AN IMPROVEMENT OR IMPROVEMENTS PREPARATION OR MANUFACTURE OF CAOUTCHOUC IN COMBINATION WITH OTHER SUBSTANCES, WHICH PREPARATION OR MANUFACTURE IS SUITABLE FOR RENDER- ING LEATHER, CLOTH, AND OTHER FABRICS WATERPROOF, AND TO VARIOUS OTHER
Year: 1843

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
THOMAS HANCOCK, of Goswell Mews, Goswell Road, in the County of
Middlesex, Waterproof Cloth Manufacturer, send greeting.
WHEREAS Her present Majesty Queen Victoria, by Her Letters
Patent under the Great Seal of the United Kingdom of Great Britain
and Ireland, bearing date at Westminster, the Twenty-first day of
November now last past, did give and grant unto me, the said Thomas
Hancock, Her especial licence, full power, sole privilege, and authority
that I, the said Thomas Hancock, my executors, administrators, and
assigns, or such others as 1, the said Thomas Hancock, my executors,
administrators, or assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term
of years therein expressed, should and lawfully might make, use, exer-
cise, and vend, within England, Wales, and the Town of Berwick-upon-
Tweed, my Invention of "AN IMPROVEMENT OR IMPROVEMENTS
PREPARATION OR MANUFACTURE OF CAOUTCHOUC IN COMBINATION WITH OTHER
SUBSTANCES, WHICH PREPARATION OR MANUFACTURE IS SUITABLE FOR RENDER-
ING LEATHER, CLOTH, AND OTHER FABRICS WATERPROOF, AND TO VARIOUS OTHER

page_text: PURPOSES FOR WHICH CAOUTCHOUC IS EMPLOYED," in which said Letters Pa-
tent there is contained a proviso obliging me, the said Thomas Han-
cock, by an instrument in writing under my hand and seal, particularly
to describe and ascertain the nature of my said Invention, and in what
manner the same is to be performed, and to cause the same to be
inrolled in Her said Majesty's High Court of Chancery, within six
calendar months next and immediately after the date of the said Letters
Patent, as in and by the same reference being thereunto had will more
fully appear.
NOW KNOW YE, that in compliance with the said proviso, ] the
said Thomas Hancock, do hereby declare that the nature of my said
Invention, and the manner in which the same is to be performed, is
particularly described and ascertained as follows (that is to say):-
The nature of my improvement or improvements in the preparation
or manufacture of caoutchouc in combination with other substances
consists in diminishing or obviating their clammy adhesiveness, and also
in diminishing or entirely preventing their tendency to stiffen and
harden by cold, and to become softened or decomposed by heat, grease,
and oil. I will first describe the means by which I correct. obviate, or
lessen the clammy adhesiveness of caoutchouc, and caoutchouc in com-
bination with other substances; and I would first premise that as the
essential oils employed in softening and dissolving caoutchouc are ulti-
mately almost entirely evaporated, I wish to be understood, when
speaking of proportions, that the dry materials are meant; more or
less solvent may be used, according as it may be convenient, to
employ the combination in a stiff and plastic state, or diluted in
any degree down to the consistence of painters varnish. I take
ten pounds of caoutchouc, and pass it two or three times between
iron rollers until a roughly uniform sheet is obtained. I then take
twenty pounds of silicate of magnesia (sometimes called Venetian or
French chalk and talc) and reduce it to a fine powder, and I continue
rolling the sheet, sifting the silicate upon it as it passes through or
between the rollers, and I carry on this operation until the whole is well
mixed in; I then work up the mass into a state of uniform consistence by
means of the machine or apparatus commonly employed in making what is

page_text: called manufactured eaoutchouc. which machine is fully described in the
Specification of a Patent granted to me on the Eighteenth day of April.
One thousand cight hundred and thirty-seven. If the mass is intended
for cutting into sheets or other forms I press it in moulds, and cut it up in
the manner commonly practised and well known to persons acquainted
with such manufactures. When I require this combination in the form
of large sheets, and they are not required of very fine quality, I pass it
between rollers, beginning with them rather wide apart, and gradually
closing them each time of passing through, until they produce the thick-
ness I want. The rollers may be used cold, or heated to about 80°
Fahrenheit. When it is required to spread the combination on cloth
either for the purpose of rendering a previous coating of caoutchouc
unadhesive, or upon the surface of the cloth itself, I proceed to soften
the combination by the application of a small quantity of solvent, so as
to make it of the consistence of dough or putty, in the manner set forth
in the before-mentioned Specification of a Patent granted to me in One
thousand eight hundred and thirty-seven in respect to caoutchouc, and
I spread it also in the manner and by a spreading machine similar to
the one therein described. If very thin sheets or films are required, I
spread the combination on cloth, previously saturated with size, and
proceed with this operation in the same manner as is set forth with
respect to caoutchouc sheets under a Patent granted to me bearing
date the twenty-third day of January, One thousand eight hundred
and thirty-eight. The combination in this state, if not of too soft a
consistence, may be spread by means of iron rollers into sheets, either
alone or upon cloth, so as to remain permanently attached to the same,
or upon sized cloth to be afterwards stripped off; the surface of the
iron in contact with the sheet should be kept. wet, to lessen or prevent
adhesion. Instead of a smooth even face, I sometimes obtain impres-
sions on the surface by pressure between plates previously engraved of
the desired pattern, or, by means of rollers, by engraving one or both so
as to produce the required graining or device: these plates or rollers
may be used cold, or, if the consistence of the combination is hard and
stiff, they may be heated to any required degree. If a dead or dull
matted appearance is required. I pass woollen cloth or other suitable

page_text: fabric through or between the rollers in contact with the coated surface
of the cloth or sheet, and afterwards strip off the fabric, which should
be previously sized as before stated. By these and similar means 1
frequently give to sheets of the combination, or to fabrics coated with
it, a very close resemblance to a variety of woven and other manufac-
tures, some of which may be used as substitutes for the article
imitated. For coarse and cheap articles a proportion of washed lime
or fuller's earth dried and sifted very fine may be mixed with the sili-
cate, and the quantity of the latter proportionately reduced.
I some-
times make the exterior of an article of a combination that will be
unadhesive and of fine materials, and the interior with a combination
containing either more caoutchouc, or more of the lime or fuller's
earth, as the case may require. The combinations herein-before
described will be of a light drab colour, or of a darker shade according
to the proportion of the silicate: but if required of other colours, I mix
with the silicate any suitable pigment commonly used for such purposes.
If patterns are required to be printed on these manufactures, I mix the
colour with a thin solution of caoutchouc, as mentioned in the Specifica-
tion of my Patent of the Twenty-third day of January. One thousand
eight hundred and thirty-eight. When a dark colour is not objection-
able, I employ asphalte, instead of or combined with the silicate. The
combination of asphalte with caoutchouc may be effected in the dry
state by reducing the asphalte to a fine powder, and treating it in the
same manner as before stated in respect to the silicate. Plumbago may
also be introduced when the colour is dark. I find that from six to
seven pounds of asphalte, according to its quality, to eight pounds of
caoutchouc answers the purpose; if silicate also is used, the quantity
of asphalte should be proportionately less. When this combination is
required for spreading on cloth or for thin sheets, I soften it and treat
it in the same manner as before described for the silicate; if it is wished,
more asphalte or silicate may be added during this operation. Nearly
the same results are obtained by dissolving the asphalte in coal naptha,
and employing such solution instead of naptha or other solvent in
softening the caoutchouc to bring it to a suitable consistence for the
spreading machine; and if silicate is employed with the asphalte, it

page_text: may be sifted in as directed in respect of colouring matters in the
Specification before referred to of One thousand eight hundred and
thirty-seven. Raised patterns may also be produced on the surface
by the means before described. These combinations may be manufac-
tured into sheets and various other articles, or applied generally to
caoutchouc and caoutchouc manufactures where it is desirable to
obviate the clammy adhesiveness of the surface; and I apply them for
the purpose of rendering cloth more or less waterproof by means of the
spreading machine before alluded to, and to other purposes by means
of a spatula or other convenient instrument, and in a more diluted state,
Of
in the manner of painting or varnishing with a common brush.
course the different proportions may be varied according to the purposes
to which the combinations are to be applied. It may be necessary
here to observe, that all the substances employed in the before-men-
tioned combinations have a tendency to weaken more or less the elastic
properties of caoutchouc, and in particular the proportion of silicate of
magnesia may be increased until the caontchouc is nearly deprived of
those properties. Any person practically acquainted with caoutchouc
manufactures will be able from the descriptions already given to obtain
the proper consistence and quality, and to adapt the combinations to the
It is well known
various purposes for which they may be required.
that caoutchouc stiffens and becomes hard when exposed to a cold tem-
perature, and that it is liable to become soft and decomposed by heat
and exposure to the atmosphere, and by contact with oil or grease, that
it is easily acted upon by solvents, and its elastic properties weakened
I diminish or
by the means usually employed for its manufacture.
obviate these effects by intimately blending sulphur with the caoutchouc
during the process of its manufacture or preparation, and then treating
Sulphur may be
the combination in the manner hereafter described.
blended with caoutchouc in various ways, but the following I find to
answer the desired purpose:-I melt in an iron vessel a quantity of
sulphur at a temperature ranging from about 240° to 250° Fahrenheit,
and immerse in it the caoutchouc previously rolled into rough sheets,
or cut to any convenient form or size, and allow it to remain until
the sulphur has penetrated quite through the caoutchouc, which may

page_text: be ascertained by cutting a portion of it asunder with a wet knife;
if the operation is complete, the colour of the caoutchouc will be
changed throughout to a yellowish tint; if there is only a margin of
yellow around the cut part, the operation must be continued longer
until the colour of the whole is changed, the sulphur adhering
to the surface being scraped off. the caoutchouc will then have taken up
a quantity of sulphur from one sixth to one tenth of its weight. With
caoutchouc thus prepared I proceed with the further manufacture of it
into the consistence of dough or putty, or make solutions of it and
spread it on cloth or into sheets in the manner already stated or referred
to. Sulphur may also be blended with caoutchouc by reducing the
former to a fine powder, and mixing it mechanically in the manner and
by the means before mentioned; for silicate of magnesia, sulphur may
also be blended with the surface of some articles, such as sheet caout-
chouc, by heating the latter to about 200°, and sifting and rubbing
flowers of sulphur on it. Instead of the preceding, I sometimes blend
In that case | satu-
sulphur with caoutchouc by means of a solvent.
rate the solvent I mean to employ with as much sulphur as it will take
up by boiling, and employ as much of this saturated solvent as will,
after evaporation, leave the requisite proportion of sulphur before indi-
cated blended with the caoutchouc. When this saturated solvent is
allowed to cool, any excess of sulphur will fall down in crystals; if,
therefore, for any purpose it is wished to employ a larger proportion of
sulphur, it must be kept hot. I prefer in this case to use oil of tur-
pentine as the solvent. Either of the foregoing or any other conve-
nient mode may be adopted for blending the sulphur and caoutchouc
together, care being taken to ensure as much as possible a uniform
mixture. The silicate of magnesia, and the other substances mentioned
in the first part of this Specification, may, if wished, be mixed with the
combination of sulphur and caoutchouc in such proportions as may be
necessary to obviate or correct the clammy adhesiveness before mentioned;
but I wish it to be clearly understood that the combination of the
silicate of magnesia with caoutchouc has the effect in all cases of lessen-
ing its clastic properties in proportion to the quantity of silicate
employed. This combination of sulphur and caoutchouc, and of sulphur

page_text: and caoutchouc mixed with the silicate of magnesia and the other
substances before mentioned, may be applied to various purposes in the
manner herein-before stated or referred to, and introduced by similar
or other convenient means into caoutchouc manufactures. Having
described the methods by which I blend sulphur with caoutchouc, and
the manner in which I apply the same to various purposes, I would
here observe, that the combination is still as soluble as before, and
has not yet undergone the change or modification by which the improve-
ment or improvements contemplated in this portion of my Invention
are carried out. When caoutchouc alone is to be operated upon, I
find that the desired effect, which for brevity sake I will hereafter call
the change, may be produced by immersing the caoutchouc in melted
sulphur, as herein-before mentioned; I then raise the temperature to
300°, or from 300° to 370°, and continuing it so immersed for a longer
or shorter period according to the thickness or bulk of the caoutchouc,
or the extent to which the change is to be carried; for instance, if
sheet.caoutchouc one sixteenth of an inch thick is continued in sulphur
at 350° to 370° from ten to fifteen minutes, the change before alluded
to is produced; or, instead of so high a temperature, the sulphur is
raised only from 310 to 320, and the caoutchouc immersed in it from
fifty to sixty minutes, the result will be much the same, and if con-
tinued for two hours at the same temperature the effect will be propor-
tionably increased, and if continued longer the caoutchouc becomes of
a darker colour, and nearly loses its property of stretching, and if
carried still farther turns nearly black, and has something the appear-
ance of horn, and may be pared with a knife similarly to that substance.
By the effect of this high temperature such a change in or modification
of the properties of the caoutchouc and most of its combinations will
be produced, that the elastic force or property of manufactured caout-
chouc to recover its form after being extended is greatly increased, and
it will, after being so treated, also resist to a considerable extent the
action of heat, oil, and grease, as well as the effect of cold, and
be more capable of resisting the menstrua by which caoutchouc is
commonly dissolved. I would here observe, that the temperature and
the time which have been stated produce a degree of change suitable

page_text: for many purposes, but may be varied discretionally; and I would here
make this general remark, that the higher the temperature the shorter
is the time required; and, on the contrary, a lower temperature requires
a longer time. And I would here observe, that the proportion of
sulphur is to a certain extent increased by continued immersion, and
the time and temperature just indicated is equally applicable to the
combinations of caoutchouc and sulphur with the silicate of magnesia
and other substances mentioned in the first part of this my Specifica-
tion.
The sulphur which adheres to the surface may easily be removed
by friction or scraping. I employ this mode of operating in preference
generally, where practicable, particularly for articles made of manufac-
tured caoutchouc, such as sheets and thread for elastic manufactures,
whether made from manufactured caoutchouc or of the raw material
as imported. When the combination is spread upon cloth or attached
to other substances capable of enduring the necessary temperature, I
pass such articles over plates or cylinders heated sufficiently to effect
the change; if the side on which the combination of caoutchouc and
sulphur is spread is brought into contact with the heated surface of the
plate or cylinder, the temperature and the time in contact formerly
indicated in respect of melted sulphur will answer the purpose; and this
is the mode I prefer in cases where substances, such as leather, coated
with the combination will not so well endure a high temperature;
but when the combination is spread on cloth or other substance which
is to be brought into contact with the heated surface, the temperature
will require to be raised, or the article longer exposed to it, according to
the extent to which the heat is impeded by the thickness or quality of the
intervening substance, which may be easily ascertained by testing small
pieces as a guide. In some cases, such as for the strapping on the seams
of garments, it may be useful to employ hot irons to effect the change.
Another mode of submitting the articles to the necessary temperature
is by means of a stove heated to the required degree, which degree and
the proper period for the article to remain in it must, as before stated,
depend on the nature of the case; if it is sheet caoutchouc or thread,
or any similar article, the time and temperature before indicated will
answer according to the extent to which the change is to be carried, or

page_text: the size or bulk of the article to be operated on. If the article is partly
composed of cloth coated on one side, as, for instance, a single texture
of calico rendered waterproof by a very thin coating of the combination,
a temperature of from 290 to 300 will be sufficient, and the period for
remaining in or passing through the stove from one and a half to two
minutes. If a thicker coat of the combination is laid on the calico, a
somewhat longer time must be given: and so in respect of a union of
two plies of cloth, the time and temperature must be regulated accord-
ing to the thickness of the textures and the interposed coating of the
combination. When a greater number of plies of cloth are required
to be united, as in the manufacture of artificial leather for straps, card
backs, hose pipe, and the like, I proceed as in the case just mentioned;
but if from the thickness of the cloth or the number of plies required I
conceive the heat will not readily or sufficiently penetrate the mass, I
unite two folds of the cloth first, and pass them through the stove until
the change is effected; I then unite another fold to the former, and pass
it again through the stove, and so proceed until the required number of
folds are united; and, if required, I lastly coat the surfaces in the above
manner, and finish by again submitting the whole to the stove.
Another mode of obtaining the temperature for effecting the change is
by immersing the articles in water or steam under pressure raised to the
required temperature. I find that a very small quantity of boiled linseed
oil, stearine, or spermacetti introduced with the sulphur communicates
an agreeable smoothness to the surface. I would here also remark,
that when surfaces are to be united, the union should be effected before
the change takes place. When the combination is required for pur-
poses where it could not be conveniently used of the consistence of
dough, such as for saturating cloth, felt, or other similar purposes, or
for coating uneven surfaces, I dilute it with solvent to any required
consistence, and apply it with a brush or other convenient means, and
afterwards submit the articles to the influence of heat in the manner
already described, or by any other that may be convenient. The
sulphur may, if required, be more or less discharged from the caout-
chouc after it has undergone the change by submitting it to the known
solvents of sulphur, of which I prefer a solution of the sulphite of soda

page_text: in water kept to a temperature of about 200°. Other and similar
modes may be devised for carrying these improvements into effect; but
enough has now been said to enable any. person of common skill and
practically acquainted with caoutchouc manufactures to follow out these
operations with success. What I claim as my Invention and discovery
is, first, the combination of caoutchouc with silicate of magnesia, whereby
manufactured caoutchouc is rendered free from that clammy and adhe-
sive character which it usually possesses. Secondly, 1 claim the modes
herein described of combining asphalte with caoutchouc; and, thirdly,
I claim the treating of caoutchouc (either alone or in combination with
other substances) with sulphur when acted on by heat, and thus
changing the character of caoutchouc, as herein described.
In witness whereof, I, the said Thomas Hancock, have hereunto
set my hand and seal, this Twenty-first day of May, One thou-
sand eight hundred and forty-four.
THOMAS (L.S.) HANCOCK.
AND BE IT REMEMBERED, that on the same Twenty-first day of
May, in the year above mentioned, the aforesaid Thomas Hancock
came before our Lady the Queen, in Her Chancery, and acknow-
ledged the Specification aforesaid, and all and every thing therein con-
tained in form above written: and also the Specification aforesaid was

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
THOMAS HANCOCK, late of Goswell Mews, but now of Stoke Newing-
ton, in the County of Middlesex, Esquire, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster the Twenty-first
day of November, in the seventh year of Her reign, did, for Herself,
Her heirs and successors, give and grant unto me, the said Thomas
Hancock, my executors, administrators, and assigns, Her especial
licence, full power, sole privilege, and authority that I, the said
Thomas Hancock, my executors, administrators, or assigns, or such
others as I, my executors, administrators, or assigns, should at any
time agree with, and no others, from time to time and at all times there-
after during the term of years therein expressed, should and lawfully
might make, use, exercise, and vend, within that part of the said
United Kingdom called England, the dominion of Wales, and town of
Berwick-upon-Tweed, my Invention of "AN IMPROVEMENT OR IMPROVE-
MENTS IN THE PREPARATION OR MANUFACTURE OF CAOUTCHOUC, IN COMBINA-
TION WITH OTHER SUBSTANCES, WHICH PREPARATION OR MANUFACTURE IS
SUITABLE FOR RENDERING LEATHER, CLOTH, AND OTHER FABRICS WATER-
PROOF,
CAOUTCHOUC IS EM-
AND TO VARIOUS OTHER PURPOSES FOR WHICH
PLOYED."
And whereas I, in pursuance of a proviso in the said in
part recited Letters Patent contained, did cause a particular descrip-
the
tion of the nature of my said Invention, and in what manner
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
on the Twenty-first day of May, in the year of our Lord One thousand
eight hundred and forty-four. And whereas I, the said Thomas
Hancock, am desirous, for good and sufficient reasons herein-after
mentioned, to enter a memorandum of alteration in the said Specifi-
cation, and have obtained leave of Her Majesty's Attorney-General,

page_text: certified by his fiat and signature according to the form of the statute
in that case made and provided.
KNOW YE THEREFORE, that I, the said Thomas Hancock, do
hereby enter the following memorandum of alteration, that is to say:
In that part of the Specification where it is stated that "having
described the methods by which I blend sulphur with caoutchouc, and
the manner in which I apply the same to various purposes, I would
here observe that the combination is still as soluble as before," I add
the words "except when I use a solvent that has been saturated at a
high temperature, as in the case of oil of turpentine." And I, the
said Thomas Hancock, do also hereby declare that my reasons for
making and entering the above memorandum of alteration are as fol-
low That without such alteration the said Specification and the
description of the said Invention would be obscure and not fully
explained. And 1 do further declare, that the above memorandum of
alteration is not such an alteration as will extend the exclusive right.
granted by the said Letters Patent..
In witness whereof, I have hereunto set my hand and seal, this
Thirteenth day of October, in the year of our Lord One thou-
sand eight hundred and forty-five.
Rolls Yard, Chancery Lane.
THIS IS TO CERTIFY that the within-named Thomas Hancock has
applied to me for leave to enter the within-written memorandum of altera-
tion of part of the Specification of a certain Invention for which
Letters Patent were duly granted to him under the Great Seal of Great
Britain, dated at Westminster, the Twenty-first day of November, in
the year of our Lord One thousand eight hundred and forty-three, and
the Specification of which was enrolled on the Twenty-first day of May,
One thousand eight hundred and forty-four. And having considered
of the said application, and no objection having been made to the

page_text: same, I have accordingly granted leave to the said Thomas Hancock
to file his said memorandum of alteration pursuant to the statute
passed in the fifth and sixth years of the reign of His late Majesty
King William the Fourth, entituled An Act to amend the Law touch-
ing Letters Patent for Inventions.
Temple, October 14th, 1845.
Inrolled the Fourteenth day of October, in the year above written.