Process for the treatment of cellulosic materials to prevent deterioration and decay

Claim 1

A PROCESS FOR TREATING CELLULOSIC MATERIALS TO RENDER THEM HIGHLY RESISTANT TO THE DETERIORATION AND DECAY CAUSED BY THE ATTACK OF BIOLOGICAL ORGANISM AND CELLULOSEATTACKING INSECTS WHICH COMPRISES IMPREGNATING A CELLULOSIC MATERIAL BY CONTACT WITH AN AQUEOUS SOLUTION HAVING A PH BETWEEN 6.0 AND 8.0 AND CONSISTING ESSENTIALLY OF FROM 9% TO ABOUT 20% AMMONIUM FORMATE AND FROM ABOUT 0.15% TO ABOUT 15% BY WEIGHT COPPER IN THE FORM OF CUPRIC AMMONIUM FORMATE, SAID AQUEOUS SOLUTION BEING MAINTAINED IN THE RANGE OF 10* TO 45*C. AND AT A PRESSURE BETWEEN 0.2 AND 20 ATMOSPHERES, REMOVING THE IMPREGNATED CELLULOSIC MATERIAL FROM CONTACT WITH THE SOLUTION, AND FIXING THE COPPER WITHIN THE CELLULOSIC MATERIAL BY HEATING TO TEMPERATURES WITHIN THE RANGE OF 100*C. TO 200*C., AND RECOVERING A PRODUCT HAVING 0.5% TO ABOUT 8% BY WEIGHT OF COPPER DEPOSITED IN THE CELLULOSIC MATERIAL INCLUDING FROM ABOUT 0.3% TO ABOUT 6% BY WEIGHT OF COPPER CHEMICALLY BOUND TO THE CELLULOSE AS DETERMINED BY THE FACT THAT THE COPPER IS INSOLUBLE WHEN SAID CELLULOSIC MATERIAL IS LEACHED WITH 4% AQUEOUS AMMONIA.