Method for producing polyimide resin powder composition

Abstract

A method for producing a polyimide resin powder composition comprising a polyimide resin powder (Z) and a metal-containing compound (D) containing at least one metal selected from the group consisting of transition metals and cerium, the method comprising predetermined steps (I) to (IV) in this order, and including a step of adding the metal-containing compound (D) prior to step (IV).

Description

[Technical Field]

[0001] The present invention relates to a method for producing a polyimide resin powder composition. [Background technology]

[0002] Polyimide resins are useful engineering plastics with high thermal stability, strength, and solvent resistance due to the rigidity of their molecular chains, resonance stabilization, and strong chemical bonds, and are used in a wide range of fields. Furthermore, because polyimide resins have crystallinity, their heat resistance, strength, and chemical resistance can be further improved, making them promising candidates for use as metal replacements. However, while polyimide resins have high heat resistance, they lack thermoplasticity and have poor moldability.

[0003] Although high-heat-resistant resins such as Vespel (registered trademark) are known as polyimide molding materials (Patent Document 1), they have extremely low fluidity even at high temperatures, making molding difficult and cost-inefficient due to the need for long molding times under high-temperature and high-pressure conditions. In contrast, resins that have a melting point and fluidity at high temperatures, such as crystalline resins, can be molded easily and inexpensively.

[0004] In recent years, thermoplastic polyimide resins have been reported. Thermoplastic polyimide resins have the inherent heat resistance of polyimide resins, but also have excellent moldability. Therefore, thermoplastic polyimide resins can be used in molded articles used in harsh environments, which is not possible with general-purpose thermoplastic resins such as nylon and polyester.

[0005] Studies have also been made to improve the heat aging resistance of thermoplastic polyimide resins. For example, Patent Document 2 describes that a polyimide resin having a specific polyimide structural unit and a chain aliphatic group having 5 to 14 carbon atoms at its terminal has excellent moldability, heat resistance, and heat aging resistance. It also describes that additives such as antioxidants may be added to the polyimide resin to form a polyimide resin composition. Patent Document 3 describes that a polyimide resin composition containing a polyimide resin having specific polyimide structural units and a specific antioxidant has excellent long-term heat resistance, a high crystallization temperature, and good moldability. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-28524 [Patent Document 2] International Publication No. 2016 / 147997 [Patent Document 3] International Publication No. 2020 / 184355 Summary of the Invention [Problem to be solved by the invention]

[0007] In the examples of Patent Documents 2 and 3, in the evaluation of heat aging resistance or long-term heat resistance, a molded article is used which is prepared by melt-kneading a thermoplastic polyimide resin or a composition thereof to prepare pellets, and then heat-melting the pellets and producing them by extrusion molding, injection molding, etc. The maximum temperature during the evaluation of heat aging resistance or long-term heat resistance of the molded article is 200°C.

[0008] In contrast, in the production of compression molded articles, the thermoplastic polyimide resin or its composition is not pelletized but is used in a powder state and subjected to hot and pressure molding. In the production of fiber-reinforced composite materials, the powdered thermoplastic polyimide resin or its composition may be sprinkled on the surface of continuous reinforcing fibers and then subjected to hot and pressure molding. In the above-mentioned hot and pressure molding, the thermoplastic polyimide resin is subjected to hot and pressure conditions, for example, at a temperature exceeding 200° C. for several minutes, and therefore it is important that the molecular weight of the thermoplastic polyimide resin is maintained without decreasing during this time. Furthermore, from the viewpoint of improving the appearance of the resulting molded article, it is desirable that the color of the thermoplastic polyimide resin or its composition change little even after heating.

[0009] However, in the prior art, there is still room for improvement in terms of suppressing the decrease in molecular weight and the change in color of the polyimide resin powder under high temperature conditions, particularly at temperatures exceeding 200°C. An object of the present invention is to provide a method for producing a polyimide resin powder composition which exhibits little decrease in molecular weight and little change in color even when subjected to high temperature conditions, particularly temperatures above 200°C. [Means for solving the problem]

[0010] The present inventors have found that the above problems can be solved by adding a specific metal-containing compound in a specific step in the process of producing a polyimide resin powder. That is, the present invention relates to the following. [1] A method for producing a polyimide resin powder composition containing a polyimide resin powder (Z) and a metal-containing compound (D) containing at least one metal selected from the group consisting of transition metals and cerium, comprising: The production method includes the following steps (I) to (IV) in this order: A method for producing a polyimide resin powder composition, comprising the step of adding the metal-containing compound (D) before the step (IV). Step (I): Mixing the tetracarboxylic acid component (A) and the solvent (C) to prepare a mixture 1 Step (II): A step of mixing the mixture 1 with a diamine component (B) containing an aliphatic diamine to prepare a solution 2 containing a polyimide resin precursor containing a polyamic acid. Step (III): A step of heating the solution 2 to imidize the polyimide resin precursor, thereby precipitating a polyimide resin powder (Z) in the solution, and preparing a slurry 3 containing the polyimide resin powder (Z). Step (IV): A step of subjecting the slurry 3 to solid-liquid separation [2] The method for producing a polyimide resin powder composition according to [1], wherein the step of adding the metal-containing compound (D) is carried out simultaneously with the step (I) or between the step (II) and the step (III). [3] The method for producing a polyimide resin powder composition according to [1] or [2], wherein the metal in the metal-containing compound (D) contains at least one metal selected from the group consisting of copper, zinc, and cerium. [4] The method for producing a polyimide resin powder composition according to any one of [1] to [3], wherein the amount of the metal-containing compound (D) added is in the range of 0.00001 to 0.05 moles per mole of the tetracarboxylic acid component (A). [5] The method for producing a polyimide resin powder composition according to any one of [1] to [4], wherein the step (II) further comprises a step of adding an end-capping agent. [6] The method for producing a polyimide resin powder composition according to any one of [1] to [5], wherein the tetracarboxylic acid component (A) contains a tetracarboxylic acid dianhydride represented by the following formula (A-1): [ka] (X is a tetravalent group containing at least one aromatic ring and having 6 to 22 carbon atoms.) [7] The method for producing a polyimide resin powder composition according to any one of [1] to [6], wherein the diamine component (B) contains, as the aliphatic diamine, a diamine represented by the following formula (B1-1) and a diamine represented by the following formula (B2-1): [ka] (R1 is a divalent group having 6 to 22 carbon atoms containing at least one alicyclic hydrocarbon structure, and R2 is a divalent chain aliphatic group having 5 to 16 carbon atoms.) [8] The method for producing a polyimide resin powder composition according to any one of [1] to [7], wherein the solvent (C) contains an alkylene glycol solvent represented by the following formula (C-1): [ka] (Ra1 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, Ra2 is a linear alkylene group having 2 to 6 carbon atoms, and n is an integer of 1 to 3.) [9] The method for producing a polyimide resin powder composition according to any one of [1] to [8], wherein the polyimide resin powder (Z) contains a repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (2), and the content of the repeating structural unit of the formula (1) relative to the total of the repeating structural units of the formula (1) and the repeating structural units of the formula (2) is 15 to 70 mol %. [ka] (R1 is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure. R2 is a divalent chain aliphatic group having 5 to 16 carbon atoms. X1 and X2 are each independently a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring.)

[10] [9] The method for producing a polyimide resin powder composition according to [9], wherein the content ratio of the repeating structural unit of the formula (1) to the total of the repeating structural unit of the formula (1) and the repeating structural unit of the formula (2) is 15 mol % or more and less than 40 mol %.

[11] The volume average particle size (D 50 ) is 5 to 50 μm. [Effects of the Invention]

[0011] According to the present invention, a polyimide resin powder composition can be produced that undergoes little molecular weight reduction and little color change even when subjected to high temperature conditions, particularly temperatures above 200°C. DETAILED DESCRIPTION OF THE INVENTION

[0012] [Definition] In this specification, a polyimide resin powder composition that exhibits little molecular weight loss and little color change even when subjected to high-temperature conditions refers to a polyimide resin powder composition that exhibits high retention of number-average molecular weight (Mn) and little loss of whiteness after heating at high temperatures, particularly at temperatures above 200° C. In particular, a polyimide resin powder composition that exhibits little loss of Mn retention and little loss of whiteness even after heating at temperatures above 200° C. for several minutes (in this example, heating at 300° C. for 20 minutes) is advantageous for use in hot-press molding at high temperatures. The retention rate of the number average molecular weight (Mn) and the change in whiteness of the polyimide resin powder composition after heating can be specifically evaluated by the methods described in the Examples.

[0013] [Method of producing polyimide resin powder composition] The method for producing a polyimide resin powder composition of the present invention (hereinafter also simply referred to as the "(production) method of the present invention") is a method for producing a polyimide resin powder composition containing a polyimide resin powder (Z) and a metal-containing compound (D) containing at least one metal selected from the group consisting of transition metals and cerium, and the production method has the following steps (I) to (IV) in this order, and includes a step of adding the metal-containing compound (D) before step (IV). Step (I): Mixing the tetracarboxylic acid component (A) and the solvent (C) to prepare a mixture 1 Step (II): A step of mixing the mixture 1 with a diamine component (B) containing an aliphatic diamine to prepare a solution 2 containing a polyimide resin precursor containing a polyamic acid. Step (III): A step of heating the solution 2 to imidize the polyimide resin precursor, thereby precipitating a polyimide resin powder (Z) in the solution, and preparing a slurry 3 containing the polyimide resin powder (Z). Step (IV): A step of subjecting the slurry 3 to solid-liquid separation

[0014] The production method of the present invention, having the above-mentioned features, can produce a polyimide resin powder composition with little molecular weight reduction and little color change even when subjected to high temperature conditions, particularly temperatures exceeding 200° C. The reason for this is not clear, but is thought to be as follows. The polyimide resin powder (Z) in the polyimide resin powder composition is obtained by reacting a tetracarboxylic acid component (A) with a diamine component (B) containing an aliphatic diamine in a solvent (C) in steps (I) and (II) to form a polyimide resin precursor containing a polyamic acid, and then imidizing and precipitating the polyimide resin precursor in the solvent (C) in step (III).Furthermore, in step (IV), the slurry containing the polyimide resin powder (Z) obtained in step (III) is subjected to solid-liquid separation to recover a composition containing the polyimide resin powder (Z). By carrying out the reaction between the tetracarboxylic acid component (A) and the diamine component (B) containing an aliphatic diamine, the imidization of the polyimide resin precursor, and the precipitation of the polyimide resin powder (Z) all in the solvent (C), it is believed that a sudden temperature rise during the reaction and clumping of the resulting polyimide resin are unlikely to occur, and a powdery resin composition containing the polyimide resin powder (Z) can be easily obtained.

[0015] When the diamine component (B) contains at least an aliphatic diamine, the resulting polyimide resin powder (Z) can be imparted with thermoplasticity.

[0016] The metal-containing compound (D) used in the present invention, which contains at least one metal selected from the group consisting of transition metals and cerium (hereinafter simply referred to as "metal-containing compound (D)" or "component (D)"), is believed to have the effect of suppressing oxidative degradation of the polyimide resin powder (Z). For example, when a methylene group is adjacent to the nitrogen of an imide group, abstraction of a hydrogen radical from the methylene group is likely to occur in the presence of oxygen. This is thought to be because the electrons of the methylene group form a resonance structure with the unpaired electron of the nitrogen in the imide group or the electrons of the π bond of the carbonyl group, making it easier for the electrons of the methylene group to move. The metal contained in the metal-containing compound (D) is at least one selected from the group consisting of transition metals and cerium, and the metal ions have the ability to coordinate to nitrogen atoms and / or carbonyl groups. The coordination of the metal ions to nitrogen atoms and / or carbonyl groups in the polyimide resin obtained by imidizing the polyamic acid in the polyimide resin precursor obtained in step (II) is believed to make it difficult for the electrons of the methylene groups to adopt the resonance structure described above, thereby suppressing the abstraction of hydrogen radicals from the methylene groups. Furthermore, if the timing of adding the metal-containing compound (D) is before step (IV), the coordination of the metal ions is likely to occur, thereby improving the effect of suppressing oxidative degradation of the polyimide resin. This is believed to enable the production of a polyimide resin powder composition that exhibits minimal molecular weight loss and color change even when stored at high temperatures.

[0017] <Process (I)> In step (I), a mixture 1 is prepared by mixing a tetracarboxylic acid component (A) and a solvent (C).

[0018] (Tetracarboxylic acid component (A)) From the viewpoint of easily producing a powdery resin composition containing the polyimide resin powder (Z), the tetracarboxylic acid component (A) used in the present invention preferably contains a tetracarboxylic acid dianhydride, preferably contains a tetracarboxylic acid dianhydride containing at least one aromatic ring, and more preferably contains a tetracarboxylic acid dianhydride represented by the following formula (A-1): [ka] (X is a tetravalent group containing at least one aromatic ring and having 6 to 22 carbon atoms.)

[0019] X is a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring. The aromatic ring may be a single ring or a condensed ring, and examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, and a tetracene ring. Among these, a benzene ring or a naphthalene ring is preferred, and a benzene ring is more preferred. X has 6 to 22 carbon atoms, and preferably 6 to 18 carbon atoms. X contains at least one aromatic ring, preferably 1 to 3.

[0020] X is preferably a tetravalent group represented by any one of the following formulae (X-1) to (X-4). [ka] (R 11 ~R 18 are each independently an alkyl group having 1 to 4 carbon atoms. 11 ~p 13 are each independently an integer of 0 to 2, preferably 0. 14 , p 15 , p 16 and p 18 are each independently an integer of 0 to 3, preferably 0. 17 is an integer of 0 to 4, preferably 0. 11 ~L 13 are each independently a single bond, an ether group, a carbonyl group, or an alkylene group having 1 to 4 carbon atoms. Since X is a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring, R 12 , R 13 , p 12 and p 13 is selected so that the number of carbon atoms in the tetravalent group represented by formula (X-2) falls within the range of 10 to 22. Similarly, L in formula (X-3) 11 , R 14 , R 15 , p 14 and p 15 is selected so that the number of carbon atoms of the tetravalent group represented by formula (X-3) is in the range of 12 to 22, and L in formula (X-4) 12 , L 13 , R 16 , R 17 , R 18 , p 16 , p 17 and p 18is selected so that the number of carbon atoms in the tetravalent group represented by formula (X-4) falls within the range of 18 to 22.

[0021] X is more preferably a tetravalent group represented by the following formula (X-5) or (X-6), and more preferably contains a tetravalent group represented by the following formula (X-5). [ka]

[0022] Specific examples of the tetracarboxylic dianhydride represented by formula (A-1) include pyromellitic dianhydride, 2,3,5,6-toluenetetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, and 1,4,5,8-naphthalenetetracarboxylic dianhydride. These tetracarboxylic dianhydrides may be used alone or in combination of two or more. Among these, the tetracarboxylic dianhydride represented by formula (A-1) preferably includes pyromellitic dianhydride.

[0023] The tetracarboxylic acid component (A) may contain, in addition to a tetracarboxylic dianhydride, a derivative of the tetracarboxylic dianhydride (a tetracarboxylic acid and / or an alkyl ester of the tetracarboxylic acid). Examples of the tetracarboxylic acid include pyromellitic acid, 2,3,5,6-toluenetetracarboxylic acid, 3,3',4,4'-benzophenonetetracarboxylic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, etc. Among these, the tetracarboxylic acid preferably includes pyromellitic acid. Examples of alkyl esters of tetracarboxylic acids include dimethyl pyromellitate, diethyl pyromellitate, dipropyl pyromellitate, diisopropyl pyromellitate, dimethyl 2,3,5,6-toluenetetracarboxylate, dimethyl 3,3',4,4'-diphenylsulfonetetracarboxylate, dimethyl 3,3',4,4'-benzophenonetetracarboxylate, dimethyl 3,3',4,4'-biphenyltetracarboxylate, dimethyl 1,4,5,8-naphthalenetetracarboxylate, etc. In the alkyl esters of the above tetracarboxylic acids, the alkyl group preferably has 1 to 3 carbon atoms. These tetracarboxylic acids and derivatives thereof can be used alone or in combination of two or more.

[0024] The proportion of tetracarboxylic acid in the tetracarboxylic acid component (A) is preferably as low as possible, and is preferably 50 mol % or less, more preferably 30 mol % or less, and even more preferably 0 mol %.

[0025] (Solvent (C)) The solvent (C) used in the production method of the present invention preferably contains an alkylene glycol solvent represented by the following formula (C-1), from the viewpoint of easily producing a powdery resin composition containing the polyimide resin powder (Z). [ka] (Ra1 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, Ra2 is a linear alkylene group having 2 to 6 carbon atoms, and n is an integer of 1 to 3.) The alkylene glycol solvent preferably has a boiling point of 140°C or higher, more preferably 160°C or higher, and even more preferably 180°C or higher at normal pressure (1 atmosphere), from the viewpoint of enabling the polymerization reaction of the tetracarboxylic acid component (A) and the diamine component (B) under normal pressure in Step (II) and Step (III).

[0026] In formula (C-1), Ra1 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group or an ethyl group. In formula (C-1), Ra2 is a linear alkylene group having 2 to 6 carbon atoms, preferably a linear alkylene group having 2 to 3 carbon atoms, and more preferably an ethylene group. In formula (C-1), n ​​is an integer of 1 to 3, preferably 2 or 3. Specific examples of the alkylene glycol solvent represented by formula (C-1) include ethylene glycol monomethyl ether, diethylene glycol monomethyl ether (also known as 2-(2-methoxyethoxy)ethanol), triethylene glycol monomethyl ether (also known as 2-[2-(2-methoxyethoxy)ethoxy]ethanol), ethylene glycol monoethyl ether, diethylene glycol monoethyl ether (also known as 2-(2-ethoxyethoxy)ethanol), ethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, triethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, diethylene glycol monoisobutyl ether, ethylene glycol monoisobutyl ether, ethylene glycol, and 1,3-propanediol, and one or more of these may be used. Among the above, the solvent (C) preferably contains at least one selected from the group consisting of 2-(2-methoxyethoxy)ethanol, 2-[2-(2-methoxyethoxy)ethoxy]ethanol, 2-(2-ethoxyethoxy)ethanol, and 1,3-propanediol, and more preferably contains at least one selected from the group consisting of 2-(2-methoxyethoxy)ethanol and 2-(2-ethoxyethoxy)ethanol.

[0027] From the viewpoint of easily producing a powdery resin composition containing polyimide resin powder (Z), the content of the alkylene glycol solvent in solvent (C) is preferably 30% by mass or more, more preferably 50% by mass or more, even more preferably 70% by mass or more, still more preferably 80% by mass or more, and still more preferably 90% by mass or more, and 100% by mass or less.

[0028] When the solvent (C) contains the alkylene glycol solvent and other solvents, specific examples of the "other solvents" include toluene, xylene, acetone, hexane, heptane, chlorobenzene, methanol, ethanol, n-propanol, isopropanol, N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylformamide, N,N-diethylformamide, N-methylcaprolactam, hexamethylphosphoramide, tetramethylene sulfone, dimethyl sulfoxide, o-chloroisothiazolinone, methyl ... Examples include resol, m-cresol, p-cresol, phenol, p-chlorophenol, 2-chloro-4-hydroxytoluene, diglyme, triglyme, tetraglyme, dioxane, γ-butyrolactone, dioxolane, cyclohexanone, cyclopentanone, dichloromethane, chloroform, 1,2-dichloroethane, 1,1,2-trichloroethane, dibromomethane, tribromomethane, 1,2-dibromoethane, 1,1,2-tribromoethane, and 2-ethylhexanol, and one or more of these can be used.

[0029] From the viewpoint of easily producing a powdery resin composition containing the polyimide resin powder (Z), it is preferable that the solvent (C) does not contain water. The water content of the solvent (C) is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 1% by mass or less, and still more preferably 0% by mass.

[0030] In the step (I), the method for mixing the tetracarboxylic acid component (A) and the solvent (C) is not particularly limited, and a conventional method can be used. The concentration of the tetracarboxylic acid component (A) in the mixture 1 obtained in step (I) is preferably 5 to 70 mass%, more preferably 20 to 60 mass%, and even more preferably 30 to 50 mass%, from the viewpoint of easy control of the reaction temperature in step (II) and from the viewpoint of improving the reaction efficiency. The mixture 1 obtained in step (I) is usually in the form of a suspension.

[0031] <Process (II)> In step (II), the mixture 1 prepared in step (I) is mixed with a diamine component (B) containing an aliphatic diamine to prepare a solution 2 containing a polyimide resin precursor containing a polyamic acid.

[0032] (Diamine component (B)) The diamine component (B) used in the present invention contains an aliphatic diamine. By using an aliphatic diamine as a raw material diamine component of the polyimide resin powder (Z), a powdery resin composition containing the thermoplastic polyimide resin powder (Z) can be easily produced. The aliphatic diamine includes a diamine containing at least one alicyclic hydrocarbon structure and a chain aliphatic diamine. The diamine component (B) preferably contains, as the aliphatic diamine, a diamine (B1) containing at least one alicyclic hydrocarbon structure and a chain aliphatic diamine (B2), and more preferably contains a diamine represented by the following formula (B1-1) and a diamine represented by the following formula (B2-1): [ka] TIFF0007798243000010.tif561 (R1 is a divalent group having 6 to 22 carbon atoms containing at least one alicyclic hydrocarbon structure, and R2 is a divalent chain aliphatic group having 5 to 16 carbon atoms.) Hereinafter, diamines containing at least one alicyclic hydrocarbon structure and chain aliphatic diamines will be described.

[0033] [Diamine (B1)] The diamine (B1) is a diamine containing at least one alicyclic hydrocarbon structure, and preferably includes a diamine represented by the following formula (B1-1). [ka] (R1 is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure.) Here, the alicyclic hydrocarbon structure means a ring derived from an alicyclic hydrocarbon compound, and the alicyclic hydrocarbon compound may be saturated or unsaturated, and may be monocyclic or polycyclic. Examples of the alicyclic hydrocarbon structure include a cycloalkane ring such as a cyclohexane ring, a cycloalkene ring such as a cyclohexene ring, a bicycloalkane ring such as a norbornane ring, and a bicycloalkene ring such as norbornene. Among these, a cycloalkane ring is preferred, a cycloalkane ring having 4 to 7 carbon atoms is more preferred, and a cyclohexane ring is even more preferred. R1 has 6 to 22 carbon atoms, and preferably 8 to 17 carbon atoms. R1 contains at least one alicyclic hydrocarbon structure, and preferably contains 1 to 3 alicyclic hydrocarbon structures.

[0034] R1 is preferably a divalent group represented by the following formula (R1-1) or (R1-2), and more preferably a divalent group represented by the following formula (R1-3). [ka] (m 11 and m 12 are each independently an integer of 0 to 2, preferably 0 or 1. 13 ~m 15 are each independently an integer of 0 to 2, preferably 0 or 1. [ka] In the divalent group represented by the above formula (R1-3), the positional relationship of the two methylene groups with respect to the cyclohexane ring may be either cis or trans, and the ratio of cis to trans may be any value.

[0035] The diamine (B1) more preferably includes a diamine represented by the following formula (B1-2): [ka] (m 11 and m 12 are each independently an integer of 0 to 2, preferably 0 or 1.

[0036] Specific examples of the diamine (B1) include 1,2-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 4,4'-diaminodicyclohexylmethane, 4,4'-methylenebis(2-methylcyclohexylamine), carvonediamine, limonenediamine, isophoronediamine, norbornanediamine, bis(aminomethyl)tricyclo[5.2.1.0]diamine, and bis(aminomethyl)tricyclo[5.2.1.0]diamine. 2,6 ]decane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 4,4'-diaminodicyclohexylpropane, etc., and one or more of these can be used. Among the above, the diamine (B1) preferably includes at least one selected from the group consisting of 1,3-bis(aminomethyl)cyclohexane and 1,4-bis(aminomethyl)cyclohexane, and more preferably includes 1,3-bis(aminomethyl)cyclohexane.

[0037] [Diamine (B2)] The diamine (B2) is a chain aliphatic diamine, and preferably includes a diamine represented by the following formula (B2-1). [ka] (R2 is a divalent chain aliphatic group having 5 to 16 carbon atoms.) Here, the chain aliphatic group means a group derived from a chain aliphatic compound, and the chain aliphatic compound may be saturated or unsaturated, may be linear or branched, and may contain a heteroatom such as an oxygen atom. R2 is preferably an alkylene group having 5 to 16 carbon atoms, more preferably an alkylene group having 6 to 14 carbon atoms, even more preferably an alkylene group having 7 to 12 carbon atoms, and even more preferably an alkylene group having 8 to 10 carbon atoms. The alkylene group may be a linear alkylene group or a branched alkylene group, but is preferably a linear alkylene group. R2 is preferably at least one selected from the group consisting of an octamethylene group and a decamethylene group, and more preferably an octamethylene group.

[0038] Another preferred embodiment of R2 is a divalent chain aliphatic group containing an ether group and having 5 to 16 carbon atoms (preferably 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms). Among these, preferred are divalent groups represented by the following formula (R2-1) or (R2-2): [ka] (m 21 and m 22 are each independently an integer of 1 to 15, preferably 1 to 13, more preferably 1 to 11, and even more preferably 1 to 9. 23 ~m 25 are each independently an integer of 1 to 14, preferably 1 to 12, more preferably 1 to 10, and even more preferably 1 to 8. Since R2 is a divalent chain aliphatic group having 5 to 16 carbon atoms (preferably 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms, and even more preferably 8 to 10 carbon atoms), m in formula (R2-1) 21 and m 22is selected so that the carbon number of the divalent group represented by formula (R2-1) is in the range of 5 to 16 (preferably 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms, and even more preferably 8 to 10 carbon atoms). That is, m 21 +m 22 is 5 to 16 (preferably 6 to 14, more preferably 7 to 12, and even more preferably 8 to 10). Similarly, m in formula (R2-2) 23 ~m 25 is selected so that the carbon number of the divalent group represented by formula (R2-2) is in the range of 5 to 16 (preferably 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms, and even more preferably 8 to 10 carbon atoms). That is, m 23 +m 24 +m 25 has 5 to 16 carbon atoms (preferably 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms, and even more preferably 8 to 10 carbon atoms).

[0039] Specific examples of the diamine (B2) include 1,5-pentamethylenediamine, 2-methylpentane-1,5-diamine, 3-methylpentane-1,5-diamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine, 1,10-decamethylenediamine, 1,11-undecamethylenediamine, 1,12-dodecamethylenediamine, 1,13-tridecamethylenediamine, 1,14-tetradecamethylenediamine, 1,16-hexadecamethylenediamine, and 2,2'-(ethylenedioxy)bis(ethyleneamine), and one or more of these can be used. Among the above, the diamine (B2) preferably includes a chain aliphatic diamine having 8 to 10 carbon atoms, more preferably includes at least one selected from the group consisting of 1,8-octamethylenediamine and 1,10-decamethylenediamine, and even more preferably includes 1,8-octamethylenediamine.

[0040] The aliphatic diamine contained in the diamine component (B) preferably includes the diamine (B1) and the diamine (B2), more preferably includes the diamine represented by the formula (B1-1) and the diamine represented by the formula (B2-1), even more preferably includes the diamine represented by the formula (B1-2) and a chain aliphatic diamine having 8 to 10 carbon atoms, and still more preferably includes 1,3-bis(aminomethyl)cyclohexane and 1,8-octamethylenediamine.

[0041] From the viewpoint of easily obtaining a polyimide resin powder composition containing a polyimide resin powder (Z) having thermoplasticity, the amount of diamine (B1) relative to the total amount of diamine (B1) and diamine (B2) is preferably 15 to 70 mol%, more preferably 15 to 65 mol%, even more preferably 15 to 60 mol%, still more preferably 15 to 50 mol%, still more preferably 15 mol% or more and less than 40 mol%, still more preferably 20 mol% or more and less than 40 mol%, still more preferably 25 to 38 mol%, still more preferably 30 to 38 mol%, and still more preferably 32 to 36 mol%.

[0042] The diamine component (B) may consist solely of an aliphatic diamine, or may contain an aromatic ring-containing diamine (B3) in addition to the aliphatic diamine. The aromatic ring-containing diamine (B3) is preferably a diamine containing at least one aromatic ring, and more preferably includes a diamine represented by the following formula (B3-1): [ka] (R3 is a divalent group containing at least one aromatic ring and having 6 to 22 carbon atoms.) The aromatic ring may be a single ring or a condensed ring, and examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, and a tetracene ring. Among these, a benzene ring or a naphthalene ring is preferred, and a benzene ring is more preferred. R3 has 6 to 22 carbon atoms, and preferably 6 to 18 carbon atoms. R3 contains at least one aromatic ring, preferably 1 to 3. The aromatic ring may have a monovalent or divalent electron-withdrawing group bonded thereto. Examples of the monovalent electron-withdrawing group include a nitro group, a cyano group, a p-toluenesulfonyl group, halogen, a halogenated alkyl group, a phenyl group, and an acyl group. Examples of the divalent electron-withdrawing group include a fluorinated alkylene group (e.g., -C(CF3)2-, -(CF2) p In addition to halogenated alkylene groups such as - (where p is an integer of 1 to 10), examples include -CO-, -SO2-, -SO-, -CONH-, -COO-, and the like.

[0043] R3 is preferably a divalent group represented by the following formula (R3-1) or (R3-2). [ka] (m 31 and m 32 are each independently an integer of 0 to 2, preferably 0 or 1. 33 and m 34 are each independently an integer of 0 to 2, preferably 0 or 1. 21 , R 22 , and R 23 are each independently an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, or an alkynyl group having 2 to 4 carbon atoms. 21 , p 22 and p 23 is an integer of 0 to 4, preferably 0. 21 is a single bond, an ether group, a carbonyl group, or an alkylene group having 1 to 4 carbon atoms. Since R3 is a divalent group having 6 to 22 carbon atoms and containing at least one aromatic ring, m in formula (R3-1) 31 , m 32 , R 21 and p 21 is selected so that the divalent group represented by formula (R3-1) has 6 to 22 carbon atoms. Similarly, L in formula (R3-2) 21 , m 33 , m 34 , R 22 , R23 , p 22 and p 23 is selected so that the divalent group represented by formula (R3-2) has 12 to 22 carbon atoms.

[0044] Specific examples of the diamine (B3) include ortho-xylylenediamine, meta-xylylenediamine, para-xylylenediamine, 1,2-diethynylbenzenediamine, 1,3-diethynylbenzenediamine, 1,4-diethynylbenzenediamine, 1,2-diaminobenzene, 1,3-diaminobenzene, 1,4-diaminobenzene, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, α,α'-bis(4-aminophenyl)1,4-diisopropylbenzene, α,α'-bis(3-aminophenyl)-1,4-diisopropylbenzene, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, 2,6-diaminonaphthalene, and 1,5-diaminonaphthalene, and these may be used alone or in combination of two or more.

[0045] The diamine component (B) may contain a diamine (B4) represented by the following formula (B4-1). [ka] (R4 is -SO2- or -Si(R x )(R y )O-containing divalent group, and R x and R y each independently represents a chain aliphatic group having 1 to 3 carbon atoms or a phenyl group.

[0046] However, from the viewpoint of easily obtaining a polyimide resin powder composition containing a thermoplastic polyimide resin powder (Z), the content of the aliphatic diamines (preferably the diamines (B1) and (B2), more preferably the diamines represented by the formula (B1-1) and the diamines represented by the formula (B2-1)) in the diamine component (B) is preferably 50 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, and still more preferably 90 mol% or more, and 100 mol% or less, based on the total number of moles of diamines in the diamine component (B).

[0047] In step (II), the mixture 1 is mixed with the diamine component (B) to prepare a solution 2 containing a polyimide resin precursor containing a polyamic acid. The mixing ratio of the mixture 1 and the diamine component (B) in the step (II) is preferably in the range of 0.9 to 1.1 moles of the diamine component (B) per mole of the tetracarboxylic acid component (A) in the mixture 1.

[0048] The method for mixing the mixture 1 with the diamine component (B) in step (II) is not particularly limited. However, from the viewpoint of making it easier to control the reaction temperature between the tetracarboxylic acid component (A) and the diamine component (B), it is preferable to mix the mixture 1 with a solution of the diamine component (B), and it is more preferable to mix the mixture 1 with the diamine component (B) by gradually adding the solution of the diamine component (B) while stirring the mixture 1. The solvent used for the solution of diamine component (B) may be any organic solvent capable of dissolving diamine component (B), and examples thereof include the same solvents as solvent (C) used in step (I). Preferably, the solvent used for the solution of diamine component (B) is a solvent containing an alkylene glycol-based solvent represented by formula (C-1). The concentration of the diamine component (B) in the solution of the diamine component (B) is not particularly limited, but from the viewpoint of easily controlling the reaction temperature between the tetracarboxylic acid component (A) and the diamine component (B) and improving the reaction efficiency, it is preferably 20 to 70 mass%, more preferably 30 to 50 mass%, and even more preferably 30 to 45 mass%.

[0049] The rate at which the solution of diamine component (B) is added to mixture 1 varies depending on the production scale. However, from the viewpoint of easily controlling the reaction temperature between tetracarboxylic acid component (A) and diamine component (B) and from the viewpoint of easily producing a powdery resin composition containing polyimide resin powder (Z), the rate is preferably such that the amount of the solution of diamine component (B) added per mole of tetracarboxylic acid component (A) in mixture 1 is 0.1 mole / min or less.

[0050] From the viewpoint of further improving the heat aging resistance of the polyimide resin powder (Z) and the polyimide resin powder composition, it is preferable that the step (II) further includes a step of adding a terminal blocking agent, which is preferably at least one selected from the group consisting of monoamines and dicarboxylic acids. Among the above, the end-capping agent is preferably a monoamine, more preferably a chain aliphatic monoamine, and from the viewpoint of further improving the heat aging resistance of the polyimide resin powder (Z) and the polyimide resin powder composition, it further preferably contains a monoamine having a chain aliphatic group having 5 to 14 carbon atoms, even more preferably contains a monoamine having a saturated linear aliphatic group having 5 to 14 carbon atoms, still more preferably contains at least one selected from the group consisting of n-octylamine, isooctylamine, 2-ethylhexylamine, n-nonylamine, isononylamine, n-decylamine, and isodecylamine, still more preferably contains at least one selected from the group consisting of n-octylamine, isooctylamine, 2-ethylhexylamine, n-nonylamine, and isononylamine, and still more preferably contains at least one selected from the group consisting of n-octylamine, isooctylamine, and 2-ethylhexylamine.

[0051] The amount of the terminal blocking agent added in step (II) may be any amount that allows the desired number of terminal groups to be introduced into the polyimide resin powder (Z). From the viewpoint of further improving the heat aging resistance of the polyimide resin powder (Z) and the polyimide resin powder composition, and from the viewpoint of adjusting the molecular weight to a desired value, the amount is preferably 0.0001 to 0.1 mol, more preferably 0.001 to 0.06 mol, and even more preferably 0.002 to 0.035 mol per mol of the tetracarboxylic acid component (A) used in step (I).

[0052] In step (II), the step of adding the end-capping agent is preferably carried out after mixing the mixture 1 with the diamine component (B). The method for adding the terminal blocking agent is not particularly limited, but it is more preferable to add a solution of the terminal blocking agent to the mixture of mixture 1 and diamine component (B). The solvent used for the solution of the terminal blocking agent may be any organic solvent capable of dissolving the terminal blocking agent, and examples thereof include the same solvents as the solvent (C) used in step (I). Preferably, the solvent used for the solution of the terminal blocking agent is a solvent containing the alkylene glycol solvent represented by the formula (C-1). The concentration of the terminal blocking agent in the solution is not particularly limited, but from the viewpoint of facilitating control of the reaction temperature and improving the reaction efficiency, it is preferably 0.1 to 20% by mass, more preferably 0.2 to 10% by mass, and even more preferably 0.5 to 5% by mass.

[0053] In step (II), the temperature at which solution 2 is prepared is not particularly limited and can be appropriately selected depending on the production scale and the like. Step (II) can be carried out either under normal pressure or under pressure, but is preferably carried out under normal pressure from the viewpoint of reducing production costs, and is preferably carried out under a flow of an inert gas such as nitrogen gas.

[0054] By the above method, in step (II), a solution 2 containing a polyimide resin precursor containing polyamic acid is obtained. The polyimide resin precursor contained in solution 2 may consist of only polyamic acid. The solid content concentration of solution 2 is preferably 10 to 40 mass%, more preferably 15 to 35 mass%, and even more preferably 15 to 30 mass%, from the viewpoint of improving the reaction efficiency in step (III) and from the viewpoint of easily producing a powdery resin composition containing polyimide resin powder (Z). The "solid content concentration" here means the concentration of components in solution 2 excluding water and organic solvents.

[0055] <Process (III)> In step (III), the solution 2 prepared in step (II) is heated to imidize the polyimide resin precursor, thereby precipitating a polyimide resin powder (Z) in the solution, and a slurry 3 containing the polyimide resin powder (Z) is prepared. In the step (III), the solution 2 is heated to cause imidization of the polyimide resin precursor, and polyimide resin powder (Z) is precipitated in the reaction solution.

[0056] The heating temperature of solution 2 in step (III) is not particularly limited as long as it is a temperature at which the polyimide resin precursor containing polyamic acid can be imidized. From the viewpoints of easily controlling the reaction temperature, improving the reaction efficiency, and easily producing a powdery resin composition containing polyimide resin powder (Z), the heating temperature is preferably 100 to 250°C, more preferably 150 to 230°C, and even more preferably 180 to 220°C. The heating temperature here means the upper limit of the set temperature during heating.

[0057] The temperature rise rate during heating of solution 2 in step (III) varies depending on the production scale, but is preferably 0.5 to 8°C / min, more preferably 0.5 to 6°C / min, and even more preferably 0.5 to 4°C / min, from the viewpoints of easily controlling the reaction temperature, improving the reaction efficiency, and easily producing a powdery resin composition containing polyimide resin powder (Z).

[0058] The heating time of solution 2 in step (III) varies depending on the production scale, but from the viewpoints of easily controlling the reaction temperature, improving the reaction efficiency, and easily producing a powdery resin composition containing polyimide resin powder (Z), the holding time after reaching the heating temperature is preferably in the range of 10 to 240 minutes, more preferably 15 to 120 minutes, and even more preferably 15 to 60 minutes.

[0059] In step (III), as the imidization of the polyimide resin precursor in solution 2 progresses, polyimide resin powder (Z) precipitates in the solution, and the reaction liquid becomes a slurry. The slurry 3 obtained in the step (III) is preferably cooled to 0 to 60° C. before being subjected to the step (IV) in order to promote the precipitation of the polyimide resin powder (Z).

[0060] <Process (IV)> In step (IV), the slurry 3 prepared in step (III) is subjected to solid-liquid separation. Since the production method of the present invention includes a step of adding the metal-containing compound (D) prior to step (IV), a polyimide resin powder composition containing the polyimide resin powder (Z) and the metal-containing compound (D) can be recovered by the solid-liquid separation. The method for solid-liquid separation of the slurry 3 is not particularly limited, and a common method such as filtration can be used. After the solid-liquid separation, the resulting solid is washed and dried to obtain a polyimide resin powder composition.

[0061] <Step of adding a metal-containing compound (D) containing at least one metal selected from the group consisting of transition metals and cerium> The step of adding the metal-containing compound (D) may be carried out at any timing before step (IV). The step of adding the transition metal-containing compound (D) may be carried out, for example, simultaneously with step (I), between steps (I) and (II), simultaneously with step (II), between steps (II) and (III), simultaneously with step (III), or between steps (III) and (IV). Among the above, from the viewpoint of obtaining a polyimide resin powder composition with little molecular weight reduction and little color change even under high temperature conditions, particularly at temperatures exceeding 200°C, the step of adding the metal-containing compound (D) is preferably carried out simultaneously with step (I), between steps (II) and (III), or between steps (III) and (IV), and more preferably simultaneously with step (I) or between steps (II) and (III).

[0062] When the step of adding the metal-containing compound (D) is carried out simultaneously with the step (I), examples of the method include a method in which the tetracarboxylic acid component (A) and the solvent (C) are mixed in the step (I) and the metal-containing compound (D) is added to the resulting mixture, and a method in which the tetracarboxylic acid component (A), the solvent (C), and the metal-containing compound (D) are added and mixed simultaneously in the step (I). Note that the step of adding the metal-containing compound (D) simultaneously with the step (I) also includes a method in which the tetracarboxylic acid component (A) or the solvent (C) containing the metal-containing compound (D) in advance is used and then mixed.

[0063] When the step of adding the metal-containing compound (D) is carried out between steps (II) and (III), for example, the metal-containing compound (D) may be added to the solution 2 containing the polyimide resin precursor obtained in step (II), and then step (III) may be carried out. When the step of adding the metal-containing compound (D) is carried out between steps (III) and (IV), for example, the metal-containing compound (D) is added to the slurry 3 obtained in step (III), and then step (IV) is carried out.

[0064] (Metal-containing compounds (D)) The metal-containing compound (D) in the present invention means a compound containing a transition metal of Groups 6 to 12 in the long periodic table or cerium. Note that in this specification, the metal-containing compound (D) does not include compounds consisting only of a transition metal or cerium (the metal itself). The transition metal in the metal-containing compound (D) is preferably a transition metal of Groups 8 to 12 in the long periodic table, and more preferably includes at least one selected from the group consisting of iron, copper, and zinc, from the viewpoint of suppressing a decrease in molecular weight and a change in color of the polyimide resin powder (Z) under high-temperature conditions. That is, in the metal-containing compound (D), the at least one metal selected from the group consisting of transition metals and cerium more preferably includes at least one metal selected from the group consisting of iron, copper, zinc, and cerium, even more preferably includes at least one metal selected from the group consisting of copper, zinc, and cerium, and even more preferably includes copper.

[0065] From the viewpoint of suppressing a decrease in molecular weight and a change in color of the polyimide resin powder (Z) under high-temperature conditions, the metal-containing compound (D) is preferably at least one selected from the group consisting of halides, oxides, hydroxides, nitrates, carbonates, and carboxylates of a transition metal or cerium, more preferably at least one selected from the group consisting of halides, oxides, and carboxylates of a transition metal or cerium, and even more preferably at least one selected from the group consisting of halides and carboxylates of a transition metal. The metal-containing compound (D) may be a hydrate.

[0066] The transition metal or cerium halide may be at least one selected from the group consisting of chlorides, bromides, and iodides of transition metals or cerium. From the viewpoint of suppressing a decrease in molecular weight and a change in color of the polyimide resin powder (Z) under high-temperature conditions, the transition metal or cerium halide preferably contains an iodide of a transition metal, more preferably contains at least one selected from the group consisting of iron iodide (FeI), copper iodide (CuI), and zinc iodide (ZnI), and even more preferably contains copper iodide (CuI).

[0067] As the oxide of a transition metal or cerium, from the viewpoint of suppressing a decrease in molecular weight and a change in color of the polyimide resin powder (Z) under high temperature conditions, preferably, at least one selected from the group consisting of iron oxide (II) (FeO), iron oxide (III) (FeO), triiron tetroxide (FeO), copper oxide (I) (CuO), copper oxide (II) (CuO), zinc oxide (ZnO), and cerium oxide (CeO), is used, and more preferably, cerium oxide (CeO).

[0068] Examples of the carboxylate of a transition metal or cerium include salts of a transition metal or cerium with a monocarboxylic acid having 1 to 24 carbon atoms, preferably 2 to 18 carbon atoms. The carboxylic acid is preferably an aliphatic carboxylic acid, specific examples of which include acetic acid, propionic acid, butyric acid, octanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, etc. Among these, from the viewpoint of suppressing a decrease in molecular weight and a change in color of the polyimide resin powder (Z) under high-temperature conditions, the carboxylic acid preferably contains at least one selected from the group consisting of acetic acid, propionic acid, butyric acid, octanoic acid, lauric acid, myristic acid, palmitic acid, and stearic acid, more preferably contains at least one selected from the group consisting of acetic acid, propionic acid, butyric acid, octanoic acid, lauric acid, and stearic acid, even more preferably contains at least one selected from the group consisting of acetic acid, lauric acid, and stearic acid, and still more preferably contains acetic acid.

[0069] From the viewpoint of suppressing a decrease in molecular weight and a change in color of the polyimide resin powder (Z) under high-temperature conditions, the carboxylate of a transition metal or cerium preferably includes a carboxylate of a transition metal, more preferably includes a salt of iron, copper, or zinc with a monocarboxylic acid having 2 to 18 carbon atoms, and even more preferably includes a salt of copper or zinc with at least one acid selected from the group consisting of acetic acid, octanoic acid, lauric acid, and stearic acid.

[0070] Specific preferred examples of component (D) include iron iodide (FeI), copper iodide (CuI), zinc iodide (ZnI), iron (II) oxide (FeO), iron (III) oxide (FeO), triiron tetroxide (FeO), copper (II) oxide (CuO), zinc oxide (ZnO), cerium oxide (CeO), iron acetate, iron octoate, iron laurate, iron stearate, copper acetate, copper octoate, copper laurate, copper stearate, zinc acetate, zinc octoate, zinc laurate, and zinc stearate, and one or more of these can be used. Among the above, from the viewpoint of suppressing a decrease in molecular weight and a change in color of the polyimide resin powder (Z) under high-temperature conditions, component (D) preferably contains at least one selected from the group consisting of copper iodide (CuI), cerium oxide (CeO), copper acetate, copper octoate, copper laurate, copper stearate, and zinc acetate, more preferably contains at least one selected from the group consisting of copper iodide (CuI), cerium oxide (CeO), copper acetate, and zinc acetate, and even more preferably contains at least one selected from the group consisting of copper iodide (CuI) and copper acetate.

[0071] In the production method of the present invention, the amount of metal-containing compound (D) added is in a range such that the molar amount of at least one metal selected from the group consisting of transition metals and cerium per mole of the tetracarboxylic acid component (A) is preferably 0.00001 to 0.05 moles, more preferably 0.0001 to 0.03 moles, even more preferably 0.0001 to 0.02 moles, still more preferably 0.0001 to 0.01 moles, still more preferably 0.0001 to 0.005 moles, still more preferably 0.0001 to 0.002 moles, and still more preferably 0.0002 to 0.002 moles, from the viewpoints of suppressing a decrease in molecular weight and a change in color of the polyimide resin powder (Z) under high-temperature conditions and improving dispersibility.

[0072] In the method for producing the polyimide resin powder composition of the present invention, from the viewpoint of suppressing a decrease in molecular weight and a change in color of the polyimide resin powder (Z) under high temperature conditions, preferably, the step of adding the metal-containing compound (D) is carried out simultaneously with the step (I) or between the step (II) and the step (III); the metal in the metal-containing compound (D) includes copper; The amount of the metal-containing compound (D) added is in the range of 0.0001 to 0.02 moles of the metal relative to 1 mole of the tetracarboxylic acid component (A).

[0073] <Polyimide resin powder (Z)> The polyimide resin powder (Z) contained in the polyimide resin powder composition is a polyimide resin powder obtained by the production method of the present invention, in which the tetracarboxylic acid component (A) and the diamine component (B) are reacted in the solvent (C), followed by imidization and precipitation in the solvent (C). From the viewpoint of obtaining a polyimide resin powder composition having thermoplasticity, the polyimide resin powder (Z) preferably contains a repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (2), and the content ratio of the repeating structural unit of the formula (1) to the total of the repeating structural units of the formula (1) and the repeating structural units of the formula (2) is 15 to 70 mol %. [ka] (R1 is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure. R2 is a divalent chain aliphatic group having 5 to 16 carbon atoms. X1 and X2 are each independently a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring.)

[0074] In formula (1), R1 is a divalent group having 6 to 22 carbon atoms containing at least one alicyclic hydrocarbon structure, and is preferably the same as R1 in formula (B1-1) above. That is, R1 is preferably a divalent group represented by the following formula (R1-3): [ka]

[0075] In formula (1), X1 is a tetravalent group having 6 to 22 carbon atoms containing at least one aromatic ring, and is preferably the same as X in formula (A-1) above. That is, X1 is more preferably a tetravalent group represented by the following formula (X-5) or (X-6). [ka]

[0076] In formula (2), R2 is a divalent chain aliphatic group having 5 to 16 carbon atoms, and is preferably the same as R2 in formula (B2-1). That is, R2 is preferably at least one selected from the group consisting of an octamethylene group and a decamethylene group, and more preferably an octamethylene group.

[0077] X2 is defined in the same manner as X1 in formula (1), and the preferred embodiments are also the same.

[0078] The content ratio of the repeating structural unit of formula (1) to the total of the repeating structural units of formula (1) and formula (2) is preferably 15 to 70 mol%, more preferably 15 to 65 mol%, even more preferably 15 to 60 mol%, still more preferably 15 to 50 mol%, still more preferably 15 mol% or more and less than 40 mol%, still more preferably 20 mol% or more and less than 40 mol%, still more preferably 25 to 38 mol%, still more preferably 30 to 38 mol%, and still more preferably 32 to 36 mol%, from the viewpoint of exhibiting high crystallinity and improving thermoformability.

[0079] The polyimide resin powder (Z) may further contain a repeating structural unit of the following formula (3). [ka] (R3 is a divalent group having 6 to 22 carbon atoms and containing at least one aromatic ring. X3 is a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring.)

[0080] R3 is a divalent group containing at least one aromatic ring and having 6 to 22 carbon atoms, and is preferably the same as R3 in the above formula (B3-1). X3 is defined in the same manner as X1 in formula (1), and the preferred embodiments are also the same.

[0081] The polyimide resin powder (Z) may further contain a repeating structural unit of the following formula (4). [ka] (R4 is -SO2- or -Si(R x )(R y )O-containing divalent group, and R x and R y each independently represents a chain aliphatic group having 1 to 3 carbon atoms or a phenyl group. X4 is a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring. X4 is defined in the same manner as X1 in formula (1), and the preferred embodiments are also the same.

[0082] However, the total content ratio of the repeating structural units of formula (1) and the repeating structural units of formula (2) to all repeating structural units constituting the polyimide resin powder (Z) is preferably 50 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, and even more preferably 90 mol% or more, and is 100 mol% or less. Here, the "total content ratio of the repeating structural units of formula (1) and the repeating structural units of formula (2) relative to all repeating structural units constituting the polyimide resin powder (Z)" refers to the total content ratio (mol %) of the repeating structural units of formula (1) and the repeating structural units of formula (2) relative to all polyimide units in the polyimide resin powder (Z), where one repeating structural unit represented by formula (1) is counted as 1 mole and one repeating structural unit represented by formula (2) is counted as 1 mole.

[0083] There are no particular restrictions on the terminal structure of the polyimide resin powder (Z), but from the viewpoint of improving heat aging resistance, it is preferable that the polyimide resin powder (Z) has a chain aliphatic group having 5 to 14 carbon atoms at the terminal. The chain aliphatic group may be saturated or unsaturated, but is preferably a saturated chain aliphatic group. The chain aliphatic group may be linear or branched. Examples of saturated chain aliphatic groups having 5 to 14 carbon atoms include an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, a lauryl group, an n-tridecyl group, an n-tetradecyl group, an isopentyl group, a neopentyl group, a 2-methylpentyl group, a 2-methylhexyl group, a 2-ethylpentyl group, a 3-ethylpentyl group, an isooctyl group, a 2-ethylhexyl group, a 3-ethylhexyl group, an isononyl group, a 2-ethyloctyl group, an isodecyl group, an isododecyl group, an isotridecyl group, and an isotetradecyl group.

[0084] Among the above, the chain aliphatic group having 5 to 14 carbon atoms preferably includes at least one selected from the group consisting of an n-octyl group, an isooctyl group, a 2-ethylhexyl group, an n-nonyl group, an isononyl group, an n-decyl group, and an isodecyl group, more preferably includes at least one selected from the group consisting of an n-octyl group, an isooctyl group, a 2-ethylhexyl group, an n-nonyl group, and an isononyl group, and even more preferably includes at least one selected from the group consisting of an n-octyl group, an isooctyl group, and a 2-ethylhexyl group.

[0085] From the viewpoint of improving heat aging resistance, the polyimide resin powder (Z) preferably has, at its terminals, only chain aliphatic groups having 5 to 14 carbon atoms in addition to terminal amino groups and terminal carboxy groups. When groups other than the above are present at its terminals, the content thereof is preferably 10 mol % or less, more preferably 5 mol % or less, based on the chain aliphatic groups having 5 to 14 carbon atoms.

[0086] From the viewpoint of exhibiting excellent heat aging resistance, the content of the chain aliphatic groups having 5 to 14 carbon atoms in the polyimide resin powder (Z) is preferably 0.01 mol % or more, more preferably 0.1 mol % or more, and even more preferably 0.2 mol % or more, based on 100 mol % of all repeating units constituting the polyimide resin powder (Z). Furthermore, in order to ensure a sufficient molecular weight and obtain good mechanical properties, the content of the chain aliphatic groups having 5 to 14 carbon atoms in the polyimide resin powder (Z) is preferably 10 mol % or less, more preferably 6 mol % or less, and even more preferably 3.5 mol % or less, based on 100 mol % of all repeating units constituting the polyimide resin powder (Z). Here, "100 mol % of all repeating structural units constituting the polyimide resin powder (Z)" means, for example, that when the polyimide resin powder (Z) is composed only of repeating structural units represented by the formula (1) and repeating structural units represented by the formula (2) excluding the terminal group portions, one repeating structural unit represented by the formula (1) is counted as 1 mole, and one repeating structural unit represented by the formula (2) is counted as 1 mole, and the total is considered to be 100 mol %. The content of the chain aliphatic group having 5 to 14 carbon atoms in the polyimide resin powder (Z) can be determined by depolymerizing the polyimide resin powder (Z).

[0087] The content of the polyimide resin powder (Z) in the polyimide resin powder composition is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, still more preferably 80% by mass or more, still more preferably 90% by mass or more, still more preferably 95% by mass or more, still more preferably 98% by mass or more, still more preferably 99% by mass or more, still more preferably 99.5% by mass or more, still more preferably 99.7% by mass or more, and preferably 99.9999% by mass or less, more preferably 99.9995% by mass or less.

[0088] From the viewpoint of suppressing a decrease in molecular weight and a change in color under high-temperature conditions, the content of the metal-containing compound (D) in the polyimide resin powder composition is preferably 0.0001 to 3.0 mass%, more preferably 0.0005 to 1.0 mass%, even more preferably 0.001 to 0.60 mass%, still more preferably 0.001 to 0.50 mass%, still more preferably 0.005 to 0.20 mass%, still more preferably 0.008 to 0.10 mass%, and still more preferably 0.01 to 0.08 mass%. Furthermore, the molar amount of at least one metal selected from the group consisting of transition metals and cerium in the polyimide resin powder composition is preferably in the range of 0.00001 to 0.05 mol, more preferably 0.0001 to 0.03 mol, even more preferably 0.0001 to 0.02 mol, still more preferably 0.0001 to 0.01 mol, still more preferably 0.0001 to 0.005 mol, still more preferably 0.0001 to 0.002 mol, and still more preferably 0.0002 to 0.002 mol, relative to 1 mol of repeating units derived from the tetracarboxylic acid component (A) in the polyimide resin powder (Z). The content of the metal-containing compound (D) in the polyimide resin powder composition can be calculated from the molar amount of the metal derived from the metal-containing compound (D) relative to 1 mole of the tetracarboxylic acid component (A) used in the production. When quantifying the molar amount of the metal contained in the polyimide resin powder composition, which is the product, the quantification can be performed using, for example, ICP atomic emission spectroscopy.

[0089] The total content of the polyimide resin powder (Z) and the metal-containing compound (D) in the polyimide resin powder composition is preferably 55% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, still more preferably 80% by mass or more, still more preferably 90% by mass or more, still more preferably 95% by mass or more, still more preferably 98% by mass or more, still more preferably 99% by mass or more, still more preferably 99.5% by mass or more, still more preferably 99.7% by mass or more, still more preferably 99.8% by mass or more, and is 100% by mass or less.

[0090] Additives such as fillers, matting agents, nucleating agents, plasticizers, antistatic agents, coloring inhibitors, antigelling agents, colorants, sliding property improvers, conductive agents, flame retardants, and resin modifiers may be blended into the polyimide resin powder composition as needed, provided that the effects of the present invention are not impaired.

[0091] <Properties> The volume average particle size (D 50 ) is preferably 5 to 50 μm, more preferably 10 to 40 μm, and even more preferably 12 to 35 μm. The volume average particle size (D 50 ) can be determined by particle size measurement using a laser diffraction light scattering particle size distribution analyzer, and specifically, can be determined by the method described in the examples.

[0092] The polyimide resin powder (Z) or the polyimide resin powder composition preferably has a melting point of 360° C. or lower and a glass transition temperature of 150° C. or higher. From the viewpoint of improving heat resistance, the melting point of the polyimide resin powder (Z) or the polyimide resin powder composition is more preferably 280° C. or higher, and even more preferably 290° C. or higher, and from the viewpoint of ease of thermoforming, it is preferably 345° C. or lower, more preferably 340° C. or lower, and even more preferably 335° C. or lower. The glass transition temperature of the polyimide resin powder (Z) or the polyimide resin powder composition is preferably 160°C or higher, more preferably 170°C or higher, from the viewpoint of improving heat resistance, and is preferably 250°C or lower, more preferably 230°C or lower, and even more preferably 200°C or lower, from the viewpoint of ease of thermoforming.

[0093] The crystallization temperature Tc of the polyimide resin powder (Z) or the polyimide resin powder composition is preferably 200°C or higher, more preferably 220°C or higher, and even more preferably 250°C or higher from the viewpoint of improving heat resistance, and is preferably 350°C or lower, more preferably 320°C or lower, and even more preferably 300°C or lower from the viewpoint of ease of thermoforming.

[0094] The heat of fusion Hm of the polyimide resin powder (Z) or the polyimide resin powder composition is preferably 5.0 mJ / mg or more, more preferably 10 mJ / mg or more, and even more preferably 17 mJ / mg or more, from the viewpoint of improving crystallinity, heat resistance, mechanical strength, and chemical resistance. The upper limit of the heat of fusion Hm is not particularly limited, but is usually 45 mJ / mg or less. The heat of fusion Hm of the polyimide resin powder (Z) or polyimide resin powder composition is calculated from the area of ​​the heat of fusion peak (endothermic peak) near the melting point observed when the polyimide resin powder (Z) or polyimide resin powder composition is heated at a heating rate of 10°C / min to melt it at a temperature above the melting point, then cooled at a heating rate of 20°C / min, and then heated again at a heating rate of 10°C / min to melt it, by differential scanning calorimetry.

[0095] The melting point Tm, glass transition temperature Tg, crystallization temperature Tc, and heat of fusion Hm of the polyimide resin powder (Z) or polyimide resin powder composition can be measured specifically by the methods described in the Examples.

[0096] The logarithmic viscosity of a 0.5 mass % solution of polyimide resin powder (Z) or polyimide resin powder composition in concentrated sulfuric acid at 30°C is preferably in the range of 0.2 to 2.0 dL / g, more preferably 0.3 to 1.8 dL / g. If the logarithmic viscosity is 0.2 dL / g or higher, the resulting molded article will have sufficient mechanical strength, while if it is 2.0 dL / g or lower, the thermoformability and handleability will be good. The logarithmic viscosity μ is calculated from the following formula by measuring the flow times of concentrated sulfuric acid and the polyimide resin powder (Z) or polyimide resin powder composition solution at 30°C using a Cannon-Fenske viscometer: μ=ln(ts / t0) / C t0: Time when concentrated sulfuric acid flows ts: Flow time of polyimide resin powder (Z) or polyimide resin powder composition solution C: 0.5 (g / dL)

[0097] The number average molecular weight Mn of the polyimide resin powder (Z) or polyimide resin powder composition is preferably in the range of 5,000 to 100,000, more preferably 7,000 to 50,000, even more preferably 8,000 to 25,000, and still more preferably 10,000 to 22,000. If the number average molecular weight Mn of the polyimide resin powder (Z) or polyimide resin powder composition is 5,000 or more, the mechanical strength of the resulting molded article will be good, and if it is 100,000 or less, the thermoformability will be good.

[0098] The weight-average molecular weight Mw of the polyimide resin powder (Z) or polyimide resin powder composition is preferably in the range of 10,000 to 150,000, more preferably 15,000 to 100,000, even more preferably 20,000 to 80,000, still more preferably 30,000 to 80,000, and even more preferably 35,000 to 75,000. If the weight-average molecular weight Mw of the polyimide resin powder (Z) or polyimide resin powder composition is 10,000 or more, the mechanical strength of the resulting molded article will be good; if it is 40,000 or more, the stability of the mechanical strength will be good; and if it is 150,000 or less, the thermoformability will be good. The number average molecular weight Mn and weight average molecular weight Mw can be measured by gel permeation chromatography (GPC) using polymethyl methacrylate (PMMA) as a standard sample.

[0099] The whiteness of the polyimide resin powder (Z) or polyimide resin powder composition is preferably 70 or more, more preferably 75 or more, even more preferably 80 or more, and still more preferably 85 or more, from the viewpoint of improving appearance. The whiteness is determined by a method in accordance with JIS Z8715:1999, specifically by the method described in the Examples.

[0100] The polyimide resin powder composition obtained by the production method of the present invention undergoes little decrease in molecular weight and little change in color even when subjected to high temperature conditions, particularly temperatures exceeding 200°C. For example, the retention of the number average molecular weight after heating the polyimide resin powder composition at 300°C for 20 minutes is preferably 60% or more, more preferably 70% or more, even more preferably 80% or more, still more preferably 85% or more, and even more preferably 90% or more. The retention of the number average molecular weight may exceed 100%. The retention rate of the number average molecular weight (Mn) is calculated by the following formula, and specifically, can be determined by the method described in the Examples. Mn retention rate (%) = (Mn after heating) / (Mn before heating) × 100

[0101] Furthermore, the change in whiteness calculated by the following formula after heating the polyimide resin powder composition at 300°C for 20 minutes is preferably not less than -20, more preferably not less than -15, and even more preferably not less than -10. Specifically, the whiteness change value can be determined by the method described in the examples. Change in whiteness = (whiteness after heating) - (whiteness before heating) [Example]

[0102] The present invention will now be described in more detail with reference to examples, but the present invention is not limited thereto. In each example, various measurements and evaluations were carried out as follows.

[0103] <Dispersibility of component (D) during solid-liquid separation in step (IV)> In step (IV) of each example, the dispersibility of the metal-containing compound (D) in the slurry used for solid-liquid separation was visually observed. When stirring of the slurry was stopped, the state in which the metal-containing compound was separated was judged as "heterogeneous," and the state in which no separation was observed was judged as "homogeneous," and these results are shown in the table.

[0104] <Infrared spectroscopy (IR measurement)> The IR measurement of the polyimide resin powder (Z) was carried out using a JIR-WINSPEC50 manufactured by JEOL Ltd.

[0105] <Logarithmic viscosity μ> The polyimide resin powder (Z) was dried at 190 to 200°C for 2 hours, and then 0.100 g of the polyimide resin powder (Z) was dissolved in 20 mL of concentrated sulfuric acid (96%, manufactured by Kanto Chemical Co., Inc.) to prepare a polyimide resin solution for measurement. Measurement was carried out at 30°C using a Cannon-Fenske viscometer. The logarithmic viscosity μ was calculated using the following formula. μ=ln(ts / t0) / C t0: Time when concentrated sulfuric acid flows ts: Flow time of polyimide resin solution C: 0.5 g / dL

[0106] <Melting point, glass transition temperature, crystallization temperature, heat of fusion> The melting point Tm, glass transition temperature Tg, crystallization temperature Tc, and heat of fusion Hm of the polyimide resin powder (Z) and the polyimide resin powder composition (hereinafter collectively referred to as "polyimide resin powder (composition)") were measured using a differential scanning calorimeter ("DSC-25" manufactured by TA Instruments). Under a nitrogen atmosphere (nitrogen gas flow rate: 50 mL / min), the polyimide resin powder (composition) used as the measurement sample was subjected to the following thermal history: a first heating cycle (heating rate: 10°C / min), followed by cooling (cooling rate: 20°C / min), followed by a second heating cycle (heating rate: 10°C / min). The melting point Tm was determined by reading the peak top value of the endothermic peak observed during the second heating. The glass transition temperature Tg was determined by reading the value observed during the second heating. The crystallization temperature Tc was determined by reading the peak top value of the exothermic peak observed during cooling. When multiple peaks were observed for Tm, Tg, and Tc, the peak top value of each peak was read. The heat of fusion Hm (mJ / mg) was calculated from the area of ​​the heat of fusion peak (endothermic peak) observed near the melting point when the measurement sample was heated to a temperature above the melting point at a heating rate of 10°C / min to melt it, cooled at a heating rate of 20°C / min, and then melted again at a heating rate of 10°C / min.

[0107] <Crystallization half time> The half-crystallization time of the polyimide resin powder (Z) was measured using a differential scanning calorimeter (DSC-6220, manufactured by SII NanoTechnology Inc.). The polyimide resin powder (Z) was completely melted by holding at 420°C for 10 minutes under a nitrogen atmosphere, and then rapidly cooled at a cooling rate of 70°C / min. The time required from the appearance of the observed crystallization peak until it reached its peak top was calculated.

[0108] <Number average molecular weight, weight average molecular weight> The number average molecular weight (Mn) and weight average molecular weight (Mw) of the polyimide resin powder (composition) were measured under the following conditions using a gel permeation chromatography (GPC) measuring device "Shodex GPC-101" manufactured by Showa Denko K.K. Column: Shodex HFIP-806M Mobile phase solvent: HFIP containing 2 mM sodium trifluoroacetate Column temperature: 40℃ Mobile phase flow rate: 1.0mL / min Sample concentration: approximately 0.1% by mass Detector: IR detector Injection volume: 100μL Calibration curve: Standard PMMA

[0109] <Volume average particle size (D 50 )> The volume average particle size (D 50 ) was determined by laser diffraction particle size distribution measurement. The measurement device used was a Malvern Laser Diffraction Light Scattering Particle Size Distribution Analyzer "LMS-2000e." Water was used as the dispersion medium for the polyimide resin powder (composition), and measurements were performed under ultrasonic conditions to ensure that the polyimide resin powder (composition) was sufficiently dispersed. The measurement range was 0.02 to 2000 μm.

[0110] <Whiteness> The whiteness of the polyimide resin powder (composition) was measured for Lab values and YI values by the reflection method using a color difference meter ("ZE2000" manufactured by Nippon Denshoku Industries Co., Ltd.), and calculated based on the Lab values and YI values by a method conforming to JIS Z8715:1999.

[0111] Approximately 15 g of the polyimide resin powder (composition) was placed in a 50 cc screw vial and heated in a hot air dryer at 200 °C for 2 weeks and in a hot air dryer at 300 °C for 20 minutes. Mn was measured in the same manner as described above using the heated polyimide resin powder (composition), and the Mn retention rate was calculated from the following formula. Mn retention rate (%) = (Mn after heating) / (Mn before heating) × 100 A larger value of the Mn retention rate means less decrease in molecular weight even under high temperature conditions, which is a good result. Also, those with a Mn retention rate of 15% or more after heating at 200 °C for 2 weeks and a Mn retention rate of 60% or more after heating at 300 °C for 20 minutes are considered qualified.

[0112] <Change in whiteness> Approximately 15 g of the polyimide resin powder (composition) was placed in a 50 cc screw vial and heated in a hot air dryer at 200 °C for 2 weeks and in a hot air dryer at 300 °C for 20 minutes. The whiteness was measured in the same manner as described above using the heated polyimide resin powder (composition), and the change in whiteness value was calculated from the following formula. A larger change in whiteness value means less variation in color even under high temperature conditions, which is a good result. Change in whiteness = (Whiteness after heating) - (Whiteness before heating) A larger change in whiteness value means less variation in color even under high temperature conditions, which is a good result. Also, those with a change in whiteness value of -30 or more after heating at 200 °C for 2 weeks and a change in whiteness value of -20 or more after heating at 300 °C for 20 minutes are considered qualified.

[0113] Comparative Example 1 (Production and Evaluation of Polyimide Resin Powder (Z)) 〔Step (I)〕 Into a 2 L separable flask equipped with a Dean-Stark apparatus, a Liebig condenser, a thermocouple, and a four-paddle impeller, 500 g of (C-1) 2-(2-methoxyethoxy)ethanol (manufactured by Nippon Nyukazai Co., Ltd.) and 218.12 g (1.00 mol) of (A-1) pyromellitic dianhydride (manufactured by Mitsubishi Gas Chemical Company, Inc.) were introduced, and after flowing nitrogen, the mixture was stirred at 150 rpm to obtain a uniform suspension, thereby obtaining Mixture 1.

[0114] [Step (II)] Separately, a mixed diamine solution was prepared in a 500 mL beaker by dissolving 49.79 g (0.35 mol) of (B1-1) 1,3-bis(aminomethyl)cyclohexane (Mitsubishi Gas Chemical Company, Inc., cis / trans ratio = 7 / 3) and 93.77 g (0.65 mol) of (B2-1) 1,8-octamethylenediamine (Kanto Chemical Co., Inc.) in 250 g of (C-1) 2-(2-methoxyethoxy)ethanol. This mixed diamine solution was gradually added using a plunger pump. Although heat was generated during the dropwise addition, the internal temperature was adjusted to remain within the range of 40 to 80 °C. A nitrogen flow was maintained throughout the dropwise addition of the mixed diamine solution, and the stirring impeller rotation speed was set to 250 rpm. After the dropwise addition was completed, 130 g of (C-1) 2-(2-methoxyethoxy)ethanol and 1.284 g (0.010 mol) of n-octylamine (manufactured by Kanto Chemical Co., Inc.) as an end-capping agent were added and further stirred. At this stage, a pale yellow polyamic acid solution 2 was obtained.

[0115] [Step (III)] Next, the stirring speed was increased to 200 rpm, and the polyamic acid solution 2 in the 2 L separable flask was heated to a temperature in the range of 185 to 190°C. The temperature increase rate was adjusted to a range of 0.5 to 4.0°C / min. During the temperature increase process, precipitation of polyimide resin powder and dehydration due to imidization were confirmed when the liquid temperature was between 120 and 140°C. After maintaining the temperature at 190°C for 30 minutes, the solution was allowed to cool to room temperature, yielding slurry 3.

[0116] [Step (IV)] The slurry 3 obtained in step (III) was filtered and subjected to solid-liquid separation. The obtained polyimide resin powder was washed with 300 g of 2-(2-methoxyethoxy)ethanol and 300 g of methanol, filtered, and then dried in a dryer at 180°C for 10 hours to obtain 317 g of polyimide resin powder (Z).

[0117] The obtained polyimide resin powder (Z) was subjected to various measurements and evaluations by the above-mentioned methods. The results are shown in Table 1. When the IR spectrum of the polyimide resin powder (Z) was measured, ν(C=O) 1768, 1697 (cm -1 The characteristic absorption of the imide ring was observed in the 2000-kJ / 2000 sigma-based copolymer. The inherent viscosity measured by the above method was 1.30 dL / g, and the half-crystallization time was 20 seconds or less.

[0118] Comparative Example 2 (Production and Evaluation of Comparative Polyimide Resin Powder Composition) The polyimide resin powder (Z) obtained in Comparative Example 1 and (D-1) copper iodide (CuI) were blended in a 500 mL plastic container so that the total amount was 100 g. The amount of CuI blended was adjusted so that the metal (Cu) content in the resulting polyimide resin powder composition would be the amount shown in Table 1. The plastic container was capped and shaken up and down 50 times to dry blend, thereby preparing a comparative polyimide resin powder composition. The powder composition thus obtained was subjected to various measurements and evaluations using the methods described above. The results are shown in Table 1.

[0119] Example 1 (Production and Evaluation of Polyimide Resin Powder Composition) [Process (I)] Into a 2 L separable flask equipped with a Dean-Stark apparatus, a Liebig condenser, a thermocouple, and a four-paddle impeller, 500 g of (C-1) 2-(2-methoxyethoxy)ethanol (manufactured by Nippon Nyukazai Co., Ltd.), 218.12 g (1.00 mol) of (A-1) pyromellitic dianhydride (manufactured by Mitsubishi Gas Chemical Company, Inc.), and the amount of (D-1) CuI shown in Table 1 were introduced, and after flowing nitrogen, the mixture was stirred at 150 rpm to obtain a uniform suspension, thereby obtaining Mixture 1.

[0120] Except for the above, steps (II) to (IV) were carried out in the same manner as in Comparative Example 1, to produce and evaluate a polyimide resin powder composition. The results are shown in Table 1.

[0121] Examples 2 to 5 Polyimide resin powder compositions were produced and evaluated in the same manner as in Example 1, except that the amount of (D-1) CuI added in Example 1 was changed to the amount shown in Table 1. The results are shown in Table 1.

[0122] Example 6 Steps (I) and (II) were carried out in the same manner as in Comparative Example 1. Next, steps (III) and (IV) were carried out in the same manner as in Comparative Example 1, except that (D-1) CuI was added to the polyamic acid solution 2 obtained in step (II) in the amount shown in Table 2, thereby producing and evaluating a polyimide resin powder composition. The results are shown in Table 2.

[0123] Example 7 Steps (I) to (III) were carried out in the same manner as in Comparative Example 1. Furthermore, steps (III) and (IV) were carried out in the same manner as in Comparative Example 1, except that (D-1) CuI was added to the slurry 3 obtained in step (III) in the amount shown in Table 2, to produce and evaluate a polyimide resin powder composition. The results are shown in Table 2.

[0124] Examples 8 to 11 Polyimide resin powder compositions were produced and evaluated in the same manner as in Example 3, except that the type and amount of component (D) used in Example 3 was changed as shown in Table 3. The results are shown in Table 3.

[0125] [Table 1]

[0126] [Table 2]

[0127] [Table 3]

[0128] Details of the component (D) used are as follows: The content (mass%) of each component shown in the table means the active amount. (D-1) CuI: manufactured by Nippon Chemical Industry Co., Ltd. (D-2) Cu(OAc)2: Copper(II) acetate, manufactured by Tokyo Chemical Industry Co., Ltd. (D-3) Zn(OAc)2: Zinc acetate, manufactured by Tokyo Chemical Industry Co., Ltd. (D-4) CeO2: "Cerium Hydrate 90" manufactured by Treibacher Industrie AG, hydrate of cerium (IV) oxide represented by CeO2·nH2O, CeO2 content: 93% by mass

[0129] As shown in the table, the polyimide resin powder composition obtained by the manufacturing method of this example exhibited less decrease in Mn and less change in whiteness even after storage under high temperature conditions compared to the comparative example. In particular, the polyimide resin powder composition obtained by the manufacturing method of the present invention exhibits superior effects to the comparative example in that it exhibited less change in whiteness after heating at 300°C. [Industrial Applicability]

[0130] According to the present invention, a polyimide resin powder composition can be produced that undergoes little molecular weight reduction and little color change even when subjected to high temperature conditions, particularly temperatures above 200°C.

Claims

1. A method for producing a polyimide resin powder composition comprising polyimide resin powder (Z) and a metal-containing compound (D) containing at least one metal selected from the group consisting of transition metals and cerium, The above manufacturing method comprises the following steps (I) to (IV) in order: A method for producing a polyimide resin powder composition, comprising the step of adding the metal-containing compound (D) prior to step (IV) above. Step (I): A step of mixing tetracarboxylic acid component (A) and solvent (C) to prepare mixture 1. Step (II): A step of mixing the mixture 1 with a diamine component (B) containing an aliphatic diamine to prepare a solution 2 containing a polyimide resin precursor containing polyamic acid. Step (III): A step of heating the solution 2 to imidize the polyimide resin precursor, precipitating polyimide resin powder (Z) in the solution, and preparing a slurry 3 containing the polyimide resin powder (Z). Step (IV): Step of separating the slurry 3 into solid and liquid components.

2. A method for producing a polyimide resin powder composition according to claim 1, wherein the step of adding the metal-containing compound (D) is performed simultaneously with step (I) or between step (II) and step (III).

3. A method for producing a polyimide resin powder composition according to claim 1 or 2, wherein the metal in the metal-containing compound (D) is selected from the group consisting of copper, zinc, and cerium, wherein the metal is selected from the group consisting of copper, zinc, and cerium.

4. A method for producing a polyimide resin powder composition according to claim 1 or 2, wherein the amount of the metal-containing compound (D) added is in the range of 0.00001 to 0.05 moles of the metal per mole of the tetracarboxylic acid component (A).

5. A method for producing a polyimide resin powder composition according to claim 1 or 2, wherein step (II) further includes a step of adding an end-capturing agent.

6. A method for producing a polyimide resin powder composition according to claim 1 or 2, wherein the tetracarboxylic acid component (A) comprises a tetracarboxylic dianhydride represented by the following formula (A-1). 【Chemistry 1】 (X is a tetravalent group with 6 to 22 carbon atoms that contains at least one aromatic ring.)

7. A method for producing a polyimide resin powder composition according to claim 1 or 2, wherein the diamine component (B) comprises, as the aliphatic diamine, a diamine represented by the following formula (B1-1) and a diamine represented by the following formula (B2-1). 【Chemistry 2】 (R １ R is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure, ２ (It is a divalent, chain-like aliphatic group with 5 to 16 carbon atoms.)

8. A method for producing a polyimide resin powder composition according to claim 1 or 2, wherein the solvent (C) comprises an alkylene glycol-based solvent represented by the following formula (C-1). 【Transformation 3】 (Ra １ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, Ra ２ (where n is a straight-chain alkylene group with 2 to 6 carbon atoms, and n is an integer from 1 to 3.)

9. A method for producing a polyimide resin powder composition according to claim 1 or 2, wherein the polyimide resin powder (Z) comprises repeating structural units represented by the following formula (1) and repeating structural units represented by the following formula (2), and the content ratio of the repeating structural units of formula (1) to the total of the repeating structural units of formula (1) and the repeating structural units of formula (2) is 15 to 70 mol%. 【Chemistry 4】 (R １ R is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure. ２ X is a divalent, chain-like aliphatic group having 5 to 16 carbon atoms. １ and X ２ Each of these is independently a tetravalent group with 6 to 22 carbon atoms containing at least one aromatic ring.

10. A method for producing a polyimide resin powder composition according to claim 9, wherein the content ratio of the repeating structural units of formula (1) to the total of the repeating structural units of formula (1) and the repeating structural units of formula (2) is 15 mol% or more and less than 40 mol%.

11. The volume average particle diameter (D ５０ ) of the polyimide resin powder composition is 5 to 50 μm, and the method for producing a polyimide resin powder composition according to claim 1 or 2.

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