PURPOSE: To obtain the subject composition, excellent in electrical characteristics and punchability, hardly causing a migrating phenomenon of silver and useful as a varnish, etc., for laminated sheets used in printed circuits by adding an addition reactional product of an aliphatic amine with aldehydes to a phenolic resin.

CONSTITUTION: The objective phenolic resin composition useful as laminated sheets is obtained by mixing tung oil with m-cresol and p-toluenesulfonic acid, reacting the resultant mixture at 100°C for 1hr, then adding p-tertiary butylphenol, paraformaldehyde and aqueous ammonia thereto, carrying out reaction at 90°C for 2hr, removing water under reduced pressure, adding a solvent to the prepared mixture, providing a phenolic resin varnish and adding a compound obtained by performing addition reaction of an aliphatic polyamine (e.g. hexamethylenediamine) with aldehydes (e.g. furfural) to the produced phenolic resin varnish. Furthermore, sheets of kraft paper are impregnated with this composition and dried to afford resin-impregnated substrates. The obtained eight substrates are then superposed and thermally contact bonded under laminating conditions of 160-165°C) and 80kg/cm2 for 60min to provide a resin laminated sheet.