Curable resin, curable resin composition, and cured product thereof

Abstract

To provide a curable resin with sufficiently low dielectric loss tangent, and a curable resin composition.SOLUTION: The present invention provides a curable resin represented by formula (1). (In formula (1), A represents a methylene group, a dicyclopentadiene group, a xylylene group, or a 4,4-dimethylene biphenyl group, and X represents a styryl group or (meth)acryloyl group. A plurality of R1 moieties independently represent an oligostyrene residue, a plurality of R2 moieties independently represent a C1-10 hydrocarbon group, a C1-6 alkoxy group, an amino group, or a hydroxy group.)SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a curable resin, a curable resin composition, and a cured product thereof, and is suitably used in electrical and electronic components such as semiconductor encapsulants, printed circuit boards, and build-up laminates.

[0002] Due to its versatility, curing properties, and excellent balance of characteristics, epoxy resins are widely used as an important component of film-type adhesives in various fields, particularly in the electrical and electronic fields, where they are used in interlayer insulating layers of printed circuit boards and in resin-coated copper foil.

[0003] In the currently accelerating development of the fifth-generation communication system "5G," further increases in capacity and speed of communication are expected, and the need for low-dielectric materials is increasing. Furthermore, the attenuation rate of signals flowing through the dielectric material that makes up printed circuit boards is proportional to the dielectric loss tangent (tanδ). Since signal attenuation directly translates into heat generation and causes a temperature rise, a low dielectric loss tangent is particularly important for printed circuit board materials (Non-Patent Literature 1). However, when epoxy resins use phenol or amine as a curing agent, due to their reaction mechanism, hydroxyl groups are generated during the curing reaction, which tends to worsen water absorption and electrical properties.

[0004] In light of this situation, maleimide compounds and polyphenylene ethers have recently been investigated as printed circuit board materials for high-frequency applications. Maleimide compounds themselves have the characteristic of high heat resistance due to their high crosslinking density, but on the other hand, they have the problem of being more susceptible to water absorption than epoxy resins, and their properties tend to deteriorate due to water absorption (Patent Document 1). Patent Document 2 discloses a curable resin composition comprising a polyphenylene ether oligomer having specific vinyl groups at both ends, and a polyfunctional vinyl aromatic copolymer having structural units derived from monomers consisting of divinyl aromatic compounds and ethyl vinyl aromatic compounds. However, it has the drawback that the dielectric loss tangent deteriorates after thermal oxidation degradation tests, making it unsuitable for use as a substrate material in the field of advanced electronic equipment (Patent Document 3). [Prior art documents]

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Non-Patent Documents

[0006]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The present invention has been made in view of the above points, and an object thereof is to provide a curable resin having an excellent low dielectric loss tangent, and a curable resin composition.

Means for Solving the Problems

[0008] That is, the present invention relates to the following [1] to

[14] . In the present invention, the expression "(numerical value 1) to (numerical value 2)" indicates that the upper and lower limit values are included. [1] A curable resin represented by the following formula (1).

[0009]

Chemical Formula

[0010] (In formula (1), A represents one of the following formulas (1-a) to (1-d), and X represents one of the following formulas (1-e) to (1-g). Each of the multiple R1s independently represents a substituent represented by the following formula (1-h). Each of the multiple R2s independently represents a hydrocarbon group having 1 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an amino group, or a hydroxyl group. Each p is a real number from 0 to 3, and the average value of the multiple ps is p ave is 0 <p ave The limit is ≤ 3. Each q is a real number between 0 and 3, and the average value of multiple qs is q. ave is 0≦q ave <3. The sum of p and q present in the same aromatic ring is 3 or less. n is the number of repetitions, and the mean value of n is n. ave is 1≦n ave (≤ 5.)

[0011] [ka]

[0012] (In formulas (1-a) to (1-d), each of the multiple R3 atoms independently represents either a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. The dashed lines indicate the bonding sites to the benzene ring in formula (1).)

[0013] [ka]

[0014] (In equations (1-e) to (1-g), the wavy lines indicate the bonding sites to the oxygen atom in equation (1).)

[0015] [ka]

[0016] (In formula (1-h), each of the multiple R4s independently represents a hydrocarbon group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an amino group, or a hydroxyl group. Each r is a real number from 0 to 5, and the average value of the multiple r's is r.) aveis 0≦r ave ≦5. m is the number of repetitions, and the average value of m, m ave is 1≦m ave ≦10. The wavy line indicates the bonding site to the benzene ring in formula (1).) [2] The curable resin according to the preceding item [1], wherein in the formula (1), A is the formula (1-a), and R3 is a hydrogen atom. [3] A curable resin composition comprising the curable resin according to the preceding item [1] or [2]. [4] The curable resin composition according to the preceding item [3], further comprising an active ester compound. [5] The curable resin composition according to the preceding item [3] or [4], further comprising a maleimide compound. [6] The curable resin composition according to any one of the preceding items [3] to [5], further comprising an inorganic filler. [7] The curable resin composition according to any one of the preceding items [3] to [6], further comprising a curing accelerator. [8] The curable resin composition according to any one of the preceding items [3] to [7], further comprising a polymerization initiator. [9] A cured product of the curable resin composition according to any one of the preceding items [3] to [8].

[10] A resin sheet comprising the curable resin composition according to any one of the preceding items [3] to [8] and a support.

[11] A cured product of the resin sheet according to the preceding item

[10] .

[12] An insulating layer formed from the cured product according to the preceding item [9] or

[10] .

[13] A printed wiring board comprising the insulating layer according to the preceding item

[12] .

[14] A semiconductor device comprising the printed wiring board according to the preceding item

[13] . [Advantageous Effects of the Invention]

[0017] According to the present invention, it is possible to provide a curable resin having excellent low dielectric loss tangent, a curable resin composition, and cured products thereof, an insulating layer, a printed wiring board, and a semiconductor device. [Brief explanation of the drawing]

[0018] [Figure 1] The GPC chart for synthesis example 1 is shown. [Figure 2] The GPC chart for synthesis example 2 is shown. [Figure 3] The 1H-NMR chart for synthesis example 2 is shown. [Figure 4] The GPC chart for the raw materials in synthesis example 2 is shown. [Figure 5] The GPC chart for synthesis example 3 is shown. [Figure 6] The 1H-NMR chart for synthesis example 3 is shown. [Figure 7] The GPC chart for synthesis example 4 is shown. [Figure 8] The IR chart for synthesis example 4 is shown. [Figure 9] The GPC chart for comparative synthesis example 1 is shown. [Figure 10] The 1H-NMR chart for comparative synthesis example 1 is shown. [Figure 11] The GPC chart for comparative synthesis example 2 is shown. [Figure 12] The IR chart for comparative synthesis example 2 is shown. [Modes for carrying out the invention]

[0019] The curable resin composition of this embodiment contains a curable resin represented by the following formula (1).

[0020] [ka]

[0021] In formula (1), A represents one of the following formulas (1-a) to (1-d), preferably (1-a). X represents one of the following formulas (1-e) to (1-g). Each of the multiple R1s independently represents a substituent represented by the following formula (1-h). Each of the multiple R2s independently represents a hydrocarbon group having 1 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an amino group, or a hydroxyl group. Each p is a real number from 0 to 3, and the average value of the multiple ps is p ave is 0 <p ave The limit is ≤ 3. Furthermore, there are multiple possible values ​​of q, all of which are real numbers between 0 and 3, and the mean value of q is q. ave is 0≦q ave < 3. n is a real number between 1 and 20. The mean value of n is n. ave is 1≦n ave The limit is 5.

[0022] [ka]

[0023] In formulas (1-a) to (1-d), each of the multiple R3 atoms independently represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, preferably a hydrogen group or a methyl group. The dashed lines indicate the bonding site to the benzene ring in formula (1).

[0024] [ka]

[0025] In equations (1-e) to (1-g), the wavy lines indicate the bonding sites to the oxygen atom in equation (1).

[0026] [ka]

[0027] In formula (1-h), each of the multiple R4s independently represents a hydrocarbon group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an amino group, or a hydroxyl group, and it is preferable that each R4 is a hydrocarbon group having 1 to 6 carbon atoms. Each r is a real number from 0 to 5, and the average value of the multiple r's is r. ave is 0 ≤ r ave The value is ≤ 5. m is a real number between 1 and 20, and the mean value of m is m ave is 1 ≤ m ave The value is ≤10. The dashed lines indicate the bonding sites to the benzene ring in equation (1).

[0028] The compound represented by formula (1) above is derived from the compound represented by formula (2) below.

[0029] [ka]

[0030] In equation (2), A, R1, R2, n, p, and q have the same meanings as in equation (1).

[0031] The compound represented by formula (2) can be obtained by an addition reaction between a polyvalent hydroxy resin represented by formula (3) and a compound represented by formula (4).

[0032] [ka]

[0033] In equation (3), A, R2, n, and q have the same meanings as in equation (1).

[0034] [ka]

[0035] In equation (4), R4, m, and r have the same meanings as in equation (1-h) above.

[0036] In equations (1) to (4) above, the value of n can be calculated from the number-average molecular weight obtained by gel permeation chromatography (GPC, detector: RI) of the polyvalent hydroxy resin represented by equation (3), or from the area ratio of each separated peak. n is a real number between 1 and 20. The average value of n is n ave is 1≦n ave Preferably, ≤ 5, and 1 ≤ n ave It is more preferable that ≤ 3, and 1 <n ave It is particularly preferable that the value be ≤ 3.

[0037] In this embodiment, gel permeation chromatography analysis is performed under the following conditions.

[0038] • GPC (Gel Permeation Chromatography) Analysis Manufacturer: Waters Columns: Guard columns SHODEX GPC KF-601 (2 pieces), KF-602, KF-602.5, KF-603 Flow rate: 1.23ml / mIn. Column temperature: 25℃ Solvent used: THF (tetrahydrofuran) Detector: RI (Differential Refraction Detector)

[0039] In equations (1) and (2) above, the mean value of p is p ave The value of p can be calculated from the charging ratio, or from the hydroxyl group equivalent of the polyvalent hydroxy resin represented by formula (2), the hydroxyl group equivalent of the polyvalent hydroxy resin represented by formula (3), which is its raw material, and the ethylenic double bond equivalent of the polystyrene represented by formula (4). Multiple values ​​of p exist, and they are real numbers from 0 to 3. The average value of p is p. ave is 0 <p ave Preferably, ≤ 3, 0 <p ave It is more preferable that ≤ 2, and 0.3 ≤ <p ave It is particularly preferable that ≤ 1.5. Furthermore, multiple values ​​of q exist, and the mean value of q is q. ave is 0≦q ave It is preferable that <3, and 0≦q aveIt is even more preferable that p ≤ 1. ave If p is 0, properties such as dielectric loss tangent remain unimproved, ave If the number is greater than 3, the functional group density tends to become too low, resulting in reduced curability. Also, q ave If the value is 3 or higher, the functional group density tends to become too high, leading to a decrease in curability.

[0040] In equations (1-h) and (4) above, the average value of m is m ave The value of m can be calculated from the number-average molecular weight obtained by measuring polystyrene gel permeation chromatography (GPC, detector: RI) represented by formula (4) above, or from the area ratio of each separated peak. m is a real number between 1 and 20, and the average value of m is m ave is 1 ≤ m ave Preferably, ≤10, and 1 ≤ m ave It is even more preferable that ≤ 5. Multiple values ​​of r exist, and the mean value of r is r. ave is 0 ≤ r ave Preferably, ≤ 5, and 0 ≤ r ave It is even more preferable that m ≤ 1. ave If it is less than 1, properties such as dielectric loss tangent remain unimproved, and m ave If the number is greater than 10, the functional group density tends to become too low, resulting in reduced curability.

[0041] The compound represented by formula (2) can be obtained by adding the compound represented by formula (4) to the phenolic aromatic ring of the polyvalent hydroxy resin represented by formula (3). The hydroxyl group equivalent can be arbitrarily adjusted by the charging ratio. Here, adding the compound represented by formula (4) means substituting the hydrogen of the benzene ring of the polyvalent hydroxy resin represented by formula (3) with the substituent represented by formula (1-h). Adding the substituent represented by (1-h) reduces the proportion of polar functional groups, which is effective in further improving the low dielectric loss tangent.

[0042] The compound represented by formula (1) can be obtained, for example, by dehalogenating the compound represented by formula (2) in a solvent in the presence of a basic catalyst. Examples of solvents that can be used include, but are not limited to, water-insoluble solvents such as aromatic solvents like toluene and xylene, aliphatic solvents like cyclohexane and n-hexane, ethers like diethyl ether, diisopropyl ether, and 4-methyltetrahydropyran, ester solvents like ethyl acetate and butyl acetate, and ketone solvents like methyl isobutyl ketone and cyclopentanone, and two or more may be used in combination. In addition to the water-insoluble solvent, an aprotic polar solvent may also be used in combination. Examples include dimethyl sulfone, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, and N-methylpyrrolidone, and two or more may be used in combination. When using an aprotic polar solvent, it is preferable to use one with a higher boiling point than the water-insoluble solvent used in combination. The catalyst is not particularly limited, but examples include basic catalysts such as sodium hydroxide, potassium hydroxide, and potassium carbonate. Since it is difficult to completely carry out the dehalogenation reaction, a large excess of aprotic polar solvent relative to the substrate may be used, and the dehalogenation reaction may be repeated two or three or more times. For example, the dehalogenation reaction of the compound represented by formula (2) may be carried out in an organic solvent in the presence of a base catalyst, the resulting solution may be washed with water, returned to the reaction vessel, and the base catalyst added to carry out the reaction again. This can increase the progress of the dehalogenation reaction, that is, it is possible to reduce the amount of residual halogen contained in the target compound.

[0043] The curable resin represented by formula (1) above can also be purified using known methods. The purification method is not particularly limited, but examples include separatory water washing and reprecipitation using a poor solvent. Adding a purification step can remove phenolic hydroxyl groups derived from the raw materials and alcoholic hydroxyl groups purified during the reaction, thereby improving the low dielectric loss tangent.

[0044] The method for producing the compound represented by formula (2) is not particularly limited, but it is common to either charge all the raw materials together and react them at a predetermined temperature, or to charge the polyvalent hydroxy resin represented by formula (3) and the catalyst, and react them while maintaining a predetermined temperature and dropping the compound represented by formula (4) dropwise. In this case, the dropping time is usually 1 to 10 hours. After the reaction, if a solvent is used, the catalyst component can be removed as needed, and the solvent can be distilled off to obtain the resin used in this embodiment. If no solvent is used, the target product can be obtained by directly discharging the heat.

[0045] The method for producing the compound represented by formula (4) is not particularly limited, but it can be obtained by polymerization using known methods. Cationic polymerization using an acid is preferred in order to efficiently impart reactive unsaturated double bonds to the ends of the main chain. The acid catalyst is not particularly limited, but it is even more preferable to use a cation exchange resin in order to control the molecular weight distribution to have excellent solvent solubility and handling properties. When using a solvent, it is preferable to use one that does not react with styrene, such as cyclohexane.

[0046] [Epoxy resin] The curable resin composition of this embodiment may contain an epoxy resin. Preferred epoxy resins are exemplified below, but are not limited to these. These may be used individually or in combination.

[0047] Among the epoxy resins mentioned above, 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. Of these, bisphenol A type epoxy resin is particularly preferred. 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), "HP4032", "HP4032D", "HP4032SS" (all manufactured by DIC Corporation, naphthalene type epoxy resin), "828US", "jER828EL", "825", "828EL" (all manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin), "jE807", "1750" (both manufactured by Mitsubishi Chemical Corporation, bisphenol F type epoxy resin), and "jER152" (manufactured by Mitsubishi Chemical Corporation, phenol Examples include novolac-type epoxy resins, "630", "630LSD" (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 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.

[0048] Among the epoxy resins mentioned above, 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. Examples of naphthol-type epoxy resin, bisphenol AF-type epoxy resin, naphthalene-type epoxy resin, and biphenyl-type epoxy resin can be cited.Specific examples include "HP4032H" (manufactured by DIC, naphthalene-type epoxy resin), "HP-4700", "HP-4710" (both manufactured by DIC, naphthalene-type tetrafunctional epoxy resins), "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 resins). (Fat), "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 (Larkyl type epoxy resin), "XD-1000-2L", "XD-1000-L", "XD-1000-H", "XD-1000-H" (all manufactured by Nippon Kayaku Co., Ltd., dicyclopentadiene type epoxy resin), "ESN475V" (manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., naphthol type epoxy resin), "ESN485" (manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., naphthol novolac type epoxy resin), "YX-4000H", "YX-4000", "YL6121" (all manufactured by Mitsubishi Chemical Corporation, biphenyl type epoxy resin), "YX-4000HK" (manufactured by Mitsubishi Chemical Corporation, biphenyl type epoxy resin) Examples include lenol-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.

[0049] [Activated ester compounds] The curable resin composition of this embodiment may contain an active ester compound. An active ester compound is a compound that contains at least one ester bond in its structure, and on both sides of the ester bond, an aliphatic chain, an aliphatic ring, or an aromatic ring is bonded. For example, compounds having two or more highly reactive ester groups in one molecule can be cited, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. These can be obtained by a condensation reaction between at least one compound of a carboxylic acid compound, an acid chloride, or a thiocarboxylic acid compound and at least one compound of a hydroxy compound or a thiol compound. In particular, from the viewpoint of improving heat resistance, it is preferable that the compound is obtained from a carboxylic acid compound or an acid chloride and a hydroxy compound, and as the hydroxy compound, a phenol compound or a naphthol compound is preferred. Furthermore, it is preferable that the active ester compound has a vinyl group. Examples of active ester compounds having a vinyl group include the compound described in Example 2 of International Publication No. 2020 / 095829 and the compounds disclosed in International Publication No. 2020 / 059625. These may be used individually or in combination of two or more.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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, and active ester compounds containing a benzoylated phenol novolac. 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.

[0054] 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 naphthalene structure, and "EXB9416-70BK" (manufactured by DIC Corporation), and phenol novola Examples of active ester compounds containing acetylated phenol novolacs include "DC808" (manufactured by Mitsubishi Chemical Corporation), examples of active ester compounds containing benzoylated phenol novolacs include "YLH1026", "YLH1030", and "YLH1048" (manufactured by Mitsubishi Chemical Corporation), examples of active ester curing agents that are acetylated phenol novolacs include "DC808" (manufactured by Mitsubishi Chemical Corporation), and examples of phosphorus atom-containing active ester curing agents include "EXB-9050L-62M" manufactured by DIC Corporation.

[0055] [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.

[0056] The amount of maleimide compound added is preferably 10 times or less by mass, more preferably 5 times or less by mass, and particularly preferably 3 times or less by mass, relative to the compound represented by formula (1). The preferred lower limit is 0.01 times or more by mass, and more preferably 0.1 times or more by mass. Within the above range, the low dielectric loss tangent and low water absorption effects of the compound represented by formula (1) can be utilized.

[0057] [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.

[0058] 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, prepregs, RCCs, and other substrate materials, 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.

[0059] [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 heating, or cationic curing accelerators that promote the curing reaction by generating cations upon heating.

[0060] 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.

[0061] 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.

[0062] The amount of curing accelerator used is 0.01 to 5.0 parts by mass per 100 parts by mass of the curable resin of this embodiment, as needed.

[0063] [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 heating and initiates a chain polymerization reaction. Examples of radical polymerization initiators that can be used include organic peroxides, azo compounds, and benzopinacols, and it is preferable to use organic peroxides because they have less influence on curing temperature control, outgassing suppression, and the electrical properties of decomposition products.

[0064] 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.

[0065] 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.

[0066] 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, the low dielectric loss tangent properties may be impaired.

[0067] [Polymerization inhibitor] The curable resin composition of this embodiment may contain a polymerization inhibitor. Including a polymerization inhibitor improves storage stability and allows control of the reaction initiation temperature. Controlling the reaction initiation temperature makes it easier to ensure fluidity, prevents impregnation into glass cloth and other materials, 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.

[0068] The polymerization inhibitor may be added when synthesizing the compound represented by formula (1) 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 compound represented by formula (1).

[0069] 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.

[0070] 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.

[0071] Examples of sulfur-based polymerization inhibitors include, but are not limited to, dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, and distearylul-3,3'-thiodipropionate.

[0072] 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 neopentanetetraylbi(2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbi(2,4-di-t-butyl-4-methylphenyl) phosphite, and bis[2-t Examples include, but are not limited to, phosphites such as -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.

[0073] Examples of the above hindered amine polymerization inhibitors include Adekastab LA-40MP, Adekastab LA-40SI, Adekastab LA-402AF, Adekastab LA-87, Adekastab LA-82, Adekastab LA-81, Adekastab LA-77Y, Adekastab LA-77G, Adekastab LA-72, Adekastab LA-68, Adekastab LA-63P, Adekastab LA-57, and Adekastab L Examples include, but are not limited to, A-52, ChImassorb2020FDL, ChImassorb944FDL, ChImassorb944LD, TInuvIn622SF, TInuvInPA144, TInuvIn765, TInuvIn770DF, TInuvInXT55FB, TInuvIn111FDL, TInuvIn783FDL, TInuvIn791FB, etc.

[0074] Examples of the nitroso polymerization inhibitors mentioned above include, but are not limited to, p-nitrosophenol, N-nitrosodiphenylamine, ammonium salts of N-nitrosophenylhydroxyamine, and (cuperone). Of these, ammonium salts of N-nitrosophenylhydroxyamine (cuperone) are preferred.

[0075] 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.

[0076] [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. 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, trixylenyl phosphate, cresyl diphenyl phosphate, cresyl-2,6-dixylenyl phosphate, 1,3-phenylenebis(dixylenyl phosphate), 1,4-phenylenebis(dixylenyl phosphate), and 4,4'-biphenyl(dixylenyl phosphate); phosphanes such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 10(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide; phosphorus-containing epoxy compounds obtained by reacting epoxy resin with the active hydrogen of the aforementioned 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(dixylenyl phosphate), 1,4-phenylenebis(dixylenyl phosphate), 4,4'-biphenyl(dixylenyl phosphate), or phosphorus-containing epoxy compounds are particularly preferred.

[0077] The flame retardant content is preferably in the range of 0.1 to 0.6 parts by mass, when the total non-volatile content of the curable resin composition, excluding inorganic fillers, is taken as 100 parts by mass. 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 low dielectric loss tangent of the cured product.

[0078] [Light stabilizer] The curable resin composition of this embodiment may also contain a light stabilizer. Suitable light stabilizers include hindered amine-based light stabilizers, particularly 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.

[0079] The amount of light stabilizer is preferably in the range of 0.001 to 10 parts by mass, when the total amount of nonvolatile matter excluding inorganic fillers in the curable resin composition is 100 parts by mass. 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 10 parts by mass, it may adversely affect the hygroscopicity and low dielectric loss tangent of the cured product.

[0080] [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.

[0081] 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. When the total amount of the curable resin composition is 100 parts by mass, the amount is preferably 0.05 to 50 parts by mass, and more preferably 0.05 to 20 parts by mass.

[0082] [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.

[0083] The amount of additive added is preferably 1,000 parts by mass or less, and more preferably 700 parts by mass or less, per 100 parts by mass of the curable resin composition.

[0084] The curable resin composition of this embodiment may further contain phenolic resins, polyphenylene ether compounds, amine resins, compounds having ethylenically unsaturated bonds, isocyanate resins, polyamide resins, polyimide resins, cyanate ester resins, polybutadiene and its modified counterparts, polystyrene 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, cyanate ester resins, polybutadiene and its modified counterparts, polystyrene and its modified counterparts, in order to balance heat resistance, adhesion, and low dielectric loss tangent. By including these compounds, the brittleness of the cured product can be improved and adhesion to metal can be enhanced, and cracks in the package can be suppressed during reliability tests such as solder reflow and thermal cycling.

[0085] Unless otherwise specified, the amount of the above-mentioned compounds used is preferably 10 times or less by mass, more preferably 5 times or less by mass, and most preferably 3 times or less by mass, relative to the curable resin composition. 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. Within this range, the effect of each added compound can be added while taking advantage of the low dielectric loss tangent effect of the curable resin composition of this embodiment. Examples of these components can be used as shown below.

[0086] [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.

[0087] [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 molecular weight is less than 500, the heat resistance of the cured product tends not to be sufficient. If the molecular weight is greater than 5000, the melt viscosity increases, and sufficient fluidity cannot be obtained, which tends to lead to molding defects. In addition, the reactivity decreases, the curing reaction takes a long time, the amount of unreacted material that is not incorporated into the curing system increases, the glass transition temperature of the cured product decreases, and the heat resistance of the cured product tends to decrease. 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 a low dielectric loss tangent. Specifically, the number-average molecular weight can be measured using methods such as gel permeation chromatography.

[0088] 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 methacrylic chloride, acrylic 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.

[0089] The molecular weight of polyphenylene ether compounds can be adjusted by adjusting polymerization conditions, etc., in the case of polyphenylene ether compounds obtained by polymerization reactions. In the case of polyphenylene ether compounds obtained by redistribution reactions, the molecular weight of the resulting polyphenylene ether compound can be adjusted by adjusting the conditions of the redistribution reaction, etc. More specifically, this can be done by adjusting the amount of phenolic compound used in the redistribution reaction. That is, the higher the amount of phenolic compound used, the lower the molecular weight of the resulting polyphenylene ether compound. In this case, poly(2,6-dimethyl-1,4-phenylene ether) can be used as the high molecular weight polyphenylene ether compound that undergoes the redistribution reaction. Furthermore, the phenolic compound used in the redistribution reaction is not particularly limited, but polyfunctional phenolic compounds having two or more phenolic hydroxyl groups in the molecule, such as bisphenol A, phenol novolac, and cresol novolac, are preferably used. These may be used individually or in combination of two or more.

[0090] 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, when the total mass of the curable resin composition is 100 parts by mass. 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 terms of heat resistance, etc., but also in that the excellent low dielectric loss tangent of the polyphenylene ether compound is fully exhibited.

[0091] [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, aniline and substituted biphenyls (such as 4,4'-bis(chloromethyl)-1,1'-biphenyl and 4,4'-bis(methoxymethyl)-1,1'-biphenyl) as described in Japanese Patent Publication No. 6429862, aniline and substituted phenyls (such as 1,4-bis(chloromethyl)benzene, 1,4-bis(methoxymethyl)benzene and 1,4-bis(hydroxymethyl)benzene), 4,4'-(1,3-phenylenediisopropylidene)bisaniline, 4,4'-(1,4-phenylenediisopropylidene)bisaniline, aniline and diisopropenylbenzene, and dimer amines. Furthermore, these may be used individually or in combination.

[0092] [Compounds containing ethylenically unsaturated bonds] A compound containing an ethylenically unsaturated bond is a compound that has one or more ethylenically unsaturated bonds in its molecule that can be polymerized by heat or light, regardless of whether a polymerization initiator is used or not. Examples of compounds containing ethylenically unsaturated bonds include, but are not limited to, the reaction products of the phenolic resin and 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.) and halogenated compounds (1,4-bis(chloromethyl)benzene, 4,4'-bis(chloromethyl)biphenyl, 4,4'-difluorobenzophenone, 4,4'-dichlorobenzophenone, 4,4'-dibromobenzophenone, cyanuryl chloride, etc.), the reaction products of epoxy resins or alcohols and (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.

[0093] [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.

[0094] [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, dimer amine, 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, diaminodiphenyl sulfone, 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.

[0095] [Polyimide resin] Examples of polyimide resins include, but are not limited to, the reaction products of the diamine and the tetracarboxylic dianhydrides exemplified below. Furthermore, these 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-Tetracarboxylic dianhydride, Cyclohexane-1,2,4,5-Tetracarboxylic dianhydride Tracarboxylic acid dianhydride, 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.

[0096] [Cyanate ester resin] Cyanate ester resins are compounds obtained by reacting phenolic resins with cyanide halides. Specific examples include, but are not limited to, dicyanate benzene, tricyanate benzene, dicyanate naphthalene, dicyanate biphenyl, 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 compounds obtained by converting the hydroxyl groups of phenol-dicyclopentadiene cocondensates 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 exhibits excellent low hygroscopicity, flame retardancy, and low dielectric loss tangent. 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.

[0097] 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 total mass of the curable resin composition containing the cyanate ester resin and the compound represented by formula (1).

[0098] [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 low dielectric loss tangent. 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, the compatibility with other curable resins deteriorates.

[0099] [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 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: Hybrar 7125F, Hybrar 7311F, both manufactured by Kuraray Co., Ltd.), SIBS (styrene-isobutylene-styrene block copolymers: SIBSTAR073T, SIBSTAR102T, SIBSTAR103T (all manufactured by Kaneka Corporation), Septon V9827 (manufactured by Kuraray Co., Ltd.)), but are not limited to these. 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. Furthermore, while there are no particular restrictions on the weight-average molecular weight of polystyrene and its modified products as long as it is 10,000 or more, if it is too high, the compatibility with polyphenylene ether compounds, as well as low molecular weight components with a weight-average molecular weight of about 50 to 1,000 and oligomer components with a weight-average molecular weight of about 1,000 to 5,000 deteriorates, making it difficult to ensure mixing and solvent stability. Therefore, it is preferable that the molecular weight be around 10,000 to 300,000.

[0100] The curable resin composition of this embodiment is obtained by preparing the above components in predetermined proportions, and a sufficient curing reaction proceeds by curing at 150 to 250°C for 1 to 15 hours, yielding 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.

[0101] The method for preparing the curable resin composition of this embodiment is not particularly limited, but the components may be uniformly mixed or prepolymerized. For example, a mixture containing the compound represented by formula (1) can be prepolymerized by heating in the presence or absence of a curing accelerator and polymerization initiator, and in the presence or absence of a solvent. Similarly, 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 may be added and prepolymerized. Mixing or prepolymerizing the components can be done using, for example, an extruder, kneader, or roll in the absence of a solvent, and using a reaction vessel with a stirring device in the presence of a solvent.

[0102] 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.

[0103] 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 weight, preferably 15 to 70% by weight, of the mixture of the curable resin composition of this embodiment and the solvent. If the composition is liquid, a cured product of the curable resin containing carbon fibers can also be obtained directly, for example, by the RTM method.

[0104] Furthermore, the curable composition of this embodiment can also be used as a modifier for film-type compositions. Specifically, it can be used to improve flexibility 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 curable resin composition varnish onto a release film, removing the solvent under heating, and then performing B-stage formation. This sheet-like adhesive can be used as an interlayer insulating layer in multilayer substrates and the like.

[0105] 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 varnish and then heating and drying them.

[0106] 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.

[0107] 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 the curable resin composition of this embodiment is used to make a resin sheet, it is important that the film softens at the lamination temperature conditions (70°C to 140°C) in the vacuum lamination method and exhibits fluidity (resin flow) that allows for simultaneous lamination of the circuit board and resin filling of via holes or through holes present in the circuit board. It is preferable to blend each component in such a way as to exhibit such characteristics. Furthermore, in order to ensure that the resulting resin sheet and circuit board (copper-clad laminate, etc.) exhibit consistent performance in any desired area, and to prevent phenomena such as locally different characteristic values ​​caused by phase separation, uniformity of appearance is required.

[0108] 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.

[0109] A specific method for manufacturing the aforementioned resin sheet is to prepare a varnished resin composition by incorporating an organic solvent, apply the varnished resin composition to the surface of a support film (Y), and then dry the organic solvent by heating or blowing hot air to form a resin composition layer (X).

[0110] 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; and it is preferable to use them in a proportion that results in a non-volatile content of 30 to 60% by mass.

[0111] Furthermore, the thickness of the formed resin composition layer (X) must be greater than or equal to the thickness of the conductor layer. Since the thickness of the conductor layer of the circuit board is in the range of 5 to 70 μm, it is preferable that the thickness of the resin composition layer (X) be 10 to 100 μm. In this embodiment, the resin composition layer (X) may be protected by a protective film, which will be described later. By protecting it with a protective film, it is possible to prevent dust and other debris from adhering to the surface of the resin composition layer and to prevent scratches.

[0112] The support film and protective film can be made of polyolefins such as polyethylene, polypropylene, and polyvinyl chloride, polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate, polycarbonate, polyimide, and also release paper, copper foil, aluminum foil, and other metal foils. The support film and protective film may be treated with a mat treatment, corona treatment, or release treatment. The thickness of the support film is not particularly limited, but is 10 to 150 μm, preferably in the range of 25 to 50 μm. The thickness of the protective film is preferably 1 to 40 μm.

[0113] The support film (Y) is peeled off after lamination to the circuit board or after an insulating layer has been formed by heat curing. Peeling off the support film (Y) after the resin composition layer constituting the resin sheet has been heat cured prevents the adhesion of dust and other debris during the curing process. When peeling off after curing, the support film is treated with a release agent beforehand.

[0114] Furthermore, a multilayer printed circuit board can be manufactured from the resin sheet obtained as described above. For example, if the resin composition layer (X) is protected by a protective film, these are removed, and then the resin composition layer (X) is laminated to one or both sides of the circuit board so that it is in direct contact with the circuit board, for example, by a vacuum lamination method. The lamination method may be batch or continuous on a roll. If necessary, the resin sheet and circuit board may be heated (preheated) before lamination. The lamination conditions are preferably a pressing temperature (lamination temperature) of 70 to 140°C and a pressing pressure of 1 to 11 kgf / cm². 2 (9.8 × 10 4 ~107.9×10 4 N / m 2 It is preferable to use this method, and it is preferable to laminate under reduced pressure of 20 mmHg (26.7 hPa) or less.

[0115] Furthermore, semiconductor devices can be manufactured using the curable resin composition of this embodiment. Examples of semiconductor devices include DIP (Dual In-Line Package), QFP (Quad Flat Package), BGA (Ball Grid Array), CSP (Chip Size Package), SOP (Small Outline Package), TSOP (Thin Small Outline Package), and TQFP (Thin Quad Flat Package).

[0116] 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 low dielectric loss tangent, 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 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]

[0117] 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.

[0118] The various analytical methods used in the examples are described below.

[0119] • Hydroxyl equivalent The following method was used for measurement, and the unit is g / eq. The phenolic resin is reacted with an excess of acetic anhydride, and the amount of free acetic acid is measured by titration with a 0.5N KOH ethanol solution using a potentiometric analyzer. Reagents: Acetic anhydride, triphenylphosphine, pyridine Solvents: Tetrahydrofuran, propylene glycol monomethyl ether Automatic titrator: COM-1600, manufactured by HIRANUMA Co., Ltd. Burette: HIRANUMA Co., Ltd. B-2000

[0120] · 1 H-NMR analysis Equipment: JNM-ECS400 Total number of times: 8 Relaxation time: 5 seconds Solvent: CDCl3 Measurement temperature: room temperature

[0121] ·IR analysis Equipment: FTIR-8400 (manufactured by Shimadzu Corporation) Frequency: 400-4000cm -1

[0122] • GPC (Gel Permeation Chromatography) Analysis Manufacturer: Waters Columns: Guard columns SHODEX GPC KF-601 (2 pieces), KF-602, KF-602.5, KF-603 Flow rate: 1.23ml / mIn. Column temperature: 25℃ Solvent used: THF (tetrahydrofuran) Detector: RI (Differential Refraction Detector)

[0123] [Synthesis Example 1] In a flask equipped with a thermometer, condenser, and stirrer, 150.0 g of styrene (Tokyo Chemical Industries), 150.0 g of cyclohexane, 9.0 g of 2-ethoxyethyl acetate (Fujifilm Wako Pure Chemical Industries), and 0.45 g of Aquivion (Sigma-AldrIch) were charged. The mixture was reacted at 80°C for 7 hours, after which Aquivion was removed by natural filtration to obtain 221.3 g of a cyclohexane solution of the compound represented by formula (6) below. The GPC chart of the obtained compound is shown in Figure 1. In this GPC chart, the area ratio of the peaks is as follows: m=1 in 21.4 is 32.32%, m=2 in 20.2 is 21.29%, m=3 in 19.5 is 13.76%, m=4 in 19.0 is 9.41%, m=5 in 18.6 is 6.28%, m=6 in 18.3 is 4.95%, and m≧7 is 11.98%. ave The value was calculated to be 3.0, and the ethylenic double bond equivalent was calculated to be 404.1 g / eq.

[0124] [ka]

[0125] [Synthesis Example 2] In a flask fitted with a thermometer, condenser, stirrer, and Dean-Stark tube, 15.0 g of phenol novolac (hydroxyl equivalent 100.0 g / eq.), 0.75 g of toluene, and 2.88 g of methanesulfonic acid as an acid catalyst were charged. After stirring and dissolution, the mixture was heated to 100°C, and 86.7 g of the polystyrene cyclohexane solution obtained in Example 1 was added dropwise over 3 hours. The mixture was then reacted at 100°C for 6 hours while removing the cyclohexane using a Dean-Stark tube. After cooling to room temperature, the mixture was dissolved in 100 g of toluene and neutralized by adding 3.18 g of sodium carbonate (Tokyo Chemical Industries, Ltd.). After repeated washing with water until the wastewater was neutral, the toluene and unreacted phenol were removed by distillation under reduced pressure and heating to obtain the compound represented by the following formula (7) (where R1 represents the substituent represented by the following formula (7-h). ave The same as in Synthesis Example 1.) 44.0 g was obtained. Its hydroxyl group equivalent was 334.4 g / eq. From this hydroxyl group equivalent and the ethylenic double bond equivalent of the polystyrene obtained in Synthesis Example 1, the p in the following formula (7) was obtained. ave The value was calculated to be 0.58. The GPC chart for this resin is shown in Figure 2. 1 The 1H-NMR chart is shown in Figure 3. 1 The peaks at 3.5–4.0 ppm in the 1H-NMR chart can be assigned to the methylene group hydrogens derived from the polyvalent hydroxy resin used as the raw material, the peaks at 1.9–2.4 ppm to the methylene group hydrogens in the following formula (7-h), and the peaks at 1.5–1.6 ppm to the hydrogens of the methyl group in the following formula (7-h). Furthermore, the GPC chart of the raw material, phenol novolac, is shown in Figure 4. In this GPC chart, the area ratio of the peaks is 50.90% for n=1 in 20.3, 26.40% for n=2 in 19.3, 12.42% for n=3 in 18.8, 5.31% for n=4 in 18.3, and 4.97% for n≧5. The average value of the repeating units is n ave The value is calculated to be 1.87.

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[0128] [Synthesis Example 3] In a flask equipped with a thermometer, condenser, and stirrer, 15.2 g of the phenolic resin represented by formula (7) synthesized in Synthesis Example 2, 3.50 g of potassium carbonate (manufactured by Junsei Chemical Co., Ltd.), and 70.0 g of N,N-dimethylformamide were charged. After stirring and dissolving, the mixture was heated to 70°C, and 4.05 g of chloromethylstyrene (manufactured by AGC Seikamika Co., Ltd.) was added dropwise over 10 minutes. The mixture was then reacted at 70°C for 20 hours. After cooling to room temperature, the mixture was dissolved in 150 g of toluene. After repeated washing with water until the wastewater was neutral, the toluene was removed by distillation under reduced pressure and heating until a 50% toluene solution was obtained. Subsequently, the reaction solution was added dropwise to a mixed solvent of 500 g of acetone and 500 g of methanol. The precipitated powder was filtered by suction and dried at 40°C for 1 hour to obtain a powdered curable resin represented by the following formula (8) (where R1 represents the substituent represented by the following formula (8-h). ave , p ave , n ave The result was the same as in synthesis example 2. 0.45 g was obtained. The obtained GPC chart is shown in Figure 5. 1 The 1H-NMR spectrum (400 MHz, CDCl3) is shown in Figure 6. 1 The peaks in the 5.0–6.0 ppm range on the 1H-NMR chart can be attributed to the hydrogen atoms of the olefin portion of the styryl group.

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[0131] [Synthesis Example 4] An aspirator and base trap were placed in a flask equipped with a thermometer, condenser, and stirrer. 19.7 g of the phenolic resin represented by formula (7) synthesized in Synthesis Example 2, 18.2 g of triethylamine (Tokyo Chemical Industries), and 35.5 g of 4-methyltetrahydropyran (Kanto Chemical Co., Ltd.) were charged into this flask. After stirring and dissolution, 9.41 g of methacroyl chloride (Tokyo Chemical Industries) was added dropwise over 1 hour at room temperature, while collecting the generated hydrogen chloride with a base trap. The mixture was then heated to 40°C and reacted for 6 hours while collecting the generated hydrogen chloride with a base trap. The reaction solution was dissolved in 100 g of methyl isobutyl ketone, then 12 g of 30 wt% sodium hydroxide aqueous solution was added dropwise to make the reaction solution basic. The organic layer was then washed 5 times with 50 g of water. After removing the solvent under reduced heat, 80g of toluene is added and the excess solvent is removed again under reduced heat to obtain a curable resin represented by the following formula (9) (where R1 represents the substituent represented by the following formula (9-h). ave , p ave , n ave The same as in Synthesis Example 2.) 14.4 g was obtained. The GPC chart of the obtained curable resin is shown in Figure 7, and the IR chart is shown in Figure 8. In the IR chart, 1700~1800 cm -1 The absorption is due to the carbonyl group in the methacrylate.

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[0134] [Comparative Synthesis Example 1] In a flask equipped with a thermometer, condenser, and stirrer, 8.00 g of phenol novolac (hydroxyl equivalent 100.0 g / eq.), 11.06 g of potassium carbonate (manufactured by Junsei Chemical Co., Ltd.), and 70.0 g of N,N-dimethylformamide were charged, stirred, dissolved, and heated to 60°C. Then, 12.82 g of chloromethylstyrene (manufactured by AGC Seikamika Co., Ltd.) was added dropwise over 10 minutes, and the mixture was reacted at 62.5°C for 15 hours. After cooling to room temperature, the mixture was dissolved in 150 g of toluene, and after repeated washing with water until the wastewater was neutral, the toluene was removed by distillation under reduced pressure and heating until a 50% toluene solution was obtained. After washing with 500 g of methanol, the solvent was removed under reduced pressure and the liquid curable resin (n) represented by the following formula (10) was obtained. ave The result was the same as in synthesis example 2. 4.06 g was obtained. The obtained GPC chart is shown in Figure 9. 1 The 1H-NMR spectrum (400 MHz, CDCl3) is shown in Figure 10. 1 The peaks in the 5.0–6.0 ppm range on the 1H-NMR chart can be attributed to the hydrogen atoms of the olefin portion of the styryl group.

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[0136] [Comparative Synthesis Example 2] An aspirator and base trap were placed in a flask equipped with a thermometer, condenser, and stirrer. 10.0 g of phenol novolac (hydroxyl equivalent 100.0 g / eq.), 30.36 g of triethylamine (Tokyo Chemical Industries), and 35.0 g of 4-methyltetrahydropyran (Kanto Chemical Industries) were charged into the flask. After stirring and dissolution, 15.7 g of methacroyl chloride (Tokyo Chemical Industries) was added dropwise over 0.5 hours at room temperature, while collecting the generated hydrogen chloride with a base trap. The mixture was then heated to 40°C and reacted for 6 hours while collecting the generated hydrogen chloride with a base trap. The reaction solution was diluted with 200 g of toluene, and 20 g of 30 wt% sodium hydroxide aqueous solution was added dropwise to make the reaction solution basic. The organic layer was then washed 10 times with 100 g of water. The solvent was removed by distillation under reduced pressure, resulting in a curable resin (n) represented by the following formula (11). aveThe same as in Synthesis Example 2.) 17.91 g was obtained. The GPC chart of the obtained curable resin is shown in Figure 11, and the IR chart is shown in Figure 12. In the IR chart, 1650~1800 cm -1 The absorption is due to the carbonyl group in the methacrylate.

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[0138] [Example 1, Comparative Example 1] A 250 μm cushion paper with a 100 mm x 50 mm cutout in the center was placed on a copper foil. 0.5 g of the curable resin obtained in Synthesis Example 3 or Comparative Synthesis Example 1 was placed in the center of the frame, and with copper foil sandwiched on either side, the mixture was molded using a vacuum heating press and cured at 220°C for 1 hour. Subsequently, the copper foil was etched using ferric chloride to obtain a cured film. The results of testing the cured film using the method described below are shown in Table 1.

[0139] [Example 2, Comparative Example 2] OPE-2St-1200 (manufactured by Mitsubishi Gas Chemical Co., Ltd., a polyphenylene ether compound having a styrene structure, number average molecular weight 1200, functional group equivalent 600 g / eq) and the curable resin obtained in Synthesis Example 2 (theoretical functional group equivalent 662 g / eq when the entire amount of methacrylic reacts with the hydroxyl group equivalent of the precursor hydroxyl group) or the curable resin obtained in Comparative Synthesis Example 2 (theoretical functional group equivalent 168 g / eq when the entire amount of methacrylic reacts with the hydroxyl group equivalent of the precursor hydroxyl group) were mixed in equal amounts to prepare a toluene solution. 1% by weight of DCP (dicumyl peroxide) was added to the solution, and a thin polyimide film was cast onto it. The mixture was then pre-dried under vacuum at 80°C. The resulting dried material was ground in an agate mortar to obtain a powder sample. The material was placed on a copper foil, with a 250 μm cushion paper cut out in the center to 100 mm x 50 mm. 0.5 g of the material was placed in the center of this frame, and with another piece of copper foil on either side, it was molded using a vacuum heating press. After curing at 220°C for 2 hours, the copper foil was removed to obtain a cured film. The results of testing the cured film using the method described below are shown in Table 2.

[0140] <Dielectric Loss Tangent Test> Tests were conducted using a 10GHz cavity resonator manufactured by AET Co., Ltd., employing the cavity resonator perturbation method. Each cured film was cut into pieces measuring 2.5mm wide x 50mm long x 0.25mm thick using a laser cutter and tested to obtain the initial values.

[0141] <Oxidation Test> Each cured film was placed in a 150°C oven, and dielectric loss tangent tests were performed after 24 hours and again after 168 hours. The results are shown in Table 2.

[0142] <Water absorption test> Each cured film was immersed in water in a 25°C environmental test chamber and allowed to absorb water for 24 hours. After removal, it was air-dried in the same chamber for 24 hours, and then a dielectric loss tangent test was performed.

[0143] [Table 1]

[0144] The results in Table 1 confirm that Example 1 has excellent low dielectric loss tangent characteristics.

[0145] [Table 2]

[0146] The results in Table 2 confirm that Example 2 exhibits excellent low dielectric loss tangent not only initially but also after water absorption and oxidation tests. The attenuation rate of signals flowing through the dielectric material constituting a printed circuit board is proportional to the dielectric loss tangent. Since signal attenuation directly translates into heat generation and causes a temperature rise, a low dielectric loss tangent is important for printed circuit board materials and the like. [Industrial applicability]

[0147] The curable resin composition, resin sheet, and cured product of the present invention are suitably used in electrical and electronic components such as semiconductor encapsulants, printed circuit boards, and build-up laminates.

Claims

1. A curable resin represented by the following formula (1). 【Chemistry 1】 (In equation (1), A represents one of the following equations (1-a) to (1-d), and X represents one of the following equations (1-e) to (1-g). There are multiple R １ Each of these independently represents a substituent represented by the following formula (1-h). There are multiple R ２ Each of these independently represents a hydrocarbon group with 1 to 10 carbon atoms, an alkoxy group with 1 to 6 carbon atoms, an amino group, or a hydroxyl group. Each of these is a real number from 0 to 3, and the average value of multiple p values ​​is p. ａｖｅ is 0 < p ａｖｅ The limit is ≤ 3. q is a real number between 0 and 3, and the average value of multiple q values ​​is q. ａｖｅ is 0 ≤ q ａｖｅ < 3. The sum of p and q present in the same aromatic ring is 3 or less. n is the number of repetitions, and the average value of n is n. ａｖｅ is 1 ≤ n ａｖｅ (≤ 5.) 【Chemistry 2】 (In formulas (1-a) to (1-d), a plurality of R present ３ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. The wavy line indicates the bonding site to the benzene ring in formula (1).) 【Transformation 3】 (In equations (1-e) to (1-g), the wavy lines indicate the bonding sites to the oxygen atom in equation (1).) 【Chemistry 4】 (In equation (1-h), there are multiple R ４ Each of these independently represents a hydrocarbon group with 1 to 6 carbon atoms, an alkoxy group with 1 to 6 carbon atoms, an amino group, or a hydroxyl group. r is a real number from 0 to 5, and the average value of multiple r values ​​is r. ａｖｅ is 0 ≤ r ａｖｅ ≤ 5. m is the number of repetitions, and the average value of m is m. ａｖｅ is 1 ≤ m ａｖｅ The value is ≤ 10. The wavy lines indicate the bonding sites to the benzene ring in equation (1).

2. In formula (1) above, A is formula (1-a) above, and R ３ The curable resin according to claim 1, wherein is a hydrogen atom.

3. A curable resin composition comprising the curable resin described in claim 1.

4. Furthermore, the curable resin composition according to claim 3, further comprising an active ester compound.

5. Furthermore, the curable resin composition according to claim 3, further comprising a maleimide compound.

6. Furthermore, the curable resin composition according to claim 3, further comprising an inorganic filler.

7. Furthermore, the curable resin composition according to claim 3, further comprising a curing accelerator.

8. Furthermore, the curable resin composition according to claim 3, further comprising a polymerization initiator.

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

10. A resin sheet comprising the curable resin composition and support according to claim 3.

11. A cured resin sheet according to claim 10.

12. An insulating layer formed by the cured product according to claim 9 or 11.

13. A printed circuit board comprising an insulating layer as described in claim 12.

14. A semiconductor device including a printed circuit board as described in claim 13.

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