An Improved Method of Treating Decayed or other Rubber.
Year: 1898

page_text: Date of Application, 24th Nov., 1898-Accepted, 4th Feb., 1899
COMPLETE SPECIFICATION.
An Improved Method of Treating Decayed or other Rubber.
I, MAXIMILIAN ZINGLER, Fellow of the Chemical Society, of 19, Buckland Crescent
Belsize Park, London, N.W., Gentleman, do hereby declare the nature of this inven-
tion 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 the treatment of decayed or other rubber and has for its
object the production from decayed oxidised, or deteriorated rubber, of a product
which is purified and dessicated, and will not afterwards absorb moisture; and
added to this advantage it has gained considerably in tensile strength and solidity,
by the thorough coagulation of the vegetable albumen and the contraction of its
gummy and oleaginous particles.
Such product is adapted for commercial use for any purposes to which rubber is
applicable and for vulcanizing in the usual way. It can be kept or preserved for
a long time without deterioration and a great saving of time in drying the rubber is
gained, as the same can be effected in as many hours, as, by the known processes,
weeks are required.
To carry my improved process into effect I first wash the rubber in the usual way
through washing machines, to remove all dirt therefrom, and to draw it out into
thin sheets, which is technically known as "crushed rubber."
I then immerse in an appropriate earthen ware vessel or wooden vat the clean
"crushed" rubber for one or two days or longer, according to the nature or quality
of the rubber in either of the following solutions, according to the quality of
rubber which being treated.
To treat 100 lbs. of rubber where the material is more or less oxidized :-
1st. I dissolve in from 30 to 40 gallons of hot water, at a temperature of about
212° F. 5 lbs. of tartar emetic first, and then add 7 lbs. or more of pure or com-
mercial tannic acid or an equivalent greater quantity of substances containing
tannates or tannic acid, such as catechu or extracts of oak or willow bark and the
like.
2nd. When the material is in a sticky condition, I may alternately substitute for
the tartar emetic about 5 lbs. of calcium sulphite solution or about 2½ lbs. in
crystallised powder; or other sulphites of other metallic bases may be used according
to the quality of the rubber that it is desired to treat. In this case the water of
solution must be cold.
3rd. When the material has an intermediate quality between that for which I use
the 1st and 2nd solutions, to the first solution I may add 2 lbs. or more of calcium
sulphite solution or powder, or other sulphites of other metallic bases in place of
calcium sulphite for cheapness.
After the immersion of the rubber in one or other of the above solutions it is
taken out and hung up to dry in a current of cold or warm air, which dries it in a
few hours, or the drying may be still more accelerated by placing the wet rubber in
a hydro-extractor; and once dry the rubber so prepared does not attract further
moisture.
•

page_text: It is then rolled out or callendered through cold rollers and cut into any required
shape.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
A process for the treatment of deteriorated and oxidised or other rubber, after
the usual washing, by immersing it for a period of from one to two days or longer,
according to the quality of the rubber treated, in one of the following solutions:-
a) to treat 100 lbs. of crushed clean rubber, about 5 lbs. of tartar emetic and 7 lbs.
or more of tannic acid, (or equivalent tannates), dissolved in 30 to 40 gallons of
hot water at a temperature of about 212° F.
b) In the same quantity of cold water about 7 lbs. of tannic acid (or equivalent
tannates) and 5 lbs. or more of calcium sulphite solution or powder, or the same
amount of any sulphite of another metallic base.
c) In the same quantity of hot water about 7 lbs. of tannic acid (or equivalent
tannates) about 2 lbs. of tartar emetic and about 2 lbs. of calcium sulphite or
equivalent sulphite of another metallic base, all substantially as and for the purposes
described.
Dated this 24th day of November 1898.
FELL & JAMES,
1, Queen Victoria Street, London, E.C., Agents for the Applicant.