IMPROVEMENTS IN THE MANUFACTURE OF ELASTIC WATERPROOF COMPOUNDS "
Year: 1883

page_text: LETTERS PATENT to Walter Burnham, of Chicago, Illinois, United States of
America. for an Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
ELASTIC WATERPROOF COMPOUNDS "
PROVISIONAL SPECIFICATION left by the said Walter Burnham at the
Office of the Commissioners of Patents on the 29th May 1883.
WALTER BURNHAM, of Chicago, Illinois, United States of America,
MENTS IN THE MANUFACTURE OF ELASTIC WATERPROOF COMPOUNDS
"
" IMPROVE-
My invention is designed to provide means for utilizing the adhesiveness and
insolubility in water peculiar to the sap of the mangrove tree, sometimes called
nangrove rosin and known in the United States of Columbia as cativo; I combine
this sap with caoutchouc in variable proportions as hereinafter described, thereby
producing permanently elastic waterproof compounds which are capable of being
of the solvents and additional
made into waterproof varnishes by the use
ingredients ordinarily employed in making so called rubber varnishes, and are also.
capable of conversion into products of less or greater hardness by the ordinary
process of vulcanization, either with or without the addition of the whiting, white
lead, or other ingredients usually introduced into ordinary caoutchouc compounds.
It will thus be seen that my new compound, of which cativo is the base, may
be treated by the same methods, and employed for the same purposes, as
caoutchouc.
The so-called cativo is semi-solid at ordinary temperatures but becomes fluid at
about 130° Fahrenheit.
In preparing it to serve as the base of my new compound I preferably heat it
to a temperature slightly above that of boiling water for the double purpose of
diminishing the strength of its natural odor and separating it from insoluble
impurities, which I effect by straining it while hot through a bag filter.
strained and purified it exhibits a clear reddish brown color.
When
In this condition I
mix it with caoutchouc either by using appropriate solvents, such as bisulphide of
carbon, naphtha, or the like, or by the employment of hot kneading rolls, by means

page_text: of which the mixture is effected mechanically. In the latter case the temperature
is elevated until the mixture acquires any desired degree of plasticity.
My new compound may be used as the base for a waterproof varnish, in which
case it will be preferable to effect the mixture by dissolving the cativo and
caoutchouc, in any desired proportion, as for example three parts of cativo to one
of caoutchouc, in bisulphide of carbon, or naphtha or other solvent, to which may
be added linseed oil, tar, or asphalt, or either of the ingredients ordinarily
employed in the manufacture from caoutchouc of so-called rubber varnishes.
When it is desired to produce a vulcanized product I prefer to effect the mixture
of the cativo and caoutchouc mechanically by the use of the ordinary kneading
rolls, by means of which I, at the same time, incorporate into the mixture the
ingredients, ordinarily employed in the formation of caoutchouc compounds,
preparatory to subjecting them to the ordinary process of vulcanization, thus I
introduce into my compound sulphur or metallic sulphides in variable proportions.
By vulcanizing my compound with say five per cent of sulphur, I obtain a strong
elastic product suitable for employment for purposes in which flexibility is
required. For special purposes the proportion of sulphur may be largely increased,
by means of which the product will acquire additional hardness.
Metallic oxides, carbonates, or other solid substances may be mixed with the
compound for increasing the weight or bulk or for other purposes. Thus a product
suitable for application to canvas may be made by using the ingredients in the
following proportions namely:-
Cativo
Caoutchouc
Whiting
White Lead
Litharge
Sulphur
23 parts
23 parts
36 parts
7 parts
5.5 parts
5.5 parts
This formula is given as an example merely of one of many formulæ which may
be usefully employed. The said invention is not limited either to the relative
proportions or to the kind of substances which may be incorporated with my
compound of cativo and caoutchouc.
It is to be remarked with reference to the mixture made substantially under the
formula above set forth, that it has sufficient plasticity, prior to vulcanization, to
enable it to be spread upon cloth or to be moulded into any desired shape.
The vulcanization of the mixture is effected by subjecting it to a heat of about
275° Fahrenheit.
The said invention, however, is not limited to vulcanization at this especial
temperature, as the temperature may be varied according to circumstances as is
well understood, and any temperature may be used by which the well-known
action of vulcanization will result.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Walter Burnham in the Great Seal Patent Office on the
29th November 1883.
WALTER BURNHAM, of Chicago, Illinois, United States of America,
MENTS IN THE MANUFACTURE OF ELASTIC WATERPROOF COMPOUNDS "
«
IMPROVE-
My invention is based upon the properties of adhesiveness and insolubility in
water peculiar to the sap of the mangrove tree, which sap is sometimes called
mangrove rosin and is known in the United States of Columbia as "Cativo."
I have discovered that, by combining this sap with caoutchouc in variable
proportions as hereinafter described, I am enabled to produce permanently elastic
waterproof compounds. These compounds are capable of being made into water-
proof varnishes by the use of the solvents and additional ingredients ordinarily
employed in making so called india-rubber or caoutchouc varnishes, and are also
capable of conversion into products of greater or less hardness by the ordinary
process of vulcanization, either with or without the addition of the whiting, white
lead, or other ingredients usually introduced into caoutchouc compounds.
It will thus be seen that my improved compound, of which "Cativo" is the
base, may be treated by the same methods and employed for the same purposes as
caoutchouc.
The so-called "Cativo" is semi-solid at the ordinary temperature of the
atinosphere, but becomes fluid at about 130° Fahrenheit.
In preparing this material to serve as the base of my improved compound, I
preferably heat it to a temperature slightly above that of boiling water for the
purpose of diminishing the strength of its natural odour, and I then strain it in its
heated state through a bag-filter to separate it from insoluble impurities. When
strained and purified it exhibits a clear reddish brown color. In this condition I
mix it with caoutchouc either by using appropriate solvents, such as bisulphide of
carbon or naphtha, or by the employment of hot kneading rolls, by means of which
the mixture is effected mechanically. In the latter case, the temperature is elevated
until the mixture acquires the desired degree of plasticity.
My improved compound may be used as the base for a waterproof varnish, in
which case it is preferable to effect the mixture by dissolving the cativo and
caoutchouc, in any desired proportion (for example three parts of cativo to one of
caoutchouc), in bisulphide of carbon, naphtha or other solvent, to which may be
added linseed oil, tar or asphalt, or either of the ingredients ordinarily employed in
the manufacture of varnishes from caoutchouc.
When it is desired to produce a vulcanized product, I prefer to effect the mixture
of the cativo and caoutchouc mechanically by the use of the ordinary kneading
rolls, by means of which, I, at the same time, incorporate into the mixture the
ingredients ordinarily employed in the formation of caoutchouc compounds
preparatory to subjecting them to the ordinary processes of vulcanization. Thus
I introduce into my compound, sulphur or metallic sulphides in variable
proportions.
By vulcanizing my compound with say five per cent of sulphur, I obtain a
strong elastic product suitable for purposes for which flexibility is required. For
special purposes the proportion of sulphur may be largely increased, so that the
product will acquire additional hardness.
Metallic oxides, carbonates, or other solid substances may be mixed with the
compound for increasing its weight or bulk, or for other purposes. For example, a

page_text: Caoutchouc
23 parts
Whiting
36 parts
White Lead
7 parts
Litharge
5.5 parts
5.5 parts
Sulphur
This formula is given as an example, but other substances may be incorporated
with my compound of cativo and caoutchouc, and I may vary the relative
proportions of the substances which I employ.
The mixture made substantially according to the formula above set forth has
sufficient plasticity, prior to vulcanization, to enable it to be spread upon cloth or
to be moulded into any desired shape.
The vulcanization of the mixture is effected by subjecting it to a temperature of
about 275° Fahrenheit.
The said invention, however, is not limited to vulcanization at this particular
temperature; the temperature may be varied according to circumstances, as is well
understood, and any temperature may be used which will produce the well-known
action of vulcanization.
Having thus fully described my said invention and the manner of performing
the same, I wish it understood that I claim ;-
First. The improved waterproof compound herein described, which consists
essentially of a mixture of the sap of the mangrove tree (sometimes called mangrove
rosin and also known as cativo) with caoutchouc, effected either by the use of
solvents or by mechanical means, as, and for the purposes, set forth.
Second. The herein described process of manufacturing waterproof compounds,
which process consists in mixing cativo or the sap of the mangrove tree, caoutchouc
and sulphur, or other vulcanizing agent (with or without additional ingredients)
and then vulcanizing the mixture, in the ordinary manner, by subjecting it to a
suitable temperature, as above set forth.
Third. The vulcanized compound herein described, composed essentially of cativo
or the sap of the mangrove tree, caoutchouc, and sulphur or other vulcanizing
agent.
In witness whereof I the said Walter Burnham have hereunto set my hand and
seal this Twenty third day of August in the year of our Lord One thousand eight
hundred and eighty three.
חרזה
TTA10זגמזזם
זומזזם
(c)