Thermosetting maleimide resin composition

Abstract

To provide a thermosetting maleimide resin composition which has low melt viscosity during heating, has excellent flexibility of the cured film in its cured product, has low dielectric constant and dielectric loss tangent, has high glass transition temperature, has a low coefficient of thermal expansion, and has excellent long-term heat resistance and moisture resistance.SOLUTION: A thermosetting maleimide resin composition contains (A) a bismaleimide compound represented by the following formula (1) (in the formula (1), A represents a tetravalent organic group including a cyclic structure, B represents a divalent hydrocarbon group derived from a dimer acid skeleton, Q represents a divalent group having a fluorene skeleton or an indene skeleton, W is B or Q, n is 1 to 100, and m is 1 to 100, (B) a thermosetting resin having one or more maleimide group reactive functional groups selected from an alkenyl group, a maleimide group, an epoxy group, a cyanate group, a hydroxyl group, an acid anhydride group, a (meth)acrylic group and a thiol group, and (C) a reaction accelerator.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a thermosetting maleimide resin composition. [Background technology]

[0002] In recent years, the next-generation communication system known as 5G (millimeter wave region of 26 GHz to 80 GHz) has become widespread, and development of the next-generation communication system known as 6G has also begun. These communication systems aim to achieve faster speeds, larger capacity, and lower latency than ever before. To achieve this, materials for the high-frequency band of 3 to 80 GHz are required, and reducing transmission loss as a noise countermeasure is essential. Transmission loss is the sum of conductor loss and dielectric loss, and reducing conductor loss requires low surface roughness of the metal foil used. On the other hand, dielectric loss is proportional to the product of the square root of the relative dielectric constant and the dielectric loss tangent, so there is a demand for the development of insulating materials with excellent dielectric properties. Furthermore, printed wiring boards and electronic components that use insulating materials require a reflow process during mounting, so there is a demand for highly heat-resistant materials that have a high glass transition temperature (Tg).

[0003] Among these, insulating materials with excellent dielectric properties are particularly required for circuit board applications. For example, reactive polyphenylene ether resin (PPE) is used for rigid circuit boards, and liquid crystal polymer (LCP) and modified polyimide (MPI) with improved properties are used for flexible printed circuit boards (FPC).

[0004] Although these materials have excellent characteristics, it is also true that they have many problems. For example, reactive PPE resins have excellent dielectric properties and high Tg, but the cured products are brittle and have poor handling properties, so their use is limited to prepregs, etc. (e.g., Patent Document 1). Many inventions have been disclosed for LCPs, such as base films and coverlay films for FPCs that use LCPs and have further improved performance (e.g., Patent Document 2). However, LCPs have many areas for improvement, such as limited use due to the difficulty of mass production and the need for adhesives with excellent dielectric properties when producing copper-clad laminates. MPIs require high temperatures of 300°C or more to imidize polyamic acid (polyamic acid), and have problems with processability (e.g., Patent Document 3).

[0005] In recent years, maleimide resins such as bismaleimide resins have been attracting attention as materials that combine heat resistance and dielectric properties. Many bismaleimide resins are known to be low molecular weight and have excellent heat resistance, such as a high Tg, but they have poor fluidity when heated, and the cured product is hard and brittle. In addition, the dielectric properties of bismaleimide resins are insufficient compared to LCP and MPI, and the relative dielectric constant and dielectric loss tangent increase significantly under high temperature and high humidity conditions. Therefore, there is a strong demand for the development of resins that maintain heat resistance and moisture resistance while also having excellent dielectric properties, low melt viscosity when heated, and film formability.

[0006] In response to this, it has been reported that special maleimide compounds having a dimer diamine skeleton derived from dimer acid are used as the main resin for substrates (Patent Documents 4 to 8). Unlike the properties of general maleimide resins, special maleimide compounds have very excellent dielectric properties, are flexible, and have excellent adhesion to adherends such as metals. On the other hand, because of their low Tg and high coefficient of thermal expansion (CTE), the dielectric properties change significantly in high-temperature environments, and the heat resistance is not sufficient. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] WO 2019 / 65940 [Patent Document 2] JP 2013-74129 A [Patent Document 3] JP 2019-104818 A [Patent Document 4] JP 2016-131243 A [Patent Document 5] JP 2016-131244 A [Patent Document 6] International Publication No. 2016 / 114287 [Patent Document 7] JP 2018-201024 A [Patent Document 8] Patent Publication No. 2021-25051 Summary of the Invention [Problem to be solved by the invention]

[0008] Accordingly, an object of the present invention is to provide a thermosetting maleimide resin composition which has a low melt viscosity when heated, and which has excellent flexibility as a cured film when cured, a low dielectric constant and dielectric dissipation factor, a high glass transition temperature, a low thermal expansion coefficient, and excellent heat resistance and moisture resistance even over a long period of time. [Means for solving the problem]

[0009] Means for Solving the Problems The present inventors have conducted intensive research to solve the above problems and have found that the following thermosetting maleimide resin composition can achieve the above object, thereby completing the present invention.

[0010] That is, the present invention provides the following <1> ~ <6> Regarding. <1> (A) The following formula (1) [ka] In formula (1), A independently represents a tetravalent organic group containing a cyclic structure. B independently represents a divalent hydrocarbon group derived from a dimer acid skeleton. Q independently represents a divalent group having a fluorene skeleton or an indene skeleton represented by either formula (2-1) or (2-2) below. [ka] (In formula (2-1), R 1 are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a (hetero)aryl group having 4 to 10 carbon atoms, a hydroxyl group, an alkoxy group, a halogeno group, a trifluoromethyl group, an amino group, or a sulfenyl group, and in formula (2-2), R 2 are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a (hetero)aryl group having 4 to 10 carbon atoms, a hydroxyl group, an alkoxy group, a halogeno group, a trifluoromethyl group, an amino group, or a sulfenyl group. W is B or Q. n is 1 to 100, and m is 1 to 100. The order of the repeating units bracketed by n and m is not limited, and the bonding pattern may be alternating, block, or random. A bismaleimide compound represented by the formula: (B) a thermosetting resin having one or more maleimide group-reactive functional groups selected from an alkenyl group, a maleimide group, an epoxy group, a cyanate group, a hydroxyl group, an acid anhydride group, a (meth)acrylic group, and a thiol group; and (C) Reaction accelerator 1. A thermosetting maleimide resin composition comprising: <2> The content ratio of the component (A) to the component (B) is, in terms of mass ratio, (A):(B)=95:5 to 50:50. <1> 2. The thermosetting maleimide resin composition according to claim 1 . <3> The number average molecular weight of the bismaleimide compound of the formula (1) is 3,000 to 50,000. <1> or <2> 2. The thermosetting maleimide resin composition according to claim 1 . <4> In the bismaleimide compound of the formula (1), the bonding pattern of each repeating unit bounded by n and m is a block. <1> ~ <3> 2. The thermosetting maleimide resin composition according to claim 1 . <5> In formula (1), A is any of the tetravalent organic groups represented by the following formulas: <1> ~ <4> 2. The thermosetting maleimide resin composition according to claim 1 . [ka] <6> The number average molecular weight of the (B) component is 6,000 or less. <1> ~ <5> 2. The thermosetting maleimide resin composition according to claim 1 . Effect of the Invention

[0011] The thermosetting maleimide resin composition of the present invention has a low melt viscosity when heated. In addition, the cured product thereof has excellent flexibility. Furthermore, the cured product has excellent dielectric properties, such as low dielectric constant and dielectric loss tangent at high frequencies, a high glass transition temperature, a low thermal expansion coefficient, and excellent heat resistance and moisture resistance. Therefore, the thermosetting maleimide resin composition of the present invention can be suitably used for films with uncured resin, cured resin films, prepregs, copper-clad laminates, printed wiring boards, semiconductor encapsulants, adhesives, and resin-coated metal foils, etc. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention will be described in detail below.

[0013] The component (A) used in the present invention is a bismaleimide compound represented by the following formula (1). [ka] In formula (1), A independently represents a tetravalent organic group containing a cyclic structure. B independently represents a divalent hydrocarbon group derived from a dimer acid skeleton. Q independently represents a divalent group having a fluorene skeleton or an indene skeleton represented by either of the following formulas (2-1) or (2-2). In formula (1), W represents B or Q. n represents 1 to 100, and m represents 1 to 100. The order of the repeating units bracketed by n and m is not limited, and the bonding pattern may be alternate, block, or random. The bismaleimide compound of component (A) has a skeleton derived from a dimer acid in the molecule, and also has a fluorene skeleton or an indene skeleton, and thus the cured product of the resin composition containing the compound has excellent dielectric properties and heat resistance.

[0014] [ka] In formula (2-1), R 1 are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a (hetero)aryl group having 4 to 10 carbon atoms, a hydroxyl group, an alkoxy group, a halogeno group, a trifluoromethyl group, an amino group or a sulfenyl group. R in formula (2-1) 1 Examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, and a pentyl group. R in formula (2-1) 1 Examples of the (hetero)aryl group having 4 to 10 carbon atoms include aryl groups having 6 to 10 carbon atoms, such as a phenyl group, a tolyl group, a xylyl group, and a naphthyl group, and heteroaryl groups having 4 to 10 carbon atoms, such as a furyl group, a thienyl group, a pyridyl group, and an indolyl group. R in formula (2-1) 1Examples of the alkoxy group represented by the formula (I) include a methoxy group, an ethoxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, an isobutyloxy group, a t-butyloxy group, an n-pentyloxy group, an isopentyloxy group, a hexyloxy group, a benzyloxy group, a phenethyloxy group, an allyloxy group, a phenyloxy group, a tolyloxy group, a xylyloxy group, a naphthyloxy group, a furyloxy group, a thienyloxy group, a pyridyloxy group, and an indolyloxy group. R in formula (2-1) 1 Examples of the halogeno group represented by the formula (I) include a fluoro group, a chloro group, a bromo group, and an iodo group.

[0015] R in formula (2-1) 1 is preferably a hydrogen atom, and specific examples of Q having a fluorene skeleton represented by formula (2-1) include those represented by the following structural formulas. [ka] (The bond not bonded to a substituent in the above structural formula is bonded to the nitrogen atom forming a cyclic imide structure in formula (1).)

[0016] As Q having a fluorene skeleton represented by formula (2-1), a group represented by the following structural formula is particularly preferable. [ka]

[0017] In formula (2-2), R 2 are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a (hetero)aryl group having 4 to 10 carbon atoms, a hydroxyl group, an alkoxy group, a halogeno group, a trifluoromethyl group, an amino group or a sulfenyl group. R in formula (2-2) 2 Examples of the alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, and a pentyl group. R in formula (2-2)2 Examples of the (hetero)aryl group having 4 to 10 carbon atoms include aryl groups having 6 to 10 carbon atoms, such as a phenyl group, a tolyl group, a xylyl group, and a naphthyl group; and heteroaryl groups having 4 to 10 carbon atoms, such as a furyl group, a thienyl group, a pyridyl group, and an indolyl group. R in formula (2-2) 2 Examples of the alkoxy group represented by the formula (I) include a methoxy group, an ethoxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, an isobutyloxy group, a t-butyloxy group, an n-pentyloxy group, an isopentyloxy group, a hexyloxy group, a benzyloxy group, a phenethyloxy group, an allyloxy group, a phenyloxy group, a tolyloxy group, a xylyloxy group, a naphthyloxy group, a furyloxy group, a thienyloxy group, a pyridyloxy group, and an indolyloxy group. R in formula (2-2) 2 Examples of the halogeno group represented by the formula (I) include a fluoro group, a chloro group, a bromo group, and an iodo group.

[0018] R in formula (2-2) 2 is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and particularly preferably a hydrogen atom or a methyl group. Specific examples of Q having an indene skeleton represented by formula (2-2) include the following structural formulas. [ka] (The bond not bonded to a substituent in the above structural formula is bonded to the nitrogen atom forming a cyclic imide structure in formula (1).)

[0019] The divalent group having an aromatic ring represented by Q is a group derived from a diamine having an aromatic ring in the manufacturing method described below. Examples of the diamine having an aromatic ring include 9,9-bis(4-aminophenyl)fluorene (hereinafter also referred to as FDA), 9,9-bis(4-amino-3-methylphenyl)fluorene, 9,9-bis(4-amino-3-fluorophenyl)fluorene (hereinafter also referred to as FFDA), 9,9-bis(4-amino-3-chlorophenyl)fluorene, 9,9-bis(4-amino-3-hydroxyphenyl)fluorene, and 9,9-bis[4-(4-aminophenoxy)phenyl]fluorene. , 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-inden-5-amine (hereinafter also referred to as PIDA), 3-(4-aminophenyl)-2,3-dihydro-3-methyl-1,1-diphenyl-1H-inden-5-amine, 2-(4-aminophenyl)-1-ethyl-2,3-dihydro-3-methyl-1H-inden-5-amine, 1,3,3-tris(4-aminophenyl)-2,3-dihydro-1-methyl-1H-inden-5-amine, etc. These diamines may be used alone or in combination of two or more depending on the purpose, application, etc. From the viewpoint that the resin composition containing the bismaleimide compound represented by formula (1) has excellent dielectric properties, a high glass transition temperature, and a low thermal expansion coefficient, the diamine having an aromatic ring is preferably FDA, FFDA, or PIDA.

[0020] In formula (1), A independently represents a tetravalent organic group containing a cyclic structure, and is a group derived from a tetracarboxylic dianhydride monomer, and may be a group having a fluorene skeleton or may be a group not having a fluorene skeleton. Examples of the tetracarboxylic dianhydride monomer include pyromellitic dianhydride, 4,4'-carbonyldiphthalic dianhydride, 4,4'-oxydiphthalic dianhydride, 3,4'-oxydiphthalic anhydride, 4,4'-biphthalic dianhydride, 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1,2, 3,4-Cyclopentanetetracarboxylic dianhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, 9,9-bis[4-(3,4-dicarboxyphenoxy)phenyl]fluorene dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic dianhydride, dicyclohexyl-3,4,3',4'-tetracarboxylic dianhydride, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2"-norbornane-5 ,5”,6,6”-tetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 4,4'-(ethyne-1,2-diyl)diphthalic dianhydride, 3-(carboxymethyl)-1,2,4-cyclopentanetricarboxylic 1,4:2,3-dianhydride, 2,3,6,7-naphthalenetetracarboxylic 2,3:6,7-dianhydride, naphthalene-1,4,5,8-tetracarboxylic dianhydride, bis(1,3-dioxo-1,3- Examples of the acid anhydride include 1,4-phenylene dihydroisobenzofuran-5-carboxylate, and 3,4,9,10-perylenetetracarboxylic dianhydride. These acid anhydrides may be used alone or in combination of two or more depending on the purpose and application. From the viewpoint of excellent dielectric properties of the bismaleimide compound represented by formula (1) and excellent solubility in solvents, 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic dianhydride is preferred.

[0021] In formula (1), B is independently one or more divalent hydrocarbon groups derived from a dimer acid skeleton. Dimer acid is a liquid dibasic acid that is produced by dimerization of unsaturated fatty acids with 18 carbon atoms, derived from natural products such as vegetable oils, and is composed mainly of dicarboxylic acids with 36 carbon atoms. The dimer acid skeleton is not a single skeleton, but has multiple structures, and there are several types of isomers. Representative dimer acids are classified as linear (a), monocyclic (b), aromatic (c), and polycyclic (d). In this specification, the dimer acid skeleton refers to a group derived from a dimer diamine having a structure in which the carboxy group of such a dimer acid is substituted with a primary aminomethyl group. In other words, examples of the divalent hydrocarbon group derived from the dimer acid skeleton of B in formula (1) include, but are not limited to, branched divalent hydrocarbon groups in which the two carboxy groups are substituted with methylene groups in each of the dimer acids shown in (a) to (d) below. Furthermore, from the viewpoint of heat resistance and reliability of the cured product, it is more preferable that the hydrocarbon group derived from the dimer acid skeleton has a structure in which the carbon-carbon double bonds in the hydrocarbon group derived from the dimer acid skeleton are reduced by a hydrogenation reaction.

[0022] [ka] As described above, the dimer acid skeleton has a plurality of structures, and therefore, in this specification, the divalent hydrocarbon group derived from the dimer acid skeleton is referred to as the average structure, i.e., -C 36 H 70 It may be written as -.

[0023] In the formula (1), W is B or Q. Whether W is B or Q is determined depending on the production method described below.

[0024] In formula (1), n ​​is 1 to 100, preferably 1 to 50, and more preferably 1 to 10. Furthermore, m is 1 to 100, preferably 1 to 50, and more preferably 1 to 10. If n or m is too small, the cured product will be brittle and prone to cracking, whereas if n or m is too large, the flowability will decrease and moldability may be poor.

[0025] The number average molecular weight (Mn) of the bismaleimide compound of component (A) is not particularly limited, but is preferably 3,000 to 50,000, more preferably 3,500 to 20,000, and even more preferably 4,000 to 10,000. Within this range, the viscosity of the thermosetting maleimide resin composition of the present invention does not become too high, and the resin composition has excellent flowability. Furthermore, the cured product of the resin composition has high strength.

[0026] The number average molecular weight (Mn) referred to in this specification refers to the number average molecular weight measured by GPC under the following conditions using polystyrene as the standard substance. [GPC measurement conditions] Developing solvent: Tetrahydrofuran Flow rate: 0.35mL / min column: TSKgel guardcolumn SuperHZ-L(4.6mmI.D.×2cm×1) TSKgel SuperH-RC(6.0mmI.D.×15cm×2) TSKgel SuperHZ4000(4.6mmI.D.×15cm×1) TSKgel SuperHZ3000(4.6mmI.D.×15cm×1) TSKgel SuperHZ2000 (4.6mmI.D.×15cm×2) (All manufactured by Tosoh Corporation) Column temperature: 40℃ Sample injection volume: 10 μL (sample concentration: 0.2% by mass in tetrahydrofuran solution) Detector: Differential refractometer (RI)

[0027] In the bismaleimide compound of the present invention represented by formula (1), the order of the repeating units bracketed by n and m in the formula is not limited, and the bonding mode may be alternate, block, or random, but is preferably a block bond.

[0028] There are no particular limitations on the method for producing the bismaleimide compound of component (A). For example, the compound can be efficiently produced by the following two methods.

[0029] Manufacturing method 1 One method is to use the following formula (3): [ka] (In formula (3), A is the same as that shown in formula (1) above.) and an acid anhydride represented by the formula: The following formula (4) H2N-Q-NH2(4) (In formula (4), Q is the same as that shown in formula (1) above.) and a diamine having an aromatic ring represented by the formula: Following step A, the reaction product obtained in step A and The following formula (5) H2N-B-NH2(5) (In formula (5), B is the same as that shown in formula (1) above.) and a diamine derived from a dimer acid skeleton represented by the formula: This method for producing a bismaleimide compound includes, subsequent to the step B, a step C of synthesizing maleamic acid using the reaction product obtained in the step B and maleic anhydride, and capping the molecular chain terminals with maleimide groups by ring-closing dehydration.

[0030] Manufacturing method 2 Another method is to use the following formula (3): [ka] (In formula (3), A is the same as that shown in formula (1) above.) and an acid anhydride represented by the formula: The following formula (5) H2N-B-NH2(5) (In formula (5), B is the same as that shown in formula (1) above.) and a diamine derived from a dimer acid skeleton represented by the formula: Following the step A', the reaction product obtained in the step A' and The following formula (4) H2N-Q-NH2(4) (In formula (4), Q is the same as that shown in formula (1) above.) and a diamine having an aromatic ring represented by the formula: The method for producing a bismaleimide compound includes, subsequent to the step B', a step C' of synthesizing maleamic acid using the reaction product obtained in the step B' and maleic anhydride, and capping the molecular chain terminals with maleimide groups by ring-closing dehydration.

[0031] The above two manufacturing methods are shown, but the basic flow is to synthesize an amic acid from a tetracarboxylic dianhydride and a diamine, go through step A (or step A') where they perform ring-closing dehydration, after step A (or step A'), add a diamine different from the previous step A (or step A') to synthesize an amic acid, go through step B (or step B') where they perform ring-closing dehydration, after step B (or step B'), react with maleic anhydride to synthesize a maleamic acid, and finally go through step C (or step C') where the molecular chain end is blocked with a maleimide group by ring-closing dehydration to obtain a bismaleimide compound. The difference between the above two manufacturing methods is mainly only the order of the types of diamines added.

[0032] In the above two production methods, each step can be roughly divided into two: a synthesis reaction of an amic acid or a maleamic acid, and a ring-closing dehydration reaction, which will be described in detail below.

[0033] In step A (or step A'), a specific tetracarboxylic dianhydride is reacted with a specific diamine to synthesize an amic acid. This reaction generally proceeds in an organic solvent (e.g., a non-polar solvent or a high-boiling point aprotic polar solvent) at room temperature (25°C) to 100°C. The subsequent ring-closing dehydration reaction of the amic acid is carried out at 100 to 160° C., and then the water by-produced by the condensation reaction is removed from the system. In order to promote the ring-closing dehydration reaction, an organic solvent (e.g., a non-polar solvent, a high-boiling aprotic polar solvent, etc.) or an acid catalyst can be added.

[0034] Examples of the organic solvent include toluene, xylene, anisole, biphenyl, naphthalene, N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), and dimethylacetamide (DMAC). These may be used alone or in combination of two or more. Among these, from the viewpoint of solubility, aromatic solvents such as toluene, xylene, anisole, biphenyl, and naphthalene are preferred, and toluene, xylene, or anisole are particularly preferred.

[0035] Examples of the acid catalyst include sulfuric acid, methanesulfonic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, etc. These may be used alone or in combination of two or more. The amount of the acid catalyst used is preferably 0.1 mol or more and 2.0 mol or less, and more preferably 0.2 mol or more and 1.0 mol or less, per mol of the diamine raw material.

[0036] The molar ratio of the tetracarboxylic dianhydride to the diamine is preferably tetracarboxylic dianhydride / diamine=1.01 to 1.99 / 1.0, more preferably tetracarboxylic dianhydride / diamine=1.01 to 1.80 / 1.0, and even more preferably tetracarboxylic dianhydride / diamine=1.10 to 1.60 / 1.0. By mixing them in this ratio, a copolymer containing imide groups at both ends can be synthesized.

[0037] In step B (or step B'), first, the copolymer containing imide groups at both ends obtained in step A (or step A') is reacted with a specific diamine to synthesize an amic acid. This reaction also generally proceeds in an organic solvent (e.g., a non-polar solvent or a high-boiling point aprotic polar solvent) at room temperature (25°C) to 100°C. Similarly, the subsequent ring-closing dehydration reaction of the amic acid is carried out at 100 to 160° C., and then the water by-produced by the condensation reaction is removed from the system. In order to promote the ring-closing dehydration reaction, an organic solvent (e.g., a non-polar solvent, a high-boiling aprotic polar solvent, etc.) or an acid catalyst can be added.

[0038] Examples of the organic solvent include toluene, xylene, anisole, biphenyl, naphthalene, N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), and dimethylacetamide (DMAC). These may be used alone or in combination of two or more. Among these, from the viewpoint of solubility, aromatic solvents such as toluene, xylene, anisole, biphenyl, and naphthalene are preferred, and toluene, xylene, or anisole are particularly preferred.

[0039] Examples of the acid catalyst include sulfuric acid, methanesulfonic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, etc. These may be used alone or in combination of two or more. The amount of the acid catalyst used is preferably 0.1 mol or more and 2.0 mol or less, and more preferably 0.2 mol or more and 1.0 mol or less, per mol of the diamine raw material.

[0040] The molar ratio of the copolymer containing imide groups at both ends to the diamine is preferably 1.0:0.01-1.0, and more preferably 1.0:0.1-1.0.

[0041] In step C (or step C'), the diamine having amino groups at both ends obtained in step B (or step B') is reacted with maleic anhydride at room temperature (25°C) to 100°C to synthesize maleamic acid, and finally, the molecular chain ends are blocked with maleimide groups by ring-closing dehydration at 100 to 160°C while removing the water by-produced in the system, thereby obtaining the desired bismaleimide compound. According to such a production method, the bismaleimide compound obtained has a block copolymer structure, and therefore the compatibility of the synthesized resin can be made uniform and improved.

[0042] The molar ratio of the diamine having amino groups at both ends to maleic anhydride is preferably 1.0:1.6-2.5, and more preferably 1.0:1.8-2.2.

[0043] The solution of the bismaleimide compound obtained by the above-mentioned production method can be washed to remove catalysts and the like by a known method (for example, adding water, alcohol, etc., stirring, and allowing to stand to separate the organic solvent from the aqueous solution).

[0044] The bismaleimide compound obtained by the above-mentioned production method can be taken out in a varnish state, and can be purified and isolated as a solid powder by adding a poor solvent to cause reprecipitation, etc. From the viewpoint of production costs, it is preferable to take out the bismaleimide compound obtained by the above-mentioned production method in a varnish state. In this case, a resin varnish containing the bismaleimide compound and the organic solvent used in the production method is obtained. As the solvent for the resin varnish, the same organic solvents as those used in the production method can be used. Preferred are aromatic solvents such as toluene, xylene, anisole, biphenyl and naphthalene, and more preferred are toluene, xylene or anisole.

[0045] In the total amount of the composition of the present invention, the content of the component (A) is preferably from 25 to 95 mass %, and more preferably from 30 to 90 mass %.

[0046] [(B) Thermosetting resin having a maleimide group-reactive functional group] The component (B) used in the present invention is a thermosetting resin having a maleimide group-reactive functional group. Examples of reactive functional groups that can react with a maleimide group include alkenyl groups such as allyl and vinyl groups, maleimide groups, epoxy groups, cyanate groups, hydroxyl groups, acid anhydride groups, (meth)acrylic groups, and thiol groups. However, when the component (B) is a thermosetting resin having a maleimide group, the component (B) does not include those corresponding to the maleimide compound of the component (A). From the viewpoint of reactivity, the reactive group of the thermosetting resin, component (B), is preferably a group selected from an alkenyl group such as an allyl group or a vinyl group, a maleimide group, an epoxy group, or a (meth)acrylic group, and from the viewpoint of dielectric properties, an alkenyl group such as an allyl group or a vinyl group, a maleimide group, or a (meth)acrylic group is more preferable.

[0047] The type of thermosetting resin is not limited, but examples thereof include allyl compounds having an allyl group and an isocyanuric ring, such as triallyl isocyanurate (TAIC), modified polyphenylene ether resins in which the terminal hydroxyl groups of polyphenylene ether are modified with vinyl groups, methacrylic groups, etc., maleimide resins, epoxy resins, phenolic resins, melamine resins, silicone resins, cyclic imide resins, urea resins, thermosetting polyimide resins, thermosetting acrylic resins, and epoxy-silicone hybrid resins. From the viewpoint of dielectric properties, allyl compounds, modified polyphenylene ether resins, and maleimide resins are more preferable. In addition, the component (B) may be one or more types, and may be used alone or in combination of two or more types.

[0048] In the resin composition of this embodiment, the content ratio of the (A) component to the (B) component is preferably (A):(B)=95:5 to 50:50 by mass ratio, and more preferably (A):(B)=90:10 to 60:40. If the content ratio of the (A) component is less than this range, the flexibility of the cured film may be poor, the relative dielectric constant and the dielectric loss tangent may be high, and Tg may be low. On the other hand, if the content ratio of the (B) component is less than this range, the fluidity of the resin composition when heated may be poor.

[0049] The number average molecular weight of the thermosetting resin of component (B) is preferably not more than 6000, more preferably not more than 4000, and even more preferably not more than 3000. If the number average molecular weight is greater than this range, compatibility may deteriorate and the melt viscosity during heating may become high.

[0050] [(C) Reaction accelerator] The component (C) used in the present invention is a reaction accelerator, which is added to accelerate the crosslinking reaction of the maleimide compound, component (A), and the reaction between the maleimide group in component (A) and the maleimide group-reactive functional group in component (B). The component (C) is not particularly limited as long as it accelerates the crosslinking reaction, and examples thereof include thermal radical polymerization initiators and thermal anionic polymerization initiators.

[0051] Examples of the thermal radical polymerization initiator include methyl ethyl ketone peroxide, methylcyclohexanone peroxide, methylacetoacetate peroxide, acetylacetone peroxide, 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane, 1,1-bis(t-hexylperoxy)cyclohexane, 1,1-bis(t-hexylperoxy)3,3,5-trimethylcyclohexane, 1,1-bis(t-butylperoxy)cyclohexane, 2,2-bis(4,4-di-t -butylperoxycyclohexyl)propane, 1,1-bis(t-butylperoxy)cyclododecane, n-butyl-4,4-bis(t-butylperoxy)valerate, 2,2-bis(t-butylperoxy)butane, 1,1-bis(t-butylperoxy)-2-methylcyclohexane, t-butyl hydroperoxide, p-menthane hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, t-hexyl hydroperoxide, dicumyl peroxide, 2,5-dimethyl 2,5-diethyl-2,5-bis(t-butylperoxy)hexane, α,α'-bis(t-butylperoxy)diisopropylbenzene, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyne-3, isobutyryl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, cinnamic acid peroxide, m-toluoyl peroxide, benzoyl peroxide, diisopropyl Pyl peroxydicarbonate, bis(4-t-butylcyclohexyl) peroxydicarbonate, di-3-methoxybutyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, di(3-methyl-3-methoxybutyl) peroxydicarbonate, di(4-t-butylcyclohexyl) peroxydicarbonate, α,α'-bis(neodecanoylperoxy)diisopropylbenzene, cumyl peroxyneodecanoate, 1,1,3,3-Tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-bis(2-ethylhexanoylperoxy)hexane, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy peroxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxymaleic acid, t-butylperoxylaurate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-2-ethylhexyl monocarbonate, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, t-butylperoxyacetate, t-hexylperoxybenzoate, t-butylperoxyethylhexanoate, Organic peroxides such as 2,2'-azobis(N-butyl-2-methylpropionamide), 2,2'-azobis(N-cyclohexyl-2-methylpropionamide), 2,2'-azobis[N-(2-methylpropyl)-2-methylpropionamide], 2,2'-azobis[N-(2-methylethyl)-2- ... 2,2'-azobis(N-hexyl-2-methylpropionamide), 2,2'-azobis(N-propyl-2-methylpropionamide), 2,2'-azobis(N-ethyl-2-methylpropionamide), 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], 2,2'-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide}, 2,Examples of the azo compounds include 2'-azobis[N-(2-propenyl)-2-methylpropionamide] and dimethyl-1,1'-azobis(1-cyclohexanecarboxylate).

[0052] Examples of the thermal anionic polymerization initiator include amine compounds such as triethylamine, triethylenediamine, 2-(dimethylaminomethyl)phenol, 1,8-diaza-bicyclo[5.4.0]undecene-7, tris(dimethylaminomethyl)phenol, and benzyldimethylamine; and isomers such as 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2,4-diamino-6-[2-(2-methyl-1-imidazolyl)ethyl]-1,3,5-triazine, and 2-phenyl-4-hydroxy-5-methylimidazole. Midazole compounds; and organic phosphorus compounds such as triphenylphosphine, tributylphosphine, trioctylphosphine, tetrabutylphosphonium hexafluorophosphate, tetrabutylphosphonium tetraphenylborate, tetrabutylphosphonium acetate, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium bromide, tetrabutylphosphonium bromide, tetrabutylphosphonium laurate, tetraphenylphosphonium hydrogen phthalate, bis(tetraphenylphosphonium) dihydrogen pyromellitate, and bis(tetrabutylphosphonium) dihydrogen pyromellitate.

[0053] Among these, organic peroxides, which are thermal radical polymerization initiators, are preferred when the (A) component is reacted alone or when the reactive group in the (B) component is a group having a carbon-carbon double bond such as a maleimide group, an alkenyl group, or a (meth)acrylic group. When the (B) component is reacted with an epoxy group, a hydroxyl group, or an acid anhydride group, basic compounds, such as imidazole compounds and amine compounds, which are thermal anionic polymerization initiators, are preferred. These polymerization initiators may be used alone or in combination of two or more.

[0054] The amount of component (C) is not particularly limited, but is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.3 to 3 parts by mass, relative to 100 parts by mass of component (A). Within this range, the resin composition can be sufficiently cured without adversely affecting the physical properties of the resin composition.

[0055] [Adhesion promoter] The resin composition of the present invention may contain an adhesion imparting agent (component (D)) as necessary to impart adhesiveness or tackiness (pressure-sensitive adhesiveness). Examples of adhesion imparting agents include acrylic resins, urethane resins, phenolic resins, terpene resins, and silane coupling agents. Among these, acrylic resins and silane coupling agents are preferred for imparting adhesiveness, and terpene resins are preferred for imparting tackiness (pressure-sensitive adhesiveness). The adhesion imparting agent of component (D) may be used alone or in combination of two or more types.

[0056] The acrylic resin is not particularly limited, and examples thereof include lauryl acrylate, stearyl acrylate, isostearyl acrylate, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate, 2-acryloyloxyethyl phthalate, 2-acryloyloxyethyl acid phosphate, polyethylene glycol diacrylate, dimethylol tricyclodecane diacrylate, trimethylolpropane triacrylate, dipentaerythritol hexaacrylate, and the like. Examples of suitable methacrylates include tetrahydrofurfuryl methacrylate, dioxane glycol diacrylate, 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene diacrylate, lauryl methacrylate, phenoxyethyl methacrylate, phenoxydiethylene glycol methacrylate, tetrahydrofurfuryl methacrylate, isobornyl methacrylate, 2-methacryloyloxyethyl phthalate, 2-methacryloyloxyethyl acid phosphate, polyethylene glycol dimethacrylate, and dimethylol tricyclodecane dimethacrylate.

[0057] The terpene resin is not particularly limited, and examples thereof include homopolymers of terpenes such as monoterpenes such as α-pinene, β-pinene, dipentene, and limonene, sesquiterpenes such as cedrene and farnesene, and diterpenes such as abietic acid, aromatic modified terpene resins which are copolymers of aromatic vinyl compounds such as styrene and α-methylstyrene with the above-mentioned terpenes, and terpene phenol resins which are copolymers of phenols such as phenol, cresol, hydroquinone, naphthol, and bisphenol A with the above-mentioned terpenes, etc. In addition, hydrogenated terpene resins obtained by hydrogenating these terpene resins can also be used.

[0058] The silane coupling agent is not particularly limited, and examples thereof include silane coupling agents such as n-propyltrimethoxysilane, n-propyltriethoxysilane, n-octyltrimethoxysilane, n-octyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, 2-[methoxy(polyethyleneoxy)propyl]-trimethoxysilane, methoxytri(ethyleneoxy)propyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-(methacryloyloxy)propyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, and 3-isocyanatopropyltrimethoxysilane.

[0059] The amount of the adhesion promoter is not particularly limited, but is preferably 0.1 to 20 parts by mass, more preferably 0.3 to 10 parts by mass, and even more preferably 0.5 to 5 parts by mass, per 100 parts by mass of the total of the (A) and (B) components. Within this range, the adhesive strength or cohesive strength of the resin composition can be further improved without changing the mechanical properties of the resin composition.

[0060] [Flame retardant] The resin composition of the present invention may contain a flame retardant (component (E)) as necessary in order to impart flame retardancy. The flame retardant is not particularly limited, and examples thereof include phosphorus-based flame retardants, metal hydrates, halogen-based flame retardants, guanidine-based flame retardants, etc. Examples of phosphorus-based flame retardants include red phosphorus, ammonium phosphates such as monoammonium phosphate, diammonium phosphate, triammonium phosphate, and ammonium polyphosphate, inorganic nitrogen-containing phosphorus compounds such as guanidine phosphate and phosphoric acid amide, phosphoric acid, phosphine oxide, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, cresyl di-2,6-xylenyl phosphate, resorcinol bis-dixylenyl phosphate, resorcinol bis(diphenyl phosphate), 1,3-phenylene bis(di-2,6-xylenyl phosphate), bisphenol A bis(diphenyl phosphate), Examples of suitable phosphazene compounds include 1,3-phenylenebis(diphenylphosphate), divinyl phenylphosphonate, diallyl phenylphosphonate, bis(1-butenyl) phenylphosphonate, phenyl diphenylphosphinate, methyl diphenylphosphinate, bis(2-allylphenoxy)phosphazene, and dicresylphosphazene, as well as melamine phosphate, melamine pyrophosphate, melamine polyphosphate, melam polyphosphate, melem polyphosphate, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide. Examples of suitable metal hydrates include aluminum hydroxide hydrate and magnesium hydroxide hydrate. Examples of halogen-based flame retardants include hexabromobenzene, pentabromotoluene, ethylene bis(pentabromophenyl), ethylene bistetrabromophthalimide, 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane, tetrabromocyclooctane, hexabromocyclododecane, bis(tribromophenoxy)ethane, brominated polyphenylene ether, brominated polystyrene, 2,4,6-tris(tribromophenoxy)-1,3,5-triazine, etc. Examples of guanidine-based flame retardants include guanidine sulfamate, guanidine phosphate, etc.The flame retardant of component (E) may be used alone or in combination of two or more kinds.

[0061] The amount of the flame retardant is not particularly limited, but is preferably 0.1 to 100 parts by mass, more preferably 0.5 to 50 parts by mass, and even more preferably 1 to 30 parts by mass, per 100 parts by mass of the total of components (A) and (B). Within this range, flame retardancy can be imparted to the resin composition without changing the mechanical properties of the resin composition.

[0062] [Inorganic filler] The resin composition of the present invention may further contain an inorganic filler (component (F)). The inorganic filler is not particularly limited, and examples thereof include metal oxides such as silica, titanium dioxide, yttrium oxide, aluminum oxide, magnesium oxide, zinc oxide, and beryllium oxide; metal nitrides such as boron nitride, aluminum nitride, and silicon nitride; carbon-containing particles such as silicon carbide, diamond, and graphene; hollow particles such as silica balloons (hollow silica), carbon balloons, alumina balloons, and aluminosilicate balloons; simple metals such as gold, silver, copper, palladium, aluminum, nickel, iron, cobalt, titanium, manganese, zinc, tungsten, platinum, lead, and tin; and alloys such as solder, steel, and stainless steel. ferrites such as stainless steel, Fe-Cr-Al-Si alloy, Fe-Si-Al alloy, Fe-Ni alloy, Fe-Cu-Si alloy, Fe-Si alloy, Fe-Si-B(-Cu-Nb) alloy, Fe-Si-Cr-Ni alloy, Fe-Si-Cr alloy, Fe-Si-Al-Ni-Cr alloy, etc.; hematite (Fe2O3), magnetite (Fe3O4), Mn-Zn ferrite, Ni-Zn ferrite, Mg-Mn ferrite, Zr-Mn ferrite, Ti-Mn ferrite, Mn-Zn-Cu ferrite, barium ferrite, strontium ferrite, etc. These may be used alone or in combination of two or more.

[0063] By adding metal oxides, metal nitrides, and carbon-containing particles, the linear expansion coefficient of the cured resin composition can be reduced and the thermal conductivity can be increased; by adding hollow particles, the relative dielectric constant, dielectric tangent, density, etc. of the cured resin composition can be reduced; by adding metals and alloys, the electrical conductivity, thermal conductivity, etc. of the cured resin composition can be increased; and by adding ferrites, the cured resin composition can be endowed with electromagnetic wave absorption ability.

[0064] The shape of the inorganic filler is not particularly limited, and examples thereof include spherical, scaly, flake-like, needle-like, rod-like, and elliptical shapes. Among these, spherical, scaly, flake-like, elliptical, and rod-like shapes are preferred, and spherical, scaly, flake-like, and elliptical shapes are more preferred.

[0065] The primary particle size of the inorganic filler is not particularly limited, but is preferably 0.05 to 500 μm, more preferably 0.1 to 300 μm, and even more preferably 1 to 100 μm, as a median diameter measured by a laser diffraction particle size distribution measuring device. If it is within this range, it is easy to uniformly disperse the inorganic filler in the resin composition, and the inorganic filler does not settle, separate, or become unevenly distributed over time, which is preferable.

[0066] The amount of the inorganic filler is not particularly limited, but is preferably 10 to 500 parts by mass, more preferably 30 to 400 parts by mass, and even more preferably 50 to 300 parts by mass, per 100 parts by mass of the total of the components (A) and (B) in the composition of the present invention. Within this range, the inorganic filler can fully exert its function while maintaining the strength of the resin composition.

[0067] (Other additives) The thermosetting maleimide resin composition of the present invention may further contain various additives as necessary within a range that does not impair the effects of the present invention. Examples of such additives include organopolysiloxanes having reactive functional groups, non-functional silicone oils, thermoplastic resins, thermoplastic elastomers, organic synthetic rubbers, photosensitizers, light stabilizers, polymerization inhibitors, pigments, dyes, etc. In order to improve the electrical properties of the cured product of the thermosetting maleimide resin composition, other additives such as ion trapping agents may also be added.

[0068] [Manufacturing method] The method for producing the resin composition of the present invention includes a method in which component (A), component (B), component (C), and other additives as necessary are added and mixed using, for example, a planetary mixer, a stirrer, a ball mill, a bead mill, a roll mill, or the like. The thermosetting maleimide resin composition of the present invention can be dissolved in an organic solvent and treated as a varnish. The thermosetting maleimide resin composition can be easily molded into a sheet or film by forming it into a varnish, and can also be easily applied to and impregnated into glass cloth made of E-glass, low dielectric glass, quartz glass, or the like. Any organic solvent can be used without limitation as long as it dissolves the thermosetting resin components of the (A) and (B) components. Suitable organic solvents include, for example, toluene, xylene, anisole, methyl ethyl ketone (MEK), cyclohexanone, and cyclopentanone. The above organic solvents may be used alone or in combination of two or more. The concentration of the thermosetting maleimide resin composition of the present invention in the varnish is preferably 5 to 80% by mass, more preferably 10 to 75% by mass.

[0069] The thermosetting maleimide resin composition of the present invention can be prepared by applying the varnish to a substrate, removing the solvent to form an uncured resin sheet or film, and further curing the uncured resin sheet or film. It can also be used as a prepreg, a substrate material, an adhesive, a semiconductor encapsulant, or a resin-coated metal foil. There are no limitations on the method or form of use. Examples of use are given below, but the present invention is not limited thereto.

[0070] For example, after applying a thermosetting maleimide resin composition dissolved in an organic solvent to a substrate, the organic solvent is removed by heating the composition at a temperature of usually 80° C. or higher, preferably 100° C. or higher for 0.5 to 5 hours, and then heating the composition at a temperature of 130° C. or higher, preferably 150° C. or higher for 0.5 to 10 hours to form a maleimide resin cured film having a flat surface and a strong surface. The temperature in the drying step for removing the organic solvent and the subsequent heat curing step may be constant, but it is preferable to increase the temperature stepwise. This allows the organic solvent to be efficiently removed from the composition and the curing reaction of the resin to proceed efficiently. Examples of the application method include a spin coater, a slit coater, a spray, a dip coater, a bar coater, and the like, but there is no particular limitation.

[0071] The substrate may be a commonly used one, for example, polyolefin resin such as polyethylene (PE) resin, polypropylene (PP) resin, polystyrene (PS) resin, etc., polyester resin such as polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, polycarbonate (PC) resin, etc., and the surface may be subjected to a release treatment. The thickness of the coating layer is not particularly limited, but the thickness after distillation of the solvent is in the range of 1 to 100 μm, preferably 3 to 80 μm. Furthermore, a cover film may be used on the coating layer.

[0072] Alternatively, the components may be premixed and extruded into a sheet or film using a melt kneader to produce an uncured resin film (uncured resin sheet) or a cured resin film (cured resin sheet).

[0073] [Prepreg] A prepreg according to one embodiment of the present invention comprises the thermosetting maleimide resin composition of the present invention and a fiber substrate. The thermosetting maleimide resin composition in the prepreg may be a semi-cured product of the resin composition. The semi-cured product is a product in which the resin composition has been partially cured to such an extent that it can be further cured. In other words, the semi-cured product is a product in which the resin composition has been semi-cured, that is, in a so-called B-stage. On the other hand, the uncured state may also be called the A-stage.

[0074] Examples of the fiber substrate include E glass, low dielectric glass, quartz glass, S glass, T glass, and the like, and any type of glass can be used. From the viewpoint of making the most of the properties of the thermosetting maleimide resin composition of the present invention, however, quartz glass cloth, which has a low relative dielectric constant and dielectric tangent, is preferred. The thickness of the fiber base material is not particularly limited, but is preferably 5 to 500 μm, more preferably 10 to 100 μm, and even more preferably 20 to 80 μm. Within this range, a prepreg with excellent flexibility, low warpage, and high strength can be obtained. These fiber substrates may be surface-treated by heating or with a silane coupling agent or the like in order to improve the dielectric properties and affinity to resins.

[0075] When producing a prepreg, the thermosetting maleimide resin composition is preferably prepared as a resin varnish in a varnish form so as to be impregnated into a fiber substrate, which is a substrate for forming the prepreg. Such a varnish-like resin composition (resin varnish) is prepared, for example, as follows. First, each component of the resin composition that can be dissolved in an organic solvent is added to the organic solvent and dissolved. At this time, heating may be performed as necessary. Then, a component that is not dissolved in an organic solvent, such as an inorganic filler, is added as necessary, and dispersed until a predetermined dispersion state is reached using a ball mill, a bead mill, a planetary mixer, a roll mill, or the like, to prepare a varnish-like resin composition (resin varnish). The organic solvent used here is not particularly limited as long as it does not inhibit the curing reaction. Specific examples include toluene, xylene, anisole, methyl ethyl ketone (MEK), cyclohexanone, cyclopentanone, and the like.

[0076] Next, the fiber substrate is impregnated with the varnish-like resin composition (resin varnish) by immersion, coating, or the like, and then dried. Impregnation can be repeated multiple times as necessary. In addition, by repeating the impregnation using multiple resin compositions with different compositions and concentrations, it is also possible to adjust the final composition and impregnation amount to the desired one. The fiber substrate impregnated with the resin composition (resin varnish) is heated under desired heating conditions, for example, at 80° C. to 200° C. for 1 minute to 2 hours. By heating, a prepreg including a thermosetting maleimide resin composition in an uncured (A stage) or semi-cured (B stage) state is obtained. The content of the resin composition in the prepreg is not particularly limited, but is preferably 20 to 90% by volume, more preferably 30 to 80% by volume, and even more preferably 40 to 70% by volume. Within this range, the adhesive strength to the conductor can be increased while maintaining the dielectric properties and low warpage.

[0077] The thickness of the prepreg of the present invention is not particularly limited, but is preferably 10 to 500 μm, more preferably 25 to 300 μm, and even more preferably 40 to 200 μm. If it is within this range, a copper-clad laminate can be satisfactorily produced.

[0078] [Copper-clad laminate] The prepreg of the present invention may be used as a copper-clad laminate by overlapping copper foil, pressing, and heat curing. There are no particular limitations on the method for producing a copper-clad laminate, but it can be produced, for example, by using 1 to 20 sheets, preferably 2 to 10 sheets, of the prepreg, placing copper foil on one or both sides of the prepreg, pressing the prepreg, and heat-curing the prepreg. The thickness of the copper foil is not particularly limited, but is preferably 3 to 70 μm, more preferably 10 to 50 μm, and even more preferably 15 to 40 μm. Within this range, a multi-layer copper-clad laminate that maintains high reliability can be formed. The molding conditions for the copper-clad laminate are not particularly limited, but for example, molding can be performed using a multi-stage press, a multi-stage vacuum press, a continuous molding machine, an autoclave molding machine, etc., at a temperature of 100 to 400°C, a pressure of 1 to 100 MPa, and a heating time of 0.1 to 4 hours. Also, the prepreg of the present invention, copper foil, and an inner layer wiring board can be combined and molded to form a copper-clad laminate.

[0079] [Printed wiring board] The copper-clad laminate of the present invention may be subjected to circuit processing and used as a printed wiring board. The method of circuit processing is not particularly limited, but examples thereof include circuit formation processing by drilling, metal plating, etching of metal foil, and the like. Furthermore, a printed wiring board may be produced by a build-up method in which the resin composition or prepreg of the present invention and copper foil are laminated in that order.

[0080] [Semiconductor encapsulation materials] The thermosetting maleimide resin composition of the present invention may be used as a semiconductor encapsulant. The method for producing the semiconductor encapsulant is not particularly limited, but for example, the semiconductor encapsulant can be produced by blending the components (A) and (B) and, if necessary, other components in a predetermined composition ratio, mixing them sufficiently uniformly using a mixer or the like, melt-mixing them using a hot roll, kneader, extruder, etc., then cooling and solidifying them, and pulverizing them to an appropriate size. The resulting resin composition can be used as an encapsulant. Common molding methods using semiconductor encapsulation materials include transfer molding and compression molding. In the transfer molding method, a transfer molding machine is used and the molding pressure is 5 to 20 N / mm2 In the compression molding method, the molding temperature is 120 to 190° C. and the molding time is 30 to 500 seconds, preferably 150 to 185° C. and 30 to 180 seconds. In the compression molding method, a compression molding machine is used and the molding temperature is 120 to 190° C. and the molding time is 30 to 600 seconds, preferably 130 to 160° C. and 120 to 300 seconds. In either molding method, post-curing may be performed at 150 to 225° C. for 0.5 to 20 hours.

[0081] [glue] The thermosetting maleimide resin composition of the present invention may be used as an adhesive. The method for producing the adhesive is not particularly limited, but for example, the adhesive can be produced by blending the (A) component, the (B) component, and other components as necessary in a predetermined composition ratio, mixing them using a mixer such as a planetary mixer, and then kneading and mixing them using a three-roll mill as necessary to improve dispersibility. The obtained resin composition can be used as an adhesive. The adhesive may be used by a conventional method and device. Typical curing conditions are a temperature of 100° C. to 200° C., preferably 120° C. to 180° C., and a time of 1 hour to 8 hours, preferably 1.5 hours to 3 hours.

[0082] [Metal foil with resin] The thermosetting maleimide resin composition of the present invention may be used as a resin-coated metal foil. The method for producing the resin-coated metal foil is not particularly limited, but for example, the above-mentioned varnish-like resin composition is prepared, and the varnish is applied to a supporting substrate using a die coater or the like, and then the organic solvent is dried by heating or blowing hot air or the like to semi-cure the substrate, and further a metal foil is attached onto an uncured resin film to produce the metal foil. The obtained film can be used as the resin-coated metal foil. The drying conditions are not particularly limited, but it is preferable to dry so that the content of the organic solvent in the resin composition layer is 10% by mass or less, preferably 5% by mass or less. Although it varies depending on the amount of the organic solvent in the varnish and the boiling point of the organic solvent, for example, in the case of a varnish containing 30 to 60% by mass of the organic solvent, the resin composition layer can be formed by drying at 50 to 150°C for about 3 to 10 minutes. Note that if drying is performed at a higher temperature for a longer period of time, the curing reaction of the composition may proceed and the composition may harden. The metal foil to be attached is not particularly limited, but examples thereof include copper foil and aluminum foil. A protective film conforming to the support may be further laminated on the surface not in contact with the support. By laminating the protective film, it is possible to prevent the adhesion of dirt and the like to the surface of the metal foil and to prevent scratches. The resin-coated metal foil can be wound up in a roll for storage. EXAMPLES

[0083] The present invention will be described in detail below with reference to examples and comparative examples. However, the present invention is not limited to the following examples. In the examples and comparative examples, "room temperature" means 25°C.

[0084] The molecular weights shown in the following examples are number average molecular weights (Mn) measured by gel permeation chromatography (GPC) using polystyrene as a standard substance. The measurement conditions are as follows: [GPC measurement conditions] Developing solvent: Tetrahydrofuran Flow rate: 0.35mL / min column: TSKgel guardcolumn SuperHZ-L(4.6mmI.D.×2cm×1) TSKgel SuperH-RC(6.0mmI.D.×15cm×2) TSKgel SuperHZ4000(4.6mmI.D.×15cm×1) TSKgel SuperHZ3000(4.6mmI.D.×15cm×1) TSKgel SuperHZ2000 (4.6 mm I.D. × 15 cm × 2) (All are manufactured by Tosoh Corporation) Column temperature: 40 °C Sample injection volume: 10 μL (sample concentration: 0.2 mass% - tetrahydrofuran solution) Detector: differential refractive index detector (RI)

[0085] <Component A: bismaleimide compound> [Synthesis Example 1] Synthesis of bismaleimide compound A-1 In a 1 L four-necked glass flask equipped with a stirrer, Dean-Stark tube, cooling condenser and thermometer, 52.27 g (0.150 mol) of 9,9-bis(4-aminophenyl)fluorene (hereinafter also referred to as FDA), 104.10 g (0.200 mol) of 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride, 250 g of toluene, 250 g of N-methyl-2-pyrrolidone and 9.61 g (0.100 mol) of methanesulfonic acid were added, and the mixture was stirred at 80 °C for 3 hours to synthesize an amic acid. Then, the temperature was raised to 120 °C as it was, and the mixture was stirred for 8 hours while distilling off the by-produced water to synthesize a block copolymer. Then, to the flask containing the block copolymer solution cooled to 80 °C, Priamine-1075 (manufactured by CRODA, average composition formula H2N-C 36 H 70Amic acid was synthesized by adding 53.44g (0.100 mol) of dimer diamine represented by -NH2 and stirring at 80 ° C for 2 hours. Then, the temperature was raised to 120 ° C as it was, and stirring was continued for 8 hours while distilling off the by-produced water, to synthesize a diamine at both ends. The flask containing the obtained diamine at both ends solution was cooled to room temperature, and then 10.79g (0.110 mol) of maleic anhydride was added, and stirring was continued for 2 hours at room temperature to synthesize maleamic acid. Then, the temperature was raised to 120 ° C as it was, and stirring was continued for 8 hours while distilling off the by-produced water, to synthesize bismaleimide. The obtained solution was washed 10 times with a mixed aqueous solution of water and isopropyl alcohol to remove impurities such as catalysts. Then, the water in the system was azeotropically dehydrated with toluene by vacuum distillation to obtain a brown varnish solution with a solid content of 50 mass % in which a bismaleimide compound having a structure represented by the following formula (A-1) was dissolved in toluene. The number average molecular weight of the resulting bismaleimide compound was 6,200. [ka] m≒3, n≒4 (both average values) -C 36 H 70 - represents a hydrocarbon group derived from a dimer acid skeleton derived from dimer diamine (Priamine-1075).

[0086] [Synthesis Example 2] Synthesis of bismaleimide compound A-2 64.07g (0.167 mol) of 9,9-bis(4-amino-3-fluorophenyl)fluorene, 104.10g (0.20 mol) of 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride, 250g of toluene, 250g of N-methyl-2-pyrrolidone, and 9.61g (0.10 mol) of methanesulfonic acid were added to a 1L glass four-neck flask equipped with a stirrer, a Dean-Stark tube, a cooling condenser, and a thermometer, and amic acid was synthesized by stirring at 80°C for 3 hours. Thereafter, the mixture was heated to 120°C and stirred for 8 hours while distilling off the by-product water, synthesizing a block copolymer. Then, Priamine-1075 (manufactured by CRODA, average composition formula H2N-C 36 H 70 Amic acid was synthesized by adding 44.53 g (0.083 mol) of dimer diamine represented by -NH2 and stirring at 80 ° C for 2 hours. Then, the temperature was raised to 120 ° C as it was, and stirring was continued for 8 hours while distilling off the by-produced water, to synthesize a diamine at both ends. The flask containing the obtained diamine at both ends solution was cooled to room temperature, and then 10.79 g (0.110 mol) of maleic anhydride was added, and stirring was continued for 2 hours at room temperature to synthesize maleamic acid. Then, the temperature was raised to 120 ° C as it was, and stirring was continued for 8 hours while distilling off the by-produced water, to synthesize bismaleimide. The obtained solution was washed 10 times with a mixed aqueous solution of water and isopropyl alcohol to remove impurities such as catalysts. Then, the water in the system was azeotropically dehydrated with toluene by vacuum distillation to obtain a brown varnish solution with a solid content of 50 mass % in which a bismaleimide compound having a structure represented by the following formula (A-2) was dissolved in toluene. The number average molecular weight of the resulting bismaleimide compound was 6,800. [ka] m≒2, n≒4 (both average values) -C 36 H 70 - represents a hydrocarbon group derived from a dimer acid skeleton derived from dimer diamine (Priamine-1075).

[0087] [Synthesis Example 3] Synthesis of bismaleimide compound A-3 In a 1L glass four-neck flask equipped with a stirrer, a Dean-Stark tube, a cooling condenser and a thermometer, 44.40g (0.167 mol) of 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-inden-5-amine, 104.10g (0.20 mol) of 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride, 250g of toluene, 250g of N-methyl-2-pyrrolidone and 9.61g (0.10 mol) of methanesulfonic acid were added and stirred at 80°C for 3 hours to synthesize an amic acid. Thereafter, the mixture was heated to 120°C and stirred for 8 hours while distilling off the by-product water to synthesize a block copolymer. After that, Priamine-1075 (CRODA, average composition H2N-C 36 H 70 Amic acid was synthesized by adding 44.53 g (0.083 mol) of dimer diamine represented by -NH2 and stirring at 80 ° C for 2 hours. Then, the temperature was raised to 120 ° C as it was, and stirring was continued for 8 hours while distilling off the by-produced water, to synthesize a diamine at both ends. The flask containing the obtained diamine at both ends solution was cooled to room temperature, and then 10.79 g (0.110 mol) of maleic anhydride was added, and stirring was continued for 2 hours at room temperature to synthesize maleamic acid. Then, the temperature was raised to 120 ° C as it was, and stirring was continued for 8 hours while distilling off the by-produced water, to synthesize bismaleimide. The obtained solution was washed 10 times with a mixed aqueous solution of water and isopropyl alcohol to remove impurities such as catalysts. Then, the water in the system was azeotropically dehydrated with toluene by vacuum distillation to obtain a brown varnish solution with a solid content of 50 mass % in which a bismaleimide compound having a structure represented by the following formula (A-3) was dissolved in toluene. The number average molecular weight of the resulting bismaleimide compound was 7,700. [ka] m≒3, n≒6 (both average values) -C 36 H 70- represents a hydrocarbon group derived from a dimer acid skeleton derived from dimer diamine (Priamine-1075).

[0088] [Synthesis Example 4] Synthesis of bismaleimide compound A'-1 29.71g (0.167 mol) of 2,5-diethyl-4-methylbenzene-1,3-diamine, 104.10g (0.20 mol) of 4,4'-(4,4'-isopropylidenediphenoxy)diphthalic anhydride, 250g of toluene, 250g of N-methyl-2-pyrrolidone, and 9.61g (0.10 mol) of methanesulfonic acid were added to a 1L glass four-neck flask equipped with a stirrer, a Dean-Stark tube, a cooling condenser, and a thermometer, and amic acid was synthesized by stirring at 80°C for 3 hours. Thereafter, the mixture was heated to 120°C and stirred for 8 hours while distilling off the by-product water, synthesizing a block copolymer. Then, Priamine-1075 (manufactured by CRODA, average composition formula H2N-C 36 H 70 Amic acid was synthesized by adding 44.53 g (0.083 mol) of dimer diamine represented by -NH2 and stirring at 80 ° C for 2 hours. Then, the temperature was raised to 120 ° C as it was, and stirring was continued for 8 hours while distilling off the by-produced water, to synthesize a diamine at both ends. The flask containing the obtained diamine at both ends solution was cooled to room temperature, and then 10.79 g (0.110 mol) of maleic anhydride was added, and stirring was continued for 2 hours at room temperature to synthesize maleamic acid. Then, the temperature was raised to 120 ° C as it was, and stirring was continued for 8 hours while distilling off the by-produced water, to synthesize bismaleimide. The obtained solution was washed 10 times with a mixed aqueous solution of water and isopropyl alcohol to remove impurities such as catalysts. Then, the water in the system was azeotropically dehydrated with toluene by vacuum distillation to obtain a brown varnish solution with a solid content of 50 mass % in which a bismaleimide compound having a structure represented by the following formula (A'-1) was dissolved in toluene. The number average molecular weight of the resulting bismaleimide compound was 5,900. [ka] m≒2, n≒3 (both average values) -C 36 H 70 - represents a hydrocarbon group derived from a dimer acid skeleton derived from dimer diamine (Priamine-1075).

[0089] (A’-2): A bismaleimide compound (BMI-2500, number average molecular weight: 4,500, manufactured by Designer Molercules Inc.) represented by the following formula (A’-2) [Chemical formula] m ≒ 3, n ≒ 5 (both are average values) -C 36 H 70 - represents a hydrocarbon group derived from a dimer acid skeleton derived from dimer diamine (Priamine-1075).

[0090] (A’-3): A bismaleimide compound (BMI-2300, number average molecular weight: 400, manufactured by Daiwa Kasei Kogyo Co., Ltd.) represented by the following formula (A’-3) [Chemical formula] n ≒ 2 (average value)

[0091] <Component B: Thermosetting resin> (B-1): A compound having one isocyanurate ring and three allyl groups in one molecule (TAIC, number average molecular weight: 200, manufactured by Mitsubishi Chemical Corporation) (B-2): A compound having one isocyanurate ring and two allyl groups in one molecule (L-DAIC, number average molecular weight: 400, manufactured by Shikoku Kasei Holdings Co., Ltd.) (B-3): A dimer acid skeleton-containing bismaleimide compound (SLK-6895, number average molecular weight: 1,000, manufactured by Shin-Etsu Chemical Co., Ltd.) (B-4) Terminal methacryl-modified polyphenylene ether resin (SA9000, number average molecular weight: 2,000, manufactured by SABIC)

[0092] <Component C: Reaction accelerator> (C-1): 2,5-dimethyl-2,5-di(t-butylperoxy)hexane (Trigonox 101, manufactured by Nouryon Chemical Co., Ltd.)

[0093] <Other ingredients> (D) Adhesion promoter (D-1): 3-(methacryloyloxy)propyltrimethoxysilane (KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) (E) Flame retardants (E-1): Resorcinol bis-dixylenyl phosphate (PX-200, manufactured by Daihachi Chemical Industry Co., Ltd.) (E) Inorganic filler (E-1): Spherical silica slurry having an average particle size of 0.5 μm in toluene (5SV-CT1, manufactured by Admattex Co., Ltd., solid concentration 75% by mass)

[0094] <Preparation of Resin Varnish> For Examples 1 to 11 and Comparative Examples 1 to 6, in addition to the formulations (parts by mass) shown in Tables 1 and 2, 100 parts by mass of anisole was added for a total of 100 parts by mass of each component. Each component was placed in a 500 mL four-neck flask equipped with a Dimroth condenser and a stirrer, stirred at 80°C for 30 minutes, and then cooled to room temperature to obtain a varnish-like resin composition (resin varnish).

[0095] <Preparation of uncured resin film> The resin varnish obtained by the above procedure was applied to a support film made of a 38 μm-thick PET film using a roller coater, and then dried at 120° C. for 10 minutes to remove the solvent, forming an uncured resin film with a thickness of 80 μm on the support film.

[0096] <Minimum melt viscosity> The uncured resin film was peeled off from the support film, and then compressed while being heated to 100°C to prepare a 1 mm thick test piece. Using this test piece, the minimum melt viscosity (Pa·s) was measured using a parallel plate type viscoelasticity measuring device (Rheology Corp. "Soliquid Meter MR-300"). The measurement conditions were a starting temperature range of 120°C to 180°C, a heating rate of 10°C / min, a measurement temperature interval of 2°C, and a vibration frequency of 2 Hz. The lowest value measured continuously as the measured value of the minimum melt viscosity was evaluated according to the following criteria. The results are shown in Tables 1 and 2. (○) Minimum melt viscosity is less than 1,200 Pa·s (×) Minimum melt viscosity is 1,200 Pa·s or more

[0097] <Preparation of cured resin film> The uncured resin film obtained by the above procedure was heated at 180° C. for 2 hours in a nitrogen atmosphere to obtain a cured resin film.

[0098] <Flexibility of cured resin film> The cured resin film was folded 180° 5 times, and the film without defects such as cracks was rated as ◯, and the film with defects such as cracks was rated as ×. The results are shown in Tables 1 and 2.

[0099] <Dielectric constant, dielectric loss tangent> A network analyzer (Keysight E5063-2D5) was connected to a strip line (Keycom), and the cured resin film was dried at 120°C for 1 hour, and then stored in a room at 25°C and 50% humidity for 24 hours, after which the relative dielectric constant and dielectric loss tangent at a frequency of 10 GHz were measured. The results are shown in Tables 1 and 2.

[0100] <Moisture resistance test> To confirm the moisture resistance, the cured resin film was left at 85°C and 85% humidity for 1000 hours, and then the dielectric constant and dielectric loss tangent at a frequency of 10 GHz were measured in the same manner as above. The results are shown in Tables 1 and 2.

[0101] <Heat resistance test> In order to confirm the high temperature resistance, the cured resin film was left at 150° C. in an air atmosphere for 1000 hours, and then the dielectric constant and the dielectric loss tangent at a frequency of 10 GHz were measured in the same manner as above. The results are shown in Tables 1 and 2.

[0102] <Glass transition temperature> The storage modulus (MPa) of the cured resin film was measured in the range of -20°C to 300°C using a DMA Q800 (manufactured by TA Instruments Co., Ltd.), and the peak top temperature obtained from a graph plotting Tan δ values ​​derived from the obtained storage modulus and loss modulus values ​​was taken as the glass transition temperature (Tg). The measurement conditions were a sample of 40 mm x 5 mm x 80 μm thickness, a heating rate of 5°C / min, a frequency of 10 Hz, a tensile mode, and an amplitude of 15 μm. The results are shown in Tables 1 and 2.

[0103] <Thermal expansion coefficient> The coefficient of thermal expansion (CTE) of the cured resin film was measured using a TMA Q400 (manufactured by TA Instruments) in the range of -50°C to 300°C, and the coefficient of thermal expansion was calculated in the range of 0°C to 40°C. The measurement was performed under the following conditions: a sample of 30 mm x 3 mm x 80 μm thickness, a heating rate of 5°C / min, and a test load of 0.075 N. The results are shown in Tables 1 and 2.

[0104] [Table 1]

[0105] [Table 2]

[0106]

[0113] From the above results, the thermosetting maleimide resin composition of the present invention has a low minimum melt viscosity, and a cured resin film of the thermosetting maleimide resin composition has good flexibility, a low dielectric constant and dielectric tangent, excellent moisture resistance and heat resistance, a high glass transition temperature, and a low thermal expansion coefficient. In particular, compared to Comparative Example 1, which has the same resin skeleton except that the divalent group having an aromatic ring in component (A) contained in the thermosetting maleimide resin composition of the present invention is replaced with a divalent group not having a fluorene skeleton or an indene skeleton, it was found that the thermosetting maleimide resin composition of the present invention has a lower minimum melt viscosity, and the cured resin film of the thermosetting maleimide resin composition has low relative dielectric constant and dielectric tangent, and changes in dielectric properties are small even in high-temperature environments, resulting in excellent heat resistance. [Industrial Applicability]

[0107] The thermosetting maleimide resin composition of the present invention has a low minimum melt viscosity, and a cured product of the thermosetting maleimide resin composition has a low thermal expansion coefficient, a high glass transition temperature (Tg), and excellent moisture resistance and heat resistance, so that it is possible to provide a thermosetting maleimide resin composition that gives a cured product having a low relative dielectric constant and a low dielectric tangent and high reliability even in a high-temperature environment. Specifically, the thermosetting maleimide resin composition of the present invention is useful for applications such as prepregs, copper-clad laminates, printed wiring boards, semiconductor encapsulants, adhesives, and resin-coated metal foils used in electronic devices for high-frequency bands that require insulating materials with excellent dielectric properties.

Claims

1. (A) Formula (1) below 【Chemistry 1】 (In formula (1), A independently represents a tetravalent organic group containing a cyclic structure. B independently represents a divalent hydrocarbon group derived from a dimer acid skeleton. Q independently represents a divalent group having a fluorene skeleton or an indene skeleton, as represented by either formula (2-1) or (2-2) below: 【Chemistry 2】 (In formula (2-1), R 1 are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a (hetero)aryl group having 4 to 10 carbon atoms, a hydroxyl group, an alkoxy group, a halogeno group, a trifluoromethyl group, an amino group, or a sulfenyl group; 2 are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a (hetero)aryl group having 4 to 10 carbon atoms, a hydroxyl group, an alkoxy group, a halogeno group, a trifluoromethyl group, an amino group, or a sulfenyl group. W is B or Q. n is 1 to 100, and m is 1 to 100. The order of the repeating units bounded by n and m is not limited, and the bonding pattern may be alternating, block, or random. A bismaleimide compound represented by the formula: (B) a thermosetting resin having one or more maleimide group-reactive functional groups selected from an alkenyl group, a maleimide group, an epoxy group, a cyanate group, a hydroxyl group, an acid anhydride group, a (meth)acrylic group, and a thiol group; and (C) Reaction accelerator 1. A thermosetting maleimide resin composition comprising:

2. 2. The thermosetting maleimide resin composition according to claim 1, wherein the content ratio of the component (A) to the component (B) is, in terms of mass ratio, (A):(B)=95:5 to 50:

50.

3. 2. The thermosetting maleimide resin composition according to claim 1, wherein the bismaleimide compound of formula (1) has a number average molecular weight of 3,000 to 50,000.

4. 2. The thermosetting maleimide resin composition according to claim 1, wherein in the bismaleimide compound of the formula (1), the bonding pattern of each repeating unit bound by n and m is a block.

5. 2. The thermosetting maleimide resin composition according to claim 1, wherein A in formula (1) is any one of tetravalent organic groups represented by the following formulae: 【Chemistry 3】

6. 2. The thermosetting maleimide resin composition according to claim 1, wherein the number average molecular weight of component (B) is 6,000 or less.

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