Year: 1888

page_text: Date of Application, 9th Apr., 1898
Complete Specification Left, 7th Jan., 1889
Complete Specification Accepted, 9th Mar., 1889
د
I, le Vicomte HULAIRE DE CHARDONNET of Besançon (Doubs) France,
Proprietor, do hereby declare the nature of this invention to be as follows:-
When pyroxilin in filaments or strips is digested in a bath containing certain
reducing agents such as sugar, acetic acid, alcohol, protochiloride of iron, &c., or even
if pure water is used, the pyroxilin, under the influence of time and temperature,
gradually loses its combined nitrogen. Nitric acid produces the same effect in a more
regular and complete manner, the action depending on the time, concentration and
temperature, which may vary within a wide range. The denitrating process according
to my invention is as follows:-
This trans-
The pyroxilin is maintained at a temperature of 30° to 35° C. in a bath of nitric
acid of a density of about 1.82. In a few hours it loses part of its nitrogen and
reaches a condition below that of tetranitric cellulose (M. Vicille).
formation is recognized by analysis or by sampling for solubility, or by observing the
beginning of a softening which the pyroxilin undergoes. It is rapidly washed
in warm or cold water and immediately immersed in the dye val, then washed
with cold water and dried in a current of warm air. This process when
applied to artificial silk (spun collodion) renders it unnecessary to introduce into
the mother solution metallic chlorides or alkaloids for lessening combustibility.
ABEL & IMRAY,
Agents for the Applicant.

page_text: I, Le Vicomto HILAIRE DE CHARDONNET of Besancon (Doubs) France,
Proprietor 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 :-
When pyroxilin in filaments or small strips moulded in various ways is digested in
a bath containing certain reducing agents such as sugar, acetic acid, alcohol proto-
chloride of iron &c., or even when pure water is employed it will be observed that,
under the influence of time and of temperature, the pyroxilin will gradually lose its
combined nitrogen. Nitric acid, by a phenomenon of dissociation produces the same
effect in a more regular and complete manner; the action is accelerated in direct
proportion to the time, degree of concentration and temperature, which may vary
between wide limits, while bringing about the desired results.
The denitrating process according to my invention is as follows:-
The pyroxilin is maintained at a temperature of from 30 to 40 degrees Cent. in a
bath of acid of about 1-32 density. In a few hours (from 2 to 24, according to the
thickness of the threads or strips) it loses a part of its nitrogen and reaches a condition
below that of tetranitric cellulose (Mr. Vieille) that is to say, it will not contain more
than from 6 to 6 per cent. of combined nitrogen.
This transformation is recognised either by analysis, or by a test of solubility, or by
observing the beginning of softening which the pyroxilin undergoes.
This softening renders the pyroxilin permeable in respect of a great number of
substances which can be incorporated therewith, whether for the purpose of dyeing
the same, or for increasing its weight or rendering it incombustible or for combining
metals therewith. The material is washed rapidly in warm or cold water or it is
dipped at once into the dye vat, then washed, spread out, and dried in a current of
warm air.
This process, applied to artificial silk (spun collodion) flexible glass &c. renders it
unnecessary to introduce into the mother solution metallic chlorides, for decreasing
the combustibility of the material.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what
I claim is :-
1. The process of denitrating pyroxilin by immersing the same for some hours in a
bath of nitric acid, and then washing and immersing in a dye bath, substantially as
herein described.
2. The application of the process referred to in the preceding claim to the
manufacture of artificial silk (spun collodion) flexible glass, and the like whereby
the introduction into the mother solution of metallic chlorides and for diminishing
combustibility is dispensed with, substantially as herein described.
D.
1 1
T
1000
ABEL & IMRAY,
Agents for the Applicant.