Epoxy resin, curable resin composition, cured product, and phenol resin

Abstract

Provided are: an epoxy resin having excellent high fluidity and low dielectric loss tangent; a curable resin composition; and a phenolic resin serving as a starting material for these. The epoxy resin is represented by formula (1). In # imgabs0 # formula (1), a plurality of Rs are each independently present and each represents a hydrogen atom or a C1-5 hydrocarbon group. And Q represents a substituent represented by formula (1-1). L represents an integer from 0 to 3, m represents an integer from 1 to 4, p represents an integer from 0 to 3, q represents an integer from 0 to 3, and r represents an integer from 0 to 4. And n is an average value of the number of repeating units and represents a number of 1 to 50. In # imgabs 1 # formula (1-1), R represents a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms. And s represents an integer of 1 to 4. * represents a bonding position with the aromatic ring of formula (1).

Description

Technical Field

[0001] The present invention relates to an epoxy resin, a curable resin composition, a cured product, and a phenolic resin having a specific structure, and can be suitably used for electrical / electronic parts such as semiconductor encapsulation materials, printed wiring boards, build-up laminates, and optical waveguide devices, lightweight and high-strength materials such as carbon fiber reinforced plastics and glass fiber reinforced plastics, and 3D printing applications. Background Art

[0002] Epoxy resins are widely used in the fields of electrical / electronic fields such as castings, laminates, and IC encapsulation materials, structural materials, adhesives, and coatings because of their excellent electrical properties (dielectric constant / dielectric loss tangent, insulation), mechanical properties, adhesiveness, and thermal properties (heat resistance, etc.).

[0003] In recent years, in the electrical / electronic field, further improvements in various properties such as flame resistance, moisture resistance, adhesion, low dielectric properties (low dielectric constant and low dielectric loss tangent), high purity, low viscosity for high filling of fillers (inorganic or organic fillers), and reactivity for shortening the molding cycle have been required (Patent Document 1). In addition, for structural materials, materials that are lightweight and have excellent mechanical properties are required for aerospace materials, recreational sports equipment applications, etc. In particular, in the semiconductor packaging field and substrates (the substrate itself or its peripheral materials), due to the evolution of semiconductors, they have become increasingly complex and have become thinner, stacked, systematized, and three-dimensional, so characteristics such as very high levels of heat resistance or high fluidity / low dielectric constant / low dielectric loss tangent are required.

[0004] Regarding the fifth-generation communication system "5G" that is currently being accelerated in development, it has been predicted that there will be a larger capacity and higher communication speed. In the case of 5G, the frequency used will progress to a higher frequency. In order to achieve high-speed communication using high frequencies, "reducing transmission losses" is important, and lower dielectric properties (low dielectric constant and low dielectric loss tangent) of the substrate material are required. The transmission losses that occur on printed boards are due to conductor losses and dielectric losses. As described in Non-Patent Document 1, the dielectric loss α D is proportional to "the square root of the relative dielectric constant ε of the dielectric γ and the dielectric loss tangent tanδ". If one wants to reduce the dielectric loss, it is more effective to reduce the dielectric loss tangent, which has a higher contribution, than the relative dielectric constant.

[0005] In view of this situation, attempts have been made to design an epoxy resin curing system having low dielectric properties. For example, in Patent Document 2, an epoxy resin curing agent capable of achieving low dielectric properties is studied. In Patent Document 3, an epoxy resin is subjected to a fusion reaction through an ester compound.

[0006] [Prior Art Documents]

[0007] [Patent Documents]

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2015-147854

[0009] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2022-157197

[0010] Patent Document 3: Japanese Unexamined Patent Application Publication No. 2022-146918.

[0011] [Non-Patent Documents]

[0012] Non-Patent Document 1: "Causes of Signal Loss in High-Speed Signal Transmission on Printed Circuit Boards", The 29th Spring Conference of the Institute of Electronics Packaging, Session ID: 16P1-17, 2015. Summary of the Invention

[0013] [Problems to be Solved by the Invention]

[0014] However, in Patent Document 2, a strong base catalyst such as N,N-dimethyl-4-aminopyridine must be used, and in order to ensure the working time of the curable resin composition, there are still problems such as the necessity of cold storage. In Patent Document 3, unlike the case of fusion reaction with a phenolic compound, the generation of secondary hydroxyl groups due to the ring opening of the epoxy group can be suppressed, but there are the following problems: it is not suitable for the synthesis of polyfunctional epoxy resins due to fear of gelation, or the viscosity of the resulting epoxy resin tends to increase. Based on such a background, there is an expectation for the development of a material having both high fluidity and low dielectric characteristics.

[0015] The present invention has been completed in view of such a situation, and an object thereof is to provide an epoxy resin, a curable resin composition, a cured product thereof, and a phenolic resin as a raw material therefor, which are excellent in high fluidity and low dielectric loss tangent.

[0016] [Means for Solving the Problems]

[0017] That is, the present invention relates to the following [1] to [5]. In addition, in the present application, "(numerical value 1) to (numerical value 2)" means including upper and lower limits.

[0018] [1] An epoxy resin represented by the following formula (1).

[0019]

[0020] In formula (1), the multiple present Rs each independently represent a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms. Q represents a substituent represented by the following formula (1-1). l represents an integer of 0 to 3, m represents an integer of 1 to 4, p represents an integer of 0 to 3, q represents an integer of 0 to 3, r represents an integer of 0 to 4. n is the average value of the number of repeating units and represents a number from 1 to 50.

[0021]

[0022] In formula (1-1), R represents a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms. s represents an integer of 1 to 4. * represents the bonding position to the aromatic ring of formula (1).

[0023] [2] A curable resin composition containing the epoxy resin described in the previous item [1].

[0024] [3] The curable resin composition described in the previous item [2], which further contains a curing agent and / or a curing accelerator.

[0025] [4] A cured product obtained by curing the curable resin composition described in the previous item [3].

[0026] [5] A phenol resin represented by the following formula (a).

[0027]

[0028] In formula (a), the multiple present Rs each independently represent a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms. Q represents a substituent represented by the following formula (a-1). l represents an integer of 0 to 3, m represents an integer of 1 to 4, p represents an integer of 0 to 3, q represents an integer of 0 to 3, r represents an integer of 0 to 4. n is the average value of the number of repeating units and represents a number from 1 to 50.

[0029]

[0030] In formula (a-1), R represents a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms. s represents an integer of 1 to 4. * represents the bonding position to the aromatic ring of formula (a).

[0031] [Advantages of the Invention]

[0032] According to the present invention, an epoxy resin, a curable resin composition and a cured product thereof with excellent high fluidity and low dielectric loss tangent, and a phenol resin as a raw material for these can be provided. Description of the Drawings

[0033] Figure 1 A GPC chart showing Synthesis Example 1.

[0034] Figure 2Represents the GPC chart of Synthesis Example 2.

[0035] Figure 3 Represents the GPC chart of Synthesis Example 3.

[0036] Figure 4 Represents the GPC chart of Synthesis Example 4. Detailed implementation mode

[0037] The epoxy resin of the present invention has a structure represented by the following formula (1).

[0038]

[0039] In formula (1), multiple Rs present independently, and represent a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, preferably a hydrogen atom. Q represents a substituent represented by the following formula (1-1). l represents an integer from 0 to 3, m represents an integer from 1 to 4, p represents an integer from 0 to 3, preferably represents an integer from 1 to 3. q represents an integer from 0 to 3, preferably represents an integer from 0 to 2. r represents an integer from 0 to 4. n is the average value of the number of repeating units, and represents a number from 1 to 50, preferably represents a number from 1 to 30.

[0040]

[0041] In formula (1-1), R represents a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, preferably a hydrogen atom. s represents an integer from 1 to 4. * represents the bonding position to the aromatic ring of formula (1).

[0042] In the aforementioned formula (1), the value of n can be obtained from the number average molecular weight determined by gel permeation chromatography (GPC, detector: RI), or calculated from the area ratio of each separated peak.

[0043] For the epoxy resin of the present invention, the number average molecular weight obtained by GPC measurement is preferably 300 to 7000, more preferably 350 to 5000, and even more preferably 400 to 4000. When the number average molecular weight is less than 300, in addition to the concern that the operability of formulation at room temperature becomes difficult due to the low softening point, there is also a concern about the stickiness generated in prepregs etc. after forming the composition. In addition, when the number average molecular weight is greater than 7000, in addition to being difficult to purify by washing with water etc., the viscosity becomes too high when used in semiconductor encapsulation materials etc., making it impossible to ensure fluidity. It is not only difficult to fill in the wiring space, but also difficult to ensure the fluidity of the prepreg in the substrate application, and the embedding property of the wiring is impaired.

[0044] The epoxy resin of the present invention is preferably a resinous substance that is semi-solid to solid at normal temperature. The softening point of the epoxy resin is preferably 100 °C or lower, more preferably 90 °C or lower. When the softening point is higher than 100 °C, the viscosity is high and the fiber impregnation property is reduced when making a prepreg.

[0045] The epoxy equivalent of the epoxy resin of the present invention is preferably 200 to 1000 g / eq, more preferably 220 to 800 g / eq, particularly preferably 240 to 700 g / eq, and most preferably 250 to 600 g / eq.

[0046] The viscosity of the epoxy resin of the present invention at 150 °C is preferably 0.01 to 1.2 Pa·s, more preferably 0.01 to 1.0 Pa·s, and particularly preferably 0.01 to 0.8 Pa·s. Here, the viscosity can be measured by a cone-plate viscometer described in JIS K5600-2-3:2014. If the viscosity at 150 °C is in the range of 0.01 to 1.2 Pa·s, appropriate fluidity can be ensured when making a curable resin composition.

[0047] The epoxy resin of the present invention has high fluidity by having the substituent shown in the aforementioned formula (1-1) in the molecule. This is because the intermolecular force becomes low and the viscosity becomes low relative to the molecular weight by introducing the substituent shown in the aforementioned formula (1-1) with less polarization.

[0048] In addition, when there is only a network of epoxy groups, the electrical properties deteriorate significantly due to the polarization of the hydroxyl groups or ether groups caused by the ring-opening of the epoxy groups. However, the epoxy resin of the present invention introduces crosslinking caused by the α-methylstyrene structure that is not crosslinked by epoxy, so the electrical properties become good and low dielectric properties are exhibited.

[0049] An example of a more preferred structure of the epoxy resin of the present invention is an epoxy resin having the structure shown in the following formula (A).

[0050]

[0051] In formula (A), the values and more preferred ranges of m, p, and n are the same as those in the aforementioned formula (1). Q is a substituent shown in the following formula (A-1).

[0052]

[0053] In formula (A-1), * represents the bonding position to the aromatic ring of formula (a).

[0054] The epoxy resin of the present invention can contain an "α-methylstyrene polymer having an epoxy group in the molecule" by polymerizing the α-methylstyrene structure in formula (A-1). The "α-methylstyrene polymer having an epoxy group in the molecule" can increase the molecular weight without changing the density of polar groups in one molecule. Therefore, the dielectric constant and the dielectric loss tangent of the epoxy resin represented by the aforementioned formula (1) will not increase. In addition, since the "α-methylstyrene polymer having an epoxy group in the molecule" is a low-polarity molecule with low intermolecular forces, a low viscosity can be maintained. The "α-methylstyrene polymer having an epoxy group in the molecule" can coexist with the epoxy resin represented by the aforementioned formula (1) to form an epoxy resin mixture.

[0055] The aforementioned α-methylstyrene polymer having an epoxy group in the molecule can be represented by a structure such as the following formula (2), for example. The α-methylstyrene polymer having an epoxy group in the molecule can be obtained by polymerizing the α-methylstyrene structure during or after the synthesis of the epoxy resin represented by formula (1). Alternatively, it can be obtained by epoxidizing a poly-α-methylstyrene polymer having phenolic hydroxyl groups (represented by formula (b) described later) obtained by polymerizing the α-methylstyrene structure at the phenolic resin stage, to obtain an epoxy resin containing the poly-α-methylstyrene polymer represented by formula (2). The detailed content is described later.

[0056]

[0057] In formula (2), the values and more preferred ranges of R, l, n, p, q, and r are the same as those in the aforementioned formula (1). m - 1 represents an integer from 0 to 3. Q is a substituent represented by the following formula (2-1). u is the average value of the number of repeating units and represents a number from 1 to 20, and more preferably represents a number from 1.1 to 10.

[0058]

[0059] In formula (2-1), R represents a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, and more preferably represents a hydrogen atom. s represents an integer from 1 to 4. * represents the bonding position to the aromatic ring of formula (2).

[0060] In the aforementioned formula (2), the value of u can be obtained from the number average molecular weight determined by gel permeation chromatography (GPC, detector: RI), or calculated from the area ratio of each separated peak.

[0061] The poly-α-methylstyrene polymer having an epoxy group in the molecule described above preferably has a number average molecular weight of 600 to 14,000 as measured by GPC, more preferably 700 to 10,000, and even more preferably 800 to 8,000. When the number average molecular weight is less than 600, there are concerns not only that the operability of formulation at room temperature becomes difficult due to the low softening point, but also that stickiness may occur in prepregs and the like after the composition is prepared. On the other hand, when the number average molecular weight is greater than 14,000, in addition to being difficult to purify by washing with water or the like, the viscosity becomes too high when used in semiconductor encapsulation materials or the like, making it impossible to ensure fluidity. It is difficult to fill the wiring space and also difficult to ensure the fluidity of the prepreg in substrate applications, impairing the embedding property of the wiring.

[0062] The poly-α-methylstyrene polymer having an epoxy group in the molecule described above is preferably a resinous substance that is semi-solid to solid at normal temperature. The softening point of the poly-α-methylstyrene polymer represented by the aforementioned formula (2) is preferably 100 °C or lower, more preferably 90 °C or lower. When the softening point is higher than 100 °C, the viscosity is high and the fiber impregnation property deteriorates when making a prepreg.

[0063] The epoxy equivalent of the poly-α-methylstyrene polymer having an epoxy group in the molecule described above is preferably 400 to 2,000 g / eq, more preferably 440 to 1,600 g / eq, particularly preferably 480 to 1,400 g / eq, and most preferably 500 to 1,200 g / eq.

[0064] The poly-α-methylstyrene polymer having an epoxy group in the molecule described above has a viscosity of 0.01 to 3.0 Pa·s at 150 °C, more preferably 0.02 to 2.0 Pa·s, and even more preferably 0.02 to 1.5 Pa·s. If within the above range, appropriate fluidity as an encapsulation material can be ensured when preparing the encapsulation material composition.

[0065] An example of a preferred structure of the poly-α-methylstyrene polymer having an epoxy group in the molecule described above is the poly-α-methylstyrene polymer represented by the following formula (B).

[0066]

[0067] In formula (B), the values of n, m-1, p, and u and the preferred ranges are the same as those of the aforementioned formula (2). Q is a substituent represented by the following formula (B-1).

[0068]

[0069] In formula (B-1), * represents the bonding position to the aromatic ring of formula (B).

[0070] The production method of the epoxy resin of the present invention is not particularly limited. For example, it can be obtained by subjecting a phenolic resin represented by the following formula (a) and epichlorohydrin to an addition or ring-closing reaction in the presence of a solvent and a catalyst. The usage amount of epichlorohydrin is preferably 1.0 to 20.0 moles, more preferably 1.5 to 10.0 moles, relative to 1 mole of the phenolic hydroxyl group of the phenolic resin.

[0071]

[0072] In formula (a), the values of R, l, m, p, q, r, n and the more preferred ranges are the same as those of the aforementioned formula (1). Q is a substituent represented by the following formula (a-1).

[0073]

[0074] In formula (a-1), R represents a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, and preferably represents a hydrogen atom. s represents an integer of 1 to 4. * represents the bonding position to the aromatic ring of formula (a).

[0075] For the phenolic resin represented by the aforementioned formula (a), the number average molecular weight measured by GPC is preferably 200 to 6000, more preferably 250 to 4000, and still more preferably 250 to 3000. The more preferred range of the hydroxyl equivalent is 100 to 900 g / eq., more preferably 120 to 700 g / eq., and still more preferably 120 to 600 g / eq. The more preferred range of the melt viscosity (viscosity) at 150 °C is preferably 0.01 to 1.2 Pa·s, more preferably 0.01 to 1.0 Pa·s, and still more preferably 0.01 to 0.8 Pa·s. The more preferred range of the softening point is 40 to 180 °C, more preferably 40 to 150 °C, and still more preferably 40 to 140 °C. When the softening point is less than 40 °C, there is a concern that the operability of formulation at room temperature becomes difficult due to the low softening point. In addition, when the softening point is higher than 180 °C, in addition to being difficult to purify by washing with water, etc., the viscosity becomes too high when used as a hardener for semiconductor encapsulation materials, etc., or when making epoxides, making it impossible to ensure fluidity. It is not only difficult to focus on wiring, but also difficult to ensure the fluidity of prepregs in substrate applications, thus impairing the embedding property of wiring.

[0076] In the epoxidation reaction of the phenolic resin and epichlorohydrin shown in the aforementioned formula (a), sodium hydroxide, potassium hydroxide, etc. can be cited as the alkali metal hydroxide that can be used. If the alkali metal hydroxide is a solid, its aqueous solution can also be used. When using the aqueous solution, the following method can be used: the aqueous solution of the alkali metal hydroxide is continuously added to the reaction system, and water and epichlorohydrin are continuously distilled out under reduced pressure or normal pressure, and further liquid separation is given to remove water so that epichlorohydrin is continuously returned to the reaction system. Relative to 1 mole of the phenolic hydroxyl group of the phenolic resin, the usage amount of the alkali metal hydroxide is generally 0.9 to 2.5 moles, and more preferably 0.95 to 1.5 moles. If the usage amount of the alkali metal hydroxide is small, the reaction will not be fully carried out. On the other hand, the excessive use of the alkali metal hydroxide exceeding 2.5 moles relative to 1 mole of the phenolic hydroxyl group of the phenolic resin will lead to the by-generation of unnecessary waste.

[0077] In order to promote the above-mentioned reaction, quaternary ammonium salts such as tetramethyl ammonium chloride, tetramethyl ammonium bromide, trimethylbenzyl ammonium chloride can be added as catalyst. With regard to the usage amount of quaternary ammonium salt, relative to 1 mole of phenolic hydroxyl group of phenolic resin, be generally 0.1 to 15g, more preferably 0.2 to 10g. If the usage amount is too little, then can't obtain sufficient reaction promotion effect, if the usage amount is too much, then the quaternary ammonium salt amount remaining in the epoxy resin will increase, so also can become the reason that makes electrical reliability deteriorate.

[0078] In the epoxidation reaction, it is more preferable to add alcohols such as methanol, ethanol, isopropanol, dimethyl sulfone, dimethyl sulfoxide, tetrahydrofuran, dimethicone, etc. The reaction is carried out in an aprotic polar solvent such as alkane. When alcohols are used, the amount used is usually 2 to 50% by weight, preferably 4 to 20% by weight, relative to the amount used of epichlorohydrin. In addition, relative to the amount used of epichlorohydrin, when an aprotic polar solvent is used, it is usually 5 to 100% by weight, preferably 10 to 80% by weight. The reaction temperature is usually 30 to 90° C., preferably 35 to 80° C. The reaction time is usually 0.5 to 100 hours, preferably 1 to 30 hours.

[0079] After the reaction is terminated, epichlorohydrin or a solvent, etc. is removed by heating under reduced pressure after washing the reaction product with water or without water washing. In addition, in order to form an epoxy resin with less hydrolyzable halogen, the recovered epoxy resin may also be dissolved in a solvent such as toluene or methyl isobutyl ketone, and an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is added to carry out the reaction, and the ring is surely closed. At this time, with respect to 1 mole of the phenolic hydroxyl group of the phenolic resin used for glycidyl etherification, the usage amount of the alkali metal hydroxide is usually 0.01 to 0.3 moles, more preferably 0.05 to 0.2 moles. The reaction temperature is usually 50 to 120 ° C, and the reaction time is usually 0.5 to 24 hours. After the reaction is terminated, the generated salt is removed by filtration, washing with water, etc., and further, the solvent is distilled off under heating under reduced pressure, and the epoxy resin of the present invention can be obtained.

[0080] Next, a method for producing the phenolic resin represented by the aforementioned formula (a) will be described. The method for producing the phenolic resin represented by the aforementioned formula (a) is not particularly limited. For example, it can be obtained by reacting a phenol and α,α,α’,α’-tetramethylbenzene dimethanol (or diisopropenylbenzene, or halogen compounds such as α,α,α’,α’-tetramethylbenzene difluoride, α,α,α’,α’-tetramethylbenzene dichloride, α,α,α’,α’-tetramethylbenzene dibromide, α,α,α’,α’-tetramethylbenzene diiodide) in an acid catalyst in a solvent. At this time, as the raw materials, it is more preferable to use raw materials substituted at the meta position. Specifically, in addition to α,α,α’,α’-tetramethyl-1,3-benzenedimethanol and 1,3-diisopropenylbenzene, halogen compounds such as α,α,α’,α’-tetramethyl-1,3-benzenedifluoride, α,α,α’,α’-tetramethyl-1,3-benzenedichloride, α,α,α’,α’-tetramethyl-1,3-benzenedibromide, and α,α,α’,α’-tetramethyl-1,3-benzenediiodide can be cited. Using raw materials with a substitution position at the meta position can reduce crystallinity and reduce the risk of solvent solubility or crystallization precipitation in the solvent. In the synthesis, as the acid catalyst, in addition to hydrochloric acid, phosphoric acid, sulfuric acid, formic acid, p-toluenesulfonic acid, and methanesulfonic acid, Lewis acids such as aluminum chloride and zinc chloride, solid acids such as activated clay, acid clay, white carbon, zeolite, and silica-alumina, and acidic ion exchange resins can also be used. These can be used alone or in combination of two or more. The usage amount of the catalyst is 0.01 to 10% by weight, more preferably 0.1 to 5% by weight, based on the total weight of the phenol and α,α,α’,α’-tetramethylbenzene dimethanol (or diisopropenylbenzene, or halogen compounds such as α,α,α’,α’-tetramethylbenzene difluoride, α,α,α’,α’-tetramethylbenzene dichloride, α,α,α’,α’-tetramethylbenzene dibromide, α,α,α’,α’-tetramethylbenzene diiodide) which are reaction substrates. If the usage amount of the catalyst is too large, there is a concern that a large amount of isopropylidene bonds in the product will decompose. If it is too small, there is a concern that the reaction rate will slow down. As the solvent used, for example, non-aqueous solvents such as aromatic solvents such as toluene and xylene, aliphatic solvents such as cyclohexane and n-hexane, ethers such as diethyl ether and diisopropyl ether, ester solvents such as ethyl acetate and butyl acetate, and ketone solvents such as methyl isobutyl ketone and cyclopentanone can be cited, but it is not limited to these, and two or more can also be used in combination. In addition to the aforementioned non-aqueous solvents, aprotic polar solvents can also be used in combination. For example, dimethyl sulfone, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, N-methylpyrrolidone, etc. can be cited, and two or more can also be used in combination. When using aprotic polar solvents, it is more preferable to use those with a boiling point higher than the non-aqueous solvents used in combination.The reaction temperature is preferably 80 to 150°C, more preferably 90 to 140°C, and even more preferably 100 to 130°C. If the reaction temperature is too high, there is a concern that the isopropylidene bond will decompose, and if the reaction temperature is too low, there is a concern that the reaction will not proceed sufficiently. When using an alcohol raw material, water is generated as a by-product, so it is removed from the system while azeotroping with the solvent when the temperature is raised. After the reaction is terminated, after neutralizing the acidic catalyst with an alkaline aqueous solution, a water-insoluble organic solvent is added to the oil layer and washed repeatedly until the wastewater becomes neutral, and then the solvent is removed under heating and reduced pressure. When using activated clay or ion exchange resin, the catalyst is removed by filtering the reaction solution after the reaction is terminated.

[0081] The method for preparing the poly-α-methylstyrene polymer having an epoxy group in the molecule is not particularly limited, but can be obtained, for example, by subjecting a poly-α-methylstyrene polymer having a phenolic hydroxyl group represented by the following formula (b) to addition or ring-closure reaction with epichlorohydrin in the presence of a solvent and a catalyst. The amount of epichlorohydrin used is usually 1.0 to 20.0 mol, preferably 1.5 to 10.0 mol, relative to 1 mol of the phenolic hydroxyl group of the poly-α-methylstyrene polymer having a phenolic hydroxyl group.

[0082]

[0083] In the above formula (b), R, l, m-1, n, p, q, and r are the same as those in the above formula (1). u is the average value of the number of repeating units and represents a number from 1 to 20. Q is a substituent represented by the following formula (b-1).

[0084]

[0085] In formula (b-1), R represents a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, and more preferably represents a hydrogen atom. s represents an integer of 1 to 4. * represents a bonding position to the aromatic ring of formula (B).

[0086] The aforementioned poly-α-methylstyrene polymer having a phenolic hydroxyl group can be obtained by heating the phenol resin represented by the aforementioned formula (a) in the presence or absence of a catalyst at a temperature in the range of 40 to 250° C. (preferably 50 to 180° C.) to polymerize the α-methylstyrene structure in the phenol resin.

[0087] The aforementioned poly-α-methylstyrene polymer having phenolic hydroxyl groups preferably has a number average molecular weight of 500 to 14,000 as measured by GPC, more preferably 600 to 10,000, and still more preferably 700 to 8,000. When the number average molecular weight is less than 500, there are concerns not only about the difficulty of handling in formulations at room temperature due to the low softening point after epoxidation, but also about the stickiness that may occur in prepregs and the like after epoxidation to form a composition. In addition, when the number average molecular weight is greater than 14,000, in addition to the difficulty of purification by washing with water, etc., the viscosity becomes too high when used in semiconductor encapsulation materials, etc., making it impossible to ensure fluidity. It is difficult to fill in the wiring space and also difficult to ensure the fluidity of the prepreg in substrate applications, thereby impairing the embedding property of the wiring. The poly-α-methylstyrene polymer having phenolic hydroxyl groups in the molecule may also be mixed with the phenolic resin represented by the aforementioned formula (a) to form a phenolic resin mixture.

[0088] Hereinafter, the curable resin composition of the present invention will be described.

[0089] In the curable resin composition of the present invention, the epoxy resin or epoxy resin mixture of the present invention can be used alone or in combination with other epoxy resins described later. When used in combination, the proportion of the epoxy resin or epoxy resin mixture of the present invention in all the epoxy resins is preferably 10 to 98% by weight, more preferably 20 to 95% by weight, and still more preferably 30 to 95% by weight. If the addition amount is set to 10% or more, low dielectric characteristics can be exhibited.

[0090] [Hardener]

[0091] In the curable resin composition of the present invention, the curability can be improved by adding a hardener. As for the hardener, any compound can be used as long as it is a compound capable of reacting with an epoxy group. For example, in addition to the active ester compounds, phenolic resins, polyphenylene ether compounds, amine resins, isocyanate resins, polyamide resins, maleimide compounds, cyanate ester resins, polyimide resins, polybutadiene and its modified products, polystyrene and its modified products, polyethylene and its modified products described later, the following exemplified acid anhydrides can also be used as hardeners. From the viewpoint of exhibiting a low dielectric loss tangent, it is more preferable to use active ester compounds, polyphenylene ether compounds, maleimide compounds, cyanate ester compounds, and acid anhydrides as hardeners.

[0092] [Acid anhydride]

[0093] Examples include phthalic anhydride, trimellitic anhydride, pyromellitic dianhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, alkenyl succinic anhydride, styrene-maleic anhydride copolymer, butadiene-maleic anhydride copolymer, propylene-maleic anhydride copolymer, etc., but are not limited thereto. In addition, one type of these may be used, or multiple types may be used in combination.

[0094] [Hardening accelerator]

[0095] The curable resin composition of the present invention can also improve its curability by adding a hardening accelerator. Regarding the hardening accelerator, an anionic hardening accelerator that generates anions by irradiation with ultraviolet or visible light or heating to promote the hardening reaction, or a cationic hardening accelerator that generates cations by irradiation with ultraviolet or visible light or heating to promote the hardening reaction is more preferable.

[0096] Examples of the anionic hardening accelerator include imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo[5.4.0]undecene, etc., and 4-dimethylaminopyridine and 1,8-diazabicyclo[5.4.0]undecene are more preferable. In addition, phosphines such as triphenylphosphine, quaternary ammonium salts such as tetrabutylammonium salt, triisopropylmethylammonium salt, trimethyldecylammonium salt, cetyltrimethylammonium salt, cetyltrimethylammonium hydroxide, etc. may be mentioned, but are not limited thereto. In addition, one type of these may be used, or multiple types may be used in combination.

[0097] Examples of the cationic hardening accelerator include quaternary phosphonium salts such as triphenylbenzylphosphonium salt, triphenylethylphosphonium salt, tetrabutylphosphonium salt (the counter ions of the quaternary salt are not particularly specified, but organic acid ions and hydroxide ions are particularly preferable), tin octoate, zinc carboxylates (zinc 2-ethylhexanoate, zinc stearate, zinc docosanoate, zinc myristate), zinc phosphate esters (zinc octyl phosphate, zinc stearyl phosphate) and other transition metal compounds (transition metal salts), etc., but are not limited thereto. In addition, one type of these may be used, or multiple types may be used in combination.

[0098] In 100 parts by mass of the curable resin composition, the blending amount of the hardening accelerator can be 0.01 to 5.0 parts by mass as needed.

[0099] [Inorganic filler]

[0100] The curable resin composition of the present invention may contain an inorganic filler. Examples of the inorganic filler include 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, phthalic oxide, talc, clay, iron oxide asbestos, glass powder, etc. in powder form, or inorganic fillers made into spherical or crushed shapes from these, but are not limited to these. In addition, one type of these may be used, or multiple types may be used in combination.

[0101] When obtaining the curable resin composition for semiconductor packaging, in 100 parts by mass of the total amount of the curable resin composition, the usage amount of the inorganic filler is preferably 80 to 92 parts by mass, more preferably 83 to 90 parts by mass. In addition, when obtaining the curable resin composition for substrate materials such as interlayer insulating layer forming materials, copper foil laminates or prepregs, RCC, etc., in 100 parts by mass of the total amount of the curable resin composition, the usage amount of the above inorganic filler is preferably 5 to 80 parts by mass, more preferably 10 to 60 parts by mass.

[0102] [Polymerization initiator]

[0103] The curable resin composition of the present invention can also improve its curability by adding a polymerization initiator. The so-called polymerization initiator refers to a compound that can polymerize olefin functional groups such as ethylenically unsaturated bonds, and examples include olefin metathesis polymerization initiators, anionic polymerization initiators, cationic polymerization initiators, radical polymerization initiators, etc. Among them, a radical polymerization initiator having curability and appropriate stability is preferably used. The so-called radical polymerization initiator refers to a compound that generates radicals by irradiation with ultraviolet or visible light or heating and starts a chain polymerization reaction. Examples of the radical polymerization initiator that can be used include organic peroxides, azo compounds, 1,1,2,2-tetraphenyl-1,2-ethanediol (benzopinacol) compounds, etc. From the viewpoints of controlling the curing temperature, suppressing gas evolution, and having little influence of decomposition products on electrical properties, organic peroxides are preferably used.

[0104] Regarding the above-mentioned organic peroxides, for example, ketone peroxides such as methyl ethyl ketone peroxide and acetylacetone peroxide, diacyl peroxides such as benzoyl peroxide, dialkyl peroxides such as diisopropylbenzene peroxide and 1,3-bis(tert-butylperoxyisopropyl)benzene, peroxyketals such as tert-butyl peroxybenzoate and 1,1-di-tert-butylperoxycyclohexane, α-cumyl peroxyisodecanoate, tert-butyl peroxyisodecanoate, tert-butyl peroxypivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, tert-amyl peroxy-2-ethylhexanoate, tert-butyl peroxy-2-ethylhexanoate, tert-amyl peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-amyl peroxybenzoate and other peroxyalkyl esters, diperoxycarbonates such as di-2-ethylhexyl diperoxycarbonate and bis(4-tert-butylcyclohexyl) diperoxycarbonate, tert-butyl peroxyisopropyl carbonate, 1,6-bis(tert-butylperoxycarbonyloxy)hexane and other peroxycarbonates, tert-butyl hydroperoxide, cumene hydroperoxide, tert-butyl peroxycaprylate, lauroyl peroxide, etc. are exemplified, but not limited thereto. In addition, one type of these can be used, or multiple types can be used in combination. Among the above-mentioned organic peroxides, ketone peroxides, diacyl peroxides, hydroperoxides, dialkyl peroxides, peroxyketals, peroxyalkyl esters, peroxycarbonates, etc. are more preferred, and dialkyl peroxides are more preferred.

[0105] Regarding the above-mentioned azo compounds, for example, azobisisobutyronitrile, 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(2,4-dimethylvaleronitrile), etc. are exemplified, but not limited thereto. In addition, one type of these can be used, or multiple types can be used in combination.

[0106] Regarding the addition amount of the polymerization initiator, in 100 parts by mass of the curable resin composition, 0.01 to 5 parts by mass is more preferred, and 0.01 to 3 parts by mass is particularly preferred. If the amount of the polymerization initiator used is less than 0.01 part by mass, there is a concern that the molecular weight may not sufficiently elongate during the polymerization reaction. If it is more than 5 parts by mass, there is a concern that dielectric properties such as the dielectric constant and dielectric loss tangent may be impaired.

[0107] [Polymerization inhibitor]

[0108] The curable resin composition of the present invention may contain a polymerization inhibitor. By containing the polymerization inhibitor, the storage stability can be improved, and the reaction start temperature can be controlled. By controlling the reaction start temperature, it becomes easy to ensure fluidity, and the B-stage formation such as prepreg formation becomes easy without impairing the impregnation property with respect to glass cloth, etc. At the time of prepreg formation, if the polymerization reaction proceeds excessively, an unfavorable situation such as difficulty in laminating in the lamination step is likely to occur.

[0109] Regarding the polymerization inhibitor, it can be added during the synthesis of the epoxy resin or epoxy resin mixture of the present invention, or added after synthesis. With respect to 100 parts by weight of the epoxy resin or epoxy resin mixture of the present invention, the amount of the polymerization inhibitor used is 0.008 to 1 part by weight, more preferably 0.01 to 0.5 part by weight.

[0110] Regarding the polymerization inhibitor, examples thereof include phenolic, sulfur-based, phosphorus-based, hindered amine-based, nitroso-based, nitroxyl radical-based, etc. In addition, one type of polymerization inhibitor system can be used, or multiple types can be used in combination. Among these, in the present invention, phenolic, hindered amine-based, nitroso-based, and nitroxyl radical-based are more preferred.

[0111] Regarding the above phenolic polymerization inhibitor, for example, 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-tert-butyl-p-ethylphenol, stearyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, isooctyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylanilino)-1,3,5-tri Monophenols such as 2,4-bis[(octylthio)methyl]-o-cresol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyhydrocinnamide), 2,2'-thio-diethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], diethyl 3,5-di-tert-butyl-4-hydroxybenzylphosphonate, 3,9-bis[1,1-dimethyl-2-{β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]2,4,8,10-tetraoxaspiro[5,5]undecane, bis(3,5-di-tert-butyl-4-hydroxybenzylsulfonic acid ethyl) calcium and other bisphenols, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tetra-[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]methane, glycol bis[3,3'-bis-(4'-hydroxy-3'-tert-butylphenyl)butyrate], tris(3,5-di-tert-butyl-4-hydroxybenzyl)-isocyanurate, 1,3,5-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl)-s-tri -2,4,6-(1H,3H,5H)trione, tocopherol and other polymeric phenols, etc., but not limited to these.

[0112] Regarding the above sulfur-based polymerization inhibitors, for example, dilauryl 3,3'-thiodipropionate, dimyristyl 3,3'-thiodipropionate, distearyl 3,3'-thiodipropionate, etc. can be cited, but not limited to these.

[0113] Regarding the above-mentioned phosphorus-based polymerization inhibitors, for example, triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris(nonylphenyl) phosphite, diisodecyl pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, distearyl pentaerythritol diphosphite (Cyclicneopentanetetraylbis(octadecylphosphite)), bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,4-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis[2-tert-butyl-6-methyl-4-{2-(octadecyloxycarbonyl)ethyl}phenyl] hydrogen phosphite and other phosphite esters, 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (9,10-Dihydro-9-oxa-10-phosphaphenanthrene 10-Oxide), 10-(3,5-di-tert-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide, 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide and other phosphaphenanthrene oxides, etc., but not limited to these.

[0114] Regarding the above-mentioned amine-based polymerization inhibitors, for example, ADK STAB LA-40MP, ADK STAB LA-40Si, ADK STAB LA-402AF, ADK STAB LA-87, ADK STAB LA-82, ADK STAB LA-81, ADK STABLA-77Y, ADK STAB LA-77G, ADK STAB LA-72, ADK STAB LA-68, ADK STAB LA-63P, ADK STABLA-57, ADK STAB LA-52, Chimassorb20 20FDL, Chimassorb944FDL, Chimassorb944LD, Tinuvin622SF, TinuvinPA144, Tin uvin765, Tinuvin770DF, TinuvinXT55FB, Tinuvin111FDL, Tinuvin783FDL, Tinuvin791FB, etc., but not limited to these.

[0115] Regarding the above-mentioned nitroso-based polymerization inhibitors, for example, p-nitrosophenol, N-nitrosodiphenylamine, ammonium salt of N-nitrosophenylhydroxylamine (Cupferron), etc., but not limited to these. Among these, the ammonium salt of N-nitrosophenylhydroxylamine (Cupferron) is more preferred.

[0116] Regarding the above-mentioned nitroxide radical polymerization inhibitors, for example, di-tert-butyl nitroxide, 2,2,6,6-tetramethyl-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, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl, etc. can be mentioned, but are not limited thereto.

[0117] [Flame retardant]

[0118] The curable resin composition of the present invention can use a flame retardant. Regarding the flame retardant, for example, halogen-based flame retardants, inorganic flame retardants (antimony compounds, metal hydroxides, nitrogen compounds, boron compounds, etc.), phosphorus-based flame retardants, etc. can be mentioned. However, from the viewpoint of achieving halogen-free flame retardancy, phosphorus-based flame retardants are more preferred.

[0119] The above-mentioned phosphorus-based flame retardants can be reactive or additive. Regarding specific examples, in addition to phosphate esters such as trimethyl phosphate, triethyl phosphate, tris(tolyl) phosphate, tris(xylenyl) phosphate, tolyl diphenyl phosphate, tolyl-2,6-bis(xylenyl) phosphate, 1,3-phenylene bis(bis-xylenyl phosphate), 1,4-phenylene bis(bis-xylenyl phosphate), 4,4'-biphenyl (bis-xylenyl phosphate), etc., phosphane compounds such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, etc., phosphorus-containing epoxy compounds obtained by reacting epoxy resins with the active hydrogen of the aforementioned phosphane compounds, red phosphorus, etc. can be mentioned, but are not limited thereto. In addition, one type of these can be used, or multiple types can be used in combination. Among the above-exemplified substances, phosphate esters, phosphane compounds, or phosphorus-containing epoxy compounds are more preferred, and 1,3-phenylene bis(bis-xylenyl phosphate), 1,4-phenylene bis(bis-xylenyl phosphate), 4,4'-biphenyl (bis-xylenyl phosphate), or phosphorus-containing epoxy compounds are particularly preferred.

[0120] In 100 parts by mass of the curable resin composition, the content of the flame retardant is preferably in the range of 0.1 to 10 parts by mass. When it is less than 0.1 part by mass, there is a concern that the flame retardancy is insufficient. If it is more than 10 parts by mass, there is a concern that it may have an adverse effect on the hygroscopicity and dielectric properties of the cured product.

[0121] [Light stabilizer]

[0122] A light stabilizer can be used in the curable resin composition of the present invention. Regarding the light stabilizer, a hindered amine-based light stabilizer (especially HALS, etc.) is suitable. Regarding HALS, for example, dibutylamine / 1,3,5-tri / Reaction product of N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)-1,6-hexamethylenediamine and N-(2,2,6,6-tetramethyl-4-piperidyl)butylamine, dimethyl succinate-1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine reaction product, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-tri -2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino}], bis(1,2,2,6,6-pentamethyl-4-piperidyl) malonate [[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butyl ester, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, 2-(3,5-di-tert-butyl-4-hydroxybenzyl)-2-n-butylmalonic acid bis(1,2,2,6,6-pentamethyl-4-piperidyl) ester, etc., but not limited to these. In addition, one type of these can be used, or multiple types can be used in combination.

[0123] In 100 parts by mass of the curable resin composition, the content of the light stabilizer is preferably in the range of 0.001 to 0.1 part by mass. When it is less than 0.001 part by mass, there is a concern that the light stabilizing effect is insufficient. If it is more than 0.1 part by mass, there is a concern that it may have an adverse effect on the hygroscopicity and dielectric properties of the cured product.

[0124] [Binder resin]

[0125] A binder resin can be used in the curable resin composition of the present invention. Regarding the binder resin, for example, butyral resin, acetal resin, acrylic resin, epoxy-nylon resin, NBR-phenol resin, epoxy-NBR resin, polysiloxane resin, etc. can be mentioned, but not limited to these. In addition, one type of these can be used, or multiple types can be used in combination.

[0126] Regarding the blending amount of the binder resin, a range that does not impair the flame resistance and heat resistance of the cured product is more preferable. In 100 parts by mass of the curable resin composition, 0.05 to 50 parts by mass is more preferable, and more preferably 0.05 to 20 parts by mass can be used as needed.

[0127] [Additive]

[0128] Additives can be used in the curable resin composition of the present invention. Examples of the additives include modified products of acrylonitrile copolymers, polyethylene, fluororesins, polysiloxane gels, polysiloxane oils, surface treatment agents for fillers of silane coupling agents, release agents, carbon black, phthalocyanine blue, phthalocyanine green and other colorants.

[0129] Regarding the blending amount of the additive, relative to 100 parts by mass of the total amount of the curable resin composition, it is more preferably 1 part by mass or less, and more preferably in the range of 0.7 part by mass or less.

[0130] In the curable resin composition of the present invention, other epoxy resins, active ester compounds, phenolic resins other than those of the present invention, polyphenylene ether compounds, amine resins, compounds having ethylenically unsaturated bonds, isocyanate resins, polyamide resins, maleimide compounds, cyanate ester resins, polyimide resins, polybutadiene and its modified products, polystyrene and its modified products, polyethylene and its modified products, etc. can be further used. These can be used singly or in combination of multiple types. Among these compounds, from the viewpoint of the balance of heat resistance, adhesion, and dielectric properties, it is more preferable to contain polyphenylene ether compounds, compounds having ethylenically unsaturated bonds, cyanate ester resins, polybutadiene and its modified products, polystyrene and its modified products. By containing these compounds, the brittleness of the cured product can be improved and the adhesion to metals can be enhanced, and the cracking of the package in reliability tests such as reflow soldering or thermal cycling can be suppressed. Regarding the total usage amount of the above compounds, if not otherwise specified, it is more preferably 10 times by mass or less, more preferably 5 times by mass or less, and particularly preferably 3 times by mass or less relative to the epoxy resin of the present invention. In addition, the lower limit value is more preferably 0.1 times by mass or more, more preferably 0.25 times by mass or more, and still more preferably 0.5 times by mass or more. By setting it within the above range, the effects of the epoxy resin characteristics of the present invention can be utilized, and the effects of the added various compounds can be added. The following examples can be used for this component.

[0131] [Other Epoxy Resins]

[0132] In the present invention, in addition to the epoxy resin of the present invention, other epoxy resins may be used in combination. Regarding more preferred examples of other epoxy resins, they will be exemplified below, but are not limited thereto. In addition, the properties of other epoxy resins may be liquid or solid, and one type may be used, or multiple types may be used in combination.

[0133] Regarding liquid epoxy resins, for example, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins, naphthalene type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, phenol novolac type epoxy resins, alicyclic epoxy resins having an ester skeleton, cyclohexane type epoxy resins, cyclohexanedimethanol type epoxy resins, glycidyl amine type epoxy resins, and epoxy resins having a butadiene structure, etc. can be cited. As specific examples, "RE310S", "RE410S" (the above are bisphenol A type epoxy resins manufactured by Nippon Kayaku Co., Ltd.), "RE303S", "RE304S", "RE403S", "RE404S" (the above are bisphenol F type epoxy resins manufactured by Nippon Kayaku Co., Ltd.), "HP4032", "HP4032D", "HP4032SS" (the above are naphthalene type epoxy resins manufactured by DIC Corporation), "828US", "jER828EL", "825", "828EL" (the above are bisphenol A type epoxy resins manufactured by Mitsubishi Chemical Corporation), "jE807", "1750" (the above are bisphenol F type epoxy resins manufactured by Mitsubishi Chemical Corporation), "jER152" (phenol novolac type epoxy resin manufactured by Mitsubishi Chemical Corporation), "630", "630LSD" (the above are glycidyl amine type epoxy resins manufactured by Mitsubishi Chemical Corporation), "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), "EX-721" (glycidyl ester type epoxy resin manufactured by NAGASE CHEMTEX Corporation), "CELOXIDE 2021P" (alicyclic epoxy resin having an ester skeleton manufactured by Daicel Corporation), "PB-3600" (epoxy resin having a butadiene structure manufactured by Daicel Corporation), "ZX1658", "ZX1658GS" (the above are liquid 1,4-glycidylcyclohexane type epoxy resins manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), etc. These can be used alone or in combination of two or more.

[0134] In the case of solid epoxy resins, for example, bixylenol type epoxy resins, naphthalene type epoxy resins, naphthalene type tetrafunctional epoxy resins, cresol novolac type epoxy resins, dicyclopentadiene type epoxy resins, terphenol type epoxy resins, naphthol type epoxy resins, biphenyl type epoxy resins, naphthalene ether type epoxy resins, anthracene type epoxy resins, bisphenol A type epoxy resins, bisphenol AF type epoxy resins, and tetraphenylethane type epoxy resins can be cited. Among them, naphthol type epoxy resins, bisphenol AF type epoxy resins, naphthalene type epoxy resins, and biphenyl type epoxy resins are more preferred.For specific examples, “HP 4032H” (naphthalene-type epoxy resin manufactured by DIC Corporation), “HP-4700”, “HP-4710” (the above are naphthalene-type tetrafunctional epoxy resins manufactured by DIC Corporation), “N-690” (cresol novolac-type epoxy resin manufactured by DIC Corporation), “N-695” (cresol novolac-type epoxy resin manufactured by DIC Corporation), “HP-7200” (dicyclopentadiene-type epoxy resin manufactured by DIC Corporation), “HP-7200”, “HP-7200HH”, “HP-7200H” (the above are dicyclopentadiene-type epoxy resins manufactured by DIC Corporation), “EX A-7311”, “EXA-7311-G3”, “EXA-7311-G4”, “EXA-7311-G4S”, “HP-6000” (the above are naphthalene ether-type epoxy resins manufactured by DIC Corporation), “EPPN-502H” (terphenol-type epoxy resin manufactured by Nippon Kayaku Co., Ltd.), “NC-7000L”, “NC-7300” (the above are naphthol-cresol novolac-type epoxy resins manufactured by Nippon Kayaku Co., Ltd.), “NC-3000H”, “NC-3000”, “NC-3000L”, “NC-3100” (the above are biphenyl aralkyl-type epoxy resins manufactured by Nippon Kayaku Co., Ltd.), “XD-1000-2L”, “XD-1000-L”, “XD-1000-H”, “XD-1000-H” (the above are dicyclopentadiene-type epoxy resins manufactured by Nippon Kayaku Co., Ltd.), “ESN475V” (naphthol-type epoxy resin manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), “ESN485” (naphthol novolac-type epoxy resin manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), “YX-4000H”, “YX-4000”, “YL6121” (the above are biphenyl-type epoxy resins manufactured by Mitsubishi CHEMICAL Corporation), “YX-4000HK” (bixylenol-type epoxy resin manufactured by Mitsubishi CHEMICAL Corporation), “YX-8800” (anthracene-type epoxy resin manufactured by Mitsubishi CHEMICAL Corporation), “PG-100”, “CG-500” (fluorene-based epoxy resins manufactured by Osaka Gas CHEMICAL Co., Ltd.), “YL-7760” (bisphenol AF-type epoxy resin manufactured by Mitsubishi CHEMICAL Corporation), “YL-7800” (fluorene-type epoxy resin manufactured by Mitsubishi CHEMICAL Corporation) “jER1010” (solid bisphenol A-type epoxy resin manufactured by Mitsubishi CHEMICAL Corporation), “jER1031S” (tetraphenylethane-type epoxy resin manufactured by Mitsubishi CHEMICAL Corporation), etc. These can be used alone or in combination of two or more.

[0135] [Active ester compound]

[0136] The so-called active ester compound means a compound containing at least one ester bond in its structure and having aliphatic chains, aliphatic rings or aromatic rings bonded to both sides of the ester bond. For the active ester compound, for example, phenolic esters, thiophenolic esters, N-hydroxyamine esters, esters of heterocyclic hydroxy compounds, etc., which are compounds having two or more highly reactive ester groups in one molecule, can be cited. Moreover, it can be obtained by the condensation reaction of "at least any one of carboxylic acid compounds, acyl chlorides, or thiocarboxylic acid compounds" and "at least any one of hydroxy compounds or thiol compounds". In particular, from the viewpoint of improving heat resistance, it is more preferably obtained from a carboxylic acid compound or an acyl chloride and a hydroxy compound, and the hydroxy compound is preferably a phenolic compound or a naphthol compound. The active ester compound can be used alone or in combination of two or more kinds.

[0137] For the above-mentioned carboxylic acid compounds, for example, benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid, etc. can be cited.

[0138] For the above-mentioned acyl chlorides, for example, acetyl chloride, acryloyl chloride, methacryloyl chloride, malonyl chloride, succinyl dichloride, diglycolyl chloride, glutaroyl chloride, suberoyl chloride, sebacoyl chloride, adipoyl chloride, dodecanedioyl chloride, azelaoyl chloride, 2,5-furandicarbonyl chloride, phthaloyl chloride, isophthaloyl chloride, terephthaloyl chloride, trimellitic anhydride chloride, bis(4-chlorocarbonylphenyl) ether, 4,4'-diphenyldicarbonyl chloride, 4,4'-azodibenzoyl dichloride, etc. can be cited.

[0139] For the above-mentioned phenolic compounds and the above-mentioned naphthol compounds, for example, 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, benzene triol, dicyclopentadiene type diphenol compound, phenolic novolac, phenolic resins described later, etc. can be cited. Here, the so-called "dicyclopentadiene type diphenol compound" means a diphenol compound obtained by condensing two molecules of phenol in one molecule of dicyclopentadiene.

[0140] As for more preferable specific examples of the active ester compound, the following can be cited: an active ester compound containing a dicyclopentadiene type diphenol structure, an active ester compound containing a naphthalene structure, an active ester compound containing an acetylated product of novolak, an active ester compound containing a benzoylated product of novolak, a compound described in Example 2 of International Publication No. 2020 / 095829, a compound disclosed in International Publication No. 2020 / 059625, etc. Among them, an active ester compound containing a naphthalene structure and an active ester compound containing a dicyclopentadiene type diphenol structure are more preferable. The dicyclopentadiene type diphenol structure means a divalent structural unit composed of phenylene - dicyclopentylene - phenylene.

[0141] Regarding commercially available products of the active ester compound, for example, as for the active ester compound containing a dicyclopentadiene type diphenol structure, “EXB9451”, “EXB9460”, “EXB9460S”, “HPC - 8000 - 65T”, “HPC - 8000H - 65TM”, “EXB - 8000L - 65TM”, “EXB - 8150 - 65T” (manufactured by DIC Corporation) can be cited; as for the active ester compound containing a naphthalene structure, “EXB9416 - 70BK” (manufactured by DIC Corporation) can be cited; as for the active ester compound containing an acetylated product of novolak, “DC808” (manufactured by Mitsubishi Chemical Corporation) can be cited; as for the active ester compound containing a benzoylated product of novolak, “YLH1026”, “YLH1030”, “YLH1048” (manufactured by Mitsubishi Chemical Corporation) can be cited; as for the active ester - type curing agent belonging to an acetylated product of novolak, “DC808” (manufactured by Mitsubishi Chemical Corporation) can be cited; as for the active ester - type curing agent containing a phosphorus atom, “EXB - 9050L - 62M” manufactured by DIC Corporation, etc. can be cited.

[0142] Regarding the blending ratio of the active ester compound and the epoxy resin, it is more preferably that the ratio (α / β) of the active ester equivalent (α) to the epoxy equivalent (β) is from 0.5 to 1.5, still more preferably from 0.8 to 1.2, and even more preferably from 0.90 to 1.10. When exceeding the above range, there is a concern that excessive epoxy groups or active ester groups remain in the system, and there is a concern that the characteristics deteriorate in long - term reliability tests such as high - temperature storage tests (150 °C, 1000 hours, etc.) or high - temperature and high - humidity conditions (temperature: 85 °C, humidity: 85%, etc.).

[0143] [Other phenolic resins]

[0144] A phenolic resin means a compound having two or more phenolic hydroxyl groups in the 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, reaction products of bisphenols and aldehydes, etc. In addition, one type of these can be used, or multiple types can be used in combination.

[0145] Hereinafter, specific examples of the above raw materials are illustrated, but are not limited thereto.

[0146] <Phenols>

[0147] Phenol, alkyl-substituted phenol, aromatic-substituted phenol, hydroquinone, resorcinol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, alkyl-substituted dihydroxybenzene, dihydroxynaphthalene, etc.

[0148] <Aldehydes>

[0149] Formaldehyde, acetaldehyde, alkyl aldehyde, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzaldehyde, naphthaldehyde, glutaraldehyde, phthalaldehyde, crotonaldehyde, cinnamaldehyde, furfural, etc.

[0150] <Diene Compounds>

[0151] Dicyclopentadiene, terpinene, vinylcyclohexene, norbornadiene, vinylnorbornene, tetrahydroindene, divinylbenzene, divinylbiphenyl, diisopropenylbiphenyl, butadiene, isoprene, etc.

[0152] <Ketones>

[0153] Acetone, methyl ethyl ketone, methyl isobutyl ketone, acetylbenzene, benzophenone, fluorenone, etc.

[0154] <Substituted Biphenyls>

[0155] 4,4'-bis(chloromethyl)-1,1'-biphenyl, 4,4'-bis(methoxymethyl)-1,1'-biphenyl, 4,4'-bis(hydroxymethyl)-1,1'-biphenyl, etc.

[0156] <Substituted Phenyls>

[0157] 1,4-bis(chloromethyl)benzene, 1,4-bis(methoxymethyl)benzene, 1,4-bis(hydroxymethyl)benzene, etc.

[0158] [Polyphenylene Oxide Compound]

[0159] Regarding polyphenylene ether compounds, from the viewpoints of heat resistance and electrical properties, polyphenylene ether compounds having ethylenically unsaturated bonds are more preferable, and polyphenylene ether compounds having acryloyl groups, methacryloyl groups or styrene structures are even more preferable. Examples of commercially available products include SA-9000 (manufactured by SABIC, a polyphenylene ether compound having a methacryloyl group) and OPE-2St1200 (manufactured by Mitsubishi Gas Chemical Company, a polyphenylene ether compound having a styrene structure).

[0160] The number average molecular weight (Mn) of the polyphenylene ether compound is more preferably from 500 to 5000, even more preferably from 2000 to 5000, and still even more preferably from 2000 to 4000. If the molecular weight is less than 500, the heat resistance of the cured product tends not to be sufficiently obtained. On the other hand, if the molecular weight is greater than 5000, the melt viscosity becomes high and sufficient fluidity cannot be obtained, so there is a tendency for poor moldability to occur easily. In addition, there is a tendency for the reactivity to decrease, the curing reaction to require a long time, unreacted substances to increase without introducing a curing system, the glass transition temperature of the cured product to decrease, and the heat resistance of the cured product to decrease.

[0161] If the number average molecular weight of the polyphenylene ether compound is from 500 to 5000, excellent heat resistance, moldability, etc. can be exhibited while maintaining excellent dielectric properties. In addition, the number average molecular weight here can be specifically measured by gel permeation chromatography or the like.

[0162] The polyphenylene ether compound can be obtained by a polymerization reaction or by subjecting a high molecular weight polyphenylene ether compound having a number average molecular weight of about 10000 to 30000 to a redistribution reaction. In addition, these can be used as raw materials and reacted with compounds having ethylenically unsaturated bonds such as methacryloyl chloride, acryloyl chloride, and chloromethylstyrene to impart free radical polymerizability. The polyphenylene ether compound obtained by the redistribution reaction is 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 and performing a redistribution reaction. The polyphenylene ether compound thus obtained by the redistribution reaction is preferable in that it has "hydroxyl groups derived from phenolic compounds that contribute to curing" at both ends of the molecular chain, so that higher heat resistance can be maintained, and functional groups can be introduced at both ends of the molecular chain even after modification with a compound having an ethylenically unsaturated bond. In addition, from the viewpoint of exhibiting excellent fluidity, the polyphenylene ether compound obtained by the polymerization reaction is more preferable.

[0163] Regarding the adjustment of the molecular weight of the polyphenylene ether compound, when the polyphenylene ether compound is obtained by a polymerization reaction, it can be adjusted by adjusting the polymerization conditions or the like. In addition, when the polyphenylene ether compound is obtained by a redistribution reaction, the molecular weight of the obtained polyphenylene ether compound can be adjusted by adjusting the conditions of the redistribution reaction or the like. More specifically, the blending amount of the phenolic compound used in the redistribution reaction can be considered for adjustment. That is, the more the blending amount of the phenolic compound, the lower the molecular weight of the obtained polyphenylene ether compound. At this time, a high molecular weight polyphenylene ether compound subjected to the redistribution reaction can be poly(2,6-dimethyl-1,4-phenylene ether) or the like. In addition, the phenolic compound that can be used in the aforementioned redistribution reaction is not particularly limited. For example, a polyfunctional phenolic compound having two or more phenolic hydroxyl groups in the molecule such as bisphenol A, phenol novolac, and cresol novolac is preferably used. These can be used alone or in combination of two or more kinds.

[0164] [amine resin]

[0165] An amine resin means a compound having two or more amino groups in the molecule. Examples of the amine resin include diaminodiphenylmethane, diaminodiphenylsulfone, isophoronediamine, naphthalenediamine, aniline novolac (reactant of aniline and formalin), N-methylaniline novolac (reactant of N-methylaniline and formalin), o-ethylaniline novolac (reactant of o-ethylaniline and formalin), reactant of 2-methylaniline and formalin, reactant of 2,6-diisopropylaniline and formalin, reactant of 2,6-diethylaniline and formalin, reactant of 2-ethyl-6-ethylaniline and formalin, reactant of 2,6-dimethylaniline and formalin, aniline resin obtained by the reaction of aniline and dimethylxylene chloride, aniline and substituted biphenyls (such as 4,4'-bis(chloromethyl)-1,1'-biphenyl and 4,4'-bis(methoxymethyl)-1,1'-biphenyl) described in Japanese Patent 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)dianiline, 4,4'-(1,4-phenylenediisopropylidene)dianiline, reactant of aniline and diisopropenylbenzene, dimer diamine, etc., but are not limited thereto. In addition, these can be used singly or in combination of multiple kinds.

[0166] [compound containing an ethylenically unsaturated bond]

[0167] A compound containing an ethylenically unsaturated bond means a compound having one or more ethylenically unsaturated bonds in the molecule that can be polymerized by heat or light, whether or not a polymerization initiator is used.

[0168] Regarding compounds containing ethylenically unsaturated bonds, examples include reactants of the aforementioned phenolic resins and halogen-based compounds containing ethylenically unsaturated bonds (such as chloromethylstyrene, allyl chloride, methallyl chloride, acryloyl chloride, methacryloyl chloride, etc.), reactants of phenols containing ethylenically unsaturated bonds (such as 2-allylphenol, 2-propenylphenol, 4-allylphenol, 4-propenylphenol, eugenol, isoeugenol, etc.) and halogen-based compounds (such as 1,4-bis(chloromethyl)benzene, 4,4'-bis(chloromethyl)biphenyl, 4,4'-difluorobenzophenone, 4,4'-dichlorobenzophenone, 4,4'-dibromobenzophenone, cyanuric chloride, etc.), reactants of epoxy resins or alcohols and (meth)acrylic acids (such as acrylic acid, methacrylic acid, etc.), and acid-modified products thereof, etc., but are not limited thereto. In addition, one type of these can be used, or multiple types can be used in combination.

[0169] [Isocyanate resin]

[0170] The so-called isocyanate resin refers to a compound having two or more isocyanate groups in the molecule. Regarding isocyanate resins, for example, aromatic diisocyanate such as p-phenylene diisocyanate, m-phenylene diisocyanate, p-xylene diisocyanate, m-xylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, naphthalene diisocyanate, etc., aliphatic or alicyclic structure diisocyanate such as isophorone diisocyanate, hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, hydrogenated xylene diisocyanate, norbornene diisocyanate, lysine diisocyanate, etc., polyisocyanate such as a biuret of one or more isocyanate monomers, or an isocyanate body obtained by trimerizing the above diisocyanate compounds, and polyisocyanate obtained by the urethanization reaction of the above isocyanate compounds and polyol compounds, etc., but are not limited thereto. In addition, one type of these can be used, or multiple types can be used in combination.

[0171] [Polyamide resin]

[0172] Regarding polyamide resins, for example, reactants of any one or more of diamine, diisocyanate, oxazoline and dicarboxylic acid, reactants of diamine and acyl chloride, and ring-opening polymers of caprolactam compounds. In addition, one type of these can be used, or multiple types can be used in combination.

[0173] Specific examples of the above-mentioned raw materials are exemplified below, but are not limited thereto.

[0174] <Diamine>

[0175] 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 diamine, cyclohexanediamine, bis-(4-aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)methane, xylenediamine, norbornanediamine, isophoronediamine, bisaminomethyltricyclodecane, phenylenediamine, diethyltoluenediamine, naphthalenediamine, diaminodiphenylmethane, bis(4-amino-3,5-dimethylphenyl)methane, bis(4-amino-3,5-diethylphenyl)methane, 4,4'-methylenebis-o-toluidine, 4,4'-methylenebis-o-ethylaniline, 4,4'-methylenebis-2-ethyl-6-methylaniline, 4,4'-methylenebis-2,6-diisopropylaniline, 4,4-ethylenedianiline, diaminodiphenylsulfone, diaminodiphenylether, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4-bis(4-aminophenoxy)biphenyl, 2,2-bis[4-(4-aminobenzyl)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)dianiline, 4,4'-(1,4-phenylenediisopropylidene)dianiline, 9,9-bis(4-aminophenyl)fluorene, 2,7-diaminofluorene, aminobenzylamine, diaminobenzophenone, etc.

[0176] <Diisocyanate>

[0177] Phenyl 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'-diisocyanato, etc.

[0178] <Dicarboxylic acid>

[0179] Oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, 5-hydroxyisophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, Sodium 5-Sulfoisophthalate, hexahydroterephthalic acid, hexahydroisophthalic acid, cyclohexanedicarboxylic acid, biphenyldicarboxylic acid, naphthalenedicarboxylic acid, benzophenonedicarboxylic acid, furandicarboxylic acid, 4,4'-dicarboxydiphenyl ether, 4,4'-dicarboxydiphenyl sulfide, etc.

[0180] <Acyl chlorides>

[0181] Acetyl chloride, acryloyl chloride, methacryloyl chloride, malonyl chloride, succinyl dichloride, diglycolyl chloride, glutaroyl chloride, suberoyl chloride, sebacoyl chloride, adipoyl chloride, dodecanedioyl chloride, azeloyl chloride, 2,5-furandicarbonyl chloride, phthaloyl chloride, isophthaloyl chloride, terephthaloyl chloride, trimellitic anhydride chloride, bis(4-chlorocarbonylphenyl) ether, 4,4'-diphenyldicarbonyl chloride, 4,4'-azodibenzoyl dichloride, etc.

[0182] <Lactams>

[0183] ε-Caprolactam, ω-undecanolactam, ω-laurolactam, etc.

[0184] [Polyimide resin]

[0185] Examples of the polyimide resin include the reaction products of the aforementioned diamines and the tetracarboxylic dianhydrides exemplified below, but are not limited thereto. In addition, one type of these can be used, or multiple types can be used in combination.

[0186] <Tetracarboxylic dianhydrides>

[0187] Examples include 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-cyclohexene-1,2-dicarboxylic anhydride, pyromellitic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 2,2',3,3'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, methylene-4,4'-diphthalic dianhydride, 1,1-ethylidene-4,4'-diphthalic dianhydride, 2,2'-propylidene-4,4'-diphthalic dianhydride, 1,2-ethylene-4,4'-diphthalic dianhydride, 1,3-trimethylene-4,4'-diphthalic dianhydride, 1,4-tetramethylene-4,4'-diphthalic dianhydride, 1,5-pentamethylene-4,4'-diphthalic dianhydride, 4,4'-oxydiphthalic dianhydride, sulfur-4,4'-diphthalic dianhydride, sulfonyl-4,4'-diphthalic dianhydride, 1,3-bis(3,4-dicarboxyphenyl)benzene dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,3-bis[2-(3,4-dicarboxyphenyl)-2-propyl]benzene dianhydride, 1,4-bis[2-(3,4-dicarboxyphenyl)-2-propyl]benzene dianhydride, bis[3-(3,4-dicarboxyphenoxy)phenyl]methane dianhydride, bis[4-(3,4-dicarboxyphenoxy)phenyl]methane dianhydride, 2,2-bis[3-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, bis(3,4-dicarboxyphenoxy)dimethylsilane dianhydride, 1,3-bis(3,4-dicarboxyphenyl)-1,1,3,3-tetramethyldisiloxane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, vinyltetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexane-1,2,3,4-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, 3,3',4,4'-bicyclohexyltetracarboxylic dianhydride, carbonyl-4,4'-bis(cyclohexane-1,2-dicarboxylic) dianhydride, methylene-4,4'-bis(cyclohexane-1,2-dicarboxylic) dianhydride, 1,2-ethylene-4,4'-bis(cyclohexane-1,2-dicarboxylic) dianhydride, 1,1-ethylidene-4,4'-bis(cyclohexane-1,2-dicarboxylic) dianhydride, 2,2'-propylidene-4,4'-bis(cyclohexane-1,2-dicarboxylic) dianhydride, oxygen-4,4'-bis(cyclohexane-1,2-dicarboxylic) dianhydride, sulfur-4,4'-bis(cyclohexane-1,2-dicarboxylic anhydride), sulfonyl-4,4'-bis(cyclohexane-1,2-dicarboxylic anhydride), bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic 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 anhydride, ethylene glycol-bis-(3,4-dicarboxyanhydride phenyl) ether, 4,4'-biphenyl bis(trimellitic monoester anhydride), 9,9'-bis(3,4-dicarboxyphenyl)fluorene dianhydride, etc.,

[0188] [Maleimide compound]

[0189] The curable resin composition of the present invention may contain a maleimide compound. The so-called maleimide compound means a compound having one or more maleimide groups in the molecule. Examples of the maleimide compound include 4,4'-diphenylmethane bismaleimide, polyphenylmethane maleimide, m-phenylene bismaleimide, 2,2'-bis[4-(4-maleimidophenoxy)phenyl]propane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, 4,4'-diphenyl ether bismaleimide, 4,4'-diphenyl sulfone bismaleimide, 1,3-bis(3-maleimidophenoxy)benzene, 1,3-bis(4-maleimidophenoxy)benzene), ZYLOK type maleimide compound (ANILIX maleimide, manufactured by Mitsui Chemicals FINE Inc.), biphenyl aralkyl type maleimide compound (solidified by distilling off the solvent under reduced pressure from the resin solution containing the maleimide compound (M2) described in Example 4 of Japanese Unexamined Patent Application Publication No. 2009-001783), diaminoisopropylphenylbenzene type maleimide (maleimide compound described in International Publication No. 2020 / 054601), maleimide compound having an indane structure described in Patent No. 6629692 or International Publication No. 2020 / 217679, maleimide compound described in MATERIAL STAGE Vo l.18, No.12 2019 '~Continued / Epoxy Resin CAS Number Story~Hardener CAS Number Memorandum No. 31 Bismaleimide (1)' or MATERIAL STAGE Vol.19, No.2 2019 '~Continued / Epoxy Resin CAS Number Story~Hardener CAS Number Memorandum No. 32 Bismaleimide (2)' etc., but not limited to these. In addition, one type of these may be used, or multiple types may be used in combination.

[0190] [Cyanate Resin]

[0191] The cyanate ester resin means a cyanate ester compound obtained by reacting a phenolic resin with a cyanogen halide. Specific examples thereof include dicyanoxybenezene, tricyanoxybenezene, dicyanoxynaphthalene, dicyanoxybiphenyl, 2,2'-bis(4-cyanoxyphenyl)propane, bis(4-cyanoxyphenyl)methane, bis(3,5-dimethyl-4-cyanoxyphenyl)methane, 2,2'-bis(3,5-dimethyl-4-cyanoxyphenyl)propane, 2,2'-bis(4-cyanoxyphenyl)ethane, 2,2'-bis(4-cyanoxyphenyl)hexafluoropropane, bis(4-cyanoxyphenyl)sulfone, bis(4-cyanoxyphenyl)sulfide, cyanate ester of novolak phenol, and conversion of the hydroxyl group of a phenol / dicyclopentadiene co-condensate into a cyanate ester group, etc., but are not limited thereto. In addition, one type of these may be used, or multiple types may be used in combination.

[0192] In addition, the cyanate ester compound whose synthesis method is described in Japanese Patent Laid-Open No. 2005-264154 is particularly preferred as a cyanate ester compound because of its excellent low hygroscopicity, flame resistance, and dielectric properties.

[0193] Regarding the cyanate ester resin, if it is desired to trimerize the cyanate ester group to form a 1,3,5-triazine ring, catalysts such as zinc naphthenate, cobalt naphthenate, copper naphthenate, lead naphthenate, zinc octanoate, tin octanoate, lead acetylacetonate, and dibutyltin maleate may also be contained.

[0194] With respect to 100 parts by mass of the cyanate ester resin, the catalyst is 0.0001 to 0.10 parts by mass, and it is more preferably used in an amount of 0.00015 to 0.0015 parts by mass.

[0195] [Polybutadiene and its modified products]

[0196] The so-called polybutadiene and its modified products mean polybutadiene or a compound having a structure derived from polybutadiene in the molecule. The structure derived from polybutadiene can convert a part or all of the unsaturated bonds into single bonds by hydrogenation.

[0197] ​Regarding polybutadiene and its modified products, examples include polybutadiene, hydroxyl-terminated polybutadiene, (meth)acrylated-terminated polybutadiene, carboxylic acid-terminated polybutadiene, amine-terminated polybutadiene, styrene-butadiene rubber, etc., but are not limited thereto. In addition, one type of these can be used, or multiple types can be used in combination. Among these, from the viewpoint of dielectric properties, polybutadiene or styrene-butadiene rubber is more preferred. Regarding styrene-butadiene rubber (SBR), examples include RICON-100, RICON-181, RICON-184 (all manufactured by Cray Valley), 1,2-SBS (manufactured by Nippon Soda Co., Ltd.), etc. Regarding polybutadiene, examples include B-1000, B-2000, B-3000 (all manufactured by Nippon Soda Co., Ltd.), etc. Regarding the molecular weight of polybutadiene and styrene-butadiene rubber, a weight-average molecular weight of 500 to 10,000 is more preferred, more preferably 750 to 7,500, and still more preferably 1,000 to 5,000. When the lower limit of the above range is not reached, the volatilization amount is large, and it is difficult to adjust the solid content when producing a prepreg. When the upper limit of the above range is exceeded, the compatibility with other curable resins deteriorates. Generally, when it is a compound containing heteroatoms such as oxygen or nitrogen, such as bismaleimide or polypyrrole maleimide, due to its polarity, it is difficult to ensure its compatibility with "low-polarity compounds such as compounds mainly composed of hydrocarbons or compounds composed only of hydrocarbons". On the other hand, since the compound of the present invention is not designed with a skeleton into which heteroatoms such as oxygen or nitrogen are actively introduced, its compatibility with "materials having low polarity and low dielectric properties or compounds composed only of hydrocarbons" is also excellent.

[0198] [Polystyrene and its modified products]

[0199] Polystyrene and its modified products mean polystyrene or a compound having a structure derived from polystyrene in the molecule.

[0200] Regarding polystyrene and its modified products, for example, polystyrene, styrene / 2-isopropenyl-2- Oxazoline copolymers (EPOCROS RPS-1005 and RP-61 are both manufactured by Nippon Catalyst 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 are all manufactured by Kuraray Co., Ltd.), SEEPS (styrene-44-ethylene / ethylene / propylene-styrene block copolymer: SEPTON 4003, SEPTON 4044, SEPTON 4055, SEPTON 4077, SEPTON 4099 are all manufactured by Kuraray Co., Ltd.), SEBS (styrene-ethylene / butene-styrene block copolymer: SEPTON 8004, SEPTON 8006, SEPTON 8007L are all manufactured by Kuraray Co., Ltd.), SEEPS-OH (a compound having a hydroxyl group at the end of a styrene-ethylene / ethylene / propylene-styrene block copolymer: SEPTON HG252 manufactured by Kuraray Co., Ltd.), SIS (styrene-isoprene-styrene block copolymer: SEPTON 5125, SEPTON 5127 are all manufactured by Kuraray Co., Ltd.), hydrogenated SIS (hydrogenated styrene-isoprene-styrene block copolymer: HYBRAR 7125F, HYBRAR 7311F are all manufactured by Kuraray Co., Ltd.), SIBS (styrene-isobutene-styrene block copolymer: SIBSTAR073T, SIBSTAR102T, SIBSTAR103T (all manufactured by Kaneka Corporation), SEPTON V9827 (manufactured by Kuraray Co., Ltd)), etc., but are not limited thereto. In addition, one type of these may be used, or multiple types may be used in combination. Polystyrene and its modified products are preferably those without unsaturated bonds because they have higher heat resistance and are less likely to oxidize and deteriorate. In addition, the weight-average molecular weight of polystyrene and its modified products may be 10,000 or more, and there is no particular limitation. However, if it is too large, the compatibility with the polyphenylene ether compound, the low-molecular-weight component with a weight-average molecular weight of about 50 to 1000, and the oligomer component with a weight-average molecular weight of about 1000 to 5000 deteriorates, and it is difficult to ensure mixing and solvent stability. Therefore, it is preferably about 10,000 to 300,000.

[0201] [Polyethylene and its modified products]

[0202] The so-called polyethylene and its modified products mean polyethylene or a compound having a structure derived from polyethylene in the molecule. For polyethylene and its modified products, examples include ethylene-propylene copolymer, ethylene-styrene copolymer, ethylene-propylene-ethylidene norbornene copolymer (EBT manufactured by Mitsui Chemicals, Inc.: K-8370EM, K-9330M, etc.), ethylene-propylene-vinyl norbornene copolymer (VNB-EPT manufactured by Mitsui Chemicals, Inc.: PX-006M, PX-008M, PX-009M, etc.), ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, etc., but are not limited thereto. From the viewpoint of improving heat resistance, it is more preferable to use an ethylene-propylene-ethylidene norbornene copolymer or an ethylene-propylene-vinyl norbornene copolymer containing a crosslinkable structure. In addition, one type of these can be used, or multiple types can be used in combination. The weight average molecular weight of polyethylene and its modified products may be 10,000 or more, and there is no particular limitation, but if it is too large, the compatibility with the polyphenylene ether compound, the low molecular weight component having a weight average molecular weight of about 50 to 1000, and the oligomer component having a weight average molecular weight of about 1000 to 5000 becomes poor, and it is difficult to ensure mixing and solvent stability. Therefore, it is more preferably about 10,000 to 300,000.

[0203] The curable resin composition of the present invention is obtained by formulating the above-mentioned respective components in a predetermined ratio, and is pre-cured in the range of 130 to 180 °C for 30 to 500 seconds. In addition, by post-curing at 150 to 200 °C for 2 to 15 hours, a sufficient curing reaction is carried out to obtain the cured product of the present invention. In addition, the components of the curable resin composition may be uniformly dispersed or dissolved in a solvent, and after removing the solvent, it may be cured.

[0204] The method for preparing the curable resin composition of the present invention is not particularly limited, and each component may be only uniformly mixed or prepolymerized. For example, for a mixture containing the epoxy resin of the present invention, heating is carried out in the presence or absence of a curing accelerator or a polymerization initiator and in the presence or absence of a solvent, whereby prepolymerization is carried out. Similarly, compounds such as amine compounds, compounds having an ethylenically unsaturated bond, maleimide compounds, cyanate ester compounds, polybutadiene and its modified products, polystyrene and its modified products, inorganic fillers, and other additives may be added for prepolymerization. Regarding the mixing or prepolymerization of each component, in the absence of a solvent, for example, an extruder, a kneader, a roll, etc. are used, and in the presence of a solvent, a reaction kettle equipped with a stirring device is used.

[0205] Regarding the method of uniform mixing, it is mixed by kneading using a kneader, roller, planetary mixer or other device at a temperature in the range of 50 to 100 °C to form a uniform resin composition. Regarding the obtained resin composition, after pulverization, it can be formed into a cylindrical ingot shape by a molding machine such as an ingot press, or formed into a granular powder or a powdery molded body, or these compositions are melted on a surface support and formed into a sheet-like shape with a thickness of 0.05 mm to 10 mm to form a curable resin composition molded body. The obtained molded body becomes a non-sticky molded body at 0 to 20 °C, and its fluidity and curability hardly decrease even when stored at -25 to 0 °C for more than one week.

[0206] For the obtained molded body, it can be formed into a hardened product by a transfer molding machine or a compression molding machine.

[0207] The curable resin composition of the present invention can also be added with an organic solvent to form a varnish-like composition (hereinafter also simply referred to as varnish). The curable resin composition of the present invention is dissolved in a solvent such as toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone as needed to form a varnish, impregnated into a substrate such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, paper, etc., and heated and dried to obtain a prepreg, and the prepreg is hot-pressed to produce a hardened product of the curable resin composition of the present invention. The solvent at this time is used in an amount of 10 to 70% by weight in the mixture of the curable resin composition of the present invention and the solvent, and more preferably in an amount of 15 to 70% by weight. In addition, if it is a liquid composition, a curable resin hardened product containing carbon fiber in, for example, the RTM method can also be directly obtained.

[0208] In addition, the curable resin composition of the present invention can also be used as a modifier for a film-type composition. Specifically, it can be used in cases where the flexibility is improved in the B-stage. Regarding such a film-type resin composition, the curable resin composition of the present invention can be coated on a release film as a varnish, and after removing the solvent by heating, a sheet-like adhesive can be obtained by performing B-stage treatment. This sheet-like adhesive can be used as an interlayer insulating layer in a multilayer substrate or the like.

[0209] The curable resin composition of the present invention can also be impregnated into reinforcing fibers such as glass fibers, carbon fibers, polyester fibers, polyamide fibers, and alumina fibers by heating and melting to lower the viscosity to obtain a prepreg. Specific examples thereof include glass fibers such as E glass cloth, D glass cloth, S glass cloth, Q glass cloth, spherical glass cloth, NE glass cloth, and T glass cloth. In addition, fibers of inorganic substances other than glass or organic fibers such as polyparaphenyleneterephthalamide (KEVLAR (registered trademark), manufactured by DUPONT), wholly aromatic polyamide, polyester, polyparaphenylene benz oxazole, polyimide, and carbon fiber can be mentioned, but it is not particularly limited to these. Regarding the shape of the base material, there is no particular limitation, and for example, woven fabric, non-woven fabric, yarn bundle, chopped strand mat, etc. can be mentioned. In addition, regarding the weaving method of the woven fabric, plain weave, twill weave, damask weave, etc. are known, and these can be appropriately selected and used according to the intended use or performance. In addition, glass woven fabric that has been fibrillated or surface-treated with a silane coupling agent or the like is preferably used. The thickness of the base material is not particularly limited, and it is more preferably about 0.01 to 0.4 mm. In addition, a prepreg can also be obtained by impregnating the aforementioned varnish into reinforcing fibers and heating and drying.

[0210] In addition, the above prepreg can also be used to manufacture a laminate. The laminate only needs to have one or more prepregs and is not particularly limited, and it can also have any other layers. Regarding the manufacturing method of the laminate, generally, publicly known methods can be suitably applied and there is no particular limitation. For example, when forming a metal foil-clad laminate, a multi-stage press, a multi-stage vacuum press, a continuous forming machine, an autoclave forming machine, etc. can be used, and a laminate can be obtained by laminating the above prepregs with each other and heating and pressing to form. At this time, the heating temperature is not particularly limited, and it is more preferably 65 to 300 °C, and even more preferably 120 to 270 °C. In addition, the pressure applied is not particularly limited, but if the pressure is too high, it is difficult to adjust the solid content of the resin in the laminate and the quality becomes unstable. In addition, if the pressure is too small, the air bubbles or the adhesion between the layers becomes poor, so it is more preferably 2.0 to 5.0 MPa, and even more preferably 2.5 to 4.0 MPa. Since the laminate of the present embodiment has a layer composed of a metal foil, it can be suitably used as a metal foil-clad laminate described later.

[0211] After cutting the above prepreg into a desired shape and laminating it with a copper foil or the like as needed, while applying pressure to the laminate by a pressure forming method, an autoclave forming method, a sheet winding forming method, etc., the curable resin composition is heated and cured, whereby an electrical and electronic laminate (printed wiring board) or a carbon fiber reinforced material can be obtained.

[0212] The curable resin composition of the present invention can also be made into a resin sheet. Examples of the method for obtaining a resin sheet from the curable resin composition of the present invention include: a method of forming a resin composition layer on a support film (support) by coating the curable resin composition thereon and then drying it. When the curable resin composition of the present invention is used for a resin sheet, the key point is that the film shows "softening under the lamination temperature conditions (70°C to 140°C) in the vacuum lamination method, and has fluidity (resin flow) for resin filling in the through holes or vias existing in the circuit board during lamination with the circuit board". It is more preferable to formulate the above-mentioned respective components in such a way that such characteristics can be exhibited. In addition, in the obtained resin sheet or circuit board (such as a copper-clad laminate), in order to prevent the phenomenon of showing locally different characteristic values due to phase separation or the like and to exhibit certain properties at any part, appearance uniformity is required.

[0213] Here, the diameter of the through hole of the circuit board is 0.1 to 0.5 mm, and the depth is 0.1 to 1.2 mm. It is more preferable to be able to fill resin within this range. In addition, when laminating both sides of the circuit board, it is desirable to fill about 1 / 2 of the through hole.

[0214] Regarding the specific method for manufacturing the above-mentioned resin sheet, examples include: after formulating a varnished resin composition by blending an organic solvent, coating the varnished resin composition on the surface of a support film (Y), and further drying the organic solvent by heating or blowing hot air, etc., to form a resin composition layer (X).

[0215] Here, as the organic solvent used, it is more preferable to use, for example, ketones such as acetone, methyl ethyl ketone, cyclohexanone, acetate esters such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, carbitol acetate, cellosolve, carbitols such as butyl carbitol, aromatic hydrocarbons such as toluene, xylene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. In addition, it is more preferable to use the organic solvent in a proportion such that the non-volatile component is 30 to 60% by mass of the whole.

[0216] In addition, the thickness of the above-mentioned resin composition layer (X) formed must be set to be equal to or greater than the thickness of the conductor layer of the circuit board on which the resin composition layer (X) is laminated. Since the thickness of the conductor layer of the circuit board is in the range of 5 to 70 μm, it is more preferable that the thickness of the resin composition layer (X) is 10 to 100 μm. In addition, the resin composition layer (X) in the present invention can be protected by a protective film described later. By protecting with a protective film, it is possible to prevent the adhesion or scratching of dust, etc., to the surface of the resin composition layer (X).

[0217] Regarding the aforementioned support film and protective film, examples include polyolefins such as polyethylene, polypropylene, and polyvinyl chloride, polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate, polycarbonate, polyimide, and more preferably, release paper or metal foils such as copper foil and aluminum foil. In addition, the support film and protective film can be subjected to matting treatment, corona treatment, or release treatment. The thickness of the support film is not particularly limited, and is 10 to 150 μm, more preferably used in the range of 25 to 50 μm. In addition, the thickness of the protective film is preferably set to 1 to 40 μm.

[0218] After laminating the aforementioned resin composition layer (X) on the circuit board, or after heating and curing the aforementioned resin composition layer (X) to form an insulating layer, the aforementioned support film (Y) is peeled off. After the resin composition layer (X) constituting the resin sheet is heated and cured, if the support film (Y) is peeled off, it is possible to prevent the adhesion of dust and the like during the curing step. When peeling after the curing of the aforementioned resin composition layer (X), a release treatment can be first applied to the support film (Y).

[0219] In addition, a multilayer printed circuit board can be manufactured from the resin sheet obtained in the above-described manner. For example, when the aforementioned resin composition layer (X) is protected by the protective film, after peeling off the protective film, the layer (X) of the resin composition is directly brought into contact with the circuit board, and is laminated on one or both sides of the circuit board by, for example, a vacuum lamination method. The lamination method can be a batch type or a continuous type using a roller. In addition, if necessary, the resin sheet and the circuit board can be heated (preheated) as needed before lamination. Regarding the lamination conditions, it is more preferable to set the pressing temperature (lamination temperature) to 70 to 140 °C, and to set the pressing pressure to 1 to 11 kgf / cm 2 (9.8×10 4 to 107.9×10 4 N / m 2 ) is more preferable, and it is more preferable to perform lamination under a reduced pressure where the air pressure is 20 mmHg (26.7 hPa) or less.

[0220] In addition, the curable resin composition of the present invention can be used to manufacture semiconductor devices. Examples of semiconductor devices include DIP (Dual Inline Package), QFP (Quad Flat Package), BGA (Ball grid array), CSP (Chip size Package), SOP (Small outline Package), TSOP (Thin Small Outline Package), TQFP (Thin Quad Flat Package), etc.

[0221] The curable resin composition of the present invention and its cured product are used in a wide range of fields. Specifically, they can be used in various applications such as molding materials, adhesives, composite materials, coatings, etc. The cured product of the curable resin composition described in the present invention exhibits excellent heat resistance and dielectric properties, so it can be used in encapsulation materials for semiconductor elements, encapsulation materials for liquid crystal display elements, encapsulation materials for organic EL elements, laminated boards (printed wiring boards, substrates for BGA, Build Up substrates, etc.), optical waveguide devices, and other electrical / electronic parts, or composite materials for lightweight and high-strength structural materials such as carbon fiber reinforced plastics and glass fiber reinforced plastics, 3D printing, etc.

[0222] (Examples)

[0223] Next, the present invention will be described in more detail based on the examples. Hereinafter, parts are by mass unless otherwise specified. In addition, the present invention is not limited by these examples.

[0224] Hereinafter, various analysis methods used in the examples will be described.

[0225] ·GPC (Gel Permeation Chromatography) analysis

[0226] Apparatus: On-line degassing unit (DGU-20A), liquid delivery unit (LC-20AD), automatic sampler (SIL-20A), photodiode array detector (SPD-M40), column oven (CTO-20A), system controller (CBM-20A), all manufactured by Shimadzu Corporation

[0227] Columns: SHODEX GPC KF-601 (2 pieces), KF-602, KF-602.5, KF-603

[0228] Flow rate: 1.5 ml / min.

[0229] Column temperature: 40 °C

[0230] Solvent used: THF (tetrahydrofuran)

[0231] Detector: Differential refractive index detector (RID-20A), manufactured by Shimadzu Corporation · LC-MS analysis (liquid chromatography mass spectrometry)

[0232] Equipment: System controller (SCL-40), degassing unit (DGU-405), liquid delivery unit (LC-40B XR), autosampler (SIL-40CXR), photodiode array detector (SPD-M40), column oven (CTO-40C), high-performance liquid chromatography mass spectrometer (LCMS-2050), all manufactured by Shimadzu Corporation

[0233] Column: Shim-pack Velox C18 (5 μm, 4.6 × 250 mm)

[0234] Flow rate: 0.4 ml / min.

[0235] Injection volume: 10 μL

[0236] Column temperature: 40 °C

[0237] Mobile phase A: 5 mM ammonium acetate aqueous solution

[0238] Mobile phase B: Acetonitrile

[0239] Gradient: Start the measurement with 60% of solution B, reach 100% of solution B in 7 minutes, and then maintain for 9 minutes

[0240] Ionization method: Atmospheric pressure chemical ionization method (APCI)

[0241] · Hydroxyl equivalent: Acetylate the sample in a pyridine solution using acetic anhydride. After the acetylation is completed, decompose the remaining acid anhydride with water, and titrate the free acetic acid amount using a 0.5 N KOH ethanol solution with a potentiometric titrator to determine the hydroxyl equivalent from the results.

[0242] · Viscosity (150 °C): Measure using a cone-plate viscometer according to the method of JIS K5600-2-3:2014.

[0243] · Softening point: Measure using a softening point tester FP90 from METLER TOLEDO. · Epoxy equivalent: Measure according to the method of JIS K-7236.

[0244] [Synthesis Example 1]

[0245] Nitrogen purging was carried out in a flask equipped with a thermometer, a cooling tube, a stirrer, and a Dean Stark apparatus, and 388.5 parts of α,α,α’,α’-tetramethyl-1,3-benzenedimethanol, 200 parts of toluene, 7.6 parts of p-toluenesulfonic acid, and 235.3 parts of phenol were added. After reacting at 80 to 90 °C for 1 hour, it took 30 minutes to draw out the generated water out of the system and raise the internal temperature to 122 °C. The reaction was directly carried out at this temperature for 7 hours and then left to cool to room temperature. The GPC chart of the reaction product is shown in Figure 1 (The number average molecular weight Mn is 965, and the weight average molecular weight Mw is 1266).

[0246] [Synthesis Example 2]

[0247] 600 parts of toluene was added to the reaction solution obtained in Synthesis Example 1, and the organic layer was washed with water until the drained water became neutral. The obtained organic layer was distilled off the solvent under reduced pressure at 180 °C to obtain 424.8 parts of phenol resin (P1). The GPC chart of the obtained phenol resin (P1) is shown in Figure 2 (The number average molecular weight Mn is 991, and the weight average molecular weight Mw is 1679). In addition, by 1 1H-NMR (manufactured by JEOL Ltd., 400 MHz, measurement solvent: deuterated chloroform) measurement, it was confirmed that a peak derived from the α-methylstyrene structure was present at 5.04 - 5.36 ppm.

[0248] [Synthesis Example 3]

[0249] Synthesis was carried out in the same manner as in Synthesis Example 2 except that 624 parts of toluene and 376.4 parts of phenol were used and the reaction temperature was changed to 112 °C to obtain 522.5 parts of phenol resin (P2). The hydroxyl equivalent was 214.6 g / eq., the viscosity at 150 °C was 0.68 Pa·s, and the softening point was 73.9 °C. The GPC chart of the obtained phenol resin (P2) is shown in Figure 3 (The number average molecular weight Mn is 755, and the weight average molecular weight Mw is 873). In addition, by 1 1H-NMR (manufactured by JEOL Ltd., 400 MHz, measurement solvent: deuterated chloroform) measurement, it was confirmed that a peak derived from the α-methylstyrene structure was present at 5.04 - 5.36 ppm.

[0250] [Synthesis Example 4]

[0251] A nitrogen purge was performed in a flask equipped with a thermometer, a cooling tube, and a stirrer, and 350 parts of P2 obtained in Synthesis Example 3, 906.5 parts of epichlorohydrin, 302.2 parts of dimethyl sulfoxide, and 6.7 parts of water were added, and the internal temperature was raised to 55 °C. 70 parts of sodium hydroxide were added in portions over 90 minutes, and the reaction was carried out at 55 °C for 2 hours and at 70 °C for 1 hour. The solvent and excess epichlorohydrin were distilled off under reduced pressure, and 882 parts of methyl isobutyl ketone were added. After washing the organic layer with 400 parts of water, 21.7 parts of a 30 wt% aqueous sodium hydroxide solution were added, and the reaction was carried out at 75 °C for 1 hour. The organic layer was washed with water until the drained water became neutral. The resulting solution was distilled off the solvent under reduced pressure to obtain 388.7 parts of the epoxy resin (E1) of the present invention. The epoxy equivalent was 288.6 g / eq., the viscosity at 150 °C was 0.39 Pa·s, and the softening point was 53.6 °C. The GPC chart of the obtained epoxy resin (E1) is shown in Figure 4 (The number average molecular weight Mn was 740, and the weight average molecular weight Mw was 911). By LC-MS analysis, an adduct ion peak derived from the compound shown in the following formula (C) (mass-to-charge ratio m / z: 616) was detected.

[0252]

[0253] [Comparative Synthesis Example 1]

[0254] According to Example 7 of JP-A-2004-352938, an epoxy resin (E2) represented by the following formula (D) was synthesized.

[0255]

[0256] [Example 1]

[0257] The epoxy resin (E1) obtained in Synthesis Example 4 and 2-ethyl-4-methylimidazole (2E4MZ) as a curing accelerator in the amounts shown in Table 1 were sandwiched between mirror copper foils (T4X: manufactured by Fukuda Metal Foil Co., Ltd.) and subjected to vacuum pressure molding, and cured at 220 °C for 2 hours. At this time, a spacer was made by hollowing out 150 mm in both the horizontal and vertical directions in the center of a cushion paper with a thickness of 250 μm. At the time of evaluation, the test piece was cut into a desired size using a laser cutting knife as needed for evaluation.

[0258] [Comparative Example 1]

[0259] Using the epoxy resin (E2) obtained in Comparative Synthesis Example 1 and 2-ethyl-4-methylimidazole (2E4MZ) as a curing accelerator in the amounts shown in Table 1, sandwich with a mirror copper foil (T4X: manufactured by Fukuda Metal Foil & Powder Co., Ltd.) and perform vacuum pressure molding, and cure at 220 °C for 2 hours. At this time, a spacer was used by hollowing out 150 mm in both the vertical and horizontal directions in the center of a cushioning paper with a thickness of 250 μm. At the time of evaluation, the test piece was cut into a desired size using a laser cutter as needed to perform the evaluation.

[0260] <Dielectric Constant Test / Dielectric Loss Tangent Test>

[0261] Using a 10 GHz cavity resonator manufactured by AET Co., Ltd., the test was performed by the cavity resonance method at 25 °C. The sample size was set to a width of 1.7 mm × a length of 100 mm, and the test was performed with a thickness of 0.3 mm. The evaluation results are shown in Table 1.

[0262] [Table 1]

[0263]

[0264] · 2E4MZ: 2-ethyl-4-methylimidazole

[0265] From the results in Table 1, it was confirmed that the dielectric constant and dielectric loss tangent of the epoxy resin (E1) of Example 1 were smaller than those of the epoxy resin (E2) of Comparative Example 1, and the low dielectric characteristics were excellent.

[0266] This application claims priority based on Japanese Patent Application No. 2022-195053 filed on December 6, 2022.

[0267] [Industrial Applicability]

[0268] The epoxy resin of the present invention can be suitably used for electrical / electronic parts such as semiconductor encapsulation materials, printed wiring boards, build-up laminates, and optical waveguide devices.

Claims

1. An epoxy resin represented by the following formula (1), wherein: In formula (1), multiple Rs present independently and represent a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms; Q represents a substituent represented by the following formula (1-1); l represents an integer from 0 to 3, m represents an integer from 1 to 4, p represents an integer from 0 to 3, q represents an integer from 0 to 3, r represents an integer from 0 to 4, and n is the average value of the number of repeating units and represents a number from 1 to 50; In formula (1-1), R represents a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, s represents an integer from 1 to 4, and * represents the bonding position to the aromatic ring of formula (1).

2. A curable resin composition containing the epoxy resin according to claim 1.

3. The curable resin composition according to claim 2, further containing a curing agent and / or a curing accelerator.

4. A cured product obtained by curing the curable resin composition according to claim 3.

5. A phenol resin represented by the following formula (a), wherein: In formula (a), multiple Rs present independently and represent a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms; Q represents a substituent represented by the following formula (a-1); l represents an integer from 0 to 3, m represents an integer from 1 to 4, p represents an integer from 0 to 3, q represents an integer from 0 to 3, r represents an integer from 0 to 4, and n is the average value of the number of repeating units and represents a number from 1 to 50; In formula (a-1), R represents a hydrogen atom or a hydrocarbon group having 1 to 5 carbon atoms, s represents an integer from 1 to 4, and * represents the bonding position to the aromatic ring of formula (a).

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