DE501282C - Process for the production of copper oxide ammonia cellulose solutions for spinning rayon - Google Patents

Description

Process for the preparation of copper oxide ammonia cellulose solutions for spinning rayon The subject of the invention is a method for Manufacture of copper oxide ammonium cellulose solutions as a starting material for the manufacture of rayon.

It is known to use such solutions for rayon production use. However, there is an excess of ammonia in relation to the solution of the cellulose to the amount required to maintain the final solution his nut. This excess is done after the dissolution process has ended Suction removed. This procedure was cumbersome and associated with ammonia losses. For example, a solution of copper-sulfate monial cellulose has been prepared in such a way that that the cellulose is impregnated with aqueous ammonia, and copper hydroxide is added and stirred the whole thing until it was completely dissolved. There was about 1q. "1" of ammonia necessary to completely dissolve the cellulose while maintaining it of the finished solution only about 7% ammonia, sometimes even less, are necessary.

According to the invention, the ammonia production is lossless Spinnable Kupferoxy dammoniakcelluloselösungen made possible by that after solution of the main part of the cellulose by means of a to maintain the spinning ability of the The finished solution is sufficient, but insufficient to dissolve the entire amount of cellulose Amount of copper oxide ammonia mechanically crushes the still undissolved cellulose particles he follows.

It is known per se to use copper oxide ammonia solutions and pulp in a Kolloi, dmühle or a similar device for the purpose of acceleration to deal with the solution process. In contrast, the invention is that this known process is used to produce an unfinished copper oxide ammonia cellulose solution, the only proportion necessary to maintain the spinnability of the finished solution contains small amount of ammonia, to turn into a complete solution, like set out to save ammonia.

If you do so, the amount of cellulose that is initially not goes into solution, but initially only swells due to the mechanical aftertreatment the half-finished solution also brought into solution. You get one as well spinnable solution, as if, according to the known method, an overshoot Applies ammonia.

Mechanical crushing can be done in all suitable machines and fixtures happen. There come z. B. Mills in question how to achieve them fine dispersions are known. You can also create the half-finished solution by layering it finest filter material, e.g. B. sand, press through. Apparently the just swollen Cellulose particles when passing through the filter layer completely crushed. Solutions prepared in this way are straightforward spinnable.

Exemplary embodiment roo kg cotton, 40 kg copper hydroxide, 70 kg 25 percent aqueous ammonia solution is subjected to a preparatory mixture and then diluted with roughly 1 liter of water, whereby in the approach ro per cent cellulose, 4 per cent It contains copper and 7% ammonia. The mixture is now stirred in a kettle, until most of the cellulose is dissolved. Now about the undissolved cellulose residue Also still to dissolve, the mixture is filtered through high pressure filter pressing with one pressure pushed through by several hundred atmospheres and to a dilution kettle directed. The filters of the presses consist, for example, of 6o to 8o stacked one on top of the other close-meshed nickel. seven. The spinning solution is now immediately ready for spinning.

Claims (1)

PATENT CLAIM: Process for the production of copper oxide ammonia cellulose solutions for spinning artificial silk, characterized in that after the main part has been dissolved the cellulose by means of a solution to maintain the spinnability of the finished solution sufficient but insufficient amount of copper oxide ammonia to dissolve the total amount of cellulose a mechanical comminution of the still undissolved cellulose parts takes place.