Abstract: The invention provides resin-having metal foil for a multilayered wiring board which comprises metal foil having provided on one side thereof a film of a thermosetting resin having a relative dielectric constant of not higher than 3.3 at a frequency range of not lower than 1 MHz and having a resin flow of from 1 to 50% or from 5 to 50%, and a process for producing the same. The invention also provides a (sequentially) multilayered wiring board produced by using the resin-having metal foil and an electronic device comprising the multilayered wiring board and an electronic element connected thereto with a wiring means.

Abstract: A novel curable polyphenylene ether resin composition caontains (a) a curable polyphenylene ether resin containing at least a reaction product of a polyphenylene ether with an unsaturated carboxylic acid or an acid anhydride, (b) at least one cyanurate selected from the group consisting of triallyl isocyanurate and triallyl cyanurate, optionally (c) a resin composition comprising an epoxy resin and a curing agent and/or (d) a compound having at least one unsaturated double bond and at least one epoxy group and/or (e) a reinforcement material. The resin composition has excellent film-forming properties, resin flowability in pressing and storage stability. A cured polyphenylene ether resin composition obtained by curing the curable polyphenylene ether resin composition has excellent chemical resistance, heat resistance, dielectric properties and dimensional stability.

Abstract: A novel curable polyphenylene ether resin composition is disclosed, which comprises (a) a curable polyphenylene ether resin having at least one group selected from the group consisting of an allyl group and a propargyl group and (b) at least one cyanurate. The resin composition has excellent storage stability, film-forming properties and melt moldability. If desired, a fire retardant, optionally together with an antimony-containing auxiliary fire retardant, and/or a reinforcement is incorporated into the resin composition in order to improve the fire retardance and mechanical properties of the resin composition, respectively. By curing the resin composition, a cured polyphenylene ether resin composition comprising a chloroform nonextractable polyphenylene ether resin component and a chloroform extractable, polyphenylene ether-containing component is obtained, which has excellent chemical resistance, electrical properties, dimensional stability and heat resistance.

Abstract: A novel cured polyphenylene ether resin is disclosed comprising a chloroform nonextractable polyphenylene ether and a chloroform extractable polyphenylene ether. By subjecting the resin to pyrolysis gas chromatography, the resin is decomposed to form 3,5-dimethylphenol specifically. The chloroform extractable polyphenylene ether is contained in the resin in an amount of 0.01 to 20% by weight and comprises polyphenylene ether units substituted by an alkenyl group and/or an alkynyl group. The novel cured polyphenylene ether resin has excellent mechanical properties, electrical properties, heat resistance and chemical resistance. The cured polyphexylene ether resin is prepared by curing a novel curable polyphenylene ether resin comprising polyphenylene ether units substituted with an alkenyl groups and/or an alkynyl groups at a specific average substitution degree.