Polyphenolic condensates and epoxidized products prepared from said condensates are prepared by a reaction utilizing multi catalysts to control the weight average molecular weight (Mw) and the number average molecular weight (Mn). Improved color and ultraviolet absorbance are possessed by the condensates described herein.

Treated aldehyde-based resins containing one or more polyamines and methods for making and same. The treated aldehyde-based resin can be or include an aldehyde-based resin and a polyamine. The polyamine can be or include one or more aromatic polyamines, one or more poly(C.sub.2-C.sub.5 alkylene) polyamines, or a mixture thereof. The treated aldehyde-based resin can include about 0.05 wt % to about 10 wt % of the polyamine, based on a solids weight of the aldehyde-based resin.

The present invention provides a novel cyanate ester compound which has excellent solvent solubility and from which a hardened product having a low coefficiency of thermal expansion and excellent flame retardancy and heat resistance is obtained. The present invention is a cyanate ester compound obtained by cyanating a naphthol-dihydroxynaphthalene aralkyl resin or a dihydroxynaphthalene aralkyl resin.

The present invention provides a novel cyanate ester compound which has excellent solvent solubility and from which a hardened product having a low coefficiency of thermal expansion and excellent flame retardancy and heat resistance is obtained. The present invention is a cyanate ester compound obtained by cyanating a naphthol-dihydroxynaphthalene aralkyl resin or a dihydroxynaphthalene aralkyl resin.

Provided is a highly versatile heat-curable resin composition for semiconductor encapsulation that exhibits a favorable water resistance and abradability when used to encapsulate a semiconductor device; and a superior fluidity and a small degree of warpage even when used to perform encapsulation on a large-sized wafer.

The heat-curable resin composition for semiconductor encapsulation comprises: (A) a cyanate ester compound having not less than two cyanato groups in one molecule, and containing a particular cyanate ester compound that has a viscosity of not higher than 50 Pa.Math.s; (B) a phenol curing agent containing a resorcinol-type phenolic resin; (C) a curing accelerator; (D) an inorganic filler surface-treated with a silane coupling agent; and (E) an ester compound.

The object is to provide a resin composition for a printed circuit board capable of realizing a printed circuit board that not only has heat resistance and flame retardancy but also is excellent in heat resistance after moisture absorption. The resin composition is a resin composition for a printed circuit board containing a cyanate ester compound (A) obtained by cyanation of a naphthol-dihydroxynaphthalene aralkyl resin or a dihydroxynaphthalene aralkyl resin, and an epoxy resin (B).

The present invention provides a material for forming an underlayer film for lithography, including a cyanic acid ester compound obtained by cyanation of a modified naphthalene formaldehyde resin.

A novel rein excellent in dielectric properties, a method for producing a resin, a curable resin composition, and a cured product thereof are provided. The resin has constituent units described in Group (1), wherein a, b, c and d each independently represent a molar ratio of the constituent unit, wherein a is a number of 1 or more, b is a number of 0 or more, c is a number of 1 or more, and d is a number of 0 or more.

##STR00001##

A novel rein excellent in dielectric properties, a method for producing a resin, a curable resin composition, and a cured product thereof are provided. The resin has constituent units described in Group (1), wherein a, b, c and d each independently represent a molar ratio of the constituent unit, wherein a is a number of 1 or more, b is a number of 0 or more, c is a number of 1 or more, and d is a number of 0 or more.

##STR00001##

Novel thermosetting resin composition is provided. A thermosetting resin composition containing a polymer having a repeating structural unit of the following Formula (1-a): ##STR00001##
(wherein each of R.sup.1 and R.sup.2 is independently a hydrogen atom, a C.sub.1-4 alkyl group, phenyl group, or a C.sub.3-6 cyclic alkyl group, X is a single bond or a divalent organic group, and Y is a divalent organic group), and a terminal structure of the following Formula (1-b): ##STR00002##
(wherein Q is a C.sub.1-5 alkylene group, phenylene group in which at least one hydrogen atom may be substituted by a halogen atom, or a 5- or 6-membered divalent saturated heterocyclic group containing at least one nitrogen atom, and R.sup.3 is a hydrogen atom or methyl group).