The Manufacture of Yellow Coloring Matters by the Reaction or Tetrazodiphenyl or Tetrazoditolyl on Phenol or Orthocresylol.
Year: 1887

page_text: The Manufacture of Yellow Coloring Matters by the Reaction or
Tetrazodiphenyl or Tetrazoditolyl on Phenol or Orthocresylol.
I SYLVESTRE FOREL, of Mülhausen, Alsace, Chemist 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 :-
Although many somewhat complicated azoic coloring matters derived from
di-phenyl and di-tolyl have been patented, the most simple examples of this class are
not mentioned either in patents or in scientific papers. Now, I have discovered that
some of these most simple derivatives viz. :-the oxyazoic compounds resulting from
the reaction of tetrazodiphenyl and tetrazoditolyl on phenol and orthocresylol, possess
interesting coloring properties and are suited for an extended industrial use because
they are capable of dyeing vegetable fibres without the use of any mordant, and of
imparting to them a bright yellow color.
My Invention consists therefore, in the manufacture and application for dyeing
purposes of
Benzidine-azo-Phenol
-
CHN N-C.H. (OH)
The Manufacture of Yellow Coloring Matters by the Reaction of
Tetrazodiphenyl or Tetrazoditolyl on Phenol or Orthocresylol.
I SYLVESTRE FOREL, of Mülhausen, Alsace, Chemist 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 :-
Although many somewhat complicated azoic coloring matters derived from
di-phenyl and di-tolyl have been patented, the most simple examples of this class are
not mentioned either in patents or in scientific papers. Now, I have discovered that
some of these most simple derivatives viz. :-the oxyazoic compounds resulting from
the reaction of tetrazodiphenyl and tetrazoditolyl on phenol and orthocresylol, possess
interesting coloring properties and are suited for an extended industrial use because
they are capable of dyeing vegetable fibres without the use of any mordant, and of
imparting to them a bright yellow color.
My Invention consists therefore, in the manufacture and application for dyeing
purposes of -
Benzidine-azo-Phenol
CH.N=NCH (OH)
CH. N-N-CH (ОH)
Benzidine-azo-Ortho-cresylol C.H. N-N-CH, (CH₂) (OH)
=
CH.N-N-CH(CH) (OH)
Tolidine-azo-Phenol
CH, (CH) NN - CH. (OH)
OTY

page_text: The method of manufacturing the dyes is as follows :-
28.2 Kilos of dry Sulphate of Benzidine; or
56.4 Kilos of the same in the form of a 50% paste; are mixed with
400 to 500 litres of water and
24 kilos of hydrochloric acid at 30° Tw. and to the well cooled mixture 14 kilos
of Nitrite of Soda, are added.
I thus obtain a solution of chloride of tetrazodiphenyl which is poured into a well
cooled solution of
18.8 Kilos of Phenol
90 Kilos of caustic soda at 72° Tw. and
600 to 700 litres of water.
In
After some hours, the coloring matter is filtered and well washed with water.
this state it is insoluble in water but is easily soluble in dilute alkali. The alkaline
solution can be used directly for dyeing and yields on cotton a bright yellow shade.
In order to obtain a commercial product soluble in water either dry or in the form
of a paste, the following method is adopted;-I dissolve the precipitate in rather dilute
alkali, say
24 kilos of caustic soda at 72° Tw. and
50 to 100 litres of water
according to the state of dryness of the precipitate and I pour this solution into a
concentrated solution of common salt. The di-sodic salt of the oxyazoic compound is
precipitated in the form of a brown paste which is almost completely soluble in water.
The paste is filtered and mixed when still wet with 10 to 15 kilos of soda-ash. By
this means, the substance becomes completely soluble both in hot and cold water.
It is ready for sale in the form of a paste; if I want to obtain a powder I allow it
to dry at a low temperature (say 50° C.).
II. If, and in the same conditions as above described, 21.6 kilos of Ortho-cresylol
be substituted for the 18.8 kilos of phenol, the corresponding derivative of Ortho-
cresylol will be obtained.
III. and IV. If finally in the two above operations 31 kilos of Tolidine be substituted
for the 28.2 kilos of Benzidine, the corresponding derivatives of di-tolyl will be
obtained.
In the four cases the re-action is the same.
I give, for example, the chemical equations for the reaction of the chloride of
tetrazodiphenyl on phenol:
CH, N=N-CL
CH, N=N-CL
C₂H N=N—CH Он
+2CH, OH+2Na OH=2Na CL+2H₂O+
CH_N=N-CH, OH
EQUATION II.
CH. N=N-CH, OH
CH_N=N-CH, O Na
CH.N=N-CH, O Na
CH. N=N-CH, OH
+2NaOH=2H, O+ H
It will be understood that instead of the sulphates of Benzidine or Tolidine, any
other salt of the bases can be used. The degree of concentration and the proportion
of the alkali can also be somewhat varied. If, for instance, the proportion of alkali
used for the solution of the phenol or cresylol is larger, I obtain directly a soluble
compound, the sodic salt of the oxyazoic body which may be precipitated by common
salt.
The dyes prepared in this way yield on vegetable fibres a bright yellow when applied
in a bath containing alkali or soap. The best temperature for dyeing is between 60°
and 100° C. The cotton when removed from the dye bath is of an orange s shade;
; by

page_text: washing with water or dilute acid and drying it becomes changed to yellow. The
coloring matter is not at all removed by washing and scouring. The colors resist
soap, dilute acids, and sunlight, quite well.
The salts of the alkaline earths (chalk) yield with these coloring matters sparingly
soluble salts; it is therefore necessary to use for dyeing, pure (distilled) water or, if
no pure water is available, to correct the hard water with caustic soda or soda ash.
The dye bath is not immediately exhausted as is also the case with analogous coloring
matters; it may be reserved for subsequent operations and be strengthened if necessary
by the addition of further quantities of dye.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is ;-
The manufacture of oxyazoic compounds from tetrazodiphenyl or tetrazoditolyl by
the reaction thereof on phenol or orthocresylol in alkaline solution.
Dated this 11th day of November 1887.
S. FOREL.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.