| 摘要 |
<p>Cellulosic raw materials are digested in an alkaline digesting liquor contg. cpds. of formula R-Y-(R1)m-X (I) in free acid or salt form. In (I) m is 0-15; X is sulpho, -P(O)(OH)2 or -P(O)(OH)(R2), R2 is R-Y-(R1)m and is same as or different to R-Y-(R1)m- in (I). Y is a direct bond, O or, when m is not = O, also -CO-O-; R is 1-22C alkyl, 2-14C alkenyl, 5 or 6C cycloalkyl opt. substd. by 1-3 1-6C alkyl, or phenyl or naphthyl opt. substd. by 1-2 1-12C alkyl, and R1- is -CnH2n-O-, where n is 1-6, and when m is 1. R1 is also -CH2-CH(OH)-CH2- or -CH2-CHOH-CH2-O-). The liquor must contain >=1 cpd. (I) in which X is different from a sulpho gp. when m is O. Also claimed are mixts. of surfactants, comprising (I). Presence of (I) speeds up the digestion and gives improved yield and quality of pulp. The pulp tends itself better to bleaching, reducing the amt. of bleaching agent required.</p> |
