Resin compositions including at least two different inert fillers that are useful for preparing prepregs and laminates that are used in manufacturing printed circuit boards.

##STR00001##

The present invention relates to a resin composition, comprising (a) an epoxy resin; (b) a curing agent comprising the structure of formula C1; (c) an inorganic filler; wherein R.sup.C1 is (a) a siloxane group of formula C1a or (b) or both a siloxane group of formula C1a and an ester group of formula C1b; R.sup.C2 is selected from a bulky C.sub.4 to C.sub.12 alkyl group comprising at least one tertiary or quaternary carbon atom; R.sup.C11, R.sup.C12, R.sup.C13 are independently selected from methyl, ethyl and 1-propyl; R.sup.C14 is selected from a linear or branched C.sub.1 to C.sub.8 alkyl; X.sup.C1 is selected from a divalent C.sub.1 to C.sub.4 alkanediyl group; and n is an average number of repeating units and is from 1.05 to 200.

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; and a curing catalyst, the epoxy resin including an epoxy resin represented by Formula 1: ##STR00001##

The present invention provides a resin composition comprising: (A) 100 parts by weight of epoxy resin; (B) from 10 to 80 parts by weight of benzoxazine resin; (C) from 10 to 50 parts by weight of dicyclopentadiene phenol resin; and (D) from 0.5 to 5 parts by weight of amine hardener; wherein the resin composition is free of diallyl bisphenol A (DABPA).

The present application provides a rapid curing epoxy resin composition for fiber-reinforced plastic materials that can be used with modern fast-cure heating systems without loss of heat resistance, surface quality, or mechanical properties of the cured epoxy matrix composite as well as prepregs and fiber-reinforced plastic materials based thereon as their matrix resins. The epoxy resin composition includes an epoxy resin, a dicyandiamide, an aromatic urea, and a clathrate complex comprising at least one compound selected from the group consisting of carboxylic acid compounds and tetrakisphenol compounds and at least one epoxy accelerator which is an imidazole and/or imidazoline.

An epoxy resin obtained by a reaction of an epoxy resin monomer having a mesogen backbone and having two glycidyl groups in one molecule with a divalent phenol compound having, as substituents, two hydroxyl groups on one benzene ring, in which a number average molecular weight in gel permeation chromatographic measurement is from 600 to 2,500.

An epoxy resin obtained by a reaction of an epoxy resin monomer having a mesogen backbone and having two glycidyl groups in one molecule with a divalent phenol compound having, as substituents, two hydroxyl groups on one benzene ring, in which a number average molecular weight in gel permeation chromatographic measurement is from 600 to 2,500.

A primer for forming a primer layer on the surface of a substrate having surface free energy of 50 mN/m or higher, the primer including a liquid crystalline epoxy compound and a curing agent.

A primer for forming a primer layer on the surface of a substrate having surface free energy of 50 mN/m or higher, the primer including a liquid crystalline epoxy compound and a curing agent.

A composition of epoxide-functionalized resins comprises at least a first epoxide-functionalized novolac resin, a second epoxide-functionalized novolac resin, and a curing agent selected from phenolic or amine-type curing agents, the average molar mass of the group consisting of the entirety of the epoxidized novolac resins in the said composition being between 550 and 650 g/mol, the average epoxide functionality of the said group being between 3 and 3.5 eq epoxide/mol, and the said composition having a glass transition temperature Tg of at least 160° C.