IMPROVEMENTS IN THE MANUFACTURE OF TANNIC BLACK, AND THE APPLICATION THEREOF FOR USEFUL PURPOSES
Year: 1881

page_text: LETTERS PATENT to William Gostwyck Gard and Thomas Henry Cobley,
both of Dunstable, in the County of Bedford, for an Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF TANNIC BLACK, AND THE
APPLICATION THEREOF FOR USEFUL PURPOSES."
PROVISIONAL SPECIFICATION left by the said William Gostwyck Gard
and Thomas Henry Cobley at the Office of the Commissioners of Patents on
the 2nd March 1881.
WILLIAM GOSTWYCK GARD and THOMAS HENRY COBLEY, both of Dunstable,
in the County of Bedford. "IMPROVEMENTS IN THE MANUFACTURE OF TANNIC
BLACK, AND THE APPLICATION THEREOF FOR USEFUL PURPOSES."
This Invention relates to improvements in the manufacture of tannic black,
and the employment of the same for making blacking, printing ink, and other
purposes.
By employing our improved method we are enabled to manufacture tannic black
in a direct manner.
In order to carry out our Invention we proceed mainly as follows:-
To each hundred parts more or less of leather waste, shavings, cuttings, or
scraps we add a suitable quantity of salts of iron, preferably chloride or sesqui-
chloride of iron, according to the quantity of tannic acid contained in the leather
waste to be treated, and to this quantity of leather waste we generally employ
6 parts more or less of crystallized sesquichloride of iron, or the equivalent of the
same..
The leather waste and iron liquor are placed in a suitable vessel and water
(when necessary), let in or added to the same until the waste is entirely covered.
Steam is now turned on, and the mass brought to the boiling point. The ingre-
dients are boiled for five or six hours, more or less, until the contents of the boiler
or vessel are converted into one black mass. Instead of heating the water by
means of a serpentine tube a direct firing can be employed, or steam can be made
to circulate around the boiler or receptacle. The mass so produced is now drawn
T

page_text: off, and well washed with hot water or steam. The liquor containing acid is
neutralized by adding powdered ironstone or iron filings, scrap iron, or waste iron,
of any kind, and can then be employed for treating a further quantity of leather
waste. This neutralized liquid must be strengthened by the addition of sesqui-
chloride of iron, to bring it up to the proper strength or equivalent proportions
above described. After being well washed the mass or tannic black can be dried,
and in this form employed instead of lamp black for the manufacture of printing
ink, paint, blacking, or pigment, being first ground to an impalpable powder. In
the condition in which it is produced, viz., as it comes undried from the boiler or
vat, this tannic acid is employed for manufacturing blacking, harness paste, and
other articles.
For blacking we prefer the following mixture, although we do not confine
ourselves to the proportions or ingredients, which may be varied with any known
substitutes or additions:-About 56 parts tannic black, calculated in dry con-
dition, 1 non drying oil, 1/16 oil of tar or carbolic acid, 27 molasses, 14 water.
These ingredients are well mixed, and the mass ground in a suitable mill. If our
tannic black is used in a dry state the water is added, if in a moist or freshly
made condition then the amount of water is determined and less water in proportion
added.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Gostwyck Gard and Thomas Henry Cobley in the
Great Seal Patent Office on the 2nd September 1881.
WILLIAM GOSTWYCK GARD and THOMAS HENRY COBLEY, both of Dunstable,
in the County of Bedford. "IMPROVEMENTS IN THE MANUFACTURE OF TANNIC
BLACK, AND THE APPLICATION THEREOF FOR USEFUL PURPOSES."
This Invention relates to improvements in the manufacture of a black which we
designate tannic black, and the employment of the same for making blacking,
printing ink, and for other
purposes.
By our method we are enabled to manufacture tannic black in an improved
manner. In order to carry out our Invention we proceed substantially as follows :-
To each one hundred parts, more or less, of leather waste, shavings, cuttings, scraps,
or waste leather of any kind, we add a suitable quantity of salts of iron, preferably
a chloride or sesquichloride, or both, of iron, according to the quantity of tannic
acid contained in the leather waste to be treated; and to this leather waste we
generally employ a solution of chloride or sesquichloride, or both, of iron, such as
the waste pickle from galvanizing works or other industries, or directly prepared
from any source of iron, as scrap slag or iron ore acted upon by hydrochloric acid
or salt, such solution being brought to a strength of 70°, more or less Twaddel,
and of this solution 16 parts more or less to the 100 parts of leather waste we
find work sufficiently well. The leather waste and iron liquor are placed in a
suitable vessel, which may be open or partially closed, and sufficient water is added
to cover the leather waste. Steam is now employed in any convenient manner to
bring the mass to the boiling point, or the same may be boiled by direct firing.
The ingredients are steamed or boiled for five or six hours, more or less, until the
contents of the boiler or vessel are converted into one black mass which forms our
tannic black, a black substantially formed of the gelatine and fibrine of the leather
or other substances impregnated with the tannate of iron, the former ingredients
constituting the body, and the latter the colouring matter thereof, such tannate of
iron being produced by the action of the chloride or sesquichloride of iron upon the
tannin present in the leather waste. The liquor is now drawn off, and the
resulting mass well washed with hot water or steam to withdraw any undecomposed
chloride or sesquichloride of iron or free acid produced, these liquors being likewise
afterwards drawn off. The liquors containing acid are neutralized and used to
form fresh chlorides of iron by adding powdered ironstone or iron filings, scrap
iron, or waste iron of any kind, and can then be employed for treating a further
quantity of leather waste. Fresh chlorides or sesquichlorides of iron must be
added to these liquors to regulate and bring them up to the proper strength or
equivalent proportion above described. After being well washed the mass or tannic
black can be dried, and in this form is employed instead of lamp black, bone black,
and various other substances for the manufacture of blacking, printing ink, paint,
harness paste, and other articles for which it may be found suitable, being first
ground to such degrees of fineness as may be desirable for the various purposes.
For making blacking we may use the following mixture, although we do not confine
ourselves to the proportions or ingredients, which may be varied with any known
substitutes or additions, i.e., 56 parts tannic black, calculated in dry condition,
1 oil, 1/16 oil of tar or carbolates, or analogous substances of an antiseptic nature,
27 parts (more or less) molasses, and water in due proportion. These ingredients
are well mixed, and the mass ground in a suitable mill. If the tannic black is used
n a dry state the water is added, if in a moist or freshly made condition then the
mount of water is determined and less added.

page_text: Having now particularly described and ascertained the nature of the said
Invention, and in what manner the same is to be performed or carried out in
practice, we hereby declare that we claim,-
(1.) The production of tannate of iron from the tannic acid contained in leather
waste by the action of salts of iron, preferably a chloride or sesquichloride of iron,
or both, and fixing the same upon the gelatine and fibrine of the leather and
analogous substances.
(2.) The production of tannic black hereinbefore described from leather waste
and salts of iron, preferably chloride or sesquichloride of iron, substantially as
described.
(3.) The use of tannic black produced as hereinbefore described, specially adapted
for the production of a superior blacking, and for other purposes.
In witness whereof, I, the said William Gostwyck Gard, have hereunto set
my hand and seal, this Thirtieth day of August, in the year of our Lord
One thousand eight hundred and eighty one.
TTYM
ADD