Process for the production of hard paper

A process for the preparation of hard paper by impregnating lengths of cellulose-containing material with a plasticizer-containing phenol- and cresol-resol resin impregnating solution according to a one-step method, subsequent drying, and then hardening of the resin-impregnated paper, characterized in that the mixed resin impregnating solution consists of a mixture of a 50-80% by weight phenol-resol resin solution with a 40-70% by weight cresol-resol resin solution, to which has been admixed, before impregnation, between 20 and 35% by weight of plasticizer based on the sum total weight of solid resins and plasticizer, additionally 4-12% by weight of water, based on the sum total weight of solid resins and plasticizer in the impregnating solution and an organic water-miscible solvent in an amount up to a weight ratio of water:solvent ranging from 1:1 to 1:2.