Cyanate ester compound, resin composition, cured product, prepreg, sealing material, fiber-reinforced composite material, and adhesive

Abstract

To provide a cyanate ester compound, a resin composition, a cured product, a prepreg, a sealing material, a fiber-reinforced composite material, and an adhesive, having a low dielectric constant and a low dielectric loss tangent, and having excellent water absorbency, a low thermal expansion coefficient, and a high glass transition temperature.SOLUTION: The cyanate ester compound of the present invention has a structure represented by the following formula (1), and has a number average molecular weight (Mn) of 850 or more and 3000 or less in terms of standard polystyrene measured by gel permeation chromatography.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a cyanate ester compound, a resin composition, a cured product, a prepreg, a sealing material, a fiber-reinforced composite material, and an adhesive. [Background technology]

[0002] Cyanate ester compounds have been known as compounds for printed wiring boards that have excellent heat resistance and electrical properties. Resin compositions containing cyanate ester compounds and, for example, epoxy resins or bismaleimide compounds, are widely used as materials for high-performance printed wiring boards, such as for semiconductor plastic packages.

[0003] Meanwhile, the signal bandwidth of information and communication devices such as PHS and mobile phones, as well as computer CPU clock times, has reached the 5 GHz band, and studies are underway to further increase this to 6 GHz. The dielectric loss of an electrical signal is proportional to the product of the square root of the dielectric constant, the dielectric loss tangent, and the frequency of the electrical signal. Therefore, the higher the frequency of the signal used, the greater the dielectric loss. Increased dielectric loss attenuates the electrical signal, impairing its reliability. To suppress this, it is necessary to select materials with low dielectric constants and dielectric loss tangents. This has led to a growing demand for materials with reduced dielectric loss.

[0004] Patent Document 1 describes a resin composition containing a cyanate ester compound of a specific structure and other components, and a cured product of the composition. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2012 / 105547 Summary of the Invention [Problem to be solved by the invention]

[0006] However, although the cured product containing the cyanate ester compound described in Patent Document 1 has low water absorption, a low coefficient of thermal expansion, and excellent heat resistance, there is a problem in that the dielectric properties of the dielectric constant and the dielectric loss tangent are reduced.

[0007] The present invention has been made in view of the above problems, and an object of the present invention is to provide a cyanate ester compound, a resin composition, a cured product, a prepreg, a sealing material, a fiber-reinforced composite material, and an adhesive, which have a low dielectric constant, a low dielectric dissipation factor, excellent water absorption, a low thermal expansion coefficient, and a high glass transition temperature. [Means for solving the problem]

[0008] As a result of extensive research into solving the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by using a specific cyanate ester compound, a resin composition, a cured product, a prepreg, an encapsulating material, a fiber-reinforced composite material, and an adhesive, and have thus completed the present invention.

[0009] That is, the present invention is as follows.

[0010] [1] A cyanate ester compound having a structure represented by the following formula (1), and having a number average molecular weight (Mn) of 850 or more and 3,000 or less in terms of standard polystyrene as measured by gel permeation chromatography:

[0011] [ka]

[0012] (In formula (1), Tx represents a group containing a structural unit represented by formula (a) in formula (2) below, and optionally one or more structural units selected from the group consisting of structural units represented by formula (b) and formula (c) in formula (2) below; each Ar1 independently represents an aromatic ring; each Ra and Rb independently represents a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, an alkenyl group having from 2 to 6 carbon atoms, an aryl group having from 6 to 12 carbon atoms, or an alkoxy group having from 1 to 4 carbon atoms; a represents the number of cyanate groups bonded to Ar1, and each independently represents an integer of from 1 to 3; b represents the number of Ra bonds to Ar1, and each independently represents the number obtained by subtracting (a+1) from the number of substitutable groups in Ar1; and each c independently represents an integer of from 0 to 4.)

[0013] [ka]

[0014] (In formula (2), n, o, and p are the average number of repetitions, n is a number of 3.0 or more and 15.0 or less, o and p each independently are a number of 0 or more and 15.0 or less, and n, o, and p satisfy 3.0≦n+o+p≦15.0, each Rb independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, each c independently represents an integer of 0 to 4, an asterisk (*) represents a bonding site, and the structural units represented by formulas (a), (b), and (c) are bonded to structural units represented by formulas (a), (b), and (c), or other groups or carbon atoms, respectively, at an asterisk (*), and the structural units may be bonded in blocks or randomly.)

[0015] [2] The cyanate ester compound according to [1], which is a compound represented by the following formula (3):

[0016] [ka]

[0017] (In formula (3), n is the average number of repetitions, and is a number between 3.0 and 15.0.)

[0018] [3] A resin composition comprising the cyanate ester compound according to [1] or [2].

[0019] [4] The resin composition according to [3], further comprising at least one selected from the group consisting of cyanate ester compounds other than the cyanate ester compounds and prepolymers thereof, phenolic resins, epoxy resins, and maleimide compounds.

[0020] [5] The resin composition according to [4], wherein the cyanate ester compound other than the cyanate ester compound is a compound represented by the following formula (4) or a compound represented by the following formula (5):

[0021] [ka]

[0022] (In formula (4), each Ar2 independently represents an aromatic ring; each Rc independently represents a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, an alkenyl group having from 2 to 6 carbon atoms, an aryl group having from 6 to 12 carbon atoms, or an alkoxy group having from 1 to 4 carbon atoms; d represents the number of cyanate groups bonded to Ar2, and each e independently represents an integer of from 1 to 3; e represents the number of Rc bonds to Ar2, and each e independently represents the number obtained by subtracting (d+2) from the number of substitutable groups in Ar2; f is an integer of from 1 to 50; and each X independently represents a single bond, a divalent organic group having from 1 to 50 carbon atoms in which a hydrogen atom may be substituted with a heteroatom, a divalent organic group having from 1 to 10 nitrogen atoms, a carbonyl group, a carboxy group, a carbonyl dioxide group, a sulfonyl group, a divalent sulfur atom, or a divalent oxygen atom.)

[0023] [ka]

[0024] (In formula (5), Ar3 represents an aromatic ring; each Rd independently represents a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, an alkenyl group having from 2 to 6 carbon atoms, an aryl group having from 6 to 12 carbon atoms, or an alkoxy group having from 1 to 4 carbon atoms; h represents the number of cyanate groups bonded to Ar3 and is an integer of from 2 to 3; i represents the number of Rd bonds to Ar3 and is the number obtained by subtracting (h+2) from the number of substitutable groups of Ar3.)

[0025] [6] A cured product obtained by curing the resin composition according to any one of [3] to [5].

[0026] [7] A prepreg comprising a substrate and the resin composition according to any one of [3] to [5], which is impregnated into or applied to the substrate.

[0027] [8] An encapsulating material comprising the resin composition according to any one of [3] to [5].

[0028] [9] A fiber-reinforced composite material comprising the resin composition according to any one of [3] to [5] and reinforcing fibers.

[0029]

[10] An adhesive comprising the resin composition according to any one of [3] to [5]. [Effects of the Invention]

[0030] According to the present invention, it is possible to provide a cyanate ester compound, a resin composition, a cured product, a prepreg, a sealing material, a fiber-reinforced composite material, and an adhesive, which have a low dielectric constant and a low dielectric dissipation factor, excellent water absorption, a low thermal expansion coefficient, and a high glass transition temperature. [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 1 is a 1H-NMR chart of the indane compound (IC-1) obtained in Synthesis Example 1. [Figure 2] FIG. 2 is a 1H-NMR chart of the cyanate ester compound (C-1) obtained in Example 1. [Figure 3] FIG. 3 is a GPC chart of the cyanate ester compound (C-1) obtained in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0032] Hereinafter, a mode for carrying out the present invention (hereinafter referred to as "the present embodiment") will be described in detail. The following present embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following content. The present invention can be carried out with appropriate modifications within the scope of its gist.

[0033] In this embodiment, unless otherwise specified, "resin solid content" or "resin solid content in a resin composition" refers to the resin components in a resin composition excluding fillers, additives (silane coupling agents, wetting and dispersing agents, polymerization catalysts, curing accelerators, and other components), and solvents. "100 parts by mass of resin solid content" or "100 parts by mass of the total resin solid content in a resin composition" refers to 100 parts by mass of the total resin components in a resin composition excluding fillers, additives (silane coupling agents, wetting and dispersing agents, polymerization catalysts, curing accelerators, and other components), and solvents.

[0034] In this specification, the substituent is not particularly limited, and examples thereof include halogen atoms such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, a hydroxy group, a cyano group, a nitro group, a thiol group, a heterocyclic group, a linear aliphatic hydrocarbon group, a branched aliphatic hydrocarbon group, a cyclic aliphatic hydrocarbon group, an aryl group, an aralkyl group, an alkoxy group, an alkenyl group, an acyl group, an alkoxycarbonyl group, an alkyloyloxy group, an aryloyloxy group, and an alkylsilyl group.

[0035] [Cyanate ester compounds] The cyanate ester compound of this embodiment (hereinafter also simply referred to as "cyanate ester compound (A)" or "compound (A)") has a structure represented by the following formula (1), and has a number average molecular weight (Mn) of 850 or more and 3000 or less in terms of standard polystyrene, as measured by gel permeation chromatography.

[0036] [ka]

[0037] In formula (1), Tx represents a group containing a structural unit represented by formula (a) in formula (2) below, and optionally one or more structural units selected from the group consisting of structural units represented by formula (b) and formula (c) in formula (2) below; each Ar1 independently represents an aromatic ring; each Ra and Rb independently represents a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, an alkenyl group having from 2 to 6 carbon atoms, an aryl group having from 6 to 12 carbon atoms, or an alkoxy group having from 1 to 4 carbon atoms; a represents the number of cyanate groups bonded to Ar1, and each independently represents an integer of from 1 to 3; b represents the number of Ra bonds to Ar1, and each independently represents the number obtained by subtracting (a+1) from the number of substitutable groups in Ar1; and each c independently represents an integer of from 0 to 4.

[0038] [ka]

[0039] In formula (2), n, o, and p are the average number of repeats, n is a number of 3.0 or more and 15.0 or less, o and p each independently are a number of 0 or more and 15.0 or less, and n, o, and p satisfy 3.0≦n+o+p≦15.0, each Rb independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, each c independently represents an integer of 0 to 4, an asterisk (*) represents a bonding site, and the structural units represented by formulas (a), (b), and (c) are bonded to structural units represented by formulas (a), (b), and (c), or other groups or carbon atoms, respectively, at the asterisk (*), and the respective structural units may be bonded in blocks or randomly.

[0040] According to this embodiment, it is possible to provide a cyanate ester compound, a resin composition, a cured product, a prepreg, a sealing material, a fiber-reinforced composite material, and an adhesive that have a low dielectric constant and a low dielectric loss tangent, excellent water absorption, a low coefficient of thermal expansion, and a high glass transition temperature. The reason for this is unclear, but the inventors presume it as follows. Hereinafter, the resin composition, the cured product, the prepreg, the sealing material, the fiber-reinforced composite material, and the adhesive will also be simply referred to as a "resin composition, etc."

[0041] That is, because the indan skeleton is rigid and low polarity, compounds having an indan skeleton tend to exhibit a relatively low dielectric constant and low dielectric loss tangent. Furthermore, by controlling the number-average molecular weight of the compound within the range of 850 to 3000, the triazine skeleton generated during curing of the cyanate ester compound can be suitably controlled, thereby exhibiting excellent water absorption, a low thermal expansion coefficient, and a high glass transition temperature. Therefore, it is presumed that the cyanate ester of this embodiment has a low dielectric constant and a low dielectric loss tangent, and can exhibit excellent water absorption, a low thermal expansion coefficient, and a high glass transition temperature. However, the reason is not limited to this.

[0042] The number-average molecular weight (Mn) of compound (A) measured by gel permeation chromatography (GPC) in terms of standard polystyrene is 850 to 3000, preferably 1000 to 2800, more preferably 1100 to 2500, and even more preferably 1200 to 2200. When the number-average molecular weight (Mn) of compound (A) is within the above range, the compound tends to have a lower dielectric constant and a lower dielectric loss tangent, better moldability, handleability, and water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature. In this specification, the weight-average molecular weight (Mw), number-average molecular weight (Mn), and polydispersity (Mw / Mn) can be determined by GPC using standard polystyrene as a standard substance. For specific measurement methods, see the description in the Examples.

[0043] The weight average molecular weight (Mw) of the compound (A) is preferably 1900 or more and 8000 or less, more preferably 2000 or more and 7000 or less, even more preferably 2100 or more and 6000 or less, and even more preferably 2200 or more and 5000 or less. When the weight average molecular weight (Mw) of the compound (A) is within the above range, the compound (A) tends to have a lower dielectric constant and a lower dielectric loss tangent, and to have better moldability, handleability, and water absorbency, as well as a lower thermal expansion coefficient and a higher glass transition temperature.

[0044] The polydispersity (Mw / Mn) of the compound (A) is preferably 1.60 or more and 2.50 or less, more preferably 1.65 or more and 2.40 or less, even more preferably 1.70 or more and 2.30 or less, and even more preferably 1.75 or more and 2.20 or less. When the polydispersity (Mw / Mn) of the compound (A) is within the above range, the compound (A) tends to have a lower dielectric constant and a lower dielectric loss tangent, better moldability, handleability, and water absorbency, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0045] (Structural unit represented by formula (2)) In formula (1), Tx is a group containing a constitutional unit represented by formula (2). In formula (2), n, o, and p each represent the average number of repetitions in all molecules of compound (A).

[0046] In formula (2), the sum of n, o, and p is 3.0≦n+o+p, preferably 3.2≦n+o+p, more preferably 3.5≦n+o+p, and even more preferably 3.7≦n+o+p. In formula (2), the sum of n, o, and p is n+o+p≦15.0, preferably n+o+p≦14.0, more preferably n+o+p≦12.5, and even more preferably n+o+p≦11.0.

[0047] In formula (2), n represents a number of 3.0 or more and 15.0 or less, preferably 3.2 or more and 14.0 or less, more preferably 3.5 or more and 12.5 or less, and even more preferably 3.7 or more and 11.0 or less. o represents a number of 0 or more and 15.0 or less, preferably 0 or more and 10.0 or less, more preferably 0 or more and 5.0 or less, and even more preferably 0 or more and 3.0 or less. o may be 0. p represents a number of 0 or more and 15.0 or less, preferably 0 or more and 10.0 or less, more preferably 0 or more and 5.0 or less, and even more preferably 0 or more and 3.0 or less. p may be 0. When n, o, and p are within the above ranges, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0048] In formula (2), each Rb independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms.

[0049] Examples of alkyl groups having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, neopentyl, n-hexyl, cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. The alkyl group may be linear, branched, or cyclic. A linear alkyl group is preferred, with methyl and ethyl groups being more preferred. When Rb contains such a group, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0050] Examples of alkenyl groups having 2 to 6 carbon atoms include vinyl, allyl, butenyl, pentenyl, and hexenyl groups. The alkenyl group may be linear, branched, or cyclic. As the alkenyl group having 2 to 6 carbon atoms, an alkenyl group having 2 to 5 carbon atoms is preferred. When Rb has such a group, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, and to have better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0051] Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group and a naphthyl group.

[0052] Examples of the alkoxy group having 1 to 4 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. The alkoxy group may be linear, branched, or cyclic.

[0053] In formula (2), each c is independently an integer of 0 or more and 4 or less, preferably an integer of 0 or more and 3 or less, more preferably an integer of 0 or more and 2 or less, even more preferably 0 or 1, and still more preferably 0. When the number of c is within the above range, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, and to have better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0054] "*" indicates a bonding site, and the structural units represented by formulas (a), (b), and (c) are bonded to structural units represented by formulas (a), (b), and (c), or to other groups or carbon atoms at "*". The other groups or carbon atoms are the carbon atoms of the benzene ring or methylene chain in formula (1). The structural units may be bonded in blocks or randomly.

[0055] (Structure represented by formula (1)) In formula (1), each Ar1 independently represents an aromatic ring. Examples of aromatic rings include a benzene ring, a naphthalene ring, and an anthracene ring. The aromatic ring is preferably a benzene ring or a naphthalene ring, and more preferably a benzene ring. When the aromatic ring is such a ring, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric tangent, and to have better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0056] When Ar1 is a benzene ring and b is an integer of 1 or more and 4 or less, the cyanate group bonded to Ar1 and Ra are preferably bonded to one or two of the ortho and para positions, and more preferably bonded to at least one or two of the ortho positions.

[0057] In formula (1), Ra and Rb each independently represent a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, an alkenyl group having from 2 to 6 carbon atoms, an aryl group having from 6 to 12 carbon atoms, or an alkoxy group having from 1 to 4 carbon atoms. For details of these groups, see Rb in formula (2) above.

[0058] In formula (1), the alkyl group having 1 to 6 carbon atoms in Ra and Rb is preferably a methyl group, an ethyl group, an isopropyl group, an isobutyl group, a t-butyl group, or a pentyl group. The aryl group having 6 to 12 carbon atoms is preferably a cumyl group, a phenyl group, or a benzyl group. Among these, Ra and Rb are more preferably each independently a methyl group, an ethyl group, an isopropyl group, an isobutyl group, a t-butyl group, or a benzyl group. When Ra and Rb are such groups, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, and to have better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0059] In formula (1), a represents the number of cyanate groups bonded to Ar1, and each a is independently an integer of 1 to 3, preferably 1 or 2, and more preferably 1. When the number of a's is within the above range, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0060] In formula (1), b represents the number of bonds of Ra to Ar1, and each b independently represents the number obtained by subtracting (a+1) from the number of substitutable groups in Ar1. Each b is independently preferably an integer of 0 to 4, more preferably an integer of 0 to 3, and even more preferably an integer of 0 to 2. When the number of b's is within the above range, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, and to have better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0061] In formula (1), each c is independently an integer of 0 or more and 4 or less, preferably an integer of 0 or more and 3 or less, more preferably an integer of 0 or more and 2 or less, even more preferably 0 or 1, and still more preferably 0. When the number of c is within the above range, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, and to have better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0062] [Compound represented by formula (3)] Compound (A) is preferably a compound represented by the following formula (3): The compound represented by formula (3) may be a mixture of compounds having different average repeating numbers of n. In the case of a mixture, the average repeating number of n is the average value of the mixture. When compound (A) is such a compound, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, and also to have better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0063] [ka]

[0064] In formula (3), n is the average number of repetitions and is a number of 3.0 to 15.0. n is preferably a number of 3.2 to 14.0, more preferably a number of 3.5 to 12.5, and even more preferably a number of 3.7 to 11.0. When the number of n is within the above range, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0065] [Compound represented by formula (6)] Compound (A) is preferably a compound represented by the following formula (6). The compound represented by formula (6) may be a mixture of compounds having different average repeating numbers of n. In the case of a mixture, the average repeating number of n is the average value of the mixture. When compound (A) is such a compound, the resin composition or the like tends to have an even lower dielectric constant and an even lower dielectric loss tangent, even better water absorption, an even lower thermal expansion coefficient, and even a higher glass transition temperature.

[0066] [ka]

[0067] In formula (6), n is the average number of repetitions and is a number of 3.0 to 15.0. n is preferably a number of 3.2 to 14.0, more preferably a number of 3.5 to 12.5, and even more preferably a number of 3.7 to 11.0. When the number of n is within the above range, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, and to have better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0068] [Method for producing cyanate ester compound (A)] (Resin (T)) The compound (A) is preferably produced using a resin (T). The method for producing the compound (A) may include a step of synthesizing the resin (T). The resin (T) is a resin represented by the following formula (T), and is preferably a resin represented by the following formula (T1).

[0069] [ka]

[0070] In formula (T), Tx, Rb, and c have the same meanings as in formula (1) above, including preferred ranges.

[0071] [ka]

[0072] In formula (T1), Tx, Rb, and c have the same meanings as in formula (1) above, including preferred ranges.

[0073] The number average molecular weight (Mn) of the resin (T) measured by GPC in terms of standard polystyrene is preferably from 400 to 3000, more preferably from 450 to 2500, even more preferably from 500 to 2000, and still more preferably from 530 to 1500. When the number average molecular weight (Mn) of the resin (T) is within the above range, the resulting cyanate ester compound (A) tends to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0074] The weight average molecular weight (Mw) of the resin (T) measured by GPC in terms of standard polystyrene is preferably from 500 to 6000, more preferably from 600 to 5000, even more preferably from 700 to 4000, and still more preferably from 800 to 3000. When the weight average molecular weight (Mw) of the resin (T) is within the above range, the resulting cyanate ester compound (A) tends to have a lower dielectric constant and a lower dielectric dissipation factor, as well as better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0075] The polydispersity (Mw / Mn) of the resin (T) is preferably 1.20 or more and 2.50 or less, more preferably 1.30 or more and 2.40 or less, even more preferably 1.40 or more and 2.30 or less, still more preferably 1.50 or more and 2.20 or less, and even more preferably 1.60 or more and 2.10 or less. When the polydispersity (Mw / Mn) of the resin (T) is within the above range, the resulting cyanate ester compound (A) tends to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0076] The resin (T) is not particularly limited, and known resins such as commercially available products can be used. When synthesizing the resin (T), the raw materials, reaction temperature, catalyst type, catalyst amount, reaction solvent, raw material concentration, and the like are not particularly limited, and can be appropriately selected or controlled depending on the desired physical properties.

[0077] Examples of raw materials used in synthesizing the resin (T) include m-bis(α-hydroxyisopropyl)benzene, p-bis(α-hydroxyisopropyl)benzene, 1,3-diisopropenylbenzene, and 1,4-diisopropenylbenzene. The raw materials can be used alone or in combination of two or more.

[0078] The lower limit of the reaction temperature when synthesizing resin (T) is preferably 40°C or higher, more preferably 50°C or higher, even more preferably 60°C or higher, and may be 70°C or higher. When the reaction temperature is at or above the above lower limit, the reaction rate and the ratio of the indane skeleton (structural unit (a) in formula (2)) tend to be improved. The upper limit of the reaction temperature is preferably 180°C or lower, more preferably 150°C or lower, even more preferably 140°C or lower, and even more preferably 130°C or lower. When the reaction temperature is at or below the above upper limit, the production of by-products tends to be effectively suppressed.

[0079] The reaction temperature does not need to be the same from the start to the end of the reaction, and may be varied. In this case, it is preferable that the average reaction temperature throughout the entire process is within the above range.

[0080] Examples of catalysts used in synthesizing the resin (T) include acid catalysts. Examples of such acid catalysts include inorganic acids such as hydrochloric acid, sulfuric acid, and phosphoric acid; organic acids such as oxalic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, and fluoromethanesulfonic acid; Lewis acids such as BF ether complex, BF phenol complex, aluminum chloride, zinc chloride, and indium chloride; solid acids such as activated clay, acid clay, silica alumina, and zeolite; heteropolyhydrochloric acid; and strongly acidic ion exchange resins.

[0081] When a catalyst is used, the amount thereof is usually 0.01 parts by mass or more and 20.0 parts by mass or less per 100 parts by mass of the raw material of the resin (T).

[0082] The catalyst can be used alone or in combination of two or more. When two or more catalysts are used in combination, the total amount thereof is preferably within the above range.

[0083] Examples of reaction solvents used in synthesizing the resin (T) include aromatic hydrocarbon solvents such as toluene, benzene, chlorobenzene, and xylene; halogenated hydrocarbon solvents such as methylene chloride and chloroform; aliphatic hydrocarbon solvents such as hexane and heptane; ester solvents such as ethyl acetate and propyl acetate; and amide solvents such as dimethylformamide and dimethylacetamide. The reaction solvent may be a combination of the above solvents with an alcohol solvent or a ketone solvent, or water may be added. Examples of alcohol solvents include methanol, ethanol, butanol, propanol, methyl propylene diglycol, diethylene glycol ethyl ether, butyl propylene glycol, and propyl propylene glycol. Examples of ketone solvents include acetone, methyl ethyl ketone, diethyl ketone, methyl butyl ketone, and methyl isobutyl ketone. Cyclic ether compounds such as tetrahydrofuran and dioxane may also be used in combination with the reaction solvent. The reaction solvents may be used alone or in combination.

[0084] The reaction solvent preferably contains a highly polar solvent. By using such a solvent, the intermediate carbocation can be stabilized, and therefore, a compound (A) having a desired number average molecular weight (Mn) tends to be obtained. The highly polar solvent preferably contains tetrahydrofuran.

[0085] The lower limit of the raw material concentration when synthesizing resin (T) is preferably 5% or more, more preferably 8% or more, and even more preferably 10% or more, and may be 12% or more, 15% or more, 17% or more, or 20% or more. When the raw material concentration is at or above the above lower limit, the reaction rate and the ratio of the indane skeleton (structural unit (a) in formula (2)) tend to be improved. The upper limit of the raw material concentration is preferably 49% or less, and more preferably 40% or less. When the upper limit of the raw material concentration is at or below the above upper limit, the production of by-products tends to be effectively suppressed.

[0086] Furthermore, the concentration does not need to be the same from the start to the end of the reaction, and may be changed.

[0087] (Hydroxylation step of resin (T)) The method for producing compound (A) includes a step of reacting resin (T) with a compound represented by the following formula (P) to hydroxylate it. Through this step, a compound in which resin (T) is hydroxylated (hereinafter also simply referred to as "hydroxylated resin (TOH)") is obtained. The compound represented by the following formula (P) can be used alone or in combination of two or more.

[0088] The hydroxylated resin (TOH) is a resin represented by the following formula (TOH), preferably a resin represented by the following formula (TOH1), and more preferably a resin represented by the following formula (TOH1A).

[0089] [ka]

[0090] In formula (TOH), Tx, Ar1, Ra, Rb, a, b, and c have the same meanings as in formula (1), including preferred ranges. Tx is preferably a structural unit represented by formula (a).

[0091] [ka]

[0092] In formula (TOH1), Tx, Ar1, Ra, Rb, a, b, and c have the same meanings as in formula (1) above, including preferred ranges. Tx is preferably a structural unit represented by formula (a).

[0093] [ka]

[0094] In formula (TOH1A), n is the average number of repeating units and is a number of 3.0 to 15.0. n is preferably a number of 3.2 to 14.0, more preferably a number of 3.5 to 12.5, and even more preferably a number of 3.7 to 11.0. When the number of n is within the above range, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0095] The hydroxy group equivalent of the hydroxylated resin (TOH) is preferably 400 mgKOH / g or more and 1500 mgKOH / g or less, more preferably 420 mgKOH / g or more and 1200 mgKOH / g or less, and even more preferably 450 mgKOH / g or more and 1150 mgKOH / g or less. When the hydroxy group equivalent of the hydroxylated resin (TOH) is within the above range, the resulting cyanate ester compound (A) tends to have a lower dielectric constant and a lower dielectric dissipation factor, as well as better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature. In this specification, the hydroxy group equivalent refers to the number of milligrams of potassium hydroxide required to acetylate the hydroxy groups contained in 1 g of the hydroxylated resin (TOH). The hydroxy group equivalent (g / eq.) is 56000 / hydroxy value (mgKOH / g). Specifically, it is measured according to JIS K 0070. For specific measurement methods, see the Examples.

[0096] It is believed that using a compound represented by formula (P) in the hydroxylation step can increase the proportion of structural unit (a) in formula (2) during the addition reaction of the compound represented by formula (P). This is believed to be because structural units (b) and (c) in formula (2) become structural unit (a) during the addition reaction. It is also believed that cationic polymerization of resin (T) also progresses during the addition reaction of the compound represented by formula (P), increasing the total value of the sum (n + o + p) in formula (2). As a result, the molecular weight of the resulting compound (A) increases, and resin compositions with lower dielectric constants and dielectric loss tangents, better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature are likely to be obtained.

[0097] [ka]

[0098] In formula (P), Ar1, Ra, and b have the same meanings as in formula (1) above, including preferred ranges.

[0099] The compound represented by formula (P) preferably includes a compound represented by the following formula (P1).

[0100] [ka]

[0101] In formula (P1), Ra and b have the same meanings as in formula (1) above, including their preferred ranges.

[0102] Examples of the compound represented by formula (P) include cresols such as o-cresol, m-cresol, and p-cresol; phenol; xylenols such as 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol (2,6-dimethylphenol), 3,4-xylenol, and 3,5-xylenol; ethylphenols such as o-ethylphenol, m-ethylphenol, and p-ethylphenol; butylphenols such as isopropylphenol, butylphenol, and pt-butylphenol; p-pentylphenol, p-octylphenol, p-nonylphenol, and p-cumylphenol; halogenated phenols such as fluorophenol, chlorophenol, bromophenol, and iodophenol; mono-substituted phenols such as o-phenylphenol, p-phenylphenol, 2-cyclohexylphenol, and 2-benzylphenol; condensed polycyclic phenols such as 1-naphthol, 2-naphthol, 1-anthracenol, and 2-anthracenol; and polyhydric phenols such as resorcinol, alkylresorcinol, pyrogallol, catechol, alkylcatechol, hydroquinone, alkylhydroquinone, and phloroglucinol. These phenols or derivatives thereof can be used either individually or in combination of two or more.

[0103] The compound represented by formula (P) is preferably at least one selected from the group consisting of phenol, o-cresol, 2,6-xylenol, 2,4-xylenol, 2-cyclohexylphenol, 2-cyclohexyl-6-methylphenol, and 2-benzylphenol, more preferably at least one selected from the group consisting of phenol, o-cresol, 2,6-xylenol, and 2-benzylphenol, and even more preferably at least one selected from the group consisting of phenol and o-cresol.

[0104] In the reaction system in which the compound represented by formula (P) is reacted with resin (T), the total content of m-bis(α-hydroxyisopropyl)benzene, p-bis(α-hydroxyisopropyl)benzene, 1,3-diisopropenylbenzene, and 1,4-diisopropenylbenzene is preferably 10% by mass or less, more preferably 8% by mass or less, even more preferably 5% by mass or less, even more preferably 3% by mass or less, even more preferably 2% by mass or less, and even more preferably 1% by mass or less, based on the amount of resin (T). When the total content is below the upper limit, the molecular weight of compound (A) tends to be improved. The lower limit is not particularly limited, but is usually 0.1 parts by mass or more.

[0105] The weight average molecular weight (Mw), number average molecular weight (Mn), and dispersity (Mw / Mn) of the compound (A) can be controlled by the reaction temperature, catalyst type, catalyst amount, reaction solvent, and the like in the reaction system when the resin (T) is reacted with the compound represented by formula (P).

[0106] When the compound represented by formula (P) is reacted with the resin (T), the amount of the compound represented by formula (P) used is preferably 1 part by mass or more and 200 parts by mass or less per 100 parts by mass of the resin (T).

[0107] The lower limit of the reaction temperature when the resin (T) is reacted with the compound represented by formula (P) is preferably 50°C or higher, more preferably 60°C or higher, even more preferably 70°C or higher, even more preferably 80°C or higher, even more preferably 90°C or higher, and even more preferably 100°C or higher. When the reaction temperature is at or above the above lower limit, the reaction rate improves, and the cyclization of the structural units (b) and (c) in formula (2) progresses, which tends to increase the proportion of the indane skeleton (structural unit (a) in formula (2)). Furthermore, the upper limit of the reaction temperature is preferably 200°C or lower, more preferably 150°C or lower. When the reaction temperature is at or below the above upper limit, the production of by-products tends to be effectively suppressed. The reaction temperature does not need to be the same from the start to the end of the reaction, and may be varied. In this case, it is preferable that the average reaction temperature throughout the entire process is within the above range.

[0108] The catalyst used when reacting the resin (T) with the compound represented by formula (P) is, for example, an acid catalyst. For such an acid catalyst, see the catalyst used in synthesizing the above-mentioned resin (T).

[0109] When a catalyst is used, the amount thereof is usually 0.01 parts by mass or more and 30.0 parts by mass or less relative to 100 parts by mass of the resin (T) that is the raw material.

[0110] The catalyst can be used alone or in combination of two or more. When two or more catalysts are used in combination, the total amount thereof is preferably within the above range.

[0111] As the reaction solvent used when reacting the resin (T) with the compound represented by formula (P), reference may be made to the reaction solvents used when synthesizing the resin (T). The reaction solvents may be used alone or in combination of two or more.

[0112] When a reaction solvent is used, the amount thereof is usually 10 parts by mass or more and 1000 parts by mass or less relative to 100 parts by mass of the resin (T) which is the raw material.

[0113] (Cyanation process of hydroxylated resin (TOH)) The method for producing the compound (A) includes a step of cyanating a hydroxylated resin (TOH). Preferably, the method for producing compound (A) includes a raw material solution preparation step of preparing a first solution (hereinafter also referred to as "solution 1") containing a hydroxylated resin (TOH), a basic compound (hereinafter also referred to as "basic compound 1"), and an organic solvent (hereinafter also referred to as "organic solvent 1"), and a cyanation step (hereinafter also referred to as "cyanation step") of contacting and reacting the first solution with a second solution (hereinafter also referred to as "solution 2") containing a cyanogen halide, a hydrogen halide, a second organic solvent (hereinafter also referred to as "organic solvent 2"), and water to cyanate the compound (A) to obtain a reaction solution containing the compound (A). Note that organic solvent 2 may be the same as or different from organic solvent 1.

[0114] By undergoing such a specific process, the hydroxylated resin (TOH) can be suitably cyanated to obtain the desired cyanated compound (A). Resin compositions containing such compound (A) tend to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0115] Next, each step will be explained, and the components to be used in the raw material solution preparation step, the cyanation step, etc. will be described later.

[0116] (Raw material solution preparation process) The method for producing compound (A) includes a raw material solution preparation step of preparing a solution 1 containing a hydroxylated resin (TOH), a basic compound 1, and an organic solvent 1. Organic solvent 1 may be the same as or different from organic solvent 2, but it is preferable that they are the same.

[0117] In the raw material solution preparation step, the temperature of solution 1 containing hydroxylated resin (TOH), basic compound 1, and organic solvent 1 is preferably 5.0°C or lower, more preferably −20°C or higher and 3.0°C or lower, and even more preferably −10°C or higher and 1.0°C or lower. By keeping the solution temperature within the above range, the hydroxylated resin (TOH) can be more suitably cyanated to obtain the desired compound (A). Resin compositions containing such compound (A) tend to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0118] In the raw material solution preparation step, the pressure is not particularly limited as long as it is a pressure at which the desired solution can be obtained in the raw material solution preparation step.

[0119] In the raw material solution preparation step, the raw material solution is preferably prepared while flowing an inert gas. Examples of the inert gas include nitrogen, helium, and argon. Nitrogen is preferred as the inert gas.

[0120] In the raw material solution preparation step or in preparation of the solution obtained in the raw material solution preparation step, the amount of organic solvent 1 blended is preferably an amount capable of dissolving basic compound 1 and hydroxylated resin (TOH). The amount of organic solvent 1 blended is usually 50% by mass or more and 90% by mass or less relative to 100% by mass of the solution (raw material).

[0121] In the raw material solution preparation step or in preparation of the solution obtained in the raw material solution preparation step, the amount of basic compound 1 is preferably 0.1 mol to 8.0 mol, more preferably 0.5 mol to 3.0 mol, per mol of hydroxyl groups in the hydroxylated resin (TOH). By ensuring that the blending ratio of basic compound 1 to hydroxylated resin (TOH) is within the above range, the hydroxylated resin (TOH) can be more suitably cyanated to obtain the desired compound (A). Resin compositions containing such compound (A) tend to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0122] (Cyanation process) The method for producing compound (A) includes a cyanation step in which solution 1 and solution 2 are contacted and reacted to cyanate, thereby obtaining a reaction solution containing compound (A). Because the cyanation step is such a specific step, the hydroxylated resin (TOH) can be more suitably cyanated to obtain the desired compound (A). Resin compositions and the like containing such compound (A) tend to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0123] As a method for contacting and reacting Solution 1 with Solution 2, for example, a method can be mentioned in which the cyanogen halide contained in Solution 2 and the hydroxylated resin (TOH) contained in Solution 1 are stirred in the presence of a basic compound contained in Solution 1 to contact and react the two components.

[0124] In the cyanation step, the contacting of Solution 1 with Solution 2 can be carried out in either a semi-batch or continuous flow manner. Specific examples of the contacting method include (a) adding Solution 1 dropwise to Solution 2 while stirring and mixing, (b) adding Solution 2 dropwise to Solution 1 while stirring and mixing, and (c) supplying a portion of Solution 2 and a portion of Solution 1 continuously or intermittently, alternately, or simultaneously to a reaction vessel. In these methods, the solution may be added dropwise in appropriate portions. For example, in Method (a), Solution 1 may be added dropwise in portions to Solution 2 while stirring and mixing. The number of separate additions is typically between two and five.

[0125] Among methods (a) to (c), method (a) is preferred. When method (a) is used as a contacting operation method, the hydroxylated resin (TOH) can be more suitably cyanated to obtain the desired compound (A). Resin compositions containing such compound (A) tend to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0126] In the cyanation step, the reaction time is not particularly limited, but the dropwise addition time in the contacting operation of method (a) and method (b), and the contact time in the contacting operation of method (c) are preferably 1 minute to 20 hours, more preferably 3 minutes to 10 hours. Furthermore, it is preferable to subsequently stir the mixture for 10 minutes to 10 hours while maintaining the reaction temperature. By keeping the reaction time within the above range, the target cyanate ester compound tends to be obtained more economically and industrially efficiently. The stirring method may be as described above.

[0127] Examples of the stirring method include a method using a known stirrer such as a stirring blade, stirrer, paddle, ribbon, screw, mixer, etc. The stirring time can be determined by referring to the above reaction time, and is preferably from 1 minute to 20 hours, more preferably from 3 minutes to 10 hours.

[0128] In the cyanation step, the temperature of the reaction solution is preferably 5.0°C or lower, more preferably -20°C or higher and 3.0°C or lower, and even more preferably -10°C or higher and 2.0°C or lower. By keeping the temperature of the reaction solution within the above range, the hydroxylated resin (TOH) can be more suitably cyanated to obtain the desired compound (A). Resin compositions containing such compound (A) tend to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0129] In the cyanation step, the pressure inside the vessel is not particularly limited as long as it is a pressure that allows a reaction liquid containing the desired compound (A) to be obtained. If necessary, an inert gas such as nitrogen, helium, or argon may be passed through the reaction system.

[0130] In the solution 1 used in the cyanation step, the content of the organic solvent 1 is preferably an amount capable of dissolving the basic compound and the hydroxylated resin (TOH). The content of the organic solvent 1 is usually 50% by mass or more and 90% by mass or less relative to 100% by mass of the solution 1.

[0131] In the solution 1 used in the cyanation step, the content of the basic compound 1 is preferably 0.1 mol to 8.0 mol, more preferably 0.5 mol to 3.0 mol, per mol of hydroxy groups in the hydroxylated resin (TOH). By ensuring that the content ratio of the basic compound 1 to the hydroxylated resin (TOH) is within the above range, the hydroxylated resin (TOH) can be more suitably cyanated to obtain the desired compound (A). Resin compositions containing such compound (A) tend to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0132] The amounts of cyanogen halide and hydrogen halide blended in Solution 2 may refer to the amounts of hydrogen halide used and the amount of cyanogen halide charged as raw materials, respectively, which will be described later. The amount of water used is preferably sufficient to dissolve the hydrogen halide. In Solution 2, the mass ratio of water to organic solvent 2 (water / organic solvent 2) is not particularly limited, but is preferably 1 / 100 to 100 / 1, more preferably 1 / 10 to 10 / 1, and even more preferably 1 / 5 to 5 / 1.

[0133] The cyanation step is more preferably a step of contacting Solution 2 with Solution 1 containing a hydroxylated resin (TOH) to cyanate the compound (A) to obtain a reaction solution containing the compound (A), and then pouring a third solution (hereinafter also referred to as "Solution 3") containing a basic compound (hereinafter also referred to as "Basic Compound 2") and an organic solvent (hereinafter also referred to as "Organic Solvent 3") into the reaction solution. Basic Compound 2 may be the same as or different from Basic Compound 1, but is preferably the same. Organic Solvent 3 may be the same as Organic Solvent 1, but is preferably the same. Organic Solvent 3 may be the same as Organic Solvent 2, but is preferably the same. Adding Solution 3 to the reaction solution after obtaining the reaction solution tends to produce a high-purity compound (A) in a high yield.

[0134] The basic compound 2 and organic solvent 3 contained in solution 3 are preferably the same components as the basic compound 1 and organic solvent 1 contained in solution 1. By performing the cyanation step in this manner, the hydroxylated resin (TOH) can be more suitably cyanated to obtain the desired compound (A). Resin compositions and the like containing such compound (A) tend to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0135] In solution 3, the amount of basic compound 2 is preferably 0.05 mol to 2.5 mol, more preferably 0.1 mol to 2.3 mol, per mol of hydroxy groups in the hydroxylated resin (TOH). By using basic compound 2 in the above range, the hydroxylated resin (TOH) can be more suitably cyanated to obtain the desired compound (A). Resin compositions containing such compound (A) tend to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0136] In the solution 3, the organic solvent 3 is preferably present in an amount sufficient to dissolve the basic compound 2. The content of the organic solvent 3 is usually 30% by mass or more and 90% by mass or less relative to 100% by mass of the solution 3.

[0137] The temperature at which Solution 3 is added to the reaction solution may be determined by reference to the temperature of the reaction solution described above. Since this tends to result in a high-purity compound (A) in high yield, the temperature at which Solution 3 is added to the reaction solution is preferably the same as the temperature of the reaction solution described above.

[0138] The pressure inside the vessel when adding Solution 3 to the reaction mixture is not particularly limited as long as the desired solution is obtained. If necessary, an inert gas such as nitrogen, helium, or argon may be passed through the system.

[0139] The time for adding Solution 3 to the reaction solution is preferably 1 minute to 20 hours, more preferably 1.5 minutes to 10 hours. Furthermore, it is preferable to subsequently stir the reaction solution for 10 minutes to 10 hours while maintaining the same temperature as that at which Solution 3 was added to the reaction solution. When the time for adding Solution 3 to the reaction solution is within the above range, the target compound (A) tends to be obtained economically and industrially more efficiently.

[0140] [Other steps] After the cyanation step or the step of dropping solution 3 into the reaction solution, the target compound (A) can be isolated by performing conventional post-treatment procedures and, if desired, separation and / or purification procedures. Specifically, after separating the solution into an organic phase containing compound (A) and an aqueous phase, the separated organic phase is heated and distilled to remove the cyanogen halide and organic solvent. Subsequently, an organic solvent is added, followed by washing with water and concentration, thereby precipitating or crystallizing the target compound (A). Alternatively, after washing with water and concentration, compound (A) can be precipitated or crystallized by replacing the solvent in the organic phase with a solvent in which compound (A) is insoluble or poorly soluble. During washing, an acidic aqueous solution such as dilute hydrochloric acid may be used to remove excess amines. Furthermore, to remove water from the thoroughly washed organic phase, a drying procedure using a common method such as sodium sulfate or magnesium sulfate may be performed.

[0141] Furthermore, during concentration and solvent substitution, in order to more suitably suppress polymerization of compound (A), it is preferable to distill off the organic solvent under reduced pressure and heating at a temperature of 90°C or less. Precipitation or crystallization can be carried out by adding dropwise a solvent having low solubility for compound (A) to a solution containing compound (A), or by adding dropwise a solution containing compound (A) to a solvent having low solubility for compound (A). Examples of solvents having low solubility for compound (A) include ether-based solvents; hydrocarbon-based solvents such as hexane; and alcohol-based solvents.

[0142] To wash the obtained crude product, the concentrate of the reaction solution or the precipitated or crystallized crystals may be washed with a solvent having low solubility for compound (A). The crystals obtained by concentrating the reaction solution may be redissolved and then recrystallized. When crystallization is desired, the reaction solution may simply be concentrated or cooled.

[0143] The structure of the obtained compound (A) is, for example, 1The purity of the resulting compound (A) can be analyzed by H-NMR measurement. The purity of the resulting compound (A) can be analyzed, for example, by liquid chromatography or FT-IR (Fourier transform infrared spectroscopy). Volatile components in compound (A), such as by-products such as dialkyl cyanoamide and residual solvents, can be quantitatively analyzed by gas chromatography. Residual halides in compound (A) can be identified by liquid chromatography-mass spectrometry and quantitatively analyzed by potentiometric titration using a silver nitrate solution or ion chromatography after decomposition by combustion. The polymerization reactivity of compound (A) can be evaluated by gelation time using the hot plate method or torque measurement method.

[0144] Next, each component to be subjected to the cyanation step will be described.

[0145] (hydrogen halide) In the cyanation step, hydrogen halide is used to adjust the pH and suppress the by-production of impurities.

[0146] In the cyanation step, the pH of the reaction solution is preferably less than 7.0, more preferably 6.5 or less, and even more preferably 6.0 or less. By carrying out the reaction while maintaining the pH of the reaction solution below 7.0, the hydroxylated resin (TOH) can be more suitably cyanated to obtain the desired compound (A). Resin compositions containing such compound (A) tend to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0147] Examples of methods for adding hydrogen halide include a method in which hydrogen halide is added to Solution 1 before cyanation, and a method in which hydrogen halide is added to Solution 1 while appropriately measuring the pH with a pH meter. In addition to hydrogen halide, the acid used in this case may be, for example, inorganic acids such as nitric acid, sulfuric acid, and phosphoric acid, or organic acids such as acetic acid, lactic acid, and propionic acid.

[0148] Examples of hydrogen halides include hydrogen fluoride, hydrogen chloride, hydrogen bromide, and hydrogen iodide. The hydrogen halide may be an acidic aqueous solution such as hydrofluoric acid or hydrochloric acid. These hydrogen halides can be used alone or in combination of two or more.

[0149] Hydrochloric acid is preferred as the hydrogen halide. By using chlorine as the hydrogen halide, the hydroxylated resin (TOH) can be more suitably cyanated to obtain the desired compound (A). Resin compositions containing such compound (A) tend to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature. When the hydrogen halide is hydrochloric acid, its concentration in the reaction solution is preferably, for example, 1.0% or more and 10% or less. Using hydrochloric acid at such a concentration tends to produce a highly pure compound (A).

[0150] The amount of hydrogen halide used is preferably 0.5 mol to 5.0 mol, more preferably 1.0 mol to 3.5 mol, per mol of hydroxyl groups in the hydroxylated resin (TOH). By using hydrogen halide in the above range, the hydroxylated resin (TOH) can be more suitably cyanated to obtain the desired compound (A). Resin compositions containing such compound (A) tend to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0151] (organic solvent) As the organic solvents 1 to 3, any commonly known organic solvent can be used as long as it is immiscible with water and inert to the cyanation reaction. Examples of such organic solvents include halogenated hydrocarbon solvents such as dichloromethane, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, chlorobenzene, and bromobenzene; aliphatic solvents such as n-hexane, cyclohexane, and isooctane; aromatic solvents such as benzene, toluene, xylene, and ethylbenzene; ketone solvents such as methyl ethyl ketone, cyclohexanone, cyclopentanone, and methyl isobutyl ketone; nitrile solvents such as benzonitrile; nitro solvents such as nitrobenzene; ether solvents such as diethyl ether, diisopropyl ether, and tetrahydrofuran; and ester solvents such as ethyl acetate and ethyl benzoate. These organic solvents can be used alone or in combination. Among these, halogenated hydrocarbon solvents having 1 to 2 carbon atoms, such as dichloromethane, chloroform, carbon tetrachloride, dichloroethane, and trichloroethane, are preferred.

[0152] In this embodiment, as long as the effects of the present invention are achieved, the organic solvent may be mixed with the organic solvent described above, for example, a solvent miscible with water, etc. Examples of such organic solvents include acetone, dimethyl cellosolve, diglyme, tetraethylene glycol dimethyl ether, methanol, ethanol, isopropanol, methyl cellosolve, propylene glycol monomethyl ether, N,N-dimethylformamide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidone, dimethyl sulfoxide, and acetonitrile.

[0153] (water) Examples of water include tap water, distilled water, and deionized water. Among these, it is preferable to use distilled water or deionized water with few impurities from the viewpoint of efficiently obtaining the target cyanate ester compound.

[0154] The total amount of solvents used in the cyanation step, i.e., the total amount of organic solvents 1 to 3 and water, is preferably 1.0 to 200 parts by mass, more preferably 1.5 to 150 parts by mass, and even more preferably 2.5 to 100 parts by mass, relative to 1 part by mass of hydroxylated resin (TOH). By keeping the total amount of solvents within the above range, the hydroxylated resin (TOH) can be uniformly dissolved, which tends to further improve the production efficiency of compound (A).

[0155] (Cyanogen halide) In the cyanation step, a cyanogen halide is used to cyanate the hydroxylated resin (TOH).

[0156] Examples of cyanogen halides include cyanogen fluoride, cyanogen chloride, cyanogen bromide, and cyanogen iodide. Cyanogen chloride is preferred as the cyanogen halide. By using cyanogen chloride as the cyanogen halide, the hydroxylated resin (TOH) can be more suitably cyanated to obtain the desired compound (A). Resin compositions containing such compound (A) tend to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0157] The amount of cyanogen halide used as a raw material is preferably 0.5 mol to 5.0 mol, more preferably 1.0 mol to 3.5 mol, per mol of hydroxyl groups in the hydroxylated resin (TOH). By using cyanogen halide in the above range, the hydroxylated resin (TOH) can be more suitably cyanated to obtain the desired compound (A). Resin compositions containing such compound (A) tend to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0158] (basic compounds) In the cyanation step, basic compounds 1 and 2 are used as desalting agents in the cyanation reaction between cyanogen halide and hydroxylated resin (TOH). Examples of such basic compounds include organic bases and inorganic bases. The basic compounds may be used in a solid state or in a solution state.

[0159] Preferred organic bases include tertiary amines such as trimethylamine, triethylamine, tri-n-butylamine, triamylamine, diisopropylethylamine, diethyl-n-butylamine, methyldi-n-butylamine, methylethyl-n-butylamine, dodecyldimethylamine, tribenzylamine, triethanolamine, N,N-dimethylaniline, N,N-diethylaniline, diphenylmethylamine, pyridine, diethylcyclohexylamine, tricyclohexylamine, 1,4-diazabicyclo[2.2.2]octane, 1,8-diazabicyclo[5.4.0]-7-undecene, and 1,5-diazabicyclo[4.3.0]-5-nonene. Among these, the basic compound is more preferably one or more selected from the group consisting of trimethylamine, triethylamine, tri-n-butylamine, and diisopropylethylamine, and even more preferably triethylamine. By using such a basic compound, the hydroxylated resin (TOH) can be more suitably cyanated to obtain the desired compound (A). Resin compositions containing such compound (A) tend to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0160] As the inorganic base, for example, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide are preferred. Among these, sodium hydroxide is more preferred from the viewpoint of inexpensive availability.

[0161] In the cyanation step, the amount (total amount) of the basic compounds 1 and 2 used is preferably 0.1 mol to 8.0 mol, more preferably 1.0 mol to 6.0 mol, per mol of hydroxy groups in the hydroxylated resin (TOH). By using the basic compounds in the above range, the hydroxylated resin (TOH) can be more suitably cyanated to obtain the desired compound (A). Resin compositions containing such compound (A) tend to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0162] In the cyanation step, the basic compound can be used as a solution dissolved in water or an organic solvent. When the basic compound is an organic base, it is preferable to use an organic solvent, and when the basic compound is an inorganic base, it is preferable to use water.

[0163] When the solution containing a basic compound contains a hydroxylated resin (TOH), the content of the solvent in the solution containing a basic compound is preferably 0.10 to 100 parts by mass, more preferably 0.10 to 80 parts by mass, per part by mass of the hydroxylated resin (TOH). This solution containing a basic compound is, for example, solution 1 in the raw material solution preparation step.

[0164] When the solution containing the basic compound does not contain a hydroxylated resin (TOH), the content of the solvent in the solution containing the basic compound is preferably 0.10 to 100 parts by mass per part by mass of the basic compound. This solution containing the basic compound is, for example, solution 3 in the cyanation step.

[0165] Examples of organic solvents and water may be found above. The organic solvent is preferably immiscible with water and inert to the cyanation reaction. By using an organic solvent immiscible with water, an organic solvent layer containing compound (A) can be separated from the reaction solution, which is a mixture of organic solvent and water, at the end of the cyanation step, thereby enabling separation of compound (A).

[0166] [Resin composition] The resin composition of this embodiment contains the cyanate ester compound (A) of this embodiment. By having the above-described configuration, it is possible to obtain a resin composition having a low dielectric constant and a low dielectric loss tangent, excellent water absorption, a low thermal expansion coefficient, and a high glass transition temperature. The compound (A) can be used alone or in combination of two or more.

[0167] The content of compound (A) is preferably 1 part by mass or more and 100 parts by mass or less, more preferably 30 parts by mass or more and 90 parts by mass or less, even more preferably 50 parts by mass or more and 85 parts by mass or less, and even more preferably 55 parts by mass or more and 80 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of compound (A) is within the above range, the resin composition etc. tends to have a lower dielectric constant and a lower dielectric loss tangent, and to have better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0168] <Resin or compound> The resin composition preferably further contains one or more cyanate ester compounds other than the cyanate ester compound (A) of this embodiment (hereinafter simply referred to as "cyanate ester compound (B)" or "compound (B)") and their prepolymers, phenolic resins, epoxy resins, maleimide compounds, oxetane resins, benzoxazine compounds, and compounds having a polymerizable unsaturated group, as needed. The resin composition more preferably contains one or more compounds selected from the group consisting of compound (B) and its prepolymers, phenolic resins, epoxy resins, and maleimide compounds. By including such a resin or compound in the resin composition, the resin composition tends to have a lower dielectric constant and a lower dielectric loss tangent, better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature. These resins or compounds can be used alone or in combination. Each of these components is described below.

[0169] The total content of the resins or compounds is preferably 0 to 99 parts by mass, more preferably 10 to 70 parts by mass, even more preferably 15 to 50 parts by mass, and even more preferably 20 to 45 parts by mass, relative to 100 parts by mass of the resin solid content in the resin composition. When the total content of the resins or compounds is within the above range, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, and to have better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0170] [Cyanate ester compound (B) and its prepolymer] The resin composition preferably contains the compound (B) and a prepolymer thereof. By containing the compound (B) and a prepolymer thereof, the resin composition tends to have a lower dielectric constant and a lower dielectric loss tangent, better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0171] The compound (B) and its prepolymer are not particularly limited as long as they are different from the compound (A). Examples of such a compound (B) and its prepolymer include a cyanate ester compound having one or more cyanate groups in the molecule and its prepolymer. The compound (B) and the prepolymer can each be used alone or in combination of two or more.

[0172] The compound (B) may be partially oligomerized in advance to a trimer or a pentamer. Examples of the prepolymer include those having a weight average molecular weight (Mw) of 500 to 8,000 in terms of polystyrene as measured by gel permeation chromatography. The prepolymer can be prepared, for example, by the method described in JP-A-2000-191776.

[0173] Compound (B) is more preferably a compound represented by the following formula (4) or a compound represented by the following formula (5), and even more preferably a compound represented by formula (4). When compound (B) is the above compound, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, and also tends to have better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0174] (Compound represented by formula (4)) The compound represented by formula (4) is shown below.

[0175] [ka]

[0176] In formula (4), each Ar2 independently represents an aromatic ring; each Rc independently represents a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, an alkenyl group having from 2 to 6 carbon atoms, an aryl group having from 6 to 12 carbon atoms, or an alkoxy group having from 1 to 4 carbon atoms; d represents the number of cyanate groups bonded to Ar2, each independently an integer of from 1 to 3; e represents the number of Rc bonds to Ar2, each independently representing the number of substitutable groups on Ar2 minus (a + 2); f is an integer of from 1 to 50; and each X independently represents a single bond, a divalent organic group having from 1 to 50 carbon atoms in which a hydrogen atom may be substituted with a heteroatom, a divalent organic group having from 1 to 10 nitrogen atoms, a carbonyl group, a carboxy group, a carbonyl dioxide group, a sulfonyl group, a divalent sulfur atom, or a divalent oxygen atom. Each group in formula (4) may have a substituent.

[0177] In formula (4), each Ar2 independently represents an aromatic ring. Examples of the aromatic ring represented by Ar2 include a benzene ring and a naphthalene ring. A benzene ring is preferred as Ar2 because it tends to result in a resin composition having a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0178] Each Rc independently represents a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, an alkenyl group having from 2 to 6 carbon atoms, an aryl group having from 6 to 12 carbon atoms, or an alkoxy group having from 1 to 4 carbon atoms. For these groups, see Rb in formula (2) above. Rc is preferably a hydrogen atom or an alkenyl group having from 2 to 6 carbon atoms, since this tends to result in a resin composition or the like having a lower dielectric constant and a lower dielectric dissipation factor, better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0179] As the alkyl group having 1 to 6 carbon atoms, a methyl group and an ethyl group are preferred.

[0180] As the alkenyl group having from 2 to 6 carbon atoms, an alkenyl group having from 2 to 5 carbon atoms is preferred, since this tends to result in a resin composition or the like having a lower dielectric constant and a lower dielectric dissipation factor, better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0181] d represents the number of bonds of cyanate groups to Ar2, and each d is independently an integer of 1 or more and 3 or less. d is preferably an integer of 1 or more and 2 or less, more preferably 1, since a resin composition having a lower dielectric constant and a lower dielectric dissipation factor, as well as better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature, tends to be obtained.

[0182] e represents the number of bonds of Rc to Ar2, and each e independently represents the number of substitutable groups of Ar2 minus (d+2).

[0183] f is an integer of 1 or more and 50 or less. Since a resin composition or the like having a lower dielectric constant and a lower dielectric loss tangent, better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature tends to be obtained, f is preferably an integer of 1 or more and 10 or less, more preferably an integer of 1 or more and 5 or less, and even more preferably 1.

[0184] Each X independently represents a single bond, a divalent organic group having from 1 to 50 carbon atoms in which a hydrogen atom may be substituted with a heteroatom, a divalent organic group having from 1 to 10 nitrogen atoms (-NRN-, where R represents an organic group), a carbonyl group (-CO-), a carboxy group (-C(=O)O-), a carbonyl dioxide group (-OC(=O)O-), a sulfonyl group (-SO2-), a divalent sulfur atom, or a divalent oxygen atom.

[0185] Examples of the divalent organic group having 1 to 50 carbon atoms in which a hydrogen atom may be substituted with a heteroatom include linking groups selected from the group consisting of divalent groups represented by formulas (7) to (18).

[0186] Since a resin composition or the like having a lower dielectric constant, a lower dielectric loss tangent, better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature tends to be obtained, each X in the compound represented by formula (4) is preferably independently The following formula (7):

[0187] [ka]

[0188] a divalent organic group having 1 to 50 carbon atoms, represented by formula (7): (in formula (7), each Ar4 independently represents an aromatic ring; Re, Rf, Ri, and Rj independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms; Rg and Rh independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms; and g represents an integer of 0 to 5); The following formula (8):

[0189] [ka]

[0190] (in formula (8), each Ar5 independently represents an aromatic ring; each Rl and Rm independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms; and i represents an integer of 0 to 5), and a divalent organic group having 1 to 5 carbon atoms, The following equations (9) to (18):

[0191] [ka]

[0192] (in formula (12), h represents an integer of 4 or more and 7 or less, and in formula (17), each Rk independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms).

[0193] In formulas (7) and (8), examples of aromatic rings represented by Ar4 and Ar5 are the same as those exemplified for Ar2. In formulas (7) and (8), examples of alkyl groups having 1 to 6 carbon atoms or aryl groups having 6 to 12 carbon atoms represented by Re, Rf, Ri, and Rj, and alkyl groups having 1 to 6 carbon atoms, aryl groups having 6 to 12 carbon atoms, and alkoxy groups having 1 to 4 carbon atoms represented by Rg, Rh, Rl, and Rm are the same as those exemplified for Rc. Each group in formulas (7) and (8) may have a substituent.

[0194] Examples of compounds represented by formula (4) include bisphenol A cyanate, bisphenol E cyanate, bisphenol M cyanate, bisphenol F cyanate, tetramethyl bisphenol F cyanate, phenol novolac cyanate, dicyclopentadiene cyanate, biphenyl aralkyl cyanate, naphthol aralkyl cyanate, and diallyl bisphenol A cyanate. The compound represented by formula (4) is preferably at least one selected from the group consisting of bisphenol A cyanate and bisphenol E cyanate, since this tends to result in a resin composition or the like having a lower dielectric constant, a lower dielectric dissipation factor, better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0195] As the compound represented by formula (4), a compound represented by the following formula (19) is preferred, since there is a tendency to obtain a resin composition having a lower dielectric constant and a lower dielectric loss tangent, better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0196] [ka]

[0197] In formula (19), each Ar6 independently represents an aromatic ring, each Rn independently represents a methylene group, a methyleneoxy group, a methyleneoxymethylene group, an oxymethylene group, or a group formed by linking two or more of these, each Ro and Rp independently represents a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, an aryl group having from 6 to 12 carbon atoms, or an alkoxy group having from 1 to 4 carbon atoms, j represents the number of cyanate groups bonded to Ar6, and each is independently an integer of from 1 to 3, k represents the number of Ro bonds to Ar6 and represents the number obtained by subtracting (j + 2) from the number of substitutable groups in Ar6, l represents the number of Rp bonds to Ar6 and represents the number obtained by subtracting 2 from the number of substitutable groups in Ar6, m represents an integer of 1 or greater, n represents an integer of 1 or greater, and the arrangement of each repeating unit is arbitrary. Each group in formula (19) may have a substituent.

[0198] In formula (19), examples of the aromatic ring represented by Ar6 include the same as those exemplified for Ar2. In formula (19), examples of the alkyl group having 1 to 6 carbon atoms, the aryl group having 6 to 12 carbon atoms, and the alkoxy group having 1 to 4 carbon atoms represented by Ro and Rp include the same as those exemplified for Rc. m represents an integer of 1 or more, preferably an integer of 1 to 10, and more preferably an integer of 1 to 5. n represents an integer of 1 or more, preferably an integer of 1 to 10, and more preferably an integer of 1 to 5.

[0199] (Compound represented by formula (5)) The compound represented by formula (5) is shown below.

[0200] [ka]

[0201] In formula (5), Ar3 represents an aromatic ring, each Rd independently represents a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, an alkenyl group having from 2 to 6 carbon atoms, an aryl group having from 6 to 12 carbon atoms, or an alkoxy group having from 1 to 4 carbon atoms, h represents the number of cyanate groups bonded to Ar3 and is an integer of from 2 to 3, and i represents the number of Rd bonds to Ar3 and is the number obtained by subtracting (h+2) from the number of substitutable groups in Ar3. Each group in formula (5) may have a substituent.

[0202] In formula (5), examples of the aromatic ring represented by Ar3 include the same as those exemplified for Ar2. In formula (5), examples of the alkenyl group having 2 to 6 carbon atoms, the aryl group having 6 to 12 carbon atoms, and the alkoxy group having 1 to 4 carbon atoms represented by Rd ​​include the same as those exemplified for Rc.

[0203] The compound (B) is preferably a compound represented by the following formula (20).

[0204] [ka]

[0205] In formula (20), each Ar7 independently represents an aromatic ring, each Rq independently represents a methylene group, a methyleneoxy group, a methyleneoxymethylene group, an oxymethylene group, or a group formed by linking two or more of these, each Rr and Rs independently represents a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, an aryl group having from 6 to 12 carbon atoms, or an alkoxy group having from 1 to 4 carbon atoms, o represents the number of cyanate groups bonded to Ar7 and is an integer of from 1 to 3, p represents the number of Rr bonds to Ar7 and is the number obtained by subtracting (o + 2) from the number of substitutable groups of Ar7, q represents the number of Rs bonds to Ar7 and is the number obtained by subtracting 2 from the number of substitutable groups of Ar7, and m is an integer of 1 or greater. Each group in formula (20) may have a substituent.

[0206] In formula (20), examples of the aromatic ring represented by Ar7 include the same as those exemplified for Ar2. In formula (20), examples of the alkyl group having 1 to 6 carbon atoms, the aryl group having 6 to 12 carbon atoms, and the alkoxy group having 1 to 4 carbon atoms represented by Rr and Rs include the same as those exemplified for Rc. m represents an integer of 1 or more, preferably an integer of 1 to 10, and more preferably an integer of 1 to 5.

[0207] As the cyanate ester compound or a prepolymer thereof, for example, commercially available products such as CYTESTER (registered trademark) TA (trade name), CYTESTER (registered trademark) TA-100, CYTESTER (registered trademark) TA-1500, and CYTESTER (registered trademark) P-201 (all of which are trade names, manufactured by Mitsubishi Gas Chemical Company, Inc.) may be used.

[0208] The total content of compound (B) and its prepolymer is preferably 0 to 99 parts by mass, more preferably 10 to 70 parts by mass, even more preferably 15 to 50 parts by mass, and still more preferably 20 to 45 parts by mass, relative to 100 parts by mass of the resin solid content in the resin composition. When the total content of compound (B) and its prepolymer is within the above range, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, and to have better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0209] (Method for producing compound (B)) The method for producing compound (B) is not particularly limited, and known methods can be used. Examples of such production methods include a method in which a hydroxyl-containing compound having a desired skeleton is obtained or synthesized, and the hydroxyl group is modified by a known method to form a cyanate group. Examples of methods for forming a cyanate group include the method described in Ian Hamerton, "Chemistry and Technology of Cyanate Ester Resins," Blackie Academic & Professional.

[0210] [Phenol resin] The resin composition preferably contains a phenolic resin, which tends to have a lower dielectric constant and a lower dielectric loss tangent, better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0211] As the phenolic resin, any known phenolic resin having two or more hydroxy groups in one molecule can be used. The phenolic resin can be used alone or in combination of two or more.

[0212] Examples of phenolic resins include bisphenol A type phenolic resins, bisphenol E type phenolic resins, bisphenol F type phenolic resins, bisphenol S type phenolic resins, phenol novolac resins, bisphenol A novolac type phenolic resins, aralkyl novolac type phenolic resins, biphenyl aralkyl type phenolic resins, cresol novolac type phenolic resins, polyfunctional phenolic resins, naphthol resins, naphthol novolac resins, polyfunctional naphthol resins, anthracene type phenolic resins, naphthalene skeleton-modified novolac type phenolic resins, phenol aralkyl type phenolic resins, naphthol aralkyl type phenolic resins, dicyclopentadiene type phenolic resins, biphenyl type phenolic resins, alicyclic skeleton-containing phenolic resins, phosphorus-containing phenolic resins, and hydroxyl group-modified silicone resins.

[0213] As the phenolic resin, for example, commercially available products such as PS-4271 (trade name) manufactured by Gun-ei Chemical Industry Co., Ltd., LVR-8210DL (trade name) manufactured by Gun-ei Chemical Industry Co., Ltd., SN485 (trade name) manufactured by Nippon Steel Chemical & Material Co., Ltd., and MEH-7851 (trade name) manufactured by UBE Corporation may be used.

[0214] The total content of the phenolic resins is preferably from 0 to 99 parts by mass, more preferably from 10 to 70 parts by mass, even more preferably from 15 to 50 parts by mass, and even more preferably from 20 to 45 parts by mass, relative to 100 parts by mass of the resin solid content in the resin composition. When the total content of the phenolic resins is within the above range, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0215] [Epoxy resin] The resin composition preferably contains an epoxy resin. By containing an epoxy resin, the resin composition tends to have a lower dielectric constant and a lower dielectric loss tangent, better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0216] As the epoxy resin, for example, any generally known compound having two or more epoxy groups in one molecule can be used. The epoxy resin can be used alone or in combination of two or more types.

[0217] Examples of epoxy resins include bisphenol A type epoxy resins, bisphenol E type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol A novolac type epoxy resins, biphenyl type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, xylene novolac type epoxy resins, multifunctional phenol type epoxy resins, naphthalene type epoxy resins, naphthalene skeleton modified novolac type epoxy resins, naphthylene ether type epoxy resins, phenol aralkyl type epoxy resins, anthracene type epoxy resins, trifunctional phenol type epoxy resins, tetrafunctional phenol type epoxy resins, triglycidyl isocyanurate, glycidyl ether Examples of the epoxy resin include diethyl ester type epoxy resins, alicyclic epoxy resins, dicyclopentadiene novolac type epoxy resins, biphenyl novolac type epoxy resins, phenol aralkyl novolac type epoxy resins, naphthol aralkyl novolac type epoxy resins, aralkyl novolac type epoxy resins, biphenyl aralkyl type epoxy resins, naphthol aralkyl type epoxy resins, dicyclopentadiene type epoxy resins, polyol type epoxy resins, phosphorus-containing epoxy resins, glycidylamine, compounds in which the double bond of butadiene or the like has been epoxidized (butadiene skeleton-containing epoxy resins), compounds obtained by reacting hydroxyl group-containing silicone resins with epichlorohydrin, and halides of these.

[0218] The epoxy resin is preferably at least one selected from the group consisting of biphenylaralkyl epoxy resins, naphthylene ether epoxy resins, polyfunctional phenolic epoxy resins, and naphthalene epoxy resins, more preferably at least one selected from the group consisting of naphthalene epoxy resins and biphenylaralkyl epoxy resins, and even more preferably a biphenylaralkyl epoxy resin. The biphenylaralkyl epoxy resin is preferably a compound represented by the following formula (21). By including such an epoxy resin in a resin composition, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0219] [ka]

[0220] In formula (21), ka represents an integer of 1 or more, preferably an integer of 1 to 20, and more preferably an integer of 1 to 10.

[0221] As the epoxy resin, for example, commercially available products such as EPICRON (registered trademark) 830 (trade name) manufactured by DIC Corporation, jER (registered trademark) 828 (trade name) manufactured by Mitsubishi Chemical Corporation, NC-3000 (trade name, a compound represented by the above formula (21), in formula (21), ka is an integer of 1 to 10), NC-3000L (trade name), NC-3000H (trade name), and NC-3000FH (trade name) manufactured by Nippon Kayaku Co., Ltd. may be used.

[0222] The total content of the epoxy resins is preferably 0 to 99 parts by mass, more preferably 10 to 70 parts by mass, even more preferably 15 to 50 parts by mass, and even more preferably 20 to 45 parts by mass, relative to 100 parts by mass of the resin solid content in the resin composition. When the total content of the epoxy resins is within the above range, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, and to have better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0223] [Maleimide Compound] The resin composition preferably contains a maleimide compound. By containing a maleimide compound, the resin composition tends to have a lower dielectric constant and a lower dielectric loss tangent, as well as better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0224] As the maleimide compound, any generally known compound having one or more maleimide groups in one molecule can be used. The maleimide compounds can be used alone or in combination of two or more.

[0225] Examples of the maleimide compound include bis(4-maleimidophenyl)methane, bis(3-ethyl-5-methyl-4-maleimidophenyl)methane, 4,4'-diphenylmethane bismaleimide, phenylmethane maleimide, m-phenylene bismaleimide, 2,2-bis(4-(4-maleimidophenoxy)-phenyl)propane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, 1 ,6-bismaleimide-(2,2,4-trimethyl)hexane, 4,4'-diphenyletherbismaleimide, 4,4'-diphenylsulfonebismaleimide, 1,3-bis(3-maleimidophenoxy)benzene, 1,3-bis(4-maleimidophenoxy)benzene, polyphenylmethanemaleimide, maleimide compounds represented by the following formula (22), and prepolymers of these maleimide compounds, or prepolymers of maleimide compounds and amine compounds.

[0226] (Compound represented by formula (22)) The compound represented by formula (22) is the following compound.

[0227] [ka]

[0228] In formula (22), R 20 each independently represents a hydrogen atom or a methyl group, and n4 represents an integer of 1 to 10.

[0229] As the maleimide compound, for example, commercially available products such as BMI-70, BMI-80, and BMI-1000P (all trade names, manufactured by KI Chemical Industry Co., Ltd.); BMI-3000, BMI-4000, BMI-5100, BMI-7000, and BMI-2300 (all trade names, manufactured by Daiwa Chemical Industry Co., Ltd.); and MIR-3000 (trade name, manufactured by Nippon Kayaku Co., Ltd., a maleimide compound represented by the following formula (23)) may be used.

[0230] [ka]

[0231] In formula (23), n 31 is an integer between 1 and 10.

[0232] The total content of the maleimide compounds is preferably 0 to 99 parts by mass, more preferably 10 to 70 parts by mass, even more preferably 15 to 50 parts by mass, and even more preferably 20 to 45 parts by mass, relative to 100 parts by mass of the resin solid content in the resin composition. When the total content of the maleimide compounds is within the above range, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, and to have better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0233] [Oxetane resin] The resin composition preferably contains an oxetane resin. By containing an oxetane resin, the resin composition tends to have a lower dielectric constant and a lower dielectric loss tangent, better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0234] As the oxetane resin, generally known ones can be used. The oxetane resins can be used alone or in combination of two or more.

[0235] Examples of oxetane resins include alkyloxetanes such as oxetane, 2-methyloxetane, 2,2-dimethyloxetane, 3-methyloxetane, and 3,3-dimethyloxetane, 3-methyl-3-methoxymethyloxetane, 3,3'-di(trifluoromethyl)perfluoxetane, 2-chloromethyloxetane, 3,3-bis(chloromethyl)oxetane, and biphenyl-type oxetane.

[0236] As the oxetane resin, for example, commercially available products such as OXT-101 and OXT-121 (trade names, manufactured by Toagosei Co., Ltd.) may be used.

[0237] The total content of the oxetane resins is preferably from 0 to 99 parts by mass, more preferably from 10 to 70 parts by mass, even more preferably from 15 to 50 parts by mass, and still more preferably from 20 to 45 parts by mass, relative to 100 parts by mass of the resin solid content in the resin composition. When the total content of the oxetane resins is within the above range, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, and to have better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0238] [Benzoxazine Compounds] The resin composition preferably contains a benzoxazine compound. By containing a benzoxazine compound, the resin composition tends to have a lower dielectric constant and a lower dielectric loss tangent, better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0239] As the benzoxazine compound, any generally known compound having two or more dihydrobenzoxazine rings in one molecule can be used. The benzoxazine compound can be used alone or in combination of two or more.

[0240] Examples of benzoxazine compounds include bisphenol A benzoxazine, bisphenol F benzoxazine, and bisphenol S benzoxazine.

[0241] As the benzoxazine compound, for example, commercially available products such as BA-BXZ, BF-BXZ, and BS-BXZ (all trade names, manufactured by Konishi Chemical Industry Co., Ltd.) may be used.

[0242] The total content of the benzoxazine compounds is preferably 0 to 99 parts by mass, more preferably 10 to 70 parts by mass, even more preferably 15 to 50 parts by mass, and even more preferably 20 to 45 parts by mass, relative to 100 parts by mass of the resin solid content in the resin composition. When the total content of the benzoxazine compounds is within the above range, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, and to have better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0243] [Compound having a polymerizable unsaturated group] The resin composition preferably contains a compound having a polymerizable unsaturated group. By containing a compound having a polymerizable unsaturated group, the resin composition tends to have a lower dielectric constant and a lower dielectric loss tangent, better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0244] As the compound having a polymerizable unsaturated group, generally known compounds can be used. The compound having a polymerizable unsaturated group can be used alone or in combination of two or more.

[0245] Examples of compounds having a polymerizable unsaturated group include vinyl compounds such as ethylene, propylene, styrene, divinylbenzene, and divinylbiphenyl; (meth)acrylates of monohydric or polyhydric alcohols such as methyl(meth)acrylate, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, polypropylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol hexa(meth)acrylate; epoxy(meth)acrylates such as bisphenol A-type epoxy(meth)acrylate and bisphenol F-type epoxy(meth)acrylate; and benzocyclobutene resins.

[0246] The total content of the compounds having a polymerizable unsaturated group is preferably 0 to 99 parts by mass, more preferably 10 to 70 parts by mass, even more preferably 15 to 50 parts by mass, and even more preferably 20 to 45 parts by mass, relative to 100 parts by mass of the resin solid content in the resin composition. When the total content of the compounds having a polymerizable unsaturated group is within the above range, the resin composition or the like tends to have a lower dielectric constant and a lower dielectric loss tangent, and to have better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0247] [Filling material] The resin composition may contain a filler. By containing a filler, the resin composition tends to have better flame retardancy, low thermal expansion, high thermal conductivity, toughness, etc. Furthermore, the resin composition tends to have a lower dielectric constant and a lower dielectric loss tangent, better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0248] As the filler, a generally known filler can be used. Examples of such fillers include inorganic fillers and organic fillers. The fillers can be used alone or in combination of two or more.

[0249] Examples of inorganic fillers include silicates such as kaolin, calcined kaolin, talc, calcined talc, calcined clay, uncalcined clay, mica, E glass, A glass, NE glass, C glass, L glass, D glass, S glass, M glass G20, glass short fibers (including glass fine powders such as E glass, T glass, D glass, S glass, and Q glass), hollow glass, and spherical glass; silicas such as white carbon (wet silica), natural silica, fused silica, synthetic silica, amorphous silica, aerosil, and hollow silica; oxides such as titanium oxide, alumina, boehmite, zinc oxide, magnesium oxide, and zirconium oxide; calcium carbonate, magnesium carbonate, and high-temperature silica. Examples of inorganic fillers include carbonates such as dorotalcite; hydroxides such as aluminum hydroxide, heat-treated aluminum hydroxide (aluminum hydroxide that has been heat-treated to remove some of the water of crystallization), magnesium hydroxide, and calcium hydroxide; sulfates or sulfites such as barium sulfate, calcium sulfate, and calcium sulfite; borates such as zinc borate, barium metaborate, aluminum borate, calcium borate, and sodium borate; nitrides such as aluminum nitride, boron nitride, agglomerated boron nitride, silicon nitride, and carbon nitride; titanates such as strontium titanate and barium titanate; stannates such as zinc stannate; and molybdenum compounds such as molybdenum oxide and zinc molybdate. These inorganic fillers can be used alone or in combination of two or more.

[0250] Examples of organic fillers include rubber powders such as styrene powder, butadiene powder, and acrylic powder; core-shell rubber powder; silicone resin powder; silicone rubber powder; silicone composite powder; etc. These organic fillers can be used alone or in combination of two or more.

[0251] The filler may be used in combination with a silane coupling agent or a wetting and dispersing agent. The resin composition may contain one or more agents selected from the group consisting of silane coupling agents and wetting and dispersing agents.

[0252] Silane coupling agents generally used for surface treatment of inorganic or organic materials can be suitably used. Specific examples include aminosilanes such as γ-aminopropyltriethoxysilane and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, epoxysilanes such as γ-glycidoxypropyltrimethoxysilane and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, vinylsilanes such as γ-methacryloxypropyltrimethoxysilane and vinyl-tri(β-methoxyethoxy)silane, cationic silanes such as N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride, and phenylsilanes. These silane coupling agents can be used alone or in combination of two or more.

[0253] As the wetting and dispersing agent, those generally used for paints can be suitably used. Preferably, a copolymer-based wetting and dispersing agent is used. Specific examples include Disperbyk (registered trademark)-110, 111, 161, and 180 (all trade names, manufactured by BYK Japan Co., Ltd.), BYK (registered trademark)-W996, BYK-W9010, BYK-W903, and BYK-W940 (all trade names, manufactured by BYK Japan Co., Ltd.). These wetting and dispersing agents can be used alone or in combination of two or more.

[0254] The content of the filler is preferably 0.0 parts by mass or more and 1600 parts by mass or less, more preferably 50 parts by mass or more and 1600 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the filler is within the above range, the resin composition tends to have better flame retardancy, low thermal expansion, toughness, etc. Furthermore, the resin composition tends to have a lower dielectric constant and a lower dielectric loss tangent, better water absorption, a lower coefficient of thermal expansion, and a higher glass transition temperature.

[0255] [Polymerization catalyst and curing accelerator] The resin composition may contain one or more selected from the group consisting of a polymerization catalyst and a curing accelerator. When the resin composition contains a curing accelerator, the curing rate can be appropriately adjusted. Furthermore, by containing one or more selected from the group consisting of a polymerization catalyst and a curing accelerator, the resin composition tends to have a lower dielectric constant and a lower dielectric loss tangent, better water absorption, a lower thermal expansion coefficient, and a higher glass transition temperature.

[0256] As the polymerization catalyst and curing accelerator, generally known ones can be used. The polymerization catalyst and curing accelerator can be used alone or in combination of two or more kinds.

[0257] Examples of the polymerization catalyst and the curing accelerator include organic metal salts such as zinc octylate, zinc naphthenate, cobalt naphthenate, copper naphthenate, iron acetylacetonate, nickel octylate, and manganese octylate; phenolic compounds such as phenol, xylenol, cresol, resorcinol, catechol, octylphenol, and nonylphenol; alcohols such as 1-butanol and 2-ethylhexanol; 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5- Examples of the compound include imidazole derivatives such as hydroxymethylimidazole; derivatives of these imidazoles such as adducts of carboxylic acids or their acid anhydrides; amine compounds such as dicyandiamide, benzyldimethylamine, and 4-methyl-N,N-dimethylbenzylamine; phosphorus compounds such as phosphine compounds, phosphine oxide compounds, phosphonium compounds, and diphosphine compounds; peroxides such as epoxy-imidazole adduct compounds, benzoyl peroxide, p-chlorobenzoyl peroxide, di-t-butyl peroxide, diisopropyl peroxycarbonate, and di-2-ethylhexyl peroxycarbonate; and azo compounds such as azobisisobutyronitrile.

[0258] These polymerization catalysts and curing accelerators may be commercially available. Examples of such commercially available products include Amicure (registered trademark) PN-23 (trade name, manufactured by Ajinomoto Fine-Techno Co., Ltd.), Novacure (registered trademark) HX-3721 (trade name, manufactured by Asahi Kasei Corporation), and Fujicure (registered trademark) FX-1000 (trade name, manufactured by Fuji Chemical Industry Co., Ltd.). These polymerization catalysts and curing accelerators may be used alone or in combination of two or more.

[0259] The total content of the polymerization catalyst and the curing accelerator can be adjusted as appropriate taking into consideration the degree of curing of the resin, the viscosity of the resin composition, etc., but is usually 0.005 parts by mass or more and 10 parts by mass or less, respectively, per 100 parts by mass of the resin solid content in the resin composition.

[0260] [Other additives] The resin composition may contain additives other than the above-mentioned compounds or resins, fillers, polymerization catalysts, and curing accelerators, as needed. The additives may be used alone or in combination of two or more.

[0261] Examples of additives include, in addition to the above-mentioned compounds or resins, fillers, polymerization catalysts and curing accelerators, other thermosetting resins and their oligomers, other thermoplastic resins and their oligomers, various polymeric compounds such as elastomers, coloring pigments, antifoaming agents, surface conditioners, flame retardants, solvents, ultraviolet absorbers, antioxidants, photopolymerization initiators, fluorescent brighteners, photosensitizers, dyes, pigments, thickeners, lubricants, flow conditioners, antifoaming agents, dispersants, leveling agents, gloss agents, and polymerization inhibitors.

[0262] The content of each additive is usually 0.005 parts by mass or more and 10 parts by mass or less relative to 100 parts by mass of the resin solid content in the resin composition.

[0263] [Organic solvent] The resin composition may contain an organic solvent as needed. In this case, the resin composition can be used in a form (solution or varnish) in which at least a part, preferably all, of the various resin components described above are dissolved or compatible with the organic solvent. The organic solvent can be used alone or in combination of two or more kinds.

[0264] Any known organic solvent can be used as long as it can dissolve or be compatible with at least a portion, preferably all, of the various resin components described above. Specific examples include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; cellosolve solvents such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate; ester solvents such as ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, isoamyl acetate, ethyl lactate, methyl methoxypropionate, and methyl hydroxyisobutyrate; polar solvents such as amides such as dimethylacetamide and dimethylformamide; alcohol solvents such as methanol, ethanol, isopropanol, and 1-ethoxy-2-propanol; and aromatic hydrocarbons such as toluene, xylene, and anisole.

[0265] The resin composition can be obtained by mixing compound (A) and, if necessary, other components together with an organic solvent using a known mixer, such as a high-speed mixer, a Nauta mixer, a ribbon blender, a kneader, an intensive mixer, a universal mixer, a dissolver, a static mixer, etc. The method of adding the cyanate ester compound, various additives, and the solvent during mixing is not particularly limited.

[0266] [Application] Compound (A) and the resin composition are suitable for use in, for example, cured products, prepregs, laminates, metal foil-clad laminates, multilayer plates, sealing materials, fiber-reinforced composite materials, adhesives, resin composite sheets, films, and printed wiring boards. Compound (A) and the resin composition are also useful as high-performance polymer materials, for example, because they have a low dielectric constant and a low dielectric dissipation factor, excellent water absorption, a low coefficient of thermal expansion, and a high glass transition temperature. Compound (A) and the resin composition can also be used as materials with excellent thermal, electrical, and mechanical properties. Examples of such materials include electrical insulating materials, sealing materials, adhesives, laminate materials, resists, and build-up laminate materials, as well as fixing materials, structural members, reinforcing agents, and molding materials in fields such as civil engineering and construction, electrical and electronics, automobiles, railways, ships, aircraft, sporting goods, and arts and crafts. Among these, it is suitable for electrical insulating materials, semiconductor sealing materials, adhesives for electronic components, aircraft structural members, satellite structural members, and railway vehicle structural members, which require a low dielectric constant and a low dielectric loss tangent, excellent water absorption, a low thermal expansion coefficient, and a high glass transition temperature.

[0267] [Cured product] The cured product of this embodiment is obtained by curing the resin composition of this embodiment. The curing agent contains a resin composition containing compound (A), and therefore has a low dielectric constant and a low dielectric loss tangent, excellent water absorption, a low coefficient of thermal expansion, and a high glass transition temperature.

[0268] A cured product can be obtained, for example, by melting or dissolving the resin composition in a solvent, pouring the resulting mixture into a mold, and curing the resulting mixture under normal conditions using heat, light, or the like. In the case of heat curing, the curing temperature is preferably within the range of 120°C to 300°C inclusive, from the viewpoint of efficient curing and preventing deterioration of the resulting cured product. In the case of photocuring, the wavelength of light is preferably within the range of 100 nm to 500 nm inclusive, in which efficient curing is achieved by a photopolymerization initiator or the like.

[0269] [Prepreg] The prepreg of this embodiment includes a substrate and the resin composition of this embodiment impregnated into or coated on the substrate. Because the prepreg contains the resin composition containing compound (A), it has a low dielectric constant and a low dielectric loss tangent, as well as excellent water absorption, a low coefficient of thermal expansion, and a high glass transition temperature. The prepreg can be used as an insulating layer for printed wiring boards and as a material for semiconductor packages.

[0270] (base material) The substrate can be selected from commonly known materials depending on the performance requirements of the prepreg, such as strength, water absorption, and thermal expansion coefficient. Specific examples include glass fiber substrates, synthetic fiber substrates, organic fiber substrates, and inorganic fiber substrates. Examples of glass fibers constituting the glass fiber substrate include A-glass, C-glass, D-glass, E-glass, H-glass, L-glass, NE-glass, Q-glass, S-glass, T-glass, UN-glass, and spherical glass. Examples of synthetic fibers constituting the synthetic fiber substrate include polyamide-based resin fibers such as polyamide resin fibers, aromatic polyamide resin fibers, and wholly aromatic polyamide resin fibers; polyester-based resin fibers such as polyester resin fibers, aromatic polyester resin fibers, and wholly aromatic polyester resin fibers; polyimide resin fibers; and fluororesin fibers. Examples of organic fiber substrates include paper substrates primarily composed of kraft paper, cotton linter paper, and mixed paper of linter and kraft pulp. Examples of inorganic fibers constituting the inorganic fiber substrate include inorganic fibers other than glass, such as quartz. Examples of the substrate shape include woven fabric, nonwoven fabric, roving, chopped strand mat, and surfacing mat. The substrate can be used alone or in combination of two or more types. Furthermore, the thickness of the substrate is preferably in the range of 0.01 mm to 0.2 mm for laminate applications. When the substrate thickness is within the above range, woven fabrics that have been subjected to fiber-opening or clogging treatment are preferred from the viewpoint of dimensional stability. Furthermore, glass woven fabrics that have been surface-treated with silane coupling agents such as epoxy silane treatment and amino silane treatment are preferred from the viewpoint of moisture absorption and heat resistance. Furthermore, liquid crystal polyester woven fabrics are preferred from the viewpoint of electrical properties.

[0271] As a method for producing a prepreg, a generally known method can be appropriately applied. For example, a prepreg can be produced by preparing a resin varnish using a resin composition and immersing a substrate in the resin varnish, applying the resin varnish to the substrate using various coaters, or spraying the resin varnish onto the substrate using a sprayer. Among these, the method of immersing the substrate in the resin varnish is preferred. This improves the impregnation of the resin composition into the substrate. When immersing the substrate in the resin varnish, a conventional impregnation coating device can be used. For example, a method can be applied in which an inorganic and / or organic fiber substrate is impregnated with the resin varnish using impregnation coating device, and the resin varnish is dried at 120°C to 220°C for approximately 2 to 15 minutes to produce a B-stage prepreg. In this case, the amount of the resin composition attached to the substrate, i.e., the amount of the resin composition (including the filler) relative to the total amount (100% by mass) of the semi-cured prepreg, is preferably in the range of 20% by mass to 99% by mass.

[0272] [Laminate] The laminate has a layer containing at least one prepreg and a metal foil laminated on one or both sides of the layer. A generally known method can be appropriately applied as a method for manufacturing a laminate. For example, a laminate can be obtained by laminating a prepreg and a metal foil and then hot-pressing the laminate. The heating temperature is preferably 65°C or higher and 300°C or lower, more preferably 120°C or higher and 270°C or lower. The pressure applied is preferably 2.0MPa or higher and 5.0MPa or lower, more preferably 2.5MPa or higher and 4.0MPa or lower. The laminate can also be used as a metal foil-clad laminate or a multilayer board.

[0273] [Metal foil-clad laminate] A metal foil-clad laminate is a laminate formed by stacking at least one prepreg and disposing a metal foil on one or both sides of the prepreg. Specifically, it can be produced by stacking one or more prepregs and disposing a metal foil such as copper or aluminum on one or both sides of the prepreg, followed by lamination molding. Examples of the metal foil include those used in printed wiring board materials. Preferred examples of such metal foil include copper foil such as rolled copper foil and electrolytic copper foil. The thickness of the metal foil is preferably 2.0 μm to 70 μm, more preferably 3.0 μm to 35 μm. Typical molding conditions for laminates and multilayer boards for printed wiring boards can be applied. For example, a multi-stage press, a multi-stage vacuum press, a continuous molding machine, an autoclave molding machine, or the like can be used at a temperature of 180°C to 350°C, a heating time of 100 minutes to 300 minutes, and a surface pressure of 20 kg / cm. 2 More than 100kg / cm 2 A metal foil-clad laminate can be manufactured by laminating and molding as follows.

[0274] [Multilayer board] The multilayer board is obtained by combining prepreg and a separately prepared wiring board for an inner layer and laminating the combined result. A multilayer board can be produced, for example, by placing 35 μm copper foil on both sides of a single prepreg, laminating them under the above conditions, forming an inner layer circuit, and then blackening the circuit to form an inner layer circuit board. The inner layer circuit board and the above prepreg are then alternately placed one by one, and copper foil is placed on the outermost layer, followed by laminating and molding under the above conditions, preferably in a vacuum.

[0275] [Sealing material] The encapsulating material of this embodiment includes the resin composition of this embodiment. Because the encapsulating material includes the resin composition containing compound (A), the encapsulating material has a low dielectric constant and a low dielectric loss tangent, excellent water absorption, a low coefficient of thermal expansion, and a high glass transition temperature.

[0276] As a method for producing the encapsulating material, a generally known method can be appropriately applied. For example, a method of mixing a resin composition with various known additives or solvents generally used in the application of encapsulating materials using a known mixer can be mentioned. In addition, as a method for adding each component such as compound (A), resin or compound, filler, polymerization catalyst, curing accelerator, various additives, organic solvent, etc. during mixing, a generally known method can be appropriately applied.

[0277] [Fiber-reinforced composite materials] The fiber-reinforced composite material of this embodiment includes the resin composition of this embodiment and reinforcing fibers. Since the fiber-reinforced composite material includes the resin composition containing compound (A) and reinforcing fibers, it has a low dielectric constant and a low dielectric loss tangent, excellent water absorption, a low coefficient of thermal expansion, and a high glass transition temperature. The fiber-reinforced composite material also exhibits the effects of high strength and high toughness.

[0278] Generally known reinforcing fibers can be used. Specific examples include carbon fibers, glass fibers, aramid fibers, boron fibers, PBO fibers, high-strength polyethylene fibers, alumina fibers, and silicon carbide fibers. The form and arrangement of the reinforcing fibers can be appropriately selected from, for example, woven fabrics, nonwoven fabrics, mats, knits, braided cords, unidirectional strands, rovings, and chopped fibers. Preforms (layers of woven fabric base fabrics made of reinforcing fibers, or fabrics sewn together with stitching threads, or fiber structures such as three-dimensional woven fabrics and braided fabrics) can also be used as the form of the reinforcing fibers.

[0279] Fiber-reinforced composite materials can be manufactured using commonly known methods. Specific examples include liquid composite molding, resin film infusion, filament winding, hand layup, and pultrusion. Among these, resin transfer molding, a type of liquid composite molding, allows materials other than preforms, such as metal plates, foam cores, and honeycomb cores, to be pre-set in the mold, making it suitable for a variety of applications. Therefore, it is preferred for mass-producing composite materials with relatively complex shapes in a short period of time.

[0280] [glue] The adhesive of this embodiment contains the resin composition of this embodiment. A generally known method can be appropriately applied as a method for producing the adhesive. For example, a method of mixing a resin composition with various known additives or solvents generally used in adhesive applications using a known mixer can be mentioned. Note that, when mixing, a generally known method can be appropriately applied as a method for adding each component such as compound (A), resin or compound, filler, polymerization catalyst, curing accelerator, various additives, organic solvent, etc.

[0281] [Resin composite sheet] The resin composite sheet includes a support and a resin layer disposed on the surface of the support, and the resin layer includes the resin composition of the present embodiment. The resin composite sheet can also be obtained by applying a solution of the resin composition of the present embodiment dissolved in a solvent to the support and drying the applied solution. Examples of substrates include polyethylene film, polypropylene film, polycarbonate film, polyethylene terephthalate film, ethylene tetrafluoroethylene copolymer film, and release films obtained by coating the surface of these films with a release agent; organic film substrates such as polyimide film; conductive foils such as copper foil and aluminum foil; and plate-shaped substrates such as glass plates, SUS plates, and FRP. Examples of application methods include coating a solution of the resin composition dissolved in a solvent onto the substrate using a bar coater, die coater, doctor blade, baker applicator, or the like. Furthermore, a single-layer sheet (resin sheet) can be obtained by peeling or etching the substrate from the laminated sheet after drying. Furthermore, a single-layer sheet (resin sheet) can also be obtained without using a substrate by, for example, feeding a solution of the resin composition dissolved in a solvent into a mold having a sheet-shaped cavity and drying it to form a sheet.

[0282] In producing a single-layer or laminate sheet, the drying conditions for removing the solvent are preferably a temperature of 20°C to 200°C for 1 minute to 90 minutes, since low temperatures tend to leave the solvent in the resin composition, and high temperatures accelerate curing of the resin composition. The thickness of the resin layer of the single-layer or laminate sheet can be adjusted by the concentration of the resin composition solution and the coating thickness, but generally, a thicker coating thickness tends to leave the solvent during drying, so the thickness is preferably 0.1 μm to 500 μm.

[0283] [film] The film is formed by molding the resin composition into a sheet. Such a film can be used, for example, as a build-up film or a dry film solder resist. Examples of methods for producing the film include a method in which a peelable plastic film is used as a substrate, and a solution prepared by dissolving the resin composition in a solvent is applied to the plastic film and then dried. The solvent can be dried by heating at a temperature of 20°C or higher and 150°C or lower for 1 minute to 90 minutes. The film can be used in an uncured state, in which the solvent has simply been dried from the resin composition, or, if necessary, in a semi-cured (B-staged) state.

[0284] [Printed wiring board] The printed wiring board includes an insulating layer and a conductor layer formed on the surface of the insulating layer, and the insulating layer includes a resin composition. That is, the insulating layer is preferably composed of an insulating layer including the resin composition of the present embodiment.

[0285] Metal foil-clad laminates can be suitably used as printed wiring boards. Printed wiring boards can be manufactured according to conventional methods. An example of a method for manufacturing a printed wiring board is shown below. First, a metal foil-clad laminate, such as a copper-clad laminate, is prepared. Next, the surface of the metal foil-clad laminate is etched to form an inner layer circuit, thereby producing an inner layer substrate. The inner layer circuit surface of this inner layer substrate is then subjected to a surface treatment to enhance adhesive strength, if necessary. A required number of prepregs are then stacked on the inner layer circuit surface, and a metal foil for an outer layer circuit is further laminated on the outer surface, followed by heating and pressurization to form an integral mold. In this way, a multilayer laminate is manufactured, in which an insulating layer consisting of a substrate and a cured resin composition is formed between the inner layer circuit and the metal foil for the outer layer circuit. Next, the multilayer laminate is drilled for through holes or via holes, and a plated metal film that connects the inner layer circuit and the metal foil for the outer layer circuit is formed on the wall surface of the hole, electrically connecting the inner layer circuit and the metal foil for the outer layer circuit. The metal foil for the outer layer circuit is then etched to form the outer layer circuit, thereby manufacturing a printed wiring board. [Example]

[0286] The present embodiment will be described in more detail below using examples and comparative examples, but the present embodiment is not limited to the following examples.

[0287] [Measurement method] (1) 1 H-NMR measurement 1 H-NMR measurements were carried out under the following conditions. (conditions) Measuring device: Nuclear magnetic resonance device (ECA500 (product name) manufactured by JEOL Ltd.) Frequency: 500MHz Solvent: CDCl3 Internal standard: TMS Measurement temperature: 23℃

[0288] (2) FT-IR measurement The FT-IR measurement was carried out under the following conditions. (conditions) Measurement equipment: Fourier transform infrared spectrometer (Nicolet (registered trademark) 6700 (product name) manufactured by Thermo Fisher Scientific) Measurement method: ATR spectroscopy

[0289] (3) GPC measurement Measurement of the weight average molecular weight (Mw), number average molecular weight (Mn), and dispersity (Mw / Mn) by GPC (gel permeation chromatography) was carried out under the following conditions. (conditions) Measuring equipment: High-performance liquid chromatograph (Chromaster (registered trademark, product name) manufactured by Hitachi High-Tech Corporation) Column: HPLC column (TSKgel (registered trademark) GMH manufactured by Tosoh Corporation) HR -N(product name)) Flow rate: 1mL / min Column temperature: 40℃ Detector: RI (Refractive Index) detector Standard material: polystyrene

[0290] (4) Measurement of hydroxy group equivalent The hydroxy group equivalent (g / eq.) was measured in accordance with JIS K 0070. Specifically, 12.5 g of acetic anhydride was added to a glass flask, and pyridine was added to bring the total volume to 50 mL. The mixture was thoroughly stirred to prepare the acetylation reagent. 2 g of hydroxylated resin (indan hydroxy compound) and 3 mL of acetylation reagent were added to a glass recovery flask and heated in an oil bath at 100 °C for 1 hour. After cooling, 1 mL of water was added. This solution was again heated in the oil bath, allowed to cool, and then ethanol was added to obtain a sample solution. The sample solution was subjected to potentiometric titration with a 0.1 mol / L potassium hydroxide-ethanol solution (Fujifilm Wako Pure Chemical Industries, Ltd.) using a potentiometric titrator (OMNIS® Titration, Metrohm Japan Co., Ltd.) to determine the hydroxyl group equivalent.

[0291] [Synthesis Example 1] <Synthesis of indane compound (IC-1, resin (T))> A flask equipped with a stirrer, thermometer, condenser, and nitrogen inlet tube was charged with 1,050 g of toluene, 10.5 g of tetrahydrofuran, 30 g of activated clay (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 300 g of 1,3-diisopropenylbenzene (manufactured by Tokyo Chemical Industry Co., Ltd.) (raw material concentration: approximately 22%), and heated to an internal temperature of 70°C with stirring under nitrogen. After reaching 70°C, the mixture was allowed to react at that temperature for 3 hours. After allowing the mixture to cool, the activated clay was removed by filtration, and the solvent was distilled off under heating and reduced pressure, yielding 282 g of a white solid.

[0292] GPC measurement of the obtained white solid confirmed that the indan compound (IC-1) had a number average molecular weight (Mn) of 545, a weight average molecular weight (Mw) of 1100, a polydispersity (Mw / Mn) of 2.02, and a residual monomer content of 1% by mass or less. 1 Measurement was carried out using H-NMR (ECA500 (trade name) manufactured by JEOL Ltd.), and the compound was confirmed to be an indane compound (IC-1) represented by the following formula (T1A). 1The H-NMR (500 MHz, CDCl3, δ (ppm)) chart is shown in Figure 1. The NMR peaks of 2.31-2.55 (1H, m) derived from the structural unit represented by formula (a) of Tx in formula (T1A), 5.91-6.24 (1H, m) derived from the structural unit represented by formula (b), and 2.55-2.98 (2H, m) derived from the structural unit represented by formula (c) were used to calculate the abundance ratios of structural units (a), (b), and (c) from the integral ratios of these three NMR peaks. GPC and NMR analysis revealed that the average repeat number n of structural unit (a) was 1.9, and the sum (n + o + p) of the average repeat number n of structural unit (a), the average repeat number o of structural unit (b), and the average repeat number p of structural unit (c) was 3.4.

[0293] [ka]

[0294] In formula (T1A), Tx is a group consisting of a constitutional unit represented by formula (a), a constitutional unit represented by formula (b), and a constitutional unit represented by formula (c) in the following formula (2A).

[0295] [ka]

[0296] [Synthesis Example 2] <Synthesis of indane hydroxy compound (IH-1) (addition of compound represented by formula (P))> 50 g of the indane compound (IC-1) obtained above, 200 g of toluene, 50 g of phenol, and 8 g of activated clay (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were placed in a reactor equipped with a stirrer, a thermometer, a condenser, and a nitrogen inlet tube, and the mixture was heated to an internal temperature of 70°C with stirring under nitrogen. After reaching 70°C, the mixture was allowed to react at that temperature for 1 hour. The internal temperature was then raised to 100°C, and the mixture was allowed to react at that temperature for an additional 1 hour. After allowing the mixture to cool, the activated clay was removed by filtration, and the toluene and remaining phenol were distilled off under heating and reduced pressure, yielding 51 g of a solid.

[0297] The obtained solid was subjected to GPC measurement, and it was confirmed that the indan hydroxy compound (IH-1) had a number average molecular weight (Mn) of 943, a weight average molecular weight (Mw) of 1809, and a dispersity (Mw / Mn) of 1.92. 1 Measurement was carried out using H-NMR (ECA500 (trade name) manufactured by JEOL Ltd.), and the compound was confirmed to be an indan hydroxy compound (IH-1) represented by the following formula (TOH1A). 1 H-NMR (500 MHz, CDCl3) δ (ppm) confirmed the presence of NMR peaks at approximately 2.31–2.55 (ppm) (1H, m) due to the structural unit represented by formula (a) of Tx in formula (TOH1A), at approximately 5.91–6.24 (ppm) (1H, m) due to the structural unit represented by formula (b), and at approximately 2.55–2.98 (ppm) (2H, m) due to the structural unit represented by formula (c). GPC and NMR analyses confirmed that Tx in formula (TOH1A) is the structural unit represented by formula (a), with an average repeat number n of 4.8. The hydroxyl group equivalent weight of the resulting indane hydroxy compound (IH-1) was 568 (g / eq.).

[0298] [ka]

[0299] (In formula (TOH1A), n was 4.8).

[0300] [Synthesis Example 3] <Synthesis of indane hydroxy compound (IH-2) (addition of compound represented by formula (P))> An indan hydroxy compound (IH-2) represented by the above formula (TOH1A) was obtained in the same manner as in Synthesis Example 2, except that the amount of phenol was changed from 50 g to 25 g. GPC and NMR analyses were performed in the same manner as in Synthesis Example 2, and the results showed that the number average molecular weight (Mn) was 1164, the weight average molecular weight (Mw) was 2257, the polydispersity (Mw / Mn) was 1.94, and Tx in formula (TOH1A) was a structural unit represented by formula (a) with an average repeat number n of 6.2. The hydroxy group equivalent of the resulting indan hydroxy compound (IH-2) was 690 (g / eq.).

[0301] [Synthesis Example 4] <Synthesis of indane hydroxy compound (IH-3) (addition of compound represented by formula (P))> An indan hydroxy compound (IH-3) represented by the above formula (TOH1A) was obtained in the same manner as in Synthesis Example 2, except that the amount of phenol was changed from 50 g to 2.5 g. GPC and NMR analyses were performed in the same manner as in Synthesis Example 2, and the results showed that the number average molecular weight (Mn) was 1915, the weight average molecular weight (Mw) was 3884, the dispersity (Mw / Mn) was 2.03, and Tx in formula (TOH1A) was a structural unit represented by formula (a) with an average repeat number n of 10.9. The hydroxy group equivalent of the resulting indan hydroxy compound (IH-3) was 1111 (g / eq.).

[0302] [Synthesis Example 5] <Synthesis of indane hydroxy compound (IH-4) (addition of compound represented by formula (P))> An indan hydroxy compound (IH-4) represented by the above formula (TOH1A) was obtained in the same manner as in Synthesis Example 2, except that the amount of phenol was changed from 50 g to 200 g. GPC and NMR analyses were performed in the same manner as in Synthesis Example 2, and the results showed that the number average molecular weight (Mn) was 649, the weight average molecular weight (Mw) was 953, the dispersity (Mw / Mn) was 1.47, and Tx in formula (TOH1A) was a structural unit represented by formula (a) and its average repeat number n was 2.9. The hydroxy group equivalent of the resulting indan hydroxy compound (IH-4) was 291 (g / eq.).

[0303] [Synthesis Example 6] <Synthesis of indane hydroxy compound (IH-5) (addition of compound represented by formula (P))> Synthesis was attempted in the same manner as in Synthesis Example 2, except that the amount of phenol was changed from 50 g to 1 g, and the internal temperature was heated from 70° C. to 130° C. and the reaction was carried out at that temperature. However, during the reaction at 130° C., insoluble matter precipitated and a gel formed, and therefore an indan hydroxy compound suitable for use in the synthesis of a cyanate ester compound could not be obtained.

[0304] Example 1 <Synthesis of cyanate ester compound (C-1)> 50.00 g of the indan hydroxy compound (IH-1) obtained in Synthesis Example 2 and 6.75 g of triethylamine (0.066 mol, an amount equivalent to 0.75 mol per 1 mol of the hydroxy group in the indan hydroxy compound (IH-1)) as a basic compound were dissolved in 250 g of dichloromethane as an organic solvent while maintaining the solution temperature at 0°C, and this was designated solution 1.

[0305] A mixture (cyanogen halide solution) of 22.20 g (0.14 mol, an amount equivalent to 1.60 mol per mol of hydroxy groups in the indan hydroxy compound (IH-1)) of cyanogen chloride as cyanogen halide, 6.66 g of dichloromethane as organic solvent, 14.71 g (0.15 mol, an amount equivalent to 1.65 mol per mol of hydroxy groups in the indan hydroxy compound (IH-1)) of 36% hydrochloric acid as hydrogen halide, and 91.20 g of water was stirred and kept at a liquid temperature of -6 to -2°C. To this mixture, solution 1 obtained above was added over 10 minutes to obtain solution 2. Then, while maintaining the same liquid temperature, Solution 2 was further stirred for 5 minutes, and then, while maintaining the same liquid temperature, Solution 3, prepared by dissolving 9.00 g of triethylamine (0.088 mol, an amount equivalent to 1.25 mol per 1 mol of hydroxy groups in the indan hydroxy compound (IH-1)) as a basic compound in 9.00 g of dichloromethane as an organic solvent, was poured into Solution 2 over 5 minutes to obtain Solution 4. Then, while maintaining the same liquid temperature, the reaction was completed by further stirring for 30 minutes to obtain Reaction Solution 1. The pH of the aqueous phase (upper phase) of Reaction Solution 1 was measured using a pH meter (IQ Scientific Instruments, IQ150 (trade name)) and found to be 0.55.

[0306] The reaction solution 1 was then allowed to stand, and the lower organic phase (dichloromethane phase) was separated from the upper aqueous phase. The resulting dichloromethane phase was washed twice with 250 mL of 0.1 N hydrochloric acid, and then six times with 250 mL of water. The electrical conductivity of the wastewater after the sixth water wash was measured using a portable EC meter (HI8733N, product name, manufactured by Hanna Instruments) and found to be 23.8 μS / cm. This electrical conductivity value confirmed that ionic compounds had been sufficiently removed by washing with water.

[0307] The dichloromethane phase after washing with water was concentrated under reduced pressure and finally concentrated to dryness at 70°C for 1 hour to obtain 47.80 g of a pale yellow solid. The obtained pale yellow solid was subjected to FT-IR measurement, GPC measurement, and 1As a result of H-NMR measurement, it was confirmed that the compound was the cyanate ester compound (C-1) represented by formula (3). The infrared absorption spectrum of the cyanate ester compound (C-1) was -1 and 2261 cm -1 The absorption of the cyanate ester group was observed, and the absorption of the hydroxyl group was not observed. 1 The H-NMR assignments are shown below: 1 The H-NMR chart is shown in Figure 2. GPC measurement confirmed that the cyanate ester compound (C-1) had a number average molecular weight (Mn) of 993, a weight average molecular weight (Mw) of 1859, and a dispersity (Mw / Mn) of 1.87. The GPC chart of the cyanate ester compound (C-1) is shown in Figure 3.

[0308] 1 H-NMR (500 MHz, CDCl3) δ (ppm): 2.31-2.55 (1H, m, originating from the indane skeleton in formula (3)). The average number of repetitions n in formula (3) was calculated from the results of GPC analysis and NMR analysis, and the result was that the average number of repetitions n in formula (3) was 4.8.

[0309] Example 2 <Synthesis of cyanate ester compound (C-2)> 50.00 g of the indan hydroxy compound (IH-2) obtained in Synthesis Example 3 and 5.56 g of triethylamine (0.054 mol, an amount equivalent to 0.75 mol per 1 mol of the hydroxy group in the indan hydroxy compound (IH-2)) as a basic compound were dissolved in 250 g of dichloromethane as an organic solvent while maintaining the solution temperature at 0°C, and this was designated solution 1.

[0310] A mixture (cyanogen halide solution) of 18.27 g (0.12 mol, an amount equivalent to 1.60 mol per mol of hydroxy groups in the indan hydroxy compound (IH-2)) of cyanogen chloride as the cyanogen halide, 5.48 g of dichloromethane as the organic solvent, 12.11 g (0.12 mol, an amount equivalent to 1.65 mol per mol of hydroxy groups in the indan hydroxy compound (IH-2)) of 36% hydrochloric acid as the hydrogen halide, and 75.08 g of water was stirred and kept at a liquid temperature of -6 to -2°C. To this mixture, solution 1 obtained above was added over 10 minutes to obtain solution 2. Then, while maintaining the same liquid temperature, Solution 2 was further stirred for 5 minutes, and then, while maintaining the same liquid temperature, Solution 3, prepared by dissolving 7.41 g (0.073 mol, 1.25 mol per mol of hydroxy groups in the indan hydroxy compound (IH-2)) of a basic compound in 7.41 g of dichloromethane as an organic solvent, was poured into the mixture over 3 minutes to obtain Solution 4. Then, while maintaining the same liquid temperature, the mixture was further stirred for 30 minutes to complete the reaction, obtaining Reaction Solution 1. The pH of the aqueous phase (upper phase) of Reaction Solution 1 was measured using a pH meter (IQ Scientific Instruments, IQ150 (trade name)) and found to be 0.6.

[0311] The reaction solution 1 was then allowed to stand, and the lower organic phase (dichloromethane phase) was separated from the upper aqueous phase. The resulting dichloromethane phase was washed twice with 250 mL of 0.1 N hydrochloric acid, and then six times with 250 mL of water. The electrical conductivity of the wastewater after the sixth water wash was measured using a portable EC meter (HI8733N, product name, manufactured by Hanna Instruments) and found to be 17.3 μS / cm. This electrical conductivity value confirmed that ionic compounds had been sufficiently removed by washing with water.

[0312] The dichloromethane phase after washing with water was concentrated under reduced pressure and finally concentrated to dryness at 70°C for 1 hour to obtain 46.12 g of a pale yellow solid. The obtained pale yellow solid was subjected to FT-IR measurement, GPC measurement, and 1As a result of H-NMR measurement, it was confirmed that the compound was a cyanate ester compound (C-2) represented by formula (3). As a result of NMR analysis carried out in the same manner as in Example 1, the average repeat number n in formula (6) was found to be 6.2. The infrared absorption spectrum of the cyanate ester compound (C-2) showed a peak at 2235 m -1 and 2261 cm -1 The cyanate ester compound (C-2) exhibited absorption due to the cyanate ester group, but did not exhibit absorption due to the hydroxy group. GPC measurement confirmed that the cyanate ester compound (C-2) had a number average molecular weight (Mn) of 1,214, a weight average molecular weight (Mw) of 2,307, and a dispersity (Mw / Mn) of 1.90. As a result of carrying out GPC analysis and NMR analysis in the same manner as in Example 1, the average repeat number n in formula (3) was found to be 6.2.

[0313] Example 3 <Synthesis of cyanate ester compound (C-3)> 50.00 g of the indan hydroxy compound (IH-3) obtained in Synthesis Example 4 and 3.45 g of triethylamine (0.034 mol, an amount equivalent to 0.75 mol per 1 mol of the hydroxy group in the indan hydroxy compound (IH-3)) as a basic compound were dissolved in 250 g of dichloromethane as an organic solvent while maintaining the solution temperature at 0°C, and this was designated solution 1.

[0314] A mixture (cyanogen halide solution) of 11.35 g (0.072 mol, an amount equivalent to 1.60 mol per mol of hydroxy groups in the indan hydroxy compound (IH-3)) of cyanogen chloride as the cyanogen halide, 3.40 g of dichloromethane as the organic solvent, 7.52 g (0.074 mol, an amount equivalent to 1.65 mol per mol of hydroxy groups in the indan hydroxy compound (IH-3)) of 36% hydrochloric acid as the hydrogen halide, and 46.63 g of water was stirred and kept at a liquid temperature of -6 to -2°C. To this mixture, solution 1 obtained above was added over 10 minutes to obtain solution 2. Then, while maintaining the same liquid temperature, Solution 2 was further stirred for 5 minutes, and then, while maintaining the same liquid temperature, Solution 3, prepared by dissolving 4.60 g of triethylamine (0.045 mol, an amount equivalent to 1.25 mol per 1 mol of hydroxy groups in the indan hydroxy compound (IH-3)) as a basic compound in 4.60 g of dichloromethane as an organic solvent, was poured into the mixture over 1 minute to obtain Solution 4. Then, while maintaining the same liquid temperature, the mixture was further stirred for 30 minutes to complete the reaction, thereby obtaining Reaction Solution 1. The pH of the aqueous phase (upper phase) of Reaction Solution 1 was measured using a pH meter (IQ Scientific Instruments, IQ150 (trade name)) and found to be 0.65.

[0315] The reaction solution 1 was then allowed to stand, and the lower organic phase (dichloromethane phase) was separated from the upper aqueous phase. The resulting dichloromethane phase was washed twice with 250 mL of 0.1 N hydrochloric acid, and then six times with 250 mL of water. The electrical conductivity of the wastewater after the sixth water wash was measured using a portable EC meter (HI8733N, product name, manufactured by Hanna Instruments) and found to be 21.2 μS / cm. This electrical conductivity value confirmed that ionic compounds had been sufficiently removed by washing with water.

[0316] The dichloromethane phase after washing with water was concentrated under reduced pressure and finally concentrated to dryness at 70°C for 1 hour to obtain 49.80 g of a pale yellow solid. The obtained pale yellow solid was subjected to FT-IR measurement, GPC measurement, and 1As a result of H-NMR measurement, it was confirmed that the compound was a cyanate ester compound (C-3) represented by formula (3). The infrared absorption spectrum of the cyanate ester compound (C-3) was -1 and 2261 cm -1 The cyanate ester compound (C-3) exhibited absorption due to the cyanate ester group, but did not exhibit absorption due to the hydroxy group. GPC measurement confirmed that the cyanate ester compound (C-3) had a number average molecular weight (Mn) of 1965, a weight average molecular weight (Mw) of 3934, and a dispersity (Mw / Mn) of 2.00. As a result of carrying out GPC analysis and NMR analysis in the same manner as in Example 1, the average repeat number n in formula (3) was found to be 10.9.

[0317] Comparative Example 1 <Synthesis of cyanate ester compound (C-4)> 50.00 g of the indan hydroxy compound (IH-4) obtained in Synthesis Example 5 and 13.17 g of triethylamine (0.130 mol, an amount equivalent to 0.75 mol per 1 mol of the hydroxy group in the indan hydroxy compound (IH-4)) as a basic compound were dissolved in 250 g of dichloromethane as an organic solvent while maintaining the solution temperature at 0°C, and this was designated solution 1.

[0318] A mixture (cyanogen halide solution) of 43.33 g (0.27 mol, an amount equivalent to 1.60 mol per mol of hydroxy groups in the indan hydroxy compound (IH-4)) of cyanogen chloride as the cyanogen halide, 13.00 g of dichloromethane as the organic solvent, 28.71 g (0.28 mol, an amount equivalent to 1.65 mol per mol of hydroxy groups in the indan hydroxy compound (IH-4)) of 36% hydrochloric acid as the hydrogen halide, and 178.02 g of water was stirred and kept at a liquid temperature of -6 to -2°C. To this mixture, solution 1 obtained above was added over 11 minutes to obtain solution 2. Then, while maintaining the same liquid temperature, Solution 2 was further stirred for 5 minutes, and then, while maintaining the same liquid temperature, Solution 3, prepared by dissolving 17.56 g of triethylamine (0.17 mol, an amount equivalent to 1.25 mol per mol of hydroxy groups in the indan hydroxy compound (IH-4)) as a basic compound in 17.56 g of dichloromethane as an organic solvent, was poured into the mixture over 11 minutes to obtain Solution 4. Then, while maintaining the same liquid temperature, the mixture was further stirred for 30 minutes to complete the reaction, thereby obtaining Reaction Solution 1. The pH of the aqueous phase (upper phase) of Reaction Solution 1 was measured using a pH meter (IQ Scientific Instruments, IQ150 (trade name)) and found to be 0.7.

[0319] The reaction solution 1 was then allowed to stand, and the lower organic phase (dichloromethane phase) was separated from the upper aqueous phase. The resulting dichloromethane phase was washed twice with 250 mL of 0.1 N hydrochloric acid, and then six times with 250 mL of water. The electrical conductivity of the wastewater after the sixth water wash was measured using a portable EC meter (HI8733N, product name, manufactured by Hanna Instruments) and found to be 21.8 μS / cm. This electrical conductivity value confirmed that ionic compounds had been sufficiently removed by washing with water.

[0320] The dichloromethane phase after washing with water was concentrated under reduced pressure and finally concentrated to dryness at 70°C for 1 hour to obtain 51.20 g of a pale yellow solid. The obtained pale yellow solid was subjected to FT-IR measurement, GPC measurement, and 1As a result of H-NMR measurement, it was confirmed that the compound was a cyanate ester compound (C-4) having a structure represented by formula (3). The infrared absorption spectrum of the cyanate ester compound (C-4) was -1 and 2261 cm -1 The cyanate ester compound (C-4) exhibited absorption due to the cyanate ester group, but did not exhibit absorption due to the hydroxy group. GPC measurement confirmed that the cyanate ester compound (C-4) had a number average molecular weight (Mn) of 699, a weight average molecular weight (Mw) of 1003, and a dispersity (Mw / Mn) of 1.43. As a result of carrying out GPC analysis and NMR analysis in the same manner as in Example 1, the average repeat number n in formula (3) was found to be 2.9.

[0321] Example 4 <Preparation of cured product (1)> 75 parts by mass of the cyanate ester compound (C-1) obtained in Example 1 and 25 parts by mass of a bisphenol A-type cyanate ester (CYTESTER (registered trademark) TA (product name) manufactured by Mitsubishi Gas Chemical Company, Inc.) were placed in an eggplant-shaped flask, heated to melt at 130°C, and degassed using a vacuum pump to prepare a resin composition.

[0322] Mold 1 was created by stacking a stainless steel plate, copper foil, and a fluorine-coated stainless steel spacer with a central gap of 80 mm length x 60 mm width x 0.5 mm thickness in that order. The resulting resin composition was poured over the spacer, and mold 1 was placed in an oven (electric muffle furnace "FUW253PB" (trade name) manufactured by Advantec Toyo Co., Ltd.) and heated to 150°C to homogenize the resin. Then, copper foil and a stainless steel plate were stacked in that order on top of the homogenized resin to obtain mold 2. Mold 2 was then placed in a high-temperature vacuum press (KVHC-PRESS (trade name) manufactured by Kitagawa Seiki Co., Ltd.) and heated to 240°C. At that temperature, a surface pressure of 100 kg / cm was applied. 2 The mixture was cured by vacuum pressing for 90 minutes to obtain a cured product (1) measuring 80 mm long x 60 mm wide x 0.5 mm thick.

[0323] Example 5 <Preparation of hardened product (2)> A cured product (2) was obtained in the same manner as in Example 4, except that bisphenol E cyanate ester (CYTESTER (registered trademark) P-201 (product name) manufactured by Mitsubishi Gas Chemical Company, Inc.) was used instead of bisphenol A cyanate ester (CYTESTER (registered trademark) TA (product name) manufactured by Mitsubishi Gas Chemical Company, Inc.).

[0324] Example 6 <Preparation of hardened product (3)> A cured product (3) was obtained in the same manner as in Example 4, except that the cyanate ester compound (C-2) obtained in Example 2 was used instead of the cyanate ester compound (C-1) in Example 4.

[0325] Example 7 <Preparation of cured product (4)> A cured product (4) was obtained in the same manner as in Example 4, except that the cyanate ester compound (C-3) obtained in Example 3 was used instead of the cyanate ester compound (C-1) in Example 4.

[0326] Example 8 <Preparation of hardened product (5)> A cured product (5) was obtained in the same manner as in Example 4, except that the amount of cyanate ester compound (C-1) was changed from 75 parts by mass to 60 parts by mass, and 40 parts by mass of a maleimide compound (MIR-3000 (trade name) manufactured by Nippon Kayaku Co., Ltd.) was used instead of 25 parts by mass of a bisphenol A-type cyanate ester (CYTESTER (registered trademark) TA (trade name) manufactured by Mitsubishi Gas Chemical Company, Inc.).

[0327] Example 9 <Preparation of cured product (6)> A cured product (6) was obtained in the same manner as in Example 4, except that the amount of cyanate ester compound (C-1) was changed from 75 parts by mass to 60 parts by mass, 40 parts by mass of epoxy resin (NC-3000 (product name) manufactured by Nippon Kayaku Co., Ltd.) was used instead of 25 parts by mass of bisphenol A-type cyanate ester (CYTESTER (registered trademark) TA (product name) manufactured by Mitsubishi Gas Chemical Company, Inc.), and the vacuum press temperature was changed from 240°C to 200°C.

[0328] Comparative Example 2 <Preparation of cured product (7)> A cured product (7) was obtained in the same manner as in Example 4, except that the cyanate ester compound (C-1) was not used, the amount of bisphenol A-type cyanate ester (CYTESTER (registered trademark) TA (product name) manufactured by Mitsubishi Gas Chemical Company, Inc.) was changed from 25 parts by mass to 100 parts by mass, and 0.1 parts by mass of zinc octylate (Nihon Kagaku Sangyo Co., Ltd., Nikka Octix (registered trademark) zinc, zinc 2-ethylhexanoate, zinc content 18%) was further added.

[0329] Comparative Example 3 <Preparation of cured product (8)> A cured product (8) was obtained in the same manner as in Example 4, except that the cyanate ester compound (C-4) obtained in Comparative Example 1 was used instead of the cyanate ester compound (C-1) in Example 4, and the bisphenol E cyanate ester (CYTESTER (registered trademark) P-201 (registered trademark) manufactured by Mitsubishi Gas Chemical Company, Inc.) was used instead of the bisphenol A cyanate ester (CYTESTER (registered trademark) TA (registered trademark) manufactured by Mitsubishi Gas Chemical Company, Inc.).

[0330] Comparative Example 4 <Preparation of hardened product (9)> A cured product (9) was obtained in the same manner as in Example 4, except that the cyanate ester compound (C-1) was not used, and instead 70 parts by mass of an epoxy resin (NC-3000 (trade name) manufactured by Nippon Kayaku Co., Ltd.) and 30 parts by mass of a novolac phenolic resin (PS-4271 (trade name) manufactured by Gun-ei Chemical Industry Co., Ltd.) were used, and the vacuum press temperature was changed from 240°C to 200°C.

[0331] [Evaluation method] The cured products (1) to (9) obtained above were evaluated by the following methods. The results are shown in Table 1.

[0332] (1) Glass transition temperature (Tg) The dynamic viscoelasticity of the cured products obtained in the Examples and Comparative Examples was measured in accordance with JIS-K7244-2 (Plastics - Testing methods for dynamic mechanical properties - Part 2: Torsion pendulum method) using a dynamic viscoelasticity measuring device (Discovery Hybrid Rheometer HR-2 (trade name) manufactured by TA Instruments Japan, Inc.) at a starting temperature of 30°C, an ending temperature of 400°C, a heating rate of 3°C / min, a measurement frequency of 10 Hz, and in a nitrogen atmosphere. The maximum value of the loss tangent (tan δ) obtained was taken as the glass transition temperature (°C).

[0333] (2) Dielectric constant (Dk) and dielectric loss tangent (Df) The cured products obtained in the Examples and Comparative Examples were dried at 50°C for 24 hours and then cooled to room temperature in a desiccator containing a desiccant. The dielectric constant (Dk, 10 GHz) and dielectric loss tangent (Df, 10 GHz) of the dried products at a frequency of 10 GHz were then measured using a split cylinder resonator (CR-710 (trade name), 10 GHz, manufactured by EM Lab Co., Ltd.). The measurements of the dielectric constant (Dk) and dielectric loss tangent (Df) were carried out in an environment of 23±1°C and 50±5%RH.

[0334] (3) Coefficient of thermal expansion (CTE) In accordance with JIS-K7197-2012 (Testing method for linear expansion coefficient by thermomechanical analysis of plastics), the thermal expansion coefficient of the cured materials obtained in the examples and comparative examples was measured using a dynamic viscoelasticity measuring device (TMA-60 (product name) manufactured by Shimadzu Corporation) under a nitrogen atmosphere with a starting temperature of 30°C, an ending temperature of 380°C, a heating rate of 3°C / min, and a compressive force of 0.5 N. The thermal expansion per degree Celsius from 60°C to 120°C obtained in this test was taken as CTE (ppm / °C).

[0335] (4) Water absorption rate Approximately 4 g of the cured product obtained in each of the Examples and Comparative Examples was stored for 5 hours at 121°C in a water vapor atmosphere of 2 atm (humidity: 100%). The mass of the cured product was measured before and after storage, and the water absorption (%) was calculated using the following formula (24). Water absorption (%) = ((mass of cured product after storage) - (mass of cured product before storage)) / (mass of cured product before storage) × 100 (24)

[0336] [Table 1] [Industrial Applicability]

[0337] According to this embodiment, it is possible to provide a cyanate ester compound, a resin composition, a cured product, a prepreg, an encapsulating material, a fiber-reinforced composite material, and an adhesive that have a low dielectric constant and a low dielectric loss tangent, excellent water absorption, a low thermal expansion coefficient, and a high glass transition temperature. Therefore, the cyanate ester compound, the resin composition, the cured product, the prepreg, the encapsulating material, the fiber-reinforced composite material, and the adhesive of this embodiment are suitable for semiconductor-related applications.

Claims

1. A cyanate ester compound having a structure represented by the following formula (1), and having a number average molecular weight (Mn) of 850 or more and 3,000 or less in terms of standard polystyrene as measured by gel permeation chromatography: 【Chemistry 1】 (In formula (1), Tx is a group containing a structural unit represented by formula (a) in formula (2) below, and optionally one or more structural units selected from the group consisting of structural units represented by formula (b) and formula (c) in formula (2) below, Ar 1 each independently represents an aromatic ring, Ra and Rb each independently represent a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, an alkenyl group having from 2 to 6 carbon atoms, an aryl group having from 6 to 12 carbon atoms, or an alkoxy group having from 1 to 4 carbon atoms; a is Ar 1 each independently represents an integer of 1 to 3, b is Ar 1 each independently represents the number of bonds of Ra to Ar 1 represents the number obtained by subtracting (a+1) from the substitutable base of Each c is independently an integer of 0 to 4. 【Chemistry 2】 (In formula (2), n, o, and p are the average number of repetitions, n represents a number of 3.0 or more and 15.0 or less, o and p each independently represent a number of 0 or more and 15.0 or less, n, o, and p satisfy 3.0≦n+o+p≦15.0, each Rb independently represents a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, an alkenyl group having from 2 to 6 carbon atoms, an aryl group having from 6 to 12 carbon atoms, or an alkoxy group having from 1 to 4 carbon atoms; c's each independently represent an integer of 0 to 4, "*" indicates a binding site, The structural units represented by formulas (a), (b), and (c) are bonded to structural units represented by formulas (a), (b), and (c), or other groups or carbon atoms, respectively, at "*", and each structural unit may be bonded in blocks or randomly.

2. The cyanate ester compound according to claim 1, which is a compound represented by the following formula (3): 【Transformation 3】 (In formula (3), n is the average number of repetitions, and is a number of 3.0 or more and 15.0 or less).

3. A resin composition comprising the cyanate ester compound according to claim 1.

4. The resin composition according to claim 3, further comprising at least one selected from the group consisting of cyanate ester compounds other than the cyanate ester compound and prepolymers thereof, phenolic resins, epoxy resins, and maleimide compounds.

5. The resin composition according to claim 4, wherein the cyanate ester compound other than the cyanate ester compound is a compound represented by the following formula (4) or a compound represented by the following formula (5): 【Chemistry 4】 (In formula (4), Ar 2 each independently represents an aromatic ring, each Rc independently represents a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, an alkenyl group having from 2 to 6 carbon atoms, an aryl group having from 6 to 12 carbon atoms, or an alkoxy group having from 1 to 4 carbon atoms; d is Ar 2 each independently represents an integer of 1 to 3, e is Ar 2 each independently represents the number of bonds of Rc to Ar 2 represents the number obtained by subtracting (d+2) from the number of substitutable bases of f is an integer of 1 to 50, Each X independently represents a single bond, a divalent organic group having from 1 to 50 carbon atoms in which a hydrogen atom may be substituted with a heteroatom, a divalent organic group having from 1 to 10 nitrogen atoms, a carbonyl group, a carboxy group, a carbonyl dioxide group, a sulfonyl group, a divalent sulfur atom, or a divalent oxygen atom. 【Transformation 5】 (In formula (5), Ar 3 indicates an aromatic ring, Each Rd independently represents a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, an alkenyl group having from 2 to 6 carbon atoms, an aryl group having from 6 to 12 carbon atoms, or an alkoxy group having from 1 to 4 carbon atoms; h is Ar 3 represents the number of cyanate groups bonded to the i is Ar 3 indicates the number of bonds of Rd to Ar 3 This represents the number obtained by subtracting (h+2) from the number of substitutable bases.

6. A cured product obtained by curing the resin composition according to any one of claims 3 to 5.

7. A substrate; The resin composition according to any one of claims 3 to 5, which is impregnated into or applied to the substrate; Prepreg.

8. An encapsulating material comprising the resin composition according to any one of claims 3 to 5.

9. A fiber-reinforced composite material comprising the resin composition according to any one of claims 3 to 5 and reinforcing fibers.

10. An adhesive comprising the resin composition according to any one of claims 3 to 5.

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