Sclerosing resin, sclerosing resin composition, and hardened product

Abstract

The present invention provides a cured product having excellent heat resistance and dielectric properties (low dielectric properties) by using a curable resin having a specific structure and a curable resin composition containing the curable resin, a prepreg having these properties, a circuit board, an interlayer film, a semiconductor encapsulant, and a semiconductor device. Specifically, a curable resin is provided, which is characterized by having a structural unit (1) represented by the following general formula (1) and a terminal structure (2) represented by the following general formula (2). (In the general formula (1) and the general formula (2), the details of R1, R2, R3, k, and X are as described herein)

Description

Technical Field

[0001] The present invention relates to a curable resin having a specific structure, a curable resin composition containing the curable resin, and a cured product obtained from the curable resin composition. Background Art

[0002] With the increase in information communication volume in recent years, information communication in high frequency bands has been actively carried out. In order to obtain more excellent electrical characteristics, particularly to reduce transmission loss in high frequency bands, an electrical insulating material having a low dielectric constant and a low dielectric loss tangent is required.

[0003] Furthermore, printed circuit boards or electronic components using these electrical insulating materials are exposed to high-temperature reflow soldering during installation. Therefore, a material having excellent heat resistance and a high glass transition temperature is required. In particular, recently, from the perspective of environmental issues, lead-free solders with a high melting point are used, so the demand for electrical insulating materials with even higher heat resistance is increasing.

[0004] In response to these requirements, vinyl-containing curable resins having various chemical structures have been proposed since before. As such curable resins, for example, divinylbenzyl ethers of bisphenol or polyvinylbenzyl ethers of novolac have been proposed (for example, refer to Patent Document 1 and Patent Document 2). However, these vinylbenzyl ethers cannot provide a cured product with a sufficiently small dielectric property. The obtained cured product has problems in terms of stable use in high frequency bands. Furthermore, the divinylbenzyl ether of bisphenol is not sufficiently high in terms of heat resistance.

[0005] Regarding vinylbenzyl ethers for improving the above characteristics, in order to improve dielectric properties and the like, several polyvinylbenzyl ethers with specific structures have been proposed (for example, refer to Patent Documents 3 to 5). However, although attempts have been made to suppress the dielectric loss tangent or to improve heat resistance, the improvement of these characteristics is not yet sufficient, and further improvement of the characteristics is expected.

[0006] Thus, vinyl-containing curable resins containing existing polyvinylbenzyl ethers cannot provide a cured product that combines a low dielectric loss tangent necessary for use as an electrical insulating material, particularly for electrical insulating materials for high frequencies, and heat resistance that can withstand lead-free solder processing.

[0007] Prior Art Documents

[0008] Patent Documents

[0009] Patent Document 1: Japanese Patent Laid-Open No. 63-68537

[0010] Patent Document 2: Japanese Patent Laid-Open No. 64-65110

[0011] Patent Document 3: Japanese Patent Publication No. Hei 1-503238

[0012] Patent Document 4: Japanese Patent Laid-Open No. Hei 9-31006

[0013] Patent Document 5: Japanese Patent Laid-Open No. 2005-314556 Summary of the Invention

[0014] Problems to be Solved by the Invention

[0015] Therefore, the problem to be solved by the present invention is to provide a cured product having excellent heat resistance (high glass transition temperature) and low dielectric properties by using a curable resin having a specific structure.

[0016] Technical Means for Solving the Problem

[0017] Therefore, the present inventors made diligent studies to solve the above problems, and as a result, found that a curable resin that contributes to heat resistance and low dielectric properties and a cured product obtained from a curable resin composition containing the curable resin have excellent heat resistance and low dielectric properties, thereby completing the present invention.

[0018] That is, the present invention relates to a curable resin characterized by having a structural unit (1) represented by the following general formula (1) and a terminal structure (2) represented by the following general formula (2).

[0019] [Chemical Formula 1]

[0020]

[0021] [Chemical Formula 2]

[0022]

[0023] (In the general formula (1) and the general formula (2), each R1 independently represents an alkyl group, an aryl group, an aralkyl group or a cycloalkyl group having 1 to 12 carbon atoms, and k represents an integer of 1 to 3. Each R2 independently represents a hydrogen atom or a methyl group. X represents a (meth)acryloyloxy group, a vinylbenzyl ether group or an allyl ether group. In addition, in the general formula (2), each R3 independently represents an alkyl group, an aryl group, an aralkyl group, a cycloalkyl group or an alkenyl group having 1 to 12 carbon atoms)

[0024] The curable resin of the present invention is preferably represented by the following general formula (1-1) for the general formula (1).

[0025] [Chemical Formula 3]

[0026]

[0027] The curable resin of the present invention is preferably represented by the following general formula (2-1) for the general formula (2).

[0028] [Chemical Formula 4]

[0029]

[0030] (In the general formula (2-1), R4 represents a hydrogen atom, a methyl group or a phenyl group, and R5 represents an alkyl group having 1 to 4 carbon atoms)

[0031] The curable resin of the present invention is preferably represented by the following general formula (1-2) for the general formula (1), and the general formula (2) is represented by the following general formula (2-2) or general formula (2-3).

[0032] [Chemical Formula 5]

[0033]

[0034] [Chemical Formula 6]

[0035]

[0036] [Chemical Formula 7]

[0037]

[0038] (In the general formula (1-2), general formula (2-2) and general formula (2-3), R6 independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an aryl group, an aralkyl group or a cycloalkyl group)

[0039] The curable resin of the present invention preferably has a weight average molecular weight of 500 to 50,000.

[0040] The present invention relates to a curable resin composition containing the curable resin.

[0041] The present invention relates to a cured product obtained by subjecting the curable resin composition to a curing reaction.

[0042] Effects of the Invention

[0043] The curable resin of the present invention can contribute to heat resistance and low dielectric properties, and thus the cured product obtained from the curable resin composition containing the curable resin is excellent and useful in heat resistance and low dielectric properties (especially low dielectric loss tangent). Detailed Description of the Invention

[0044] The present invention will be described in detail below.

[0045] <Curable Resin>

[0046] The present invention relates to a curable resin, which is characterized by having a structural unit (1) represented by the following general formula (1) and a terminal structure (2) represented by the following general formula (2).

[0047] [Chemical formula 8]

[0048]

[0049] [Chemical formula 9]

[0050]

[0051] (In the general formula (1) and the general formula (2), R1 independently represents an alkyl group, an aryl group, an aralkyl group or a cycloalkyl group having 1 to 12 carbon atoms, and k represents an integer of 1 to 3. R2 independently represents a hydrogen atom or a methyl group. X represents a (meth)acryloyloxy group, a vinylbenzyl ether group or an allyl ether group. In addition, in the general formula (2), R3 independently represents an alkyl group, an aryl group, an aralkyl group, a cycloalkyl group or an alkenyl group having 1 to 12 carbon atoms)

[0052] Since the terminal structure and the main chain structure of the curable resin have specific structures, the proportion of polar functional groups in the structure of the curable resin is reduced, and the cured product manufactured using the curable resin has excellent low dielectric properties, which is therefore preferable. In addition, since the curable resin has a crosslinking group, the obtained cured product has excellent heat resistance, which is therefore preferable.

[0053] In the general formula (1), R1 independently represents an alkyl group, an aryl group, an aralkyl group or a cycloalkyl group having 1 to 12 carbon atoms, preferably an alkyl group, an aryl group or a cycloalkyl group having 1 to 6 carbon atoms. Since R1 is an alkyl group or the like having 1 to 12 carbon atoms, the planarity near the benzene ring in the general formula (1) is reduced, the crystallinity is reduced, whereby the solvent solubility is improved, and at the same time the melting point becomes low, which becomes a preferable form.

[0054] In the general formula (1), k represents an integer of 1 to 3, preferably an integer of 1 to 2. Since k is within the above range, the planarity near the benzene ring in the general formula (1) is reduced, the crystallinity is reduced, whereby the solvent solubility is improved, and at the same time the melting point becomes low, which becomes a preferable form.

[0055] In the general formula (1), R2 is independently a hydrogen atom or a methyl group. Since R2 is a hydrogen atom or the like, the dielectric constant becomes low, which becomes a preferable form.

[0056] In the general formula (1), X is a (meth)acryloyloxy group, a vinylbenzyl ether group, or an allyl ether group, preferably a (meth)acryloyloxy group, and more preferably a methacryloyloxy group. By having the crosslinking group in the curable resin, a cured product having a low dielectric loss tangent can be obtained, which is a preferred form. Furthermore, it is speculated that compared with other crosslinking groups (for example, an ether group such as a vinylbenzyl ether group or an allyl ether group as a polar group), since the structure of the curable resin contains a methyl group, the steric hindrance becomes larger and the molecular mobility becomes further lower, and a cured product with a lower dielectric loss tangent can be obtained, so it is preferred. In addition, when there are a plurality of crosslinking groups, the crosslinking density increases and the heat resistance increases.

[0057] In addition, although X as the crosslinking group is also a polar group, due to the adjacency of R1 as a substituent, steric hindrance will occur, the molecular mobility of X is inhibited, and the dielectric loss tangent of the obtained cured product becomes low, which is a preferred form.

[0058] In the general formula (2), R3 each independently represents an alkyl group, an aryl group, an aralkyl group, a cycloalkyl group, or an alkenyl group having 1 to 12 carbon atoms, preferably an alkyl group, an aryl group, or a cycloalkyl group having 1 to 10 carbon atoms. By having R3 as an alkyl group having 1 to 12 carbon atoms or the like, the planarity near the benzene ring in the general formula (2) is reduced, the crystallinity is reduced, thereby the solvent solubility is increased, and at the same time the melting point becomes low, which is a preferred form. In addition, although X as the crosslinking group is also a polar group, due to the adjacency of R3 as a substituent, steric hindrance will occur, the molecular mobility of X is inhibited, and the dielectric loss tangent of the obtained cured product becomes low, which is a preferred form.

[0059] The curable resin of the present invention is characterized by containing the general formula (1) and the general formula (2), preferably a structure formed by repeating the structural unit (1) and a terminal structure based on the general formula (2). As structures (or structural units) other than the structural unit (1) and the terminal structure (2), a phenylethylene skeleton (structure), an indane skeleton (structure), a dicyclopentadiene skeleton (structure), an aralkyl group (structure) having a substituent, etc. may also be included. That is, the structural unit (1) can form a block structure, and within the range that does not affect the characteristics of the present invention, it can also form a random structure together with other structural units. The polarity of the phenylethylene skeleton (structure), etc. other than the structural unit (1) and the terminal structure (2) is small and is not a structure that increases the dielectric constant or the dielectric loss tangent, so it does not particularly affect the characteristics of the curable resin in the present invention.

[0060] The curable resin of the present invention is preferably represented by the following general formula (1-1) for the general formula (1).

[0061] [Chemical formula 10]

[0062]

[0063] The curable resin of the present invention is preferably represented by the following general formula (2-1) from the general formula (2).

[0064] [Chemical formula 11]

[0065]

[0066] In the general formula (2-1), R4 is preferably represented by a hydrogen atom, a methyl group or a phenyl group, more preferably a hydrogen atom or a methyl group, and R5 is preferably represented by an alkyl group having 1 to 4 carbon atoms, more preferably an alkyl group having 1 to 2 carbon atoms. When R4 is the hydrogen atom or the like, the tangent of dielectric loss becomes low, resulting in a preferred form. In addition, when R5 is the alkyl group or the like, the tangent of dielectric loss becomes low, resulting in a preferred form.

[0067] The curable resin of the present invention is preferably represented by the following general formula (1-2) from the general formula (1), and the general formula (2) is represented by the following general formula (2-2) or general formula (2-3).

[0068] [Chemical formula 12]

[0069]

[0070] [Chemical formula 13]

[0071]

[0072] [Chemical formula 14]

[0073]

[0074] In the general formula (1-2), general formula (2-2) and general formula (2-3), R6 is preferably independently represented by a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an aryl group, an aralkyl group or a cycloalkyl group, more preferably represented by a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group or a cycloalkyl group. When R6 is the hydrogen atom or the like, the tangent of dielectric loss becomes low, resulting in a preferred form.

[0075] Furthermore, in the general formulas (1) to (2-3), the same symbol, or the same substituent and the same functional group (k, X, R1, etc.) are made common. The same also applies to the following general formulas (3-1) to (7) described later.

[0076] <Manufacturing method of intermediate phenolic compound>

[0077] As the manufacturing method of the curable resin, first, the manufacturing method of the intermediate phenolic compound as the raw material (precursor) of the curable resin will be described below.

[0078] As a method for producing the intermediate phenolic compound, an aralkyl compound represented by the following general formula (3-1) or general formula (3-2) (hereinafter, sometimes referred to as "compound (a)") is mixed with phenol or a derivative thereof represented by the following general formula (4) (hereinafter, sometimes referred to as "compound (b)"), and the reaction product (c) is obtained by reacting in the presence of an acid catalyst. Then, an aralkyl compound represented by the following general formula (5-1) or general formula (5-2) (hereinafter, sometimes referred to as "compound (d)") is reacted with the reaction product (c), and the intermediate phenolic compound having the structural unit (6) represented by the following general formula and the terminal structure represented by the following general formula (7) can be obtained.

[0079] In addition, as a method for producing the intermediate phenolic compound, the compound (b) and the compound (d) can be added simultaneously, and the intermediate phenolic compound can be synthesized by one-pot.

[0080] Furthermore, in the general formula (3-1), Y is preferably a halogen atom, a hydroxyl group or an oxyalkyl group, more preferably a hydroxyl group.

[0081] [Chemical formula 15]

[0082]

[0083] [Chemical formula 16]

[0084]

[0085] [Chemical formula 17]

[0086]

[0087] [Chemical formula 18]

[0088]

[0089] [Chemical formula 19]

[0090]

[0091] [Chemical formula 20]

[0092]

[0093] [Chemical formula 21]

[0094]

[0095] As specific examples of the compound (a), the following can be cited: 1,2-bis(chloromethyl)benzene, 1,2-bis(bromomethyl)benzene, 1,3-bis(chloromethyl)benzene, 1,3-bis(fluoromethyl)benzene, 1,4-bis(chloromethyl)benzene, 1,4-bis(bromomethyl)benzene, 1,4-bis(fluoromethyl)benzene, 1,4-bis(chloromethyl)-2,5-dimethylbenzene, 1,3-bis(chloromethyl)-4,6-dimethylbenzene, 1,3-bis(chloromethyl)-2,4-dimethylbenzene, 4,4'-bis(chloromethyl)biphenyl, 2,2'-bis(chloromethyl)biphenyl, 2,4'-bis(chloromethyl)biphenyl, 2,3'-bis(chloromethyl)biphenyl, 4,4'-bis(bromomethyl)biphenyl, 4,4'-bis(chloromethyl)diphenyl ether, 2,7-bis(chloromethyl)naphthalene, p-xylene glycol, m-xylene glycol, 1,4-bis(2-hydroxy-2-ethyl)benzene, 4,4'-bis(dihydroxymethyl)biphenyl, 2,4'-bis(dihydroxymethyl)biphenyl, 4,4'-bis(2-hydroxy-2-propyl)biphenyl, 2,4'-bis(2-hydroxy-2-propyl)biphenyl, 1,4'-bis(methoxymethyl)benzene, 1,4'-bis(ethoxymethyl)benzene, 1,4'-bis(isopropoxy)benzene, 1,4'-bis(butoxy)benzene, 1,3'-bis(methoxymethyl)benzene, 1,3'-bis(ethoxymethyl)benzene, 1,3'-bis(isopropoxy)benzene, 1,3'-bis(butoxy)benzene, 1,4-bis(2-methoxy-2-ethyl)benzene, 1,4-bis(2-hydroxy-2-ethyl)benzene, 1,4-bis(2-ethoxy-2-ethyl)benzene, 4,4'-bis(methoxymethyl)biphenyl, 2,4'-bis(methoxymethyl)biphenyl, 2,2'-bis(methoxymethyl)biphenyl, 2,3'-bis(methoxymethyl)biphenyl, 3,3'-bis(methoxymethyl)biphenyl, 3,4'-bis(methoxymethyl)biphenyl, 4,4'-bis(ethoxymethyl)biphenyl, 2,4'-bis(ethoxymethyl)biphenyl, 4,4'-bis(isopropoxy)methylbiphenyl, 2,4'-bis(isopropoxy)methylbiphenyl, bis(1-methoxy-1-ethyl)biphenyl, bis(1-methoxy-1-ethyl)biphenyl, bis(1-isopropoxy-1-ethyl)biphenyl, bis(2-hydroxy-2-propyl)biphenyl, bis(2-methoxy-2-propyl)biphenyl, bis(2-isopropoxy-2-propyl)biphenyl, 1,3-bis(α-hydroxyisopropyl)benzene, 1,4-bis(α-hydroxyisopropyl)benzene, p-divinylbenzene, m-divinylbenzene, 4,4'-bis(vinyl)biphenyl, 1,3-bis(1-hydroxyethyl)benzene, 1,4-bis(1-hydroxyethyl)benzene, etc. These compounds (a) can be used separately or in combination of two or more kinds.Among them, as the compound (a), from the viewpoint of easy availability in industry, for example, using p-xylene glycol, m-xylene glycol, 1,3-bis(α-hydroxyisopropyl)benzene, 1,4-bis(α-hydroxyisopropyl)benzene, p-divinylbenzene, m-divinylbenzene becomes a more preferred form.

[0096] There is no particular limitation on the compound (b). Specifically, examples include: cresols such as o-cresol, m-cresol, p-cresol; xylenols such as 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol (2,6-dimethylphenol), 3,4-xylenol, 3,5-xylenol, 3,6-xylenol; 2,3,5-trimethylphenol, 2,3,6-trimethylphenol; ethylphenols such as o-ethylphenol (2-ethylphenol), m-ethylphenol, p-ethylphenol; butylphenols such as isopropylphenol, butylphenol, p-tert-butylphenol; alkylphenols such as p-amylphenol, p-octylphenol, p-nonylphenol, p-cumylphenol; monosubstituted phenols such as o-phenylphenol (2-phenylphenol), p-phenylphenol, 2-cyclohexylphenol, 2-benzylphenol, etc. These compounds (b) can be used alone or in combination of two or more. Among them, from the viewpoint of easy availability in industry, as the compound (b), for example, using cresol or xylenol becomes a more preferred form. Among them, if the steric hindrance is too large, there is also a concern about hindering the reactivity during the synthesis of the intermediate phenolic compound. Therefore, it is preferred to use, for example, the compound (b) having a methyl group, an ethyl group, a cyclohexyl group, or a phenyl group.

[0097] In the method for manufacturing the intermediate phenolic compound, by charging the compound (a) and the compound (b) with the molar ratio of the compound (b) to the compound (a) (compound (b) / compound (a)) preferably being 2.5 / 1 to 1.05 / 1, more preferably 2 / 1 to 1.1 / 1, and reacting them in the presence of an acid catalyst, the reaction product (c) of the compound (a) and the compound (b) can be obtained.

[0098] Examples of the acid catalyst used in the reaction include: inorganic acids such as phosphoric acid, hydrochloric acid, sulfuric acid; organic acids such as oxalic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, fluoromethanesulfonic acid; solid acids such as activated clay, acid clay, silica-alumina, zeolite, strongly acidic ion exchange resin; heteropolyacids, etc. However, it is preferred to use oxalic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, fluoromethanesulfonic acid, which are homogeneous catalysts that can be easily removed by neutralization with an alkali and washing with water after the reaction.

[0099] Regarding the blending amount of the acid catalyst, relative to 100 parts by mass of the total amount of the compound (a) and the compound (b) initially charged as raw materials, the acid catalyst is blended in the range of 0.001 part by mass to 40 parts by mass. However, in terms of processability and economy, it is preferably in the range of 0.001 part by mass to 25 parts by mass.

[0100] The reaction temperature is generally in the range of 80°C to 200°C. However, in order to suppress the formation of isomeric structures, avoid side reactions such as thermal decomposition, and obtain a high-purity intermediate phenolic compound, it is preferably in the range of 100°C to 150°C.

[0101] As the reaction time, since the reaction cannot be completed in a short time, and if it is set for a long time, side reactions such as thermal decomposition of the product will occur. Therefore, under the reaction temperature conditions, it is generally in the range of a total of 0.5 hours to 24 hours, preferably in the range of a total of 0.5 hours to 15 hours.

[0102] Specific examples of the compound (d) (functioning as a terminal sealant) are not particularly limited. Specifically, examples include: styrene, styrene dimer, α-methylstyrene, α-methylstyrene dimer, methylstyrene, vinyltoluene, ethylstyrene, tert-butylstyrene and other styrenes or styrene derivatives, vinylnaphthalene, vinylbiphenyl, diphenylethylene, 1-octene, etc.

[0103] Regarding the blending amount of the compound (d), relative to 100 parts by mass of the total amount of the compound (a) and the compound (b) initially charged as raw materials, the compound (d) is blended in the range of 1 part by mass to 200 parts by mass. However, in terms of reactivity, it is preferably in the range of 10 parts by mass to 100 parts by mass.

[0104] The reaction temperature between the compound (b) and the reaction product (c) is generally in the range of 80°C to 200°C. However, in order to suppress the formation of isomeric structures, avoid side reactions such as thermal decomposition, and obtain a high-purity intermediate phenolic compound, it is preferably in the range of 100°C to 150°C.

[0105] As the reaction time, since the reaction cannot be completed in a short time, and if it is set for a long time, side reactions such as thermal decomposition of the product will occur. Therefore, under the reaction temperature conditions, it is generally in the range of a total of 0.5 hours to 24 hours, preferably in the range of a total of 0.5 hours to 15 hours.

[0106] Furthermore, when the reaction product (c) reacts with the compound (d), the acid catalyst used in the reaction of the above-mentioned compound (a) and the compound (b) can be similarly used.

[0107] In the method for manufacturing the intermediate phenolic compound, the raw material sometimes also serves as a solvent, so it may not be necessary to use other solvents, but solvents can also be used. In addition, regarding the solvent generated during the reaction (such as methanol, etc.), a method of distilling it off and then carrying out the reaction within the range of the reaction temperature can also be adopted.

[0108] Examples of the organic solvent used for synthesizing the intermediate phenolic compound include: ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, cyclohexanone, and acetophenone; alcohols such as 2-ethoxyethanol and methanol; aprotic solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, acetonitrile, and sulfolane; cyclic ethers such as dioxane and tetrahydrofuran; esters such as ethyl acetate and butyl acetate; and aromatic solvents such as benzene, toluene, and xylene. In addition, these can be used alone or in combination.

[0109] Regarding the hydroxyl equivalent (phenol equivalent) of the intermediate phenolic compound, from the viewpoint of heat resistance, it is preferably 100 g / eq to 1000 g / eq, more preferably 200 g / eq to 500 g / eq. Furthermore, the hydroxyl equivalent (phenol equivalent) of the intermediate phenolic compound is calculated by a titration method, which refers to the neutralization titration method based on Japanese Industrial Standards (JIS) K0070.

[0110] <Manufacturing Method of Curable Resin>

[0111] Hereinafter, the manufacturing method of the curable resin (introducing a (meth)acryloyloxy group, a vinyl benzyl ether group, or an allyl ether group into the intermediate phenolic compound) will be described.

[0112] The curable resin can be obtained by a known method such as reacting (meth)acrylic anhydride, (meth)acryloyl chloride, chloromethylstyrene, chlorostyrene, allyl chloride, or allyl bromide (hereinafter sometimes referred to as "compound (e)") with the intermediate phenolic compound in the presence of a basic or acidic catalyst. By reacting them, a crosslinking group (X) can be introduced into the intermediate phenolic compound, and in addition, a thermosetting property with a low dielectric constant and a low dielectric loss tangent is formed, resulting in a preferred form.

[0113] Regarding the compound (e) (functioning as a crosslinking group introducing agent), examples of the (meth)acrylic anhydride include acrylic anhydride and methacrylic anhydride. Examples of the (meth)acryloyl chloride include methacryloyl chloride and acryloyl chloride. Further, examples of chloromethylstyrene include p-chloromethylstyrene and m-chloromethylstyrene, examples of chlorostyrene include p-chlorostyrene and m-chlorostyrene, examples of allyl chloride include 3-chloro-1-propene, and examples of allyl bromide include 3-bromo-1-propene. These can be used alone or in combination. Among them, methacrylic anhydride or methacryloyl chloride that can obtain a cured product with a lower dielectric loss tangent is preferably used.

[0114] Specific examples of the basic catalyst include dimethylaminopyridine, alkaline earth metal hydroxides, alkali metal carbonates, and alkali metal hydroxides. Specific examples of the acidic catalyst include sulfuric acid and methanesulfonic acid. In particular, dimethylaminopyridine is excellent in terms of catalyst activity.

[0115] Examples of the reaction between the intermediate phenolic compound and the compound (e) include the following method: relative to 1 mole of the hydroxyl group contained in the intermediate phenolic compound, 1 mole to 10 moles of the compound (e) is added, and 0.01 mole to 0.2 mole of a basic catalyst is added all at once or slowly, and the reaction is carried out at a temperature of 30°C to 150°C for 1 hour to 40 hours.

[0116] Further, when reacting with the compound (e) (introduction of a crosslinking group), an organic solvent is used in combination, whereby the reaction rate during the synthesis of the curable resin can be increased. There is no particular limitation on such an organic solvent, and examples include ketones such as acetone and methyl ethyl ketone, alcohols such as methanol, ethanol, 1-propanol, isopropyl alcohol, 1-butanol, sec-butanol, and tert-butanol, cellosolves such as methyl cellosolve and ethyl cellosolve, ethers such as tetrahydrofuran, 1,4-dioxane, 1,3-dioxane, and diethoxyethane, aprotic polar solvents such as acetonitrile, dimethyl sulfoxide, and dimethylformamide, and toluene. These organic solvents can be used alone, and in addition, two or more of them can be appropriately used in combination to adjust the polarity.

[0117] After the reaction (introduction of a crosslinking group) with the compound (e) is completed, the reaction product is reprecipitated in a poor solvent, and the precipitate is stirred in the poor solvent at a temperature of 20°C to 100°C for 0.1 hour to 5 hours. After filtration under reduced pressure, the precipitate is dried at a temperature of 40°C to 80°C for 1 hour to 10 hours, whereby the target curable resin can be obtained. Examples of the poor solvent include hexane.

[0118] Furthermore, the curable resin of the present invention is characterized by containing the general formula (1) and the general formula (2), preferably a structure formed by repeating the structural unit (1) and a terminal structure based on the general formula (2). According to the manufacturing method, as a side reaction, even if it contains structures other than these structural units (1) and the terminal structure (2), as long as it does not affect the properties of the curable resin in the present invention, there is no particular problem.

[0119] The weight average molecular weight (Mw) of the curable resin of the present invention is preferably 500 to 50,000, more preferably 500 to 20,000, and still more preferably 800 to 10,000. When the weight average molecular weight of the curable resin is within the above range, the workability or the molding processability is excellent, and thus it is preferred.

[0120] As the softening point of the curable resin, it is preferably 150 °C or lower, more preferably 50 °C to 100 °C. When the softening point of the curable resin is within the above range, the processability is excellent, and thus it is preferred.

[0121] <Curable Resin Composition>

[0122] The curable resin composition of the present invention preferably contains the curable resin. Since the curable resin has a substituent R1 in the structure and -C(CH3)R3R3 in the terminal structure, the molecular motion of the crosslinking group is suppressed, and the low dielectric loss tangent is excellent. In addition, since it has -CR2R2-C6H4-CR2R2- in the structural unit, the free volume becomes small, the low dielectric constant is excellent, flexibility is exhibited, the solvent solubility is excellent, it is easy to prepare a curable resin composition, the handleability is excellent, and the proportion of polar functional groups in the structure of the curable resin is small. Therefore, the cured product obtained by using the curable resin composition has excellent low dielectric properties and becomes a preferred form.

[0123] 〔Other Resins, etc.〕

[0124] In the curable resin composition of the present invention, other resins, curing agents, curing accelerators, etc. can be used without particular limitation within the range that does not impair the object of the present invention. As described later, the curable resin can obtain a cured product by heating, etc. without blending a curing agent. For example, when other resins, etc. are blended together, a curing agent or a curing accelerator can be blended and used.

[0125] Furthermore, the curable resin composition of the present invention contains the curable resin. In the curable resin, when X is an allyl ether group, X is different from a (meth)acryloyloxy group and a vinyl benzyl ether group and cannot be polymerized (crosslinked) alone (a cured product cannot be obtained if alone). Therefore, when X is an allyl ether group, a curing agent, a curing accelerator, or the like must be used.

[0126] 〔Other resins〕

[0127] As the other resins, for example, vinyl group-containing compounds such as bismaleimide compounds, allyl ether-based compounds, allyl amine-based compounds, triallyl cyanurate, vinyl phenol-based compounds, vinyl group-containing polyolefin compounds, etc. may be added. In addition, other thermosetting resins such as thermosetting polyimide resins, epoxy resins, phenol resins, reactive ester resins, benzoxazine resins, cyanate ester resins, etc. may be appropriately blended according to the purpose.

[0128] 〔Curing agent〕

[0129] As the curing agent, for example, amine-based compounds, amide-based compounds, acid anhydride-based compounds, phenol-based compounds, cyanate ester compounds, etc. may be mentioned. These curing agents may be used alone or in combination of two or more.

[0130] 〔Curing accelerator〕

[0131] As the curing accelerator, various substances can be used. For example, phosphorus-based compounds, tertiary amines, imidazoles, organic acid metal salts, Lewis acids, amine complex salts, etc. may be mentioned. Especially when used as a semiconductor encapsulant, phosphorus-based compounds such as triphenylphosphine or imidazoles are preferred in terms of excellent curability, heat resistance, electrical properties, moisture resistance reliability, etc. These curing accelerators may be used alone or in combination of two or more.

[0132] 〔Flame retardant〕

[0133] In the curable resin composition of the present invention, a flame retardant may be blended as needed to exhibit flame retardancy, and a non-halogen-based flame retardant substantially free of halogen atoms is preferably blended. As the non-halogen-based flame retardant, for example, phosphorus-based flame retardants, nitrogen-based flame retardants, silicone-based flame retardants, inorganic-based flame retardants, organometallic salt-based flame retardants, etc. may be mentioned. These flame retardants may be used alone or in combination of two or more.

[0134] 〔Filler〕

[0135] In the curable resin composition of the present invention, an inorganic filler may be blended as needed. Examples of the inorganic filler include fused silica, crystalline silica, alumina, silicon nitride, aluminum hydroxide, etc. When the blending amount of the inorganic filler is particularly increased, it is preferable to use fused silica. The fused silica can be either in a crushed form or a spherical form, but in order to increase the blending amount of the fused silica and suppress the increase in the melt viscosity of the molding material, it is preferable to mainly use spherical silica. In order to further increase the blending amount of the spherical silica, it is preferable to appropriately adjust the particle size distribution of the spherical silica. In addition, when the curable resin composition is used for applications such as conductive paste described in detail below, a conductive filler such as silver powder or copper powder can be used.

[0136] 〔Other Blending Agents〕

[0137] In the curable resin composition of the present invention, various blending agents such as a silane coupling agent, a release agent, a pigment, an emulsifier, etc. may be added as needed.

[0138] <Cured Product>

[0139] The cured product of the present invention is preferably obtained by causing the curable resin composition to undergo a curing reaction. The curable resin composition can be obtained by the curable resin alone, or in addition to the curable resin, each component such as the curing agent is also uniformly mixed, and a cured product can be easily formed by the same method as a conventionally known method. Examples of the cured product include molded cured products such as laminates, castings, adhesive layers, coating films, and films.

[0140] Examples of the curing reaction include a thermal curing or ultraviolet curing reaction, etc. Among them, as the thermal curing reaction, it is easy to proceed even without a catalyst, but when a faster reaction is desired, it is effective to add a polymerization initiator such as an organic peroxide or an azo compound, or a basic catalyst such as a phosphine compound or a tertiary amine. Examples include benzoyl peroxide, dicumyl peroxide, azobisisobutyronitrile, triphenylphosphine, triethylamine, imidazoles, etc.

[0141] <Applications>

[0142] The cured product obtained from the curable resin composition of the present invention is excellent in heat resistance and low dielectric properties, and thus can be preferably used for heat-resistant members or electronic members. In particular, it can be preferably used for prepregs, circuit boards, semiconductor encapsulants, semiconductor devices, build-up films, build-up substrates, adhesives, or resist materials, etc. In addition, it can also be preferably used as the matrix resin of fiber-reinforced resins and is particularly suitable as a prepreg with high heat resistance. In addition, since the curable resin contained in the curable resin composition exhibits excellent solubility in various solvents, it can be made into a coating. The heat-resistant member or electronic member thus obtained can be preferably used for various applications, such as industrial machine parts, general machine parts, parts of automobiles / railways / vehicles, etc., space / aerospace-related parts, electronic / electrical parts, building materials, container / packaging members, daily necessities, sports / leisure goods, frame members for wind power generation, etc., but is not limited to these.

[0143] Examples

[0144] Hereinafter, the present invention will be specifically described by way of examples and comparative examples. Unless otherwise specified, "parts" and "%" are based on mass. Furthermore, the curable resin was synthesized under the following conditions, and the cured product obtained using the curable resin was measured and evaluated under the following conditions.

[0145] <GPC measurement (evaluation of the weight average molecular weight (Mw) of the curable resin)>

[0146] The measurement was carried out using the following measurement apparatus and measurement conditions to obtain the GPC chart of the curable resin obtained by the synthesis method shown below. Based on the results of the GPC chart, the weight average molecular weight (Mw) of the curable resin was calculated.

[0147] Measurement apparatus: "HLC-8320GPC" manufactured by Tosoh Corporation

[0148] Column: Guard column "HXL-L" manufactured by Tosoh Corporation + "TSK-GEL G2000HXL" manufactured by Tosoh Corporation + "TSK-GEL G2000HXL" manufactured by Tosoh Corporation + "TSK-GEL G3000HXL" manufactured by Tosoh Corporation + "TSK-GEL G4000HXL" manufactured by Tosoh Corporation

[0149] Detector: RI (differential refractometer)

[0150] Data processing: "GPC workstation EcoSEC-WorkStation" manufactured by Tosoh Corporation

[0151] Measurement conditions: Column temperature 40°C

[0152] Developing solvent: Tetrahydrofuran

[0153] Flow rate: 1.0 ml / min

[0154] Standard: According to the measurement manual of the "GPC workstation EcoSEC-WorkStation", the following monodisperse polystyrenes with known molecular weights are used.

[0155] (Using polystyrene)

[0156] "A-500" manufactured by Tosoh Corporation

[0157] "A-1000" manufactured by Tosoh Corporation

[0158] "A-2500" manufactured by Tosoh Corporation

[0159] "A-5000" manufactured by Tosoh Corporation

[0160] "F-1" manufactured by Tosoh Corporation

[0161] "F-2" manufactured by Tosoh Corporation

[0162] "F-4" manufactured by Tosoh Corporation

[0163] "F-10" manufactured by Tosoh Corporation

[0164] "F-20" manufactured by Tosoh Corporation

[0165] "F-40" manufactured by Tosoh Corporation

[0166] "F-80" manufactured by Tosoh Corporation

[0167] "F-128" manufactured by Tosoh Corporation

[0168] Sample: The sample is obtained by filtering a 1.0 mass% tetrahydrofuran solution of the curable resin obtained in the synthesis example in terms of solid content through a microfilter (50 μl).

[0169] (Example 1)

[0170] In a 3 L four-neck separable flask equipped with a stirrer, a cooling tube, a nitrogen inlet tube, and a thermometer, 324.4 g of o-cresol, 276.3 g of p-xylene glycol, and 19.0 g of p-toluenesulfonic acid monohydrate were charged, and the temperature was raised to 150 °C with stirring and reacted for 5 hours. During this period, the methanol generated by the reaction was removed outside the system. Then, the temperature was lowered to 120 °C, and 260.4 g of styrene was added dropwise over 5 hours and reacted to obtain an intermediate phenolic compound.

[0171] In a 100 mL four-neck flask equipped with a stirrer, a cooling tube, a nitrogen inlet tube, and a thermometer, 10.0 g of the synthesized intermediate phenolic compound, 10.0 g of N,N-dimethylformamide, 9.2 g of 4-chloromethylstyrene, and 7.0 g of a 48% aqueous potassium hydroxide solution were charged, and the temperature was raised to 60 °C with stirring and reacted for 20 hours. The reaction solution was poured into 100 g of methanol to reprecipitate the polymer. The polymer was redissolved in 100 g of tetrahydrofuran and again poured into 100 g of methanol to reprecipitate the polymer. The obtained polymer was washed twice with 100 g of methanol. Then, it was dried under reduced pressure at 50 °C for 2 hours to obtain a curable resin (Mw: 2100).

[0172] (Example 2)

[0173] In a 3 L four-neck separable flask equipped with a stirrer, a cooling tube, a nitrogen inlet tube, and a thermometer, 324.4 g of o-cresol, 388.5 g of 1,3-bis(α-hydroxyisopropyl)benzene, and 19.0 g of p-toluenesulfonic acid monohydrate were charged, and the temperature was raised to 150 °C with stirring and reacted for 5 hours. During this period, the water generated by the reaction was removed outside the system. Then, the temperature was lowered to 120 °C, and 260.4 g of styrene was added dropwise over 5 hours and reacted to obtain an intermediate phenolic compound.

[0174] In a 100 mL four-neck flask equipped with a stirrer, a cooling tube, a nitrogen inlet tube, and a thermometer, 10.0 g of the synthesized intermediate phenolic compound, 10.0 g of N,N-dimethylformamide, 9.2 g of 4-chloromethylstyrene, and 7.0 g of a 48% aqueous potassium hydroxide solution were charged, and the temperature was raised to 60 °C with stirring and reacted for 20 hours. The reaction solution was poured into 100 g of methanol to reprecipitate the polymer. The polymer was redissolved in 100 g of tetrahydrofuran and again poured into 100 g of methanol to reprecipitate the polymer. The obtained polymer was washed twice with 100 g of methanol. Then, it was dried under reduced pressure at 50 °C for 2 hours to obtain a curable resin (Mw: 2200).

[0175] (Example 3)

[0176] In a 3 L four-neck separable flask equipped with a stirrer, a cooling tube, a nitrogen inlet tube, and a thermometer, 324.4 g of o-cresol, 332.4 g of 1,4-bis(1-hydroxyethyl)benzene, and 19.0 g of p-toluenesulfonic acid monohydrate were charged, and the temperature was raised to 150 °C with stirring and reacted for 5 hours. During this period, the water generated by the reaction was removed outside the system. Then, the temperature was lowered to 120 °C, and 260.4 g of styrene was added dropwise over 5 hours and reacted to obtain an intermediate phenolic compound.

[0177] In a 100 mL four-neck flask equipped with a stirrer, a cooling tube, a nitrogen inlet tube, and a thermometer, 10.0 g of the synthesized intermediate phenolic compound, 10.0 g of N,N-dimethylformamide, 9.2 g of 4-chloromethylstyrene, and 7.0 g of 48% aqueous potassium hydroxide solution were charged, and the temperature was raised to 60 °C with stirring and reacted for 20 hours. The reaction solution was poured into 100 g of methanol to reprecipitate the polymer. The polymer was redissolved in 100 g of tetrahydrofuran and again poured into 100 g of methanol to reprecipitate the polymer. The obtained polymer was washed twice with 100 g of methanol. Then, it was dried under reduced pressure at 50 °C for 2 hours to obtain a curable resin (Mw: 2200).

[0178] (Example 4)

[0179] Synthesis was carried out in the same manner as in Example 3 except that 260.4 g of styrene in Example 3 was changed to 295.5 g of α-methylstyrene, and a curable resin (Mw: 2000) was obtained.

[0180] (Example 5)

[0181] Synthesis was carried out in the same manner as in Example 3 except that 260.4 g of styrene in Example 3 was changed to 295.5 g of 4-methylstyrene, and a curable resin (Mw: 1900) was obtained.

[0182] (Example 6)

[0183] Synthesis was carried out in the same manner as in Example 3 except that 260.4 g of styrene in Example 3 was changed to 450.8 g of 1,1-diphenylethylene, and a curable resin (Mw: 1900) was obtained.

[0184] (Example 7)

[0185] Synthesis was carried out in the same manner as in Example 3 except that 260.4 g of styrene in Example 3 was changed to 280.6 g of 1-octene, and a curable resin (Mw: 1800) was obtained.

[0186] (Example 8)

[0187] Except for changing 324.4 g of o - cresol in Example 3 to 366.5 g of 2 - ethylphenol, synthesis was carried out in the same manner as in Example 3 to obtain a curable resin (Mw: 1800).

[0188] (Example 9)

[0189] Except for changing 324.4 g of o - cresol in Example 3 to 510.6 g of 2 - phenylphenol, synthesis was carried out in the same manner as in Example 3 to obtain a curable resin (Mw: 1800).

[0190] (Example 10)

[0191] Except for changing 324.4 g of o - cresol in Example 3 to 528.8 g of 2 - cyclohexylphenol, synthesis was carried out in the same manner as in Example 3 to obtain a curable resin (Mw: 1900).

[0192] (Example 11)

[0193] Except for changing 324.4 g of o - cresol in Example 3 to 324.4 g of p - cresol, synthesis was carried out in the same manner as in Example 3 to obtain a curable resin (Mw: 2600).

[0194] (Example 12)

[0195] Except for changing 9.2 g of 4 - chloromethylstyrene in Example 3 to 9.3 g of methacrylic anhydride and changing 7.0 g of 48% aqueous potassium hydroxide solution to 0.2 g of 4 - dimethylaminopyridine, synthesis was carried out in the same manner as in Example 3 to obtain a curable resin (Mw: 2200).

[0196] (Example 13)

[0197] 324.4 g of o - cresol and 19.0 g of p - toluenesulfonic acid monohydrate were charged into a 3 L four - necked separable flask equipped with a stirrer, a cooling tube, a nitrogen inlet tube, and a thermometer. While stirring, the temperature was raised to 120°C, and 280.4 g of divinylbenzene was added dropwise over 5 hours and allowed to react. Then, 260.4 g of styrene was added dropwise over 5 hours and allowed to react to obtain an intermediate phenolic compound.

[0198] In a 100 mL four-necked flask equipped with a stirrer, a cooling tube, a nitrogen inlet tube, and a thermometer, 10.0 g of the synthesized intermediate phenolic compound, 10.0 g of N,N-dimethylformamide, 9.2 g of 4-chloromethylstyrene, and 7.0 g of a 48% aqueous potassium hydroxide solution were added. The mixture was heated to 60 °C with stirring and reacted for 20 hours. The reaction solution was poured into 100 g of methanol to reprecipitate the polymer. The polymer was redissolved in 100 g of tetrahydrofuran and again poured into 100 g of methanol to reprecipitate the polymer. The obtained polymer was washed twice with 100 g of methanol. Then, it was dried under reduced pressure at 50 °C for 2 hours to obtain a curable resin (Mw: 2100).

[0199] (Example 14)

[0200] Synthesis was carried out in the same manner as in Example 3, except that 324.4 g of o-cresol in Example 3 was changed to 366.49 g of 2,5-xylenol, to obtain a curable resin (Mw: 2300).

[0201] (Example 15)

[0202] Synthesis was carried out in the same manner as in Example 3, except that 324.4 g of o-cresol in Example 3 was changed to 408.54 g of 2,3,5-trimethylphenol, to obtain a curable resin (Mw: 2500).

[0203] (Example 16)

[0204] Synthesis was carried out in the same manner as in Example 3, except that 9.2 g of 4-chloromethylstyrene in Example 3 was changed to 7.3 g of bromoacrylate, and 7.0 g of a 48% aqueous potassium hydroxide solution was changed to 20.0 g of potassium carbonate, to obtain a curable resin (Mw: 1800).

[0205] (Comparative Example 1)

[0206] 282.3 g of phenol, 276.3 g of p-xylene glycol, and 19.0 g of p-toluenesulfonic acid monohydrate were added to a 3 L four-necked separable flask equipped with a stirrer, a cooling tube, a nitrogen inlet tube, and a thermometer. The mixture was heated to 150 °C with stirring and reacted for 5 hours. During this period, methanol generated by the reaction was removed outside the system to obtain an intermediate phenolic compound.

[0207] In a 100 mL four-necked flask equipped with a stirrer, a cooling tube, a nitrogen inlet tube, and a thermometer, 10.0 g of the synthesized intermediate phenolic compound, 10.0 g of N,N-dimethylformamide, 9.2 g of 4-chloromethylstyrene, and 7.0 g of a 48% aqueous potassium hydroxide solution were added. The mixture was heated to 60 °C with stirring and reacted for 20 hours. The reaction solution was poured into 100 g of methanol to reprecipitate the polymer. The polymer was redissolved in 100 g of tetrahydrofuran and again poured into 100 g of methanol to reprecipitate the polymer. The obtained polymer was washed twice with 100 g of methanol. Then, it was dried under reduced pressure at 50 °C for 2 hours to obtain a curable resin (Mw: 2300).

[0208] (Comparative Example 2)

[0209] 324.4 g of o-cresol, 276.3 g of p-xylene glycol, and 19.0 g of p-toluenesulfonic acid monohydrate were added to a 3 L four-necked separable flask equipped with a stirrer, a cooling tube, a nitrogen inlet tube, and a thermometer. The mixture was heated to 150 °C with stirring and reacted for 5 hours. During this period, the methanol generated by the reaction was removed outside the system to obtain an intermediate phenolic compound.

[0210] In a 100 mL four-necked flask equipped with a stirrer, a cooling tube, a nitrogen inlet tube, and a thermometer, 10.0 g of the synthesized intermediate phenolic compound, 10.0 g of N,N-dimethylformamide, 9.2 g of 4-chloromethylstyrene, and 7.0 g of a 48% aqueous potassium hydroxide solution were added. The mixture was heated to 60 °C with stirring and reacted for 20 hours. The reaction solution was poured into 100 g of methanol to reprecipitate the polymer. The polymer was redissolved in 100 g of tetrahydrofuran and again poured into 100 g of methanol to reprecipitate the polymer. The obtained polymer was washed twice with 100 g of methanol. Then, it was dried under reduced pressure at 50 °C for 2 hours to obtain a curable resin (Mw: 2400).

[0211] <Production of Resin Film (Cured Product)>

[0212] The curable resins (solid powders) obtained in the examples and comparative examples were placed in a 5 cm square mold frame, clamped with a stainless steel plate, and set in a vacuum press. It was pressurized to 1.5 MPa at normal pressure and room temperature. Next, after reducing the pressure to 10 torr, it was heated to a temperature 50 °C higher than the heat curing temperature over 30 minutes. Furthermore, after standing for 2 hours, it was slowly cooled to room temperature. As a result, a uniform resin film (cured product) with an average film thickness of 100 μm was produced.

[0213] Furthermore, in Example 16 (where X is an allyl ether group), homopolymerization (crosslinking) of the curable resin alone is not carried out. Therefore, only the manufacture of the curable resin is confirmed, and the evaluation of the resin film (cured product) based on the following is not carried out.

[0214] <Evaluation of Dielectric Properties>

[0215] Regarding the in-plane dielectric properties of the obtained resin film (cured product), using the network analyzer N5247A of Keysight Technology, the dielectric constant and dielectric loss tangent at a frequency of 10 GHz are measured by the split dielectric resonator method. Furthermore, as the dielectric loss tangent, if it is 10×10 -3 or less, there is no practical problem, preferably 5.5×10 -3 or less, and more preferably 4.5×10 -3 or less. In addition, as the dielectric constant, if it is 3 or less, there is no practical problem, preferably 2.8 or less, and more preferably 2.6 or less.

[0216] <Evaluation of Heat Resistance (Glass Transition Temperature)>

[0217] For the obtained resin film (cured product), using a differential scanning calorimeter (DSC) device (Pyris Diamond) manufactured by PerkinElmer, after observing the exothermic peak temperature (thermal curing temperature) that can be observed when measuring from room temperature under a temperature increase condition of 20 °C / minute, it is held at a temperature 50 °C higher than that for 30 minutes. Then, the sample is cooled to room temperature under a temperature decrease condition of 20 °C / minute, and then heated again under a temperature increase condition of 20 °C / minute to measure the glass transition temperature (Tg) (°C) of the resin film (cured product). Furthermore, as the glass transition temperature (Tg), if it is 100 °C or higher, there is no practical problem, preferably 130 °C or higher, and more preferably 150 °C or higher.

[0218] [Table 1]

[0219]

[0220] Note) Regarding R1 in Table 1 above, in Examples 1 to 10, Example 12, and Example 13, a methyl group or the like is present at the ortho position relative to the crosslinking group X. In addition, a methyl group is present at the ortho position relative to the crosslinking group X in Example 11, a methyl group is present at the ortho position (2-) and meta position (5-) relative to the crosslinking group X in Example 14, and a methyl group is present at the ortho position (2-), meta position (3-), and meta position (5-) relative to the crosslinking group X in Example 15.

[0221] [Table 2]

[0222]

[0223] Note) In Table 1 and Table 2 above, Ph represents phenyl and Cy represents cyclohexyl.

[0224] Based on the evaluation results of Table 1 and Table 2 above, it can be confirmed that in all examples, the cured product obtained by using the curable resin can achieve coexistence of heat resistance and low dielectric properties, which is at a level with no practical problems.

[0225] On the other hand, based on the evaluation results of Table 2 above, it can be confirmed that in Comparative Example 1, due to the high molecular mobility of the crosslinking groups (polar parts) in the main chain and at the ends of the obtained curable resin, the dielectric loss tangent or the dielectric constant shows a high value, the dielectric properties are poor (low dielectric properties cannot be obtained), the rigidity of the main chain is low, and thus the glass transition temperature (Tg) is low and the heat resistance is poor. It can also be confirmed that in Comparative Example 2, since the molecular mobility of the crosslinking groups (polar parts) at the ends of the curable resin is high, the dielectric loss tangent or the dielectric constant shows a high value, the dielectric properties are poor, the rigidity of the main chain is low, and thus the glass transition temperature (Tg) is low and the heat resistance is poor.

[0226] Industrial Applicability

[0227] Since the cured product obtained by using the curable resin of the present invention has excellent heat resistance and dielectric properties, it can preferably be used for heat-resistant members or electronic members, and in particular can preferably be used for prepregs, semiconductor encapsulants, circuit boards, thick films, thick substrates, etc., or adhesives or resist materials. In addition, it can also preferably be used as the matrix resin of fiber-reinforced resins and is suitable as a prepreg with high heat resistance.

Claims

1. A hardenable resin, characterized in that, It has a structural unit (1) represented by the following general formula (1) and a terminal structure (2) represented by the following general formula (2); In the general formula (1) and the general formula (2), R1 independently represents an alkyl group having 1 to 12 carbon atoms, an aryl group, an aralkyl group or a cycloalkyl group, and k represents an integer of 1 to 3; R2 independently represents a hydrogen atom or a methyl group; X represents an acryloyloxy group, a methacryloyloxy group, a vinylbenzyl ether group or an allyl ether group; further, in the general formula (2), R3 independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an aryl group, an aralkyl group, a cycloalkyl group or an alkenyl group.

2. The curable resin according to claim 1, wherein, The general formula (1) is represented by the following general formula (1-1); 3. The curable resin according to claim 1 or 2, characterized in that, The general formula (2) is represented by the following general formula (2-1); In the general formula (2-1), R4 represents a hydrogen atom, a methyl group or a phenyl group, and R5 represents an alkyl group having 1 to 4 carbon atoms.

4. The curable resin according to claim 1 or 2, characterized in that, The general formula (1) is represented by the following general formula (1-2), The general formula (2) is represented by the following general formula (2-2) or general formula (2-3); In the general formula (1-2), the general formula (2-2) and the general formula (2-3), R4 represents a hydrogen atom, a methyl group or a phenyl group, R5 represents an alkyl group having 1 to 4 carbon atoms, and R6 independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an aryl group, an aralkyl group or a cycloalkyl group.

5. The curable resin according to claim 1 or 2, wherein The weight average molecular weight is 500 to 50000.

6. A curable resin composition, characterized in that, It contains the curable resin according to any one of claims 1 to 5.

7. A hardened material, characterized in that, It is formed by subjecting the curable resin composition according to claim 6 to a curing reaction.

Images