| 摘要 |
The invention relates to a method for producing a cellulose derivative with formate substituents by reacting a cellulose material that has been impregnated with excess alkaline and/or alkaline-earth lye, with a formylating agent. The method is characterised in that the cellulose material that has been impregnated with the excess base is reacted with a formylating agent until a degree of substitution (DS) of at least approximately 0.5 has been reached. The invention also relates to a method for producing a cellulose derivative with formate substituents by reacting a cellulose material that has been treated with excess alkaline lye with a formylating agent. This method is characterised in that a cellulose material that has been pre-treated with ammonia is reacted with a formylating agent until a degree of substitution (DS) of at least approximately 0.1 has been reached. These methods provide a simple and economical means of producing intermediate products, whose further derivatisation, for example with an acetylation agent, can be better controlled. The resulting products have an essentially homogenous distribution of substituents and in certain cases, have advantageous acetone solubility. |
