Improvements in Artificial India-rubber.
Year: 1893

page_text: Date of Application, 26th Oct., 1893
Complete Specification Left, 25th Aug., 1894-Accepted, 29th Sept., 1894
[Communicated from abroad by ALFRED NOBEL, of 59, Avenue Malakoff, Paris,
in the Republic of France, Engineer.]
Improvements in Artificial India-rubber.
I PHILIP ARTHUR NEWTON, of The Office for Patents, 6 Bream's Buildings,
Chancery Lane, in the County of London, Patent Agent, do hereby declare the
nature of this invention to be as follows:-
On dissolving nitrocellulose, or nitrated hydrocellulose, or nitrated oxycellulose,
in a suitable non-volatile, or slightly volatile, solvent, such as nitronaphthalene,
dinitrobenzol, nitrotoluol, nitrocynene, heavy camphor oil, camphor, acetine,
diacetine, triacetine, products are obtained which vary from a viscous or gelatinous
consistency to the hardness of ebonite, according as the proportion of dissolved
nitrocellulose, or above mentioned equivalent substance, increases therein. But
between these two extremes, there is an intermediate stage when the quantity of
nitrocellulose, or its aforesaid equivalent, dissolved, produces a substance, the
consistency of which bears a striking resemblance to india-rubber. The exact
quantity of dissolved nitrocellulose, or its aforesaid equivalent, which produces that
result; will depend on the nature of the nitrocellulose employed, and as that
substance is rarely, if ever, quite uniform, it must needs be left to practice to
find, for each case, the quantity to be incorporated, by dissolving action, for the
purpose of producing the desired consistency and elasticity. The proportion of
dissolved nitrocellulose needed to produce the wished-for result, moreover, depends
on the nature of the solvent chosen, and also on the temperature at which it is
intended that the artificial indiarubber herein described should be used, it being
understood that the hardness and elasticity of the same substance decreases with
increasing temperature, so that the aforesaid material, if intended to be used at a
relatively high temperature, should be made to contain, of dissolved nitrocellulose,
the proportion needed to give it, at such temperature, the requisite consistency and
elasticity. When such stage is reached is easily ascertained by comparing the
consistency and elasticity with that of india-rubber intended to be employed for a
similar purpose, and at the same temperature.
With the object of reducing the inflammability of the product herein described,
it is well to make use of nitrocellulose of the lowest nitration convenient for the
purpose in view.
The least volatile solvents are most suitable for the aforesaid purpose, especially
when it is intended that the product obtained should be used at a relatively high
temperature. As a rule, liquid solvents, such as triacetine, nitrobenzol, nitrotoluol,
heavy camphor oil, castor oil mixed with predisposing solvents, such as acetone or
acetate of amyle, give a more elastic product, when nitrocellulose is dissolved
therein, than is obtained with solvents solid at the ordinary temperature, such as
nitronaphthalene, dinitrobenzol, dinitrotoluol. But solvents composed partly of
substances liquid at the ordinary temperature, and partly of substances solid at that
temperature, as, for instance, mixtures of nitrobenzol and dinitrobenzol, or of nitro-
toluol and dinitrotoluol, or of triacetine and mononitronaphthalene, give, with the
requisite proportion of dissolved nitrocellulose, very elastic compositions.
By aid of malaxation, the aforesaid substitute for india rubber is easily made
with or without the addition of a volatile solvent, such volatile solvent, if employed
(after evaporation) leaving the material in its elastic condition. Wet nitrocellulose
is, without the aid of volatile solvents, easily incorporated with the aforementioned

page_text: non-volatile solvents at a temperature at which they are liquid, and after due
evaporation of the adhering water, the substance obtained possesses the requisite
elastic properties, which are easily increased or decreased by incorporating more
of nitrocellulose or more of solvent.
Dated this 26th day of October 1893
NEWTON & SON,
Agents for the Applicant.
Improvements in Artificial India-rubber.
I, PHILIP ARTHUR NEWTON, of The Office for Patents, 6 Bream's Buildings,
Chancery Lane in the County of London, Patent Agent, do hereby declare the
nature of this invention and in what the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
On dissolving nitrocellulose, or nitrated hydrocellulose, or nitrated oxycellulose
(which substances are hereinafter called collectively nitrocellulose), in a suitable
non-volatile, or slightly volatile solvent, such as nitronaphthalene, dinitrobenzol,
nitrotoluol, nitrocymene, nitroxylol, nitrocumol, products are obtained which vary
from a viscuous or gelatinous consistency, to the hardness of ebonite, according as
the proportion of dissolved nitrocellulose is increased. But between these two
extremes, there is an intermediate stage, when the quantity of nitrocellulose dis-
solved produces a substance the consistency of which bears a striking resemblance
to india-rubber. The exact quantity of nitrocellulose which produces that result,
will depend on the nature of the nitrocellulose employed, and as that substance is
rarely, if ever, quite uniform, it must needs be left to practice to find, for each case,
the exact quantity to be incorporated, for the purpose of producing the desired
consistency and elasticity. The proportion of nitrocellulose needed to produce the
wished for result, moreover, depends on the nature of the solvent chosen, and also
on the temperature at which it is intended that the artificial india rubber herein
described should be used, it being understood that the consistency and elasticity of
the compound decrease with increasing temperature, so that the aforesaid material,
if intended to be used at a relatively high temperature, shall be made to contain,
of dissolved nitrocellulose, the proportion needed to give it, at such temperature,
the requisite consistency and elasticity. When such stage is reached is easily
ascertained by comparing the consistency and elasticity with that of india rubber
intended to be employed for a similar purpose, and at the same temperature.
With the object of reducing the inflammability of the product herein described,
it is well to make use of nitrocellulose of the lowest nitration, which is sufficiently
soluble to suit the purpose in view.
The least volatile solvents are most suitable for the aforesaid purpose, especially
when it is intended that the product obtained should be used at a relatively
high temperature. As a rule, liquid solvents give a much more elastic product,
when nitrocellulose is dissolved therein, than is obtained with solvents solid at
the ordinary temperature, such as nitronaphthalene, dinitrobenzol, dinitrotoluol.
But solvents composed partly of substances liquid at the ordinary temperature,
and partly of substances solid at that temperature, and dissolved in a liquid
non-volatile solvent, as, for instance, mixtures of nitrotoluol and dinitrotoluol, or of
nitrocumol and nitronaphthalene, give, with the requisite proportion of dissolved
nitrocellulose, very elastic compositions.
By aid of kneading between rollers, steam heated, if desired, or in a suitable
kneading machine, the aforesaid substitute for india rubber is easily made with
or without the addition of a volatile solvent. Wet nitrocellulose is, without the
aid of volatile solvents, easily incorporated with the before-mentioned non-
volatile solvents at a temperature at which they are rendered liquid, and after

page_text: due evaporation of the water, the compound obtained will be found to possess
the requisite elastic properties, which are easily increased or decreased by varying
the proportions of nitrocellulose and solvent.
If dry nitrocellulose is made use of, 20% of its weight of acetone, or equivalent
volatile solvent. is conveniently added to the nonvolatile solvent or solvents afore-
said, and if the mixture is treated in a kneading machine sufficiently protected
against evaporation, such addition of acetone will vary materially facilitate the
incorporation. Said acetone is driven off while treating the material between
rollers, it being understood that it should form no part of the final product.
Very suitable solvents for producing, when incorporated with nitrocellulose, a
substitute for india rubber, are obtained from such mixtures as, say, 1 part (part
means here and hereafter part by weight) of nitrocymol, 1 part of nitrotoluol, and
1 part of nitronaphthalene; or, say, 1 part of nitrotoluol, 1 part of dinitrobenzol,
and 1 part of nitronaphthalene; or nitrotoluol alone, without the addition of other
solvent.
Of course the composition of the solvent can be greatly varied, and chemical
equivalents for such purpose are numerous, but it should be borne in mind, that
a solvent incorporated with nitrocellulose, can form no proper substitute for india-
rubber, unless it possesses the following properties, viz. :-
(1.) It must be a solvent for nitrocellulose, that neither exudes nor gives rise to
any brittleness of the final product.
(2.) It must be insoluble, or next to insoluble in water.
(3.) It must have no explosive or highly oxidising properties.
(4.) It must be nonvolatile, or so little volatile that no change can take place
through evaporation from the final product.
(5.) Its chemical stability must be perfect.
The proportion of nitrocellulose to be incorporated with the aforesaid solvent or
solvents, will depend on the degree of elasticity and consistency required. When
the final product contains 20% of nitrocellulose, it resembles soft india rubber;
with 50%, it is something intermediate between india rubber and celluloid; and
between those two proportions, every gradation can be obtained by increasing or
decreasing the proportion of dissolved nitrocellulose.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed (as communicated to
me from abroad), I declare that what I claim is :-
A substitute for india rubber, consisting of nitrocellulose, or hydronitrocellulose,
or oxynitrocellulose, combined with a nonvolatile solvent, substantially as and for
the purposes herein set forth.
Dated this 23rd of August 1894.
NEWTON & SON,
Agents for the Applicant.