Curable resin, method for producing curable resin, curable composition, cured product, prepreg, circuit board, build-up film, semiconductor sealing material, and semiconductor device

Abstract

This curable resin contains a structural unit represented by formula (1) and / or a structural unit represented by formula (2), a structural unit represented by formula (3), and a structural unit represented by formula (4). (In the formulae, Q1 each independently is a hydrogen atom or a methyl group; one of Q2 is a single bond and the remaining three Q2 each independently is a hydrogen atom or a methyl group; one of Q3 is a single bond and the remaining three Q3 each independently is a hydrogen atom or a methyl group; R1 each independently is an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom; m1 is an integer of 0-3; R2 each independently is an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom; m2 is an integer of 0-4; and * is a bond.)

Description

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

[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.

[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. In recent years, with the increasing speed and frequency of signals, there has been a demand for thermosetting resin compositions that provide cured products exhibiting sufficiently low dielectric constants and low dielectric loss tangents 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.

[0004] International Publication No. 2020 / 217679

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

[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.

[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 the present invention is as follows. [1] A curable resin containing one or both of a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2), a structural unit represented by the following formula (3), and a structural unit represented by the following formula (4). (In the formula, ２ Q is each independently a hydrogen atom or a methyl group, and ２ one of the Qs is a single bond, and the remaining three Qs ２ are each independently a hydrogen atom or a methyl group, and ３ one of the Qs is a single bond, and the remaining three Qs ３ are each independently a hydrogen atom or a methyl group, and １ R is each independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group or a halogen atom, and １ m is an integer of 0 to 3, and ２ R is each independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group or a halogen atom, and ２ m is an integer of 0 to 4, and * is a bond.) [2] The curable resin according to [1], containing a structural unit represented by the following formula (6) at the terminal. (In the formula, * is a bond.) [3] The curable resin according to [1] or [the curable resin according to [2], containing a structural unit represented by the following formula (5). (In the formula, １ R is each independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group or a halogen atom, and １ m is an integer of 0 to 3, and * is a bond.) [4] A method for producing the curable resin according to any one of [1] to [3], including the following steps (i) and (ii). Step (i): A step of reacting 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); Step (ii): A step of subjecting the reaction product obtained in the step (i) to a dehydrohalogenation reaction in the presence of a base to obtain a curable resin. (In the formula, １Each of these is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom, and X １ X is a hydrogen atom, ２ is either a halogen atom or X １ X is a halogen atom, ２ is a hydrogen atom, m １ R is an integer between 0 and 3. ２ Each of these is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom, and Y is a halogen atom, m ２ (where is an integer from 0 to 4.) [5] A curable composition comprising any curable resin from [1] to [3] and one or both of a curing agent and a curing catalyst. [6] A cured product of the curable composition of [5]. [7] A prepreg having a reinforcing substrate and a semi-cured product of the curable composition of [5] impregnated into the reinforcing substrate. [8] A circuit board having a laminate of the prepreg of [7] and copper foil. [9] A build-up film containing the curable composition of [5].

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

[11] A semiconductor device containing a cured product of the semiconductor encapsulant of

[10] .

[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.

[0010] This is the GPC measurement result of resin (A) in the example. This is the FD-MS measurement result of resin (A) in the example. １３ This is the measurement result of C-NMR (NNE and DEPT). This is the GPC measurement result of resin (B) of the example. This is the FD-MS measurement result of resin (B) of the example. １３ These are the measurement results of C-NMR (bcm and DEPT). The resin (B) of the example. １ This is the result of the H-NMR measurement.

[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 essence.

[0012] [Terminology] 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 this specification, "reaction raw material" specifically refers to a precursor for obtaining a target intermediate through a chemical reaction. In this specification, "structural unit" refers to a (repeating) unit of a chemical structure formed during a reaction or polymerization. In other words, it refers to a substructure other than the chemical bond structure involved in the reaction or polymerization in the resulting compound formed by the reaction or polymerization, and is a so-called residue. In this specification, "intermediate" specifically refers to the reaction product produced in each elementary reaction when the chemical reaction of the reaction raw material is a multi-step reaction. In other words, it refers to a precursor of the target final product that is 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" is, for example, phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, mesityl group, o-biphenyl group, m-biphenyl group, p-biphenyl group, 1-naphthyl group, 2-naphthyl group, 2-fluorenyl group, 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 group, ethoxy group, propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, etc. The number of carbon atoms can be 1 to 20, preferably 1 to 10, more preferably 1 to 6. In this specification, "aryloxy group" has an aryl-O- structure, and the definition of 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 resin] 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 materials. (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, and X １ X is a hydrogen atom, ２ is either a halogen atom or X １ X is a halogen atom, ２ is a hydrogen atom, m １ R is an integer between 0 and 3. ２ Each of these is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom, and Y is a halogen atom, m ２ (This 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)> (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, and X １ X is a hydrogen atom, ２ is either a halogen atom or X １ X is a halogen atom, ２ is a hydrogen atom, m １ (This 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). (In the formula, Hal is a halogen atom, and R１ and m １ This is equivalent to equation (8).

[0020] In the compound of formula (8), m １ It is preferable that this is 0, in which case equations (8-1) and (8-2) can be expressed as equations (8-1-1) and (8-2-1), respectively. (In the formula, Hal represents a halogen atom.)

[0021] I understand １ Specific examples of compounds of formula (8) where 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] I understand １ It can also be 1 to 3, in which case R １ Preferably, alkyl groups and aryl groups are used. １ If there are 2 or 3, multiple R １ They may be the same or they may be different.

[0023] I understand １ Specifically, compounds of formula (8) 1 to 3 include (2-bromoethyl)benzene and (1-bromoethyl)benzene.

[0024] X １ and X ２ Regarding this, a bromine atom is preferred as the halogen atom.

[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)> (In the formula, R ２Each of these is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom, and Y is a halogen atom, m ２ (This is an integer between 0 and 4.)

[0028] The vinyl group and -CH in the compound of formula (9) ２ - The bond position with the Y group may be ortho, meta, or para, but is preferably meta or para, and more preferably para.

[0029] In the compound of formula (9), m ２ It is preferable that this value is 0, in which case it can be expressed by the following formula (9-1). (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] I understand ２ can also be 1 to 4, in which case R ２ Preferred elements include alkyl groups, aryl groups, and halogen atoms (preferably chlorine atoms or bromine atoms). ２ If the number is 2 to 4, multiple R ２ They may be the same or they may be different.

[0032] I understand ２ Examples of compounds of formula (9) where 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 producing 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 dehalogenation reaction. Specifically, it can be produced by a production method comprising the steps of (i) synthesizing an intermediate by an aromatic electrophilic substitution reaction and (ii) subjecting the intermediate to a dehalogenation reaction. Step (i): A step of reacting a compound represented by formula (7), a compound represented by formula (8), and a compound represented by formula (9); Step (ii): A step of subjecting the reaction product obtained in step (i) to a dehalogenation reaction in the presence of a base to obtain a curable resin.

[0037] <Step (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, the compound of formula (7), the compound of formula (8), and the compound of formula (9), can be, for example, 0.4 to 40 moles of the compound of formula (8), preferably 0.8 to 20 moles, and 0.05 to 5 moles of the compound of formula (9), preferably 0.1 to 2.5 moles, per mole of the compound of formula (7).

[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. One or more acid catalysts can be used 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. One or more organic solvents can be used 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, from the viewpoint of allowing the reaction to proceed sufficiently and 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 obtained organic layer can then 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). (In the formula, Q １ Each of these is independently 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 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 a hydrogen atom or a methyl group, and R １ Each of these is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom, and X １ X is a hydrogen atom, ２ is either a halogen atom or X １ X is a halogen atom, ２ is a hydrogen atom, m １ R is an integer between 0 and 3. ２ Each of these is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom, m ２R is an integer from 0 to 4, and * is a combination.) R in equation (3') １ , X １、 X ２ and m １ For this, 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, but 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). (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. (In the formula, * represents a coupling.)

[0052] Structural units of formula (2) include those formed when one of the two isopropenyl groups in 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 in formula (7) react with the compound of formula (9). When the compound of formula (7) is a compound in which an isopropenyl group is bonded at the meta position (1,3-diisopropenylbenzene), it can be represented by formulas (2-1-1) and (2-2-1), respectively. (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. (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). (In the formula, Hal is a halogen atom, and R １ Each of these is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom, m １ (where * is an integer between 0 and 3, and * is a combination.)

[0055] In the structural unit of formula (3'), m １ It is preferable that this value is 0, and 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 (3'-1-1) and (3'-2-1). (In the formula, Hal represents a halogen atom, and * represents a bond.)

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

[0057] The single bond (-*) group and methylene bond (-CH) in the structural unit of formula (4)２ The bond position relationship with -*) may be ortho, meta, or para, but is preferably meta or para, and more preferably para.

[0058] In the structural unit of equation (4), m ２ It is preferable that this value is 0, in which case it can be expressed by the following formula (4-1). (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), preferably the structural units of formulas (4-1-2) and (4-1-3). (In the formula, * represents a coupling.)

[0060] I understand ２ can also be 1 to 4, in which case R ２ Preferably, the elements are alkyl groups, aryl groups, and halogen atoms (preferably chlorine atoms or bromine atoms). ２ If the number is 2 to 4, multiple R ２ They may be the same or they may be different.

[0061] The intermediate may contain the structural unit represented by formula (5'). (In the formula, X １ X is a hydrogen atom, ２ is either a halogen atom or X １ X is a halogen atom, ２ R is a hydrogen atom. １ Each of these is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom, m １ (where * is an integer between 0 and 3, and * is a combination.)

[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). (In the formula, Hal is a halogen atom, and R １is, independently of one another, an alkyl group, an aryl group, an alkoxy group, an aryloxy group or a halogen atom, and m １ is an integer of 0 to 3, and * is a bond.)

[0063] In the structural unit of formula (5'), m １ is preferably 0, and these structural units are derived from the compounds of formula (8-1-1) and the compounds of formula (8-2-1), and are represented by formula (5'-1-1) and formula (5'-2-1). (In the formula, Hal is a halogen atom, and * is a bond.)

[0064] As the structural unit of formula (5'), a divalent group derived from (1-bromoethyl)benzene, (2-bromoethyl)benzene is preferable.

[0065] The intermediate can contain a structural unit represented by formula (6) at the terminal. (In the formula, * is a bond.)

[0066] The structural unit of formula (6) can be included in the structure derived from the compound of formula (7), and can be, for example, a partial structure of the following formula. (In the formula, Q １ is, independently of one another, a hydrogen atom or a methyl group, and * is a bond.)

[0067] The terminal of each compound of the intermediate is preferably a structural unit of formula (3'), and more preferably, among all the terminals, 1 mol% or more is a structural unit of formula (3').

[0068] The intermediate can contain a compound represented by formula (10'). The compound of formula (10') is derived from the compound of formula (8) and the compound of formula (9). (In the formula, R １ is, independently of one another, an alkyl group, an aryl group, an alkoxy group or a halogen atom, and R ２ is, independently of one another, an alkyl group, an aryl group, an alkoxy group or a halogen atom, and R ３ is a hydrogen atom, R ４ is a methyl group, or R３ is a methyl group, and R ４ is a hydrogen atom, and X １ is a hydrogen atom, and X ２ is a halogen atom, or X １ is a halogen atom, and X ２ is a hydrogen atom, and m １ are each independently an integer of 0 to 3, and m ２ is an integer of 0 to 4, and n is an integer of 1 to 20. )

[0069] In the formula (10'), R １ , R ２ , X １ , X ２ , m １ and m ２ The preferred examples of are the same as those in formula (8) and formula (9). In the formula (10'), n is preferably an integer of 1 to 10, and more preferably 1 to 5.

[0070] In the intermediate obtained in step (i), the mass ratio 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, more preferably 90% by mass or less, from the viewpoint of curability.

[0071] In the compound of formula (10'), m １ and m ２ are preferably 0, and in this case, it can be represented by the following formula (10'-l). (In the formula, R ３ , R ４ , X １ , X ２ and n are synonymous with formula (10'), and the preferred examples are also synonymous. )

[0072] In the compound of formula (10'-l), n is preferably 1 to 10, and more preferably 1 to 5. When n is 1, R ３ is a methyl group, and R<.. ４ is a hydrogen atom, it can be represented by the following formula (10'-l-l). (In the formula, X １ and X ２This is equivalent to formula (10'), and the preferred example is similar.

[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. (In the formula, X １ , X ２ , R １ , R ２ , m １ , m ２ This is synonymous with formula (10'), and the preferred example is similar, Q １ Q ２ and Q ３ Each of these is independently a hydrogen atom or a methyl group, n １ n is an integer between 0 and 1000. ２ n is an integer between 0 and 1000, but n １ and n ２ It is impossible for both to be zero at the same time.) In equation (11'), n １ The units enclosed in and n ２ The units enclosed in quotation marks may be random or block-based.

[0074] n １ n 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. ２ n 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, n １ and n ２ It is impossible for both to be 0 at the same time, n １ and n ２ The sum 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). (In the formula, X １ , X ２ , R １ , R ２ , m １ , m ２ This is equivalent to formula (10'), and the preferred example is similar.

[0077] In the compounds of formula (11'-1) and formula (11'-2), m １ and m ２ It is preferable that this value is 0, in which case it can be expressed by the following equations (11'-1-1) and (11'-2-1).

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

[0079] Examples of compounds include the following: (In the formula, X １ X is a hydrogen atom, ２ is either a halogen atom or X １ X is a halogen atom, ２ (where is a hydrogen atom, and Ra is independently either a hydrogen atom or a methyl group.)

[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] <Step (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 contained 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. One or more base catalysts can be used 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 an aprotic polar solvent in combination is preferable because it can increase the progress of the dehalogenation reaction. One or more organic solvents can be used in any ratio.

[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 being 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 base catalyst and organic solvent can be added again to carry out the reaction.

[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 resin. These organic acids can be used individually or in any ratio of two or more types.

[0089] <Curable 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. (In the formula, Q １ Each of these is independently 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 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 a hydrogen atom or a methyl group, and R １ Each of these is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom, m １R is an integer between 0 and 3. ２ Each of these is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom, m ２ (where * is an integer between 0 and 4, and * is a combination.)

[0091] Curable resins are typically mixtures of multiple compounds, and the above-mentioned 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. (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, m １ (where * is an integer between 0 and 3, and * is a combination.)

[0093] The end of the curable resin may be a structural unit of formula (6). (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. (In the formula, R １ Each of these is independently an alkyl group, an aryl group, an alkoxy group, or a halogen atom, and R ２ Each of these is independently an alkyl group, an aryl group, an alkoxy group, or a halogen atom, and R ３ is a hydrogen atom, and R ４ is either a methyl group or R ３ R is a methyl group, ４ is a hydrogen atom, m １ Each of these is an integer between 0 and 3, and m ２ R is an integer from 0 to 4, and n is an integer from 1 to 20.) In equation (10), １ , R ２ , m １ , m ２ And preferred examples of n are the same as those of 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), m １ and m ２ It is preferable that this value is 0, in which case it can be expressed by the following formula (10-1). (In the formula, R ３ , R ４ 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, R ３ is a methyl group, R ４ When is a hydrogen atom, it can be expressed by the following equation (10'-1-1).

[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) can be cited. 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. (In the formula, R １ , R ２ Q １ Q ２ Q ３ , m １ , m ２ , n １ and n ２ This is synonymous with formula (11'), and the preferred example is similar.) In formula (11), n １ The units enclosed in and n ２ The units enclosed in quotation marks may be random or block-based.

[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 the compounds 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. (In the formula, R １ , R ２ , m １ and m ２ This is equivalent to formula (11), and the preferred example is similar.

[0102] In the compounds of formula (11-1) and formula (11-2), m １ and m ２It is preferable that is 0, in which case it 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 is removed from the haloethyl group in formulas (11'-1-1) and (11'-2-1) to form a vinyl group.

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

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

[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 through analysis such as C-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). One or more curing agents can be used in any ratio.

[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, galbinoxyl, 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 used. The cured product can be in the form of a laminate, a cast product, an adhesive layer, a coating, a film, etc.

[0114] [Semiconductor Encapsulation Material] The semiconductor encapsulation material 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 encapsulation material 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 examples include 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. For example, this can be done by 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 the curable composition is not particularly limited, and one method is to impregnate a reinforcing substrate (for example, paper, glass cloth, glass nonwoven fabric, aramid paper, aramid cloth, glass mat, glass roving cloth, etc.) with a curable composition that has been varnished by incorporating an organic solvent, as described later, and then heat it at a heating temperature (preferably 50 to 170°C) according to the type of solvent used to semi-cure (or not cure) 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 the prepreg so that the resin content 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 curing of the semi-cured product can be calculated by measuring the heat of curing when the curable composition is heated and the heat of curing of the semi-cured product using DSC, and using the following formula: Degree of curing (%) = [1 - (heat of curing of semi-cured product / heat of curing of 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, place copper foil on top, 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 in the vacuum lamination method (usually 70 to 140°C) 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 polyethylene, polypropylene, polyvinyl chloride or other polyolefins, polyethylene terephthalate (hereinafter sometimes abbreviated as "PET"), polyethylene naphthalate or other polyesters, polycarbonate, polyimide, and also release paper, copper foil, aluminum foil or 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 support film (Y) described above is peeled off after lamination to the circuit board or after an insulating layer is formed by heat curing. Peeling off the support film (Y) after heat curing the adhesive film prevents the adhesion of dust and other contaminants during the curing process. When peeling off after curing, the support film is usually treated with a release agent beforehand.

[0133] [Applications] Cured products obtained from the curable composition containing the curable resin of the present invention have excellent heat resistance and dielectric properties, making them suitable for use in heat-resistant members or electronic components. In particular, they are suitable for use in prepregs, circuit boards, semiconductor encapsulants, semiconductor devices, build-up films, build-up substrates, adhesives and resist materials using conductive pastes, etc. They can also be suitable for use as matrix resins for fiber-reinforced resins, and are especially suitable as high-heat-resistant prepregs. Furthermore, the curable resin contained in the curable composition exhibits excellent solubility in various solvents, making it possible to manufacture paints. The heat-resistant members and electronic components thus obtained can be suitable for use in a variety of applications, including, but are not limited to, industrial machine parts, general machine parts, automobile, railway, and vehicle parts, aerospace-related parts, electronic and electrical components, building materials, containers and packaging materials, household goods, sports and leisure goods, wind power generation housing components, etc.

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

[0135] The physical properties were evaluated as follows: (1) GPC measurement The number-average molecular weight (Mn) and weight-average molecular weight (Mw) of the resins obtained in the examples and comparative examples were calculated using the following measuring equipment and conditions. <GPC Measurement> Measuring device: Tosoh Corporation "HLC-8320 GPC", Column: Tosoh Corporation Guard Column "HXL-L" + Tosoh Corporation "TSK-GEL G2000HXL" + Tosoh Corporation "TSK-GEL G2000HXL" + Tosoh Corporation "TSK-GEL G3000HXL" + Tosoh Corporation "TSK-GEL G4000HXL" Detector: RI (Differential Refractometer) Data processing: Tosoh Corporation "GPC Workstation EcoSEC-WorkStation" Measurement conditions: Column temperature 40℃ Developing solvent tetrahydrofuran flow rate 1.0 ml / min Standard: In accordance with the measurement manual for the "GPC Workstation EcoSEC-WorkStation", the following monodisperse polystyrene with known molecular weight was used. (Polystyrene used) Tosoh Corporation "A-500" Tosoh Corporation "A-1000" Tosoh Corporation "A-2500" Tosoh Corporation "A-5000" Tosoh Corporation "F-1" Tosoh Corporation "F-2" Tosoh Corporation "F-4" Tosoh Corporation "F-10" Tosoh Corporation "F-20" Tosoh Corporation "F-40" Tosoh Corporation "F-80" Tosoh Corporation "F-128" Sample: 50 μl of a tetrahydrofuran solution containing 1.0% by mass in terms of resin solids content, filtered through a microfilter.

[0136] (2) The FD-MS spectra of the resins obtained in the FD-MS measurement examples were measured using the following measuring device and conditions: Measuring device: JMS-T100GC AccuTOF Measuring conditions Measurement range: m / z = 4.00 to 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 The resin obtained in the C-NMR measurement example １３ The C-NMR spectrum was measured using the following measuring equipment and conditions. １３ C-NMR: JEOL JNM-ECA500 SuperCOOL probe. Resonance frequency: 126 MHz. Number of cumulative cycles: 2000. Solvent: Chloroform-d. Sample concentration: 30% by mass. Relaxation reagent: Chromium(III) acetylacetonate.

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

[0139] <Example 1 Synthesis of Curable Resin> 370 g of 2-bromoethylbenzene and 28.8 g of methanesulfonic acid were added to a 2 L separatory flask and 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 addition, the mixture was heated at 130°C for 3 hours. After cooling to 60°C, the mixture was washed with 243 g of water six times, and then unreacted 2-bromoethylbenzene was removed by distillation under vacuum to obtain resin (A) having bromoethyl groups. The Mn of 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 C-NMR (NNE and DEPT) charts are shown in Figure 3.

[0140] The following compounds were found to be present in resin (A).

[0141] In a 2 L separatory flask, 131 g of resin (A), 107 g of toluene, 321 g of dimethyl sulfoxide, 31 mg of methoquinone, and 64 g of 48.5% sodium hydroxide aqueous solution were added and heated at 40°C for 6 hours. Then, 44 g of water was added and allowed to stand, and the lower layer of water was discarded. 107 g of toluene, 321 g of dimethyl sulfoxide, and 4.3 g of 48.5% sodium hydroxide aqueous solution were added and heated at 40°C for 1 hour. Then, 44 g of water was added and allowed to stand, and the lower layer of water was discarded. After washing with 100 g of water six times, the solvent was removed under vacuum until the non-volatile content was 60%, obtaining 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 C-NMR charts (bcm and DEPT) are shown in Figure 6. １ The H-NMR chart is shown in Figure 7. It was confirmed that the curable resin contains a compound equivalent to the de-HBr form of the compound contained in the intermediate. Furthermore, it was confirmed that the terminals were almost entirely styrene in structure.

[0142] <Example 2 and Comparative Example 1: Dielectric Properties of Cured Products After Water Absorption> In the amounts shown in Table 1 (unit: parts by mass), a toluene solution of resin (B) obtained in Example 1 and maleimide resin (DIC Corporation's "NE-X-9470S") were mixed. After distillation of the toluene by vacuum drying, cumene hydroperoxide (NOF Corporation's "Parkmill H-80") was added in the amounts shown in Table 1 (unit: parts by mass) 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 maleimide resin (DIC Corporation's "NE-X-9470S") and cumene hydroperoxide (NOF Corporation's "Parkmill H-80") in the amounts shown in Table 1 (unit: parts by mass).

[0143] The obtained curable resin composition was cured under the following conditions to obtain a cured product. Resin plate size: 110 mm x 50 mm x 1.6 mm Curing conditions: Heat curing using a vacuum press at 200°C for 2 hours, followed by heating at 250°C for 2 hours.

[0144] The dielectric properties of the obtained cured material were evaluated 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 to a size of 90 mm in length x 1.6 mm in width x 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 using an Agilent Technologies impedance material analyzer "HP4291B". A Df of 0.0070 or less and a Dk of 2.50 or less were considered good.

[0145]

[0146] <Example 3 and Comparative Example 2: Tackiness> 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 was then examined by touching the resin 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 resin synthesized in the same manner as in Synthesis Examples 1 and 2 of Japanese Patent Application 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 was then examined by touching the resin through latex gloves. The resin was liquid and exhibited tackiness.

Claims

1. A curable resin comprising one or both of a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2), a structural unit represented by the following formula (3), and a structural unit represented by the following formula (4). (In the formula, Q １ are each independently a hydrogen atom or a methyl group, and one of Q ２ is a single bond, and the remaining three Q ２ are each independently a hydrogen atom or a methyl group, and one of Q ３ is a single bond, and the remaining three Q ３ are each independently a hydrogen atom or a methyl group, and R １ are each independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group or a halogen atom, and m １ is an integer of 0 to 3, and R ２ are each independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group or a halogen atom, and m ２ is an integer of 0 to 4, and * is a bond.) 2. The curable resin according to claim 1, comprising a structural unit represented by the following formula (6) at its end. (In the formula, * represents a coupling.) 3. The curable resin according to claim 2, comprising a structural unit represented by the following formula (5). (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, m １ (where * is an integer between 0 and 3, and * is a combination.) 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 the following formula (7) with a compound represented by the following formula (8) and a compound represented by the following formula (9); Step (ii): A step of subjecting the reaction product obtained in step (i) to a dehalogenation reaction in the presence of a base to obtain a curable resin. (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, and X １ X is a hydrogen atom, ２ is either a halogen atom or X １ X is a halogen atom, ２ is a hydrogen atom, m １ R is an integer between 0 and 3. ２ Each of these is independently an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a halogen atom, and Y is a halogen atom, m ２ (This is an integer between 0 and 4.) 5. A curable composition comprising the curable resin according to any one of claims 1 to 3, and 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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