An Improvement in the Manufacture of Pyroxylines.
Year: 1891

page_text: Date of Application, 11th Nov., 1891
Complete Specification Left. 16th July. 1892-Accepted 20th Aug. 1392
PROVISIONAL SPECIFICATION.
An Improvement in the Manufacture of Pyroxylines.
I, HILAIRE DE CHARDONNET, of 23 Boulevard de Strasbourg, Paris, France,
do hereby declare the nature of this invention to be as follows:-
All the known methods of preparing pyroxylines include a preliminary drying at
a temperature of about 100° C. or sometimes considerably more or less, the object
and result being simply removal of the moisture which always penetrates cellulose
materials. All these methods give results which are incomplete and uncertain,
affecting both the purity and the solubility of the products.
I have discovered that methodical application of high temperatures modifies the
composition of cellulose materials, first, by attacking the foreign and incrusting
matters so as to prepare for their destruction in the nitrating bath, secondly, by
modifying the cellulose itself, so that the pyroxylines produced from it acquire
special solubility which allows of making collodions containing from 20 to 25
per cent. of pyroxyline.
I operate as follows :
I heat during 6 to 8 hours continuously at a constant temperature, from 150°
to 170° C., the cellulose material, wood, cotton, ramie &c. in a stove having shelves,
which are gratings of tubes for circulation of steam at a pressure of 8 to 10 atmo-
spheres. Suitable valves serve to regulate the air circulation, so as to determine
the desired temperature. The cellulose, when the operation is ended, is immersed
still warm in the nitrating bath.
Dated this 11th day of November 1891.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improvement in the Manufacture of Pyroxylines.
I, HILAIRE DE CHARDONNET of 23 Boulevard de Strasbourg, Paris, France
do hereby declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement :-
All the known methods of preparing pyroxylines include a preliminary drying at
a temperature of about 100° C. or sometimes considerably more or less, the object
and result being simply removal of the moisture which always penetrates cellulose
materials. All these methods give results which are incomplete and uncertain,
affecting both the purity and the solubility of the products.
I have discovered that methodical application of high temperatures modifies the
composition of cellulose materials, first, by attacking the foreign and incrusting
matters so as to prepare for their destruction in the nitrating bath, secondly, by
modifying the cellulose itself, so that the pyroxylines produced from it acquire
special solubility which allows of making collodions containing from 20 to 25
per cent. of pyroxyline.
I operate as follows:
I heat during from 4 to 8 hours continuously at a constant temperature, from 150°
to 170° C., the cellulose material, wood, cotton ramie &c., in a stove having shelves,
which are gratings of tubes of iron or copper for circulation of steam at a pressure
of 8 to 10 atmospheres. Suitable valves serve to regulate the air circulation, so
as to determine the desired temperature. The cellulose when the operation is ended,
is immersed still warm in the nitrating bath.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. Imparting increased solubility to pyroxylines and facilitating the destruction
of foreign matters contained in the cellulose employed therefor, by subjecting the
cellulose matters to a continued heating of several hours at a temperature of from
150° to 170° C.
2. The preparatory treatment of cellulose matters intended for nitration,
consisting in heating the same during from 4 to 8 hours in a current of dry air at
a constant temperature of from 150° to 170° C.
1003
ABEL & IMRAY,
Agents for the Applicant.