of Thiobases of Diamines.
Year: 1885

page_text: of Thiobases of Diamines.
I, JOHN IMRAY, of No 28 Southampton Buildings, Chancery Lane in the County
of Middlesex, Consulting Engineer and Patent Agent, do hereby declare the nature
of my invention for " MANUFACTURE OF BLUE AND VIOLET COLORING MATTERS BY
OXIDATION OF THIOBASES OF DIAMINES to be as follows:-
This invention relates to the manufacture of blue and violet coloring matters by
oxidation of thiobases resulting from fusion in close vessels of sulphur with
paraphenylene-diamine and other diamines, such as are produced by the reaction of
bodies of the azoamido class, such as amidoazobenzol, orthoamidoazotoluol, para-
azoamidotoluol, azoamidoxylol, azoamidonaphthaline &c.
For this purpose a process is employed which will be understood by the
following example describing the manufacture of blue colouring matter by
oxidation of thioparaphenylenediamine.
Amidoazobenzol prepared in the known way is heated in solution in aniline
at 45° C. and under agitation a current of sulphuretted hydrogen is passed through
it until a sample diluted in acidulated water ceases to give yellow colour. After
cooling, crystals are formed and separated by filtering and pressing, dissolved in
boiling water and filtered. The liquor being rendered alkaline by caustic soda, the
aniline is separated by steam; the paraphenylene-diamine remains, crystallises in
cooling, and is purified by distillation. The purified material is heated to 170°
or 180° C. for several hours along with sulphur in a close vessel, producing the
thiobase of the diamine while hydrosulphate of ammonia is formed. The thiobase
is dissolved in dilute hydrochloric acid, and the hydrochlorate thus produced, after
filtration and cooling, is oxidated by addition of an oxidant such as perchloride of
iron or bichromate of potassa. The oxidated material is precipitated by salt,.
filtered and pressed, again dissolved in boiling water, filtered and again precipitated,
Pin G21

page_text: producing a colouring matter which, with suitable mordants, dyes animal and
vegetable fibres an indigo blue.
In like manner diamines obtained from other bodies of the azoamido class can
be treated, for production of blue colouring matters with tints more or less violet
according to the character of the amine employed.
Dated thin ofth dair of M 100%
ABEL & IMRAY,
Agents for the Applicant,
28, Southampton Buildings,
London, W.C.
Manufacture of Blue and Violet Coloring Matters by Oxidation
of Thiobases of Diamines.
I, JOHN IMRAY of No 28 Southampton Buildings, Chancery Lane, in the County
of Middlesex, Consulting Engineer and Patent Agent, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
This invention relates to the manufacture of blue and violet coloring matters by
oxidation of thiobases resulting from fusion in close vessels, of sulphur with
paraphenylene-diamine and other diamines, such as are produced by the reaction of
bodies of the azoamido class, such as amidoazobenzol, orthoamidoazotoluol, para-
azoamidotoluol, azoamidoxylol, azoamidonaphthaline &c.
In order that this invention may be clearly understood, I will, as an example,
describe the manufacture of a blue coloring matter obtained by oxidation of
thioparaphenylenediamine.
After making amidoazobenzol by the known method, it is heated in solution in
aniline at 45° C., a current of sulphuretted hydrogen is passed through it with
agitation of the mixture, and the operation is stopped as soon as a sample diluted
in acidulated water ceases to give a yellow color.
The reaction is ranresented by the farmula
Ag
Aniline.
Paraphenylenediamine.
The mass is allowed to cool, the paraphenylenediamine crystallises, and the
material is filtered and pressed. The crystals are then dissolved in boiling water,
and the solution is filtered to separate sulphur.
In order to separate the paraphenylenediamine from the aniline, the liquor is
rendered alkaline by caustic soda, and the aniline is withdrawn by steam.

page_text: The paraphenylenediamine remains in the solution and crystallises on cooling in
beautiful crystals. It is purified by distillation.
The paraphenylenediamine thus obtained is heated in a closed vessel for about
4 hours at 170° to 180° C. along with sulphur. Thus is obtained the thiobase of
the diamine, that is to say, 1 molecule of sulphur unites with 2 molecules of the
paraphenylenediamine, and during the reaction hydrosulphate of ammonia is
formed.
The thiobase is dissolved in about 50 times its weight of water and 4 times its
weight of hydrochloric acid. The solution of hydrochlorate of the thiobase is
filtered, allowed to cool and oxidated with perchloride of iron, bichromate of
potassa or any other oxidant, until a sample precipitated by salt and filtered,
no longer gives blue. This oxidation produces a blue coloring matter which is
precipitated by sea salt, to be afterwards filtered and pressed. The coloring
matter is again dissolved in boiling water, filtered and again precipitated. The
coloring matter thus obtained dyes vegetable and animal fibres in presence of
certain mordants a blue of indigo tint.
By employing diamines obtained by reduction of other bodies of the azoamido
class of the type of azoamidobenzol, such as orthoamidoazotoluol, paranzoamido-
toluol, azoamidoxylol, azoamidonaphthaline &c, I obtain by the same process blue
and violet coloring matters similar to those, the production of which I have just
described. The tint of blue becomes more violet the.greater the molecular weight
of the amine.
The above described new coloring matters can be applied to all vegetable and
animal fibres and materials, and in all works in which coloring matters are
employed.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed, I declare that what
I claim is
1. The herein described improved manufacture of blue and violet coloring
matters resulting from the oxidation of thiobases of diamines.
2. The herein described process for the production of blue and violet coloring
matters wherein paraphenylenediamine and other diamines are first obtained by.
the reduction of azoamidobenzol and other bodies of the azoamido class of the
same type, and after transformation into their thiobases by fusion with sulphur in
closed vessels, such thiobases are converted into blue and violet coloring matters
by oxidation.