Polymaleimide resin, curable composition, cured product, prepreg, circuit board, build-up film, semiconductor sealant and semiconductor device

Abstract

To provide a polymaleimide resin having high solubility in a solvent and exhibiting a low dielectric loss tangent and high heat resistance when cured, a curable composition and a cured product thereof, a prepreg, a circuit board, a build-up film, a semiconductor sealant, and a semiconductor device.SOLUTION: A polymaleimide resin mixture contains a polymaleimide resin with a partial structural unit represented by the general formula (1a) and a maleimide multimer compound with a specific structure.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a polymaleimide resin, a curable composition, a cured product, a prepreg, a circuit board, a build-up film, a semiconductor encapsulant, and a semiconductor device. [Background technology]

[0002] Prepregs obtained by impregnating a thermosetting resin such as an epoxy resin or a BT (bismaleimide-triazine) resin into a glass cloth and drying it by heating, laminates obtained by heating and curing the prepregs, and multilayers obtained by combining the laminates and the prepregs and curing them by heating are widely used as circuit board materials for electronic devices. In particular, package substrates, which are a type of printed wiring board that serves as an interposer for mounting semiconductors, are becoming thinner and warping of the package substrate during mounting is becoming a problem, so that materials that exhibit high heat resistance are required to suppress warping of the package substrate during mounting. In addition, in recent years, signals have become faster and higher in frequency, 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 under such an environment. In particular, in recent years, in various electrical material applications, particularly in advanced material applications, there is a demand for improved performance, such as heat resistance and dielectric properties, and for materials and compositions that combine these.

[0003] In response to such demands, maleimide resins have attracted attention as materials that combine heat resistance and low dielectric properties. In particular, maleimide resins used in materials for printed circuit boards are required to have improved performance in terms of fine pattern processability, dimensional stability, heat resistance, or high-frequency electrical properties. For example, Patent Documents 1 and 2 disclose techniques in which a cured product of a curable resin composition using a novel maleimide resin exhibits heat resistance and a low dielectric constant. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-176190 A [Patent Document 2] JP 2020-176191 A Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, the higher the frequency, the greater the transmission loss, so there is a demand for reducing transmission loss in the high frequency range. However, the technologies of Patent Documents 1 and 2 only consider dielectric properties in the frequency bands (range of several hundred MHz to 3 GHz) that are already in use, and do not consider whether they are compatible with technology for fifth-generation mobile communication systems (5G) that use the so-called Sub6 frequency band. In addition, maleimide resins that exhibit heat resistance and low dielectric constant are also required to be easy to handle (workable) as thermosetting resins, and therefore are particularly required to have excellent solubility in major solvents. The maleimide resins of Patent Document 1 use unsubstituted aniline, so that the aromatic rings derived from the aniline have low electron density and tend to be less reactive with xylene-formaldehyde resins. In addition, the technology of Patent Document 1 uses unsubstituted aniline. Since the aniline aromatic ring has three reaction points at the ortho and para positions of the amino group, a three-dimensional bond-forming reaction tends to proceed, and molecular weight control tends to be difficult. Furthermore, maleimide resins in which three-dimensional bonds are formed tend to have large steric hindrance near the maleimide groups, and there is a concern that unreacted maleimide groups will remain in the curing reaction. In fact, the maleimide resins of Patent Document 1 that use unsubstituted aniline have insufficient heat resistance. In addition, since the aniline ring in the aromatic amine resin of Patent Document 2 has a structure in which the 2- and 6-positions are substituted with alkyl groups, methylene bis(2,6-dialkylaniline) is generated as a by-product during the production of the aromatic amine resin. Maleimides derived from methylene bis(2,6-dialkylaniline) tend to be low molecular weight and highly crystalline, which creates a new problem of reduced solubility in solvents. However, the technology of Patent Document 2 does not consider solubility in solvents at all. Therefore, the technical problem to be solved by the present disclosure is to provide a polymaleimide resin that has high solubility in solvents and exhibits a low dielectric tangent and high heat resistance when cured, a curable composition containing the polymaleimide resin and a cured product thereof, a prepreg, a circuit board, a build-up film, a semiconductor encapsulant, and a semiconductor device. [Means for solving the problem]

[0006] Means for Solving the Problems The present inventors have conducted intensive research to solve the above-mentioned problems, and as a result have found that by using a polymaleimide resin having a predetermined chemical structure, it is possible to obtain a polymaleimide resin that has high solubility in solvents and exhibits a low dielectric tangent and high heat resistance when cured, a curable composition containing the polymaleimide resin, and a cured product thereof, and have completed the following polymaleimide resin. The present disclosure relates to a polymaleimide resin having a partial structure represented by the following general formula (1), a partial structure represented by general formula (T-1) that is chemically bonded to the partial structure represented by general formula (1), and a partial structure represented by general formula (T-2) that is chemically bonded to the partial structure represented by general formula (1). [ka] (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 between 0 and 4, and n 1 represents the average number of repeating units, and two * represent bonds. One bond is L in the following general formula (T-1). 13 Or L 14 and the other bond is L in the following general formula (T-2): 11 Or L 12 It represents a chemical bond at the position.) [ka] (In the above general formula (T-1) or (T-2), R 11 and R 15each 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 ~L 14 each independently represents a bond or a hydrogen atom; L 11 Or L 12 is chemically bonded to the partial structure represented by general formula (1) at the position of L 13 Or L 14 and L which is not chemically bonded to the partial structure represented by general formula (1) at the position 11 ~L 14 is a hydrogen atom, m 1 and m 3 Each represents 2.) Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a polymaleimide resin that has high solubility in solvents and exhibits a low dielectric tangent and high heat resistance when cured, a curable composition containing the polymaleimide resin and a cured product thereof, a prepreg, a circuit board, a build-up film, a semiconductor encapsulant, and a semiconductor device. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 shows an FD-MS spectrum chart of the intermediate amine compound (c-1). [Diagram 2] FIG. 2 shows the 13C-NMR chart of the intermediate amine compound (c-1). [Diagram 3] FIG. 3 shows a GPC chart of the polymaleimide resin (A-1). [Figure 4] FIG. 4 shows an FD-MS spectrum chart of the polymaleimide resin (A-1). [Diagram 5] FIG. 5 shows the 13C-NMR chart of the polymaleimide resin (A-1). [Figure 6] FIG. 6 shows an FD-MS spectrum chart of the intermediate amine compound (c-2). [Figure 7] FIG. 7 shows the 13C-NMR chart of the intermediate amine compound (c-2). [Figure 8] FIG. 8 shows a GPC chart of the polymaleimide resin (A-2). [Figure 9] FIG. 9 shows an FD-MS spectrum chart of the polymaleimide resin (A-2). [Figure 10] FIG. 10 shows the 13C-NMR chart of the polymaleimide resin (A-2). [Figure 11] FIG. 11 shows an FD-MS spectrum chart of the comparative intermediate amine compound (c1). [Figure 12] FIG. 12 shows a 13C-NMR chart of the comparative intermediate amine compound (c1). [Figure 13] FIG. 13 shows a GPC chart of the comparative maleimide compound (1). [Figure 14] FIG. 14 shows an FD-MS spectrum chart of the comparative maleimide compound (1). [Figure 15] FIG. 15 shows a 13C-NMR chart of the comparative maleimide compound (1). [Figure 16] FIG. 16 shows an FD-MS spectrum chart of the comparative intermediate amine compound (c2). [Figure 17] FIG. 17 shows a 13C-NMR chart of the comparative intermediate amine compound (c2). [Figure 18] FIG. 18 shows an FD-MS spectrum chart of the comparative maleimide compound (2). [Figure 19] FIG. 19 shows a 13C-NMR chart of the comparative maleimide compound (2). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Below, an embodiment of the present invention (hereinafter referred to as the "present embodiment") will be described in detail, but the present disclosure is not limited to the description below and can be implemented in various modifications within the scope of its gist.

[0010] <Terminology> In this specification, the following terminology applies unless stated otherwise. In this specification, the term "reaction raw material" refers to a compound that is used to obtain a target compound by a chemical reaction such as synthesis or decomposition and that partially constitutes the chemical structure of the target compound, and excludes substances that play the role of chemical reaction auxiliaries such as solvents and catalysts. In particular, in this specification, the term "reaction raw material" refers to a precursor for obtaining a target polymaleimide resin or its precursor compound (e.g., an intermediate amine compound (C) in which aromatic amine compounds (A) are linked to each other via a structural unit derived from a compound (B) having a benzyl ether skeleton) by a chemical reaction. In this specification, the term "structural unit" refers to a unit of a chemical structure formed during a reaction or polymerization, in other words, a partial structure other than the structure of the chemical bonds involved in the reaction or polymerization in a product compound formed by a reaction or polymerization, i.e., a so-called residue. In the case of polymerization, it is also called a repeating unit. The "aromatic group" in this specification preferably has an aromatic ring having 3 to 30 carbon atoms, and more preferably has an aromatic ring having 4 to 26 carbon atoms. In addition, the "aromatic group" in this specification may have a hydrogen atom of the aromatic ring in the aromatic group substituted with a substituent, for example, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a halogen atom. In addition, the "aromatic group" includes heteroaromatic groups, and the -CH in the "aromatic group" may be substituted with a substituent such as an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a halogen atom. 2 - or -CH= may be substituted with -O-, -S- or -N= so that they are not adjacent to each other. Examples of the aromatic ring include a monocyclic aromatic ring, a condensed aromatic ring, and an aromatic ring of a ring assembly. Examples of the monocyclic aromatic ring include benzene, furan, pyrrole, thiophene, imidazole, pyrazole, oxazole, isoxazole, thiazole, isothiazole, pyridine, pyrimidine, pyridazine, pyrazine, and triazine. Examples of the condensed aromatic ring include naphthalene, anthracene, phenalene, phenanthrene, quinoline, isoquinoline, quinazoline, phthalazine, pteridine, coumarin, indole, benzimidazole, benzofuran, and acridine. Examples of the aromatic ring of a ring assembly include biphenyl, binaphthalene, bipyridine, bithiophene, phenylpyridine, phenylthiophene, terphenyl, diphenylthiophene, and quaterphenyl. In addition, a hydrogen atom of the aromatic ring in the aromatic group may be substituted with, for example, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a halogen atom. The monovalent aromatic group refers to a group in which one hydrogen atom has been removed from an "aromatic group." The "alkyl group" in this specification may be linear, branched, or cyclic, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a tert-pentyl group, a neopentyl group, a 1,2-dimethylpropyl group, an n-hexyl group, an isohexyl group, a (n-)heptyl group, a (n-)octyl group, a (n-)nonyl group, a (n-)decyl group, a (n-)undecyl group, a (n-)dodecyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group, a norbornyl group, and an adamantyl group. In the present specification, examples of a "cycloalkyl group" include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group, a norbornyl group, and an adamantyl group. As used herein, the term "alkylthio group" includes a methylthio group, an ethylthio group, a propylthio group, a butylthio group, an octylthio group, and a 2-ethylhexylthio group. In the present specification, the "alkenyl group" includes an ethynyl group, a 1-propynyl group, a 2-propynyl group, a 2-butynyl group, a pentynyl group, a hexynyl group, a vinyl group, an allyl group, an isopropenyl group, etc. In addition, the "alkenylene group" includes a divalent group obtained by removing any one hydrogen atom from the above-mentioned "alkenyl group". In the present specification, examples of the "alkoxy group" include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a 2-ethylhexyloxy group, an octyloxy group, and a nonyloxy group. In the present specification, examples of the "aryl group" include a phenyl group, a naphthyl group, a phenalenyl group, a phenanthrenyl group, an anthryl group, an azulenyl group, an indenyl group, an indanyl group, a tetralinyl group, etc. In addition, the "aryl group" may be such that a hydrogen atom of an aromatic ring in the aryl group is substituted with, for example, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a halogen atom. As used herein, examples of the "aralkyl group" include a benzyl group, a diphenylmethyl group, a biphenyl group, a naphthylmethyl group, etc. A hydrogen atom of an aromatic ring in the aralkyl group may be substituted with, for example, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a halogen atom. In the present specification, examples of the "aryloxy group" include a phenoxy group, a naphthyloxy group, an anthryloxy group, a phenanthryloxy group, and a pyrenyloxy group. As used herein, the term "arylthio group" includes arylthio groups such as a phenylthio group, a naphthylthio group, an anthrylthio group, a phenanthrylthio group, or a pyrenylthio group. As used herein, the term "halogen atom" includes, for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like. Examples of the "alkylene group" in this specification include 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, and a dodecylene group. As used herein, examples of an "alkyleneoxy group" include 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, and an oxydodecylene group. In the present specification, the term "hydrocarbon group" refers to a monovalent group, and includes linear, branched, or cyclic saturated hydrocarbons, unsaturated hydrocarbons, or aromatic groups. For example, the term "hydrocarbon group" refers to one type of group selected from the group consisting of an alkyl group (e.g., the alkyl group described above), an alkenyl group (e.g., the alkenyl group described above), an aryl group (e.g., the aryl group described above), an aryloxy group (e.g., the aryloxy group described above), an aralkyl group (e.g., the aralkyl group described above), and an alkoxy group (e.g., the alkoxy group described above), and the group contains one or more -CH 2 - may be replaced by -O-, -C(=O)- or -S- so as not to be adjacent to each other, or one or more -CH 2 -CH 2 - may be replaced with -CH=CH- so that they are not adjacent to each other.

[0011] <Polymaleimide resin> The polymaleimide resin according to the present embodiment is a polymaleimide resin having a partial structure represented by the following general formula (1), a partial structure represented by general formula (T-1) that is chemically bonded to the partial structure represented by general formula (1), and a partial structure represented by general formula (T-2) that is chemically bonded to the partial structure represented by general formula (1). [ka] (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 between 0 and 4, and n 1 represents the average number of repeating units, and two * represent bonds. One bond is L in the following general formula (T-1). 13 Or L 14 and the other bond is L in the following general formula (T-2): 11 Or L 12 It represents a chemical bond at the position.) [ka] (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 ~L 14 each independently represents a bond or a hydrogen atom, provided that L 11 Or L 12 is chemically bonded to the partial structure represented by general formula (1) at the position of L 13 Or L 14 and L which is not chemically bonded to the partial structure represented by general formula (1) at the position 11 ~L 14 is a hydrogen atom, m 1 represents 2, m 3 represents 2.) As a result, it has high solubility in solvents and exhibits a low dielectric tangent and high heat resistance when cured. The chemical structure of the polymaleimide resin of this embodiment has only one bonding site each at the ortho-position and para-position of the benzene ring to which the maleimide group is bonded, so that a polymaleimide resin in which the chain extends in a linear manner is obtained, making it easy to control the molecular weight and enabling the achievement of both heat resistance, low dielectric properties, and solvent solubility.

[0012] In the above general formula (1), two *'s each represent a bond. One of the two bonds is L in the above general formula (T-1). 13 Or L 14 The other bond is chemically bonded at the position of L in the above general formula (T-2). 11 Or L 12 Thus, the polymaleimide resin of this embodiment has a structural unit in which a partial structure represented by general formula (T-1) and a partial structure represented by general formula (T-2) are linked by a partial structure represented by general formula (1), and the partial structure represented by general formula (1) is chemically bonded at the para position or one ortho position relative to the maleimide group on the benzene ring in general formula (T-1) and general formula (T-2). In the above general formula (1), n 1 If is 2 or more, there are multiple R 13 may be the same or different. 2 If is 2 or more, there are multiple R 13 may be the same or different from each other.

[0013] In the above general formula (1), R 13 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, preferably a hydrocarbon group having 1 to 12 carbon atoms, and more preferably a hydrocarbon group having 1 to 6 carbon atoms. 2 If is an integer equal to or greater than 2, there are multiple R 13 may be the same or different. 13is preferably a linear alkyl group, and more preferably a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, tert-pentyl group, or neopentyl group. In addition, R in the general formula (1) 13 The benzene ring to which is bonded can be the benzene ring of a compound (B) having a benzyl ether skeleton.

[0014] In the above general formula (1), m 2 represents an integer of 0 to 4, preferably an integer of 2 or less, and more preferably 2. 13 In the benzene ring to which is bonded, when the 1st and 3rd positions are bonded by methylene groups, R 13 are preferably linked to each other. In the above general formula (1), n 1 represents the average number of repeating units, and from the viewpoint of the viscosity of the obtained polymaleimide resin, it is preferably from 0 to 50, preferably from 0 to 30, and preferably from 0 to 15. The average number of repeating units can be calculated from the charge ratio or NMR, as shown in the Examples section described later.

[0015] The polymaleimide resin in this embodiment preferably contains the partial structure represented by general formula (1) in an amount of 1 to 99 mass %, more preferably 3 to 97 mass %, and even more preferably 5 to 95 mass %, relative to the total amount (100 mass %) of the polymaleimide resin.

[0016] In the above general formula (T-1), R 15 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, preferably a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and more preferably a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. 15 can be a hydrogen atom or a linear alkyl group having 1 to 6 carbon atoms. 3 Since is 2, two R15 may be the same or different from each other. In the above general formula (T-1), R 14 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, preferably a hydrocarbon group having 1 to 12 carbon atoms, and more preferably a hydrocarbon group having 1 to 6 carbon atoms. 14 The alkyl group may be a linear alkyl group having 1 to 6 carbon atoms. By allowing a bonding site with the partial structure represented by general formula (1) at the ortho position (6-position) of the benzene ring of the above general formula (T-1) or the above general formula (T-2), the compound has higher solubility in solvents and exhibits excellent low dielectric tangent and high heat resistance when cured. 14 The benzene ring to which is bonded can be the benzene ring of the aromatic amine compound (A). In the above general formula (T-1), L 13 Or L 14 Each independently represents a bond or a hydrogen atom. 13 Or L 14 The partial structure represented by the general formula (1) and the partial structure represented by the general formula (T-1) are chemically bonded at at least one position of the general formula (1). 13 Or L 14 is a hydrogen atom. 13 and L 14 A partial structure represented by general formula (1) may be chemically bonded to each of the two positions.

[0017] 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 a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and more preferably a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. 11 can be a hydrogen atom or a linear alkyl group having 1 to 6 carbon atoms. 1 Since is 2, two R 11 may be the same or different from each other. In the above general formula (T-2), R12 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, preferably a hydrocarbon group having 1 to 12 carbon atoms, and more preferably a hydrocarbon group having 1 to 6 carbon atoms. 12 represents a linear alkyl group having 1 to 6 carbon atoms. In addition, R in the general formula (T-2) 12 The benzene ring to which is bonded can be the benzene ring of the aromatic amine compound (A). In the above general formula (T-2), L 11 Or L 12 Each independently represents a bond or a hydrogen atom. 11 Or L 12 The partial structure represented by general formula (1) and the partial structure represented by general formula (T-2) are chemically bonded at at least one position of the general formula (1). 11 Or L 12 is a hydrogen atom. 11 and L 12 A partial structure represented by general formula (1) may be chemically bonded to each of the two positions.

[0018] The polymaleimide resin in this embodiment preferably contains the partial structure represented by general formula (T-1) in an amount of 1 to 99 mass %, more preferably 3 to 97 mass %, and even more preferably 5 to 95 mass %, relative to the total amount (100 mass %) of the polymaleimide resin. The polymaleimide resin in this embodiment preferably contains the partial structure represented by general formula (T-2) in an amount of 1 to 99 mass %, more preferably 3 to 97 mass %, and even more preferably 5 to 95 mass %, relative to the total amount (100 mass %) of the polymaleimide resin.

[0019] The polymaleimide resin of the present embodiment is preferably prepared by using, as reaction raw materials (1), an aromatic amine compound (A) represented by the following general formula (a-1) (hereinafter, also simply referred to as aromatic amine compound (A)), a compound (B) having a benzyl ether skeleton, and maleic anhydride. [ka] (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.

[0020] The polymaleimide resin of the present embodiment preferably uses, as reaction raw materials (2), an intermediate amine compound (C) in which aromatic amine compounds (A) are linked to each other via a structural unit derived from a compound (B) having a benzyl ether skeleton, and maleic anhydride. Furthermore, the intermediate amine compound (C) is preferably a compound obtained by reacting, as reaction raw materials (3), an aromatic amine compound (A) and a compound (B) having a benzyl ether skeleton. In other words, the intermediate amine compound (C) in this embodiment preferably has a structural unit in which a structural unit of an aromatic amine compound (A) having an aromatic ring to which an amino group is bonded and a structural unit derived from a compound (B) having a benzyl ether skeleton are linked by a chemical bond. The polymaleimide resin in this embodiment has a structure in which the amino group bonded to the aromatic ring of the intermediate amine compound (C) is substituted with an N-substituted maleimide ring. In this specification, the term "amino group" refers to -NH 2 It also includes a substituted amino group in which the hydrogen atom is further substituted with an alkyl group having 1 to 6 carbon atoms. Therefore, the "polymaleimide resin" in this embodiment and the "intermediate amine compound (C)" which is the precursor of the "polymaleimide resin" are polymer compounds that differ in that the amino group bonded to the aromatic ring is replaced with an N-substituted maleimide ring. The structural unit of the aromatic amine compound (A) refers to a group obtained by removing at least one hydrogen atom from the aromatic ring of the aromatic amine compound (A). For example, when the aromatic amine compound (A) is represented by the general formula (a-1) described below, a group obtained by removing at least one hydrogen atom from the benzene ring of the general formula (a-1) is referred to as a structural unit of the aromatic amine compound (A). In addition, the structural unit derived from the compound (B) having a benzyl ether skeleton refers to a -(CH) other than the terminal group in the compound (B) having a benzyl ether skeleton. 2 O)- is -(CH 2 )- and directly attached to the benzene ring 2 O)-R b All of this -(CH 2 )-substituted groups. b represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms. In the present embodiment, since the aromatic amino compound (A) having an aromatic ring structure with a substituent at a specific position is used as the reaction raw material, it becomes easier to control the reaction site with the compound (B) having a benzyl ether skeleton described below, and therefore it becomes easier to obtain a linear polymaleimide resin having a homogeneous chemical structure. As a result, a polymaleimide resin can be provided that exhibits excellent solubility in solvents, high heat resistance during curing, and low dielectric tangent.

[0021] Below, we will explain the aromatic amine compound (A) represented by general formula (a-1), the compound (B) having a benzyl ether skeleton, and maleic anhydride, which are the components of the reaction raw material (1) of the polymaleimide resin, and then we will explain another preferred embodiment of the polymaleimide resin and a method for producing the polymaleimide resin.

[0022] -Aromatic amine compound (A) represented by general formula (a-1)- The aromatic amine compound (A) in the present embodiment, as represented by the following general formula (a-1), essentially has an aromatic ring to which an amino group is bonded and a structure in which a hydrocarbon group having 1 to 18 carbon atoms is bonded to one of the ortho positions of the aromatic ring. [ka] (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.

[0023] In the aromatic amine compound (A) of the present embodiment, a hydrocarbon group (R 2 ,R 3 ) includes linear, branched or cyclic hydrocarbon groups having 1 to 18 carbon atoms, preferably linear or branched hydrocarbon groups having 1 to 12 carbon atoms, more preferably linear or branched alkyl groups having 1 to 6 carbon atoms. As shown in the above general formula (a-1), it has a bonding site with the compound (B) having a benzyl ether skeleton at each of the ortho-position and para-position of the aromatic ring. In the above general formula (a-1), R 1 represents a hydrocarbon group having 1 to 18 carbon atoms, preferably a hydrocarbon group having 1 to 12 carbon atoms, and more preferably a hydrocarbon group having 1 to 6 carbon atoms. 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, and more preferably a hydrocarbon group having 1 to 6 carbon atoms. 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, and more preferably a hydrocarbon group having 1 to 6 carbon atoms.

[0024] Furthermore, by making the number of hydrocarbon groups (e.g., alkyl groups) substituted on the aromatic ring of the aromatic amine compound (A) 1 or more, it becomes easier to control the reaction site with the compound (B) having a benzyl ether skeleton described below, making it easier to obtain a polymaleimide resin having a specific chemical structure. As a result, the cured product of the polymaleimide resin is more likely to exhibit solvent solubility, heat resistance, and excellent high-frequency electrical properties. In particular, the aromatic amine compound (A) is provided with a substituent (R 1 ) is introduced, it is considered that after the amino group derived from the aromatic amine compound (A) is maleimidized, the dihedral angle between the plane of the aromatic ring of the aniline skeleton and the plane of the nitrogen-containing five-membered ring of the maleimide becomes large, which makes the crystallinity derived from the maleimide group more likely to collapse, thereby improving the solubility.

[0025] In this embodiment, it is preferable that, among the carbon atoms in the benzene ring constituting the aromatic amine compound (A), one or more carbon atoms having the largest HOMO electron density (Huckel coefficient) are unsubstituted (substituted with hydrogen atoms). Therefore, it is preferable that the aromatic amine compound (A) represented by the general formula (a-1) of this embodiment has any two of the 2-, 4-, and 6-positions substituted with hydrogen atoms. A particularly preferable form of the aromatic amine compound (A) represented by the general formula (a-1) of this embodiment is that the 2-position is substituted with an alkyl group, and the 4- and 6-positions are hydrogen atoms. This allows the catalysis of ArS by a cationoid reagent formed from a compound (B) having a benzyl ether skeleton, which will be described later. E This makes it easier to control the reaction and molecular design. As a result, the cured product of the polymaleimide resin is more likely to exhibit solvent solubility, heat resistance, and excellent high-frequency electrical properties. In particular, by substituting hydrogen atoms at the 4- and 6-positions of the benzene ring in general formula (a-1), a polymaleimide resin (or intermediate amine resin) with linearly extended molecules can be obtained.

[0026] Specific examples of the aromatic amine compound (A) of the present embodiment include, for example, o-toluidine, 2-ethylaniline, 2-propylaniline, 2-butylaniline, 2-cyclobutylaniline, 2-cyclopentylaniline, 2-cyclohexylaniline, dimethylaniline (2,3-xylidine, 2,4-xylidine, or 2,5-xylidine), diethylaniline (2,3-diethylaniline, 2,4-diethylaniline, or 2,5-diethylaniline), diisopropylaniline (2,3-diisopropylaniline, 2,4-diisopropylaniline, or can be used. Examples of the butyl include n-butyl, tert-butyl, and sec-butyl. The aromatic amine compound (A) in the present embodiment may be used alone or in combination of two or more thereof.

[0027] For example, in the case of a chemical structure in which a maleimide group is directly bonded to an unsubstituted benzene ring, such as N-phenylmaleimide, the benzene ring and the five-membered ring of the maleimide are stable in a state in which they are arranged on the same plane, so that they tend to stack, resulting in high crystallinity. This causes poor solvent solubility. In contrast, in the case of the present disclosure, for example, in the case of 2-ethylaniline, where an alkyl group (e.g., an ethyl group) is present as a substituent on the benzene ring, the benzene ring and the five-membered ring of the maleimide take a twisted conformation due to the steric hindrance of the ethyl group, making it difficult to stack, resulting in reduced crystallinity and improved solvent solubility, which is a preferred embodiment. However, if the steric hindrance is too large or depending on the substitution position of the alkyl group, there is a concern that the reactivity during synthesis of maleimide conversion may be inhibited, or the curability of the maleimide group may be deteriorated when a cured product is produced, so it is preferable to use, for example, an aromatic amine compound (A) having a hydrocarbon group having 1 to 6 carbon atoms. In this embodiment, the aromatic amine compound (A) represented by the above general formula (a-1) may be used alone or in combination of two or more kinds.

[0028] -Compound (B) having a benzyl ether skeleton- The compound (B) having a benzyl ether skeleton in this embodiment may be a single compound or a mixture. When the compound (B) having a benzyl ether skeleton in this embodiment is a single compound, it is preferably a compound having a partial structure represented by formula (b) described below, more preferably a compound represented by formula (b-1) described below, and even more preferably a compound represented by formula (b-2) described below. On the other hand, when the compound (B) having a benzyl ether skeleton in the present embodiment is a mixture, it is preferable that the mixture contains not only a compound having a partial structure represented by the following formula (b) and / or a compound having a benzyl ether skeleton represented by the following formula (b-1), but also a component having a partial structure represented by the following general formula (b-3) accounts for 95 mass% or more and 100 mass% or less of the total. The compound (B) having a benzyl ether skeleton in the present embodiment is preferably a compound having a benzyl ether skeleton represented by the following formula (b). [ka] (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 between 0 and 4, and j 1 and j 2 are each independently an integer of 0 to 4, 1 +j 2 ≧1, k 1 and k 2 are each independently 0 or 1, and * represents a bond to another atom.) The compound (B) having a benzyl ether skeleton in this embodiment is preferably a product obtained by reacting an alkylbenzene with formaldehyde in the presence of an acid catalyst.

[0029] --Physical properties of compound (B) having a benzyl ether skeleton-- The compound (B) having a benzyl ether skeleton in this embodiment preferably has a benzyl ether skeleton represented by the above formula (b) and satisfies at least one of the following physical properties, which allows synthesis of a resin that can exhibit better solvent solubility, heat resistance and dielectric properties. In the present embodiment, the upper limit of the number average molecular weight (Mn) of the compound (B) having a benzyl ether skeleton is preferably 1200 or less, more preferably 800 or less, and even more preferably 500 or less. The lower limit of the number average molecular weight (Mn) of the compound (B) having a benzyl ether skeleton is preferably 200 or more, more preferably 240 or more, and even more preferably 250 or more. In the present embodiment, the upper limit of the oxygen content of the compound (B) having a benzyl ether skeleton is preferably 15% by mass or less, more preferably 13% by mass or less, and even more preferably 12% by mass or less. The lower limit of the oxygen content of the compound (B) having a benzyl ether skeleton is preferably 4% by mass or more, more preferably 5% by mass or more, and even more preferably 7% by mass or more. In the present embodiment, the upper limit of the specific gravity of the compound (B) having a benzyl ether skeleton is preferably less than 1.2, more preferably less than 1.15, and even more preferably less than 1.10. The lower limit of the specific gravity of the compound (B) having a benzyl ether skeleton is preferably 1.0 or more, more preferably 1.01 or more, and even more preferably 1.02 or more. In the present embodiment, the upper limit of the viscosity (75°C) of the compound (B) having a benzyl ether skeleton is preferably 1500 mPa·s or less, more preferably 1000 mPa·s or less, and even more preferably 900 mPa·s or less. The lower limit of the viscosity (75°C) of the compound (B) having a benzyl ether skeleton is preferably 30 mPa·s or more, more preferably 50 mPa·s or more, and even more preferably 70 mPa·s or more. In the present embodiment, the upper limit of the indirect viscosity (20°C) of the compound (B) having a benzyl ether skeleton is preferably 1000 mPa·s or less, more preferably 800 mPa·s or less, and even more preferably 500 mPa·s or less. The lower limit of the indirect viscosity (20°C) of the compound (B) having a benzyl ether skeleton is preferably 10 mPa·s or more, more preferably 20 mPa·s or more, and even more preferably 30 mPa·s or more. The hydroxyl value of the compound (B) having a benzyl ether skeleton in this embodiment is preferably 16 to 50 (mgKOH / g), more preferably 18 to 40 (mgKOH / g), and further preferably 22 to 35 (mgKOH / g).

[0030] --Preferable form of the compound (B) having a benzyl ether skeleton-- An example of the compound (B) having a benzyl ether skeleton, which is the reaction raw material (1) for the polymaleimide resin of the present disclosure, is preferably a compound having a structural unit represented by the following formula (b-1). [ka] (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 -CH 2 - may be replaced by -O- or -C(=O)- so that they are not adjacent 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, 2 - may be replaced by -O- so that they are not adjacent to each other, L 2 represents a single bond or an alkylene group having 1 to 11 carbon atoms, and one or more -CH 2 - may be replaced by -O- or -(C=O)- so that they are not adjacent 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 between 0 and 20, m b1 and m b2 each independently represents an integer of 0 to 4, R b1 Or L 2 At least one of the following is -CH 2 O-group.

[0031] 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 a hydrogen atom or a hydrocarbon group having 1 to 9 carbon atoms, and one or more -CH 2- may be replaced by -O- so that they are not adjacent to each other. b1 is 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, -(CH 2 O) p1 -C(=O)-R b4 , -(CH 2 O) p1 -R b4 , -(CH 2 O) p1 -(CH 2 ) p2 -R b4 , -(CH 2 ) p3 -(CH 2 O) p1 -(CH 2 ) p2 -R b4 , -(OCH 2 ) q1 -R b4 , -(OCH 2 ) q1 -(CH 2 ) q2 -R b4 and -(CH 2 ) q3 -(OCH 2 ) q1 -(CH 2 ) q2 -R b4 Preferably, R is one selected from the group consisting of b4 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. In addition, p1 to p3 and q1 to q3 each independently preferably represent an integer of 1 to 11, more preferably an integer of 1 to 6, further preferably an integer of 1 to 3, and particularly preferably an integer of 1 or 2. Furthermore, R b1 Or L 2 At least one of the following is -CH 2 It is preferred that R b1 and L 2 Both -CH 2 It is more preferred that it has an O-group.

[0032] R in the above general formula (b-1) b2 and R b3 are each independently R in general formula (1). 13 Therefore, R in the above general formula (b-1) can correspond to b2 and R b3 As in 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, and further preferably an alkyl group having 1 to 6 carbon atoms. b1 is an integer equal to or greater than 2, R equal to or greater than 2 b2 may be the same or different groups. b2 is an integer equal to or greater than 2, R equal to or greater than 2 b3 may be the same as each other or may be different groups.

[0033] In the above general formula (b-1), L 1 each independently represents an alkylene group preferably having 1 to 11 carbon atoms, more preferably an alkylene group having 1 to 9 carbon atoms, 2 - may be replaced by -O- so that they are not adjacent to each other. 1 represents an alkylene group having 1 to 11 carbon atoms, an alkyleneoxy group having 1 to 11 carbon atoms, -(CH 2 O) p1 -C(=O)-R b4 , -(CH 2 O) p1 -R b4 , -(CH 2 O) p1 -(CH 2 ) p2 -, -(CH 2 ) p3 -(CH 2 O) p1 -(CH 2 ) p2 -, -(OCH 2 ) q1 -, -(OCH 2 ) q1 -(CH 2 ) q2 - and -(CH2 ) q3 -(OCH 2 ) q1 -(CH 2 ) q2 -, and -. In addition, p1 to p3 and q1 to q3 each independently preferably represent an integer of 1 to 11, more preferably an integer of 1 to 6, further preferably an integer of 1 to 3, and particularly preferably an integer of 1 to 2.

[0034] In the above general formula (b-1), L 2 each independently represents preferably a single bond or an alkylene group having 1 to 11 carbon atoms, more preferably a single bond or an alkylene group having 1 to 9 carbon atoms, 2 - may be replaced by -O- so that they are not adjacent to each other. 2 represents a single bond, an alkylene group having 1 to 11 carbon atoms, an alkyleneoxy group having 1 to 11 carbon atoms, -(CH 2 O) p1 -C(=O)-, -(CH 2 O) p1 -, -(CH 2 O) p1 -(CH 2 ) p2 -, -(CH 2 ) p3 -(CH 2 O) p1 -(CH 2 ) p2 -, -(OCH 2 ) q1 -, -(OCH 2 ) q1 -(CH 2 ) q2 - and -(CH 2 ) q3 -(OCH 2 ) q1 -(CH 2 ) q2-, and -. In addition, p1 to p3 and q1 to q3 each independently preferably represent an integer of 1 to 11, more preferably an integer of 1 to 6, further preferably an integer of 1 to 3, and particularly preferably an integer of 1 to 2. Furthermore, R b1 Or L 2 At least one of the following is -CH 2 It is preferred that R b1 and L 2 Both -CH 2 It is more preferred that it has an O-group.

[0035] Z in the above general formula (b-1) 1 preferably represents a hydrogen atom or an alkyl group having 1 to 11 carbon atoms, and more preferably represents a hydrogen atom or an alkyl group having 1 to 9 carbon atoms.

[0036] 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 further preferably an integer of 0 to 10. When k is 2 or more, a plurality of L 1 may be the same group or different groups.

[0037] A preferred embodiment of the compound (B) having a benzyl ether skeleton in this embodiment is a compound having a structural unit represented by the following general formula (b-2). [ka] (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 -CH 2 - may be replaced by -O- or -C(=O)- so that they are not adjacent to each other; R b2 and R b3 each independently represents an alkyl group having 1 to 18 carbon atoms, L 1each independently represents an alkylene group having 1 to 11 carbon atoms, 2 - may be replaced by -O- so that they are not adjacent to each other, L 2 represents a single bond or an alkylene group having 1 to 11 carbon atoms, and one or more -CH 2 - may be replaced by -O- or -(C=O)- so that they are not adjacent 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 between 0 and 20, m b1 and m b2 each independently represents an integer of 0 to 4, R b1 Or L 2 At least one of the following is -CH 2 O-group. 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 form of is the same as that of the above general formula (b-1).

[0038] In the present embodiment, the compound (B) having a benzyl ether skeleton may be used alone or in combination of two or more kinds, or may be a mixture containing two or more kinds of compounds (B) having different benzyl ether skeletons. For the sake of convenience, in this specification, the term "compound (B) having a benzyl ether skeleton" refers to a mixture containing two or more compounds (B) having different benzyl ether skeletons as a mixture (B) having a benzyl ether skeleton. Therefore, "compound (B) having a benzyl ether skeleton" does not only refer to one type of compound, but also includes a mixture (B) having a benzyl ether skeleton.

[0039] The mixture (B) having a benzyl ether skeleton of the present embodiment has a partial structure represented by the following general formula (b-3): [ka] (In the above general formula (b-3), L 3 and L 4 are linking groups, each independently being -CH 2 -, -CH 2 O-CH 2 -, -(CH 2 O) 2 -CH 2 - and -(CH 2 O) 3 -CH 2 -, where * represents a bond to another atom.) preferably accounts for 95% by mass or more and 100% by mass or less of the entire mixture (B) having a benzyl ether skeleton. In the mixture (B) having a benzyl ether skeleton of the present embodiment, the component having the partial structure represented by the above general formula (b-3) occupies 95% by mass or more and 100% by mass or less of the entire mixture (B) having a benzyl ether skeleton, and preferably satisfies the following requirement (I) or (II). (I) The number of linking groups per molecule constituting the component having the partial structure represented by the above general formula (b-3) (L 3 and L 4 The total number of cases (above) is between 1.1 and 2.4. (II) The number of terminal groups bonded to the terminals of the molecules constituting 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 molecule.

[0040] In this embodiment, the linking group (L 3 and L 4 ) is -CH 2 -, -CH 2 O-CH 2 -, -(CH 2 O) 2 -CH 2- and -(CH 2 O) 3 -CH 2 - is an integer of 1 to 5. An example of the group consisting of In the entire mixture (B) having a benzyl ether skeleton, the following linking group (L 3 and L 4 It is preferable that the number of the components (total number of the components) is any of the following compositions (1) to (4). (1) Linking group “-CH 2 The number of "-" is preferably 0.65 or greater and 1.4 or less. (2) Linking group “-CH 2 O-CH 2 The number of "-" is preferably 0.07 or more and 0.2 or less, and more preferably 0.08 or more and 0.14 or less. (3) Linking group “-(CH 2 O) 2 -CH 2 The number of "-" is preferably 0.10 or more and 0.8 or less, and more preferably 0.2 or more and 0.8 or less. In another embodiment, it is preferably more than 0.41 and 0.8 or less. (4) Linking group “-(CH 2 O) 3 -CH 2 The number of "-" is preferably 0.05 or more and 0.65 or less, more preferably 0.09 or more and 0.6 or less, and even more preferably 0.10 or more and 0.55 or less.

[0041] In the mixture (B) having a benzyl ether skeleton of this embodiment, -CH 2 -OH, -CH 2 O-CH 3 , -(CH 2 O) 2 -CH 3 , -(CH 2 O) 3 -CH 3 and -(CH 2It is preferable that the component having the partial structure represented by general formula (b-3) has one or more groups selected from the group consisting of —COH) as a terminal group bonded to the terminal of a molecule constituting the component. It is preferable that the entire mixture (B) having a benzyl ether skeleton has a benzyl ether skeleton represented by the above general formula (b-3) and has 0.5 or more and 1.5 or less terminal groups per molecule. In the entire mixture (B) having a benzyl ether skeleton, the number of the following terminal groups per molecule having a benzyl ether skeleton preferably satisfies the following compositions (5) to (10). (5) Terminal group “-CH 2 The number of "-OH" is preferably 0.17 or more and 0.4 or less, and more preferably 0.18 or more and 0.25 or less. (6) Terminal group “-CH 2 O-CH 3 The number is preferably 0.17 or more and 0.7 or less, and more preferably 0.18 or more and 0.44 or less. (7) Terminal group “-(CH 2 O) 2 -CH 3 The number " is preferably 0.08 or more and 0.6 or less, and more preferably 0.09 or more and 0.3 or less. (8) Terminal group “-(CH 2 O) 3 -CH 3 It is preferable that the number of "is substantially not included," is more preferable that it is 0.3 or less, and further preferable that it is 0.2 or less. (9) Terminal group “-(CH 2 The number of "O)--COH" is preferably 0 or more and 0.1 or less, and more preferably 0.01 or more and 0.1 or less. In the mixture (B) having a benzyl ether skeleton of this embodiment, the chemical structure and the number of linking groups, and the chemical structure and the number of terminal groups can be calculated from NMR as shown in the Examples section below, or the manufacturer's catalog can be referenced.

[0042] In this embodiment, the compound (B) having a benzyl ether skeleton may be a synthetic product or a commercially available product. A preferred example of the commercially available compound (B) having a benzyl ether skeleton is a xylene resin (trade name: Nikanol (Y-50, Y-100, Y-300, Y-1000, LLL, LL, L, or H)) manufactured by Fudow Co., Ltd. In the present embodiment, the structural unit of the compound (B) having a benzyl ether skeleton is preferably contained in an amount of 1 to 99 mass%, more preferably 5 to 95 mass%, relative to the total amount (100 mass%) of the polymaleimide resin. The structural unit of the compound (B) having a benzyl ether skeleton refers to a group represented by the above general formula (1).

[0043] -Maleic anhydride- In the present embodiment, maleic anhydride is an essential component of the reaction raw material (1) of the polymaleimide resin, and is used in the reaction of maleimidizing the amino group derived from the aromatic amine compound (A), as will be described later in the section on the production method of the polymaleimide resin.

[0044] <Physical properties of polymaleimide resin> The number average molecular weight (Mn) of the polymaleimide resin of the present disclosure is preferably in the range of 200 to 1500, and more preferably in the range of 300 to 800. In addition, the weight average molecular weight (Mw) of the polymaleimide resin is preferably in the range of 280 to 2000, and more preferably in the range of 330 to 1200. In view of excellent solvent solubility, heat resistance, and low dielectric tangent, the polymaleimide resin of the present disclosure preferably has a molecular weight distribution (weight average molecular weight (Mw) / number average molecular weight (Mn)) calculated from gel permeation chromatography (GPC) measurement in the range of 1.01 to 4.0, more preferably 1.05 to 2.0, and even more preferably 1.10 to 1.8. Note that, when the molecular weight distribution is wide and there are many high molecular weight components from the GPC chart obtained from the GPC measurement, the proportion of high molecular weight components that contribute to flexibility increases, and therefore, compared to cured products using conventional maleimides, a cured product with reduced brittleness and excellent flexibility and pliability can be obtained, which is a preferred embodiment. 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 polymaleimide resin of the present embodiment were measured using gel permeation chromatography (hereinafter abbreviated as "GPC") under the measurement conditions described in the examples described later.

[0045] <Method of producing polymaleimide resin> Hereinafter, a method for producing the polymaleimide resin of the present disclosure will be described. The polymaleimide resin of this embodiment may be produced in any manner as long as it has a partial structure represented by the 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). As a preferred embodiment of the method for producing a polymaleimide resin of this embodiment, it is preferable to use an aromatic amine compound (A) represented by the following general formula (a-1) (hereinafter also simply referred to as aromatic amine compound (A)), a compound (B) having a benzyl ether skeleton, and maleic anhydride as reaction raw materials (1). [ka] (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.

[0046] A specific embodiment of the method for producing a polymaleimide resin according to the present disclosure includes, for example, a production method including the following steps (1) and (2). Step (1): A step of reacting an aromatic amine compound (A) represented by the above general formula (a-1) with a compound (B) having a benzyl ether skeleton, as a reaction raw material (2), to obtain an intermediate amine compound (C) of the present embodiment; Step (2): A step of reacting the intermediate amine compound (C) obtained in the above step (1) with maleic anhydride as the reaction raw material (3) to obtain the polymaleimide resin of the present disclosure. Specifically, the method for producing a polymaleimide resin of the present embodiment preferably comprises a step (1) (also referred to as a crosslinking step) of reacting an aromatic amine compound (A) represented by the above general formula (a-1) with a compound (B) having a benzyl ether skeleton in the presence of a solid acid catalyst, and a step (2) (also referred to as a condensation step) of condensing an intermediate amine compound (C) produced in the step (1) with maleic anhydride.

[0047] Each step of the method for producing the polymaleimide resin of the present disclosure will be described in order below. <<Step (1): Production process of intermediate amine compound (C)>> The process for producing the intermediate amine compound (C) in this embodiment will be described below. The step (1) in this embodiment is not particularly limited, but may be, for example, a step of reacting the above-mentioned aromatic amine compound (A), the above-mentioned compound (B) having a benzyl ether skeleton (e.g., nicanol, etc.), and other compounds added as necessary, in the presence of an acid catalyst, thereby producing an intermediate amine compound (C).

[0048] With regard to the blending ratio of the aromatic amine compound (A) and the compound having a benzyl ether skeleton (B), in consideration of the balance of physical properties such as moldability during production of the resulting cured product and curability, the molar ratio of the compound having a benzyl ether skeleton (B) to 1 mole of the aromatic amine compound (A) is preferably 0.001 to 1 mole, and more preferably 0.1 to 0.5 moles. In addition, when a mixture such as the above-mentioned mixture (B) having a benzyl ether skeleton is used as the compound (B) having a benzyl ether skeleton, the reaction site with the aromatic amine compound (A) is a methyleneoxy moiety (for example, a benzyl ether moiety (Ph-CH 2 O-CH 2 -), benzyl alcohol part (Ph-CH 2 OH) or methyleneoxy part (-CH 2 In addition, when the total number of these reaction sites is 1, the amount of the aromatic amine compound (A) is preferably equal to or more than 10 times, and for example, the amount of the aromatic amine compound (A) is preferably 1 to 10 moles per mole of the total number of the reaction sites.

[0049] In addition, as a specific method for carrying out the above reaction, all the raw materials are charged at once and reacted at a predetermined temperature as it is, or one of the aromatic amine compound (A) or the compound (B) having a benzyl ether skeleton and an acid catalyst are charged and reacted while keeping at a predetermined temperature and dropping the other of the aromatic amine compound (A) or the compound (B) having a benzyl ether skeleton. In this case, the dropping time is usually 0.1 to 12 hours, preferably 6 hours or less. After the reaction, if a solvent is used, the solvent and unreacted matter can be distilled off as necessary to obtain the intermediate amine compound (C), and if no solvent is used, the intermediate amine compound (C) can be obtained by distilling off the unreacted matter.

[0050] The acid catalyst used in step (1) of this embodiment can be any of organic acids, inorganic acids, and solid acids. Examples of the organic acid include aliphatic sulfonic acids such as methanesulfonic acid or fluoromethanesulfonic acid; aromatic sulfonic acids such as 3-morpholinopropanesulfonic acid, piperazine-1,4-bis(2-ethanesulfonic acid), 10-camphorsulfonic acid, 4-chlorobenzenesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, or trifluoromethanesulfonic acid; alkyl phosphoric acids such as dimethyl phosphate or diethyl phosphate; alkyl sulfuric acids such as dimethyl sulfate, diethyl sulfate, or lauryl sulfate; aromatic sulfuric acids such as phenyl sulfate or phenyl fluoride sulfate; and oxalic acid. Examples of the inorganic acid include phosphoric acid, hydrochloric acid, sulfuric acid, nitric acid, and boric acid. Examples of the solid acid include activated clay, acid clay, alumina, silica alumina, zeolite, layered silicate, heteropolyhydrochloric acid, and strong acid ion exchange resin. Examples of the layered silicate include kaolin group such as dickite, nacrite, kaolinite, anoxite, metahalloysite, and halloysite, serpentine group such as chrysotile, lizardite, and antigorite, smectite group such as montmorillonite, sauconite, beidellite, nontronite, saponite, taeniolite, hectorite, and stevensite, vermiculite group such as vermiculite, mica group such as mica, illite, sericite, and glauconite, attapulgite, sepiolite, palygorskite, bentonite, pyrophyllite, talc, and chlorite. These layered silicates may form a mixed layer. The above acid catalysts may be used alone or in combination of two or more. A solid acid that allows easy removal of the catalyst by filtration after the reaction in the above step (1) is preferred from the viewpoint of handling. When other acids are used, it is preferable to neutralize the acid with a base and wash the acid with water after the reaction. The base is not particularly limited and may be an organic base or an inorganic salt. Examples of the organic base include alkali metal alkoxides such as sodium methoxide, lithium methoxide, sodium ethoxide, lithium ethoxide, sodium tertiary butoxide, and potassium tertiary butoxide; trialkylamines such as triethylamine and ethyldiisopropylamine; aniline derivatives having an alkyl group with 1 to 4 carbon atoms such as N,N-dimethylaniline and N,N-diethylaniline; pyridine derivatives that may have an alkyl substituent with 1 to 4 carbon atoms such as pyridine and 2,6-lutidine; and nitrogen-containing heterocyclic compounds such as 1,8-diazabicyclo[5.4.0]-7-undecene. On the other hand, examples of the inorganic base include alkali metal hydrides such as sodium hydride and lithium hydride, alkaline earth metal hydrides such as calcium hydride, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal or alkaline earth metal carbonates or hydrogen carbonates such as sodium carbonate, potassium carbonate, sodium hydrogen carbonate and potassium hydrogen carbonate, and alkali metal or alkaline earth metal halide compounds such as potassium fluoride, cesium fluoride and potassium iodide. These bases may be used alone or in combination of two or more.

[0051] In this embodiment, the amount of the acid catalyst is within a range of 0.1 to 50 parts by mass relative to 100 parts by mass of the total amount of the raw materials (the compound (B) having a benzyl ether skeleton and the aromatic amine compound (A)) to be charged, but from the viewpoint of ease of handling and economic efficiency, a range of 1 to 20 parts by mass is preferable. The reaction temperature is usually within a range of 100 to 300°C, but a range of 120 to 250°C is preferable in order to suppress the formation of isomeric structures and to avoid side reactions such as thermal decomposition.

[0052] In step (1) of the present embodiment, the reaction time of the mixture of the compound (B) having a benzyl ether skeleton and the aromatic amine compound (A), i.e., the time of the crosslinking reaction, is usually in the range of 1 to 60 hours in total under the above reaction temperature conditions, and preferably in the range of 1 to 20 hours in total, since the reaction does not proceed completely in a short time and side reactions such as thermal decomposition of the product occur in a long time. In the method for producing the intermediate amine compound (C) in this embodiment, since the aromatic amine compound (A) or a derivative thereof also serves as a solvent, other solvents are not necessarily used, but it is possible to use a solvent. For example, when reacting Nikanol L as the compound (B) having a benzyl ether skeleton as a raw material, a method may be adopted in which a solvent capable of azeotropic dehydration such as toluene, xylene, or chlorobenzene is used, and the water contained in the catalyst, etc. is azeotropically dehydrated as necessary, and then the solvent is distilled off, followed by reaction within the above reaction temperature range.

[0053] The intermediate amine compound (C) obtained in the above step (1) preferably has a partial structure represented by the following general formula (1), a partial structure represented by general formula (t-1) that is chemically bonded to the partial structure represented by general formula (1), and a partial structure represented by general formula (t-2) that is chemically bonded to the partial structure represented by general formula (1). [ka] (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 between 0 and 4, and n 1 represents the average number of repeating units, and two * each represent a bond. One of the bonds is L in the following general formula (t-1): 13 Or L 14 and the other bond is L in the following general formula (t-2): 11 Or L 12 It represents a chemical bond at the position.) [ka] (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 ~L 14 each independently represents a bond, L 11 Or L 12 is chemically bonded to the partial structure represented by general formula (1) at the position of L 13 Or L 14 is chemically bonded to the partial structure represented by general formula (1) at the position m 1 represents an integer between 0 and 2, and m 3 represents an integer between 0 and 2.) In the above general formula (1), "R 13 , m 2 and n 1 " is the same as "R 13 , m 2 and n 1 " is synonymous with "L in general formula (t-1) and general formula (t-2)." 11 , L 12 , L 13 , L 13 , R 11 , R 12 , R 14 , R 15 , m 1 and m 3 " in general formulas (T-1) and (T-2) 11 , L 12 , L 13 , L 13 , R 11 , R 12 , R 14 , R 15 , m 1 and m 3 " is synonymous with "

[0054] In the present embodiment, the amine equivalent of the intermediate amine compound (C) is preferably from 160 to 1200 g / equivalent, and more preferably from 180 to 600 g / equivalent. In this specification, the amine equivalent of the intermediate amine compound (C) is a value measured by a method based on the neutralization titration method specified in JIS K 0070 (1992).

[0055] <<Step (2): Maleimidation>> Step (2) in this 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) undergoes a maleimidization reaction to form a chemical structure in which the amino group is substituted with an N-substituted maleimide ring, thereby obtaining the polymaleimide resin of the present disclosure. In this embodiment, the intermediate amine compound (C) having the partial structure represented by the 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 in step (1) is charged into a reactor, dissolved in a suitable solvent, and then reacted with maleic anhydride in the presence of a catalyst. 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 to obtain the target polymaleimide resin. If necessary, a dehydrating agent may be used during the reaction.

[0056] 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, acetophenone, etc.; aprotic solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, acetonitrile, sulfolane, etc.; cyclic ethers such as dioxane, tetrahydrofuran, etc.; esters such as ethyl acetate, butyl acetate, etc.; aromatic solvents such as benzene, toluene, xylene, etc.; and these may be used alone or in combination.

[0057] In step (2) of the present embodiment, the mixing ratio of the intermediate amine compound (C) and maleic anhydride is preferably in the range of 1 to 5, and more preferably 1 to 3, in terms of the equivalent ratio of maleic anhydride to the amino equivalent of the intermediate amine compound (C), and a preferred embodiment is to charge them and react them in an organic solvent having a mass ratio of 0.1 to 10, and preferably 0.2 to 5, relative to the total amount of the intermediate amine compound (C) and maleic anhydride.

[0058] Examples of the catalyst that can be used in step (2) of the present embodiment include inorganic salts such as acetates, chlorides, bromides, sulfates, and nitrates of nickel, cobalt, sodium, calcium, iron, lithium, manganese, or the like; 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, zeolites, and strongly acidic ion exchange resins; and heteropolyhydrochloric acids. Toluenesulfonic acid is particularly preferred.

[0059] Examples of the dehydrating agent used in step (2) of the present embodiment include lower aliphatic carboxylic acid 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. Of these, acetic anhydride is preferably used. The amounts of the catalyst and dehydrating agent used in step (2) of the present embodiment are not particularly limited. 2 The catalyst can be used in an amount of 0.0001 to 1 mol, preferably 0.01 to 0.3 mol, and the dehydrating agent can be used in an amount of 1 to 3 mol, preferably 1 to 1.5 mol, relative to 1 equivalent of the compound. In step (2) of the present embodiment, the reaction conditions for maleimidization are as follows: the intermediate amine compound (C) and maleic anhydride are charged and reacted at a temperature range of 10 to 100°C, preferably 30 to 60°C, for 0.5 to 12 hours, preferably 1 to 4 hours, and then the catalyst is added and the reaction is continued at a temperature range of 90 to 130°C, preferably 105 to 120°C, for 1 to 24 hours, preferably 1 to 10 hours.

[0060] <Polymaleimide resin mixture> The present disclosure provides a polymaleimide resin mixture containing a polymaleimide resin component having a partial structural unit represented by the following general formula (1a) and a maleimide polymer compound represented by the following general formula (2), wherein the polymaleimide resin is contained in an amount of 1 to 99 mass% based on the total amount of the polymaleimide resin component, The polymaleimide resin mixture contains 80 mass % or less of the maleimide polymer compound based on the total amount of the polymaleimide resin mixture. [ka] (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 between 0 and 2, and m 2 represents an integer between 0 and 4, and n 1 represents the average number of repeating units.) [ka] (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 21represents an integer between 1 and 5.) As a result, the maleimide polymer compound has high solubility in solvents and exhibits a low dielectric tangent and high heat resistance when cured. 21 The dimer with n = 1 is highly crystalline, 21 The solubility tends to improve as the number of substituents (R 11 or R 15 , R 12 or R 14 By setting the number and position of the aryl groups as in the present invention, the proportion of trimers and tetramers, which have excellent solubility, can be increased. In the above general formula (1a), "R 11 , R 12 , R 13 , n 1 , m 1 and m 2 " in the above-mentioned general formula (1) or general formula (T-1) "R 11 , R 12 , R 13 , n 1 , m 1 and m 2 " is synonymous with " In addition, in the general formula (2), "R 21 and R 25 " each independently represents "R 11 or R 15 " in the general formula (2) 22 and R 24 " each independently represents "R 12 or R 14 " is synonymous with "

[0061] [Preparation of Curable Composition] The curable composition of the present disclosure preferably contains the above-mentioned polymaleimide resin. The polymaleimide resin of the present embodiment is excellent in solvent solubility, dielectric loss tangent, and heat resistance, and further contributes to fluidity during heat melting, handleability, dimensional stability, low moisture absorption, brittleness, and low dielectric constant, so that a cured product obtained from the curable composition containing the polymaleimide resin is excellent in solvent solubility, dielectric properties, and heat resistance.

[0062] The curable composition of the present disclosure may contain a curing agent, and further, if necessary, various compounding agents such as a curing accelerator, a silane coupling agent, a release agent, a pigment, an emulsifier, a non-halogen flame retardant, an inorganic filler, etc. In addition, in addition to the polymaleimide resin, an epoxy resin, a phenol resin, an active ester resin, a cyanate resin, etc. can also be appropriately compounded within a range that does not impair the object of the present disclosure.

[0063] [Cured product] 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 components, and can be easily made into a cured product by a method similar to a conventionally known method. Examples of the cured product include molded cured products such as laminates, cast products, adhesive layers, coating films, and films.

[0064] [Semiconductor encapsulation materials] The present disclosure relates to a semiconductor encapsulation material containing the curable composition of the present embodiment. The semiconductor encapsulation material obtained using the curable composition of the present embodiment has improved moisture absorption, low dielectric loss tangent rate, or dimensional stability due to the use of the polymaleimide compound of the present disclosure, and therefore has excellent processability, moldability, and reflow resistance in the manufacturing process, making it a preferred embodiment. The curable composition of the present embodiment used for the semiconductor encapsulation material may contain an inorganic filler. The filling rate of the inorganic filler may be, for example, in the range of 0.5 to 1200 parts by mass per 100 parts by mass of the curable composition of the present embodiment. Examples of the inorganic filler include barium sulfate, barium titanate, amorphous silica, crystalline silica, Neuburg silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, silicon nitride, and aluminum nitride.

[0065] The method for obtaining the semiconductor encapsulation material may include a method in which the curable composition of the present embodiment and, if necessary, additives as optional components are thoroughly melt-mixed until homogeneous using an extruder, kneader, roll, or the like.

[0066] [Semiconductor Devices] The present disclosure relates to a semiconductor device including a cured product of the semiconductor encapsulation material. The semiconductor device obtained using the semiconductor encapsulation material obtained using the curable composition of the present embodiment uses the polymaleimide compound of the present disclosure, and therefore has low viscosity and excellent flowability, and further has improved moisture absorption, elastic modulus at heat, or adhesion to metal materials, and therefore has excellent processability, moldability, and reflow resistance in the manufacturing process, which is a preferred embodiment.

[0067] The semiconductor device can be obtained by molding the semiconductor encapsulation material using a casting machine, a transfer molding machine, an injection molding machine or the like, and then curing the material by heating in a temperature range of room temperature (20°C) to 250°C.

[0068] [Prepreg] The present disclosure relates to a prepreg having a reinforcing substrate and a semi-cured product of the curable composition of the present embodiment impregnated into the reinforcing substrate. As a method for obtaining a prepreg from the curable composition, a method is mentioned in which the curable composition is impregnated into a reinforcing substrate (paper, glass cloth, glass nonwoven fabric, aramid paper, aramid cloth, glass mat, glass roving cloth, etc.) by blending an organic solvent described later and converting the varnish into a curable composition, and then the curable composition is semi-cured (or uncured) to obtain a prepreg by heating at a heating temperature according to the type of solvent used, preferably at 50 to 170 ° C. The mass ratio of the curable composition and the reinforcing substrate used at this time is not particularly limited, but it is usually preferable to prepare the resin content in the prepreg to be 20 to 60 mass %. In this embodiment, the semi-cured product of the curable composition is obtained by adjusting the heating temperature and heating time to stop the curing reaction midway without completing it. Also, for example, the semi-cured product may have a degree of curing of, for example, 5% or more and 85% or less. On the other hand, the cured product in this embodiment may have a higher degree of curing than the semi-cured product. The degree of curing of the semi-cured product can be calculated from the following formula by measuring the amount of heat generated during curing when the curable composition is heated and the amount of heat generated during curing of the semi-cured product by DSC. Degree of cure (%)=[1-(cure heat generation amount of semi-cured product / cure heat generation amount of curable composition)]×100

[0069] Examples of organic solvents used in the production of prepregs include methyl ethyl ketone, acetone, dimethylformamide, methyl isobutyl ketone, methoxypropanol, cyclohexanone, methyl cellosolve, ethyl diglycol acetate, and propylene glycol monomethyl ether acetate. The selection and appropriate amount of the organic solvent used can be appropriately selected depending on the application. For example, when a printed circuit board is further produced from the prepreg as described below, it is preferable to use a polar solvent having a boiling point of 160° C. or less, such as methyl ethyl ketone, acetone, or dimethylformamide, and it is also preferable to use such a solvent in such a proportion that the nonvolatile content is 40 to 80 mass%.

[0070] [Circuit board] The present disclosure relates to a circuit board which is a laminate of the prepreg and copper foil. A method for obtaining a printed circuit board from the curable composition of the present embodiment includes laminating the prepreg by a conventional method, appropriately stacking copper foil, and subjecting the laminate to heat-pressure bonding at 170 to 300° C. under a pressure of 1 to 10 MPa for 10 minutes to 3 hours.

[0071] [Build-up film] The present disclosure relates to a build-up film containing the curable composition of the present embodiment. A method for producing the build-up film of the present embodiment includes a method for producing the build-up film by applying the curable composition onto a support film to form a curable composition layer to form an adhesive film for a multilayer printed wiring board.

[0072] When producing a build-up film from the curable composition, it is essential that the film softens under the lamination temperature conditions (usually 70 to 140°C) in the vacuum lamination method and exhibits fluidity (resin flow) that allows the resin to fill via holes or through holes present in the circuit board at the same time as lamination of the circuit board, and it is preferable to blend the above-mentioned components so as to exhibit such properties.

[0073] Here, the diameter of the through-holes in the multilayer printed wiring board is usually 0.1 to 0.5 mm, and the depth is usually 0.1 to 1.2 mm, and it is usually preferable to make it possible to fill the resin within this range. When both sides of the circuit board are laminated, it is preferable to fill about 1 / 2 of the through-holes.

[0074] Specifically, the adhesive film can be produced by preparing the curable composition in a varnish form, applying the varnish-like composition to the surface of the support film (Y), and then drying the organic solvent by heating or blowing hot air or the like to form a composition layer (X) made of the curable composition.

[0075] The thickness of the composition layer (X) formed 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 is preferably 10 to 100 μm.

[0076] The composition layer (X) in this embodiment may be protected with a protective film described later. By protecting the resin composition layer with a protective film, it is possible to prevent the adhesion of dirt and the like to the surface of the resin composition layer and prevent scratches.

[0077] 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 abbreviated as "PET") and polyethylene naphthalate, polycarbonate, polyimide, and further release paper and metal foils such as copper foil and aluminum foil. The support film and protective film may be subjected to a release treatment in addition to a mud treatment and a corona treatment.

[0078] The thickness of the support film is not particularly limited, but is usually in the range of 10 to 150 μm, preferably 25 to 50 μm, and the thickness of the protective film is preferably 1 to 40 μm.

[0079] The above-mentioned support film (Y) is peeled off after laminating it onto the circuit board or after forming an insulating layer by heat curing. If the support film (Y) is peeled off after the adhesive film is heat cured, the adhesion of dust and the like during the curing process can be prevented. When peeling off after curing, the support film is usually subjected to a release treatment in advance.

[0080] <Heat-resistant materials and electronic materials> The cured product obtained by the curable composition containing the polymaleimide resin of the present disclosure exhibits low moisture absorption and excellent heat resistance and dielectric properties, and therefore can be suitably used for heat-resistant members or electronic members. In particular, it can be suitably used for prepregs, circuit boards, semiconductor encapsulants, semiconductor devices, build-up films, build-up boards, adhesives using conductive pastes, resist materials, etc. It can also be suitably used for matrix resins of fiber-reinforced resins, and is particularly suitable as highly heat-resistant prepregs. In addition, the maleimide having the indane skeleton contained in the curable composition exhibits excellent solubility in various solvents, and can be made into paint. The heat-resistant members and electronic members thus obtained can be suitably used for various applications, such as industrial machine parts, general machine parts, automobile, railway, vehicle parts, space and aviation related parts, electronic and electrical parts, building materials, containers and packaging materials, daily necessities, sports and leisure goods, and housing members for wind power generation, but are not limited thereto. EXAMPLES

[0081] The present invention will be described in detail with reference to Examples and Comparative Examples. The physical properties of the synthesized polymaleimide resins were measured as follows, and the results are shown in Table 1.

[0082] (1) Amine equivalent The amine equivalents of the intermediate amine compounds (c-1) to (c-2) and the intermediate amine compounds (c1) to (c2) were measured by the following measurement method. Approximately 2.5 g of each of the above intermediate amine compounds, 7.5 g of pyridine, 2.5 g of acetic anhydride, and 7.5 g of triphenylphosphine were precisely weighed into a 500 mL Erlenmeyer flask equipped with a stopper, and then the mixture was heated to reflux for 150 minutes in an oil bath set to 120°C and equipped with a cooling tube. After cooling, 5.0 mL of distilled water, 100 mL of propylene glycol monomethyl ether, and 75 mL of tetrahydrofuran were added, and the mixture was titrated potentiometrically with 0.5 mol / L potassium hydroxide-ethanol solution. A blank test was performed in the same manner to correct the value. Amine equivalent (g / equivalent) = (S x 2,000) / (Blank-A) S: Amount of sample (g) A: Consumption of 0.5 mol / L potassium hydroxide-ethanol solution (mL) Blank: Amount of 0.5 mol / L potassium hydroxide-ethanol solution consumed in the blank test (mL)

[0083] (2) GPC measurement The number average molecular weight (Mn), weight average molecular weight (Mw), and molecular weight distribution (Mw / Mn) of the polymaleimide resins obtained in the examples and comparative examples were calculated using the following measuring equipment and conditions. "Measuring device" Tosoh Corporation "HLC-8320 GPC" "Measurement conditions" Column: Tosoh Corporation guard column "HXL-L" + Tosoh Corporation "TSK-GEL G2000HXL" + Tosoh Corporation "TSK-GEL G2000HXL" + Tosoh Corporation "TSK-GEL G3000HXL" + Tosoh Corporation "TSK-GEL G4000HXL" Detector: RI (differential refractometer) Data processing: Tosoh Corporation's "GPC Workstation EcoSEC-WorkStation" Measurement conditions: Column temperature 40℃ Developing solvent: Tetrahydrofuran Flow rate 1.0ml / min Standard: In accordance with the measurement manual for the "GPC Workstation EcoSEC-WorkStation," the following monodisperse polystyrene with known molecular weight was used. (Polystyrene used) "A-500" manufactured by Tosoh Corporation "A-1000" manufactured by Tosoh Corporation "A-2500" manufactured by Tosoh Corporation "A-5000" manufactured by Tosoh Corporation "F-1" manufactured by Tosoh Corporation "F-2" manufactured by Tosoh Corporation "F-4" manufactured by Tosoh Corporation "F-10" manufactured by Tosoh Corporation "F-20" manufactured by Tosoh Corporation "F-40" manufactured by Tosoh Corporation "F-80" manufactured by Tosoh Corporation "F-128" manufactured by Tosoh Corporation Sample: A tetrahydrofuran solution (1.0 mass % in terms of resin solid content) of the polymaleimide resin obtained in Synthesis Example was filtered through a microfilter (50 μl).

[0084] (3)NMR measurement < 1 H-NMR measurement> 1 H-NMR: “JNM-ECA600” manufactured by JEOL RESONANCE Magnetic field strength: 600MHz Number of times: 32 Solvent: DMSO-d 6 < 13 C-NMR measurement> 13 C-NMR: “JNM-ECA600” manufactured by JEOL RESONANCE Magnetic field strength: 125MHz Number of times: 1000 Solvent: CDCL3 Sample concentration: 12% by mass The above 13 From the results of the C-NMR chart, peaks derived from the target products were confirmed, confirming that the target products were obtained in each reaction.

[0085] (4) Synthesis of polymaleimide resin Example 1: Synthesis of polymaleimide resin (A-1) (I) Synthesis of intermediate amine compound (c-1) In a flask equipped with a thermometer, a condenser, a Dean-Stark trap and a stirrer, 400 g (3.3 mol) of 2-ethylaniline, 127 g of a compound (B) having a benzyl ether skeleton (Nikanol L, manufactured by Fudow Co., Ltd.), 193 g of toluene and 53 g of activated clay were charged, and the mixture was heated to 120°C with stirring and held for 30 minutes. The mixture was then heated to 150°C and held for 3 hours. After the hold was completed, the mixture was heated to 200°C over 30 minutes and held for 10 hours. After the hold was completed, the mixture was diluted with 193 g of toluene and the activated clay was filtered off. The filtrate was heated and reduced pressure to remove the solvent and excess 2-ethylaniline, and intermediate amine compound (c-1) was obtained (amine equivalent 209 g / equivalent). MS and 13 C-NMR is shown in Figures 1 and 2. (II) Maleimidation A 2L flask equipped with a thermometer, a condenser, a Dean-Stark trap and a stirrer was charged with 73.2g (126mol, 1.3 equivalents) of maleic anhydride and 461g of toluene, which were stirred at room temperature. Next, a mixed solution of 209g (1 equivalent) of intermediate amine compound (c-1) and 57.7g of DMF was added dropwise over 1 hour, and the mixture was allowed to react for 2 hours. 9.72g of p-toluenesulfonic acid monohydrate was added to the reaction solution, and the reaction solution was heated and the azeotropic water and toluene were cooled and separated under reflux, and then the reaction solution was heated to 115°C and the azeotropic water and toluene were cooled and separated under reflux, and only the toluene was returned to the system, and the dehydration reaction was carried out for 5 hours. After cooling to room temperature, the mixture was concentrated under reduced pressure, and the brown solution was dissolved in 600 g of ethyl acetate, washed three times with 200 g of ion-exchanged water and three times with 150 g of a 2% by mass aqueous solution of sodium bicarbonate, dried by adding sodium sulfate, and concentrated under reduced pressure. The resulting reaction product was vacuum-dried at 80°C for 4 hours to obtain a product containing polymaleimide resin (A-1). The GPC chart of the polymaleimide resin (A-1) is shown in FIG. 3, the FD-MS spectrum is shown in FIG. 13 The C-NMR spectrum results are shown in Figure 5.

[0086] Example 2: Synthesis of polymaleimide resin (A-2) Except for changing the 2-ethylaniline in Example 1 to 400 g (3.3 mol) of 2,3-dimethylaniline, the reaction was carried out in the same manner as in (I) of Example 1 to prepare intermediate amine compound (c-2), which was then reacted in the same manner as in (II) of Example 1 to maleimidize the intermediate amine compound (c-2) to obtain the target polymaleimide resin (A-2). The amine equivalent of intermediate amine compound (c-2) was 216 (g / equivalent). The MS and 13 The C-NMR is shown in Figures 6 and 7. The GPC chart of the polymaleimide resin (A-2) is shown in Figure 8, the FD-MS spectrum is shown in Figure 9, 13 The C-NMR spectrum results are shown in FIG.

[0087] Comparative Example 1: Synthesis of Comparative Maleimide Compound (1) A reaction was carried out in the same manner as in (I) of Example 1, except that 447.0 g (3.3 mol) of 2-ethyl-6-methylaniline was used instead of 2-ethylaniline in Example 1, to prepare comparative intermediate amine compound (c1). Then, a reaction was carried out in the same manner as in (II) of Example 1 to maleimide the comparative intermediate amine compound (c1) to obtain the target comparative maleimide compound (1) (amine equivalent: 210 g / equivalent). The MS and 13 The C-NMR is shown in Figures 11 and 12. The GPC chart of the comparative maleimide compound (1) is shown in Figure 13, the FD-MS spectrum is shown in Figure 14, 13 The C-NMR spectrum results are shown in Figure 15.

[0088] Comparative Example 2: Synthesis of Comparative Maleimide Compound (2) Except for changing the 2-ethylaniline in Example 1 to 307.4 g (3.3 mol) of aniline, a reaction was carried out in the same manner as in (I) of Example 1 to prepare a comparative intermediate amine compound (c2), which was then maleimidized in the same manner as in (II) of Example 1 to obtain the target comparative maleimide compound (2). The amine equivalent of the comparative intermediate amine compound (c2) was 201 (g / equivalent). The MS and 13 The C-NMR spectrum is shown in Figures 16 and 17. The FD-MS spectrum of the comparative maleimide compound (2) is shown in Figure 18. 13 The C-NMR spectrum results are shown in FIG.

[0089] <Examples 3 to 4 and Comparative Examples 3 to 5> <<Preparation of curable composition and production of cured product>> The polymaleimide resins (A-1) and (A-2) obtained in the above Examples 1 and 2, the comparative maleimide compounds (1) and (2) obtained in the above Comparative Examples 1 and 2, and compounds represented by the following formula (i): [ka] Comparative maleimide compound (3) represented by the formula (3) ("BMI-5100" manufactured by Daiwa Chemical Industry Co., Ltd.), polyphenylene ether compound (1) having a reactive double bond ("SA-9000" manufactured by SABIC, Mw: 1700), and DCPO ("Percumyl D" manufactured by NOF Corporation, dicumyl peroxide) as a catalyst were mixed in the ratios shown in Table 1 below to prepare curable compositions of Examples 3 to 4 and Comparative Examples 3 to 5.

[0090] Next, the curable compositions of Examples 3 to 4 and Comparative Examples 3 to 5 were cured under the following curing conditions to produce the cured products of Examples 3 to 4 and Comparative Examples 3 to 5. The physical properties of the dielectric tangent, heat resistance, and solvent solubility were evaluated by the following methods. The results are shown in Table 1. <<Curing conditions>> Heat cure at 200℃ for 2 hours using a vacuum press, then at 250℃ for 2 hours Thickness after molding: 1.3mm

[0091] <<Measurement of dielectric tangent>> In accordance with JIS-C-6481, the dielectric loss tangent at 10 GHz of the test specimens was measured using the cavity resonance method with an Agilent Technologies network analyzer "E8362C" after drying and storing them indoors at 23°C and 50% humidity for 24 hours. A dielectric tangent value of 0.0025 or less is considered good.

[0092] <<Heat resistance (DMA Tg) measurement>> Using a viscoelasticity measuring device ("Solid Viscoelasticity Measuring Device RSAII" manufactured by Rheometrics, rectangular tension method: frequency 1 Hz, heating rate 3°C / min), the temperature at which the change in elastic modulus of the cured products of Examples 3 to 4 and Comparative Examples 3 to 5 was maximized (the rate of change in Tan δ was the largest) was evaluated as the glass transition temperature (Tg). Note that a Tg value of 230°C or higher is considered good from the viewpoint of heat resistance.

[0093] <<Solvent solubility>> Methyl ethyl ketone (MEK) solutions were prepared for the polymaleimide compounds (A-1)-(A-2) and the comparative maleimide compounds (1)-(3) so that the non-volatile content was 60% by mass, and the number of days until precipitation was measured. MEK was selected as a solvent that is commonly used in circuit board applications because it has a lower boiling point than DMF (dimethylformamide) and can suppress residual dissolution. A period of 30 days or more that does not cause precipitation is considered to be good.

[0094] [Table 1]

Claims

1. A polymaleimide resin mixture containing a polymaleimide resin component having a partial structural unit represented by the following general formula (1a) and a maleimide polymer compound represented by the following general formula (2), and containing, as reaction raw materials (1), an aromatic amine compound (A) represented by the following general formula (a-1), a compound (B) having a benzyl ether skeleton and having a structural unit represented by the following formula (b-1), and maleic anhydride: The polymaleimide resin component contains 1 to 99 mass % of a polymaleimide resin having a partial structure represented by the following general formula (1), a partial structure represented by general formula (T-1) that is chemically bonded to the partial structure represented by general formula (1), and a partial structure represented by general formula (T-2) that is chemically bonded to the partial structure represented by general formula (1), relative to the total amount of the polymaleimide resin component: A polymaleimide resin mixture containing the maleimide polymer compound in an amount of 80 mass % or less based on the total amount of the polymaleimide resin mixture. 【Chemical 1】 (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, and 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 to 4, １ represents the average number of repeating units.) 【Chemistry 2】 (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.) 【Chemistry 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, and R ２ and R ３ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms. 【Chemistry 4】 (In the above general formula (b-1), each R b1 independently represents a hydrogen atom or an alkyl group having 1 to 11 carbon atoms, and one or more —CH 2 — in the alkyl group may be replaced by —O— or —C(═O)— so that they are not adjacent to each other, R b2 and R b3 each independently represent a hydrocarbon group having 1 to 18 carbon atoms; each L 1 independently represents an alkylene group having 1 to 11 carbon atoms, and one or more —CH 2 — in the alkylene group may be replaced with —O— so that they are not adjacent to each other; L 2 represents a single bond or an alkylene group having 1 to 11 carbon atoms, and one or more —CH 2 — in the alkylene group may be replaced by —O— or —(C═O)— so that they are not adjacent to each other; Z 1 's each independently represent a hydrogen atom or a hydrocarbon group having 1 to 11 carbon atoms; k represents an integer of 0 to 20, m b1 and m b2 each independently represent an integer of 0 to 4, At least one of R b1 and L 2 has a —CH 2 O— group. 【Chemistry 5】 (In the above general formula (1), each R 13 independently represents an alkyl group having 1 to 18 carbon atoms, m 2 represents an integer of 0 to 4, n 1 represents the average number of repeating units, and two * represent bonds, with one bond being chemically bonded to the position of L 13 or L 14 in the following general formula (T-1), and the other bond being chemically bonded to the position of L 11 or L 12 in the following general formula (T-2).) 【Chemistry 6】 (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 bond or a hydrogen atom, provided that L 11 or L 12 is chemically bonded to the partial structure represented by general formula (1) at the position of L 11 or L 12 , and L 13 or L 14 is chemically bonded to the partial structure represented by general formula (1), and L 11 to L 14 that is not chemically bonded to the partial structure represented by general formula (1) is a hydrogen atom; m 1 and m 3 each represent 2.

2. 2. The polymaleimide resin mixture according to claim 1, wherein the aromatic amine compound (A) and the compound (B) having a benzyl ether skeleton are blended in a proportion of 0.001 to 1 mole, expressed as a molar ratio of methyleneoxy moieties in the compound (B) having a benzyl ether skeleton, per 1 mole of the aromatic amine compound (A).

3. A curable composition comprising the polymaleimide resin mixture according to claim 1 or 2.

4. A cured product of the curable composition according to claim 3.

5. A prepreg comprising a reinforcing substrate and a semi-cured product of the curable composition according to claim 3 impregnated into the reinforcing substrate.

6. A circuit board which is a laminate comprising the prepreg according to claim 5 and copper foil.

7. A build-up film comprising the curable composition according to claim 3.

8. A semiconductor encapsulant comprising the curable composition according to claim 3 .

9. A semiconductor device comprising the cured product of the semiconductor encapsulation material according to claim 8.

10. A method for producing the polymaleimide resin mixture according to claim 1, comprising the following steps (1) and (2): Step (1): A step of reacting an aromatic amine compound (A) represented by the general formula (a-1) with a compound (B) having a benzyl ether skeleton as a reaction raw material (2) to obtain a compound containing an intermediate amine compound (C); Step (2): A step of reacting a compound containing the intermediate amine compound (C) obtained in the step (1) as a reaction raw material (3) with maleic anhydride to obtain a polymaleimide resin mixture.

11. 11. The method for producing a polymaleimide resin mixture according to claim 10, wherein a blending ratio of the aromatic amine compound (A) to the compound (B) having a benzyl ether skeleton is such that a molar ratio of methyleneoxy moieties in the compound (B) having a benzyl ether skeleton is 0.001 to 1 mol per 1 mol of the aromatic amine compound (A).

12. 12. The method for producing a polymaleimide resin mixture according to claim 10 or 11, wherein the reaction site with the aromatic amine compound (A) is a methyleneoxy moiety in the compound (B) having a benzyl ether skeleton contained in the compound (B) having a benzyl ether skeleton.

13. 12. The method for producing a polymaleimide resin mixture according to claim 10, wherein in the step (1), the aromatic amine compound (A) and the compound having a benzyl ether skeleton (B) are reacted in the presence of an acid catalyst, and the reaction temperature is in the range of 100 to 300°C.

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