Improvements in the Production of Black Dyes suitable for Dyeing Wool.
Year: 1892

page_text: Date of Application, 11th Feb., 1892
Complete Specification Left, 7th Mar., 1892-Accepted, 16th Apr., 1892
PROVISIONAL SPECIFICATION.
Improvements in the Production of Black Dyes suitable for Dyeing
Wool.
I, SYDNEY PITT, of Sutton in the County of Surrey, Gentleman, (a communi-
cation to be from abroad by Leopold Cassella & Co., of Frankfort on Main, in the
Empire of Germany, Manufacturing Chemists,) do hereby declare the nature of
this invention to be as follows :-
Black azo coloring matters for wool dyeing have first been described in a Patent
taken on behalf of my correspondents by Messrs. Hoffmann and Weinberg No. 9214".
The said dyes were produced by a process which consists in the reaction of certain
diazosulpho acids upon alpha naphtylamine, diazotation of the amido azo compounds
and combination with naphthols, etc. One of the essential characteristics of the
dyestuffs was the central position of the alpha naphtylamine. Afterwards my
correspondents found (see my Patent No. 70678) that instead of alpha naphtyl-
amine some of its products of substitution can be used. The present invention
relates to the use of certain naphtylamine mono sulpho acids in the place of alpha
naphtylamine.
The said acids have been first prepared by Cleve, who got them by nitration and
reduction of the naphtalene beta sulpho acid. Cleve has designated the two acids
by the letters "beta" and "delta." Their chemical constitution is 1-6 (beta) and
1-7 (delta). The new process therefore consists of the following reactions. Diazo
compounds for instance the diazo derivatives of aniline, aniline sulpho acid or
homologues, naphtylamine, naphtylamine mono or disulpho acids-are allowed to
react upon the alpha naphtylamine mono sulpho acid 16 or 17, the amido azo
sulpho acids thus obtained are diazotised again and combined with phenols or
amines such as naphthol, naphthol mono or disulpho acids, amido-naphtholsulpho
acids, dioxynaphtalenesulpho acids, naphtylamine, mono alkyl naphtylamine,
phenyl naphtylamine, diphenyl m-phenylene diamine.
The process is explained more exactly by the following example:
24-5 kil. of the sodium salt of naphtionic acid are diazotised and the diazo
compound is introduced into the solution of 24-5 kil. of the sodium salt of alpha
naphtylamine sulpho acid 1.7 or 1.6 and a sufficient quantity of sodium acetate is
added. As soon as the amido azo disulpho acid has been completely formed, it is
converted into the diazo azo disulpho acid by means of muriatic acid and 7 kil. of
nitrite. The diazo azo compound can easily be separated. If it is combined with
35 kil. of beta naphthol-disulphonate R in alkaline solution, a black dye is obtained
which resembles naphtol black.
Dated this 11th day of February 1892.
CARPMAEL & Co.,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Production of Black Dyes suitable for Dyeing
Wool.
I, SYDNEY PITT, of Sutton in the County of Surrey, Gentleman (a communi-
cation to me from abroad by Leopold Cassella & Co. of Frankfort-on-Main, in the
Empire of Germany, Manufacturing Chemists) 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 :-
Black azo coloring matters for wool dyeing have first been described in a Patent

page_text: taken on behalf of my correspondents by Messrs. Hoffmann and Weinberg No. 9214.
The said dyes were produced by a process which consists in the reaction of certain
diazosulpho acids upon alpha naphty lamine, diazotation of the amido azo compounds
and combination with naphthols etc. One of the essential characteristics of the
dyestuffs was the central position of the alpha naphtylamine. Afterwards my
correspondents found (see my Patent No. 7087") that instead of alpha naphtyl-
amine some of its products of substitution can be used. The present invention
relates to the use of certain alpha naphtylamine beta mono sulpho acids in the
place of alpha naphtylamine.
The said acids have been first prepared by Cleve who got them by nitration and
reduction of the naphtalene beta sulpho acid. Cleve has designated the two acids
by the letters "beta" and "delta." Their chemical constitution is 1.6 (beta) and
17 (delta). The new process therefore consists of the following reactions diazo
compounds-for instance the diazo derivatives of aniline, aniline sulpho acid or
homologues, naphtylamine, naphtylamine mono or di sulpho acids, are allowed to
react upon the alpha naphtylamine mono sulpho acid 16 or 17, the amido azo
sulpho acids thus obtained are diazotised again and combined with phenols or
amines such as naphthol, naphthol mono or di sulpho acids, amido-naphtholsulpho
acids dioxynaphtalene-sulpho acids, naphtylamine, mono alkyl naphtylamine, phenyl
naphtylamine, diphenyl m-phenylene diamine.
:-
The process is explained more exactly by the following example
24-5 kil. of the sodium salt of naphtionic acid are diazotised and the diazo
compound is introduced into the solution of 24-5 kil. of the sodium salt of alpha
naphtylamine sulpho acid 1.7 or 1-6 and a sufficient quantity of sodium acetate is
added. As soon as the amido azo disulpho acid has been completely formed, it is
converted into the diazo azo disulpho acid by means of muriatic acid and 7 kil. of
nitrite. The diazo azo compound can easily be separated. If it is combined with
35 kil. of beta naphtholdisulphonate R in alkaline solution, a black dye is obtained
which resembles naphtol black.
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 I
claim is :-
1. The process of preparing new azo dyes by the reaction of diazo compounds-
such as the diazo derivatives of aniline, aniline sulpho acids or homologues,
naphylamine, naphtylamine mono- or di-sulpho acids-upon alpha naphtylamine
mono sulpho acid 1-6 or upon alpha naphtylamine mono sulpho acid 1-7 diazotation
of the products thus obtained and combination of the resulting diazo- azo- bodies
with phenols-such as naphthol, naphthol mono- or di-sulpho acids, dioxynaphtalene,
dioxynaphtalene sulpho acid, or with amines-such as naphtylamine, monoalkyl
naphtylamine, phenyl- alpha-naphtylamine, diphenyl m-phenylene, diamine
substantially as described.
2. The new coloring matters hereinbefore described.
Dated this 7th day of March 1909
CARPMAEL & Co.,
Agents for the Applicant.