Improvements in and connected with the Manufacture of Nitro- cellulose or Pyroxyline Compounds.
Year: 1894

page_text: Date of Application, 14th Nov., 1894
Complete Specification Left, 16th Sept., 1895-Accepted, 9th Nov., 1895
PROVISIONAL SPECIFICATION.
Improvements in and connected with the Manufacture of Nitro-
cellulose or Pyroxyline Compounds.
I, FREDERICK GREENING Junior, of 71, Listria Park, Stoke Newington, in the
County of London, Manufacturing Chemist, do hereby declare the nature of this
invention to be as follows:-
This invention relates to the manufacture of nitro-cellulose or pyroxyline
compounds and of a solvent therefor, for use as substitutes for ivory, whalebone,
horn, india-rubber, gutta percha, vulcanite and the like, for covering and protecting
electric wires or as a solution for capsuling and hermetically sealing any kind of
vessels, bottles, jars and the like, for waterproofing textile fabrics, also for producing
photographic films, or as a varnish for wood, stone, iron metals and other substances,
my improved compounds being less inflammable than those hitherto produced.
In carrying out my invention I first treat fibrous substances of any suitable kind,
such as paper, rag, grass or cotton by immersing the same in a bath composed of
alumina sulphate. The fibrous substances after removal from the alumina bath
are dried and placed in a bath of sulphuric acid of about 1840 S.G. and sub-nitrous
acid 1.52 S.G. in the proportion of about 70% of the sulphuric acid to 30% of
the sub-nitrous acid. This acid mixture I prefer to use at a temperature not
exceeding 100 degrees Fahrenheit, and I find good results are obtained by employing
about one pound of the fibrous substance to one gallon of this mixture of acids,
such proportion of acid being sufficient to saturate the fibrous substance. The
saturated mass is then submitted to pressure or otherwise to expel any excess of
acid and allowed to remain for from two to three hours, when the conversion into a
soluble condition will be effected. It is then washed in a bath composed of alumina
sulphate in the proportions of about one 1 lb. of alumina sulphate to five gallons of
water, after which it is washed in a plentiful supply of water until all trace of the
treatment is expelled. It is then thoroughly dried and is ready to be converted
into a plastic or liquid state by means of a suitable solvent.
The solvent which I prefer to employ is picamar obtained from the distillation of
wood tar, which product I have found by experiment gives good results as
a solvent.
I sometimes mix with the picamar methylated alcohol in the proportions of about
70% of alcohol to 30% of the wood tar product. I then add chromic acid salt in
the proportions of about lb. of the salt to every gallon of the mixture of picamar
and alcohol, but more or less can be used; and I distil the same at a temperature
not exceeding 300 degrees Fht.
The distillate thus obtained is also suitable as a solvent for pyroxyline.
The plastic or liquid pyroxyline may be combined with any suitable material or
pigment according to the compound to be produced in any well-known manner.
I have found that asbestos in a finely divided condition is very suitable for almost
all purposes.
Dated the 14th day of November 1894.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant,

page_text: Improvements in and connected with the Manufacture of Nitro-
cellulose or Pyroxyline Compounds.
I, FREDERICK GREENING Junior, of 71, Listria Park, Stoke Newington, in
the County of London, Manufacturing Chemist, 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 :-
This invention relates to the manufacture of nitro-cellulose or pyroxyline com-
pounds and of a solvent therefor, for use as substitutes for ivory, whalebone, horn,
india-rubber, gutta percha, vulcanite and the like, for covering and protecting
electric wires or as a solution for capsuling and hermetically sealing any kind of
vessels, bottles, jars and the like, for waterproofing textile fabrics, also for pro-
ducing photographic films, or as a varnish for wood, stone, iron, metals and other
substances, my improved compounds being less inflammable than those hitherto
produced.
In carrying out my invention I first treat fibrous substances of any suitable kind,
such as paper, rag, grass or cotton by immersing the same in a bath composed of
alumina sulphate in the proportion of say one lb. of alumina sulphate to one gallon
of water at a temperature of 212° Fah. In practice I find it advantageous to
combine with this bath of alumina sulphate a bleaching agent such as hypo-
chlorite of lime of which I add say two pounds, the said bleaching agent not
only having the effect of improving the colour of the finished product but also of
rendering the base more susceptible to the action of the solvent. The fibrous
substances after removal from the alumina bath are dried and placed in a bath
of sulphuric acid of about 1840 S.G. and nitrous acid 1.52 S.G. in the proportion
of about 70% of the sulphuric acid to 30% of the nitrous acid. This acid
mixture I prefer to use at a temperature not exceeding 100 degrees Fah. and I
find good results are obtained by employing about one pound of the fibrous
substance to one gallon of this mixture of acids, such proportion of acid being
sufficient to saturate the fibrous substance. The saturated mass is then submitted
to pressure or otherwise to expel any excess of acid and allowed to remain for from
two to three hours, when the conversion into a soluble condition will be effected.
It is then washed in a bath composed of alumina sulphate in the proportions of
about one lb. of alumina sulphate to five gallons of water, after which it is washed
in a plentiful supply of water until all trace of the treatment is expelled. It is
then thoroughly dried and is ready to be converted into a plastic or liquid state by
means of a suitable solvent.
The solvent which I prefer to employ is obtained from the distillation of
wood tar, which product (say picamar) I have found by experiment gives good
results as a solvent.
I sometimes mix with the picamar methylated alcohol in the proportions of
about 70% of alcohol to 30% of the wood tar product. I then add chromic
acid salt in the proportions of about lb. of the salt to every gallon of the mixture
of picamar and alcohol, but more or less can be used; and I distil the same at a
temperature not exceeding 300 degrees Fab.
The distillate thus obtained is also suitable as a solvent for pyroxyline.
The plastic or liquid pyroxyline may be combined with any suitable material or
pigment, according to the compound to be produced, in any well-known manner.
I have found that asbestos in a finely divided condition is very suitable for almost
all purposes.

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. The described process for treating the base nitro-cellulose or pyroxyline for
the purpose stated, such process consisting in first treating the base in a bath of
alumina sulphate prepared as described and drying the same, then submitting the
dried mass to a bath composed of sulphuric and nitrous acids, then removing the
excess of acid and then, after drying, treating the mass with a solvent of the kind
set forth, substantially as described.
2. An acid bath for treating the base nitro-cellulose or pyroxyline consisting of
nitrous and sulphuric acids substantially in the proportions described.
Dated the 16th day of September 1895.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Apdlicant.