GB300551A - - Google Patents

Abstract

300,551. I. G. Farbenindustrie Akt.- Ges. Nov. 14, 1927, [Convention date]. Void [Published under Sect. 91 of the Acts]. Cellulose nitrate.-Nitrocelluloses of high homogeneity or solubility in alcohol are prepared by a two stage process. In the first stage, nitrocelluloses having a nitrogen content below 11.6 per cent are prepared by treating cellulose of any origin and even of low purity at a temperature below 30‹ C. with a mixture of nitric and sulphuric acids containing less than 18 per cent of water. In the second stage, these nitrocelluloses are subjected to the action of water under pressure at a temperature above 100‹ C. with the result that the solubility of the nitrocellulose in alcohol is increased from 15 per cent to about 100 per cent while the nitrogen content is diminished to about 10.5 per cent according to the time and temperature and consequently the pressure of the treatment with water. The nitrocelluloses prepared in this manner are suitable for the manufacture of varnishes, artificial leather, celluloid, &c. In an example, cellulose is nitrated for about one hour at a temperature of 20‹ C. in a nitrating acid containing 17 per cent of water 23 per cent of nitric acid and 60 per cent of sulphuric acid. The nitrated product is then washed in the usual manner and treated with water in an autoclave for one hour at 130‹ C. The nitrogen content is tiiereby reduced from about 11.5 per cent to about 11 per cent and the solubility in alcohol is increased from about 15-20 per cent to about 98 per cent.