ES364196A1 - Granular nitrocellulose manufacture - Google Patents

Abstract

Granular nitrocellulose is prepared by dispersing fibrous nitrocellulose in an aqueous medium containing an organic solvent for the nitrocellulose, the solvent being miscible or partially miscible with water and being present in an amount sufficient to soften but insufficient to dissolve the nitrocellulose, and also containing a dispersant, followed by removing the solvent, e.g. by distillation or steam-stripping, to obtain a dispersion of granular nitrocellulose in the aqueous medium. The organic solvent may be methyl, propyl or butyl acetate, isopropyl isobutyrate, methyl isobutyl ketone or preferably acetone, ethyl acetate or methyl ethyl ketone. The dispersant may be Na, K, Li or ammonium hydroxides or salts thereof with a polybasic acid having a first dissociation constant of less than 0À2, and more than one equivalent, per mole of the acid of the hydroxide, e.g. salts of azeleic, boric, carbonic, citric, maleic, oxalic, orthophosphoric, ortho-phthalic, pyrophosphoric, tartaric and silicic acids, e.g. trisodium phosphate salts of organic phosphates such as the watersoluble salts of acid polyoxyethylene nonylphenol phosphate, acid alkyl phosphate and acid fluoroalkyl phosphate.