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Патент USA US2410319

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2,410,319
Patented Oct. 29, 1946
UNITED. STATES PATENT’ OFFICE
METHOD OF PRODUCING NITRO
CELLULOSE
Henry Von Kohorn, New York, N. Y.
No Drawing. Application May 22, 1941,
Serial No. 394,619
5 Claims. (01. 260--222)
My invention relates to an improved nitro-cel
lulose having a high and stable nitrogen content,
2
I shall now describe in detail how I carry out
my improved process. When speaking of cellu
lose herein, I refer to alpha-cellulose.
and. to a method of producing the same.
It also relates to the manufacture of nitro
cellulose or cellulose nitrate with a more stable
Example 1
Wood pulp with a cellulose content of 83% is
dissolved according to the viscose method into
nitrogen content than known ‘up to now, from
cellulose-containing materials which are com
viscose containing 16% alpha-cellulose. The said
paratively poor in cellulose. I can produce 'by
the method hereinafter described a satisfactory
viscose is squirted through a spinneret into a
10 bath containing by weight 2/3 of sulphuric acid
nitro-cellulose from raw materials heretofore con
‘ :and 1/5. of nitric acid, the balance of the bath
being water. The threads formed are wound up
on a bobbin, which bobbin runs in the same bath.
Up to the present time, nitro-cellulose has been
sidered unsuitable for the manufacture of nitro
cellulose.
'
When the bobbin is completely Wound, the
mainly produced from puri?ed cotton or other
cellulosic material which was puri?ed to such an 15 threads are unwound and boiled in water in or
' der to remove the acid.
extent as to contain almost only pure alpha-cel
The threads are then dried and cut into pieces.
lulose. There exist, of course, a large number of
cellulose-containing plants of an alpha-cellulose
Example 2
content of less than 80% and such materials
Straw
is
dissolved
according to the cuprammo~
have been considered unsuitable for the manu 20
nium method into a cellulose cuprammonium so
facture of nitro-cellulose.
lution containing 12% cellulose. The said solu
Nitro-cellulose was produced by dipping puri
tion is forced through a nozzle into a bath con
?ed cotton or other puri?ed cellulosic matters into
taining 60% sulphuric acid, 20% nitric acid and
a bath containing, for example, 60% ~sulphuric
acid, 23% nitric acid and 17% water. Another 25 water. The ?laments obtained are withdrawn
and stored in a tank at the end of the machine
suggested nitrating solution contained 2%; of sul
containing the same type of bath. When nitra
phuric acid and 1/5 nitric acid, the balance being
tion is complete, the said ?laments are Washed
water. The cellulose is left in this bath for a
free of acid, dried and cut.
.
suf?cient length of time, for instance one hour,’
at a temperature which was not allowed to rise 30
Emample ‘3 '
freely but which Was kept constant.
The cellulose is dissolved into viscose and the
The use of puri?ed cotton linters or even pure
said viscose is stored until it is so ripe as to be
alpha-cellulose prepared from other cellulose-con
close to the coagulation point. The viscose is
taining materials,. such as wood, straw, reeds,
or other plants, is of course a costly one due to 35 then forced through spinnerets into‘ a bath con
the puri?cation.
taining 55% sulphuric acid, 25% nitric acid and
Also the nitration of ‘ such
20% water. The ?brous mass obtained is then
?brous matters by the method described above
removed from this ?rst bath and is immediately
does not result in a very stable nitrogen content
placed, without :intermediate treatment, into a
of the nitro-cellulose, and many attempts have
been made to improve the stability of the said 4-0 second bath containing % sulphuric acid, 1/5 ni
tric acid and the balance consisting of water.
nitrogen content.
After remaining in the second bath for 30
I have discovered a method which enables me
minutes, the ?bers are removed, desulphurized by
treatment with sodium sulphide solution, washed‘
taining 100% alpha-cellulose, but also many cel
lulose-containing materials comparatively poor 4-5 and dried.
. Example 4
in alpha-cellulose content. In addition to this,
my method results in a nitro-cellulose having a
Wood pulp with a cellulose content of 90% is
more stable nitrogen content which, if required,
brought into solution according to the viscose
may also be higher than produced heretobefore.
method. The viscose is delivered into a bath
According to my invention, nitro-cellulose hav 50 containing 2/3 of sulphuric acid, 1A; of nitric acid,
ing a high and stable nitrogen content is man;
the balance being water. The regenerated cel
ufactured by bringing cellulose or cellulose-con
lulose is kept in this bath for 30 minutes at a
taining materials into solution by any of the
temperature of 25° C.
‘
‘
known methods (viscose, cuprammonium, ace
Example
5
tate), and then regenerating said cellulose and 55
Cellulose is regenerated and nitrated as in Ex
at the same time nitrating it; by precipitating the
ample 4 with the di?erence that the time dur
solution containing dissolved cellulose in a bath
which not only has a precipitating, but at the
ing which the cellulose is kept in the bath is 90
minutes.
same time, a nitrating effect on the regenerated
60
By following any one of the above-described
to use as raw material not only materials con
cellulose.
~
7
a
2#110,319
examples, cli?erent types of Intro-cellulose are
produced which ‘may have varying contents of
As another feature of my invention (as de
scribed in the examples), I havediscovered that
nitrogen, but which are extremely stable; It is
my'process can be carried out very economically
obvious that by applying a nitrating agent to the
by producing a cellulose solution with a high cel
cellulose while still in the “status nascendi,” the’ 5 lulose content which ordinarily would. not be
mtratmg e?ect is much stronger and more thorconsidered suitable for the manufacture of rayon.
gggkartgailufohen appljeld to oroinary solid cellu- ~ [In View Of Z126 T6205 [11% I125’ ??/
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