The Synthetic Production of India Rubber.
Year: 1899

page_text: The Synthetic Production of India Rubber.
I, WILLIAM JAMES CORDNER, of 17, Shaftesbury Avenue, in the County of
London, Merchant, do hereby declare the nature of this invention to be as
follows:
-
The object of this invention is the synthetic production of india rubber by
the assimilation of kindred gums and fibres which under certain conditions
appear to have a natural affinity for each other, and yield in the after produc
tion an elastic material possessing the qualities of natural rubber. This is
effected by combining cleaned China grass or rhea fibre with the latex of the
tabernaemontana crassa at a temperature of 300 to 400 degrees Fah., assimila-
tion commencing at 300, and perfect combination between 350 and 400; time
of operation about four hours.
The mass thus formed is then allowed to cool, when on examination it will
be found that although the fibrous structure of the rhea remains, its textile
strength has completely broken down and a chemical change taken place, that
is to say, synthetically the carbon of the fibre has combined with the hydrogen
of the latex.
At a temperature of 120 Fah. the material is worked through mixing rolls
until its fibrous structure has disappeared and the whole is reduced to a uniform
mass. During the working, oxygen yielding substances when heated are intro-
duced, such as borate of manganese, per manganate of potassium &c., or a curing
substance such as sulphur to the extent of 5 to 8 per cent. The mass is then
allowed to rest for about forty eight hours, for the purpose of what might be
termed synthetic digestion or assimilation.
It is then subjected to steam heat at a pressure of forty to forty five pounds
to the square inch, the pressure being gradually raised from nil until the work-
ing pressure is reached, the time allowed for raising being about one hour.
This pressure is kept up for one to two hours and then allowed to fall back to
zero, when the material should be removed and allowed to cool; it will then
be found to have absorbed the remaining quantity viz. oxygen. This completes
the synthesis and the result possesses all the qualities of india rubber.
From this stage it can be worked the same as cleaned rubber, and loaded up
in accordance with the purpose for which it is intended.
י
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1
1000

page_text: COMPLETE SPECIFICATION.
The Synthetic Production of India Rubber.
I, WILLIAM JAMES CORDNER, of 17, Shaftesbury Avenue, London, W., Gentle-
man, 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:-
The object of this invention is the synthetic production of india rubber by
the assimilation of kindred gums and fibres which under certain conditions
appear to have a natural affinity for each other, and yield in the after produc-
tion an elastic material possessing the qualities of natural rubber.
In carrying out my process I take China grass or rhea fibre, which I have
previously dessicated to remove any oil or volatile matter therefrom and the
latex of the taberncemontana crassa (a Chinese plant, the latex being commer-
cially known here as pontianak gum and on the Continent as Borneo mort)
in or about the proportions hereinafter mentioned. I thoroughly incorporate
these materials by feeding them in between a pair of hot rolls at a temperature
of about 120° Fah. and work the materials until they are thoroughly incor-
porated. I then place the mixed materials in an oven, the temperature of which
is about 300° Fah. The oven heat is gradually raised to a temperature between
350° Fah. and 400° Fah. The whole time of the working operation will be
about four hours, and I find that the required combination will take place if
during the last two hours of the process a temperature of about 360° Fah. is
maintained.
The mass thus formed is then allowed to cool, when on examination it will be
found that although the fibrous structure of the rhea or other similar fibre
remains, its textile strength has completely broken down. The material is
then worked at a temperature of about 120° Fah. through mixing rolls until
its fibrous structure has disappeared and the whole is reduced to a uniform mass.
During this latter treatment oxygen giving substances are introduced such as
borate of manganese, per manganate of potassium, or a curing agent such as
sulphur to the extent of 5 to 8 per cent. and if desired a toughening material
such as balata to the extent of about 10% may be added to give strength to the
resultant product.
The mass is then allowed to rest for about forty eight hours, for the purpose
of what might be termed synthetic digestion or assimilation. It is then placed
in a suitable vessel inside a steam chest and subjected to steam heat at a pressure
of forty to forty five pounds to the square inch, the pressure being gradually
raised from nil until the working pressure is reached, the time allowed for
raising being about one hour. This pressure is kept up for one to two hours
and then allowed to fall back to zero, when the material should be removed and
allowed to cool. This completes the synthesis and the resultant product possesses
all the qualities of india rubber. From this stage it can be worked the same
as cleaned rubber, and loaded up in accordance with the purpose for which it is
intended.
We have found from experience the following proportions to give excellent
results for various grades of material.

page_text: 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:-
1st. A process for the synthetic production of india rubber, consisting in the
mixture and treatment, substantially as herein before described of cleaned China
grass or rhea fibre and the latex of the tabernaemontana crassa.
2nd. A material consisting of China grass or rhea fibre and the latex of the
tabernaemontana crassa mixed and treated, substantially as described.
Dated this 26th day of January 1900.
FELL & JAMES,
1, Queen Victoria Street, London, E.C., Agents for the Applicant.