| 摘要 |
The present invention solves the problem of the yellowing, often pronounced yellowing, of lignin containing cellulose pulps, e.g. high yield pulp. In accordance with the invention the pulp, subsequent to being bleached is: a) always treated with at least one chemical, which chemically reduces alpha -carbonyl and gamma -carbonyl groups in the lignin; and in at least one further step is b) treated with at least one chemical, which will block the phenolic hydroxyl groups of the lignin and/or c) supplied with at least one chemical, which will convert short-wave light quanta to long-wave light quanta. According to a preferred embodiment of the invention cellulose pulp is subjected to all of the above treatment processes, i.e. a) + b) + c) and is washed after the two initial treatment stages. |
