A resin composition constituted by containing an epoxy resin monomer having a mesogenic structure, a novolac resin containing a compound having a structural unit represented by the following general formula (I), and an inorganic filler is superior in preservation stability before curing, and can attain high thermal conductivity after curing.

In the following general formula (I), R.sup.1, R.sup.2 and R.sup.3 independently represent a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group; m represents an integer of 0 to 2; and n an integer of 1 to 7.

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An epoxy resin composition (A), having an epoxy resin represented by formula (1):

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and an epoxy resin represented by formula (2):

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where R.sup.1 is a linear aliphatic hydrocarbon group having 1 to 6 carbon atoms, and n is an integer of 0 or 1. An epoxy resin composition (B), having 100 parts by weight of the epoxy resin composition (A) and 0.01 to 1,000 parts by weight of a curing agent.

The invention relates to a method for producing a cured composition which has at least one oxazolidinone ring and at least one isocyanurate ring and is cross-linked by the same, starting from a liquid reactive mixture which, based on the total weight thereof, contains at least one epoxy resin, at least one polyisocyanate, at least one polyol, and at least one catalyst composition. The invention further relates to the cured composition obtainable thereby.

The invention relates to a method for producing a cured composition which has at least one oxazolidinone ring and at least one isocyanurate ring and is cross-linked by the same, starting from a liquid reactive mixture which, based on the total weight thereof, contains at least one epoxy resin, at least one polyisocyanate, at least one polyol, and at least one catalyst composition. The invention further relates to the cured composition obtainable thereby.

To provide an epoxy resin composition that exhibits excellent low-dielectric properties and that is excellent in copper foil peel strength and interlayer cohesion strength in a printed-wiring board application. An epoxy resin composition containing an epoxy resin and a curing agent, wherein the curing agent is partially or fully a polyvalent hydroxy resin represented by the following general formula (1). Each R.sup.1 independently represents a hydrocarbon group having 1 to 8 carbon atoms, each R.sup.2 independently represents a hydrogen atom or a dicyclopentenyl group, and at least one R.sup.2 is a dicyclopentenyl group; and n represents a number of repetitions of 0 to 5.

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To provide an epoxy resin composition that exhibits excellent low-dielectric properties and that is excellent in copper foil peel strength and interlayer cohesion strength in a printed-wiring board application. An epoxy resin composition containing an epoxy resin and a curing agent, wherein the curing agent is partially or fully a polyvalent hydroxy resin represented by the following general formula (1). Each R.sup.1 independently represents a hydrocarbon group having 1 to 8 carbon atoms, each R.sup.2 independently represents a hydrogen atom or a dicyclopentenyl group, and at least one R.sup.2 is a dicyclopentenyl group; and n represents a number of repetitions of 0 to 5.

##STR00001##

A process is disclosed for the production of an epoxy resin. This process includes providing lignin, one or more acids and/or esters derived from epoxidized vegetable oil(s), optionally a solvent and optionally a catalyst, to form a reactive mixture. The reactive mixture is mixed and cured in the presence of a curing agent to form the epoxy resin.

A process is disclosed for the production of an epoxy resin. This process includes providing lignin, one or more acids and/or esters derived from epoxidized vegetable oil(s), optionally a solvent and optionally a catalyst, to form a reactive mixture. The reactive mixture is mixed and cured in the presence of a curing agent to form the epoxy resin.

The present invention provides a thermally conductive material having excellent thermal conductivity. Furthermore, the present invention provides a device with a thermally conductive layer that has a thermally conductive layer containing the thermally conductive material and a composition for forming a thermally conductive material that is used for forming the thermally conductive material. The thermally conductive material according to an embodiment of the present invention contains a cured substance of a disk-like compound, which has one or more reactive functional groups selected from the group consisting of a hydroxyl group, a carboxylic acid group, a carboxylic acid anhydride group, an amino group, a cyanate ester group, and a thiol group, and a crosslinking compound which has a group reacting with the reactive functional groups.

A resin composition for a printed wiring board, including: a phenolic compound (A); a maleimide compound (B); an epoxy compound (C); a cyclic carbodiimide compound (D); an inorganic filler (E); and a curing accelerator (F), wherein a content of the inorganic filler (E) is 100 to 250 parts by mass based on 100 parts by mass of a resin solid content.