Process for the preparation of nitrocellulose solutions having a low water content
AssigneeDow Global Technologies LLC
InventorsHolger Tanneberger, Lutz Driesen, Juergen Engelstardt, Werner Lange, Hans-Guenter Poersch-Panke
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Abstract
The present invention relates to the continuous preparation of alcohol- and plasticizer-free finished nitrocellulose solutions having a particularly low water content by partial distillative falling-film evaporation of comparatively water-rich, optionally emulsion-like crude nitrocellulose solutions which are preferably provided by dissolving nitrocelluloses of the customary solid forms offered, which are known to be initially water-moist as a result of the preparation, in preferably ethyl acetate.
Claims6
A continuous process for the preparation of low water content nitrocellulose solutions, comprising the steps of:
- providing a crude nitrocellulose solution comprising a solvent, water, and 3.5 to 12.5% nitrocellulose by mass,
- introducing the crude nitrocellulose solution into a first falling-film evaporator;
- passing the crude nitrocellulose solution through the first falling-film evaporator into a second falling-film evaporator;
- taking off from the second falling-film evaporator a finished nitrocellulose solution having 20 to 35% nitrocellulose by mass and a residual proportion of water of up to 1% by mass;
- and
- recirculating a portion of the solvent for subsequent reuse in preparing an additional crude nitrocellulose solution.
Dependencies are inferred from the claim text.