JP6103992B2 - Polyimide - Google Patents

Description

  The present invention relates to a novel polyimide, a polyamic acid as a precursor thereof, and a method for producing the polyimide and the polyamic acid.

  Polyimide is widely used in the electronics field because of its excellent heat resistance and mechanical properties. Conventionally, polyimide is often insoluble in a solvent, so in general, a solution of a precursor polyamic acid (polyamic acid) is applied to a substrate and heated at a high temperature of 250 ° C. or higher to remove the solvent and imidize. The film was formed (made into a film). However, this method has a drawback that the base material and peripheral materials may be deteriorated by heating at a high temperature. Therefore, a polyimide soluble in a solvent has been demanded so that molding at a lower temperature is possible.

  As a method for making polyimide a solvent-soluble type, a method is known in which an aliphatic group is introduced into the main chain to form a flexible bent structure. However, when this method is used, there is a problem that the heat resistance, which is the original characteristic of polyimide, is impaired by lowering the glass transition point of polyimide. For example, the isopropyl group-containing polyimide shown in Non-Patent Document 1 shows a glass transition point as low as 215 ° C.

  It is also known that polyimides using silicone diamines are also solvent soluble. However, the glass transition point of the silicone-modified polyimide disclosed in Patent Document 1 is 170 to 190 ° C., which is a low glass transition point.

  In addition, it is known that polyimide having a bulky structure also suppresses aggregation between polymers and enhances solvent solubility. For example, Non-Patent Document 2 discloses a polyimide having a tetraphenyl group. However, such a polyimide raw material has a problem that it is difficult to obtain industrially.

JP-A-5-112760

Functional materials, vol.19, 1989, p.14 Polym. J., vol.29, 1994, p.273

  An object of this invention is to provide the polyimide excellent in solvent solubility, maintaining high heat resistance in view of the said present condition.

  As a result of intensive studies by the present inventors, the use of an anhydrohexitol-type diamine component as all or part of the diamine component used when synthesizing a polyimide results in excellent solvent solubility and high heat resistance. The present inventors have found that a polyimide showing can be synthesized and have completed the present invention.

  That is, the present invention is a polyimide formed by dehydrating and ring-closing the polyamic acid represented by the following general formula (I).

Wherein all or part of A is a group represented by the following formula (II);

Wherein some or all of the hydrogen atoms on the ring in formula (II) may be substituted;
B ₁ is a group represented by the following formula (III);

B ₂ is H or a group represented by the following general formula (IV), (V) or (VI);

Where D ₁ is a tetracarboxylic acid residue;
D ₂ is a dicarboxylic acid residue;
n is an integer of 1 to 200. ]
The present invention also relates to a polyamic acid that is a precursor of the polyimide.

Furthermore, the present invention is a method for producing a polyamic acid,
An amidation step of reacting a compound represented by the following formula (VII) or a mixture of a compound represented by the following formula (VII) and another diamine with a compound represented by the following general formula (VIII): Also related to the manufacturing method.

[Wherein, some or all of the hydrogen atoms on the ring may be substituted]

[Wherein D ₁ is a tetracarboxylic acid residue]
In the production method, the compound represented by the formula (VII) and the compound represented by the general formula (VIII) and the compound represented by the following general formula (IX) are simultaneously reacted in the amidation step. Or
It is preferable to further react the compound represented by the following general formula (IX) with the polyamic acid obtained by the amidation step.

[Wherein D ₂ is a dicarboxylic acid residue].

  Furthermore, the present invention also relates to a method for producing polyimide, comprising a step of dehydrating and ring-closing the obtained polyamic acid after obtaining the polyamic acid by the above production method.

  Furthermore, the present invention provides a resin composition comprising at least one polymer selected from the group consisting of the polyimide, the polyamic acid, the polyamic acid obtained by the production method, and the polyimide obtained by the production method, and a solvent. Also related to things.

  The present invention also relates to a molded article formed from the resin composition.

  The polyimide provided by the present invention is excellent in solvent solubility while maintaining high heat resistance. For this reason, the polyimide can be dissolved in a solvent to form a solution, and the polyimide film is formed on the substrate simply by applying the solution to the substrate and heating it to a relatively low temperature above the boiling point of the solvent. be able to. Since the film can be formed at a low temperature as described above, it is possible to avoid thermal degradation of the base material and peripheral materials.

The polyimide of the present invention is formed by dehydrating and ring-closing a polyamic acid represented by the following general formula (I). The polyamic acid is a precursor of polyimide, by reacting in the presence of a high temperature or dehydrating agent, NH group and (carboxyl groups in B ₁₎ carboxyl groups in the polyamic acid internal amide group dehydration condensation By forming a ring, polyimide is formed.

  In the formula (I), all or part of A is a group represented by the following formula (II). Since the polyimide of the present invention contains the group, it can exhibit excellent solvent solubility while maintaining high heat resistance.

  In the present invention, all of a plurality of A may be groups represented by the formula (II). In addition, a part of A is a group represented by the formula (II), and the remaining A is a residue of a diamine compound used in the synthesis of a conventional polyimide (residue excluding two amino groups from the diamine compound). Group). At this time, the content ratio of the group represented by the formula (II) is not particularly limited as long as the effect of the present invention can be achieved, but 10 mol% or more of A is a group represented by the formula (II). It is preferable that More preferably, it is 30 mol% or more, More preferably, it is 50 mol% or more, Most preferably, it is 70 mol% or more. A plurality of diamine compound residues may be the same or different from each other.

In addition, as long as the effects of the present invention can be achieved, some or all of the hydrogen atoms on the ring in formula (II) may be substituted. For example, an alkyl group (C _1-20 alkyl group such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, s-butyl group and t-butyl group), cycloalkyl group (cyclopentyl group, cyclohexyl group, etc.) C _3-10 cycloalkyl group, etc.), cycloalkenyl groups (cyclo Pentel group, such as C _3-10 cycloalkenyl groups such as cyclohexylidene cell group), a Hajime Tamaki (an oxygen atom, a nitrogen atom, a hetero atom such as a sulfur atom C _2-10 heterocyclic group, etc.), aryl group [phenyl group, alkyl phenyl group (C _6-10 aryl group such as methylphenyl group (tolyl group), dimethylphenyl group (xylyl group)), etc.], aralkyl Carbon (C _6-10 aryl-C _1-4 alkyl group such as benzyl group, phenethyl group, etc.), methylene group, vinyl group, allyl group, etc. Hydrogen group, alkoxy group (C _1-4 alkoxy group such as methoxy group), hydroxyl group, hydroxy (poly) alkyleneoxy group (hydroxy (poly) C _2-4 alkyleneoxy group etc.), acyl group (acetyl group) C _1-6 acyl group such as oxy group, thioxy group, phosphino group, halogeno group (fluoro group, chloro group, etc.), amino group, imino group, N-oxide group, nitro group, cyano group Each may be independently substituted.

B ₁ in the formula (I) is a group represented by the following formula (III).

In the formula (III), D ₁ is a tetracarboxylic acid residue. Examples of the tetracarboxylic acid include tetracarboxylic acids (for example, pyromellitic anhydride, biphenyltetracarboxylic dianhydride, etc.) used in conventional polyimide synthesis, and have four carboxyl groups, and these carboxyl groups Is not particularly limited as long as it is a compound capable of forming two acid anhydride groups. A tetracarboxylic acid residue means the remaining group which remove | excluded four carboxyl groups from tetracarboxylic acid. A plurality of D ₁ may be the same or different.

Further, B ₂ in the formula (I) is H or a group represented by the following general formula (IV), (V) or (VI).

D ₁ in the formulas (IV) and (V) is a tetracarboxylic acid residue, and may be the same as or different from D ₁ in the formula (III). Further, a plurality of D ₁ of the formula (IV) and (V) may be the same or may be different from one another.

D ₂ in the formula (VI) is a dicarboxylic acid residue. The dicarboxylic acid is not particularly limited as long as it has two carboxyl groups and these carboxyl groups can form an acid anhydride group. A dicarboxylic acid residue means the remaining group which remove | excluded two carboxyl groups from dicarboxylic acid. A plurality of D ₂ may be the same or different.

  N in the formula (I) is a number representing the number of repeating units, and is not particularly limited, but is an integer of 1 to 200, for example.

  The polyamic acid represented by the formula (I) may partially have an imide bond.

  By placing the polyamic acid represented by the formula (I) at a high temperature or in the presence of a dehydrating agent, the NH group and the carboxyl group in the amide group inside the polyamic acid are dehydrated and condensed to form a ring. The inventive polyimide is formed.

  The polyamic acid represented by the formula (I) is a compound represented by the following formula (VII) or a mixture of the compound represented by the following formula (VII) and another diamine, and the following general formula (VIII): It can be produced by carrying out an amidation step in which the compound represented is reacted.

As long as the effects of the present invention can be achieved, some or all of the hydrogen atoms on the ring in formula (VII) may be substituted. For example, an alkyl group (C _1-20 alkyl group such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, s-butyl group and t-butyl group), cycloalkyl group (cyclopentyl group, cyclohexyl group, etc.) C _3-10 cycloalkyl group, etc.), cycloalkenyl groups (cyclo Pentel group, such as C _3-10 cycloalkenyl groups such as cyclohexylidene cell group), a Hajime Tamaki (an oxygen atom, a nitrogen atom, a hetero atom such as a sulfur atom C _2-10 heterocyclic group, etc.), aryl group [phenyl group, alkyl phenyl group (C _6-10 aryl group such as methylphenyl group (tolyl group), dimethylphenyl group (xylyl group)), etc.], aralkyl Carbon (C _6-10 aryl-C _1-4 alkyl group such as benzyl group, phenethyl group, etc.), methylene group, vinyl group, allyl group, etc. Hydrogen group, alkoxy group (C _1-4 alkoxy group such as methoxy group), hydroxyl group, hydroxy (poly) alkyleneoxy group (hydroxy (poly) C _2-4 alkyleneoxy group etc.), acyl group (acetyl group) C _1-6 acyl group such as oxy group, thioxy group, phosphino group, halogeno group (fluoro group, chloro group, etc.), amino group, imino group, N-oxide group, nitro group, cyano group Each may be independently substituted.

  The compound represented by the formula (VII) can be synthesized, for example, by converting two hydroxyl groups of isosorbide obtained from sorbitol into two amino groups. A specific synthesis method is disclosed in Tetrahedron, 67, 2011, p.383-389. The structure of isosorbide diamine used in the examples of the present application is shown below.

  The other diamine that can be used in combination with the compound represented by the formula (VII) is not particularly limited, and may be any compound having two amino groups that can be used as a raw material for polyimide. Examples thereof include cyclic diamines and aliphatic diamines. Aromatic diamines include 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl esulfide, 4 , 4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2'-bis (4-aminophenyl) propane, 2,2'-bis (4-aminophenyl) hexafluoropropane, bis [4- ( 3-aminophenoxy) phenyl] methane, bis [4- (4-aminophenoxy) phenyl] methane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- ( 4-Aminophenoxy) phenyl] propane, 2,2-bis [3- (3-aminophenoxy) Enyl] -1,1,1,3,3,3-hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoro Propane, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4- Aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4 -(4-aminophenoxy) phenyl] sulfone, 1,4-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-aminopheno) Shi) benzoyl] benzene, 4,4-bis [3- (4-aminophenoxy) benzoyl] diphenylether, 4,4-bis [3- (3-aminophenoxy) benzoyl] diphenyl ether. Examples of the alicyclic diamine include isophorone diamine, 4,4′-methylenebis (4-cyclohexylamine), 1,4-diaminocyclohexane, bicyclo [2.2.1] heptanebis (methylamine), 1,3- Diaminoadamantane, 1,3-bis (aminomethyl) benzene, 1,4-bis (aminomethyl) benzene, etc., and aliphatic diamines include ethylenediamine, 1,4-diaminobutane, 1,6-diaminohexane, etc. Can be mentioned. Such a diamine may or may not be used in the present invention, but when used, only one type may be used or two or more types may be used in combination.

  The compound represented by the general formula (VIII) is a tetracarboxylic acid anhydride. The tetracarboxylic acid that can be used in the present invention is not particularly limited, and may be any compound having two acid anhydride groups that can be used as a raw material for polyimide. For example, aromatic tetracarboxylic dianhydride, alicyclic ring Aliphatic tetracarboxylic dianhydride, aliphatic tetracarboxylic dianhydride and the like. Aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride, 3,4,3 ', 4'-benzophenonetetracarboxylic dianhydride, 3,4,3', 4'-diphenylsulfone tetracarboxylic Acid dianhydride, 3,4,3 ′, 4′-biphenyltetracarboxylic dianhydride, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, 2,3,3 ′, 4 ′ -Oxydiphthalic anhydride, 3,4,3 ', 4'-oxydiphthalic anhydride, 3,4,3', 4'-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,4,3 ', 4' -Tetraphenylsilane tetracarboxylic dianhydride, 4,4'-hexafluoroisopropylidene tetracarboxylic dianhydride and the like. The alicyclic tetracarboxylic dianhydrides include cyclobutane-1,2,3,4-tetracarboxylic dianhydride, 1-carboxymethyl-2,3,5-cyclopentanetricarboxylic acid-2,6. : 3,5-dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride and the like, but as aliphatic tetracarboxylic dianhydride, butane-1,2,3,4-tetra Examples thereof include carboxylic dianhydrides. As an acid anhydride of tetracarboxylic acid, only 1 type may be used and 2 or more types may be used together.

  The diamine (the total of the compound represented by the formula (VII) and other diamine) and the tetracarboxylic acid anhydride may be used so as to be substantially equimolar. A polyamic acid can be synthesized by reacting these in an organic solvent.

  Examples of the organic solvent that can be used in this case include those capable of dissolving diamine and acid anhydride, such as N, N'-dimethylformamide (DMF), N, N'-dimethylacetamide (DMAc), N-methyl- Examples include aprotic polar solvents such as 2-pyrrolidone (NMP), dimethyl sulfoxide (DMSO), and hexamethylphosphoramide (HMPA). These may use only 1 type and may use 2 or more types together.

  In addition, when the diamine and the acid anhydride of the tetracarboxylic acid are reacted, the acid anhydride of the dicarboxylic acid may be reacted at the same time, or after the diamine and the acid anhydride of the tetracarboxylic acid are reacted, An acid anhydride of an acid may be further reacted. The acid anhydride of dicarboxylic acid is represented by the following general formula (IX). By reacting such an acid anhydride of a dicarboxylic acid, the group represented by the above formula (VI) can be introduced into the terminal of the polyamic acid or polyimide.

  The polyimide of the present invention can be obtained by performing imidization by dehydrating and ring-closing the polyamic acid obtained as described above. Dehydration ring closure can be carried out under heating or in the presence of a dehydrating agent.

  As temperature at the time of imidation under heating, the same temperature as at the time of conventional imidization can be applied. For example, although it is about 200-500 degreeC, it is not limited to this temperature.

  When imidation is performed in the presence of a dehydrating agent, as in the case of conventional imidization, for example, an organic acid anhydride such as acetic anhydride or propionic anhydride is used as a dehydrating agent, and pyridine, picoline as a catalyst. An organic base such as triethylamine can be used in combination. After the imidization, the dehydrating agent and the catalyst base may be removed.

  The polyimide or polyamic acid of this invention can comprise a resin composition by making it melt | dissolve in the solvent which melt | dissolves this. In particular, since the polyimide of the present invention has solvent solubility, a polyimide solution can be obtained, which is advantageous as compared with conventional polyimides.

  A molded article can be produced by removing the solvent from such a resin composition. Specifically, a film can be formed on a substrate by applying the resin composition onto a substrate and then removing the solvent under heating or reduced pressure. In the case of a resin composition containing a polyamic acid, it is preferable to place the resin composition on the substrate under a high temperature at which imidization is possible in order to proceed with imidization after coating to obtain a molded article made of polyimide. On the other hand, in the case of a resin composition containing polyimide, a film can be formed on a substrate simply by placing it at a temperature necessary for the solvent to volatilize after application to the substrate. Therefore, molding at a lower temperature is possible, and there is an advantage that it is not necessary to use a base material and a peripheral member having high heat resistance.

  In addition to exhibiting solvent solubility, the polyimide of the present invention exhibits high heat resistance. Therefore, it can be suitably used as a substitute for conventional polyimide. The use of the resin composition and molded product of the present invention is not particularly limited. For example, an insulating base material for electronic circuit materials, an interlayer insulating material for multilayer wiring boards, a protective film for a surface layer of a semiconductor element, a resist material, and a pigment Examples of the binder resin of the dispersion, paints and ink compositions, additives for various heat-resistant resin compositions, and matrix resins for fiber-reinforced plastics.

(Measurement method of glass transition temperature)
Based on JIS K7121, the temperature was raised from 100 ° C. to 300 ° C. at a rate of 20 ° C. per minute while flowing nitrogen at 50 ml per minute using DSC 6220 manufactured by Seiko Instruments Inc., and the glass transition temperature was measured.

(Measurement method of 5% weight loss temperature)
Based on JISK-7210, when the temperature was raised from 100 ° C. to 600 ° C. at a rate of 10 ° C./min while flowing nitrogen at 100 ml / min by Seiko Instruments TG / DTA6200, the weight was reduced by 5% from the initial weight. The temperature was measured.

(Example 1: Resin A)
In a 300 mL four-necked flask, 14.4 g of isosorbide diamine and 144.8 g of N-methyl-2-pyrrolidone were charged and dissolved while flowing nitrogen gas. After dissolution, 21.8 g of pyromellitic anhydride was added over 1 hour with stirring, heated at 200 ° C. for 8 hours at room temperature, and stirred for 24 hours to obtain an N-methyl-2-pyrrolidone solution of polyimide (solid content) 20%). The obtained polyimide solution was poured into 1000 ml of methanol, and the precipitated polyimide was collected by filtration and dried at 200 ° C. for 2 hours to obtain 35 g of a light brown powdery polyimide.

  About the obtained polyimide, the glass transition temperature and the 5% weight loss temperature were measured. The results are shown in Table 1. The glass transition temperature and the 5% weight reduction temperature are indicators of heat resistance.

  Moreover, about the obtained polyimide, solubility with respect to N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, chloroform, tetrahydrofuran and 1,4-dioxane (polyimide 20% by weight, normal temperature) As a result, it was dissolved in any solvent.

(Example 2: Resin B)
In a 300 mL four-necked flask, 14.4 g of isosorbide diamine and 151 g of N-methyl-2-pyrrolidone were charged and dissolved while introducing nitrogen gas. After dissolution, 17.4 g of pyromellitic anhydride was charged over 1 hour with stirring and stirred at room temperature for 8 hours. Thereafter, 5.9 g of phthalic anhydride was charged over 1 hour and stirred at room temperature for 8 hours. The mixture was heated to 200 ° C. and stirred for 24 hours to obtain an N-methyl-2-pyrrolidone solution of polyimide (solid content 20%). The obtained polyimide solution was poured into 1000 ml of methanol, and the precipitated polyimide was collected by filtration and dried at 200 ° C. for 2 hours to obtain 35 g of a light brown powdery polyimide.

  About the obtained polyimide, the glass transition temperature and the 5% weight loss temperature were measured. The results are shown in Table 1.

  Moreover, about the obtained polyimide, solubility with respect to N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, chloroform, tetrahydrofuran and 1,4-dioxane (polyimide 20% by weight, normal temperature) As a result, it was dissolved in any solvent.

(Example 3: Resin C)
In a 300 mL four-necked flask, 14.4 g of isosorbide diamine and 175.2 g of N-methyl-2-pyrrolidone were charged and dissolved while introducing nitrogen gas. After dissolution, 29.4 g of biphenyltetracarboxylic dianhydride was charged over 1 hour with stirring and stirred at room temperature for 8 hours. Then, it stirred at room temperature for 8 hours. The mixture was heated to 200 ° C. and stirred for 24 hours to obtain an N-methyl-2-pyrrolidone solution of polyimide (solid content 20%). The obtained polyimide solution was poured into 1000 ml of methanol, and the precipitated polyimide was collected by filtration and dried at 200 ° C. for 2 hours to obtain 35 g of a light brown powdery polyimide.

  About the obtained polyimide, the glass transition temperature and the 5% weight loss temperature were measured. The results are shown in Table 1.

  Moreover, about the obtained polyimide, solubility with respect to N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, chloroform, tetrahydrofuran and 1,4-dioxane (polyimide 20% by weight, normal temperature) As a result, it was dissolved in any solvent.

(Example 4: Resin D)
In a 300 mL four-necked flask, 11.5 g of isosorbide diamine, 4.2 g of 4,4′-diaminodicyclohexylmethane and 149.8 g of N-methyl-2-pyrrolidone were charged and dissolved while introducing nitrogen gas. After dissolution, 21.8 g of pyromellitic anhydride was charged over 1 hour with stirring and stirred at room temperature for 8 hours. Then, it heated at 200 degreeC and stirred for 24 hours, and obtained the N-methyl- 2-pyrrolidone solution (solid content 20%) of the polyimide. The obtained polyimide solution was poured into 1000 ml of methanol, and the precipitated polyimide was collected by filtration and dried at 200 ° C. for 2 hours to obtain 40 g of a light brown powdery polyimide.

  About the obtained polyimide, the glass transition temperature and the 5% weight loss temperature were measured. The results are shown in Table 1.

  Moreover, about the obtained polyimide, solubility with respect to N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, chloroform, tetrahydrofuran and 1,4-dioxane (polyimide 20% by weight, normal temperature) As a result, it was dissolved in any solvent.

(Comparative Example 1: Resin E)
In a 300 mL four-necked flask, 20.0 g of 4,4′-diaminodiphenyl ether and 167.2 g of N-methyl-2-pyrrolidone were charged and dissolved while introducing nitrogen gas. After dissolution, 21.8 g of pyromellitic anhydride was charged over 1 hour with stirring and stirred at room temperature for 8 hours. Then, it heated at 200 degreeC and stirred for 24 hours, and obtained the N-methyl-2-pyrrolidone dispersion liquid (solid content 20%) of the polyimide. The obtained polyimide solution was poured into 1000 ml of methanol, and the precipitated polyimide was collected by filtration and dried at 200 ° C. for 2 hours to obtain 35 g of a light brown powdery polyimide.

  About the obtained polyimide, the glass transition temperature and the 5% weight loss temperature were measured. The results are shown in Table 1.

  Moreover, about the obtained polyimide, solubility with respect to N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, chloroform, tetrahydrofuran and 1,4-dioxane (polyimide 20% by weight, normal temperature) As a result, it was insoluble in any solvent.

From the above results, it can be seen that the polyimide of the present invention has excellent solvent solubility while maintaining high heat resistance (glass transition temperature, 5% weight loss temperature).

Claims (7)

A polyimide formed by dehydrating and ring-closing a polyamic acid represented by the following general formula (I).

Wherein all or part of A is a group represented by the following formula (II);

Wherein some or all of the hydrogen atoms on the ring in formula (II) may be substituted;
B ₁ is a group represented by the following formula (III);

B ₂ is H or a group represented by the following general formula (IV), (V) or (VI);

Where D ₁ is a tetracarboxylic acid residue;
D ₂ is a dicarboxylic acid residue;
n is an integer of 1 to 200. ]   A polyamic acid which is a precursor of the polyimide according to claim 1. A method for producing a polyamic acid, comprising:
An amidation step of reacting a compound represented by the following formula (VII) or a mixture of a compound represented by the following formula (VII) and another diamine with a compound represented by the following general formula (VIII): ,Production method.

[Wherein, some or all of the hydrogen atoms on the ring may be substituted]

[Wherein D ₁ is a tetracarboxylic acid residue] In the amidation step, the compound represented by the formula (VII) and the compound represented by the general formula (VIII) are simultaneously reacted with a compound represented by the following general formula (IX), or
The manufacturing method of Claim 3 which further makes the compound represented by the following general formula (IX) react with the polyamic acid obtained by the said amidation process.

[Wherein D ₂ is a dicarboxylic acid residue].   A method for producing polyimide, comprising a step of dehydrating and ring-closing the obtained polyamic acid after obtaining the polyamic acid by the production method according to claim 3 or 4. A resin composition comprising at least one polymer selected from the group consisting of the polyimide according to claim 1 and the polyamic acid according to claim 2, and a solvent.   A molded article formed from the resin composition according to claim 6.