Abstract: Provided are an epoxy resin including: an epoxidized product of monoalkyl dihydroxybenzene; and a compound that is detected in the molecular weight range from a molecular weight at the peak top of the epoxidized product of the monoalkyl dihydroxybenzene to the molecular weight at the peak top+20 to 40 and has a peak area % of 0.1% to 0.8% in a GPC chart, and an epoxy resin including an epoxidized product of monoalkyl catechol in which the ratio of the total content of a cyclic compound having a cyclic structure that has two adjacent oxygen atoms derived from the monoalkyl catechol as constituent atoms and a monoglycidyletherified product of the monoalkyl catechol to the content of a diglycidyletherified product of the monoalkyl catechol is in the range of 0.10 to 0.40 as measured by high performance liquid chromatography.

Abstract: A phenol novolak resin having an excellent balance between the mold shrinkage of a composition containing the phenol novolak resin during heat curing and the modulus of elasticity at high temperature. A phenol novolak resin that is an alkyl phenol novolak resin produced by bonding alkyl phenol (I), in which an alkyl group having a carbon number of 4 to 8 is included as a substituent on an aromatic ring, to each other with a methylene group interposed therebetween, wherein the ratio (a)/(b) of a value (a) of integration from 146 to 148 ppm to a value (b) of integration from 146 to 153 ppm based on the 13C-NMR measurement is within the range of 0.05 to 0.30, and the area ratio of alkyl phenol (I) based on GPC measurement is within the range of 0.01% to 3.0%, a curable resin composition using the same, and a cured product thereof.

Abstract: A phenol novolak resin having an excellent balance between the mold shrinkage of a composition containing the phenol novolak resin during heat curing and the modulus of elasticity at high temperature. A phenol novolak resin that is an alkyl phenol novolak resin produced by bonding alkyl phenol (I), in which an alkyl group having a carbon number of 4 to 8 is included as a substituent on an aromatic ring, to each other with a methylene group interposed therebetween, wherein the ratio (a)/(b) of a value (a) of integration from 146 to 148 ppm to a value (b) of integration from 146 to 153 ppm based on the 13C-NMR measurement is within the range of 0.05 to 0.30, and the area ratio of alkyl phenol (I) based on GPC measurement is within the range of 0.01% to 3.0%, a curable resin composition using the same, and a cured product thereof.

Abstract: Provided are an epoxy resin including: an epoxidized product of monoalkyl dihydroxybenzene; and a compound that is detected in the molecular weight range from a molecular weight at the peak top of the epoxidized product of the monoalkyl dihydroxybenzene to the molecular weight at the peak top+20 to 40 and has a peak area % of 0.1% to 0.8% in a GPC chart, and an epoxy resin including an epoxidized product of monoalkyl catechol in which the ratio of the total content of a cyclic compound having a cyclic structure that has two adjacent oxygen atoms derived from the monoalkyl catechol as constituent atoms and a monoglycidyletherified product of the monoalkyl catechol to the content of a diglycidyletherified product of the monoalkyl catechol is in the range of 0.10 to 0.40 as measured by high performance liquid chromatography.

Abstract: Provided are an epoxy resin which has high fluidity, a method for producing the epoxy resin, a cured product thereof, and a use thereof. The epoxy resin is represented by the structural formula (1) below and exhibits a peak P appearing between peaks with n=0 and n=1 in a GPC measurement in which the area of the peak P is 0.0100 to 0.0750 times the area of the peak with n=0, wherein G represents a glycidyl group, R1 represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a phenyl group, a hydroxyphenyl group, or a halogen-substituted phenyl group, symbol * indicates bonding to any of the carbon atoms capable of forming a bond on the naphthalene ring, and n represents the number of repeats and is 0 to 10 on average.

Abstract: An epoxy resin exhibits a small change in volume after thermal history, is excellent in low thermal expansion and low moisture absorption, and has high heat resistance, in terms of a cured product obtained therefrom; a curable resin composition; a cured product which has all the above properties; a semiconductor encapsulating material; a semiconductor device; a prepreg; a circuit board; a buildup film; a buildup substrate; a fiber-reinforced composite material; and a molded article. The present invention is characterized by an epoxy resin, characterized by including as essential components, a cresol-naphthol co-condensed novolac type epoxy resin (A), a naphthol glycidyl ether compound (B), and one or more xanthene compounds (C) selected from the group of compounds represented by the following structural formulae (1) to (3), wherein the content of the xanthene compound(s) (C) is from 0.1% to 5.5% in terms of area ratio in a GPC measurement.

Abstract: An epoxy resin exhibits a small change in volume after thermal history, is excellent in low thermal expansion and low moisture absorption, and has high heat resistance, in terms of a cured product obtained therefrom; a curable resin composition; a cured product which has all the above properties; a semiconductor encapsulating material; a semiconductor device; a prepreg; a circuit board; a buildup film; a buildup substrate; a fiber-reinforced composite material; and a molded article. The present invention is characterized by an epoxy resin, characterized by including as essential components, a cresol-naphthol co-condensed novolac type epoxy resin (A), a naphthol glycidyl ether compound (B), and one or more xanthene compounds (C) selected from the group of compounds represented by the following structural formulae (1) to (3), wherein the content of the xanthene compound(s) (C) is from 0.1% to 5.5% in terms of area ratio in a GPC measurement.

Abstract: Provided are a phenolic-hydroxyl containing resin, an epoxy resin, and a curable resin composition containing either resin that have high flowability and exhibit high heat resistance and flame retardancy after curing, a cured composition formed therefrom, and a sealant. A phenolic-hydroxyl containing resin is prepared by reacting a polycondensate of a phenolic compound (a) and formaldehyde with an aralkylating agent. The phenolic-hydroxyl containing resin contains as essential components a monoaralkylated derivative (x1) of the phenolic compound (a) having one aralkyl group on an aromatic nucleus thereof and a diaralkylated derivative (x2) of the phenolic compound (a) having two aralkyl groups on an aromatic nucleus thereof. An epoxy resin is prepared by converting the phenolic-hydroxyl containing resin into a polyglycidyl ether.

Abstract: Provided are a phenolic-hydroxyl containing resin, an epoxy resin, and a curable resin composition containing either resin that have high flowability and exhibit high heat resistance and flame retardancy after curing, a cured composition formed therefrom, and a sealant. A phenolic-hydroxyl containing resin is prepared by reacting a polycondensate of a phenolic compound (a) and formaldehyde with an aralkylating agent. The phenolic-hydroxyl containing resin contains as essential components a monoaralkylated derivative (x1) of the phenolic compound (a) having one aralkyl group on an aromatic nucleus thereof and a diaralkylated derivative (x2) of the phenolic compound (a) having two aralkyl groups on an aromatic nucleus thereof. An epoxy resin is prepared by converting the phenolic-hydroxyl containing resin into a polyglycidyl ether.

Abstract: A high degree of resistance to moisture and solder and high flame retardancy are realized without incorporating a halogen in view of environmental friendliness. A phenolic resin has structural moieties which are a naphthylmethyloxy group- or anthrylmethyloxy group-containing aromatic hydrocarbon group (ph1), a phenolic hydroxyl group-containing aromatic hydrocarbon group (ph2), and a divalent aralkyl group (X) represented by general formula (1) below: (where Ar represents a phenylene group or a biphenylene group and Rs each independently represent a hydrogen atom or a methyl group) and has a structure in which plural aromatic hydrocarbon groups selected from the group consisting of the naphthylmethyloxy group- or anthrylmethyloxy group-containing aromatic hydrocarbon group (ph1) and the phenolic hydroxyl group-containing aromatic hydrocarbon group (ph2) are bonded through the divalent aralkyl group (X). This phenolic resin is used as a curing agent for an epoxy resin.

Abstract: A high degree of resistance to moisture and solder and high flame retardancy are realized without incorporating a halogen in view of environmental friendliness. A phenolic resin has structural moieties which are a naphthylmethyloxy group- or anthrylmethyloxy group-containing aromatic hydrocarbon group (ph1), a phenolic hydroxyl group-containing aromatic hydrocarbon group (ph2), and a divalent aralkyl group (X) represented by general formula (1) below: (where Ar represents a phenylene group or a biphenylene group and Rs each independently represent a hydrogen atom or a methyl group) and has a structure in which plural aromatic hydrocarbon groups selected from the group consisting of the naphthylmethyloxy group- or anthrylmethyloxy group-containing aromatic hydrocarbon group (ph1) and the phenolic hydroxyl group-containing aromatic hydrocarbon group (ph2) are bonded through the divalent aralkyl group (X). This phenolic resin is used as a curing agent for an epoxy resin.

Abstract: The present invention provides a heat-curable resin composition having excellent fluidity and realizing moisture-resistance reliability suitable for recent electronic component-related materials and high flame retardancy in a halogen-free state for harmony with the environment, a cured product thereof, a semiconductor encapsulating material using the composition, and a phenol resin and epoxy resin which give these performances. The heat-curable resin composition includes, as essential components, an epoxy resin (A) and a phenol resin (B), the phenol resin (B) having a phenol resin structure having, as a basic skeleton, a structure in which a plurality of phenolic hydroxyl group-containing aromatic skeletons (ph) are bonded to each other through an alkylidene group or a methylene group having an aromatic hydrocarbon structure, and an aromatic nucleus of the phenol resin structure has a naphthylmethyl group or an anthrylmethyl group.