To obtain a thermosetting resin compsn. which gives a film or a cured item having low permittivity and dissipation factor and a high glass transition point by incorporating a propargyl ether compd. and a cure catalyst comprising nickel naphthenate or cobalt naphthenate into the same.

The propargyl ether compd. is represented by the formula (wherein R is H or 1-3C alkyl). A difunctional propargyl ether compd. may be used jointly, usually in an amt. of up to 250 wt.% of the trifunctional propargyl ether compd. represented by the formula. The cure catalyst is used usually in an amt. of 0.1-10 wt.% of the sum of propargyl ether compds. A thermosetting resin may be used to facilitate the sheeting of the compsn. The compsn. is useful for binders for coating materials, sealants, or composites or laminates of ceramics or fibers.