Year: 1887

page_text: Date of Application, 27th Oct., 1887
Complete Specification Left, 27th Aug., 1888
Complete Specification Accepted, 26th Oct., 1888
I, CARL AUGUST BENNERT, of Hebburn-on-Tyne in the County of Durham
Chemist, do hereby declare the nature of this Invention to be as follows:-
This Invention relates to the manufacture or production of coloured compounds or
colouring materials and consists in causing Sulphur to act upon Nitro compounds of
the aromatic series.
I have found that if Alpha Nitronaphtalene be mixed with sulphur and heated to
about 190° Centigrade (374° F) the Sulphur begins to react upon the Alpha Nitro-
naphtalene which reaction becomes more violent with the further increase of tempera-
ture. Sulphurdioxide is liberated and a melt is formed in which is found a green
compound containing Sulphur. This green compound is easily soluble in Carbon-
bisulphide and may be extracted from the crude melt by that or other solvents.
In order to diminish the violence of the reaction I find it advantageous to heat the
Alpha Nitronaphtalene up to 260° Centigrade (500° F) and to add the Sulphur so
gradually that the heat of the reaction keeps at about such temperature.
I have further found that Sulphur acts upon certain other Nitro compounds of the
aromatic series.
I call the coloured compounds or colouring materials obtained by these reactions
"Thiazines."
By submitting "Thiazines" to the process of sulphonation by one or other of the
means already well known sulpho-acids can be obtained from them.
"
Nitric acid acts upon "Thiazines as well as upon their sulpho-acids in such a
manner as to produce coloured compounds or sulpho-acids of such compounds
possessing colour other than that of the "Thiazine" or of its sulpho-acid which was so
treated.
Dated this 27th dow of Astahan 1887
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C.,
Agents for the said Carl August Bennert.

page_text: COMPLETE SPECIFICATION.
The Manufacture or Production of Colored Compounds or Coloring
Materials.
1 CARL AUGUST BENNERT of Hebburn on Tyne in the County of Durham Chemist
do hereby declare the nature of this Invention and in what manner the same is to he
performed to be particularly described and ascertained in and by the following
statement:
This Invention relates to the manufacture or production of colored compounds or
colouring materials and consists in causing sulphur to act upon Alpha nitronaphtalene.
I have found that if alpha nitronaphtalene be mixed with sulphur and heated to about
190° C (374° F), the sulphur begins to react upon the alpha nitronaphtalene which
reaction becomes more violent with the further increase of temperature. Sulphur-
dioxide is liberated and a melt is formed in which is found a green compound con-
taining sulphur.
This green compound is easily soluble in carbon-bisulphide and may be extracted
from the crude melt by that or other solvent.
The following is the best method with which I am acquainted of carrying my
Invention into effect.
200 parts.(by weight) of alpha nitronaphtalene are heated to about 210° C, (410° F),
to this 45 parts (by weight) of flowers of sulphur are added in small portions whilst
stirring so gradually that such temperature is maintained. The reaction between
nitronaphalene and sulphur gives off considerable heat and the addition of sulphur
has therefore to be managed judiciously.
It is best to use as little exterior heat as possible and to keep up the aforesaid
temperature mainly by the heat of the reaction itself and only a little by direct
heating.
The melt evolves sulphurdioxide and gets, eventually so thick as not to allow of
further proper stirring.
The melt becomes hard and brittle on cooling and has a spongy appearance: and
when powdered it has an almost black colour.
For obtaining the desired product (namely the green compound or colouring
material) the melt is finely powdered and treated with hot aethylic alcohol or hot
methylated spirit until all matters which are soluble in this solvent are removed.
The object of this treatment is to free the melt from nitronaphtalene and sulphur
not entered into reaction and mainly to remove all those bye products which are
soluble in alcohol.
On treatment of the residue left after this treatment with hot carbon-bisulphide
a green solution is obtained which on evaporation of the carbon-bisulphide yields the
main product in the form of a glossy looking dark molten mass. This treatment
with carbon-bisulphide has likewise to be continued until all matters soluble in that
solvent are obtained.
The residue presents a dull looking and dark powder with hardly any characteristic
properties.

page_text: If the melt has been conducted as aforesaid the treatment with hot aethylic alcohol
or methylated spirit presents no difficulty and if the treatment with alcohol has
been carried to the end as proscribed, the treatment with carbonbisulphide yields a
satisfactory product.
Instead of treating the melt first with alcohol and then with carbon-bisulphide it
may be treated first with carbon-bisulphide and then the product so obtained be treated
with alcohol.
[ :
extraction with carbon bisulphide can easily be done in that way, but the treat-
ment of the powdered crude main product with hot alcohol presents the difficulty
that, it often bakes together. Well conducted melts may however advantageously be
treated in that manner if care be taken to extract in the beginning with cold and only
in the end with hot alcohol.
The green compound or colouring material is not a uniform chemical substance
but is a mixture of at least one green and one blue substance, the latter however only
in small quantity.
By treatment with hot Ligroïne these substances may be separated to a certain
extent and there be obtained as an extract a substance of a more bluish shade and as
a residue a substance of a less bluish shade and by admixture of these other shades
may be obtained if required.
To render the green compound obtained soluble in alkali and suitable for dyeing
and printing I sulphonate it. For this purpose I have found the use of sulphuric
acid containing 20% sulphurtrioxide most advantageous.
I may proceed as
follows:-
1 part (by weight) of the green substance is dissolved in 5 parts (by weight) of
sulphuric acid containing 20% sulphurtrioxide and is heated to and maintained at about
45 to 60° C (113° F to 140° F) until a test shews that the whole is soluble in alkali.
It is then poured into five times its volume of water and the sulpho-acid produced
filtered off. The crude sulpho-acid so obtained may be treated for purification by
either of the methods well known to Chomists.
I have given the foregoing manner in which the invention may be performed
without necessarily limiting myself to the precise details given.
«
I call the compounds obtained in this manner by acting with sulphur upon
alpha nitronaphtlene "Naphtylthiazine" and its sulpho acids Naphtylthiazine-
|sulpho-acids."
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 1
claim is
1. The manufacture and use of the coloured compounds or colouring materials
herein described and termed by me "Naphtylthiazine" by causing sulphur to act
upon alpha nitronaphtlene.
"
2. The manufacture and use of the coloured compounds or colouring materials
herein described and termed by me Naphtylthiazine-sulpho-acids" by causing sulphur
to act upon alpha nitronaphtlene and then sulphonating the product obtained as
aforesaid.
3. The new products hereinbefore referred to and termed by me "Naphtylthiazine"
and "Naphtylthiazine-sulpho-acids."