Abstract: A curable composition to be cured to provide a cured product excellent in heat resistance and dielectric properties, a cured product of the curable composition, a printed wiring board, a semiconductor sealing material, and a build-up film using the curable composition. There is provided a curable composition containing an aromatic ester resin (A) and a maleimide compound (B), the aromatic ester resin (A) being an active ester resin that is a reaction product of a first aromatic compound having two or more phenolic hydroxy groups, a second aromatic compound having a phenolic hydroxy group, and a third aromatic compound having two or more carboxy groups and/or an acid halide thereof or an esterified compound thereof, in which at least one of the first aromatic compound, the second aromatic compound, and the third aromatic compound and/or the acid halide thereof or the esterified compound thereof has a polymerizable unsaturated bond-containing substituent.

Abstract: To provide a curable resin composition, from which a cured product having high heat resistance, a low dielectric loss tangent, high adhesion to a conductor can be obtained. A dry film, a resin-clad copper foil, a cured product, and an electronic component containing the curable resin composition are to be provided. A curable resin composition containing (A) an epoxy resin and (B) a compound having an active ester group is obtained, which has ratio of the total amount of epoxy group(s) in (A) the epoxy resin/the total amount of active ester group(s) in (B) the compound having an active ester group in the composition in the range of 0.2 to 0.6. A dry film, a resin-clad copper foil, a cured product, and an electronic component containing the curable resin composition are also obtained.

Abstract: A curable composition to be cured to a cured product excellent in heat resistance and dielectric properties, a cured product of the curable composition, a printed wiring board, a semiconductor sealing material, and a build-up film. There is a curable composition containing an aromatic ester compound (A) and a maleimide compound (B), the aromatic ester compound (A) being represented by structural formula (1) (where in the formula, Ar1 is a substituted or unsubstituted aromatic ring group, each R1 is a polymerizable unsaturated bond-containing substituent, each 1 is 0 or 1, each R2 is any of an alkyl group, an alkoxy group, an alkyloxycarbonyl group, an alkylcarbonyloxy group, and a halogen atom, each m is 0 or an integer of 1 to 5, and n is 2 or 3, provided that at least one polymerizable unsaturated bond-containing substituent is contained in one molecule as a substituent on Ar1 or as R1).

Abstract: The present invention aims to provide a means by which a cured product to be obtained has a low dielectric loss tangent and higher heat resistance. Specifically, provided is an active ester resin that is a reaction product of a first aromatic compound having two or more phenolic hydroxy groups, a second aromatic compound having a phenolic hydroxy group, and a third aromatic compound having two or more carboxy groups and/or an acid halide thereof or an esterified compound thereof, in which at least one of the first aromatic compound, the second aromatic compound, and the third aromatic compound and/or the acid halide thereof or the esterified compound thereof has an unsaturated bond-containing substituent.

Abstract: The present invention aims to provide a means by which a cured product to be obtained has a low dielectric loss tangent and higher heat resistance. Specifically, provided are an active ester compound represented by chemical formula (1): (where in chemical formula (1), Ar1 is a substituted or unsubstituted first aromatic ring group, and each Ar2 is independently a substituted or unsubstituted second aromatic ring group, in which at least one of Ar1 and Ar2 has an unsaturated bond-containing substituent, and n is an integer of 2 or 3), a curable composition containing the active ester compound, and a cured product thereof.

Abstract: To provide a curable resin composition, from which a cured product having high heat resistance, a low dielectric loss tangent, high adhesion to a conductor can be obtained. A dry film, a resin-clad copper foil, a cured product, and an electronic component containing the curable resin composition are to be provided. A curable resin composition containing (A) an epoxy resin and (B) a compound having an active ester group is obtained, which has ratio of the total amount of epoxy group(s) in (A) the epoxy resin/the total amount of active ester group(s) in (B) the compound having an active ester group in the composition in the range of 0.2 to 0.6. A dry film, a resin-clad copper foil, a cured product, and an electronic component containing the curable resin composition are also obtained.

Abstract: A curable composition to be cured to a cured product excellent in heat resistance and dielectric properties, a cured product of the curable composition, a printed wiring board, a semiconductor sealing material, and a build-up film. There is a curable composition containing an aromatic ester compound (A) and a maleimide compound (B), the aromatic ester compound (A) being represented by structural formula (1) (where in the formula, Ar1 is a substituted or unsubstituted aromatic ring group, each R1 is a polymerizable unsaturated bond-containing substituent, each 1 is 0 or 1, each R2 is any of an alkyl group, an alkoxy group, an alkyloxycarbonyl group, an alkylcarbonyloxy group, and a halogen atom, each m is 0 or an integer of 1 to 5, and n is 2 or 3, provided that at least one polymerizable unsaturated bond-containing substituent is contained in one molecule as a substituent on Ar1 or as R1).

Abstract: A curable composition to be cured to provide a cured product excellent in heat resistance and dielectric properties, a cured product of the curable composition, a printed wiring board, a semiconductor sealing material, and a build-up film using the curable composition. There is provided a curable composition containing an aromatic ester resin (A) and a maleimide compound (B), the aromatic ester resin (A) being an active ester resin that is a reaction product of a first aromatic compound having two or more phenolic hydroxy groups, a second aromatic compound having a phenolic hydroxy group, and a third aromatic compound having two or more carboxy groups and/or an acid halide thereof or an esterified compound thereof, in which at least one of the first aromatic compound, the second aromatic compound, and the third aromatic compound and/or the acid halide thereof or the esterified compound thereof has a polymerizable unsaturated bond-containing substituent.

Abstract: Provided are an active ester composition capable of exhibiting high curability and forming a cured product with various excellent properties such as low dielectric properties, a cured product thereof, and a semiconductor encapsulating material and a printed wiring board which are obtained using the active ester composition. The active ester composition includes, as essential components, an active ester compound (A) and a phenolic hydroxyl group-containing compound (B), in which the active ester compound (A) is an esterification product of a compound having one phenolic hydroxyl group in the molecular structure (a1) and an aromatic polycarboxylic acid or an acid halide thereof (a2). Also provided are a cured product thereof, and a semiconductor encapsulating material and a printed wiring board which are obtained using the active ester composition.

Abstract: The present invention aims to provide a means by which a cured product to be obtained has a low dielectric loss tangent and higher heat resistance. Specifically, provided is an active ester resin that is a reaction product of a first aromatic compound having two or more phenolic hydroxy groups, a second aromatic compound having a phenolic hydroxy group, and a third aromatic compound having two or more carboxy groups and/or an acid halide thereof or an esterified compound thereof, in which at least one of the first aromatic compound, the second aromatic compound, and the third aromatic compound and/or the acid halide thereof or the esterified compound thereof has an unsaturated bond-containing substituent.

Abstract: The present invention aims to provide a means by which a cured product to be obtained has a low dielectric loss tangent and higher heat resistance. Specifically, provided are an active ester compound represented by chemical formula (1): (where in chemical formula (1), Ar1 is a substituted or unsubstituted first aromatic ring group, and each Ar2 is independently a substituted or unsubstituted second aromatic ring group, in which at least one of Ar1 and Ar2 has an unsaturated bond-containing substituent, and n is an integer of 2 or 3), a curable composition containing the active ester compound, and a cured product thereof.

Abstract: [Abstract] An epoxy resin composition having an excellent balance among the shrinkage rate during cure-molding, heat resistance of the cured product, and the thermoelastic modulus of the cured product, is provided. More specifically, provided is an epoxy resin composition including a naphthalene-type epoxy compound and a curing agent for an epoxy resin, the naphthalene-type epoxy compound having: a naphthalene ring; at least one group (A) which is directly bonded to the naphthalene ring and selected from the group consisting of an allyl group and a glycidyl group; and at least one group (B) which is directly bonded to the naphthalene ring and selected from the group consisting of an allyloxy group and a glycidyloxy group, with the proviso that the compound has at least one of the allyl group and the allyloxy group and at least one of the glycidyl group and the glycidyloxy group.

Abstract: It is an issue to provide an epoxy resin that has excellent fluidity and curability, that provides a cured product with favorable moisture resistance and mechanical strength, and that is suitable for use in a semiconductor sealing material, a circuit board, and the like, to provide a method for producing the epoxy resin, and to provide an epoxy resin composition containing the epoxy resin and a cured product of the epoxy resin composition. Specifically, an epoxy resin that is epoxy resin (A) primarily containing epoxidized dihydroxybenzene in which an alkyl group having a carbon number of 1 to 8 may be included as a substituent on an aromatic ring, wherein the area ratio of the maximum peak in GPC measurement is 90% or more, a method for producing the epoxy resin, an epoxy resin composition containing the epoxy resin, and a cured product of the epoxy resin composition are provided.

Abstract: Provided are an active ester composition capable of exhibiting high curability and forming a cured product with various excellent properties such as low dielectric properties, a cured product thereof, and a semiconductor encapsulating material and a printed wiring board which are obtained using the active ester composition. The active ester composition includes, as essential components, an active ester compound (A) and a phenolic hydroxyl group-containing compound (B), in which the active ester compound (A) is an esterification product of a compound having one phenolic hydroxyl group in the molecular structure (a1) and an aromatic polycarboxylic acid or an acid halide thereof (a2). Also provided are a cured product thereof, and a semiconductor encapsulating material and a printed wiring board which are obtained using the active ester composition.

Abstract: A triazine ring-containing phenol resin obtained by reacting melamine, para-alkylphenol, and formalin is used to provide an epoxy resin composition capable of providing a cured product with excellent flame retardancy, excellent dielectric characteristics such as a low dielectric tangent and a low dielectric constant, and excellent thermal conductivity, a cured product thereof, and a prepreg, a circuit board, a build-up film, a build-up board, a semiconductor sealing material, a semiconductor device, a fiber reinforced composite material, and a formed article using the epoxy resin composition.