Improvements in the Manufacture of Colouring Matters or Dyes.
Year: 1890

page_text: Date of Application, 30th May, 1890-Accepted, 2nd Aug., 1890
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Colouring Matters or Dyes.
We, Dr. ALBERT REMY, Dr. ROBERT KRAMER and WILHELM HERKING
of Neuwied-Weissenthurm in the German Empire, Chemists, do hereby declare
the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
This invention has for object the production of the metallic double salts of the
ketones and the reduction of the hydrols (hydrole) to a form allowing of their
application as dyestuffs.
The reduction of the phenones (ketones) to their metallic double salts is as
a rule carried out as for the tetramethyldiamidobenzophenone in the following
manner:
220 lbs. of tetramethyldiamidobenzophenone is dissolved in the same weight of
muriatic acid of 21° Beaumé and 2200 lbs. of hot water, and the hot solution
mixed with kitchen salt and 880 lbs. chloride of zinc solution of 1.50 specific
gravity. Upon cooling the metallic double salt separates in a crystalline form.
The metallic double salts of the hydrols may be obtained from the ketones, from the
metallic double salts-of-the-ketones-or-from-the-hydrols-themselves.
In the case of the tetramethyldiamidobenzhydrol the process is as follows:
11 lbs. of tetramethyldiamidobenzophenone is boiled with 330 lbs. of water and
18-7 lbs. of muriatic acid of 21° Beaumé until dissolution takes place. This for the
purpose of reduction is then treated with 6-6 lbs. of zinc powder until the intense blue
colour which the liquid takes is just commencing to diminish. It is then quickly filtered
and the filtered liquid slightly acidulated with muriatic acid so that just a clear
solution is obtained from which the dyestuff is precipitated by means of kitchen
salt and about 130 lbs. of chloride of zinc solution of 155 specific gravity. Instead
of separating the dyestuff by precipitation this may be done by concentrating the
slightly acidulated filtered liquid under addition of some kitchen salt and the dyestuff
obtained in the form of small gold bright needles.
The reduction of the metallic double salts of the ketones is carried out in a
corresponding manner the ketones being replaced by an equivalent quantity of the
metallic double salts.
Instead of employing zine for the reduction and precipitation any other metal or
metallic salt may be employed for these purposes.
The reduction of the hydrols to their metallic double salts is carried out simply by
reducing the hot and as far as practicable neutral solutions of the former in an
acid with chloride of zinc or other metallic salt and kitchen salt and left to cool.
Further we have found that the alcoholic solutions of the hydrols may be used
direct for dying purposes if to the hydrol solution or to the dye bath mineral or
organic acids, their salts, or metallic salts are added, also the hydrols may be left
to crystallise out of their solutions in organic acids and may be employed as dyestuffs
in this form.
The dyestuffs so obtained dye cotton mordanted with tannin and emetic tartar a
strong clear blue violet to red violet which shades stand in artificial light. The dye-
stuff dissolved in hot or cold water with addition of some acetic acid is applied for
dyeing in a weak acetic acid bath.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:
1. The process for obtaining the metallic double salts of the non alkilised and
alkil'sed mono and diamidobenzophenones and their sulpho-acids as also of the

page_text: tetra-alkilised diam idothiobenzophenones by dissolving the same in weak hot acid,
adding metallic salis and leaving the solution to cool for the purpose specified
substantially as described.
2. The process for obtaining colouring matters or dyes by reduction of the
phenones referred to in the preceding claim or their metallic double salts by ordinary
imedia of reduction, especially zinc and muriatic acid, and adding to the liquid of
reduction chloride of zinc or other metallic salt and kitchen salt substantially as
described.
3. The process for the production of colouring matters or dyes by treating the
hot and as far as practicable neutral solutions of the hydrol salts corresponding
to the phenones referred to in claim 1 with chloride of zine or other metallic
salt und kitchen salt and leaving the solution to cool substantially as described.
4. The employment as dye stuff solutions of the alcoholic solutions of the hydrols
referred to in claim 3 or their compounds in combination with mineral or organic
acids substantially as described.
Deted this 30th day of May 1890.
CAPITAINE & VON HERTLING,
89, Chancery Lane, London, W.C., Agents for the Applicants.