Active ester resin, resin composition, cured product and use thereof, and phenolic hydroxyl group-containing resin

Abstract

An object of the present invention is to provide an active ester resin that gives a cured product having a high relative dielectric constant and a low dielectric loss tangent, a resin composition containing the active ester resin, a cured product obtained by curing the resin composition, and a high-frequency device.SOLUTION: The active ester resin is obtained by reacting a phenolic hydroxyl group-containing resin (A) with an aromatic (poly) carboxylic acid or its acid halide (B), wherein the phenolic hydroxyl group-containing resin (A) uses a phenolic hydroxyl group-containing compound (a1) and a maleimide group-containing compound (a2) as essential reaction raw materials. Further, a resin composition containing the active ester resin and a cured product obtained by curing the resin composition are used.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an active ester resin, a resin composition containing the active ester resin, and a cured product obtained by curing the resin composition. [Background technology]

[0002] In recent years, the amount of information handled has increased and data processing speeds have accelerated due to the advancement of network-based services and the high performance and functionality of information terminal devices, sensors, etc. Since the amount of information that can be transmitted increases as the frequency of radio waves increases, the use of high-frequency bands of several tens of GHz or more is being considered, and components such as circuit boards and antennas used in compatible devices require materials with low dielectric loss that can handle high frequency bands.

[0003] On the other hand, it is known that the wavelength of radio waves in a dielectric material shortens in proportion to the reciprocal of the square root of the dielectric constant. Therefore, the higher the dielectric constant of a material, the more advantageous it is for miniaturizing components, and therefore resin materials with high dielectric constants are required for applications such as antennas and high-frequency phase shifters.

[0004] Epoxy resin compositions containing an epoxy resin and a curing agent exhibit high heat resistance and insulating properties when cured, and are therefore widely used in electronic components such as semiconductors and circuit boards. Active ester resins having an ester structure in the molecule have been reported as curing agents (see, for example, Patent Document 1). In particular, in order to achieve both a high dielectric constant and a low dielectric loss tangent, it has been reported that a specific inorganic filler is used in combination with a curing agent containing an epoxy resin and an active ester compound (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-235165 [Patent Document 2] Japanese Patent Publication No. 2022-093228 Summary of the Invention [Problem to be solved by the invention]

[0006] As disclosed in Patent Document 1, it has been possible to obtain a cured product with a low dielectric loss tangent by using an active ester compound as a curing agent. However, improving the dielectric constant has been limited to a method of using a specific inorganic filler in combination, as in Patent Document 2, making it difficult to expand into applications that do not use fillers and difficult to obtain the material. Therefore, there is a need for an active ester resin that can achieve both a low dielectric loss tangent and a high dielectric constant. Therefore, the problem to be solved by the present invention is to provide an active ester resin having a high dielectric constant and a low dielectric loss tangent in the cured product, a resin composition containing the active ester resin, a cured product obtained by curing the resin composition, a high-frequency device, a printed wiring board, a build-up film, and a semiconductor encapsulating material. [Means for solving the problem]

[0007] The present inventors have conducted extensive research to solve the above-mentioned problems, and as a result have developed an activated ester resin having a specific structure. Specifically, the present invention provides an activated ester resin obtained by reacting a phenolic hydroxyl group-containing resin (A) with an aromatic (poly)carboxylic acid or its acid halide (B), wherein the phenolic hydroxyl group-containing resin (A) contains a phenolic hydroxyl group-containing compound (a1) and a maleimide group-containing compound (a2) as essential reaction raw materials, and also provides a resin composition containing the activated ester resin and a cured product obtained by curing the resin composition. [Effects of the Invention]

[0008] The active ester resin of the present invention, when cured, has a high relative dielectric constant and a low dielectric loss tangent, and is therefore useful as a resin composition material for high-frequency devices, miniaturized antenna materials, printed wiring boards, build-up films, semiconductor encapsulation materials, and the like. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a GPC chart of a toluene / cyclohexanone solution of the active ester resin (I-1) described in Example 1. [Figure 2] 1 is a GPC chart of a toluene solution of the phenolic hydroxyl group-containing resin (s-2) described in Example 2. [Figure 3] 1 is a GPC chart of a toluene / cyclohexanone solution of the active ester resin (I-2) described in Example 2. [Figure 4] 1 is a GPC chart of a toluene solution of the phenolic hydroxyl group-containing resin (s-3) described in Example 3. [Figure 5] 1 is a GPC chart of a toluene / cyclohexanone solution of the active ester resin (I-3) described in Example 3. [Figure 6] 1 is a GPC chart of the phenolic hydroxyl group-containing resin (s-4) described in Example 4. [Figure 7] 1H NMR chart of the phenolic hydroxyl group-containing resin (s-4) described in Example 4. [Figure 8] 13C NMR chart of the phenolic hydroxyl group-containing resin (s-4) described in Example 4. [Figure 9] FD-MS chart of the phenolic hydroxyl group-containing resin (s-4) described in Example 4. [Figure 10] 1 is a GPC chart of the phenolic hydroxyl group-containing resin (s-6) described in Example 6. [Figure 11] 1 is a GPC chart of the phenolic hydroxyl group-containing resin (s-7) described in Example 7. [Figure 12] 1 is a GPC chart of the phenolic hydroxyl group-containing resin (s-8) described in Example 8. DETAILED DESCRIPTION OF THE INVENTION

[0010] One embodiment of the present invention is an active ester resin obtained by reacting a phenolic hydroxyl group-containing resin (A) with an aromatic (poly)carboxylic acid or an acid halide thereof (B), wherein the phenolic hydroxyl group-containing resin (A) contains a phenolic hydroxyl group-containing compound (a1) and a maleimide group-containing compound (a2) as essential reaction raw materials.

[0011] In the active ester resin, from the viewpoint of compatibility with other components and solubility in a solvent when used as a resin composition, the phenolic hydroxyl group-containing resin (A) is preferably represented by the following general formula (S):

[0012] [ka] [In the formula, X 1 , X 2 and X 3 are each independently represented by the following formula (x-1) or formula (x-2):

[0013] [ka] (where * represents A 1 , A 2 or A 3 represents the bonding position with A 4 When a plurality of m are present, each independently represents a hydrocarbon ring or heterocycle having 3 to 16 carbon atoms which may have a substituent, m4 is 1 or more, and A 4 represents an integer equal to or less than the number of substitutable ring-constituting atoms in the ring represented by In the general formula (S), X represents a group represented by 1 , X 2 and X 3 At least one of the groups represented by formula (x-1) is A 1 , A 2 and A 3 When a plurality of groups are present, each group independently represents a hydrocarbon ring or heterocycle having 3 to 16 carbon atoms which may have a substituent; Z 1 and Z 2 When a plurality of groups are present, each group independently represents a single bond or a divalent linking group, m1, m2, and m3 each independently represent an integer of 0 to 10, provided that m1+m2+m3 is 1 or greater. It is preferable that the formula be represented by the following formula:

[0014] From the viewpoint of ease of synthesis and availability of raw materials, the phenolic hydroxyl group-containing resin (A) is represented by the following general formula (S1):

[0015] [ka] [In the formula, X 11 , X 21 and X 31 are each independently represented by the following formula (x-11) or formula (x-21):

[0016] [ka] (where * represents A 11 , A 21 or A 31 represents the bonding position with A 41 When a plurality of X's are present, each independently represents a benzene ring or a naphthalene ring which may have a substituent. 11 , X 21 and X 31 At least one of the groups represented by formula (x-11) is a group represented by formula (x-11). A 11 , A 21 and A 31 When a plurality of rings are present, each independently represents an optionally substituted benzene ring or naphthalene ring, Z 11 and Z 21when there are a plurality of, each independently represents a group selected from a single bond, -CH2-, -CH(CH3)-, -C(CH3)2-, -O-, -CH(Ph)-, -C(Ph)2-, -CF2-, -C(CF3)2-, -S-, -SO-, -SO2-, -COO-, -OCO-, -CHO- and -OCH2-; m11, m21, and m31 each independently represent an integer of 0 to 10, provided that m11 + m21 + m31 represents 1 or more. and the phenolic hydroxyl group-containing resin (A) is more preferably represented by the following general formula (S11):

[0017] [ka] [In the formula, X 111 and X 211 are each independently the following formula (x-111) or formula (x-211)

[0018] [ka] (where * represents A 111 or A 211 represents the bonding position with X. 111 and X 211 At least one of the groups represented by formula (x-111) is a group represented by formula (x-111), A 111 and A 211 When a plurality of groups are present, each group independently represents a benzene ring which may be unsubstituted or substituted with a linear or branched alkyl group having 1 to 5 carbon atoms, Z 111 When a plurality of -R 1 -R 2 -R 3 -R 4 -R 5 -R 6 -R 7 -R 8 -R 9 -R 10 -R 11 -R 12 -R 13 -R 14 -R 15 -R 16 -R 17 -R 18 -R 19 -R 20 -R 21 -R 22 -R 23 -R 24 -R 25 -R 26 -R 27 -R 28 -R 29 -R 30 -R 31 -R 32 -R 33 -R 34 -R 35 -R 36 -R 37 -R 40 -R 41 -R 42 -R 43 -R 44 -R 45 -R 46 -R 47 -R 48 -R 50 -R 51 -R 52 -R 53 -R 54 -R 55 m111 represents 0, 1 or 2. It is more preferable that the phenolic hydroxyl group-containing resin (A) is represented by the following formula (S111):

[0019] [ka] [In the ceremony, A 1111 and A 2111 each independently represents a benzene ring which may be unsubstituted or substituted with a linear alkyl group having 1 to 3 carbon atoms; Z 1111 represents a group selected from -CH2-, -CH(CH3)-, and -C(CH3)2-. It is particularly preferred that the formula be represented by the following formula:

[0020] X present in the general formula (S1) 11 , X 21 and X 31 At least one of them represents a group represented by formula (x-11). When the stability over time of the active ester resin of the present invention is particularly important, in the phenolic hydroxyl group-containing resin (A), among the groups represented by formula (x-11) and the groups represented by formula (x-21), the proportion of groups represented by formula (x-21) is preferably 80 mol % or less, more preferably 50 mol % or less, even more preferably 30 mol % or less, even more preferably 10 mol % or less, and particularly preferably 1 mol % or less.

[0021] In this specification, a group that is not fixed to any atom constituting a ring means that it can be bonded to any of the substitutable ring-constituting atoms in the ring. For example, in the structural formula represented by the above formula (S111), the bond extending from the carbon atom on the imide group to the naphthalene ring can be bonded to any of the seven substitutable ring-constituting carbon atoms in the naphthalene ring.

[0022] In the active ester resin of the present invention, the aromatic (poly)carboxylic acid or its acid halide (B) is not particularly limited in structure, and may be any aromatic compound capable of reacting with the phenolic hydroxyl group of the phenolic hydroxyl group-containing resin (A) to form an ester bond. Specific examples include benzenedicarboxylic acids such as isophthalic acid and terephthalic acid, benzenetricarboxylic acids such as trimellitic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-2,3-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, and naphthalene-2,7-dicarboxylic acid, acid halides thereof, and compounds in which the aromatic nucleus is substituted with an aliphatic hydrocarbon group, an alkoxy group, a halogen atom, or the like. Examples of acid halides include acid chlorides, acid bromides, acid fluorides, and acid iodides. These may be used alone or in combination of two or more. Among these, benzenedicarboxylic acids such as isophthalic acid and terephthalic acid or acid halides thereof are preferred because they give active ester resins with high reactivity and excellent curability.

[0023] In the active ester resin of the present invention, the phenolic hydroxyl group-containing resin (A) contains a phenolic hydroxyl group-containing compound (a1) and a maleimide group-containing compound (a2) as essential reaction raw materials. From the viewpoints of reactivity with the maleimide group-containing compound (a2) and solubility in solvents, the phenolic hydroxyl group-containing compound (a1) is preferably a compound having one phenolic hydroxyl group or a compound having two phenolic hydroxyl groups.

[0024] Specific examples of the phenolic hydroxyl group-containing compound (a1) include compounds having one phenolic hydroxyl group, such as aromatic monohydroxy compounds, such as phenol, o-cresol, m-cresol, p-cresol, 3,5-xylenol, 2,6-xylenol, o-phenylphenol, p-phenylphenol, 2-benzylphenol, 4-benzylphenol, 4-(α-cumyl)phenol, 1-naphthol, and 2-naphthol.

[0025] Specific examples of the phenolic hydroxyl group-containing compound (a1) having two or more phenolic hydroxyl groups include aromatic dihydroxy compounds such as resorcinol, hydroquinone, trimethylhydroquinone, bisphenol A, bisphenol F, bisphenol S, 1,6-naphthalenediol, 2,6-naphthalenediol, 2,3-naphthalenediol, 2,7-naphthalenediol, 1,4-naphthalenediol, 3,3',5,5'-tetramethylbisphenol F, and 3,3',5,5'-tetramethylbiphenol; aromatic trihydroxy compounds such as 1,3,5-trihydroxybenzene, 1,2,3-trihydroxybenzene, 2,4,4'-trihydroxybenzophenone, and triphenolmethane; and 2,2',4,4'-tetrahydroxybenzophenone and 1,1,2,2-tetraphenolethane.

[0026] From the viewpoints of reactivity with the maleimide group-containing compound (a2) and the heat resistance of a cured product using the resulting active ester resin, the phenolic hydroxyl group-containing compound (a1) is preferably a compound having one phenolic hydroxyl group, more preferably a compound having a naphthalene ring, and particularly preferably 1-naphthol.

[0027] Furthermore, from the viewpoints of reactivity with the phenolic hydroxyl group-containing compound (a1), solubility in solvents, and the heat resistance and availability of a cured product using the resulting active ester resin, the maleimide group-containing compound (a2) is preferably a compound having 1 to 5 maleimide groups in the molecule, more preferably a compound having 2 to 4 maleimide groups in the molecule, even more preferably a compound having 2 or 3 maleimide groups in the molecule, and particularly preferably a bismaleimide compound having 2 maleimide groups in the molecule.

[0028] Specific examples of the maleimide group-containing compound (a2) include compounds represented by the following formulae (a2-1) to (a2-5):

[0029] [ka]

[0030] (wherein q represents an integer of 0 to 40).

[0031] In the active ester resin of the present invention, the phenolic hydroxyl group-containing resin (A) may be prepared using a single phenolic hydroxyl group-containing compound (a1) and a single maleimide group-containing compound (a2) as reaction raw materials, or may be composed of a plurality of either or both of the phenolic hydroxyl group-containing compound (a1) and the maleimide group-containing compound (a2).

[0032] In the active ester resin of the present invention, the reaction raw materials, the phenolic hydroxyl group-containing compound (a1) and the maleimide group-containing compound (a2), may be used in any ratio. From the viewpoints of the solvent solubility of the resulting active ester resin, the heat resistance of the cured product, and compatibility with other resins, the ratio of the maleimide group of the maleimide group-containing compound (a2) to 1 equivalent of the phenolic hydroxyl group-containing compound (a1) is preferably 0.01 to 10 equivalents, more preferably 0.05 to 5 equivalents, even more preferably 0.1 to 1 equivalent, and particularly preferably 0.2 to 0.5 equivalents.

[0033] The active ester resin of the present invention exhibits a low dielectric loss tangent for a cured product obtained using the same, but from the viewpoint of further controlling physical properties such as improving the heat resistance, mechanical strength, and adhesion to copper foil, etc., of the target cured product, the active ester resin may be a resin obtained by reacting the phenolic hydroxyl group-containing resin (A) with an aromatic (poly)carboxylic acid or an acid halide thereof (B) in combination with a hydroxyl group-containing compound (C) different from the phenolic hydroxyl group-containing resin (A). In this case, the specific structure of the hydroxyl group-containing compound (C) is not particularly limited, and any compound may be used as long as it is a compound that can impart the desired physical properties.

[0034] Specific examples of the hydroxyl group-containing compound (C) include compounds having one phenolic hydroxyl group, such as aromatic monohydroxy compounds, such as phenol, o-cresol, m-cresol, p-cresol, 3,5-xylenol, 2,6-xylenol, o-phenylphenol, p-phenylphenol, 2-benzylphenol, 4-benzylphenol, 4-(α-cumyl)phenol, α-naphthol, and β-naphthol. From the viewpoint of low dielectric loss tangent of the resulting cured product, α-naphthol, β-naphthol, o-phenylphenol, or p-phenylphenol is preferred.

[0035] Specific examples of the hydroxyl group-containing compound (C) include compounds having two or more phenolic hydroxyl groups, such as aromatic dihydroxy compounds, such as resorcinol, hydroquinone, trimethylhydroquinone, bisphenol A, bisphenol F, bisphenol S, 1,6-naphthalenediol, 2,6-naphthalenediol, 2,3-naphthalenediol, 2,7-naphthalenediol, 1,4-naphthalenediol, 3,3',5,5'-tetramethylbisphenol F, and 3,3',5,5'-tetramethylbiphenol; aromatic trihydroxy compounds, such as 1,3,5-trihydroxybenzene, 1,2,3-trihydroxybenzene, 2,4,4'-trihydroxybenzophenone, and triphenolmethane; and 2,2',4,4'-tetrahydroxybenzophenone and 1,1,2,2-tetraphenolethane. From the viewpoint of low dielectric loss tangent of the resulting cured product, bisphenol A, bisphenol F, bisphenol S, 3,3',5,5'-tetramethylbisphenol F, or 3,3',5,5'-tetramethylbiphenol is preferred.

[0036] Specific examples of the active ester resin of the present invention include those represented by the following formulas (E-1) to (E-10):

[0037] [ka]

[0038] [ka]

[0039] [ka]

[0040] (In the formula, p, q, and r each independently represent an integer of 0 to 40.) Examples of the resin include those represented by the following formula:

[0041] The active ester resin of the present invention can be produced, for example, by the following method. (Production Method 1) Production of an activated ester resin represented by the following formula (M5)

[0042] [ka]

[0043] (In the formula, A 1111 and A 2111 each independently represents a benzene ring which may be unsubstituted or substituted with a linear alkyl group having 1 to 3 carbon atoms; Z 1111 represents a group selected from -CH2-, -CH(CH3)-, and -C(CH3)2-, and p represents an integer of 0 to 40.

[0044] For example, a phenolic hydroxyl group-containing compound represented by formula (M1) can be reacted with a maleimide group-containing compound represented by formula (M2) in the presence of an acid to obtain a phenolic hydroxyl group-containing resin represented by formula (M3). Examples of acids include inorganic acids such as phosphoric acid, hydrochloric acid, and sulfuric acid; organic acids such as oxalic acid, benzenesulfonic acid, p-toluenesulfonic acid, and methanesulfonic acid; Lewis acids such as aluminum chloride, boron trifluoride, zinc chloride, and iron chloride; and solid acids such as activated clay. The amount of acid used is preferably 0.001 to 10 parts by weight, more preferably 0.01 to 5 parts by weight, and particularly preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the theoretical amount of the resulting phenolic hydroxyl group-containing resin. When a solid acid is used, the amount is preferably 0.01 parts by mass or more and 100 parts by mass or less, more preferably 0.1 parts by mass or more and 50 parts by mass or less, and particularly preferably 1 part by mass or more and 20 parts by mass or less, where the theoretical amount of the resulting phenolic hydroxyl group-containing resin is 100 parts by mass.

[0045] The reaction of the phenolic hydroxyl group-containing compound represented by formula (M1) with the maleimide group-containing compound represented by formula (M2) may be carried out in a solvent or without a solvent. Examples of the solvent include ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, benzene, toluene, xylene, chlorobenzene, cyclohexane, and dichloromethane. From the viewpoints of reactivity and ease of post-treatment, toluene or xylene is preferred.

[0046] The reaction may be carried out by mixing a phenolic hydroxyl group-containing compound represented by formula (M1), a maleimide group-containing compound represented by formula (M2), and a reaction solvent followed by the addition of an acid. Alternatively, the phenolic hydroxyl group-containing compound represented by formula (M1), an acid, and a reaction solvent may be mixed followed by the addition of a maleimide group-containing compound represented by formula (M2). The reaction temperature is not particularly limited, but is preferably between -30°C and 300°C, more preferably between 0°C and 250°C, and particularly preferably between 100°C and 200°C, from the viewpoints of the viscosity and solubility in the solvent of the resulting phenolic hydroxyl group-containing resin represented by formula (M3). After the reaction, the acid is removed by neutralization, washing with water, filtration, or decomposition, and the desired phenolic hydroxyl group-containing resin can be isolated by common procedures such as extraction and distillation. Neutralization and washing can be carried out according to conventional methods. For example, basic substances such as sodium hydroxide, potassium hydroxide, sodium carbonate, and ammonia can be used as neutralizing agents.

[0047] Next, the phenolic hydroxyl group-containing resin represented by formula (M3) is reacted with a compound represented by formula (M4) in the presence of a base, such as sodium hydroxide, potassium hydroxide, triethylamine, or pyridine, to obtain an activated ester resin represented by formula (M5).

[0048] The reaction can be carried out by mixing the phenolic hydroxyl group-containing resin represented by formula (M3) and the compound represented by formula (M4) in the presence of an organic solvent, and then continuously or intermittently adding dropwise a base or an aqueous solution thereof to the mixture. The concentration of the aqueous base solution is preferably in the range of 3.0 to 30% by mass. Examples of organic solvents include toluene, dichloromethane, and chloroform. After the reaction, the base is neutralized and the mixture is washed with water to obtain the activated ester resin represented by formula (M5).

[0049] The activated ester resin of the present invention obtained in this manner preferably has a softening point of 70°C or more and 200°C or less, since this will increase its solubility in organic solvents and make it a suitable material for varnishes for circuit boards, as well as providing an excellent balance between heat resistance, flame retardancy, dielectric properties, and thermal decomposition resistance.

[0050] When the total number of aromatic ester groups in the molecule is defined as the number of functional groups of the active ester, the functional group equivalent of the active ester resin of the present invention is preferably from 50 g / equivalent to 1,000 g / equivalent, more preferably from 100 g / equivalent to 500 g / equivalent, and particularly preferably from 120 g / equivalent to 400 g / equivalent, from the viewpoints of curability and dielectric properties.

[0051] The number average molecular weight (Mn) of the active ester resin of the present invention is preferably 300 or more and 5000 or less, more preferably 400 or more and 4000 or less, and particularly preferably 500 or more and 3000 or less, from the viewpoints of curability, dielectric properties, and compatibility with other components.

[0052] <Resin composition> The active ester resin of the present invention functions as a curing agent for epoxy compounds and other compounds. The active ester resin of the present invention is useful because it can prevent or suppress the generation of hydroxyl groups, particularly when reacted with epoxy resins, and therefore can give a cured product with an excellent low dielectric loss tangent.

[0053] Specific examples of epoxy resins that can be used in combination with the active ester resin of the present invention include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol E type epoxy resins, bisphenol S type epoxy resins, bisphenol sulfide type epoxy resins, biphenyl type epoxy resins, tetramethylbiphenyl type epoxy resins, polyhydroxynaphthalene type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, bisphenol A novolac type epoxy resins, triphenylmethane type epoxy resins, tetraphenylethane type epoxy resins, dicyclopentadiene-phenol addition reaction type epoxy resins, phenol aralkyl type epoxy resins, biphenyl aralkyl type epoxy resins, biphenyl novolac type epoxy resins, naphthol novolac type epoxy resins, and the like. Examples of epoxy resins include phenolic resins, naphthol aralkyl epoxy resins, naphthol-phenol co-condensed novolac epoxy resins, naphthol-cresol co-condensed novolac epoxy resins, biphenyl-modified phenolic epoxy resins (polyphenolic epoxy resins in which a phenol skeleton and a biphenyl skeleton are linked by a bismethylene group), biphenyl-modified naphthol epoxy resins (polyhydric naphthol epoxy resins in which a naphthol skeleton and a biphenyl skeleton are linked by a bismethylene group), alkoxy group-containing aromatic ring-modified novolac epoxy resins (resins in which a glycidyl group-containing aromatic ring and an alkoxy group-containing aromatic ring are linked by formaldehyde), phenylene ether epoxy resins, naphthylene ether epoxy resins, aromatic hydrocarbon formaldehyde resin-modified phenolic resin-type epoxy resins, and xanthene epoxy resins. These may be used alone or in combination of two or more.

[0054] Among the above-mentioned epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, bisphenol A novolac type epoxy resins, polyhydroxynaphthalene type epoxy resins, triphenylmethane type epoxy resins, tetraphenylethane type epoxy resins, biphenyl novolac type epoxy resins, naphthol novolac type epoxy resins, naphthol-phenol co-condensed novolac type epoxy resins, naphthol-cresol co-condensed novolac type epoxy resins, phenylene ether type epoxy resins, naphthylene ether type epoxy resins, and xanthene type epoxy resins are preferred because they give cured products with excellent low dielectric tangents, and dicyclopentadiene-phenol addition reaction type epoxy resins, naphthol novolac type epoxy resins, and phenol aralkyl type epoxy resins are also preferred. Particularly preferred are epoxy resins, biphenyl aralkyl type epoxy resins, naphthol aralkyl type epoxy resins, naphthol-phenol co-condensed novolac type epoxy resins, naphthol-cresol co-condensed novolac type epoxy resins, biphenyl-modified phenol type epoxy resins (polyhydric phenol type epoxy resins in which a phenol skeleton and a biphenyl skeleton are linked via a bismethylene group), biphenyl-modified naphthol type epoxy resins (polyhydric naphthol type epoxy resins in which a naphthol skeleton and a biphenyl skeleton are linked via a bismethylene group), alkoxy group-containing aromatic ring-modified novolac type epoxy resins (resins in which a glycidyl group-containing aromatic ring and an alkoxy group-containing aromatic ring are linked via formaldehyde), aromatic hydrocarbon formaldehyde resin-modified phenol resin-type epoxy resins, and naphthylene ether type epoxy resins.

[0055] Specific examples of commercially available epoxy resins that can be used in combination with the activated ester resin of the present invention include EPICLON (registered trademark) 840, EPICLON 840-S, EPICLON 850, EPICLON 850-S, EPICLON EXA-850CRP, EPICLON EXA-830LVP, EPICLON HP-7200L, EPICLON HP-7200, EPICLON HP-7200H, EPICLON HP-7200HHH, EPICLON HP-7200H-75M, EPICLON HP-4032SS, EPICLON HP-4032D, EPICLON HP-EXA-4850-150, EPICLON HP-EXA-4850-1000, EPICLON HP-7250, EPICLON HP-4700, EPICLON HP-4710, EPICLON HP-4770, EPICLON HP-5000, EPICLON HP-9900-75M, EPICLON HP-9500, EPICLON HP-6000, EPICLON HP-6000L (all manufactured by DIC Corporation), Epotohto (registered trademark) YD-128, Epotohto YD-128G, Epotohto YD-128S, Epotohto YD-128CA, Epotohto YD-134, Epotohto YD-011, Epotohto YD-012, Epotohto YD-013, Epotohto YDF-170, Epotohto YDF-170N, Epotohto YDF-2001, Epotohto YD-8125, Epotohto YDF-8170C, Epotohto ZX-1059, Epotohto YD-825GS, Epotohto YDF-870GS, Epotohto YDPN-638, Epotohto YDCN-700-7, Epotohto YDCN-700-10, Epotohto YDCN-704, Epotohto YDCN-704A, Epotohto FX-289BEK75, Epotohto FX-1225EK75, Epotohto ST-3000, Epotohto ST-4000D, Epotohto YDC-1312, Epotohto YSLV-70XY, Epotohto YSLV-80XY, EpotohtoYSLV-120TE (all manufactured by Nippon Steel Chemical & Material Co., Ltd.), jER (registered trademark) 825, jER 827, jER 828, jER 834, jER 801N, jER 811, jER 813, jER 816A, jER 819, jER 806, jER 806H, jER 807, jER 4005P, jER 4007P, jER 4010P, jER 152, jER 154, jER 157S70, jER 1031S, jER 1032H60, jER 604, jER 630, jER 871, jER 872, jER 872X75, jER 890, jER YL6810, jER 1750, jER YX7700, jER 8000, jER YX8034, jER YL980, jER YL983U, jER YX7400N, jER YX7105, jER YX7110B80, jER YX7760, jER YX4000, jER YX4000H, jER 4000HS, jER YL6121HA, jER YL6677 (all manufactured by Mitsubishi Chemical Corporation), NC-3100, NC-3000-L, NC-3000, NC-3000-H, NC-3000-FH-75M, NC-2000-L, XD-1000-2L, XD-1000, XD-1000-H, NC-7000-L, NC-7300-L, EPPN-201, RE-305, RE-306, RE-305S, BR-250H, EPPN-501H, EPPN-501HY, EPPN-502H, FAE-2500, GTR-1800, EOCN-102S, EOCN-103S, EOCN-104S, EOCN-1020 (all manufactured by Nippon Kayaku Co., Ltd.), and the like.

[0056] The amounts of the active ester resin and epoxy resin in the resin composition of the present invention are preferably such that the amount of carbonyloxy groups constituting the ester groups in the active ester resin per equivalent of epoxy groups in the resin composition is 0.8 to 1.5 equivalents, in terms of achieving good curability and various physical properties of the cured product. A ratio of 0.9 to 1.3 equivalents is particularly preferred, in terms of being able to reduce the dielectric tangent and improve the heat resistance of the cured product while maintaining excellent flame retardancy.

[0057] <Other hardeners> The resin composition of the present invention may contain, in addition to the active ester resin and epoxy resin described above, other epoxy resin curing agents. Examples of other epoxy resin curing agents include amine-based curing agents, amide-based curing agents, acid anhydride-based curing agents, and phenol-based curing agents. Examples of amine-based curing agents include diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, imidazole, boron trifluoride-amine complex, and guanidine derivatives. Examples of amide-based curing agents include dicyandiamide and polyamide resins synthesized from a linoleic acid dimer and ethylenediamine. Examples of acid anhydride-based curing agents include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride. Examples of phenol-based curing agents include phenol novolac resins, clays, and the like. Examples of such resins include phenolic resins modified with phenolic resins such as phenolic novolac resins, aromatic hydrocarbon formaldehyde resin-modified phenolic resins, dicyclopentadiene phenol adduct resins, phenol aralkyl resins, naphthol aralkyl resins, trimethylolmethane resins, tetraphenylolethane resins, naphthol novolac resins, naphthol-phenol co-condensed novolac resins, naphthol-cresol co-condensed novolac resins, biphenyl-modified phenolic resins (polyhydric phenolic resins in which phenol nuclei are linked via bismethylene groups), biphenyl-modified naphthol resins (polyhydric naphthol resins in which phenol nuclei are linked via bismethylene groups), and aminotriazine-modified phenolic resins (polyhydric phenolic resins in which phenol nuclei are linked via melamine, benzoguanamine, or the like).

[0058] Among these, those containing many aromatic skeletons in the molecular structure are particularly preferred from the viewpoint of flame retardant effect, and specifically, phenol novolac resins, cresol novolac resins, aromatic hydrocarbon formaldehyde resin-modified phenolic resins, phenol aralkyl resins, naphthol aralkyl resins, naphthol novolac resins, naphthol-phenol co-condensed novolac resins, naphthol-cresol co-condensed novolac resins, biphenyl-modified phenolic resins, biphenyl-modified naphthol resins, and aminotriazine-modified phenolic resins are preferred.

[0059] Specific examples of commercially available epoxy resin curing agents that can be used in combination with the active ester resin of the present invention include phenolic curing agents such as PHENOLITE (registered trademark) TD-2131, PHENOLITE TD-2093Y, PHENOLITE TD-2093Y-60M, PHENOLITE TD-2090, PHENOLITE TD-2090-60M, PHENOLITE KA-1160, PHENOLITE KA-1163, PHENOLITE KA-1165, PHENOLITE VH-4150, PHENOLITE VH-4170, PHENOLITE KH-6021, PHENOLITE LF-7911, PHENOLITE LF-6161, PHENOLITE LF-4871, EPICLON HPC-9500-60M, EPICLON HPC-9500P-53M, and PHENOLITE LA-1356, PHENOLITE LA-3018-50P, PHENOLITE LA-7052, PHENOLITE LA-7054, PHENOLITE LA-7751 (all manufactured by DIC Corporation), SK Resin HE100C-10, SK Resin HE100C-15, SK Resin HE100C-30, SK Resin HE200C-07, SK Resin HE200C-10, SK Resin HE510-05, SK Resin HE610C-07, SK Resin HE910-10, SK Resin HE910-20 (all manufactured by Air Water Performance Chemicals Inc.), KAYAHARD (registered trademark) GPH-65, KAYAHARD GPH-103, KAYAHARD KTG-105 (all manufactured by Nippon Kayaku Co., Ltd.), jER Cure (registered trademark) 170, jER Cure 171N (all manufactured by Mitsubishi Chemical Corporation), Milex (registered trademark) XL, Milex RS, Milex RN (all manufactured by Mitsui Fine Chemicals, Inc.), ZX-798P (manufactured by Nippon Steel Chemical & Material Co., Ltd.), and amine-based curing agents include EPICLON B-065 (manufactured by DIC Corporation), KAYAHARD AA (manufactured by Nippon Kayaku Co., Ltd.), jER Cure ST14, jER Cure YN100, jER Cure SA1, jER Cure TO184, jER CureExamples of acid anhydride curing agents include EPICLON B-4500MC-C, EPICLON B-4500-C, EPICLON B-4500MC (all manufactured by DIC Corporation), HN-2200, MHAC-P (all manufactured by Resonac Inc.), KAYAHARD MCD (manufactured by Nippon Kayaku Co., Ltd.), jER Cure YH306, jER Cure YH307 (all manufactured by Mitsubishi Chemical Corporation).

[0060] The other curing agents may be used alone or in combination of two or more.

[0061] The resin composition of the present invention may contain an active ester resin other than the active ester resin of the present invention as a curing agent for epoxy resins. Examples of active ester resins other than the active ester resin of the present invention include EPICLON (registered trademark) HPC-8000-65T, EPICLON HPC-8000L-65MT, EPICLON HPC-8150-62T, EPICLON EXB-8, and EPICLON NE-V-1100-70T (all manufactured by DIC Corporation).

[0062] <Other thermosetting resins> The resin composition of the present invention may be used in combination with other thermosetting resins in addition to the activated ester resin and epoxy resin described above. Examples of other thermosetting resins include maleimide resins, bismaleimide resins, polymaleimide resins, polyphenylene ether resins, polyimide resins, cyanate ester resins, benzoxazine resins, triazine-containing cresol novolac resins, cyanate ester resins, styrene-maleic anhydride resins, allyl group-containing resins such as diallyl bisphenol and triallyl isocyanurate, polyphosphate esters, and phosphate ester-carbonate copolymers. These other resins may be used alone or in combination of two or more.

[0063] <Solvent> The resin composition of the present invention may be prepared without a solvent or may contain a solvent. The solvent has the function of adjusting the viscosity of the resin composition. Examples of solvents include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether solvents such as diethyl ether and tetrahydrofuran; ester solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitols such as cellosolve and butyl carbitol; aromatic hydrocarbons such as toluene, xylene, ethylbenzene, mesitylene, 1,2,3-trimethylbenzene, and 1,2,4-trimethylbenzene; and amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone. These solvents may be used alone or in combination of two or more.

[0064] The amount of the solvent used is preferably 10% by mass or more and 90% by mass or less, and more preferably 20% by mass or more and 80% by mass or less, based on the total mass of the resin composition. A solvent use amount of 10% by mass or more is preferred because of excellent handleability. On the other hand, a solvent use amount of 90% by mass or less is preferred from the viewpoint of economy.

[0065] <Additives> The resin composition of the present invention may contain additives such as a curing accelerator, a flame retardant, and a filler.

[0066] <Curing accelerator> Examples of the curing accelerator include phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, and urea-based curing accelerators.

[0067] Examples of the phosphorus-based curing accelerator include organic phosphine compounds such as triphenylphosphine, tributylphosphine, tripartylphosphine, diphenylcyclohexylphosphine, and tricyclohexylphosphine; organic phosphite compounds such as trimethyl phosphite and triethyl phosphite; and phosphonium salts such as ethyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, butylphosphonium tetraphenylborate, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, triphenylphosphinetriphenylborane, tetraphenylphosphonium thiocyanate, tetraphenylphosphonium dicyanamide, butylphenylphosphonium dicyanamide, and tetrabutylphosphonium decanoate.

[0068] Examples of the amine-based curing accelerator include triethylamine, tributylamine, N,N-dimethylaminopyridine (DMAP), 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo[5.4.0]-undecene (DBU), and 1,5-diazabicyclo[4.3.0]-nonene-5 (DBN).

[0069] Examples of the imidazole-based curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4 ... Examples of such an alkyl acrylate include ethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, and 2-methylimidazoline.

[0070] Examples of the guanidine curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-butylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, and 1-phenylbiguanide.

[0071] Examples of the urea-based curing accelerator include 3-phenyl-1,1-dimethylurea, 3-(4-methylphenyl)-1,1-dimethylurea, chlorophenylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, and 3-(3,4-dichlorophenyl)-1,1-dimethylurea.

[0072] Of the above-mentioned curing accelerators, 2-ethyl-4-methylimidazole and N,N-dimethylaminopyridine (DMAP) are preferably used. The above-mentioned curing accelerators may be used alone or in combination of two or more.

[0073] The amount of the curing accelerator used can be adjusted as appropriate to obtain the desired curability, but is preferably 0.01 to 5 parts by mass, and more preferably 0.1 to 3 parts by mass, relative to 100 parts by mass of the total mixture of the epoxy resin and the active ester resin. An amount of 0.01 parts by mass or more is preferred because it provides excellent curability. On the other hand, an amount of 5 parts by mass or less is preferred because it provides excellent insulation reliability.

[0074] <Flame retardant> The flame retardant is not particularly limited, but examples thereof include inorganic phosphorus-based flame retardants, organic phosphorus-based flame retardants, and halogen-based flame retardants.

[0075] The inorganic phosphorus-based flame retardant is not particularly limited, but examples thereof include red phosphorus, ammonium phosphates such as monoammonium phosphate, diammonium phosphate, triammonium phosphate, and ammonium polyphosphate, and phosphoric amides.

[0076] The organic phosphorus flame retardant is not particularly limited, but examples thereof include methyl acid phosphate, ethyl acid phosphate, isopropyl acid phosphate, dibutyl phosphate, monobutyl phosphate, butoxyethyl acid phosphate, 2-ethylhexyl acid phosphate, bis(2-ethylhexyl) phosphate, monoisodecyl acid phosphate, lauryl acid phosphate, tridecyl acid phosphate, stearyl acid phosphate, Phosphate esters such as isostearyl acid phosphate, oleyl acid phosphate, butyl pyrophosphate, tetracosyl acid phosphate, ethylene glycol acid phosphate, and (2-hydroxyethyl) methacrylate acid phosphate; diphenylphosphines such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and diphenylphosphine oxide; and 10-(2,5-dihydroxyphenyl)-10H-9-oxaphosphate. phosphorus-containing phenols such as 1,4-cyclooctylenephosphinyl-1,4-phenyldiol, 1,5-cyclooctylenephosphinyl-1,4-phenyldiol, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(1,4-dioxynaphthalene)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, diphenylphosphinylhydroquinone, diphenylphosphinyl-1,4-dioxynaphthalene, 1,4-cyclooctylenephosphinyl-1,4-phenyldiol, and 1,5-cyclooctylenephosphinyl-1,4-phenyldiol; Examples of suitable phosphorus compounds include cyclic phosphorus compounds such as 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, and 10-(2,7-dihydroxynaphthyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, and compounds obtained by reacting the phosphoric acid esters, diphenylphosphine, or phosphorus-containing phenols with epoxy resins, aldehyde compounds, or phenol compounds.

[0077] The halogen-based flame retardant is not particularly limited, but examples thereof include brominated polystyrene, bis(pentabromophenyl)ethane, tetrabromobisphenol A bis(dibromopropyl ether), 1,2-bis(tetrabromophthalimide), 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine, and tetrabromophthalic acid.

[0078] The flame retardants may be used alone or in combination of two or more.

[0079] The amount of the flame retardant used is preferably 0.1 to 50 parts by mass, more preferably 1 to 30 parts by mass, per 100 parts by mass of the epoxy resin. When the amount of the flame retardant used is 0.1 parts by mass or more, flame retardancy can be imparted, which is preferable. On the other hand, when the amount of the flame retardant used is 50 parts by mass or less, flame retardancy can be imparted while maintaining dielectric properties, which is preferable.

[0080] <Filler> Examples of fillers include organic fillers and inorganic fillers. Organic fillers have the function of improving elongation and mechanical strength, while inorganic fillers have the function of reducing the thermal expansion coefficient and imparting flame retardancy.

[0081] The organic filler is not particularly limited, but examples thereof include polyamide particles.

[0082] The inorganic filler is not particularly limited, but may include silica, alumina, aluminosilicate, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, zirconium tungstate phosphate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, carbon black, etc. Among these, silica is preferred. In this case, examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. In particular, when importance is placed on a high relative dielectric constant and a low dielectric loss tangent when a cured product is produced, silica, alumina, aluminosilicate, boron nitride, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, and barium titanate are preferred, and silica, boron nitride, strontium titanate, calcium titanate, and titanium oxide are more preferred.

[0083] The filler may be surface-treated as needed. Examples of surface-treating agents include, but are not limited to, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, organosilazane compounds, and titanate coupling agents. Specific examples of surface-treating agents include 3-glycidoxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, and hexamethyldisilazane.

[0084] The fillers may be used alone or in combination of two or more.

[0085] The amount of the filler used is preferably 0.5 parts by mass or more and 95 parts by mass or less, and more preferably 5 parts by mass or more and 80 parts by mass or less, relative to 100 parts by mass of the resin composition of the present invention. A filler amount of 0.5 parts by mass or more is preferred because the effect of the filler can be fully imparted. On the other hand, the amount of the filler used is preferably 95 parts by mass or less so as not to impair moldability due to an increase in the viscosity of the compound.

[0086] <Cured product> The present invention relates to a cured product obtained by curing the resin composition. Since the active ester resin itself has a low dielectric loss tangent, a cured product obtained from the resin composition containing the active ester resin also has a low dielectric loss tangent, which is a preferred embodiment.

[0087] In a method for producing a cured product obtained by curing the resin composition of the present invention, for example, the heating temperature during heat curing is not particularly limited, but is preferably 100°C or higher and 300°C or lower, and the heating time is preferably 1 hour or higher and 24 hours or lower.

[0088] <Applications of resin composition> Applications for the resin composition of the present invention include printed wiring board materials, resin compositions for flexible wiring boards, interlayer insulating materials for buildup boards, insulating materials for circuit boards such as adhesive films for buildup, resin casting materials, adhesives, semiconductor encapsulation materials, semiconductor devices, prepregs, conductive pastes, buildup films, buildup boards, fiber-reinforced composite materials, and molded articles obtained by curing the above-mentioned composite materials. Among these various applications, the resin composition of the present invention can be used as an insulating material for so-called electronic component-embedded substrates in which passive components such as capacitors and active components such as IC chips are embedded within the substrate. Furthermore, among the above-mentioned applications, the resin composition of the present invention is preferably used for semiconductor encapsulation materials, semiconductor devices, prepregs, circuit boards, flexible wiring boards, buildup films, multilayer printed wiring boards, buildup boards, fiber-reinforced composite materials, and molded articles obtained by curing the above-mentioned composite materials, since the cured products have low dielectric properties. The resin composition of the present invention can also be used as an encapsulating material for high-frequency devices, which encapsulates electronic components obtained by mounting various electronic components on a substrate such as glass, a silicon wafer, a wiring board, etc. Hereinafter, a method for producing the semiconductor encapsulating material or the like from the resin composition will be described.

[0089] "Semiconductor encapsulation materials" The present invention relates to a semiconductor encapsulating material containing the resin composition. A method for obtaining a semiconductor encapsulating material from the resin composition of the present invention includes thoroughly melt-mixing the resin composition of the present invention, a curing accelerator, and compounding ingredients such as an inorganic filler, using an extruder, kneader, roll, or the like, as needed, until the mixture is homogeneous. In this process, fused silica is typically used as the inorganic filler. However, when used as a high-thermal-conductivity semiconductor encapsulating material for power transistors and power ICs, crystalline silica, alumina, silicon nitride, or the like, which have higher thermal conductivity than fused silica, may be used. The inorganic filler is preferably used in an amount of 30 to 95 parts by weight per 100 parts by weight of the resin composition. To improve flame retardancy, moisture resistance, and solder crack resistance and to reduce the linear expansion coefficient, an amount of 70 parts by weight or more is more preferred, and an amount of 80 parts by weight or more is even more preferred.

[0090] "Semiconductor device" The present invention relates to a semiconductor device comprising a cured product obtained by heat-curing the semiconductor encapsulating material. A method for obtaining a semiconductor device from the resin composition of the present invention includes molding the semiconductor encapsulating material using a casting machine, a transfer molding machine, an injection molding machine, or the like, and then heating the molded product at 50°C to 200°C for 2 hours to 10 hours.

[0091] "Prepreg" The present invention relates to a prepreg having a reinforcing substrate and a semi-cured product of the resin composition impregnated into the reinforcing substrate. A method for obtaining a prepreg from the resin composition of the present invention includes impregnating a reinforcing substrate (such as paper, glass cloth, glass nonwoven fabric, aramid paper, aramid cloth, glass mat, or glass roving cloth) with the resin composition varnished by blending it with an organic solvent, and then heating the resulting prepreg at a temperature appropriate for the type of solvent used, preferably 50°C to 170°C. The mass ratio of the resin composition to the reinforcing substrate used in this process is not particularly limited, but it is generally preferable to prepare the prepreg so that the resin content in the prepreg is 20% by mass to 60% by mass.

[0092] Examples of organic solvents that can be used include methyl ethyl ketone, acetone, N,N-dimethylformamide, methyl isobutyl ketone, methoxypropanol, cyclohexanone, methyl cellosolve, ethyl diglycol acetate, and propylene glycol monomethyl ether acetate. The selection of the solvent and the appropriate amount to be used can be determined appropriately depending on the application. For example, when a printed circuit board is further produced from the prepreg as described below, it is preferable to use a polar solvent with a boiling point of 160°C or less, such as methyl ethyl ketone, acetone, or N,N-dimethylformamide, and it is also preferable to use the solvent in such a proportion that the nonvolatile content is 40% by mass or more and 80% by mass or less.

[0093] "Circuit board" The present invention relates to a circuit board obtained by laminating the prepreg and copper foil and subjecting them to thermocompression molding. A method for obtaining a printed circuit board from the resin composition of the present invention includes laminating the prepreg, appropriately overlaying copper foil, and subjecting the laminate to thermocompression bonding at 170°C to 300°C under a pressure of 1 MPa to 10 MPa for 10 minutes to 3 hours.

[0094] "Flexible wiring board" A method for producing a flexible wiring board from the resin composition of the present invention includes a method comprising the following three steps: The first step is to apply a resin composition containing an active ester resin, an epoxy resin, and an organic solvent to an electrically insulating film using a coater such as a reverse roll coater or a comma coater; the second step is to heat the electrically insulating film to which the resin composition has been applied at a temperature of 60°C to 170°C for 1 minute to 15 minutes using a heater to volatilize the solvent from the electrically insulating film and bring the resin composition to a B-stage; and the third step is to thermocompress (compression pressure: 2 N / cm) a metal foil onto the adhesive of the electrically insulating film to which the resin composition has been B-staged using a heated roll or the like. 2 More than 200N / cm 2 Hereinafter, the pressure bonding temperature is preferably 40°C or higher and 200°C or lower.) If sufficient adhesive performance is obtained by going through the above three steps, the process may be terminated here, but if complete adhesive performance is required, it is preferable to further post-cure under conditions of 100°C or higher and 200°C or lower for 1 hour or lower and 24 hours or lower. The thickness of the curable resin composition film after final curing is preferably in the range of 5 μm or higher and 100 μm or lower.

[0095] Build-up film The present invention relates to a build-up film containing the resin composition of the present invention. The build-up film of the present invention can be produced by applying the resin composition of the present invention to a support film to form a resin composition layer, thereby forming an adhesive film for a multilayer printed wiring board.

[0096] When producing a build-up film from a resin composition, it is essential that the film softens under the lamination temperature conditions (usually 70°C or higher and 140°C or lower) in the vacuum lamination method and exhibits fluidity (resin flow) that allows resin to fill via holes or through holes present in the circuit board at the same time as laminating the circuit board. It is preferable to blend the above-mentioned components so as to exhibit such properties.

[0097] Here, the diameter of the through-holes in a multilayer printed wiring board is usually 0.1 mm to 0.5 mm, and the depth is usually 0.1 mm to 1.2 mm, and it is usually preferable to make it possible to fill the resin within this range. When laminating both sides of the circuit board, it is desirable to fill about half of the through-holes.

[0098] Specifically, the adhesive film can be produced by preparing the resin composition in a varnish form, applying the varnish to the surface of a support film (Y), and then drying the organic solvent by heating or blowing hot air, etc., to form a composition layer (X) made of the resin composition. The thickness of the composition layer (X) formed is usually preferably equal to or greater than the thickness of the conductor layer. Since the thickness of the conductor layer of a circuit board is usually in the range of 5 μm to 70 μm, the thickness of the resin composition layer is preferably 10 μm to 100 μm. The composition layer (X) in the present invention may be protected with a protective film, which will be described later. Protection with a protective film can prevent the adhesion of dust and other particles to the surface of the resin composition layer, as well as scratches.

[0099] Examples of the support film and the protective film include polyolefins such as polyethylene, polypropylene, and polyvinyl chloride, polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate, polycarbonate, polyimide, and even release paper and metal foils such as copper foil and aluminum foil. The support film and the protective film may be subjected to a mud treatment, a corona treatment, or a release treatment.

[0100] The thickness of the support film is not particularly limited, but is usually from 10 μm to 150 μm, preferably from 25 μm to 50 μm, and the thickness of the protective film is preferably from 1 μm to 40 μm.

[0101] The support film (Y) is peeled off after laminating it onto the circuit board or after forming an insulating layer by heat curing. If the support film (Y) is peeled off after the adhesive film has been heat cured, adhesion of dust and the like during the curing process can be prevented. When peeling off after curing, the support film is usually subjected to a release treatment in advance.

[0102] "Multilayer printed wiring board" A multilayer printed wiring board can be manufactured using the build-up film produced by the above-mentioned method. In the manufacturing method of such a multilayer printed wiring board, for example, if the composition layer (X) is protected by a protective film, the protective film is peeled off, and then the composition layer (X) is directly laminated onto one or both sides of the circuit board by, for example, a vacuum lamination method. The lamination method may be a batch method or a continuous method using a roll. Furthermore, the adhesive film and the circuit board may be heated (preheated) as necessary before lamination. The lamination conditions are a pressure bonding temperature (lamination temperature) of preferably 70°C or higher and 140°C or lower, and a pressure bonding pressure of preferably 1 kgf / cm. 2 More than 11kgf / cm 2 Less than (9.8 x 10 4 N / m 2 Over 107.9 x 10 4 N / m 2 It is preferable to laminate the laminate under a reduced pressure of 20 mmHg (26.7 hPa) or less.

[0103] Build-up board A method for producing a build-up substrate from the resin composition of the present invention includes a method consisting of the following three steps. In the first step, a resin composition containing an appropriate blend of rubber, filler, etc. is applied to a circuit board having a circuit formed thereon using a spray coating method, curtain coating method, or the like, followed by curing. In the second step, predetermined through-holes or the like are drilled as needed, followed by treatment with a roughening agent, and the surface is washed with hot water to form irregularities, followed by plating with a metal such as copper. In the third step, these operations are repeated as desired to alternately build up resin insulating layers and conductor layers of a predetermined circuit pattern. It is preferable to drill through-holes after forming the outermost resin insulating layer. In addition to the solution coating method described above, the first step can also be performed by laminating a build-up film that has been coated to the desired thickness and dried in advance. Furthermore, the build-up substrate of the present invention can be produced by forming a roughened surface and omitting the plating process by heat-pressing a copper foil with a resin, which is prepared by semi-curing the resin composition on the copper foil, onto a wiring board on which a circuit has been formed, at a temperature of 170°C or higher and 250°C or lower.

[0104] "Fiber-reinforced composite materials" A fiber-reinforced composite material can be produced from the resin composition of the present invention by uniformly mixing the components of the resin composition to prepare a varnish, impregnating a reinforcing substrate made of reinforcing fibers with the varnish, and then curing the varnish. The curing temperature is preferably from 50°C to 250°C, and more preferably from 50°C to 100°C to produce a tack-free cured product, followed by further processing at a temperature of from 120°C to 200°C. The reinforcing fibers may be twisted, untwisted, or non-twisted yarns, but untwisted or non-twisted yarns are preferred because they provide both moldability and mechanical strength for the fiber-reinforced plastic component. Furthermore, the reinforcing fibers can be unidirectionally aligned or woven. For woven fabrics, plain weave, satin weave, or other weaves can be freely selected depending on the location and application. Specifically, carbon fiber, glass fiber, aramid fiber, boron fiber, alumina fiber, silicon carbide fiber, etc., can be mentioned because they have excellent mechanical strength and durability, and two or more of these can also be used in combination. Among these, carbon fiber is particularly preferred because it provides good strength to molded products, and various types of carbon fiber can be used, such as polyacrylonitrile-based, pitch-based, and rayon-based carbon fibers. Of these, polyacrylonitrile-based fibers are preferred because they can easily produce high-strength carbon fibers. Here, when a fiber-reinforced composite material is prepared by impregnating a reinforcing substrate made of reinforcing fibers with varnish, the amount of reinforcing fibers used is preferably an amount such that the volume content of the reinforcing fibers in the fiber-reinforced composite material is in the range of 40% to 85%.

[0105] "Fiber reinforced resin molded products" Methods for producing fiber-reinforced resin molded articles from the resin composition of the present invention include hand layup and spray-up methods, in which fiber aggregates are laid in a mold and the varnish is applied in multiple layers; vacuum bag molding, in which a base material made of reinforcing fibers is impregnated with the varnish using either a male or female mold, stacked, and molded into an airtight seal with a flexible mold that can apply pressure to the molded article; SMC press molding, in which a sheet of varnish containing reinforcing fibers is compressed in a mold; and RTM, in which the varnish is injected into a mating mold filled with fibers to produce a prepreg in which the reinforcing fibers are impregnated with the varnish, which is then baked in a large autoclave. The resulting fiber-reinforced resin molded article is a molded article containing reinforcing fibers and a cured resin composition. Specifically, the amount of reinforcing fibers in the fiber-reinforced resin molded article is preferably in the range of 40 to 70% by mass, and particularly preferably in the range of 50 to 70% by mass from the viewpoint of strength.

[0106] Although the method for producing a semiconductor encapsulation material and the like has been described above, other cured products can also be produced from the resin composition of the present invention. The other cured products can be produced by a method conforming to a general curing method for resin compositions. For example, the heating temperature conditions can be appropriately selected depending on the type of curing agent to be combined, the application, etc.

[0107] The resin composition of the present invention can be used, for example, in the manufacture of high-frequency devices. A high-frequency device can be obtained, for example, by placing electronic components on a support member and encapsulating the electronic components with the resin composition. The types of support member and electronic components used are not particularly limited, and support members and electronic components commonly used in the manufacture of electronic devices can be used. Examples of methods for encapsulating electronic components include low-pressure transfer molding, injection molding, and compression molding. A curing accelerator, an inorganic filler, and the like may be added to the resin composition used, as needed. Examples of curing accelerators and inorganic fillers include those listed above, but are not particularly limited and can be selected appropriately depending on the desired physical properties.

[0108] By curing the resin composition of the present invention, a cured product exhibiting a high dielectric constant and a low dielectric loss tangent can be obtained. Therefore, it is preferably used for an antenna-in-package (AIP) application in which an antenna disposed on a substrate is sealed with a molded product obtained by curing the resin composition. In that case, only the antenna may be sealed alone, or it may include an antenna and electronic components other than the antenna. Further, the antenna is not particularly limited as long as it plays the role of an antenna, and may be an antenna element or a wiring. As the manufacturing method, the same method as that of the high-frequency device can be mentioned.

Examples

[0109] Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited to these examples. In addition, "%" in the compositions of the following examples and comparative examples means "mass%". Note that GPC, 1 H NMR, 13 The measurement conditions of 13C NMR and FD-MS are as follows.

[0110] <Measurement conditions of GPC> Measuring device: "HLC-8320GPC (registered trademark)" manufactured by Tosoh Corporation, Column: Guard column "TSKgel (registered trademark) HXL-L" manufactured by Tosoh Corporation + "TSKgel G4000HXL" manufactured by Tosoh Corporation + "TSKgel G3000HXL" manufactured by Tosoh Corporation + "TSKgel G2000HXL" manufactured by Tosoh Corporation + "TSKgel G2000HXL" manufactured by Tosoh Corporation Detector: RI (differential refractometer) Data processing: "GPC workstation EcoSEC (registered trademark) Workstation" manufactured by Tosoh Corporation Measurement conditions: Column temperature 40 °C Developing solvent: Tetrahydrofuran Flow rate: 1.0 mL / min Standard sample: The following monodisperse polystyrenes with known molecular weights were used in accordance with the measurement manual of the GPC apparatus. "A-500" manufactured by Tosoh Corporation "A-1000" manufactured by Tosoh Corporation "A-2500" manufactured by Tosoh Corporation "A-5000" manufactured by Tosoh Corporation "F-1" manufactured by Tosoh Corporation "F-2" manufactured by Tosoh Corporation <00开0546>"F-4" manufactured by Tosoh Corporation "F-10" manufactured by Tosoh Corporation "F-20" manufactured by Tosoh Corporation "F-40" manufactured by Tosoh Corporation "F-80" manufactured by Tosoh Corporation <00005出51>"F-128" manufactured by Tosoh Corporation Sample: A 1.0 mass% tetrahydrofuran solution in terms of resin solid content, filtered through a microfilter (50 μL)

[0111] < 1 Measurement conditions for 1H NMR Apparatus: "JNM-ECA600" manufactured by JEOL Ltd. Solvent: DMSO-d6 Sample concentration: 30 mass% Number of integrations: 32 times

[0112] < 13 Measurement conditions for 13C NMR Apparatus: "JNM-ECA600" manufactured by JEOL Ltd. Solvent: DMSO-d6 Sample concentration: 30 wt% Number of integrations: 4000 times

[0113] <Measurement conditions for FD-MS Apparatus: "JMS-T100GC AccuTOF (registered trademark )" Measurement range: m / z = 4.00 - 2000.00 Rate of change: 51.2 mA / min Final current value: 45 mA Cathode voltage: -10kV Recording interval: 0.07 seconds

[0114] (Example 1) Preparation of active ester resin (I-1) A reaction vessel equipped with a thermometer, dropping funnel, condenser, fractionating column, and stirrer was charged with 200.0 g of 1-naphthol, 61.4 g of the compound represented by formula (a2-1), 17.5 g of p-toluenesulfonic acid monohydrate, and 350.9 g of toluene, and the system was purged with nitrogen under reduced pressure. While purging with nitrogen gas, the mixture was heated to reflux at 120°C for 6 hours while removing moisture. After cooling to 40°C, 9.3 g of triethylamine was added and stirred for 1 hour to produce a toluene solution of phenolic hydroxyl group-containing resin (s-1). To the toluene solution of the phenolic hydroxyl group-containing resin (s-1), 701.7 g of toluene, 140.1 g of isophthalic acid chloride, and 8.5 g of 4-dimethylaminopyridine were added. While purging with nitrogen gas, 144.6 g of triethylamine was added dropwise over 1 hour while stirring so that the temperature of the reaction solution did not exceed 40°C. After the addition was completed, the mixture was heated and stirred at 40°C for 3 hours. After neutralization with a 30% aqueous solution of sodium dihydrogen phosphate, 200.0 g of cyclohexanone was added, and the organic layer was washed with water until the pH of the aqueous layer reached 7. Part of the solvent was distilled off under heating and reduced pressure to produce 524.8 g of a toluene / cyclohexanone solution of active ester resin (I-1) (63% nonvolatile content). The functional group equivalent of the active ester resin (I-1) was 253 g / equivalent, the softening point measured according to JIS K7234 was 117°C, and the number average molecular weight (Mn) was 480.

[0115] (Example 2) Preparation of active ester resin (I-2) A reaction vessel equipped with a thermometer, dropping funnel, condenser, fractionating column, and stirrer was charged with 165.0 g of 1-naphthol, 83.6 g of the compound represented by formula (a2-1), 9.7 g of p-toluenesulfonic acid monohydrate, and 322.4 g of toluene, and the system was purged with nitrogen under reduced pressure. The mixture was heated to reflux at 120°C for 6 hours while purging with nitrogen gas and removing moisture. After cooling to 40°C, 5.2 g of triethylamine was added and stirred for 1 hour to produce a toluene solution of phenolic hydroxyl group-containing resin (s-2). The number average molecular weight (Mn) of the phenolic hydroxyl group-containing resin (s-2) was 259. To the toluene solution of the phenolic hydroxyl group-containing resin (s-2), 322.4 g of cyclohexanone, 483.6 g of toluene, 115.6 g of isophthalic acid chloride, and 7.0 g of 4-dimethylaminopyridine were added, and while purging with nitrogen gas, 127.4 g of triethylamine was added dropwise over 1 hour with stirring so that the temperature of the reaction solution did not exceed 40°C. After the addition was completed, the mixture was heated and stirred at 40°C for 1 hour and then at 60°C for 4 hours. After neutralization with a 30% aqueous solution of sodium dihydrogen phosphate, the organic layer was washed with water until the pH of the aqueous layer reached 7. Part of the solvent was distilled off under heated and reduced pressure conditions to produce 592.5 g of a toluene / cyclohexanone solution of the active ester resin (I-2) (55% nonvolatile content). The active ester resin (I-2) had a functional group equivalent weight of 282 g / equivalent, a softening point of 149° C. measured in accordance with JIS K7234, and a number average molecular weight (Mn) of 692.

[0116] (Example 3) Preparation of active ester resin (I-3) A reaction vessel equipped with a thermometer, dropping funnel, condenser, fractionating column, and stirrer was charged with 175.0 g of 1-naphthol, 112.8 g of the compound represented by formula (a2-1), 11.0 g of p-toluenesulfonic acid monohydrate, and 366.1 g of toluene. The system was then purged with nitrogen under reduced pressure. The mixture was heated to reflux at 120°C for 16 hours while purging with nitrogen gas, removing moisture. After cooling to 40°C, 5.8 g of triethylamine was added and stirred for 1 hour to produce a toluene solution of phenolic hydroxyl group-containing resin (s-3). The number average molecular weight (Mn) of the phenolic hydroxyl group-containing resin (s-3) was 213. To the toluene solution of the phenolic hydroxyl group-containing resin (s-3), 366.0 g of cyclohexanone, 366.0 g of toluene, 122.6 g of isophthalic acid chloride, and 7.4 g of 4-dimethylaminopyridine were added. While purging with nitrogen gas, 126.5 g of triethylamine was added dropwise over 1 hour with stirring so that the temperature of the reaction solution did not exceed 40°C. After completion of the dropwise addition, the mixture was heated and stirred at 40°C for 3 hours. After neutralization with a 30% aqueous solution of sodium dihydrogen phosphate, 183.0 g of toluene was added, and the organic layer was washed with water until the pH of the aqueous layer reached 7. Part of the solvent was distilled off under heated and reduced pressure conditions to produce 623.1 g of a toluene / cyclohexanone solution of the active ester resin (I-3) (54% nonvolatile content). The active ester resin (I-3) had a functional group equivalent weight of 302 g / equivalent, a softening point of 167° C. as measured in accordance with JIS K7234, and a number average molecular weight (Mn) of 911.

[0117] (Example 4) Preparation of phenolic hydroxyl group-containing resin (s-4) A reaction vessel equipped with a thermometer, dropping funnel, condenser, fractionating column, and stirrer was charged with 160.0 g of 1-naphthol, 198.9 g of the compound represented by formula (a2-2), 17.9 g of p-toluenesulfonic acid monohydrate, and 358.9 g of methyl isobutyl ketone, and the system was purged with nitrogen under reduced pressure. The mixture was heated to reflux at 130°C for 16 hours while purging with nitrogen gas and removing moisture. After cooling to 80°C, 7.9 g of 49% aqueous sodium hydroxide solution was added and stirred for 1 hour. The solvent was distilled off under reduced pressure, producing phenolic hydroxyl group-containing resin (s-4). The number average molecular weight (Mn) of the phenolic hydroxyl group-containing resin (s-4) was 551.

[0118] (Example 5) Preparation of phenolic hydroxyl group-containing resin (s-5) A reaction vessel equipped with a thermometer, dropping funnel, condenser, fractionating column, and stirrer was charged with 180.0 g of 1-naphthol, 80.5 g of the compound represented by formula (a2-2), 17.1 g of p-toluenesulfonic acid monohydrate, and 341.1 g of toluene, and the system was purged with nitrogen under reduced pressure. While purging with nitrogen gas, the mixture was heated to reflux at 120°C for 16 hours while removing moisture. After cooling to 80°C, 7.4 g of 49% aqueous sodium hydroxide solution was added and stirred for 1 hour. The solvent was distilled off under heated and reduced pressure conditions to produce phenolic hydroxyl group-containing resin (s-5).

[0119] (Example 6) Preparation of phenolic hydroxyl group-containing resin (s-6) A reaction vessel equipped with a thermometer, dropping funnel, condenser, fractionating column, and stirrer was charged with 500.0 g of 1-naphthol, 124.3 g of the compound represented by formula (a2-2), 31.2 g of p-toluenesulfonic acid monohydrate, and 624.3 g of toluene, and the system was purged with nitrogen under reduced pressure. The mixture was heated to reflux at 120°C for 16 hours while purging with nitrogen gas and removing moisture. After cooling to 80°C, 18.4 g of 49% aqueous sodium hydroxide solution was added and stirred for 1 hour. The solvent was distilled off under reduced pressure, producing phenolic hydroxyl group-containing resin (s-6). The number average molecular weight (Mn) of the phenolic hydroxyl group-containing resin (s-6) was 109.

[0120] (Example 7) Preparation of phenolic hydroxyl group-containing resin (s-7) A reaction vessel equipped with a thermometer, dropping funnel, condenser, fractionating column, and stirrer was charged with 80.6 g of 2,6-dimethylphenol, 132.8 g of the compound represented by formula (a2-1), 206.1 g of toluene, and 10.3 g of methanesulfonic acid, and the system was purged with nitrogen under reduced pressure. While purging with nitrogen gas, the mixture was heated to reflux at 120°C for 2 hours while removing moisture. The mixture was then heated to 200°C while distilling off the toluene, and heated and stirred at 200°C for 50 hours. While cooling, 206.1 g of methyl isobutyl ketone was added dropwise to obtain a homogeneous solution. After cooling to 80°C, 8.8 g of 49% aqueous sodium hydroxide solution was added and stirred for 1 hour. The solvent was distilled off under reduced pressure, producing phenolic hydroxyl group-containing resin (s-7). The number average molecular weight (Mn) of the phenolic hydroxyl group-containing resin (s-6) was 1081. (Example 8) Preparation of phenolic hydroxyl group-containing resin (s-8) A reaction vessel equipped with a thermometer, dropping funnel, condenser, fractionating column, and stirrer was charged with 227.1 g of o-cresol, 154.9 g of the compound represented by formula (a2-1), and 11.5 g of methanesulfonic acid, and the system was purged with nitrogen under reduced pressure. The mixture was heated and stirred at 200°C for 50 hours while purging with nitrogen gas. While cooling, 230.6 g of methyl isobutyl ketone was added dropwise to obtain a homogeneous solution. After cooling to 80°C, 9.9 g of 49% aqueous sodium hydroxide solution was added and stirred for 1 hour. The solvent and o-cresol were distilled off under heated and reduced pressure conditions to produce phenolic hydroxyl group-containing resin (s-8). The number average molecular weight (Mn) of the phenolic hydroxyl group-containing resin (s-8) was 819.

[0121] (Synthesis Reference Example 1) Preparation of Active Ester Resin (R-1) A reaction vessel equipped with a thermometer, dropping funnel, condenser, fractionating column, and stirrer was charged with 0.6 g of tetrabutylammonium fluoride, 152 g of isophthalic acid chloride, 72 g of 1-naphthol, 165 g of a polyaddition resin of dicyclopentadiene and phenol (hydroxyl group equivalent: 165 g / eq, softening point 85°C), and 630 g of toluene. The system was then purged with nitrogen under reduced pressure. While purging with nitrogen gas, 315 g of 20% aqueous sodium hydroxide solution was added dropwise over 3 hours while stirring, ensuring that the temperature of the reaction solution did not exceed 60°C. After the addition was complete, the mixture was heated and stirred at 60°C for 3 hours. After neutralization with 30% aqueous sodium dihydrogen phosphate solution, the organic layer was washed with water until the pH of the aqueous layer reached 7. A portion of the toluene was distilled off under heated and reduced pressure conditions to produce a 65% toluene solution of activated ester resin (R-1). The active ester resin (R-1) had a functional group equivalent of 223 g / equivalent and a softening point of 150° C. as measured in accordance with JIS K7234.

[0122] (Examples 9 to 11, Comparative Example 1) Preparation of resin composition The solvent was removed from the active ester resins (I-1) to (I-3) produced in Examples 1 to 3 by distillation under reduced pressure, followed by heating and vacuum drying at 180°C for 2 hours to obtain solid resins. Each of the resulting solid resins was dissolved in methyl ethyl ketone to prepare a 65% methyl ethyl ketone solution of each active ester resin. The components were blended in the proportions shown in Table 1 below using the resulting resin solution, and then diluted with methyl ethyl ketone to obtain a resin composition with a non-volatile content (NV) of 60% after blending. The epoxy resin used was dicyclopentadiene phenol-type epoxy resin EPICLON HP-7200H-75M (manufactured by DIC Corporation, epoxy equivalent: 279 g / equivalent), and the curing catalyst used was 4-dimethylaminopyridine. The blending ratio of the curing catalyst represents the ratio relative to the solid content of the active ester resin and epoxy resin. The active ester resin in Comparative Example 1 was the active ester resin (R-1) produced in Synthesis Reference Example 1.

[0123] [Table 1]

[0124] (Examples 12 to 14, Comparative Example 2) Preparation of laminated plates Using the resin compositions prepared in Examples 9 to 11 and Comparative Example 1, laminates were produced under the following conditions. Base material: Nitto Boseki Co., Ltd., glass cloth "#2116" (210 x 280 mm) Copper foil: "JTCSLC foil" (18μm) manufactured by JX Metals Co., Ltd. Number of plies: 6 Curing conditions: 200℃, 29kg / cm 2 1.5 hours Plate thickness after molding: 0.8mm The resulting laminate was vacuum dried at 105°C for 2 hours, then stored for 24 hours in a room at 23°C and 50% humidity. The dielectric constant and dielectric loss tangent were then measured. Measurements were performed using a network analyzer E8362C (Agilent Technologies) using the cavity resonance method. The measurement results are shown in Table 2 below.

[0125] [Table 2]

[0126] As shown in Table 2, the active ester resins (I-1) to (I-3) of the present invention exhibit a higher dielectric constant and a lower dielectric loss tangent at 10 GHz compared to the comparative active ester resin (R-1). These results demonstrate that the active ester resin of the present invention can provide a cured product exhibiting a higher dielectric constant and a lower dielectric loss tangent in the high frequency band.

Claims

1. An active ester resin obtained by reacting a phenolic hydroxyl group-containing resin (A) with an aromatic (poly)carboxylic acid or an acid halide thereof (B), The phenolic hydroxyl group-containing resin (A) is an active ester resin obtained by reacting a phenolic hydroxyl group-containing compound (a1) and a maleimide group-containing compound (a2) as essential reaction raw materials.

2. The phenolic hydroxyl group-containing resin (A) is represented by the following general formula (S): 【Chemistry 1】 [In the formula, X １ , X ２ and X ３ are each independently represented by the following formula (x-1) or formula (x-2): 【Chemistry 2】 (wherein * represents A １ , A ２ or A ３ represents the bonding position with A ４ When a plurality of m are present, each independently represents a hydrocarbon ring or heterocycle having 3 to 16 carbon atoms which may have a substituent; m4 is 1 or more; A ４ represents an integer that is equal to or less than the number of substitutable ring-constituting atoms in the ring represented by In the general formula (S), X represents a group represented by １ , X ２ and X ３ At least one of the groups represented by formula (x-1) is A １ , A ２ and A ３ When a plurality of groups are present, each group independently represents a hydrocarbon ring or heterocycle having 3 to 16 carbon atoms which may have a substituent; Z １ and Z ２ When a plurality of groups are present, each group independently represents a single bond or a divalent linking group, m1, m2, and m3 each independently represent an integer of 0 to 10, provided that m1 + m2 + m3 is 1 or greater. The active ester resin according to claim 1, wherein the active ester resin is represented by the formula:

3. The active ester resin the phenolic hydroxyl group-containing resin (A); an aromatic (poly)carboxylic acid or an acid halide thereof (B); a hydroxyl group-containing compound (C) different from the phenolic hydroxyl group-containing resin (A); 2. The active ester resin according to claim 1, which is obtained by reacting

4. A resin composition comprising the active ester resin according to claim 1.

5. The resin composition according to claim 4, further comprising an epoxy resin.

6. The resin composition according to claim 4, which contains a phenolic resin and / or an active ester resin other than the active ester resin according to any one of claims 1 to 3.

7. A cured product of the resin composition according to claim 4.

8. A semiconductor encapsulating material, a semiconductor device, a prepreg, a circuit board, a flexible wiring board, a build-up film, a multilayer printed wiring board, a build-up board, a fiber-reinforced composite material, or a molded article obtained by curing the fiber-reinforced composite material, using the resin composition according to claim 4.

9. A high frequency device or antenna part using the resin composition according to claim 4.

10. The following general formula (S1) 【Transformation 3】 [In the formula, X １１ , X ２１ and X ３１ are each independently represented by the following formula (x-11) or formula (x-21): 【Chemistry 4】 (wherein * represents A １１ , A ２１ or A ３１ represents the bonding position with A ４１ When a plurality of groups are present, each independently represents a benzene ring or a naphthalene ring which may have a substituent. and X present in general formula (S1) represents a group represented by １１ , X ２１ and X ３１ At least one of the groups represented by formula (x-11) is a group represented by formula (x-11). A １１ , A ２１ and A ３１ When a plurality of rings are present, each independently represents an optionally substituted benzene ring or naphthalene ring, Z １１ and Z ２１ When there are a plurality of groups, each group independently represents a single bond, —CH ２ -, -CH(CH ３ ) -, -C(CH ３ ) ２ -, -O-, -CH(Ph)-, -C(Ph) ２ -, -CF ２ -, -C(CF ３ ) ２ -, -S-, -SO-, -SO ２ -, -COO-, -OCO-, -CH ２ O- and -OCH ２ represents a group selected from m11, m21, and m31 each independently represent an integer of 0 to 10, provided that m11 + m21 + m31 represents 1 or more. A phenolic hydroxyl group-containing resin represented by the formula:

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