IMPROVEMENTS IN OBTAINING COLOURING MATTERS FOR DURING AND PRINTING
Year: 1863

page_text: LETTERS PATENT to John Dale, of Manchester, in the County of Lan-
caster, Manufacturing Chemist; and Heinrich Caro, of the same Place,
Chemist, for the Invention of "IMPROVEMENTS IN OBTAINING COLOURING
MATTERS FOR DURING AND PRINTING
Sealed the 28th June 1864, and dated the 31st December 1863.
PROVISIONAL SPECIFICATION left by the said John Dale and Heinrich
Caro at the Office of the Commissioners of Patents, with their Petition,
on the 31st December 1868.
I, JOHN DALE, of Manchester; in the County of Lancaster, Manufacturing
Chemist, and HEINRICH CARO, of the same Place, Chemist, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN OBTAINING COLOURING
MATTERS FOR DYEING AND PRINTING," to be as follows
To obtain yellow colouring matters we treat aqueous solutions of aniline
or salts of aniline with solutions. of any alkaline nitrites containing excess of
base, whereby a yellow precipitate is formed suitable for dyeing and printing.
The desired effect may be obtained more or less by mixing the ingredients in
any proportions, but the best and most advantageous proportions to be
employed for producing various colours can only be ascertained by repeated
experiments.
For browns we adopt two methods; firstly, we treat phenylenediamine;
toluylenediamine, or their homologues with aqueous solutions of alkaline
nitrites; secondly, we submit carbolic acid to the action of nascent chlorine,
whereby chlorine compounds are obtained which dye various shades of brown'
upon animal fibre.
For purples we treat salts of aniline, the hydrochlorate, nitrate, or others,

page_text: previously mixed with metallic nitrites or with the products resulting from the
action of nitrous acid or its salts upon aniline, until the whole is converted
into a bluish purple, which may be purified by the methods in use for purifying
aniline colours.
For black, grey, or drab dyes we use the residue formed in the manu-
facture of aniline, purple, or mauve, and free it from its metallic constituents,
after which it is dissolved in any suitable solvent, as, for instance, alcohol,
acetic or sulphuric acid. This deprivation of metallic substances may be
effected by treatment with mineral acids.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Dale and Heinrich Caro in the Great Seal Patent
Office on the 30th June 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
DALE, of Manchester, in the County of Lancaster, Manufacturing Chemist,
and HEINRICH CARO, of the same Place, Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirty-first day of December, in the year of our
Lord One thousand eight hundred and sixty-three, in the twenty-seventh
year of Her reign, did, for Herself, Her heirs and successors, give and grant
unto us, the said John Dale and Heinrich Caro, Her special license that we,
the said John Dale and Heinrich Caro, our executors, administrators, and
assigns, or such others as we, the said John Dale and Heinrich Caro, our
executors, administrators, and assigns, should at any time agree with, and
no others, from time to time and at all times thereafter during the term
.therein expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
İslands, and Isle of Man, an Invention for "IMPROVEMENTS IN OBTAINING
COLORING MATTERS FOR DYEING AND PRINTING," upon the condition (amongst
others) that we, the said John Dale and Heinrich Caro, by an instrument
in writing under our hands and seals, or under the hand and seal of one
of us, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said .Letters Patent.
NOW KNOW YE, that I, the said Heinrich Caro, do hereby declare
the nature of our said Invention, and in what manner the same is to be

page_text: performed, to be particularly described and ascertained in and by the following
'statement, that is to say:-
To obtain yellow coloring matters we treat aqueous solutions of aniline or
salts of aniline with solutions of alkaline nitrites containing excess of base,
whereby a yellow precipitate is formed suitable for dyeing and printing. In
practice we proceed as follows:-Two equivalents of neutral hydrochlorate of
aniline are intimately mixed with one-equivalent of nitrite of sodium and one
equivalent of hydrate of sodium; this mixture is moistened with water, and
then for some time well triturated in a mortar or otherwise until it has
assumed a bright yellow colour, little or no aniline remaining undecomposed.
After repeated washings with cold water, filtering, pressing, and drying, the
coloring matter is obtained in the state of a fine yellow powder, which may
be further purified by crystallisation from its solution in boiling alcohol,
benzole, or petroleum, or by first dissolving it in warm and diluted hydrochloric
acid, and by precipitating it from this solution by means of caustic soda:
Although hydrochlorate of aniline, nitrate of sodium, and hydrate of sodium
only are named in the above process for the preparation of the yellow coloring
matter, other neutral salts of aniline may be employed as well, and other
alkaline nitrites or hydrates will be found to produce the same result.
'
Brown coloring matters are produced by replacing aniline as used in the
above-described process by phenylenediamine, or toluylenediamine, or their
homologues (substances produced by the reduction of bi-nitro benzole, bi-nitro
tolnole, or their homologues, as well known to chemists). The other parts of
the process may be conducted after the manner previously described in refer-
ence to the yellow coloring matter.
For purple coloring matters we heat salts of aniline, the bydrochlorate,
nitrate, or others, previously mixed with metallic nitrites. As an example
of this process, we take one part of nitrite of sodium and mix it with
nine or ten parts of aniline, and add muriatic acid slowly until the
mixture is neutral. By applying heat at 212° to 248° F., the blue
color is developed, which may be further purified by adding to it an
excess of caustic alkali, and passing a current of steam through it until the
aniline has been driven off; we then filter it, wash it, and dissolve it, if
required, in any suitable solvent, such as alcohol or acetic acid. As the first
effect of this process consists in the production of substances resulting from
the action of nitrous acid or its salts upon aniline, we can modify the said
process by. commencing with the yellow, described under the first part of our
Invention. For instance, we dissolve one part of the yellow in two parts of
aniline, and neutralize by concentrated hydrochloric acid. The mixture will

page_text: .
now, if the process has been well conducted, be a dark red, and is heated in a
closed digestor to a temperature of from 210° to 250° F. for about two hours,
when the contents of the vessel will have been changed into a blue or bluish
purple. The colour may be modified so as to afford a redder shade by adding
one part of the yellow to two parts of dry neutral hydrochlorate of aniline, 'and
gradually heating the mixture in a digestor up to about 340° F. The
purifying may be, conducted as above described. In the above-described
processes the hydrochlorate of aniline only has been mentioned, but other
compounds of aniline with mineral acids may be used in place thereof.
For black, grey, or drab dyes, we use the residue formed in the manu-
facture of aniline, purple, or mauve, and which in that state is insoluble in
solvents which would render it suitable for dyes. This substance we free
from its metallic constituents, after which it is dissolved in any suitable solvent;
as, for instance, alcohol, acetic or sulphuric acid. This deprivation of metallic
substances may
be effected by treatment with mineral acids. In practice
we have found repeated boiling with diluted hydrochloric acid to answer the
purpose.
Having thus described and ascertained the nature of our said Invention'
and the manner in which the same is to be performed, I desire it to be
understood that we claim, as secured to us under the above in part recited
Letters Patent,―
Firstly, the production of a yellow coloring matter by treating aniline or
salts of aniline with alkaline nitrites.
Secondly, the production of brown coloring matters by treating phenylene-
diamine or its homologues with alkaline nitrites.
Thirdly, the production of purple or blue coloring matters by heating salts
of aniline mixed with metallic nitrites, or with the products resulting from the
action of nitrous acid or its salts upon aniline.
Fourthly, rendering the residue of the aniline, mauve manufacture above-
mentioned suitable for a dye by depriving it of its metallic constituents.
In witness whereof, I, the said Heinrich Caro; have hereunto set my
hand and seal, this Twenty-ninth day of June, One thousand eight
hundred and sixty-four.
HEINRICH CARO. (L.S.)