Method of preparing cellulose acetate

Claim 1

IN A METHOD OF PREPARING CELLULOSE ACETATE IN WHICH CELLULOSE IS ESTERIFIED WITH AND DISSOLVES IN A MIXTURE OF ACETIC ANHYDRIDE, ACETIC ACID AND CATALYST, WHEREIN THE REACTION TEMPERATURE RISES TO BUT DOES NOT EXCEED A PEAK TEMPERATURE WITHIN THE RANGE OF 80-120* F., THE STEPS WHICH COMPRISES INITIALLY MIXING THE CELLULOSE WITH THE ACETYLATION MIXTURE CONTAINING 2.5-8% OF SULFURIC ACID BASED ON THE CELLULOSE UNTIL THE CELLULOSE IS SUBSTANTIALLY ALL ACETYLATED, THEN ADDING FURTHER SULFURIC ACID IN AN AMOUNT 1/2-11/2 TIMES THAT EMPLOYED IN THE INITIAL STEP, THUS PROMOTING THE ESTERIFICATION AND DISSOLVING OF UNESTERIFIED CELLULOSE FIBERS AND INHIBITING TRANSESTERIFICATION IN THE RESULTING ESTER FOLLOWED BY ADDING TO THE MASS DILUTE AQUEOUS ACETIC CONTAINING A MAGNESIUM NEUTRALIZING AGENT IN AN AMOUNT ONLY SUFFICIENT TO SUBSTANTIALLY NEUTRALIZE THE AMOUNT OF SULFURIC ACID WHICH WAS ADDED IN THE SECOND STEP OF THE ACETYLATION PROCEDURE, WHEREBY THE MASS IS CONVERTED TO A HYDROLYZING SYSTEM AND HYDROLYZING THE CELLULOSE ACETATE TO ACETONE SOLUBILITY.