Curable resin, method for manufacturing curable resin, curable composition, cured product, prepreg, circuit board, build-up film, semiconductor encapsulant and semiconductor device.

Abstract

A curable resin comprising one or both of the structural units represented by formula (1) and the structural units represented by formula (2) below, the structural unit represented by formula (3) below, and the structural unit represented by formula (4) below. [Formula 1] TIFF0007859613000050.tif46170(wherein Q1 is independently a hydrogen atom or a methyl group, One of the Q2 atoms is a single bond, and the remaining three Q2 atoms are independently either a hydrogen atom or a methyl group. One of the Q3 atoms is a single bond, and the remaining three Q3 atoms are independently either a hydrogen atom or a methyl group. Each R1 atom is independently an alkyl group, aryl group, alkoxy group, aryloxy group, or halogen atom. m1 is an integer from 0 to 3. Each R2 atom is independently an alkyl group, aryl group, alkoxy group, aryloxy group, or halogen atom. m2 is an integer from 0 to 4. * represents a bond.

Description

[Technical Field]

[0001] The present invention relates to a curable resin, a method for producing a curable resin, a curable composition, a cured product, a prepreg, a circuit board, a build-up film, a semiconductor encapsulant, and a semiconductor device. [Background technology]

[0002] As circuit board materials for electronic devices, prepregs obtained by impregnating glass cloth with thermosetting resins such as epoxy resins or BT (bismaleimide-triazine) resins and then heat-drying them, laminates obtained by heat-curing the prepregs, and multilayer boards obtained by combining the laminates and the prepregs and then heat-curing them are widely used. Furthermore, in recent years, with the increasing speed and frequency of signals, there is a need for thermosetting resin compositions that provide cured products exhibiting sufficiently low dielectric constant and low dielectric loss tangent under these conditions.

[0003] To address these challenges, for example, Patent Document 1 proposes using maleimide resin as a thermosetting resin having a relatively low dielectric loss tangent. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2020 / 217679 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, cured maleimide resins exhibit a high dielectric loss tangent after water absorption, and improvement in this regard is needed. Furthermore, in relation to the above applications, it is desirable that the curable resin used does not have tackiness, from the perspective of ease of assembly of semiconductors.

[0006] The present invention aims to provide a curable resin that can produce a cured product with good dielectric properties after water absorption, and which also has sufficiently reduced tackiness. [Means for solving the problem]

[0007] The inventors of this invention conducted extensive research to solve the above-mentioned problems and, as a result, discovered that the problems could be solved with a specific curable resin, thus completing the present invention.

[0008] The gist of this invention is as follows: [1] A curable resin comprising one or both of the structural units represented by formula (1) and the structural units represented by formula (2), the structural unit represented by formula (3), and the structural unit represented by formula (4). [ka] (In the formula, Q1 is independently either a hydrogen atom or a methyl group. One of the Q2 atoms is a single bond, and the remaining three Q2 atoms are, independently, either a hydrogen atom or a methyl group. One of the Q3 groups is a single bond, and the remaining three Q3 groups are, independently, either a hydrogen atom or a methyl group. R1 is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. m1 is an integer between 0 and 3. R2 is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. m2 is an integer between 0 and 4. * indicates a bonding operation. [2] A curable resin of [1], comprising a structural unit represented by the following formula (6) at its end. [ka] (In the formula, * represents a coupling.) [3] The curable resin of [1] or [2] containing a structural unit represented by the following formula (5).

Chemical formula

Chemical formula

[10] A semiconductor encapsulant containing the curable composition of [5].

[11] A semiconductor device comprising a cured semiconductor encapsulant of

[10] . [Effects of the Invention]

[0009] The curable resin of the present invention provides a cured product that has good dielectric properties after water absorption, and also provides a curable resin in which the tackiness is sufficiently reduced. [Brief explanation of the drawing]

[0010] [Figure 1] This is the GPC measurement result for resin (A) in the example. [Figure 2] This shows the FD-MS measurement results for resin (A) in the example. [Figure 3] These are the 13C-NMR (NNE and DEPT) measurement results for resin (A) of the example. [Figure 4] This is the GPC measurement result for resin (B) in the example. [Figure 5] This shows the FD-MS measurement results for resin (B) in the example. [Figure 6] These are the 13C-NMR (bcm and DEPT) measurement results for resin (B) of the example. [Figure 7] This is the 1H-NMR measurement result for resin (B) in the example. [Modes for carrying out the invention]

[0011] The following describes in detail the embodiments for carrying out the invention, but the present invention is not limited to the following description and can be implemented in various modifications within the scope of its gist.

[0012] [term] In this specification, "reaction raw material" refers to a compound used to obtain a target compound through a chemical reaction such as combination or decomposition, and which partially constitutes the chemical structure of the target compound. Substances that act as aids to chemical reactions, such as solvents and catalysts, are excluded. In particular, in this specification, "reaction raw material" refers to a precursor for obtaining a target intermediate through a chemical reaction. In this specification, "structural unit" refers to a (repeating) unit of chemical structure formed during a reaction or polymerization. In other words, in a compound formed by a reaction or polymerization, it refers to a substructure other than the chemical bond structure involved in the reaction or polymerization, and is commonly known as a residue. In this specification, "intermediate" specifically refers to the reaction products produced in each elementary reaction when the chemical reaction of the reaction raw materials is a multi-step reaction; in other words, it refers to precursors of the target final product that are produced at an intermediate stage in the manufacturing process.

[0013] In this specification, "alkyl group" may be linear or branched, and may have 1 to 20 carbon atoms. Examples include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, sec-pentyl group, tert-pentyl group, neopentyl group, amyl group, cyclopentyl group, hexyl group, heptyl group, octyl group, cumyl group, nonyl group, decyl group, undecyl group, dodecyl group, etc. The number of carbon atoms is preferably 1 to 10, and more preferably 1 to 6. In this specification, "aryl group" refers to, for example, a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a mesityl group, an o-biphenyl group, an m-biphenyl group, a p-biphenyl group, a 1-naphthyl group, a 2-naphthyl group, a 2-fluorenyl group, a phenanthryl group, etc. The number of carbon atoms can be 6 to 20, preferably 6 to 10. In this specification, "alkoxy group" has an alkyl-O- structure, and the definition of alkyl group described above applies to the alkyl group. Examples of alkoxy groups include methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, sec-butoxy, and tert-butoxy groups. The number of carbon atoms can be 1 to 20, preferably 1 to 10, and more preferably 1 to 6. In this specification, "aryloxy group" has an aryl-O- structure, and the definition of an aryl group described above applies to the aryl group. Examples of aryloxy groups include phenoxy group, o-tolyloxy group, m-tolyloxy group, p-tolyloxy group, mesityloxy group, o-biphenyloxy group, m-biphenyloxy group, p-biphenyloxy group, 1-naphthyloxy group, 2-naphthyloxy group, 2-fluorenyloxy group, phenanthryloxy group, etc. The number of carbon atoms can be 6 to 20, preferably 6 to 10. In this specification, "halogen atom" refers to fluorine, chlorine, bromine, and iodine.

[0014] In this specification, the number-average molecular weight (Mn) and weight-average molecular weight (Mw) are values ​​measured using gel permeation chromatography (hereinafter also referred to as "GPC") under the measurement conditions described in the examples below.

[0015] [Reaction materials for curable resins] The curable resin of the present invention uses a compound represented by the following formula (7), a compound represented by the following formula (8), and a compound represented by the following formula (9) as reaction raw materials. [ka] (In the formula, R1 is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. X1 is a hydrogen atom and X2 is a halogen atom, or X1 is a halogen atom and X2 is a hydrogen atom. m1 is an integer between 0 and 3. R2 is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. Y is a halogen atom, m2 is an integer between 0 and 4.

[0016] <Compound represented by formula (7)> The bonding positions of the two isopropenyl groups in the compound of formula (7) are not particularly limited and may be ortho, meta, or para, but meta and para are preferred, and meta is more preferred.

[0017] The compounds of formula (7) can be used individually or in combination of two or more in any ratio.

[0018] <Compound represented by formula (8)> [ka] (In the formula, R1 is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. X1 is a hydrogen atom and X2 is a halogen atom, or X1 is a halogen atom and X2 is a hydrogen atom. m1 is an integer between 0 and 3.

[0019] Either the compound of formula (8-1) or the compound of formula (8-2) can be used as the compound of formula (8). [ka] (In the formula, Hal is a halogen atom, R1 and m1 are equivalent to those in equation (8).

[0020] In the compound of formula (8), m1 is preferably 0. In this case, formulas (8-1) and (8-2) can be represented by the following formulas (8-1-1) and (8-2-1), respectively. [ka] (In the formula, Hal is a halogen atom.

[0021] Specific examples of compounds of formula (8) where m1 is 0 include (1-fluoroethyl)benzene, (2-fluoroethyl)benzene, (1-chloroethyl)benzene, (2-chloroethyl)benzene, (1-bromoethyl)benzene, (2-bromoethyl)benzene, (1-iodoethyl)benzene, and (2-iodoethyl)benzene.

[0022] m1 can be 1 to 3, in which case R1 is preferably an alkyl group or an aryl group. If m1 is 2 or 3, the multiple R1s may be the same or different.

[0023] Specifically, (2-bromoethyl)benzene and (1-bromoethyl)benzene are examples of compounds of formula (8) where m1 is 1 to 3.

[0024] With respect to X1 and X2, bromine atoms are preferred as halogen atoms.

[0025] Among the compounds of formula (8), (1-bromoethyl)benzene and (2-bromoethyl)benzene are preferred.

[0026] The compounds of formula (8) can be used individually or in combination of two or more in any ratio.

[0027] <Compound represented by formula (9)> [ka] (In the formula, R2 is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. Y is a halogen atom, m2 is an integer between 0 and 4.

[0028] The relationship between the vinyl group and the -CH2-Y group in the compound of formula (9) may be ortho, meta, or para, but is preferably meta or para, and more preferably para.

[0029] In the compound of formula (9), m2 is preferably 0, in which case it can be represented by the following formula (9-1). [ka] (In the equation, Y is equivalent to equation (9).)

[0030] Specific examples of compounds of formula (9) include 2-(fluoromethyl)styrene, 3-(fluoromethyl)styrene, 4-(fluoromethyl)styrene, 2-(chloromethyl)styrene, 3-(chloromethyl)styrene, 4-(chloromethyl)styrene, 2-(bromomethyl)styrene, 3-(bromomethyl)styrene, 4-(bromomethyl)styrene, 2-(iodomethyl)styrene, 3-(iodomethyl)styrene, and 4-(iodomethyl)styrene.

[0031] m2 can be 1 to 4, in which case R2 is preferably an alkyl group, an aryl group, or a halogen atom (preferably a chlorine atom or a bromine atom). When m2 is 2 to 4, the multiple R2s may be the same or different.

[0032] Examples of compounds of formula (9) where m2 is 1 to 4 include p-chloromethylstyrene, m-chloromethylstyrene, o-chloromethylstyrene, and the like.

[0033] A chlorine atom is preferred as the halogen atom in Y.

[0034] Among the compounds of formula (9), 3-(chloromethyl)styrene and 4-(chloromethyl)styrene are preferred.

[0035] The compounds of formula (9) can be used individually or in combination of two or more in any ratio.

[0036] [Method for manufacturing curable resin] The curable resin of the present invention is obtained by subjecting the reaction product of the above-mentioned reaction raw materials to a dehydrohalogenation reaction. Specifically, it can be produced by a manufacturing method comprising the steps of (i) synthesizing an intermediate by an aromatic electrophilic substitution reaction and (ii) subjecting the intermediate to a dehydrohalogenation reaction. Step (i): A step of reacting the compound represented by formula (7), the compound represented by formula (8), and the compound represented by formula (9); Step (ii): A step in which the reaction product obtained in step (i) is subjected to a dehalogenation reaction in the presence of a base to obtain a curable resin.

[0037] <Process (i)> In step (i), the compound of formula (7), the compound of formula (8), and the compound of formula (9) are reacted. The reaction is an aromatic electrophilic substitution reaction. The amounts of the reaction raw materials, compound (7), compound (8), and compound (9), used can be, for example, 0.4 to 40 moles of compound (8), preferably 0.8 to 20 moles, per 1 mole of compound (7), and 0.05 to 5 moles of compound (9), preferably 0.1 to 2.5 moles.

[0038] The reaction is preferably carried out in the presence of an acid catalyst. Examples of acid catalysts include acetates of nickel, cobalt, sodium, calcium, iron, lithium, and manganese; inorganic salts such as chlorides, bromides, sulfates, and nitrates; inorganic acids such as phosphoric acid, hydrochloric acid, and sulfuric acid; organic acids such as oxalic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, fluoromethanesulfonic acid, trifluoroacetic acid, and trifluoromethanesulfonic acid; solid acids such as activated clay, acid clay, silica alumina, zeolite, and strongly acidic ion exchange resins; and heteropolyhydrochloric acid. Among these, organic acids such as methanesulfonic acid and fluoromethanesulfonic acid are preferred. Acid catalysts can be used in combination of one or more types in any ratio.

[0039] The amount of acid catalyst used is preferably 1 to 100 parts by mass per 100 parts by mass of the total amount of reaction raw materials (compounds of formulas (7) to (9)), and more preferably 2 to 50 parts by mass from the viewpoint of handling and economy.

[0040] It is preferable to react at least some of the compounds of formula (8) with an acid catalyst and then mix them with the remaining reaction materials.

[0041] The reaction may be carried out without an organic solvent, or it may be carried out with an organic solvent.

[0042] Examples of organic solvents include ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, cyclohexanone, and acetophenone; 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. Organic solvents can be used in combination, either one or two or more, in any ratio.

[0043] The amount of organic solvent used is preferably 0.1 to 100 parts by mass, and more preferably 1 to 10 parts by mass, per 100 parts by mass of the total amount of reaction raw materials (compounds of formulas (7) to (9)).

[0044] The reaction temperature is preferably 0 to 200°C, and more preferably 80 to 150°C, from the viewpoint of promoting the reaction. The reaction time is preferably 0.5 to 72 hours, and more preferably 1 to 70 hours, in order to allow the reaction to proceed sufficiently while suppressing side reactions.

[0045] After the reaction is complete, the mixture can be washed with water as needed, and unreacted reaction materials can be removed by vacuum distillation or other means to obtain an intermediate (organic layer). The resulting organic layer can be subjected to the reaction of step (ii).

[0046] <Intermediate> The intermediate obtained in step (i) is the reaction product of the compound of formula (7), the compound of formula (8), and the compound of formula (9).

[0047] Structural units that the intermediate may contain include those represented by formulas (1), (2), (3'), and (4). The intermediate includes one or both of the structural units of formula (1) and formula (2), the structural unit of formula (3'), and the structural unit of formula (4), and preferably includes all of the structural units of formulas (1), (2), (3'), and (4). [ka] (In the formula, Q1 is independently either a hydrogen atom or a methyl group. One of the Q2 atoms is a single bond, and the remaining three Q2 atoms are, independently, either a hydrogen atom or a methyl group. One of the Q3 groups is a single bond, and the remaining three Q3 groups are, independently, either a hydrogen atom or a methyl group. R1 is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. X1 is a hydrogen atom and X2 is a halogen atom, or X1 is a halogen atom and X2 is a hydrogen atom. m1 is an integer between 0 and 3. R2 is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. m2 is an integer between 0 and 4. * indicates a bonding operation. R1, X in equation (3') 1、 For X2 and m1, the examples and preferred examples of formula (3) apply.

[0048] The intermediate is usually a mixture of several compounds, and the above structural units may be present in any of the compounds in the mixture. However, the intermediate as a whole shall have one or both of the structural units of formula (1) and formula (2), the structural unit of formula (3'), and the structural unit of formula (4).

[0049] Examples of structural units in formula (1) include the structural unit in formula (1-1) and the structural unit in formula (1-2). [ka] (In the formula, * represents a coupling.)

[0050] The structural unit of formula (1-1) is included in the structure formed by the bonding of compounds of formula (7), and the structural unit of formula (1-2) is included in the structure formed by the reaction of a compound of formula (7) and a compound of formula (9).

[0051] If the compound of formula (7) is a compound in which an isopropenyl group is bonded at the meta position (1,3-diisopropenylbenzene), then the structural units of formulas (1-1) and (1-2) can be represented by formulas (1-1-1) and (1-2-1), respectively. Similarly, if the compound is a compound in which an isopropenyl group is bonded at the para position (1,4-diisopropenylbenzene), then the structural units of formulas (1-1) and (1-2) can be represented by formulas (1-1-2) and (1-2-2), respectively. [ka] (In the formula, * represents a coupling.)

[0052] Examples of structural units of formula (2) include those formed when one of the two isopropenyl groups of formula (7) reacts with the compound of formula (9) and the other reacts with another compound of formula (7), and those formed when both isopropenyl groups of formula (7) react with the compound of formula (9). If the compound of formula (7) is a compound (1,3-diisopropenylbenzene) in which an isopropenyl group is bonded at the meta position, it can be represented by formulas (2-1-1) and (2-2-1), respectively. [ka] (In the formula, * represents a coupling.)

[0053] If the compound of formula (7) is a compound in which an isopropenyl group is bonded at the para position (1,4-diisopropenylbenzene), it can be represented by formulas (2-1-2) and (2-2-2), respectively. [ka] (In the formula, * represents a coupling.)

[0054] The structural unit of formula (3') is derived from the compound of formula (8). Examples of structural units of formula (3') include the structural unit of formula (3'-1) and the structural unit of formula (3'-2). [ka] (In the formula, Hal is a halogen atom, R1 is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. m1 is an integer between 0 and 3. * indicates a bonding operation.

[0055] In the structural unit of formula (3'), m1 is preferably 0. These structural units are derived from the compounds of formula (8-1-1) and (8-2-1), and are represented by formulas (3'-1-1) and (3'-2-1). [ka] (In the formula, Hal is a halogen atom, * indicates a bonding operation.

[0056] The structural unit of formula (3') is preferably a monovalent group derived from (1-bromoethyl)benzene or (2-bromoethyl)benzene.

[0057] The relationship between the single bond (-*) group and the methylene bond (-CH2-*) in the structural unit of formula (4) may be ortho, meta, or para, but is preferably meta or para, and more preferably para.

[0058] In the structural unit of formula (4), m2 is preferably 0, in which case it can be expressed by the following formula (4-1). [ka] (In the formula, * represents a coupling.)

[0059] Specifically, examples include structural units represented by formulas (4-1-1), (4-1-2), and (4-1-3), with the structural units of formulas (4-1-2) and (4-1-3) being preferred. [ka] (In the formula, * represents a bond.)

[0060] m2 can be 1 to 4, in which case R2 is preferably an alkyl group, an aryl group, or a halogen atom (preferably a chlorine atom or a bromine atom). When m2 is 2 to 4, the multiple R2s may be the same or different.

[0061] The intermediate may contain the structural unit represented by formula (5'). [ka] (In the formula, X1 is a hydrogen atom and X2 is a halogen atom, or X1 is a halogen atom and X2 is a hydrogen atom. R1 is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. m1 is an integer between 0 and 3. * indicates a bonding operation.

[0062] The structural unit of formula (5') is derived from the compound of formula (8). Examples of structural units of formula (5') include the structural unit of formula (5'-1) and the structural unit of formula (5'-2). [ka] (In the formula, Hal is a halogen atom, R1 is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. m1 is an integer between 0 and 3. * indicates a bonding operation.

[0063] In the structural unit of formula (5'), m1 is preferably 0. These structural units are derived from the compound of formula (8-1-1) and the compound of formula (8-2-1), and are represented by formulas (5'-1-1) and (5'-2-1). [ka] (In the formula, Hal is a halogen atom, * indicates a bonding operation.

[0064] The structural unit of formula (5') is preferably a divalent group derived from (1-bromoethyl)benzene or (2-bromoethyl)benzene.

[0065] The intermediate may contain a structural unit represented by formula (6) at its terminal end. [ka] (In the formula, * represents a coupling.)

[0066] The structural unit of formula (6) can be included in a structure derived from the compound of formula (7), and can be, for example, a substructure of the following formula. [ka] (In the formula, Q1 is independently either a hydrogen atom or a methyl group. * indicates a bonding operation.

[0067] Preferably, the terminal ends of each intermediate compound are structural units of formula (3'), and more preferably, 1 mol% or more of the total terminal ends are structural units of formula (3').

[0068] The intermediate may include the compound represented by formula (10'). The compound of formula (10') is derived from the compound of formula (8) and the compound of formula (9). [ka] (In the formula, R1 is independently an alkyl group, an aryl group, an alkoxy group, or a halogen atom. R2 is independently an alkyl group, an aryl group, an alkoxy group, or a halogen atom. R3 is a hydrogen atom and R4 is a methyl group, or R3 is a methyl group and R4 is a hydrogen atom. X1 is a hydrogen atom and X2 is a halogen atom, or X1 is a halogen atom and X2 is a hydrogen atom. Each m1 is an independent integer between 0 and 3. m2 is an integer between 0 and 4. n is an integer between 1 and 20.

[0069] Preferred examples of R1, R2, X1, X2, m1, and m2 in formula (10') are the same as those in formulas (8) and (9). In equation (10'), n is preferably an integer between 1 and 10, and more preferably between 1 and 5.

[0070] From the viewpoint of curability, the mass percentage of the compound of formula (10') in the intermediate obtained in step (i) is preferably 1% by mass or more, more preferably 5% by mass or more, and preferably 95% by mass or less, and more preferably 90% by mass or less.

[0071] In the compound of formula (10'), m1 and m2 are preferably 0, in which case it can be represented by the following formula (10'-1). [ka] (In the formula, R3, R4, X1, X2, and n are equivalent to those in formula (10'), and the preferred examples are also equivalent.)

[0072] In the compound of formula (10'-1), n ​​is preferably 1 to 10, and more preferably 1 to 5. When n is 1, R3 is a methyl group, and R4 is a hydrogen atom, it can be represented by the following formula (10'-1-1). [ka] (In the formula, X1 and X2 are equivalent to those in formula (10'), and the same applies to the preferred examples.)

[0073] The intermediate preferably has a compound containing one or both of the structural units of formula (1) and formula (2), the structural unit of formula (3'), and the structure of formula (4). For example, the following formula (11') is an example. [ka] (In the formula, X1, X2, R1, R2, m1, m2 are equivalent to equation (10'), and the preferred examples are similar. Q1, Q2, and Q3 are each independently a hydrogen atom or a methyl group. n1 is an integer between 0 and 1000, and n2 is also an integer between 0 and 1000, but n1 and n2 cannot be 0 at the same time. In equation (11'), the units enclosed by n1 and n2 may be random or block units.

[0074] n1 is preferably an integer between 0 and 100, more preferably an integer between 0 and 10, and particularly preferably an integer between 0 and 5. n2 is preferably an integer between 0 and 100, more preferably an integer between 0 and 10, and particularly preferably an integer between 0 and 5. However, n1 and n2 cannot be 0 at the same time, and the sum of n1 and n2 is preferably an integer between 1 and 20, and particularly preferably an integer between 1 and 6.

[0075] From the viewpoint of reactivity, the mass percentage of the compound of formula (11') in the intermediate obtained in step (i) is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 99% by mass or less, and more preferably 95% by mass or less.

[0076] Examples of compounds of formula (11') include those represented by the following formulas (11'-1) and (11'-2). [ka] (In the formula, X1, X2, R1, R2, m1, and m2 are equivalent to those in equation (10'), and the same applies to the preferred examples.

[0077] In the compounds of formulas (11'-1) and (11'-2), it is preferable that m1 and m2 are 0, in which case they can be represented by the following formulas (11'-1-1) and (11'-2-1). [ka]

[0078] The intermediate may contain the following structural units in addition to the structural units of formulas (1), (2), (3'), and (4). [ka] (In the formula, * represents a bond.)

[0079] Examples of compounds include the following: [ka] (In the formula, X1 is a hydrogen atom and X2 is a halogen atom, or X1 is a halogen atom and X2 is a hydrogen atom. Ra is either a hydrogen atom or a methyl group, independently of each other.

[0080] The number-average molecular weight (Mn) of the intermediate can be in the range of 200 to 10,000, preferably in the range of 300 to 9,000. The weight-average molecular weight (Mw) of the intermediate can be in the range of 200 to 50,000, preferably in the range of 300 to 40,000.

[0081] <Process (ii)> In step (ii), the intermediate obtained in step (i) is subjected to a dehydrohalogenation reaction to obtain a curable resin. In this reaction, the haloethyl groups in the intermediate are converted to vinyl groups. Because the curable resin has vinyl groups, it exhibits high reactivity.

[0082] The reaction can be carried out in the presence of a base (base catalyst). Examples of base catalysts include potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, tert-butoxypotassium, tert-butoxysodium, and triethylamine. Aqueous solutions thereof may also be used. Potassium hydroxide and sodium hydroxide are preferred from the viewpoint of reactivity. The base catalyst can be used as one or more types in any ratio.

[0083] The amount of base catalyst used can be 10 to 1000 parts by mass per 100 parts by mass of intermediate. From the viewpoint of reactivity, it is preferably 20 to 900 parts by mass.

[0084] The reaction can be carried out in an organic solvent. Examples of organic solvents include aromatic solvents such as toluene and xylene, aliphatic solvents such as cyclohexane and n-hexane, ethers such as diethyl ether and diisopropyl ether, esters such as ethyl acetate and butyl acetate, ketones such as methyl isobutyl ketone and cyclopentanone, dimethyl sulfone, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, and N-methylpyrrolidone. The use of aprotic polar solvents in combination is preferable because it can increase the progress of the dehalogenation reaction. Organic solvents can be used individually or in any ratio of two or more.

[0085] The amount of organic solvent used is not particularly limited, but it can be 25 to 1000 parts by mass per 100 parts by mass of the intermediate.

[0086] The reaction temperature can be 25 to 130°C, and is preferably 30 to 120°C from the viewpoint of promoting the reaction. The reaction time can be 0.5 to 72 hours, and is preferably 1 to 70 hours, from the viewpoint of allowing the reaction to proceed sufficiently and suppressing side reactions.

[0087] The reaction is preferably carried out in an organic solvent, with the base added dropwise to the intermediate. The addition can be carried out over, for example, 0.5 to 72 hours. After the reaction is complete, water is added to wash the organic layer, and after removing the aqueous layer, the reaction can be carried out again by adding the base catalyst and organic solvent.

[0088] After the reaction is complete, the mixture is separated into an aqueous layer and an organic layer as appropriate, and the aqueous layer is removed to obtain the reaction product. If necessary, water may be added to dissolve insoluble salts before removing the aqueous layer. The aqueous layer may be basic, neutralized by neutralization, or acidic. Examples of neutralizing agents include organic acids such as oxalic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, fluoromethanesulfonic acid, trifluoroacetic acid, trifluoromethanesulfonic acid, and ammonium chloride; inorganic acids such as phosphoric acid, monosodium phosphate, disodium phosphate, trisodium phosphate, hydrochloric acid, sulfuric acid, and nitric acid; and solid acids such as activated clay, acid clay, silica alumina, zeolite, and strong acid ion exchange resins. These organic acids can be used individually or in any ratio of two or more types.

[0089] <Curing resin> The curable resin is a dehalogenated product of the intermediate (the reaction product of the compounds of formulas (7) to (9)). The haloethyl groups contained in the intermediate are converted to vinyl groups.

[0090] Structural units that the curable resin may contain include those represented by formulas (1), (2), (3), and (4). The intermediate contains one or both of the structural units of formula (1) and formula (2), the structural unit of formula (3), and the structural unit of formula (4), and preferably contains all of the structural units of formulas (1), (2), (3), and (4). Formula (3) is a structural unit in which a hydrogen halide is removed from the haloethyl group in formula (3') to form a vinyl group. [ka] (In the formula, Q1 is independently either a hydrogen atom or a methyl group. One of the Q2 atoms is a single bond, and the remaining three Q2 atoms are, independently, either a hydrogen atom or a methyl group. One of the Q3 groups is a single bond, and the remaining three Q3 groups are, independently, either a hydrogen atom or a methyl group. R1 is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. m1 is an integer between 0 and 3. R2 is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. m2 is an integer between 0 and 4. * indicates a bonding operation.

[0091] Curable resins are typically mixtures of multiple compounds, and the above structural units may be present in any of the compounds in the mixture. However, the curable resin as a whole should have one or both of the structural units of formula (1) and formula (2), as well as the structural units of formula (3) and formula (4). Preferably, the curable resin contains a compound having one or both of the structural units of formula (1) and formula (2), as well as the structural units of formula (3) and formula (4). The structural unit of formula (3) has a highly reactive unsaturated double bond, while the structural units of formula (1) and formula (2) have a hydrophobic and rigid indan structure, which is presumed to reduce the hygroscopicity of the cured product of the curable resin.

[0092] The curable resin preferably contains the structural unit of formula (5). Formula (5) is a structural unit in which a hydrogen halide is removed from the haloethyl group in formula (5') to form a vinyl group. [ka] (In the formula, R1 is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. m1 is an integer between 0 and 3. * indicates a bonding operation.

[0093] The end of the curable resin may be a structural unit of formula (6). [ka] (In the formula, * represents a coupling.)

[0094] The terminals of each compound in the curable resin are preferably structural units of formula (3), and more preferably, 1 mol% or more of all terminals are structural units of formula (3).

[0095] The curable resin preferably contains a compound represented by formula (10). The compound of formula (10) is a compound in which a hydrogen halide is removed from the haloethyl group in formula (10') to form a vinyl group. [ka] (In the formula, R1 is independently an alkyl group, an aryl group, an alkoxy group, or a halogen atom. R2 is independently an alkyl group, an aryl group, an alkoxy group, or a halogen atom. R3 is a hydrogen atom and R4 is a methyl group, or R3 is a methyl group and R4 is a hydrogen atom. Each m1 is an independent integer between 0 and 3. m2 is an integer between 0 and 4. n is an integer between 1 and 20. Preferred examples of R1, R2, m1, m2, and n in formula (10) are the same as in formula (10').

[0096] In the curable resin obtained in step (ii), the mass percentage of the compound of formula (10) is preferably 1% by mass or more, more preferably 5% by mass or more, and preferably 95% by mass or less, and more preferably 90% by mass or less, from the viewpoint of curability.

[0097] In the compound of formula (10), m1 and m2 are preferably 0, in which case it can be represented by the following formula (10-1). [ka] (In the formula, R3, R4, and n are equivalent to those in formula (10), and the same applies to the preferred examples.)

[0098] In the compound of formula (10-1), n ​​is preferably 1 to 10, and more preferably 1 to 5. When n is 1, R3 is a methyl group, and R4 is a hydrogen atom, it can be represented by the following formula (10'-1-1). [ka]

[0099] The curable resin preferably contains one or both of the structural units of formula (1) and formula (2), the structural unit of formula (3), and a compound containing the structure of formula (4). For example, the following formula (11) is given. The compound of formula (11) is a compound in which a hydrogen halide is removed from the haloethyl group in formula (11') to form a vinyl group. [ka] (In the formula, R1, R2, Q1, Q2, Q3, m1, m2, n1, and n2 are equivalent to those in formula (11'), and the same applies to the preferred examples. In equation (11), the units enclosed by n1 and n2 may be random or block units.

[0100] In the curable resin obtained in step (ii), the mass percentage of the compound of formula (11) is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 99% by mass or less, and more preferably 95% by mass or less, from the viewpoint of curability.

[0101] Examples of compounds of formula (11) include those represented by the following formulas (11-1) and (11-2). The compounds of formulas (11-1) and (11-2) are compounds in which a hydrogen halide is removed from the haloethyl group in formulas (11'-1) and (11'-2) to form a vinyl group. [ka] (In the formula, R1, R2, m1, and m2 are equivalent to those in formula (11), and the preferred examples are similar.

[0102] In the compounds of formulas (11-1) and (11-2), m1 and m2 are preferably 0, in which case they can be represented by the following formulas (11-1-1) and (11-2-1). The compounds of formulas (11-1-1) and (11-2-1) are compounds in which a hydrogen halide has been removed from the haloethyl group in formulas (11'-1-1) and (11'-2-1) to form a vinyl group. [ka]

[0103] In addition to the structural units of formulas (1), (2), (3), and (4), the curable resin may contain the following structural units. [ka] (In the formula, * represents a coupling.)

[0104] Examples of compounds include the following: [ka] (In the formula, Ra is either a hydrogen atom or a methyl group, independently of each other.

[0105] The number-average molecular weight (Mn) of the curable resin can be in the range of 200 to 10,000, preferably in the range of 300 to 9,000. The weight-average molecular weight (Mw) of the intermediate can be in the range of 200 to 50,000, preferably in the range of 250 to 40,000.

[0106] Regarding the structural units that constitute the intermediate and curable resin, 1 H-NMR, 13 It can be identified by analysis such as 13C-NMR, FD-MS, and GPC.

[0107] [Curable composition] The curable composition of the present invention comprises one or both of the curable resin, curing agent, and curing catalyst of the present invention. By using the curable resin of the present invention, the cured product obtained from the curable composition can be provided with excellent heat resistance.

[0108] The curing agent is not particularly limited as long as it is a compound that can react with the curable resin of the present invention. Examples include resin components such as epoxy resins, phenolic resins, activated ester resins, maleimide resins, cyanate resins, unsaturated polyester resins, and polybutadiene resins, as well as compounds such as styrene, divinylbenzene, triallyl isocyanurate, triallyl cyanurate, diallyl phthalate, diallyl phthalate, diallyl isophthalate, diallyl terephthalate, and polyphenylene ether (polyphenylene ether having an ethylenically unsaturated double bond). The hardening agent can be used in any ratio of one or more types.

[0109] The ratio of the curable resin of the present invention to the total amount of the curable resin and curing agent of the present invention is adjusted as appropriate according to the desired cured product performance, but is preferably 5% by mass or more, and more preferably 10% by mass or more.

[0110] The curing catalyst is not particularly limited and includes, for example, organic peroxides (e.g., benzoyl peroxide, cumene hydroperoxide, dicumyl peroxide, lauroyl peroxide, di-t-butyl peroxide, t-butyl hydroperoxide, methyl ethyl ketone peroxide, t-butyl perbenzoate, etc.), azo compounds (e.g., azobisisobutyronitrile), and free radicals (e.g., azobisisobutyronitrile, garbinoxyl, etc.).

[0111] The curable composition may contain various additives such as curing accelerators, silane coupling agents, mold release agents, pigments, emulsifiers, non-halogenated flame retardants, inorganic fillers, flame retardants (e.g., inorganic phosphorus-based flame retardants, organophosphorus-based flame retardants, halogenated flame retardants), and solvents.

[0112] A curable composition can be obtained by uniformly mixing the curable resin of the present invention with one or both of the curing agent and the curing catalyst, and any other component (e.g., curing catalyst, compounding agent, etc.).

[0113] [Cured product] The cured product of the present invention can be obtained by curing the curable composition of the present invention. The curing method is not particularly limited, and known methods can be employed. The cured product can take the form of a laminate, a cast product, an adhesive layer, a coating, a film, or the like.

[0114] [Semiconductor encapsulant] The semiconductor encapsulant of the present invention may contain the curable composition of the present invention. Since the curable composition of the present invention contains the curable resin of the present invention, the semiconductor encapsulant can exhibit excellent dielectric properties (low dielectric constant and low dielectric loss tangent) and high heat resistance.

[0115] For semiconductor encapsulants, a curable composition of the present invention containing an inorganic filler can be used. The inorganic filler is not particularly limited and can include, for example, barium sulfate, barium titanate, amorphous silica, crystalline silica, Neuburg silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, silicon nitride, aluminum nitride, and the like. The amount of inorganic filler can be 0.5 to 1200 parts by mass per 100 parts by mass of the curable composition.

[0116] The semiconductor encapsulant may contain various compounding agents, including those described in relation to curable compositions.

[0117] The semiconductor encapsulant can be obtained by mixing the curable composition of the present invention with compounding agents as needed, for example, by thoroughly melting and mixing until uniform using an extruder, kneader, roll, etc.

[0118] [Semiconductor device] The semiconductor device of the present invention may include a cured product of the semiconductor encapsulant of the present invention. The semiconductor encapsulant used in the semiconductor device of the present invention contains a curable composition containing the curable resin of the present invention. Because the semiconductor device of the present invention includes a cured product of the semiconductor encapsulant, it has excellent heat resistance and dielectric properties.

[0119] The semiconductor device can be obtained by heat curing the semiconductor encapsulant of the present invention. Examples include casting, molding using a transfer molding machine, injection molding machine, etc., and then heat curing it in a temperature range of room temperature (20°C) to 250°C.

[0120] [Prepreg] The prepreg of the present invention may have a reinforcing substrate and a semi-cured product of the curable composition of the present invention impregnated into the reinforcing substrate. The method for obtaining a prepreg from a curable composition is not particularly limited, and one method involves impregnating a reinforcing substrate (e.g., paper, glass cloth, glass nonwoven fabric, aramid paper, aramid cloth, glass mat, glass roving cloth, etc.) with a varnished curable composition containing an organic solvent described later, and then heating it at a heating temperature (preferably 50 to 170°C) according to the type of solvent used to partially cure (or leave uncured) the curable composition. The mass ratio of the curable composition to the reinforcing substrate used is not particularly limited, but it is preferable to prepare it so that the resin content in the prepreg is 20 to 60% by mass.

[0121] A semi-cured product of a curable composition can be obtained by adjusting the heating temperature and heating time to stop the curing reaction before it is completed. The degree of curing of the semi-cured product can be, for example, 85% or less and 5% or more. Here, the cured product may have a higher degree of curing than the semi-cured product. The degree of hardening of a semi-cured product can be calculated using the following formula by measuring the heat generated during curing of the curable composition and the heat generated during curing of the semi-cured product using DSC. Degree of curing (%) = [1 - (heat generated during curing of the semi-cured material / heat generated during curing of the curable composition)] × 100

[0122] Examples of organic solvents used in the production of prepregs include methyl ethyl ketone, acetone, dimethylformamide, methyl isobutyl ketone, methoxypropanol, cyclohexanone, methyl cellosolve, ethyl diglycol acetate, and propylene glycol monomethyl ether acetate. The selection and amount of organic solvent can be appropriately chosen depending on the application. For example, when manufacturing circuit boards from prepregs, polar solvents with a boiling point of 160°C or lower, such as methyl ethyl ketone, acetone, and dimethylformamide, are preferred, and the amount used is preferably such that the non-volatile content is 40 to 80% by mass.

[0123] [Circuit board] The circuit board of the present invention consists of a laminate of the prepreg of the present invention and copper foil. The method for obtaining the circuit board is not particularly limited, and for example, one method is to laminate the prepreg of the present invention as needed, overlap the copper foil, and heat-press it at 170 to 300°C for 10 minutes to 3 hours under pressure of 1 to 10 MPa.

[0124] [Build-up film] The build-up film of the present invention may contain the curable composition of the present invention. The method for producing the build-up film is not particularly limited, and one example is to apply the curable composition of the present invention onto a support film to form a curable composition layer and use it as an adhesive film for multilayer printed circuit boards.

[0125] Since the build-up film is required to soften at the lamination temperature conditions (usually 70-140°C) in the vacuum lamination method and exhibit fluidity (resin flow) that allows for resin filling into via holes or through holes present in the circuit board simultaneously with lamination of the circuit board, it is preferable that the curable composition be formulated to exhibit these properties.

[0126] Here, the diameter of the through-holes in a multilayer printed circuit board is typically 0.1 to 0.5 mm, and the depth is typically 0.1 to 1.2 mm. It is generally preferable to be able to fill the holes with resin within this range. When laminating both sides of the circuit board, it is desirable to fill about half of the through-holes.

[0127] The adhesive film described above can be manufactured by first preparing a varnish-like curable composition, then applying this varnish-like composition to the surface of a support film (Y), and finally drying the organic solvent by heating or blowing hot air to form a composition layer (X) made of the curable composition.

[0128] The thickness of the formed composition layer (X) is usually preferably greater than or equal to the thickness of the conductor layer. Since the thickness of the conductor layer of a circuit board is usually in the range of 5 to 70 μm, the thickness of the resin composition layer is preferably 10 to 100 μm.

[0129] The composition layer (X) may also be protected by a protective film, as described later. Protecting it with a protective film prevents dirt and other debris from adhering to the surface of the resin composition layer and prevents scratches.

[0130] The support film (Y) and protective film mentioned above can be made of polyolefins such as polyethylene, polypropylene, and polyvinyl chloride, polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate, polycarbonate, polyimide, and also release paper, copper foil, aluminum foil, and other metal foils. The support film and protective film may be treated with a mat treatment, corona treatment, or release treatment.

[0131] The thickness of the support film is not particularly limited, but is usually 10 to 150 μm, and preferably in the range of 25 to 50 μm. The thickness of the protective film is preferably 1 to 40 μm.

[0132] The above-mentioned support film (Y) is peeled off after being laminated on a circuit board or after forming an insulating layer by heat curing. If the support film (Y) is peeled off after the adhesive film is heat cured, it is possible to prevent the adhesion of dust and the like in the curing process. When peeling off after curing, usually, the support film is previously subjected to a release treatment.

[0133] [Use] The cured product obtained by the curable composition containing the curable resin of the present invention is excellent in heat resistance and dielectric properties, and thus can be suitably used for heat-resistant members or electronic members. In particular, it can be suitably used for prepregs, circuit boards, semiconductor encapsulants, semiconductor devices, build-up films, build-up boards, adhesives using conductive pastes, resist materials, etc. It can also be suitably used as a matrix resin for fiber reinforced resins, and is particularly suitable as a prepreg with high heat resistance. Further, the curable resin contained in the curable composition can be made into a paint because it exhibits excellent solubility in various solvents. The heat-resistant members and electronic members thus obtained can be suitably used for various applications, and examples include industrial machine parts, general machine parts, parts of automobiles, railways, vehicles, etc., space and aviation-related parts, electronic and electrical parts, building materials, container and packaging members, daily necessities, sports and leisure goods, housing members for wind power generation, etc., but are not limited thereto.

Examples

[0134] The present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following description, and various modifications can be made and implemented within the scope of the gist. In the following, "parts" and "%" are based on mass unless otherwise specified.

[0135] Physical property evaluation was carried out as follows. (1) GPC measurement Using the following measuring apparatus and measuring conditions, the number average molecular weight (Mn) and weight average molecular weight (Mw) of the resins obtained in the examples and comparative examples were calculated. <Measurement of GPC> Measuring apparatus: "HLC-8320 GPC" manufactured by Tosoh Corporation, 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 Detector: RI (Differential Refractometer) Data processing: Tosoh Corporation's "GPC Workstation EcoSEC-WorkStation" Measurement conditions: Column temperature 40°C Developing solvent: tetrahydrofuran Flow rate 1.0ml / min Standard: In accordance with the measurement manual for the aforementioned "GPC Workstation EcoSEC-WorkStation," the following monodisperse polystyrenes with known molecular weights were used. (Uses polystyrene) "A-500" manufactured by Tosoh Corporation "A-1000" manufactured by Tosoh Corporation "A-2500" manufactured by Tosoh Corporation "A-5000" manufactured by Tosoh Corporation "F-1" manufactured by Tosoh Corporation "F-2" manufactured by Tosoh Corporation "F-4" manufactured by Tosoh Corporation Tosoh Corporation's "F-10" F-20 manufactured by Tosoh Corporation Tosoh Corporation's "F-40" Tosoh Corporation's "F-80" Tosoh Corporation's "F-128" Sample: 50 μl of a tetrahydrofuran solution containing 1.0% by mass (based on resin solids content) filtered through a microfilter.

[0136] (2) FD-MS measurement The FD-MS spectra of the resins obtained in the examples were measured using the following measuring equipment and conditions. Measuring device: JMS-T100GC AccuTOF Measurement conditions Measurement range: m / z = 4.00 - 2000.00 Rate of change: 51.2 mA / min Final current value: 45 mA Cathode voltage: -10 kV Recording interval: 0.07 seconds

[0137] (3) 13 C-NMR measurement Of the resin obtained in the example 13 The C-NMR spectrum was measured under the following measuring device and measurement conditions. 13 C-NMR: JNM-ECA500 SuperCOOL probe manufactured by JEOL Resonance frequency: 126 MHz Number of integrations: 2000 times Solvent: chloroform-d Sample concentration: 30 mass% Relaxation reagent: chromium(III) acetylacetonate

[0138] (4) 1 H-NMR measurement Of the haloethyl group-containing resin and the curable resin obtained in the example 1 The H-NMR spectrum was measured under the following measuring device and measurement conditions. 1 H-NMR: JNM-ECA500 SuperCOOL probe manufactured by JEOL Resonance frequency: 500 MHz Number of integrations: 16 times Solvent: chloroform-d Sample concentration: 10 mass%

[0139] <Synthesis of curable resin in Example 1> 370 g of 2-bromoethylbenzene and 28.8 g of methanesulfonic acid were added to a 2 L separable flask, and the mixture was stirred at 130 °C. A mixture of 370 g of 2-bromoethylbenzene, 158 g of 1,3-diisopropenylbenzene, and 76 g of chloromethylstyrene (a 1:1 mixture of meta- and para-isomers) was added dropwise to the reaction solution over 3 hours. After the dropwise addition, the mixture was heated at 130 °C for 3 hours. After cooling to 60 °C, the washing operation with 243 g of water was carried out 6 times, and then unreacted 2-bromoethylbenzene was removed by distillation under vacuum to obtain a resin (A) having a bromoethyl group. The Mn of this resin (A) was 728 and the Mw was 1358, and the GPC chart is shown in Figure 1. The FD-MS chart is shown in Figure 2, 13 The charts of C-NMR (NNE and DEPT) are shown in Figure 3.

[0140] It was confirmed that the following compounds were contained in the resin (A). [Chemical formula]

[0141] 131 g of resin (A), 107 g of toluene, 321 g of dimethyl sulfoxide, 31 mg of methoquinone, and 64 g of a 48.5% aqueous sodium hydroxide solution were added to a 2 L separable flask, and the mixture was heated at 40 °C for 6 hours. Then, 44 g of water was added and the mixture was allowed to stand, and the lower-layer water was discarded. 107 g of toluene, 321 g of dimethyl sulfoxide, and 4.3 g of a 48.5% aqueous sodium hydroxide solution were added, and the mixture was heated at 40 °C for 1 hour. Then, 44 g of water was added and the mixture was allowed to stand, and the lower-layer water was discarded. The washing operation with 100 g of water was carried out 6 times, and then the solvent was distilled off under vacuum so that the non-volatile content became 60% to obtain a toluene solution of resin (B). The Mn of resin (B) was 693 and the Mw was 1492, and the GPC chart is shown in Figure 4. The FD-MS chart is shown in Figure 5, 13 The C-NMR chart (bcm and DEPT) charts are shown in Figure 6, 1 The H-NMR chart is shown in Figure 7. It was confirmed that the curable resin contained a compound corresponding to the de-HBr product of the compound contained in the intermediate. Also, it was confirmed that the terminal had a substantially styrene structure.

[0142] <Dielectric properties after water absorption of the cured products of Example 2 and Comparative Example 1> The toluene solution of the resin (B) obtained in Example 1 and the maleimide resin ("NE-X-9470S" manufactured by DIC Corporation) were mixed in the amounts (unit: parts by mass) shown in Table 1, and after distilling off toluene by drying under reduced pressure, cumene hydroperoxide ("Perk Mill H-80" manufactured by NOF Corporation) was added in the amounts (unit: parts by mass) shown in Table 1 and mixed in a mortar to obtain the curable resin composition of Example 2. In Comparative Example 1, a curable resin composition was prepared in the same manner from the maleimide resin ("NE-X-9470S" manufactured by DIC Corporation) and cumene hydroperoxide ("Perk Mill H-80" manufactured by NOF Corporation) in the amounts (unit: parts by mass) shown in Table 1.

[0143] The obtained curable resin composition was cured under the following conditions to obtain a cured product. Size of resin plate: 110 mm × 50 mm × 1.6 mm Curing conditions: After heating at 200 °C for 2 hours using a vacuum press, heat curing at 250 °C for 2 hours

[0144] The obtained cured product was evaluated for dielectric properties as follows. The results are shown in Table 1. <Evaluation of dielectric properties after water absorption (measurement of dielectric loss tangent)> The obtained resin plate was cut into a size of 90 mm in length × 1.6 mm in width × 1.6 mm in thickness, and the resin plate was exposed to an environment of 120 °C and 100% humidity for 6 hours. Using this as a test piece, the dielectric loss tangent (Df) and dielectric constant (Dk) after water absorption were measured with an impedance material analyzer "HP4291B" manufactured by Agilent Technologies. A Df of 0.0070 or less and a Dk of 2.50 or less are considered good.

[0145]

Table 1

[0146] <Tackiness of Example 3 and Comparative Example 2> In Example 3, 1 g of a toluene solution (60% non-volatile content) of resin (B) obtained in Example 1 was cast into a 5 cm diameter round metal petri dish, dried in a 60°C oven for 1 hour, and then left at room temperature for 1 hour. The tackiness of the resin was then examined by touching it through latex gloves. The resin was solid and did not exhibit tackiness. In Comparative Example 2, 1 g of a toluene solution (60% non-volatile content) of the resin synthesized in the same manner as in Synthesis Examples 1 and 2 of Japanese Patent Publication No. 2023-130776 was cast into a 5 cm diameter round metal petri dish, dried in a 60°C oven for 1 hour, and then left at room temperature for 1 hour. The tackiness of the resin was then examined by touching it through latex gloves. The resin was liquid and exhibited tackiness.

Claims

1. A curable resin comprising one or both of the structural units represented by the following formula (1) and the structural units represented by the following formula (2), the structural unit represented by the following formula (3), and the structural unit represented by the following formula (4). 【Chemistry 1】 (In the formula, Q １ Each of these is independently either a hydrogen atom or a methyl group. Q ２ One of them is a single bond, and the remaining three Q ２ Each of these is independently either a hydrogen atom or a methyl group. Q ３ One of them is a single bond, and the remaining three Q ３ Each of these is independently either a hydrogen atom or a methyl group. R １ Each of these is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. I understand １ is an integer between 0 and 3, R ２ Each of these is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. m ２ is an integer from 0 to 4, * indicates a linking hand.

2. The curable resin according to claim 1, comprising a structural unit represented by the following formula (6) at its end. 【Chemistry 2】 (In the formula, * represents a coupling.)

3. A curable resin according to claim 2, comprising a structural unit represented by the following formula (5). 【Transformation 3】 (In the formula, R １ Each of these is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. I understand １ is an integer between 0 and 3, * indicates a linking hand.

4. A method for producing a curable resin according to any one of claims 1 to 3, comprising the following steps (i) and (ii). Step (i): A step of reacting a compound represented by formula (7) below with a compound represented by formula (8) below and a compound represented by formula (9) below; Step (ii): A step in which the reaction product obtained in step (i) is subjected to a dehalogenation reaction in the presence of a base to obtain a curable resin. 【Chemistry 4】 (In the formula, R １ Each of these is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. X １ X is a hydrogen atom, ２ is either a halogen atom or X １ X is a halogen atom, ２ It is a hydrogen atom, I understand １ is an integer between 0 and 3, R ２ Each of these is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom. Y is a halogen atom, I understand ２ (This is an integer between 0 and 4.)

5. A curable resin according to any one of claims 1 to 3, and a curable composition comprising one or both of a curing agent and a curing catalyst.

6. A cured product of the curable composition according to claim 5.

7. A prepreg having a reinforcing substrate and a semi-cured product of the curable composition according to claim 5 impregnated into the reinforcing substrate.

8. A circuit board having a laminate of prepreg and copper foil as described in claim 7.

9. A build-up film containing the curable composition described in claim 5.

10. A semiconductor encapsulant containing the curable composition described in claim 5.

11. A semiconductor device comprising a cured product of the semiconductor encapsulant according to claim 10.

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