US670346A - Process of treating nitro-cellulose. - Google Patents

Description

. a f" I I ib) I ALFRED LUCK, OF DARTFORD, COUNTY OF KENT, AND CHARLES F. GROSS, OF THE COUNTY OF LONDON, ENGLAND.

PROCESS OF TREATING NlTRO-CELLULOSE.

I sr'ncrmcstrron forming part a Letters Patent No. 670,346, dated March 19,1901.

Application filed September 17, 1898. Serial lio- 691,216. (No sp im ns-l To an whom it may concern.-

Be it known that we,ALFRED LUOK,residing at Brentcote, Dartford, Kent, and CHARLES FREDERICK ORoss, residing at No. 4 New Court, Garey street, in the county of London, England, chemists, citizens of England, have invented a certain new and useful Improve- .ment in the Treatment of Nitro-Cellulose for the Manufacture of Explosi yp sand opher Products, (for which we have applied for patcuts in Austria July 9, 1898; in Germany July 7, 1898; ,in-Great Britain March 3, 1898, No. 5,286, and in Hungary July 18, l898,) of which the following is a specification.

I5 Nitro-cellulose asitis usually manufactured retains a fibrous structure which occasions considerable difficulties in the subsequent treatment. Even in ordinary granulated nitro-cellulose the structure of the fibers still remains in the granules, not having been always destroyed by granulationifl Our invention relates to means-of avoiding these difficulties by reducing thanitro-cellulose at once in its original fibrous form to a 2 5 structureless condition without mechanical treatment. For this purpose we subject nitro-cellulose, either in the mass or in a more or less finely-divided condition, to the action,

of solvents, such as acetone, acetic ether, py ridine, nitrobenzene, and the like diluted with a proportion of inert liquid. In the case of acetone or other. solvent miscible with water we use, preferably, water as the diluent. When the solvent is not miscible with wateras, for 3 5 instance, nitrobenzene-it may be diluted with alcohol. Such liquids rapidly and completely-destroythe fibrous condition of the nitro-cellulose, and at the same time it is freed from certain impurities which remain dissolved in the liquid even" after further dilu- .-tion. The case of acetone may be taken as typical, and we shall therefore describe the flulose nitrate of, say, thirteen pericent, nitro- "gen (taken not necessarily in a dry condition) ;a cetone-that is, acetone diluted with water in the. proportion of about ninety two parts J nacetoneto eight parts water, -by'volume,is

poured upon the fibrous nitrate in quantiti -.;process as carried out with this solvent. A cel-' placed-in a suitable vessel, and adiluted f sufficient to cover it. The change of physical condition rapidly ensues, the swelling of the fiber being followed by a disintegration, so that on slight agitation the last remnants of the original fibrous structure are destroyed. .55

This effect is attended by a certain limited solvent action upon the fibrous nitrates, whereby certain constituents are taken up in solution and, in fact, in a permanently-soluble form.

The solution thus formed is diluted with wa- 6o ter, whereby any structureless cellulose nitrates which may have been dissolved are precipitated; but there remains in solution a group of constituents of strongly acid character, which it is desirable to eliminate. The

physical change from the fibrous to the struc- 7 5 tureless form, the process chemically purifies the product.

For certain purposes the fibrous nitrate may in the first place be granulated or reduced to a more or less finely-divided condition in the wet state, the granules being then treated as more or less structureless and coherent without any tendency to agglomerate into masses.

On further dilution of the acetone and wash-,

ing the granules acquire density and hardness and 011 being dried form a free granulated powder.- The product is also chemically stable. The simultaneous changes in form and composition furnish a product which 0 character of the-product we can so treat ni- 5 tro-cellulose that it becomes a fine fibrous powd'er. For this purpose-we prefer to employ a mixture' of acetone and alcohol, for instance, incqual proportions by volume.

ial is coyeredlwith this mixed solution, and

The mate- The Washed 7o on then adding water the material is reduced to the condition of an extremely fine fibrous addition of a solution of lead acetate.

lead salts thus obtained contain fifty to sixtypowder.

The removal of by-products causing instability may be efiected as a separate treatment independently of disintegration by treating the fibrous nitrate with a more dilute acetone,

. such as equal parts, by volume, of acetone and three per cent. PhD and three to four per cent. of nitric nitrogen. They are explosive and may be used in fireworks.

Having thus described the nature of this invention and the best means we know for carrying the same into practical efiect, we claim- The herein-described process of reducing nitro-cellulose to an approximately structureless condition for the manufacture of explosives or for other purposes, which consists in subjecting the nitro-cellulose in its original fibrous form to the action of a diluted solvent in a sufficient quantity to cover the nitro-eellulose to render it structureless, in greater or less degree, and simultaneously thei ewith remove the impurities, and finally washing.

In testimony whereof we have hereunto set our hands in presence of two subscribing witnesses.

ALFRED LUCK. o. F. GROSS.

Witnesses:

FRED G. HARRIS, JNO; P. M. MILLARD.