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

Abstract

The present disclosure provides a polymaleimide resin (A) that exhibits low dielectric loss tangent and low hygroscopicity after curing, a curable composition containing the polymaleimide resin (A), a cured product thereof, a prepreg, a circuit board, a laminate film, a semiconductor sealing material, and a semiconductor device. The present disclosure is a curable composition containing a polymaleimide resin (A) and a compound (D) containing a reactive double bond, the polymaleimide resin (A) has a partial structure represented by general formula (1), a partial structure represented by general formula (T-1) chemically bonded to the partial structure represented by general formula (1), and a partial structure represented by general formula (T-2) chemically bonded to the partial structure represented by general formula (1).

Description

Technical Field

[0001] The present disclosure relates to a curable composition, 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 BT (bismaleimide-triazine) resin into a glass cloth and heating and drying it, a laminated board obtained by heat-curing the prepreg, and a multilayer board obtained by combining the laminated board and the prepreg and heat-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, further improvement of properties represented by heat resistance and dielectric properties, and materials and compositions having both of them are required. In addition, if the wettability or hygroscopicity of an electrical insulating material is high, its dielectric breakdown voltage decreases compared to the dry state (normal state), so low hygroscopicity is also required.

[0004] Regarding such requirements, as a material having both heat resistance and low dielectric properties, maleimide resins have attracted attention. As technologies related to such maleimide resins, for example, Patent Documents 1 and 2 can be cited. 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 Unexamined Patent Application Publication No. 2020-176190

[0008] Patent Document 2: Japanese Unexamined Patent Application Publication 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 frequency band that has been utilized currently (the range of several hundred MHz to 3 GHz) have been studied, and it has not been studied whether it can cope with the technology for the fifth-generation mobile communication system (5G) using the so-called Sub6 band. In addition, the hygroscopicity has not been studied in Patent Documents 1 and 2 either.

[0011] Therefore, the technical problem to be solved by the present invention is to provide a curable composition, a cured product thereof, a prepreg, a circuit board, a laminated film, a semiconductor sealing material, and a semiconductor device that highly balance low dielectric properties and low moisture absorption rate after curing.

[0012] Method for Solving the Problem

[0013] The inventors of the present invention repeatedly conducted in-depth studies to solve the above problems, and as a result, it was found that by using a curable composition containing a polyimide resin (A) having a specified chemical structure and a compound (D) containing a reactive double bond, a curable composition, a cured product thereof, a prepreg, a circuit board, a laminated film, a semiconductor sealing material, and a semiconductor device that highly balance low dielectric properties and low moisture absorption rate after curing can be obtained, and thus the following invention was completed.

[0014] [1] A curable composition, characterized by containing a polyimide resin (A) and a compound (D) containing a reactive double bond having a reactive double bond.

[0015] The polyimide resin (A) has a partial structure represented by the following general formula (1), a partial structure represented by the following general formula (T-1) that is chemically bonded to the partial structure represented by the general formula (1), and a partial structure represented by the following general formula (T-2) that is chemically bonded to the partial structure represented by the general formula (1).

[0016] [Chemical Formula 1]

[0017]

[0018] [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, indicating that one bonding end is chemically bonded to the position of L 13 or L 14 in the following general formula (T-1), and the other bonding end is chemically bonded to the position of L 11 or L 12 in the following general formula (T-2).]

[0019] [Chemical formula 2]

[0020]

[0021] [In the above general formula (T-1) or (T-2), 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, 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.]

[0022] [2] The curable composition according to [1], wherein the polyimide resin (A) uses an aromatic amine compound (A-a) represented by the following general formula (a-1), a compound (B) having a benzyl ether skeleton, and maleic anhydride as reaction raw materials (1),

[0023] [Chemical formula 3]

[0024]

[0025] [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.]

[0026] [3] The curable composition according to [1] or [2], wherein the polyimide resin (A) is a polyimide resin having a partial structure represented by the following general formula (1A),

[0027] [Chemical formula 4]

[0028]

[0029] [In the above general formula (1A), R14 Each independently represents a hydrocarbon group having 1 to 18 carbon atoms, R 15 Each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, m 3 Each represents 2, 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, 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 (T-3). In addition, ran in the general formula (1A) represents a random copolymer.]

[0030] [Chemical formula 5]

[0031]

[0032] [In the above general formula (T-3), 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 3 Represents the average number of repeating units.]

[0033] [4] The curable composition according to [3], which contains a component in which the sum of the average number of repeating units n 1 of the polyimide resin (A) represented by the general formula (1A) is 1 or more 3 and n

[0034] [5] A curable composition, characterized in that it contains a polyimide resin (A) mixture and a compound (D) having a reactive double bond, the polyimide resin (A) mixture containing a polyimide resin (A) component having a partial structural unit represented by the following general formula (1a) and a maleimide polycompound represented by the following general formula (2),

[0035] The polyimide resin (A) mixture contains 1 to 99% by mass of the polyimide resin (A) relative to the total amount of the polyimide resin (A) component, and contains 80% by mass or less of the maleimide polybody compound relative to the total amount of the polyimide resin (A) mixture. The polyimide resin (A) has a partial structure represented by the following general formula (1), a partial structure represented by the following general formula (T-1) bonded to the partial structure represented by the general formula (1), and a partial structure represented by the following general formula (T-2) bonded to the partial structure represented by the general formula (1).

[0036] [Chemical formula 6]

[0037]

[0038] [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.]

[0039] [Chemical formula 7]

[0040]

[0041] [In the above general formula (2), R 21 and R 25 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, R 22 and R 24 each independently represents 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.]

[0042] [Chemical formula 8]

[0043]

[0044] [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 *s respectively represent bonding ends, and one bonding end is L in the following general formula (T-1) 13 or L14 Bonding is carried out at the position of, and the other bonding end is at L in the following general formula (T-2) 11 or L 12 Bonding is carried out at the position of.]

[0045] [Chemical Formula 9]

[0046]

[0047] [In the above general formula (T-1) or (T-2), 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 bonding is carried out with the partial structure represented by the general formula (1), and at the position of L 13 or L 14 bonding is carried out with the partial structure represented by the general formula (1), and in addition, L 11 to L 14 that does not bond with the partial structure represented by the general formula (1) is a hydrogen atom, and m 1 and m 3 each represent 2.]

[0048] [6] The curable composition according to any one of [1] to [5], wherein the polyimide resin (A) uses an aromatic amine compound (A-a) represented by the following general formula (a-1), a compound (B) having a benzyl ether skeleton, and maleic anhydride as reaction raw materials (1),

[0049] [Chemical Formula 10]

[0050]

[0051] [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.]

[0052] [7] The polyimide resin represented by the general formula (1A) described in [3].

[0053] The cured product of the curable composition according to any one of [8][1] to [6].

[0054] [9] A prepreg having a reinforcing substrate and a semi-cured product of the curable composition according to any one of [1] to [6] impregnated in the reinforcing substrate.

[0055]

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

[0056]

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

[0057]

[12] A semiconductor encapsulant containing the curable composition according to any one of [1] to [6].

[0058]

[13] A semiconductor device comprising the cured product of the semiconductor encapsulant according to

[12] .

[0059] Advantages of the Invention

[0060] According to the present disclosure, there can be provided a curable composition and its cured product, a prepreg, a circuit board, a laminated film, a semiconductor encapsulant, and a semiconductor device that exhibit a low dielectric loss tangent and low moisture absorption after curing. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 FD-MS spectrogram showing the intermediate amine compound (c-1).

[0062] Figure 2 Showing the intermediate amine compound (c-1) 13 C-NMR chart.

[0063] Figure 3 GPC chart showing the polyimide resin (A-1).

[0064] Figure 4 FD-MS spectrogram showing the polyimide resin (A-1).

[0065] Figure 5 Showing the polyimide resin (A-1) 13 C-NMR chart. DETAILED DESCRIPTION

[0066] Hereinafter, embodiments of the present invention (referred to as "the present embodiments") will be described in detail. However, the present disclosure is not limited to the following description and can be implemented with various modifications within the scope of its gist.

[0067] [TERMS]

[0068] In this specification, the following terms can be applied unless otherwise specified.

[0069] The "reaction raw material" in this specification is used to obtain a target compound through a chemical reaction such as bonding 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 aids such as solvents and catalysts. In this specification, in particular, the "reaction raw material" refers to a precursor for obtaining the target polymaleimide resin (A) or its precursor compound (for example, an intermediate amine compound (C) in which aromatic amine compounds (A-a) are linked via a structural unit derived from a compound (B) having a benzylic ether skeleton).

[0070] 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 the 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 what is called a residue. In addition, it is also called a repeating unit during polymerization.

[0071] The "aryl 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 "aryl group" in this specification, the hydrogen atoms of the aromatic ring in the aryl group can be substituted by 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 "aryl group" includes heteroaromatics and can be substituted by -O-, -S-, or -N= in such a way that -CH2- or -CH= in the "aryl group" are not adjacent to each other.

[0072] Examples of the type of the aromatic ring include a monocyclic aromatic ring, a polycyclic aromatic ring, or a ring assembly aromatic ring, etc. As the monocyclic aromatic ring, for example, benzene, furan, pyrrole, thiophene, imidazole, pyrazole, oxazole, isoxazole, thiazole, isothiazole, pyridine, pyrimidine, pyridazine, pyrazine, triazine, etc. can be cited. As the polycyclic aromatic ring, for example, naphthalene, anthracene, phenalene, phenanthrene, quinoline, isoquinoline, quinazoline, phthalazine, pteridine, coumarin, indole, benzimidazole, benzofuran, acridine, etc. can be cited. As the ring assembly aromatic ring, for example, biphenyl, binaphthyl, bipyridine, bithiophene, phenylpyridine, phenylthiophene, terphenyl, diphenylthiophene, quaterphenyl, etc. can be cited. In addition, the hydrogen atoms of the aromatic ring in the aryl group can be substituted by, for example, an alkyl group with 1 to 10 carbon atoms, an alkoxy group with 1 to 10 carbon atoms, or a halogen atom. It should be noted that a monovalent aryl group refers to a group obtained by removing 1 hydrogen atom from the "aryl group", and a divalent aryl group refers to a group obtained by removing any 2 hydrogen atoms from the "aryl group".

[0073] "Alkyl" in this specification can be any of linear, branched or cyclic, and examples thereof 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.

[0074] "Cycloalkyl" in this specification may include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, norbornyl, adamantyl, etc.

[0075] "Alkylthio" in this specification may include methylthio, ethylthio, propylthio, butylthio, octylthio or 2-ethylhexylthio.

[0076] "Alkenyl" in this specification may include ethynyl, 1-propynyl, 2-propynyl, 2-butynyl, pentynyl, hexynyl, vinyl, allyl, isopropenyl, etc. It should be noted that "alkenylene" may include a divalent group obtained by removing any one hydrogen atom from the "alkenyl".

[0077] "Alkoxy" in this specification, for example, may include methoxy, ethoxy, propoxy, isopropoxy, butoxy, pentyloxy, hexyloxy, 2-ethylhexyloxy, octyloxy, nonyloxy, etc.

[0078] "Aryl" in this specification, for example, may include phenyl, naphthyl, phenalenyl, phenanthryl, anthryl, azulenyl, indenyl, indanyl, tetrahydronaphthyl, etc. In addition, in this "aryl", a hydrogen atom of the aromatic ring in the aryl may be substituted with, for example, an alkyl having 1 to 10 carbon atoms, an alkoxy having 1 to 10 carbon atoms or a halogen atom.

[0079] As the "aralkyl" in this specification, for example, may include benzyl, diphenylmethyl, biphenyl, naphthylmethyl, etc. A hydrogen atom of the aromatic ring in the aralkyl may be substituted with, for example, an alkyl having 1 to 10 carbon atoms, an alkoxy having 1 to 10 carbon atoms or a halogen atom. It should be noted that "aralkylene" may include a divalent group obtained by removing any one hydrogen atom from the "aralkyl".

[0080] "Aryloxy" in this specification may include phenoxy, naphthoxy, anthryloxy, phenanthryloxy or pyrenyloxy, etc.

[0081] "Arylthio" in this specification may include arylthio such as phenylthio, naphthylthio, anthrylthio, phenanthrylthio or pyrenylthio.

[0082] The "halogen atom" in the present specification may be exemplified by a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.

[0083] The "alkylene group" in the present specification may be exemplified by a methylene group, an ethylene group, a propylene group, a 1-methylmethylene group, a 1,1-dimethylmethylene group, a 1-methylethylene group, a 1,1-dimethylethylene group, a 1,2-dimethylethylene group, a propylene group, a butylene group, a 1-methylpropylene group, a 2-methylpropylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, an undecylene group, a dodecylene group, etc.

[0084] The "alkyloxy group" in the present specification may be exemplified by an oxymethylene group, an oxyethylene group, an oxypropylene group, an oxy(1-methylmethylene) group, an oxy(1,1-dimethylmethylene) group, an oxy(1-methylethylene) group, an oxy(1,1-dimethylethylene) group, an oxy(1,2-dimethylethylene) group, an oxybutylene group, an oxy(1-methylpropylene) group, an oxy(2-methylpropylene) group, an oxypentylene group, an oxyhexylene group, an oxyheptylene group, an oxyoctylene group, an oxynonylene group, an oxydecylene group, an oxyundecylene group, an oxydodecylene group, etc.

[0085] The "hydrocarbon group" in the present specification is a monovalent group and includes a linear, branched, or cyclic saturated hydrocarbon, unsaturated hydrocarbon, or aromatic hydrocarbon group. For example, the "hydrocarbon group" is one group selected from the group consisting of an alkyl group (e.g., the above alkyl group), an alkenyl group (e.g., the above alkenyl group), an aryl group (e.g., the above aryl group), an aryloxy group (e.g., the above aryloxy group), an aralkyl group (e.g., the above aralkyl group), and an alkoxy group (e.g., the above alkoxy group), and may be substituted by -O-, -C(=O)-, or -S- such that one or more -CH2- in the group do not adjoin each other, or may be substituted by -CH=CH- such that one or more -CH2-CH2- in the alkyl group do not adjoin each other.

[0086] [Curable Composition]

[0087] The present disclosure is a curable composition containing a polyimide resin (A) and a compound (D) having a reactive double bond. Moreover, the polyimide resin (A) has a partial structure represented by the above general formula (1), a partial structure represented by the above general formula (T-1) that is chemically bonded to the partial structure represented by the general formula (1), and a partial structure represented by the above general formula (T-2) that is chemically bonded to the partial structure represented by the general formula (1).

[0088] Thereby, a curable composition that exhibits a low dielectric loss tangent and low hygroscopicity after curing can be provided.

[0089] The curable composition of the present disclosure must contain a polymaleimide resin (A) and a compound (D) having a reactive double bond. If necessary, it may contain one or more selected from the group consisting of an epoxy resin (E) described below, other resins (F), a curing agent (G) other than the compound (D) having a reactive double bond such as an amine compound, and additives.

[0090] Hereinafter, the polymaleimide resin (A), the compound (D) having a reactive double bond, the epoxy resin (E), other resins (F), the curing agent (G) other than the compound (D) having a reactive double bond, and the additives, which are the constituent components of the curable composition, will be described.

[0091] (Polymaleimide resin (A))

[0092] From the viewpoint of highly achieving low moisture absorption, low dielectric constant, and low dielectric loss tangent after curing, the curable composition of the present embodiment contains a polymaleimide resin (A). Moreover, the polymaleimide resin (A) of the present embodiment is a resin having a partial structure represented by the following general formula (1), a partial structure represented by the general formula (T-1) bonded to the partial structure represented by the general formula (1), and a partial structure represented by the general formula (T-2) bonded to the partial structure represented by the general formula (1).

[0093] [Chemical formula 11]

[0094]

[0095] [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, indicating that one bonding end is bonded at the position of L 13 or L 14 in the following general formula (T-1), and the other bonding end is bonded at the position of L 11 or L 12 in the following general formula (T-2).]

[0096] [Chemical formula 12]

[0097]

[0098] [In the above general formula (T-1) or (T-2), 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 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, 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). In addition, L 11 ~L 14 that do not form a chemical bond with the partial structure represented by the general formula (1) are hydrogen atoms, m 1 represents 2, and m 3 represents 2.]

[0099] Thus, the polyimide resin (A) has a small proportion of polar functional groups in its chemical structure. Therefore, the cured product containing the polyimide resin (A) can achieve both low hygroscopicity and low dielectric properties. In addition, since there is only one bonding site at the ortho and para positions of the benzene ring bonded with the maleimide group, a polyimide resin (A) with a linear chain elongation can be obtained. Therefore, the molecular weight is easily controlled, and high solubility in solvents can be exhibited.

[0100] As the mixing ratio (parts by mass) of the polyimide resin (A) and the compound (D) containing a reactive double bond as an unsaturated hydrocarbon compound having a reactive double bond, polyimide resin (A): compound (D) containing a reactive double bond having a reactive double bond is preferably 95:5 to 5:95, more preferably 90:10 to 10:90, and further preferably 88:12 to 12:88. 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.

[0101] In the above general formula (1), the two * each represent a bonding end. Moreover, one of the two bonding ends forms a chemical bond at the position of L 13 or L 14 in the above general formula (T-1). In addition, the other bonding end forms a chemical bond at the position of L 11 or L 12 in the above general formula (T-2). Therefore, the polyimide resin (A) of the present embodiment has a structural unit in which the partial structure represented by the general formula (T-1) and the partial structure represented by the general formula (T-2) are connected by the partial structure represented by the general formula (1), and at the para position or one ortho position of the maleimide group on the benzene ring in the general formula (T-1) and the general formula (T-2), the partial structure represented by the general formula (1) is chemically bonded.

[0102] It should be noted that in the above general formula (1), when n 1 is 2 or more, there are multiple Rs 13 which may be the same as each other or may be different. When m 2 is 2 or more, there are multiple Rs 13 which may be the same as each other or may be different.

[0103] In the above general formula (1), each R 13 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. Further, when m 2 is an integer of 2 or more, there are multiple Rs 13 which may be the same as each other or may be different. As the preferred R 13 in the general formula (1), it is 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.

[0104] It should be noted that the benzene ring bonded with R 13 in the general formula (1) may be the benzene ring of the compound (B) having a benzyl ether skeleton.

[0105] 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 bonded with R 13 in the general formula (1), when bonded through a methylene group at the 1-position and the 3-position, preferably Rs 13 are respectively bonded to the 4-position and the 6-position.

[0106] 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. This average number of repeating units can be calculated from the input ratio or NMR as shown in the Examples section described later.

[0107] 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 (1), more preferably contains 3 to 97% by mass, and further preferably contains 5 to 95% by mass.

[0108] In the above general formula (T-1), R 15Each 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 may be a hydrogen atom or a linear alkyl group having 1 to 6 carbon atoms. Since m 3 is 2, the two R 15 may be the same as each other or may be different.

[0109] In the above general formula (T-1), 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 may be a linear alkyl group having 1 to 6 carbon atoms.

[0110] In the ortho position (6-position) of the benzene ring in the above general formula (T-1) or the above general formula (T-2), by allowing the bonding site of the partial structure represented by the general formula (1), it has higher solubility in a solvent, and the cured product of the curable composition exhibits more excellent low dielectric loss tangent and high heat resistance. It should be noted that the benzene ring to which R 14 in the general formula (T-1) is bonded may be the benzene ring of the aromatic amine compound (A-a).

[0111] In the above general formula (T-1), L 13 or L 14 each independently represents a bonding end or a hydrogen atom. Among them, at at least one position of L 13 or L 14 , the partial structure represented by the general formula (1) is chemically bonded to the partial structure represented by the general formula (T-1). In addition, L 13 or L 14 that is not chemically bonded to 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 of L 13 and L 14 .

[0112] In the above general formula (T-2), 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 a 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.

[0113] In the above general formula (T-2), 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 a preferred R 12 , it represents a linear alkyl group having 1 to 6 carbon atoms.

[0114] It should be noted that the benzene ring bonded to R 12 in the general formula (T-2) can be the benzene ring of the aromatic amine compound (A-a).

[0115] In the above general formula (T-2), L 11 or L 12 each independently represents a bonding end or a hydrogen atom. Among them, at least one position of L 11 or L 12 is chemically bonded to the partial structure represented by the general formula (1) and the partial structure represented by the general formula (T-2). In addition, L 11 or L 12 that is not chemically bonded to 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) can also be chemically bonded to both L 11 and L 12 at these two positions.

[0116] 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 (T-1), more preferably contains 3 to 97% by mass, and further preferably contains 5 to 95% by mass.

[0117] 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 (T-2), more preferably contains 3 to 97% by mass, and further preferably contains 5 to 95% by mass.

[0118] The polyimide resin (A) of the present embodiment preferably uses the aromatic amine compound (A-a) (hereinafter, also simply referred to as the aromatic amine compound (A-a)) represented by the following general formula (a-1), the compound (B) having a benzyl ether skeleton, and maleic anhydride as the reaction raw materials (1).

[0119] [Chemical formula 13]

[0120]

[0121] [In the above general formula (a-1), R a1 and R a2each 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.]

[0122] In addition, the polyimide resin (A) of the present embodiment is preferably prepared from an intermediate amine compound (C) in which aromatic amine compounds (A-a) are linked to each other via a structural unit derived from a compound (B) having a benzylic ether skeleton and maleic anhydride as reaction raw materials (2). Further, the intermediate amine compound (C) is preferably a compound prepared from an aromatic amine compound (A-a) and a compound (B) having a benzylic ether skeleton as reaction raw materials (3).

[0123] In other words, the intermediate amine compound (C) 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 and a structural unit derived from a compound (B) having a benzylic ether skeleton are linked by a chemical bond. Moreover, 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 (C) is substituted with an N-substituted maleimide ring. It should be noted that the "amino group" in this 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.

[0124] Therefore, the "polyimide resin (A)" in the present embodiment and the "intermediate amine compound (C)" 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.

[0125] 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 called the structural unit of the aromatic amine compound (A-a). In addition, the structural unit derived from the compound (B) having a benzylic ether skeleton refers to a group in which -(CH2O)- other than the terminal group in the compound (B) having a benzylic ether skeleton is substituted with -(CH2)- and -(CH2O)-R b 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.

[0126] In this embodiment, since the aromatic amine compound (A-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 (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, low hygroscopicity, and low dielectric loss tangent when the curable composition is cured can be provided.

[0127] Hereinafter, after explaining the aromatic amine compound (A-a) represented by the general formula (a-1), the compound (B) having a benzyl ether skeleton, and maleic anhydride, which are the constituent components of the reaction raw material (1) of the polyimide resin (A), other preferred embodiments of the polyimide resin (A) and the manufacturing method of the polyimide resin (A) will be described.

[0128] - Aromatic amine compound (A-a) represented by the general formula (a-1)-

[0129] As shown in the following general formula (a-1), the aromatic amine compound (A-a) in this embodiment must have a structure in which an aromatic ring bonded to an amino group and a hydrocarbon group having 1 to 18 carbon atoms are bonded to one ortho position of the aromatic ring.

[0130] [Chemical formula 14]

[0131]

[0132] [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.]

[0133] In the aromatic amine compound (A-a) of this embodiment, as the hydrocarbon group (R 2 , R 3 ) that can be substituted for 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, and 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 (B) having a benzyl ether skeleton at each of the ortho and para positions of the aromatic ring.

[0134] In the above general formula (a-1), R 1represents 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.

[0135] 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.

[0136] 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.

[0137] In addition, by setting the number of hydrocarbon groups (such as alkyl groups) substituted on the aromatic ring of the aromatic amine compound (A-a) to 1 or more, it is easy to control the reaction site with the compound (B) having a benzyl ether skeleton described later. Therefore, it is easy to obtain a polyimide resin (A) having a specific chemical structure. As a result, the cured product of the polyimide resin (A) easily exhibits solvent solubility, low hygroscopicity, and excellent high-frequency electrical properties.

[0138] 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. As a result, the crystallinity derived from the maleimide group is easily destroyed and the solubility is improved.

[0139] 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 preferred embodiment 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.

[0140] Thereby, it is easy to control the ArS E reaction and molecular design using the cation-like reagent formed by the compound (B) having a benzyl ether skeleton described later. As a result, the cured product of the polyimide resin (A) easily exhibits 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 linear molecular elongation can be obtained.

[0141] As a specific example of the aromatic amine compound (A-a) of the present embodiment, 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) etc. can be used. 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 two or more kinds can be used in combination.

[0142] For example, in the case of a chemical structure in which a maleimide group is directly bonded to an unsubstituted benzene ring as in 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 the reason for poor solvent solubility. On the contrary, in the case of the present disclosure, for example, in the case of having an alkyl group (such as ethyl) as a substituent for the benzene ring as in 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, so the crystallinity is reduced and the solvent solubility is improved, which becomes a preferred mode. However, in the case where 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.

[0143] 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 two or more kinds can be used in combination.

[0144] - Compound (B) having a benzyl ether skeleton -

[0145] The compound (B) having a benzylic ether skeleton in the present embodiment may be a compound monomer or a mixture. When the compound (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 (b), more preferably a compound represented by the following formula (b-1), and further preferably a compound represented by the following formula (b-2).

[0146] On the other hand, when the compound (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 (b) and / or a compound having a partial structure represented by the following formula (b-1), but also a mixture in which the component having a partial structure represented by the following general formula (b-3) accounts for 95% by mass or more and 100% by mass or less of the whole.

[0147] The compound (B) having a benzylic ether skeleton in the present embodiment is preferably a compound having a benzylic ether skeleton represented by the following formula (b).

[0148] [Chemical formula 15]

[0149]

[0150] [In the above general formula (b), 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.]

[0151] The compound (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.

[0152] -Physical properties of the compound (B) having a benzylic ether skeleton-

[0153] The compound (B) having a benzylic ether skeleton in the present embodiment preferably has a benzylic ether skeleton represented by the above formula (b) and satisfies at least one of the following physical property values. Thereby, a resin that can exhibit more excellent solvent solubility, heat resistance, and dielectric properties can be synthesized.

[0154] In this embodiment, the upper limit of the number average molecular weight (Mn) of the compound (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 (B) having a benzylic ether skeleton is preferably 200 or more, more preferably 240 or more, and still more preferably 250 or more.

[0155] In this embodiment, the upper limit of the oxygen content rate of the compound (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 rate of the compound (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.

[0156] In this embodiment, the upper limit of the specific gravity of the compound (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 (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.

[0157] In this embodiment, the upper limit of the viscosity (75 °C) of the compound (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 (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.

[0158] In this embodiment, the upper limit of the indirect viscosity (20 °C, viscosity measured by diluting with toluene to 80% by weight of the resin component) of the compound (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 (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.

[0159] In this embodiment, the hydroxyl value of the compound (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).

[0160] -Preferred embodiments of the compound (B) having a benzylic ether skeleton-

[0161] As an example of the compound (B) having a benzylic ether skeleton which is a reaction raw material (1) of the polyimide resin (A) of the present disclosure, a compound having a structural unit represented by the following formula (b-1) is preferred.

[0162] [Chemical formula 16]

[0163]

[0164] [In the above general formula (b-1), 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 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 -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 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.]

[0165] R in the above general formula (b-1) 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 -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 -R b4 、-(OCH2) q1 -(CH2) q2 -R b4 and -(CH2) q3 -(OCH2) q1 -(CH2) q2 -R b4 chosen from the group 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 from 1 to 11, more preferably an integer from 1 to 6, still more preferably an integer from 1 to 3, and particularly preferably an integer from 1 to 2.

[0166] 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.

[0167] R in the above general formula (b-1) b2 and R b3 each independently can correspond to R in the general formula (1) 13 . Therefore, R in the above general formula (b-1) b2 and R b3 , similar to the general formula (1), each independently preferably represents 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. 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.

[0168] In the above general formula (b-1), 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 One selected from the group consisting of. In addition, each of p1 to p3 and q1 to q3 independently preferably 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.

[0169] In the above general formula (b-1), L 2 Each independently preferably 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 may 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 - One selected from the group consisting of. In addition, each of p1 to p3 and q1 to q3 independently preferably 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] 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.

[0171] Z in the above general formula (b-1) 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.

[0172] In the above general formula (b-1), 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.

[0173] As a preferred form of the compound (B) having a benzylic ether skeleton in the present embodiment, a compound having a structural unit represented by the following general formula (b-2) may be used.

[0174] [Chemical formula 17]

[0175]

[0176] [In the above general formula (b-2), 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 one of them has a -CH2O- group.]

[0177] In the above general formula (b-2), R b1 、R b2 and R b3 、L 1 、L 2 、Z 1 、k, and m b1 and m b2 The preferred forms are the same as those of the above general formula (b-1).

[0178] The compound (B) having a benzylic ether skeleton in the present embodiment can be used alone or in combination of two or more, and may also be a mixture containing two or more different compounds (B) having a benzylic ether skeleton.

[0179] It should be noted that in this specification, for the sake of convenience of description, a mixture containing two or more different compounds (B) having a benzylic ether skeleton in the term "compound (B) having a benzylic ether skeleton" is referred to as a mixture (B) having a benzylic ether skeleton. Therefore, the "compound (B) having a benzylic ether skeleton" includes not only the case of representing only one compound but also the mixture (B) having a benzylic ether skeleton.

[0180] In the mixture (B) having a benzylic ether skeleton of the present embodiment, the component having the partial structure represented by the following general formula (b-3) preferably accounts for 95% by mass or more and 100% by mass or less of the whole mixture (B) having a benzylic ether skeleton.

[0181] [Chemical formula 18]

[0182]

[0183] [In the above general formula (b-3), L 3 and L 4 are linking groups, each independently being one group selected from the group consisting of -CH2-, -CH2O-CH2-, -(CH2O)2-CH2-, and -(CH2O)3-CH2-, and * represents a bond to another atom. ]

[0184] In the mixture (B) having a benzylic ether skeleton of the present embodiment, the component having the partial structure represented by the above general formula (b-3) preferably accounts for 95% by mass or more and 100% by mass or less of the whole mixture (B) having a benzylic ether skeleton and satisfies the following requirement (I) or (II).

[0185] (I) The total number of the linking groups (L 3 and L 4 ) in each molecule of the component having the partial structure represented by the above general formula (b-3) is 1.1 or more and 2.4 or less.

[0186] (II) The number of the terminal groups bonded to the terminal of the molecule of the component having the partial structure represented by the above general formula (b-3) is 0.5 or more and 1.5 or less per 1 molecule.

[0187] In the present embodiment, as the linking groups (L 3 and L 4), one kind of group selected from the group consisting of -CH2-, -CH2O-CH2-, -(CH2O)2-CH2-, and -(CH2O)3-CH2- can be enumerated.

[0188] In the whole of the mixture (B) having a benzyl ether skeleton, the following linking groups (L 3 and L 4 The total number) of each molecule having the benzyl ether skeleton represented by the above general formula (b-3) is preferably the composition of the following (1) to (4).

[0189] (1) The number of the linking group "-CH2-" is preferably 0.65 or more and 1.4 or less.

[0190] (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.

[0191] (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.

[0192] (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.

[0193] In the mixture (B) having a benzyl ether skeleton of the present embodiment, it is preferable to have 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 terminals of the molecules constituting the partial structure represented by the above general formula (b-3).

[0194] Moreover, in the whole of the mixture (B) having a benzyl ether skeleton, it is preferable to have the benzyl ether skeleton represented by the above general formula (b-3) and the number of terminal groups of each molecule is 0.5 or more and 1.5 or less.

[0195] In the whole of the mixture (B) having a benzyl ether skeleton, the number of the following terminal groups of each molecule having a benzyl ether skeleton is preferably the composition of the following (5) to (10).

[0196] (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.

[0197] (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.

[0198] (7) The number of terminal groups “-(CH2O)2-CH3” is preferably 0.08 or more and 0.6 or less, and preferably 0.09 or more and 0.3 or less.

[0199] (8) The number of terminal groups “-(CH2O)3-CH3” preferably does not substantially contain, more preferably 0.3 or less, and further preferably 0.2 or less.

[0200] (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.

[0201] In the mixture (B) having a benzyl ether skeleton of the present embodiment, the chemical structure and number of the linking group, and the chemical structure and 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.

[0202] In the present embodiment, the compound (B) having a benzyl ether skeleton may be a synthetic product or a commercially available product. As the commercially available compound (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.

[0203] In the present embodiment, relative to the total amount (100% by mass) of the polyimide resin (A), the structural unit of the compound (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 above-mentioned compound (B) having a benzyl ether skeleton refers to the group represented by the above general formula (1).

[0204] -Maleic anhydride-

[0205] In the present embodiment, maleic anhydride 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.

[0206] <Preferred embodiment of polyimide resin (A)>

[0207] The polyimide resin (A) of the present embodiment is preferably a random copolymer represented by the following general formula (1A).

[0208] [Chemical formula 19]

[0209]

[0210] [In the above general formula (1A), R 14 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, and R 15 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, and m 3 each represents 2, and 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, n 1 represents the average number of repeating units, and R 11 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, and R 12 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, and m 1 each represents 2, and n 2 represents the average number of repeating units. The two * respectively represent bonding ends and are bonded to a hydrogen atom or a partial structure represented by the general formula (T-3). In addition, "ran" in the above general formula (1A) represents a random copolymer. Moreover, -CH2- in the above general formula (1A) is chemically bonded to a carbon atom at the ortho- or para-position with respect to the carbon atom in the benzene ring bonded to the maleimide group.]

[0211] [Chemical formula 20]

[0212]

[0213] [In the above general formula (T-3), 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 3 represents the average number of repeating units.]

[0214] By using a curable composition containing a polymaleimide resin (A) which is a random copolymer represented by the above general formula (1A) and a compound (D) having a reactive double bond, more excellent low dielectric characteristics and moisture absorption can be exhibited.

[0215] The polymaleimide resin (A) is represented by the above general formula (1A). In the polymaleimide resin (A) represented by the general formula (1A), preferably, 10% by mass or more of n 1 and the sum of n 3 is 1 or more (i.e., it satisfies n 1 and n 3Component of the polyimide resin (A) that satisfies the condition that the sum is 1 or more), more preferably contains 15% by mass or more, and still more preferably contains 20% by mass or more. Further, with respect to the entire polyimide resin (A), the n 1 and n 3 The upper limit of the component whose sum is 1 or more may be, for example, 100% by mass or less, 99.5% by mass or less, 99% by mass or less.

[0216] Further, from the viewpoint of heat resistance, in the polyimide resin (A) represented by the above general formula (1A), with respect to the entire polyimide resin (A), it is preferable to contain 5% by mass or more of n 2 is a component of 1 or more (= a component of the polyimide resin (A) that satisfies the condition that n 2 in the above general formula (1A) is 1 or more), more preferably contains 7% by mass or more, and still more preferably contains 10% by mass or more.

[0217] Further, with respect to the entire polyimide resin (A), the n 2 The upper limit of the component of 1 or more may be, for example, 100% by mass or less, 99.5% by mass or less, 99% by mass or less.

[0218] The present disclosure may be a polyamide resin that is a random copolymer represented by the above general formula (1A). By using the polyimide resin as a random copolymer represented by the above general formula (1A), a composition excellent in solvent solubility, low dielectric properties, and hygroscopicity can be provided.

[0219] <Physical properties of the polyimide resin (A)>

[0220] 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. Further, 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.

[0221] 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 1.05 to 2.0, and further preferably 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 high molecular weight components contributing to flexibility increases. 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.

[0222] 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 were measured under the measurement conditions described in the following examples using gel permeation chromatography (hereinafter simply referred to as "GPC").

[0223] <Manufacturing method of polyimide resin (A)>

[0224] Hereinafter, the manufacturing method of the polyimide resin (A) of the present disclosure will be described.

[0225] The production method of the polyimide resin (A) in this embodiment is not particularly limited, as long as it has the partial structure represented by the above general formula (1), the partial structure represented by the above general formula (T-1) that is chemically bonded to the partial structure represented by the above general formula (1), and the partial structure represented by the above general formula (T-2) that is chemically bonded to the partial structure represented by the above general formula (1), it can be produced in any manner. As a preferred mode of the manufacturing method of the polyimide resin (A) in this 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 (B) having a benzyl ether skeleton, and maleic anhydride as the reaction raw material (1).

[0226] [Chemical formula 21]

[0227]

[0228] [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.]

[0229] As a specific embodiment of the method for manufacturing the polyimide resin (A) of the present disclosure, for example, a manufacturing method including the following steps (1) and (2) can be cited.

[0230] Step (1): As the reaction raw material (2), a step of reacting the aromatic amine compound (A-a) represented by the above general formula (a-1) with a compound (B) having a benzyl ether skeleton to obtain the intermediate amine compound (C) in the present embodiment;

[0231] Step (2): As the reaction raw material (3), a step of reacting the intermediate amine compound (C) obtained in the above step (1) with maleic anhydride to obtain the polyimide resin (A) of the present disclosure.

[0232] Specifically, the method for manufacturing the polyimide resin (A) of the present embodiment preferably has: 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 a compound (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 (C) generated by the step (1) with maleic anhydride.

[0233] Hereinafter, each step of the method for manufacturing the polyimide resin (A) of the present disclosure will be described in turn.

[0234] <<Step (1): Manufacturing step of the intermediate amine compound (C)>>

[0235] Hereinafter, the manufacturing step of the intermediate amine compound (C) in the present embodiment will be described.

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

[0237] Regarding the mixing ratio of the aromatic amine compound (A-a) and the compound (B) having a benzyl ether skeleton, if the formability and physical property balance of curability of the obtained cured product are considered, the molar ratio of the compound (B) having a benzyl ether skeleton is preferably 0.001 to 1 mol, more preferably 0.1 to 0.5 mol, relative to 1 mol of the aromatic amine compound (A-a).

[0238] In addition, when using a mixture (B) such as the above-mentioned mixture having a benzylic ether skeleton as the compound (B) having a benzylic ether skeleton, the reaction point with the aromatic amine compound (A-a) can be the methoxymethylene group in the compound (B) having a benzylic ether skeleton contained in this mixture (for example, the benzylic ether moiety (Ph-CH2O-CH2-), the benzylic alcohol moiety (Ph-CH2O-H), or the methoxymethylene moiety (-CH2-O-)). In addition, when the total number of these respective reaction points is set to 1, the blending 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 respective reaction points, the blending 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: charging all the raw materials at once and directly carrying out the reaction at a specified temperature, or charging one of the aromatic amine compound (A-a) or the compound (B) having a benzylic ether skeleton and an acid catalyst, and while maintaining the specified temperature, adding dropwise the other of the aromatic amine compound (A-a) or the compound (B) having a benzylic ether skeleton while carrying out the reaction. 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 intermediate amine compound (C), and in the case of not using a solvent, the unreacted substances can be distilled off to obtain the intermediate amine compound (C) as the target product.

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

[0241] Examples of the inorganic acid include phosphoric acid, hydrochloric acid, sulfuric acid, nitric acid, boric acid, etc. Examples of the solid acid include activated clay, acid clay, alumina, silica alumina, zeolite, layered silicate, heteropolyacid, strongly acidic ion exchange resin, etc. 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 may also form a mixed layer. In addition, the above acid catalyst may be used alone or in combination of two or more kinds.

[0242] 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 as the catalyst. When using other acids, it is preferable to perform neutralization with an alkali and washing with water after the reaction.

[0243] It should be noted that the alkali is not particularly limited and 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, potassium tert-butoxide; trialkylamines such as triethylamine, ethyldiisopropylamine; aniline derivatives having an alkyl group with 1 to 4 carbon atoms such as N,N-dimethylaniline, N,N-diethylaniline; pyridine derivatives that may have an alkyl substituent with 1 to 4 carbon atoms such as pyridine, 2,6-dimethylpyridine; 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, lithium hydride; alkaline earth metal hydrides such as calcium hydride; alkali metal hydroxides such as sodium hydroxide, potassium hydroxide; carbonates or bicarbonates of alkali metals or alkaline earth metals such as sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate; halides of alkali metals or alkaline earth metals such as potassium fluoride, cesium fluoride, potassium iodide. These bases may be used alone or in combination of two or more kinds.

[0244] In the present embodiment, regarding the compounding amount of the acid catalyst, the acid catalyst is compounded in an amount 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 (B) having a benzylic ether skeleton and aromatic amine compound (A-a)) input. 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.

[0245] In the step (1) of the present embodiment, as the reaction time of the mixture of the compound (B) having a benzylic ether skeleton and the aromatic amine compound (A-a), that is, the crosslinking reaction time, starting from the fact that the reaction will not be completed in a short time, and on the other hand, if it is set for 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 above reaction temperature conditions.

[0246] In the method for producing the intermediate amine compound (C) 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 can also be used. For example, in the case of reacting Nikanol L as the compound (B) having a benzylic ether skeleton as a raw material, the following method can 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 above reaction temperature range.

[0247] The intermediate amine compound (C) obtained through the above step (1) preferably has a partial structure represented by the following general formula (1), a partial structure represented by the general formula (t-1) that is chemically bonded to the partial structure represented by the general formula (1), and a partial structure represented by the general formula (t-2) that is chemically bonded to the partial structure represented by the general formula (1).

[0248] [Chemical formula 22]

[0249]

[0250] [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, indicating that one bonding end is chemically bonded at the position of L 13 or L 14 in the following general formula (t-1), and the other bonding end is at the position of L 11 or L12 perform chemical bonding at the position

[0251] [Chemical formula 23]

[0252]

[0253] [In the above general formula (t-1) or (t-2), 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, and at the position of L 11 or L 12 perform chemical bonding with the partial structure represented by the general formula (1), and at the position of L 13 or L 14 perform chemical bonding with the partial structure represented by the general formula (1), 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.]

[0254] "R 13 , m 2 and n 1 " in the above general formula (1) has the same meaning as "R 13 , m 2 and n 1 " in the above general formula (1). In addition, "L 11 , L 12 , L 13 , R 11 , R 12 , R 14 , R 15 , m 1 and m 3 " in the general formulas (t-1) and (t-2) has the same meaning as "L 11 , L 12 , L 13 , R 11 , R 12 , R 14 , R 15 , m 1 and m 3 " in the general formulas (T-1) and (T-2).

[0255] In the present embodiment, the amine equivalent of the intermediate amine compound (C) is preferably 160 to 1200 g / equivalent, more preferably 180 to 600 g / equivalent. It should be noted that the measurement of the amine equivalent of the intermediate amine compound (C) in this specification is a value measured by a method based on the neutralization titration method specified in JIS K 0070 (1992).

[0256] <<Step (2): Maleimidation>>

[0257] Step (2) in the present embodiment is a step of reacting the intermediate amine compound (C) obtained in step (1) with maleic anhydride. The amino group of the intermediate amine compound (C) can form a chemical structure in which the amino group is substituted with an N-substituted maleimide ring through a maleimidation reaction, and thus the polyimide resin (A) of the present disclosure can be obtained.

[0258] In the present embodiment, the intermediate amine compound (C) having the partial structure represented by the above general formula (1), the partial structure represented by the general formula (t-1), and the partial structure represented by the general formula (t-2) obtained through step (1) is charged into a reactor, dissolved in an appropriate solvent, and then reacted with maleic anhydride in the presence of a catalyst. Then, after the reaction, unreacted maleic anhydride or other impurities are removed by washing with water or the like, and the solvent is removed under reduced pressure, whereby the target polyimide resin (A) can be obtained. Additionally, a dehydrating agent can be used during the reaction as needed.

[0259] Examples of the organic solvent used in step (2) of the present 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; and aromatic solvents such as benzene, toluene, and xylene. Additionally, they can be used alone or in combination.

[0260] In step (2) of the present embodiment, as the mixing ratio of the intermediate amine compound (C) and maleic anhydride, it is preferable to adjust the equivalent ratio of maleic anhydride to the amino equivalent of the intermediate amine compound (C) to be in the range of 1 to 5, more preferably to be charged in a ratio of 1 to 3. It is a preferred mode to conduct the reaction in an organic solvent with a mass ratio of 0.1 to 10, preferably 0.2 to 5, based on the total amount of the intermediate amine compound (C) and maleic anhydride.

[0261] 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.

[0262] 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, and porous ceramics such as molecular sieves. Acetic anhydride is preferably used.

[0263] There is no particular limitation on the usage amounts of the catalyst and dehydrating agent used in step (2) of this embodiment. Generally, relative to 1 equivalent of the amino group (-NH2) of the intermediate amine compound (C), 0.0001 to 1 mol, preferably 0.01 to 0.3 mol, of the catalyst can be used, and 1 to 3 mol, preferably 1 to 1.5 mol, of the dehydrating agent can be used.

[0264] In step (2) of this embodiment, as the reaction conditions for maleimidation, the above-mentioned intermediate amine compound (C) and maleic anhydride can be introduced, and after reacting 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, the catalyst is added, and the reaction is carried out in the temperature range of 90 to 130 °C, preferably 105 to 120 °C, for 1 to 24 hours, preferably 1 to 10 hours.

[0265] <Polymaleimide resin (A) mixture>

[0266] The polymaleimide resin (A) of this embodiment can be a mixture. For example, when using the aromatic amine compound (A-a) represented by the above general formula (a-1), the compound (B) having a benzyl ether skeleton, and maleic anhydride as the reaction raw material (1) as the polymaleimide resin (A), since there are multiple reaction points of the compound (B) having a benzyl ether skeleton with respect to the aromatic amine compound (A-a) represented by the above general formula (a-1), it can become a mixture in which the obtained intermediate amine compound (C) itself is mixed in various ways. Therefore, the polymaleimide resin (A) can also become a mixture of compounds having various chemical structures.

[0267] It should be noted that in this specification, the term "polymaleimide resin (A)" includes monomers and mixtures. On the other hand, only when the polymaleimide resin (A) represents only a mixture, it is called a polymaleimide resin (A) mixture.

[0268] The present disclosure relates to a polyimide resin (A) mixture containing a polyimide resin (A) component having a partial structural unit represented by the following general formula (1a) and a maleimide polycompound represented by the following general formula (2). Relative to the total amount of the polyimide resin (A) component, it contains 1 to 99% by mass of the polyimide resin (A). Relative to the total amount of the polyimide resin (A) mixture, it contains 80% by mass or less of the maleimide polycompound. The polyimide resin (A) has a partial structure represented by the above general formula (1), a partial structure represented by the above general formula (T-1) that is chemically bonded to the partial structure represented by the general formula (1), and a partial structure represented by the above general formula (T-2) that is chemically bonded to the partial structure represented by the general formula (1).

[0269] [Chemical formula 24]

[0270]

[0271] [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 an alkyl group having 1 to 18 carbon atoms, m 1 represents an integer of 0 or more and 2 or less, m 2 represents an integer of 0 or more and 4 or less, and n 1 represents the average number of repeating units.]

[0272] [Chemical formula 25]

[0273]

[0274] [In the above general formula (2), R 21 and R 25 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, R 22 and R 24 each independently represents 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.]

[0275] Accordingly, it exhibits high solubility in solvents, or low dielectric loss tangent and low moisture absorption in the cured product after curing. In addition, among the maleimide polycompounds represented by the general formula (2), the dimer with n 21 being 1 has high crystallinity, and as n 21Trimers and tetramers with a degree of polymerization of 2 or more show a tendency of improved solubility. It should be noted that by setting the substituents (R 11 or R 15 、R 12 or R 14 ) in the partial structure represented by the general formula (T-1) or the general formula (T-2) as in the present invention, the proportion of trimers and tetramers with excellent solubility can be increased.

[0276] "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 the general formula (T-1).

[0277] In addition, "R 21 and R 25 " in the general formula (2) independently has the same meaning as "R 11 or R 15 " in the general formula (T-1) and the general formula (T-2). "R 22 and R 24 " in the general formula (2) independently has the same meaning as "R 12 or R 14 " in the general formula (T-1) and the general formula (T-2).

[0278] Relative to the polyimide resin (A) mixture (100% by mass) of the present embodiment, it is preferably contained in an amount of 1% by mass or more and 80% by mass or less of the maleimide oligomer compound, more preferably 2% by mass or more and 79% by mass or less, and most preferably 3% by mass or more and 78% by mass or less. When the polyimide resin (A) increases, it is preferable from the viewpoints of low dielectric characteristics, low moisture absorption, and solvent solubility, and when the maleimide oligomer compound increases, it is preferable from the viewpoint of heat resistance.

[0279] In the polyimide resin (A) mixture of this embodiment, relative to the total amount of the polyimide resin (A) component, it preferably contains 10% to 99% by mass, more preferably 15% or more to 98% by mass, and still more preferably 20% to 97% by mass of a polyimide resin (A) having a partial structure represented by the above general formula (1), a partial structure represented by the following general formula (T-1) that is chemically bonded to the partial structure represented by the general formula (1), and a partial structure represented by the following general formula (T-2) that is chemically bonded to the partial structure represented by the general formula (1). And, relative to the total amount of the polyimide resin mixture (C), it preferably contains 5% to 80% by mass, more preferably 7% to 80% by mass, and still more preferably 10% or more to 80% by mass of the maleimide oligomer compound represented by the general formula (2).

[0280] As a preferred polyimide resin (A) mixture of this embodiment, it contains a polyimide resin represented by the general formula (1A) (wherein in the above general formula (1A), n1 is a polyimide resin of 1 or more) and the maleimide oligomer compound represented by the general formula (2). Relative to the polyimide resin (A) mixture, the content of the polyimide resin represented by the general formula (1A) (wherein in the general formula (1A), n1 is a polyimide resin of 1 or more) is preferably 10% to 99% by mass, more preferably 15% or more to 98% by mass, and still more preferably 20% to 97% by mass. Relative to the polyimide resin mixture (C), the content of the maleimide oligomer compound represented by the general formula (2) is preferably 5% to 80% by mass, more preferably 7% to 80% by mass, and still more preferably 10% or more to 80% by mass.

[0281] As another preferred polyimide resin (A) mixture of this embodiment, it is composed of the polyimide resin represented by the general formula (1A). The polyimide 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 (B) having a benzyl ether skeleton, and maleic anhydride as the reaction raw material (1). The reaction raw material (1) can be formulated with: preferably 5 to 98% by mass, more preferably 10 to 95% by mass, and still more preferably 15 to 90% by mass of the aromatic amine compound (A-a) represented by the above general formula (a-1); preferably 1 to 90% by mass, more preferably 2 to 85% by mass, and still more preferably 3 to 80% by mass of the compound (B) having a benzyl ether skeleton; and preferably 2 to 90% by mass, more preferably 3 to 85% by mass, and still more preferably 4 to 80% by mass of maleic anhydride.

[0282] (Compound (D) having a reactive double bond)

[0283] The curable composition of the present embodiment contains a compound (D) having a reactive double bond (also simply referred to as compound (D) having a reactive double bond). The compound (D) having a reactive double bond can exhibit a high crosslinking density by reacting a reactive double bond (such as an allyl group) with a maleimide group of the polymaleimide resin (A), and a cured product with a lower polarity can be obtained. Therefore, by using the curable composition containing the compound (D) having a reactive double bond, it can be used as a molding material for electronic materials and is thus useful. In addition, by reacting with the polymaleimide resin (A), it acts as a curing agent, can generate three-dimensional crosslinking, and a cured product having excellent heat resistance can be obtained, which is a preferred mode. Furthermore, in relation to the epoxy resin (E) as an optional component, it also acts as a curing agent, improving the adhesion to copper, and is useful, for example, in the manufacture of circuit boards using copper foil.

[0284] In the curable composition of the present embodiment, relative to the entire curable composition (100% by mass), it is preferably contains 10% by mass or more and 70% by mass or less of the compound (D) having a reactive double bond, more preferably contains 15% by mass or more and 65% by mass or less, and most preferably contains 20% by mass or more and 50% by mass or less. From the viewpoints of low dielectric properties and low moisture absorption, the content of the compound (D) having a reactive double bond is preferably in the range of 20% by mass or more and 50% by mass or less.

[0285] The compound (D) having a reactive double bond of the present embodiment is not particularly limited as long as it is a compound having a group containing two or more reactive double bonds (carbon-carbon unsaturated bonds) in the molecule. Examples of such reactive double bonds include allyl, isopropenyl, vinyl, 1-propenyl, acryloyl, methacryloyl, styryl, styrylmethyl, etc. Among these, from the aspect of showing good reactivity with the maleimide group of the polymaleimide resin (A), forming a cured product with a high crosslinking density and excellent heat resistance, allyl, vinyl, 1-propenyl, styryl, styrylmethyl, etc. are preferred.

[0286] In addition, as the compound (D) having a reactive double bond, it may further have a reactive functional group other than the group having a reactive double bond. The reactive functional group is not particularly limited, and examples thereof include a cyanate group (cyanate group), a hydroxyl group, an epoxy group, an active ester group, an amino group, an isocyanate group, a glycidyl group, and a phosphate group. Among them, at least one selected from the group consisting of a cyanate group (cyanate group), a hydroxyl group, an epoxy group, and an active ester group is preferred, and a cyanate group (cyanate group) is more preferred. By having a hydroxyl group, a cyanate group (cyanate group), an epoxy group, or an active ester group, it has a high flexural strength and flexural modulus of elasticity, a low dielectric constant, a high glass transition temperature (Tg), and a tendency of having a low coefficient of thermal expansion and a further increased thermal conductivity.

[0287] The compound (D) having a reactive double bond and having a reactive functional group other than the group having a reactive double bond may be used alone or in combination of two or more. When two or more compounds (D) having a reactive double bond and having a reactive functional group other than the group having a reactive double bond are used in combination, the reactive functional groups other than the reactive double bond may be the same or different. Among them, it is preferred to include the compound (D) having a reactive double bond with the reactive functional group being a cyanate group (cyanate group) and the compound (D) having a reactive double bond with the reactive functional group being an epoxy group. By using such compounds (D) having a reactive double bond in combination, there is a tendency for the flexural strength, flexural modulus of elasticity, glass transition temperature (Tg), and thermal conductivity to be further improved.

[0288] Examples of the compound (D) having a reactive double bond in the present embodiment include a bisphenol compound (B1) in which a hydrogen atom of an aromatic ring is substituted with an allyl group, a modified phenol compound (B2) in which a hydrogen atom of an aromatic ring is substituted with an allyl group and a phenolic hydroxyl group is modified with a reactive functional group other than a hydroxyl group among reactive functional groups, or a polyphenylene ether compound (B3) having a reactive double bond. More specifically, diallyl bisphenol A, a cyanate compound of diallyl bisphenol A, an epoxy compound of diallyl bisphenol A type, an allyl phenol terminal active ester compound, etc. can be mentioned.

[0289] The bisphenol structure in the bisphenol compound is not particularly limited, and examples thereof include bisphenol A, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol S, bisphenol P, bisphenol PH, bisphenol TMC, and bisphenol Z. Among them, bisphenol A is preferred.

[0290] The polyphenylene ether compound (B3) having a reactive double bond in the present embodiment is not particularly limited as long as it is a polyphenylene ether compound having a reactive double bond in its molecule. For example, it preferably has a structural unit selected from the group consisting of partial structures represented by the following general formula (3) and general formula (4), and a terminal structure containing a group having a reactive double bond bonded to the partial structure.

[0291] [Chemical formula 26]

[0292]

[0293] [Chemical formula 27]

[0294]

[0295] [In the above general formula (3) and (4), 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, or an alkylsulfonyl group having 1 to 5 carbon atoms. Y in the above general formula (4) represents a divalent aromatic hydrocarbon group derived from an aromatic compound having 2 phenolic hydroxyl groups, v is an integer value from 1 to 30, and w and u are integer values from 1 to 30.]

[0296] It should be noted that the partial structure represented by the above general formula (3) and / or general formula (4) has a group containing a reactive double bond in its terminal structure. Examples of the group containing a reactive double bond include an alkenyl group having 1 to 5 carbon atoms, a (meth)acryloyl group, a styryl group, a styrylmethyl group, etc.

[0297] The dielectric properties such as the dielectric constant or the dielectric loss tangent of the polyphenylene ether (PPE) contained in the structure of the polyphenylene ether compound (B3) having a reactive double bond in the present embodiment are excellent. Therefore, a curable composition capable of producing a cured product that maintains a sufficiently low dielectric constant even in a high-frequency band (high-frequency region) from the MHz band to the GHz band and exhibits a sufficiently low dielectric loss tangent 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), it acts as a curing agent, can generate three-dimensional crosslinking, and can obtain a cured product having excellent heat resistance, which is a preferred mode.

[0298] 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, a pentylthio group, etc.

[0299] The above-mentioned alkylcarbonyl groups having 2 to 5 carbon atoms are not particularly limited, and examples thereof include methylcarbonyl, ethylcarbonyl, propylcarbonyl, isopropylcarbonyl, butylcarbonyl, and the like.

[0300] The above-mentioned alkoxycarbonyl groups having 2 to 5 carbon atoms are not particularly limited, and examples thereof include methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, and the like.

[0301] The above-mentioned alkylcarbonyloxy groups having 2 to 5 carbon atoms are not particularly limited, and examples thereof include methylcarbonyloxy, ethylcarbonyloxy, propylcarbonyloxy, isopropylcarbonyloxy, butylcarbonyloxy, and the like.

[0302] The above-mentioned alkylsulfonyl groups having 1 to 5 carbon atoms are not particularly limited, and examples thereof include methylsulfonyl, ethylsulfonyl, propylsulfonyl, isopropylsulfonyl, butylsulfonyl, pentylsulfonyl, and the like.

[0303] R in the above general formulas (3) and (4) 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, or ethyl, and particularly preferably a hydrogen atom or methyl.

[0304] Y in the above general formula (4) may be exemplified by a divalent aromatic hydrocarbon group derived from an aromatic compound having two phenolic hydroxyl groups.

[0305] 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, tetramethylbisphenol A, and the like. Among them, hydroquinone, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 4,4'-biphenol, bisphenol A, bisphenol E, and bisphenol F are preferred, and 4,4'-biphenol, bisphenol A, and tetramethylbisphenol A are more preferred. In addition, since the two phenolic hydroxyl groups of the aromatic compound having two phenolic hydroxyl groups form a phenylene ether bond (the two oxygen atoms bonded to Y), Y becomes a divalent aromatic hydrocarbon 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-mentioned aromatic compound having two phenolic hydroxyl groups is used as the "divalent aromatic hydrocarbon group derived from an aromatic compound having two phenolic hydroxyl groups".

[0306] In addition, in the present embodiment, the weight-average molecular weight (Mw) of the polyphenylene ether compound (B3) having a reactive double bond is preferably 1000 to 5000, more preferably 1200 to 4000, and still more preferably 1400 to 3000. If it is within the above range, a cured product having an excellent balance between dielectric properties and heat resistance can be obtained more surely, which is a preferred mode. It should be noted that the weight-average molecular weight (Mw) here may be a value measured by a usual molecular weight measurement method. Specifically, the value measured by GPC described in the Examples section below can be cited.

[0307] (Curing agent (G) other than the compound (D) having a reactive double bond)

[0308] In the curable composition of the present embodiment, a curing agent (G) other than the compound (D) having a reactive double bond may be added within the range that does not impair the curing of the present invention. It should be noted that, relative to the entire curable composition (100% by mass), the curing agent (G) 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. When the content of the curing agent (G) is in the range of 5% by mass or more and 10% by mass or less, it is preferred from the viewpoints of low hygroscopicity and low dielectric loss tangent.

[0309] Examples of the curing agent (G) of the present embodiment include amine compounds, cyanate ester compounds, amide compounds, acid anhydride compounds, phenol compounds, polyphenylene ether compounds having a hydroxyl group at the terminal, diene polymers, and the like. These curing agents can be used alone or in combination of two or more.

[0310] Examples of the above amine compounds include diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, imidazole, BF3-amine complex, guanidine derivatives, and the like.

[0311] Examples of the above-mentioned cyanate ester compounds include bisphenol A cyanate ester resin, bisphenol F cyanate ester resin, bisphenol E cyanate ester resin, bisphenol S cyanate ester resin, bisphenol thioether cyanate ester resin, phenylene ether cyanate ester resin, naphthalene ether cyanate ester resin, biphenyl cyanate ester resin, tetramethylbiphenyl cyanate ester resin, polyhydroxynaphthalene cyanate ester resin, phenol novolac cyanate ester resin, cresol novolac cyanate ester resin, triphenylmethane cyanate ester resin, tetraphenylethane cyanate ester resin, dicyclopentadiene-phenol addition reaction type cyanate ester resin, phenol aralkyl cyanate ester resin, naphthol novolac cyanate ester resin, naphthol aralkyl cyanate ester resin, naphthol-phenol co-condensed novolac cyanate ester resin, naphthol-cresol co-condensed novolac cyanate ester resin, aromatic hydrocarbon formaldehyde resin-modified phenolic resin type cyanate ester resin, biphenyl-modified novolac cyanate ester resin, anthracene cyanate ester resin, etc. They can be used alone or in combination of two or more.

[0312] Examples of the above-mentioned amide compounds include dicyandiamide, polyamide resin synthesized from a dimer of linolenic acid and ethylenediamine, etc.

[0313] 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, etc.

[0314] Examples of the above-mentioned phenolic compounds include phenol novolac resin, cresol novolac resin, aromatic hydrocarbon formaldehyde resin-modified phenolic resin, dicyclopentadiene phenol addition resin, phenol aralkyl resin (ZYLOCK resin), polyphenol novolac resin synthesized from a polyhydroxy compound represented by resorcinol novolac resin and formaldehyde, naphthol aralkyl resin, trimethylolmethane resin, tetraphenylethane resin, naphthol novolac resin, naphthol-phenol co-condensed novolac resin, naphthol-cresol co-condensed novolac resin, biphenyl-modified phenolic resin (a polyphenol compound in which phenolic nuclei are linked by bis-methylene), biphenyl-modified naphthol resin (a polynaphthol compound in which phenolic nuclei are linked by bis-methylene), amino triazine-modified phenolic resin (a polyphenol compound in which phenolic nuclei are linked by melamine, benzoguanamine, etc.), aromatic ring-modified phenolic novolac resin containing an alkoxy group (a polyphenol compound in which a phenolic nucleus and an aromatic ring containing an alkoxy group are linked by formaldehyde), and other polyphenol compounds.

[0315] Examples of the above-mentioned polyphenylene ether compounds having a hydroxyl group at the terminal include a partial structure represented by the above general formula (3) or general formula (4), and a compound having a hydroxyl group as the terminal structure bonded to the partial structure.

[0316] As the above-mentioned diene polymer, for example, an unmodified diene polymer not modified with a polar group can be mentioned. 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.

[0317] As the above-mentioned 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.

[0318] (Epoxy resin (E))

[0319] The curable composition of the present embodiment preferably further contains an epoxy resin (E). The epoxy resin (E) makes the fluidity good when preparing the curable composition, and a curable composition capable of obtaining a cured product with excellent adhesion can be prepared, which is useful. In addition, when using the polyimide resin (A), the compound (D) containing a reactive double bond, and the epoxy resin (E) as the curable composition of the present embodiment, the adhesion to copper is improved, and for example, it is useful in the manufacture of circuit boards using copper foils.

[0320] The epoxy resin (E) of the present embodiment is not particularly limited, and examples thereof include novolak type epoxy resins such as phenol novolak type epoxy resin, cresol novolak type epoxy resin, α-naphthol novolak type epoxy resin, β-naphthol novolak type epoxy resin, bisphenol A novolak type epoxy resin, and biphenol novolak type epoxy resin; aralkyl type epoxy resins such as phenol aralkyl type epoxy resin, naphthol aralkyl type epoxy resin, and phenol biphenyl aralkyl type epoxy resin; bisphenol type epoxy resins such as bisphenol A type epoxy resin, bisphenol AP type epoxy resin, bisphenol AF type epoxy resin, bisphenol B type epoxy resin, bisphenol BP type epoxy resin, bisphenol C type epoxy resin, bisphenol E type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and tetrabromobisphenol A type epoxy resin; biphenyl type epoxy resins such as biphenyl type epoxy resin, tetramethylbiphenyl type epoxy resin, and epoxy resin having a biphenyl skeleton and a diglycidoxybenzene skeleton; naphthalene type epoxy resin; binaphthol type epoxy resin; binaphthalene type epoxy resin; dicyclopentadiene phenol type epoxy resin; glycidylamine type epoxy resins such as tetraglycidyl diaminodiphenylmethane type epoxy resin, triglycidyl p-aminophenol type epoxy resin, and glycidylamine type epoxy resin of diaminodiphenyl sulfone; diglycidyl ester type epoxy resins such as 2,6-naphthalenedicarboxylic acid diglycidyl ester type epoxy resin and glycidyl ester type epoxy resin of hexahydrophthalic anhydride; benzopyran type epoxy resins such as dibenzopyran, hexamethyldibenzopyran, and 7-phenylhexamethyldibenzopyran. They can be used alone respectively, or two or more of them can be used in combination.

[0321] Among these, from the aspect of obtaining a cured product with excellent heat resistance, phenol aralkyl type epoxy resins, biphenol novolak type epoxy resins, naphthol novolak type epoxy resins containing a naphthalene skeleton, naphthol aralkyl type epoxy resins, naphthol-phenol co-novolac type epoxy resins, naphthol-cresol co-novolac type epoxy resins, crystalline biphenyl type epoxy resins, tetramethylbiphenyl type epoxy resins, xanthene type epoxy resins, aromatic ring-modified novolak type epoxy resins containing an alkoxy group (a compound obtained by linking an aromatic ring containing a glycidyl group and an aromatic ring containing an alkoxy group with formaldehyde), etc. are particularly preferred.

[0322] When the curable composition of the present embodiment contains the epoxy resin (E), the epoxy resin (E) preferably contains 2% by mass or more and 30% by mass or less, and most preferably 5% by mass or more and 25% by mass or less, based on the total amount (100% by mass) of the curable composition. From the viewpoint of heat resistance, it is preferable that the content of the epoxy resin (E) is in the range of 5% by mass or more and 25% by mass or less.

[0323] The preferred curable composition of the present embodiment is characterized by containing a polyimide resin (A), a compound (D) having a reactive double bond, and an epoxy resin (E). The polyimide resin (A) has a chemical structure in which two or more maleimide groups are linked to an alkanediyl group having an aromatic ring, so that it has excellent solvent solubility, is easy to prepare the curable composition, has excellent workability, and has a small proportion of polar functional groups in the structure of the polyimide resin (A), so that a cured product with excellent dielectric properties can be obtained. In addition, the compound (D) having a reactive double bond that functions as a curing agent can contribute to the formation of a cured product with a high crosslink density by the reaction of the reactive double bond in the compound (D) having a reactive double bond with the maleimide group. Furthermore, the fluidity of the epoxy resin (E) during the preparation of the curable composition becomes good, and a cured product with excellent adhesion can be obtained. In addition, by reacting the compound (D) having a reactive double bond that functions as a curing agent with the polyimide resin (A) and the epoxy resin (E), three-dimensional crosslinking can be generated, and a cured product with excellent heat resistance can be obtained, which is a preferred mode. In addition, by the reaction of the compound (D) having a reactive double bond with the epoxy resin (E), the adhesion to copper is improved, and it becomes useful, for example, in the manufacture of circuit boards using copper foil.

[0324] As the compounding ratio (parts by mass) of the polymaleimide resin (A), the compound (D) having a reactive double bond, and the epoxy resin (E), the compounding amount of the polymaleimide resin (A): the total compounding amount of the compound (D) having a reactive double bond and the epoxy resin (E) is preferably 90:10 to 10:90, more preferably 80:20 to 20:80, still more preferably 65:35 to 35:65, and particularly preferably 55:45 to 45:55. By adjusting the compounding ratio to the above range, heat resistance, low dielectric constant, and low dielectric loss tangent can be achieved, which is therefore preferred.

[0325] In the curable composition of the present invention, the compounding ratio (parts by mass) of the compound (D) having a reactive double bond and the epoxy resin (E) is not particularly limited. From the viewpoint of obtaining good properties of the cured product, the compound (D) having a reactive double bond: the epoxy resin (E) is preferably 90:10 to 10:90, more preferably 80:20 to 20:80, still more preferably 65:35 to 35:65. By adjusting the compounding ratio to the above range, heat resistance, low dielectric constant, and low dielectric loss tangent can be achieved, which is therefore preferred.

[0326] (Other resin (F))

[0327] In addition, as long as it is within the range that does not impair the object of the present disclosure, other resins (F) may be contained in addition to the polymaleimide resin (A), the compound (D) having a reactive double bond, and the epoxy resin (E). As the other resin (F), bismaleimide compounds other than the above-mentioned polymaleimide resin (A), allyl ether compounds, allyl amine compounds, triallyl cyanurate, allylphenol compounds, vinyl-containing polyolefin compounds, etc., phenolic resins, active ester resins, polyphenylene ether resins, cyanate ester 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. may be appropriately compounded. With respect to 100% by mass of the total amount of the curable composition, the content of the other resin (F) 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 (F) is in the range of 5% by mass or more and 10% by mass or less, it is preferred from the viewpoints of heat resistance and compatibility.

[0328] (Additive)

[0329] The curable composition of the present embodiment may also appropriately use additives as needed. Examples of the additives include one or more selected from the group consisting of a curing accelerator, an inorganic filler, a flame retardant, a silane coupling agent, a mold release agent, a pigment, an emulsifier, and a solvent. 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, based on 100% by mass of the total amount of the curable composition.

[0330] <Curing accelerator>

[0331] The curable composition of the present embodiment may also appropriately use a curing accelerator as needed. As the curing accelerator, various curing accelerators can be used. For example, it is effective to add a polymerization initiator such as an organic peroxide or an azo compound, or a basic catalyst such as a phosphine compound or a tertiary amine. Specific examples of the curing accelerator include benzoyl peroxide, dicumyl peroxide, azobisisobutyronitrile, triphenylphosphine, TPP-MK, TPP-K, triethylamine, imidazole, etc. The curing accelerator can be used alone or in combination of two or more. As the blending amount of the curing accelerator in the present embodiment, it is preferably 0.05 to 5% by mass of the whole curable composition.

[0332] <Additives other than the curing accelerator>

[0333] Examples of the flame retardant include an inorganic phosphorus-based flame retardant, an organic phosphorus-based flame retardant, a halogen-based flame retardant, or a non-halogen-based flame retardant. In the curable composition of the present embodiment, within the range not impairing the object, in order to exhibit flame retardancy, it is more preferable to blend a non-halogen-based flame retardant substantially free of halogen atoms. Examples of the non-halogen-based flame retardant include a phosphorus-based flame retardant, a nitrogen-based flame retardant, an organosilicon-based flame retardant, an inorganic-based flame retardant, an organic metal salt-based flame retardant, etc., and they can be used alone or in combination.

[0334] 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 relative to the total amount of the curable composition. In addition, when the curable composition is used for applications such as conductive paste described in detail below, conductive fillers such as silver powder and copper powder can be used.

[0335] In addition, the above-mentioned silane coupling agent, the above-mentioned mold release agent, the above-mentioned pigment, the above-mentioned emulsifier, and the above-mentioned solvent are not particularly limited, and known substances can be used. In addition, as the above-mentioned solvent, the organic solvents described in this specification can be used.

[0336] 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 compound (D) having a reactive double bond 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 compound (D) having a reactive double bond 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.

[0337] 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 compound (D) having a reactive double bond, 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 compound (D) having a reactive double bond.

[0338] 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 compound (D) having a reactive double bond, the epoxy resin (E), and the additive is preferably 43% by mass, 45% by mass, 48% by mass, 50% by mass, or 53% 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 compound (D) having a reactive double bond.

[0339] When the curable composition of the present invention contains a compound having two or more cyanate ester groups (N≡C-O-), the content of the compound having two or more cyanate ester groups (N≡C-O-) is preferably less than 43% by mass, more preferably less than 10% by mass, more preferably less than 4% by mass, and even more preferably less than 0.5% by mass, relative to the total amount of the compound having two or more cyanate ester groups (N≡C-O-) and the polyimide resin (A).

[0340] As a more preferred embodiment of the curable composition of the present disclosure, when the curable composition contains a compound having one or more cyanate ester groups (N≡C-O-), the content of the compound having one or more cyanate ester groups (N≡C-O-) is preferably less than 15% by mass, more preferably less than 10% by mass, more preferably less than 4% by mass, and even more preferably less than 0.5% by mass, relative to the entire curable composition (100% by mass).

[0341] [Cured product]

[0342] The cured product of the present disclosure is preferably obtained from the 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-mentioned respective components (for example, curing agents, compounding agents), and can be easily formed into a cured product by the same method as the conventionally known methods. Examples of the cured product include molded cured products such as laminates, castings, adhesive layers, coating films, and films.

[0343] As the curing (thermal curing) reaction, it is easy to proceed even without a catalyst. However, in the case where a further rapid reaction is desired, it is effective to add polymerization initiators such as organic peroxides and azo compounds, phosphine compounds, and basic catalysts such as tertiary amines. For example, there are benzoyl peroxide, dicumyl peroxide, azobisisobutyronitrile, triphenylphosphine, triethylamine, imidazoles, etc. As the blending amount, it is preferably 0.05 to 5% by mass of the whole curable composition.

[0344] (Heat-resistant materials and electronic materials)

[0345] The cured product obtained from the curable composition of the present disclosure shows low hygroscopicity, and excellent heat resistance and dielectric properties. Therefore, it can be suitably used for heat-resistant members or electronic members. It is particularly suitable for prepregs, circuit boards, semiconductor encapsulants, semiconductor devices, laminated films, laminated substrates, adhesives using conductive pastes, resist materials, etc. In addition, it can also be suitably used as the matrix resin of fiber-reinforced resins, and is particularly suitable as a prepreg with high heat resistance. In addition, the polyimide resin (A) contained in the curable composition shows excellent solubility in various solvents, and thus 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, housing members for wind power generation, etc., but are not limited to these.

[0346] <Semiconductor encapsulant>

[0347] The present disclosure is a semiconductor encapsulant containing the curable composition of the present embodiment. The semiconductor encapsulant obtained by using the curable composition of the present embodiment improves hygroscopicity, low dielectric loss tangent or dimensional stability by using the curable composition of the present disclosure. Therefore, it has excellent processability, moldability, and reflow resistance in the manufacturing process, and becomes a preferred mode.

[0348] The curable composition of the present embodiment used in the semiconductor encapsulant may contain an inorganic filler. It should be noted that as the filling rate of the inorganic filler, with respect to 100 parts by mass of the curable composition of the present embodiment, the inorganic filler can be used, for example, in the range of 0.5 to 1200 parts by mass. In addition, as the inorganic filler, for example, there are barium sulfate, barium titanate, amorphous silica, crystalline silica, Noritake silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, alumina, aluminum hydroxide, silicon nitride, aluminum nitride, etc.

[0349] As a method for obtaining the semiconductor sealing material, methods such as further melting and mixing additives as optional components uniformly using an extruder, kneader, roll, etc. as needed in the curable composition of the present embodiment can be cited. In the case of being used as a high thermal conductivity semiconductor encapsulation material for power transistors and power ICs, high filling of crystalline silica, alumina, silicon nitride, etc. with a thermal conductivity higher than that of fused silica can be carried out, or fused silica, crystalline silica, alumina, silicon nitride, etc. can be used. Regarding the filling rate, relative to 100 parts by mass of the curable composition, it is preferably used in the range of 30 to 95 parts by mass of the inorganic filler. 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.

[0350] <Semiconductor device>

[0351] The present disclosure is a semiconductor device including a cured product of the semiconductor sealing material. Since the semiconductor device obtained by using the semiconductor sealing material obtained from the curable composition of the present embodiment uses the curable composition containing the polyimide resin (A) and the compound (D) having a reactive double bond of the present disclosure, it has a low viscosity and excellent fluidity, and furthermore, its hygroscopicity, thermoelastic modulus, or adhesiveness to metal materials is improved. Therefore, it has excellent processability, moldability, and reflow resistance in the manufacturing process, which is a preferred mode.

[0352] As a method for obtaining the semiconductor device, methods such as casting the semiconductor sealing material or using a transfer molding machine, injection molding machine, etc. for molding, and then heating and curing in the temperature range of room temperature (20 °C) to 250 °C can be cited.

[0353] <Prepreg>

[0354] The present disclosure is a prepreg having 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 blending an organic solvent described later and 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.), heating is carried out 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 in the prepreg becomes 20 to 60 mass%.

[0355] 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 halfway without completing it. Additionally, for example, the semi-cured product can have a curing degree of 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.

[0356] It should be noted that the curing degree of the semi-cured product can be calculated by the following formula by measuring the heat of curing during heating of the curable composition and the heat of curing of the semi-cured product using DSC.

[0357] Curing degree (%) = [1 - (heat of curing of semi-cured product / heat of curing of curable composition)] × 100

[0358] Examples of the organic solvent used in the production of the prepreg include methyl ethyl ketone, acetone, dimethylformamide, methyl isobutyl ketone, methoxypropanol, cyclohexanone, methyl cellosolve, ethyl diglycol acetate, propylene glycol monomethyl ether acetate, etc. Their selection and appropriate usage amounts can be appropriately selected according to the application. For example, when further manufacturing a printed circuit board from the prepreg as described below, it is preferable to use polar solvents with a boiling point of 160°C or lower such as methyl ethyl ketone, acetone, and dimethylformamide. Additionally, it is preferable to use them in a proportion such that the non-volatile component is 40 to 80% by mass.

[0359] <Circuit board>

[0360] The present disclosure relates to a circuit board which is a laminate of the prepreg and copper foil. As a method for obtaining a printed circuit board from the curable composition of the present embodiment, there can be mentioned a method of laminating the above prepreg by a conventional method, appropriately overlapping copper foil, and heating and pressing at 170 to 300°C for 10 minutes to 3 hours under a pressure of 1 to 10 MPa.

[0361] <Multilayer substrate>

[0362] As a method for obtaining a laminated substrate from the curable composition of the present embodiment, a method via the following steps 1 to 3 can be cited. In step 1, first, the curable composition appropriately blended with rubber, filler, etc. is applied to a circuit substrate having a circuit formed thereon by a spraying method, a curtain coating method, etc., and then cured. In step 2, if necessary, after opening a prescribed via hole portion or the like on the circuit substrate 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 carried out. In step 3, if necessary, the operations of steps 1 to 2 are sequentially repeated, and a resin insulating layer and a conductor layer of a prescribed circuit pattern are alternately laminated to form a laminated substrate. It should be noted that, in the above steps, the opening of the via hole portion can be carried out after forming the outermost resin insulating layer. In addition, the laminated substrate in the present embodiment can also be manufactured by heat-pressing a resin-coated copper foil obtained by semi-curing the composition on a copper foil at 170 to 300 °C onto a wiring substrate having a circuit formed thereon, thereby omitting the steps of forming a roughened surface and plating treatment.

[0363] <Laminated film>

[0364] The present disclosure is a laminated film containing the curable composition of the present embodiment. As a method for manufacturing the laminated film of the present embodiment, the following method can be cited: The above curable composition is applied to a support film (Y), dried, and a curable composition layer is formed on the support film (Y) to produce an adhesive film for a multilayer printed wiring board, thereby manufacturing it.

[0365] 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 substrate, it exhibits fluidity (resin flow) such that the resin can fill into the vias or through holes present in the circuit substrate. It is preferably formulated with the above components to exhibit such characteristics. It should be noted that in the obtained laminated film and circuit substrate (copper-clad laminate, etc.), in order not to cause a phenomenon in which different characteristic values are locally exhibited due to phase separation or the like, and to exhibit constant performance at any part, appearance uniformity is required.

[0366] Here, the diameter of the via 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 usually preferred that the resin can be filled within this range. It should be noted that when laminating both sides of the circuit substrate, it is preferably to fill about 1 / 2 of the via hole.

[0367] The method for manufacturing the above-mentioned adhesive film may specifically be as follows: After preparing the above-mentioned curable composition in a varnish form, coat the varnish-like composition on the surface of the support film (Y), and further dry the organic solvent by heating or blowing hot air, etc., to form a composition layer (X) formed 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, carbitols such as cellosolve and 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 such that the non-volatile component is 30 to 60% by mass.

[0368] The thickness of the formed composition layer (X) is usually preferably equal to or greater than the thickness of the conductor layer. Since the thickness of the conductor layer of the circuit board is usually in the range of 5 to 70 μm, the thickness of the resin composition layer preferably has a thickness of 10 to 100 μm.

[0369] 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.

[0370] 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 performing a matting treatment and a corona treatment on the support film and the protective film, a release treatment can also be performed.

[0371] The thickness of the support film is not particularly limited, and is usually 10 to 150 μm, and is preferably used in the range of 25 to 50 μm. In addition, the thickness of the protective film is preferably 1 to 40 μm.

[0372] 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, it is possible to prevent the adhesion of dust, etc. during the curing process. In the case of peeling off after curing, a release treatment is usually performed on the support film in advance.

[0373] It should be noted that a multilayer printed circuit board can be manufactured from the laminated film 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 by, for example, vacuum lamination in a manner of direct contact with the circuit board. The lamination method can be an intermittent type or a continuous type using a roller. Additionally, if necessary, the laminated film and the circuit board can be heated (preheated) as needed 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.

[0374] <Conductive paste>

[0375] As a method for obtaining a conductive paste from the curable composition of the present invention, for example, a method of dispersing conductive particles in the composition can be cited. The above conductive paste can be made into a paste resin composition for circuit connection or an anisotropic conductive adhesive depending on the type of conductive particles used.

[0376] Examples

[0377] The present invention will be specifically described through 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 (A) were measured as follows.

[0378] (1) Amine equivalent and maleimide group equivalent

[0379] The amine equivalent of the intermediate amine compound (C) was measured by the following measurement method.

[0380] Approximately 2.5 g of each of the above intermediate amine compounds (C) as a sample, 7.5 g of pyridine, 2.5 g of acetic anhydride, and 7.5 g of triphenylphosphine were accurately weighed in a 500 mL stoppered Erlenmeyer flask, then a condenser was installed and heated under reflux in an oil bath set at 120 °C for 150 minutes.

[0381] After cooling, 5.0 mL of distilled water, 100 mL of propylene glycol monomethyl ether, and 75 mL of tetrahydrofuran were added, and titration was performed by potentiometric titration using a 0.5 mol / L potassium hydroxide-ethanol solution. A blank test was performed in the same manner for correction.

[0382] Amine equivalent (g / equivalent) = (S × 2,000) / (Blank - A)

[0383] S: Amount of sample (g)

[0384] A: Consumption of 0.5 mol / L potassium hydroxide - ethanol solution (mL)

[0385] Blank: Consumption of 0.5 mol / L potassium hydroxide - ethanol solution in the blank test (mL)

[0386] 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 by the following formula.

[0387] Maleimide equivalent (g / equivalent) = amine equivalent + 80

[0388] (2) GPC measurement

[0389] Using the following measurement device and measurement conditions, the number average molecular weight (Mn), weight average molecular weight (Mw), and molecular weight distribution (Mw / Mn) of the polyimide resin (A) used in the examples and comparative examples are calculated.

[0390] "Measurement device"

[0391] "HLC - 8320GPC" manufactured by Tosoh Corporation

[0392] "Measurement conditions"

[0393] Column: Guard column "HXL - L" manufactured by Tosoh Corporation + "TSK - GEL G2000HXL" manufactured by Tosoh Corporation + "TSK - GEL G2000HXL" manufactured by Tosoh Corporation + "TSK - GEL G3000HXL" manufactured by Tosoh Corporation + "TSK - GEL G4000HXL" manufactured by Tosoh Corporation

[0394] Detector: RI (differential refractometer)

[0395] Data processing: "GPC workstation EcoSEC - WorkStation" manufactured by Tosoh Corporation

[0396] Measurement conditions: Column temperature 40 °C

[0397] Elution solvent: Tetrahydrofuran

[0398] Flow rate: 1.0 ml / min

[0399] Standard: According to the measurement manual of the "GPC workstation EcoSEC - WorkStation", the following monodisperse polystyrene with a known molecular weight is used.

[0400] (Using polystyrene)

[0401] "A-500" manufactured by Tosoh Corporation

[0402] "A-1000" manufactured by Tosoh Corporation

[0403] "A-2500" manufactured by Tosoh Corporation

[0404] "A-5000" manufactured by Tosoh Corporation

[0405] "F-1" manufactured by Tosoh Corporation

[0406] "F-2" manufactured by Tosoh Corporation

[0407] "F-4" manufactured by Tosoh Corporation

[0408] "F-10" manufactured by Tosoh Corporation

[0409] "F-20" manufactured by Tosoh Corporation

[0410] "F-40" manufactured by Tosoh Corporation

[0411] "F-80" manufactured by Tosoh Corporation

[0412] "F-128" manufactured by Tosoh Corporation

[0413] Sample: The substance obtained by filtering a tetrahydrofuran solution of the polyimide resin (A) obtained in the synthesis example at 1.0 mass% in terms of resin solid content through a microfilter (50 μl).

[0414] (3) 13 C-NMR measurement

[0415] Of the polyimide resin obtained in the synthesis example 13 The C-NMR spectrum was measured using the following measuring apparatus and measurement conditions.

[0416] · 13 C-NMR: "JNM-ECZ400S" manufactured by JEOL RESONANCE

[0417] Resonance frequency: 100 MHz

[0418] Number of accumulations: 4000 times

[0419] Solvent: Deuterochloroform

[0420] Sample concentration: 12 mass%

[0421] Relaxing agent: Chromium(III) acetylacetonate

[0422] (4) FD-MS measurement

[0423] The FD-MS spectrum of the polyimide resin obtained in the synthesis example was measured using the following measuring apparatus and measuring conditions.

[0424] · Measuring apparatus: JMS-T100GC AccuTOF

[0425] · Measuring conditions

[0426] Measuring range: m / z = 4.00 to 2000.00

[0427] Rate of change: 51.2 mA / min

[0428] Final current value: 45 mA

[0429] Cathode voltage: -10 kV

[0430] Recording interval: 0.07 sec

[0431] [Synthesis Example 1] Synthesis of polyimide resin (A-1)

[0432] (1) Synthesis of intermediate amine compound (c-1)

[0433] Into 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 (Nikanol L, manufactured by Fudow Co., Ltd.), 240 g of toluene, and 133.7 g of activated clay were charged, and the mixture was heated to 120 °C with stirring and held for 30 minutes. Then, the temperature was raised to 160 and held for 4 hours. After the holding was completed, the temperature was raised to 200 °C over 60 minutes and held for 15 hours. After the holding was completed, the mixture was diluted with 240 g of toluene, and the activated clay was filtered off. The filtrate was distilled under reduced pressure by heating to remove the solvent and excess 2,3-dimethylaniline, and an intermediate aromatic amine compound (c-1) (hereinafter referred to as intermediate amine compound (c-1)) (amine equivalent: 218 g / eq.) was obtained. The FD-MS spectrum of the obtained intermediate amine compound (c-1) is shown in Figure 1 , 13 The C-NMR spectrum is shown in Figure 2 .

[0434] (II) Maleimidation

[0435] Into 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 charged and stirred at room temperature. Then, a mixed solution of 120.0 g (1 equivalent) of intermediate amine compound (c-1) and 32.6 g of DMF was added dropwise over 1 hour, and then the reaction was carried out for 2 hours. 5.23 g of p-toluenesulfonic acid monohydrate was added to the reaction solution, and the reaction solution was heated. After cooling and separating the azeotropic water and toluene under reflux, it was heated to 115 °C, and after cooling and separating the azeotropic water and toluene under reflux, only toluene was returned to the system, and a dehydration reaction was carried out for 5 hours. After air-cooling to room temperature, concentration under reduced pressure was carried out, and the obtained brown solution was dissolved in 600 g of ethyl acetate, washed 3 times with 200 g of ion-exchanged water, washed 3 times with 150 g of 2% aqueous sodium bicarbonate solution, sodium sulfate was added and dried, and then concentration under reduced pressure was carried out. The obtained reactant was vacuum-dried at 80 °C for 4 hours to obtain a product containing polyimide resin (A-1). The GPC chart of this polyimide resin (A-1) is shown in Figure 3 , and the FD-MS spectrum is shown in Figure 4 , 13 , and the C-NMR spectrum is shown in Figure 5 .

[0436] Based on the results of GPC, etc., it was confirmed that the obtained polyimide resin (A-1) contains 20% by mass or more of the component represented by the above general formula (1A) and the sum of n 1 and n 3 is 1 or more, and in addition, contains 10% by mass or more of the component where n 2 is 1 or more.

[0437] For each peak of the FD-MS spectrum shown in Figure 4 , the repeat number in the polyimide resin (A-1) was confirmed. The correspondence between each peak and the repeat number [n in the general formula (1A) 1 and n 2 and the bonding object of * is shown in Table 1 below.

[0438] [Table 1]

[0439] MS NO <![CDATA[n 1 > <![CDATA[n 2 > *Bonding object 319.2 1 0 H 414.2 0 1 H 437.3 2 0 H 532.3 1 1 H 555.4 3 0 H 627.3 0 2 H 650.4 2 1 H 745.4 1 2 H 768.5 3 1 H 863.5 2 2 H 958.5 1 3 H 981.6 3 2 H 1076.6 2 3 H

[0440] [Examples 1 to 3 and Comparative Examples 1 to 33]

[0441] [Preparation of curable composition]

[0442] The polyimide resin (A-1) obtained in Synthesis Example 1, the maleimide compound for comparison (A-2) (“BMI-1000” manufactured by Daiwa Kasei Kogyo Co., Ltd., phenylmethane maleimide, formula (i)), the resin (D-1) as the compound (D) having a reactive double bond (“SA-9000” manufactured by SABIC, a polystyrene oxide modified with methacrylic acid at both ends), the resin (D-2) (“NE-V-1100” manufactured by DIC Corporation, a vinyl resin at both ends), and the resin (D-3) (“DABAP” manufactured by Daiwa Kasei Kogyo Co., Ltd., 2,2'-diallylbisphenol A), the resin (E-1) as the epoxy resin (E) (BPA type epoxy resin “850-S”, equivalent weight: 188 g / eq, manufactured by DIC Corporation), and DCPO as the curing catalyst (“PERCUMYL D” manufactured by NOF Corporation, Dicumyl Peroxide) were blended in the proportions shown in Table 1 below to prepare the curable compositions of Examples 1 to 3 and Comparative Examples 1 to 3.

[0443] [Chemical formula 28]

[0444]

[0445] <Production of cured product>

[0446] The curable composition was cured under the following conditions to obtain a cured product.

[0447] Curing conditions: Using a vacuum press, after heating and curing at 200 °C for 2 hours, then heating and curing at 250 °C for 2 hours. The plate thickness after molding was 1.3 mm.

[0448] For this cured product, the physical properties of the dielectric constant, dielectric loss tangent, and moisture absorption rate were evaluated by the following methods. The results are shown in Table 1.

[0449] <<Measurement of dielectric loss tangent>>

[0450] According to JIS-C-6481, using the network analyzer “E8362C” manufactured by Agilent Technologies, Inc., by the cavity resonance method, the dielectric constant (Dk) and dielectric loss tangent (Df) of the cured product, that is, the test piece, after being stored in a room at 23 °C and 50% humidity for 24 hours after being absolutely dried were measured at 1 GHz.

[0451] <<Measurement of moisture absorption rate>>

[0452] In this Example and Comparative Examples, as a method for evaluating low moisture absorption, the moisture absorption rate (%) was calculated and evaluated by the following method.

[0453] Using a pressure cooker testing machine, the cured product obtained above was cut into test pieces with dimensions of 5 mm × 55 mm × 1.3 mm and kept under the conditions of 85°C, 85% RH, and 1 atmospheric pressure for 50 hours. Then, the moisture absorption rate (%) was calculated using the following formula and evaluated.

[0454] 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

[0455] [Table 2]

[0456]

[0457] Based on the results shown in Table 2 above, by comparing the examples with the comparative examples, it was confirmed that by using the curable composition containing polyimide resin (A) and the compound (D) having a reactive double bond in the examples, low dielectric constant, low dielectric loss tangent, and low moisture absorption rate were achieved.

[0458] In addition, for the cured products obtained in Examples 1 to 3 and Comparative Examples 1 to 3 above, the dielectric constant (Dk) and dielectric loss tangent (Df) at 10 GHz were also measured in the same manner as the measurement at 1 GHz. The cured products obtained in Examples 1 to 3 showed lower dielectric constant (Dk) and dielectric loss tangent (Df) than the cured products of Comparative Examples 1 to 3.

[0459] Industrial applicability

[0460] According to the present disclosure, a curable composition and its cured product that highly balance low dielectric properties and low moisture absorption rate after curing can be provided.

Claims

1. A curable composition, characterized in that, containing a polyimide resin (A) and a compound (D) having a reactive double bond with a reactive double bond The polyimide resin (A) has a partial structure represented by the following general formula (1), a partial structure represented by the following general formula (T-1) bonded to the partial structure represented by the general formula (1), and a partial structure represented by the following general formula (T-2) 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, where one bonding end is chemically bonded at the position of L in the following general formula (T-1) 13 or L 14 , and the other bonding end is chemically bonded at the position of L in the following general formula (T-2) 11 or L 12 . [Chemical formula 2] In the above general formula (T-1) or (T-2), 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 in addition, L 11 to L 14 which 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 polyimide resin (A) uses an aromatic amine compound (A-a) represented by the following general formula (a-1), a compound (B) having a benzyl ether skeleton, and maleic anhydride as reaction raw materials (1). [Chemical formula 3] 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.

3. The curable composition according to claim 1, wherein, The polyimide resin (A) is a polyimide resin having a partial structure represented by the following general formula (1A). [Chemical formula 4] In the above general formula (1A), R 14 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, and R 15 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, and m 3 each represents 2, and 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, 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, and R 12 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, and m 1 each represents 2, and 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 bonding ends, which are bonded to a hydrogen atom or a partial structure represented by the general formula (T-3). [Chemical formula 5] In the above general formula (T-3), 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 a component in which the sum of the average number of repeating units n of the polyimide resin (A) represented by the general formula (1A) is 1 or more, in an amount of 10% by mass or more 1 and n 3 is 1 or more 5. A curable composition, characterized in that, containing a mixture of polyimide resin (A) and a compound (D) having a reactive double bond with a reactive double bond, the mixture of polyimide resin (A) containing a polyimide resin (A) component having a partial structural unit represented by the following general formula (1a) and a maleimide polycompound represented by the following general formula (2). The mixture of polyimide resin (A) contains 1 to 99% by mass of polyimide resin (A) relative to the total amount of the polyimide resin (A) component, and contains 80% by mass or less of the maleimide polycompound relative to the total amount of the mixture of polyimide resin (A). The polyimide resin (A) has a partial structure represented by the following general formula (1), a partial structure represented by the following general formula (T-1) bonded to the partial structure represented by the general formula (1), and a partial structure represented by the following general formula (T-2) 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 (2), 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 chemically bonded at the position of L in the following general formula (T-1) 13 or L 14 , and the other bonding end is chemically bonded at the position of L in the following general formula (T-2) 11 or L 12 . [Chemical formula 9] In the above general formula (T-1) or (T-2), 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. 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 represent 2.

6. The curable composition according to claim 5, wherein, The polyimide resin (A) uses an aromatic amine compound (A-a) represented by the following general formula (a-1), a compound (B) having a benzyl ether skeleton, and maleic anhydride 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, and R 1 represents a hydrocarbon group having 1 to 18 carbon atoms, and R 2 and R 3 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms.

7. The polyimide resin according to claim 3 represented by the general formula (1A).

8. A 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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