A Process for and Materials Used in the Production of a Substitute for Gutta Percha.
Year: 1887

page_text: Date of Application, 8th Oct., 1887
Complete Left, 12th June, 1888
Complete Accepted, 20th July, 1888
A Process for and Materials Used in the Production of a Substitute
for Gutta Percha.
'
I, HERMANN SIEBERT, of Leipzig, Germany, Chemist, do hereby declare the nature
of this invention to be as follows:-
A generally useful substitute for gutta percha is obtained in this process by
intimately mixing india rubber with a resin, or a resinous substance; or, eventually,
à material used for artificial rubber, such as balsam of sulphur or so-called volcanic
oil mixed with a substance easily melted; as paraffin, stearine, wax, and the like.
The different components may be either melted together, or used in the form of
solutions.
In the practical execution of the above, I have found in the first group, asphalt,
the most serviceable; amongst substances resembling rubber, good results have been
obtained with balsam of sulphur and with yolcanic oil: both of which give very similar
results. In the third group of substances, all tend to give about the same results,
with very slight differences; as my experiments have amply proved.
One of the best methods found was the following. 75 parts of Mexican asphalt is
melted, and mixed with the so-called balsam of sulphur, prepared out of 19 parts of
rape seed oil, 6 to 8 parts of sulphur, and 8 to 15 parts of paraffin. This balsam of
sulphur is added to the asphalt in the melted condition, and well mixed with it; after
which the mass is left to cool and laid aside to settle for six to eight weeks. Or else,
the composition may be kept in its melted condition for an hour or two at a tem-
perature of 150° to 200° C., which, I consider, increases the elasticity of the resulting
body:
The substance, thus obtained, possesses the principal qualities of gutta percha, or
which it may be used; but it differs from it in being somewhat softer, and having less
elasticity and toughness; but these defects may be overcome, to a great degree by the
admixture of substances like rubber, sulphur, bone dust, animal charcoal, fibre,
leather shavings or dust, or other substances that are usually employed in the manu-
facture of gutta percha. By volcanic oil, is meant fatty oils acted upon by chloride
of sulphur..
FAIRFAX & WETTER,
433, Strand, London,
Agents for the Applicant..

page_text: COMPLETE SPECIFICATION.
A. Process for and Materials Used in the Production of a Substitute
for Gutta Percha.
I, HERMANN SIEBERT, Chemist, of Leipzig, in the German Empire, do hereby
declare the nature of my invention and in what manner the same may be per-
formed, to be particularly described and ascertained in and by the following
statement:
A substitute for gutta percha applicable for many purposes is obtained by intimately!
mixing a resin, or resinous substance, with India rubber, or a rubber like material,
such as balsam of sulphur, or vulcanised oil (that is, the rubber-like mass obtained by
causing chloride of sulphur to act on fatty oils), or oil rubber (obtained from linseed
oil by treatment with heat and dilute nitric acid) and with an easily fusible substance,
such as paraffin, stearine, wax, and the like. The different components may be either
melted together, or used in the form of solutions.
In the practical execution of this process, I have found that in the first group,
asphalte is the most serviceable material; amongst substances resembling rubber,
good results have been obtained with balsam of sulphur. In the third group of
substances, all tend to give about the same results, with very slight differences; as my
experiments have amply proved.
The substance possesses the principal qualities of gutta percha; for which it may
be used; but it differs from the same by being somewhat softer, and having less
elasticity and toughness; these defects, however, may be overcome, to a great degree,
by the admixture of substances like rubber, bone dust, animal charcoal, fibre, leather
shavings or dust, or other substances that are usually employed in the manufacture of
gutta percha.
Further experiments have shown, that the new substitute may be most conveniently
made of asphalte in combination with balsam of sulphur, to which may be added
paraffin, wax, stearine or ozokerit, in the proportion of: Asphalte, 1 part; balsam of
sulphur, from to 1 part, eventually with the addition of paraffin &c., up to a ½ part.
The manufacture is carried out as follows :—
The asphalte is fused in a suitable receptacle, and at the same time the balsam
of sulphur prepared from the necessary quantity of fatty oil to which has been added
the paraffin or other admixture, if such is to be employed, by causing the sulphur to
act at a temperature of about 150° C. The latter liquid, when still hot, is added to
the melted asphalte, and the two are well mixed together.
The process may, of course, be modified, by melting together asphalte, oil and
eventually also paraffin, ozokerit &c., in any desired order, and allowing the sulphur
to act only on the united mass.

page_text: Having now particularly described the nature of my invention and in what manner
the same may be performed, I declare, that I claim :-
The production of a substitute for gutta percha, by intimately mixing together resin
or resinous bodies, such as asphalte, with India rubber or similar substances, such as
balsam of sulphur, vulcanized oil, oil rubber, with or without the addition of an easily
melting substance, such as paraffin, stearine, ozokerit, wax and similar substances :
and eventually incorporating with the product substances usually employed in the
manufacture of gutta percha.