JP6175032B2 - Benzofuran derivative composition, polyimide precursor composition and method for producing polyimide resin - Google Patents

Description

  The present invention relates to a benzofuran 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, N, N-dimethylformamide, N, N-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 the polyimide precursor is often unstable with respect to water, it is difficult to maintain properties suitable for coating without gelation or precipitation when water is used as a solvent or dispersion medium. This causes problems in workability and storage stability when coating and drying.

  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, which is a polyimide precursor, and a vinyl ether compound. In the presence of water molecules, the bond easily decomposes even at room temperature, and transformation into acetaldehyde and alcohol occurs, so that practical storage stability cannot be obtained.

Japanese Patent Publication 43-13387 JP 58-162658 A JP2003-13351 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.

  The present inventor has conducted extensive studies to solve the above problems, and as a result, a benzofuran derivative obtained by adding a specific tetracarboxylic acid to a double bond of a five-membered ring of a specific benzofuran compound, a specific polyamine, The polyimide precursor aqueous composition (polyimide precursor composition) obtained by mixing the two in an aqueous medium has excellent coating properties and storage stability, and is cured and cured with a solvent-resistant and water-resistant polyimide resin. As a result, it was found that the present invention is excellent in properties, and the present invention has been completed.

［式（１）中、Ｘは４価の有機基（アミノ基と反応性を有する基を含むものを除く。）であり、Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５およびＲ^６は、それぞれ独立に、水素原子、ハロゲン原子または１価の有機基（アミノ基またはカルボキシ基と反応性を有するものを除く。）である。Ｒ^３、Ｒ^４、Ｒ^５およびＲ^６は、それぞれ互いに結合して環状構造を示していてもよい。］
（２）下記式（１）で表されるベンゾフラン誘導体と、下記式（Ｃ）で表されるポリアミンと、水性媒体とを含有するポリイミド前駆体組成物。

［式（１）中、Ｘは４価の有機基（アミノ基と反応性を有する基を含むものを除く。）であり、Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５およびＲ^６は、それぞれ独立に、水素原子、ハロゲン原子または１価の有機基（アミノ基またはカルボキシ基と反応性を有するものを除く。）である。Ｒ^３、Ｒ^４、Ｒ^５およびＲ^６は、それぞれ互いに結合して環状構造を示していてもよい。式（Ｃ）中、Ｙはｍ価の有機基（カルボキシ基と反応性を有する基を含むものを除く。）であり、ｍは２以上の整数である。］
（３）下記式（Ａ）で表されるベンゾフラン化合物と、下記式（Ｂ）で表されるテトラカルボン酸と、水性媒体とを混合し、撹拌するベンゾフラン誘導体組成物製造工程、
前記ベンゾフラン誘導体組成物製造工程で得られたベンゾフラン誘導体と、下記式（Ｃ）で表されるポリアミンとを混合し、撹拌するポリイミド前駆体組成物製造工程、および
前記ポリイミド前駆体組成物製造工程で得られたポリイミド前駆体と水性媒体とを含有するポリイミド前駆体組成物を加熱処理して、硬化させるポリイミド樹脂製造工程
を備えるポリイミド樹脂の製造方法。

［式（Ａ）中、Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５およびＲ^６は、それぞれ独立に、水素原子、ハロゲン原子または１価の有機基（アミノ基またはカルボキシ基と反応性を有するものを除く。）であり、Ｒ^３、Ｒ^４、Ｒ^５およびＲ^６は、それぞれ互いに結合して環状構造を示していてもよい。式（Ｂ）中、Ｘは４価の有機基（アミノ基と反応性を有する基を含むものを除く。）である。式（Ｃ）中、Ｙはｍ価の有機基（カルボキシ基と反応性を有する基を含むものを除く。）であり、ｍは２以上の整数である。］ That is, this invention is the following (1)-( 3 ).
(1) A benzofuran derivative composition containing a benzofuran 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 , R ⁴ , R ⁵ and R ^6. Each independently represents a hydrogen atom, a halogen atom or a monovalent organic group (excluding those having reactivity with an amino group or a carboxy group). R ³ , R ⁴ , R ⁵ and R ⁶ may be bonded to each other to show a cyclic structure. ]
(2) A polyimide precursor composition containing a benzofuran 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 , R ⁴ , R ⁵ and R ^6. Each independently represents a hydrogen atom, a halogen atom or a monovalent organic group (excluding those having reactivity with an amino group or a carboxy group). R ³ , R ⁴ , R ⁵ and R ⁶ 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 benzofuran derivative composition production process in which a benzofuran compound represented by the following formula (A), a tetracarboxylic acid represented by the following formula (B), and an aqueous medium are mixed and stirred.
In the polyimide precursor composition manufacturing process in which the benzofuran derivative obtained in the benzofuran derivative composition manufacturing process and the polyamine represented by the following formula (C) are mixed and stirred, and in the polyimide precursor composition manufacturing process 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 obtained polyimide precursor and an aqueous medium.

[In formula (A), R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom, a halogen atom or a monovalent organic group (reactive with an amino group or a carboxy group) R ³ , R ⁴ , R ⁵ and R ⁶ 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. ]

  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. .

  One of the features of the present invention is that a hemiacetal ester bond is formed by addition reaction with a benzofuran compound in a carboxy group derived from a tetracarboxylic acid in a polyimide precursor.

  The hemiacetal bond formed by the reaction of a benzofuran compound and a carboxy group has resistance to hydrolysis, and deprotection due to elimination of the protective group of the carboxy group does not easily occur, so polyimide in an aqueous medium The stability of the 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. However, the hemiacetal ester bond formed by the reaction of the benzofuran compound and the carboxy group is sterically hindered by the five-membered ring of the benzofuran compound, so that the hemiacetal bond is planar. It is presumed that the resistance to hydrolysis is increased due to the inability to add water to the structure. 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 bond formed by the reaction between the benzofuran compound and the carboxy group is rapidly decomposed by heating to 170 ° C. or higher, and the benzofuran compound is eliminated. The carboxy group can be protected until just before. Furthermore, since the detached benzofuran compound is vaporized during heating, the polyimide after imidization has very little residual benzofuran 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 stable during storage.
The present invention will be described in detail below.

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

1. Benzofuran derivative composition manufacturing process The benzofuran derivative composition manufacturing process is a process in which a benzofuran compound, a tetracarboxylic acid, and an aqueous medium are mixed and stirred to produce an aqueous composition of a benzofuran derivative (benzofuran derivative composition). is there.

<Benzofuran compound and tetracarboxylic acid>
The benzofuran compound used in the manufacturing process of the benzofuran derivative composition 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 , R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom, a halogen atom or a monovalent organic group (reactive with an amino group or a carboxy group). R ³ , R ⁴ , R ⁵ and R ⁶ may be bonded to each other to represent a cyclic structure. R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are determined depending on the benzofuran 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. As the halogen atom, a fluorine atom is preferable. However, it is not limited to these.
Examples of the organic group having reactivity with the 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 organic group reactive with the 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 benzofuran compound include 1-benzofuran (2,3-benzofuran), 2,3-dimethylbenzofuran, psoralen, anglycine, and the like. Among these, 1-benzofuran or 2,3-dimethylbenzofuran is preferable, and 1-benzofuran is more preferable.

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

  In the formula (B), X is a tetravalent organic group (excluding those containing a group reactive with an amino 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.
Examples of the group having reactivity with the amino group include, but are not limited to, a carboxy group, a carboxylic acid anhydride group, a carbonyl group, an aldehyde group, a halogenocarbonyl group, and the like.

  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, 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, 2,2-bis (3,4-dicarboxyphenyl) pro 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-dicarboxy) 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-dicarboxyphenyl) 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} Examples thereof include sulfide and bis {4- [3- (1,2-dicarboxy) phenoxy] phenyl} sulfide.

  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), 3,3 ′, 4,4′-benzophenonetetracarboxylic 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 Acid, bis (3,4-dicarboxyphenyl) ether, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane, and 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 exchange water, distilled water, deionized distilled water, RO water 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 becomes insufficient, and the desired effect may not be obtained. 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 benzofuran derivative composition>
An aqueous composition of a benzofuran derivative is produced by mixing and stirring a benzofuran 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 benzofuran derivative can be obtained by a reaction between a benzofuran compound and a tetracarboxylic acid in an aqueous medium. It is not necessary to collect the benzofuran derivative, which is a product, and mix it in an aqueous medium, thereby reducing the number of steps.
Usually, the number of moles of the benzofuran compound is preferably 0.5 to 4 times the number of moles of tetracarboxylic acid, and more preferably 1 to 2 times the number of moles.
The method of mixing the benzofuran compound, the tetracarboxylic acid, and the aqueous medium is not particularly limited. For example, the aqueous composition containing the benzofuran compound and the aqueous medium, and the aqueous composition containing the tetracarboxylic acid and the aqueous medium. A method of mixing and stirring a product, a method of adding a benzofuran compound to an aqueous composition containing a tetracarboxylic acid and an aqueous medium and stirring, a tetracarboxylic acid in an aqueous composition containing a benzofuran compound and an aqueous medium The method of adding and stirring is mentioned.
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 for producing the benzofuran 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 benzofuran derivative composition, and a batch type may be sufficient as it.

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

<Benzofuran derivative composition>
A benzofuran derivative composition containing a benzofuran derivative represented by the following formula (1) and an aqueous medium is produced by the above-described method for producing a benzofuran derivative composition.

In formula (1), R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are respectively R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ in formula (A). It is synonymous and X is synonymous with X in Formula (B).
In addition to the benzofuran derivative represented by the formula (1) and the aqueous medium, the benzofuran derivative composition is obtained by adding 2 to 4 molecules of benzofuran compound to one molecule of unreacted benzofuran compound, tetracarboxylic acid, and tetracarboxylic acid. A benzofuran derivative or the like may be contained.

2. Polyimide precursor composition manufacturing process A polyimide precursor composition manufacturing process mixes and stirs a benzofuran derivative, a polyamine, and an aqueous medium, and manufactures the aqueous composition (polyimide precursor composition) of a polyimide precursor. It is a process.

<Benzofuran derivative / aqueous medium>
The benzofuran derivative is synthesized in the benzofuran derivative composition manufacturing process, and is an aqueous composition when reacted in an aqueous medium.
The aqueous medium is as described above.

<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 (excluding those containing a group reactive with a carboxy group), and m is an integer of 2 or more. The upper limit of m is not particularly limited, but is preferably 600. 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. Arbitrary m 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 in which a hydrogen atom has been removed. However, it is not limited to these.
Examples of the group having reactivity with the 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 Diphenylmethane, 2,2-di (3- Minophenyl) 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-hexafluoropropane, 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) , 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminobenzoyl) benzene, 1,3-bis (4-amino) Benzoyl) 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-ditrifluoromethylbenzyl) ben Zen, 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-aminophenoxy) 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-hexafluoropropane, 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-aminophen) Xyl) benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-aminophenoxy) -α, α-dimethyl Benzyl] 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) phenoxy] 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-amino) Phenoxy) -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) polydimethylsiloxane, bis (aminomethyl) ether, Scan (2-aminoethyl) ether, bis (3-aminopropyl) ether, bis [(2-amino) ethyl] ether, bis [2- (2-aminoethoxy) ethyl] ether, bis [2- (3 - Aminopuro Po) ethyl] ether, 1,2-bis (aminomethoxy) ethane, 1,2-bis (2-aminoethoxy) ethane, 1,2-bis [2- (amino) 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-diaminopen 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] heptane, 2,5-bis (aminomethyl) bicyclo [2.2.1] heptane and the like.

  The polyamine is a substituent selected from the group consisting of a fluorine atom, a methyl group, a methoxy group, a trifluoromethyl group, and a trifluoromethoxy group, with some or all of the hydrogen atoms on the aromatic ring of the polyamine described above. Substituted polyamines can also be used.

As the polyamine, in addition to the above-mentioned polyamine, polymers having two or more primary amino groups in one molecule (excluding those containing a group having reactivity with a carboxy group in addition to the primary amino 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, tetracarboxylic acid obtained by grafting ethyleneimine to the side chain of an acrylic acid copolymer by utilizing the reactivity between the carboxy group of the polymer side chain and ethyleneimine. dianhydride excess of diamine or triamine in a stretched polyamic acid resin, urethane polyurethaneurea polymer was extended with an excess of diamine or triamine resin, modified epoxy resin extended with epoxy resin with excess di-amine or triamine Etc.
The group reactive with the carboxy group, e.g., human Dorokishi group, a carboxy group, although vinyloxy group, and the like, without limitation.

  Depending on the purpose, the polyamine may be an ethynyl group, a benzocyclobuten-4-yl group, a vinyl group, an allyl group, a cyano group, or an isopropenyl group that serves as a crosslinking point when a crosslinking reaction is performed after the formation of a polyimide. One type or two or more types 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 selected depending on the desired physical properties. If a rigid diamine such as p-phenylenediamine is used, the finally obtained polyimide has a low expansion coefficient. Rigid diamines include p-phenylenediamine, m-phenylenediamine, 1,4-diaminonaphthalene, 1,5-diaminonaphthalene, 2, 6 as diamines in which two amino groups are bonded to the same aromatic ring. -Diaminonaphthalene, 2,7-diaminonaphthalene, 1,4-diaminoanthracene and the like can be mentioned. A dendrimer such as polyamidoamine 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 bonded to separate aromatic rings either directly or as part of a substituent. 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 is used as the polyamine, the elastic modulus of the finally obtained resin composition is lowered, and the glass transition temperature is reduced. Can be reduced.

  Here, the polyamine selected is preferably an aromatic polyamine from the viewpoint of heat resistance, but the aliphatic diamine or siloxane is within a range not exceeding 60 mol%, preferably 40 mol% of the total of the diamine depending on the desired physical properties. Non-aromatic diamines such as diamines may be used.

  The polyamine may form a hydrohalide salt, for example, a salt such as hydrochloride or hydrobromide.

A polyamine can be used individually by 1 type or in combination of 2 or more types.
<Method for producing polyimide precursor composition>
The aqueous composition of a polyimide precursor is manufactured by mixing and stirring a benzofuran derivative, a polyamine, and an aqueous medium.
According to this method, similarly to the method for producing a benzofuran derivative composition, it is not necessary to use an organic solvent having a high environmental load, and the number of steps can be reduced.
The method for mixing the benzofuran derivative, the polyamine, and the aqueous medium is not particularly limited. For example, the aqueous composition containing the benzofuran derivative and the aqueous medium is mixed with the aqueous composition containing the polyamine and the aqueous medium. And a stirring method, a method of adding a polyamine to an aqueous composition containing a benzofuran derivative and an aqueous medium, and stirring.
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 benzofuran derivative represented by the above formula (1), a polyamine represented by the above formula (C), and an aqueous medium. A mixture of these may be sufficient as the polyimide precursor composition of this invention, and salt structure like following formula (2) which made the carboxylate and ammonium a pair may be sufficient as it.

(Volatile amine)
The polyimide precursor composition may contain a small amount of volatile amine for the purpose of supplementing the stability of the composition in water.
Such volatile amine is desirably to an amount that does not exceed the number of moles of carboxyl groups that are not used for the addition reaction of a benzofuran compound and Tet Raka carboxylic acids, such as ammonia, trimethylamine, triethylamine, tributylamine are preferred.
A volatile amine can be used individually by 1 type or in combination of 2 or more types.

(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, resin components such as other polymers and elastomers 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. . Examples of such organic solvents include N-methyl-2-pyrrolidone, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylcaprolactam, acetone, γ-butyrolactone, methyl ethyl ketone, methyl isobutyl. Organic solvents with high environmental impact such as ketones can be mentioned.

(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 which the polyimide precursor composition manufactured at the polyimide precursor composition manufacturing process contains may be sufficient.

<Heat treatment / curing>
By heat treatment, drying of the polyimide precursor composition, deprotection of the carboxy group of the benzofuran derivative (that is, elimination of the benzofuran compound from the benzofuran derivative) and imidation of tetracarboxylic acid and polyamine (by polyamic acid formation and dehydration ring closure) Curing by polyimide generation).
The heat treatment includes a step of drying the polyimide precursor composition, a step of deprotecting the carboxy group of the benzofuran derivative, and a step of curing by imidation of tetracarboxylic acid and polyamine (polyamide acid generation and polyimide generation by dehydration ring closure). 3 steps, a step of drying the polyimide precursor composition, a step of deprotecting the carboxy group of the benzofuran derivative, and a step of curing by imidization (dehydration ring closure) of tetracarboxylic acid and polyamine It is preferable that
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 benzofuran 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 benzofuran derivative and curing by imidization (dehydration ring closure) of tetracarboxylic acid and polyamine, or in the stage of curing by imidization (dehydration ring closure) of tetracarboxylic acid and polyamine, 400 ° C. is preferred. 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 or the like can be adopted. Usually, after heating and crosslinking in a predetermined shape, steam heating, oven heating, hot air is performed. Post-crosslinked by heating or the like.

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

  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, airbags, etc.

  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 (45.1 g) After stirring for 10 minutes at 25 ° C., 2,3-benzofuran (4.9 g) was added and further stirred and mixed at 25 ° C. for 30 minutes to obtain an aqueous dispersion of a benzofuran derivative.
To an aqueous dispersion of the obtained benzofuran derivative, a styrene acrylic polyamine (manufactured by Nippon Shokubai Co., Ltd., Poliment ^(R) NK-200PM; nonvolatile 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 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 test (25 ° C.)” in Table 2, and the observation results of the appearance are “Appearance of“ Storage stability test (25 ° C.) ”of Table 2. It is shown in the (visual) column.

(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) 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 (44.5 g) were added. In addition, after stirring and mixing at 25 ° C. for 10 minutes, 3-methylbenzofuran (5.5 g) was added, and further stirring and mixing at 25 ° C. for 30 minutes to obtain an aqueous dispersion of a benzofuran derivative.
To an aqueous dispersion of the obtained benzofuran derivative, a styrene acrylic polyamine (manufactured by Nippon Shokubai Co., Ltd., Poliment ^(R) NK-200PM; nonvolatile 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, storage stability test, solvent resistance test, water resistance test In the same manner as in Example 1, viscosity measurement, storage stability test, solvent resistance test and water resistance test were performed. The results are shown in Table 1, Table 2 and Table 3.

[Comparative 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 (50.0 g) It was added and mixed with stirring for 10 minutes at 25 ° C., styrene-acrylic polyamine (manufactured by Nippon Shokubai Co., Ltd., POLYMENT ^(R) NK-200PM; nonvolatile content 56 wt%, an amine value 2.55mmol / 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, 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) 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) And stirred and mixed at 25 ° C. for 10 minutes, butyl vinyl ether (4.1 g) was added, and further stirred and mixed 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., Polyment ^(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 the production of the obtained polyimide precursor composition are shown in the column “Initial Viscosity (22 ° C.)” in Table 1, and the viscosity measurement results in the storage stability test are shown in “Storage Stability Test ( “Viscosity (22 ° C.)” in the “25 ° C.” column, and the observation results of the appearance are shown in the “Appearance (visual)” column of “Storage stability test (25 ° C.)” in 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) 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 N-methyl-2-pyrrolidone (50.0 g) was added and stirred and mixed at 25 ° C. for 10 minutes, and then a styrene acrylic polyamine (manufactured by Nippon Shokubai Co., Ltd., Polyment (R) NK-200PM; non-volatile residue 56% by mass, amine value 2.55 mmol / g-solid, m = 60) (71.6 g) was added and mixed with stirring at 25 ° C. for 2 hours to obtain a polyimide precursor solution (polyimide precursor composition).
(2) Viscosity measurement, storage stability test, solvent resistance test, water resistance test In the same manner as in Example 1, viscosity measurement, storage stability test, solvent resistance test and water resistance test were performed.
The obtained polyimide precursor composition showed a solution state on the first day of preparation, but crystals were deposited on the third day and thereafter, so the coating film test was not performed. The results are shown in Table 1, Table 2, and Table 3.

The polyimide precursor compositions of Example 1 and Example 2 have low viscosity and excellent coatability.
The polyimide precursor composition containing the polyimide precursor which added the vinyl ether compound instead of the benzofuran compound of the comparative example 2 is also low viscosity, and is excellent in coating property.
The polyimide precursor composition prepared as an N-methyl-2-pyrrolidone solution instead of the polyimide precursor aqueous dispersion of Comparative Example 3 has a low initial viscosity and excellent coatability. However, it has a high environmental load and is disadvantageous in terms of cost.

The polyimide precursor compositions of Example 1 and Example 2 have a low viscosity and do not impair the coatability even after a period after production.
On the other hand, the polyimide precursor composition containing a polyimide precursor to which a vinyl ether compound is added instead of the benzofuran compound of Comparative Example 2 has a low initial viscosity and excellent coatability, but the appearance changes after a period after manufacture. At the same time, the viscosity increases and the coatability is impaired.
Moreover, although 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 is low in initial viscosity and excellent in coating property, it is crystallized after 3 days. Will precipitate and become unusable.

Even if the polyimide precursor composition of Example 1 and Example 2 passes the period after manufacture, the polyimide resin obtained by heat-processing is excellent in solvent resistance and water resistance.
On the other hand, the polyimide precursor composition containing the polyimide precursor which added the vinyl ether compound instead of the benzofuran compound of the comparative example 2 is a solvent-resistant polyimide resin obtained by heat-processing when the period after manufacture passes. And water resistance becomes inferior.
Moreover, the polyimide precursor composition made into the N-methyl-2- pyrrolidone solution instead of the polyimide precursor aqueous dispersion of the comparative example 3 was crystal-deposited after 3 days of preparation, and could not be used. However, the polyimide resin obtained by heat-treating the composition one day after preparation is excellent in solvent resistance and water resistance.

Claims (3)

A benzofuran derivative composition comprising a benzofuran 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 , R ⁴ , R ⁵ and R ^6. Each independently represents a hydrogen atom, a halogen atom or a monovalent organic group (excluding those having reactivity with an amino group or a carboxy group). R ³ , R ⁴ , R ⁵ and R ⁶ may be bonded to each other to show a cyclic structure. ] A polyimide precursor composition comprising a benzofuran 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 , R ⁴ , R ⁵ and R ^6. Each independently represents a hydrogen atom, a halogen atom or a monovalent organic group (excluding those having reactivity with an amino group or a carboxy group). R ³ , R ⁴ , R ⁵ and R ⁶ 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 benzofuran derivative composition production process in which a benzofuran 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 benzofuran derivative obtained in the benzofuran derivative composition manufacturing step, a polyamine represented by the following formula (C), and an aqueous medium are mixed and stirred, and the polyimide precursor composition 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 product manufacturing process.

[In formula (A), R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom, a halogen atom or a monovalent organic group (reactive with an amino group or a carboxy group) R ³ , R ⁴ , R ⁵ and R ⁶ 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. ]