A curable composition includes an epoxy resin component that includes at least one multifunctional epoxy novolac resin and at least one multifunctional liquid epoxy resin, an amine hardener component that includes at least one aromatic amine and optionally at least one cycloaliphatic amine, and an accelerator component that includes (i) at least one transition metal complex having a transition metal ion and an oxygen donor ligand, and (ii) at least one salt having a cation including a metal ion or an onium ion, and an anion including a non-nucleophilic anion.

A curable composition includes specific amounts of a ketone, a curable component, and particulate poly(phenylene ether) having a mean particle size of 3 to 12 micrometers and a particle size relative standard deviation of 20 to 60 percent. The composition has a low viscosity that facilitates wetting of reinforcing structures, and composites formed from the composition and a reinforcing structure cure to form a dielectric material with a low dielectric constant and loss tangent.

A resin composition including an epoxy resin monomer, a novolac resin including a compound having a structural unit represented by Formula (I), and a filler; in which the filler has at least 4 peaks in a particle size distribution measured by laser diffractometry, in which four of the peaks are present respectively in ranges of not less than 0.01 μm and less than 1 μm, not less than 1 μm and less than 10 μm, from 10 μm to 50 μm, and from 20 μm to 100 μm, and in which a peak present in a range of from 10 μm to 50 μm includes an aluminum oxide particle, and a peak present in a range of from 20 μm to 100 μm includes a boron nitride particle. In Formula (I) each of R.sup.1, R.sup.2 and R.sup.3 independently represents a hydrogen atom, an alkyl group, or the like. m represents 0 to 2, and n represents 1 to 7. ##STR00001##

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.

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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.

There is provided herein a curing agent compound for curing thermosetting resins, e.g., epoxy resins, a composition comprising a thermoplastic and/or thermosetting resin, e.g., an epoxy resin and the curing agent, an article comprising the curing agent, and a method of making the curing agent.

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.

In various embodiments, the invention provides an in-situ adduct formed by reacting liquid, solid, and/or semi-solid epoxy resins with a di-carboxylic acid functionalized polymer. The adducting process at least doubles the viscosity of the mixture. A hot melt thermosetting surfacing film and composite formed using the adduct are also disclosed. Methods of preparing and using are also disclosed.

Curable compositions are provided which comprise: a) 30-80 wt % of a room temperature liquid epoxy resin; b) 0.5-10 wt % of an epoxy curative; c) 5-40 wt % of a thermoplastic resin; and d) 0.5-10 wt % of a physical blowing agent. In some embodiments, the curable compositions may be fire retardant. In some embodiments, the curable compositions may be used in the form of films, and more particularly as core splice film adhesives.

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.