Process for fixing aminoplasts in the wet state on cellulosic fibrous materials

Claim 1

IN A PROCESS FOR IMPARTING TO CELLULOSIC FIBROUS MATERIAL A WATER RESISTANT IMPREGNATION PROTECTING SUCH MATERIAL FROM ATTACK BY MICRO-ORGANISMS, WITHOUT SUBSTANTIAL CHANGE IN THE TENSILE STRENGTH OF THE SAID MATERIAL, BY TREATING IT WITH AN AQUEOUS IMPREGNATING LIQUID OF AN AMINOPLAST WHICH CONTAINS A HARDENING CATALYST, WHEREIN AFTER IMPREGNATING THE MATERIAL AND REMOVING MECHANICALLY THE EXCESS OF IMPREGNATING LIQUID THE AMINOPLAST IS HARDENED IN AND UPON THE FIBER INTO THE WATER-INSOLUBLE CONDITION, THE IMPROVEMENT CONSISTNG OF HEATING THE IMPREGNATED MATERIAL TO EFFECT SAID HARDENING WITH RETENTION OF A SUBSTANTIAL AMOUNT OF WATER OF THE IMPREGNATING LIQUID UNTIL THE RESIN CONDENSATION IS COMPLETED SO THAT THE CONDENSATION INTO THE WATER-INSOLUBLE STATE IS ACTUALLY CONDUCTED IN THE PRESENCE OF WATER ORIGINATING FROM THE IMPREGNATING LIQUID, THE SAID HARDENING CATALYST FROM A COMPOUND SELECTED FROM THE GROUP CONSISTING OF DIACETIN, MONOCHLORHYDRIN, DICHLORHYDRIN, GLYCOL DIACETATE, GLYCOL METHYL ETHER ACETATE, GLYCOL ETHYL ETHER ACETATE AND DIETHYL TARTRATE.