Paper pulp mfr. by mechanical-chemical treatment of cellulose - with intermediate treatment by oxidising agent e.g. sodium hypochlorite

摘要

Paper pulps are mfd. as described in the parent patent by (a) mechanical treatment of the cellulose material and (b) treatment with alkaline soln of peroxide, partic. treatment in an alkaline liq or contg. 1-5 (2-3) wt.% (w.r.t. dry pulp wt.) H2O2 and 3-10 (4-6) wt.% NaOH, at =100 (40-80) degrees C, for 1l4 (1-2) Hrs. Improvement is that the cellulose material is treated, between stages (a) and (b), by 1-5 (1-3) wt.% (w.r.t. dry plant wt.) of an oxidising agent, partic. Nacl or ClO2. By treating the cellulose material wit an oxidising agent between stages (a) and (b), improved mechanical characteristics can be obtd. without any resulting fall in the yield.