IMPROVEMENTS IN ABSTRACTING SULPHUR AND OTHER MATTERS FROM "IMPROVEMENTS IN ABSTRACTING SULPHUR AND OTHER MATTERS FROM VULCANIZED INDIAN-RUBBER.
Year: 1853

page_text: LETTERS PATENT to William Christopher, of Euston Square, and
Gustavus Gidley of Robert Stroot, Hoxton, for the Invention of
IMPROVEMENTS IN ABSTRACTING SULPHUR AND OTHER MATTERS FROM
"IMPROVEMENTS IN ABSTRACTING SULPHUR AND OTHER MATTERS FROM
VULCANIZED INDIAN-RUBBER.
Sealed the 16th December 1853, and dated the 16th June 1853.
PROVISIONAL SPECIFICATION left by the said William Christopher
and Gustavus Gidley at the Office of the Commissioners of
Patents, with their Petition, on the 16th June 1853.
We, WILLIAM CHRISTOPHER, of Euston Square, and GUSTAVUS
GIDLEY, of Robert Street, Hoxton, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN ABSTRACTING SULPHUR AND
OTHER MATTERS FROM VULCANIZED INDIA-RUBBER" to be as follows:-
In manufacturing vulcanized India-rubber, or articles formed of that
material, it is desirable in many cases, after the usual operations of
vulcanizing the caoutchouc or the manufactured articles themselves, to
withdraw or separate some portions of the sulphur or of the excess of
sulphur that remains interposed in the pores of or is combined with the

page_text: caoutchouc; or, in other words, to adjust the relative proportions of
the sulphur and the caoutchouc in the vulcanized material for either
ordinary or for any special applications of it.
It is desirable also to be able to work up or re-employ refuse vulca-
nized india-rubber, such as the parings or cuttings, &c., that accu-
mulate in manufactories of that material, or by some ready and
economical method of treating such refuse to seperate from it the
sulphur, or so much sulphur as leaves the caoutchouc in a condition
to be acted acted upon by its usual solvents, and consequently restoring
it to a condition admitting of its being re-worked in any form, and, if
required, re-vulcanized.
Now, our Invention consists in macerating the vulcanized India-
rubber in a hot solution of carbonated alkali, or in a solution of hydrate
of lime, or in hot water in which caustic lime is suspended, till, through
the action of the alkali or of the lime, the requisite quantity of sulphur
is abstracted; that is, either as much sulphur withdrawn as reduces the
relative proportions of the sulphur and the caoutchouc to those required
for any special purpose, or so far removes the sulphur as to leave the
residual material in a condition to be acted on by the usual solvents or
softeners of caoutchouc, so as to adapt it for re-formation into manu-
factured articles, and of being re-vulcanized, if required.
We prefer that the vulcanized caoutchouc to be so treated should,
when it admits of it (as when the refuse parings or cuttings, &c., are
to be worked up), be comminuted or cut up into small pieces, for the
action of the alkali or of the lime is the more rapid in proportion to
the extent of surface it acts upon, or the thinness of the pieces it has to
penetrate. And as the higher the temperature of the solution or of
the water the quicker is the operation, we prefer to use a boiling heat
in the process, though a lower temperature will subserve the same
purpose finally, requiring only a greater length of time. When the
caoutchouc has a large quantity of sulphur to be removed we prefer,
from reasons of economy, in the first place, to boil it along with the
caustic lime, which takes up the sulphur lying at or near the surface of
the mass or pieces of the caoutchouc, then to remove the solution so
produced and the lime, and boil with a solution of carbonate of soda.

page_text: After some time the whole of the excess of sulphur or uncombined
sulphur may be thus abstracted. In this way, after some time, and
when the process is carried far enough, the sulphur in excess is
abstracted, together with other matters (constituting impurities that
may have been formed in the process of vulcanizing or afterwards
manufacturing) from the caoutchouc, and it will then be found to be
soluble in turpentine, naptha, or any other of the usual substances
employed to dissolve or soften caoutchouc. We do not confine our pro-
cesses to the order above specified, as boiling or heating the vulcanized
material in a solution of carbonated alkali alone will abstract the sulphur,
and leave the material in a workable condition; and lime water or
lime and hot water will in time fulfil the same purpose when used
alone. But for economy we prefer the order above stated. Neither do
we restrict the practice of our Invention to the use of carbonate of
soda, as the carbonated alkali for carbonate of potash will equally well
abstract the sulphur, but it is not so economical as the soda salt.
On the addition to the vulcanized caoutchouc of the solution of the
carbonate of soda carbonic acid is evolved, and a sulphuret or a poly-
sulphuret of the alkali gradually formed, and this product can be
applied to several useful purposes. But should the sulphur compounds
thus formed with the alkali, and which are partly given off and liable
to be diffused through the atmosphere during the operation, be found
in any case to be objectionable, then we remedy this by adding to the
hot solution during the process some metallic oxide (as, for example,
oxide of copper) or some metallic carbonate capable of forming with
the sulphur as it is abstracted by the alkali an insoluble sulphuret, and
thus of fixing the sulphur in a form or combination that is unaccom-
panied by the disagreeable emission given off' by and peculiar to the
alkaline soluble sulphurets.
In producing the reactions between the sulphur and the vulcanized
material and the alkali or the lime we do not confine the operations to
the use, for facilitating the process, of hot water, or of what is properly
understood by a solution of the alkali, but in some cases find it
advantageous to steam or otherwise than by hot water to heat the
mixed materials; and for some purposes we vary these processes for

page_text: effecting the union between the sulphur and the alkali or the lime by
employing either of those agents in its dry state, or with only a little
water present, and, when mixed by any mechanical contrivance with
the vulcanized india-rubber, steaming or otherwise heating the mixture,
and finally removing the sulphurets so formed by washing with water.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Christopher and Gustavus Gidley in the
Great Seal Patent Office, on the 16th December 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we,
WILLIAM CHRISTOPHER, of Euston Square, and GUSTAVUS GIDLEY, of
Robert Street, ILoxton, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of June, in the year
of our Lord One thousand eight hundred and fifty-three, in the six-
teenth year of Her reign, did, for Herself, Iler heirs and successors,
give and grant unto us, the said William Christopher and Gustavus
Gidley, Her special licence that we, the said William Christopher and
Gustavus Gidley, our exccutors, administrators, and assigns, or such
others as we, the said William Christopher and Gustavus Gidley,
our exccutors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN ABSTRACTING SULPHUR AND OTHER MATTERS FROM VUL-
CANIZED INDIAN-RUBBER," upon the condition (amongst others) that we,
the said William Christopher and Gustavus Gidley, by an instrument
in writing under our hands and seal, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Scal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.

page_text: NOW KNOW YE, that we, the said William Christopher and
Gustavus Gidley, do hereby declare the nature of our said Invention,
and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement, that is
to say:
In manufacturing vulcanized India-rubber, or articles formed of that
material, it is desirable in many cases, after the usual operations of
vulcanizing the caoutchouc or the manufactured articles themselves,
to withdraw or separate some portion of the sulphur or of the excess of
sulphur that remains interposed in the pores of or is combined with the
caoutchouc; or, in other words, to adjust the relative proportions of
the sulphur and the caoutchouc in the vulcanized material for either
ordinary or any special application of it.
It is desirable also to be able to work up or re-employ refuse vul-
canized India-rubber, such as the parings or cuttings, &c., that
accumulate in manufactories of that material, or by some ready and
economical method of treating such refuse to separate from it the
sulphur, or so much sulphur as leaves the caoutchouc in a condition to
be acted upon by its usual solvents, and consequently restoring it to a
condition admitting of its being re-worked in any form, and, if required,
re-vulcanized either with sulphur or another material.
Now, our Invention consists in macerating the vulcanized India-
rubber in a hot solution of carbonated alkali, or in a solution of hydrate
of lime, or in hot water in which caustic lime is suspended, till, through
the action of the alkali or of the lime, the requisite quantity of sulphur
is abstracted; that is, either as much sulphur withdrawn as reduces the
relative proportions of the sulphur and the caoutchoue to those required
for any special purpose, or so far removes the sulphur as to leave the
residual material in a condition to be acted on by the usual solvents or
softeners of caoutchouc, so as to adapt it for re-formation into manu-
factured articles, and of being re-vulcanized with sulphur or another
material, if required.
We prefer that the vulcanized caoutchouc to be so treated should,
when it admits of it (as when the refuse parings or cuttings, &c., are
to be worked up), be comminuted or cut up into small pieces, for the
action of the alkali or of the lime is the more rapid in proportion to the

page_text: extent of surface it acts upon, or the thinness of the pieces it has to
penetrate. And as the higher the temperature of the solution or of
the water the quicker is the operation, we prefer to use a boiling heat
in the process, though a lower temperature will subserve the same
When the
purpose finally, requiring only a greater length of time.
caoutchouc has a large quantity of sulphur to be removed we prefer,
from reasons of economy, in the first place, to boil it along with the
caustic lime, which takes up the sulphur lying at or near the surface of
the mass or pieces of the caoutchouc, then to remove the solution so
produced and the lime, and boil with a solution of carbonate of soda.
After some time the whole of the excess of sulphur or uncombined
sulphur may be thus abstracted, acted upon or rendered soluble in
either the lime or the carbonated alkalies. In this way, after some
time, and when the process is carried far enough, the sulphur in excess
is abstracted, together with other matters, constituting impurities that
may have been formed in the process of vulcanizing or afterwards
manufacturing, from the caoutchouc, and it will then be found to be
soluble in turpentine, naptha, or any other of the usual substances
employed to dissolve or soften caoutchouc. We do not confine our
processes to the order above specified, as boiling or heating the vulcan-
ized material in a solution of carbonated alkali alone will abstract the
sulphur, and leave the material in a workable condition; and lime
water or lime and hot water will in time fulfil the same purpose when
used alone. But for economy we prefer the order as above stated.
Neither do we restrict the practice of our Invention to the use of the
carbonate of soda or the carbonated alkali, for carbonate of potash will
equally well abstract the sulphur, but it is not so economical as the
soda salt.
On the addition to the vulcanized caoutchouc of the solution of the
carbonate of soda carbonic acid is evolved, and a sulphuret or poly-
sulphuret of the alkali gradually formed, and this product can be applied
to several useful purposes. But should the sulphur compounds thus
formed with the alkali, and which are partly given off and liable to be
diffused through the atmosphere during the operation, be found in any
case to be objectionable, then we remedy this by adding to the hot
solution during the process some metallic oxide (as, for instance, oxide

page_text: of copper) or some metallic carbonate capable of forming with the
sulphur as it is abstracted by the alkali an insoluble sulphuret, by thus
of fixing the sulphur in a form of combination that is unaccompanied
by the disagreeable emissions given off by and peculiar to the alkaline
and soluble sulphurets.
In producing the reactions between the sulphur of the vulcanized
material and the alkali or the lime we do not confine the operation to
the use, in facilitating the process, of hot water, or of what is properly
understood by a solution of the alkali, but in some cases find it
advantageous to steam or otherwise than by hot water to heat the
mixed materials; and for some purposes we vary these processes for
effecting the union between the sulphur and the alkali or the lime by
employing either of those agents in its dry state, or with only a little
water present, and, when mixed by any mechanical contrivance with
the vulcanized India-rubber, steaming or otherwise heating the mixture,
and finally removing the sulphuret so mixed by washing with water.
To render vulcanized manufactured articles or the refuse more soft
and pliable they may be advantageously washed in a solution of water
and fuller's earth.
Now, what we claim as our Invention is, the before-mentioned
processes for removing sulphur from vulcanized India rubber manu-
factured articles, and also from refuse or spoiled vulcanized India-rubber
cuttings, parings, or old manufactured articles, and of re-dissolving the
same for new purposes.
In witness whereof, we, the said William Christopher and
Gustavus Gidley, have hereunto set our hands and seals, this
Sixteenth day of December, in the year of our Lord One
thousand cight hundred and fifty-three.
WILLIAM CHRISTOPHER. (L.S.)
GUSTAVUS GIDLEY.
(L.S.)