GB841738A - New process for the preparation of stabilized nitrocellulose - Google Patents

Abstract

In the production of nitrocellulose the nitration is carried out with nitric acid of a concentration not less than 97% by weight based on the total amount of nitric acid and water present in the nitration liquid and exluding any salts that may be present, in the absence of other acids and of acid anhydrides, and the nitrated product, after removing nitric acid from it, by washing with water and boiling with a dilute aqueous alkaline solution, is stabilized by boiling it for a short time with a liquid having a lower surface tension than pure water and miscible with water and nitric acid in all proportions. The liquid is preferably water containing 0,1 to 1% of a water-soluble surface-active agent, and in this case the last two stages of the process may be combined in the single operation of boiling the nitrocellulose with a dilute aqueous alkaline solution containing the surface-active agent. The alkali used is preferably sodium carbonate. The nitric acid used preferably has dissolved in it about 1 to 2% by weight of an anhydrous salt capable of dehydrating the reaction mixture. Examples of these are nitrates of ammonium, sodium, magnesium and calcium. The surface active agent may be a reaction product of ethylene oxide and a long-chain fatty acid. In an example, cellulose is nitrated for 45 minutes at 20 to 25 DEG C. with 99% nitric acid containing 1,5% of an anhydrous alkali metal or alkaline earth nitrate, the nitrocellulose formed removed from the residual acid, washed with water, boiled for one hour with sodium carbonate solution of pH 8, removed from this solution, and boiled for 2 hours with 100 times its weight of water containing 0,1% of a surfaceactive agent. The invention produces an increased yield of nitro-cellulose of improved stability. Specification 470,292 is referred to.