Maleimide resin mixture, curable resin composition, and cured product thereof

Abstract

The present invention provides: a maleimide resin mixture having excellent a high elastic modulus and low water-absorbing properties; a curable resin composition; and a cured product thereof.　This maleimide resin mixture comprises: a maleimide resin represented by formula (1); a compound represented by formula (M-1); and at least one selected from among compounds represented by formulae (A-1), (M-A-1), and (M-A-2), wherein the value (α / β) obtained by dividing the total content (α) of the compounds represented by formulae (A-1), (M-A-1), and (M-A-2) by the content (β) of the compound represented by formula (M-1) is 0.001-0.3. (In formula (1), a plurality of Rs each independently represent a C1-C5 hydrocarbon group. A plurality of Xs each independently represent a C1-C25 hydrocarbon group. p is an integer of 0-5. q is an integer of 0-4. A plurality of rs are each independently an integer of 0-3. l, m, and n are the numbers of repetitions and are each independently an integer of 0-20. The average value lave of 1 is 0.05≤lave≤20, and the sum of the average value mave of m and the average value nave of n is 0.01≤mave+nave≤10. The bonding order of the respective structures having the repeating units of l, m, and n may be random or may be a block.) (In formulae (M-1), (A-1), (M-A-1), and (M-A-2), a plurality of Rs each independently represent a C1-C5 hydrocarbon group. A plurality of Xs each independently represent a C1-C25 hydrocarbon group. A plurality of ps are each independently 0-5. A plurality of qs are each independently an integer of 0-4. r is an integer of 0-3.)

Description

Maleimide resin mixture, curable resin composition and its cured product

[0001] The present invention relates to maleimide resin mixtures, curable resin compositions, and cured products thereof, and is suitably used in electrical and electronic components such as semiconductor encapsulants, printed circuit boards, build-up laminates, and optical waveguide devices, as well as lightweight, high-strength materials such as carbon fiber reinforced plastics and glass fiber reinforced plastics, and in 3D printing applications.

[0002] In recent years, the required characteristics of laminates used to mount electrical and electronic components have become broader and more sophisticated due to the expansion of their application fields. For example, mobile communication terminals such as smartphones are rapidly becoming more multifunctional, high-performance, thinner, and smaller, and the printed circuit boards used in them are required to have finer wiring, more multilayer wiring, thinner designs, and improved mechanical properties. In particular, the thinning of printed circuit boards has led to the problem of warping in semiconductor packages, which can easily cause mounting defects. Especially in semiconductor packages (hereinafter referred to as PKGs) used in smartphones and other devices, thinning of the PKG substrate is required to meet the demands for miniaturization, thinning, and high density, but as the PKG substrate becomes thinner, its rigidity decreases, and problems such as significant warping occur due to heating when soldering the PKG to the motherboard (PCB). In addition, if insulating materials that easily absorb water are used, stress is generated when the water contained in the insulating resin evaporates during solder reflow, causing defects such as cracks and interfacial delamination. To mitigate this, there is a need for PKG substrate materials with a high Tg (transition temperature) above the soldering temperature and a low coefficient of thermal expansion, as well as the resin materials used as their raw materials. Furthermore, it is important that these materials have a high modulus of elasticity to impart rigidity.

[0003] In addition, the fifth-generation communication system "5G," whose development is currently accelerating, is expected to achieve even greater capacity and higher speed communication. 5G will utilize higher frequencies, and reducing transmission loss is crucial for realizing high-speed communication using high frequencies, thus requiring even lower dielectric properties for substrate materials. Transmission loss on printed circuit boards originates from conductor loss and dielectric loss. As described in Non-Patent Literature 1, conductor loss is proportional to the square root of the relative permittivity and the dielectric loss tangent of the dielectric material. Therefore, improving the dielectric loss tangent, which contributes more to reducing transmission loss than the relative permittivity, is effective. Examples of low-dielectric materials include thermoplastic materials such as PTFE (polytetrafluoroethylene) and LCP (liquid crystal polymer), but they have poor moldability compared to thermosetting resins. Therefore, the development of thermosetting resins with excellent low dielectric properties is desired.

[0004] Against this backdrop, polymer materials with high heat resistance and excellent low dielectric properties are being investigated. For example, Patent Document 1 proposes a composition containing maleimide resin and propenyl group-containing phenol resin. However, on the other hand, since phenolic hydroxyl groups that do not participate in the reaction remain during the curing reaction, the electrical properties and low water absorption are not sufficient. Patent Document 2 discloses an allyl ether resin in which hydroxyl groups are substituted with allyl groups. However, it has been shown that a Claisen rearrangement occurs at 190°C, and at 200°C, which is the typical molding temperature for substrates, phenolic hydroxyl groups that do not contribute to the curing reaction are generated, so the electrical properties cannot be satisfied. In addition, introducing a flexible structure such as an allyl group tends to reduce the elastic modulus.

[0005] "Signal Loss Factors in High-Speed ​​Signal Transmission on Printed Circuit Boards," 29th Spring Conference of the Japan Society for Electronics Packaging, Session ID: 16P1-17, 2015.

[0006] Japanese Patent Publication No. 04-359911, International Publication No. 2016 / 002704

[0007] The present invention has been made in view of such circumstances, and an object of the present invention is to provide a maleimide resin mixture excellent in high elastic modulus and low water absorption, a curable resin composition, and a cured product thereof.

[0008] That is, the present invention relates to the following [1] to [5]. In the present invention, "(numerical value 1) to (numerical value 2)" indicates that the upper and lower limit values are included. (Meth)acryl means acryl and / or methacryl, and (meth)acrylate means acrylate and / or methacrylate. [1] A maleimide resin represented by the following formula (1), a compound represented by the following formula (M-1), and at least one selected from the compounds represented by the following formulas (A-1), (M-A-1), and (M-A-2), wherein a value (α / β) obtained by dividing a total content (α) of the compounds represented by the following formulas (A-1), (M-A-1), and (M-A-2) by a content (β) of the compound represented by the following formula (M-1) is 0.001 to 0.3.

[0009]

[0010] (In formula (1), a plurality of R each independently represent a hydrocarbon group having 1 to 5 carbon atoms. A plurality of X each independently represent a hydrocarbon group having 1 to 25 carbon atoms. p is an integer of 0 to 5. q is an integer of 0 to 4. A plurality of r each independently represent an integer of 0 to 3. l, m, and n are the number of repetitions, each independently being an integer of 0 to 20. The average value of l ａｖｅ is 0.05≦l ａｖｅ ≦20, and the average value of m, m ａｖｅ and the average value of n, n ａｖｅの sum is 0.01≦m ａｖｅ +n ａｖｅ ≦10. The bonding order of each structure having repeating units of l, m, and n may be random or block.)

[0011]

[0012] (In formulas (M-1), (A-1), (M-A-1), and (M-A-2), a plurality of R each independently represent a hydrocarbon group having 1 to 5 carbon atoms. A plurality of X each independently represent a hydrocarbon group having 1 to 25 carbon atoms. A plurality of p are each independently 0 to 5. A plurality of q are each independently an integer of 0 to 4. r is an integer of 0 to 3.) [2] The maleimide resin mixture according to the preceding item [1], wherein X in the formulas (1), (M-1), (A-1), (M-A-1), and (M-A-2) is represented by any one or more of the following formulas (a) to (l).

[0013]

[0014] (In formulas (a) to (l), * represents a bonding position. Plural R １ each independently represent a hydrocarbon group having 1 to 5 carbon atoms. Plural R ２ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms. i is an integer of 0 to 2. A plurality of k are each independently an integer of 0 to 5. A plurality of s are each independently an integer of 0 to 4. A plurality of t are each independently an integer of 0 to 3.) [3] A curable resin composition containing the maleimide resin mixture according to the preceding item [1] or [2]. [4] The curable resin composition according to the preceding item [3], further containing any one or more of a curing accelerator, a polymerization initiator, an epoxy resin, an active ester compound, a phenol resin, a polyphenylene ether compound, an amine resin, a compound having an ethylenically unsaturated bond, an isocyanate resin, a polyamide resin, a maleimide compound, a cyanate ester resin, a polyimide resin, polybutadiene and modified products thereof, polystyrene and modified products thereof, polyethylene and modified products thereof, and a benzoxazine compound. [5] A cured product obtained by curing the curable resin composition according to the preceding item [3] or [4].

[0015] According to the present invention, a maleimide resin mixture excellent in high elastic modulus and low water absorption can be provided.

[0016] A GPC chart of Synthesis Example 1 is shown. In Synthesis Example 1 １The H-NMR chart is shown. The HPLC chart of synthesis example 2 is shown. The GPC chart of synthesis example 2 is shown. １ The H-NMR chart is shown. The GPC chart for synthesis example 3 is shown. １ The H-NMR chart is shown. The HPLC chart of synthesis example 4 is shown. The GPC chart of synthesis example 4 is shown. １ The H-NMR chart is shown.

[0017] The embodiments of the present invention (hereinafter also referred to as "this embodiment") will be described in more detail below.

[0018] The maleimide resin mixture of this embodiment contains a maleimide resin represented by the following formula (1), a compound represented by the following formula (M-1), and one or more compounds selected from the following formulas (A-1), (M-A-1), and (M-A-2).

[0019]

[0020] In formula (1) above, each of the multiple Rs independently represents a hydrocarbon group having 1 to 5 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. If the number of carbon atoms is 6 or more, molecular vibration is likely to occur when exposed to high frequencies, which may lead to increased transmission loss at high frequencies, as well as a decrease in heat resistance such as the glass transition temperature. X represents a hydrocarbon group having 1 to 25 carbon atoms. From the viewpoint of exhibiting solvent solubility, dielectric properties, mechanical strength, low water absorption, and high modulus of elasticity, it is preferable that it be one or more of the formulas (a) to (l) described later, more preferably one or more of the formulas (a), (d), (g), and (i) to (l), particularly preferably one or more of the formulas (a), (i), (k), and (l), and most preferably one or more of the formulas (a), (i), (k), and (l). Each of the multiple ps independently represents an integer from 0 to 5, preferably from 0 to 4, more preferably from 0 to 3, and particularly preferably from 0 to 2. q is an integer between 0 and 4, preferably between 0 and 3, and more preferably between 0 and 2. Each of the multiple r values ​​is an independent integer between 0 and 3, preferably between 0 and 2. l, m, and n are repeating numbers, each an independent integer between 0 and 20. The average value of l is l. ａｖｅ 0.05 ≤ l ａｖｅ ≤ 20, and 0.1 ≤ l ａｖｅ Preferably, it is ≤15, and 0.2 ≤ l ａｖｅ It is more preferable that ≤ 10, and 0.5 ≤ l ａｖｅ It is particularly preferable that the value of m is ≤ 5. ａｖｅ is 0 ≤ m ａｖｅ ≤ 5 and 0.001 ≤ m ａｖｅ Preferably, it is ≤2, and 0.002 ≤ m ａｖｅ It is even more preferable that ≤ 1, and 0.003 ≤ m ａｖｅ It is particularly preferable that n be ≤ 0.6. ａｖｅ is 0 ≤ n ａｖｅ ≤ 1 and 0 ≤ n ａｖｅ Preferably, ≤ 0.7, and 0 ≤ n ａｖｅ It is even more preferable that ≤ 0.5, and 0 ≤ n ａｖｅIt is particularly preferable that the value of m is ≤ 0.2. ａｖｅ The average value of n ａｖｅの Sum ａｖｅ +n ａｖｅ For 0.01 ≤ m ａｖｅ +n ａｖｅ ≤ 10 and 0.02 ≤ m ａｖｅ +n ａｖｅ Preferably, it is ≤5, and 0.03 ≤ m ａｖｅ +n ａｖｅ It is even more preferable that ≤ 3, and 0.05 ≤ m ａｖｅ +n ａｖｅ It is particularly preferable that the value is ≤ 1. The bonding order of each structure having repeating units of l, m, and n may be random or in blocks. The maleimide resin mixture of this embodiment has a structure with m and n repeating numbers within the molecule, resulting in a cured product with excellent high modulus of elasticity and low water absorption. When the molecule has a structure with maleimide groups and repeating units of m, the secondary amine structure acts as a curing agent by Michael addition to the maleimide group, and the lone pair of electrons of the amino group also acts as an anionic polymerization catalyst, thus improving curability and increasing the crosslinking density of the cured product. When the molecule has a structure with maleimide groups and repeating units of n, the lone pair of electrons of the amino group also acts as an anionic polymerization catalyst, thus improving curability and increasing the crosslinking density of the cured product.

[0021]

[0022] In the above formulas (a) to (l), * indicates the bonding position. There are multiple R １ Each of these independently represents a hydrocarbon group having 1 to 5 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. Multiple R groups exist. ２Each independently represents a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and particularly preferably a hydrogen atom or a methyl group. i is an integer from 0 to 2, preferably an integer from 0 to 1. Multiple k are integers from 0 to 5, preferably an integer from 0 to 3, more preferably an integer from 0 to 2, and most preferably an integer from 0 to 1. Multiple s are independently integers from 0 to 4, preferably an integer from 0 to 2, and more preferably an integer from 0 to 1. Multiple t are independently integers from 0 to 3, preferably an integer from 0 to 2, and more preferably an integer from 0 to 1.

[0023] The maleimide resin mixture of this embodiment contains a compound represented by the following formula (M-1), and one or more compounds selected from the following formulas (A-1), (M-A-1), and (M-A-2). Preferably, it contains one or more compounds selected from the following formulas (A-1), (M-A-1), and (M-A-2), and more preferably, it contains one or more compounds selected from the following formulas (M-A-1) and (M-A-2). The compounds represented by the following formulas (A-1), (M-A-1), and (M-A-2) act as curing agents by the addition of secondary amines to maleimide via Michael addition, and exhibit anionic polymerization effects due to amino groups. This improves curability and the crosslinking density of the cured product, making it possible to obtain a cured product with excellent heat resistance, high modulus of elasticity, and low water absorption. The content of the compound represented by the following formula (A-1) is preferably 0.05 to 20 parts by mass, more preferably 0.05 to 10 parts by mass, even more preferably 0.1 to 5 parts by mass, and most preferably 0.1 to 3 parts by mass, per 100 parts by mass of the compound represented by the following formula (M-1). The content of the compound represented by the following formula (M-A-1) is preferably 0.1 to 25 parts by mass, more preferably 0.3 to 22 parts by mass, and even more preferably 0.5 to 20 parts by mass, per 100 parts by mass of the compound represented by the following formula (M-1). The content of the compound represented by the following formula (M-A-2) is preferably 0 to 15 parts by mass, more preferably 0 to 12 parts by mass, even more preferably 0 to 10 parts by mass, even more preferably 0 to 7.5 parts by mass, and particularly preferably 0 to 5 parts by mass, per 100 parts by mass of the compound represented by the following formula (M-1). The value (α / β) obtained by dividing the total content (α) of the compounds represented by the following formulas (A-1), (M-A-1), and (M-A-2) by the content (β) of the compound represented by the following formula (M-1) is preferably 0.001 to 0.3, more preferably 0.0015 to 0.25, and even more preferably 0.002 to 0.22.If α / β is less than 0.001, the chemical reaction or interaction (e.g., curing acceleration or hydrogen bonding) between maleimide and the secondary amine structure decreases, which may prevent the development of high modulus of elasticity, low water absorption, and high heat resistance. If α / β is greater than 0.3, the amount of maleimide groups decreases, reducing the number of crosslinking points, which may decrease curability and the degree of curing of the cured product, potentially preventing the acquisition of the desired molded product or physical properties. For example, during high-temperature molding (e.g., 200°C) using a vacuum press, components that cannot be crosslinked may volatilize, causing void formation, and the heat decomposition resistance of the cured product may decrease. The content of each component represented by the following formulas (M-1), (A-1), (M-A-1), and (M-A-2) can be determined from the area % in the HPLC analysis (detection wavelength: 274 nm) described in the examples below.

[0024]

[0025] In the above formulas (M-1), (A-1), (M-A-1), and (M-A-2), the values ​​and preferred ranges of R, X, p, q, and r are the same as in formula (1).

[0026] The compound represented by the above formula (M-1) is preferably contained in 10 to 90 parts by mass, more preferably 20 to 80 parts by mass, even more preferably 30 to 70 parts by mass, and particularly preferably 40 to 60 parts by mass, in 100 parts by mass of the maleimide resin represented by the above formula (1).

[0027] The compounds represented by the above formulas (A-1), (M-A-1), and (M-A-2) may be added to the maleimide resin represented by the above formula (1) afterwards, or they may be synthesized simultaneously during the process of maleimidizing the amine resin represented by the following formula (2). Furthermore, the maleimide resin represented by the above formula (1) may be synthesized in two or more separate steps and then mixed.

[0028]

[0029] In formula (2) above, the values ​​and preferred ranges of R, X, p, q, r, l, m, and n are the same as in formula (1) above. When synthesizing the amine resin represented by formula (2) above, it may be synthesized by mixing anilines (primary amines) and N-alkylated anilines (secondary amines), or it may be obtained by N-alkylating a separately synthesized amine resin (primary amine). Alternatively, the N-alkylated amine resin (secondary amine) produced as a by-product during synthesis may be used as is. The method for synthesizing the amine resin represented by formula (2) above is not particularly limited, but it can be obtained by reacting anilines and N-alkylated anilines with at least one selected from aldehydes, diene compounds, ketones, substituted biphenyls, and substituted phenyls in the presence of an acid catalyst. Examples of the aforementioned anilines include, but are not limited to, aniline, o-methylaniline, m-methylaniline, p-methylaniline, o-ethylaniline, m-ethylaniline, p-ethylaniline, o-propylaniline, m-propylaniline, p-propylaniline, o-isopropylaniline, m-isopropylaniline, p-isopropylaniline, 2,6-dimethylaniline, 2,6-diethylaniline, 2,6-dipropylaniline, 2,6-diisopropylaniline, 2-ethyl-6-methylaniline, 2-propyl-6-methylaniline, 2-isopropyl-6-methylaniline, 2-ethyl-6-propylaniline, and 2-ethyl-6-isopropylaniline. These may be used individually or in combination of two or more. While a higher number of carbon atoms improves solvent solubility, it reduces heat resistance. Therefore, it is preferable that the N-alkylated anilines are unsubstituted or substituted with an alkyl group having 1 to 3 carbon atoms, more preferably unsubstituted or substituted with an alkyl group having 1 to 2 carbon atoms, and most preferably unsubstituted or substituted with a methyl group. The N-alkylated anilines are those in which the amino group of the aforementioned anilines is substituted with an alkyl group having 1 to 5 carbon atoms, preferably having 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms, and even more preferably 1 to 2 carbon atoms, and most preferably substituted with a methyl group.

[0030] In the synthesis of the amine resin represented by the above formula (2), in addition to hydrochloric acid, phosphoric acid, sulfuric acid, formic acid, p-toluenesulfonic acid, and methanesulfonic acid, Lewis acids such as aluminum chloride and zinc chloride, solid acids such as activated clay, acid clay, white carbon, zeolite, silica, and alumina, and acid ion exchange resins can be used as acid catalysts. These may be used individually or in combination of two or more. The amount of catalyst used is 0.01 to 50% by mass, preferably 0.1 to 35% by mass, relative to the total mass of the reaction substrates, anilines and N-alkylated anilines, and at least one selected from aldehydes, diene compounds, ketones, substituted biphenyls, and substituted phenyls. If too much catalyst is used, there is a risk of increased waste, and if too little is used, the reaction may proceed slowly. The amount of N-alkylated anilines used is preferably 0 to 0.9 moles per mole of aniline, more preferably 0.1 to 0.75 moles, and particularly preferably 0.2 to 0.5 moles. If the number of moles of N-alkylated anilines used exceeds the number of moles of aniline used, the maleimide group content decreases, which may worsen the curability and moldability, and may result in the inability to obtain a cured product. Examples of solvents to be used include non-water-soluble solvents such as aromatic solvents like toluene and xylene, aliphatic solvents like cyclohexane and n-hexane, ethers like diethyl ether and diisopropyl ether, ester solvents like ethyl acetate and butyl acetate, and ketone solvents like methyl isobutyl ketone and cyclopentanone, but are not limited to these, and two or more may be used in combination. In addition, a non-protic polar solvent may be used in combination with the aforementioned non-water-soluble solvents. Examples include dimethyl sulfone, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, and N-methylpyrrolidone, and two or more may be used in combination. When using an aprotic polar solvent, it is preferable to use one with a higher boiling point than the non-water-soluble solvent used in combination. The reaction temperature is preferably 80 to 250°C, more preferably 90 to 240°C, and even more preferably 100 to 230°C.If the reaction temperature is too high, it may cause unnecessary thermal decomposition, and if the reaction temperature is too low, the reaction may not proceed sufficiently. The reaction time is usually about 1 to 30 hours, and the amount of compound represented by formula (A-1) can be controlled by controlling the reaction temperature and reaction time. For example, when reacting at 200 to 210°C for the purpose of using the N-alkylated amine resin (secondary amine) produced as a by-product during synthesis, it is preferable to react for 1 to 10 hours, more preferably 1 to 5 hours, and particularly preferable to react for 1 to 3 hours. The amount of compounds represented by the following formulas (A-0) to (A-3) can be confirmed by analysis using HPLC during synthesis. Depending on the desired properties, the compound represented by the following formula (A-0), which has been synthesized separately, may be added and mixed and used in the maleimidization reaction step. The total amount of compounds represented by the following formulas (A-1), (A-2), and (A-3) is preferably 0.2 to 40 parts by mass, more preferably 0.2 to 35 parts by mass, and particularly preferably 0.2 to 30 parts by mass, per 100 parts by mass of the compound represented by the following formula (A-0). When raw materials that produce water as a by-product during the reaction or when an acidic catalyst containing water is used, the generated water and water in the system are removed from the system by azeotropic reaction with the solvent when the temperature is raised. After the reaction is complete, the acidic catalyst is neutralized with an alkaline aqueous solution, and then a water-insoluble organic solvent is added to the oil layer and the washing is repeated until the wastewater becomes neutral, and then the solvent is removed under reduced pressure after heating. When activated clay or ion exchange resin is used, the reaction solution is filtered after the reaction is complete to remove the catalyst.

[0031]

[0032] In the above formulas (A-0) to (A-3), the values ​​and preferred ranges of R, X, p, q, and r are the same as in formula (1).

[0033] When maleimidizing the amine resin represented by formula (2) above, the conditions are not particularly limited, but it is generally preferable to react the amine resin represented by formula (2) with an excess amount of maleic anhydride in moles (1.0 to 3.0 moles, preferably 1.0 to 2.5 moles, more preferably 1.0 to 2.0 moles) relative to the amine equivalent. The reaction temperature is preferably 30 to 160°C, more preferably 60 to 150°C, and even more preferably 80 to 140°C. The reaction time is usually about 1 to 30 hours. Examples of solvents to be used include non-water-soluble solvents such as aromatic solvents such as toluene and xylene, aliphatic solvents such as cyclohexane and n-hexane, ethers such as diethyl ether and diisopropyl ether, ester solvents such as ethyl acetate and butyl acetate, and ketone solvents such as methyl isobutyl ketone and cyclopentanone, but are not limited to these, and two or more may be used in combination. In addition, a non-water-soluble polar solvent may be used in combination with the aforementioned non-water-soluble solvent. Examples include dimethyl sulfone, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, and N-methylpyrrolidone, and two or more may be used in combination. When using an aprotic polar solvent, it is preferable to use one with a higher boiling point than the non-water-soluble solvent used in combination. During the reaction, if necessary, hydrochloric acid, phosphoric acid, sulfuric acid, formic acid, p-toluenesulfonic acid, methanesulfonic acid, as well as Lewis acids such as aluminum chloride and zinc chloride, solid acids such as activated clay, acid clay, white carbon, zeolite, silica alumina, and acidic ion exchange resins may be used as catalysts. These may be used alone or in combination of two or more. The amount of catalyst used is usually 0.1 to 0.8 moles per mole of amino groups of the amine resin used, preferably 0.2 to 0.7 moles. If too much catalyst is used, the viscosity of the reaction solution may become too high, making stirring difficult, and if too little is used, the reaction may proceed slowly. Furthermore, basic co-catalysts such as triethylamine can be used alone or in combination as co-catalysts for imidation. When sulfonic acid or the like is used as a catalyst, neutralization with alkali metals such as sodium hydroxide or potassium hydroxide may be performed before proceeding to the extraction step.For the extraction process, aromatic hydrocarbon solvents such as toluene or xylene may be used alone, or non-aromatic hydrocarbons such as cyclohexane or toluene may be used in combination. After extraction, the organic layer is washed with water until the wastewater becomes neutral, and the solvent is removed using an evaporator or the like to obtain the desired maleimide resin.

[0034] The softening point of the amine resin represented by formula (2) above is preferably 180°C or lower, and more preferably 150°C or lower. When the softening point of the amine resin represented by formula (2) above is 180°C or lower, the viscosity when converted to the maleimide resin represented by formula (1) above is reduced. This makes it easier to ensure fluidity, does not impair the impregnation properties into fibrous materials such as glass cloth and carbon fiber, and facilitates B-stage processes such as prepreg formation. If the viscosity is reduced by increasing the dilution solvent, the resin containing the maleimide resin represented by formula (1) above may not adhere sufficiently to the fibrous material during the impregnation process.

[0035] The maleimide resin represented by formula (1) above can be cured on its own by heating or other means, but its performance can also be improved by adding various materials to form a curable resin composition.

[0036] [Curing Accelerator] The curable resin composition of this embodiment can also have its curability improved by adding a curing accelerator. Preferred curing accelerators are anionic curing accelerators that promote the curing reaction by generating anions upon irradiation with ultraviolet light or visible light or by heating, or cationic curing accelerators that promote the curing reaction by generating cations upon irradiation with ultraviolet light or visible light or by heating.

[0037] Examples of anionic curing accelerators include imidazoles such as 2-methylimidazole, 2-ethylimidazole, and 2-ethyl-4-methylimidazole; trialkylamines such as triethylamine and tributylamine; 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene, with 4-dimethylaminopyridine and 1,8-diazabicyclo(5,4,0)-undecene being preferred. Other examples include phosphines such as triphenylphosphine, tetrabutylammonium salt, triisopropylmethylammonium salt, trimethyldecanylammonium salt, cetyltrimethylammonium salt, and quaternary ammonium salts such as hexadecyltrimethylammonium hydroxide, but are not limited to these. These may be used individually or in combination.

[0038] Examples of cationic curing accelerators include quaternary phosphonium salts such as triphenylbenzylphosphonium salt, triphenylethylphosphonium salt, and tetrabutylphosphonium salt (the counterions of the quaternary salts are halogens, organic acid ions, hydroxide ions, etc., with no particular preference, but organic acid ions and hydroxide ions are particularly preferred), tin octoate, zinc carboxylates (zinc 2-ethylhexanoate, zinc stearate, zinc behenate, zinc myristate), and zinc phosphate esters (zinc octyl phosphate, zinc stearyl phosphate), but are not limited to these. Furthermore, these may be used individually or in combination of multiple types.

[0039] The amount of curing accelerator added is 0.01 to 5.0 parts by mass per 100 parts by mass of the curable resin composition, as needed.

[0040] [Inorganic Filler] The curable resin composition of this embodiment may contain an inorganic filler. Examples of inorganic fillers include, but are not limited to, powders such as fused silica, crystalline silica, porous silica, alumina, zircon, calcium silicate, calcium carbonate, quartz powder, silicon carbide, silicon nitride, boron nitride, zirconia, aluminum nitride, graphite, forsterite, steatite, spinel, mullite, titania, talc, clay, iron oxide asbestos, and glass powder, or inorganic fillers made by shaping these into spheres or crushed forms. Furthermore, these may be used individually or in combination of multiple types.

[0041] When obtaining a curable resin composition for semiconductor encapsulation, the amount of inorganic filler used is preferably 80 to 92 parts by mass, and more preferably 83 to 90 parts by mass, per 100 parts by mass of the curable resin composition. Furthermore, when obtaining a curable resin composition for interlayer insulating layer forming materials, copper-clad laminates and prepregs, and substrate materials such as RCC (Resin Coated Copper), the amount of the above-mentioned inorganic filler used is preferably 5 to 80 parts by mass, and more preferably 10 to 60 parts by mass, per 100 parts by mass of the curable resin composition.

[0042] [Polymerization Initiator] The curable resin composition of this embodiment can also have its curability improved by adding a polymerization initiator. A polymerization initiator is a compound capable of polymerizing olefin functional groups such as ethylenically unsaturated bonds, and examples include olefin metathesis polymerization initiators, anionic polymerization initiators, cationic polymerization initiators, and radical polymerization initiators. Among these, it is preferable to use a radical polymerization initiator that has curability and appropriate stability. A radical polymerization initiator is a compound that generates radicals by irradiation with ultraviolet light or visible light or by heating, and initiates a chain polymerization reaction. Examples of radical polymerization initiators that can be used include organic peroxides, azo compounds, and benzopinacols, and it is preferable to use organic peroxides because they have little effect on curing temperature control, outgassing suppression, and the electrical properties of decomposition products.

[0043] Examples of the above organic peroxides include ketone peroxides such as methyl ethyl ketone peroxide and acetylacetone peroxide, diacyl peroxides such as benzoyl peroxide, dialkyl peroxides such as dicumyl peroxide and 1,3-bis-(t-butylperoxyisopropyl)benzene, peroxyketals such as t-butyl peroxybenzoate and 1,1-di-t-butylperoxycyclohexane, α-cumyl peroxyneodecanoate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, t-amyl peroxy-2-ethylhexanoate, and t-butyl peroxy Examples of alkyl peresters such as -oxy-2-ethylhexanoate, t-amyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxy-3,5,5-trimethylhexanoate, and t-amyl peroxybenzoate; peroxycarbonates such as di-2-ethylhexyl peroxydicarbonate, bis(4-t-butylcyclohexyl) peroxydicarbonate, t-butyl peroxyisopropyl carbonate, and 1,6-bis(t-butyl peroxycarbonyloxy)hexane; t-butyl hydroperoxide, cumene hydroperoxide, t-butyl peroxyoctoate, and lauroyl peroxide are examples, but are not limited to these. Furthermore, these may be used individually or in combination. Among the above organic peroxides, ketone peroxides, diacyl peroxides, hydroperoxides, dialkyl peroxides, peroxyketals, alkyl peresters, and peroxycarbonates are preferred, with dialkyl peroxides being more preferred.

[0044] Examples of the above-mentioned azo compounds include, but are not limited to, azobisisobutyronitrile, 4,4'-azobis(4-cyanovaleric acid), and 2,2'-azobis(2,4-dimethylvaleronitrile). Furthermore, these compounds may be used individually or in combination.

[0045] The amount of polymerization initiator added is preferably 0.01 to 5 parts by mass, and particularly preferably 0.01 to 3 parts by mass, per 100 parts by mass of the curable resin composition. If the amount of polymerization initiator used is less than 0.01 parts by mass, the molecular weight may not elongate sufficiently during the polymerization reaction, and if it is more than 5 parts by mass, dielectric properties such as dielectric constant and dielectric loss tangent may be impaired.

[0046] [Polymerization Inhibitor] The curable resin composition of this embodiment may contain a polymerization inhibitor. Including a polymerization inhibitor improves storage stability and allows control of the reaction initiation temperature. Controlling the reaction initiation temperature makes it easier to ensure fluidity, prevents impregnation into glass cloth and the like, and facilitates B-stage production such as prepreg formation. If the polymerization reaction proceeds too far during prepreg formation, problems such as difficulty in lamination during the lamination process are likely to occur.

[0047] The polymerization inhibitor may be added when synthesizing the maleimide resin represented by formula (1) above, or after synthesis. The amount of polymerization inhibitor used is 0.008 to 1 part by mass, preferably 0.01 to 0.5 parts by mass, per 100 parts by mass of the maleimide resin represented by formula (1) above.

[0048] Examples of polymerization inhibitors include phenol-based, sulfur-based, phosphorus-based, hindered amine-based, nitroso-based, and nitroxyl radical-based agents. Furthermore, one polymerization inhibitor may be used, or multiple inhibitors may be used in combination. Of these, phenol-based, hindered amine-based, nitroso-based, and nitroxyl radical-based agents are preferred in this embodiment.

[0049] Examples of the above phenolic polymerization inhibitors include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-p-ethylphenol, stearyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, isooctyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine, and 2,4-bis[(octylthio)methyl]-o-c Monophenols such as resols, 2,2'-methylenebis(4-methyl-6-t-butylphenol), 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol), triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] N,N'-Hexamethylenebis(3,5-di-t-butyl-4-hydroxyhydrocinnamamide), 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 3,5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester, 3,9-bis[1,1-dimethyl-2-{β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl], 2,4,8,10-tetraoxaspiro[5,5]undecane, bis(3,5-di-t- Bisphenols such as calcium trimethyl-4-hydroxybenzylsulfonate ethyl, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, bis[3,3'-bis-(4'-hydroxy-3'-t-butylphenyl)butyric acid]glycol ester, tris-(3,Examples include, but are not limited to, high molecular weight phenols such as 5-di-t-butyl-4-hydroxybenzyl)-isocyanurate, 1,3,5-tris(3',5'-di-t-butyl-4'-hydroxybenzyl)-s-triazine-2,4,6-(1H,3H,5H)trione, and tocopherol.

[0050] Examples of sulfur-based polymerization inhibitors include, but are not limited to, dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, and distearyl-3,3'-thiodipropionate.

[0051] Examples of the phosphorus polymerization inhibitors mentioned above include triphenyl phosphite, diphenylisodecyl phosphite, phenyldiisodecyl phosphite, tris(nonylphenyl) phosphite, diisodecylpentaerythritol phosphite, tris(2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis(octadecyl) phosphite, cyclic neopentanetetraylbis(2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis(2,4-di-t-butyl-4-methylphenyl) phosphite, and bis[2- Examples include, but are not limited to, phosphites such as t-butyl-6-methyl-4-{2-(octadecyloxycarbonyl)ethyl}phenyl]hydrogen phosphite, oxaphosphaphenanthrene oxides such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(3,5-di-t-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0052] Examples of the above hindered amine polymerization inhibitors include Adekastab (registered trademark) LA-40MP, Adekastab LA-40Si, Adekastab LA-402AF, Adekastab LA-87, Adekastab LA-82, Adekastab LA-81, Adekastab LA-77Y, Adekastab LA-77G, Adekastab LA-72, Adekastab LA-68, Adekastab LA-63P, Adekastab LA-57, Adekastab LA-52 (all from ADE Inc.) Examples include, but are not limited to, KA-made Chimassorb® 2020FDL, Chimassorb944FDL, Chimassorb944LD, Tinuvin® 622SF, TinuvinPA144, Tinuvin765, Tinuvin770DF, TinuvinXT55FB, Tinuvin111FDL, Tinuvin783FDL, and Tinuvin791FB (all manufactured by BASF).

[0053] Examples of the nitroso polymerization inhibitors mentioned above include, but are not limited to, p-nitrosophenol, N-nitrosodiphenylamine, and ammonium salts of N-nitrosophenylhydroxyamine (cuperone). Of these, ammonium salts of N-nitrosophenylhydroxyamine (cuperone) are preferred.

[0054] Examples of the above-mentioned nitroxyl radical polymerization inhibitors include, but are not limited to, di-tert-butylnitroxide, 2,2,6,6-tetramethylpiperidine-1-oxyl, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-acetoxy-2,2,6,6-tetramethylpiperidine-1-oxyl, and 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl.

[0055] [Flame retardant] The curable resin composition of this embodiment may contain a flame retardant. Examples of flame retardants include halogen-based flame retardants, inorganic flame retardants (antimony compounds, metal hydroxides, nitrogen compounds, boron compounds, etc.), and phosphorus-based flame retardants, but phosphorus-based flame retardants are preferred from the viewpoint of achieving halogen-free flame retardancy.

[0056] The phosphorus-based flame retardants mentioned above may be reactive or additive types. Specific examples include phosphorus esters such as trimethyl phosphate, triethyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, cresyl-2,6-dixylenyl phosphate, 1,3-phenylenebis(dixylenyl phosphate), 1,4-phenylenebis(dixylenyl phosphate), and 4,4'-biphenyl(dixylenyl phosphate); phosphanes such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 10(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide; phosphorus-containing epoxy compounds obtained by reacting epoxy resins with the active hydrogen of the phosphanes; and red phosphorus, but are not limited to these. Furthermore, these may be used individually or in combination of multiple types. Of the above example substances, phosphate esters, phosphans, or phosphorus-containing epoxy compounds are preferred, and 1,3-phenylenebis(dixylenyl phosphate), 1,4-phenylenebis(dixylenyl phosphate), 4,4'-biphenyl(dixylenyl phosphate), or phosphorus-containing epoxy compounds are particularly preferred.

[0057] The flame retardant content is preferably in the range of 0.1 to 0.6 parts by mass per 100 parts by mass of the curable resin composition. If the content is less than 0.1 parts by mass, the flame retardancy may be insufficient, and if it is more than 0.6 parts by mass, it may adversely affect the hygroscopicity and dielectric properties of the cured product.

[0058] [Light stabilizer] The curable resin composition of this embodiment may also contain a light stabilizer. Suitable light stabilizers include hindered amine light stabilizers (HALS) and the like. Examples of HALS include the reaction product of dibutylamine-1,3,5-triazine-N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine and N-(2,2,6,6-tetramethyl-4-piperidyl)butylamine, the reaction product of dimethyl-1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine succinate, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino}], bis(1,2 Examples include, but are not limited to, 2,6,6-pentamethyl-4-piperidyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis(1-octyroxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, 2-(3,5-di-t-butyl-4-hydroxybenzyl)-2-n-butylmalonate bis(1,2,2,6,6-pentamethyl-4-piperidyl). Furthermore, these may be used individually or in combination.

[0059] The amount of light stabilizer is preferably in the range of 0.001 to 0.1 parts by mass per 100 parts by mass of the curable resin composition. If the amount is less than 0.001 parts by mass, it may be insufficient to exhibit the light stabilization effect, and if it is more than 0.1 parts by mass, it may adversely affect the hygroscopicity and dielectric properties of the cured product.

[0060] [Binder Resin] The curable resin composition of this embodiment may also use a binder resin. Examples of binder resins include butyral resins, acetal resins, acrylic resins, epoxy-nylon resins, NBR-phenolic resins, epoxy-NBR resins, silicone resins, etc., but are not limited to these. Furthermore, these may be used individually or in combination of multiple types.

[0061] The amount of binder resin added is preferably within a range that does not impair the flame retardancy and heat resistance of the cured product, and is preferably 0.05 to 50 parts by mass per 100 parts by mass of the curable resin composition, and more preferably 0.05 to 20 parts by mass as needed.

[0062] [Additives] The curable resin composition of this embodiment may also contain additives. Examples of additives include modified acrylonitrile copolymers, polyethylene, fluororesins, silicone gels, silicone oils, surface treatment agents for fillers such as silane coupling agents, mold release agents, and colorants such as carbon black, phthalocyanine blue, and phthalocyanine green.

[0063] The amount of additive added is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and particularly preferably 10 parts by mass or less, per 100 parts by mass of the curable resin composition.

[0064] The curable resin composition of this embodiment may further contain epoxy resins, active ester compounds, phenolic resins, polyphenylene ether compounds, amine resins, compounds having ethylenically unsaturated bonds, isocyanate resins, polyamide resins, maleimide compounds, cyanate ester resins, polyimide resins, polybutadiene and its modified counterparts, polystyrene and its modified counterparts, polyethylene and its modified counterparts, benzoxazine compounds, etc., and these may be used individually or in combination of multiple compounds. Among these compounds, it is preferable to include polyphenylene ether compounds, compounds having ethylenically unsaturated bonds, cyanate ester resins, polybutadiene and its modified counterparts, polystyrene and its modified counterparts, in order to balance heat resistance, adhesion, and dielectric properties. By including these compounds, the brittleness of the cured product can be improved and adhesion to metal can be enhanced, and cracks in the package can be suppressed during reliability tests such as solder reflow and thermal cycling. Unless otherwise specified, the total amount of the above compounds used in the curable resin composition of this embodiment is preferably 80% by mass or less, more preferably 60% by mass or less, and particularly preferably 40% by mass or less. Furthermore, the preferred lower limit is 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more. Within this range, the effects of each added compound can be added while taking advantage of the low dielectric properties of the compound of this embodiment. The following examples of components can be used for these components.

[0065] [Epoxy Resin] The following are examples of preferred epoxy resins, but are not limited to these. The epoxy resin may be liquid or solid, and may be used alone or in combination of multiple types.

[0066] Examples of liquid epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, phenol novolac type epoxy resin, alicyclic epoxy resin having an ester skeleton, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, and epoxy resin having a butadiene structure. Specific examples include "RE310S", "RE410S" (both manufactured by Nippon Kayaku Co., Ltd., bisphenol A type epoxy resin), "RE303S", "RE304S", "RE403S", "RE404S" (all manufactured by Nippon Kayaku Co., Ltd., bisphenol F type epoxy resin), "HP-4032", "HP-4032D", "HP-4032SS" (all manufactured by DIC Corporation, naphthalene type epoxy resin), "jER(registered trademark)828US", "jER828EL", "jER825", "jER828EL" (all manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin), "jER807", "jER1750" (both manufactured by Mitsubishi Chemical Corporation, bisphenol F type epoxy resin), "jER152" (manufactured by Mitsubishi Chemical Corporation, Examples include phenol novolac type epoxy resin, "jER630", "jER630LSD" (both manufactured by Mitsubishi Chemical Corporation, glycidylamine type epoxy resin), "ZX1059" (manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin), "EX-721" (manufactured by Nagase ChemteX Corporation, glycidyl ester type epoxy resin), "Celoxide (registered trademark) 2021P" (manufactured by Daicel Corporation, alicyclic epoxy resin with an ester skeleton), "PB-3600" (manufactured by Daicel Corporation, epoxy resin with a butadiene structure), "ZX1658", "ZX1658GS" (both manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., liquid 1,4-glycidylcyclohexane type epoxy resin). These may be used individually or in combination of two or more types.

[0067] Preferred solid epoxy resins include, for example, bixylenol-type epoxy resin, naphthalene-type epoxy resin, naphthalene-type tetrafunctional epoxy resin, cresol novolac-type epoxy resin, dicyclopentadiene-type epoxy resin, trisphenol-type epoxy resin, naphthol-type epoxy resin, biphenyl-type epoxy resin, naphthylene ether-type epoxy resin, anthracene-type epoxy resin, bisphenol A-type epoxy resin, bisphenol AF-type epoxy resin, and tetraphenylethane-type epoxy resin.Specific examples include "HP4032H" (DIC Corporation, naphthalene-type epoxy resin), "HP-4700", "HP-4710" (both DIC Corporation, naphthalene-type tetrafunctional epoxy resins), "N-690" (DIC Corporation, cresol novolac-type epoxy resin), "N-695" (DIC Corporation, cresol novolac-type epoxy resin), "HP-7200" (DIC Corporation, dicyclopentadiene-type epoxy resin), "HP-7200HH", "HP-7200H" (both DIC Corporation, dicyclopentadiene-type epoxy resins), "EXA- "7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP-6000" (all manufactured by DIC Corporation, naphthylene ether type epoxy resin), "EPPN-502H" (manufactured by Nippon Kayaku Co., Ltd., trisphenol type epoxy resin), "NC-7000L", "NC-7300" (both manufactured by Nippon Kayaku Co., Ltd., naphthol-cresol novolac type epoxy resin), "NC-3000H", "NC-3000", "NC-3000L", "NC-3100" (all manufactured by Nippon Kayaku Co., Ltd., biphenyl aralkyl type Epoxy resins) "XD-1000-2L", "XD-1000-L", "XD-1000-H", "XD-1000-H" (all manufactured by Nippon Kayaku Co., Ltd., dicyclopentadiene type epoxy resin), "ESN475V" (manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., naphthol type epoxy resin), "ESN485" (manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., naphthol novolac type epoxy resin), "YX-4000H", "YX-4000", "YL6121" (all manufactured by Mitsubishi Chemical Corporation, biphenyl type epoxy resin), "YX-4000HK" (manufactured by Mitsubishi Chemical Corporation, bixylenol) Examples include (a type of epoxy resin), "YX-8800" (manufactured by Mitsubishi Chemical Corporation, anthracene-type epoxy resin), "PG-100", "CG-500" (manufactured by Osaka Gas Chemical Co., Ltd., fluorene-based epoxy resin), "YL-7760" (manufactured by Mitsubishi Chemical Corporation, bisphenol AF-type epoxy resin), "YL-7800" (manufactured by Mitsubishi Chemical Corporation, fluorene-type epoxy resin), "jER1010" (manufactured by Mitsubishi Chemical Corporation, solid bisphenol A-type epoxy resin), and "jER1031S" (manufactured by Mitsubishi Chemical Corporation, tetraphenylethane-type epoxy resin). These may be used individually or in combination of two or more types.

[0068] [Active Ester Compounds] Active ester compounds are compounds that contain at least one ester bond in their structure, and on both sides of the ester bond, aliphatic chains, aliphatic rings, or aromatic rings are bonded. Examples of active ester compounds include compounds having two or more highly reactive ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. They are obtained by a condensation reaction between at least one compound of a carboxylic acid compound, an acid chloride, or a thiocarboxylic acid compound and at least one compound of a hydroxy compound or a thiol compound. In particular, from the viewpoint of improving heat resistance, it is preferable that they be obtained from a carboxylic acid compound or an acid chloride and a hydroxy compound, and phenol compounds or naphthol compounds are preferred as the hydroxy compound. Active ester compounds may be used alone or in combination of two or more.

[0069] Examples of the carboxylic acid compounds mentioned above include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid.

[0070] Examples of the above-mentioned acid chlorides include acetyl chloride, acrylate chloride, methacrylate chloride, malonyl chloride, succinate dichloride, diglycolyl chloride, glutarate dichloride, suberate dichloride, sebacate dichloride, adipic acid dichloride, dodecanediol dichloride, azera oil chloride, 2,5-franzicarbonyl dichloride, phthaloyl chloride, isophthaloyl chloride, terephthaloyl chloride, trimesic acid chloride, bis(4-chlorocarbonylphenyl) ether, 4,4'-diphenyldicarbonyl chloride, and 4,4'-azodibenzoyl dichloride.

[0071] Examples of the above-mentioned phenol compounds and naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, phenol novolac, and phenol resins described later. Here, "dicyclopentadiene-type diphenol compound" refers to a diphenol compound obtained by the condensation of two molecules of phenol with one molecule of dicyclopentadiene.

[0072] Preferred examples of active ester compounds include active ester compounds containing a dicyclopentadiene-type diphenol structure, active ester compounds containing a naphthalene structure, active ester compounds containing an acetylated phenol novolac, active ester compounds containing a benzoylated phenol novolac, the compound described in Example 2 of International Publication No. 2020 / 095829, and the compounds disclosed in International Publication No. 2020 / 059625. Among these, active ester compounds containing a naphthalene structure and active ester compounds containing a dicyclopentadiene-type diphenol structure are more preferred. The dicyclopentadiene-type diphenol structure represents a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

[0073] Examples of commercially available active ester compounds include, for example, "EXB9451," "EXB9460," "EXB9460S," "HPC-8000-65T," "HPC-8000H-65TM," "EXB-8000L-65TM," and "EXB-8150-65T" (manufactured by DIC Corporation) as active ester compounds containing a dicyclopentadiene-type diphenol structure; "EXB9416-70BK" (manufactured by DIC Corporation) as an active ester compound containing a naphthalene structure; "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester compound containing an acetylated phenol novolac; "YLH1026," "YLH1030," and "YLH1048" (manufactured by Mitsubishi Chemical Corporation) as active ester compounds containing a benzoylated phenol novolac; and "EXB-9050L-62M" (manufactured by DIC Corporation) as a phosphorus atom-containing active ester curing agent.

[0074] Regarding the blending ratio of the active ester compound and epoxy resin, the ratio of the active ester equivalent (α) to the epoxy equivalent (β) (α / β) is preferably 0.5 to 1.5, more preferably 0.8 to 1.2, and even more preferably 0.90 to 1.10. If it falls outside the above range, there is a risk that excess epoxy groups or active ester groups will remain in the system, which may lead to deterioration of properties in high-temperature storage tests (e.g., 150°C, 1000 hours) or long-term reliability tests under high-temperature and high-humidity conditions (e.g., temperature: 85°C, humidity: 85%).

[0075] [Phenol Resins] Phenolic resins are compounds having two or more phenolic hydroxyl groups in their molecules. Examples of phenolic resins include, but are not limited to, reaction products of phenols and aldehydes, reaction products of phenols and diene compounds, reaction products of phenols and ketones, reaction products of phenols and substituted biphenyls, reaction products of phenols and substituted phenyls, reaction products of bisphenols and aldehydes, etc. Furthermore, these may be used individually or in combination of multiple types. Specific examples of the above raw materials are given below, but are not limited to these. <Phenols> Phenol, alkyl-substituted phenol, aromatic-substituted phenol, hydroquinone, resorcinol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, alkyl-substituted dihydroxybenzene, dihydroxynaphthalene, etc. <Aldehydes> Formaldehyde, acetaldehyde, alkylaldehyde, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzaldehyde, naphthaldehyde, biphenylaldehyde, glutaraldehyde, phthalaldehyde, crotonaldehyde, cinnamaldehyde, furfural, etc. <Diene Compounds> Dicyclopentadiene, terpenes, vinylcyclohexene, norbornadiene, vinylnorbornene, tetrahydroindene, divinylbenzene, divinylbiphenyl, diisopropenylbiphenyl, diisopropenylbenzene, butadiene, isoprene, etc. <Ketones> Acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, indanone, fluorenone, etc. <Substitutive biphenyls> 4,4'-bis(chloromethyl)-1,1'-biphenyl, 4,4'-bis(methoxymethyl)-1,1'-biphenyl, 4,4'-bis(hydroxymethyl)-1,1'-biphenyl, etc.<Substitutive Phenyls> 1,4-bis(chloromethyl)benzene, 1,3-bis(chloromethyl)benzene, 1,2-bis(chloromethyl)benzene, 1,4-bis(methoxymethyl)benzene, 1,3-bis(methoxymethyl)benzene, 1,2-bis(methoxymethyl)benzene, 1,4-bis(hydroxymethyl)benzene, 1,3-bis(hydroxymethyl)benzene, 1,2-bis(hydroxymethyl)benzene, α,α,α',α'-tetramethyl-1,4-benzenedimethanol, α,α,α',α'-tetramethyl-1,3-benzenedimethanol, α,α,α',α'-tetramethyl-1,2-benzenedimethanol, etc.

[0076] [Polyphenylene Ether Compounds] From the viewpoint of heat resistance and electrical properties, polyphenylene ether compounds are preferably polyphenylene ether compounds having ethylenically unsaturated bonds, and more preferably polyphenylene ether compounds having acrylic groups, methacrylic groups, or styrene structures. Examples of commercially available products include SA-9000 (manufactured by SABIC, a polyphenylene ether compound having methacrylic groups) and OPE-2St 1200 (manufactured by Mitsubishi Gas Chemical Co., Ltd., a polyphenylene ether compound having a styrene structure). The number average molecular weight (Mn) of the polyphenylene ether compound is preferably 500 to 5000, more preferably 2000 to 5000, and even more preferably 2000 to 4000. If the number average molecular weight is less than 500, the heat resistance of the cured product tends not to be sufficient. Also, if the number average molecular weight is greater than 5000, the melt viscosity becomes high, and sufficient fluidity cannot be obtained, which tends to lead to molding defects. Furthermore, reduced reactivity leads to a longer curing time, an increase in unreacted material not incorporated into the curing system, a decrease in the glass transition temperature of the cured product, and a tendency for the heat resistance of the cured product to decrease. If the number-average molecular weight of the polyphenylene ether compound is between 500 and 5000, it is possible to exhibit excellent heat resistance and moldability while maintaining excellent dielectric properties. Specifically, the number-average molecular weight can be measured using methods such as gel permeation chromatography.

[0077] The polyphenylene ether compound may be obtained by polymerization or by redistributing a high molecular weight polyphenylene ether compound with a number average molecular weight of about 10,000 to 30,000. Alternatively, these can be used as raw materials and reacted with compounds having ethylenically unsaturated bonds, such as methacrylate chloride, acrylate chloride, and chloromethylstyrene, to impart radical polymerizability. The polyphenylene ether compound obtained by redistribution is, for example, obtained by heating a high molecular weight polyphenylene ether compound in a solvent such as toluene in the presence of a phenolic compound and a radical initiator to redistribute it. Polyphenylene ether compounds obtained by this redistribution reaction are preferable because they have hydroxyl groups derived from phenolic compounds that contribute to curing at both ends of the molecular chain, thus maintaining even higher heat resistance, and because functional groups can be introduced to both ends of the molecular chain even after modification with a compound having ethylenically unsaturated bonds. Furthermore, polyphenylene ether compounds obtained by polymerization are preferable because they exhibit excellent fluidity.

[0078] The molecular weight of polyphenylene ether compounds can be adjusted by adjusting polymerization conditions, etc., in the case of polyphenylene ether compounds obtained by polymerization reactions. In the case of polyphenylene ether compounds obtained by redistribution reactions, the molecular weight of the resulting polyphenylene ether compound can be adjusted by adjusting the conditions of the redistribution reaction, etc. More specifically, this can be done by adjusting the amount of phenolic compound used in the redistribution reaction. That is, the higher the amount of phenolic compound used, the lower the molecular weight of the resulting polyphenylene ether compound. In this case, poly(2,6-dimethyl-1,4-phenylene ether) can be used as the high molecular weight polyphenylene ether compound that undergoes the redistribution reaction. Furthermore, the phenolic compound used in the redistribution reaction is not particularly limited, but polyfunctional phenolic compounds having two or more phenolic hydroxyl groups in the molecule, such as bisphenol A, phenol novolac, and cresol novolac, are preferably used. These may be used individually or in combination of two or more.

[0079] The content of the polyphenylene ether compound is not particularly limited, but is preferably 5 to 1000 parts by mass, and more preferably 10 to 750 parts by mass, per 100 parts by mass of the curable resin composition. When the content of the polyphenylene ether compound is within the above range, it is preferable not only to obtain a cured product that is excellent in heat resistance and the like, but also in that the excellent dielectric properties of the polyphenylene ether compound are fully exhibited.

[0080] [Amine Resins] Amine resins are compounds having two or more amino groups in their molecule. Examples of amine resins include diaminodiphenylmethane, diaminodiphenylsulfone, isophoronediamine, naphthalenediamine, aniline novolac (reaction product of aniline and formalin), N-methylaniline novolac (reaction product of N-methylaniline and formalin), orthoethylaniline novolac (reaction product of orthoethylaniline and formalin), reaction product of 2-methylaniline and formalin, reaction product of 2,6-diisopropylaniline and formalin, reaction product of 2,6-diethylaniline and formalin, reaction product of 2-ethyl-6-ethylaniline and formalin, reaction product of 2,6-dimethylaniline and formalin, and those obtained by the reaction of aniline with xylylene chloride. Examples of aniline resins include, but are not limited to, aniline and substituted biphenyls (such as 4,4'-bis(chloromethyl)-1,1'-biphenyl and 4,4'-bis(methoxymethyl)-1,1'-biphenyl) as described in Japanese Patent Publication No. 6429862, aniline and substituted phenyls (such as 1,4-bis(chloromethyl)benzene, 1,4-bis(methoxymethyl)benzene and 1,4-bis(hydroxymethyl)benzene), 4,4'-(1,3-phenylenediisopropylidene)bisaniline, 4,4'-(1,4-phenylenediisopropylidene)bisaniline, aniline and diisopropenylbenzene, and dimer amines. Furthermore, these may be used individually or in combination.

[0081] [Isocyanate resin] An isocyanate resin is a compound that has two or more isocyanate groups in its molecule. Examples of isocyanate resins include, but are not limited to, aromatic diisocyanates such as p-phenylenediisocyanate, m-phenylenediisocyanate, p-xylenediisocyanate, m-xylenediisocyanate, 2,4-tollylenediisocyanate, 2,6-tollylenediisocyanate, 4,4'-diphenylmethanediisocyanate, and naphthalenediisocyanate; aliphatic or alicyclic diisocyanates such as isophorone diisocyanate, hexamethylenediisocyanate, 4,4'-dicyclohexylmethanediisocyanate, hydrogenated xylenediisocyanate, norbornenediisocyanate, and lysinediisocyanate; biuret compounds of one or more isocyanate monomers; or isocyanates obtained by trimerizing the above diisocyanate compounds; and polyisocyanates obtained by urethane reaction between the above isocyanate compounds and polyol compounds. Furthermore, these can be used individually or in combination.

[0082] [Polyamide Resins] Examples of polyamide resins include reaction products of one or more of diamines, diisocyanates, or oxazolines with dicarboxylic acids, reaction products of diamines and acid chlorides, and ring-opening polymers of lactam compounds. These may be used individually or in combination of multiple types. Specific examples of the above raw materials are given below, but the material is not limited to these.<Diamines> Ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decanediamine, undecanediamine, dodecanediamine, tridecanediamine, tetradecanediamine, pentadecanediamine, hexadecanediamine, heptadecanediamine, octadecanediamine, nonadecanediamine, eicosanediamine, 2-methyl-1,5-diaminopentane, 2-methyl 1,8-diaminooctane, dimeramine, cyclohexanediamine, bis-(4-aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)methane, xylylenediamine, norbornanediamine, isophoronediamine, bisaminomethyltricyclodecane, phenylenediamine, diethyltoluenediamine, naphthalenediamine, diaminodiphenylmethane, bis(4-amino-3,5-dimethylphenyl)methane, bis(4-amino-3,5-diethylphenyl)methane 4,4'-methylenebis-o-toluidine, 4,4'-methylenebis-o-ethylaniline, 4,4'-methylenebis-2-ethyl-6-methylaniline, 4,4'-methylenebis-2,6-diisopropylaniline, 4,4-ethylenedianiline, diaminodiphenylsulfone, diaminodiphenyl ether, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4-bis(4-aminophenoxy)biphenyl, 2,2-bis[4-(4-amino [phenoxy)phenyl]propane, bis[4-(4-aminophenoxy)phenyl]sulfone, 2,2-bis(3-amino-4-hydroxyphenyl)propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-(1,3-phenylenediisopropylidene)bisaniline, 4,4'-(1,4-phenylenediisopropylidene)bisaniline, 9,9-bis(4-aminophenyl)fluorene, 2,7-diaminofluorene, aminobenzylamine, diaminobenzophenone, etc.<Diisocyanates> Benzene diisocyanate, toluene diisocyanate, 1,3-bis(isocyanatomethyl)benzene, 1,3-bis(isocyanatomethyl)cyclohexane, bis(4-isocyanatophenyl)methane, isophorone diisocyanate, 1,3-bis(2-isocyanato-2-propyl)benzene, 2,2-bis(4-isocyanatophenyl)hexafluoropropane, dicyclohexylmethane-4,4'-diisocyanate, etc. <Dicarboxylic acids> Oxalic acid, malonic acid, succicic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanediic acid, dodecanediic acid, terephthalic acid, isophthalic acid, 5-hydroxyisophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, cyclohexanedicarboxylic acid, biphenyldicarboxylic acid, naphthalenedicarboxylic acid, benzophenonedicarboxylic acid, francicarboxylic acid, 4,4'-dicarboxydiphenyl ether, 4,4'-dicarboxydiphenyl sulfide, etc. <Acid Chlorides> Acetyl chloride, acrylate chloride, methacrylate chloride, malonyl chloride, succinate dichloride, diglycolyl chloride, glutarate dichloride, suberate dichloride, sebacate dichloride, adipic acid dichloride, dodecane dioyl chloride, azera oil chloride, 2,5-franzicarbonyl dichloride, phthaloyl chloride, isophthaloyl chloride, terephthaloyl chloride, trimesinate chloride, bis(4-chlorocarbonylphenyl) ether, 4,4'-diphenyl dicarbonyl chloride, 4,4'-azodibenzoyl dichloride, etc. <Lactams> ε-caprolactam, ω-undecane lactam, ω-laurolactam, etc.

[0083] [Polyimide Resin] Examples of polyimide resins include, but are not limited to, the reaction products of the diamine and the tetracarboxylic dianhydrides exemplified below. Furthermore, these may be used individually or in combination of multiple types. <Tetracarboxylic Dianhydrides> 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-cyclohexene-1,2-dicarboxylic anhydride, pyromellitic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4 '-diphenylsulfontetracarboxylic acid dianhydride, 2,2',3,3'-biphenyltetracarboxylic acid dianhydride, methylene-4,4'-diphthalic acid dianhydride, 1,1-ethylidene-4,4'-diphthalic acid dianhydride, 2,2'-propyridene-4,4'-diphthalic acid dianhydride, 1,2-ethylene-4,4'-diphthalic acid dianhydride, 1,3-trimethylene-4,4'-diphthalic acid dianhydride, 1,4-tetramethylene-4,4'-diphthalic acid dianhydride, 1,5-pentamethylene-4,4'- Diphthalic acid dianhydride, 4,4'-oxydiphthalic acid dianhydride, thio-4,4'-diphthalic acid dianhydride, sulfonyl-4,4'-diphthalic acid dianhydride, 1,3-bis(3,4-dicarboxyphenyl)benzene dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,3-bis[2-(3,4-dicarboxyphenyl)-2-propyl]benzene dianhydride, 1,4-bis[2-(3,4- [Dicarboxyphenyl)-2-propyl]benzene dianhydride, bis[3-(3,4-dicarboxyphenoxy)phenyl]methane dianhydride, bis[4-(3,4-dicarboxyphenoxy)phenyl]methane dianhydride, 2,2-bis[3-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, bis(3,4-dicarboxyphenoxy)dimethylsilane dianhydride, 1,3-bis(3,4-Dicarboxyphenyl)-1,1,3,3-tetramethyldisiloxane dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid dianhydride, 3,4,9,10-perylenetetracarboxylic acid dianhydride, 2,3,6,7-anthracenetetracarboxylic acid dianhydride, 1,2,7,8-phenanthrenetetracarboxylic acid dianhydride, ethylenetetracarboxylic acid dianhydride, 1,2,3,4-butanetetracarboxylic acid dianhydride, 1, 2,3,4-cyclobutanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexane-1,2,3,4-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, 3,3',4,4'-bicyclohexyltetracarboxylic dianhydride, carbonyl-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, methylene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,2-ethylene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride (Bonic acid) dianhydride, 1,1-ethylidene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 2,2-propyridene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, oxy-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, thio-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, sulfonyl-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, bicyclo[2,2,2]octo-7-ene-2,3,5,6-tetracarboxylic acid dianhydride Water compounds, rel-[1S,5R,6R]-3-oxabicyclo[3,2,1]octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid anhydride, ethylene glycol-bis-(3,4-dicarboxylic acid anhydride phenyl) ether, 4,4'-biphenylbis(trimellitic acid monoester anhydride), 9,9'-bis(3,4-dicarboxyphenyl)fluorene dianhydride, etc.

[0084] [Maleimide Compounds] The curable resin composition of this embodiment may contain maleimide compounds. Maleimide compounds are compounds having one or more maleimide groups in their molecule. Examples of maleimide compounds include 4,4'-diphenylmethanebismaleimide, polyphenylmethanemaleimide, m-phenylenebismaleimide, 2,2'-bis[4-(4-maleimoidphenoxy)phenyl]propane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, 4,4'-diphenyletherbismaleimide, 4,4'-diphenylsulfonebismaleimide, 1,3-bis(3-maleimoidphenoxy)benzene, 1,3-bis(4-maleimoidphenoxy) (Noxy)benzene), Zyloc-type maleimide compounds (anilix maleimide, manufactured by Mitsui Chemicals Fine Co., Ltd.), biphenylaralkyl-type maleimide compounds (solidified by solvent distillation under reduced pressure of a resin solution containing the maleimide compound (M2) described in Example 4 of Japanese Patent Publication No. 2009-001783), bisaminocumylbenzene-type maleimide (maleimide compound described in International Publication No. 2020 / 054601), maleimide compounds having an indan structure described in Japanese Patent No. 6629692 or International Publication No. 2020 / 217679, MATERIAL STAGE Vol. 18, No. 12 2019 "Continued Epoxy Resin CAS Number Story - Curing Agent CAS Number Memo No. 31 Bismaleimide (1)" and MATERIAL STAGE Vol. 19, No. 2. Maleimide compounds, etc., as described in "Continued Story of Epoxy Resin CAS Numbers - Memorandum on CAS Numbers for Hardeners, Part 32: Bismaleimide (2)" (2019), are examples, but are not limited to these. Furthermore, these may be used individually or in combination of multiple types.

[0085] [Cyanate Ester Resins] Cyanate ester resins are cyanate ester compounds obtained by reacting phenol resins with cyanide halides. Specific examples include, but are not limited to, dicyanatebenzene, tricyanatebenzene, dicyanatenaphthalene, dicyanatebiphenyl, 2,2'-bis(4-cyanatephenyl)propane, bis(4-cyanatephenyl)methane, bis(3,5-dimethyl-4-cyanatephenyl)methane, 2,2'-bis(3,5-dimethyl-4-cyanatephenyl)propane, 2,2'-bis(4-cyanatephenyl)ethane, 2,2'-bis(4-cyanatephenyl)hexafluoropropane, bis(4-cyanatephenyl)sulfone, bis(4-cyanatephenyl)thioether, phenol novolac cyanate, and phenol-dicyclopentadiene cocondensates in which the hydroxyl groups have been converted to cyanate groups. Furthermore, these may be used individually or in combination of multiple types. In addition, the cyanate ester compound whose synthesis method is described in Japanese Patent Publication No. 2005-264154 is particularly preferred as a cyanate ester compound because it has excellent low hygroscopicity, flame retardancy, and dielectric properties. The cyanate ester resin may also contain catalysts such as zinc naphthenate, cobalt naphthenate, copper naphthenate, lead naphthenate, zinc octoate, tin octoate, lead acetylacetonate, or dibutyltin maleate in order to trimerize the cyanate group and form a sym-triazine ring as needed.

[0086] It is preferable to use 0.0001 to 0.10 parts by mass, preferably 0.00015 to 0.0015 parts by mass, of the catalyst per 100 parts by mass of the cyanate ester resin and the curable resin composition.

[0087] [Polybutadiene and its modified products] Polybutadiene and its modified products are compounds that have polybutadiene or a structure derived from polybutadiene within their molecule. The structure derived from polybutadiene may have some or all of its unsaturated bonds converted to single bonds by hydrogenation. Examples of polybutadiene and its modified products include, but are not limited to, polybutadiene, hydroxyl-terminated polybutadiene, terminally (meth)acrylated polybutadiene, carboxylic acid-terminated polybutadiene, amine-terminated polybutadiene, and styrene-butadiene rubber. Furthermore, these may be used individually or in combination. Of these, polybutadiene or styrene-butadiene rubber is preferred from the viewpoint of dielectric properties. Examples of styrene-butadiene rubber (SBR) include RICON-100, RICON-181, RICON-184 (all manufactured by Clay Valley Corporation), and 1,2-SBS (manufactured by Nippon Soda Co., Ltd.). Examples of polybutadiene include B-1000, B-2000, and B-3000 (all manufactured by Nippon Soda Co., Ltd.). The weight-average molecular weight of polybutadiene and styrene-butadiene rubber is preferably 500 to 10000, more preferably 750 to 7500, and even more preferably 1000 to 5000. Below the lower limit of the above range, the volatility is high, making it difficult to adjust the solid content during prepreg preparation, and above the upper limit of the above range, the compatibility with other curable resins deteriorates. In general, in the case of compounds containing heteroatoms such as oxygen and nitrogen, such as bismaleimide and polymaleimide, it is difficult to ensure compatibility with low-polarity compounds such as compounds mainly composed of hydrocarbons or compounds consisting only of hydrocarbons, due to their polarity. On the other hand, because the compounds of this embodiment do not have a framework design that actively incorporates heteroatoms such as oxygen and nitrogen, they exhibit excellent compatibility with materials that have low polarity and low dielectric properties, as well as with compounds composed solely of hydrocarbons.

[0088] [Polystyrene and its modified products] Polystyrene and its modified products are polystyrene or compounds that have a structure derived from polystyrene within their molecules. Examples of polystyrene and its modified products include polystyrene, styrene-2-isopropenyl-2-oxazoline copolymer (Epocross RPS-1005, RP-61, both manufactured by Nippon Shokubai Co., Ltd.), SEP (styrene-ethylene-propylene copolymer: Septon® 1020, manufactured by Kuraray Co., Ltd.), SEPS (styrene-ethylene-propylene-styrene copolymer: Septon 2002, Septon 2004F, Septon 2005, Septon 2006, Septon 2063, Septon 2104, all manufactured by Kuraray Co., Ltd.), SEEPS (styrene-ethylene / ethylene-propylene-styrene block copolymer: Septon 4003, Septon 4044, Septon 4055, Septon 4077, Septon 4099) All manufactured by Kuraray Co., Ltd.), SEBS (styrene-ethylene-butylene-styrene block copolymer: Septon 8004, Septon 8006, Septon 8007L, all manufactured by Kuraray Co., Ltd.), SEEPS-OH (compound having hydroxyl groups at the ends of styrene-ethylene / ethylene-propylene-styrene block copolymer: Septon HG252, manufactured by Kuraray Co., Ltd.), SIS (styrene-isoprene-styrene block copolymer: Septon 5125, Septon 5127, all manufactured by Kuraray Co., Ltd.), Hydrogenated SIS (hydrogenated styrene-isoprene-styrene block copolymer: Hybrar® 7125F, Hybrar 7311F) Examples include, but are not limited to, polystyrene-isobutylene-styrene block copolymers (SIBS: SIBSTAR® 073T, SIBSTAR 102T, SIBSTAR 103T (all manufactured by Kaneka Corporation), Septon V9827 (manufactured by Kuraray Co., Ltd.)), etc. Furthermore, these may be used individually or in combination. Polystyrene and its modified products are preferable to have those without unsaturated bonds because they have higher heat resistance and are less susceptible to oxidative degradation.Furthermore, while there are no particular restrictions on the weight-average molecular weight of polystyrene and its modified products as long as it is 10,000 or more, if it is too high, the compatibility with polyphenylene ether compounds, as well as low molecular weight components with a weight-average molecular weight of about 50 to 1,000 and oligomer components with a weight-average molecular weight of about 1,000 to 5,000 deteriorates, making it difficult to ensure mixing and solvent stability. Therefore, it is preferable that the weight-average molecular weight be around 10,000 to 300,000.

[0089] [Polyethylene and Modified Products thereof] Polyethylene and modified products thereof refer to polyethylene or compounds having a structure derived from polyethylene within their molecules. Examples of polyethylene and modified products thereof include, but are not limited to, ethylene-propylene copolymers, ethylene-styrene copolymers, ethylene-propylene-ethylidene norbornene copolymers (Mitsui Chemicals, Ltd. EBT: K-8370EM, K-9330M, etc.), ethylene-propylene-vinyl norbornene copolymers (Mitsui Chemicals, Ltd. VNB-EPT: PX-006M, PX-008M, PX-009M, etc.), ethylene-vinyl alcohol copolymers, and ethylene-vinyl acetate copolymers. From the viewpoint of improving heat resistance, it is preferable to use ethylene-propylene-ethylidene norbornene copolymers and ethylene-propylene-vinyl norbornene copolymers that contain a crosslinkable structure. Furthermore, these may be used individually or in combination of multiple types. While there are no particular restrictions on the weight-average molecular weight of polyethylene and its modified products as long as it is 10,000 or more, if it is too high, the compatibility with polyphenylene ether compounds, as well as low molecular weight components with a weight-average molecular weight of about 50 to 1,000 and oligomer components with a weight-average molecular weight of about 1,000 to 5,000 deteriorates, making it difficult to ensure mixing and solvent stability. Therefore, it is preferable that the molecular weight be around 10,000 to 300,000.

[0090] [Compounds containing ethylenically unsaturated bonds] Compounds containing ethylenically unsaturated bonds are compounds that have ethylenically unsaturated bonds in their molecule that can be polymerized by heat or light, regardless of whether a polymerization initiator is used or not. However, compounds that contain ethylenically unsaturated bonds among the aforementioned maleimide compounds, polystyrene and its modified products, polybutadiene and its modified products, polyethylene and its modified products, etc., are not included in this classification.

[0091] Functional groups having ethylenically unsaturated bonds include, but are not limited to, the following disclosures, vinyl groups, allyl groups (2-propenyl groups), 1-propenyl groups, methallyl groups (2-methyl-2-propenyl groups), (meth)acrylic groups, acenaphthyl groups, indenyl groups, citraconimide groups, itaconimide groups, nadiimide groups, allylnadiimide groups, and cyclopentadienyl groups. Vinyl groups, styryl groups, (meth)acrylic groups, acenaphthyl groups, and indenyl groups are preferred, and vinyl groups, (meth)acrylic groups, acenaphthyl groups, and indenyl groups are more preferred. (Meth)acrylic groups mean methacrylic groups and / or acrylic groups, and (meth)acrylates mean methacrylates and / or acrylates.

[0092] Examples of compounds having a vinyl group include, but are not limited to, compounds having a styryl group, trivinylcyclohexane, 9-vinylfluorene, and thermosetting cycloolefin copolymers (Gigafreak, manufactured by Mitsui Chemicals, and TU-01A, manufactured by Nippon Zeon Co., Ltd.).

[0093] Compounds having a styryl group include, but are not limited to, styrene, vinyltoluene, 2-vinylbiphenyl, 3-vinylbiphenyl, 4-vinylbiphenyl, 1-vinylnaphthalene, 2-vinylnaphthalene, 2-vinylfluorene, α-methylstyrene, α-ethylstyrene, α-propylstyrene, α-n-butylstyrene, α-isobutylstyrene, α-t-butylstyrene, α-n-pentylstyrene, α-2-methylbutylstyrene, α-3-methylbutylstyrene, α-t-pentylstyrene, α-n-hexyl Glustystyrene, α-2-methylpentylstyrene, α-3-methylpentylstyrene, α-1-methylpentylstyrene, α-2,2-dimethylbutylstyrene, α-2,3-dimethylbutylstyrene, α-2,4-dimethylbutylstyrene, α-3,3-dimethylbutylstyrene, α-3,4-dimethylbutylstyrene, α-4,4-dimethylbutylstyrene, α-2-ethylbutylstyrene, α-1-ethylbutylstyrene, α-cyclohexylstyrene, o-ethylvinylbenzene, m-ethylvinylbenzene, p-ethylvinylbenzene, 2-vinyl 2'-ethylbiphenyl, 2-vinyl-3'-ethylbiphenyl, 2-vinyl-4'-ethylbiphenyl, 3-vinyl-2'-ethylbiphenyl, 3-vinyl-3'-ethylbiphenyl, 3-vinyl-4'-ethylbiphenyl, 4-vinyl-2'-ethylbiphenyl, 4-vinyl-3'-ethylbiphenyl, 4-vinyl-4'-ethylbiphenyl, 1-vinyl-2-ethylnaphthalene, 1-vinyl-3-ethylnaphthalene, 1-vinyl-4-ethylnaphthalene, 1-vinyl-5-ethylnaphthalene, 1-vinyl-6-ethylnaphthalene, 1-vinyl- 7-ethylnaphthalene, 1-vinyl-8-ethylnaphthalene, 2-vinyl-1-ethylnaphthalene, 2-vinyl-3-ethylnaphthalene, 2-vinyl-4-ethylnaphthalene, 2-vinyl-5-ethylnaphthalene, 2-vinyl-6-ethylnaphthalene, 2-vinyl-7-ethylnaphthalene, 2-vinyl-8-ethylnaphthalene, m-methylstyrene, p-methylstyrene, m-propylstyrene, p-propylstyrene, m-n-butylstyrene, p-n-butylstyrene, m-t-butylstyrene, p-t-butylstyrene, m-n-hexylstyrene,p-n-hexylstyrene, m-cyclohexylstyrene, p-cyclohexylstyrene, 2-vinyl-2'-propylbiphenyl, 2-vinyl-3'-propylbiphenyl, 2-vinyl-4'-propylbiphenyl, 3-vinyl-2'-propylbiphenyl, 3-vinyl-3'-propylbiphenyl, 3-vinyl-4'-propylbiphenyl, 4-vinyl-2'-propylbiphenyl, 4-vinyl-3'-propylbiphenyl, 4-vinyl-4'-propylbiphenyl, 1-vinyl-2-propylnaphthalene, 1-vinyl-3-propylnaphthalene, 1- Vinyl-4-propylnaphthalene, 1-vinyl-5-propylnaphthalene, 1-vinyl-6-propylnaphthalene, 1-vinyl-7-propylnaphthalene, 1-vinyl-8-propylnaphthalene, 2-vinyl-1-propylnaphthalene, 2-vinyl-3-propylnaphthalene, 2-vinyl-4-propylnaphthalene, 2-vinyl-5-propylnaphthalene, 2-vinyl-6-propylnaphthalene, 2-vinyl-7-propylnaphthalene, 2-vinyl-8-propylnaphthalene, o-ethoxystyrene, m-ethoxystyrene, p-ethoxystyrene, o- Propoxystyrene, m-propoxystyrene, p-propoxystyrene, o-n-butoxystyrene, m-n-butoxystyrene, p-n-butoxystyrene, o-isobutoxystyrene, m-isobutoxystyrene, p-isobutoxystyrene, o-t-butoxystyrene, m-t-butoxystyrene, p-t-butoxystyrene, o-n-pentoxystyrene, m-n-pentoxystyrene, p-n-pentoxystyrene, α-methyl-o-butoxystyrene, α-methyl-m-butoxystyrene, α-methyl-p-butoxystyrene, o-t-pent Xystyrene, m-t-pentoxystyrene, p-t-pentoxystyrene, o-n-hexoxystyrene, m-n-hexoxystyrene, p-n-hexoxystyrene, α-methyl-o-pentoxystyrene, α-methyl-m-pentoxystyrene, α-methyl-p-pentoxystyrene, o-cyclohexoxystyrene, m-cyclohexoxystyrene, p-cyclohexoxystyrene, o-phenoxystyrene, m-phenoxystyrene, p-phenoxystyrene, divinylbenzene, divinylnaphthalene, divinylbiphenyl, divinylfluorene,BVPM (bis(vinylphenyl)methane), BVPE (bis(vinylphenyl)ethane), BVPH (bis(vinylphenyl)hexane), poly(arylene ether) polymers (HC-G0037, HC-G0024, HC-G0030, HC-G0038, all manufactured by JSR Corporation; these may contain monomer units containing pyridazine, pyrimidine, or pyrazine groups), fluorenes or indenes, and halogenated compounds containing ethylenically unsaturated bonds (chloromethylstyrene, allyl chloride, metharyl chloride, acrylate chloride, methacrylate chloride, etc.), as described in Japanese Patent No. 6951829. Compounds containing divinylbenzene as a constituent unit (not limited to the following examples, but including, for example, ODV-XET(X3), ODV-XET(X4), ODV-XET(X5), all manufactured by Nippon Steel Chemical & Material Co., Ltd., Snekton S-700 (development product number: LDM-03-07), Snekton S-2000 (development product number: LDM-02-C), Snekton N-5000 (development product number: LDM-05-A), Snekton N-7000 (development product number: LDM-07-A), Snekton S-710 (development product number: LDM-03L), all manufactured by Denka Co., Ltd., and the reaction products of the aforementioned phenolic resin and chloromethylstyrene.)

[0094] Compounds having an allyl group include, but are not limited to, the aforementioned phenol resin and allyl chloride reaction products, and reaction products of ethylenically unsaturated bond-containing phenols (2-allylphenol, 4-allylphenol, eugenol, etc.) and halogenated compounds (1,4-bis(chloromethyl)benzene, 4,4'-bis(chloromethyl)biphenyl, 4,4'-difluorobenzophenone, 4,4'-dichlorobenzophenone, 4,4'-dibromobenzophenone, cyanuryl chloride, etc.).

[0095] Compounds having a 1-propenyl group include, but are not limited to, the following disclosures, examples of which are reaction products of ethylenically unsaturated bond-containing phenols (2-propenylphenol, 4-propenylphenol, isoeugenol, etc.) and halogenated compounds (1,4-bis(chloromethyl)benzene, 4,4'-bis(chloromethyl)biphenyl, 4,4'-difluorobenzophenone, 4,4'-dichlorobenzophenone, 4,4'-dibromobenzophenone, cyanuryl chloride, etc.).

[0096] Compounds having a methallyl group include, but are not limited to, the reaction products of the aforementioned phenolic resin and methallyl chloride.

[0097] Compounds having a (meth)acrylic group include, but are not limited to, monofunctional (meth)acrylates, polyfunctional (meth)acrylates, urethane (meth)acrylates, polyester (meth)acrylates, epoxy (meth)acrylates, and reactive oligomers in which these bonds are used in combination, as well as acid-modified products thereof.

[0098] Examples of monofunctional (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, lauryl (meth)acrylate, polyethylene glycol (meth)acrylate, polyethylene glycol (meth)acrylate monomethyl ether, phenylethyl (meth)acrylate, isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate.

[0099] Examples of polyfunctional (meth)acrylates include tridiclodecane dimethanol di(meth)acrylate, butanediol di(meth)acrylate, hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, nonanediol di(meth)acrylate, glycol di(meth)acrylate, diethylene di(meth)acrylate, polyethylene glycol di(meth)acrylate, tris(meth)acryloyloxyethyl isocyanurate, polypropylene glycol di(meth)acrylate, bisphenolethylene oxide di(meth)acrylate, hydrogenated bisphenolethylene oxide (meth)acrylate, bisphenol di(meth)acrylate, ε- Examples include neopentyl glycol di(meth)acrylate modified from caprolactone hydroxypivalate, ε-caprolactone modified dipentaerythritol hexa(meth)acrylate, ε-caprolactone modified dipentaerythritol poly(meth)acrylate, dipentaerythritol poly(meth)acrylate, trimethylolpropane tri(meth)acrylate, triethylolpropane tri(meth)acrylate and its ethylene oxide adducts, pentaerythritol tri(meth)acrylate and its ethylene oxide adducts, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate and its ethylene oxide adducts.

[0100] Also included are mono, di, tri, or tetra(meth)acrylates of triols obtained by adding 1 mole or more of a cyclic lactone compound such as ε-caprolactone, γ-butyrolactone, or δ-valerolactone to 1 mole of pentaerythritol, dimethylolpropane, trimethylolpropane, or tetramethylolpropane; mono or poly(meth)acrylates of triols obtained by adding 1 mole or more of a cyclic lactone compound such as ε-caprolactone, γ-butyrolactone, or δ-valerolactone to 1 mole of dipentaerythritol; and mono(meth)acrylates or poly(meth)acrylates of polyhydric alcohols such as tetraol, pentaol, or hexaol.

[0101] Examples of urethane (meth)acrylates include reaction products of hydroxyl group-containing (meth)acrylates with polyisocyanates and other alcohols used as needed.

[0102] Examples of hydroxyl group-containing (meth)acrylates include hydroxyalkyl (meth)acrylates such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate; glycerin (meth)acrylates such as glycerin mono (meth)acrylate and glycerin di (meth)acrylate; sugar alcohol (meth)acrylates such as pentaerythritol di (meth)acrylate, pentaerythritol tri (meth)acrylate, dipentaerythritol penta (meth)acrylate, and dipentaerythritol hexa (meth)acrylate; and epoxy (meth)acrylates, which will be described later.

[0103] Examples of polyisocyanates include toluene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, xylene diisocyanate, hydrogenated xylene diisocyanate, dicyclohexanemethylene diisocyanate, and polyisocyanates such as their isocyanurates and biuret reaction products.

[0104] Other alcohols include, for example, tricyclodecanedimethanol, hydrogenated polybutadiene polyol, dimergol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, 1,18-octadecanediol, 1,20-icosanediol, 1-methyl-1,8- Examples include octanediol, 2-methyl-1,8-octanediol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, cyclohexane-1,4-dimethanol, polyethylene glycol, polypropylene glycol, diols such as bisphenol A poly(n≒2-20)ethoxydiol and bisphenol A poly(n≒2-20)propoxydiol, and polyester polyols which are reaction products of these diols with dibasic acids or their anhydrides (e.g., succinic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, isophthalic acid, terephthalic acid, phthalic acid, or their anhydrides).

[0105] Examples of polyester (meth)acrylates include monofunctional (poly)ester (meth)acrylates such as caprolactone-modified 2-hydroxyethyl (meth)acrylate, ethylene oxide and / or propylene oxide-modified phthalic acid (meth)acrylate, ethylene oxide-modified succinic acid (meth)acrylate, and caprolactone-modified tetrahydrofurfuryl (meth)acrylate; polyfunctional (poly)ester (meth)acrylates such as hydroxypivalate ester neopentyl glycol di(meth)acrylate, caprolactone-modified hydroxypivalate ester neopentyl glycol di(meth)acrylate, and epichlorohydrin-modified phthalic acid di(meth)acrylate; and mono, di, or tri(meth)acrylates of triols obtained by adding 1 mole or more of cyclic lactone compounds such as ε-caprolactone, γ-butyrolactone, and δ-valerolactone to 1 mole of trimethylolpropane or glycerin.

[0106] Furthermore, examples include (meth)acrylates of polyester polyols, which are reaction products of diol components such as (poly)ethylene glycol, (poly)propylene glycol, (poly)tetramethylene glycol, (poly)butylene glycol, 3-methyl-1,5-pentanediol, and hexanediol with polybasic acids such as maleic acid, fumaric acid, succinic acid, adipic acid, phthalic acid, isophthalic acid, hexahydrophthalic acid, tetrahydrophthalic acid, dimer acid, sebacic acid, azelaic acid, and 5-sodium sulfoisophthalic acid, and their anhydrides; and (meth)acrylates of cyclic lactone-modified polyester diols, which consist of diol components, polybasic acids, and their anhydrides with ε-caprolactone, γ-butyrolactone, δ-valerolactone, etc.

[0107] Examples of epoxy (meth)acrylates include reaction products of the aforementioned epoxy resin with compounds that contain both polymerizable ethylenically unsaturated groups and carboxyl groups in a single molecule.

[0108] Examples of compounds that contain both polymerizable ethylenically unsaturated groups and carboxyl groups in a single molecule include (meth)acrylic acids, crotonic acid, α-cyanocinnamic acid, cinnamic acid, or reaction products of saturated or unsaturated dibasic acids with unsaturated group-containing monoglycidyl compounds. Examples of acrylic acids include (meth)acrylic acid, β-styrylacrylic acid, β-furfurylacrylic acid, (meth)acrylic acid dimers, semi-esters which are equimolar reaction products of saturated or unsaturated dibasic acid anhydrides with (meth)acrylate derivatives having one hydroxyl group per molecule, and semi-esters which are equimolar reaction products of saturated or unsaturated dibasic acids with monoglycidyl (meth)acrylate derivatives.

[0109] Furthermore, examples of polycarboxylic acid compounds having multiple carboxyl groups in a single molecule include semi-esters which are equimolar reaction products with (meth)acrylate derivatives having multiple hydroxyl groups in a single molecule, and semi-esters which are equimolar reaction products with saturated or unsaturated dibasic acids and glycidyl (meth)acrylate derivatives having multiple epoxy groups.

[0110] Acid-modified (meth)acrylates are those obtained by reacting all or part of the alcoholic hydroxyl groups of a (meth)acrylate, which has alcoholic hydroxyl groups, with a carboxylic acid or its anhydride to introduce carboxyl groups. Examples of carboxylic acids or their anhydrides include succinic acid, maleic acid, isophthalic acid, terephthalic acid, tetrahydroisophthalic acid, hexahydroisophthalic acid, itaconic acid, 3-methyltetrahydroisophthalic acid, 4-methylhexahydroisophthalic acid, hydrogenated trimellitic acid, trimellitic acid, allylsuccinic acid, citraconic acid, methylsuccinic acid, 2,2-dimethylsuccinic acid, pentadecenylsuccinic acid, dodecenylsuccinic acid, decylsuccinic acid, dodecylsuccinic acid, hexadecylsuccinic acid, octadecylsuccinic acid, bicyclo[2.2.2]octo-2-ene-2,3-dicarboxylic acid, succinic anhydride, maleic anhydride, and phthalic acid anhydride. Examples include aqueous solutions, tetrahydroisophthalic anhydride, hexahydroisophthalic anhydride, itaconic anhydride, 3-methyl-tetrahydroisophthalic anhydride, 4-methyl-hexahydroisophthalic anhydride, hydrogenated trimellitic anhydride, trimellitic anhydride, allylsuccinic anhydride, citraconic anhydride, methylsuccinic anhydride, 2,2-dimethylsuccinic anhydride, pentadecenylsuccinic anhydride, dodecenylsuccinic anhydride, decylsuccinic anhydride, dodecylsuccinic anhydride, hexadecylsuccinic anhydride, octadecylsuccinic anhydride, and bicyclo[2.2.2]octo-2-ene-2,3-dicarboxylic acid anhydride.

[0111] Compounds having an acenaphthyl group are not limited to the following disclosures, but include, for example, acenaphthylene, 1-methylacenaphthylene, 3-methylacenaphthylene, 4-methylacenaphthylene, 5-methylacenaphthylene, 1-ethylacenaphthylene, 3-ethylacenaphthylene, 4-ethylacenaphthylene, 5-ethylacenaphthylene, 5-propylacenaphthylene, 3,8-dimethylacenaphthylene, 5,6-dimethylacenaphthylene, 1-chloroacenaphthylene, 3-chloroacenaphthylene, 4-chloroacenaphthylene, 5-chloroacenaphthylene Examples include phthalene, 1-bromoacenaphthalene, 3-bromoacenaphthalene, 4-bromoacenaphthalene, 5-bromoacenaphthalene, 1-phenylacenaphthalene, 3-phenylacenaphthalene, 4-phenylacenaphthalene, 5-phenylacenaphthalene, 3-methoxyacenaphthalene, 3-ethoxyacenaphthalene, 3-butoxyacenaphthalene, 4-methoxyacenaphthalene, 4-ethoxyacenaphthalene, 4-butoxyacenaphthalene, 5-methoxyacenaphthalene, 5-ethoxyacenaphthalene, and 5-butoxyacenaphthalene.

[0112] Compounds having an indenyl group include, but are not limited to, indene, methyl indene, ethyl indene, propyl indene, butyl indene, t-butyl indene, sec-butyl indene, n-pentyl indene, 2-methyl-butyl indene, 3-methyl-butyl indene, n-hexyl indene, 2-methyl-pentyl indene, 3-methyl-pentyl indene, 4-methyl-pentyl indene, methoxy indene, ethoxy indene, butoxy indene, t-butoxy indene, sec-butoxy indene, n-pentoxy indene, 2-methyl-butoxy indene, 3-methyl-butoxy indene, n-hexoxy indene, 2-methyl-pentoxy indene, 3-methyl-pentoxy indene, and 4-methyl-pentoxy indene.

[0113] Compounds having a citracomide group include, but are not limited to, o-phenylenebiscitraconimide, m-phenylenebiscitraconimide, p-phenylenebiscitraconimide, 4,4-diphenylmethanebiscitraconimide, 2,2-bis[4-(4-citraconimidophenoxy)phenyl]propane, bis(3,5-dimethyl-4-citraconimidophenyl)methane, bis(3-ethyl-5-methyl-4-citraconimidophenyl)methane, and bis(3,5-diethyl-4-citraconimidophenyl)methane.

[0114] Compounds having an itaconiamide group include, but are not limited to, N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, and N-laurylitaconimide.

[0115] Compounds having a nadiimide group include, but are not limited to, the following disclosures, 5-norbornene-2,3-dicarboxylic acid imide (so-called nadiimide), N-methylnadiimide, N-phenylnadiimide, o-phenylenebisnadiimide, m-phenylenebisnadiimide, p-phenylenebisnadiimide, 4,4'-diphenylmethanebisnadiimide, 2,2-bis[4-(4-nadiimoidphenoxy)phenyl]propane, bis(3,5-dimethyl-4-nadiimoidphenyl)methane, bis(3-ethyl-5-methyl-4-nadiimoidphenyl)methane, and bis(3,5-diethyl-4-nadiimoidphenyl)methane.

[0116] Compounds having an arylnadiimide group include, but are not limited to, the following disclosures, N-arylnadiimide (N-allyl-5-norbornene-2,3-dicarboxylic acid imide), N-allyl-N-methylnadiimide, N-allyl-N-phenylnadiimide, o-phenylenebis(N-arylnadiimide), m-phenylenebis(N-arylnadiimide), p-phenylenebis(N-arylnadiimide), 4,4'-diphenylmethanebis(N-arylnadiimide), 2,2-bis[4-(4-N-arylnadiimoidphenoxy)phenyl]propane, bis(3,5-dimethyl-4-N-arylnadiimoidphenyl)methane, and bis(3-ethyl-5-methyl-4-N-arylnadiimoidphenyl)methane.

[0117] Compounds having a cyclopentadienyl group include, but are not limited to, 1,3-cyclopentadiene, 1-methyl-1,3-cyclopentadiene, 2-methyl-1,3-cyclopentadiene, 1,2,3,4-tetramethyl-1,3-cyclopentadiene, and 1,2,3,4,5-pentamethyl-1,3-cyclopentadiene.

[0118] [Benzoxazine Compounds] Any benzoxazine compound may be used as a compound obtained by reacting a compound having a phenolic hydroxyl group, a compound having an amino group, or a compound having an aldehyde group. The compound having a phenolic hydroxyl group is not particularly limited, but for example, the aforementioned phenolic resins, phenols (which may have substituents such as alkenyl groups or alkyl groups), and bisphenols can be used. The compound having an amino group is not particularly limited, but for example, the aforementioned amine resins, diamines, and anilines (which may have substituents such as alkenyl groups or alkyl groups) can be used. As for the aldehyde compound, for example, the aforementioned aldehydes can be used, but formaldehyde is preferred. Commercially available benzoxazine compounds may be used, including benzoxazine P-d, F-a, ALP-d (all manufactured by Shikoku Chemicals Co., Ltd.), JBZ-BA100N, JBZ-FA100N, JBZ-DP100N, JBZ-OP100N, JBZ-OP100D, JBZ-OP100I (all manufactured by JFE Chemical Corporation), and BTBz (manufactured by Nippon Materials Technology Co., Ltd.).

[0119] The curable resin composition of this embodiment is obtained by preparing the above components in predetermined proportions, pre-curing at 130 to 180°C for 30 to 500 seconds, and then post-curing at 150 to 200°C for 2 to 15 hours to allow the curing reaction to proceed sufficiently and obtain the cured product of this embodiment. Alternatively, the components of the curable resin composition can be uniformly dispersed or dissolved in a solvent, and then cured after removing the solvent.

[0120] The method for preparing the curable resin composition of this embodiment is not particularly limited, but may be done by simply mixing each component uniformly or by prepolymerization. For example, prepolymerization can be performed by heating a mixture containing the compounds of this embodiment in the presence or absence of a curing accelerator and polymerization initiator, in the presence or absence of a solvent. Similarly, prepolymerization may be performed by adding compounds such as amine compounds, compounds having ethylenically unsaturated bonds, maleimide compounds, cyanate ester compounds, polybutadiene and its modified products, polystyrene and its modified products, inorganic fillers, and other additives. Mixing or prepolymerization of each component can be performed using, for example, an extruder, kneader, or roll in the absence of a solvent, and a reaction vessel with a stirring device can be used in the presence of a solvent.

[0121] For uniform mixing, the resin composition is kneaded using equipment such as a kneader, roll, or planetary mixer at a temperature in the range of 50 to 100°C. After pulverization, the resulting resin composition can be molded into cylindrical tablets using a molding machine such as a tablet machine, or into granular powder or powdery molded bodies. Alternatively, these compositions can be melted on a surface support and molded into sheets with a thickness of 0.05 mm to 10 mm to produce curable resin composition molded bodies. The resulting molded bodies are non-sticky at 0 to 20°C and maintain their fluidity and curability with almost no decrease even after storage at -25 to 0°C for more than a week. The resulting molded bodies can be molded into cured products using a transfer molding machine or a compression molding machine.

[0122] The curable resin composition of this embodiment can also be made into a varnish-like composition (hereinafter simply referred to as varnish) by adding an organic solvent. The curable resin composition of this embodiment can be dissolved in a solvent such as toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, dimethylformamide, dimethylacetamide, or N-methylpyrrolidone as needed to form a varnish, which can then be impregnated into a substrate such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, or paper, and heated and dried to obtain a prepreg. The resulting prepreg can then be hot-press molded to obtain a cured product of the curable resin composition of this embodiment. In this case, the solvent used is in an amount that accounts for 10 to 70% by mass, preferably 15 to 70% by mass, of the mixture of the curable resin composition of this embodiment and the solvent. If it is a liquid composition, a cured product of the curable resin composition containing carbon fibers can also be obtained directly, for example, by the RTM method.

[0123] Furthermore, the curable resin composition of this embodiment can also be used as a modifier for film-type compositions. Specifically, it can be used to improve flexibility and other properties in the B-stage. Such a film-type resin composition can be obtained as a sheet-like adhesive by applying the curable resin composition of this embodiment as a varnish onto a release film, removing the solvent under heating, and then performing the B-stage process. This sheet-like adhesive can be used as an interlayer insulating layer in multilayer substrates and the like.

[0124] The curable resin composition of this embodiment can also be heated and melted to reduce viscosity and impregnate reinforcing fibers such as glass fibers, carbon fibers, polyester fibers, polyamide fibers, and alumina fibers to obtain a prepreg. Specific examples include, but are not limited to, glass fibers such as E glass cloth, D glass cloth, S glass cloth, Q glass cloth, spherical glass cloth, NE glass cloth, and T glass cloth, as well as inorganic fibers other than glass, and organic fibers such as poly(p-phenylene terephthalamide) (Kevlar®, manufactured by DuPont), fully aromatic polyamide, polyester, poly(p-phenylene benzoxazole), polyimide, and carbon fibers. The shape of the substrate is not particularly limited, but examples include woven fabrics, nonwoven fabrics, rovings, and chopped strand mats. As for the weaving method of the woven fabric, plain weave, twill weave, etc., are known, and these can be appropriately selected and used depending on the intended application and performance. Furthermore, glass woven fabrics that have been opened or surface-treated with silane coupling agents are preferably used. The thickness of the base material is not particularly limited, but is preferably about 0.01 to 0.4 mm. Alternatively, a prepreg can be obtained by impregnating the reinforcing fibers with the varnish and then heating and drying them.

[0125] Furthermore, laminates can also be manufactured using the above-mentioned prepregs. The laminate is not particularly limited as long as it comprises one or more prepregs, and may have any other layers. The method for manufacturing the laminate is not particularly limited and can be any generally known method as appropriate. For example, when forming a metal foil laminate, a multi-stage press, a multi-stage vacuum press, a continuous molding machine, an autoclave molding machine, etc., can be used, and a laminate can be obtained by laminating the above-mentioned prepregs together and then heating and pressing them. At this time, the heating temperature is not particularly limited, but 65 to 300°C is preferred, and 120 to 270°C is more preferred. The pressurizing pressure is not particularly limited, but if the pressurizing pressure is too high it is difficult to adjust the solid content of the resin in the laminate and the quality is not stable, and if the pressurizing pressure is too low it becomes difficult to form air bubbles and the adhesion between layers is poor, so 2.0 to 5.0 MPa is preferred, and 2.5 to 4.0 MPa is more preferred. The laminate of this embodiment can be suitably used as a metal foil laminate described later by comprising a layer made of metal foil. By cutting the above prepreg into the desired shape, laminating it with copper foil or other materials as needed, and then applying pressure to the laminate using methods such as press molding, autoclave molding, or sheet winding molding while heating and curing a curable resin composition, electrical and electronic laminates (printed wiring boards) and carbon fiber reinforced materials can be obtained.

[0126] The curable resin composition of this embodiment can also be made into a resin sheet. One method for obtaining a resin sheet from the curable resin composition of this embodiment is to apply the curable resin composition onto a support film (support), and then dry it to form a resin composition layer on the support film. When the curable resin composition of this embodiment is used to make a resin sheet, it is important that the film softens at the lamination temperature conditions (70°C to 140°C) in the vacuum lamination method and exhibits fluidity (resin flow) that allows for simultaneous lamination of the circuit board and resin filling of via holes or through holes present in the circuit board. It is preferable to blend each component in such a way as to exhibit such characteristics. Furthermore, in order to prevent phenomena such as locally different characteristic values ​​caused by phase separation from occurring in the resulting resin sheet or circuit board (copper-clad laminate, etc.), uniformity of appearance is required to ensure that a certain level of performance is achieved in any desired area.

[0127] Here, the diameter of the through-holes in the circuit board is 0.1 to 0.5 mm, and the depth is 0.1 to 1.2 mm. It is preferable to be able to fill the holes with resin within this range. When laminating both sides of the circuit board, it is desirable that the through-holes be filled to about half their extent.

[0128] A specific method for manufacturing the aforementioned resin sheet is to prepare a varnished resin composition by incorporating an organic solvent, apply the varnished resin composition to the surface of a support film (Y), and then dry the organic solvent by heating or blowing hot air to form a resin composition layer (X).

[0129] The organic solvents used here preferably include ketones such as acetone, methyl ethyl ketone, and cyclohexanone; acetic acid esters such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitols such as cellosolve and butyl carbitol; aromatic hydrocarbons such as toluene and xylene; dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. It is also preferable to use the organic solvent in a proportion such that the non-volatile content is 30 to 60% by mass of the total.

[0130] Furthermore, the thickness of the formed resin composition layer (X) must be greater than or equal to the thickness of the conductive layer of the circuit board to which the resin composition layer (X) is laminated. Since the thickness of the conductive layer of the circuit board is in the range of 5 to 70 μm, it is preferable that the thickness of the resin composition layer (X) be 10 to 100 μm. In this embodiment, the resin composition layer (X) may be protected by a protective film, which will be described later. By protecting it with a protective film, it is possible to prevent dirt and other debris from adhering to the surface of the resin composition layer (X) and to prevent scratches.

[0131] The support film and protective film can be made of polyolefins such as polyethylene, polypropylene, and polyvinyl chloride, polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate, polycarbonate, polyimide, and also release paper, copper foil, aluminum foil, and other metal foils. The support film and protective film may be treated with a mat treatment, corona treatment, or release treatment. The thickness of the support film is not particularly limited, but is 10 to 150 μm, preferably in the range of 25 to 50 μm. The thickness of the protective film is preferably 1 to 40 μm.

[0132] The support film (Y) is peeled off after the resin composition layer (X) is laminated to the circuit board, or after an insulating layer is formed by heat curing the resin composition layer (X). If the support film (Y) is peeled off after the resin composition layer (X) constituting the resin sheet has been heat cured, it is possible to prevent the adhesion of dust and other debris during the curing process. When the support film (Y) is peeled off after the resin composition layer (X) has been cured, the support film (Y) is subjected to a release treatment beforehand.

[0133] Furthermore, a multilayer printed circuit board can be manufactured from the resin sheet obtained as described above. For example, if the resin composition layer (X) is protected by a protective film, the protective film is peeled off from the resin composition layer (X), and then the resin composition layer (X) is laminated to one or both sides of the circuit board so that it is in direct contact with the circuit board, for example, by a vacuum lamination method. The lamination method may be batch type or continuous type using a roll. Also, if necessary, the resin sheet and circuit board may be heated (preheated) before lamination. Preferably, the lamination conditions are a pressure temperature (lamination temperature) of 70 to 140°C and a pressure of 1 to 11 kgf / cm². ２ (9.8 x 10 ４ ~107.9 x 10 ４ N / m ２ It is preferable to use this method, and it is preferable to laminate under reduced pressure of 20 mmHg (26.7 hPa) or less.

[0134] Furthermore, semiconductor devices can be manufactured using the curable resin composition of this embodiment. Examples of semiconductor devices include DIP (Dual In-Line Package), QFP (Quad Flat Package), BGA (Ball Grid Array), CSP (Chip Size Package), SOP (Small Outline Package), TSOP (Thin Small Outline Package), and TQFP (Thin Quad Flat Package).

[0135] The curable resin composition and its cured product according to this embodiment can be used in a wide range of fields. Specifically, it can be used in various applications such as molding materials, adhesives, composite materials, and paints. Because the cured product of the curable resin composition described in this embodiment exhibits excellent heat resistance and dielectric properties, it is suitably used in electrical and electronic components such as encapsulants for semiconductor devices, encapsulants for liquid crystal display devices, encapsulants for organic EL devices, laminates (printed wiring boards, BGA (ball grid array) substrates, build-up substrates, etc.), composite materials for lightweight, high-strength structural materials such as carbon fiber reinforced plastics and glass fiber reinforced plastics, and 3D printing.

[0136] Next, the present invention will be described in more detail with reference to examples. Hereinafter, unless otherwise specified, parts refer to parts by mass. However, the present invention is not limited to these examples.

[0137] The various analytical methods used in the examples are described below. <GPC (Gel Permeation Chromatography) Analysis> Apparatus: Online degassing unit (DGU-20A), liquid delivery unit (LC-20AD), autosampler (SIL-20A), photodiode array detector (SPD-M40), column oven (CTO-20A), system controller (CBM-20A), all manufactured by Shimadzu Corporation. Columns: SHODEX GPC KF-601 (2), KF-602, KF-602.5, KF-603 Flow rate: 1.5 ml / min. Column temperature: 40°C Solvent used: THF (tetrahydrofuran) Detector: Differential refractive detector (RID-20A, Shimadzu Corporation) <High-performance liquid chromatography (HPLC)> HPLC: Liquid delivery unit (LC-20AD), online degasser (DGU-20A3), autosampler (SIL-20A), column oven (CTO-20A), system controller (CBM-20A), absorbance detector (SPD-M20A) (all manufactured by Shimadzu Corporation) Column: ODS-2 (GL Sciences, 5 μm, 4.6 × 250 mm) Mobile phase A: Acetonitrile Mobile phase B: Water Gradient: 0–28 min. : Mobile phase A / Mobile phase B = 60% / 40% → 100% / 0%, 28–40 min. Mobile phase A / Mobile phase B = 100% / 0% Flow rate: 1 ml / min Column temperature: 40°C Detection: PDA (Photodiode array detector: Quantitative detection at a wavelength of 274 nm)

[0138] [Synthesis Example 1] A flask equipped with a thermometer, condenser, stirrer, and Dean-Stark tube was purged with nitrogen, and 74.5 parts of aniline and 25 parts of toluene were added. Stirring was started, and the internal temperature was raised to 50°C. 25.1 parts of 4,4'-bis(chloromethyl)biphenyl were added in installments over 1 hour while maintaining the internal temperature at 50-60°C. After raising the internal temperature to 65°C, the mixture was reacted at 65°C for 2 hours. 20.8 parts of 35 wt% hydrochloric acid were added dropwise at an internal temperature of 80°C or less, and the internal temperature was raised to 205°C over 2 hours while removing water and toluene from the system. After reacting at 205°C for 2 hours, the mixture was allowed to cool, and 25 parts of toluene were added. 56 parts of 30 wt% aqueous sodium hydroxide solution were added dropwise over 30 minutes, and the mixture was stirred for 2 hours. The organic layer was washed with 100 parts of water until the wastewater was neutral. The obtained organic layer was concentrated to obtain 30 parts of amine resin (A1) represented by the following formula (a-1). At 150°C, the ICI viscosity was 0.06 Pa·s, the softening point (JIS) was 49.8°C, and the amine equivalent was 193 g / eq., and it was a brown solid. The GPC chart of amine resin (A1) is shown in Figure 1. １ Figure 2 shows the 1H-NMR chart (deuterated chloroform). GPC analysis revealed that the number-average molecular weight (Mn) of the amine resin (A1) was 481, the weight-average molecular weight (Mw) was 595, and the area percentage of the peak detected at a retention time of 21.1 minutes was 66.4 area%. (1) ａｖｅ +m ａｖｅ ) = 1.49.

[0139]

[0140] [Synthesis Example 2] A flask equipped with a thermometer, condenser, stirrer, and Dean-Stark tube was purged with nitrogen, and 10 parts N-methyl-2-pyrrolidone, 14.7 parts maleic anhydride, 0.4 parts methanesulfonic acid, and 30 parts toluene were added. Stirring was started, and the internal temperature was raised to 115°C. Prior to this, 19.3 parts of the amine resin (A1) obtained in Synthesis Example 1 were dissolved in 10 parts N-methyl-2-pyrrolidone and 30 parts toluene, and this solution was added dropwise over 2 hours. After reacting at an internal temperature of 117°C for 2 hours, the mixture was washed five times with 100 parts of water. The organic layer was then returned to the flask and heated to 109°C while azeotropically dehydrating, and stirred for 30 minutes. 0.4 parts methanesulfonic acid was added, and the mixture was reacted at 109°C for 2 hours. The organic layer was washed five times with 100 parts of water, and the resulting organic layer was concentrated to obtain 19.6 parts of maleimide resin (M1), represented by the following formula (m-1), as a brown solid. The ICI viscosity at 150°C was 0.74 Pa·s, and the softening point (JIS) was 96.4°C. The HPLC-LC chart of the obtained maleimide resin (M1) is shown in Figure 3, and the GPC chart is shown in Figure 4. １ Figure 5 shows the 1H-NMR chart (deuterated chloroform). GPC analysis revealed that the number-average molecular weight (Mn) of maleimide resin (M1) was 665, the weight-average molecular weight (Mw) was 904, and the area percentage of the peak detected at a retention time of 22.1 minutes was 61.5 area%. (1) ａｖｅ +m ａｖｅ ) = 1.66. From the HPLC analysis, l:m = 100:35.64, and the average value of l obtained from these (l ａｖｅ ) is 1.22, the average value of m (m ａｖｅ The ratio was 0.44. In addition, the content of structures with l=1 and m=0 in maleimide resin (M1) was 45.3 area%.

[0141]

[0142] [Synthesis Example 3] A flask fitted with a thermometer, condenser, stirrer, and Dean-Stark tube was purged with nitrogen, and 111.8 parts of aniline, 42.9 parts of N-methylaniline, and 50 parts of toluene were added. Stirring was started, and the internal temperature was raised to 50°C. 50.2 parts of 4,4'-bis(chloromethyl)biphenyl were added in installments over 1 hour while maintaining the internal temperature at 50-60°C. After raising the internal temperature to 65°C, the reaction was carried out at 65°C for 2 hours. 41.7 parts of 35 wt% hydrochloric acid were added dropwise at an internal temperature of 80°C or less, and the internal temperature was raised to 210°C over 2 hours while removing water and toluene from the system. After reacting at 210°C for 12 hours, the mixture was allowed to cool, and 50 parts of toluene were added. The water and toluene removed during the heating process were returned to the reaction vessel, 33.6 parts of sodium hydroxide were added, and the mixture was stirred for 2 hours. The organic layer was washed with 100 parts of water until the wastewater was neutral. The obtained organic layer was concentrated to obtain 55 parts of amine resin (A2) represented by the following formula (a-2). The ICI viscosity at 150°C was 0.01 Pa·s, and the softening point (JIS) was 53.0°C. The amine equivalent was 195.4 g / eq., and it was a brown solid. The GPC chart of the obtained amine resin (A2) is shown in Figure 6. １ Figure 7 shows the 1H-NMR chart (deuterated chloroform). GPC analysis revealed that the number-average molecular weight (Mn) of the amine resin (A2) was 445, the weight-average molecular weight (Mw) was 542, and the area percentage of the peak detected at a retention time of 22.7 minutes was 71.6 area%. (1) calculated from GPC analysis. ａｖｅ +m ａｖｅ +n ａｖｅ The value was 1.40.

[0143]

[0144] [Synthesis Example 4] A flask equipped with a thermometer, condenser, stirrer, and Dean-Stark tube was purged with nitrogen, and 29.4 parts of maleic anhydride, 0.8 parts of methanesulfonic acid, and 30 parts of toluene were added. Stirring was started, and the internal temperature was raised to 115°C. Prior to this, 39.1 parts of the amine resin (A2) obtained in Synthesis Example 3 were dissolved in 20 parts of N-methyl-2-pyrrolidone and 60 parts of toluene. This solution was added dropwise over 2 hours. After reacting at an internal temperature of 115°C for 2 hours, the mixture was washed five times with 100 parts of water. The organic layer was then returned to the flask and heated to 110°C while azeotropically dehydrating, and stirred for 30 minutes. 0.8 parts of methanesulfonic acid was added, and the mixture was reacted at 110°C for 4 hours. The organic layer was washed five times with 100 parts of water, and the resulting organic layer was concentrated to obtain 52 parts of maleimide resin (M2), represented by the following formula (m-2), as a brown solid. The ICI viscosity at 150°C was 1.90 Pa·s, and the softening point (JIS) was 106°C. The HP-LC chart of the obtained maleimide resin (M2) is shown in Figure 8, and the GPC chart is shown in Figure 9. １ Figure 10 shows the 1H-NMR chart (deuterated chloroform). GPC analysis revealed that the number-average molecular weight (Mn) of maleimide resin (M2) was 688, the weight-average molecular weight (Mw) was 985, and the area percentage of the peak detected at a retention time of 22.1 minutes was 57.9 area%. (1) ａｖｅ +m ａｖｅ +n ａｖｅ ) = 1.76. From the HPLC analysis, l:m:n = 100:0.33:3.56, and the average value of l obtained from these is (l ａｖｅ ) is 1.69, the average value of m (m ａｖｅ ) is 0.0056, the average value of n (n ａｖｅ The ratio was 0.0603. In addition, the content of the structure l=1, m=0, n=0 in the maleimide resin (M2) was 55.7 area%.

[0145] [Synthesis Example 5] Maleimide resin (MI1) represented by the following formula (MI-1) was synthesized according to Examples 1 and 4 described in Japanese Patent Publication No. 6429862. The l calculated from GPC analysis ａｖｅThe result was 1.63. GPC analysis revealed that the content of the component represented by l=1 in the following formula (MI-1) was 62.5% by area.

[0146]

[0147] [Examples 1-4, Comparative Examples 1, 2] <Component Analysis> The content of each component represented by (M-1), (A-1), (M-A-1), and (M-A-2) in Table 1 below was determined from the area % in the aforementioned HPLC analysis (detection wavelength: 274 nm). Table 1 shows the content of each component represented by (A-1), (M-A-1), and (M-A-2) with (M-1) set to 100. <Test Specimen Preparation> The resins (M1, M2, MI1) obtained in Synthesis Examples 2, 4, and 5, and 2E4MZ (2-ethyl-4-methylimidazole) were used in the amounts shown in Table 1, and vacuum-press molded while sandwiched between mirror-finish copper foil (T4X: manufactured by Fukuda Metal Copper Foil Co., Ltd.), and cured at 220°C for 2 hours. At this time, a cushion paper with a thickness of 250 μm, with the center cut out by 150 mm vertically and horizontally, was used as a spacer. For the evaluation, test specimens were cut to the desired size using a laser cutter as needed, and the evaluation was then carried out.

[0148] <Curing Properties> Test specimens that were successfully prepared according to the above specimen preparation procedure were marked with ○, while those that had a large number of voids after press molding and were defective were marked with ×.

[0149] <Heat Resistance (DMA)> Dynamic viscoelasticity measuring instrument: TA-instruments, DMA-2980 Measurement temperature range: -30 to 280°C Heating rate: 2°C / min Frequency: 10 Hz Test specimen size: A specimen cut to 5 mm x 50 mm was used (thickness 0.2 mm) Tg: The peak point of tanδ (= loss modulus of elasticity / storage modulus of elasticity) was defined as Tg.

[0150] <Tensile Modulus of Elasticity> Equipment: Autograph AGS-X (Shimadzu Corporation) Tensile speed: 0.5 mm / min The test specimen was clamped to a length of 5 cm and measured by pulling it in a 180° direction at the above test speed.

[0151] <Water Absorption Rate> Sample size (w x l x t): 5 mm x 40 mm x 0.25 mm. After drying at 120°C for 2 hours, the sample was immersed in water at 25°C and 30% humidity for 24 hours, then removed. The mass was measured and calculated after leaving it for 24 hours at 25°C and 30% humidity.

[0152]

[0153] The results in Table 1 show that the maleimide resin mixture of the present invention exhibits superior high modulus and low water absorption without compromising heat resistance compared to Comparative Example 1, and superior curing performance compared to Comparative Example 2.

[0154] The maleimide resin mixture of the present invention is suitably used in electrical and electronic components such as semiconductor encapsulants, printed circuit boards, build-up laminates, and optical waveguide devices.

Claims

1. A maleimide resin mixture comprising: a maleimide resin represented by the following formula (1); a compound represented by the following formula (M-1); and one or more compounds selected from the group consisting of compounds represented by the following formulas (A-1), (M-A-1) and (M-A-2), wherein a value (α / β) obtained by dividing a total content (α) of the compounds represented by formulas (A-1), (M-A-1) and (M-A-2) by a content (β) of the compound represented by formula (M-1) is 0.001 to 0.

3. (In formula (1), a plurality of R groups each independently represent a hydrocarbon group having 1 to 5 carbon atoms. A plurality of X groups each independently represent a hydrocarbon group having 1 to 25 carbon atoms. p is an integer of 0 to 5. q is an integer of 0 to 4. A plurality of r groups each independently represent an integer of 0 to 3. l, m, and n are the number of repetitions, and each is independently an integer of 0 to 20. The average value of l ａｖｅ satisfies 0.05 ≤ l ａｖｅ ≤ 20, and the sum of the average value of m ａｖｅ and the average value of n ａｖｅ satisfies 0.01 ≤ m ａｖｅ + n ａｖｅ ≤ 10. The bonding order of each structural unit having repeating units l, m, and n may be random or block.) (In formulas (M-1), (A-1), (M-A-1), and (M-A-2), a plurality of R groups each independently represent a hydrocarbon group having 1 to 5 carbon atoms. A plurality of X groups each independently represent a hydrocarbon group having 1 to 25 carbon atoms. A plurality of p groups each independently are 0 to 5. A plurality of q groups each independently are an integer of 0 to 4. r is an integer of 0 to 3.) 2. The maleimide resin mixture according to claim 1, wherein X in formulas (1), (M-1), (A-1), (M-A-1), and (M-A-2) is represented by one or more of the following formulas (a) to (l). (In formulas (a) to (l), * indicates the bonding position. There are multiple R １ Each of these independently represents a hydrocarbon group with 1 to 5 carbon atoms. There are multiple R's. ２ Each of these independently represents a hydrogen atom or a hydrocarbon group with 1 to 5 carbon atoms. i is an integer from 0 to 2. Multiple ks are each independently an integer from 0 to 5. Multiple ss are each independently an integer from 0 to 4. Multiple ts are each independently an integer from 0 to 3.

3. A curable resin composition containing the maleimide resin mixture according to claim 1 or 2.

4. The curable resin composition according to claim 3, further comprising one or more of the following: a curing accelerator, a polymerization initiator, an epoxy resin, an active ester compound, a phenol resin, a polyphenylene ether compound, an amine resin, a compound having an ethylenically unsaturated bond, an isocyanate resin, a polyamide resin, a maleimide compound, a cyanate ester resin, a polyimide resin, polybutadiene and a modified thereof, polystyrene and a modified thereof, polyethylene and a modified thereof, and a benzoxazine compound.

5. A cured product obtained by curing the curable resin composition described in claim 3.

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