IMPROVEMENTS IN PRINTING AND DYEING ANILINE BLACK
Year: 1880

page_text: LETTERS PATENT to Joseph Schmidlin, of Hyde, in the County of Chester,
Chemist, for an Invention of "IMPROVEMENTS IN PRINTING AND DYEING
ANILINE BLACK."
PROVISIONAL SPECIFICATION left by the said Joseph Schmidlin at the
Office of the Commissioners of Patents on the 23rd January 1880.
JOSEPH SCHMIDLIN, of Hyde, in the County of Chester, Chemist.
MENTS IN PRINTING AND DYEING ANILINE BLACK."
"IMPROVE-
It is known that an ordinary aniline black printed and developed, when treated
by a salt of peroxide of iron or by chromic acid, will give a black colour which will
not turn green with exposure. It is also known that aniline salts printed on
prepared cloth by bichrome will give a similar black colour with the same
properties. These blacks cannot be printed with other colours, such as red and
rose alizerines and others, as the latter colours will not sustain their reactions.
My Invention consists of an aniline black which has the property of not turning
green.
For this I substitute for the generally used oxides an insoluble chromate ; I
print on the fabric a colour composed of an aniline, salt, a chromate, a chlorate,
and a chloride thickened with white starch. When acted upon by steam, these
salts have the property of decomposing the insoluble chromate into a chromic acid,
and form a new salt with its base. This black after printing can be steamed at
once; it developes in five minutes, and if necessary the steaming can be prolonged;
therefore it can be printed with all colours which can resist steam. After steaming
the fabric must be washed to remove the salt formed by the base of the chromate.
Should the white yet not be pure it can be passed through a weak acid solution
which removes the remaining traces of the chromate base.
This colour is very
durable, and prints with extraordinary neatness, and resists the reaction of
sulphurous acids.
By saturating cloth or yarn with the ingredients above named, I obtain a uniform
black that will not fade or change colour.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Joseph Schmidlin in the Great Seal Patent Office on the 17th July
1880.
JOSEPH SCHMIDLIN, of Hyde, in the County of Chester, Chemist. "IMPROVE-
MENTS IN PRINTING AND DYEING ANILINE BLACK."
My Invention consists in producing an aniline black which has the property of
not turning green, and can be associated with all steam colours.
And in order that it may be fully understood, and readily carried into effect, I
will describe the means pursued by me to effect this object. I substitute for the
generally used oxides an insoluble chromate, and I print on calico a colour
composed of,
-
4 gall starch paste at 2lbs. per gall.
6 lbs. chromate of lead (pigment well ground)
6 lbs. ammonium hydrochlorate
6 lbs. aniline hydrochlorate
1 lbs. sodium chlorate
(Pb Cr 0.)
(Az H. Cl.)
(C° H³ Aq H* HCl.)
Na Cl O
The pieces printed, well dried by hot air or on drums (the latter is preferable),
are steamed for five minutes to develope the black; the steaming may be prolonged
without harm. By influence of the steam the salts mixed with the chromate
decompose the same to chromic acid. This chromic acid acts on the aniline,
transforming it to black, the acids of the other salts forming a chloride of lead with
its basis. The chloride of lead formed by steaming is taken off the cloth by a
thorough good wash. If insufficiently washed (which is proved by testing the
cloth with sulphurated hydrogen), by passing the pieces through very diluted
hydrochloric or acetic acid, all traces of chloride of lead will be removed.
The colour preserves itself very well, prints with extraordinary neatness, does no
harm to the doctors (blades), and resists the strongest reactions, such as bi-sulphate
of Bodium.
Insoluble chromates, such as baryta, cadmium, and others, may be substituted
for the chromate of lead, but I prefer to use chromate of lead.
Nitrates, sulphates, tartarates of aniline, and chlorate of aniline can also be
substituted for the hydrochlorate, and in the same way other salts may also be
substituted for the ammonium salt, such as nitrate of ammonium.
Iron salts at maximum help also to develope the black.
I envelope the rails in the steaming chamber, over which the printed fabric
passes, with cloth prepared in acetate of lead to saturate the sulphurous gases.
Having given a description of my Invention which will enable calico printers to
use the same, I declare that I claim the production of an aniline black that will
not turn green or fade, and that can be printed with all colours that will resist
steam, substantially as described,
In witness whereof, I, the said Joseph Schmidlin, have hereunto set my hand
and seal, this Sixteenth day of July, One thousand eight hundred and
J. SCHMIDLIN. (L.S.)