Five-membered ring condensed ring compounds and their manufacturing methods, curable compositions, cured products, prepregs, circuit boards, build-up films, semiconductor encapsulants, and semiconductor devices.

Abstract

To provide a 5-membered fused-ring compound having low dielectric loss tangents and excellent heat resistance in a well-balanced manner.SOLUTION: A 5-membered fused-ring compound has a structural unit represented by the general formula (1) and a trivalent aromatic ring-containing 5-membered fused-ring structural unit.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This disclosure relates to a five-membered ring condensed ring compound, a method for producing the same, a curable composition containing the five-membered ring condensed ring compound and its cured product, a prepreg, a circuit board, a build-up film, a semiconductor encapsulant, and a semiconductor device. [Background technology]

[0002] 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 heat-curing a combination of the laminates and the prepregs are widely used as circuit board materials for electronic devices. In particular, package substrates, a type of printed wiring board that serves as an interposer for mounting semiconductors, are becoming thinner, and warping of the package substrate during mounting is becoming a problem. Therefore, there is a demand for materials that exhibit high heat resistance to suppress warping of the package substrate during mounting. Furthermore, in recent years, with the increasing speed and frequency of signals, there is a demand for thermosetting compositions that can form cured products that maintain a sufficiently low dielectric constant and exhibit a sufficiently low dielectric loss tangent under these conditions. In particular, in recent years, there has been a need for materials and compositions that possess further improvements in performance, such as heat resistance and dielectric properties, and especially in advanced materials applications, as well as materials that combine these properties.

[0003] In response to these requirements, hydrocarbon resins are attracting attention as materials that combine heat resistance with low dielectric constant and low dielectric loss tangent. For example, Patent Document 1 discloses a curable resin mixture having a predetermined cyclopentadiene structure as a curable resin mixture that exhibits excellent heat resistance and electrical properties and has good curability. Furthermore, Patent Document 2 discloses a low dielectric material consisting of a polyindane derivative having a predetermined structure, which has a low dielectric constant even without the introduction of pores and is suitable as an interlayer insulating film material. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2020 / 031935 [Patent Document 2] Japanese Patent Publication No. 2007-311732 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, the required level of heat resistance, in particular, is high for advanced material applications, and there is still a need for materials that can meet this level and exhibit low dielectric loss tangent. Therefore, the technical problem that this disclosure aims to solve is to provide a five-membered ring fused compound that can exhibit excellent heat resistance and low dielectric loss tangent, a method for producing the same, a curable composition containing the five-membered ring fused compound and its cured product, a prepreg, a circuit board, a build-up film, a semiconductor encapsulant, and a semiconductor device. [Means for solving the problem]

[0006] As a result of diligent research to solve the above-mentioned problems, the present inventors have found that by using a five-membered ring fused compound having a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (3), it is possible to achieve a high degree of both low dielectric loss tangent and excellent heat resistance, and have completed the invention disclosed herein. [ka] (Here, R 1 This is located on any carbon atom of the benzene ring of general formula (1) and is an alkyl group, alkoxy group, allyl group, aryl group, aryloxy group, or aralkyl group. p is an integer from 0 to 4, and if p is an integer from 2 to 4, multiple R 1 They may be the same or different. Each dashed line independently indicates either absence or a double bond, however, two dashed lines cannot simultaneously indicate a double bond. *Each bond represents a bond, located on any ring-forming carbon atom of general formula (1), except that no two bonds can be located on the same carbon atom. [ka] (Here, R 3 ~R 7 Each of these is independently a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. Ring A is a trivalent aromatic cyclic group, * indicates a bonding operation. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a five-membered ring fused compound that can achieve a high degree of both low dielectric loss tangent and excellent heat resistance, and a method for producing the same. Furthermore, it is possible to provide a curable composition containing the five-membered ring fused compound and a cured product thereof. In addition, by using the curable composition or its cured product, it is possible to provide prepregs, circuit boards, build-up films, semiconductor encapsulants, and semiconductor devices that achieve a high degree of both low dielectric properties and excellent heat resistance. [Brief explanation of the drawing]

[0008] [Figure 1A] This shows the GPC measurement results for the 5-membered ring condensed ring compound synthesized in Example 1. [Figure 1B] This shows the FD-MS measurement results of the 5-membered ring condensed ring compound synthesized in Example 1. [Figure 1C] This shows the NMR measurement results of the 5-membered ring condensed ring compound synthesized in Example 1. [Figure 2] This shows the GPC measurement results for the 5-membered ring condensed compound synthesized in Example 2. [Figure 3] This shows the GPC measurement results for the 5-membered ring condensed compound synthesized in Example 3. [Modes for carrying out the invention]

[0009] The following describes in detail the embodiments for carrying out the invention, but this disclosure is not limited to the following description and can be implemented in various modifications within the scope of its essence.

[0010] [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 the chemical reaction, such as solvents and catalysts, are excluded. In particular, in this specification, "reaction raw material" refers to a precursor for obtaining a target five-membered ring condensed ring compound or a mixture containing one or more such five-membered ring condensed ring compounds 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.

[0011] In this specification, "alkyl group" may be linear, branched, or cyclic, and may have 1 to 12 carbon atoms. Examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, tert-pentyl group, neopentyl group, 1,2-dimethylpropyl group, n-hexyl group, isohexyl group, (n-)heptyl group, (n-)octyl group, (n-)nonyl group, (n-)decyl group, (n-)undecyl group, (n-)dodecyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, or cyclononyl group. In this specification, "alkoxy group" has an alkyl-O- structure, and the above description of alkyl groups applies to the alkyl portion in the structure. Examples include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, pentyloxy group, hexyloxy group, 2-ethylhexyloxy group, octyloxy group, or nonyloxy group. In this specification, "aryl group" refers to a monovalent aromatic hydrocarbon group, which may be monocyclic or polycyclic, and has 6 to 20 carbon atoms. Examples include phenyl group, 1-naphthyl group, 2-naphthyl group, anthryl group, phenanthryl group, pyrenyl group, indenyl group, or indanyl group. In this specification, "aryloxy group" has an aryl-O- structure, and the above description of an aryl group applies to the aryl portion in the structure. Examples include a phenoxy group, naphthyloxy group, anthryloxy group, phenanthryloxy group, or pyrenyloxy group. In this specification, "aralkyl group" refers to an alkyl group substituted with one or more aryl groups, preferably one or two, and particularly one, aryl groups. The above descriptions of aryl groups and alkyl groups apply to aryl groups and alkyl groups. Examples include benzyl groups and phenethyl groups. In this specification, "aromatic ring group" refers to a residue of an aromatic ring, which may be monocyclic or polycyclic, and may have 6 to 20 carbon atoms. Examples of divalent aromatic ring groups include phenylene and naphthylene, while examples of trivalent aromatic ring groups include benzenetriyl and naphthalenetriyl. Here, "residue" refers to a partial structure of the aromatic ring that remains within the molecule of a five-membered ring fused ring compound or its intermediate produced by a reaction or polymerization, and consists of a chemical bond formed by the reaction or polymerization and a structural unit other than the chemical bond, which is obtained by removing an arbitrary hydrogen atom from the aromatic ring.

[0012] In this specification, "Brønsted acid" means H +A chemical substance capable of donating a proton to another substance, which may be an inorganic or organic acid. Examples of inorganic acids include hydrochloric acid, nitric acid, nitrite, phosphoric acid, phosphorous acid, hypophosphorous acid, sulfuric acid, sulfurous acid, boric acid, hydrofluoric acid, fluorosulfonic acid, etc. Examples of organic acids include aliphatic carboxylic acids (e.g., monocarboxylic acids (formic acid, acetic acid, propionic acid, etc.), dicarboxylic acids (oxalic acid, malonic acid, succinic acid, glutaric acid, etc.), trivalent or higher polycarboxylic acids (aconitic acid, etc.)), aromatic carboxylic acids (e.g., benzoic acid, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc.), sulfonic acids (e.g., alkyl sulfonic acids (methanesulfonic acid, camphor-sulfonic acid, etc.), substituted sulfonic acids (trifluoromethanesulfonic acid, etc.), aromatic sulfonic acids (e.g., benzenesulfonic acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, etc.)). Brønsted acids may also be in hydrate form.

[0013] In this specification, "number-average molecular weight (Mn)", "weight-average molecular weight (Mw)", and "molecular weight distribution (weight-average molecular weight (Mw) / number-average molecular weight (Mn))" are values ​​measured using gel permeation chromatography (hereinafter abbreviated as "GPC") under the measurement conditions described in the examples below.

[0014] [5-membered fused ring compound] The five-membered ring condensed ring compound relating to this disclosure has a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (3). [ka] (Here, R 1 This is located on any carbon atom of the benzene ring of general formula (1) and is an alkyl group, alkoxy group, allyl group, aryl group, aryloxy group, or aralkyl group. p is an integer from 0 to 4, and if p is an integer from 2 to 4, multiple R 1 They may be the same or different. The dashed lines each independently represent absence or a double bond, provided that two dashed lines do not simultaneously represent a double bond. * each represents a bond and is located on any ring - forming carbon atom of the general formula (1), provided that two bonds are not on the same carbon atom.

Chemical formula

[0015] In the general formula (1), the two dashed lines shown in the five - membered ring each independently represent absence or a double bond, provided that two dashed lines do not simultaneously represent a double bond. When the dashed line is absent, it becomes a single bond. When the dashed line is absent, it corresponds to an indane structure. When one of the two dashed lines is absent and the other is a double bond, it corresponds to an indene structure.

[0016] In the general formula (1), the two * each represents a bond. The general formula (1) is divalent. The bonds are each on any ring - forming carbon atom of the general formula (1). Both of the two bonds may be on a carbon atom constituting the five - membered ring, one bond may be on a carbon atom constituting the five - membered ring and the other bond may be on a carbon atom constituting the benzene ring, or both of the two bonds may be on carbon atoms constituting the benzene ring. However, two bonds are not on the same carbon atom.

[0017] R 1The R is located on any carbon atom of the benzene ring in general formula (1), and in general formula (1), when p is 0, the benzene ring to which the 5-membered ring is fused is unsubstituted, and when p is an integer from 1 to 4, the benzene ring has 1 to 4 R 1 This results in a substituted structure. p is preferably 0 or 1, and particularly preferably 0. When p is 2 to 4, R 1 They may be the same or different, but preferably they are the same. If the two bonds are on carbon atoms that make up a five-membered ring, p can be an integer between 0 and 4. If the bonds are on carbon atoms that make up a benzene ring, p can be an integer of (4 - number of bonds).

[0018] If p is 1 or greater, R 1 The group is preferably an alkyl or aryl group having 1 to 4 carbon atoms, and more preferably a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl, tert-butyl group, indenyl group, or indanyl group.

[0019] General formula (1) encompasses the following general formulas (i) to (xii). [ka] [ka] [ka] [ka] (Here, R 1 This is located on any carbon atom of the benzene ring of general formula (1) and is an alkyl group, alkoxy group, allyl group, aryl group, aryloxy group, or aralkyl group. p 1 is an integer between 0 and 4, and p 1 If R is an integer between 2 and 4, multiple R 1 They may be the same or different. p 2is an integer between 0 and 3, and p 2 If is an integer between 2 and 3, multiple R 1 They may be the same or different. p 3 is an integer between 0 and 2, and p 3 If it is 2, multiple R 1 They may be the same or different. Each dashed line independently indicates either absence or a double bond, however, two dashed lines cannot simultaneously indicate a double bond. * indicates a bonding operation.

[0020] The following general formula (1A) can be given as general formula (1). [ka] (Here, Each dashed line independently represents either absence or a double bond, however, no two dashed lines can simultaneously represent a double bond. *Each of the bonds represents a bond, located on any ring-forming carbon atom of general formula (1), but no two bonds can be located on the same carbon atom.

[0021] The general formula (1A) encompasses the following general formulas (i-1A) to (xii-1A). [ka] [ka] [ka] [ka] (Here, Each dashed line independently indicates either absence or a double bond, however, two dashed lines cannot simultaneously indicate a double bond. * indicates a bonding operation.

[0022] A five-membered ring condensed ring compound only needs to have one or more structural units of general formula (1). If there are two or more structural units of general formula (1), the structural units may be identical or different.

[0023] In general formula (1), either bond can be connected to a hydrogen atom, in which case it forms the terminal portion of a five-membered fused ring compound. This portion contains an indane or indene structure derived from general formula (1). Specifically, it is the structure represented by the following general formula (2).

[0024] [ka] (Here, R 2 This is located on any carbon atom of the benzene ring in general formula (2) and is an alkyl group, alkoxy group, allyl group, aryl group, aryloxy group, or aralkyl group. q is an integer from 0 to 4, and if q is an integer from 2 to 4, multiple R 2 They may be the same or different. Each dashed line independently indicates either absence or a double bond, however, two dashed lines cannot simultaneously indicate a double bond. *Each symbol represents a bond and is located on any ring-forming carbon atom of general formula (2).

[0025] In general formula (2), * indicates a bond. General formula (2) is a monovalent group. The bonds are located on any ring-forming carbon atom of general formula (2), and may be located on carbon atoms constituting a five-membered ring or on carbon atoms constituting a benzene ring.

[0026] R 2 R is located on any benzene ring constituent carbon atom of general formula (2), and in general formula (2), when q is 0, the benzene ring to which the 5-membered ring is fused is unsubstituted, and when q is an integer from 1 to 4, the benzene ring to which the 5-membered ring is fused has 1 to 4 R 2This results in a substituted structure. q is preferably 0 or 1, and particularly preferably 0. When q is 2 to 4, R 2 They may be the same or different, but preferably they are the same. If the bond is located on a carbon atom constituting a five-membered ring, q can be an integer between 0 and 4. If the bond is located on a carbon atom constituting a benzene ring, q can be an integer between 0 and 3.

[0027] If q is 1 or greater, R 2 The group is preferably an alkyl or aryl group having 1 to 4 carbon atoms, and more preferably a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl, tert-butyl group, indenyl group, or indanyl group.

[0028] General formula (2) encompasses the following general formulas (xiii) to (xvi). [ka] (Here, R 2 These are alkyl groups, alkoxy groups, allyl groups, aryl groups, aryloxy groups, or aralkyl groups. q 1 is an integer from 0 to 4, and q 1 If R is an integer between 2 and 4, multiple R 2 They may be the same or different. q 2 is an integer between 0 and 3, and q 2 If is an integer between 2 and 3, multiple R 2 They may be the same or different. Each dashed line independently indicates either absence or a double bond, however, two dashed lines cannot simultaneously indicate a double bond. * indicates a bond.

[0029] The following general formula (2A) can be given as general formula (2). [ka] (Here, Each dashed line independently indicates either absence or a double bond, however, two dashed lines cannot simultaneously indicate a double bond. * indicates a bond and is located on any ring-forming carbon atom in formula (2A).

[0030] The general formula (2A) includes the following general formulas (xiii-2A) to (xvi-2A). [ka] (Here, Each dashed line independently indicates either absence or a double bond, however, two dashed lines cannot simultaneously indicate a double bond. * indicates a bond.

[0031] General formula (2) includes the following general formulas (2a1) and (2a2). [ka] [ka]

[0032] The terminal portion of a five-membered ring condensed compound can be, for example, a structure in which a unit represented by general formula (1) is linked to a structure represented by terminal general formula (2), or a structure in which multiple units represented by general formula (1) are linked to a structure represented by general formula (2) to form the terminal portion. For example, the structure is as follows: [ka] (Here, R 1 and R 2 These are located on any carbon atom of the benzene ring in the above formula, and each is independently an alkyl group, an alkoxy group, an allyl group, an aryl group, an aryloxy group, or an aralkyl group. p is an integer between 0 and 4, and if p is an integer between 2 and 4, multiple R 1They may be the same or different. If q is an integer from 0 to 4, and p is an integer from 2 to 4, then multiple R 1 They may be the same or different. n is an integer greater than or equal to 1, Each dashed line independently indicates either absence or a double bond, however, two dashed lines cannot simultaneously indicate a double bond. * indicates a bond.

[0033] In general formula (3), the two asterisks each represent a bond. General formula (3) is a divalent group. One of the two bonds can be located on any ring-forming carbon atom of ring A.

[0034] In general formula (3), R 3 ~R 7 The atom is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, or a tert-butyl group, and even more preferably a hydrogen atom or a methyl group. In particular, R 3 ~R 5 is a methyl group, R 6 and R 7 Preferably, it is a hydrogen atom.

[0035] In general formula (3), A is preferably a benzene ring or a naphthalene ring, and is preferably unsubstituted or substituted with an alkyl group (for example, an alkyl group having 1 to 12 carbon atoms).

[0036] The following general formula (3A) is an example of general formula (3). [ka] (Here, R 3 ~R 7 Each is independently a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. R14 is an alkyl or aryl group having 1 to 12 carbon atoms, s is an integer from 0 to 3, and if s is an integer from 2 to 3, multiple R 14 They may be the same or different. * indicates a bonding operation.

[0037] The general formula (3A) encompasses the following general formulas (xvii-3A) to (xx-3A). [ka] [ka] (Here, R 3 ~R 7 Each is independently a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. R 14 R is an alkyl group having 1 to 12 carbon atoms, s is an integer from 0 to 3, and if s is an integer from 2 to 3, multiple R 14 They may be the same or different. * indicates a bonding operation.

[0038] The following general formula (3a) is preferred as general formula (3). [ka] (Here, R 3 ~R 7 Each is independently a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. * indicates a bonding operation.

[0039] The general formula (3a) encompasses the following general formulas (xvii-3a) to (xx-3a). [ka] [ka] (Here, R 3 ~R 7 Each is independently a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. * indicates a bonding operation.

[0040] A five-membered ring condensed ring compound only needs to have one or more structural units represented by general formula (1), and the structural unit represented by general formula (1) may also be a structural unit represented by general formula (2). If there are two or more of these structural units, they may be the same or different.

[0041] A five-membered ring condensed ring compound only needs to have one or more structural units represented by general formula (3). If there are two or more of these structural units, they may be identical or different. In general formula (3), either bond can be bonded to a hydrogen atom, in which case it will form the terminal portion of the five-membered ring condensed ring compound.

[0042] [Production of 5-membered ring condensed ring compounds] The five-membered ring condensed ring compounds of this disclosure can be produced by reacting an indene compound represented by the following general formula (4) with an aromatic compound represented by the following general formula (5) in the presence of a Brønsted acid. [ka] (Here, R 8 This is located on any carbon atom of the benzene ring of general formula (4) and is an alkyl group, alkoxy group, allyl group, aryl group, aryloxy group, or aralkyl group. r is an integer from 0 to 4, and if r is an integer from 2 to 4, multiple R 8 They may be the same or different. [ka] (Here, R 9 and R 10 These are, independently, -CR11 =CH2 or -C(OH)R 12 R 13 And, R 11 These are alkyl groups having 1 to 12 carbon atoms. R 12 and R 13 These are each an alkyl group having 1 to 12 carbon atoms, M is a divalent aromatic cyclic group.

[0043] <Brønsted acid> From the viewpoint of reaction efficiency and solubility, the Brønsted acid is preferably a sulfonic acid, more preferably p-toluenesulfonic acid, methanesulfonic acid, etc. These may also be hydrates.

[0044] <Reaction materials> In the production of five-membered ring condensed ring compounds, the indene compound represented by general formula (4) and the aromatic compound represented by general formula (5) are reaction raw materials.

[0045] (Indene compounds represented by general formula (4)) In general formula (4), r is an integer from 0 to 4. In general formula (4), when r is 0, the benzene ring is unsubstituted, and when r is an integer from 1 to 4, the benzene ring has 1 to 4 R 8 This results in a substituted structure. r is preferably 0 or 1, and particularly preferably 0.

[0046] In general formula (4), if r is 1 or greater, R 8 The alkyl group is preferably a C1-C4 alkyl group, and more preferably a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, or tert-butyl group.

[0047] The indene compound represented by general formula (4) may be used alone or in any ratio of two or more compounds.

[0048] (Aromatic compounds represented by general formula (5)) In general formula (5), R9 and R 10 They may be the same or different, but are preferably the same.

[0049] Base:-CR 11 =R in CH2 11 The alkyl group is preferably a group having 1 to 4 carbon atoms, and is particularly a methyl group.

[0050] Group:-C(OH)R 12 R 13 In R 12 and R 13 The alkyl group is preferably a C1-C4 alkyl group, and particularly a methyl group. These may be the same or different, but are preferably the same.

[0051] In general formula (5), M is preferably a benzene ring or a naphthalene ring, and it is also preferable that these rings are substituted with an alkyl group (for example, an alkyl group having 1 to 12 carbon atoms).

[0052] If M is a benzene ring, then R 9 and R 10 The bonding position is preferably the meta or para position.

[0053] Examples of general formula (5) include the following general formulas (5A) and (5B). [ka] (Here, R 15 is an alkyl group, alkoxy group, allyl group, aryl group, aryloxy group, or aralkyl group, and t is an integer from 0 to 4. If t is an integer from 2 to 4, multiple R 15 They may be the same or different. R 16 and R 17 These are, independently, alkyl groups having 1 to 12 carbon atoms. [ka] (Here, R 18 is an alkyl group, alkoxy group, allyl group, aryl group, aryloxy group, or aralkyl group, and u is an integer from 0 to 4. If u is an integer from 2 to 4, multiple R 18 They may be the same or different. R 19 ~R 22 These are, independently, alkyl groups having 1 to 12 carbon atoms.

[0054] Aromatic compounds represented by general formula (5) may be used individually or in any ratio of two or more compounds.

[0055] (Other ingredients) The reaction raw materials may include components other than the indene compound represented by general formula (4) and the aromatic compound represented by general formula (5), as long as they do not impair the effects of the present invention. Preferably, the reaction raw materials do not contain other components.

[0056] (Blend amount) The molar ratio of the indene compound represented by general formula (4) to the aromatic compound represented by general formula (5) in the reaction raw materials (indene compound represented by general formula (4) / aromatic compound represented by general formula (5)) can be 1 to 9, and is preferably 1 to 7 from the viewpoint of dielectric loss tangent and heat resistance.

[0057] The total amount of the indene compound represented by general formula (4) and the aromatic compound represented by general formula (5) in the reaction raw materials can be 10% by mass or more of 100% by mass of the reaction raw materials, and is preferably 20% by mass or more from the viewpoint of dielectric loss tangent and heat resistance. The upper limit is not particularly limited and may be 100% by mass.

[0058] <Manufacturing process> The Brønsted acid and the reaction materials can be charged together into a reaction vessel and reacted at a predetermined temperature. Alternatively, one of the indene compound represented by general formula (4) and the aromatic compound represented by general formula (5) from the reaction materials and the Brønsted acid can be charged together, and the reaction can be carried out while maintaining the predetermined temperature, with the remainder of the reaction materials (including the other indene compound represented by general formula (4) and the aromatic compound represented by general formula (5)) being added dropwise. The reaction is preferably carried out in the presence of a solvent. If a solvent is used, the solvent and unreacted products can be removed by distillation after the reaction, if necessary, to obtain the target five-membered fused ring compound. If no solvent is used, the target five-membered fused ring compound can be obtained by distillation of the unreacted products.

[0059] (Amount used) The amount of Brønsted acid used can be 0.1 to 20 parts by mass per 100 parts by mass of the reaction raw material, and is preferably 0.5 to 20 parts by mass from the viewpoint of reaction efficiency.

[0060] (solvent) The reaction is preferably carried out in the presence of a solvent, and examples of solvents include organic solvents. 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. The solvent may be used alone or two or more in any ratio. When a solvent is used, the amount of solvent can be 500 parts by mass or less per 100 parts by mass of the reaction raw material, and from the viewpoint of reaction efficiency, it is preferably 30 to 300 parts by mass.

[0061] (Reaction conditions) The reaction temperature can be 60 to 250°C, but is preferably 80 to 230°C from the viewpoint of promoting the reaction. The reaction time can be 0.5 to 24 hours, but it is preferably 1 to 23 hours in order to allow the reaction to proceed sufficiently and to suppress side reactions such as the thermal decomposition of the product.

[0062] (neutralization process) After the reaction is complete, the reaction product may be neutralized by adding a basic compound. The basic compound may be an inorganic base or an organic base. Examples of inorganic bases include alkali metal hydroxides (lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, etc.) and alkaline earth metal hydroxides (calcium hydroxide, strontium hydroxide, barium hydroxide, etc.). Examples of organic bases include alkylammonium hydroxides (tetramethylammonium hydroxide, tetraethylammonium hydroxide, etc.), alkylamines (methylamine, ethylamine, etc.), aromatic amines (aniline, etc.), and heterocyclic amine compounds (pyridine, imidazole, etc.). Inorganic bases are preferred, and more preferably, sodium hydroxide, potassium hydroxide, etc., due to their strong basicity and the ability to neutralize with only a small amount.

[0063] (purification process) The resulting reaction product can be neutralized if necessary and then subjected to a purification step. The purification method is not particularly limited, and known methods (for example, washing with organic solvents, adsorption, fractional distillation, ion exchange resin treatment, reprecipitation, crystallization, filtration, heating, or removal of the reaction solvent under reduced pressure) can be employed. The purification process removes low molecular weight components such as the reaction solvent and unreacted products, as well as ionic impurities, thereby further improving dielectric properties and heat resistance.

[0064] The reaction product obtained may be a mixture containing the five-membered ring condensed ring compounds of this disclosure (a five-membered ring condensed ring system mixture), which can be subjected to a neutralization and / or purification step. A separation step may be performed to recover five-membered ring condensed ring compounds having a specific molecular weight, five-membered ring condensed ring compounds having a specific functional group or unsaturated bond, etc.

[0065] [5-membered fused ring system mixture] The reaction product contains a mixture (5-membered ring condensed ring system mixture) in which the 5-membered ring condensed ring compound of the present disclosure is mixed. The 5-membered ring condensed ring compound of the present disclosure in the 5-membered ring condensed ring system mixture may have a structural unit represented by the general formula (1) and a structural unit represented by the following general formula (3), and may have a structural unit represented by other than the general formulas (1) and (3) (hereinafter also referred to as "other structural unit"). Examples of the other structural unit include a structural unit derived from an indene compound represented by the general formula (4) and a structural unit derived from an aromatic compound represented by the general formula (5), and a part included in these structural units and represented by other than the general formulas (1) and (3).

[0066] Examples of the other structural unit include structural units represented by the following general formula (6) and the following general formula (7). [Chemical formula] (Here, R 23 and R 24 are each independently an alkyl group having 1 to 12 carbon atoms, * each represents a bond.) [Chemical formula] (Here, R 25 and R 26 are each independently an alkyl group having 1 to 12 carbon atoms, D is a divalent aromatic cyclic group, * each represents a bond.)

[0067] R 23 and R 24 in the general formula (6) are preferably alkyl groups having 1 to 4 carbon atoms, particularly a methyl group. R 23 and R 24 may be the same or different, and are preferably the same.

[0068] R in the general formula (7)25 and R 26 is preferably an alkyl group having 1 to 4 carbon atoms, particularly a methyl group. R 25 and R 26 may be the same or different, and are preferably the same.

[0069] In general formula (7), D is preferably a benzene ring or a naphthalene ring, and is preferably unsubstituted or substituted by an alkyl group (for example, an alkyl group having 1 to 12 carbon atoms).

[0070] When D is a benzene ring, it is preferably bonded to another atom at the meta or para position.

[0071] Examples of general formula (7) include the following general formula (7A).

Chemical formula

[0072] The molecular chain ends of the compounds contained in the 5-membered ring condensed ring system mixture can be a structure derived from an indene compound represented by general formula (4) or an aromatic compound represented by general formula (5). The structure derived from the indene compound represented by general formula (4) can be a structural unit represented by general formula (2). Compounds having an indene ring structure at the molecular chain ends exhibit thermosetting properties and can be applied to various reactions or uses. Compounds having unsaturated bonds at both ends of the linear molecular chain are preferred.

[0073] A five-membered ring condensed ring compound is a compound in which one or more structural units represented by general formula (3) and, optionally, structural units selected from the group consisting of general formula (1) (except in the case of general formula (2)), general formula (6), and general formula (7) are linked in a linear chain, and further having a structural unit of general formula (2) at the end of the molecular chain.

[0074] The number-average molecular weight (Mn) of the five-membered ring condensed ring mixture can be in the range of 200 to 50,000, preferably in the range of 300 to 40,000. Furthermore, the weight-average molecular weight (Mw) of the five-membered ring condensed ring mixture can be in the range of 300 to 50,000, preferably in the range of 400 to 40,000. The molecular weight distribution (weight-average molecular weight (Mw) / number-average molecular weight (Mn)) of the 5-membered ring condensed ring mixture can be in the range of 1 to 10, more preferably 1 to 7, and even more preferably 1 to 5.

[0075] The five-membered ring condensed ring mixture may contain the following components (i) to (iii): Component (i): Compounds having structural units represented by general formula (1) (except in the case of general formula (2)), general formula (2), and general formula (3). Component (ii): Compounds having structural units represented by general formula (2) and general formula (3) (excluding compounds having structural units represented by general formula (1) (except in the case of general formula (2)), general formula (2), and general formula (3)). Component (iii): Compounds having structural units represented by general formula (1) (except in the case of general formula (2)) and general formula (3) (excluding compounds having structural units represented by general formula (1) (except in the case of general formula (2)), general formula (2), and general formula (3)).

[0076] The five-membered ring condensed ring mixture of this disclosure contains a five-membered ring condensed ring compound that exhibits excellent heat resistance and low dielectric loss tangent, and can therefore be used as a curable composition, similar to the five-membered ring condensed ring compound. The five-membered ring condensed ring mixture, which is a reaction product obtained by reacting reaction materials (including an indene compound represented by general formula (4) and an aromatic compound represented by general formula (5)) in the presence of a Brønsted acid, may contain compounds other than the five-membered ring condensed ring compounds of this disclosure (other compounds). Other compounds include compounds obtained by the reaction of indene compounds represented by general formula (4) with each other, and include indene polymers, indan polymers, etc. The five-membered ring condensed ring mixture may be used in the preparation of a curable composition without separating the other compounds, as long as the purpose of this disclosure is not impaired.

[0077] [Curable composition] The curable composition of this disclosure may contain the five-membered ring condensed ring compound and the curing agent of this disclosure. The five-membered ring condensed ring compound may be incorporated into the curable composition as a five-membered ring condensed ring mixture. The five-membered ring condensed ring compounds or five-membered ring condensed ring mixtures of this disclosure can be produced by industrial synthesis means, have excellent handling properties in melt kneading into resins, and can exhibit excellent heat resistance and dielectric properties in cured products obtained from curable compositions containing the five-membered ring condensed ring compounds or five-membered ring condensed ring mixtures.

[0078] The amount of the five-membered ring condensed ring compound or five-membered ring condensed ring mixture can be 10 to 90 parts by mass, preferably 20 to 80 parts by mass, per 100 parts by mass of the curable composition.

[0079] The curing agent is not particularly limited as long as it is a compound that can react with the five-membered ring condensed ring compound of this disclosure, and 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, and diallyl terephthalate.

[0080] The amount of curing agent can be 10 to 90 parts by mass, preferably 20 to 80 parts by mass, per 100 parts by mass of the curable composition.

[0081] The curable composition may contain a curing catalyst. 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.).

[0082] 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.

[0083] A curable composition can be obtained by uniformly mixing a five-membered ring condensed ring compound or a five-membered ring condensed ring system mixture, a curing agent, and any other component (e.g., a curing catalyst, compounding agent, etc.).

[0084] [Cured product] The cured product of this disclosure can be obtained by curing the curable composition of this disclosure. The curing method is not particularly limited, and known methods can be employed. The cured product may take the form of a laminate, a cast product, an adhesive layer, a coating, a film, or the like.

[0085] [Semiconductor encapsulant] The semiconductor encapsulant of this disclosure may contain the curable composition of this disclosure. Since the curable composition of this disclosure contains the five-membered ring condensed ring compound or five-membered ring condensed ring mixture of this disclosure, the semiconductor encapsulant containing the curable composition can exhibit excellent heat resistance and dielectric properties.

[0086] For semiconductor encapsulants, a curable composition of the present disclosure 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.

[0087] The semiconductor encapsulant may contain various compounding agents, including those described in relation to curable compositions.

[0088] A semiconductor encapsulant can be obtained by mixing the curable composition of this disclosure with compounding agents as needed, for example, by thoroughly melting and mixing until homogeneous using an extruder, kneader, roll, etc.

[0089] [Semiconductor device] The semiconductor device of this disclosure may include a cured product of the semiconductor encapsulant of this disclosure. The semiconductor encapsulant used in the semiconductor device of this disclosure contains a curable composition containing the five-membered ring condensed ring compound or five-membered ring condensed ring mixture of this disclosure. Because the semiconductor device of this disclosure includes a cured product of the semiconductor encapsulant, it has excellent heat resistance and dielectric properties.

[0090] The semiconductor device can be obtained by heat curing the semiconductor encapsulant of this disclosure. 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.

[0091] [Prepreg] The prepreg of this disclosure may have a reinforcing substrate and a semi-cured product of the curable composition of this disclosure 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 curable composition that has been varnished with an organic solvent as 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.

[0092] 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

[0093] 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.

[0094] [Circuit board] The circuit board of this disclosure consists of a laminate of the prepreg of this disclosure 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 this disclosure 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.

[0095] [Build-up film] The build-up film of this disclosure may contain the curable composition of this disclosure. The method for producing the build-up film is not particularly limited, and includes, for example, a method of applying the curable composition of this disclosure onto a support film to form a curable composition layer to make an adhesive film for multilayer printed circuit boards.

[0096] Since the build 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 with the above components in such a way that it exhibits these characteristics.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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 and metal foils such as copper foil and aluminum foil. The support film and protective film may be treated with a mat treatment, corona treatment, or release treatment.

[0102] 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.

[0103] 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 debris during the curing process. When peeling off after curing, the support film is usually treated with a release agent beforehand.

[0104] [Application] The cured products obtained from the curable composition containing the five-membered ring condensed ring compound of this disclosure exhibit 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 in fiber-reinforced resins, and are especially suitable as high-heat-resistant prepregs. Furthermore, the five-membered ring condensed ring compound or five-membered ring condensed ring mixture 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 suitably used 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. [Examples]

[0105] This disclosure will be specifically described by examples and comparative examples, but this disclosure is not limited to the following description and can be implemented in various ways within the scope of its gist. In the following, "parts" and "%" are based on mass unless otherwise specified.

[0106] Five-membered ring condensed ring compounds were synthesized as five-membered ring condensed ring mixtures, and their physical properties were evaluated as follows. The results are shown in Table 1.

[0107] (1) GPC measurement The number-average molecular weight (Mn), weight-average molecular weight (Mw), and molecular weight distribution (Mw / Mn) of the five-membered ring condensed ring compounds (five-membered ring condensed ring mixtures) obtained in the examples and comparative examples were calculated using the following measuring equipment and conditions. "Measuring device" Tosoh Corporation's "HLC-8320 GPC" "Measurement conditions" Columns: 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's "GPC Workstation EcoSEC-WorkStation" Measurement conditions: Column temperature 40℃ 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: A tetrahydrofuran solution of the five-membered ring condensed ring compound obtained in the synthesis example, at a concentration of 1.0% by mass (based on resin solids content), filtered through a microfilter (50 μl).

[0108] (2) FD-MS measurement The FD-MS spectra of the five-membered ring condensed ring compounds 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: 45mA Cathode voltage: -10kV Recording interval: 0.07 seconds

[0109] (3) 13 C-NMR measurement Five-membered ring condensed ring compounds obtained in the examples 13 The 1C-NMR spectra were measured using the following measuring instrument and under the following conditions. 13 C-NMR: “JNM-ECZ400S” manufactured by JEOL RESONANCE Resonance frequency: 100MHz Total number of times: 4000 Solvent: Chloroform-d Sample concentration: 12% by mass Relaxation agent: Chromium(III) acetylacetonate

[0110] <Example 1: Synthesis of a 5-membered ring condensed ring compound (A-1)> In a flask equipped with a stirrer, a Dean-Stark apparatus, and a condenser, 156.9 parts indene, 131.2 parts m-bis(α-hydroxyisopropyl)benzene, 144.1 parts toluene, and 2.9 parts p-toluenesulfonic acid monohydrate were charged and heated. During the reaction, water produced was removed using the Dean-Stark apparatus, and the temperature was raised to 120°C, where stirring continued for 2 hours. After cooling the reaction mixture to 80°C, it was neutralized with 1.3 parts of 49% sodium hydroxide aqueous solution. Subsequently, 288.2 parts methyl isobutyl ketone (hereinafter MIBK) was added, and the organic layer was washed three times with 264 parts of water to remove catalyst residue. After that, volatile components were removed by heating and reduced pressure to obtain a five-membered ring condensed ring compound (A-1). GPC, FD-MS, and 13 The various 1C-NMR charts are shown in Figures 1A to 1C. From the GPC measurement results, the Mn value for (A-1) was 473, the Mw value was 997, and the Mw / Mn ratio was 2.106.

[0111] <Example 2: Synthesis of a 5-membered ring condensed ring compound (A-2)> In a flask equipped with a stirrer and condenser, 232.3 parts indene, 158.24 parts 1,3-diisopropenylbenzene, 195.3 parts toluene, and 3.9 parts p-toluenesulfonic acid monohydrate were charged, and the mixture was heated to 120°C and stirred for 1 hour. After cooling the reaction mixture to 80°C, it was neutralized with 1.7 parts of 49% sodium hydroxide aqueous solution. Subsequently, 585.9 parts MIBK was added, and the organic layer was washed three times with 195 parts of water to remove catalyst residue. After removing volatile components by heating and reduced pressure, a five-membered condensed ring compound (A-2) was obtained. The GPC chart of the obtained (A-2) is shown in Figure 2. From the GPC measurement results, the Mn of (A-2) was 377, the Mw was 912, and the Mw / Mn ratio was 2.422.

[0112] <Example 3: Synthesis of a 5-membered ring condensed ring compound (A-3)> In a flask equipped with a stirrer, a Dean-Stark apparatus, and a condenser, 24.0 parts indene, 20.1 parts p-bis(α-hydroxyisopropyl)benzene, 22.0 parts toluene, and 0.4 parts p-toluenesulfonic acid monohydrate were charged and heated. During the reaction, water produced was removed using the Dean-Stark apparatus, and the temperature was raised to 120°C, where stirring continued for 2 hours. After cooling the reaction mixture to 80°C, it was neutralized with 0.2 parts of 49% sodium hydroxide aqueous solution. Subsequently, 44.1 parts MIBK was added, and the organic layer was washed three times with 40.3 parts of water to remove catalyst residue. After that, volatile components were removed by heating and reduced pressure to obtain the five-membered ring condensed compound (A-3). The GPC chart of the obtained (A-3) is shown in Figure 3. From the GPC measurement results, the Mn of (A-3) was 444, the Mw was 1175, and the Mw / Mn ratio was 2.643.

[0113] <Comparative Example 1: Synthesis of a 5-membered ring condensed ring compound (B-1)> In a flask equipped with a thermometer, condenser, fractionation column, and stirrer, 116.0 parts indene, 37.0 parts potassium-tert-butoxide, and 191.0 parts toluene were charged. The mixture was heated to 80°C while stirring, and 37.5 parts by mass of 4,4'-bischloromethylbiphenyl were added in a divided manner over 30 minutes. After reacting at 80°C for 3 hours, 74.5 parts of benzaldehyde were added dropwise over 30 minutes at the same temperature, and the mixture was reacted for 2 hours. After cooling to room temperature, 104.0 parts of 35% hydrochloric acid aqueous solution were added, and the mixture was heated to 95°C while dehydrating, and reacted for 5 hours. Subsequently, the mixture was neutralized with 30% sodium hydroxide aqueous solution at room temperature, and washed with water until the aqueous layer was neutral. The resulting organic layer was removed by distillation under heated and reduced pressure conditions to remove toluene, unreacted indene, etc., and filtered to obtain a five-membered condensed ring compound (B-1).

[0114] The cured products of the synthesized five-membered ring condensed ring compounds were prepared, and their physical properties were evaluated as follows. The results are shown in Table 1. (1) Measurement of thermal decomposition resistance A 2.0 mm thick cured material was cut into small pieces, and measurements were taken using a thermogravimetric analyzer (METTLER TOREDO TGA / DSC1) at a heating rate of 5°C / min under a nitrogen atmosphere to determine the temperatures at which the material decreased by 5% and 10% by weight (Td5 and Td10). (2) Measurement of dielectric loss tangent In accordance with JIS-C-6481, the dielectric loss tangent at 1 GHz and 10 GHz was measured using the cavity resonance method with an Agilent Technologies, Inc. network analyzer "E8362C" after complete drying and storage in a room at 23°C and 50% humidity for 24 hours.

[0115] <Example 4> In the amounts (parts by mass) shown in Table 1, (A-1) from Example 1, 1,6'-bismaleimide-(2,2,4-trimethyl)hexane (BMI-TMH manufactured by Yamato Chemical Industries, Ltd.), and styrene were melt-kneaded, dicumyl peroxide (DCPO) was added, and the mixture was poured into a mold processed to a thickness of 2 mm. The mixture was then heated and cured at 150°C for 1 hour and then at 250°C for 5 hours to obtain a cured product.

[0116] <Example 5> A cured product was obtained in the same manner as in Example 1, except that (A-1) of Example 1 was changed to (A-2) of Example 2.

[0117] <Comparative Example 2> In the amounts (parts by mass) shown in Table 1, (B-1) of Comparative Example 1, 1,6'-bismaleimide-(2,2,4-trimethyl)hexane (BMI-TMH manufactured by Yamato Chemical Industries, Ltd.), and styrene were melt-kneaded, dicumyl peroxide (DCPO) was added, and the mixture was poured into a mold processed to a thickness of 2 mm. The mixture was then heated and cured at 130°C for 2 hours, 150°C for 1 hour, and 250°C for 5 hours to obtain a cured product.

[0118] [Table 1]

[0119] From the results shown in Table 1 above, a comparison of Examples 1-2 with Comparative Example 1 confirms that using the five-membered ring condensed ring compounds (five-membered ring condensed ring mixtures) of Examples 1-2 resulted in excellent dielectric properties and resistance to thermal decomposition. [Industrial applicability]

[0120] According to this disclosure, it is possible to provide a five-membered ring fused compound that can achieve a high degree of both low dielectric loss tangent and excellent heat resistance, and a method for producing the same. Furthermore, it is possible to provide a curable composition containing the five-membered ring fused compound and a cured product thereof. In addition, it is possible to provide a prepreg, circuit board, build-up film, semiconductor encapsulant, and semiconductor device with a high degree of both low dielectric properties and excellent heat resistance using the cured product.

Claims

1. A five-membered ring condensed ring compound having a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (3), wherein the indene compound represented by general formula (4) and the aromatic compound represented by general formula (5) are polymerized in a molar ratio (indene compound represented by general formula (4) / aromatic compound represented by general formula (5)) of 1 to 9, and the compound is a thermosetting compound. 【Chemistry 1】 (Here, R １ This is located on any carbon atom of the benzene ring of general formula (1) and is an alkyl group, alkoxy group, allyl group, aryl group, aryloxy group, or aralkyl group. p is an integer from 0 to 4, and if p is an integer from 2 to 4, multiple R １ They may be the same or different. Each dashed line independently indicates either absence or a double bond, however, two dashed lines cannot simultaneously indicate a double bond. *Each bond represents a different type of bond, located on any ring-forming carbon atom in general formula (1), except that no two bonds can be located on the same carbon atom. 【Chemistry 2】 (Here, R ３ ~R ７ Each of these is independently a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. Ring A is a trivalent aromatic cyclic group, * indicates a bonding position. 【Transformation 3】 (Here, R8 is located on any carbon atom of the benzene ring of general formula (4) and is an alkyl group, alkoxy group, allyl group, aryl group, aryloxy group, or aralkyl group. r is an integer between 0 and 4. If r is an integer between 2 and 4, multiple R₁₁ values ​​may be the same or different. 【Chemistry 4】 (Here, R9 and R10 are independently -CR11 = CH2 or -C(OH)R12 R13, R11 is an alkyl group having 1 to 12 carbon atoms. R12 and R13 are each independently alkyl groups having 1 to 12 carbon atoms. M is a divalent aromatic cyclic group.

2. A method for producing a five-membered ring condensed compound according to claim 1, comprising reacting an indene compound represented by the following general formula (4) with an aromatic compound represented by the following general formula (5) in the presence of a Brønsted acid. 【Transformation 5】 (Here, R ８ This is located on any carbon atom of the benzene ring of general formula (4) and is an alkyl group, alkoxy group, allyl group, aryl group, aryloxy group, or aralkyl group. r is an integer from 0 to 4, and if r is an integer from 2 to 4, multiple R ８ They may be the same or different. 【Transformation 6】 (Here, R ９ and R １０ are each independently, -CR １１ =CH ２ or -C(OH)R １２ R １３ wherein R １１ These are alkyl groups having 1 to 12 carbon atoms. R １２ and R １３ Each of these is an alkyl group having 1 to 12 carbon atoms, M is a divalent aromatic cyclic group.

3. A curable composition comprising the five-membered ring condensed ring compound described in claim 1 and a curing agent.

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

5. A prepreg having a reinforcing substrate and a semi-cured product of the curable composition according to claim 3 impregnated into the reinforcing substrate.

6. A circuit board which is a laminate of prepreg and copper foil as described in claim 5.

7. A build-up film containing the curable composition described in claim 3.

8. A semiconductor encapsulant containing the curable composition described in claim 3.

9. A semiconductor device comprising a cured product of the semiconductor encapsulant described in claim 8.

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