Improvements in the Treatment of India-rubber, Guttapercha and their Compounds.
Year: 1897

page_text: Date of Application, 13th April, 1897-Accepted, 15th May, 1897
COMPLETE SPECIFICATION (AMENDED).
Improvements in the Treatment of India-rubber, Guttapercha
and their Compounds.
We, EUGEN HORNUNG, Assistant Advocate, of XVIII. Sternwartgasse 9, and STEFAN
HANSEL, Manufacturer, of I. Wipplingerstrasse 17, both in Vienna, in the Empire of
Austria, 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 improvements in the treatment of india-rubber, gutta-
percha and their compounds.
It is well known that india-rubber, guttapercha and their compounds possess the
disadvantage that if after vulcanization they are not freed from the sulphur which is.
not chemically combined with them, they become hard and brittle from the gradual
action of the air which oxidises the surface or when they are continuously exposed to
high temperatures, as for instance, when they are used as packing for steam distri-
buting pipes or the like.
Now our invention has for its object to obviate this disadvantage and to this end
we add to the india-rubber, guttapercha or their compounds before they are vulcanized,
gelatine or glue which has been precipitated in any known manner from a solution in
a state in which it is insoluble in water and which has been carefully freed from all
its water.
We have found by experiment that a uniform intimate mixture of insoluble gelatine
with india-rubber, guttapercha or their compounds can only be obtained by adding
the gelatine in the form of a plastic mass. The gelatine or glue is indeed in this
condition directly after it has been precipitated from its solution, but as it is not free
from water it causes the formation, when the india-rubber, guttapercha or their com-
pounds are vulcanised, of a considerable number of pores. It is therefore necessary
to treat it in such a manner that it can be intimately mixed with the india-rubber,
guttapercha or their compounds when it is in a state free from water and yet in a
plastic condition.
The gelatine or glue, therefore, after it has been precipitated from its solution in
a form insoluble in water is mixed with from 0.1 to 0.5 parts by weight of vulcanized
oil. The mixture can be facilitated if the vulcanized oil is previously caused to swell
by means of turpentine, benzine, or any other volatile hydrocarbon.
The said mixture of insoluble glue and vulcanized oil is carefully dried and the
plastic mass thus obtained is intimately mixed with the india-rubber, guttapercha
or their compounds. The proportions of the mixture depend upon the quality of the
india-rubber or guttapercha mass and also on the filling materials contained in the
latter

page_text: The further treatment and vulcanization are carried out in the usual manner.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :--
1. A process for preventing india-rubber, guttapercha and their compounds from
becoming hard and brittle, such process consisting in mixing the india-rubber,
guttapercha or a compound of the same, before it is vulcanized and treated, with a
plastic mass consisting of a mixture of precipitated gelatine or glue insoluble in
water and vulcanized oil preferably swelled by means of a hydrocarbon, substantially
as herein before described.
2. As a new article of manufacture india-rubber, guttapercha or a compound of the
same mixed as herein before described with a mixture of precipitated insoluble
gelatine or glue and vulcanized oil swelled by means of a hydrocarbon as specified in
the first claim in the form of a plastic mass to prevent it from becoming hard and
brittle.
Dated this 15th day of April 1897.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.