A curable composition comprising (A) an epoxy resin containing on average more than one epoxy group per molecule; (B) a compound of formula A[—X—CO—CH.sub.2—CN].sub.n(1), wherein A is hydrogen or C.sub.1-C.sub.12 alkyl which is unsubstituted or substituted by one or more C.sub.1-C.sub.12 alkoxy groups, C.sub.1-C.sub.12 alkylcarbonyl groups, C.sub.7-C.sub.25 arylcarbonyl groups, hydroxyl groups, amino groups, C.sub.1-C.sub.12 alkylamino groups, C.sub.1-C.sub.12 dialkylamino groups, cyano groups or halogen atoms, or A is a bivalent aliphatic, cycloaliphatic, aromatic, araliphatic or heterocyclic organic radical, X denotes —O—or —NR.sub.1—, wherein R.sub.1 is hydrogen or C.sub.1-C.sub.12 alkyl which is unsubstituted or substituted by one or more C.sub.1-C.sub.12 alkoxy groups, C.sub.1-C.sub.12 alkylcarbonyl groups, C.sub.7-C.sub.25 arylcarbonyl groups, hydroxyl groups, amino groups, C.sub.1-C.sub.12 alkylamino groups, C.sub.1-C.sub.12 dialkylamino groups, cyano groups or halogen atoms, n is 1 or 2; and (C) a protected base in the form of an adduct or salt which is able to release a basic compound upon heating to a temperature greater than 70° C., is storage-stable, allows processing over a longer period of time (pot-life) and produces cured products having outstanding mechanical and thermal properties.

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%.

An epoxy resin composition for fiber reinforced composite materials comprising components (A) to (E): component (A), an epoxy resin; component (B), a dicyandiamide or a derivative thereof; component (C), a polyisocyanate compound; component (D), a urea compound as represented by formula (1): ##STR00001##
(wherein R.sup.1 and R.sup.2 are each independently H, CH.sub.3, OCH.sub.3, OC.sub.2H.sub.5, NO.sub.2, halogen, or NH—CO NR.sup.3R.sup.4; and R.sup.3 and R.sup.4 are each independently a hydrocarbon group, allyl group, alkoxy group, alkenyl group, aralkyl group, or an alicyclic compound containing both R.sup.3 and R.sup.4, all containing 1 to 8 carbon atoms); and component (E), at least one compound selected from the group consisting of quaternary ammonium salts, phosphonium salts, imidazole compounds, and phosphine compounds.

Provided is a boron nitride agglomerate. The boron nitride agglomerate is of a multi-stage structure formed by arranging flaky hexagonal boron nitride primary particles in three-dimensional directions through adhesion of an inorganic binder. Further provided is a method for preparing the boron nitride agglomerate. The method comprises: mixing flaky hexagonal boron nitride primary particles with an inorganic binder, and controlling the mass of the inorganic binder to account for 0.02-20% of the mass of the flaky hexagonal boron nitride primary particles, so as to obtain the boron nitride agglomerate. The boron nitride agglomerate provided can be added to thermosetting resin compositions, and resin sheets, resin composite metal foil, prepregs, laminates, metal foil-covered laminates, and printed wiring boards prepared using the same have higher boron nitride addition, high thermal conductivity, and high peel strength.

The present invention is directed to a liquid one component (1 K) composition comprising, based on the weight of the composition: from 10 to 90 wt.% of a) at least one epoxy resin; from 0.5 to 30 wt.% of b) at least one organoboron compound selected from tetrasubstituted borate salts of monovalent cations of tertiary amines; from 10 to 50 wt.% of c) at least one (meth)acrylamide monomer of Formula (VII): [00001] wherein: R.sup.a is H or Me; G is selected from —NH.sub.2, —NHR.sup.b and —N(R.sup.b)(R.sup.c); R.sup.b and R.sup.care independently selected from C.sub.1-C.sub.18 alkyl, C.sub.1-C.sub.18 hydroxyalkyl, C.sub.1-C.sub.18 alkalkoxy, C.sub.6-C.sub.18 aryl and —(CH.sub.2).sub.n —N(R.sup.d)(R.sup.e); n is an integer of from 1 to 4; and, R.sup.d and R.sup.e are independently selected from H and C.sub.1-C.sub.6 alkyl; and, from 0.05 to 10 wt.% of d) at least one free radical photoinitiator.

An electrode body having an electrode, and a primer layer or a plurality of primer layers laminated on the electrode, wherein the at least one primer layer is an in-situ polymerizable composition layer formed from a polymerization product of an in-situ polymerizable composition, a method for producing an electrode body, and an electrochemical element.

Provided is a curable resin composition exhibiting reduced or controlled shrinkage on curing. The composition includes (A) an epoxy resin, (B) a latent curing agent, and (C) a compound represented by formula (1):

##STR00001##

wherein X is an oxygen atom or a sulfur atom; R.sup.1 and R.sup.2 each independently represent a hydrogen atom, an alkyl group, or an aryl group; and R.sup.3 and R.sup.4 each independently represent a hydrogen atom, an alkyl group, or an aryl group, or R.sup.3 and R.sup.4 are connected to each other to represent a divalent group to form a ring.

Provided is an encapsulating resin composition that is used for collectively encapsulating a circuit board (10) and at least a part of a connector portion (20), in which the encapsulating resin composition contains a curing accelerator, the connector portion (20) includes a terminal (21) that electrically connects the circuit board (10) with the external device, and a housing (22) that is disposed on an outer periphery of the terminal (21) and is encapsulated by the encapsulating resin composition, the housing (22) contains a thermoplastic resin, and in a differential scanning calorimetry (DSC) curve of the encapsulating resin composition obtained in a case where a temperature is increased from 30° C. to 200° C. under conditions of a temperature increase rate of 10° C./min using a DSC meter, a maximum heat release peak temperature is equal to or higher than 100° C. and equal to or lower than 163° C., and a half-value width of a maximum heat release peak is equal to or higher than 5° C. and equal to or lower than 25° C.

Provided is a thermosetting resin composition which achieves both high heat resistance and high bending strength as a fiber-reinforced composite material, and also has rapid curability that enables high cycle press forming, thermal stability, and storage stability. The thermosetting resin composition of the present invention is a thermosetting resin composition comprising an epoxy resin, an epoxy resin curing agent, an imidazole compound, and an epoxy resin curing accelerator, in which the epoxy resin curing agent is dicyandiamide or a derivative thereof, and the epoxy resin curing accelerator comprises a urea derivative having two or more dimethylureido groups in a molecule.

Provided are a stereoisomer of an epoxy compound that when contained in a curable composition, can improve the heat resistance and dielectric properties of the cured product of the curable composition, a curable composition containing the stereoisomer, and a cured product of the curable composition. A stereoisomer of an epoxy compound represented by Formula (1) below, the stereoisomer being represented by Formula (2), and a curable composition containing the stereoisomer are used:

##STR00001##

in which in Formula (1), R.sup.1 to R.sup.18 are each independently selected from the group consisting of hydrogen, an alkyl group, and an alkoxy group; and

##STR00002##

in which in Formula (2), R.sup.1 to R.sup.18 are each the same as in Formula (1).