Method of waterproofing cellulosic materials and product thereof

Claim 1

METHOD OF FORMING A PAPER STOCK FROM WHICH WATERPROOFED PAPER MAY BE FORMED, COMPRISING THE STEPS OF THOROUGHTLY DISPERSING A SOLUTION OF A CONDENSATION RESIN IN AN AQUEOUS PAPER-MAKING STOCK CONTAINING FIBERS THEREBY FORMING AN EMULSION OF SAID RESIN IN SAID STOCK, SAID SOLUTION BEING THE DISCONTINUOUS PHASE OF SAID EMULSION, SAID CONDENSATION RESIN BEING FORMED BY THE STEP OF REACTING A FORMALDEHYDE SOURCE AND A SUBSTITUTED PHENOL UNDER REFLUXING CONDITIONS AT A TEMPERATURE BELOW ABOUT 200*F. TO FORM A CONDENSATION RESIN SOLUBLE IN ACETONE, SAID SUBSTITUTED PHENOL HAVING SUBSTITUENT RADICALS SO PLACED THAT NOT MORE THAN TWO METHYLOL RADICALS OF SAID FORMALDEHYDE SOURCE CAN ADD TO SAID SUBSTITUENT PHENOL, SAID SUBSTITUENT RADICALS BEING SELECTED FROM THE GROUP CONSISTING OF SATURATED AND UNSATURATED ALIPHATIC RADICALS HAVING A TOTAL OF BETWEEN 4 TO 12 CARBON ATOMS AND SATURATED AND UNSATURATED CYCLIC HYDROCARBON GROUPS WHICH WHEN JOINED TO THE PHENOLIC RING DO NOT RESULT IN THE FORMATION OF A COMPOUND HAVING CONJUGATED UNSATURATION THROUGHOUT, SAID SOLUTION OF SAID RESIN COMPRISING FROM ABOUT 0.05 TO ONE MOL OF A STRONGLY ALKALINE MATERIAL FOR EACH MOL OF SAID SUBSTITUTED PHENOL PRESENT, FROM ABOUT 15 TO ABOUT 35% RESIN SOLIDS AND A MIXTURE OF A LOWER MONOHYDDRIC ALCOHOL AND WATER AS A SOLVENT, THE QUANTITY OF SAID WATER IN SAID MIXTURE BEING LESS THAN THAT WHICH WILL PRECIPITATE OUT SAID RESIN.