IMPROVEMENTS IN TREATING CAOUTCHOUC WITH OTHER MATERIALS TO PRODUCE ELASTIC AND IMPERMEABLE COMPOUNDS
Year: 1847

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, 'STEPHEN'
MOULTON, of Norfolk Street, Strand, in the County of Middlesex, Gentleman,
send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Eighth day of February,
in the tenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Stephen Moulton, my exors, adñiors, and
assigns, Her especial licence, full power, sole privilege and authority, that 1,
the said Stephen Moulton, my exors, adñiors, and assigns, or such others as I,
the said Stephen Moulton, my exors, adñors, and assigns, should at any time
agree with, and no others, from time to time and at all times during the term
of years therein expressed, should and lawfully might make, use, exercise,
and vend, within England, Wales, and the Town of Berwick-upon-Tweed,
the Invention communicated to me by a certain Foreigner residing abroad,
of "IMPROVEMENTS IN TREATING CAOUTCHOUC WITH OTHER MATERIALS TO PRODUCE
ELASTIC AND IMPERMEABLE COMPOUNDS;" in which said Letters Patent is con-
tained a proviso that I, the said Stephen Moulton, shall cause a particular'
description of the nature of the said Invention, and in what manner the same
is to be performed, by an instrument in writing under my hand and seal, 'to be'
enrolled in Her said Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said in part recited Letters

page_text: Patent, as in and by the same, reference being thereunto had, will more fully
and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Stephen Moulton, do hereby declare that the nature of the said Invention, and
the manner in which the same is to be performed, are particularly described
and ascertained in and by, the following statement thereof, that is to say :-
The Invention consists in treating caoutchouc by combining therewith
calcined and carbonate of magnesia, and hypo-sulphite of lead, and the
artificial sulphuret of lead, and submitting the combined compound to heat,
as will be hereafter described, by which Invention I am enabled to dispense
with the use of solvents, and to manufacture various goods free from the
offensive smell occasioned by such solvents. But in order that the Invention
may be fully understood I will proceed to describe the process pursued by me.
After the caoutchouc has been cut and cleansed, I put one or more pounds
weight, as can be conveniently ground or mixed at a time, between two revolv-
ing iron cylinders or rollers, denominated the mixing rollers, heated internally
by steam, when the caoutchouc, by the action of the rollers, soon presents the
appearance of a rough uniform sheet, and is then ready for the mixing it with
the following ingredients. If the goods that are to be made from the compound
are intended to be elastic, and to be rendered unaffected by heat or cold, I mix
in with one pound of caoutchouc, from one ounce to half a pound of the hypo-
sulphite of lead, and the artificial sulphuret of lead, both or either, but I prefer
them in equal proportions, but if they are used separate then the whole quantity
mentioned will be used. If the goods are intended to be hard, of greater
tenacity, and of less elasticity, I mix in from two ounces to half a pound of
the calcined or carbonate of magnesia with one pound of caoutchouc, and then
add both the hypo-sulphite of lead and the artificial sulphuret of lend, or either,
in like manner and proportions as used for elastic goods. The materials
above mentioned and the caoutchouc having been passed repeatedly between
the mixing rollers, so that the whole compound may be well combined, which
will readily be seen by a workman accustomed to the working of 'caoutchouc,
it is then removed to another similar pair of rollers, denominated the grinding
rollers, and treated in like manner, which rollers are placed nearer to each
other than the mixing rollers, in order that by these rollers a more perfect
mixture of the compound may be effected. After this second process the
compound is again removed to the third pair of rollers, also heated by steam,"
denominated the softening rollers, and again ground or mixed thereby, when
it soon becomes fit for its final removal to the spreading machine. The

page_text: spreading machine comprises two or more iron cylinders, which are heated
internally by steam (the machine which I prefer consists of three rollers, one
above the other, and of a smoother and finer surface than that of the rollers
before mentioned. The compound is placed between the upper rollers, and
passes to the lower one, upon which the cloth for its reception passes round,
and thus receives on its surface the different coatings of the compound
required. If sheet rubber is desired the compound is placed in like manner
dispensing with the use of the cloth, and the sheet taken from the lower
roller. Both the coated cloth and the sheet roller in passing off the lower
roller are rolled up in dry cloth, to keep the surfaces apart, and is then fit for
making up into such goods as may be required. In manufacturing goods
from the compounds thus prepared, when manufactured they are dusted
over with purified pipe or other clay of similar quality, finely powdered, to
prevent the surfaces from adhering together, but they are as yet still liable to the
action of all the solvents and other influences which act upon caoutchouc, and
would accordingly become rigid in cold and soft and sticky in warm weather.
To free the caoutchouc therefore from these its natural characteristics, it has
been combined with the salts of lead above mentioned, and the goods manu-
factured from this compound have now to be subjected to heat in a suitable
chamber or cylinder, and heated either by steam or dry heat (the former
I prefer) of from two hundred and twenty to two hundred and eighty or three
hundred degrees, according to the quantity of the goods heated at one time,
and also as to the thickness of the compound put into the sheets or upon the
cloth. The time required for heating goods will likewise vary according to
circumstances last mentioned. Some heats may require three hours and some
five hours, or thereabouts, and which is easily determined by any practical man
acquainted with the business. After the goods have been heated as last-
mentioned, they become elastic and impermeable, as set forth in the title above
recited.
Having thus described the nature of the Invention, and the manner of per-
forming the same, I would have it understood that I do not confine myself to
the precise details herein given, so long as the peculiar character of the Inven-
tion be retained; and I would remark that I do not claim as new the machinery
described for reducing caoutchouc into a pulpy state; but what I claim is, the
treating caoutchouc with hypo-sulphite and artificial sulphuret of lead, and
subjecting it to a high degree of temperature, as herein described. And,
Secondly, I claim the treating caoutchouc by combining therewith calcined
aud carbonate of magnesia, and hypo-sulphite of lead, and the artificial sul-