Abstract: An epoxy resin composition used for semiconductor encapsulating, laminated boards or electrical insulation is prepared from a thermosetting resin composition containing: (A) an epoxy resin and (B) a phenol resin represented by the following general formula (1): wherein R1 and R2 are a hydrogen atom or alkyl group having 1 to 4 carbon atoms, and R3 is an amino group, alkyl group having 1 to 4 carbon atoms, phenyl group, vinyl group or the like, and wherein m is an integer of 1 or 2.

Abstract: A high molecular weight epoxy resin obtained by polymerization reaction of a difunctional epoxy resin (X) with a dihydric phenol compound (Y) containing 70-100% by weight of bisphenol S in the presence of a catalyst, the high molecular weight epoxy resin being characterized in that a weight average molecular weight thereof is 10,000-200,000. A resinous composition for a printed circuit board, comprising the high molecular weight epoxy resin, an epoxy resin other than the above-mentioned resin and a curing agent as essential components.

Abstract: The object was to provide an epoxy resin composition which has excellent flame retardancy, heat resistance and humidity resistance and is advantageously used for semiconductor encapsulating, laminated boards, electrical insulation and the like.

Abstract: The present invention provides an epoxy resin composition useful for casting applications, comprising a reaction product obtained by reacting (A) a bisphenol epoxy resin, and (B) bisphenol compounds, and if necessary, (C) monofunctional phenols or carboxylic acid compounds, in the presence of sodium compounds, wherein the epoxy resin composition has(a) an epoxy equivalent: 250 to 500 g/equivalent,(b) a sodium content: 20 to 200 ppm, and(c) a haze of its 40 wt % methyl ethyl ketone solution measured according to ASTM D 1003: 15% or less.

Abstract: A modified liquid epoxy resin composition is provided by reacting a crystalline epoxy resin, from about 3 to about 20 parts by weight, based on the epoxy resin, of a compound having two or more phenolic hydroxyl groups and/or carboxyl groups in one molecule and from about 3 to about 20 parts by weight of a compound having one phenolic hydroxyl group or carboxyl group in one molecule. The crystalline epoxy resin is preferably selected from various glycidylethers of biphenol compounds. The modified liquid epoxy resin composition has a low viscosity and good liquid stability at low temperatures, resulting in cured resins having excellent heat resistance and water resistance.