Curable composition, polymaleimide resin, cured product, prepreg, circuit board, laminate film, semiconductor sealing material, and semiconductor device

Abstract

The invention provides a curable composition, a polymaleimide resin, a cured product, a prepreg, a circuit board, a laminate film, a semiconductor sealing material, and a semiconductor device. Provided are: a polymaleimide resin which exhibits excellent dielectric properties and low hygroscopicity when cured; and a curable composition which contains the polymaleimide resin. A curable composition containing a polymaleimide resin (A) having a predetermined partial structure and a cyanate ester (B).

Description

Technical Field

[0001] The present invention relates to a curable composition, a polyimide resin, a cured product, a prepreg, a circuit board, a laminated film, a semiconductor encapsulant, and a semiconductor device. Background Art

[0002] A prepreg obtained by impregnating a thermosetting resin such as an epoxy resin or a bismaleimide-triazine (BT) resin into a glass cloth and heating and drying it, a laminate obtained by heat-curing the prepreg, and a multilayer board obtained by combining the laminate and the prepreg and heating and curing them are widely used as circuit board materials for electronic devices. Among them, a package substrate, which is a type of printed wiring board and serves as an intermediate layer for mounting a semiconductor, is being continuously thinned, and warping of the package substrate during mounting has become a problem. Therefore, in order to suppress warping of the package substrate during mounting, a material exhibiting high heat resistance is required.

[0003] In addition, in recent years, the high-speed and high-frequency of signals have been continuously advancing, and it is desired to provide a thermosetting composition capable of forming a cured product that maintains a sufficiently low dielectric constant and exhibits a sufficiently low dielectric loss tangent in these environments. In particular, recently, in various electrical material applications, especially in advanced material applications, improvements in properties represented by heat resistance and dielectric properties, as well as materials and compositions that combine them, are required.

[0004] In response to such requirements, maleimide resins have attracted attention as materials having both heat resistance and low dielectric properties. In particular, as maleimide resins used in printed circuit board materials, improvements in properties related to fine pattern processability, dimensional stability, heat resistance, or high-frequency electrical properties are required. For example, Patent Documents 1 and 2 disclose a technique in which a cured product of a curable resin composition using a novel maleimide resin exhibits heat resistance and a low dielectric constant.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2020-176190

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2020-176191 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] Generally, the higher the frequency, the greater the transmission loss. Therefore, it is required to reduce the transmission loss in the high-frequency region. However, in the technologies of Patent Documents 1 and 2, only the dielectric properties in the currently utilized frequency band (range of several hundred MHz to 3 GHz) have been studied, and whether it is possible to cope with the technology for the fifth-generation mobile communication system (5G) using the so-called Sub6 band has not been studied.

[0011] Therefore, the technical problem to be solved by the present invention is to provide a polyimide resin that exhibits excellent dielectric properties and low hygroscopicity during curing, a curable composition containing the polyimide resin, a cured product thereof, a prepreg, a circuit board, a laminated film, a semiconductor encapsulant, and a semiconductor device.

[0012] Method for solving the problem

[0013] The first curable composition of the present invention is a curable composition characterized by containing a polyimide resin (A) and a cyanate ester (B). The polyimide resin (A) has a partial structure represented by the following general formula (1), a partial structure represented by the following general formula (2) that is chemically bonded to the partial structure represented by the general formula (1), and a partial structure represented by the following general formula (3) that is chemically bonded to the partial structure represented by the general formula (1). Thereby, excellent dielectric properties and low hygroscopicity are exhibited during curing.

[0014] [Chemical formula 1]

[0015]

[0016] [In the above general formula (1), R 13 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, m 2 represents an integer of 0 or more and 4 or less, n 1 represents the average number of repeating units, and the two * respectively represent bonding ends. One bonding end is chemically bonded at the position of L 13 or L 14 in the following general formula (2), and the other bonding end is chemically bonded at the position of L 11 or L 12 in the following general formula (3).]

[0017] [Chemical formula 2]

[0018]

[0019] [In the above general formula (2) or (3), R 11 and R 15 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, R 12 and R 14Each independently represents a hydrocarbon group having 1 to 18 carbon atoms, L 11 ~L 14 Each independently represents a bonding end or a hydrogen atom. Among them, at the position of L 11 or L 12 , a chemical bond is formed with the partial structure represented by the general formula (1), and at the position of L 13 or L 14 , a chemical bond is formed with the partial structure represented by the general formula (1). In addition, L 11 ~L 14 that does not form a chemical bond with the partial structure represented by the general formula (1) is a hydrogen atom, and m 1 and m 3 each represent 2.]

[0020] In one embodiment of the first curable composition of the present invention, the polyimide resin (A) uses an aromatic amine compound (A-a) represented by the following general formula (a-1), a compound (A-b) having a benzyl ether skeleton, and maleic anhydride (A-c) as reaction raw materials (1).

[0021] [Chemical formula 3]

[0022]

[0023] [In the above general formula (a-1), R a1 and R a2 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R 1 represents a hydrocarbon group having 1 to 18 carbon atoms, R 2 and R 3 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms.]

[0024] In one embodiment of the first curable composition of the present invention, the polyimide resin (A) is a polyimide resin having a partial structure represented by the following general formula (1A).

[0025] [Chemical formula 4]

[0026]

[0027] [In the above general formula (1A), R 13 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, m 2 represents an integer of 0 or more and 4 or less, n 1 represents the average number of repeating units, R 11 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, R 12 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, and m 1 each represent 2, n2 represents the average number of repeating units, ran represents that the arrangement of each structural unit can be random, and the two * respectively represent the bonding ends, which are bonded to a hydrogen atom or a partial structure represented by the general formula (4).

[0028] [Chemical formula 5]

[0029]

[0030] [In the above general formula (4), R 13 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, m 2 represents an integer of 0 or more and 4 or less, and n 3 represents the average number of repeating units.

[0031] In one embodiment of the first curable composition of the present invention, it contains 10% by mass or more of a component represented by the above general formula (1A) and the sum of n 1 and n 3 is 1 or more.

[0032] In addition, the second curable composition of the present invention is a curable composition characterized by containing a maleimide resin mixture (C) and a cyanate ester (B). The maleimide resin mixture (C) contains a polymaleimide resin component having a partial structural unit represented by the following general formula (1a) and a maleimide polybody compound represented by the following general formula (5). The maleimide resin mixture (C) contains 1 to 99% by mass of the polymaleimide resin (A) relative to the total amount of the polymaleimide resin component, and contains 80% by mass or less of the maleimide polybody compound relative to the total amount of the maleimide resin mixture (C). The polymaleimide resin (A) has a partial structure represented by the following general formula (1), a partial structure represented by the following general formula (2) that is chemically bonded to the partial structure represented by the general formula (1), and a partial structure represented by the following general formula (3) that is chemically bonded to the partial structure represented by the general formula (1).

[0033] [Chemical formula 6]

[0034]

[0035] [In the above general formula (1a), R 11 represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, R 12 represents a hydrocarbon group having 1 to 18 carbon atoms, R 13 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, m 1 represents 2, m 2 represents an integer of 0 or more and 4 or less, and n 1 represents the average number of repeating units.

[0036] [Chemical Formula 7]

[0037]

[0038] [In the above general formula (5), R 21 and R 25 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, R 22 and R 24 each independently represent a hydrocarbon group having 1 to 18 carbon atoms, m 21 represents 2, m 23 represents 3, and n 21 represents an integer of 1 or more and 5 or less.]

[0039] [Chemical Formula 8]

[0040]

[0041] [In the above general formula (1), R 13 each independently represent a hydrocarbon group having 1 to 18 carbon atoms, m 2 represents an integer of 0 or more and 4 or less, n 1 represents the average number of repeating units, and the two * respectively represent bonding ends, indicating that one bonding end undergoes chemical bonding at the position of L 13 or L 14 in the following general formula (2), and the other bonding end undergoes chemical bonding at the position of L 11 or L 12 in the following general formula (3).]

[0042] [Chemical Formula 9]

[0043]

[0044] [In the above general formula (2) or (3), R 11 and R 15 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, R 12 and R 14 each independently represent a hydrocarbon group having 1 to 18 carbon atoms, and L 11 to L 14 each independently represent a bonding end or a hydrogen atom, where, at the position of L 11 or L 12 undergoes chemical bonding with the partial structure represented by the general formula (1), and at the position of L 13 or L 14 undergoes chemical bonding with the partial structure represented by the general formula (1). Additionally, L 11 to L 14is a hydrogen atom, m 1 and m 3 each represent 2.]

[0045] In one embodiment of the second curable composition of the present invention, the polyimide resin (A) uses an aromatic amine compound (A-a) represented by the following general formula (a-1), a compound (A-b) having a benzyl ether skeleton, and maleic anhydride (A-c) as reaction raw materials (1).

[0046] [Chemical formula 10]

[0047]

[0048] [In the above general formula (a-1), R a1 and R a2 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R 1 represents a hydrocarbon group having 1 to 18 carbon atoms, R 2 and R 3 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms.]

[0049] The maleimide resin of the present invention is a polyimide resin characterized by having a partial structure represented by the following general formula (1A).

[0050] [Chemical formula 11]

[0051]

[0052] [In the above general formula (1A), R 13 each independently represent a hydrocarbon group having 1 to 18 carbon atoms, m 2 represents an integer of 0 or more and 4 or less, n 1 represents the average number of repeating units, R 11 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, R 12 each independently represent a hydrocarbon group having 1 to 18 carbon atoms, m 1 each represent 2, n 2 represents the average number of repeating units, ran represents that the arrangement of each structural unit can be random, and the two * respectively represent the bonding ends, which are bonded to a hydrogen atom or a partial structure represented by the general formula (4).]

[0053] [Chemical formula 12]

[0054]

[0055] [In the above general formula (4), R 13 each independently represent a hydrocarbon group having 1 to 18 carbon atoms, m 2 represents an integer of 0 or more and 4 or less, n3 represents the average number of repeating units.

[0056] The cured product of the present invention is the cured product of any one of the above curable compositions.

[0057] The prepreg of the present invention is a prepreg having a reinforcing substrate and a semi-cured product of any one of the above curable compositions impregnated in the reinforcing substrate.

[0058] The circuit board of the present invention is a laminate having a prepreg and a copper foil.

[0059] The laminated film of the present invention is a laminated film containing any one of the above curable resin compositions.

[0060] The semiconductor sealing material of the present invention is a semiconductor sealing material containing any one of the above curable compositions.

[0061] The semiconductor device of the present invention is a semiconductor device containing the cured product of the above semiconductor sealing material.

[0062] Advantages of the Invention

[0063] According to the present invention, it is possible to provide a polyimide resin that exhibits excellent dielectric properties and low moisture absorption during curing, a curable composition containing the polyimide resin, and a cured product, prepreg, circuit board, laminated film, semiconductor sealing material, and semiconductor device thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 is the 13 C-NMR spectrum of the aromatic amine resin (a-1) of Synthesis Example 1.

[0065] Figure 2 is the FD-MS spectrum of the aromatic amine resin (a-1) of Synthesis Example 1.

[0066] Figure 3 is the GPC chart of the maleimide resin (A-1) of Synthesis Example 1.

[0067] Figure 4 is the FD-MS spectrum of the maleimide resin (A-1) of Synthesis Example 1.

[0068] Figure 5 is the 13 C-NMR spectrum of the maleimide resin (A-1) of Synthesis Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0069] Hereinafter, embodiments of the present invention will be described. The purpose of these descriptions is to illustrate the present invention and does not limit the present invention in any way.

[0070] In the present invention, two or more embodiments can be arbitrarily combined.

[0071] Unless otherwise specified, the materials, components, compounds, resins, structural units, catalysts, and solvents described in this specification can be used alone or in combination of two or more.

[0072] <Term>

[0073] In this specification, unless otherwise specified, the following terms can be applied.

[0074] The "reaction raw material" in this specification is used to obtain a target compound through a chemical reaction such as combination or decomposition, and refers to a compound that partially constitutes the chemical structure of the target compound, excluding substances that play the role of chemical reaction assistants such as solvents and catalysts. In this specification, in particular, the "reaction raw material" refers to a precursor for obtaining a target polymaleimide resin or its precursor compound (for example, an intermediate amine compound (I) in which aromatic amine compounds (A) are linked to each other via a structural unit derived from a compound (A-b) having a benzyl ether skeleton).

[0075] The "structural unit" in this specification refers to a unit of chemical structure formed during a reaction or polymerization. In other words, it refers to a partial structure other than the chemical bond structure involved in the reaction or polymerization in the resulting compound formed by the reaction or polymerization, and is a so-called residue. In addition, it is also called a repeating unit during polymerization.

[0076] The "aromatic group" in this specification preferably has an aromatic ring with 3 to 30 carbon atoms, more preferably an aromatic ring with 4 to 26 carbon atoms. Moreover, in the "aromatic group" in this specification, the hydrogen atoms of the aromatic ring in the aromatic group can be substituted with substituents such as an alkyl group with 1 to 10 carbon atoms, an alkoxy group with 1 to 10 carbon atoms, or a halogen atom. In addition, the "aromatic group" includes a heteroaromatic group and can be substituted with -O-, -S-, or -N= in such a way that -CH2- or -CH= in the "aromatic group" are not adjacent to each other. Examples of the type of the aromatic ring include a monocyclic aromatic ring, a fused-ring aromatic ring, or a ring-assembled aromatic ring, etc.

[0077] Examples of the monocyclic aromatic ring include benzene, furan, pyrrole, thiophene, imidazole, pyrazole, oxazole, isoxazole, thiazole, isothiazole, pyridine, pyrimidine, pyridazine, pyrazine, triazine, etc.

[0078] Examples of the fused-ring aromatic ring include naphthalene, anthracene, phenalene, phenanthrene, quinoline, isoquinoline, quinazoline, phthalazine, pteridine, coumarin, indole, benzimidazole, benzofuran, acridine, etc.

[0079] As the aromatic rings of the ring set, examples include biphenyl, binaphthyl, bipyridine, bithiophene, phenylpyridine, phenylthiophene, terphenyl, diphenylthiophene, quaterphenyl, etc. In addition, the hydrogen atoms of the aromatic rings in the aromatic group may be substituted, for example, with an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group having 1 to 12 carbon atoms, an aralkyl group having 1 to 12 carbon atoms, or a halogen atom. It should be noted that the monovalent aromatic group refers to a group obtained by removing one hydrogen atom from the "aromatic group".

[0080] The "alkyl group" in this specification may be any of linear, branched, or cyclic, and examples include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, neopentyl, 1,2-dimethylpropyl, n-hexyl, isohexyl, (n)heptyl, (n)octyl, (n)nonyl, (n)decyl, (n)undecyl, (n)dodecyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, norbornyl, or adamantyl.

[0081] The "cycloalkyl group" in this specification may include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, norbornyl, adamantyl, etc.

[0082] The "alkylthio group" in this specification may include methylthio, ethylthio, propylthio, butylthio, octylthio, or 2-ethylhexylthio.

[0083] The "alkenyl group" in this specification may include ethynyl, 1-propynyl, 2-propynyl, 2-butynyl, pentynyl, hexynyl, vinyl, allyl, isopropenyl, etc. It should be noted that the "alkenylene group" may include a divalent group obtained by removing any one hydrogen atom from the "alkenyl group".

[0084] The "alkoxy group" in this specification may include, for example, methoxy, ethoxy, propoxy, isopropoxy, butoxy, pentyloxy, hexyloxy, 2-ethylhexyloxy, octyloxy, nonyloxy, etc.

[0085] The "aryl group" in this specification may include, for example, phenyl, naphthyl, phenalenyl, phenanthryl, anthryl, azulenyl, indenyl, indanyl, tetrahydronaphthyl, etc. In addition, regarding this "aryl group", the hydrogen atoms of the aromatic rings in the aryl group may be substituted, for example, with an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a halogen atom.

[0086] As used in this specification, "aralkyl" includes, for example, benzyl, diphenylmethyl, biphenyl, naphthylmethyl, etc. The hydrogen atoms of the aromatic ring in the aralkyl may be substituted by, for example, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkenyl group having 1 to 10 carbon atoms, or a halogen atom. It should be noted that "arylene" includes a divalent group obtained by removing any one hydrogen atom from the "aryl".

[0087] As used in this specification, "aryloxy" includes, for example, phenoxy, naphthyloxy, anthryloxy, phenanthryloxy, or pyrenyloxy, etc.

[0088] As used in this specification, "arylthio" includes arylthio such as phenylthio, naphthylthio, anthrylthio, phenanthrylthio, or pyrenylthio, etc.

[0089] As used in this specification, "halogen atom" includes, for example, fluorine atom, chlorine atom, bromine atom, or iodine atom, etc.

[0090] As used in this specification, "alkylene" includes, for example, methylene, ethylene, propylene, 1-methylmethylene, 1,1-dimethylmethylene, 1-methylethylene, 1,1-dimethylethylene, 1,2-dimethylethylene, propylene, butylene, 1-methylpropylene, 2-methylpropylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, etc.

[0091] As used in this specification, "alkyloxy" includes, for example, oxymethylene, oxyethylene, oxypropylene, oxy(1-methylmethylene), oxy(1,1-dimethylmethylene), oxy(1-methylethylene), oxy(1,1-dimethylethylene), oxy(1,2-dimethylethylene), oxybutylene, oxy(1-methylpropylene), oxy(2-methylpropylene), oxypentylene, oxyhexylene, oxyheptylene, oxyoctylene, oxynonylene, oxydecylene, oxyundecylene, oxydodecylene, etc.

[0092] As used in this specification, "hydrocarbyl" is a monovalent group and includes straight-chain, branched-chain, or cyclic saturated hydrocarbons, unsaturated hydrocarbons, or aromatic groups. For example, "hydrocarbyl" is one group selected from the group consisting of alkyl (e.g., the above alkyl), alkenyl (e.g., the above alkenyl), aryl (e.g., the above aryl), aryloxy (e.g., the above aryloxy), aralkyl (e.g., the above aralkyl), and alkoxy (e.g., the above alkoxy), and may be substituted by -O-, -C(=O)-, or -S- such that one or more -CH2- in the group are not adjacent to each other, or may be substituted by -CH=CH- such that one or more -CH2-CH2- in the alkyl are not adjacent to each other.

[0093] In this specification, symbols such as first, second, (1), (2), etc. are merely used to distinguish one element from other elements, and are not symbols for limiting quantity or order.

[0094] (First curable composition)

[0095] The first curable composition of the present invention contains a polyimide resin (A) and a cyanate ester (B). The polyimide resin (A) has a partial structure represented by the following general formula (1), a partial structure represented by the following general formula (2) that is chemically bonded to the partial structure represented by the general formula (1), and a partial structure represented by the following general formula (3) that is chemically bonded to the partial structure represented by the general formula (1).

[0096] [Chemical formula 13]

[0097]

[0098] [In the above general formula (1), R 13 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, m 2 represents an integer of 0 or more and 4 or less, n 1 represents the average number of repeating units, and the two * respectively represent bonding ends. One bonding end is chemically bonded at the position of L 13 or L 14 in the following general formula (2), and the other bonding end is chemically bonded at the position of L 11 or L 12 in the following general formula (3).]

[0099] [Chemical formula 14]

[0100]

[0101] [In the above general formula (2) or (3), R 11 and R 15 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, R 12 and R 14 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, and L 11 to L 14 each independently represents a bonding end or a hydrogen atom. Among them, at the position of L 11 or L 12 is chemically bonded to the partial structure represented by the general formula (1), and at the position of L 13 or L 14 is chemically bonded to the partial structure represented by the general formula (1). In addition, L 11 to L 14is a hydrogen atom, m 1 and m 3 each represent 2.]

[0102] · Polymaleimide resin (A)

[0103] The polymaleimide resin (A) of the first curable composition has a partial structure represented by the general formula (1), a partial structure represented by the general formula (2) that is chemically bonded to the partial structure represented by the general formula (1), and a partial structure represented by the general formula (3) that is chemically bonded to the partial structure represented by the general formula (1). Thus, its cured product exhibits excellent dielectric properties and low hygroscopicity. The chemical structure of the polymaleimide resin (A) has only 1 bonding site at the ortho- and para-positions of the benzene ring bonded with the maleimide group, respectively. Therefore, a polymaleimide resin with a linear chain elongation can be obtained, and thus the molecular weight control is easy, and heat resistance, low dielectric properties, and solvent solubility can be balanced.

[0104] In the above general formula (1), the two * each represent a bonding end. Moreover, one of the two bonding ends is chemically bonded at the position of L 13 or L 14 in the above general formula (2). In addition, the other bonding end is chemically bonded at the position of L 11 or L 12 in the above general formula (3). Therefore, the polymaleimide resin (A) of the present embodiment has a structural unit in which the partial structure represented by the general formula (2) and the partial structure represented by the general formula (3) are connected by the partial structure represented by the general formula (1), and the partial structure represented by the general formula (1) is chemically bonded to the para-position or one of the ortho-positions of the benzene ring in the general formula (2) and the general formula (3) relative to the maleimide group.

[0105] It should be noted that in the above general formula (1), when n 1 is 2 or more, there are multiple R 13 which may be the same as or different from each other. When m 2 is 2 or more, there are multiple R 13 which may be the same as or different from each other.

[0106] In the above general formula (1), R 13 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, preferably represents a hydrocarbon group having 1 to 12 carbon atoms, and more preferably represents a hydrocarbon group having 1 to 6 carbon atoms. In addition, when m 2 is an integer of 2 or more, there are multiple R 13 which may be the same as or different from each other. As the preferred R 13, preferably a linear alkyl group, more preferably methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl or neopentyl.

[0107] It should be noted that R in the general formula (1) 13 The benzene ring to which it is bonded can be the benzene ring of the compound (A-b) having a benzylic ether skeleton.

[0108] In the above general formula (1), m 2 represents an integer of 0 or more and 4 or less, preferably an integer of 2 or less, and more preferably 2. It should be noted that in the benzene ring to which R in the general formula (1) 13 is bonded, when bonded through a methylene group at the 1-position and the 3-position, preferably R 13 are bonded to the 4-position and the 6-position, respectively.

[0109] In the above general formula (1), n 1 represents the average number of repeating units. From the viewpoint of the viscosity of the obtained polyimide resin (A), it is preferably 0 or more and 50 or less, preferably 0 or more and 30 or less, and preferably 0 or more and 15 or less. As shown in the Examples section described later, this average number of repeating units can be calculated from the input ratio or NMR, etc.

[0110] The polyimide resin (A) in the present embodiment preferably contains 1 to 99% by mass of the partial structure represented by the general formula (1) with respect to the total amount (100% by mass) of the polyimide resin (A), more preferably contains 3 to 97% by mass, and further preferably contains 5 to 95% by mass.

[0111] In the above general formula (2), R 15 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, preferably represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and more preferably represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. As a particularly preferred R 15 , it can be a hydrogen atom or a linear alkyl group having 1 to 6 carbon atoms. Since m 3 is 2, the two Rs 15 can be the same as each other or different.

[0112] In the above general formula (2), R 14 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, preferably represents a hydrocarbon group having 1 to 12 carbon atoms, and more preferably represents a hydrocarbon group having 1 to 6 carbon atoms. As a particularly preferred R 14 , it can be a linear alkyl group having 1 to 6 carbon atoms.

[0113] In the ortho position (6-position) of the benzene ring in the above general formula (2) or the above general formula (3), by allowing the bonding site of the partial structure represented by the general formula (1), it has higher solubility in solvents, and its cured product exhibits more excellent dielectric properties and low hygroscopicity. It should be noted that R in the general formula (2) 14 The benzene ring to which it is bonded may be the benzene ring of the aromatic amine compound (A-a).

[0114] In the above general formula (2), L 13 or L 14 Each independently represents a bonding end or a hydrogen atom. Among them, in at least one position of L 13 or L 14 , the partial structure represented by the general formula (1) undergoes a chemical bond with the partial structure represented by the general formula (2). In addition, L 13 or L 14 that does not undergo a chemical bond with the partial structure represented by the general formula (1) is a hydrogen atom. It should be noted that the partial structure represented by the general formula (1) may also be chemically bonded to both L 13 and L 14 .

[0115] In the above general formula (3), R 11 Each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, preferably represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and more preferably represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. As the preferred R 11 , it may be a hydrogen atom or a linear alkyl group having 1 to 6 carbon atoms. Since m 1 is 2, the two R 11 may be the same as each other, or may be different.

[0116] In the above general formula (3), R 12 Each independently represents a hydrocarbon group having 1 to 18 carbon atoms, preferably represents a hydrocarbon group having 1 to 12 carbon atoms, and more preferably represents a hydrocarbon group having 1 to 6 carbon atoms. As the preferred R 12 , it represents a linear alkyl group having 1 to 6 carbon atoms. It should be noted that the benzene ring to which R 12 in the general formula (3) is bonded may be the benzene ring of the aromatic amine compound (A-a).

[0117] In the above general formula (3), L 11 or L 12 Each independently represents a bonding end or a hydrogen atom. Among them, in at least one position of L 11 or L 12 , the partial structure represented by the general formula (1) undergoes a chemical bond with the partial structure represented by the general formula (3). In addition, L 11or L 12 is a hydrogen atom. It should be noted that the partial structure represented by the general formula (1) can also be chemically bonded to L 11 and L 12 at these two positions.

[0118] In the polyimide resin (A) of the present embodiment, relative to the total amount (100% by mass) of the polyimide resin (A), it preferably contains 1 to 99% by mass of the partial structure represented by the general formula (2), more preferably contains 3 to 97% by mass, and still more preferably contains 5 to 95% by mass.

[0119] In the polyimide resin (A) of the present embodiment, relative to the total amount (100% by mass) of the polyimide resin (A), it preferably contains 1 to 99% by mass of the partial structure represented by the general formula (3), more preferably contains 3 to 97% by mass, and still more preferably contains 5 to 95% by mass.

[0120] The polyimide resin (A) of the present embodiment preferably uses an aromatic amine compound (A-a) represented by the following general formula (a-1) (hereinafter, also simply referred to as the aromatic amine compound (A-a)), a compound (A-b) having a benzyl ether skeleton, and maleic anhydride (A-c) as the reaction raw material (1).

[0121] [Chemical formula 15]

[0122]

[0123] [In the above general formula (a-1), R a1 and R a2 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R 1 represents a hydrocarbon group having 1 to 18 carbon atoms, R 2 and R 3 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms.]

[0124] In addition, the polyimide resin (A) of the present embodiment preferably uses an intermediate amine compound (I) and maleic anhydride (A-c) as the reaction raw material (2), and the intermediate amine compound (I) is formed by linking aromatic amine compounds (A-a) via a structural unit derived from a compound (A-b) having a benzyl ether skeleton. Further, the intermediate amine compound (I) is preferably a compound obtained by using an aromatic amine compound (A-a) and a compound (A-b) having a benzyl ether skeleton as the reaction raw material (3).

[0125] In other words, the intermediate amine compound (I) in the present embodiment preferably has a structural unit in which a structural unit of an aromatic amine compound (A-a) having an aromatic ring bonded with an amino group is linked to a structural unit derived from a compound (A-b) having a benzyl ether skeleton by a chemical bond. Further, the polyimide resin (A) in the present embodiment has a structure in which an amino group bonded to the aromatic ring of the intermediate amine compound (I) is substituted with an N-substituted maleimide ring. It should be noted that the "amino group" in the present specification also includes a substituted amino group in which a hydrogen atom of -NH2 is further substituted with an alkyl group having 1 to 6 carbon atoms.

[0126] Therefore, the "polyimide resin (A)" in the present embodiment and the "intermediate amine compound (I)" which is a precursor of the "polyimide resin (A)" are polymer compounds that are different in that an amino group bonded to an aromatic ring is substituted with an N-substituted maleimide ring.

[0127] It should be noted that the structural unit of the aromatic amine compound (A-a) refers to a group obtained by removing at least one hydrogen atom from the aromatic ring of the aromatic amine compound (A-a). For example, when the aromatic amine compound (A-a) is represented by the following general formula (a-1), a group obtained by removing at least one hydrogen atom from the benzene ring of the general formula (a-1) is referred to as the structural unit of the aromatic amine compound (A-a). Further, the structural unit derived from the compound (A-b) having a benzyl ether skeleton refers to a group in which -(CH2O)- other than the terminal group in the compound (A-b) having a benzyl ether skeleton is substituted with -(CH2)- and -(CH2O)-R directly bonded to the benzene ring b is all substituted with -(CH2)-. It should be noted that the R b represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms.

[0128] In the present embodiment, since an aromatic amino compound (A) having an aromatic ring structure with a substituent at a specific position is used as a reaction raw material, it is easy to control the reaction site with the compound (A-b) having a benzyl ether skeleton described later. Therefore, it is easy to obtain a homogeneous chemical structure and a chain-like polyimide resin (A). As a result, a polyimide resin (A) that exhibits excellent solubility in a solvent and whose cured product exhibits high heat resistance and excellent dielectric properties can be provided.

[0129] Hereinafter, after explaining the aromatic amine compound (A-a) represented by the general formula (a-1), the compound (A-b) having a benzyl ether skeleton, and the maleic anhydride (A-c), which are constituent components of the reaction raw material (1) of the polyimide resin (A), other preferred embodiments of the polyimide resin (A) and a method for producing the polyimide resin (A) will be described.

[0130] - Aromatic amine compound (A-a) represented by general formula (a-1)-

[0131] As shown in the following general formula (a-1), the aromatic amine compound (A-a) in the present embodiment must have a structure in which an aromatic ring bonded with an amino group and a hydrocarbon group having 1 to 18 carbon atoms is bonded to one ortho-position of the aromatic ring.

[0132] [Chemical formula 16]

[0133]

[0134] [In the above general formula (a-1), R a1 and R a2 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R 1 represents a hydrocarbon group having 1 to 18 carbon atoms, R 2 and R 3 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms.]

[0135] In the aromatic amine compound (A-a) of the present embodiment, as the hydrocarbon group (R 2 , R 3 ) that can be substituted by one or more and two or less hydrogen atoms of the aromatic ring of the aromatic amine compound (A-a), a linear, branched or cyclic hydrocarbon group having 1 to 18 carbon atoms can be cited, preferably a linear or branched hydrocarbon group having 1 to 12 carbon atoms, more preferably a linear or branched alkyl group having 1 to 6 carbon atoms. As described in the above general formula (a-1), there is a bonding site with the compound (A-b) having a benzyl ether skeleton at each of the ortho-position and para-position of the aromatic ring.

[0136] In the above general formula (a-1), R 1 represents a hydrocarbon group having 1 to 18 carbon atoms, preferably a hydrocarbon group having 1 to 12 carbon atoms, more preferably a hydrocarbon group having 1 to 6 carbon atoms.

[0137] In the above general formula (a-1), R 2 represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, preferably a hydrocarbon group having 1 to 12 carbon atoms, more preferably a hydrocarbon group having 1 to 6 carbon atoms.

[0138] In the above general formula (a-1), R 3 represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, preferably a hydrocarbon group having 1 to 12 carbon atoms, more preferably a hydrocarbon group having 1 to 6 carbon atoms.

[0139] In addition, by making the number of hydrocarbon groups (such as alkyl groups) substituted on the aromatic ring of the aromatic amine compound (A-a) 1 or more, the reaction site with the compound (A-b) having a benzyl ether skeleton described later can be easily controlled, and thus a polyimide resin (A) having a specific chemical structure can be easily obtained. As a result, the cured product of the polyimide resin (A) can easily exhibit solvent solubility, heat resistance, and excellent high-frequency electrical properties.

[0140] In particular, since a substituent (R 1 ) is introduced into the ortho position (adjacent position) of the aromatic amine compound (A-a), it is considered that after the amino group derived from the aromatic amine compound (A-a) is maleimidized, the dihedral angle formed by the aromatic ring plane of the aniline skeleton and the nitrogen-containing five-membered ring plane of maleimide becomes larger, and thus the crystallinity derived from the maleimide group is easily destroyed and the solubility is improved.

[0141] In the present embodiment, among the carbon atoms in the benzene ring constituting the aromatic amine compound (A-a), it is preferable that 1 or more carbon atoms having the maximum HOMO electron density (Hückel coefficient) are unsubstituted (substituted by hydrogen atoms). Therefore, as the aromatic amine compound (A-a) represented by the general formula (a-1) of the present embodiment, it is preferable that any 2 of the 2nd, 4th, and 6th positions are substituted by hydrogen atoms. As a particularly preferable mode of the aromatic amine compound (A-a) represented by the general formula (a-1) of the present embodiment, the 2nd position is substituted by an alkyl group, and the 4th and 6th positions are hydrogen atoms. Thus, it is easy to control the ArS E reaction and molecular design using the cation-like reagent formed by the compound (A-b) having a benzyl ether skeleton described later. As a result, the cured product of the polyimide resin (A) can easily exhibit solvent solubility, heat resistance, and excellent high-frequency electrical properties. In particular, by substituting the 4th and 6th positions of the benzene ring of the general formula (a-1) with hydrogen atoms, a polyimide resin (A) (or intermediate amine resin) having a linearly extended molecule can be obtained.

[0142] Specific examples of the aromatic amine compound (A-a) of the present embodiment include, for example, o-toluidine, 2-ethylaniline, 2-propylaniline, 2-butylaniline, 2-cyclobutylaniline, 2-cyclopentylaniline, 2-cyclohexylaniline, dimethylaniline (2,3-dimethylaniline, 2,4-dimethylaniline, or 2,5-dimethylaniline), diethylaniline (2,3-diethylaniline, 2,4-diethylaniline, or 2,5-diethylaniline), diisopropylaniline (2,3-diisopropylaniline, 2,4-diisopropylaniline, or 2,5-diisopropylaniline), ethylmethylaniline (for example, ethylmethylaniline in which one of the 2,3-position, 2,4-position, or 2,5-position is methyl and the other is ethyl), methylisopropylaniline (for example, methylisopropylaniline in which one of the 2,3-position, 2,4-position, or 2,5-position is methyl and the other is isopropyl), or ethylbutylaniline (for example, ethylbutylaniline in which one of the 2,3-position, 2,4-position, or 2,5-position is ethyl and the other is butyl). In addition, the butyl group includes n-butyl, tert-butyl, and sec-butyl. It should be noted that the aromatic amine compound (A-a) in the present embodiment can be used alone or in combination of two or more.

[0143] For example, in the case of a chemical structure in which a maleimide group is directly bonded to an unsubstituted benzene ring, such as N-phenylmaleimide, the state in which the benzene ring and the 5-membered ring of maleimide are arranged in the same plane is stable, so it is easy to stack and exhibits high crystallinity. Therefore, it becomes a reason for poor solvent solubility. In contrast, in the case of the present disclosure, for example, in the case of having an alkyl group (such as an ethyl group) as a substituent for the benzene ring, such as 2-ethylaniline, due to the steric hindrance of the ethyl group, the benzene ring and the 5-membered ring of maleimide adopt a staggered conformation, making it difficult to stack. Therefore, the crystallinity is reduced and the solvent solubility is improved, which is a preferred mode. However, when the steric hindrance is too large or depending on the substitution position of the alkyl group, there is also a concern that the reactivity during the synthesis of maleimidation will be hindered and the curability of the maleimide group will deteriorate when producing a cured product. Therefore, it is preferable to use, for example, an aromatic amine compound (A-a) having a hydrocarbon group with 1 to 6 carbon atoms.

[0144] It should be noted that in the present embodiment, the aromatic amine compound (A-a) represented by the above general formula (a-1) can be used alone or in combination of two or more.

[0145] - Compound (A-b) having a benzyl ether skeleton -

[0146] The compound (A-b) having a benzylic ether skeleton in the present embodiment may be a compound monomer or a mixture. When the compound (A-b) having a benzylic ether skeleton in the present embodiment is a compound monomer, it is preferably a compound having a partial structure represented by the following formula (6), more preferably a compound represented by the following formula (7), and further preferably a compound represented by the following formula (8).

[0147] On the other hand, when the compound (A-b) having a benzylic ether skeleton in the present embodiment is a mixture, it is preferably not only a mixture containing a compound having a partial structure represented by the following formula (6) and / or a compound having a benzylic ether skeleton represented by the following formula (7), but also a mixture in which the component having a partial structure represented by the following general formula (9) accounts for 95% by mass or more and 100% by mass or less of the whole.

[0148] The compound (A-b) having a benzylic ether skeleton in the present embodiment is preferably a compound having a benzylic ether skeleton represented by the following formula (6).

[0149] [Chemical formula 17]

[0150]

[0151] [In the above general formula (6), R b3 each independently represents an alkyl group having 1 to 18 carbon atoms, m b2 represents an integer of 0 or more and 4 or less, j 1 and j 2 each independently is an integer of 0 or more and 4 or less, j 1 +j 2 ≥1, k 1 and k 2 each independently is 0 or 1, and * represents a bond to another atom.]

[0152] The compound (A-b) having a benzylic ether skeleton in the present embodiment is preferably a product obtained by reacting an alkylbenzene with formaldehyde in the presence of an acid catalyst.

[0153] - Physical properties of the compound (A-b) having a benzylic ether skeleton -

[0154] The compound (A-b) having a benzylic ether skeleton in the present embodiment preferably has a benzylic ether skeleton represented by the above formula (6) and satisfies at least one of the following physical property values. Thereby, a resin having more excellent solvent solubility, heat resistance, and dielectric properties can be synthesized.

[0155] In this embodiment, the upper limit of the number-average molecular weight (Mn) of the compound (A-b) having a benzylic ether skeleton is preferably 1200 or less, more preferably 800 or less, and still more preferably 500 or less. The lower limit of the number-average molecular weight (Mn) of the compound (A-b) having a benzylic ether skeleton is preferably 200 or more, more preferably 240 or more, and still more preferably 250 or more.

[0156] In this embodiment, the upper limit of the oxygen content of the compound (A-b) having a benzylic ether skeleton is preferably 15% by mass or less, more preferably 13% by mass or less, and still more preferably 12% by mass or less. The lower limit of the oxygen content of the compound (A-b) having a benzylic ether skeleton is preferably 4% by mass or more, more preferably 5% by mass or more, and still more preferably 7% by mass or more.

[0157] In this embodiment, the upper limit of the specific gravity of the compound (A-b) having a benzylic ether skeleton is preferably less than 1.2, more preferably less than 1.15, and still more preferably less than 1.10. The lower limit of the specific gravity of the compound (A-b) having a benzylic ether skeleton is preferably 1.0 or more, more preferably 1.01 or more, and still more preferably 1.02 or more.

[0158] In this embodiment, the upper limit of the viscosity (75 °C) of the compound (A-b) having a benzylic ether skeleton is preferably 1500 mPa·s or less, more preferably 1000 mPa·s or less, and still more preferably 900 mPa·s or less. The lower limit of the viscosity (75 °C) of the compound (A-b) having a benzylic ether skeleton is preferably 30 mPa·s or more, more preferably 50 mPa·s or more, and still more preferably 70 mPa·s or more.

[0159] In this embodiment, the upper limit of the indirect viscosity (20 °C, viscosity measured by diluting to 80% by weight of the resin component with toluene) of the compound (A-b) having a benzylic ether skeleton is preferably 1000 mPa·s or less, more preferably 800 mPa·s or less, and still more preferably 500 mPa·s or less. The lower limit of the indirect viscosity (20 °C) of the compound (A-b) having a benzylic ether skeleton is preferably 10 mPa·s or more, more preferably 20 mPa·s or more, and still more preferably 30 mPa·s or more.

[0160] In this embodiment, the hydroxyl value of the compound (A-b) having a benzylic ether skeleton is preferably 16 to 50 (mgKOH / g), more preferably 18 to 40 (mgKOH / g), and still more preferably 22 to 35 (mgKOH / g).

[0161] -Preferred embodiments of the compound (A-b) having a benzylic ether skeleton-

[0162] As an example of the compound (A-b) having a benzylic ether skeleton, which is the reaction raw material (1) of the polyimide resin (A) of the present disclosure, a compound having a structural unit represented by the following formula (7) is preferred.

[0163] [Chemical formula 18]

[0164]

[0165] [In the above general formula (7), R b1 each independently represents a hydrogen atom or an alkyl group having 1 to 11 carbon atoms, and one or more of -CH2- in the alkyl group may be replaced by -O- or -C(=O)- in a non-adjacent manner to each other. R b2 and R b3 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, L 1 each independently represents an alkylene group having 1 to 11 carbon atoms, and one or more of -CH2- in the alkylene group may be replaced by -O- in a non-adjacent manner to each other. L 2 represents a single bond or an alkylene group having 1 to 11 carbon atoms, and one or more of -CH2- in the alkylene group may be replaced by -O- or -(C=O)- in a non-adjacent manner to each other. Z 1 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 11 carbon atoms, k represents an integer of 0 or more and 20 or less, m b1 and m b2 each independently represents an integer of 0 or more and 4 or less, R b1 or L 2 at least any one of them has a -CH2O- group.

[0166] R in the above general formula (7) b1 preferably represents a hydrogen atom or a hydrocarbon group having 1 to 11 carbon atoms, more preferably represents a hydrogen atom or a hydrocarbon group having 1 to 9 carbon atoms, and one or more of -CH2- in the hydrocarbon group may be replaced by -O- in a non-adjacent manner to each other. Preferred R b1 is preferably selected from a hydrogen atom, an alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 9 carbon atoms, a hydroxyalkyl group having 1 to 9 carbon atoms, -(CH2O) p1 -C(=O)-R b4 , -(CH2O) p1 -R b4 , -(CH2O) p1 -(CH2) p2 -R b4 , -(CH2) p3 -(CH2O) p1 -(CH2) p2 -R b4 , -(OCH2) q1 -Rb4 , -(OCH2) q1 -(CH2) q2 -R b4 and -(CH2) q3 -(OCH2) q1 -(CH2) q2 -R b4 is one of the groups consisting of. Herein, said R b4 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Additionally, said p1 to p3 and said q1 to q3 each independently preferably represent an integer of 1 to 11, more preferably an integer of 1 to 6, still more preferably an integer of 1 to 3, and particularly preferably an integer of 1 to 2.

[0167] Furthermore, it is preferred that at least one of R b1 or L 2 has a -CH2O- group, and more preferably both R b1 and L 2 have a -CH2O- group.

[0168] R in the above general formula (7) b2 and R b3 each independently can correspond to R in the general formula (1) 13 . Therefore, R in the above general formula (7) b2 and R b3 each independently preferably represent an alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms, still more preferably an alkyl group having 1 to 6 carbon atoms, in the same manner as in the general formula (1). Additionally, when m b1 is an integer of 2 or more, two or more R b2 can be the same as each other, or can also be different groups respectively. Similarly, when m b2 is an integer of 2 or more, two or more R b3 can be the same as each other, or can also be different groups respectively.

[0169] In the above general formula (7), L 1 each independently preferably represents an alkylene group having 1 to 11 carbon atoms, more preferably an alkylene group having 1 to 9 carbon atoms, and one or more -CH2- in this alkylene group can be replaced by -O- in a non-adjacent manner. Specifically, L 1 is preferably selected from the group consisting of an alkylene group having 1 to 11 carbon atoms, an alkoxy group having 1 to 11 carbon atoms, -(CH2O) p1 -C(=O)-, -(CH2O) p1 -, -(CH2O) p1 -(CH2) p2 -, -(CH2)p3 -(CH2O) p1 -(CH2) p2 -, -(OCH2) q1 -, -(OCH2) q1 -(CH2) q2- and -(CH2) q3 -(OCH2) q1 -(CH2) q2 - is one of the groups composed of. In addition, each of p1 to p3 and q1 to q3 preferably independently represents an integer of 1 to 11, more preferably an integer of 1 to 6, still more preferably an integer of 1 to 3, and particularly preferably an integer of 1 to 2.

[0170] In the above general formula (7), L 2 each preferably independently represents a single bond or an alkylene group having 1 to 11 carbon atoms, more preferably represents a single bond or an alkylene group having 1 to 9 carbon atoms, and one or more -CH2- in the alkylene group can be replaced by -O- in a non-adjacent manner. Specifically, L 2 is preferably selected from the group consisting of a single bond, an alkylene group having 1 to 11 carbon atoms, an alkoxy group having 1 to 11 carbon atoms, -(CH2O) p1 -C(=O)-, -(CH2O) p1 -, -(CH2O) p1 -(CH2) p2 -, -(CH2) p3 -(CH2O) p1 -(CH2) p2 -, -(OCH2) q1 -, -(OCH2) q1 -(CH2) q2 - and -(CH2) q3 -(OCH2) q1 -(CH2) q2 - is one of the groups composed of. In addition, each of p1 to p3 and q1 to q3 preferably independently represents an integer of 1 to 11, more preferably an integer of 1 to 6, still more preferably an integer of 1 to 3, and particularly preferably an integer of 1 to 2.

[0171] Furthermore, it is preferred that at least one of R b1 or L 2 has a -CH2O- group, and more preferably both R b1 and L 2 have a -CH2O- group.

[0172] Z in the above general formula (7) 1Preferably represents a hydrogen atom or an alkyl group having 1 to 11 carbon atoms, more preferably represents a hydrogen atom or an alkyl group having 1 to 9 carbon atoms.

[0173] In the above general formula (7), k is preferably an integer of 0 to 20, more preferably an integer of 0 to 15, and still more preferably an integer of 0 to 10. It should be noted that when k is 2 or more, there are multiple Ls 1 may be the same group as each other, or may also be different groups.

[0174] As a preferred embodiment of the compound (A-b) having a benzylic ether skeleton in the present embodiment, a compound having a structural unit represented by the following general formula (8) may be used.

[0175] [Chemical formula 19]

[0176]

[0177] [In the above general formula (8), R b1 each independently represents a hydrogen atom or an alkyl group having 1 to 11 carbon atoms, and one or more -CH2- in the alkyl group may be replaced by -O- or -C(=O)- in a non-adjacent manner to each other, R b2 and R b3 each independently represents an alkyl group having 1 to 18 carbon atoms, L 1 each independently represents an alkylene group having 1 to 11 carbon atoms, and one or more -CH2- in the alkylene group may be replaced by -O- in a non-adjacent manner to each other, L 2 represents a single bond or an alkylene group having 1 to 11 carbon atoms, and one or more -CH2- in the alkylene group may be replaced by -O- or -(C=O)- in a non-adjacent manner to each other, Z 1 each independently represents a hydrogen atom or an alkyl group having 1 to 11 carbon atoms, k represents an integer of 0 or more and 20 or less, m b1 and m b2 each independently represents an integer of 0 or more and 4 or less, R b1 or L 2 at least any one of them has a -CH2O- group.

[0178] In the above general formula (8), R b1 、R b2 and R b3 、L 1 、L 2 、Z 1 、k, and m b1 and m b2 The preferred embodiments are the same as those of the above general formula (7).

[0179] The compound (A-b) having a benzylic ether skeleton in the present embodiment can be used alone, or two or more thereof can be used in combination. Further, it can also be a mixture containing two or more different compounds (A-b) having a benzylic ether skeleton.

[0180] Note that, for the sake of convenience in explanation in the present specification, a mixture containing two or more different compounds (A-b) having a benzylic ether skeleton among the terms "compound (A-b) having a benzylic ether skeleton" is referred to as a mixture (A-b) having a benzylic ether skeleton. Therefore, the "compound (A-b) having a benzylic ether skeleton" includes not only the case where it represents only one kind of compound, but also the mixture (A-b) having a benzylic ether skeleton.

[0181] In the mixture (A-b) having a benzylic ether skeleton of the present embodiment, it is preferable that the component having the partial structure represented by the following general formula (9) accounts for 95% by mass or more and 100% by mass or less of the whole mixture (A-b) having a benzylic ether skeleton.

[0182] [Chemical formula 20]

[0183]

[0184] [In the general formula (9), L 3 and L 4 are linking groups, each independently being one kind of group selected from the group consisting of -CH2-, -CH2O-CH2-, -(CH2O)2-CH2-, and -(CH2O)3-CH2-, and * represents a bond to another atom.]

[0185] In the mixture (A-b) having a benzylic ether skeleton of the present embodiment, it is preferable that the component having the partial structure represented by the above general formula (9) accounts for 95% by mass or more and 100% by mass or less of the whole mixture (A-b) having a benzylic ether skeleton, and satisfies the following requirement (I) or (II).

[0186] (I) The total number of the linking groups (L 3 and L 4 ) of each molecule of the component having the partial structure represented by the above general formula (9) is 1.1 or more and 2.4 or less.

[0187] (II) The number of the terminal groups bonded to the ends of the molecules of the component having the partial structure represented by the above general formula (9) is 0.5 or more and 1.5 or less per 1 molecule.

[0188] In the present embodiment, as the linking groups (L 3 and L 4) One group selected from the group consisting of -CH2-, -CH2O-CH2-, -(CH2O)2-CH2-, and -(CH2O)3-CH2- can be enumerated.

[0189] In the entire mixture (A-b) having a benzyl ether skeleton, the following linking groups (L 3 and L 4 The total number of) in each molecule having the benzyl ether skeleton represented by the above general formula (9) preferably has the following compositions (1) to (4).

[0190] (1) The number of the linking group "-CH2-" is preferably 0.65 or more and 1.4 or less.

[0191] (2) The number of the linking group "-CH2O-CH2-" is preferably 0.07 or more and 0.2 or less, more preferably 0.08 or more and 0.14 or less.

[0192] (3) The number of the linking group "-(CH2O)2-CH2-" is preferably 0.10 or more and 0.8 or less, more preferably 0.2 or more and 0.8 or less. In other embodiments, it is preferably more than 0.41 and 0.8 or less.

[0193] (4) The number of the linking group "-(CH2O)3-CH2-" is preferably 0.05 or more and 0.65 or less, preferably 0.09 or more and 0.6 or less, and further preferably 0.10 or more and 0.55 or less.

[0194] In the mixture (A-b) having a benzyl ether skeleton of the present embodiment, it preferably has one or more groups selected from the group consisting of -CH2-OH, -CH2O-CH3, -(CH2O)2-CH3, -(CH2O)3-CH3, and -(CH2O)-COH as the terminal groups bonded to the ends of the molecules constituting the partial structure represented by the above general formula (9).

[0195] Moreover, in the entire mixture (A-b) having a benzyl ether skeleton, it preferably has the benzyl ether skeleton represented by the above general formula (9), and the number of terminal groups in each molecule is 0.5 or more and 1.5 or less.

[0196] In the entire mixture (A-b) having a benzyl ether skeleton, the number of the following terminal groups in each molecule having a benzyl ether skeleton preferably has the following compositions (5) to (10).

[0197] (5) The number of the terminal group "-CH2-OH" is preferably 0.17 or more and 0.4 or less, more preferably 0.18 or more and 0.25 or less.

[0198] (6) The number of terminal groups “-CH2O-CH3” is preferably 0.17 or more and 0.7 or less, more preferably 0.18 or more and 0.44 or less.

[0199] (7) The number of terminal groups “-(CH2O)2-CH3” is preferably 0.08 or more and 0.6 or less, preferably 0.09 or more and 0.3 or less.

[0200] (8) The number of terminal groups “-(CH2O)3-CH3” is preferably substantially not contained, more preferably 0.3 or less, further preferably 0.2 or less.

[0201] (9) The number of terminal groups “-(CH2O)-COH” is preferably 0 or more and 0.1 or less, more preferably 0.01 or more and 0.1 or less.

[0202] In the mixture (A-b) having a benzyl ether skeleton of the present embodiment, the chemical structure and the number of the linking group, and the chemical structure and the number of the terminal group are as shown in the Examples column described later, and can be calculated by NMR or referred to the manufacturer's catalog.

[0203] In the present embodiment, the compound (A-b) having a benzyl ether skeleton may be a synthetic product or a commercially available product. As the commercially available compound (A-b) having a benzyl ether skeleton, for example, xylene resin (trade name: Nikanol (Y-50, Y-100, Y-300, Y-1000, LLL, LL, L or H)) manufactured by Fudow Co., Ltd. is preferred.

[0204] In the present embodiment, relative to the total amount (100% by mass) of the polyimide resin (A), the structural unit of the compound (A-b) having a benzyl ether skeleton preferably contains 1 to 99% by mass, more preferably 5 to 95% by mass. The structural unit of the compound (A-b) having a benzyl ether skeleton refers to the group represented by the above general formula (1).

[0205] -Maleic anhydride (A-c)-

[0206] In the present embodiment, maleic anhydride (A-c) is an essential component of the reaction raw material (1) of the polyimide resin (A), and is used for the reaction of maleimidizing the amino group derived from the aromatic amine compound (A-a) as described in the manufacturing method column of the polyimide resin (A) described later.

[0207] In one embodiment of the first curable composition of the present invention, the polyimide resin (A) is a polyimide resin having a partial structure represented by the following general formula (1A).

[0208] [Chemical formula 21]

[0209]

[0210] [In the above, ran indicates that the arrangement of each structural unit can be random, and the two * respectively represent bonding ends, which are bonded to a hydrogen atom or a partial structure represented by the general formula (4).]

[0211] [Chemical formula 22]

[0212]

[0213] [In the above general formula (4), R 13 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, m 2 represents an integer of 0 or more and 4 or less, and n 3 represents the average number of repeating units.]

[0214] In one embodiment of the first curable composition of the present invention, it contains 10% by mass or more of a component represented by the above general formula (1A) and the sum of n 1 and n 3 is 1 or more.

[0215] In the general formula (1A), R 11 , R 12 , R 13 , m 1 , m 2 and n 1 are preferably the same as those in the above general formula (1). Also, in the general formula (4), R 13 and m 2 are preferably the same as those in the above general formula (1).

[0216] In the general formula (1A), from the viewpoint of the viscosity of the obtained polyimide resin, the average number of repeating units n 2 is preferably 0 or more and 50 or less, preferably 0 or more and 30 or less, more preferably 0 or more and 15 or less.

[0217] In the general formula (4), from the viewpoint of the viscosity of the obtained polyimide resin, the average number of repeating units n 3 is preferably 0 or more and 50 or less, preferably 0 or more and 30 or less, more preferably 0 or more and 15 or less.

[0218] ran indicates that the arrangement of each structural unit can be random. Therefore, the polyimide resin having a partial structure represented by the general formula (1A) can be any one of a random copolymer, a block copolymer, and an alternating copolymer.

[0219] In one embodiment of the first curable composition of the present invention, it preferably contains 10% by mass or more, more preferably 15% by mass or more, and still more preferably 20% by mass or more of the component represented by the above general formula (1A) and having the sum of n 1 and n 3 being 1 or more. Further, from the viewpoint of heat resistance, it preferably contains 5% by mass or more, more preferably 7% by mass or more, and still more preferably 10% by mass or more of the component having n 2 being 1 or more.

[0220] <Physical properties of polyimide resin (A)>

[0221] The number average molecular weight (Mn) of the polyimide resin (A) of the present disclosure is preferably in the range of 200 to 1500, more preferably in the range of 300 to 800. In addition, the weight average molecular weight (Mw) of the polyimide resin (A) is preferably in the range of 280 to 2000, more preferably in the range of 330 to 1200.

[0222] From the aspects of excellent solvent solubility, heat resistance and low dielectric loss tangent, the molecular weight distribution (weight average molecular weight (Mw) / number average molecular weight (Mn)) of the polyimide resin (A) of the present disclosure calculated by gel permeation chromatography (GPC) is preferably in the range of 1.01 to 4.0, more preferably in the range of 1.05 to 2.0, and still more preferably in the range of 1.10 to 1.8. It should be noted that according to the GPC chart obtained by GPC measurement, when the molecular weight distribution covers a wide range and there are many high molecular weight components, the proportion of the high molecular weight components contributing to flexibility becomes larger. Therefore, compared with the cured products using maleimide in the past, brittleness is suppressed, and a cured product with excellent flexibility and softness can be obtained, which is a preferred mode.

[0223] It should be noted that the number average molecular weight (Mn), weight average molecular weight (Mw) and molecular weight distribution (weight average molecular weight (Mw) / number average molecular weight (Mn)) of the polyimide resin (A) in this embodiment are measured under the measurement conditions described in the following examples using gel permeation chromatography (hereinafter abbreviated as "GPC").

[0224] The amount of the polyimide resin (A) in the curable composition can be appropriately adjusted. For example, as the mixing ratio (parts by mass) of the polyimide resin (A) and the cyanate ester (B), polyimide resin (A):cyanate ester (B) is preferably 90:10 to 10:90, more preferably 85:15 to 15:85, and still more preferably 80:20 to 20:80. By adjusting the mixing ratio to the above range, excellent low hygroscopicity, low dielectric constant and low dielectric loss tangent can be exhibited, so it is preferred.

[0225] <Manufacturing Method of Polymaleimide Resin (A)>

[0226] The manufacturing method of the polymaleimide resin (A) of the present embodiment is not particularly limited. As long as it has a partial structure represented by the above general formula (1), a partial structure represented by the above general formula (2) that is chemically bonded to the partial structure represented by the general formula (1), and a partial structure represented by the above general formula (3) that is chemically bonded to the partial structure represented by the general formula (1), it can be arbitrarily manufactured. As a preferred mode of the manufacturing method of the polymaleimide resin (A) of the present embodiment, it is preferable to use an aromatic amine compound (A-a) represented by the following general formula (a-1) (hereinafter also simply referred to as the aromatic amine compound (A-a)), a compound (A-b) having a benzyl ether skeleton, and maleic anhydride (A-c) as the reaction raw material (1).

[0227] [Chemical Formula 23]

[0228]

[0229] [In the above general formula (a-1), R a1 and R a2 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R 1 represents a hydrocarbon group having 1 to 18 carbon atoms, and R 2 and R 3 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms.]

[0230] As a specific mode of the manufacturing method of the polymaleimide resin (A) of the present disclosure, for example, a manufacturing method including the following steps (1) and (2) can be cited.

[0231] Step (1): A step of reacting the aromatic amine compound (A-a) represented by the above general formula (a-1) with the compound (A-b) having a benzyl ether skeleton as the reaction raw material (2) to obtain the intermediate amine compound (I) in the present embodiment;

[0232] Step (2): A step of reacting the intermediate amine compound (I) obtained in the above step (1) with maleic anhydride (A-c) as the reaction raw material (3) to obtain the polymaleimide resin (A) of the present disclosure.

[0233] Specifically, the manufacturing method of the polymaleimide resin (A) of the present embodiment preferably includes: a step (1) (also referred to as a crosslinking step) of reacting the aromatic amine compound (A-a) represented by the above general formula (a-1) with the compound (A-b) having a benzyl ether skeleton under a solid acid catalyst; and a step (2) (also referred to as a condensation step) of condensing the intermediate amine compound (I) generated by the step (1) with maleic anhydride (A-c).

[0234] Hereinafter, each step of the method for producing the polyimide resin (A) of the present disclosure will be described in sequence.

[0235] <<Step (1): Manufacturing step of intermediate amine compound (I)>>

[0236] Step (1) in the present embodiment is not particularly limited. For example, it is a step of reacting the above-mentioned aromatic amine compound (A-a), the compound (A-b) having a benzylic ether skeleton (e.g., Nikanol, etc.) and other compounds added as needed in the presence of an acid catalyst. Thereby, the intermediate amine compound (I) can be generated.

[0237] Regarding the mixing ratio of the aromatic amine compound (A-a) and the compound (A-b) having a benzylic ether skeleton, considering the physical property balance of moldability and curability of the obtained cured product during production, the molar ratio of the compound (A-b) having a benzylic ether skeleton is preferably 0.001 to 1 mole, more preferably 0.1 to 0.5 mole, relative to 1 mole of the aromatic amine compound (A-a).

[0238] In addition, when using a mixture such as the mixture (A-b) having a benzylic ether skeleton as the compound (A-b) having a benzylic ether skeleton, the reaction point with the aromatic amine compound (A-a) can be the methoxymethylene group in the compound (A-b) having a benzylic ether skeleton contained in the mixture (e.g., benzylic ether moiety (Ph-CH2O-CH2-), benzylic alcohol moiety (Ph-CH2O-H) or methoxymethylene group (-CH2-O-)). In addition, when the total number of these reaction points is set to 1, the compounding amount of the aromatic amine compound (A-a) is preferably equal to or more than the equivalent amount and 10 times or less. For example, relative to 1 mole of the total number of these reaction points, the compounding amount of the aromatic amine compound (A-a) is preferably 1 to 10 moles.

[0239] In addition, as a specific method for carrying out the above reaction, it is usually the following method: all raw materials are charged at once and directly reacted at a specified temperature, or one of the aromatic amine compound (A-a) or the compound (A-b) having a benzylic ether skeleton and an acid catalyst are charged, and while maintaining the specified temperature, the other of the aromatic amine compound (A-a) or the compound (A-b) having a benzylic ether skeleton is added dropwise while reacting. At this time, the dropping time is usually 0.1 to 12 hours, preferably 6 hours or less. After the reaction, in the case of using a solvent, the solvent and unreacted substances can be distilled off as needed to obtain the above intermediate amine compound (I). In the case of not using a solvent, the unreacted substances can be distilled off to obtain the target intermediate amine compound (I).

[0240] As the acid catalyst used in step (1) of this embodiment, an organic acid, an inorganic acid, or a solid acid can be used.

[0241] Examples of the organic acid include aliphatic sulfonic acids such as methanesulfonic acid or fluoromethanesulfonic acid; aromatic sulfonic acids such as 3-morpholinopropanesulfonic acid, piperazine-1,4-bis(2-ethanesulfonic acid), 10-camphorsulfonic acid, 4-chlorobenzenesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, or trifluoromethanesulfonic acid; alkyl phosphates such as dimethyl phosphate or diethyl phosphate; alkyl sulfates such as dimethyl sulfate, diethyl sulfate, or lauryl sulfate; aromatic sulfates such as phenyl sulfate or fluorophenyl sulfate; and various acids such as oxalic acid.

[0242] Examples of the inorganic acid include phosphoric acid, hydrochloric acid, sulfuric acid, nitric acid, or boric acid.

[0243] Examples of the solid acid include activated clay, acid clay, alumina, silica-alumina, zeolite, layered silicate, heteropolyacid, or strongly acidic ion exchange resin.

[0244] Examples of the layered silicate include dickite, nacrite, kaolinite, anauxite, metahalloysite, halloysite, etc. of the kaolin group; chrysotile, lizardite, antigorite, etc. of the serpentine group; montmorillonite, sauconite, beidellite, nontronite, saponite, vermiculite mica, hectorite, etc. of the montmorillonite group; vermiculite of the vermiculite group; mica, illite, sericite, glauconite, etc. of the mica group; attapulgite, sepiolite, palygorskite, bentonite, pyrophyllite, talc, chlorite group. These layered silicates can also form mixed layers.

[0245] In addition, the above acid catalyst can be used alone as one kind, or two or more kinds can be used in combination.

[0246] After the reaction in the above step (1), from the viewpoint of operability, it is also preferable to use a solid acid that can be easily removed by filtration. When using other acids, it is preferable to perform neutralization with an alkali and washing with water after the reaction.

[0247] It should be noted that there is no particular limitation on the base described above, and it may be an organic base or an inorganic base. Examples of the organic base include alkali metal alkoxides such as sodium methoxide, lithium methoxide, sodium ethoxide, lithium ethoxide, sodium tert-butoxide, and potassium tert-butoxide; trialkylamines such as triethylamine and ethyldiisopropylamine; aniline derivatives having an alkyl group with 1 to 4 carbon atoms such as N,N-dimethylaniline and N,N-diethylaniline; pyridine derivatives that may have an alkyl substituent with 1 to 4 carbon atoms such as pyridine and 2,6-dimethylpyridine; and nitrogen-containing heterocyclic compounds such as 1,8-diazabicyclo[5.4.0]-7-undecene. On the other hand, examples of the inorganic base include alkali metal hydrides such as sodium hydride and lithium hydride; alkaline earth metal hydrides such as calcium hydride; alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; carbonates or bicarbonates of alkali metals or alkaline earth metals such as sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate; and halides of alkali metals or alkaline earth metals such as potassium fluoride, cesium fluoride, and potassium iodide. These bases may be used alone or in combination of two or more.

[0248] In the present embodiment, regarding the blending amount of the acid catalyst, the acid catalyst is blended in the range of 0.1 to 50 parts by mass, preferably in the range of 1 to 20 parts by mass, based on 100 parts by mass of the total amount of the raw materials (compound (A-b) having a benzylic ether skeleton and aromatic amine compound (A-a)) from the viewpoints of operability and economy.

[0249] The reaction temperature is usually in the range of 100 to 300 °C, but in order to suppress the formation of isomeric structures and avoid side reactions such as thermal decomposition, it is preferably in the range of 120 to 250 °C.

[0250] In the step (1) of the present embodiment, as the reaction time of the mixture of the compound (A-b) having a benzylic ether skeleton and the aromatic amine compound (A-a), that is, the crosslinking reaction time, from the fact that the reaction does not proceed completely in a short time, and on the other hand, if it is set to a long time, side reactions such as thermal decomposition reaction of the product will occur, it is usually in the range of 1 to 60 hours in total, preferably in the range of 1 to 20 hours in total, under the conditions of the reaction temperature.

[0251] In the method for producing the intermediate amine compound (I) in the present embodiment, since the aromatic amine compound (A-a) or its derivative also serves as a solvent, it is not necessary to use other solvents, and solvents may also be used. For example, in the case of using Nikanol L, which is a compound (A-b) having a benzylic ether skeleton, as a raw material for reaction, the following method may be adopted: using a solvent capable of azeotropic dehydration such as toluene, xylene, or chlorobenzene, azeotropically dehydrating the water contained in the catalyst or the like as needed, then distilling off the solvent, and then carrying out the reaction within the range of the above reaction temperature.

[0252] The intermediate amine compound (I) obtained through the above-mentioned step (1) preferably has a partial structure represented by the following general formula (1), a partial structure represented by the general formula (10) that is chemically bonded to the partial structure represented by the general formula (1), and a partial structure represented by the general formula (11) that is chemically bonded to the partial structure represented by the general formula (1).

[0253] [Chemical formula 24]

[0254]

[0255] [In the above general formula (1), R 13 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, m 2 represents an integer of 0 or more and 4 or less, n 1 represents the average number of repeating units, and the two * respectively represent bonding ends. One bonding end is chemically bonded at the position of L 13 or L 14 in the following general formula (10), and the other bonding end is chemically bonded at the position of L 11 or L 12 in the following general formula (11).]

[0256] [Chemical formula 25]

[0257]

[0258] [In the above general formula (10) or (11), R 11 and R 15 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, R 12 and R 14 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, and L 11 to L 14 each independently represents a bonding end. It is chemically bonded to the partial structure represented by the general formula (1) at the position of L 11 or L 12 , and is chemically bonded to the partial structure represented by the general formula (1) at the position of L 13 or L 14 . m 1 represents an integer of 0 or more and 2 or less, and m 3 represents an integer of 0 or more and 2 or less.]

[0259] "R 13 , m 2 and n 1 " in the above general formula (1) and "R 13 , m 2 and n 1” have the same meaning. Additionally, "L 11 ," "L 12 ," "L 13 ," "L 14 ," "R 11 ," "R 12 ," "R 14 ," "R 15 ," "m 1 ," and "m 3 " in General Formulas (10) and (11) have the same meaning as "L 11 ," "L 12 ," "L 13 ," "L 14 ," "R 11 ," "R 12 ," "R 14 ," "R 15 ," "m 1 ," and "m 3 " in General Formulas (2) and (3).

[0260] In this embodiment, the amine equivalent of the intermediate amine compound (I) is preferably 160 to 1200 g / equivalent, more preferably 180 to 600 g / equivalent. It should be noted that the determination of the amine equivalent of the intermediate amine compound (I) in this specification is a value measured by the method of neutralization titration specified in JIS K 0070 (1992).

[0261] <<Step (2): Maleimidation>>

[0262] Step (2) in this embodiment is a step of reacting the intermediate amine compound (I) obtained in step (1) with maleic anhydride (A-c). The amino group of the intermediate amine compound (I) can form a chemical structure in which the amino group is substituted by an N-substituted maleimide ring through a maleimidation reaction, and thus the polyimide resin (A) of the present disclosure can be obtained.

[0263] In this embodiment, the intermediate amine compound (I) having the partial structure represented by the above general formula (1), the partial structure represented by the general formula (10), and the partial structure represented by the general formula (11) obtained through step (1) is put into a reactor, dissolved in an appropriate solvent, and then reacted with maleic anhydride (A-c) in the presence of a catalyst. Then, after the reaction, unreacted maleic anhydride (A-c) or other impurities are removed by washing with water, etc., and the solvent is removed by reduced pressure, whereby the target polyimide resin (A) can be obtained. Additionally, a dehydrating agent can also be used during the reaction as needed.

[0264] Examples of the organic solvent used in step (2) of this embodiment include ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, cyclohexanone, and acetophenone; aprotic solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, acetonitrile, and sulfolane; cyclic ethers such as dioxane and tetrahydrofuran; esters such as ethyl acetate and butyl acetate; aromatic solvents such as benzene, toluene, and xylene. In addition, they can be used alone or in combination.

[0265] In step (2) of this embodiment, as the mixing ratio of the intermediate amine compound (I) and maleic anhydride (A-c), it is preferable to adjust the equivalent ratio of maleic anhydride (A-c) to the amino equivalent of the intermediate amine compound (I) to be in the range of 1 to 5, more preferably to be added in an amount of 1 to 3. The preferred method is to carry out the reaction in an organic solvent having a mass ratio of 0.1 to 10, preferably 0.2 to 5, based on the total amount of the intermediate amine compound (I) and maleic anhydride (A-c).

[0266] Examples of the catalyst that can be used in step (2) of this embodiment include inorganic salts such as acetates, chlorides, bromides, sulfates, and nitrates of nickel, cobalt, sodium, calcium, iron, lithium, and manganese; inorganic acids such as phosphoric acid, hydrochloric acid, and sulfuric acid; organic acids such as oxalic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, and fluoromethanesulfonic acid; solid acids such as activated clay, acid clay, silica alumina, zeolite, and strongly acidic ion exchange resin; heteropoly hydrochloric acid, etc. Toluene sulfonic acid is particularly preferably used.

[0267] Examples of the dehydrating agent used in step (2) of this embodiment include lower aliphatic carboxylic anhydrides such as acetic anhydride, propionic anhydride, and butyric anhydride; oxides such as phosphorus pentoxide, calcium oxide, and barium oxide; inorganic acids such as sulfuric acid; porous ceramics such as molecular sieves, etc. Acetic anhydride can preferably be used.

[0268] There is no particular limitation on the usage amounts of the catalyst and dehydrating agent that can be used in step (2) of this embodiment. Generally, per 1 equivalent of the amino group (-NH2) of the intermediate amine compound (I), 0.0001 to 1 mole, preferably 0.01 to 0.3 mole, of the catalyst can be used, and 1 to 3 moles, preferably 1 to 1.5 moles, of the dehydrating agent can be used.

[0269] In step (2) of this embodiment, as the reaction conditions for maleimidation, the above-mentioned intermediate amine compound (I) and maleic anhydride (A-c) can be added and reacted in the temperature range of 10 to 100 °C, preferably 30 to 60 °C, for 0.5 to 12 hours, preferably 1 to 4 hours, and then the catalyst is added and reacted in the temperature range of 90 to 130 °C, preferably 105 to 120 °C, for 1 to 24 hours, preferably 1 to 10 hours.

[0270] · Cyanate ester (B)

[0271] In addition to the polyimide resin (A), the curable composition of the present disclosure further contains a cyanate ester (B). Since the cyanate ester (B) has excellent dielectric properties such as a dielectric constant or a dielectric loss tangent, a curable composition capable of obtaining a cured product that maintains a sufficiently low dielectric constant and exhibits a sufficiently low dielectric loss tangent even in a high-frequency band (high-frequency region) from the MHz band to the GHz band can be prepared. Therefore, it can be used as a molding material for high frequencies and is useful. In addition, by reacting with the polyimide resin (A) to function as a curing agent, three-dimensional crosslinking can be generated, and thus a cured product having excellent heat resistance, low thermal expansion, adhesion, and further excellent mechanical properties or chemical resistance can be obtained, which is a preferred mode.

[0272] The cyanate ester (B) of the present embodiment may be a compound having one or more cyanate groups (cyanate ester: -O-C≡N). Examples of the cyanate ester (B) include bisphenol A type cyanate ester resin, bisphenol F type cyanate ester resin, bisphenol E type cyanate ester resin, bisphenol S type cyanate ester resin, bisphenol sulfide type cyanate ester resin, phenylene ether type cyanate ester resin, naphthalene ether type cyanate ester resin, biphenyl type cyanate ester resin, tetramethyl biphenyl type cyanate ester resin, polyhydroxynaphthalene type cyanate ester resin, phenol novolac type cyanate ester resin, cresol novolac type cyanate ester resin, triphenylmethane type cyanate ester resin, tetraphenylethane type cyanate ester resin, dicyclopentadiene-phenol addition reaction type cyanate ester resin, phenol aralkyl type cyanate ester resin, naphthol novolac type cyanate ester resin, naphthol aralkyl type cyanate ester resin, naphthol-phenol co-novolac type cyanate ester resin, naphthol-cresol co-novolac type cyanate ester resin, aromatic hydrocarbon formaldehyde resin-modified phenolic resin type cyanate ester resin, biphenyl-modified novolac type cyanate ester resin, anthracene type cyanate ester resin, and the like. They can be used alone or in combination of two or more. Among the cyanate esters (B), bisphenol A type cyanate ester resin, bisphenol F type cyanate ester resin, bisphenol E type cyanate ester resin, polyhydroxynaphthalene type cyanate ester resin, naphthalene ether type cyanate ester resin, and novolac type cyanate ester resin are preferably used in terms of obtaining a cured product having excellent heat resistance, and dicyclopentadiene-phenol addition reaction type cyanate ester resin is preferably used in terms of obtaining a cured product having excellent dielectric properties.

[0273] In the curable composition of the present embodiment, relative to the whole curable composition, it is preferably contained 5% by mass or more and 60% by mass or less of the cyanate ester (B), more preferably 10% by mass or more and 50% by mass or less, still more preferably 12% by mass or more and 45% by mass or less, particularly preferably 15% by mass or more and 40% by mass or less, and most preferably 20% by mass or more and 30% by mass or less. From the viewpoint of heat resistance, the content of the cyanate ester (B) is preferably in the range of 20% by mass or more and 30% by mass or less.

[0274] (Curing agent (D) other than the cyanate ester (B))

[0275] In the curable composition of the present embodiment, a curing agent (D) other than the cyanate ester (B) may be added within the range that does not impair the curing of the present invention. It should be noted that, relative to 100% by mass of the total amount of the curable composition, the curing agent (D) is preferably 2% by mass or more and 20% by mass or less, and most preferably 5% by mass or more and 10% by mass or less. From the viewpoints of curability and low dielectric loss tangent, the content of the curing agent (D) is preferably in the range of 5% by mass or more and 10% by mass or less.

[0276] Examples of the curing agent (D) of the present embodiment include amine compounds, amide compounds, acid anhydride compounds, phenol compounds, polyphenylene ether compounds, compounds having a substituent containing an unsaturated double bond, diene polymers, and the like. These curing agents can be used alone or in combination of two or more.

[0277] Examples of the above-mentioned amine compounds include diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, imidazole, BF3-amine complex, guanidine derivatives, and the like.

[0278] Examples of the above-mentioned amide compounds include dicyandiamide, polyamide resin synthesized from a dimer of linolenic acid and ethylenediamine, and the like.

[0279] Examples of the above-mentioned acid anhydride compounds include phthalic anhydride, trimellitic anhydride, pyromellitic dianhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, and the like.

[0280] Examples of the phenolic compound include polyphenolic compounds such as phenol novolak resin, cresol novolak resin, aromatic hydrocarbon formaldehyde resin-modified phenolic resin, dicyclopentadiene phenol addition resin, phenol aralkyl resin (ZYLOCK resin), polyphenol novolak resin synthesized from a polyhydroxy compound represented by resorcinol novolak resin and formaldehyde, naphthol aralkyl resin, trimethylolmethane resin, tetraphenylethane resin, naphthol novolak resin, naphthol-phenol co-condensed novolak resin, naphthol-cresol co-condensed novolak resin, biphenyl-modified phenolic resin (a polyphenolic compound in which phenolic nuclei are linked by a bis-methylene group), biphenyl-modified naphthol resin (a polynaphtholic compound in which phenolic nuclei are linked by a bis-methylene group), amino triazine-modified phenolic resin (a polyphenolic compound in which phenolic nuclei are linked by melamine, benzoguanamine, etc.), and aromatic ring-modified novolak resin containing an alkoxy group (a polyphenolic compound in which a phenolic nucleus and an aromatic ring containing an alkoxy group are linked by formaldehyde).

[0281] As the above-mentioned polyphenylene ether compound, for example, a structure represented by the following general formula (12) or (13) is preferably used.

[0282] [Chemical formula 26]

[0283]

[0284] [Chemical formula 27]

[0285]

[0286] In the above general formulas (12) and (13), R d1 ~R d8 Each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 1 to 5 carbon atoms, a cycloalkyl group having 3 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a thioether group having 1 to 5 carbon atoms, an alkylcarbonyl group having 2 to 5 carbon atoms, an alkoxycarbonyl group having 2 to 5 carbon atoms, an alkylcarbonyloxy group having 2 to 5 carbon atoms, an alkylsulfonyl group having 1 to 5 carbon atoms, etc. As the terminal structure of the structure represented by the above general formulas (12) and (13), a terminal structure having a hydroxyl group or a group containing a reactive double bond can be mentioned. In addition, v is an integer value of 1 to 30, and w and u are also integer values of 1 to 30.

[0287] The thioether group having 1 to 5 carbon atoms is not particularly limited, and examples thereof include a methylthio group, an ethylthio group, a propylthio group, an isopropylthio group, a butylthio group, and a pentylthio group.

[0288] The alkylcarbonyl group having 2 to 5 carbon atoms is not particularly limited, and examples thereof include a methylcarbonyl group, an ethylcarbonyl group, a propylcarbonyl group, an isopropylcarbonyl group, and a butylcarbonyl group.

[0289] The alkoxycarbonyl group having 2 to 5 carbon atoms as described above is not particularly limited, and examples thereof include methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl and the like.

[0290] The alkylcarbonyloxy group having 2 to 5 carbon atoms as described above is not particularly limited, and examples thereof include methylcarbonyloxy, ethylcarbonyloxy, propylcarbonyloxy, isopropylcarbonyloxy, butylcarbonyloxy and the like.

[0291] The alkylsulfonyl group having 1 to 5 carbon atoms as described above is not particularly limited, and examples thereof include methylsulfonyl, ethylsulfonyl, propylsulfonyl, isopropylsulfonyl, butylsulfonyl, pentylsulfonyl and the like.

[0292] In the present embodiment, R in the above general formulas (12) and (13) d1 ~R d8 may be the same as or different from each other, and are preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a cycloalkyl group having 3 to 5 carbon atoms, more preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, still more preferably a hydrogen atom, methyl, ethyl, and particularly preferably a hydrogen atom, methyl.

[0293] Y in the above general formula (13) may be exemplified by a divalent aromatic group derived from an aromatic compound having two phenolic hydroxyl groups. Moreover, the aromatic compound having two phenolic hydroxyl groups is not particularly limited, and examples thereof include catechol, resorcinol, hydroquinone, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 4,4'-biphenol, bisphenol A, bisphenol B, bisphenol BP, bisphenol C, bisphenol F, tetramethyl bisphenol A and the like. Among them, hydroquinone, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 4,4'-biphenol, bisphenol A, bisphenol E, bisphenol F are preferred, and 4,4'-biphenol, bisphenol A, tetramethyl bisphenol A are more preferred. In addition, two phenolic hydroxyl groups of the aromatic compound having two phenolic hydroxyl groups form a phenylene ether bond (two oxygen atoms bonded to Y), and thus Y becomes a divalent aromatic group derived from an aromatic compound having two phenolic hydroxyl groups. In other words, the group obtained by removing two arbitrary hydrogen atoms from the above aromatic compound having two phenolic hydroxyl groups is used as the "divalent aromatic group derived from an aromatic compound having two phenolic hydroxyl groups".

[0294] As the compound having a substituent containing an unsaturated double bond as described above, for example, as long as it is a compound having two or more substituents containing an unsaturated bond in the molecule, there is no particular limitation, and examples thereof include compounds having allyl, isopropenyl, 1-propenyl, acryloyl, methacryloyl, styryl, styrylmethyl and the like as the substituent containing an unsaturated bond.

[0295] As the above diene polymer, for example, an unmodified diene polymer not modified with a polar group can be cited. Here, the polar group refers to a functional group that affects dielectric properties, and examples thereof include a phenolic group, an amino group, an epoxy group, etc. The diene polymer is not particularly limited, and for example, 1,2-polybutadiene, 1,4-polybutadiene, etc. can be used.

[0296] As the above diene polymer, a homopolymer of butadiene and its derivatives in which 50% or more of the butadiene units in the polymer chain are 1,2-bonds can also be used.

[0297] (Other resin (E))

[0298] In addition, as long as it is within the range that does not impair the object of the present disclosure, other resins (E) may be contained in addition to the polyimide resin (A) and the cyanate ester (B). As the other resin (E), bismaleimide compounds other than the above polyimide resin (A), allyl ether compounds, allyl amine compounds, triallyl cyanurate, allylphenol compounds, vinyl-containing polyolefin compounds, etc., epoxy resins, phenolic resins, active ester resins, polyphenylene ether resins, benzoxazine resins, styrene maleic anhydride copolymers, polybutadiene and its modified products, polyacetal resins, polyvinyl alcohol resins, liquid crystal polymers, fluororesins, polystyrene, polyethylene, polyimide resins, thermosetting polyimide resins, silicone gels, silicone oils, etc. can be appropriately blended. With respect to 100% by mass of the total amount of the curable composition, the content of the other resin (E) is preferably 2% by mass or more and 20% by mass or less, and most preferably 5% by mass or more and 10% by mass or less. If the content of the other resin (E) is in the range of 5% by mass or more and 10% by mass or less, it is preferable from the viewpoints of heat resistance and compatibility.

[0299] (Curing accelerator)

[0300] The curable composition of the present embodiment may also be appropriately used in combination with a curing accelerator as needed. As the curing accelerator, various curing accelerators can be used. In order to use the cyanate ester (B), for example, phenols, amines, Lewis acids, tertiary sulfonium salts, quaternary ammonium salts, quaternary phosphonium salts, epoxy group-containing compounds, etc. can be cited. Among these, nonylphenol, 2,4,6-tris(dimethylaminomethyl)phenol, carboxylates of copper, lead, tin, manganese, nickel, iron, zinc, cobalt, etc., tetra-n-butoxytitanium and its polymers, pentanedionato salts of copper, nickel, cobalt, etc., tetrabutylammonium bromide, tetrabutylphosphonium chloride, tetraphenylphosphonium tetrakis(methylphenyl)borate, zinc octoate, etc. can be used. In addition, the curing accelerator has high compatibility with the cyanate ester (B), and the curing reaction proceeds smoothly, so it is preferred. Further, among them, tetraphenylphosphonium tetrakis(methylphenyl)borate is particularly preferred. By using tetraphenylphosphonium tetrakis(methylphenyl)borate as the curing accelerator, the curing reaction proceeds faster than with other substances, so it is preferred. In addition, the addition amount of the curing accelerator is preferably 0.001 to 1.00 parts by mass relative to 100 parts by mass of the cyanate ester (B).

[0301] (Additive)

[0302] The curable composition of the present embodiment may also be appropriately used in combination with additives as needed. As the additives, silane coupling agents, mold release agents, pigments, emulsifiers, non-halogen flame retardants, inorganic fillers, flame retardants, solvents, etc. can be cited. The content of the additives is preferably 1% by mass or more and 20% by mass or less, and most preferably 3% by mass or more and 10% by mass or less, based on 100% by mass of the total amount of the curable composition.

[0303] As the above-mentioned flame retardants, inorganic phosphorus-based flame retardants, organic phosphorus-based flame retardants, halogen-based flame retardants or non-halogen-based flame retardants can be cited. In the curable composition of the present embodiment, within the range not impairing the purpose, in order to exhibit flame retardancy, it is more preferable to compound a non-halogen-based flame retardant substantially free of halogen atoms. As the non-halogen-based flame retardant, for example, phosphorus-based flame retardants, nitrogen-based flame retardants, organosilicon-based flame retardants, inorganic-based flame retardants, organometallic salt-based flame retardants, etc. can be cited, and they can be used alone or in combination.

[0304] In the curable composition of the present embodiment, an inorganic filler can be blended as needed. Examples of the inorganic filler include fused silica, crystalline silica, alumina, silicon nitride, aluminum hydroxide, etc. When the blending amount of the inorganic filler is particularly increased, fused silica is preferably used. The fused silica can be either in a crushed form or a spherical form, but in order to increase the blending amount of the fused silica and suppress the increase in the melt viscosity of the molding material, spherical fused silica is preferably mainly used. In order to further increase the blending amount of the spherical silica, it is preferable to appropriately adjust the particle size distribution of the spherical silica. Considering the flame retardancy, its filling rate is preferably high, and particularly preferably 30% by mass or more and 50% by mass or less based on the total amount of the curable composition. In addition, when the curable composition is used for applications such as the conductive paste described in detail below, conductive fillers such as silver powder and copper powder can be used.

[0305] In the curable composition of the present embodiment, with respect to the entire curable composition (100% by mass), the lower limit of the total content of the polyimide resin (A) and the cyanate ester (B) is preferably 40% by mass, 42% by mass, 45% by mass, 47% by mass, 48% by mass, or 50% by mass. In addition, the upper limit of the total content is preferably 100% by mass, 99% by mass, 98% by mass, or 97% by mass. The above upper limit value and the above lower limit value can be arbitrarily combined. Therefore, for example, in the curable composition of the present embodiment, with respect to the entire curable composition (100% by mass), the total content of the polyimide resin (A) and the cyanate ester (B) is preferably 40% by mass or more and 100% by mass or less, more preferably 45% by mass or more and 100% by mass or less, and still more preferably 50% by mass or more and 100% by mass or less.

[0306] In the curable composition of the present embodiment, with respect to the entire curable composition (100% by mass), the lower limit of the total content of the polyimide resin (A), the cyanate ester (B), the inorganic filler, and the additive is preferably 70% by mass, 72% by mass, 75% by mass, 77% by mass, or 80% by mass. In addition, the upper limit of the total content is preferably 100% by mass, 99% by mass, 98% by mass, or 97% by mass. The upper limit value and the lower limit value can be arbitrarily combined in the same manner as the range of the total content of the polyimide resin (A) and the cyanate ester (B).

[0307] In the curable composition of the present embodiment, the lower limit of the total content of the polyimide resin (A), the cyanate ester (B), and the additive is preferably 43% by mass, 45% by mass, 48% by mass, 50% by mass, or 53% by mass with respect to the total curable composition (100% by mass). In addition, the upper limit of the total content is preferably 100% by mass, 99% by mass, 98% by mass, or 97% by mass. The upper limit value and the lower limit value can be arbitrarily combined in the same manner as the range of the total content of the polyimide resin (A) and the cyanate ester (B).

[0308] (Second curable composition)

[0309] The second curable composition of the present invention is characterized by containing a maleimide resin mixture (C) and a cyanate ester (B). The maleimide resin mixture (C) contains a polyimide resin component having a partial structural unit represented by the following general formula (1a) and a maleimide polycondensation compound represented by the following general formula (5). The maleimide resin mixture (C) contains 1 to 99% by mass of the polyimide resin (A) with respect to the total amount of the polyimide resin component, and contains 80% by mass or less of the maleimide polycondensation compound with respect to the total amount of the maleimide resin mixture (C). The polyimide resin (A) has a partial structure represented by the following general formula (1), a partial structure represented by the following general formula (2) that is chemically bonded to the partial structure represented by the general formula (1), and a partial structure represented by the following general formula (3) that is chemically bonded to the partial structure represented by the general formula (1).

[0310] [Chemical formula 28]

[0311]

[0312] [In the above general formula (1a), R 11 represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, R 12 represents a hydrocarbon group having 1 to 18 carbon atoms, R 13 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, m 1 represents 2, m 2 represents an integer of 0 or more and 4 or less, n 1 represents the average number of repeating units.]

[0313] [Chemical formula 29]

[0314]

[0315] [In the above general formula (5), R 21 and R 25 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, R22 and R 24 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, and m 21 represents 2, and m 23 represents 3, and n 21 represents an integer of 1 or more and 5 or less.]

[0316] [Chemical formula 30]

[0317]

[0318] [In the above general formula (1), R 13 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, and m 2 represents an integer of 0 or more and 4 or less, and n 1 represents the average number of repeating units. The two * respectively represent the bonding ends, and one bonding end is chemically bonded at the position of L in the following general formula (2) 13 or L 14 , and the other bonding end is chemically bonded at the position of L in the following general formula (3) 11 or L 12 .]

[0319] [Chemical formula 31]

[0320]

[0321] [In the above general formula (2) or (3), R 11 and R 15 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, R 12 and R 14 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, and L 11 to L 14 each independently represents a bonding end or a hydrogen atom. Among them, at the position of L 11 or L 12 , it is chemically bonded to the partial structure represented by the general formula (1), and at the position of L 13 or L 14 , it is chemically bonded to the partial structure represented by the general formula (1). In addition, L 11 to L 14 that are not chemically bonded to the partial structure represented by the general formula (1) are hydrogen atoms, and m 1 and m 3 each represent 2.]

[0322] · Maleimide resin mixture (C)

[0323] The polyimide resin (A) of the present embodiment may be a mixture. For example, when the resin using the aromatic amine compound (A-a) represented by the above general formula (a-1), the compound (A-b) having a benzylic ether skeleton, and maleic anhydride (A-c) as the reaction raw materials (1) is used, since there are a plurality of reaction points of the compound (A-b) having a benzylic ether skeleton with respect to the aromatic amine compound (A-a) represented by the above general formula (a-1), the resulting intermediate amine compound (I) itself can be a mixture of various mixtures. Therefore, the polyimide resin (A) can also be a mixture of compounds having various chemical structures.

[0324] It should be noted that in this specification, the term "polyimide resin (A)" includes monomers and mixtures. On the other hand, when the polyimide resin (A) only represents a mixture, it is called a maleimide resin mixture (C).

[0325] The maleimide resin mixture (C) contains a polyimide resin component having a partial structural unit represented by the general formula (1a) and a maleimide polybody compound represented by the following general formula (5).

[0326] (Maleimide resin component)

[0327] "R 11 , R 12 , R 13 , n 1 , m 1 and m 2 " in the above general formula (1a) has the same meaning as "R 11 , R 12 , R 13 , n 1 , m 1 and m 2 " in the above general formula (1) or general formula (2).

[0328] (Maleimide polybody compound)

[0329] In addition, "R 21 and R 25 " in the general formula (5) each independently has the same meaning as "R 11 or R 15 " in the general formulas (2) and (3). "R 22 and R 24 " in the general formula (5) each independently has the same meaning as "R 12 or R 14 " in the general formulas (2) and (3).

[0330] The amount of the maleimide polybody compound in the maleimide resin mixture (C) is 80% by mass or less.

[0331] The polyimide resin (A) contained in the polyimide resin component having a partial structural unit represented by the general formula (1a) is the same as the polyimide resin (A) described in the first curable composition.

[0332] In one embodiment of the second curable composition of the present invention, the polyimide resin (A) uses an aromatic amine compound (A-a) represented by the general formula (a-1), a compound (A-b) having a benzyl ether skeleton, and maleic anhydride (A-c) as reaction raw materials (1). Regarding the aromatic amine compound (A-a) represented by the general formula (a-1), the compound (A-b) having a benzyl ether skeleton, the maleic anhydride (A-c), and the reaction raw materials (1), they are the same as the polyimide resin (A) described in the first curable composition.

[0333] The amount of the polyimide resin (A) in the maleimide resin mixture (C) is 1 to 99% by mass relative to the total amount of the maleimide resin component.

[0334] In the maleimide resin mixture (C) of the present embodiment, relative to the total amount of the maleimide resin component, it contains preferably 10% by mass to 99% by mass, more preferably 15% by mass or more to 98% by mass, and still more preferably 20% by mass to 97% by mass of the polyimide resin (A) having a partial structure represented by the above general formula (1), a partial structure represented by the following general formula (2) that is chemically bonded to the partial structure represented by the general formula (1), and a partial structure represented by the following general formula (3) that is chemically bonded to the partial structure represented by the general formula (1), and relative to the total amount of the maleimide resin mixture (C), it contains preferably 5% by mass to 80% by mass, more preferably 7% by mass to 80% by mass, and still more preferably 10% by mass or more to 80% by mass or less of the maleimide polybody compound represented by the general formula (5).

[0335] As a preferred maleimide resin mixture (C) of the present embodiment, it contains a polymaleimide resin represented by the general formula (1A) (wherein, in the general formula (1A), n1 is a polymaleimide resin of 1 or more) and a maleimide polybody compound represented by the general formula (2). With respect to the maleimide resin mixture (C), the content of the polymaleimide resin represented by the general formula (1A) (wherein, in the general formula (1A), n1 is a polymaleimide resin of 1 or more) is preferably 10% by mass to 99% by mass, more preferably 15% by mass or more to 98% by mass, and further preferably 20% by mass to 97% by mass. With respect to the maleimide resin mixture (C), the content of the maleimide polybody compound represented by the general formula (5) is preferably 5% by mass to 80% by mass, more preferably 7% by mass to 80% by mass, and further preferably 10% by mass or more to 80% by mass.

[0336] As another preferred maleimide resin mixture (C) of the present embodiment, it is composed of a polymaleimide resin represented by the general formula (1A). The polymaleimide resin represented by the general formula (1A) is a resin using the aromatic amine compound (A-a) represented by the above general formula (a-1), the compound (A-b) having a benzylic ether skeleton, and maleic anhydride (A-c) as reaction raw materials (1). The reaction raw materials (1) can be formulated as follows: the aromatic amine compound (A-a) represented by the above general formula (a-1) is preferably 5 to 98% by mass, more preferably 10 to 95% by mass, and further preferably 15 to 90% by mass; the compound (A-b) having a benzylic ether skeleton is preferably 1 to 90% by mass, more preferably 2 to 85% by mass, and further preferably 3 to 80% by mass; maleic anhydride (A-c) is preferably 2 to 90% by mass, more preferably 3 to 85% by mass, and further preferably 4 to 80% by mass.

[0337] [Preparation of curable composition]

[0338] The solvent solubility, dielectric loss tangent, and heat resistance of the polymaleimide resin (A) of the present embodiment are excellent, and further can contribute to the fluidity, processability, dimensional stability, low hygroscopicity, brittleness resistance, and low dielectric constant during heat melting. Therefore, the solvent solubility, dielectric properties, and heat resistance of the cured product obtained from the curable composition containing the polymaleimide resin (A) are excellent.

[0339] The second curable composition may contain a curing agent (D) other than the cyanate ester (B), another resin (E), and a curing accelerator, which are the same as those described in the first curable composition. The second curable composition may also be appropriately combined with additives as needed. The additives are the same as those described in the first curable composition. With respect to 100% by mass of the total amount of the curable composition, the content of the additive is preferably 1% by mass or more and 20% by mass or less, and most preferably 3% by mass or more and 10% by mass or less.

[0340] [Cured product]

[0341] The cured product of the present embodiment is preferably obtained from the above curable composition. The cured product can be obtained by subjecting the curable composition to a curing reaction. The curable composition can be obtained by uniformly mixing the above components (for example, a curing agent, a compounding agent), and a cured product can be easily produced by a method similar to a conventionally known method. Examples of the cured product include molded cured products such as a laminate, a casting, an adhesive layer, a coating film, and a film.

[0342] As the curing (thermal curing) reaction, it is easy to proceed even without a catalyst, but in the case where a further rapid reaction is desired, it is effective to add a polymerization initiator such as an organic peroxide or an azo compound, a phosphine compound, or a basic catalyst such as a tertiary amine. For example, there are benzoyl peroxide, dicumyl peroxide, azobisisobutyronitrile, triphenylphosphine, triethylamine, imidazoles, etc., and the compounding amount is preferably 0.05 to 5% by mass of the entire curable resin composition.

[0343] The cured product obtained from the curable composition containing the polymaleimide resin (A) and the cyanate ester (B) has both excellent low moisture absorption and low dielectric properties, and thus can be suitably used for heat-resistant members or electronic members. In particular, it can be suitably used for prepregs, circuit boards, semiconductor sealing materials, semiconductor devices, laminated films, laminated substrates, adhesives using conductive pastes, resist materials, etc. In addition, it can also be suitably used as a matrix resin for fiber-reinforced resins, and is particularly suitable as a prepreg having high heat resistance or a small dimensional change rate. In addition, since the polymaleimide resin (A) contained in the curable composition exhibits excellent solubility in various solvents, it can be made into a coating. The heat-resistant members and electronic members thus obtained can be suitably used for various applications, such as industrial machine parts, general machine parts, parts of automobiles, railways, and vehicles, parts related to space and aviation, electronic and electrical parts, building materials, container and packaging members, daily necessities, sports and leisure goods, and housing members for wind power generation, but are not limited thereto.

[0344] Hereinafter, representative articles (prepregs, circuit boards, laminated boards, laminated films, semiconductor encapsulants, semiconductor devices, conductive pastes) manufactured using the curable composition of the present embodiment will be described by way of example.

[0345] <Prepreg>

[0346] The prepreg of the present embodiment has a reinforcing substrate and a semi-cured product of the curable composition of the present embodiment impregnated in the reinforcing substrate. As a method for obtaining a prepreg from the curable composition, the following method can be cited: After impregnating a varnished curable composition into a reinforcing substrate (paper, glass cloth, glass non-woven fabric, aramid paper, aramid cloth, glass fiber mat, glass fiber gauze, etc.) in combination with an organic solvent described later, heating is performed at a heating temperature corresponding to the type of solvent used, preferably 50 to 170°C, whereby the curable composition is semi-cured (or uncured) to obtain a prepreg. As the mass ratio of the curable composition to the reinforcing substrate used at this time, there is no particular limitation, and it is generally preferably prepared such that the resin amount contained in the composition in the prepreg becomes 20 to 60% by mass.

[0347] In the present embodiment, a semi-cured product of the curable composition can be obtained by adjusting the heating temperature and heating time to stop the curing reaction midway without completing it. In addition, for example, the semi-cured product can have a curing degree of, for example, 85% or less and 5% or more. On the other hand, the cured product in the present embodiment can have a higher curing degree than the semi-cured product.

[0348] It should be noted that the curing degree of the semi-cured product can be measured by DSC for the heat of curing release when heating the curable composition and the heat of curing release of the semi-cured product, and calculated by the following formula.

[0349] Curing degree (%) = [1 - (Heat of curing release of semi-cured product / Heat of curing release of curable composition)] × 100

[0350] As the organic solvent used in the manufacture of the prepreg of the present embodiment, for example, methyl ethyl ketone, acetone, dimethylformamide, methyl isobutyl ketone, methoxypropanol, cyclohexanone, methyl cellosolve, ethyl diglycol acetate, propylene glycol monomethyl ether acetate, etc. can be cited. The selection and appropriate usage amount thereof can be appropriately selected according to the use. For example, in the case of further manufacturing a printed circuit board from a prepreg as described below, polar solvents having a boiling point of 160°C or less such as methyl ethyl ketone, acetone, and dimethylformamide are preferably used, and further, it is preferably used in a proportion such that the non-volatile component becomes 40 to 80% by mass.

[0351] In addition, as the reinforcing base material used in the production of the prepreg of the present embodiment, woven fabrics, non-woven fabrics, mats, papers, etc. formed of inorganic fibers such as glass fibers, polyester fibers, and polyamide fibers and organic fibers can be used alone or in combination.

[0352] As the conditions for heat treatment of the prepreg of the present embodiment, they are appropriately selected according to the types and amounts of organic solvents, catalysts, various additives used, etc., and are usually preferably carried out under conditions of a temperature of 80 to 220°C and 3 minutes to 30 minutes.

[0353] <Circuit board>

[0354] The circuit board of the present embodiment is a laminate having the above prepreg and copper foil. As a method for obtaining a printed circuit board from the curable composition of the present embodiment, a method can be cited in which the above prepreg is laminated by a conventional method, copper foil is appropriately overlapped, and heat-pressed at 170 to 300°C under a pressure of 1 to 10 MPa for 10 minutes to 3 hours.

[0355] <Multilayer substrate>

[0356] As a method for obtaining a multilayer substrate from the curable composition of the present embodiment, a method via the following steps 1 to 3 can be cited.

[0357] In step 1, first, the curable composition appropriately mixed with rubber, filler, etc. is coated on a circuit board having a circuit formed thereon by a spraying method, a curtain coating method, etc., and then cured.

[0358] In step 2, if necessary, after opening a prescribed via hole portion, etc. on the circuit board coated with the curable composition, it is treated with a roughening agent, and its surface is washed with hot water, thereby forming irregularities on the substrate, and a plating treatment of a metal such as copper is performed.

[0359] In step 3, if necessary, the operations of steps 1 to 2 are sequentially repeated, and a multilayer substrate is molded by alternately laminating a resin insulating layer and a conductor layer of a prescribed circuit pattern.

[0360] It should be noted that in the above steps, the opening of the via hole portion can be performed after forming the outermost resin insulating layer. In addition, the multilayer substrate of the present embodiment can also be produced by heat-pressing a resin-coated copper foil obtained by semi-curing the composition on a copper foil at 170 to 300°C on a wiring substrate having a circuit formed thereon, thereby omitting the steps of forming a roughened surface and a plating treatment.

[0361] <Multilayer film>

[0362] The laminated film of the present embodiment contains the curable composition of the present embodiment. As a method for manufacturing the laminated film of the present embodiment, the following method can be mentioned: After coating the curable composition on the support film (Y), it is dried to form a curable composition layer on the support film (Y), and a bonding film for a multilayer printed wiring board is produced, thereby manufacturing.

[0363] In the case of manufacturing a laminated film from a curable composition, it is important that the film softens under the lamination temperature conditions (usually 70 to 140 °C) in the vacuum lamination method, and while laminating the circuit board, it shows the fluidity (resin flow) that the resin can fill into the vias or through holes existing in the circuit board. It is preferably formulated with the above-mentioned respective components to exhibit such characteristics. It should be noted that in the obtained laminated film and circuit board (copper-clad laminate, etc.), in order not to cause a phenomenon where different characteristic values are locally shown due to phase separation or the like, and to exhibit constant performance at any part, appearance uniformity is required.

[0364] Here, the diameter of the through hole of the multilayer printed wiring board is usually 0.1 to 0.5 mm, and the depth is usually 0.1 to 1.2 mm. It is generally preferred that the resin can be filled within this range. It should be noted that when laminating both sides of the circuit board, it is preferably to fill about 1 / 2 of the through hole.

[0365] The method for manufacturing the above-mentioned bonding film can be specifically manufactured as follows: After preparing the varnish-like curable composition, the varnish-like composition is coated on the surface of the support film (Y), and the organic solvent is further dried by heating or blowing hot air, etc., to form a composition layer (X) composed of the curable composition. As the organic solvent, for example, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate, cellosolves, carbitols such as butyl carbitol, aromatic hydrocarbons such as toluene and xylene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. are preferably used. In addition, it is preferably used in a proportion of 30 to 60 mass% of the non-volatile component.

[0366] The thickness of the formed composition layer (X) is generally preferably equal to or greater than the thickness of the conductor layer. The thickness of the conductor layer of the circuit board is usually in the range of 5 to 70 μm, so the thickness of the resin composition layer is preferably 10 to 100 μm. It should be noted that the composition layer (X) in the present embodiment can be protected by a protective film described later. By protecting with a protective film, it is possible to prevent the adhesion and damage of dust, etc. on the surface of the resin composition layer.

[0367] Examples of the above-mentioned support film (Y) and protective film include polyolefins such as polyethylene, polypropylene, and polyvinyl chloride, polyesters such as polyethylene terephthalate (hereinafter sometimes simply referred to as "PET") and polyethylene naphthalate, polycarbonate, polyimide, and metal foils such as release paper, copper foil, and aluminum foil. It should be noted that, in addition to matte treatment and corona treatment, the support film and the protective film may also be subjected to release treatment.

[0368] The thickness of the support film is not particularly limited, and is usually 10 to 150 μm, preferably used in the range of 25 to 50 μm. In addition, the thickness of the protective film is preferably 1 to 40 μm.

[0369] The above-mentioned support film (Y) is peeled off after being laminated on the circuit board or after forming an insulating layer by heat curing. If the support film (Y) is peeled off after the adhesive film is heat cured, the adhesion of dust, etc. during the curing process can be prevented. In the case of peeling off after curing, the support film is usually subjected to release treatment in advance.

[0370] It should be noted that a multilayer printed circuit board can be manufactured from the laminate obtained as described above. For example, when the resin composition layer (X) is protected by a protective film, after peeling them off, the layer (X) of the resin composition is laminated on one or both sides of the circuit board in direct contact with the circuit board by, for example, a vacuum lamination method. The lamination method can be intermittent or continuous using a roller. In addition, if necessary, the laminate and the circuit board can be heated (preheated) as required before lamination. Regarding the lamination conditions, it is preferable to set the crimping temperature (lamination temperature) to 70 to 140 °C, and it is preferable to set the crimping pressure to 1 to 11 kgf / cm 2 (9.8×10 4 ~107.9×10 4 N / m 2 ), and it is preferable to perform lamination under reduced pressure with an air pressure of 20 mmHg (26.7 hPa) or less.

[0371] <Semiconductor encapsulant>

[0372] The semiconductor encapsulant of the present embodiment contains the curable composition of the present embodiment. The semiconductor encapsulant obtained by using the curable composition of the present embodiment uses the polyimide resin (A) and cyanate ester (B), so that the moisture absorption, dielectric constant, and dielectric loss tangent are reduced. Therefore, the processability, moldability, and reflow resistance during the manufacturing process are excellent, which is a preferred method.

[0373] The curable composition of the present embodiment used in the semiconductor sealing material may contain an inorganic filler. It should be noted that as the filling rate of the inorganic filler, the inorganic filler can be used, for example, in the range of 0.5 to 1200 parts by mass with respect to 100 parts by mass of the curable composition of the present embodiment. In addition, as the inorganic filler, as described above, for example, barium sulfate, barium titanate, amorphous silica, crystalline silica, Nuremberg silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, alumina, aluminum hydroxide, silicon nitride, aluminum nitride, etc. can be cited.

[0374] As a method for obtaining the semiconductor sealing material, a method can be cited in which a curing accelerator and / or an additive as optional components are further sufficiently melt-mixed using an extruder, a kneader, a roll, etc. as needed until the curable composition of the present embodiment becomes uniform. In the case of being used as a high thermal conductivity semiconductor sealing material for power transistors and power ICs, high filling of crystalline silica, alumina, silicon nitride, etc. with a higher thermal conductivity than fused silica can be carried out, or fused silica, crystalline silica, alumina, silicon nitride, etc. can be used. Regarding its filling rate, with respect to 100 parts by mass of the curable composition, it is preferable to use the inorganic filler in the range of 30 to 95 parts by mass. Among them, in order to achieve improvement in flame retardancy, moisture resistance, solder crack resistance, and reduction of the linear expansion coefficient, it is more preferably 70 parts by mass or more, and further preferably 80 parts by mass or more.

[0375] <Semiconductor device>

[0376] The semiconductor device of the present embodiment includes a cured product of the above semiconductor sealing material. Since the polyimide resin (A) and cyanate ester (B) are used in the semiconductor sealing material obtained by using the curable composition of the present embodiment, the viscosity is low and the fluidity is excellent. Furthermore, the hygroscopicity, the elastic modulus at high temperature, or the adhesiveness to the metal material is improved. Therefore, the processability, moldability, and reflow resistance during the manufacturing process are excellent, which is a preferred mode.

[0377] As a method for obtaining the semiconductor device, a method can be cited in which the semiconductor sealing material is cast, or molded using a transfer molding machine, an injection molding machine, etc., and then heat-cured in the temperature range of room temperature (20 °C) to 250 °C.

[0378] <Conductive paste>

[0379] As a method for obtaining a conductive paste from the curable composition of the present embodiment, for example, a method can be cited in which conductive particles are dispersed in the composition. The above conductive paste can be made into a paste resin composition for circuit connection or an anisotropic conductive adhesive according to the type of conductive particles used.

[0380] Example

[0381] The present invention will be specifically described by way of Examples and Comparative Examples. Hereinafter, unless otherwise specified, "parts" and "%" are based on mass. It should be noted that the physical properties of the synthesized polyimide resin were measured as follows and are shown in Tables 1 and 2.

[0382] (1) Measurement of GPC

[0383] Measurement device: "HLC-8320GPC" manufactured by Tosoh Corporation,

[0384] Column: Guard column "HXL-L" manufactured by Tosoh Corporation

[0385] + "TSK-GEL G2000HXL" manufactured by Tosoh Corporation

[0386] + "TSK-GEL G2000HXL" manufactured by Tosoh Corporation

[0387] + "TSK-GEL G3000HXL" manufactured by Tosoh Corporation

[0388] + "TSK-GEL G4000HXL" manufactured by Tosoh Corporation

[0389] Detector: RI (differential refractometer)

[0390] Data processing: "GPC Workstation EcoSEC-WorkStation" manufactured by Tosoh Corporation

[0391] Measurement conditions: Column temperature 40 °C

[0392] Elution solvent tetrahydrofuran

[0393] Flow rate 1.0 ml / min

[0394] Standard: According to the measurement manual of the "GPC Workstation EcoSEC-WorkStation", the following monodisperse polystyrene with known molecular weight was used.

[0395] (Using polystyrene)

[0396] "A-500" manufactured by Tosoh Corporation

[0397] "A-1000" manufactured by Tosoh Corporation

[0398] "A-2500" manufactured by Tosoh Corporation

[0399] "A-5000" manufactured by Tosoh Corporation

[0400] "F-1" manufactured by Tosoh Corporation

[0401] "F-2" manufactured by Tosoh Corporation

[0402] "F-4" manufactured by Tosoh Corporation

[0403] "F-10" manufactured by Tosoh Corporation

[0404] "F-20" manufactured by Tosoh Corporation

[0405] "F-40" manufactured by Tosoh Corporation

[0406] "F-80" manufactured by Tosoh Corporation

[0407] "F-128" manufactured by Tosoh Corporation

[0408] Sample: The substance (50 μL) obtained by filtering a 1.0 mass% tetrahydrofuran solution in terms of resin solid content through a microfilter.

[0409] (2) Amine equivalent and maleimide group equivalent

[0410] The amine equivalent of the aromatic amine obtained in the synthesis example was determined by the following method.

[0411] Precisely weigh approximately 2.5 g of aromatic amine, 7.5 g of pyridine, 2.5 g of acetic anhydride, and 7.5 g of triphenylphosphine in a 500 mL stoppered Erlenmeyer flask, then install a condenser and heat under reflux in an oil bath set at 120 °C for 150 minutes.

[0412] After cooling, add 5.0 mL of distilled water, 100 mL of propylene glycol monomethyl ether, and 75 mL of tetrahydrofuran, and titrate with a 0.5 mol / L potassium hydroxide-ethanol solution by potentiometric titration. A blank test was conducted in the same manner for correction.

[0413] Amine equivalent (g / equivalent) = (S × 2,000) / (Blank - A)

[0414] S: Amount of sample (g)

[0415] A: Consumption of 0.5 mol / L potassium hydroxide-ethanol solution (mL)

[0416] Blank: Consumption of 0.5 mol / L potassium hydroxide-ethanol solution in the blank test (mL)

[0417] The maleimide group equivalent of the polyimide resin obtained in the synthesis example is a value converted from the amine equivalent of the intermediate amine compound and is obtained from the following formula.

[0418] Maleimide equivalent (g / equivalent) = Amine equivalent + 80

[0419] (3) FD-MS measurement

[0420] The FD-MS spectrum of the polyimide resin obtained in the synthesis example was measured using the following measuring apparatus and measurement conditions.

[0421] · Measuring apparatus: JMS-T100 GC AccuTOF

[0422] · Measurement conditions

[0423] Measurement range: m / z = 4.00 to 2000.00

[0424] Rate of change: 51.2 mA / min

[0425] Final current value: 45 mA

[0426] Cathode voltage: -10 kV

[0427] Recording interval: 0.07 sec

[0428] (4) 13 13C-NMR measurement

[0429] The 13C-NMR spectrum of the polyimide resin obtained in the synthesis example 13 was measured using the following measuring apparatus and measurement conditions.

[0430] · 13 13C-NMR: JEOL RESONANCE "JNM-ECZ400S"

[0431] Resonance frequency: 100 MHz

[0432] Number of accumulations: 4000 times

[0433] Solvent: deuterated chloroform

[0434] Sample concentration: 12 mass%

[0435] Relaxing agent: chromium(III) acetylacetonate

[0436] The materials and apparatuses used in the synthesis examples and the examples are as described below.

[0437] Xylene formaldehyde resin: manufactured by Fudow Co., Ltd., product name "Nikanol L"

[0438] Maleimide resin (A-2) for comparison: 4,4'-diphenylmethane bismaleimide, BMI-1000, manufactured by Daiwa Kasei Kogyo Co., Ltd.

[0439] Cyanate ester (B): 2,2-bis(4-cyanoxyphenyl)propane, manufactured by Tokyo Chemical Industry Co., Ltd.

[0440] Curing catalyst: Tetraphenylphosphonium tetra-p-tolylborate, manufactured by Kitakyo Chemical Industry Co., Ltd., product name "TPP-MK (registered trademark)"

[0441] Network analyzer: manufactured by Agilent Technologies, product name "E8362C"

[0442] [Synthesis Example 1] Synthesis of maleimide resin (A-1)

[0443] (1) Synthesis of intermediate amine

[0444] In a flask equipped with a thermometer, a condenser, a Dean-Stark separator, and a stirrer, 350 g of 2,3-dimethylaniline, 127.3 g of xylene formaldehyde resin, 240 g of toluene, and 133.7 g of activated clay were added. While stirring the mixture, the temperature was raised to 120 °C and maintained for 30 minutes. Then, the temperature was raised to 160 °C and maintained for 4 hours. Next, the temperature was raised to 200 °C over 60 minutes and maintained for 15 hours. Then, the mixture was diluted with 240 g of toluene, and the activated clay was filtered off. The filtrate was heated under reduced pressure to distill off the solvent and excess 2,3-dimethylaniline, obtaining the intermediate aromatic amine resin (a-1) (amine equivalent: 218 g / equivalent). The 13 C-NMR spectrum and FD-MS spectrum are shown in Figure 1 、 Figure 2 。

[0445] (2) Maleimidation

[0446] In a 2 L flask equipped with a thermometer, a cooling tube, a Dean-Stark separator, and a stirrer, 70.08 g (1.3 equivalents) of maleic anhydride and 260.4 g of toluene were added. The mixture was stirred at room temperature. Then, a mixed solution of 120.0 g (1 equivalent) of aromatic amine resin (a-1) and 32.6 g of DMF was added dropwise to the mixture over 1 hour. The mixture was allowed to react for 2 hours. 5.23 g of p-toluenesulfonic acid monohydrate was added to the reaction solution. Then, the reaction solution was heated, and the water and toluene that azeotroped under reflux were cooled and separated. Then, the mixture was heated to 115 °C, and the water and toluene that azeotroped under reflux were cooled and separated. Then, only toluene was returned to the system for a 5-hour dehydration reaction. After air-cooling to room temperature, it was concentrated under reduced pressure, and the obtained brown solution was dissolved in 600 g of ethyl acetate, washed 3 times with 200 g of ion-exchanged water, and washed 3 times with 150 g of 2% aqueous sodium bicarbonate solution. Then, sodium sulfate was added to the oil layer for drying, and it was concentrated under reduced pressure. The obtained reactant was vacuum-dried at 80 °C for 4 hours to obtain a product containing maleimide resin (A-1). The GPC diagram of this maleimide resin (A-1) is shown in Figure 3 , and the FD-MS spectrum is shown in Figure 4 , and the 13 C NMR spectral results are shown in Figure 5 . According to the results of GPC and the like, it was confirmed that the obtained polymaleimide resin (A-1) contained 20% by mass or more of the component represented by the above general formula (1A) and the sum of n 1 and n 3 was 1 or more, and in addition, contained 10% by mass or more of the component with n 2 being 1 or more.

[0447] For each peak of the FD-MS spectrum shown in Figure 4 , the repeat number in the polymaleimide resin (A-1) was confirmed. The results are shown in Table 1.

[0448] [Table 1]

[0449]

[0450] [Example 1] Preparation of Composition and Molding

[0451] The maleimide resin (A-1), cyanate ester (B), and curing catalyst obtained in Synthesis Example 1 were blended in the amounts shown in Table 2 to prepare a curable composition.

[0452] [Examples 2 and Comparative Examples 1-2]

[0453] A curable composition was prepared in the same manner as in Example 1, except that the maleimide resin and the curing catalyst were changed as shown in Table 2.

[0454] <Cured product>

[0455] The curable composition was cured under the following conditions to obtain a cured product.

[0456] Curing conditions: Using a vacuum press, heat curing was carried out at 200 °C for 2 hours and then at 250 °C for 2 hours. After molding, the plate thickness was 1.3 mm. For this cured product, the physical properties of dielectric properties and moisture absorption rate were evaluated by the following method. The results are shown in Table 2.

[0457] <Measurement of dielectric properties>

[0458] According to JIS C 6481, using a network analyzer manufactured by Agilent Technologies, Inc., the dielectric constant (Dk) and dielectric loss tangent (Df) at 1 GHz of the test piece (cured product) after being kept in a room at 23 °C and 50% humidity for 24 hours after complete drying were measured by the cavity resonance method.

[0459] <Moisture absorption rate>

[0460] In this example and comparative examples, as an evaluation method for low moisture absorption, the moisture absorption rate (%) was calculated and evaluated by the following method.

[0461] Using a pressure cooker testing machine, after a test piece with dimensions of 5 mm × 55 mm × 1.3 mm cut from the cured product obtained above was kept at 85 °C, 85% RH, and 1 atmosphere for 50 hours, the moisture absorption rate (%) was calculated using the following formula and evaluated.

[0462] Moisture absorption rate (%) = (mass of the test piece after the test - mass of the test piece before the test) / (mass of the test piece before the test) × 100

[0463] [Table 2]

[0464]

[0465] According to the present invention, it is possible to provide a polyimide resin that exhibits excellent dielectric properties and low moisture absorption during curing, and a curable composition containing the polyimide resin.

[0466] Industrial applicability

[0467] According to the present invention, it is possible to provide a polyimide resin that exhibits excellent dielectric properties and low moisture absorption during curing, a curable composition containing the polyimide resin, its cured product, prepreg, circuit board, laminated film, semiconductor encapsulant, and semiconductor device.

Claims

1. A curable composition, characterized in that, It contains a polymaleimide resin (A) and a cyanate ester (B). The polymaleimide resin (A) has a partial structure represented by the following general formula (1), a partial structure represented by the following general formula (2) that is chemically bonded to the partial structure represented by the general formula (1), and a partial structure represented by the following general formula (3) that is chemically bonded to the partial structure represented by the general formula (1). [Chemical Formula 1] In the above general formula (1), R 13 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, m 2 represents an integer of 0 or more and 4 or less, n 1 represents the average number of repeating units, and the two * respectively represent bonding ends, and one bonding end is bonded by a chemical bond at the position of L in the following general formula (2) 13 or L 14 , and the other bonding end is bonded by a chemical bond at the position of L in the following general formula (3) 11 or L 12 . [Chemical Formula 2] In the above general formula (2) or (3), R 11 and R 15 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, R 12 and R 14 each independently represent a hydrocarbon group having 1 to 18 carbon atoms, L 11 to L 14 each independently represent a bonding end or a hydrogen atom, wherein, at the position of L 11 or L 12 a chemical bond is formed with the partial structure represented by the general formula (1), and at the position of L 13 or L 14 a chemical bond is formed with the partial structure represented by the general formula (1), and further, L 11 to L 14 that do not form a chemical bond with the partial structure represented by the general formula (1) are hydrogen atoms, m 1 and m 3 each represent 2.

2. The curable composition according to claim 1, wherein, The polymaleimide resin (A) uses an aromatic amine compound (A-a) represented by the following general formula (a-1), a compound (A-b) having a benzyl ether skeleton, and maleic anhydride (A-c) as reaction raw materials (1). [Chemical Formula 3] In the above general formula (a-1), R a1 and R a2 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R 1 represents a hydrocarbon group having 1 to 18 carbon atoms, R 2 and R 3 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms.

3. The curable composition according to claim 1, wherein, The polymaleimide resin (A) is a polymaleimide resin having a partial structure represented by the following general formula (1A). [Chemical Formula 4] In the above general formula (1A), R 13 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, m 2 represents an integer of 0 or more and 4 or less, n 1 represents the average number of repeating units, R 11 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, R 12 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, m 1 respectively represent 2, n 2 represents the average number of repeating units, ran represents that the arrangement of each structural unit can be random, and the two * respectively represent the bonding ends, which are bonded to a hydrogen atom or a partial structure represented by the general formula (4). [Chemical Formula 5] In the above general formula (4), R 13 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, m 2 represents an integer of 0 or more and 4 or less, and n 3 represents the average number of repeating units.

4. The curable composition according to claim 3, which contains 10% by mass or more of a component represented by the general formula (1A) and the sum of n 1 and n 3 is 1 or more.

5. A curable composition, characterized in that, It contains a maleimide resin mixture (C) and a cyanate ester (B). The maleimide resin mixture (C) contains a polymaleimide resin component having a partial structural unit represented by the following general formula (1a) and a maleimide polybody compound represented by the following general formula (5). The maleimide resin mixture (C) contains 1 to 99% by mass of the polymaleimide resin (A) relative to the total amount of the polymaleimide resin component, and contains 80% by mass or less of the maleimide polybody compound relative to the total amount of the maleimide resin mixture (C). The polymaleimide resin (A) has a partial structure represented by the following general formula (1), a partial structure represented by the following general formula (2) that is chemically bonded to the partial structure represented by the general formula (1), and a partial structure represented by the following general formula (3) that is chemically bonded to the partial structure represented by the general formula (1). [Chemical Formula 6] In the above general formula (1a), R 11 represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, and R 12 represents a hydrocarbon group having 1 to 18 carbon atoms, and R 13 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, m 1 represents 2, and m 2 represents an integer of 0 or more and 4 or less, and n 1 represents the average number of repeating units. [Chemical Formula 7] In the above general formula (5), R 21 and R 25 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, R 22 and R 24 each independently represent a hydrocarbon group having 1 to 18 carbon atoms, m 21 represents 2, m 23 represents 3, n 21 represents an integer of 1 or more and 5 or less. [Chemical Formula 8] In the above general formula (1), R 13 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, m 2 represents an integer of 0 or more and 4 or less, n 1 represents the average number of repeating units, and the two * respectively represent bonding ends, and one bonding end is bonded by a chemical bond at the position of L in the following general formula (2) 13 or L 14 , and the other bonding end is bonded by a chemical bond at the position of L in the following general formula (3) 11 or L 12 . [Chemical Formula 9] In the above general formula (2) or (3), R 11 and R 15 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, R 12 and R 14 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, and L 11 to L 14 each independently represents a bonding end or a hydrogen atom. Among them, at the position of L 11 or L 12 , a chemical bond is formed with the partial structure represented by the general formula (1), and at the position of L 13 or L 14 , a chemical bond is formed with the partial structure represented by the general formula (1). In addition, L 11 to L 14 that do not form a chemical bond with the partial structure represented by the general formula (1) are hydrogen atoms, and m 1 and m 3 each represents 2.

6. The curable composition according to claim 5, wherein, The polymaleimide resin (A) uses an aromatic amine compound (A-a) represented by the following general formula (a-1), a compound (A-b) having a benzyl ether skeleton, and maleic anhydride (A-c) as reaction raw materials (1). [Chemical Formula 10] In the above general formula (a-1), R a1 and R a2 each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R 1 represents a hydrocarbon group having 1 to 18 carbon atoms, R 2 and R 3 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms.

7. A polyimide resin, characterized in that, It has a partial structure represented by the following general formula (1A). [Chemical Formula 11] In the above general formula (1A), R 13 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, m 2 represents an integer of 0 or more and 4 or less, n 1 represents the average number of repeating units, R 11 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, R 12 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, m 1 each represents 2 respectively, n 2 represents the average number of repeating units, ran indicates that the arrangement of each structural unit can be random, and the two * respectively represent the bonding ends, which are bonded to a hydrogen atom or a partial structure represented by the general formula (4). [Chemical Formula 12] In the above general formula (4), R 13 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, m 2 represents an integer of 0 or more and 4 or less, and n 3 represents the average number of repeating units.

8. The cured product of the curable composition according to any one of claims 1 to 6.

9. A prepreg having a reinforcing substrate and a semi-cured product of the curable composition according to any one of claims 1 to 6 impregnated in the reinforcing substrate.

10. A circuit board which is a laminate having the prepreg according to claim 9 and a copper foil.

11. A laminated film containing the curable composition according to any one of claims 1 to 6.

12. A semiconductor sealing material containing the curable composition according to any one of claims 1 to 6.

13. A semiconductor device comprising a cured product of the semiconductor sealing material according to claim 12.

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