Maleimide compound,curable resin compositi0n,and cured product thereof,and amine compound and reaction product of amine compound and maleic anhydride

Abstract

This invention provides a maleic anhydride compound with excellent high heat resistance, low dielectric properties, and good curability, a curable resin composition and its cured product, as well as an amine compound as a raw material therefrom, and a reactant of the amine compound and maleic anhydride. The maleic anhydride compound is shown in the following formula (1). (In formula (1), there exist multiple R series that exist independently and represent hydrocarbon groups or alkyl halides with 1 to 10 carbon atoms. The X series is shown in formula (2) below. m is an integer from 0 to 4, n is the number of repetitions, and the average value of n, nav, conforms to 1 ≤ nav ≤ 20). (In formula (2), there are multiple R groups that exist independently and represent hydrocarbon groups or alkyl halides with 1 to 10 carbon atoms. p represents an integer from 0 to 4 and q represents an integer from 0 to 3. r is the number of repetitions and the average value of r, rave, conforms to 1 ≤ rave ≤ 20. * indicates the bonding position with the aromatic ring in the aforementioned formula (1).)

Description

Technical Field

[0001] The present invention relates to maleimide compounds, curable resin compositions, and cured products thereof, as well as amine compounds and reaction products of amine compounds and maleic anhydride. These compounds are suitable for use in semiconductor encapsulants, printed wiring boards, build-up laminates, and other electrical and electronic components, as well as lightweight, high-strength materials such as carbon fiber reinforced plastics and glass fiber reinforced plastics, and in 3D printing applications. Prior Art

[0002] In recent years, as the application areas of build-up boards carrying electrical and electronic components have expanded, the required properties have become more diverse and sophisticated. Conventionally, semiconductor chips were primarily mounted on metal lead frames. However, high-performance semiconductor chips such as those in central processing units (CPUs) are increasingly being mounted on build-up boards made of polymer materials.

[0003] Furthermore, in order to satisfy the heating characteristics that are standard values ​​for heat-resistant laminates, a heat resistance (Tg) of at least 160°C or higher is required (Non-Patent Document 1).

[0004] Furthermore, the fifth-generation (5G) communication system, currently under rapid development, is expected to achieve even higher capacity and higher-speed communications. The demand for low-k-tangent materials is increasing daily, with a k-tangent of at least 0.005 at 10 GHz being required.

[0005] Furthermore, in the automotive industry, with the increasing use of electronics, precision electronic devices are sometimes placed near engine drive units, requiring even higher levels of heat and humidity resistance. SiC semiconductors are beginning to be used in electric vehicles and air conditioners, and because the encapsulants used for semiconductor components require extremely high heat resistance, conventional epoxy resin encapsulants are unable to meet this requirement.

[0006] Against this backdrop, research is underway to explore polymer materials that combine heat resistance with low dielectric tangent properties. For example, Patent Document 1 proposes a composition comprising a maleimide resin and a phenolic resin containing an allyl group. Furthermore, Patent Document 2 discloses an allyl ether resin in which hydroxyl groups are substituted with allyl groups.

[0007] In addition, in recent years, 3D printing has attracted much attention as a three-dimensional modeling technique, and this 3D printing technique has begun to be applied to fields that require reliability, such as aviation, space, vehicles, and connectors for electronic parts used therein. In particular, photo-curable and thermosetting resins are being explored for applications represented by Stereolithography (SLA) and Digital Light Processing (DLP). Therefore, in the conventional method of transferring from a mold, mainly shape stability and accuracy are required, but in 3D printing applications, various properties such as heat resistance, mechanical properties, toughness, flame retardancy, and even electrical properties are required, and the development of materials therefor has been underway. In addition, when used in structural members, there is a problem of property changes due to moisture absorption or the like. At present, acrylate resins and epoxy resins are applied to such uses. [Prior Art Documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 04-359911 [Patent Document 2] International Publication No. 2016 / 002704 [Non-Patent Document 1] Tooru Katayama, "Basic Course "Substrate Materials" - 5th Heat-Resistant Glass Epoxy Laminated Board", Circuit Technology, The Institute of Electronics Packaging, General Incorporated Association, 1993, Vol.8, No.6, p.505-511 Summary of the Invention Problems to be Solved by the Invention

[0009] However, in a composition containing a maleimide resin and a phenolic resin having an allyl group, since phenolic hydroxyl groups that do not participate in the curing reaction remain during the curing reaction, it is difficult to say that the electrical properties are sufficient. In addition, in an allyl ether resin in which a hydroxyl group is substituted with an allyl group, it is shown that a Claisen Rearrangement occurs at 190 °C, so phenolic hydroxyl groups that do not contribute to the curing reaction are generated at 200 °C, which is the molding temperature of a general substrate, and thus the electrical properties cannot be satisfied. In addition, in cured products of acrylate resins and epoxy resins applied to 3D printing applications, a large amount of ester bonds, ether bonds, and hydroxyl groups are contained, and the moisture absorption characteristics are insufficient.

[0010] The present invention was developed in view of this situation, and its purpose is to provide a maleimide compound, a curable resin composition, and a cured product thereof, which have high heat resistance, excellent low dielectric properties, and good curability, as well as an amine compound as a raw material thereof and a reaction product of the amine compound and maleic anhydride. The means to solve the problem

[0011] That is, the present invention relates to the following [1] to [8]. In the present invention, "(numerical value 1) to (numerical value 2)" means that the upper and lower limits are included. [1] A maleimide compound represented by the following formula (1),

[0012]

[0013] (In formula (1), the multiple Rs are independently present and represent a hydrocarbon group or a halogenated alkyl group having 1 to 10 carbon atoms. X is as shown in the following formula (2). m is an integer from 0 to 4, n is the number of repetitions, and the average value of n, nave, satisfies 1≦nave≦20.)

[0014]

[0015] (In formula (2), the multiple R systems exist independently and represent a hydrocarbon group or a halogenated alkyl group having 1 to 10 carbon atoms. p represents an integer from 0 to 4, and q represents an integer from 0 to 3. r is the number of repetitions, and the average value of r, rave, satisfies 1≦rave≦20. * represents the bonding position to the aromatic ring of the aforementioned formula (1)). [2] A maleimide compound represented by the following formula (3),

[0016]

[0017] (In formula (3), X is as shown in the following formula (4). n is the number of repetitions, and the average value of n, nave, satisfies 1.1≦nave≦20.)

[0018]

[0019] (In formula (4), there are plural Rs which exist independently of each other and represent a hydrocarbon group having 1 to 5 carbon atoms. p represents an integer of 0 to 4, r is a repeating number, and the average value rave of r satisfies 1.1 ≦ rave ≦ 20. * represents the bonding position to the aromatic ring of the compound of formula (3)). 〔3〕The maleimide compound according to the previous item 〔2〕, wherein in the aforementioned formula (4), p is 2, and the substitution position of R is ortho to the maleimide group. 〔4〕A curable resin composition containing: the maleimide compound according to any one of the previous items 〔1〕 to 〔3〕. 〔5〕The curable resin composition according to the previous item 〔4〕, further containing a radical polymerization initiator. 〔6〕A cured product obtained by curing the curable resin composition according to the previous item 〔4〕 or 〔5〕. 〔7〕An amine compound represented by the following formula (5),

[0020]

[0021] (In formula (5), there are plural Rs which exist independently of each other and represent a hydrocarbon group having 1 to 10 carbon atoms or a halogenated alkyl group. p represents an integer of 0 to 4, q represents an integer of 0 to 3. r is a repeating number, and the average value rave of r satisfies 1 ≦ rave ≦ 20). 〔8〕A reaction product of the compound according to the previous item 〔7〕 and maleic anhydride. Advantages of the Invention

[0022] The cured product of the maleimide compound of the present invention has excellent properties of high heat resistance and low dielectric characteristics. Therefore, it is a material useful for sealing electrical and electronic parts, circuit boards, carbon fiber composite materials, etc. Brief Explanation of the Drawings

[0023] Figure 1 shows the GPC chart of the amine compound of Example 1. Figure 2 shows the GPC chart of the maleimide compound of Example 1. FIG3 shows a 1H-NMR chart of the maleimide compound of Example 1. FIG4 shows a GPC chart of the amine compound of Example 2. FIG5 shows a GPC chart of the maleimide compound of Example 2. FIG6 shows a 1H-NMR chart of the maleimide compound of Example 2. FIG7 shows a GPC chart of the amine compound of Synthesis Example 1. FIG8 shows a GPC chart of the maleimide compound of Synthesis Example 2. Implementation Method

[0024] The maleimide compound of this embodiment is represented by the following formula (1).

[0025]

[0026] (In formula (1), the multiple Rs are each independently present and represent a hydrocarbon group or a halogenated alkyl group having 1 to 10 carbon atoms. X is as shown in the following formula (2). m is an integer from 0 to 4, n is the number of repetitions, and the average value of n, nave, satisfies 1≦nave≦20.)

[0027]

[0028] (In formula (2), the presence of multiple Rs is independent and represents a hydrocarbon group or a halogenated alkyl group having 1 to 10 carbon atoms. p represents an integer from 0 to 4, and q represents an integer from 0 to 3. r is the number of repetitions, and the average value of r, rave, satisfies 1≦rave≦20. * represents the bonding position to the aromatic ring of the aforementioned formula (1).)

[0029] In the aforementioned formula (1) and formula (2), R is a hydrocarbon group having 1 to 10 carbon atoms or a halogenated alkyl group, preferably a hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrocarbon group having 1 to 5 carbon atoms, and particularly preferably a hydrocarbon group having 1 to 3 carbon atoms. When R has a small number of carbon atoms, molecular vibration is less likely to occur when exposed to high frequencies. Therefore, in the aforementioned description, a hydrocarbon group having 1 to 3 carbon atoms results in particularly excellent electrical properties.

[0030] In the aforementioned formula (1), m is generally an integer of 0 to 4, preferably 0 to 3, more preferably 0 to 1, and particularly preferably 0. n is the number of repetitions, and the average value of n, nave, generally satisfies 1≦nave≦20, preferably 1.1≦nave≦20, more preferably 1.1≦nave≦18, and particularly preferably 1.1≦nave≦15. The average value of n, nave, can be calculated from the value of the number average molecular weight (Mn) determined by gel permeation chromatography (GPC) of the compound represented by the aforementioned formula (1). The number average molecular weight is preferably 200 or more and less than 10,000, more preferably 1,000 or more and less than 7,500, and particularly preferably 2,000 or more and less than 5,000. If the number average molecular weight is less than 10,000, purification by water washing is easy, and if it is 200 or more, the target compound is less likely to volatilize during the solvent distillation step.

[0031] In the aforementioned formula (2), p generally represents an integer from 0 to 4, preferably from 0 to 3, more preferably from 0 to 2. q generally represents an integer from 0 to 3, preferably from 0 to 2, more preferably from 0 to 1, and particularly preferably 0. r represents the number of repetitions, and the average value of r, rave, generally satisfies 1≦rave≦20, preferably satisfies 1.1≦rave≦20, more preferably satisfies 1.1≦rave≦18, and particularly preferably satisfies 1.1≦rave≦15.

[0032] A preferred embodiment of the maleic imide compound represented by the aforementioned formula (1) includes the maleic imide compound represented by the following formula (3).

[0033]

[0034] (In formula (3), X is as shown in the following formula (4). n is the number of repetitions, and the average value of n, nave, satisfies 1.1 ≤ nave ≤ 20.)

[0035]

[0036] (In formula (4), the multiple Rs are independently present and represent hydrocarbon groups with 1 to 5 carbon atoms. p represents an integer from 0 to 4, r represents the number of repetitions, and the average value of r, rave, satisfies 1.1≦rave≦20. * represents the bonding position to the aromatic ring of the compound of formula (3).)

[0037] In the above formula (4), from the viewpoints of molecular weight control, solvent solubility, dielectric properties, low water absorption, and heat resistance, it is particularly preferred that R is substituted with two substituents at the ortho position relative to the maleimide group.

[0038] The maleimide compound represented by the aforementioned formula (1) can be obtained, for example, by reacting a polymer of an amine compound represented by the following formula (5) with maleic anhydride. The polymerization of the amine compound represented by the following formula (5) and the maleimide reaction can be carried out separately, but the polymerization reaction of the amine compound represented by the following formula (5) and the maleimide reaction can be carried out at once in the presence of an acid catalyst such as methanesulfonic acid. The conditions for the maleimide reaction are not particularly limited, and the solvent used can include, for example, 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 is not limited to these, and two or more solvents can be used in combination. In addition to the aforementioned non-water-soluble solvents, aprotic polar solvents can also be used in combination. Examples include dimethylsulfonium, dimethylsulfoxide, dimethylformamide, dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, and N-methylpyrrolidone. Two or more of these solvents may be used in combination. When using an aprotic polar solvent, it is preferred to use one with a higher boiling point than the water-insoluble solvent being used. During the reaction, catalysts such as hydrochloric acid, phosphoric acid, sulfuric acid, formic acid, p-toluenesulfonic acid, and methanesulfonic acid may be used as needed. Other catalysts that can be used include Lewis acids such as aluminum chloride and zinc chloride, activated clay, acidic clay, white carbon, zeolite, and solid acids such as silica-alumina, and acidic ion exchange resins. These may be used alone or in combination of two or more. The amount of catalyst used is generally 0.1 to 0.8 mol, preferably 0.2 to 0.7 mol, per 1 mol of amino groups in the amine compound used. If the amount of catalyst used is too high, the viscosity of the reaction solution may be too high, making stirring difficult. If the amount is too low, the reaction may proceed slowly. Furthermore, as a co-catalyst for the imidization reaction, alkaline co-catalysts such as triethylamine may be used alone or in combination. When using a sulfonic acid as a catalyst, the extraction step can be performed after neutralization with an alkali metal such as sodium hydroxide or potassium hydroxide. For the extraction step, aromatic hydrocarbon solvents such as toluene or xylene may be used alone, or in combination with non-aromatic hydrocarbons such as cyclohexane or toluene. After extraction, the organic layer is washed with water until the effluent is neutral. The solvent is then distilled off using an evaporator to obtain the desired maleimide compound.

[0039]

[0040] (In formula (5), the multiple Rs exist independently and represent a hydrocarbon group or a halogenated alkyl group having 1 to 10 carbon atoms. p represents an integer from 0 to 4, and q represents an integer from 0 to 3. r is the number of repetitions, and the average value of r, rave, satisfies 1≦rave≦20).

[0041] The definition of R and the preferred ranges of p, q, and rave in the aforementioned formula (5) are the same as those in the aforementioned formula (2).

[0042] In the aforementioned formula (5), from the viewpoints of molecular weight control, solvent solubility, dielectric properties, low water absorption, and heat resistance, in the benzene ring bonded to the amino group, it is particularly preferred that: p = 2 and the substitution position of R is two positions ortho to the amino group.

[0043] The softening point of the amine compound represented by the aforementioned formula (5) is preferably 120°C or lower, more preferably 110°C or lower. If the softening point is 120°C or lower, the viscosity of the maleimide compound represented by the aforementioned formula (1) becomes lower. This makes it easier to ensure the fluidity of the curable resin composition, without impairing the impregnation properties of fibrous materials such as glass cloth and carbon fiber, and to easily perform prepreg and bring the curable resin composition to a semi-cured state (B-stage). Although the viscosity of the curable resin composition can be reduced by adding a diluent solvent, in this case, the curable resin composition may not be sufficiently adhered to the fibrous material during the impregnation step. Therefore, it is preferable to set the softening point of the amine compound represented by the aforementioned formula (5) to 120°C or lower.

[0044] The amine compound represented by the aforementioned formula (5) can be obtained, for example, by reacting aniline with an excess of diisopropenylbenzene (or α,α,α',α'-tetramethylbenzenedimethanol) in the presence of an acid catalyst. In this case, the substituent of the aniline compound is preferably unsubstituted or has an alkyl group with 1 to 5 carbon atoms. From the viewpoints of molecular weight control, solvent solubility, dielectric properties, low water absorption, and heat resistance, it is more preferably unsubstituted or has two alkyl groups with 1 to 3 carbon atoms at the ortho position of the benzene ring bonded to the amine group. During the synthesis, acid catalysts can be used, in addition to liquid acid catalysts such as hydrochloric acid, phosphoric acid, sulfuric acid, formic acid, p-toluenesulfonic acid, and methanesulfonic acid. Lewis acids such as aluminum chloride and zinc chloride, solid acid catalysts such as activated clay, acidic clay, white carbon, zeolite, and silica-alumina, and acidic ion exchange resins can also be used. These acid catalysts can be used alone or in combination. The amount of acid catalyst used is 0.01 to 50% by weight, preferably 0.1 to 35% by weight, relative to the combined weight of the reaction substrates, diisopropenylbenzene (or α,α,α',α'-tetramethylbenzenedimethanol) and aniline. Excessive amounts of acid catalyst may increase waste, while insufficient amounts may slow the reaction. Examples of solvents include, but are not limited to, 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. Two or more solvents may be used in combination. In addition to the aforementioned non-water-soluble solvents, aprotic polar solvents may also be used. Examples include dimethyl sulfone, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, and N-methylpyrrolidone. Two or more solvents may be used in combination. When using an aprotic polar solvent, it is preferably 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, unnecessary thermal decomposition may occur. If the reaction temperature is too low, the reaction may not proceed sufficiently. When using α,α,α',α'-tetramethylbenzenedimethanol as a raw material or an acid catalyst containing water, the generated water and the water in the system are removed from the system while azeotropically co-existing with the solvent as the temperature rises. After the reaction is terminated, the acid catalyst is neutralized with an alkaline aqueous solution, and a non-water-soluble organic solvent is added to the oil layer. Water washing is repeated until the wastewater is neutral, and the solvent is then removed under reduced pressure with heating. When using activated clay or ion exchange resin, the reaction liquid is filtered after the reaction is terminated, and the acid catalyst is removed.

[0045] Examples of the anilines include, but are not limited to, aniline, o-toluidine, m-toluidine, p-toluidine, 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-isopropylaniline, 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 alone or in combination of two or more. If the number of carbon atoms is large, the solvent solubility will be improved, but the heat resistance will be reduced. Therefore, it is preferably 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.

[0046] Examples of the diisopropenylbenzene include 1,2-diisopropylbenzene, 1,3-diisopropylbenzene, 1,4-diisopropylbenzene, and alkyl-substituted forms thereof. Examples of the aforementioned α,α,α',α'-tetramethylbenzenedimethanol include α,α,α',α'-tetramethyl-1,2-benzenedimethanol, α,α,α',α'-tetramethyl-1,3-benzenedimethanol, α,α,α',α'-tetramethyl-1,4-benzenedimethanol, and alkyl-substituted derivatives thereof. The aforementioned diisopropenylbenzene and α,α,α',α'-tetramethylbenzenedimethanols can be used alone or in combination of two or more. The amount of these used is preferably 1.0 to 10 times the mole, more preferably 1.0 to 7.5 times the mole, and even more preferably 1.0 to 5.0 times the mole, relative to 1 mole of amino groups in the aniline.

[0047] [Polymerization initiator] The curable resin composition of this embodiment can also enhance its curability by adding a polymerization initiator. A polymerization initiator is a compound capable of polymerizing olefin functional groups, such as ethylenically unsaturated bonds. Examples include olefin metathesis polymerization initiators, anionic polymerization initiators, cationic polymerization initiators, and free radical polymerization initiators. Free radical polymerization initiators that exhibit both curability and moderate stability are preferred. Olefin metathesis polymerization initiators, such as Schrock catalysts with platinum as the central metal, anionic polymerization initiators such as n-butyllithium (n-BuLi), and cationic polymerization initiators such as triethylaluminum, can react with moisture in the air, resulting in poor stability. Free radical polymerization initiators are compounds that generate free radicals upon exposure to ultraviolet or visible light or heating, initiating chain polymerization reactions. Examples of usable free radical polymerization initiators include organic peroxides, azo compounds, and tetraphenyl-1,2-ethylene glycol (Benzopinacol). Organic peroxides are preferred from the perspectives of controlling the curing temperature, suppressing outgassing, and minimizing the effect on the electrical properties of the decomposed product. Examples of the organic peroxides include ketone peroxides such as methyl ethyl ketone peroxide and acetyl propyl ketone peroxide, diacyl peroxides such as benzoyl peroxide, dialkyl peroxides such as dicumyl peroxide and 1,3-bis-(tertiary butylperoxyisopropyl)-benzene, peroxyketals such as tertiary butyl peroxybenzoate and 1,1-di-tertiary butylperoxycyclohexane, α-cumyl peroxyneodecanoate, tertiary butyl peroxyneodecanoate, tertiary butyl peroxypivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, tertiary pentyl peroxy-2-ethylhexanoate, and tertiary butyl peroxy-2-ethylhexanoate. Alkyl peroxyesters such as tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxy-3,5,5-trimethylhexanoate, and tert-pentyl peroxybenzoate; peroxycarbonates such as di-2-ethylhexyl peroxydicarbonate, bis(4-tert-butylcyclohexyl) peroxydicarbonate, tert-butyl peroxyisopropylcarbonate, and 1,6-bis(tert-butylperoxycarbonyloxy)-n-hexane; tert-butyl hydroperoxide, cumene hydroperoxide, tert-butyl peroxyoctanoate, and lauryl peroxide; however, these may be used alone or in combination. Among the above-mentioned organic peroxides, preferred are ketone peroxides, diacyl peroxides, hydroperoxides, dialkyl peroxides, peroxyketals, alkyl peroxyesters, peroxycarbonates, and the like, and more preferred are dialkyl peroxides. Examples of the azo compounds include, but are not limited to, azobisisobutyronitrile, 4,4'-azobis(4-cyanovaleric acid), and 2,2'-azobis(2,4-dimethylvaleronitrile). These compounds may be used alone or in combination.

[0048] The amount of polymerization initiator added is preferably 0.01 to 5 parts by mass, particularly preferably 0.01 to 3 parts by mass, based on 100 parts by mass of the total non-volatile matter in the curable resin composition excluding the inorganic filler. If the amount of polymerization initiator used is less than 0.01 parts by mass, the molecular weight may not be sufficiently increased during the polymerization reaction. If the amount exceeds 5 parts by mass, dielectric properties such as the dielectric constant and dielectric tangent may be impaired.

[0049] 〔Polymerization inhibitor〕 The curable resin composition of this embodiment may contain a polymerization inhibitor. This improves storage stability and allows for control of the reaction initiation temperature. Controlling the reaction initiation temperature facilitates ensuring the fluidity of the curable resin composition, preventing impregnation of fibrous materials such as glass cloth and carbon fibers, and facilitating B-stage formation, such as prepreg formation. Excessive polymerization during prepreg formation can easily lead to difficulties in lamination during the lamination step.

[0050] The polymerization inhibitor can be added during the synthesis of the compound represented by formula (1) or after the synthesis. The amount of the polymerization inhibitor used is 0.008 to 1 part by weight, preferably 0.01 to 0.5 part by weight, relative to 100 parts by weight of the compound represented by formula (1).

[0051] Examples of polymerization inhibitors include phenolic, sulfur, phosphorus, hindered amine, nitroso, and nitro radical inhibitors. A single inhibitor may be used, or multiple inhibitors may be used in combination. Among these, phenolic, hindered amine, nitroso, and nitro radical inhibitors are preferred in this embodiment.

[0052] The phenolic polymerization inhibitors include, for example, 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-tert-butyl-p-ethylphenol, β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylaniline)-1,3,5-tri-butylbenzene ... , 2,4-bis[(octylthio)methyl]o-cresol and other monophenols, 2,2'-methylenebis(4-methyl-6-tertiary butylphenol), 2,2'-methylenebis(4-ethyl-6-tertiary butylphenol), 4,4'-thiobis(3-methyl-6-tertiary butylphenol), 4,4'-butylenebis(3-methyl-6-tertiary butylphenol), triethylene glycol-bis[3-(3-tertiary butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-n-hexanediol-bis[3-(3,5-di-tertiary butyl-4-hydroxyphenyl) propionate], N,N'-hexamethylenebis(3,5-di-tertiary butyl-4 -Hydroxy-hydrocinnamamide), 2,2-thio-divinylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid-diethyl ester, 3,9-bis[1,1-dimethyl-2-{β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]2,4,8,10-tetraoxaspiro[5,5]undecane, bis(3,5-di-tert-butyl-4-hydroxybenzylsulfonic acid ethyl) calcium, etc. bisphenols, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl- 2,4,6-Tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tetrakis-[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]methane, bis[3,3'-bis-(4'-hydroxy-3'-tert-butylphenyl)butyrate]ethylene glycol, tris-(3,5-di-tert-butyl-4-hydroxybenzyl)-isocyanurate, 1,3,5-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl)-S-tris -2,4,6-(1H,3H,5H) trione, tocopherol and other high molecular weight phenols, but not limited to these.

[0053] Examples of the sulfur-based polymerization inhibitor include, but are not limited to, dilauryl 3,3'-thiodipropionate, dimyristyl 3,3'-thiodipropionate, and distearyl 3,3'-thiodipropionate.

[0054] Examples of the phosphorus-based polymerization inhibitor include triphenyl phosphite, diphenyl isodecyl phosphite, phenyl diisodecyl phosphite, bis(nonylphenyl)phosphite, diisodecyl neopentyl ethiol phosphite, bis(2,4-di-tert-butylphenyl)phosphite, cyclic neopentane tetrayl bis(octadecyl)phosphite, cyclic neopentane tetrayl bis(2,4-di-tert-butylphenyl)phosphite, cyclic neopentane tetrayl bis(2,4-di-tert-butyl-4-methylphenyl)phosphite, bis(2-tert-butylphenyl)phosphite, and bis(2-tert-butylphenyl)phosphite. Phosphites such as 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-tert-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, but are not limited thereto.

[0055] Examples of the hindered amine polymerization inhibitor include Adekastab 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, Chimassorb 2020FDL, Chimassorb 944FDL, Chimassorb 944LD, Tinuvin 622SF, Tinuvin PA144, Tinuvin 765, Tinuvin 770DF, Tinuvin XT55FB, Tinuvin 111FDL, Tinuvin 783FDL, Tinuvin 791FB, etc., but not limited to these.

[0056] Examples of the nitroso-based polymerization inhibitor include, but are not limited to, p-nitrosophenol, N-nitrosodiphenylamine, and the ammonium salt of N-nitrosophenylhydroxylamine (cupferron). Among these, the ammonium salt of N-nitrosophenylhydroxylamine (cupferron) is preferred.

[0057] Examples of the nitro radical polymerization inhibitor include, but are not limited to, di- and tri-butyl nitroxides, 2,2,6,6-tetramethylpiperidine-1-oxide, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxide, 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxide, 4-amino-2,2,6,6-tetramethylpiperidine-1-oxide, 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxide, 4-acetyloxy-2,2,6,6-tetramethylpiperidine-1-oxide, and 4-benzyloxy-2,2,6,6-tetramethylpiperidine-1-oxide.

[0058] 〔Inorganic fillers〕 The curable resin composition of this embodiment may contain an inorganic filler. Examples of such inorganic fillers include, but are not limited to, fused silica, crystalline silica, porous silica, alumina, zircon, calcium silicate, calcium carbonate, quartz powder, silicon carbide, silicon nitride, boron nitride, zirconium oxide, aluminum nitride, graphite, forsterite, steatite, spinel, mullite, titanium dioxide, talc, clay, iron oxide asbestos, glass powder, and other powders, as well as spherical or crushed inorganic fillers. Furthermore, these fillers may be used singly or in combination.

[0059] When obtaining a curable resin composition for encapsulating semiconductors, the amount of the inorganic filler used is preferably 80 to 92 parts by mass, 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 use as an interlayer insulating layer forming material, copper-clad laminates, prepregs, RCC substrate materials, etc., the amount of the inorganic filler used is preferably 5 to 80 parts by mass, more preferably 10 to 60 parts by mass, per 100 parts by mass of the curable resin composition.

[0060] 〔Hardening accelerator〕 The curable resin composition of this embodiment can be cured by adding a curing accelerator. Preferred curing accelerators are anionic curing accelerators that generate anions upon exposure to ultraviolet or visible light or heating to accelerate the curing reaction, or cationic curing accelerators that generate cations upon exposure to ultraviolet or visible light or heating to accelerate the curing reaction. Examples of anionic hardening 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. Furthermore, examples include phosphines such as triphenylphosphine; and quaternary ammonium salts such as tetrabutylammonium salts, triisopropylmethylammonium salts, trimethyldecylammonium salts, hexadecyltrimethylammonium salts, and hexadecyltrimethylammonium hydroxide. Cationic hardening accelerators include, but are not limited to, quaternary phosphonium salts such as triphenylbenzylphosphonium salts, triphenylethylphosphonium salts, and tetrabutylphosphonium salts (the counter ions of the quaternary salts are halogens, organic acid ions, hydroxide ions, etc., although not particularly limited, organic acid ions and hydroxide ions are particularly preferred); transition metal compounds (transition metal salts) such as tin octoate, zinc carboxylates (zinc 2-ethylhexanoate, zinc stearate, zinc behenate, zinc myristate); and zinc phosphates (zinc octylphosphate, zinc stearylphosphate). These accelerators may be used alone or in combination.

[0061] The curing accelerator is added in an amount of 0.01 to 5.0 parts by mass based on the total 100 parts by mass of the non-volatile matter excluding the inorganic filler in the curable resin composition.

[0062] 〔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 (such as antimony compounds, metal hydroxides, nitrogen compounds, and boron compounds), and phosphorus-based flame retardants. However, phosphorus-based flame retardants are preferred for achieving halogen-free flame retardancy. The phosphorus-based flame retardants mentioned above can be reactive or additive. Specific examples include, but are not limited to, phosphate esters such as trimethyl phosphate, triethyl phosphate, tricresyl phosphate, tricresyl phosphate, cresol diphenyl phosphate, cresol-di-2,6-xylyl phosphate, 1,3-phenylenebis(xylyl phosphate), 1,4-phenylenebis(xylyl phosphate), and 4,4'-biphenyl(xylyl 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 aforementioned phosphanes; and red phosphorus. Furthermore, these phosphanes may be used alone or in combination. Among the above-mentioned exemplified substances, preferred are phosphates, phosphanes or phosphorus-containing epoxy compounds, and particularly preferred are 1,3-phenylenebis(di(xylyl)phosphate), 1,4-phenylenebis(di(xylyl)phosphate), 4,4'-biphenyl(di(xylyl)phosphate) or phosphorus-containing epoxy compounds.

[0063] The flame retardant content is preferably in the range of 0.1 to 0.6 parts by mass, based on 100 parts by mass of the total non-volatile matter in the curable resin composition excluding the inorganic filler. If the content is less than 0.1 parts by mass, the flame retardancy may be insufficient, while if it is greater than 0.6 parts by mass, the hygroscopicity and dielectric properties of the cured product may be adversely affected.

[0064] 〔Light stabilizer〕 The curable resin composition of this embodiment can use a light stabilizer. As for the light stabilizer, a hindered amine light stabilizer is suitable, and HALS (Hindered Amine Light Stabilizers) is particularly suitable. HALS can be exemplified by dibutylamine / 1,3,5-triazolidine / N,N'-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,6-hexamethylenediamine and N-(2,2,6,6-tetramethyl-4-piperidinyl)butylamine reaction product, dimethyl-1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidinyl succinate reaction product, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazol-1,3,5-dimethylamino]-1,3,5-di ... butyl]malonate, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) 2-(3,5-di-tert-butyl-4-hydroxybenzyl)-2-n-butylmalonate, etc., but are not limited thereto. In addition, these systems may be used alone or in combination.

[0065] The light stabilizer content is preferably in the range of 0.001 to 10 parts by mass, based on 100 parts by mass of the total non-volatile matter in the curable resin composition excluding the inorganic filler. If the content is less than 0.001 parts by mass, the light stabilization effect may not be fully exerted. If the content is greater than 10 parts by mass, the hygroscopicity and dielectric properties of the cured product may be adversely affected.

[0066] 〔Binder resin〕 The curable resin composition of this embodiment can use a binder resin. Examples of binder resins include, but are not limited to, butyral resins, acetal resins, acrylic resins, epoxy-nylon resins, NBR-phenol resins, epoxy-NBR resins, and silicone resins. Furthermore, one or more of these resins may be used.

[0067] The binder resin is preferably added in an amount that does not impair the flame retardancy and heat resistance of the cured product. When the total non-volatile matter in the curable resin composition excluding the inorganic filler is taken as 100 parts by mass, the amount is preferably 0.05 to 50 parts by mass, and more preferably 0.05 to 20 parts by mass.

[0068] 〔additive〕 The curable resin composition of this embodiment may contain additives. Examples of such additives include modified acrylonitrile copolymers, polyethylene, fluororesins, silicone gels, silicone oils, silane coupling agents, and other filler surface treatment agents, mold release agents, and colorants such as carbon black, phthalocyanine blue, and phthalocyanine green.

[0069] The amount of the additives added is preferably 1,000 parts by mass or less, more preferably 700 parts by mass or less, relative to 100 parts by mass of the curable resin composition.

[0070] The curable resin composition of this embodiment may further include epoxy resins, active ester compounds, phenol resins, amine resins, maleimide compounds, compounds with ethylenically unsaturated bonds, isocyanate resins, polyamide resins, polyimide resins, cyanate resins, polyphenylene ether compounds, polybutadiene and its modified products, polystyrene and its modified products, and the like. These compounds may be used singly or in combination. Among these compounds, compounds with ethylenically unsaturated bonds, cyanate resins, polyphenylene ether compounds, polybutadiene and its modified products, and polystyrene and its modified products are preferred for achieving a good balance between heat resistance, adhesion, and dielectric properties. The inclusion of these compounds can improve the brittleness of the cured product and enhance its adhesion to metal, thereby suppressing package cracking during reflow soldering or reliability testing such as thermal cycling.

[0071] Unless otherwise specified, the amount of the compound used is preferably 10 times or less by mass, more preferably 5 times or less by mass, and particularly preferably 3 times or less by mass relative to the compound represented by formula (1). Furthermore, the lower limit is preferably 0.1 times or more by mass, more preferably 0.25 times or more by mass, and even more preferably 0.5 times or more by mass. By setting the amount within the above range, the heat resistance and dielectric properties of the compound represented by formula (1) can be exerted, and the effects of the added compounds can be enhanced. For these components, the following examples can be used.

[0072] 〔Epoxy resin〕 As for epoxy resins, the following are preferred examples, but are not limited to these. Epoxy resins can be in liquid or solid form, and one or more types can be used.

[0073] Examples of liquid epoxy resins include bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol AF epoxy resins, naphthalene epoxy resins, glycidyl ester epoxy resins, glycidyl amine epoxy resins, phenol novolac epoxy resins, alicyclic epoxy resins having an ester skeleton, cyclohexane epoxy resins, cyclohexanedimethanol epoxy resins, glycidyl amine epoxy resins, and epoxy resins having a butadiene structure. Specific examples include: "RE310S", "RE410S" (these are bisphenol A epoxy resins manufactured by Nippon Kayaku Co., Ltd.), "RE303S", "RE304S", "RE403S", "RE404S" (these are bisphenol F epoxy resins manufactured by Nippon Kayaku Co., Ltd.), "HP4032", "HP4032D", "HP4032SS" (these are naphthalene epoxy resins manufactured by DIC Corporation), "828US", "jER828EL", "825", "828EL" "(the above are bisphenol A type epoxy resins manufactured by Mitsubishi Chemical Corporation), "jE807", "1750" (the above are bisphenol F type epoxy resins manufactured by Mitsubishi Chemical Corporation), "jER152" (phenol novolac type epoxy resins manufactured by Mitsubishi Chemical Corporation), "630", "630LSD" (the above are glycidylamine type epoxy resins manufactured by Mitsubishi Chemical Corporation), "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin manufactured by Nippon Steel Sumikin Chemical Corporation), "EX-721" (Nagase These include glycidyl ester epoxy resins manufactured by ChemteX, CELLOXIDE 2021P (an alicyclic epoxy resin with an ester skeleton manufactured by Daicel), PB-3600 (an epoxy resin with a butadiene structure manufactured by Daicel), and ZX1658 and ZX1658GS (liquid 1,4-glycidylcyclohexane epoxy resins manufactured by Nippon Steel & Sumikin Chemicals). These can be used alone or in combination.

[0074] Preferred solid epoxy resins include bixylene-type epoxy resins, naphthalene-type epoxy resins, naphthalene-type tetrafunctional epoxy resins, cresol novolac-type epoxy resins, dicyclopentadiene-type epoxy resins, phenol-type epoxy resins, naphthol-type epoxy resins, biphenyl-type epoxy resins, naphthyl ether-type epoxy resins, onion-type epoxy resins, bisphenol A-type epoxy resins, bisphenol AF-type epoxy resins, and tetraphenylethane-type epoxy resins. Examples of the solid epoxy resins include naphthol-type epoxy resins, bisphenol AF-type epoxy resins, naphthalene-type epoxy resins, and biphenyl-type epoxy resins. Specific examples include: "HP4032H" (naphthalene-type epoxy resin manufactured by DIC Corporation), "HP-4700", "HP-4710" (naphthalene-type tetrafunctional epoxy resin manufactured by DIC Corporation), "N-690" (cresol novolac-type epoxy resin manufactured by DIC Corporation), "N-695" (cresol novolac-type epoxy resin manufactured by DIC Corporation), "HP-7200" (dicyclopentadiene-type epoxy resin manufactured by DIC Corporation), "HP-7200", "HP-7200HH", "HP-7200H ..." (dicyclopentadiene-type epoxy resin manufactured by DIC Corporation), "HP-7 Cyclopentadiene-type epoxy resin), EXA-7311, EXA-7311-G3, EXA-7311-G4, EXA-7311-G4S, HP-6000 (all naphthyl ether-type epoxy resins manufactured by DIC Corporation), EPPN-502H (all naphthol-type epoxy resins manufactured by Nippon Kayaku Corporation), NC-7000L, NC-7300 (all naphthol-cresol novolac-type epoxy resins manufactured by Nippon Kayaku Corporation), NC-3000H, NC-3000, NC-30 00L", "NC-3100" (the above are biphenyl aralkyl type epoxy resins manufactured by Nippon Kayaku Co., Ltd.), "XD-1000-2L", "XD-1000-L", "XD-1000-H", "XD-1000-H" (the above are dicyclopentadiene type epoxy resins manufactured by Nippon Kayaku Co., Ltd.), "ESN475V" (naphthol type epoxy resin manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd.), "ESN485" (naphthol novolac type epoxy resin manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd.), "YX-4000H", "YX-4000", "YL6121 "(The above are biphenyl type epoxy resins manufactured by Mitsubishi Chemical Corporation), "YX-4000HK" (biphenyl type epoxy resin manufactured by Mitsubishi Chemical Corporation), "YX-8800" (onion type epoxy resin manufactured by Mitsubishi Chemical Corporation), "PG-100", "CG-500" (fluorene type epoxy resin manufactured by Osaka Gas Chemical Co., Ltd.), "YL-7760" (bisphenol AF type epoxy resin manufactured by Mitsubishi Chemical Corporation), "YL-7800" (fluorene type epoxy resin manufactured by Mitsubishi Chemical Corporation) "jER1010" (solid bisphenol A type epoxy resin manufactured by Mitsubishi Chemical Corporation), "jER1031S" (tetraphenylethane type epoxy resin manufactured by Mitsubishi Chemical Corporation), etc.These can be used alone or in combination of two or more.

[0075] 〔Active ester compound〕 Active ester compounds refer to compounds containing at least one ester bond in their structure, with aliphatic chains, aliphatic rings, or aromatic rings bonded to both sides of the ester bond. Examples of active ester compounds include phenolic esters, thiophenolic esters, N-hydroxylamine esters, and esters of heterocyclic hydroxyl compounds, all of which have two or more highly reactive ester groups per molecule. These compounds are obtained by condensing at least one of a carboxylic acid compound, an acyl chloride, or a thiocarboxylic acid compound with at least one of a hydroxyl compound or a thiol compound. In particular, from the perspective of improving heat resistance, compounds obtained from a carboxylic acid compound or an acyl chloride with a hydroxyl compound are preferred, with the hydroxyl compound preferably being a phenolic compound or a naphthol compound. Active ester compounds may be used alone or in combination of two or more.

[0076] Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyrophyllic acid.

[0077] Examples of the acyl chloride include acetyl chloride, acryloyl chloride, methacryloyl chloride, malonyl chloride, succinoyl chloride, diglycol chloride, glutaryl chloride, octanedichlor, decanedichlor, hexamethylenedichlor, dodecanoyl chloride, nonanoyl chloride, 2,5-furandicarbonyl chloride, o-phthalyl chloride, isophthalyl chloride, terephthalyl chloride, trimesic chloride, bis(4-chlorocarbonylphenyl) ether, 4,4'-diphenyldicarbonyl chloride, and 4,4'-azodiphenylcarbonyl chloride.

[0078] Examples of the phenolic 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, pyrogallol, benzenetriol, dicyclopentadiene-type diphenolic compounds, phenol novolac, and the phenolic resins described below. Here, "dicyclopentadiene-type diphenolic compounds" refer to diphenolic compounds obtained by condensing one dicyclopentadiene molecule with two phenolic molecules.

[0079] 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 acetylated phenolic novolacs, active ester compounds containing benzoylated phenolic novolacs, the compounds 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 refers to a divalent structural unit composed of phenylene-dicyclopentene-phenylene.

[0080] Commercially available active ester compounds include, for example, those containing a dicyclopentadiene-type diphenol structure such as "EXB9451," "EXB9460," "EXB9460S," "HPC-8000-65T," "HPC-8000H-65TM," "EXB-8000L-65TM," and "EXB-8150-65T" (manufactured by DIC Corporation). Active ester compounds containing a naphthalene structure include "EXB9416-70BK" (manufactured by DIC Corporation). Examples of active ester compounds containing acetylated phenolic novolacs include "DC808" (manufactured by Mitsubishi Chemical Corporation), examples of active ester compounds containing benzoylated phenolic novolacs include "YLH1026," "YLH1030," and "YLH1048" (manufactured by Mitsubishi Chemical Corporation), examples of active ester-based hardeners belonging to "acetylated phenolic novolacs" include "DC808" (manufactured by Mitsubishi Chemical Corporation), and examples of active ester-based hardeners containing phosphorus atoms include "EXB-9050L-62M" manufactured by DIC Corporation.

[0081] Regarding the mixing ratio of the active ester compound and epoxy resin, the ratio (α / β) of active ester equivalent weight (α) to epoxy equivalent weight (β) is preferably 0.5 to 1.5, more preferably 0.8 to 1.2, and even more preferably 0.90 to 1.10. Outside of this range, there is a risk of excessive epoxy or active ester groups remaining in the system, potentially leading to performance degradation during high-temperature exposure tests (e.g., 150°C for 1000 hours) or long-term reliability tests under high-temperature, high-humidity conditions (e.g., 85°C and 85% humidity).

[0082] 〔Phenolic resin〕 Phenolic resins refer to compounds having two or more phenolic hydroxyl groups within their molecules. Examples of phenolic resins include, but are not limited to, reaction products of phenols and aldehydes, reaction products of phenols and dienes, reaction products of phenols and ketones, reaction products of phenols and substituted biphenyls, reaction products of phenols and substituted phenyls, and reaction products of bisphenols and aldehydes. These resins may be used alone or in combination. Specific examples of the above-mentioned raw materials are shown below, but the present invention is 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, alkyl aldehydes, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzaldehyde, naphthaldehyde, glutaraldehyde, o-phthalaldehyde, crotonaldehyde, cinnamaldehyde, furfural, etc. <Diene Compound> Dicyclopentadiene, terpenes, vinylcyclohexene, norbornanediene, vinylnorbornane, tetrahydroindene, divinylbenzene, divinylbiphenyl, diisopropenylbiphenyl, butadiene, isoprene, etc. <Ketones> Acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, fluorenone, etc. <Substituted biphenyls> 4,4'-bis(chloromethyl)-1,1'-biphenyl, 4,4'-bis(methoxymethyl)-1,1'-biphenyl, 4,4'-bis(hydroxymethyl)-1,1'-biphenyl, etc. <Substituted phenyl groups> 1,4-bis(chloromethyl)benzene, 1,4-bis(methoxymethyl)benzene, 1,4-bis(hydroxymethyl)benzene, etc.

[0083] 〔Amine resin〕 Amine resins refer to compounds having two or more amino groups in the molecule. Examples of amine resins include diaminodiphenylmethane, diaminodiphenylsulfone, isophoronediamine, naphthalene diamine, aniline phenol formaldehyde (a reaction product of aniline and formalin), N-methylaniline phenol formaldehyde (a reaction product of N-methylaniline and formalin), o-ethylaniline phenol formaldehyde (a reaction product of o-ethylaniline and formalin), a reaction product of 2-methylaniline and formalin, a reaction product of 2,6-diisopropylaniline and formalin, a reaction product of 2,6-diethylaniline and formalin, a reaction product of 2-ethyl-6-ethylaniline and formalin, a reaction product of 2,6-dimethylaniline and formalin, an aniline resin obtained by the reaction of aniline and xylene chloride, and Japanese The reaction products of aniline and substituted biphenyls (e.g., 4,4'-bis(chloromethyl)-1,1'-biphenyl and 4,4'-bis(methoxymethyl)-1,1'-biphenyl), reaction products of aniline and substituted phenyls (e.g., 1,4-bis(chloromethyl)benzene, 1,4-bis(methoxymethyl)benzene, and 1,4-bis(hydroxymethyl)benzene), 4,4'-(1,3-phenylenediisopropylidene)dianiline, 4,4'-(1,4-phenylenediisopropylidene)dianiline, reaction products of aniline and diisopropenylbenzene, and dimerized diamines described in Patent No. 6429862 are not limited thereto. Furthermore, any one or more of these may be used.

[0084] [Maleic imide compounds other than the maleic imide compound represented by formula (1)] Maleic imide compounds refer to compounds having one or more maleic imide groups in the molecule. The curable resin composition of this embodiment may further contain maleic imide compounds other than the maleic imide compound represented by formula (1). Maleic imide compounds other than the maleic imide compound represented by formula (1) include, for example, 4,4'-diphenylmethane bismaleic imide, polyphenylmethane bismaleic imide, metaphenyl bismaleic imide, 2,2'-bis[4-(4-maleic imide phenoxy)phenyl]propane, 3,3'-dimethyl- 5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, 4,4'-diphenylether bismaleimide, 4,4'-diphenylsulfonium bismaleimide, 1,3-bis(3-maleimidephenoxy)benzene, 1,3-bis(4-maleimide phenoxy)benzene), Xyloc-type maleimide compound (ANILIX maleimide, manufactured by Mitsui Chemicals FINE Co., Ltd.), biphenylaralkyl-type maleimide compound (solidified by distilling off the solvent from a resin solution containing the maleimide compound (M2) under reduced pressure as described in Example 4 of JP-A-2009-001783), bisaminoisopropylphenylbenzene-type maleimide (maleimide compound described in International Publication No. 2020 / 054601), maleimide compound having an indane structure as described in Japanese Patent No. 6629692 or International Publication No. 2020 / 217679, MATERIAL The maleic anhydride compounds disclosed in STAGE, Vol. 18, No. 12, 2019, "~Continued‧Epoxy Resin CAS Numbering Stories~Curing Agent CAS Numbering Memorandum No. 31 Bismaleic Anhydride (1)" and MATERIAL STAGE, Vol. 19, No. 2, 2019, "~Continued‧Epoxy Resin CAS Numbering Stories~Curing Agent CAS Numbering Memorandum No. 32 Bismaleic Anhydride (2)" are not limited thereto. Furthermore, these compounds may be used alone or in combination.

[0085] The amount of the maleimide compound other than the maleimide compound represented by formula (1) is preferably 10 times or less by mass, more preferably 5 times or less by mass, and particularly preferably 3 times or less by mass relative to the maleimide compound represented by formula (1). Furthermore, the lower limit is preferably 0.01 times or more by mass, more preferably 0.1 times or more by mass. Within the above range, the heat resistance, dielectric properties, and low water absorption properties of the compound represented by formula (1) can be exerted.

[0086] [Compounds with ethylenically unsaturated bonds] The compound having an ethylenically unsaturated bond means a compound having one or more ethylenically unsaturated bonds in the molecule that can be polymerized by heat or light, regardless of whether a polymerization initiator is used or not. Examples of compounds having ethylenically unsaturated bonds include, but are not limited to, reaction products of the aforementioned phenol resins and halogen compounds having ethylenically unsaturated bonds (such as chloromethylstyrene, allyl chloride, methallyl chloride, acryloyl chloride, and methacryloyl chloride); reaction products of phenols having ethylenically unsaturated bonds (such as 2-allylphenol, 2-propenylphenol, 4-allylphenol, 4-propenylphenol, eugenol, and isoeugenol); and halogen compounds (such as 1,4-bis(chloromethyl)benzene, 4,4'-bis(chloromethyl)biphenyl, 4,4'-difluorobenzophenone, 4,4'-dichlorobenzophenone, 4,4'-dibromobenzophenone, and cyanuric chloride); reaction products of epoxy resins or alcohols and (meth)acrylic acids (such as acrylic acid and methacrylic acid); and acid-modified products thereof. Furthermore, these compounds may be used alone or in combination.

[0087] 〔Isocyanate resin〕 Isocyanate resin refers to a compound having two or more isocyanate groups in the molecule. Examples of isocyanate resins include aromatic diisocyanates such as p-phenylene diisocyanate, m-phenylene diisocyanate, p-xylene diisocyanate, m-xylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, and naphthalene diisocyanate, as well as isophorone diisocyanate, hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, hydrogenated xylene diisocyanate, and diisocyanate. Aliphatic or alicyclic diisocyanates such as camphene diisocyanate and lysine diisocyanate, polyisocyanates such as biuret forms of one or more isocyanate monomers, or isocyanate forms obtained by trimerization of the above diisocyanate compounds, and polyisocyanates obtained by urethanization of the above isocyanate compounds with polyol compounds may be used, but are not limited to these. These may be used alone or in combination.

[0088] 〔Polyamide resin〕 Examples of polyamide resins include diamines, diisocyanates, Reaction products of any one or more oxazolines with dicarboxylic acids, reaction products of diamines with acyl chlorides, and ring-opening polymers of lactam compounds. These may be used alone or in combination. Specific examples of the above-mentioned raw materials are shown below, but the present invention is not limited to these. <Diamine> 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, dimerized diamine Amine, cyclohexanediamine, bis-(4-aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)methane, xylene diamine, norbornene diamine, isophorone diamine, bisaminomethyl tricyclodecane, phenylenediamine, diethyltoluenediamine, naphthalene diamine, diaminodiphenylmethane, bis(4-amino-3,5-dimethylphenyl)methane bis(4-amino-3,5-diethylphenyl)methane, 4,4'-methylenebis-o-methylaniline, 4,4'-methylenebis-o-ethylaniline, 4,4'-methylenebis-2-ethyl-6-methylaniline, 4,4'-methylenebis-2,6-diisopropylaniline, 4,4-ethylenediphenylamine, 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-aminophenoxy)] [4-aminophenyl] 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)dianiline, 4,4'-(1,4-phenylenediisopropylidene)dianiline, 9,9-bis(4-aminophenyl)fluorene, 2,7-diaminofluorene, aminobenzylamine, diaminobenzophenone, etc. <Diisocyanate> Phenylene 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 Acid> Oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, 5-hydroxyisophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalate, hexahydroterephthalic acid, hexahydroisophthalic acid, cyclohexanedicarboxylic acid, biphenyl dicarboxylic acid, naphthalene dicarboxylic acid, benzophenone dicarboxylic acid, furandicarboxylic acid, 4,4'-dicarboxydiphenyl ether, 4,4'-dicarboxydiphenyl sulfide, etc. <Acyl chloride> Acetyl chloride, acryloyl chloride, methacryloyl chloride, malonyl chloride, succinylated dichloride, diglycolamidoyl chloride, glutaryl chloride, octanedichloride, decanedichloride, hexamethylenedichloride, dodecanedichloride, nonanoyl chloride, 2,5-furandicarbonyl chloride, o-phthaloyl chloride, isophthaloyl chloride, terephthaloyl chloride, trimesic chloride, bis(4-chlorocarbonylphenyl) ether, 4,4'-diphenyldicarbonyl chloride, 4,4'-azodiphenylcarbonyl chloride, etc. <Lactamide> ε-caprolactam, ω-undecanolactam, ω-laurolactam, etc.

[0089] 〔Polyimide resin〕 Examples of polyimide resins include, but are not limited to, the reaction products of the aforementioned diamines and the tetracarboxylic dianhydrides exemplified below. Furthermore, these may be used alone or in combination. <Tetracarboxylic Dianhydride> 4,4'-(Hexafluoroisopropylidene)diphthalic anhydride, 5-(2,5-dioxotetrahydro-3-furyl)-3-methyl-cyclohexene-1,2-dicarboxylic anhydride, pyromelitic dianhydride, 1,2,3,4-pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfoniumtetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, methylene-4,4'-diphthalic dianhydride, 1,1-ethylene-4,4'-diphthalic dianhydride, 2,2'-propylene-4,4'-diphthalic dianhydride, 1,2-ethylene -4,4'-diphthalic dianhydride, 1,3-trimethylene-4,4'-diphthalic dianhydride, 1,4-tetramethylene-4,4'-diphthalic dianhydride, 1,5-pentamethylene-4,4'-diphthalic dianhydride, 4,4'-oxydiphthalic dianhydride, thio-4,4'-diphthalic dianhydride, sulfonyl-4,4'-diphthalic dianhydride, 1,3-bis(3,4-dicarboxyphenyl)phthalic dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)phthalic dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)phthalic dianhydride, 1,3-bis[2-(3,4-dicarboxyphenyl)-2-propyl]phthalic dianhydride, 1,4-bis[2-(3,4-dicarboxyphenyl)-2-propyl]phthalic dianhydride phthalic anhydride, 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 dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-oniontetracarboxylic dianhydride, 1,2,7 ,8-phenanthrenetetracarboxylic dianhydride, ethylenetetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic 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'-dicyclohexyltetracarboxylic 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, 1,1-ethylene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 2,2-propylene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, oxy-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, sulfanyl-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, sulfonyl-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, rel-[1S,5R,6R]-3-oxabicyclo[3,2,1]octan-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4- Tetralin-1,2-dicarboxylic anhydride, ethylene glycol-bis-(3,4-dicarboxylic anhydride phenyl) ether, 4,4'-biphenyl bis(trimellitic acid monoester anhydride), 9,9'-bis(3,4-dicarboxyphenyl)fluorene dianhydride, etc.

[0090] 〔Cyanate ester resin〕 Cyanate resins are cyanate compounds obtained by reacting a phenol resin with a cyanogen halide. Specific examples include, but are not limited to, dicyanatobenzene, tricyanatobenzene, dicyanatonaphthalene, dicyanatobiphenyl, 2,2'-bis(4-cyanatophenyl)propane, bis(4-cyanatophenyl)methane, bis(3,5-dimethyl-4-cyanatophenyl)methane, 2,2'-bis(3,5-dimethyl-4-cyanatophenyl)propane, 2,2'-bis(4-cyanatophenyl)ethane, 2,2'-bis(4-cyanatophenyl)hexafluoropropane, bis(4-cyanatophenyl)sulfonium, bis(4-cyanatophenyl)thioether, phenol novolac cyanate, and compounds obtained by converting the hydroxyl groups of a phenol-dicyclopentadiene co-condensate into cyanate groups. Furthermore, these compounds may be used alone or in combination. In addition, the cyanate compound whose synthesis method is described in Japanese Patent Application Laid-Open No. 2005-264154 is particularly preferred as a cyanate compound due to its low hygroscopicity, flame retardancy, and excellent dielectric properties. In order to meet the need to trimerize the cyanate groups to form homotrimers Cyclocyanate resins may contain catalysts such as zinc naphthenate, cobalt naphthenate, copper naphthenate, lead naphthenate, zinc octoate, tin octoate, lead acetylacetonate, and dibutyltin maleate.

[0091] The catalyst is preferably used in an amount of 0.0001 to 0.10 parts by mass, more preferably 0.00015 to 0.0015 parts by mass, relative to 100 parts by mass of the cyanate ester resin.

[0092] [Polyphenylene ether compounds] Regarding polyphenylene ether compounds, those having ethylenically unsaturated bonds are preferred from the perspective of heat resistance and electrical properties, and those having an acryl group, a methacryl group, or a styrene structure are more preferred. Commercially available products include SA-9000 (a polyphenylene ether compound having a methacryl group, manufactured by SABIC) and OPE-2St 1200 (a polyphenylene ether compound having a styrene structure, manufactured by Mitsubishi Gas Chemical Co., Ltd.). 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 molecular weight is less than 500, the cured product tends to lack sufficient heat resistance. Furthermore, if the molecular weight exceeds 5000, the melt viscosity becomes high, insufficient fluidity is achieved, and molding defects tend to occur. Furthermore, reactivity is reduced, the curing reaction takes a long time, unreacted materials accumulate due to not being incorporated into the curing system, the glass transition temperature of the cured product decreases, and the heat resistance of the cured product tends to decrease. When the number average molecular weight of the polyphenylene ether compound is 500 to 5000, it can maintain excellent dielectric properties while exhibiting excellent heat resistance and moldability. Specifically, the number average molecular weight can be measured using gel permeation chromatography or the like.

[0093] Polyphenylene ether compounds can be obtained by polymerization or by subjecting high-molecular-weight polyphenylene ether compounds with a number-average molecular weight of approximately 10,000 to 30,000 to a redistribution reaction. Furthermore, these compounds can be rendered free-radical polymerizable by reacting them with compounds having ethylenically unsaturated bonds, such as methacrylic acid chloride, acrylic acid chloride, and chloromethylstyrene. Polyphenylene ether compounds obtained by the redistribution reaction are obtained by heating the high-molecular-weight polyphenylene ether compound in a solvent such as toluene in the presence of a phenolic compound and a free-radical initiator, and then subjecting it to a redistribution reaction. Polyphenylene ether compounds obtained by such a redistribution reaction have hydroxyl groups at both ends of the molecular chain, derived from the phenolic compound that facilitates curing, thereby maintaining high heat resistance. Furthermore, even after modification with a compound having ethylenically unsaturated bonds, functional groups can be introduced at both ends of the molecular chain, making them advantageous. Furthermore, the polyphenylene ether compound obtained by the polymerization reaction exhibits excellent fluidity and is therefore preferred.

[0094] The molecular weight of the polyphenylene ether compound can be adjusted by adjusting polymerization conditions, for example, if the polyphenylene ether compound is obtained through a polymerization reaction. Furthermore, if the polyphenylene ether compound is obtained through a redistribution reaction, the molecular weight of the obtained polyphenylene ether compound can be adjusted by adjusting the redistribution reaction conditions, for example. More specifically, the amount of the phenolic compound used in the redistribution reaction can be adjusted. In other words, the greater the amount of the phenolic compound used, the lower the molecular weight of the obtained polyphenylene ether compound. In this case, poly(2,6-dimethyl-1,4-phenylene ether) can be used as a high-molecular-weight polyphenylene ether compound that undergoes the redistribution reaction. The phenolic compound used in the redistribution reaction is not particularly limited, but preferably, a polyfunctional phenolic compound having two or more phenolic hydroxyl groups in the molecule, such as bisphenol A, phenol novolac, and cresol novolac, is used. These compounds can be used alone or in combination.

[0095] The content of the polyphenylene ether compound is not particularly limited, but is preferably 5 to 1000 parts by mass, more preferably 10 to 750 parts by mass, relative to 100 parts by mass of the compound represented by formula (1). The polyphenylene ether compound content within the above range is preferred because it not only exhibits excellent heat resistance, but also allows for a cured product that fully utilizes the excellent dielectric properties of the polyphenylene ether compound.

[0096] 〔Polybutadiene and its modified products〕 Polybutadiene and its modified compounds refer to compounds with a structure similar to or derived from polybutadiene within their molecules. In polybutadiene-derived structures, some or all of the unsaturated bonds can be converted to single bonds through hydrogenation. Examples of polybutadiene and its modified products include, but are not limited to, polybutadiene, hydroxyl-terminated polybutadiene, (meth)acrylate-terminated polybutadiene, carboxylic acid-terminated polybutadiene, amine-terminated polybutadiene, and styrene butadiene rubber. These may be used alone or in combination. Among these, polybutadiene or styrene butadiene rubber is preferred from the perspective of dielectric properties. Examples of styrene butadiene rubber (SBR) include RICON-100, RICON-181, and RICON-184 (all manufactured by Cray Valley Co., Ltd.) 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.). Regarding the molecular weight of polybutadiene and styrene butadiene rubber, the weight average molecular weight is preferably 500 to 10,000, more preferably 750 to 7,500, and even more preferably 1,000 to 5,000. If it is below the lower limit of the above range, the amount of volatility is large, making it difficult to adjust the solid content when making the prepreg. If it is above the upper limit of the above range, the compatibility with other curing resins is deteriorated. Generally speaking, in the case of compounds containing heteroatoms such as oxygen or nitrogen, such as bis-maleimide or poly-maleimide, due to their polarity, it is difficult to ensure compatibility with low-polarity compounds such as compounds mainly composed of hydrocarbons or compounds composed only of hydrocarbons. On the other hand, the compound represented by the above formula (1) has a skeleton design that does not actively introduce heteroatoms such as oxygen or nitrogen, so it also has excellent compatibility with materials with low polarity and low dielectric properties or compounds composed only of hydrocarbons.

[0097] The content of polybutadiene and its modified products is not particularly limited, but is preferably 5 to 1000 parts by mass, more preferably 10 to 750 parts by mass, relative to 100 parts by mass of the compound represented by formula (1). Polybutadiene and its modified products within the above ranges are preferred because they not only exhibit excellent heat resistance, but also provide a cured product that fully utilizes the excellent dielectric properties of polybutadiene and its modified products.

[0098] 〔Polystyrene and its modified products〕 Polystyrene and its modified products refer to compounds having a structure of polystyrene or derived from polystyrene in the molecule. Regarding polystyrene and its modified products, for example, polystyrene, styrene and 2-isopropenyl-2- Oxazoline copolymers (Epocros RPS-1005 and RP-61 are both manufactured by Nippon Shokubai Co., Ltd.), SEP (styrene-ethylidene and propylene copolymer: SEPTON 1020 manufactured by Kuraray Co., Ltd.), SEPS (styrene-ethylidene and propylene-styrene copolymers: SEPTON 2002, SEPTON 2004F, SEPTON 2005, SEPTON 2006, SEPTON 2063, SEPTON 2104 are all manufactured by Kuraray Co., Ltd.), SEEPS (styrene-ethylidene / ethylene and propylene-styrene block copolymers: SEPTON 4003, SEPTON 4044, SEPTON 4055, SEPTON 4077, SEPTON 4099 are all manufactured by Kuraray Co., Ltd.), SEBS (styrene-ethylidene and butylene-styrene block copolymers: SEPTON 8004, SEPTON 8006, SEPTON Examples include, but are not limited to, SEEPS-OH (a compound having hydroxyl groups at the terminals of a styrene-ethylidene / ethylene and propylene-styrene block copolymer: SEPTON HG252 (manufactured by KURARAY), SIS (styrene-isoprene-styrene block copolymers: SEPTON 5125 and SEPTON 5127 (manufactured by KURARAY), hydrogenated SIS (hydrogenated styrene-isoprene-styrene block copolymers: HYABRAR 7125F and HYABRAR 7311F (manufactured by KURARAY), SIBS (styrene-isobutylene-styrene block copolymers: SIBSTAR 073T, SIBSTAR 102T, and SIBSTAR 103T (manufactured by Kaneka Corporation), and SEPTON V9827 (manufactured by KURARAY)). These may be used alone or in combination. Polystyrene and its modified products preferably lack unsaturated bonds, thus exhibiting high heat resistance and resisting oxidative degradation. Furthermore, the weight-average molecular weight of polystyrene and its modified products is not particularly limited, as long as it is 10,000 or greater. However, if the weight-average molecular weight is too high, compatibility with polyphenylene ether compounds, low-molecular-weight components with a weight-average molecular weight of approximately 50 to 1,000, and oligomer components with a weight-average molecular weight of approximately 1,000 to 5,000 will deteriorate, making it difficult to ensure mixing and solvent stability. Therefore, the weight-average molecular weight is preferably between 10,000 and 300,000.

[0099] The content of polystyrene and its modified products is not particularly limited, but is preferably 5 to 1000 parts by mass, more preferably 10 to 750 parts by mass, relative to 100 parts by mass of the compound represented by formula (1). When the content of styrene and its modified products is within the above range, not only excellent heat resistance and other properties are achieved, but also a cured product that fully utilizes the excellent dielectric properties of polystyrene and its modified products is obtained, which is preferable.

[0100] The curable resin composition of this embodiment is obtained by mixing the aforementioned components in a predetermined ratio, pre-curing at 130 to 180°C for 30 to 500 seconds, and post-curing at 150 to 200°C for 2 to 15 hours to fully achieve the curing reaction, thereby obtaining the cured product of this embodiment. Alternatively, the components of the curable resin composition may be uniformly dispersed or dissolved in a solvent, etc., and then cured after removing the solvent.

[0101] The preparation method of the curable resin composition of this embodiment is not particularly limited, but the components may be uniformly mixed or prepolymerized. For example, a mixture containing the maleimide compound represented by the above-mentioned formula (1) and other compounds may be heated in the presence or absence of a curing accelerator or a polymerization initiator, and in the presence or absence of a solvent, thereby prepolymerizing. Similarly, an amine compound, a compound having an ethylenically unsaturated bond, a maleimide compound other than the maleimide compound represented by the formula (1), a cyanate compound, polybutadiene and its modified products, polystyrene and its modified products, an inorganic filler, and other additives may be added and prepolymerized. Regarding the mixing or prepolymerization of the components, if in the absence of a solvent, for example, an extruder, a kneader, a roller press, etc. are used, and if in the presence of a solvent, a reactor with a stirring device, etc., may be used.

[0102] The uniform mixing method involves kneading at a temperature between 50 and 100°C using a kneader, roller press, planetary mixer, or other device to obtain a uniform resin composition. Alternatively, the obtained resin composition can be pulverized and then formed into cylindrical ingots, granular powders, or powdered molded bodies using a tablet press or other molding machine. Alternatively, the composition can be melted onto a surface support and formed into sheets with a thickness of 0.05 mm to 10 mm to obtain a curable resin composition molded body. The resulting molded body is non-sticky at temperatures between 0 and 20°C, and its fluidity and curability are barely degraded even when stored at -25 to 0°C for more than one week. The obtained molded body can be molded into a hardened product using a transfer molding machine or a compression molding machine.

[0103] The curable resin composition of this embodiment may also be prepared by adding an organic solvent to form a varnish-like composition (hereinafter referred to as varnish). If necessary, 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 to form a varnish. This varnish is then impregnated onto a substrate such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, or paper, and then heated and dried. The resulting prepreg is then hot-pressed to produce a cured product of the curable resin composition of this embodiment. In this case, the amount of solvent used in the mixture of the curable resin composition of this embodiment and the solvent is 10 to 70% by weight, preferably 15 to 70% by weight. Furthermore, if the composition is in liquid form, a cured product of the curable resin containing carbon fibers can be obtained directly by, for example, RTM.

[0104] Furthermore, the curable composition of this embodiment can also be used as a modifier for film-type compositions. Specifically, it can be used to improve flexibility, etc., during the B-stage. Such a film-type resin composition is prepared by applying the curable resin composition of this embodiment as the aforementioned curable resin composition varnish onto a release film, heating to remove the solvent, and then B-staging to obtain a sheet-like adhesive. This sheet-like adhesive can be used as an interlayer insulating layer in multilayer substrates, etc.

[0105] The curable resin composition of this embodiment can also be heated and melted to reduce viscosity, and then impregnated into reinforcing fibers such as glass fibers, carbon fibers, polyester fibers, polyamide fibers, and alumina fibers to obtain a prepreg. Specific examples include 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, fibers of inorganic materials other than glass, and poly(p-phenylene terephthalate) (Kevlar (registered trademark), manufactured by DuPont), wholly aromatic polyamide, polyester, poly(p-phenylene terephthalate), and poly(p-phenylene terephthalate). Organic fibers such as azoles, polyimides, and carbon fibers are used, but are not limited to these. There are no particular restrictions on the shape of the substrate, but examples thereof include woven fabrics, non-woven fabrics, rovings, and chopped strand mats. Furthermore, as for weaving methods for woven fabrics, plain weaves, basket weaves, and twill weaves are known, and appropriate selections can be made from these known methods depending on the intended use and performance. Furthermore, it is preferred to use woven fabrics that have been subjected to fiber opening treatment or glass fabrics that have been surface-treated with a silane coupling agent or the like. There are no particular restrictions on the thickness of the substrate, but it is preferably about 0.01 to 0.4 mm. Furthermore, a prepreg can be obtained by impregnating the reinforcing fibers in the aforementioned varnish and then heating and drying.

[0106] Furthermore, the above-mentioned prepregs can also be used to manufacture laminates. The laminates are not particularly limited as long as they have one or more prepregs, and may have any other layers. There are no particular limitations on the method for manufacturing the laminates, and generally known methods can be used as appropriate. For example, when molding a metal foil-clad laminate, a multi-stage press, a multi-stage vacuum press, a continuous molding machine, an autoclave molding machine, etc. can be used to laminate the above-mentioned prepregs and heat and press mold them to obtain a laminate. At this time, the heating temperature is not particularly limited, but is preferably 65 to 300°C, more preferably 120 to 270°C. Furthermore, the pressurizing pressure is not particularly limited, but if the pressure is too high, it will be difficult to adjust the solid content of the resin in the laminate and the quality will be unstable. Furthermore, if the pressure is too low, bubbles will appear and the adhesion between the layers will deteriorate. Therefore, it is preferably 2.0 to 5.0 MPa, more preferably 2.5 to 4.0 MPa. Since the laminated board of this embodiment includes a layer composed of metal foil, it can be suitably used as a metal foil-clad laminated board described later. The prepreg is cut into the desired shape and laminated with copper foil or the like as needed. The laminate is then heated and cured while being pressed using a press molding method, autoclave molding method, sheet winding method, or other methods. This allows the production of laminated boards (printed wiring boards) for electrical and electronic applications and carbon fiber reinforced materials.

[0107] The curable resin composition of this embodiment can also be made into a resin sheet. For example, a method for obtaining a resin sheet from the curable resin composition of this embodiment includes coating the curable resin composition onto a support film (support) and then drying it to form a resin composition layer on the support film. When using the curable resin composition of this embodiment as a resin sheet, it is preferred that the film soften under the lamination temperature conditions (70°C to 140°C) during vacuum lamination. During lamination with a circuit board, it is important to exhibit fluidity (resin flow) sufficient to fill the vias or through-holes present in the circuit board. The aforementioned components are formulated to achieve these properties. Furthermore, the resulting resin sheet and circuit board (copper-clad laminate, etc.) must exhibit uniform appearance to ensure consistent performance in all locations, without causing localized differences in property values ​​due to phase separation.

[0108] Here, the through-holes of the circuit board have a diameter of 0.1 to 0.5 mm and a depth of 0.1 to 1.2 mm. It is preferable that resin filling can be performed within this range. Furthermore, when laminating both sides of the circuit board, it is desirable to fill the through-holes to about 1 / 2.

[0109] Specific methods for producing the resin sheet include, for example, preparing a varnished resin composition by mixing an organic solvent, coating the varnished resin composition on the surface of a support film (Y), and drying the organic solvent by further heating or blowing hot air, thereby forming a resin composition layer (X).

[0110] The organic solvent used herein preferably includes ketones such as acetone, methyl ethyl ketone, and cyclohexanone; acetates such as ethyl acetate, butyl acetate, cellulose acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitols such as cellulose and butyl carbitol; aromatic hydrocarbons such as toluene and xylene; dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. Furthermore, the organic solvent is preferably used at a non-volatile content of 30 to 60% by mass.

[0111] Furthermore, the thickness of the formed resin composition layer (X) must be greater than the thickness of the conductive layer. Since the thickness of the conductive layer of the circuit board ranges from 5 to 70 μm, the thickness of the resin composition layer (X) is preferably 10 to 100 μm. Furthermore, in this embodiment, the resin composition layer (X) may be protected by a protective film described below. Protection by the protective film prevents dust and scratches on the surface of the resin composition layer.

[0112] Examples of the support film and protective film include polyolefins such as polyethylene, polypropylene, and polyvinyl chloride; polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate; polycarbonates; polyimides; release paper; and metal foils such as copper foil and aluminum foil. The support film and protective film may be subjected to MAD treatment, corona treatment, and release treatment. The thickness of the support film is not particularly limited but is between 10 and 150 μm, preferably between 25 and 50 μm. Furthermore, the thickness of the protective film is preferably between 1 and 40 μm.

[0113] The support film (Y) is removed after lamination onto the circuit board or after forming the insulating layer by heat curing. Removing the support film (Y) after the resin composition layer constituting the resin sheet has been heat cured can prevent the adhesion of dust and the like during the curing step. If removal is performed after curing, the support film should be subjected to a release treatment in advance.

[0114] 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 can be peeled off and then the resin composition layer (X) can be laminated onto one or both sides of the circuit board in direct contact with the circuit board, for example, by vacuum lamination. The lamination method can be batch or continuous using a roller press. Furthermore, if necessary, the resin sheet and circuit board can be heated (preheated) before lamination. Lamination conditions preferably include a pressing temperature (lamination temperature) of 70 to 140°C, a pressing pressure of 1 to 11 kgf / cm² (9.8 × 10⁴ to 107.9 × 10⁴ N / m²), and preferably performed under reduced pressure of 20 mmHg (26.7 hPa) or less.

[0115] Furthermore, the curable resin composition of this embodiment can be used to manufacture semiconductor devices. 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).

[0116] The curable resin composition and its cured product of this embodiment can be used in a wide range of fields. Specifically, they can be used in various applications, including molding materials, adhesives, composite materials, and coatings. Because the cured product of the curable resin composition described in this embodiment exhibits excellent heat resistance and dielectric properties, it is preferably used in sealing materials for semiconductor devices, liquid crystal display devices, organic EL devices, electrical and electronic components such as build-up boards (printed wiring boards, BGA substrates, assembly substrates, etc.), composite materials for lightweight, high-strength structural materials such as carbon fiber reinforced plastics and glass fiber reinforced plastics, and 3D printing. [Example]

[0117] Next, the present invention will be described in more detail with reference to Examples. Hereinafter, parts are by mass unless otherwise specified. The present invention is not limited to these Examples.

[0118] Various analytical methods used in the Examples are described below. ‧GPC (gel permeation chromatography) analysis The weight average molecular weight (Mw) and the number average molecular weight (Mn) were calculated by polystyrene conversion using a polystyrene standard solution. GPC: Online degasser (DGU-20A3R), binary liquid handling device (LC-20AD), autosampler (SIL-20AHT), differential refractive index detector (RID-20A), column oven (CTO-20A), system controller (CBM-20A) (all manufactured by Shimadzu Corporation) Column: Shodex KF-603×1, KF-602.5×1, KF-602×1, KF-601×1 (all made by Showa Denko) Protection column: Shodex KF-G 4A (Showa Denko Co., Ltd.) Combined eluent: tetrahydrofuran Flow rate: 1.5ml / min. Column temperature: 40℃ Detection: RI (differential refractometer)

[0119] ‧1H-NMR analysis Apparatus: Nuclear magnetic resonance apparatus (JNM-ECS400) manufactured by JEOL Ltd.

[0120] [Example 1] In a flask equipped with a thermometer, cooling tube, stirrer, and Dean-Stark apparatus, 24.3 parts of 2,6-dimethylaniline, 136 parts of α,α,α',α'-tetramethyl-1,3-benzenedimethanol, 100 parts of toluene, and 35 parts of activated clay were placed. The reaction was carried out at an internal temperature of 110 to 135°C for 1.5 hours while removing the generated water by azeotropic dehydration. The internal temperature was then raised to 210°C while extracting the toluene, and the reaction was continued for 4 hours. After cooling by standing, the extracted toluene was returned to the system, and 200 parts of toluene was newly added. The activated clay was removed by filtration, yielding a toluene solution (T-1) containing the amine compound represented by the following formula (6). The GPC chart of the obtained amine compound is shown in Figure 1. Next, 100 parts of toluene, 29.4 parts of maleic anhydride, and 5.4 parts of methanesulfonic acid were added to a flask equipped with a thermometer, a cooling tube, a stirrer, and a Dean-Stark apparatus. While maintaining the internal temperature at 110°C, T-1 was added dropwise over 4 hours. Furthermore, a polymerization reaction of the olefin portion of the amine represented by the following formula (6) and a maleimide reaction of the amino group were carried out at 110°C for 9 hours. After standing and cooling, 200 parts of toluene were added, and the organic layer was washed five times with 100 parts of water. The solvent was distilled off under reduced pressure by heating to obtain 133 parts of a maleimide compound (M-1) represented by the following formula (7) as a brown solid resin. The GPC chart of the obtained maleimide compound is shown in Figure 2. The number average molecular weight (Mn) was 2082, and the weight average molecular weight (Mw) was 3169. In addition, the 1H-NMR chart (heavy chloroform) of the obtained maleimide compound is shown in Figure 3. A signal derived from the maleimide group was observed at 6.85 ppm in the 1H-NMR chart.

[0121]

[0122]

[0123] [Example 2] In a flask equipped with a thermometer, cooling tube, stirrer, and Dean-Stark apparatus, 35.4 parts of 2,6-diisopropylaniline, 136 parts of α,α,α',α'-tetramethyl-1,3-benzenedimethanol, 100 parts of toluene, and 35 parts of activated clay were placed. The mixture was reacted at an internal temperature of 110 to 135°C for 2 hours while removing the generated water by azeotropic dehydration. The internal temperature was then raised to 210°C while extracting the toluene, and the reaction was continued for 9 hours. After cooling, the extracted toluene was returned to the system, and 200 parts of toluene was newly added. The activated clay was removed by filtration, yielding a toluene solution (T-2) containing the amine compound represented by the following formula (8). The GPC chart of the obtained amine compound is shown in Figure 4. Next, 100 parts of toluene, 29.4 parts of maleic anhydride, and 5.4 parts of methanesulfonic acid were added to a flask equipped with a thermometer, a cooling tube, a stirrer, and a Dean-Stark apparatus. While maintaining the internal temperature at 110°C, T-2 was added dropwise over 2 hours. Furthermore, a polymerization reaction of the olefin portion of the amine compound represented by the following formula (8) and a maleimide reaction of the amino group were carried out at 110°C for 10 hours. After standing and cooling, 200 parts of toluene were added, and the organic layer was washed five times with 100 parts of water. The solvent was distilled off under reduced pressure by heating to obtain 125 parts of a maleimide compound (M-2) represented by the following formula (9) as a brown solid resin. The GPC chart of the obtained maleimide compound is shown in Figure 5. The number average molecular weight (Mn) was 2007, and the weight average molecular weight (Mw) was 3301. In addition, the 1H-NMR chart (heavy chloroform) of the obtained maleimide compound is shown in Figure 6. A signal derived from the maleimide group was observed at 6.85 ppm in the 1H-NMR chart.

[0124]

[0125]

[0126] [Synthesis example 1] In a flask equipped with a thermometer, cooling tube, stirrer, and Dean-Stark apparatus, 48.5 parts of 2,6-dimethylaniline, 155.4 parts of α,α,α',α'-tetramethyl-1,3-benzenedimethanol, 100 parts of toluene, and 30.6 parts of activated clay were charged. While removing toluene and generated water by azeotropic dehydration, the internal temperature was raised to 210°C over 2 hours, and the mixture was reacted for 3 hours (GPC chart is shown in Figure 7). After cooling the internal temperature to 120°C, 145.4 parts of 2,6-dimethylaniline was added, and the mixture was reacted at 220°C for 3 hours. After cooling by standing, the extracted toluene was returned to the system, and 200 parts of toluene was newly added. The activated clay was removed by filtration, and the solvent and excess 2,6-dimethylaniline were distilled off to obtain 207 parts of the amine compound (A-1) represented by the following formula (10) (amine equivalent: 272.7 g / eq.) as a brown solid resin. The GPC chart of the obtained amine compound is shown in FIG7 . The number average molecular weight (Mn) was 1048, and the weight average molecular weight (Mw) was 1252.

[0127]

[0128] [Synthesis example 2] In a flask equipped with a thermometer, cooling tube, stirrer, and Dean-Stark apparatus, 50 parts of toluene, 53.9 parts of maleic anhydride, and 2 parts of methanesulfonic acid were added. While maintaining the reflux state, a toluene and N-methylpyrrolidone (NMP) solution of A-1 (100 parts of A-1, 75 parts of toluene, 25 parts of NMP) was added dropwise over 1 hour. Maleic imidization of the amino group was carried out under reflux conditions for 2 hours. After standing and cooling, 100 parts of toluene were added, and the organic layer was washed five times with 100 parts of water. The solvent was distilled off under reduced pressure by heating to obtain 117 parts of a maleic imide compound (M-3) represented by the following formula (11) as a brown solid resin. The GPC chart of the obtained maleic imide compound is shown in Figure 8. The number average molecular weight (Mn) was 1353, and the weight average molecular weight (Mw) was 1562.

[0129]

[0130] [Examples 3 to 6, Comparative Example 1] The maleimide compounds (M-1, M-2, and M-3) obtained in Examples 1 and 2 and Synthesis Example 2 were mixed with the thermal radical initiator DCP (dicumyl peroxide, manufactured by Tokyo Chemical Industry Co., Ltd.) in the ratios shown in Tables 1 and 2, respectively. The mixture was then vacuum-pressed while sandwiched between mirror-finish copper foil (T4X, manufactured by Fukuda Metal Copper Foil Co., Ltd.) and cured at 220°C for 2 hours. The spacers used were 250 μm thick cushioning paper with a 150 mm vertical and horizontal hole cut out in the center. Test pieces of the desired size were cut using a laser cutter as needed for evaluation. The evaluation results are shown in Tables 1 and 2.

[0131] <Dielectric constant test, dielectric tangent test> The test was conducted using a 10 GHz cavity resonator manufactured by ATE Corporation using the cavity resonator perturbation method. The specimen dimensions were set to 1.7 mm wide by 100 mm long, with a thickness of 0.3 mm.

[0132] [Table 1]

[0133] <Heat resistance: Differential scanning calorimetry (DSC)> The glass transition points Tg of the samples of Examples 5 and 6 were measured using a differential scanning calorimeter. Differential scanning calorimeter: DSC6220 (manufactured by SII Nanotechnology) Measuring temperature range: 30 to 330°C Heating rate: 10℃ / min Ambient gas: nitrogen (30 mL / min) Sample amount: 5mg Tg: The inflection point of the DSC graph is set as Tg.

[0134] [Table 2]

[0135] According to the results in Tables 1 and 2, it is confirmed that the curable resin composition of the present invention has excellent dielectric properties and heat resistance.

[0136] This patent application claims priority based on Japanese patent application No. 2022-052578 filed on March 28, 2022. [Industrial Applicability]

[0137] The curable resin composition containing the maleimide compound of the present invention and the cured product obtained by curing the same are suitable for use in semiconductor sealing materials, printed wiring boards, assembled laminates and other electrical and electronic parts.

Claims

1. A maleic diamide compound represented by formula (1) below, wherein, In formula (1), there are multiple R systems that exist independently and represent hydrocarbon groups or alkyl halogenates with 1 to 10 carbon atoms; the X system is shown in formula (2) below; m is an integer from 0 to 4, n is the average of the number of repetitions, 1 ≤ n ≤ 20; in formula (2), there are multiple R systems that exist independently and represent hydrocarbon groups or alkyl halogenates with 1 to 10 carbon atoms; p represents an integer from 0 to 4, q represents an integer from 0 to 3; r is the average of the number of repetitions, 1 ≤ r ≤ 20; * indicates the bonding position with the aromatic ring in the aforementioned formula (1).

2. A maleic diamide compound represented by formula (3) below, wherein, In equation (3), the X system is as shown in equation (4) below; n is the average of the number of repetitions, 1.1≦n≦20; in equation (4), there are multiple R systems that exist independently and represent hydrocarbon groups with 1 to 5 carbon atoms; p represents an integer from 0 to 4, r is the average of the number of repetitions, 1.1≦r≦20; * represents the bonding position with the aromatic ring of the compound in equation (3).

3. The maleic diamide compound as described in claim 2, wherein, In the aforementioned formula (4), p is 2, and the substitution position of R is ortho relative to the maleic diimide group.

4. A curable resin composition comprising: a maleic diamide compound as described in any one of claims 1 to 3.

5. The curable resin composition as described in claim 4 further contains a free radical polymerization initiator.

6. A cured material obtained by curing the curable resin composition described in claim 4 or 5.

7. A mixture obtained by reacting an amine compound of formula (5) with maleic anhydride in the presence of an acid catalyst, wherein the maleic anhydride compound containing double bonds of an α-methylstyrene structure has a number average molecular weight of 1,000 or more but less than 10,000 after the reaction, and a maleic anhydride compound of formula (12), wherein, In equation (5), there exist multiple R systems that exist independently and represent hydrocarbon groups or alkyl halides with 1 to 10 carbon atoms; p represents an integer from 0 to 4, q represents an integer from 0 to 3; r is the average of the number of repetitions, 1 ≦ r ≦ 20; In equation (12), there exist multiple R systems that exist independently and represent hydrocarbon groups or alkyl halides with 1 to 10 carbon atoms; p represents an integer from 0 to 4, q represents an integer from 0 to 3; r is the average of the number of repetitions, 1 ≦ r ≦ 20.

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