Year: 1896

page_text: Date of Application, 16th Nov., 1896
Complete Specification Left, 29th June, 1897-Accepted, 31st July, 1897
We, IVAN LEVINSTEIN and LEVINSTEIN LIMITED, both of Minshull Street, Manchester
in the county of Lancaster, Chemical Manufacturers, do hereby declare the nature of
this invention to be as follows:-
Hitherto, Chlorinated Benzidine derivatives have been produced from Metachlor-
nitrobenzene and from Parachlorazobenzene. Ewer and Pick produced Colouring
Matters from Dichlorbenzidine, which they obtained from Metachlornitrobenzene. The
Colouring Matters thus produced are not direct dyes.
We have discovered new Chlorinated Benzidines, the Tetrazo Compounds of which
form, with Amines or Phenols, or their Sulpho- or Carboxyllic-Acids, Colouring Matters
which dye cotton fibres without a mordant.
In proceeding according to our Invention, for the production of our new Chlor-
benzidines, we may, for example, proceed as follows:-
26-8 kilos of Diacet-benzidine are dissolved in about 3 kilos. of ordinary Concentrated
Sulphuric Acid at ordinary temperature, and the resulting solution is poured into ice-
cold water. The mixture, being kept at a low temperature, has then gradually added
to it, with constant stirring, a sufficiency of a solution of ten per cent. Bleaching Powder
to form a Dichlorbenzidine. The reaction is finished when the original green colour
changes to a light yellow. The temperature is then raised to 40° C. and after standing
for about 12 hours, our new Chlordiacetbenzidine is obtained in the form of a yellowish
precipitate which is filtered off, and saponified by boiling it with from 3 to 4 times its
quantity of 20 per cent. Hydrochloric Acid. On cooling, the greater part of the
Chlorbenzidine Hydrochloride separates out and from it our new Colour Base is obtained
in the usual well known manner.
This new base possesses very valuable properties for the production of direct dyeing
Colouring Matters or Dye-stuffs.
The Tetrazo Compound of our new Chlorbenzidine forms, for example, with
Naphthionate of Soda, Red Colouring Matters which are much bluer and faster to
acid than the corresponding Colouring Matters obtained from Tetrazodiphenyl or
Tetrazoditolyl.
EXAMPLE.
FOR THE PRODUCTION OF A DIRECT DYEING BLUEISH-RED COLOURING MATTER.
26.0 kilos of our new Base are dissolved in 300 litres of water containing 70 kilos
of Hydrochloric Acid, 18° Bè., the whole cooled with ice. To this there is slowly
added an aqueous solution of 140 kilos of Sodium Nitrite, with stirring.
The Tetrazo Compound thus obtained is run into an aqueous solution of 50 kilos. of
Sodium Naphthionate (100 per cent.), containing sufficient Sodium Acetate to neutralise
all mineral acid. The Colouring Matter thus formed separates out as a red
precipitate.

page_text: After 12 hours stirring, the mixture is made alkaline, heated to 80° C., filtered,
pressed and dried.
The dried product forms a dark red powder which dyes unmordanted cotton a blueish-
red, and distinguished by its fastness to acid.
W. E. HEYS & SON,
Agents for the Applicants.
Production of a New Colour Base and of Colouring Matters therefrom.
We, IVAN LEVINSTEIN and LEVINSTEIN LIMITED, both of Minshull Street, Manchester
in the County of Lancaster, Chemical Manufacturers, 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:-
Hitherto, chlorinated benzidine derivatives have been produced from metachlor-
nitrobenzene and from parachlorazobenzene. Ewer and Pick produced colouring
matters from dichlorbenzidine which they obtained from metachlornitrobenzene. But
these colouring matters are not direct dyes.
We have discovered new chlorinated benzidines, the tetrazo compounds of which
form, with amines and phenols, or with their sulphonic or carboxylic acids, colouring
matters which dye cotton fibres without a mordant.
In proceeding according to this Invention, for the production of the new
chlorobenzidines, the hereinafter described process may be followed by way of
example. Thus :-
26-8 kilos. of diacetbenzidine are dissolved in about 3 kilos. of ordinary concentrated
sulphuric acid at ordinary temperatures and the resulting solution is poured into ice-
cold water. The mixture, being kept at a low temperature, has then gradually added
to it with constant stirring, a sufficiency of a solution of ten per cent. bleaching powder
(or of other suitable hypochlorite), to form a dichlorbenzidine. The reaction is com-
pleted when the original green colour changes to a light yellow. The temperature is
then raised to 400 C.and after standing for about 12 hours, the new chlordiacetbenzidine
is obtained in the form of a yellowish precipitate which is filtered off and saponified
by known means as for example by boiling it with from three to four times its
quantity of 20 per cent. hydrochloric acid, on cooling, the greater part of the chlor-
benzidine hydrochloride separates out and the new colour base is obtained from it in
the usual well known manner.
Instead of chlorinating diacetbenzidine by means of hypochlorites in acid solution,
free chlorine may be allowed to act on the diacetbenzidine in the following manner:
26-8 kilos of diacetbenzidine are suspended in about 200 litres of solution of common
salt, a little iron wire is added as a carrier, and whilst the solution is cooled by external
application in the known manner, chlorine is passed into the mixture as long as it
continues to be absorbed. Subsequent saponification is afterwards effected as herein-
before described. We however prefer to employ the hypochlorites as the source of
chlorine as first herein set forth.
This new base possesses very valuable properties for the production of direct dyeing
colouring matters or dye-stuffs.
The tetrazo compound of the new chlorbenzidine forms, for example with
sodium naphthionate, red colouring matters which are much bluer and faster to
acids than the corresponding colouring matters obtained from tetrazodiphenyl or
etrazoditolyl.

page_text: 26.0 kilos. of the new base are dissolved in 300 litres of water containing 70
kilos. of hydrochloric acid 18° Bè., the whole cooled with ice. To this there is
slowly added, whilst stirring, an aqueous solution of 140 kilos. of sodium
nitrite.
The tetrazo compound thus obtained is run into an aqueous solution of 50 kilos. of
sodium naphthionate (100 per cent), containing sufficient sodium acetate to neutralise
all mineral acid. The colouring matter thus formed separates out as a red precipitate.
After 12 hours stirring the mixture is made alkaline, heated to about 809 C., salted
out, filtered, pressed and dried.
The dried product formis a dark red powder which dyes unmordanted cotton a
blueish red distinguished by its comparative fastness to acid.
If, instead of naphthionic acid, a corresponding quantity of the sodium salt of the
beta-naphthylamine sulphonic acid (Brönner) is combined with the tetrazo body of
our new dichlort enzidine, a colouring matter results which dyes unmordanted cotton
a bright blueish red which is fast to organic acids.
Having now particularly described and ascertained the nature of our said invention
and in what manner the same is to be performed, we declare that what we
claim is:-
1. As a new substance, the herein before described new chlorbenzidine colour
base.
2. As new substances, the new direct dyeing colouring matters being tetrazo com-
pounds of chlorbenzidine combined with amines or with phenols or with their sulphonic
or carboxylic acids, substantially as hereinbefore described.
3. The hereinbefore described process for the production of the new chlorbenzidine
base, substantially as set forth.
4. The herein before described process for the production of the new direct dyeing
colouring matters which consists in the tetrazotisation of chlorbenzidine and the com-
bination therewith of amines or phenols or their sulphonic or carboxylic acids,
substantially as set forth.
Dated this 28th day of Tum 1007