Curable resin composition and its cured product

Abstract

The present invention provides a curable resin composition and a cured product thereof that have excellent heat decomposition resistance. [Solution] A curable resin composition comprising a curable resin represented by formula (1), and one or more of the following: epoxy resin, active ester compound, phenol resin, amine resin, compound having an ethylenically unsaturated bond, isocyanate resin, polyamide resin, maleimide compound, cyanate ester resin, and benzoxazine compound. TIFF2026142541000020.tif44170 (In formula (1), R1 represents a hydrocarbon group having 1 to 5 carbon atoms. R2 represents a hydrocarbon group having 1 to 5 carbon atoms, etc. l and m are integers from 0 to 4.)

Description

[Technical Field]

[0001] The present invention relates to a curable resin composition containing a curable resin having a specific structure and its cured product, and is suitably used in electrical and electronic components such as semiconductor encapsulants, printed circuit boards, build-up laminates, optical waveguide devices, and redistribution layers, as well as lightweight, high-strength materials such as carbon fiber reinforced plastics and glass fiber reinforced plastics, and in 3D printing applications. [Background technology]

[0002] In recent years, the required characteristics of laminates used to mount electrical and electronic components have become broader and more sophisticated due to the expansion of their application fields. While conventional semiconductor chips were mainly mounted on metal lead frames, high-performance semiconductor chips such as central processing units (hereinafter referred to as CPUs) are increasingly being mounted on laminates made of polymer materials.

[0003] Furthermore, with the recent emergence of generative AI and the resulting increase in computational load, the development of advanced packages for HPC (High Performance Computing), such as AI servers, is accelerating. In these advanced packages, performance has traditionally been improved by miniaturizing semiconductors, but in recent years, with the advent of chiplet technology, the mounting of chips for each function is becoming mainstream. Consequently, package substrates are getting larger year by year, and coupled with multi-layering and complexity, the development of highly heat-resistant (thermal decomposition resistance, high Tg, low coefficient of thermal expansion) resin materials is becoming crucial. Behind this demand is the aim of preventing connection failures during solder reflow. It is said that the temperature of a reflow oven when using lead-free solder can reach 260°C, and if materials with low thermal decomposition resistance are used, the risk of outgassing and connection failures increases.

[0004] Against this backdrop, polymer materials with excellent thermal decomposition resistance are being investigated. For example, Patent Document 1 investigates a curable resin composition using aliphatic maleimide, but in the case of maleimide resins that incorporate long-chain aliphatic structures in particular, compatibility with other resins can be an issue, limiting the composition, and there is also the problem of a decrease in the glass transition temperature (Tg). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2019-65075 [Overview of the project] [Problems that the invention aims to solve]

[0006] This invention has been made in view of the above circumstances, and aims to provide a curable resin composition and a cured product thereof that have excellent heat decomposition resistance. [Means for solving the problem]

[0007] In other words, the present invention relates to a curable resin composition containing a curable resin represented by formula (1) and one or more of the following: epoxy resin, active ester compound, phenol resin, amine resin, compound having an ethylenically unsaturated bond, isocyanate resin, polyamide resin, maleimide compound, cyanate ester resin, and benzoxazine compound.

[0008] [ka]

[0009] (In formula (1), each of the multiple R1s independently represents a hydrocarbon group having 1 to 5 carbon atoms. Each of the multiple R2s independently represents a hydrocarbon group having 1 to 5 carbon atoms or a structure represented by formula (1-1) below. Each of the multiple l and m are independent integers from 0 to 4.)

[0010]

Chem.

[0011] (In formula (1-1), * represents the bonding position to the fluorene structure of formula (1). A plurality of R3 each independently represent a hydrocarbon group having 1 to 5 carbon atoms. E1 represents a direct bond or a methylene group. E2 and E3 represent a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group. p represents an integer of 0 to 2, and q represents an integer of 0 to 5.)

[0012] In the present invention, "from (numerical value 1) to (numerical value 2)" indicates that the upper and lower limit values are included.

Effects of the Invention

[0013] According to the present invention, a curable resin composition having excellent thermal decomposition resistance can be provided.

Brief Description of Drawings

[0014] [Figure 1] Fig. 1 shows an HPLC chart of Synthesis Example 1.

[0015] Hereinafter, an embodiment according to the present invention (hereinafter also referred to as "the present embodiment") will be described in further detail.

[0016] The curable resin composition of the present embodiment contains a curable resin represented by the following formula (1), and at least one selected from the group consisting of epoxy resins, active ester compounds, phenolic resins, amine resins, compounds having an ethylenically unsaturated bond, isocyanate resins, polyamide resins, maleimide compounds, cyanate ester resins, and benzoxazine compounds.

[0017]

Chem.

[0018] In formula (1), each of the multiple R1s independently represents a hydrocarbon group having 1 to 5 carbon atoms, preferably a hydrocarbon group having 1 to 3 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. When a hydrocarbon group having 1 to 5 carbon atoms is introduced, molecular vibrations when exposed to high frequencies are suppressed, leading to a reduction in transmission loss. Each of the multiple R2s independently represents a hydrocarbon group having 1 to 5 carbon atoms or a structure represented by the following formula (1-1), preferably a hydrocarbon group having 1 to 3 carbon atoms or a structure represented by the following formula (1-1), and more preferably an alkyl group having 1 to 3 carbon atoms or a structure represented by the following formula (1-1). When a hydrocarbon group having 1 to 5 carbon atoms or a structure represented by the following formula (1-1) is introduced, molecular vibrations when exposed to high frequencies are suppressed, leading to a reduction in transmission loss. Each of the multiple l and m are independently integers from 0 to 4, with a more preferred range for l being 0 to 3, more preferably 0 to 2, even more preferably 0 to 1, and most preferably 0. A preferred range for m is 0 to 3, more preferably 0 to 2, and even more preferably 0 to 1.

[0019] [ka]

[0020] In formula (1-1), * represents the bond position to the fluorene structure of formula (1). Each of the multiple R3s independently represents a hydrocarbon group having 1 to 5 carbon atoms, preferably a hydrocarbon group having 1 to 3 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. When the number of carbon atoms is 5 or less, molecular vibration is less likely when exposed to high frequency, resulting in excellent electrical properties. E1 represents a direct bond or a methylene group. E2 and E3 represent a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group, and it is preferable that the hydrocarbon group having 1 to 5 carbon atoms is a methyl group. p represents an integer from 0 to 2, and q represents an integer from 0 to 5, preferably 0 to 4, more preferably 0 to 3, even more preferably 0 to 2, and most preferably 0 to 1.

[0021] The hydrocarbon group represented by formula (1-1) above is preferably one or more selected from the following formulas (a-1) to (a-8), more preferably one or more selected from (a-1) to (a-4) and (a-7) to (a-8), and even more preferably one or more selected from (a-1) to (a-4).

[0022] [ka]

[0023] In the above formulas (a-1) to (a-8), * represents the bond position to the fluorene structure in formula (1). Each of the multiple R3 groups independently represents a hydrocarbon group having 1 to 5 carbon atoms, preferably a hydrocarbon group having 1 to 3 carbon atoms, and more preferably a hydrogen atom. When the number of carbon atoms is 5 or less, molecular vibration is less likely to occur when exposed to high frequencies, resulting in excellent electrical properties. Also, when it is a hydrogen atom, deterioration of dielectric properties and water absorption properties due to the formation of polar groups resulting from the oxidation reaction of alkyl groups during high-temperature storage tests can be suppressed. q represents an integer from 0 to 5, preferably 0 to 4, more preferably 0 to 3, even more preferably 0 to 2, and most preferably 0 to 1.

[0024] The method for producing the compound represented by formula (1) above is not particularly limited, but it can be obtained by reacting the compound represented by formula (A) below with the compound represented by formula (B) below.

[0025] [ka]

[0026] In the above formula (A), each of the multiple R2s independently represents a hydrocarbon group represented by the following formula (1-1). Each of the multiple ms independently represents an integer from 0 to 4. The average value of m is m ave is 0≦m ave m ≤ 4. ave This can be calculated from the raw material mixing ratio or from the NMR analysis results. From the viewpoint of solvent solubility and heat resistance, 0 ≤ m avePreferably, ≤3.0, and 0 ≤ m ave It is more preferable that m ≤ 2. ave If the value is greater than 4, steric hindrance may increase, potentially reducing the hardening properties.

[0027] [ka]

[0028] In formula (1-1), * represents the bond position to the fluorene structure of formula (1). Each of the multiple R3s independently represents a hydrocarbon group having 1 to 5 carbon atoms, preferably a hydrocarbon group having 1 to 3 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. When the number of carbon atoms is 5 or less, molecular vibration is less likely when exposed to high frequency, resulting in excellent electrical properties. E1 represents a direct bond or a methylene group. E2 and E3 represent a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group, and it is preferable that the hydrocarbon group having 1 to 5 carbon atoms is a methyl group. p represents an integer from 0 to 2, and q represents an integer from 0 to 5, preferably from 0 to 4, more preferably from 0 to 3, even more preferably from 0 to 2, and most preferably from 0 to 1. Preferred specific structures of formula (1-1) are the structures represented by formulas (a-1) to (a-8).

[0029] [ka]

[0030] In the above formula (B), R1 represents a hydrocarbon group having 1 to 5 carbon atoms, preferably a hydrocarbon group having 1 to 3 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. When the number of carbon atoms is 5 or less, molecular vibration is less likely to occur when exposed to high frequency, resulting in excellent electrical properties. X represents a halogen atom, and from the viewpoint of reactivity and waste generation suppression, it is preferably a bromine atom or a chlorine atom, and more preferably a chlorine atom. l represents an integer from 0 to 4, preferably 0 to 3, more preferably 0 to 2, even more preferably 0 to 1, and most preferably 0.

[0031] When synthesizing the compound represented by formula (1) above, if α is the number of moles of the compound represented by formula (A) above and β is the number of moles of the compound represented by formula (B) above, then β / α is preferably 1.8 or more and 2.1 or less, more preferably 1.8 or more and 2.0 or less, and particularly preferably 1.8 or more and 1.95 or less. If β / α is less than 1.8, the compound represented by formula (A) above remains unreacted, which may reduce the toughness of the cured film and worsen the dielectric properties. This is because the unreacted compound represented by formula (A) above does not have a structure that can be crosslinked, and oxygen reacts with the methylene structure at position 9 of the compound represented by formula (A) above to generate a ketone, increasing its polarity. If β / α is greater than 2.1, halogen elements of the compound represented by formula (B) above that could not be completely removed by purification may desorb during curing (for example, at temperatures of 175°C or higher) or during high-temperature and high-humidity testing (85°C, 85% humidity or 120°C, 100% humidity, etc.), potentially leading to corrosion of copper wiring. The amount of residual halogen contained in the compound of this embodiment is preferably 1 to 10,000 ppm, more preferably 1 to 3,000 ppm, and even more preferably 1 to 2,000 ppm.

[0032] The reaction between the compound represented by formula (A) and the compound represented by formula (B) will be described in detail. The compound represented by formula (1) is obtained by reacting the compound represented by formula (A) and the compound represented by formula (B) in an aprotic polar solvent in the presence of a basic catalyst. Examples of aprotic polar solvents include dimethyl sulfone, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, and N-methylpyrrolidone, and two or more may be used in combination. In addition, a water-insoluble solvent may be used in combination as needed. Examples of water-insoluble solvents include aromatic solvents such as toluene and xylene, aliphatic solvents such as cyclohexane and n-hexane, ethers such as diethyl ether and diisopropyl ether, ester solvents such as ethyl acetate and butyl acetate, and ketone solvents such as methyl isobutyl ketone and cyclopentanone, but are not limited to these, and two or more may be used in combination. The catalyst is not particularly limited, but basic catalysts such as sodium hydroxide, potassium hydroxide, and potassium carbonate are examples. The order in which the compound represented by formula (A), the compound represented by formula (B), and the base are added can be changed as needed, but it is preferable to add the compound represented by formula (A), an aprotic polar solvent, and a base, and after the compound represented by formula (A) has been sufficiently ionized, add the compound represented by formula (B). If the reaction is carried out without using an aprotic polar solvent, the reaction rate will decrease significantly. When an aprotic polar solvent is not used, the reaction is generally carried out using an interlayer transfer catalyst. In this case, the raw materials are dissolved in a water-insoluble solvent such as toluene, and the compound represented by formula (A) and the compound represented by formula (B) are reacted in the presence of a base catalyst such as an aqueous sodium hydroxide solution and an interlayer transfer catalyst such as tetrabutylammonium bromide. In this case, it is difficult to completely remove the interlayer transfer catalyst such as tetrabutylammonium bromide, making it difficult to achieve low dielectric properties (low dielectric constant and low dielectric loss tangent). Furthermore, residual interlayer transfer catalyst may cause problems such as ion migration when the substrate material using the compound of this embodiment is subjected to long-term moist heat reliability tests.The reaction temperature is preferably 0 to 120°C, more preferably 0 to 100°C, and even more preferably 0 to 80°C. Above the upper limit, self-polymerization of the compound in this embodiment may proceed, potentially leading to gelation. Below the lower limit, the reaction may not proceed sufficiently. As a post-reaction treatment, neutralization may be performed with any acid compound. Alternatively, if necessary, an alcohol compound or water may be added to the reaction solution to recover the target product as crystals. The obtained reaction solution or crystals may also be redissolved in any solvent and an extraction step may be performed. For the extraction step, aromatic hydrocarbon solvents such as toluene or xylene may be used alone, or non-aromatic hydrocarbons such as cyclohexane, methylocyclohexane, hexane, heptane, or octane may be used in combination. After extraction, the organic layer is washed with water until the wastewater is neutral, and the solvent is removed using an evaporator or the like to obtain the target compound.

[0033] The compound represented by formula (A) above is derived from fluorene and the compound represented by formula (c) or (d) below.

[0034] [ka]

[0035] In formulas (c) and (d) above, each of the multiple R3s independently represents a hydrocarbon group having 1 to 5 carbon atoms, preferably a hydrocarbon group having 1 to 3 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. When the number of carbon atoms is 5 or less, molecular vibration is less likely to occur when exposed to high frequency, resulting in excellent electrical properties. E1 represents a direct bond or a methylene group. E2 and E3 represent a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group, and it is preferable that the hydrocarbon group having 1 to 5 carbon atoms is a methyl group. p represents an integer from 0 to 2, and q represents an integer from 0 to 5, preferably from 0 to 4, more preferably from 0 to 3, even more preferably from 0 to 2, and most preferably from 0 to 1. Preferred structures of specific examples of formula (1-1) are the structures represented by formulas (a-1) to (a-8). Z represents a hydroxyl group or a halogen atom, and is preferably a hydroxyl group, a bromine atom, or a chlorine atom from the viewpoint of reactivity and waste generation suppression, and more preferably a hydroxyl group or a chlorine atom. Of the compounds represented by formula (c) or (d) above, it is preferable to use the compound represented by formula (c) above from the viewpoint of suppressing the self-polymerization reaction of the raw materials.

[0036] When reacting fluorene with the compound represented by formula (c) or (d) above, it is preferable to react 0.01 to 10 moles of the compound represented by formula (c) or (d) above with 1 mole of fluorene, more preferably 0.1 to 7.5 moles, even more preferably 0.2 to 5 moles, and most preferably 0.3 to 4 moles. If the number of moles of compound (c) or (d) reacted with fluorene is less than 0.01 moles, there is a concern that the storage stability after solvent dissolution will deteriorate, such as the precipitation of crystals when left standing for a long time after solvent dissolution. If the amount is greater than 10 moles, there is a risk of decreased heat resistance, or that the compound represented by formula (c) or (d) above will be in excess, leading to self-polymerization and a decrease in the purity of the desired product.

[0037] When reacting fluorene with the compound represented by formula (c) or (d) above, a catalyst such as hydrochloric acid, phosphoric acid, sulfuric acid, formic acid, p-toluenesulfonic acid, methanesulfonic acid, Lewis acids such as aluminum chloride and zinc chloride, solid acids such as activated clay, acid clay, white carbon, zeolite, and silica alumina, and acidic ion exchange resins may be used as necessary. These may be used alone or in combination of two or more. The amount of catalyst used is preferably 0.1 to 40% by mass, more preferably 0.1 to 20% by mass, relative to the total mass of fluorene and the compound represented by formula (c) or (d) above. If too much catalyst is used, the viscosity of the reaction solution may become too high, making stirring difficult, and if too little is used, the reaction may proceed slowly. The reaction may be carried out using organic solvents such as hexane, cyclohexane, octane, toluene, and xylene as needed, or it may be carried out without a solvent. For example, an acidic catalyst is added to a mixed solution of fluorene, a compound represented by formula (c) or (d) above, and a solvent (or no solvent). If the catalyst contains water, the water is removed from the system by azeotropy or the like. After that, the reaction is carried out at 40 to 300°C, preferably 50 to 250°C, for 0.5 to 40 hours. After the reaction is complete, the acidic catalyst may be neutralized with an alkaline aqueous solution, but the process can also proceed to the water washing step without neutralization. In the water washing step, a water-insoluble organic solvent is added to the oil layer and the washing is repeated until the wastewater becomes neutral.

[0038] Furthermore, with respect to the compound represented by formula (A) obtained in the above reaction, a neutralizing agent such as an alkali and an aprotic polar solvent may be added to the reaction solution, followed by the addition of a base catalyst and the compound represented by formula (B) to continuously convert it to the compound represented by formula (1).

[0039] The softening point of the compound represented by formula (A) above is preferably 150°C or lower, and more preferably 120°C or lower. A softening point of 150°C or lower results in a lower viscosity when the compound is converted to the compound represented by formula (1) above. This makes it easier to ensure fluidity, does not impair the impregnation properties of glass cloth or carbon fiber, and facilitates B-stage processes such as prepreg formation. If the viscosity is lowered by increasing the amount of diluting solvent, the resin may not adhere sufficiently to the fibrous material during the impregnation process. The compound represented by formula (A) above may have a melting point. The melting point is preferably 250°C or lower, more preferably 225°C or lower, even more preferably 200°C or lower, and particularly preferably 180°C or lower. A melting point of 250°C or lower reduces the crystallinity of the compounds represented by formulas (A) and (B) above, improving solvent solubility and the storage stability of the varnish after solvent dissolution.

[0040] The components used together with the curable resin represented by formula (1) preferably contain one or more of the following: epoxy resin, activated ester compound, phenol resin, amine resin, compound having an ethylenically unsaturated bond, isocyanate resin, polyamide resin, maleimide compound, cyanate ester resin, and benzoxazine compound. More preferably, the components contain one or more of the following: epoxy resin, activated ester compound, phenol resin, amine resin, compound having an ethylenically unsaturated bond, maleimide compound, cyanate ester resin, and benzoxazine compound. These components and the curable resin represented by formula (1) do not necessarily crosslink directly, but the curable resin represented by formula (1) can be cured on its own and exhibits excellent thermal decomposition resistance. Therefore, it is possible to consistently impart high thermal decomposition resistance to the curable resin composition and its cured product of this embodiment. Even if direct crosslinking does not occur, the above effects can be obtained by contributing to the formation of an IPN (interpenetrating polymer network).

[0041] The amount of curable resin represented by formula (1) is preferably 10 to 90 parts by mass, more preferably 30 to 80 parts by mass, and even more preferably 50 to 70 parts by mass, per 100 parts by mass of the solvent-free curable resin composition.

[0042] The amount of epoxy resin, active ester compound, phenol resin, amine resin, compound having an ethylenically unsaturated bond, isocyanate resin, polyamide resin, maleimide compound, cyanate ester resin, or benzoxazine compound blended is preferably 1 to 50 parts by mass, more preferably 5 to 40 parts by mass, and even more preferably 10 to 30 parts by mass, per 100 parts by mass of the solvent-free curable resin composition.

[0043] The curable resin of this embodiment preferably further contains one or more of the curing accelerator and polymerization initiator.

[0044] In one embodiment of this invention, the curable resin composition preferably contains a curable resin represented by formula (1), an epoxy resin, and a curing accelerator. These components and the curable resin represented by formula (1) do not necessarily crosslink directly, but the curable resin represented by formula (1) can be cured on its own and exhibits excellent thermal decomposition resistance, making it possible to consistently impart high thermal decomposition resistance to the curable resin composition and its cured product of this application. Even if direct crosslinking does not occur, the above effect can be obtained by contributing to the formation of an IPN (interpenetrating polymer network). Furthermore, the curable resin composition preferably contains one or more of the following: an active ester compound, a phenol resin, an amine resin, a compound having an ethylenically unsaturated bond, a maleimide compound, a cyanate ester resin, and a benzoxazine compound.

[0045] [Curing accelerator] The curable resin composition of this embodiment can also have its curability improved by adding a curing accelerator. Preferred curing accelerators are anionic curing accelerators that promote the curing reaction by generating anions upon irradiation with ultraviolet light or visible light or by heating, or cationic curing accelerators that promote the curing reaction by generating cations upon irradiation with ultraviolet light or visible light or by heating.

[0046] Examples of anionic curing accelerators include imidazoles such as 2-methylimidazole, 2-ethylimidazole, and 2-ethyl-4-methylimidazole; trialkylamines such as triethylamine and tributylamine; 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene, with 4-dimethylaminopyridine and 1,8-diazabicyclo(5,4,0)-undecene being preferred. Other examples include phosphines such as triphenylphosphine, tetrabutylammonium salt, triisopropylmethylammonium salt, trimethyldecanylammonium salt, cetyltrimethylammonium salt, and quaternary ammonium salts such as hexadecyltrimethylammonium hydroxide, but are not limited to these. These can be used individually or in combination.

[0047] Examples of cationic curing accelerators include quaternary phosphonium salts such as triphenylbenzylphosphonium salt, triphenylethylphosphonium salt, and tetrabutylphosphonium salt (the counterions of the quaternary salts are halogens, organic acid ions, hydroxide ions, etc., with no particular preference, but organic acid ions and hydroxide ions are particularly preferred), tin octoate, zinc carboxylates (zinc 2-ethylhexanoate, zinc stearate, zinc behenate, zinc myristate), and zinc phosphate esters (zinc octyl phosphate, zinc stearyl phosphate), but are not limited to these. Furthermore, these may be used individually or in combination of multiple types.

[0048] The amount of curing accelerator added is 0.01 to 5.0 parts by mass per 100 parts by mass of the curable resin composition, as needed.

[0049] [Polymerization initiator] The curable resin composition of this embodiment can also have its curability improved by adding a polymerization initiator. A polymerization initiator is a compound capable of polymerizing olefin functional groups such as ethylenically unsaturated bonds, and examples include olefin metathesis polymerization initiators, anionic polymerization initiators, cationic polymerization initiators, and radical polymerization initiators. Among these, it is preferable to use a radical polymerization initiator that has both curability and appropriate stability. A radical polymerization initiator is a compound that generates radicals upon irradiation with ultraviolet or visible light or heating, thereby initiating a chain polymerization reaction. Examples of radical polymerization initiators that can be used include organic peroxides, azo compounds, and benzopinacols, and it is preferable to use organic peroxides because they have less influence on curing temperature control, outgassing suppression, and the electrical properties of decomposition products.

[0050] Examples of the above organic peroxides include ketone peroxides such as methyl ethyl ketone peroxide and acetylacetone peroxide, diacyl peroxides such as benzoyl peroxide, dialkyl peroxides such as dicumyl peroxide and 1,3-bis-(t-butylperoxyisopropyl)benzene, peroxyketals such as t-butyl peroxybenzoate and 1,1-di-t-butylperoxycyclohexane, α-cumyl peroxyneodecanoate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, t-amyl peroxy-2-ethylhexanoate, and t-butyl peroxy Examples of such substances include alkyl peresters such as -oxy-2-ethylhexanoate, t-amyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxy-3,5,5-trimethylhexanoate, and t-amyl peroxybenzoate; peroxycarbonates such as di-2-ethylhexyl peroxydicarbonate, bis(4-t-butylcyclohexyl) peroxydicarbonate, t-butyl peroxyisopropyl carbonate, and 1,6-bis(t-butyl peroxycarbonyloxy)hexane; t-butyl hydroperoxide, cumene hydroperoxide, t-butyl peroxyoctoate, and lauroyl peroxide, but are not limited to these. Furthermore, these may be used individually or in combination. Among the above organic peroxides, ketone peroxides, diacyl peroxides, hydroperoxides, dialkyl peroxides, peroxyketals, alkyl peresters, and peroxycarbonates are preferred, with dialkyl peroxides being more preferred.

[0051] Examples of the above-mentioned azo compounds include, but are not limited to, azobisisobutyronitrile, 4,4'-azobis(4-cyanovaleric acid), and 2,2'-azobis(2,4-dimethylvaleronitrile). Furthermore, these compounds may be used individually or in combination.

[0052] The amount of polymerization initiator added is preferably 0.01 to 5 parts by mass, and particularly preferably 0.01 to 3 parts by mass, per 100 parts by mass of the curable resin composition. If the amount of polymerization initiator used is less than 0.01 parts by mass, the molecular weight may not elongate sufficiently during the polymerization reaction, and if it is more than 5 parts by mass, dielectric properties such as dielectric constant and dielectric loss tangent may be impaired.

[0053] [Epoxy resin] The following are examples of preferred epoxy resins, but are not limited to these. The epoxy resin may be liquid or solid, and may be used alone or in combination of multiple types. From the viewpoint of improving heat decomposition resistance, the epoxy resin is preferably one that has a structure containing an aromatic ring, and more preferably one that contains an aralkyl structure. Examples of aralkyl structures include phenol aralkyl, naphthol aralkyl, biphenol aralkyl, phenol biphenyl aralkyl, naphthol biphenyl aralkyl, and biphenol biphenyl aralkyl. In addition, the raw material phenols may include hydroquinone, resorcinol, catechol, naphthalenediol, dihydroxybiphenyl, etc.

[0054] Examples of liquid epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, phenol novolac type epoxy resin, alicyclic epoxy resin having an ester skeleton, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, glycidylamine type epoxy resin, and epoxy resin having a butadiene structure. Specific examples include "RE310S", "RE410S" (both manufactured by Nippon Kayaku Co., Ltd., bisphenol A type epoxy resin), "RE303S", "RE304S", "RE403S", "RE404S" (all manufactured by Nippon Kayaku Co., Ltd., bisphenol F type epoxy resin), "HP-4032", "HP-4032D", "HP-4032SS" (all manufactured by DIC Corporation, naphthalene type epoxy resin), "jER(registered trademark)828US", "jER828EL", "jER825", "jER828EL" (all manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin), "jER807", "jER1750" (both manufactured by Mitsubishi Chemical Corporation, bisphenol F type epoxy resin), "jER152" (manufactured by Mitsubishi Chemical Corporation, Examples include phenol novolac type epoxy resins, "jER630", "jER630LSD" (both manufactured by Mitsubishi Chemical Corporation, glycidylamine type epoxy resins), "ZX1059" (manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin), "EX-721" (manufactured by Nagase ChemteX Corporation, glycidyl ester type epoxy resin), "Celoxide (registered trademark) 2021P" (manufactured by Daicel Corporation, alicyclic epoxy resin with an ester skeleton), "PB-3600" (manufactured by Daicel Corporation, epoxy resin with a butadiene structure), "ZX1658", "ZX1658GS" (both manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., liquid 1,4-glycidylcyclohexane type epoxy resins), etc. These may be used individually or in combination of two or more types.

[0055] Preferred solid epoxy resins include, for example, bixylenol-type epoxy resin, naphthalene-type epoxy resin, naphthalene-type tetrafunctional epoxy resin, cresol novolac-type epoxy resin, dicyclopentadiene-type epoxy resin, trisphenol-type epoxy resin, naphthol-type epoxy resin, biphenyl-type epoxy resin, naphthylene ether-type epoxy resin, anthracene-type epoxy resin, bisphenol A-type epoxy resin, bisphenol AF-type epoxy resin, and tetraphenylethane-type epoxy resin.Specific examples include "HP4032H" (manufactured by DIC, naphthalene-type epoxy resin), "HP-4700", "HP-4710" (both manufactured by DIC, naphthalene-type tetrafunctional epoxy resin), "N-690" (manufactured by DIC, cresol novolac-type epoxy resin), "N-695" (manufactured by DIC, cresol novolac-type epoxy resin), "HP-7200" (manufactured by DIC, dicyclopentadiene-type epoxy resin), "HP-7200", "HP-7200HH", "HP-7200H" (both manufactured by DIC, dicyclopentadiene-type epoxy resin) Xylyl epoxy resin), "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP-6000" (all manufactured by DIC Corporation, naphthylene ether type epoxy resin), "EPPN-502H" (manufactured by Nippon Kayaku Co., Ltd., trisphenol type epoxy resin), "NC-7000L", "NC-7300" (both manufactured by Nippon Kayaku Co., Ltd., naphthol-cresol novolac type epoxy resin), "NC-3000H", "NC-3000", "NC-3000L", "NC-3100" (all manufactured by Nippon Kayaku Co., Ltd., Biphenyl aralkyl epoxy resin), "XD-1000-2L", "XD-1000-L", "XD-1000-H" (all manufactured by Nippon Kayaku Co., Ltd., dicyclopentadiene epoxy resin), "ESN475V" (manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., naphthol epoxy resin), "ESN485" (manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., naphthol novolac epoxy resin), "YX-4000H", "YX-4000", "YL6121" (all manufactured by Mitsubishi Chemical Corporation, biphenyl epoxy resin), "YX-4000HK" (manufactured by Mitsubishi Chemical Corporation, bixylenol) Examples include (type epoxy resin), "YX-8800" (manufactured by Mitsubishi Chemical Corporation, anthracene-type epoxy resin), "PG-100", "CG-500" (manufactured by Osaka Gas Chemical Co., Ltd., fluorene-based epoxy resin), "YL-7760" (manufactured by Mitsubishi Chemical Corporation, bisphenol AF-type epoxy resin), "YL-7800" (manufactured by Mitsubishi Chemical Corporation, fluorene-type epoxy resin), "jER1010" (manufactured by Mitsubishi Chemical Corporation, solid bisphenol A-type epoxy resin), and "jER1031S" (manufactured by Mitsubishi Chemical Corporation, tetraphenylethane-type epoxy resin). These may be used individually or in combination of two or more types.

[0056] [Activated ester compounds] An active ester compound is a compound that contains at least one ester bond in its structure, with aliphatic chains, aliphatic rings, or aromatic rings bonded to both sides of the ester bond. Examples of active ester compounds include compounds having two or more highly reactive ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. These are obtained by a condensation reaction between at least one compound of a carboxylic acid compound, an acid chloride, or a thiocarboxylic acid compound and at least one compound of a hydroxy compound or a thiol compound. Particularly from the viewpoint of improving heat resistance, it is preferable that they be obtained from a carboxylic acid compound or an acid chloride and a hydroxy compound, and phenol compounds or naphthol compounds are preferred as the hydroxy compound. Active ester compounds may be used alone or in combination of two or more.

[0057] Examples of the carboxylic acid compounds mentioned above include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid.

[0058] Examples of the above-mentioned acid chlorides include acetyl chloride, acrylate chloride, methacrylate chloride, malonyl chloride, succinate dichloride, diglycolyl chloride, glutarate dichloride, suberic acid dichloride, sebacate dichloride, adipic acid dichloride, dodecanediol dichloride, azera oil chloride, 2,5-franzicarbonyl dichloride, phthaloyl chloride, isophthaloyl chloride, terephthaloyl chloride, trimesic acid chloride, bis(4-chlorocarbonylphenyl) ether, 4,4'-diphenyldicarbonyl chloride, and 4,4'-azodibenzoyl dichloride.

[0059] Examples of the above-mentioned phenol compounds and naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, phenol novolac, and phenol resins described later. Here, "dicyclopentadiene-type diphenol compound" refers to a diphenol compound obtained by the condensation of two molecules of phenol with one molecule of dicyclopentadiene.

[0060] Preferred examples of active ester compounds include active ester compounds containing a dicyclopentadiene-type diphenol structure, active ester compounds containing a naphthalene structure, active ester compounds containing an acetylated phenol novolac, active ester compounds containing a benzoylated phenol novolac, the 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 represents a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

[0061] Examples of commercially available active ester compounds include, for example, "EXB9451," "EXB9460," "EXB9460S," "HPC-8000-65T," "HPC-8000H-65TM," "EXB-8000L-65TM," and "EXB-8150-65T" (manufactured by DIC Corporation) as active ester compounds containing a dicyclopentadiene-type diphenol structure; "EXB9416-70BK" (manufactured by DIC Corporation) as an active ester compound containing a naphthalene structure; "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester compound containing an acetylated phenol novolac; "YLH1026," "YLH1030," and "YLH1048" (manufactured by Mitsubishi Chemical Corporation) as active ester compounds containing a benzoylated phenol novolac; and "EXB-9050L-62M" (manufactured by DIC Corporation) as a phosphorus atom-containing active ester curing agent.

[0062] Regarding the blending ratio of the active ester compound and epoxy resin, the ratio of the active ester equivalent (α) to the epoxy equivalent (β) (α / β) is preferably 0.5 to 1.5, more preferably 0.8 to 1.2, and even more preferably 0.90 to 1.10. If it falls outside the above range, there is a risk that excess epoxy groups or active ester groups will remain in the system, which may lead to deterioration of properties in high-temperature storage tests (e.g., 150°C, 1000 hours) or long-term reliability tests under high-temperature and high-humidity conditions (e.g., temperature: 85°C, humidity: 85%).

[0063] [Phenolic resin] Phenolic resins are compounds having two or more phenolic hydroxyl groups in their molecule. Examples of phenolic resins include, but are not limited to, reaction products of phenols and aldehydes, reaction products of phenols and diene compounds, reaction products of phenols and ketones, reaction products of phenols and substituted biphenyls, reaction products of phenols and substituted phenyls, and reaction products of bisphenols and aldehydes. Furthermore, these can be used individually or in combination of multiple types. Specific examples of each of the above ingredients are given below, but this list is not exhaustive. <Phenols> Phenols, alkyl-substituted phenols, aromatic-substituted phenols, hydroquinones, resorcinols, naphthols, alkyl-substituted naphthols, dihydroxybenzenes, alkyl-substituted dihydroxybenzenes, dihydroxynaphthalenes, etc. <Aldehydes> Formaldehyde, acetaldehyde, alkylaldehyde, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzaldehyde, naphthaldehyde, glutaraldehyde, phthalaldehyde, crotonaldehyde, cinnamaldehyde, furfural, etc. <Diene compounds> Dicyclopentadiene, terpenes, vinylcyclohexene, norbornadiene, vinylnorbornene, 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.

[0064] [Amine resin] Amine resins are compounds that have two or more amino groups in their molecule. Examples of amine resins include diaminodiphenylmethane, diaminodiphenylsulfone, isophoronediamine, naphthalenediamine, aniline novolac (reaction product of aniline and formalin), N-methylaniline novolac (reaction product of N-methylaniline and formalin), orthoethylaniline novolac (reaction product of orthoethylaniline and formalin), reaction product of 2-methylaniline and formalin, reaction product of 2,6-diisopropylaniline and formalin, reaction product of 2,6-diethylaniline and formalin, reaction product of 2-ethyl-6-ethylaniline and formalin, reaction product of 2,6-dimethylaniline and formalin, and those obtained by the reaction of aniline with xylylene chloride. Examples of aniline resins include, but are not limited to, those described in Japanese Patent Publication No. 6429862, reaction products of aniline and substituted biphenyls (such as 4,4'-bis(chloromethyl)-1,1'-biphenyl and 4,4'-bis(methoxymethyl)-1,1'-biphenyl), reaction products of aniline and substituted phenyls (such as 1,4-bis(chloromethyl)benzene, 1,4-bis(methoxymethyl)benzene and 1,4-bis(hydroxymethyl)benzene), 4,4'-(1,3-phenylenediisopropylidene)bisaniline, 4,4'-(1,4-phenylenediisopropylidene)bisaniline, reaction products of aniline and diisopropenylbenzene, and dimer amines. Furthermore, these may be used individually or in combination of multiple types.

[0065] [Isocyanate resin] Isocyanate resins are compounds that have two or more isocyanate groups in their molecule. Examples of isocyanate resins include, but are not limited to, aromatic diisocyanates such as p-phenylenediisocyanate, m-phenylenediisocyanate, p-xylenediisocyanate, m-xylenediisocyanate, 2,4-tollylenediisocyanate, 2,6-tollylenediisocyanate, 4,4'-diphenylmethanediisocyanate, and naphthalenediisocyanate; aliphatic or alicyclic diisocyanates such as isophorone diisocyanate, hexamethylenediisocyanate, 4,4'-dicyclohexylmethanediisocyanate, hydrogenated xylenediisocyanate, norbornenediisocyanate, and lysinediisocyanate; biuret compounds of one or more isocyanate monomers; or isocyanates obtained by trimerizing the above diisocyanate compounds; and polyisocyanates obtained by urethane reaction between the above isocyanate compounds and polyol compounds. Furthermore, these can be used individually or in combination.

[0066] [Polyamide resin] Examples of polyamide resins include reaction products of one or more of diamines, diisocyanates, or oxazolines with dicarboxylic acids, reaction products of diamines and acid chlorides, and ring-opening polymers of lactam compounds. These can be used individually or in combination. Specific examples of each of the above ingredients are given below, but this list is not exhaustive. <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, dimeramine, cyclohexanediamine, bis-(4-aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)methane, xylylenediamine, norbornanediamine, isophoronediamine, bisaminomethyltricyclodecane, phenylenediamine, diethyltoluenediamine, naphthalenediamine, diaminodiphenylmethane, bis(4-amino-3,5-dimethylphenyl)methane, bis(4-amino-3,5-diethylphenyl)methane 4,4'-methylenebis-o-toluidine, 4,4'-methylenebis-o-ethylaniline, 4,4'-methylenebis-2-ethyl-6-methylaniline, 4,4'-methylenebis-2,6-diisopropylaniline, 4,4-ethylenedianiline, diaminodiphenylsulfone, diaminodiphenyl ether, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4-bis(4-aminophenoxy)biphenyl, 2,2-bis[4-(4-amino [phenoxy)phenyl]propane, bis[4-(4-aminophenoxy)phenyl]sulfone, 2,2-bis(3-amino-4-hydroxyphenyl)propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-(1,3-phenylenediisopropylidene)bisaniline, 4,4'-(1,4-phenylenediisopropylidene)bisaniline, 9,9-bis(4-aminophenyl)fluorene, 2,7-diaminofluorene, aminobenzylamine, diaminobenzophenone, etc. <Diisocyanate> Benzene diisocyanate, toluene diisocyanate, 1,3-bis(isocyanatomethyl)benzene, 1,3-bis(isocyanatomethyl)cyclohexane, bis(4-isocyanatophenyl)methane, isophorone diisocyanate, 1,3-bis(2-isocyanato-2-propyl)benzene, 2,2-bis(4-isocyanatophenyl)hexafluoropropane, dicyclohexylmethane-4,4'-diisocyanate, etc. <Dicarboxylic acid> Oxalic acid, malonic acid, succicic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanediic acid, dodecanediic acid, terephthalic acid, isophthalic acid, 5-hydroxyisophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, cyclohexanedicarboxylic acid, biphenyldicarboxylic acid, naphthalenedicarboxylic acid, benzophenonedicarboxylic acid, francicarboxylic acid, 4,4'-dicarboxydiphenyl ether, 4,4'-dicarboxydiphenyl sulfide, etc. <Acid chlorides> Acetyl chloride, acrylate chloride, methacrylate chloride, malonyl chloride, succinate dichloride, diglycolyl chloride, glutarate dichloride, suberate dichloride, sebacate dichloride, adipic acid dichloride, dodecanediol dichloride, azera oil chloride, 2,5-franzicarbonyl dichloride, phthaloyl chloride, isophthaloyl chloride, terephthaloyl chloride, trimesinate chloride, bis(4-chlorocarbonylphenyl) ether, 4,4'-diphenyldicarbonyl chloride, 4,4'-azodibenzoyl dichloride, etc. <Lactam> ε-caprolactam, ω-undecanlactam, ω-laurolactam, etc.

[0067] [Maleimide compounds] The curable resin composition of this embodiment may contain a maleimide compound. A maleimide compound is a compound having one or more maleimide groups in its molecule. Examples of maleimide compounds include 4,4'-diphenylmethanebismaleimide, polyphenylmethanemaleimide, m-phenylenebismaleimide, 2,2'-bis[4-(4-maleimoidphenoxy)phenyl]propane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, 4,4'-diphenyletherbismaleimide, 4,4'-diphenylsulfonebismaleimide, 1,3-bis(3-maleimoidphenoxy)benzene, 1,3-bis(4-maleimoidphenoxy)benzene, and Zylok-type maleimide compounds (anilix). Maleimide (manufactured by Mitsui Chemicals Fine Co., Ltd.), biphenylaralkyl type maleimide compound (solidified by solvent distillation under reduced pressure of a resin solution containing the maleimide compound (M2) described in Example 4 of Japanese Patent Publication No. 2009-001783), bisaminocumylbenzene type maleimide (maleimide compound described in International Publication No. 2020 / 054601), maleimide compound having an indan structure described in Japanese Patent No. 6629692 or International Publication No. 2020 / 217679, MATERIAL STAGE Vol. 18, No. 12 2019 "~Continued Epoxy Resin CAS Number Story~ Curing Agent CAS Number Memo No. 31 Bismaleimide (1)" and MATERIAL STAGE Vol. 19, No. 2 2019 "~Continued Epoxy Resin CAS Number Story~ Curing Agent CAS Number Memo No. 32" Examples include, but are not limited to, the maleimide compounds listed in "Bismaleimide (2)". Furthermore, these may be used individually or in combination.

[0068] [Cyanate ester resin] Cyanate ester resins are cyanate ester compounds obtained by reacting phenol resins with cyanide halides. Specific examples include, but are not limited to, dicyanatebenzene, tricyanatebenzene, dicyanatenaphthalene, dicyanatebiphenyl, 2,2'-bis(4-cyanatephenyl)propane, bis(4-cyanatephenyl)methane, bis(3,5-dimethyl-4-cyanatephenyl)methane, 2,2'-bis(3,5-dimethyl-4-cyanatephenyl)propane, 2,2'-bis(4-cyanatephenyl)ethane, 2,2'-bis(4-cyanatephenyl)hexafluoropropane, bis(4-cyanatephenyl)sulfone, bis(4-cyanatephenyl)thioether, phenol novolac cyanate, and phenol-dicyclopentadiene cocondensates in which the hydroxyl groups have been converted to cyanate groups. These compounds may be used individually or in combination. Furthermore, the cyanate ester compound whose synthesis method is described in Japanese Patent Publication No. 2005-264154 is particularly preferred as a cyanate ester compound because it has excellent low hygroscopicity, flame retardancy, and dielectric properties. Cyanate ester resins may also contain catalysts such as zinc naphthenate, cobalt naphthenate, copper naphthenate, lead naphthenate, zinc octoate, tin octoate, lead acetylacetonate, and dibutyltin maleate to trimerize the cyanate groups as needed and form sym-triazine rings.

[0069] It is preferable to use 0.0001 to 0.10 parts by mass, preferably 0.00015 to 0.0015 parts by mass, of the catalyst per 100 parts by mass of the cyanate ester resin and the curable resin composition.

[0070] [Compounds containing ethylenically unsaturated bonds] Compounds containing ethylenically unsaturated bonds are compounds that have one or more ethylenically unsaturated bonds in their molecule that can be polymerized by heat or light, regardless of whether a polymerization initiator is used or not. Compounds containing ethylenically unsaturated bonds are compounds other than the maleimide compounds mentioned above, polybutadienes described later, and their modified products. Examples of compounds containing ethylenically unsaturated bonds other than the curable resin represented by formula (1) include, but are not limited to, the reaction products of the above-mentioned phenolic resin with halogenated compounds containing ethylenically unsaturated bonds (chloromethylstyrene, allyl chloride, methyl chloride, acrylate chloride, methacrylate chloride, etc.), the reaction products of ethylenically unsaturated phenols (2-allylphenol, 2-propenylphenol, 4-allylphenol, 4-propenylphenol, eugenol, isoeugenol, etc.) with halogenated compounds (1,4-bis(chloromethyl)benzene, 4,4'-bis(chloromethyl)biphenyl, 4,4'-difluorobenzophenone, 4,4'-dichlorobenzophenone, 4,4'-dibromobenzophenone, cyanuryl chloride, etc.), the reaction products of epoxy resins or alcohols with (meth)acrylic acids (acrylic acid, methacrylic acid, etc.), and acid-modified products thereof. Furthermore, these may be used individually or in combination of multiple types.

[0071] [Benzoxazine compounds] As the benzoxazine compound, any compound obtained by reacting a compound having a phenolic hydroxyl group, a compound having an amino group, or a compound having an aldehyde group may be used. The compound having a phenolic hydroxyl group is not particularly limited, but for example, the aforementioned phenolic resins, phenols (which may have substituents such as alkenyl groups or alkyl groups), and bisphenols can be used. The compound having an amino group is not particularly limited, but for example, the aforementioned amine resins, diamines, and anilines (which may have substituents such as alkenyl groups or alkyl groups) can be used. As the aldehyde compound, for example, the aforementioned aldehydes can be used, but formaldehyde is preferred. Commercially available benzoxazine compounds may be used, including benzoxazine Pd, Fa, ALP-d (all manufactured by Shikoku Chemicals Co., Ltd.), JBZ-BA100N, JBZ-FA100N, JBZ-DP100N, JBZ-OP100N, JBZ-OP100D, JBZ-OP100I (all manufactured by JFE Chemical Corporation), and BTBz (manufactured by Nippon Materials Technology Co., Ltd.).

[0072] The curable resin composition of this embodiment can be cured on its own by heating or other means, but its performance can also be improved by adding various materials to form a curable resin composition.

[0073] [Inorganic fillers] The curable resin composition of this embodiment may contain an inorganic filler. Examples of inorganic fillers include, but are not limited to, powders such as fused silica, crystalline silica, porous silica, alumina, zircon, calcium silicate, calcium carbonate, quartz powder, silicon carbide, silicon nitride, boron nitride, zirconia, aluminum nitride, graphite, forsterite, steatite, spinel, mullite, titania, talc, clay, iron oxide, asbestos, and glass powder, or inorganic fillers made by shaping these into spheres or crushed forms. Furthermore, these may be used individually or in combination of multiple types.

[0074] When obtaining a curable resin composition for semiconductor encapsulation, the amount of inorganic filler used is preferably 80 to 92 parts by mass, and more preferably 83 to 90 parts by mass, per 100 parts by mass of the curable resin composition. Furthermore, when obtaining a curable resin composition for interlayer insulating layer forming materials, copper-clad laminates and prepregs, and substrate materials such as RCC (Resin Coated Copper), the amount of the above-mentioned inorganic filler used is preferably 5 to 80 parts by mass, and more preferably 10 to 60 parts by mass, per 100 parts by mass of the curable resin composition.

[0075] [Polymerization inhibitor] The curable resin composition of this embodiment may contain a polymerization inhibitor. Including a polymerization inhibitor improves storage stability and allows control of the reaction initiation temperature. Controlling the reaction initiation temperature makes it easier to ensure fluidity, prevents impregnation of glass cloth and the like, and facilitates B-stage processes such as prepreg formation. If the polymerization reaction proceeds too far during prepreg formation, problems such as difficulty in lamination during the lamination process are likely to occur.

[0076] The polymerization inhibitor may be added when synthesizing the curable resin of this embodiment, or after synthesis. The amount of polymerization inhibitor used is 0.008 to 1 part by mass, preferably 0.01 to 0.5 parts by mass, per 100 parts by mass of the curable resin of this embodiment.

[0077] Examples of polymerization inhibitors include phenol-based, sulfur-based, phosphorus-based, hindered amine-based, nitroso-based, and nitroxyl radical-based agents. Furthermore, polymerization inhibitors may be used individually or in combination of multiple types. Of these, phenol-based, hindered amine-based, nitroso-based, and nitroxyl radical-based agents are preferred in this embodiment.

[0078] Examples of the above phenolic polymerization inhibitors include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-p-ethylphenol, stearyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, isooctyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine, and 2,4-bis[(octylthio)methyl]-o-c Monophenols such as resols, 2,2'-methylenebis(4-methyl-6-t-butylphenol), 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol), triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] [T], N,N'-Hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 3,5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester, 3,9-bis[1,1-dimethyl-2-{β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]2,4,8,10-tetraoxaspiro[5,5]undecane, bis(3,5-di-t- Bisphenols such as calcium ethyl hydroxybenzylsulfonate, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, bis[3,3'-bis-(4'-hydroxy-3'-t-butylphenyl)butyric acid]glycol ester, tris-(3,Examples include, but are not limited to, high molecular weight phenols such as 5-di-t-butyl-4-hydroxybenzyl)-isocyanurate, 1,3,5-tris(3',5'-di-t-butyl-4'-hydroxybenzyl)-S-triazine-2,4,6-(1H,3H,5H)trione, and tocopherol.

[0079] Examples of sulfur-based polymerization inhibitors include, but are not limited to, dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, and distearyl-3,3'-thiodipropionate.

[0080] Examples of the phosphorus polymerization inhibitors mentioned above include triphenyl phosphite, diphenylisodecyl phosphite, phenyldiisodecyl phosphite, tris(nonylphenyl) phosphite, diisodecylpentaerythritol phosphite, tris(2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis(octadecyl) phosphite, cyclic neopentanetetraylbis(2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis(2,4-di-t-butyl-4-methylphenyl) phosphite, and bis[2- Examples include, but are not limited to, phosphites such as t-butyl-6-methyl-4-{2-(octadecyloxycarbonyl)ethyl}phenyl]hydrogen phosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(3,5-di-t-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0081] Examples of the above hindered amine polymerization inhibitors include Adekastab (registered trademark) LA-40MP, Adekastab LA-40Si, Adekastab LA-402AF, Adekastab LA-87, Adekastab LA-82, Adekastab LA-81, Adekastab LA-77Y, Adekastab LA-77G, Adekastab LA-72, Adekastab LA-68, Adekastab LA-63P, Adekastab LA-57, Adekastab LA-52 (all from ADE Inc.) Examples include, but are not limited to, products such as KA, Chimassorb® 2020FDL, Chimassorb 944FDL, Chimassorb 944LD, Tinuvin® 622SF, Tinuvin PA144, Tinuvin 765, Tinuvin 770DF, Tinuvin XT55FB, Tinuvin 111FDL, Tinuvin 783FDL, and Tinuvin 791FB (all manufactured by BASF).

[0082] Examples of the nitroso polymerization inhibitors mentioned above include, but are not limited to, p-nitrosophenol, N-nitrosodiphenylamine, and ammonium salts of N-nitrosophenylhydroxyamine (cuperone). Of these, ammonium salts of N-nitrosophenylhydroxyamine (cuperone) are preferred.

[0083] Examples of the above-mentioned nitroxyl radical polymerization inhibitors include, but are not limited to, di-tert-butylnitroxide, 2,2,6,6-tetramethylpiperidine-1-oxyl, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-acetoxy-2,2,6,6-tetramethylpiperidine-1-oxyl, and 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl.

[0084] [Flame retardant] The curable resin composition of this embodiment may contain a flame retardant. Examples of flame retardants include halogen-based flame retardants, inorganic flame retardants (antimony compounds, metal hydroxides, nitrogen compounds, boron compounds, etc.), and phosphorus-based flame retardants, but phosphorus-based flame retardants are preferred from the viewpoint of achieving halogen-free flame retardancy.

[0085] The phosphorus-based flame retardants mentioned above may be reactive or additive types. Specific examples include phosphate esters such as trimethyl phosphate, triethyl phosphate, tricresyl phosphate, trixyllenyl phosphate, cresyl diphenyl phosphate, cresyl-2,6-dixyllenyl phosphate, 1,3-phenylenebis(dixyllenyl phosphate), 1,4-phenylenebis(dixyllenyl phosphate), and 4,4'-biphenyl(dixyllenyl 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 resin with the active hydrogen of the above phosphanes; and red phosphorus, but are not limited to these. Furthermore, these may be used individually or in combination of multiple types. Among the above example substances, phosphate esters, phosphans, or phosphorus-containing epoxy compounds are preferred, and 1,3-phenylenebis(dixyllenyl phosphate), 1,4-phenylenebis(dixyllenyl phosphate), 4,4'-biphenyl(dixyllenyl phosphate), or phosphorus-containing epoxy compounds are particularly preferred.

[0086] The flame retardant content is preferably in the range of 0.1 to 0.6 parts by mass per 100 parts by mass of the curable resin composition. If the content is less than 0.1 parts by mass, the flame retardancy may be insufficient, and if it is more than 0.6 parts by mass, it may adversely affect the hygroscopicity and dielectric properties of the cured product.

[0087] [Light stabilizer] The curable resin composition of this embodiment may also contain a light stabilizer. Suitable light stabilizers include hindered amine light stabilizers (HALS). Examples of HALS include the reaction product of dibutylamine·1,3,5-triazine·N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine and N-(2,2,6,6-tetramethyl-4-piperidyl)butylamine, the reaction product of dimethyl-1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine succinate, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino}], bis(1,2 Examples include, but are not limited to, 2,6,6-pentamethyl-4-piperidyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis(1-octyroxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, and 2-(3,5-di-t-butyl-4-hydroxybenzyl)-2-n-butylmalonate bis(1,2,2,6,6-pentamethyl-4-piperidyl). Furthermore, these may be used individually or in combination.

[0088] The amount of light stabilizer is preferably in the range of 0.001 to 0.1 parts by mass per 100 parts by mass of the curable resin composition. If the amount is less than 0.001 parts by mass, it may be insufficient to exhibit the light stabilization effect, and if it is more than 0.1 parts by mass, it may adversely affect the hygroscopicity and dielectric properties of the cured product.

[0089] [Binder resin] The curable resin composition of this embodiment may also use a binder resin. Examples of binder resins include, but are not limited to, but include butyral resins, acetal resins, acrylic resins, epoxy-nylon resins, NBR-phenolic resins, epoxy-NBR resins, and silicone resins. Furthermore, these may be used individually or in combination of multiple types.

[0090] The amount of binder resin added is preferably within a range that does not impair the flame retardancy and heat resistance of the cured product, and is preferably 0.05 to 50 parts by mass per 100 parts by mass of the curable resin composition, and more preferably 0.05 to 20 parts by mass as needed.

[0091] [Additives] The curable resin composition of this embodiment may also contain additives. Examples of additives include modified acrylonitrile copolymers, polyethylene, fluororesins, silicone gels, silicone oils, surface treatment agents for fillers such as silane coupling agents, mold release agents, and colorants such as carbon black, phthalocyanine blue, and phthalocyanine green.

[0092] The amount of additive added is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and particularly preferably 10 parts by mass or less, per 100 parts by mass of the curable resin composition.

[0093] The curable resin composition of this embodiment may further contain polyphenylene ether compounds, polyimide resins, polybutadiene and its modified counterparts, polystyrene and its modified counterparts, polyethylene and its modified counterparts, etc., and these may be used individually or in combination of multiple types. Among these compounds, it is preferable to include polyphenylene ether compounds, compounds having ethylenically unsaturated bonds, polybutadiene and its modified counterparts, and polystyrene and its modified counterparts, based on a balance of heat resistance, adhesion, and dielectric properties. By including these compounds, the brittleness of the cured product can be improved and adhesion to metals can be enhanced, and cracks in the package can be suppressed during reliability tests such as solder reflow and thermal cycling. Unless otherwise specified, the total amount of the above compounds used 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 curable resin of this embodiment. Furthermore, the preferred lower limit is 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 staying within the above range, the effect of each added compound can be added while taking advantage of the low dielectric properties of the curable resin of this embodiment. The following examples of ingredients can be used for these components.

[0094] [Polyphenylene ether compounds] From the viewpoint of heat resistance and electrical properties, the polyphenylene ether compound is preferably a polyphenylene ether compound having an ethylenically unsaturated bond, and more preferably a polyphenylene ether compound having an acrylic group, a methacrylic group, or a styrene structure. Examples of commercially available products include SA-9000 (manufactured by SABIC, a polyphenylene ether compound having a methacrylic group) and OPE-2St 1200 (manufactured by Mitsubishi Gas Chemical Company, a polyphenylene ether compound having a styrene structure). The number-average molecular weight (Mn) of the polyphenylene ether compound is preferably 500 to 5000, more preferably 2000 to 5000, and even more preferably 2000 to 4000. If the number-average molecular weight is less than 500, the heat resistance of the cured product tends not to be sufficient. If the number-average molecular weight is greater than 5000, the melt viscosity increases, and sufficient fluidity cannot be obtained, which tends to lead to molding defects. Furthermore, the reactivity decreases, requiring a long time for the curing reaction, increasing the amount of unreacted material that is not incorporated into the curing system, lowering the glass transition temperature of the cured product, and tending to reduce the heat resistance of the cured product. If the number-average molecular weight of the polyphenylene ether compound is between 500 and 5000, it is possible to achieve excellent heat resistance and moldability while maintaining excellent dielectric properties. Specifically, the number-average molecular weight can be measured using methods such as gel permeation chromatography.

[0095] Polyphenylene ether compounds may be obtained by polymerization reactions, or by redistributing high molecular weight polyphenylene ether compounds with a number average molecular weight of approximately 10,000 to 30,000. Alternatively, these may be used as raw materials and reacted with compounds having ethylenically unsaturated bonds, such as methacrylate chloride, acrylate chloride, and chloromethylstyrene, to impart radical polymerizability. Polyphenylene ether compounds obtained by redistribution reactions can be obtained, for example, by heating a high molecular weight polyphenylene ether compound in a solvent such as toluene in the presence of a phenolic compound and a radical initiator to induce a redistribution reaction. Polyphenylene ether compounds obtained by such redistribution reactions are preferable because they maintain even higher heat resistance due to having hydroxyl groups derived from phenolic compounds that contribute to curing at both ends of the molecular chain, and because functional groups can be introduced to both ends of the molecular chain even after modification with compounds having ethylenically unsaturated bonds. Furthermore, polyphenylene ether compounds obtained by polymerization reactions are preferable because they exhibit excellent fluidity.

[0096] The molecular weight of polyphenylene ether compounds can be adjusted by adjusting polymerization conditions, etc., in the case of polyphenylene ether compounds obtained by polymerization reactions. In the case of polyphenylene ether compounds obtained by redistribution reactions, the molecular weight of the resulting polyphenylene ether compound can be adjusted by adjusting the conditions of the redistribution reaction, etc. More specifically, this can be done by adjusting the amount of phenolic compound used in the redistribution reaction. That is, the higher the amount of phenolic compound used, the lower the molecular weight of the resulting polyphenylene ether compound. In this case, poly(2,6-dimethyl-1,4-phenylene ether) can be used as the high molecular weight polyphenylene ether compound that undergoes the redistribution reaction. Furthermore, the phenolic compound used in the above redistribution reaction is not particularly limited, but polyfunctional phenolic compounds having two or more phenolic hydroxyl groups in the molecule, such as bisphenol A, phenol novolac, and cresol novolac, are preferably used. These may be used individually or in combination of two or more.

[0097] The content of the polyphenylene ether compound is not particularly limited, but is preferably 5 to 1000 parts by mass, and more preferably 10 to 750 parts by mass, per 100 parts by mass of the curable resin composition. When the content of the polyphenylene ether compound is within the above range, it is preferable not only to obtain a cured product that is excellent in heat resistance and the like, but also in that the excellent dielectric properties of the polyphenylene ether compound are fully exhibited.

[0098] [Polyimide resin] Examples of polyimide resins include, but are not limited to, the reaction products of the above-mentioned diamine and the tetracarboxylic dianhydride exemplified below. Furthermore, these can be used individually or in combination. <Tetracarboxylic acid dianhydride> 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methylcyclohexene-1,2-dicarboxylic acid anhydride, pyromellitic dianhydride, 1,2,3,4-benzenetetracarboxylic acid dianhydride, 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, 2,2',3,3'-benzophenonetetracarboxylic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic acid dianhydride, 2,2',3, 3'-Biphenyltetracarboxylic acid dianhydride, methylene-4,4'-diphthalic acid dianhydride, 1,1-ethylidene-4,4'-diphthalic acid dianhydride, 2,2'-propyridene-4,4'-diphthalic acid dianhydride, 1,2-ethylene-4,4'-diphthalic acid dianhydride, 1,3-trimethylene-4,4'-diphthalic acid dianhydride, 1,4-tetramethylene-4,4'-diphthalic acid dianhydride, 1,5-pentamethylene-4,4'-diphthalic acid dianhydride, 4,4'-oxydiphthalic acid dianhydride, thio-4,4'-diphthalic acid dianhydride, sulfonyl-4,4'-diphthalic acid Dianhydride, 1,3-bis(3,4-dicarboxyphenyl)benzene dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,3-bis[2-(3,4-dicarboxyphenyl)-2-propyl]benzene dianhydride, 1,4-bis[2-(3,4-dicarboxyphenyl)-2-propyl]benzene dianhydride, bis[3-(3,4-dicarboxyphenoxy)phenyl]methane dianhydride, bis[4-(3,4-dicarboxyphenoxy)phenyl]meth Dianhydride, 2,2-bis[3-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, bis(3,4-dicarboxyphenoxy)dimethylsilane dianhydride, 1,3-bis(3,4-dicarboxyphenyl)-1,1,3,3-tetramethyldisiloxane dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid dianhydride, 3,4,9,10-Perylenetetracarboxylic dianhydride, 2,3,6,7-Anthracenetetracarboxylic 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-Tetocarboxylic dianhydride, Cyclohexane-1,2,4,5-Tetocarboxylic dianhydride Dianhydride of 3,3',4,4'-bicyclohexyltetracarboxylic acid 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-ethylidene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 2,2-propyridene- 4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, oxy-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, thio-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, sulfonyl-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, bicyclo[2,2,2]octo-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, rel-[1S,5R,6R]-3-oxabicyclo[3,2 ,1] Octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid anhydride, ethylene glycol-bis-(3,4-dicarboxylic acid anhydride phenyl) ether, 4,4'-biphenylbis(trimellitic acid monoester anhydride), 9,9'-bis(3,4-dicarboxyphenyl)fluorene dianhydride, etc.

[0099] [Polybutadiene and its modified forms] Polybutadiene and its modified products are compounds that contain polybutadiene or a structure derived from polybutadiene within their molecule. The structure derived from polybutadiene may have some or all of its unsaturated bonds converted to single bonds by hydrogenation. Examples of polybutadiene and its modified products include, but are not limited to, polybutadiene, hydroxyl-terminated polybutadiene, terminally (meth)acrylated polybutadiene, carboxylic acid-terminated polybutadiene, amine-terminated polybutadiene, and styrene-butadiene rubber. These may be used individually or in combination. Of these, polybutadiene or styrene-butadiene rubber is preferred from the viewpoint of dielectric properties. Examples of styrene-butadiene rubber (SBR) include RICON-100, RICON-181, RICON-184 (all manufactured by Clay Valley Corporation), and 1,2-SBS (manufactured by Nippon Soda Co., Ltd.), while examples of polybutadiene include B-1000, B-2000, and B-3000 (all manufactured by Nippon Soda Co., Ltd.). The weight-average molecular weight of polybutadiene and styrene-butadiene rubber is preferably 500 to 10000, more preferably 750 to 7500, and even more preferably 1000 to 5000. Below the lower limit of the above range, the volatilization rate is high, making it difficult to adjust the solid content during prepreg preparation, and above the upper limit of the above range, compatibility with other curable resins deteriorates. Generally, in the case of compounds containing heteroatoms such as oxygen and nitrogen, such as bismaleimide and polymaleimide, it is difficult to ensure compatibility with low-polarity compounds such as compounds composed mainly of hydrocarbons or compounds composed only of hydrocarbons, due to their polarity. On the other hand, the compound of this embodiment does not have a framework design that actively incorporates heteroatoms such as oxygen and nitrogen, and therefore exhibits excellent compatibility with materials that have low polarity and low dielectric properties, as well as compounds composed only of hydrocarbons.

[0100] [Polystyrene and its modified forms] Polystyrene and its modified products are compounds that have polystyrene or a structure derived from polystyrene within their molecule. Examples of polystyrene and its modified products include polystyrene, styrene-2-isopropenyl-2-oxazoline copolymer (Epocross RPS-1005, RP-61, both manufactured by Nippon Shokubai Co., Ltd.), SEP (styrene-ethylene-propylene copolymer: Septon® 1020, manufactured by Kuraray Co., Ltd.), SEPS (styrene-ethylene-propylene-styrene copolymer: Septon 2002, Septon 2004F, Septon 2005, Septon 2006, Septon 2063, Septon 2104, all manufactured by Kuraray Co., Ltd.), SEEPS (styrene-ethylene / ethylene-propylene-styrene block copolymer: Septon 4003, Septon 4044, Septon 4055, Septon 4077, Septon 4099, all manufactured by Kuraray Co., Ltd.), and SEBS (styrene-ethylene-butylene-styrene). Examples of block copolymers include, but are not limited to, Septon 8004, Septon 8006, Septon 8007L (all manufactured by Kuraray Co., Ltd.), SEEPS-OH (a compound having hydroxyl groups at the ends of styrene-ethylene / ethylene-propylene-styrene block copolymers: Septon HG252, manufactured by Kuraray Co., Ltd.), SIS (styrene-isoprene-styrene block copolymers: Septon 5125, Septon 5127, both manufactured by Kuraray Co., Ltd.), Hydrogenated SIS (hydrogenated styrene-isoprene-styrene block copolymers: Hybler® 7125F, Hybler 7311F, both manufactured by Kuraray Co., Ltd.), SIBS (styrene-isobutylene-styrene block copolymers: SIBSTAR® 073T, SIBSTAR 102T, SIBSTAR 103T (all manufactured by Kaneka Corporation), Septon V9827 (manufactured by Kuraray Co., Ltd.)), etc. Furthermore, these can be used individually or in combination of multiple types. Polystyrene and its modified products are preferable to be those without unsaturated bonds, as they have higher heat resistance and are less susceptible to oxidative degradation. In addition, there are no particular restrictions on the weight-average molecular weight of polystyrene and its modified products as long as it is 10,000 or more, but if it is too high, the compatibility with polyphenylene ether compounds, as well as low molecular weight components with a weight-average molecular weight of about 50 to 1,000 and oligomer components with a weight-average molecular weight of about 1,000 to 5,000 deteriorates, making it difficult to ensure mixing and solvent stability. Therefore, it is preferable that it be around 10,000 to 300,000.

[0101] [Polyethylene and its modified forms] Polyethylene and its modified products refer to polyethylene or compounds having a polyethylene-derived structure within their molecules. Examples of polyethylene and its modified products include, but are not limited to, ethylene-propylene copolymers, ethylene-styrene copolymers, ethylene-propylene-ethylidene norbornene copolymers (Mitsui Chemicals EBT: K-8370EM, K-9330M, etc.), ethylene-propylene-vinyl norbornene copolymers (Mitsui Chemicals VNB-EPT: PX-006M, PX-008M, PX-009M, etc.), ethylene-vinyl alcohol copolymers, and ethylene-vinyl acetate copolymers. From the viewpoint of improving heat resistance, it is preferable to use ethylene-propylene-ethylidene norbornene copolymers or ethylene-propylene-vinyl norbornene copolymers that contain a crosslinkable structure. Furthermore, these may be used individually or in combination of multiple types. While there are no particular restrictions on the weight-average molecular weight of polyethylene and its modified products as long as it is 10,000 or more, if it is too high, the compatibility with polyphenylene ether compounds, as well as low molecular weight components with a weight-average molecular weight of about 50 to 1,000 and oligomer components with a weight-average molecular weight of about 1,000 to 5,000 deteriorates, making it difficult to ensure mixing and solvent stability. Therefore, it is preferable that the molecular weight be around 10,000 to 300,000.

[0102] [Acid anhydride] Any known compound can be used as the acid anhydride curing agent, but examples include tetrahydrophthalic anhydride (Shin-Nippon Rika Co., Ltd.: Ricacid TH), hexahydrophthalic anhydride (Shin-Nippon Rika Co., Ltd.: Ricacid HH), methyltetrahydrophthalic anhydride (Resonac Corporation: HN-2200), methylhexahydrophthalic anhydride (Shin-Nippon Rika Co., Ltd.: Ricacid MH-700), and methylnadic anhydride (Nippon Kayaku Co., Ltd.: KAYAHARD MCD, Resonac Corporation: MHAC-P).

[0103] The curable resin composition of this embodiment is obtained by preparing the above components in predetermined proportions, pre-curing at 130-180°C for 30-500 seconds, and then post-curing at 150-200°C for 2-15 hours to allow the curing reaction to proceed sufficiently and obtain the cured product of this embodiment. Alternatively, the components of the curable resin composition can be uniformly dispersed or dissolved in a solvent, and then cured after removing the solvent.

[0104] The method for preparing the curable resin composition of this embodiment is not particularly limited, but may be done by simply uniformly mixing each component or by prepolymerization. For example, prepolymerization can be performed by heating a mixture containing the curable resin of this embodiment in the presence or absence of a curing accelerator and polymerization initiator, in the presence or absence of a solvent. Similarly, prepolymerization may be performed by adding compounds such as amine compounds, compounds having ethylenically unsaturated bonds, maleimide compounds, cyanate ester compounds, polybutadiene and its modified products, polystyrene and its modified products, inorganic fillers, and other additives. Mixing or prepolymerization of each component can be performed using, for example, an extruder, kneader, or roll in the absence of a solvent, and a reaction vessel with a stirring device can be used in the presence of a solvent.

[0105] For uniform mixing, the resin composition is kneaded using equipment such as a kneader, roll, or planetary mixer at a temperature in the range of 50 to 100°C. After pulverization, the resulting resin composition can be molded into cylindrical tablets using a molding machine such as a tablet machine, or into granular powder or powdered molded bodies. Alternatively, these compositions can be melted on a surface support and molded into sheets with a thickness of 0.05 mm to 10 mm to produce curable resin composition molded bodies. The resulting molded bodies are non-sticky at 0 to 20°C and maintain almost no decrease in fluidity or curability even after storage at -25 to 0°C for more than a week. The resulting molded body can be molded into a hardened product using a transfer molding machine or a compression molding machine.

[0106] The curable resin composition of this embodiment can also be converted into a varnish-like composition (hereinafter simply referred to as varnish) by adding an organic solvent. The curable resin composition of this embodiment can be dissolved in a solvent such as toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, dimethylformamide, dimethylacetamide, or N-methylpyrrolidone as needed to form a varnish, which can then be impregnated into a substrate such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, or paper, and heated and dried to obtain a prepreg. The resulting prepreg can then be hot-press molded to obtain a cured product of the curable resin composition of this embodiment. In this case, the solvent used should account for 10 to 70% by mass, preferably 15 to 70% by mass, of the mixture of the curable resin composition of this embodiment and the solvent. Alternatively, if the composition is in liquid form, a cured resin product containing carbon fibers can be obtained directly, for example, by the RTM method.

[0107] Furthermore, the curable resin composition of this embodiment can also be used as a modifier for film-type compositions. Specifically, it can be used to improve flexibility and other properties in the B-stage. Such a film-type resin composition can be obtained as a sheet-like adhesive by applying the curable resin composition of this embodiment as a varnish onto a release film, removing the solvent under heating, and then performing the B-stage process. This sheet-like adhesive can be used as an interlayer insulating layer in multilayer substrates and the like.

[0108] The curable resin composition of this embodiment can also be heated and melted to reduce viscosity and impregnate reinforcing fibers such as glass fibers, carbon fibers, polyester fibers, polyamide fibers, and alumina fibers to obtain a prepreg. Specific examples include, but are not limited to, glass fibers such as E glass cloth, D glass cloth, S glass cloth, Q glass cloth, spherical glass cloth, NE glass cloth, and T glass cloth, as well as inorganic fibers other than glass, and organic fibers such as poly(p-phenylene terephthalamide) (Kevlar®, manufactured by DuPont), fully aromatic polyamide, polyester, poly(p-phenylene benzoxazole), polyimide, and carbon fiber. The shape of the substrate is not particularly limited, but examples include woven fabrics, nonwoven fabrics, rovings, and chopped strand mats. As for the weaving method of the woven fabric, plain weave, twill weave, etc., are known, and these can be appropriately selected and used depending on the intended application and performance. Furthermore, glass woven fabrics that have been opened or surface-treated with silane coupling agents are preferably used. The thickness of the base material is not particularly limited, but is preferably about 0.01 to 0.4 mm. Alternatively, a prepreg can be obtained by impregnating reinforcing fibers with the above varnish and then heating and drying them.

[0109] Furthermore, laminates can also be manufactured using the above-mentioned prepregs. The laminate is not particularly limited as long as it comprises one or more prepregs, and may have any other layers. The method for manufacturing the laminate is not particularly limited and can be any generally known method as appropriate. For example, when forming a metal foil laminate, a multi-stage press, a multi-stage vacuum press, a continuous molding machine, an autoclave molding machine, etc., can be used, and a laminate can be obtained by laminating the above-mentioned prepregs together and heating and pressing them. At this time, the heating temperature is not particularly limited, but 65 to 300°C is preferred, and 120 to 270°C is more preferred. The pressurizing pressure is not particularly limited, but if the pressurizing pressure is too high it is difficult to adjust the solid content of the resin in the laminate and the quality is not stable, and if the pressurizing pressure is too low it becomes difficult to form air bubbles and the adhesion between layers is poor, so 2.0 to 5.0 MPa is preferred, and 2.5 to 4.0 MPa is more preferred. The laminate of this embodiment can be suitably used as a metal foil laminate described later by comprising a layer made of metal foil. By cutting the above prepreg into the desired shape, laminating it with copper foil or other materials as needed, and then applying pressure to the laminate using methods such as press molding, autoclave molding, or sheet winding molding while heating and curing a curable resin composition, electrical and electronic laminates (printed wiring boards) and carbon fiber reinforced materials can be obtained.

[0110] The curable resin composition of this embodiment can also be made into a resin sheet. One method for obtaining a resin sheet from the curable resin composition of this embodiment is to apply the curable resin composition onto a support film (support), dry it, and then form a resin composition layer on the support film. When using the curable resin composition of this embodiment to make a resin sheet, it is important that the film softens at the lamination temperature conditions (70°C to 140°C) in the vacuum lamination method and exhibits fluidity (resin flow) that allows for simultaneous lamination of the circuit board and resin filling of via holes or through holes present in the circuit board. It is preferable to blend the above components in such a way as to exhibit such characteristics. Furthermore, in order to prevent phenomena such as locally different characteristic values ​​caused by phase separation from occurring in the resulting resin sheet or circuit board (copper-clad laminate, etc.), uniformity of appearance is required to ensure that a certain level of performance is achieved in any desired area.

[0111] Here, the diameter of the through-holes in the circuit board is 0.1 to 0.5 mm, and the depth is 0.1 to 1.2 mm. It is preferable to be able to fill the holes with resin within this range. When laminating both sides of the circuit board, it is desirable that the through-holes be filled to about half their extent.

[0112] A specific method for manufacturing the above-mentioned resin sheet is to prepare a varnished resin composition by incorporating an organic solvent, apply the varnished resin composition to the surface of a support film (Y), and then dry the organic solvent by heating or blowing hot air to form a resin composition layer (X).

[0113] The organic solvents used here preferably include ketones such as acetone, methyl ethyl ketone, and cyclohexanone; acetic acid esters such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitols such as cellosolve and butyl carbitol; aromatic hydrocarbons such as toluene and xylene; dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. It is also preferable to use the organic solvent in a proportion such that the non-volatile content is 30 to 60% by mass of the total.

[0114] Furthermore, the thickness of the formed resin composition layer (X) must be greater than or equal to the thickness of the conductive layer of the circuit board to which the resin composition layer (X) is laminated. Since the thickness of the conductive layer of the circuit board is in the range of 5 to 70 μm, it is preferable that the thickness of the resin composition layer (X) be 10 to 100 μm. In addition, the resin composition layer (X) in this embodiment may be protected by a protective film, which will be described later. By protecting it with a protective film, it is possible to prevent dust and other debris from adhering to the surface of the resin composition layer (X) and to prevent scratches.

[0115] The above-mentioned support film and protective film can be made of polyolefins such as polyethylene, polypropylene, and polyvinyl chloride, polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate, polycarbonate, polyimide, and also release paper, copper foil, aluminum foil, and other metal foils. The support film and protective film may be treated with a mat treatment, corona treatment, or release treatment. The thickness of the support film is not particularly limited, but is 10 to 150 μm, preferably in the range of 25 to 50 μm. The thickness of the protective film is preferably 1 to 40 μm.

[0116] The support film (Y) is peeled off after laminating the resin composition layer (X) onto a circuit board, or after forming an insulating layer by heat-curing the resin composition layer (X). If the support film (Y) is peeled off after the resin composition layer (X) constituting the resin sheet is heat-cured, adhesion of dust and the like during the curing step can be prevented. When the support film (Y) is peeled off after the resin composition layer (X) is cured, the support film (Y) is subjected to a release treatment in advance.

[0117] A multilayer printed circuit board can be manufactured from the resin sheet obtained as described above. For example, when the resin composition layer (X) is protected by a protective film, after peeling the protective film from the resin composition layer (X), the resin composition layer (X) is laminated on one or both sides of the circuit board so as to be in direct contact with the circuit board, for example, by a vacuum lamination method. The lamination method may be a batch method or a continuous roll method. If necessary, the resin sheet and the circuit board may be heated (preheated) before lamination. For lamination conditions, the pressure bonding temperature (lamination temperature) is preferably 70 to 140°C, and the pressure bonding pressure is 1 to 11 kgf / cm 2 (9.8×10 4 ~107.9×10 4 N / m 2 ), and lamination is preferably performed under reduced pressure with an air pressure of 20 mmHg (26.7 hPa) or less.

[0118] Furthermore, a semiconductor device can be manufactured using the curable resin composition of the present embodiment. Examples of the semiconductor device 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), TQFP (thin quad flat package), and the like.

[0119] The curable resin composition and its cured product according to this embodiment can be used in a wide range of fields. Specifically, it can be used in various applications such as molding materials, adhesives, composite materials, and paints. Because the cured product of the curable resin composition described in this embodiment exhibits excellent heat resistance and dielectric properties, it is suitably used in electrical and electronic components such as encapsulants for semiconductor devices, encapsulants for liquid crystal display devices, encapsulants for organic EL devices, laminates (printed wiring boards, BGA (ball grid array) substrates, build-up substrates, etc.), composite materials for lightweight, high-strength structural materials such as carbon fiber reinforced plastics and glass fiber reinforced plastics, and 3D printing. [Examples]

[0120] Next, the present invention will be described in more detail with reference to examples. Hereinafter, unless otherwise specified, parts refer to parts by mass. However, the present invention is not limited to these examples.

[0121] The various analytical methods used in the examples are described below.

[0122] <High-Performance Liquid Chromatography (HP-LC)> HP-LC: Liquid delivery unit (LC-20AB), online degasser (DGU-20A3), autosampler (SIL-20A), column oven (CTO-20A), system controller (CBM-20A), absorbance detector (SPD-M20A) (all manufactured by Shimadzu Corporation) Column: ODS-2 (manufactured by GL Sciences Co., Ltd.) Linking eluent: tetrahydrofuran:water = 3:1 (no gradient) Flow rate: 0.5ml / min. Column temperature: 40℃ Detection: PDA (Photodiode Array Detector)

[0123] [Synthesis Example 1] A flask equipped with a thermometer, condenser, and stirrer was purged with nitrogen, and 200 parts of DMSO, 33.3 parts of fluorene, and 24 parts of sodium hydroxide were added and stirred at 35°C for 30 minutes. Then, while maintaining the internal temperature below 40°C, 58.0 parts of CMS-P (AGC Seimi Chemical Co., Ltd., a mixture of 4-chloromethylstyrene and 3-chloromethylstyrene, 4-chloromethylstyrene:3-chloromethylstyrene = 1:1 (mol ratio), purity 95.59 wt%) were added dropwise over 1 hour and reacted at 40°C for 20 hours. 200 parts of methanol and 100 parts of water were added to crystallize, and the crystals were collected by filtration. The collected crystals were dissolved in 200 parts of toluene, and the organic layer was washed five times with 100 parts of water. The obtained organic layer was concentrated to obtain 56.4 parts of curable resin (O-1). The HP-LC chart of the obtained curable resin (O-1) is shown in Figure 1. The olefin equivalent calculated from the structural formula was 199 g / eq.

[0124] [ka]

[0125] [Examples 1-3, Comparative Examples 1-3] Using the curable resin (O-1) obtained in Synthesis Example 1 and the individual components in the amounts shown in Table 1, the mixture was combined. A portion of the resulting varnish was placed in an aluminum cup and heated in an inert oven at 120°C for 10 minutes. After drying the solvent, it was cured at 220°C for 2 hours. The cured product obtained was then used for evaluation.

[0126] <Dielectric constant test / Dielectric loss tangent test> Tests were conducted using a 10GHz cavity resonator manufactured by AET Co., Ltd. at 25°C using the cavity resonator perturbation method. The sample size was 1.7 mm wide x 100 mm long with a thickness of 0.1 mm. The evaluation results are shown in Table 1.

[0127] <Thermal decomposition temperature (Td5)> Using a differential thermal-thermogravimetric analyzer, the temperature was increased from 30°C to 580°C, and the temperature at which the weight decreased by 5% from the initial value was determined.

[0128] [Table 1]

[0129] • NC-3000: Biphenyl aralkyl type epoxy resin, manufactured by Nippon Kayaku Co., Ltd. • MI-1: MIR-3000-70MT (manufactured by Nippon Kayaku Co., Ltd., maleimide compound) • P-1: KAYAHARD GPH-65 (manufactured by Nippon Kayaku Co., Ltd., biphenyl aralkyl type phenolic resin) • MDEA: 4,4'-Methylenebis(2-ethyl-6-methylaniline) (manufactured by Tokyo Chemical Industry Co., Ltd.) • BisA-OCN:CYTESTER TA (manufactured by Mitsubishi Gas Chemical Company, bisphenol A type cyanate resin) • E-1: Active ester resin (solid product with solvent removed) as described in Synthesis Example 1 of Japanese Patent Publication No. 2009-235165 • BO-1: Benzoxazine Pd (manufactured by Shikoku Chemicals Co., Ltd., a benzoxazine compound) • DICY: Dicyandiamide (manufactured by Tokyo Chemical Industry Co., Ltd.) TPP: Triphenylphosphine (manufactured by Tokyo Chemical Industry Co., Ltd.) • 2E4MZ: 2-Ethyl-4-methylimidazole (manufactured by Shikoku Chemicals Co., Ltd.) • Octop Zn: 18% Octop Zn (manufactured by Hope Pharmaceutical Co., Ltd., curing accelerator) • SI-B5: San-Aid SI-B5 (manufactured by Sanshin Chemical Co., Ltd., curing accelerator)

[0130] The results in Table 1 confirm that the curable resin composition of the present invention exhibits excellent resistance to thermal decomposition. [Industrial applicability]

[0131] The curable resin of the present invention is suitably used in electrical and electronic components such as semiconductor encapsulants, printed circuit boards, build-up laminates, optical waveguide devices, and redistribution layers.

[0132] [Note] As described above, this embodiment includes the following disclosures.

[0133] [1] A curable resin composition comprising a curable resin represented by formula (1), and one or more of the following: epoxy resin, active ester compound, phenol resin, amine resin, compound having an ethylenically unsaturated bond, isocyanate resin, polyamide resin, maleimide compound, cyanate ester resin, and benzoxazine compound.

[0134] [ka]

[0135] (In formula (1), each of the multiple R1s independently represents a hydrocarbon group having 1 to 5 carbon atoms. Each of the multiple R2s independently represents a hydrocarbon group having 1 to 5 carbon atoms or a structure represented by formula (1-1) below. Each of the multiple l and m are independent integers from 0 to 4.)

[0136] [ka]

[0137] (In formula (1-1), * represents the bond position to the fluorene structure in formula (1). Each of the multiple R3s independently represents a hydrocarbon group having 1 to 5 carbon atoms. E1 represents a direct bond or a methylene group. E2 and E3 represent a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group. p represents an integer from 0 to 2, and q represents an integer from 0 to 5.) [2] Furthermore, the curable resin composition according to [1] contains one or more curing accelerators and polymerization initiators. [3] A curable resin composition comprising a curable resin represented by formula (1), an epoxy resin, and a curing accelerator.

[0138] [ka]

[0139] (In formula (1), each of the multiple R1s independently represents a hydrocarbon group having 1 to 5 carbon atoms. Each of the multiple R2s independently represents a hydrocarbon group having 1 to 5 carbon atoms or a structure represented by formula (1-1) below. Each of the multiple l and m are independent integers from 0 to 4.)

[0140] [ka]

[0141] (In formula (1-1), * represents the bond position to the fluorene structure in formula (1). Each of the multiple R3s independently represents a hydrocarbon group having 1 to 5 carbon atoms. E1 represents a direct bond or a methylene group. E2 and E3 represent a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group. p represents an integer from 0 to 2, and q represents an integer from 0 to 5.) [4] The curable resin composition according to [3] further contains an active ester compound. [5] The curable resin composition according to [3] or [4] further contains one or more of the following: a phenolic resin, an amine resin, a compound having an ethylenically unsaturated bond, a maleimide compound, a cyanate ester resin, or a benzoxazine compound. [6] A curable resin composition according to any one of [1] to [5], further containing an inorganic filler. [7] A cured product obtained by curing any of the cured resin compositions described in [1] to [6].

Claims

1. A curable resin composition comprising a curable resin represented by formula (1), and one or more of the following: epoxy resin, active ester compound, phenol resin, amine resin, compound having an ethylenically unsaturated bond, isocyanate resin, polyamide resin, maleimide compound, cyanate ester resin, and benzoxazine compound. 【Chemistry 1】 (In equation (1), there are multiple R １ Each of these independently represents a hydrocarbon group with 1 to 5 carbon atoms. There are multiple R's. ２ Each of these is an independent hydrocarbon group having 1 to 5 carbon atoms or a structure represented by the following formula (1-1). The multiple l and m values ​​are each independent integers from 0 to 4. 【Chemistry 2】 (In equation (1-1), * represents the bonding position to the fluorene structure of equation (1). Multiple Rs exist.) ３ Each of these independently represents a hydrocarbon group having 1 to 5 carbon atoms. １ E represents a direct bond or a methylene group. ２ and E ３ (where p represents a hydrogen atom, a hydrocarbon group with 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group; where p represents an integer from 0 to 2, and q represents an integer from 0 to 5.)

2. Furthermore, the curable resin composition according to claim 1, further containing one or more of a curing accelerator and a polymerization initiator.

3. A curable resin composition comprising a curable resin represented by formula (1), an epoxy resin, and a curing accelerator. 【Transformation 3】 (In equation (1), there are multiple R １ Each of these independently represents a hydrocarbon group with 1 to 5 carbon atoms. There are multiple R's. ２ Each of these is an independent hydrocarbon group having 1 to 5 carbon atoms or a structure represented by the following formula (1-1). The multiple l and m values ​​are each independent integers from 0 to 4. 【Chemistry 4】 (In formula (1-1), * represents a bonding position to the fluorene structure of formula (1). A plurality of R ３ each independently represent a hydrocarbon group having 1 to 5 carbon atoms. E １ represents a direct bond or a methylene group. E ２ and E ３ represent a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenyl group. p represents an integer of 0 to 2, and q represents an integer of 0 to 5.)

4. The curable resin composition according to claim 3, further containing an active ester compound.

5. The curable resin composition according to claim 3 or 4, further comprising one or more of the following: a phenolic resin, an amine resin, a compound having an ethylenically unsaturated bond, a maleimide compound, a cyanate ester resin, and a benzoxazine compound.

6. The curable resin composition according to claim 2 or 3, further containing an inorganic filler.

7. A cured product obtained by curing the cured resin composition according to claim 2 or 3.

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