摘要 |
A process for the preparation of hard paper involves impregnating lengths of cellulose-containing material with plasticizer-containing mixture of a phenol-resol resin solution and cresol-resol resin solution according to a one-step method, subsequent drying, and then hardening of the resin-impregnated paper. The impregnating solution employed is 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, a plasticizer and additional water. The water is added in amounts of 4-12% by weight, based on the sum total weight of solid resins and plasticizer in the total solution mixture. |