JP6240799B1 - Method for synthesizing diamine compound, and method for synthesizing polyimide compound using diamine compound synthesized by this method - Google Patents

Abstract

A novel diamine compound synthesis method capable of synthesizing a polyimide compound having high solubility in an organic solvent and melt moldability is provided. A 4-nitrobenzoic acid derivative such as 4-nitrobenzoyl chloride is reacted with a 4-nitrophenol derivative such as 2-hydroxy-5-nitrobiphenyl, and then the nitro group of the reaction product is reduced. A method for synthesizing a diamine compound represented by 1). Further, a method of synthesizing a polyamic acid by reacting the dian compound with an acid anhydride. (R1 to R8 are each independently H, F, a substituted / unsubstituted alkyl group or a substituted / unsubstituted aromatic group; at least one of R1 to R8 is a substituted / unsubstituted aromatic group) ] None

Description

  The present invention relates to a method for synthesizing a novel diamine compound, and more particularly, to a method for synthesizing a novel diamine compound capable of synthesizing a polyimide compound having improved solubility in organic solvents and melt moldability. The present invention relates to a polyimide compound synthesized using a synthesized diamine compound.

  In general, polyimide resin has excellent heat resistance, mechanical strength, wear resistance, dimensional stability, chemical resistance, insulation, etc. In the field of electronic materials such as flexible printed boards and printed wiring boards. Widely used. In addition to the electronic equipment field, it is widely used in the space / aviation field, the automobile field, and the like. Among these polyimides, polyimides using aromatic diamines and aromatic acid anhydrides as raw materials are known as polyimides having excellent mechanical strength and heat resistance. For example, polyimide compounds made from aromatic diamines such as 4-aminophenyl-4-aminobenzoate and pyromellitic dianhydride are excellent in heat resistance, mechanical properties, electrical insulation, etc. It is suitably used as a protective material or insulating material in the device field (Patent Document 1, etc.).

  On the other hand, the aromatic polyimide compound described above has a low solubility in an organic solvent because of its rigid structure. Therefore, when producing a cover film of a flexible printed wiring substrate (FPC), an insulating layer of an electronic circuit, etc., instead of using a polyimide compound, a diamine compound and an acid anhydride are reacted in an organic solvent, and high It has been performed by applying a polyamic acid solvent having organic solvent solubility to a base material and the like, followed by heat drying at a high temperature to cause a cyclization dehydration reaction (polyimidation) (Patent Document 1, etc.).

JP 2014-173071 A

However, the base material on which the polyimide film is provided must have high heat resistance that can withstand the cyclization dehydration reaction (generally 300 to 400 ° C.). Furthermore, it must be carried out in an environment where a special heating device for the cyclization dehydration reaction can be used, and there are various limitations in the production of a molded product using a polyimide compound. In addition, the polyamic acid compound is unstable, reacts with water, easily hydrolyzes, and tends to cause a decrease in molecular weight.
Furthermore, most polyimide compounds do not have a melting point, and even if they have a melting point, the temperature is extremely high and it is difficult to perform melt molding, which is a problem in terms of melt moldability. was there.

The present invention has been made in view of the above problems, and its object is to provide a novel method for synthesizing a diamine compound capable of synthesizing a polyimide compound having high solubility in organic solvents and high melt moldability. It is.
Another object of the present invention is to provide a method for synthesizing a polyimide compound having high organic solvent solubility and melt moldability synthesized using a diamine compound synthesized by this method.

The method for synthesizing a diamine compound, which is represented by the following general formula (1) of the present invention,
A step of reacting a compound represented by the following general formula (3) and a compound represented by the following general formula (4) to obtain a reaction product;
Reducing the nitro group of the reactant.
(In the above formula,
R _{1 to} R ₈ are each independently selected from the group consisting of hydrogen, fluorine, a substituted or unsubstituted alkyl group and a substituted or unsubstituted aromatic group;
At least one of R _{1 to} R ₈ is a substituted or unsubstituted aromatic group;
R ₁ ′ to R ₈ ^′ are each independently selected from the group consisting of hydrogen, fluorine, a substituted or unsubstituted alkyl group and a substituted or unsubstituted aromatic group,
At least one of R ₁ ′ to R ₈ ′ is an aromatic group. )

In the said aspect, it is preferable that one or two of R < ₅ > -R < ₈ > is a substituted or unsubstituted aromatic group.

In the above embodiment, one or two of R _{5 to} R ₈ is a substituted or unsubstituted aromatic group, and R _{1 to} R ₈ other than the aromatic group are hydrogen, fluorine, and substituted or unsubstituted alkyl. It is preferably a group.

  In the above embodiment, the reaction with the compound represented by the general formula (3) and the compound represented by the general formula (4) is carried out in the presence of a catalyst, a dehydrating condensing agent or an acid acceptor. Are preferred.

  In the above embodiment, X is preferably a halogen group.

  In the said aspect, it is preferable that carbon number of a substituted or unsubstituted aromatic group is 5-20.

  In the above embodiment, the substituted or unsubstituted aromatic group is preferably selected from the group consisting of a phenyl group, a methylphenyl group, a phenoxy group, a benzyl group, and a benzyloxy group.

  The method for synthesizing the polyimide compound of the present invention includes a step of reacting the diamine compound obtained by the above method with an acid anhydride to obtain a polyamic acid, and a step of subjecting the polyamic acid to a cyclization dehydration reaction. Features.

  In the said aspect, it is preferable that the mixing ratio of a diamine compound and an acid anhydride is 0.5 mol%-1.5 mol% of the total amount of a diamine compound with respect to 1 mol% of the total amount of an acid anhydride.

  In the above embodiment, the acid anhydride is pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2-bis [3- (3,4-dicarboxyl). Phenoxy) phenyl] propane dianhydride, 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride and 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride And oxy-4,4′-diphthalic dianhydride.

  In the said aspect, it is preferable that reaction of a diamine compound and an acid anhydride is performed in an organic solvent.

According to the method of the present invention, a diamine compound capable of remarkably improving the organic solvent solubility and melt moldability of the polyimide compound can be provided. Therefore, a molded article of a polyimide compound can be produced without considering the heat resistance of the substrate.
In addition, since it is not necessary to use a special apparatus for heat treatment for manufacturing the molded product, the molded product can be manufactured at various places.
Further, the molded product thus produced has a 5% weight loss rate, glass transition temperature (Tg), melting temperature, thermal expansion coefficient, tensile strength, similar to that of a molded product produced using a conventional polyimide compound. Since it has an elastic modulus and a water absorption rate and has high heat resistance and mechanical properties, it can be widely used in various fields such as the electronic equipment field, the space / aviation field, and the automobile field.

FIG. 1 shows a ¹ H-NMR chart of the compound represented by the chemical formula (2) obtained in the example. FIG. 2 shows a ¹³ C-NMR chart of the compound represented by the chemical formula (2) obtained in the example. FIG. 3 shows an FT-IR chart of the compound represented by the chemical formula (2) obtained in the example.

(Diamine compound)
The diamine compound synthesized by the method of the present invention is represented by the following general formula (1).

In the above formula, R _{1 to} R ₈ are each independently selected from the group consisting of hydrogen, fluorine, a substituted or unsubstituted alkyl group and a substituted or unsubstituted aromatic group, and at least _one of R _{1 to} R ₈ One is an aromatic group. Preferably, one or two of R _{1 to} R ₈ are aromatic groups.
Preferably, one or two of R _{5 to} R ₈ is a substituted or unsubstituted aromatic group, more preferably at least R ₅ or R ₇ is an aromatic group.
By having an aromatic group at the above-described position, the steric hindrance of the diamine compound can be suppressed, and the polymerization reaction with an acid anhydride or the like can be favorably advanced.
In a particularly preferred embodiment, one or two of R _{5 to} R ₈ are a substituted or unsubstituted aromatic group, and R _{1 to} R ₈ other than the aromatic group are hydrogen, fluorine, and a substituted or unsubstituted alkyl group. Selected from the group consisting of Specific examples include the following compounds (an embodiment in which R ₇ is an aromatic group, and R _{1 to} R ₆ and R ₈ other than R ₇ are hydrogen).

In the present invention, the alkyl group includes straight-chain, branched-chain, and cyclic groups, and further, an alkoxy group, an alkylamino group, and the like that are bonded to the main skeleton via an oxygen atom or a nitrogen atom. Is included.
Similarly, the aromatic group includes a substituent bonded to the main skeleton through an oxygen atom, a nitrogen atom, or a carbon atom. Furthermore, the aromatic group includes a heteroaromatic group such as a pyrrole group.

  The alkyl group and the aromatic group are preferably unsubstituted from the viewpoint of ease of synthesis of the diamine compound and use in the field of electronic component materials, but may have a substituent, for example, an alkyl group, Examples include halogen groups such as a fluoro group and a chloro group, amino groups, nitro groups, hydroxyl groups, cyano groups, carboxyl groups, and sulfonic acid groups. The alkyl group and the aromatic group may have one or more or two or more of these substituents.

The alkyl group preferably has 1 to 10 carbon atoms, and more preferably 1 to 3 carbon atoms.
Examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, tert-butyl group, n-pentyl group, sec-pentyl group, and n-to. Xyl group, cyclohexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, fluoromethyl group, difluoromethyl group, trifluoromethyl group, chloromethyl group, dichloromethyl group, Trichloromethyl group, bromomethyl group, dibromomethyl group, tribromomethyl group, fluoroethyl group, difluoroethyl group, trifluoroethyl group, chloroethyl group, dichloroethyl group, trichloroethyl group, bromoethyl group, dibromoethyl group, tribromoethyl Group, hydroxymethyl group, hydroxyethyl group, hydroxylpropyl group, methoxy Group, ethoxy group, n-propoxy group, n-butoxy group, n-pentyloxy group, sec-pentyloxy group, n-hexyloxy group, cyclohexyloxy group, n-heptyloxy group, n-octyloxy group, Examples include n-nonyloxy group, n-decyloxy group, trifluoromethoxy group, methylamino group, dimethylamino group, trimethylamino group, ethylamino group, propylamino group and the like.
Among the alkyl groups described above, a methyl group, an ethyl group, a methoxy group, an ethoxy group, and a trifluoromethyl group are preferable because of steric hindrance and heat resistance.

The aromatic group preferably has 5 to 20 carbon atoms, and more preferably 6 to 10 carbon atoms.
Examples of the aromatic group having 5 to 20 carbon atoms include phenyl group, tolyl group, methylphenyl group, dimethylphenyl group, ethylphenyl group, diethylphenyl group, propylphenyl group, butylphenyl group, fluorophenyl group, and pentafluoro. Phenyl, chlorophenyl, bromophenyl, methoxyphenyl, dimethoxyphenyl, ethoxyphenyl, diethoxyphenyl, benzyl, methoxybenzyl, dimethoxybenzyl, ethoxybenzyl, diethoxybenzyl, aminophenyl Group, aminobenzyl group, nitrophenyl group, nitrobenzyl group, cyanophenyl group, cyanobenzyl group, phenethyl group, phenylpropyl group, phenoxy group, benzyloxy group, phenylamino group, diphenylamino group, biphenyl group, Phthyl group, phenylnaphthyl group, diphenylnaphthyl group, anthryl group, anthrylphenyl group, phenylanthryl group, naphthacenyl group, phenanthryl group, phenanthrylphenyl group, phenylphenanthryl group, pyrenyl group, phenylpyrenyl group, Fluorenyl group, phenylfluorenyl group, naphthylethyl group, naphthylpropyl group, anthracenylethyl group, phenanthrylethyl group, pyrrole group, imidazole group, thiazole group, oxazole group, furan group, thiophene group, triazole group Heteroaromatic groups such as pyrazole group, isoxazole group, isothiazole group, pyridine group, pyrimidine group, benzofuran group, benzothiophene group, quinoline group, isoquinoline group, indolyl group, benzothiazolyl group, carbazolyl group It is below.
Among the aromatic groups described above, a phenyl group, a phenoxy group, a benzyl group, and a benzyloxy group are preferable from the viewpoint of availability of starting materials and synthesis cost.

(Method for synthesizing diamine compound)
The diamine compound represented by the general formula (1) reduces the nitro group after reacting the compound represented by the following general formula (3) with the compound represented by the following general formula (4). Can be obtained.

In the above formula, R ₁ ′ to R ₈ ′ are each independently selected from the group consisting of hydrogen, fluorine, a substituted or unsubstituted alkyl group and a substituted or unsubstituted aromatic group, and R ₁ ′ to R _{1 At} least one of ₈ 'is an aromatic group.
Preferably, at least one of R ₅ ′ to R ₈ ′ is a substituted or unsubstituted aromatic group, and more preferably, at least R ₅ ′ or R ₇ ′ is an aromatic group.
In a particularly preferred embodiment, one of R ₅ ′ to R ₈ ′ is a substituted or unsubstituted aromatic group, and R ₁ ′ to R ₈ ′ other than the aromatic group are hydrogen, fluorine and substituted or unsubstituted alkyl. It is a group.
In the above formula, X represents a hydroxyl group or a halogen group selected from a fluoro group, a chloro group, a bromo group and an iodo group. From the viewpoint of reactivity with the compound represented by the general formula (4), X is preferably a halogen group, particularly preferably a chloro group or a bromo group.

In the general formula (3), when X is a hydroxyl group, the reaction of the compounds represented by the general formulas (3) and (4) is preferably performed in the presence of a catalyst or a dehydrating condensing agent.
Examples of the catalyst include organic or inorganic basic compounds such as dimethylaminopyridine, tri-n-butylamine, pyridine, lysine, imidazole, sodium carbonate, sodium alcoholate, and potassium bicarbonate, and organic compounds such as toluenesulfonic acid, methanesulfonic acid, and sulfuric acid. An acid or an inorganic acid can be illustrated.
Examples of the dehydrating condensing agent include carbodiimides such as N, N′-dicyclohexylcarbodiimide (DCC), N, N′-diisopropylcarbodiimide, N-cyclohexyl-N ′-(4-diethylamino) cyclohexylcarbodiimide.
In the general formula (3), when X is a halogen group, the reaction of the compounds represented by the general formulas (3) and (4) is preferably performed in the presence of an acid acceptor. Specifically, trialkylamines such as triethylamine, tributylamine, N, N-dimethylcyclohexylamine, aliphatic cyclic tertiary amines such as N-methylmorpholine, N, N-dimethylaniline, triphenylamine and the like. Examples include aromatic amines, heterocyclic amines such as pyridine, picoline, lutidine, and quinoline.

More specifically, the diamine compound represented by the above formula (2) can be obtained by reacting the compounds represented by the following formulas (5) and (6).

The compound represented by the general formula (4) can be obtained by nitrating a compound represented by the following general formula (7) which is commercially available or synthesized. Nitration of the compound represented by the following general formula (7) uses mixed acid of concentrated sulfuric acid and concentrated nitric acid, nitric acid, fuming nitric acid, concentrated alkali metal salt of sulfuric acid, acetyl nitrate, nitronium salt, nitrogen oxide, etc. The conventional nitration method can be used.

R ₅ ″ to R ₈ ″ are each independently selected from the group consisting of hydrogen, fluorine, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted aromatic group. Preferably at least one of R ₅ ″ to R ₈ ″ is more preferably one or two is an aromatic group.

The diamine compound synthesized by the method of the present invention can also be used for the synthesis of compounds other than the polyimide compound described below.
For example, terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, diphenyl ether carboxylic acid, diphenyl sulfone carboxylic acid, biphenyl dicarboxylic acid, terphenyl dicarboxylic acid, diphenylmethane dicarboxylic acid, 2,2-bis (4-carboxyphenyl) propane, 2,2 A polyamide compound can be synthesized by reacting with a dicarboxylic acid derivative such as -bis (4-carboxyphenyl) hexafluoropropane, cyclohexanedicarboxylic acid, dicyclohexanedicarboxylic acid, and these acid halides.
The diamine compound of the present invention can also be used for the synthesis of polyamideimide compounds, polyurethane compounds, and epoxy compounds.

(Polyimide compound)
The polyimide compound synthesized by the method of the present invention is a reaction product of the diamine compound represented by the general formula (1) and an acid anhydride. About the structure of the diamine compound represented by General formula (1), since it mentioned above, it abbreviate | omits here.
By using the diamine compound represented by the general formula (1) as a component of the polyimide compound, the solubility of the polyimide compound in the organic solvent can be remarkably improved.

  In the polyimide compound, the content of the diamine compound represented by the general formula (1) in the total diamine is preferably 10 mol% to 100 mol%, and preferably 30 mol% to 100 mol%. More preferably, it is more preferably 50 mol% to 100 mol%. By setting the content of the diamine compound in the above numerical range, it is possible to introduce a rigid ester structure and further improve the solubility in an organic solvent.

The number average molecular weight of the polyimide compound is preferably 2000 to 200000, and more preferably 4000 to 100,000.
In the present invention, the number average molecular weight is a polystyrene conversion value based on a calibration curve prepared using standard polystyrene by a gel permeation chromatography (GPC) apparatus.
By making a number average molecular weight into the said numerical range, while being able to improve the mechanical physical property of the film obtained using this polyimide compound, a moldability can be improved.

  The melting point of the polyimide compound is preferably 150 ° C. or higher and 420 ° C. or lower, more preferably 200 ° C. or higher and 350 ° C. or lower, from the viewpoints of heat resistance of the molded product, productivity of the molded product, and cost. .

(Acid anhydride)
Examples of the acid anhydride include oxydiphthalic acid, pyromellitic dianhydride, 3-fluoropyromellitic dianhydride, 3,6-difluoropyromellitic dianhydride, and 3,6-bis (trifluoromethyl). Pyromellitic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 2,2 ′, 3,3′-benzophenonetetracarboxylic dianhydride, 3,3 ′, 4,4 ′ -Benzophenone tetracarboxylic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'-biphenylsulfone tetracarboxylic dianhydride, 4,4 '-(4,4'-isopropylidenediphenoxy) bisphthalic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride Thing, 3, 3 ″, 4,4 ″ -terphenyltetracarboxylic dianhydride, 3,3 ′ ″, 4,4 ′ ″-quaterphenyltetracarboxylic dianhydride, 2,2 ′, 3 3′-biphenyltetracarboxylic dianhydride, methylene-4,4′-diphthalic dianhydride, 1,1-ethynylidene-4,4′-diphthalic dianhydride, 2,2-propylidene-4,4 '-Diphthalic dianhydride, 1,2-ethylene-4,4'-diphthalic dianhydride, 1,3-trimethylene-4,4'-diphthalic dianhydride, 1,4-tetramethylene-4 , 4′-diphthalic dianhydride, 1,5-pentamethylene-4,4′-diphthalic dianhydride, 1,3-bis [2- (3,4-dicarboxyphenyl) -2-propyl] Benzene dianhydride, 1,4-bis [2- (3,4-dicarboxyphenyl) -2-propyl] benzene dianhydride Bis [3- (3,4-dicarboxyphenoxy) phenyl] methane dianhydride, bis [4- (3,4-dicarboxyphenoxy) phenyl] methane dianhydride, 2,2-bis [3- (3 4-dicarboxyphenoxy) phenyl] propane dianhydride, 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride, difluoromethylene-4,4′-diphthalic dianhydride 1,1,2,2-tetrafluoro-1,2-ethylene-4,4′-diphthalic dianhydride, 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride, oxy- 4,4′-diphthalic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, thio-4,4′-diphthalic dianhydride, sulfonyl-4,4′-diphthalic acid Dianhydride, 1,3-bi (3,4-dicarboxyphenyl) benzene dianhydride, 1,4-bis (3,4-dicarboxyphenyl) benzene dianhydride, 1,3-bis (3,4-dicarboxyphenoxy) benzene dianhydride 1,4-bis (3,4-dicarboxyphenoxy) benzene dianhydride, bis (3,4-dicarboxyphenoxy) dimethylsilane dianhydride, 1,3-bis (3,4-dicarboxyphenoxy) ) -1,1,3,3-tetramethyldisiloxane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexane-1,2,3,4 -Tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, 3,3 ', 4,4'-bicyclohexyltetracarboxylic dianhydride, carbonyl-4,4' -Bis (cyclohexane-1,2-dicarboxylic acid) dianhydride, methylene-4,4'-bis (cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,2-ethylene-4,4'-bis (Cyclohexane-1,2-dicarboxylic acid) dianhydride, oxy-4,4′-bis (cyclohexane-1,2-dicarboxylic acid) dianhydride, thio-4,4′-bis (cyclohexane-1,2) -Dicarbo Acid) dianhydride, sulfonyl-4,4′-bis (cyclohexane-1,2-dicarboxylic acid) dianhydride, 3,3 ′, 5,5′-tetrakis (trifluoromethyl) oxy-4,4 '-Diphthalic dianhydride, 3,3', 6,6'-tetrakis (trifluoromethyl) oxy-4,4'-diphthalic dianhydride, 5,5 ', 6,6'-tetrakis (tri Fluoromethyl) oxy-4,4′-diphthalic dianhydride, 3,3 ′, 5,5 ′, 6,6′-hexakis (trifluoromethyl) oxy-4,4′-diphthalic dianhydride, 3,3′-difluorosulfonyl-4,4′-diphthalic dianhydride, 5,5′-difluorosulfonyl-4,4′-diphthalic dianhydride, 6,6′-difluorosulfonyl-4,4 ′ -Diphthalic dianhydride, 3,3 ', 5,5', 6,6'-hexafluorosulfonate 4,4′-diphthalic dianhydride, 3,3′-bis (trifluoromethyl) sulfonyl-4,4′-diphthalic dianhydride, 5,5′-bis (trifluoromethyl) sulfonyl- 4,4′-diphthalic dianhydride, 6,6′-bis (trifluoromethyl) sulfonyl-4,4′-diphthalic dianhydride, 3,3 ′, 5,5′-tetrakis (trifluoromethyl) ) Sulfonyl-4,4′-diphthalic dianhydride, 3,3 ′, 6,6′-tetrakis (trifluoromethyl) sulfonyl-4,4′-diphthalic dianhydride, 5,5 ′, 6 6′-tetrakis (trifluoromethyl) sulfonyl-4,4′-diphthalic dianhydride, 3,3 ′, 5,5 ′, 6,6′-hexakis (trifluoromethyl) sulfonyl-4,4′- Diphthalic dianhydride, 3,3'-difluoro-2,2-perfluoro Propyridene-4,4′-diphthalic dianhydride, 5,5′-difluoro-2,2-perfluoropropylidene-4,4′-diphthalic dianhydride, 6,6′-difluoro-2,2 -Perfluoropropylidene-4,4'-diphthalic dianhydride, 3,3 ', 5,5', 6,6'-hexafluoro-2,2-perfluoropropylidene-4,4'-diphthal Examples thereof include acid dianhydride, 3,3′-bis (trifluoromethyl) -2,2-perfluoropropylidene-4,4′-diphthalic dianhydride, ethylene glycol bistrimellitate dianhydride, and the like.
Among the above anhydrides, pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2-bis [3- (3,4-dicarboxyphenoxy) phenyl Propane dianhydride, 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride and 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride, oxy -4,4'-diphthalic dianhydride is preferred from the viewpoint of reactivity with the diamine compound of the present invention.
In the synthesis of the polyimide compound, one or more of the above anhydrides may be used.

(Other diamine compounds)
The polyimide compound may contain other diamine compounds other than the diamine compound represented by the general formula (1) as a constituent element.
Examples of other diamine compounds include m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,4 (6) -diamino-3,5-diethyltoluene, 5 (6) -amino-1 , 3,3-trimethyl-1- (4-aminophenyl) -indane, 4,4′-diamino-2,2′-dimethyl-1,1′-biphenyl, 4,4′-diamino-2,2 ′ -Ditrifluoromethyl-1,1'-biphenyl, 4,4'-diamino-3,3'-dimethyl-1,1'-biphenyl, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3, , 3′-diaminodiphenylsulfone, 4,4′-diaminodiphenylsulfone, 4,4′-diaminodiphenylsulfide, 4-aminophenyl-4-aminobenzoate, 4,4 ′ (9-fluorenylidene) dianiline, 9,9'-bis (3-methyl-4-aminophenyl) fluorene, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene 1,4-bis (4-aminophenoxy) benzene, 2,2-bis (4-aminophenyl) propane, 2,2-bis (3-methyl-4-aminophenyl) propane, 4,4 ′-( Hexafluoroisopropylidene) dianiline, 2,2-bis (3-amino-4-methylphenyl) hexafluoropropane, 2,2-bis (3-methyl-4-aminophenyl) benzene, 2,2-bis [4 -(4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, α, α-bis [4- (4 -Aminophenoxy) phenyl] -1,3-diisopropylbenzene, α, α-bis [4- (4-aminophenoxy) phenyl] -1,4-diisopropylbenzene, 3,7-diamino-dimethyldibenzothiophene 5,5 Dioxide, bis (3-carboxy-4-aminophenyl) methylene, 3,3′-diamino-4,4′-dihydroxy-1,1′-biphenyl, 4,4′-diamino-3,3′-dihydroxy- 1,1′-biphenyl, 2,2-bis (3-amino-4-hydroxyphenyl) propane, 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 1,3-bis (3 -Hydroxy-4-aminophenoxy) benzene, 2,2-bis (3-hydroxy-4-aminophenyl) benzene, 3,3'-diamino-4,4 ' -Dihydroxy diphenyl sulfone etc. are mentioned.
The polyimide compound may contain one or more of the other diamine compounds described above as a constituent element.

The polyimide compound can be formed into a film or the like as will be described later, and used as a base film or cover film of a flexible printed wiring substrate (FPC). It can also be used as an adhesive in flexible wiring boards and the like.
In addition, it can be used as an electric insulation coating material for wires, a heat insulating material, a transparent substrate for liquid crystal display elements, a thin film transistor substrate, and the like.

(Synthesis method of polyimide compound)
In the method for synthesizing the polyimide compound of the present invention, the diamine compound represented by the above general formula (1) is reacted with an acid anhydride to obtain a polyamic acid, and then a cyclized dehydration reaction is performed to convert it into a polyimide compound. Can be obtained.

  The mixing ratio of the acid anhydride and the diamine compound is preferably 0.5 mol% to 1.5 mol% of the total amount of the diamine compound with respect to 1 mol% of the total amount of acid anhydride, and 0.9 mol% More preferably, it is -1.1 mol%.

The reaction between the diamine compound and the acid anhydride is preferably performed in an organic solvent.
The organic solvent is not particularly limited as long as it does not react with the diamine compound and acid anhydride of the present invention and can dissolve the reaction product of the diamine compound and acid anhydride. -Methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, N, N'-dimethylimidazolidinone, γ-butyrolactone, dimethyl sulfoxide, sulfolane, 1,3-dioxolane, tetrahydrofuran, ethylene glycol Monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene group Cole dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, dipropylene glycol dimethyl ether, diethylene glycol dibutyl ether, dibenzyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propyl acetate, propylene glycol diacetate , Butyl acetate, isobutyl acetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, benzyl acetate, butyl carbitol acetate, methyl lactate, ethyl lactate, butyl lactate, methyl benzoate, ethyl benzoate, triglyme , Tetraglyme, a Tylacetone, methyl propyl ketone, methyl butyl ketone, methyl isobutyl ketone, cyclopentanone, 2-heptanone, butyl alcohol, isobutyl alcohol, pentanol, 4-methyl-2-pentanol, 3-methyl-2-butanol, 3- Examples include methyl-3-methoxybutanol, diacetone alcohol, toluene, xylene and the like.
From the viewpoint of the solubility of the polyimide compound synthesized by the method of the present invention, N-methyl-2-pyrrolidone, N, N′-dimethylimidazolidinone and γ-butyrolactone are preferable in the polyimide.

  The reaction temperature between the diamine compound and the acid anhydride is preferably 40 ° C. or lower in the case of chemical imidization. Moreover, in the case of thermal imidation, it is preferable that it is 150-220 degreeC, and it is more preferable that it is 170-200 degreeC.

During the cyclization dehydration reaction, an imidation catalyst may be used, for example, methylamine, ethylamine, trimethylamine, triethylamine, propylamine, tripropylamine, butylamine, tributylamine, tert-butylamine, hexylamine, triethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, triethylenediamine, N-methylpyrrolidine, N-ethylpyrrolidine, aniline, benzylamine, toluidine, trichloroaniline, pyridine, collidine, lutidine, picoline, quinoline, isoquinoline , Valerolactone and the like can be used.
If necessary, an azeotropic dehydrating agent such as toluene, xylene, and ethylcyclohexane, and an acid catalyst such as acetic anhydride, propionic anhydride, butyric anhydride, and benzoic anhydride can be used.

Sealing agents such as benzoic acid, phthalic anhydride, and hydrogenated phthalic anhydride can be used in the reaction of the diamine compound and the acid anhydride.
Furthermore, by using maleic anhydride, ethynyl phthalic anhydride, methyl ethynyl phthalic anhydride, phenyl ethynyl phthalic anhydride, phenyl ethynyl trimellitic anhydride, 3- or 4-ethynyl aniline, etc. A double bond or a triple bond can also be introduced at the terminal.
By introducing a double bond or a triple bond into a polyimide compound, the polyimide compound of the present invention can be used as a thermosetting resin.

(Molded product)
The molded product of the present invention comprises a polyimide compound obtained by using the diamine compound represented by the general formula (1).
Examples of molded products containing a polyimide compound include cylinder head covers, bearing retainers, intake manifolds, automobile parts such as pedals, casings used in personal computers, mobile phones, flexible printed boards, printed wiring boards, etc. Examples thereof include electronic material parts and fuel cell parts such as ion conductive separators.

  The shape of the molded product of the present invention is not particularly limited, and can be appropriately changed according to the application. For example, it can be a film or a sheet.

  The content of the polyimide compound obtained by using the diamine compound represented by the general formula (1) in the molded product of the present invention is preferably 30% by mass or more and 100% by mass or less, and 50% by mass or more. 100% by mass or less, more preferably 60% by mass or more and 100% by mass or less.

  The molded product of the present invention may contain other compounds as long as the characteristics are not impaired. For example, polyolefin resin, polyester resin, cellulose resin, vinyl resin, polycarbonate resin, polyamide resin. Styrene resin, ionomer resin and the like.

  Further, the molded product of the present invention may contain various additives as long as the characteristics are not impaired. For example, as additives, plasticizers, UV stabilizers, anti-coloring agents, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, yarn friction reducing agents, slip agents, mold release agents, antioxidants Agents, ion exchangers, dispersants, ultraviolet absorbers, and colorants such as pigments and dyes.

The 5% weight reduction temperature of the molded product of the present invention is preferably 480 ° C. or higher, and more preferably 500 ° C. or higher.
In the present invention, the 5% weight reduction temperature of the molded product is in accordance with JIS K 7120, using a thermomechanical analyzer (for example, trade name: TGA-50 manufactured by Shimadzu Corporation), in nitrogen at 5 ° C. / It can be measured at a rate of temperature rise of minutes.

The glass transition temperature (Tg) of the molded product of the present invention is preferably 200 ° C. or higher, more preferably 210 ° C. or higher, and further preferably 220 ° C. or higher.
In the present invention, the glass transition temperature (Tg) of the molded product conforms to JIS K 7121, using a thermomechanical analyzer (manufactured by Shimadzu Corporation, trade name: DSC-60Plus) under a nitrogen stream at 10 ° C. / It can be measured at a rate of temperature rise of minutes.

The melting temperature of the molded product of the present invention is preferably 150 ° C. or higher, and more preferably 200 ° C. or higher. In addition, the melting temperature is preferably 420 ° C. or lower, and more preferably 350 ° C. or lower.
In the present invention, the melting temperature of the molded product can be measured by a DSC measuring device and / or a dynamic viscoelasticity measuring device.

The thermal expansion coefficient (CTE) of the molded product of the present invention is preferably 30.0 × 10 ⁻⁶ / K or less, more preferably 20.0 × 10 ⁻⁶ / K or less, and 15.0. It is more preferable that it is not more than × 10 ⁻⁶ / K.
In the present invention, the thermal expansion coefficient (CTE) of the molded article is TMA-60 (trade name) manufactured by Shimadzu Corporation, and the temperature rises at 10 ° C./min while applying a weight of 5 g. The temperature is raised from room temperature to 450 ° C., and the average coefficient of thermal expansion (CTE) from 100 ° C. to 250 ° C. is indicated.

The molded article of the present invention preferably has a tensile strength of 80 MPa or more, more preferably 100 MPa or more, and further preferably 120 MPa or more.
In the present invention, the tensile strength of the molded product is determined in the MD direction and the TD direction by measuring the molded product using a tensile tester (manufactured by Shimadzu Corporation, trade name: AG-Xplus 50 kN) at a tensile speed of 10 mm / min. The average value of the tensile strength.

The elastic modulus of the molded product of the present invention is preferably 5.0 GPa or more, more preferably 7.0 GPa or more, and further preferably 9.0 GPa or more.
The elastic modulus of the molded product of the present invention is measured in the MD direction and the TD direction measured using a tensile tester (manufactured by Shimadzu Corporation, trade name: AG-Xplus 50 kN) at a tensile speed of 10 mm / min. The average value of elastic modulus.

The water absorption of the molded product of the present invention is preferably 1.5% or less, and more preferably 1.0% or less.
The water absorption rate of the molded product of the present invention was determined by measuring the weight after immersing the molded product in distilled water for 24 hours, wiping off the water attached to the surface with a waste cloth, and then drying the film at 120 ° C. for 2 hours. The weight can be measured and determined from the rate of decrease.

(Method for producing molded product)
In one embodiment, the molded product of the present invention is obtained by dissolving the above-described polyimide compound in the above organic solvent such as N-methyl-2-pyrrolidone (NMP), applying it on a base material such as copper foil, and drying. Can be manufactured. Thereby, a film-like molded product can be obtained.
Moreover, according to a use, you may remove a base material by peeling a base material from a molded object, or performing an etching process.
The molded product using the polyimide compound of the present invention can be produced only by applying a polyisoimide compound or a polyimide compound on a substrate and drying it, and is accompanied by an imidization reaction performed by a conventional method. This heating and drying step can be omitted. Moreover, since a heat drying process can be skipped, it is not necessary to consider the heat resistance of a base material, and the molded product of this invention can be manufactured on various base materials.
The molded product of the present invention can also be produced by a conventionally known method such as press molding, transfer molding, injection molding or the like.

  In another embodiment, the molded article of the present invention can be produced by a conventional method using a polyamic acid solution or a polyisoimide solution.

  For example, while maintaining a temperature of 40 ° C. or lower, preferably 0 to 25 ° C., while stirring the tetracarboxylic dianhydride and the diamine compound represented by the general formula (1) in an organic solvent, preferably 2 React for -24 hours to obtain a polyamic acid solution. The obtained polyamic acid solution is applied with a desired base material (copper foil or the like), and is dried by heating at a final drying temperature of 250 to 450 ° C., more preferably 350 to 400 ° C. to imidize the polyamic acid compound, and the present invention. A molded product containing the polyimide compound can be produced on a substrate.

The polyisoimide solution can be obtained by adding a dehydrating condensing agent such as N, N′-dicyclohexylcarbodiimide or trifluoroacetic anhydride to the polyamic acid solution. By doing, the molding containing the polyimide compound of this invention can be manufactured on a base material.
When N, N′-dicyclohexylcarbodiimide is used, it is preferable to remove N, N′-dicyclohexylurea produced by the reaction by filtration. In addition, when trifluoroacetic anhydride is used, it is preferable to use a poor solvent such as methanol for the isolation and purification of the polyisoimide compound. The isolated and purified polyisoimide compound can be thermally converted to a polyimide compound by heating at a temperature of 140 ° C. or higher, more preferably 180 ° C. or higher.

(Example 1-1)
Synthesis of diamine compounds

To a 1 L four-necked flask equipped with a thermometer and a stirrer, 500 g of toluene and 51.06 g (0.30 mol) of commercially available o-phenylphenol (manufactured by Wako Pure Chemical Industries, Ltd.) were added, and the reaction temperature was lowered by cooling. While maintaining at −5 to 0 ° C., 30 g (0.33 mol) of 70% by weight nitric acid (d = 1.42) was added dropwise over 2 hours. Further, the reaction was terminated by stirring at the same temperature for 3 hours.
The product slurry was collected by filtration and washed with aqueous sodium bicarbonate and then water.
Subsequently, it dried under reduced pressure and obtained the pale yellow-yellow 2-hydroxy-5-aminobiphenyl represented by following formula (5).
The purity by HPLC analysis (area%) was 97.01%, and the melting point by DSC measurement was 128 ° C. (endothermic peak). ¹ H-NMR (CDCl 3) σ 5.84 ppm (1H of phenol OH), σ 6.99 ppm (1H of o-position of phenol), σ 7.15-7.50 ppm (5H of o-phenyl), σ 8.12- It was 8.20 ppm (2H at the m-position of phenol), and it was confirmed that a nitro group was introduced at the p-position of phenol.

In a 1 L four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser, 43.04 g (0.20 mol) of 2-hydroxy-5-nitrobiphenyl synthesized as described above, the following formula (6 4) -nitrobenzoyl chloride represented by (.) Was added and 500 g of N, N'-dimethylformamide was added, and the mixture was stirred at about 15 ° C.
Then, 30.36 g (0.30 mol) of triethylamine was slowly added. After completion of the addition, the reaction was continued for 3 hours while heating at 50 ° C. After completion of the reaction, the reaction mixture was cooled to 25 ° C. and ion exchange water was added to obtain a precipitate. After the temperature reached 25 ° C., the precipitate was collected by filtration, washed several times with methanol and ion-exchanged water, and dried under reduced pressure to obtain a compound represented by the following formula (8).

To a 500 cc autoclave equipped with a thermometer and a stirrer, 22 g (0.06 mol) of the compound represented by the chemical formula (8), 150 ml of dimethylacetamide, 5% Pd-carbon (as a dry product) was added, and after nitrogen substitution, Replaced with hydrogen.
When reduction was carried out while maintaining the hydrogen pressure at 9 kg / cm 2 (gauge pressure) and 80 ° C., hydrogen absorption stopped in about 2 hours. The mixture was further aged at 80 ° C. for 1 hour and then cooled to room temperature. After purging with nitrogen, the product solution was taken out and filtered to remove the catalyst. The filtrate was put into 50% methanol to precipitate crystals, and the crystals were collected.
By drying under vacuum at 50 ° C., a diamine compound represented by the following chemical formula (2) satisfying the general formula (1) was obtained. The purity by HPLC analysis (area%) was 99.04%, and the melting point was 154 ° C. (endothermic peak) by DSC measurement.
Further, as a result of identification and structure confirmation by ¹ H-NMR, ¹³ C-NMR, FT-IR, and elemental analysis, it was confirmed to be a compound represented by the chemical formula (2). ¹ H-NMR (300 MHz, measuring instrument: Varian 300-MR spectrometer, heavy solvent: DMSO-d ₆ ), ¹³ C-NMR (75 MHz, measuring instrument: Varian 300-MR spectrometer, heavy solvent: DMSO-d ₆ ) and The results of FT-IR (KBr method, measuring instrument: FTIR-410 spectrometer) are shown in FIGS.

Synthesis of polyimide compound In a 500 ml separable flask equipped with a nitrogen introducing tube and a stirrer, 9.13 g (30 mmol) of the diamine compound represented by the chemical formula (2) obtained as described above, 4,4′- (4,4′-isopropylidenediphenoxy) bisphthalic dianhydride 15.61 g (30 mmol), N-methyl-2-pyrrolidone 94.64 g, pyridine 0.47 g (6 mmol), and toluene 10 g were added, Under a nitrogen atmosphere, the reaction was carried out for 4 hours at 180 ° C. while removing toluene out of the system to obtain a 20% by weight polyimide solution. In the polyimide solution, no precipitation of the synthesized polyimide compound was observed. 207 ° C for DSC measurement
A glass transition temperature was observed, which was an amorphous polyimide.

(Example 1-2)
Synthesis of Polyimide Compound Instead of 4,4 ′-(4,4′-isopropylidenediphenoxy) bisphthalic dianhydride, 10.75 g of 3,3 ′, 4,4′-biphenylsulfonetetracarboxylic dianhydride ( 30 mmol) was used, and a 20 wt% polyimide solution was obtained in the same manner as in Example 1-1 except that the amount of N-methyl-2-pyrrolidone used was changed to 75.20 g. In the polyimide solution, no precipitation of the synthesized polyimide compound was observed. In the DSC measurement, it was a semicrystalline polyimide in which an endothermic peak was observed at 271 ° C.

(Comparative Example 1-1)
In place of the diamine compound represented by the synthetic chemical formula (2) of the polyimide compound, 6.85 g (30 mmol) of 4-aminophenyl-4-aminobenzoate represented by the following formula was used, and N-methyl-2-pyrrolidone was used. A polyimide solution was prepared in the same manner as in Example 1-1 except that the amount used was changed to 85.52 g, but the synthesized polyimide compound was precipitated in the polyimide solution.

(Comparative Example 1-2)

Synthetic Chemical Formula of Polyimide Compound Instead of the diamine compound represented by the chemical formula (2), 6.85 g (30 mmol) of 4-aminophenyl-4-aminobenzoate was replaced with 4,4 ′-(4,4′-isopropylidenediphenoxy. ) In place of bisphthalic dianhydride, 10.75 g (30 mmol) of 3,3 ′, 4,4′-biphenylsulfonetetracarboxylic dianhydride was used, and the amount of N-methyl-2-pyrrolidone used was 66 A polyimide solution was prepared in the same manner as in Example 1-1 except that it was changed to 0.08 g. However, the synthesized polyimide compound was precipitated in the polyimide solution.

(Example 2-1)
Preparation of molded product In a 500 mL separable flask equipped with a nitrogen introducing tube and a stirring device, 8.83 g (30 mmol) of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride was used as described above. By adding 9.13 g (30 mmol) of the diamine compound represented by the chemical formula (2) and 67.52 g of N-methyl-2-pyrrolidone and stirring for 8 hours under a nitrogen atmosphere, 20 wt% A polyamic acid solution was obtained.
This polyamic acid solution was applied onto a copper foil by spin coating, and dried at 100 ° C. for 0.5 hour, 200 ° C. for 0.5 hour, 300 ° C. for 2 hours, and 350 ° C. for 0.5 hour. Thereafter, the copper foil was removed by etching to obtain a film-like molded product having a thickness of about 15 μm.

(Example 2-2)
Preparation of molded article Instead of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 9.31 g (30 mmol) of bis (3,4-dicarboxyphenyl) ether dianhydride was used. A film-like molded article having a thickness of about 20 μm was obtained in the same manner as in Example 2-1, except that the amount of N-methyl-2-pyrrolidone used was changed to 69.44 g.

(Reference Example 2-1)
In place of the diamine compound represented by the chemical formula (2) for molding, 6.85 g (30 mmol) of 4-aminophenyl-4-aminobenzoate represented by the following formula was replaced with pyromellitic dianhydride, Example, except that 8.83 g (30 mmol) of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride was used and the amount of N-methyl-2-pyrrolidone used was changed to 58.40 g. A film-like molded product having a thickness of about 20 μm was obtained in the same manner as in 2-1.

<< Performance Evaluation of Molded Article >>
<5% weight loss temperature>
In accordance with JIS K 7120, using TGA-50 (trade name) manufactured by Shimadzu Corporation, in the air at a heating rate of 10 ° C./min, 5 of the molded products obtained in the above examples and comparative examples. The% weight loss temperature was measured. The measurement results are shown in Table 2.

<Glass transition temperature (Tg)>
In accordance with JIS K 7121, DSC-60Plus (trade name) and TMA-60 (trade name) manufactured by Shimadzu Corporation were used, and the above examples and comparisons were performed at a rate of temperature increase of 10 ° C./min in a nitrogen stream. The glass transition temperature (Tg) of the molded product obtained in the example was measured. The measurement results are shown in Table 2.
In addition, since the molded object obtained in Comparative Example 2-1 did not show a clear displacement point, the glass transition temperature could not be measured.

<Melting temperature>
The melting temperature was also measured by a similar method using DSC-60Plus (trade name) manufactured by Shimadzu Corporation, and the peak of the endothermic peak was defined as the melting temperature (Tm).

<Coefficient of thermal expansion (CTE)>
The moldings obtained in the above Examples and Comparative Examples were used as test pieces having a size of 5 mm × 20 mm, and TMA-60 (trade name) manufactured by Shimadzu Corporation was used to increase the temperature by 10 ° C./min while applying a weight of 5 g. The temperature was raised from room temperature to 450 ° C., and the average coefficient of thermal expansion (CTE) from 100 ° C. to 250 ° C. was determined. The results are shown in Table 2.

<Tensile strength>
The molded products obtained in the above Examples and Comparative Examples were used as test pieces having a size of 10 mm × 80 mm, and using a tensile tester (manufactured by Shimadzu Corporation, trade name: AG-Xplus 50 kN) at a tensile speed of 10 mm / min. Then, the tensile strength in the MD direction and the TD direction was measured. The average values of the tensile strength in the MD direction and the tensile strength in the TD direction were calculated and listed in Table 2.

<Elastic modulus>
The molded products obtained in the above Examples and Comparative Examples were used as test pieces having a size of 10 mm × 80 mm, and using a tensile tester (manufactured by Shimadzu Corporation, trade name: AG-Xplus 50 kN) at a tensile speed of 10 mm / min. The elastic modulus in the MD direction and the TD direction was measured. The average values of the elastic modulus in the MD direction and the elastic modulus in the TD direction were calculated and listed in Table 2.

<Water absorption rate>
The molded products obtained in the above examples and comparative examples were used as test pieces having a size of 50 mm × 50 mm, immersed in distilled water for 24 hours, wiped off the water attached to the surface with a waste, and then weighed. The weight of the molded product dried at 2 ° C. for 2 hours was measured, and the absorption rate was determined from the decrease rate.

As is apparent from Table 2, the molded product produced using the polyimide compound synthesized by the method of the present invention has the same 5% weight loss temperature and heat as the molded product produced using the conventionally known polyimide compound. It has an expansion coefficient, tensile strength, elastic modulus and water absorption, and has high heat resistance and mechanical properties.
Further, it has become possible to produce a polyimide having a melting point that is difficult to produce with conventional polyimides. As a result, it has become possible to provide a highly heat-resistant polyimide molded article that can be melt-molded such as extrusion molding and injection molding and that has a high normal use temperature.

Claims (7)

A method for synthesizing a diamine compound represented by the following general formula (1):
A step of reacting a compound represented by the following general formula (3) and a compound represented by the following general formula (4) to obtain a reaction product;
Reducing the nitro group of the reactant,
A method comprising the steps of:
(In the above formula,
Any one of R _{5 to} R ₈ is an aromatic group having 6 to 10 carbon atoms , a phenoxy group, a benzyl group, or a benzyloxy group , and other R _{5 to} R ₈ are hydrogen,
R _{1 to} R ₄ are hydrogen,
One of R ₅ '~R _8' is an aromatic group having 6 to 10 carbon atoms, a phenoxy group, a benzyl group or a benzyl group, a other _{R 5 '~R 8'} is hydrogen,
R ₁ ′ to R ₄ ′ are hydrogen,
X is a halogen group. )   The reaction between the compound represented by the general formula (3) and the compound represented by the compound represented by the general formula (4) is performed in the presence of a catalyst, a dehydrating condensing agent, or an acid acceptor. Item 2. The method according to Item 1. The aromatic group is a phenyl group or a methylphenyl group, The method of claim 1 or 2. A method for synthesizing a polyimide compound,
A step of reacting the diamine compound obtained by the method according to any one of claims 1 to 3 with an acid anhydride to obtain a polyamic acid;
Cyclizing and dehydrating the polyamic acid;
A method comprising the steps of:   The mixing ratio of the diamine compound and the acid anhydride is 0.5 mol% to 1.5 mol% of the total amount of the diamine compound with respect to 1 mol% of the total amount of the acid anhydride. The method described.   The acid anhydride is pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,2-bis [3- (3,4-dicarboxyphenoxy) phenyl]. Propane dianhydride, 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride and 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride and oxy- 6. A process according to claim 4 or 5 selected from the group consisting of 4,4'-diphthalic dianhydride.   The method according to any one of claims 4 to 6, wherein the reaction between the diamine compound and the acid anhydride is performed in an organic solvent.