An Improved Electric Insulating Compound and Process of Preparing same.
Year: 1893

page_text: Date of Application, 9th June, 1893-Accepted, 19th Aug., 1893
COMPLETE SPECIFICATION.
An Improved Electric Insulating Compound and Process of
Preparing same.
We, ADOLF GENTZSCH, Mineralogist, Kurhausgasse 2, JULIUS GOLDSCHMIDT,
Consul General for the United States of America, in Vienna Austria, Wasagasse 2,
and ETIENNE RITTER VON SCANAVI, Banker, Elizabethstrasse 15, all of Vienna,
aforesaid, 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 an inproved electric insulating compound and to the
process of preparing same. In carrying out the invention we take shellac,
(bleached shellac or "orangelac" being the best) and heat it in a suitable vessel
or distilling apparatus. In this vessel the shellac becomes soft, melts into a thick
pulp and begins to swell up; if it be allowed to cool in this condition, it would
become as brittle as before; but the temperature is now raised (to about 400° and
over) by which means the melted product increases in volume about tenfold and
changes its original yellow colour into a dark blackish brown one; a decom-
position now takes place in which first a watery, but later on an oily fluid is
separated (or steamed off) and caught in the receiving-vessel of the distilling
apparatus. During this process the mass subsides to about the former volume, and
a substance remains in the still, which continues soft and pliable after cooling, and
possesses the valuable property of being able to be vulcanized in the usual manner.
Fluxes can be added to the shellac, for the purpose of accelerating the melting
process, carbureted hydrogens such as aniline oil, anthracene and the like being
particularly adapted for the purpose.
The vulcanized product produced possesses the property of mingling with oils, fats
and wax in desired quantities without losing its vulcanizing properties. I have
found suitable proportions to be 80 parts by weight of shellac 12 parts by weight
of anthracene and 8 parts by weight of aniline oil.
The product is pre-eminently insulating, free from water and durable particularly
in respect to the action of acids, which renders it particularly adapted for electrical
purposes such as insulating, impregnating etc. Vessels made of paste board or
wood steeped in, impregnated with or rubbed over and vulcanized with the above
substance are particularly adapted for accumulator boxes.
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. The process of producing a vulcanizable shellac which consists in distilling
shellac under a gradually increasing temperature substantially as described.
2. In the production of a vulcanizable shellac as described in the foregoing claim
the addition to the shellac under treatment of suitable carburetted hydrogens such
as aniline oil or anthracene substantially as described.
3. The improved insulating compound substantially as described.
Dated the 9th day of June 1893.
For the Applicants,
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London, Chartered Patent Agent.