IMPROVEMENTS IN THE PREPARATION OF COLORING MATTERS APPLICABLE TO DYEING AND PRINTING
Year: 1862

page_text: LETTERS PATENT to Edward Chambers Nicholson, of the Atlas Works,
Locksfields, in the County of Surrey, Manufacturing Chemist, for the
Invention of "IMPROVEMENTS IN THE PREPARATION OF COLORING MATTERS
APPLICABLE TO DYEING AND PRINTING."
Sealed the 3rd October 1862, and dated the 24th June 1862.
PROVISIONAL SPECIFICATION left by
SPECIFICATION left by the said Edward Chambers
Nicholson at the Office of the Commissioners of Patents, with his
Petition, on the 24th June 1862.
I, EDWARD CHAMBERS NICHOLSON, of the Atlas Works, Locksfields, in the
County of Surrey, Manufacturing Chemist, do hereby declare the nature of the
Invention for "IMPROVEMENTS IN THE PREPARATION OF COLORING MATTERS APPLICABLE
TO DYEING AND PRINTING," to be as follows:-
The blue coal tar dyes at present known, although soluble to a certain
extent in alcohol and similar solvents, are almost insoluble in water, so that
practically it is necessary to use alcohol or some other expensive solvent; and
when the solutions prepared in this manner are added to water to make a dye
bath they become precipitated or remain only suspended in water, consequently
it is difficult to dye evenly and brightly with such a bath; the object of this
Invention is to overcome these difficulties. For the purpose of preparing a

page_text: blue coal tar dye, soluble in water, either alone or mixed with acid or alkaline,
I employ the following process:-I take blue aniline dye in a solid form, for
instance, such dye as that known in commerce under the name of "bleu de
Lyon," and I mix it with about four times its weight of concentrated sulphuric
acid, and I expose the mixture to a temperature between 200° and 300°
Fahrenheit until a sample taken out is entirely soluble when diluted with
water. If the temperature be too high sulphurous acid is evolved and a portion
of the dye is destroyed. The acid solution can be diluted and used for dyeing
or printing in the ordinary way, or if too acid the excess of sulphuric acid may
be removed by lime or other suitable alkali, or if an excess of lime be added
the sulphuric acid is entirely precipitated in the form of sulphate of lime and a
colourless solution is obtained which, when neutralized with any vegetable or
other acid, developes the improved soluble blue dye.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Edward Chambers Nicholson in the Great Seal Patent Office
on the 24th December 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
CHAMBERS NICHOLSON, of the Atlas Works, Locksfields, in the County of
Surrey, Manufacturing Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of June, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-sixth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Edward Chambers Nicholson, Her special licence, that I, the said Edward
Chambers Nicholson, my executors, administrators, and assigns, or such others
as I, the said Edward Chambers Nicholson, my 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 Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN THE PREPARATION OF COLORING MATTERS APPLICABLE TO DYEING
AND PRINTING," upon the condition (amongst others) that I, the said Edward
Chambers Nicholson, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, 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

page_text: Scal Patent Office within six calendar months next and immediately after the
date of the said Letters Patent.
NOW KNOW YE, that I, the said Edward Chambers Nicholson, do hereby
declare the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say:-
The blue coal tar dyes at present known, although soluble to a certain
extent in alcohol and similar solvents, are almost insoluble in water, so that
practically it is necessary to use alcohol or some other expensive solvent; and
when the solutions prepared in this manner are added to water to make a dye
bath they become precipitated or remain only suspended in water, consequently
it is difficult to dye evenly and brightly with such a bath. The object of this
Ivention is to overcome these difficulties and to produce the dye for use in a
less expensive and more convenient form. For the purpose of preparing a
blue coal tar dye soluble in water, either alone or mixed with acid or alkali,
I employ the following process:-I take, by preference, the substance known
as "bleu de Lyon," or that known as "azuline." These being blue coloring
matters obtained from aniline and similar bases I extract all soluble matter
from it by boiling it with water containing sulphuric acid. I employ for this
purpose the said acid in the proportion of about four ounces by weight to
every gallon of water. When all or nearly all the soluble matter is extracted
I collect the insoluble matter and dry it thoroughly and completely. I then
take this substance, reduced to powder, and add it to about four times its
weight of sulphuric acid, say, sp. gr. 1.845 (i.e. concentrated sulphuric acid
of commerce), and I raise the temperature of the mixture to about 300°
Fahrenheit and keep it stirred until all is dissolved, and I then maintain it at
about this temperature until a sample, when added to water, is entirely dis-
solved. If the temperature is raised too high sulphurous acid is evolved and
the dye gradully destroyed. The acid solution can be diluted and used for
dycing or printing in the ordinary way; or if too acid the excess of sulphuric
acid may be removed by lime or other suitable alkali; or if an excess of limo
be added the sulphuric acid is entirely precipitated in the form of sulphate of
lime and a colourless solution is obtained which, when neutralized with any
vegetable or other acid, developes the improved soluble blue dye; or I find
that the excess of acid may be separated from the acid solution by adding to
it say, four times its bulk of water and then filtering for the color, although
soluble in concentrated acid, and also in water, is practically insoluble in water
containing a large quantity of acid; or the slight loss of coloring matter
which would arise from the use of water in this manner may be avoided by

page_text: the use of brine in place thereof. In the manner above described I produce
a new soluble blue color, a substance, in fact, entirely different in its chemical
properties from either "bleu de Lyon" or "azuline."
I do not limit myself to the proportions of sulphuric acid to be used, nor to
the temperature employed, as the concentrated sulphuric acid may be replaced
by anhydrous sulphuric acid, which renders the blue soluble without the
application of heat, or the two acids may be used in admixture, as, for example,
the "Nordhausen acid" of commerce may be employed.
In witness whereof, I, the said Edward Chambers Nicholson, have here-
unto set my hand and seal, this Twenty-third day of
the year
of our Lord One thousand eight hundred and sixty-two.
T CITAMDERS NICHOLSON
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