The present invention provides a low-dielectric resin composition comprising (A) a urethane resin obtained by reacting a polycarbonate diol and an isocyanate, (B) an epoxy resin, and (C) a filler, wherein the (A) urethane resin has a carboxyl group equivalent weight of 1,100 to 5,700 g/eq; the epoxy equivalent weight of the (B) epoxy resin is 0.3 to 4.5 equivalents per 1.0 equivalent of the carboxyl group of the (A) urethane resin, the (A) urethane resin has a weight-average molecular weight of 5,000 to 80,000; the (A) urethane resin has a polycarbonate content of 35% by mass or lower; the resin composition comprises 50 parts by mass or less of the (C) filler per 100 parts by mass of the (A) urethane resin; and the resin composition comprises substantially no imido group.

Provided is a waterborne epoxy curing agent comprising a reaction product of a) at least one amine having at least one moiety in the formula of -QNH, wherein Q is a divalent hydrocarbon group, and wherein the amine has at least one tertiary amino group and at least one primary amino group per molecule; and b) at least one polyether polyol modified epoxide having one or more epoxide groups. Also provided is preparation methods thereof.

Disclosed herein is a capped poly(phenylene ether) having an activated ester end group and a structure as further defined herein. The capped poly(phenylene ether) can be particularly useful in curable compositions, thermoset compositions, and articles formed therefrom.

Provided is a waterborne epoxy curing agent comprising a reaction product of a) at least one amine having at least one moiety in the formula of -QNH, wherein Q is a divalent hydrocarbon group, and wherein the amine has at least one tertiary amino group and at least one primary amino group per molecule; and b) at least one polyether polyol modified epoxide having one or more epoxide groups. Also provided is preparation methods thereof.

A silicone-modified epoxy resin which yields a cured product having low gas permeability and excellent strength; a composition of the silicone-modified epoxy resin; and an epoxy resin cured product obtainable by curing the composition, are provided.

An epoxy resin represented by the following Formula (1):

##STR00001## wherein R.sup.1 represents a hydrocarbon group having 1 to 6 carbon atoms; X represents an organic group having a norbornane epoxy structure, or a hydrocarbon group having 1 to 6 carbon atoms; n represents an integer from 1 to 3; plural R.sup.1s and plural Xs present in the formula may be respectively identical or different; and two or more of plural Xs represent an organic group having a norbornane epoxy structure.

An epoxy resin composition for encapsulation of semiconductor devices and a semiconductor device encapsulated using the epoxy resin composition, the epoxy resin composition including an epoxy resin, a curing agent, an inorganic filler, a curing catalyst, and an additive including at least one compound represented by Formula 1,

##STR00001##

An epoxy resin composition contains an epoxy resin (A) and an epoxy resin curing agent (B). The epoxy resin (A) includes an epoxy resin (A1) having a glycidyl group derived from resorcinol, and an epoxy resin (A2) such as an epoxy resin having a glycidyl group derived from bisphenol F. The epoxy resin curing agent (B) includes resorcinol (B1) and/or the like. The epoxy resin composition has from 7 to 60 mass % epoxy resin curing agent (B) content.

A bisphenol-type diglycidyl ether composition containing a bisphenol C-type diglycidyl ether represented by the following formula (1) and a compound represented by the following formula (2):

##STR00001##

wherein, in the above formula (2), substituents R.sup.1 to R.sup.4 are each independently selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 5 carbon atoms; a linking group X each independently represents a divalent hydrocarbon group having 1 to 13 carbon atoms, O, S, SO.sub.2, C(CF.sub.3).sub.2, CO, or a direct bond; and m represents the number of repetitions and is an integer of 0 or more.