test and a water resistance test were conducted in the same manner as in Example 1 using the obtained polyimide precursor composition. The evaluation results of the solvent resistance are shown in the “Solvent Resistance Test” column of Table 3, and the evaluation results of the water resistance are shown in the “Water Resistance Test” column of Table 3, respectively.

[Comparative Example 3]
(1) Manufacture of polyimide precursor (1) Manufacture of polyimide precursor In a separable flask (200 mL; cylinder type) equipped with a stirrer, 1,2,4,5-benzenetetracarboxylic acid (11.1 g) and N -After adding methyl-2-pyrrolidone (50.0 g) and stirring and mixing at 25 ° C. for 10 minutes, styrene acrylic polyamine (manufactured by Nippon Shokubai Co., Ltd., Polyment ^(R) NK-200PM; nonvolatile content 56% by mass, amine) 2.55 mmol / g-solid; m = 60) (71.6 g) was added and stirred and mixed at 25 ° C. for 2 hours to obtain an N-methyl-2-pyrrolidone solution of polyimide precursor (polyimide precursor composition). Got.
(2) Viscosity measurement, storage stability test, solvent resistance test, water resistance test Using the obtained polyimide precursor composition, in the same manner as in Example 1, viscosity measurement, storage stability test, solvent resistance A test and a water resistance test were conducted. The results are shown in Table 1, Table 2, and Table 3.

As is clear from the results shown in Table 1, the polyimide precursor composition of the present invention was low in viscosity and excellent in coatability.
The polyimide precursor composition containing the polyimide precursor which added the vinyl ether compound instead of the dihydrofuran compound of the comparative example 2 was also low viscosity, and was excellent in coating property.

As is clear from the results shown in Table 2, the polyimide precursor composition of the present invention was excellent in storage stability, and even after a period after production, the coating property was not impaired due to low viscosity.
On the other hand, the polyimide precursor composition containing the polyimide precursor which added the vinyl ether compound instead of the dihydrofuran compound of the comparative example 2 was inferior in storage stability. In Comparative Example 2, the initial viscosity was low and the coating property was excellent as shown in Table 1, but after the post-manufacturing period, the appearance changed, the viscosity increased, and the coating property was impaired.

As is clear from the results shown in Table 3, the polyimide precursor composition of the present invention is excellent in storage stability, and the polyimide resin obtained by heat treatment even after a period after production is solvent resistant. Excellent water resistance.
On the other hand, the polyimide precursor composition containing the polyimide precursor which added the vinyl ether compound instead of the dihydrofuran compound of the comparative example 2 was inferior in storage stability. Moreover, after the period after manufacture passed, the polyimide resin obtained by heat-processing the composition of the comparative example 2 was inferior in solvent resistance and water resistance.
Moreover, about the polyimide precursor composition made into the N-methyl-2- pyrrolidone solution instead of the aqueous dispersion of the polyimide precursor of the comparative example 3, the polyimide resin obtained by heat-processing the composition one day after preparation Was excellent in solvent resistance and water resistance. However, after 3 days from the preparation, crystals were precipitated in the polyimide composition of Comparative Example 3, and it became unusable. For this reason, it was not possible to evaluate the solvent resistance and water resistance of Comparative Example 3 after 3 days and 7 days after preparation.

Claims (4)

A dihydrofuran derivative composition containing a dihydrofuran derivative represented by the following formula (1) and an aqueous medium.
[In the formula (1), X is a tetravalent organic group (excluding those having a group reactive with an amino group), and R ¹ , R ² , R ³ and R ⁴ are each independently It is a hydrogen atom, a halogen atom or a monovalent organic group (excluding those containing a group reactive with an amino group or a carboxy group). R ² , R ³ and R ⁴ may be bonded to each other to show a cyclic structure. ] A polyimide precursor composition comprising a dihydrofuran derivative represented by the following formula (1), a polyamine represented by the following formula (C), and an aqueous medium.
[In the formula (1), X is a tetravalent organic group (excluding those having a group reactive with an amino group), and R ¹ , R ² , R ³ and R ⁴ are each independently It is a hydrogen atom, a halogen atom or a monovalent organic group (excluding those containing a group reactive with an amino group or a carboxy group). R ² , R ³ and R ⁴ may be bonded to each other to show a cyclic structure. In formula (C), Y is an m-valent organic group (excluding those containing a group reactive with a carboxy group), and m is an integer of 2 or more. ] A dihydrofuran derivative composition production process in which a dihydrofuran compound represented by the following formula (A), a tetracarboxylic acid represented by the following formula (B), and an aqueous medium are mixed and stirred;
A polyimide precursor composition manufacturing step in which the dihydrofuran derivative obtained in the dihydrofuran derivative composition manufacturing step, a polyamine represented by the following formula (C), and an aqueous medium are mixed and stirred, and the polyimide precursor The manufacturing method of a polyimide resin provided with the polyimide resin manufacturing process which heat-processes and cures the polyimide precursor composition containing the polyimide precursor and aqueous medium which were obtained at the body composition manufacturing process.
[In Formula (A), R ¹ , R ² , R ³ and R ⁴ each independently include a hydrogen atom, a halogen atom or a monovalent organic group (a group having reactivity with an amino group or a carboxy group) R ² , R ³ and R ⁴ may be bonded to each other to show a cyclic structure. In the formula (B), X is a tetravalent organic group (excluding those containing a group reactive with an amino group). In formula (C), Y is an m-valent organic group (excluding those containing a group reactive with a carboxy group), and m is an integer of 2 or more. ]   A polyimide resin obtained by the production method according to claim 3.