Prepn. of cellulose carbamate forming stable spinning soln

Cellulose carbamate is obtd. from opt. degraded cellulose by subjecting 1 pt. wt. cellulose (esp. as flakes) to alkaline reaction with 0.1-3 pts. urea (or salt). The reaction is effected in presence of a synergistic activating system comprising gaseous anhydrides of (in)organic acids and 0.001-10 pts. wt. (per 100 pts. wt. cellulose) of salts of (in)organic acids. The reaction occurs at 130-170 deg C for 10-600 mins., with the prod. opt. being purified. Pref. the anhydrides in the activating system are CO2, SO2, CO and/or acetic anhydride, while the salts are Na-acetate, -formate, -carbonate or -sulphate, urea-formate or -acetate and/or Co(II)-formate or -acetate. The components of the activating system can be introduced separately, together or with the urea (or salt), such introduction into the cellulose being by mixing or soaking for 1-600 mins. at 20-60 deg C. Alternatively, the salts of the actuating system can be introduced into the cellulose in the course of a neutralisation reaction, again by mixing or soaking for 1-600 mins. at 20-60 deg C.