Improvements in and in the Method of Obtaining Dyestuffs from Petroleum.
Year: 1893

page_text: Date of Application; 25th May, 1893-Accepted, 15th July, 1893
COMPLETE SPECIFICATION.
Improvements in and in the Method of Obtaining Dyestuffs from
Petroleum.
I, HANS ALBERT FRASCH, of 962 Willson Avenue, Cleveland, Ohio, United
States of America, Chemical Engineer, do hereby declare the nature of my inven-
tion and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement, that is to say :-
In the manufacture of anilin, artificial alizarin, and kindred dyestuffs and bases
for dyestuffs and colors, coal tar obtained from illuminating gas works has hitherto
been employed. The ordinary process of conversion is by fractional distillation of
the coal tar. The aromatic series of hydrocarbons contained in such coal tar
furnishes the source whence these dyestuff's or colors have been derived. A kindred
or similar series of hydrocarbons exists also in petroleum or natural mineral oil or
the distillates or derivatives, residual or otherwise, thereof; and it is upon these
hydrocarbons of the petroleum series as distinguished from the hydrocarbons of the
coal tar series, that I act for obtaining my new dyestuffs.
My invention relates, first, to a method of obtaining dyestuffs from hydrocarbons
contained in such natural oils by nitration, and second, to the product so obtained.
In practicing my invention I subject crude petroleum or its distillates or
products, residual or otherwise, to the action of a mixture of sulphuric and nitric
acids until all the aromatic hydrocarbons, olefines, naphthenes and unsaturated
hydrocarbons in the oil are taken up in the acid mixture as oxidized and corre-
sponding nitro products. I prefer to use one part of nitric acid to three parts
of sulphuric acid in the mixture, but these proportions may be varied; and
so also the proportion of acid mixture to oil may be varied, according to
the quality of the oil being treated and according to the quantity of sulphuric
and other acids that may be in the petroleum or its products being treated. The
mixture of acid and oil is agitated, mechanically or by a forced current of air,
until a sample from which the acid has been permitted to settle will discolor
little, if any, upon the addition thereto of fresh concentrated acid. The mixture
of acid and oil is then permitted to rest until the acid is separated from the oil,
when the acid containing the aromatic hydrocarbons and tarry substances is drawn
from the oil. The acid mixture taken from the oil is then heated until the hydro-
carbons contained therein are converted into nitro or oxidised products.
Nitration may be effected without heat by keeping the mixture agitated a long
time, say, from four to eight weeks, and even longer, thus permitting the acid to
act upon the hydrocarbons.
The requisite degree or extent of nitration is determined when the bulk of a
test sample will dissolve in a hot solution of alkali. The free acid is then removed
and this may be readily accomplished by neutralization or repeatedly washing the
mixture with cold water or by precipitating the nitro compound from the acid
After the free acid is removed, the residuum is heated with water until the water is
saturated with the more soluble nitro products. The solution is left to settle,
whereby the soluble products and the insoluble matter and oily matter are
separated. The soluble products are then drawn off and consist in a mixture of
different higher and lower nitro products. To separate these products, carbonate
of lime or caustic lime is added, with or without heating, until precipitation
ceases, whereby a soluble and an insoluble calcium salt are obtained. Any other
substance which will form a soluble and an insoluble salt with the nitro product
may be substituted for the calcium. The solution is separated from the precipitate,

page_text: and a reddish brown dyestuff precipitated from the solution by addition of hydro
chloric acid, sodium chloride, or any other salt in whose watery solution the
dyestuff is insoluble. The dyestuff is then separated by filtration.
Instead of obtaining the dyestuff directly, as just described, it may be obtained
indirectly by converting the calcium salt into a salt of potassium, ammonium, &c.
and then separating the dyestuff as before.
The insoluble salt separated from the solution first above mentioned may be
converted into a soluble salt by the addition thereto of carbonate of sodium,
potassium, ammonium, or any other substance that will unite therewith and form a
soluble compound or dyestuff and displace the calcium.
precipitated from the solution thereby obtained by the addition of hydrochloric
The dyestuff itself is
acid, sodium chloride or any other salt in whose solution the dyestuff is insoluble.
The dyestuff obtained by the method first above described is in the form of a
reddish brown powder, soluble in water and glycerine, alcohol and most of the
aromatic hydrocarbons. In its solutions, and more especially its alcoholic solutions,
it has a bluish green fluorescence. It forms a soluble calcium salt, and emits the
characteristic odour of burning coal oil when exposed to high heat. It dyes silk
and wool, in acidulated solutions, without mordant, a reddish brown.
The dyestuff obtained by the second mentioned process is a distinct brown color
and in the form of a powder. It has a resinous appearance or texture when first
made, but can be pulverized. This dyestuff is soluble slightly in cold water, but
readily soluble in hot water. It is also soluble in alcohol and glycerine but very
slightly soluble in the aromatic hydrocarbons. It forms an insoluble calcium salt,
and is thus mainly distinguishable from the first named salt. It emits the
characteristic odour of burning coal oil when highly heated, and dyes cotton, without
mordant, a brownish color.
If, instead of using a mixture of sulphuric acid and nitric acid, sulphuric acid
be substituted in the process above described, a sulpho product will be obtained.
In contemporaneous application I have fully described this sulpho process and
product, and to them reference is hereby made for further particulars. The sulpho
product referred to may be treated to obtain a nitro product, by dissolving the
finished sulpho product in water and heating it with nitric acid until effervescence
ceases, after which the product is precipitated from the solution as before.
The same or a similar body may be obtained by the addition to a watery solution
of the sulpho product of sodium nitrite and hydrochloric acid, and it can be
obtained also by the addition of nitrous acid to the sulpho product.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :
1. The art of manufacturing dyestuffs from petroleum, natural mineral oils, or
the distillates or derivatives thereof, which consists
removing the free acid, separating the soluble from the insoluble and oily matters
nitrating the substance and
in the remainder, splitting the soluble matter into soluble and insoluble lime salts,
and ultimately converting these salts into distinct dyestuffs, substantially as
described.
4
2. The art of manufacturing dyestuffs from petroleum, natural mineral oil, or the
distillates or derivatives thereof, which consists in nitrating the substance, removing
the free acid, separating the soluble and insoluble and oily matters from the
remainder, splitting the soluble matter into a soluble and an insoluble lime salt, and
precipitating from the soluble lime salt solution a dyestuff by addition of hydro- 5
chloric acid, chloride of sodium or any other salt in whose solution the dyestuff is
insoluble, substantially as described.
3. The art of manufacturing dyestuffs from petroleum, natural mineral oil, or
the distillates or derivatives thereof, which consists in nitrating the substance,
removing the free acid, separating the soluble and insoluble and oily matters from 5
the remainder, splitting the soluble matter into a soluble and an insoluble lime salt,

page_text: adding to the insoluble lime salt an alkali or any other base which will displace the
calcium and precipitating from the resulting solution a dyestuff by the addition of
hydrochloric acid, chloride of sodium or any other salt in whose solution the
dyestuff is insoluble, substantially as described.
4. As an article of manufacture, a nitro body producing with carbonate of lime
or caustic lime a salt soluble in water, and another salt insoluble in water, and
emitting the characteristic odour of petroleum or coal oil when highly heated,
substantially as described.
5. As an article of manufacture, a nitro dyestuff or color base, emitting the
characteristic odour of coal oil when highly heated, and whose calcium salt is soluble
in water, substantially as described.
6. As an article of manufacture, a nitro dyestuff or color base, which will dye
silk or wool in an acidulated solution a reddish brown without the use of a
mordant, substantially as described.
Dated this 19th day of April 1893.
HANS ALBERT FRASCH.