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.

##STR00001##

Curable compositions comprising an epoxy mixture comprising a) an epoxy mixture comprising i) a first epoxy component comprising epoxy phenol novolac oligomers having a content of 2-functional monomers of less than 10 weight percent based on the total weight of the first epoxy component and having an epoxide equivalent weight in the range of 170 to 200; and ii) a second epoxy component comprising an epoxy resin having monomers with an average functionality of at least 2 and b) a hardener, are disclosed. The curable compositions can be used to prepare prepregs for hot-melt applications.

Curable compositions comprising an epoxy mixture comprising a) an epoxy mixture comprising i) a first epoxy component comprising epoxy phenol novolac oligomers having a content of 2-functional monomers of less than 10 weight percent based on the total weight of the first epoxy component and having an epoxide equivalent weight in the range of 170 to 200; and ii) a second epoxy component comprising an epoxy resin having monomers with an average functionality of at least 2 and b) a hardener, are disclosed. The curable compositions can be used to prepare prepregs for hot-melt applications.

Disclosed herein are compositions and methods of making phenolic compounds, and resins comprising these phenolic compounds. The compounds include multifunctional epoxies, amino glycidyl derivatives, and multi-functional amines prepared from hydroxymethyl derivatives of phenols and bisphenols

A two-component curable epoxy resin system having an epoxy component containing a unique combination of two or more epoxy resins with at least one of the epoxy resins being an epoxy novolac type resin. The composite made from such resin system exhibits high glass transition temperature.

A two-component curable epoxy resin system having an epoxy component containing a unique combination of two or more epoxy resins with at least one of the epoxy resins being an epoxy novolac type resin. The composite made from such resin system exhibits high glass transition temperature.

The present invention provides a curable resin composition, a cured product of which has a small change in heat resistance after receiving a thermal history and a low thermal expansion property; a cured product of the curable resin composition; a printed circuit board having a small change in heat resistance; and an epoxy resin which imparts the characteristics described above. The epoxy resin is an epoxy resin which is obtained by polyglycidyl etherification of a reaction product formed from ortho-cresol, a β-naphthol compound, and formaldehyde and which includes as a necessary component, a dimer (x2, formula (1)), a trifunctional compound (x3, formula (2)), and a tetrafunctional compound (x4, formula (3)). The total content of those components is 65% or more in terms of the area rate in GPC measurement. ##STR00001##

The present invention provides a curable resin composition, a cured product of which has a small change in heat resistance after receiving a thermal history and a low thermal expansion property; a cured product of the curable resin composition; a printed circuit board having a small change in heat resistance; and an epoxy resin which imparts the characteristics described above. The epoxy resin is an epoxy resin which is obtained by polyglycidyl etherification of a reaction product formed from ortho-cresol, a β-naphthol compound, and formaldehyde and which includes as a necessary component, a dimer (x2, formula (1)), a trifunctional compound (x3, formula (2)), and a tetrafunctional compound (x4, formula (3)). The total content of those components is 65% or more in terms of the area rate in GPC measurement. ##STR00001##

A polyhydric phenol resin is provided. The polyhydric phenol resin comprises a polyhydric phenol resin component and a first component. When the polyhydric phenol resin is characterized in a high-performance liquid chromatography (HPLC), the first component is eluted at a retention time ranging from 27.1 minutes to 28.0 minutes, and based on the total area of the chromatographic peaks of the polyhydric phenol resin, the area percentage of the chromatographic peak of the first component at the corresponding retention time in the spectrum ranges from 1.0% to 20%.

The present disclosure relates to a modified epoxy resin having the formula (I):

##STR00001## wherein R is R1, R2 or a combination of R1 and R2; R1 and R2 are independently alkyl group having 1 to 32 C atoms, branched alkyl group having 1 to 32 C atoms, Cyclo-aliphatic group, substituted cycloaliphatic group, aromatic group, substituted aromatic group, biaryl or alkyl substituted biaryl group, methyl bridged aromatic group, cycloaliphatic-aromatic group or Ar—Z—Ar group; X and Y are independently O, —C(O)O—, or an amine group. Z is dicyclopentadiene; R3 and R4 are independently either H, alkyl group, branched alkyl group, alkoxy group, substituted biaryl group or methyl bridged aromatic group; R4 and R3 optionally forming a fused aromatic ring or a fused hetero aromatic ring; n is 0 to 1 with n=0>75%; and N is 1-20.