Production method for polyimide resin powder composition

Abstract

Provided is a production method for 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. The production method includes predetermined steps (I) to (IV) in this order, and includes a step for adding the metal-containing compound (D) before the step (IV).

Description

Method for producing polyimide resin powder composition

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

[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 conducted to improve the heat aging resistance of thermoplastic polyimide resins. For example, Patent Document 2 describes that a polyimide resin having specific polyimide structural units 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 having specific polyimide structural units and a polyimide resin composition containing a specific antioxidant have excellent long-term heat resistance, a high crystallization temperature, and good moldability.

[0006] JP 2005-28524 A International Publication No. 2016 / 147997 International Publication No. 2020 / 184355

[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 thermally 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 bodies, thermoplastic polyimide resins or compositions thereof are not pelletized, but are used in a powdered state and subjected to hot-press molding. In the production of fiber-reinforced composites, powdered thermoplastic polyimide resins or compositions thereof may be sprinkled on the surface of continuous reinforcing fibers and then subjected to hot-press molding. In the above-mentioned hot-press molding, the thermoplastic polyimide resin is subjected to hot-press conditions, for example, at a temperature exceeding 200°C for several minutes. Therefore, it is important that the molecular weight of the thermoplastic polyimide resin is not reduced and maintained during this time. Furthermore, from the viewpoint of improving the appearance of the resulting molded body, it is desirable that the color of the thermoplastic polyimide resin or its composition does not change much even after heating.

[0009] However, in the prior art, there is room for further improvement in 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 that exhibits little decrease in molecular weight and little change in color even when subjected to high temperature conditions, particularly at temperatures exceeding 200° C.

[0010] The present inventors have found that the above-mentioned problems can be solved by adding a specific metal-containing compound in a specific step in the production process of 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, the method comprising the following steps (I) to (IV) in this order, and including a step of adding the metal-containing compound (D) prior to step (IV):

[0013] [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 steps (II) and (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) comprises at least one metal selected from the group consisting of copper, zinc, and cerium. [4] A 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] A 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] A 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): (X is a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring.) [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): (R １ is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure, and R ２ 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-based solvent represented by the following formula (C-1): (Ra １ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and Ra ２ 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 %. (R １ is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure. ２ is a divalent chain aliphatic group having 5 to 16 carbon atoms. １ and X ２ are each independently a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring.)

[10] 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

[11] The method for producing a polyimide resin powder composition according to any one of [1] to

[10] , wherein the particle size is 5 to 50 μm.

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

[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 in whiteness after heating at high temperatures, particularly at temperatures above 200°C. In particular, a polyimide resin powder composition that exhibits little loss in Mn retention and 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 of number-average molecular weight (Mn) and change in whiteness of a polyimide resin powder composition after heating can be evaluated specifically by the methods described in the Examples.

[0013] [Method for 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 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, 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) prior to step (IV). Step (I): A step of mixing a tetracarboxylic acid component (A) and a 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 performing solid-liquid separation of the slurry 3.

[0014] The manufacturing method of the present invention, having the above-described configuration, can produce a polyimide resin powder composition that exhibits minimal molecular weight reduction and color variation even when subjected to high-temperature conditions, particularly temperatures exceeding 200°C. The reason for this is unclear, 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). It is believed that by carrying out the reaction of the tetracarboxylic acid component (A) with 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), 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 presumed 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, facilitating the movement of the electrons of the methylene group. The metal contained in the metal-containing compound (D) is at least one selected from the group consisting of transition metals and cerium, and ions of the metal have the ability to coordinate to nitrogen atoms and / or carbonyl groups. Furthermore, it is believed that the coordination of the metal ions with 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) makes it difficult for the electrons of the methylene groups to take the above-mentioned resonance structure, 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 and enabling the production of a polyimide resin powder composition that exhibits little molecular weight reduction and little color change even when stored under high-temperature conditions.

[0017] <Step (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): (X is a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring.)

[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. The number of carbon atoms in X is 6 to 22, and preferably 6 to 18. X contains at least one aromatic ring, and preferably 1 to 3.

[0020] X is preferably a tetravalent group represented by any one of the following formulae (X-1) to (X-4). (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 of the tetravalent group represented by formula (X-2) is in 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 p１８ is 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).

[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 acid dianhydride, a derivative of the tetracarboxylic acid 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, and 1,4,5,8-naphthalenetetracarboxylic acid. Among these, the tetracarboxylic acid preferably contains pyromellitic acid. Examples of alkyl esters of tetracarboxylic acids include dimethyl pyromellitic acid, diethyl pyromellitic acid, dipropyl pyromellitic acid, diisopropyl pyromellitic acid, dimethyl 2,3,5,6-toluenetetracarboxylate, dimethyl 3,3',4,4'-diphenylsulfonetetracarboxylate, dimethyl 3,3',4,4'-benzophenonetetracarboxylate, dimethyl 3,3',4,4'-biphenyltetracarboxylate, and dimethyl 1,4,5,8-naphthalenetetracarboxylate. In the alkyl esters of the above tetracarboxylic acids, the number of carbon atoms in the alkyl group is preferably 1 to 3. These tetracarboxylic acids and their derivatives 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, preferably 50 mol % or less, more preferably 30 mol % or less, and even more preferably 0 mol %.

[0025] (Solvent (C)) From the viewpoint of easily producing a powdery resin composition containing polyimide resin powder (Z), the solvent (C) used in the production method of the present invention preferably contains an alkylene glycol-based solvent represented by the following formula (C-1): (Ra １ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and Ra ２is 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 steps (II) and (III).

[0026] Ra in formula (C-1) １ 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. ２is 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, and 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 the polyimide resin powder (Z), the content of the alkylene glycol solvent in the 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 is 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 of such solvents 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 may 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] The method for mixing the tetracarboxylic acid component (A) and the solvent (C) in step (I) 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 viewpoints of ease of control of the reaction temperature in step (II) and improvement of reaction efficiency. The mixture 1 obtained in step (I) is usually in the form of a suspension.

[0031] <Step (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 the 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. Examples of the aliphatic diamine include 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). (R １ is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure, and R ２ is a divalent chain aliphatic group having 5 to 16 carbon atoms.) Diamines containing at least one alicyclic hydrocarbon structure and chain aliphatic diamines will be described below.

[0033] [Diamine (B1)] The diamine (B1) is a diamine containing at least one alicyclic hydrocarbon structure, and preferably contains a diamine represented by the following formula (B1-1). (R １is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure.) Here, the alicyclic hydrocarbon structure refers to 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 alicyclic hydrocarbon structures include cycloalkane rings such as a cyclohexane ring, cycloalkene rings such as cyclohexene, bicycloalkane rings such as a norbornane ring, and bicycloalkene rings 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. R １ has 6 to 22 carbon atoms, preferably 8 to 17. １ contains at least one alicyclic hydrocarbon structure, preferably 1 to 3.

[0034] R １ 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). (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. 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): (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). (R ２ 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, linear or branched, and may contain a heteroatom such as an oxygen atom. ２ 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. ２ 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] Also, R２ Another preferred embodiment of the alkyl group 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, a divalent group represented by the following formula (R2-1) or (R2-2) is preferred. (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. ２ 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), and therefore, m in formula (R2-1) ２１ and m ２２ is 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). ２１ +m ２２ is 5 to 16 (preferably 6 to 14, more preferably 7 to 12, and even more preferably 8 to 10). 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 contains a diamine represented by the following formula (B3-1): (R ３ is a divalent 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. R ３ has 6 to 22 carbon atoms, preferably 6 to 18. ３ 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(CF ３ ) ２ -, - (CF ２ ) ｐ In addition to halogenated alkylene groups such as - (where p is an integer from 1 to 10), -CO-, -SO ２ -, -SO-, -CONH-, -COO- and the like.

[0043] R ３ is preferably a divalent group represented by the following formula (R3-1) or (R3-2). (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. ３ is a divalent group having 6 to 22 carbon atoms and containing at least one aromatic ring, and therefore, m ３１ , m ３２ , R ２１ and p ２１ is selected so that the number of carbon atoms in the divalent group represented by formula (R3-1) is in the range of 6 to 22. Similarly, L in formula (R3-2) ２１ , m ３３ , m ３４ , R ２２ , R ２３ , 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 orthoxylylenediamine, metaxylylenediamine, paraxylylenediamine, 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): (R ４ Ha-SO ２ - or -Si(R ｘ ) (R ｙ) is a divalent group containing O—, 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 polyimide resin powder (Z) having thermoplasticity, 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 and the diamine component (B) are mixed to prepare a solution 2 containing a polyimide resin precursor containing a polyamic acid. The mixing ratio of the mixture 1 to the diamine component (B) in 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 and the diamine component (B) in step (II) is not particularly limited. However, from the viewpoint of easily controlling 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). 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 the diamine component (B) may be any organic solvent capable of dissolving the diamine component (B), and examples thereof include solvents similar to the solvent (C) used in step (I). Preferably, the solvent used for the solution of the diamine component (B) is a solvent containing an alkylene glycol-based solvent represented by the 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% by mass, more preferably 30 to 50% by mass, and even more preferably 30 to 45% by mass.

[0049] The rate of addition of the solution of diamine component (B) 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 addition of the solution of diamine component (B) per mole of tetracarboxylic acid component (A) in mixture 1 is 0.1 mol / 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, the step (II) preferably further comprises a step of adding an end-capping 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 end-capping agent added in step (II) may be any amount that allows a desired amount of end 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 terminal blocking agent is preferably carried out after mixing the mixture 1 and the diamine component (B). While the method for adding the terminal blocking agent is not particularly limited, it is more preferable to add a solution of the terminal blocking agent to a mixture of the mixture 1 and the diamine component (B). The solvent used in the terminal blocking agent solution may be any organic solvent capable of dissolving the terminal blocking agent, including solvents similar to the solvent (C) used in step (I). Preferably, the solvent used in the terminal blocking agent solution is a solvent containing the alkylene glycol-based solvent represented by formula (C-1). The concentration of the terminal blocking agent in the terminal blocking agent solution is not particularly limited, but 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, from the viewpoints of facilitating control of the reaction temperature and improving reaction efficiency.

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

[0054] By the above method, in step (II), solution 2 containing a polyimide resin precursor containing polyamic acid is obtained. The polyimide resin precursor contained in solution 2 may consist solely of polyamic acid. The solids 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). Here, "solids concentration" refers to the concentration of components in solution 2 excluding water and organic solvents.

[0055] <Step (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 preparing a slurry 3 containing the polyimide resin powder (Z). In step (III), the heating of solution 2 causes imidization of the polyimide resin precursor, and the 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, 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), it is preferably 100 to 250° C., more preferably 150 to 230° C., and even more preferably 180 to 220° C. Note that the heating temperature here means the upper limit of the temperature set 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 facilitating control of 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 viewpoint 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 proceeds, polyimide resin powder (Z) precipitates in the solution, and the reaction liquid becomes a slurry. From the viewpoint of promoting the precipitation of polyimide resin powder (Z), the slurry 3 obtained in step (III) is preferably cooled to 0 to 60°C before being subjected to step (IV).

[0060] <Step (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 conventional method such as filtration can be used. After the solid-liquid separation, the obtained solid is washed and dried to obtain a polyimide resin powder composition.

[0061] <Step of adding 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 performed at any timing before step (IV). The step of adding the transition metal-containing compound (D) can be performed, 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 color variation even under high temperature conditions, particularly at temperatures exceeding 200°C, the step of adding the metal-containing compound (D) is preferably performed 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) is added to the solution 2 containing the polyimide resin precursor obtained in step (II), followed by step (III). 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), followed by step (IV).

[0064] (Metal-Containing Compound (D)) In the present invention, the metal-containing compound (D) refers to a compound containing a transition metal of Groups 6 to 12 in the long periodic table or cerium. In this specification, the metal-containing compound (D) does not include compounds consisting solely of a transition metal or cerium (the metal itself). 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 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 metal selected from the group consisting of iron, copper, and zinc. That is, the at least one metal selected from the group consisting of a transition metal and cerium in the metal-containing compound (D) 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 iron iodide (FeI ２ ), copper iodide (CuI), and zinc iodide (ZnI ２ ), and 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, iron (II) oxide (FeO), iron (III) oxide (Fe ２ O ３ ), triiron tetroxide (Fe ３ O ４ ), copper(I) oxide (Cu ２ O), copper(II) oxide (CuO), zinc oxide (ZnO), and cerium oxide (CeO ２ ), and more preferably cerium oxide (CeO ２ ) is included.

[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, and behenic acid. 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 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 at least one selected from the group consisting of acetic acid, lauric acid, and stearic acid, and even more preferably 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] A preferred example of component (D) is iron iodide (FeI ２ ), copper iodide (CuI), zinc iodide (ZnI ２ ), iron(II) oxide (FeO), iron(III) oxide (Fe ２ O ３ ), triiron tetroxide (Fe ３ O ４ ), copper(II) oxide (CuO), zinc oxide (ZnO), cerium oxide (CeO ２), iron acetate, iron octanoate, iron laurate, iron stearate, copper acetate, copper octanoate, copper laurate, copper stearate, zinc acetate, zinc octanoate, zinc laurate, zinc stearate, etc., and one or more of these may be used. Among these, from the viewpoint of suppressing the decrease in molecular weight and the change in color of the polyimide resin powder (Z) under high temperature conditions, copper iodide (CuI), cerium oxide (CeO ２ ), copper acetate, copper octanoate, copper laurate, copper stearate, and zinc acetate, and more preferably copper iodide (CuI), cerium oxide (CeO ２ ), copper acetate, and zinc acetate, and 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, 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, and from the viewpoint of improving dispersibility, the amount of the metal-containing compound (D) added is 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 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.

[0072] In the method for producing a 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, the step of adding the metal-containing compound (D) is preferably carried out simultaneously with the step (I) or between the steps (II) and (III), the metal in the metal-containing compound (D) includes copper, and the amount of the metal-containing compound (D) added is in a range such that the molar amount of the metal per mole of the tetracarboxylic acid component (A) is 0.0001 to 0.02 mol.

[0073] <Polyimide Resin Powder (Z)> The polyimide resin powder (Z) contained in the polyimide resin powder composition is a polyimide resin powder obtained by reacting the tetracarboxylic acid component (A) with the diamine component (B) in the solvent (C), followed by imidization and precipitation in the solvent (C) according to the production method of the present invention. 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 formula (1) to the total of the repeating structural units of formula (1) and formula (2) is 15 to 70 mol %. (R １ is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure. ２ is a divalent chain aliphatic group having 5 to 16 carbon atoms. １ and X ２ are each independently a tetravalent group containing at least one aromatic ring and having 6 to 22 carbon atoms.

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

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

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

[0077] X ２ is X in formula (1). １ The definitions and preferred embodiments are the same as above.

[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). (R ３ is a divalent group having 6 to 22 carbon atoms and containing at least one aromatic ring. ３ is a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring.

[0080] R ３ is a divalent group having 6 to 22 carbon atoms and containing at least one aromatic ring, and is preferably R ３ It is the same as: X ３ is X in formula (1). １ The definitions and preferred embodiments are the same as above.

[0081] The polyimide resin powder (Z) may further contain a repeating structural unit of the following formula (4). (R ４ Ha-SO ２ - or -Si(R ｘ ) (R ｙ ) is a divalent group containing O—, and R ｘ and R ｙeach independently represents a chain aliphatic group having 1 to 3 carbon atoms or a phenyl group. ４ is a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring. ４ is X in formula (1). １ The definitions and preferred embodiments are the same as above.

[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 polyimide resin powder (Z) 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 is 100 mol% or less. As used herein, "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 polyimide resin powder (Z)" means the total content ratio (mol%) of the repeating structural units of formula (1) and the repeating structural units of formula (2) to all polyimide units in polyimide resin powder (Z), when 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, respectively.

[0083] The terminal structure of the polyimide resin powder (Z) is not particularly limited, 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. Furthermore, 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 the polyimide resin powder (Z) has groups other than the above 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 group 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, relative to the total 100 mol % of all repeating structural 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 group 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, relative to the total 100 mol % of all repeating structural units constituting the polyimide resin powder (Z). The phrase "100 mol % of all repeating structural units constituting the polyimide resin powder (Z)" used herein means that, for example, 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 one mole, and one repeating structural unit represented by the formula (2) is counted as one mole, and the total is regarded as 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%. 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 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, even more preferably 0.0001 to 0.005 mol, still more preferably 0.0001 to 0.002 mol, and even more preferably 0.0002 to 0.002 mol, relative to 1 mole 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. Furthermore, when determining the molar amount of metal contained in the polyimide resin powder composition, which is the product, the determination can be performed using, for example, ICP 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 The volume average particle diameter (D) is preferably 5 to 50 μm, more preferably 10 to 40 μm, and even more preferably 12 to 35 μm. 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. From the viewpoint of ease of thermoforming, the melting point is preferably 345° C. or lower, more preferably 340° C. or lower, and even more preferably 335° C. or lower. Furthermore, from the viewpoint of improving heat resistance, the glass transition temperature of the polyimide resin powder (Z) or the polyimide resin powder composition is more preferably 160° C. or higher, and even more preferably 170° C. or higher. From the viewpoint of ease of thermoforming, the glass transition temperature is preferably 250° C. or lower, more preferably 230° C. or lower, and even more preferably 200° C. or lower.

[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 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 by differential scanning calorimetry from the area of ​​the heat of fusion peak (endothermic peak) observed near the melting point 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.

[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 the 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 determined 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, and then using the following formula: μ=ln(ts / t ０ ) / C t ０ ts: time for concentrated sulfuric acid to flow; C: 0.5 (g / dL);

[0097] The number average molecular weight Mn of the polyimide resin powder (Z) or the 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 the polyimide resin powder composition is 5,000 or more, the mechanical strength of the obtained 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] From the viewpoint of improving appearance, the whiteness of the polyimide resin powder (Z) or the polyimide resin powder composition is preferably at least 70, more preferably at least 75, even more preferably at least 80, and still more preferably at least 85. 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 exhibits little molecular weight reduction and little color change 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, even 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 of the number-average molecular weight (Mn) is calculated using the following formula, and specifically can be determined by the method described in the Examples. Mn retention (%) = (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 -20 or more, more preferably -15 or more, and even more preferably -10 or more. The whiteness change value can be specifically determined by the method described in the Examples. Whiteness change = (whiteness after heating) - (whiteness before heating)

[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 to be "heterogeneous," and the state in which no separation was observed was judged to be "homogeneous," and these results are shown in the table.

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

[0105] <Logarithmic Viscosity μ> 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 as a measurement sample. Measurement was carried out at 30°C using a Cannon-Fenske viscometer. Logarithmic viscosity μ was calculated using the following formula: μ=ln(ts / t ０ ) / C t ０ : Time during which concentrated sulfuric acid flows ts: Time during which polyimide resin solution flows C: 0.5 g / dL

[0106] <Melting Point, Glass Transition Temperature, Crystallization Temperature, and 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 (TA Instruments' "DSC-25"). Under a nitrogen atmosphere (nitrogen gas flow rate 50 mL / min), the polyimide resin powder (composition) used as the measurement sample was subjected to a thermal history under the following conditions. The thermal history conditions were a first heating (heating rate 10°C / min), followed by cooling (cooling rate 20°C / min), followed by a second heating (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) near the melting point observed when the measurement sample was heated to a temperature above the melting point at a heating rate of 10°C / min, melted, cooled at a cooling rate of 20°C / min, and then melted again at a heating rate of 10°C / min.

[0107] <Crystallization Half Time> The crystallization half 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 held at 420°C for 10 minutes in a nitrogen atmosphere to completely melt, 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°C Mobile phase flow rate: 1.0 mL / min Sample concentration: approximately 0.1% by mass Detector: IR detector Injection volume: 100 μL Calibration curve: standard PMMA

[0109] <Volume average particle size (D ５０ )>Volume average particle size (D ５０ ) was determined by laser diffraction particle size distribution measurement. The measurement device used was a laser diffraction light scattering particle size distribution analyzer "LMS-2000e" manufactured by Malvern Instruments. Water was used as the dispersion medium for the polyimide resin powder (composition), and measurements were performed under ultrasonic conditions under which 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 determined by measuring the Lab value and the YI value by a reflection method using a color difference meter ("ZE2000" manufactured by Nippon Denshoku Industries Co., Ltd.), and calculating the whiteness based on the Lab value and the YI value in accordance with JIS Z8715:1999.

[0111] Approximately 15 g of polyimide resin powder (composition) was placed in a 50 cc screw cap bottle 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 Mn of the heated polyimide resin powder (composition) was measured in the same manner as above, and the Mn retention was calculated using the following formula: Mn Retention (%) = (Mn after heating) / (Mn before heating) × 100. A higher Mn retention value indicates less molecular weight loss even under high-temperature conditions, resulting in a better result. Furthermore, a sample with an Mn retention of 15% or more after heating at 200°C for 2 weeks and an Mn retention of 60% or more after heating at 300°C for 20 minutes was considered acceptable.

[0112] <Whiteness Change> Approximately 15 g of polyimide resin powder (composition) was placed in a 50 cc screw cap bottle and heated in a hot air dryer at 200°C for two weeks and in a hot air dryer at 300°C for 20 minutes. The whiteness of the heated polyimide resin powder (composition) was measured in the same manner as described above, and the whiteness change value was calculated using the following formula. A larger whiteness change value indicates less color variation even under high-temperature conditions and a better result. Whiteness Change = (Whiteness after heating) - (Whiteness before heating) A larger whiteness change value indicates less color variation even under high-temperature conditions and a better result. Furthermore, a whiteness change value of -30 or more after heating at 200°C for two weeks and -20 or more after heating at 300°C for 20 minutes was considered acceptable.

[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 blade, 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 500 mL beaker was used to prepare a mixed diamine solution by dissolving 49.79 g (0.35 mol) of (B1-1) 1,3-bis(aminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Company, Inc., cis / trans ratio = 7 / 3) and 93.77 g (0.65 mol) of (B2-1) 1,8-octamethylenediamine (manufactured by 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 a slurry 3.

[0116] [Step (IV)] The slurry 3 obtained in step (III) was filtered to carry out 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, it was found that ν(C═O) 1768, 1697 (cm －１The characteristic absorption of the imide ring was observed. 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 total amount of 100 g in a 500 mL plastic container. The amount of CuI blended was such 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 the components, thereby preparing a comparative polyimide resin powder composition. The resulting powder composition 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) [Step (I)] Into a 2 L separable flask equipped with a Dean-Stark apparatus, a Liebig condenser, a thermocouple, and a four-paddle blade, 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 (D-1) CuI in an amount 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. Then, steps (III) and (IV) were carried out in the same manner as in Comparative Example 1, except that (D-1) CuI was added in the amount shown in Table 2 to the polyamic acid solution 2 obtained in step (II), 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]

[0126]

[0127]

[0128] Details of the components (D) used are as follows. The content (mass%) of each component listed 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) CeO ２ : "Cerium Hydrate 90" manufactured by Treibacher Industry AG, CeO ２ ・nH ２ Hydrated cerium (IV) oxide, represented by O, CeO ２ 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.

[0130] According to the present invention, a polyimide resin powder composition can be produced which exhibits 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 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, the method comprising the following steps (I) to (IV) in this order, and including a step of adding the metal-containing compound (D) prior to step (IV): step (I): mixing a tetracarboxylic acid component (A) with a solvent (C) to prepare mixture 1; step (II): mixing mixture 1 with a diamine component (B) containing an aliphatic diamine to prepare solution 2 containing a polyimide resin precursor containing a polyamic acid; step (III): heating solution 2 to imidize the polyimide resin precursor, thereby precipitating polyimide resin powder (Z) in the solution, and preparing slurry 3 containing the polyimide resin powder (Z); and step (IV): performing solid-liquid separation of the slurry 3.

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

4. A method for producing a polyimide resin powder composition according to any one of claims 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 claims 1 to 4, wherein 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 claims 1 to 5, wherein the tetracarboxylic acid component (A) comprises a tetracarboxylic acid dianhydride represented by the following formula (A-1): (X is a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring.) 7. The method for producing a polyimide resin powder composition according to any one of claims 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): (R １ is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure, and R ２ 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 claims 1 to 7, wherein the solvent (C) comprises an alkylene glycol solvent represented by the following formula (C-1): (Ra １ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and Ra ２ is a linear alkylene group having 2 to 6 carbon atoms, and n is an integer of 1 to 3.

9. A method for producing a polyimide resin powder composition according to any one of claims 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 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 %. (R １ is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure. ２ is a divalent chain aliphatic group having 5 to 16 carbon atoms. １ and X ２ are each independently a tetravalent group containing at least one aromatic ring and having 6 to 22 carbon atoms.

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

11. The volume average particle size (D ５０ 11. The method for producing a polyimide resin powder composition according to claim 1, wherein the particle size is 5 to 50 μm.

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