PURPOSE: To obtain the title paste excellent in the dispersibility of the electrically conductive powder, affinity for metals and electrical insulating layer surfaces, reactivity etc., suitable for circuit board wiring by incorporating an organic binder with an electron beam-curable polyhydroxystyrene derivative.
CONSTITUTION: (A) A copolymerization is made between hydroxystyrene and a vinyl monomer into a polyhydroxystyrene derivative of formula I [R1-R3 are each H or 1-5C alkyl; A is H, of formula II, etc.; Y and Z are each of formula III, etc. ; X is vinyl monomer, being electron beam-curable monomer when A is H; m≥0, n≥3; k, p and u are each 0-2]. This derivative is dissolved in a solvent such as ethyl cellosolve, and the resulting solution is incorporated with (B) pref. 50-95wt.%, based on the cured coating film, of electrically conductive powder such as copper powder, thus obtaining the objective paste.
YONEDA YASUHIRO
