Violet Dye-stuffs suitable for Dyeing Wool.
Year: 1896

page_text: Date of Application, 8th June, 1896
Complete Specification Left, 6th Mar., 1897-Accepted, 17th Apr., 1897
NAL SPECIFICATION
Production of Violet Dye-stuffs suitable for Dyeing Wool.
1, SYDNEY PITT, of Sutton in the County of Surrey, Gentleman do hereby
declare the nature of this invention (a communication to me by Leopold Cassella
and Company of Frankfort-on-Main in the Empire of Germany) to be as
follows:-
It is known that the secondary derivatives of alpha-naphtylamine combine with
simple diazo bodies of the naphtalene series, as for instance diazonaphtalene
sulpho acids, forming dyestuffs, the shades of which, ranging between orange and
red, are changed by the influence of acids to violet. For this reason, these
combinations are not useful for dyeing purposes. Another circumstance, which
prevents their industrial application, is their relatively inferior fastness to light.
Tests have proved that by introducing a hydroxyle group at a certain position
of the nucleus of the diazona phtalenesulpho acid brought into reaction, an essential
alteration of the beforementioned azo bodies is effected.
If, for instance, the diazo derivatives of periamidonaphtolsulpho acids are
allowed to react upon secondary alpha-naphtylamine, violet dye-stuffs are obtained
which are stable against alkalis and acids and which possess a remarkable fastness
to light.
In order to obtain easily soluble combinations it is advisable to start from the
diazotised periamidonaphtoldisulpho acids.
Example:-32 parts by weight of amidonaphtoldisulpho acid H are diazotised
at 10°-15° C. with 7 parts by weight of nitrite of soda. Then a solution, having
a temperature of about 60° C., of the chlorhydrate of 18 parts by weight of
monoethyl-alpha-naphtylamine is introduced. The formation of the dyestuff is
terminated in about 12 hours. The solution is neutralised with soda and the dye-
stuff precipitated with common salt. It dyes wool a violet shade in an acid bath.
Dyestuffs of quite similar properties are obtained from, for instance, the 2.4. or
from the 4.6. disulpho acid of 1.8. amidonaphtol or by using the monomethyl base
instead of monoethylnaphtylamine.
Doted this 8th day of June 1806
Production of Violet Dye-stuffs suitable for Dyeing Wool.
I, SYDNEY PITT, of Sutton, in the County of Surrey, Gentleman, do hereby
declare the nature of this invention, (which has been communicated to me from
abroad by Leopold Cassella and Company, of Frankfort-on-Main, in the Empire
of Germany,) and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
It is known that the secondary derivatives of alpha-naphtylamine combine with
simple diazo bodies of the naphtalene series, as for instauce diazo-naphtalenesulpho
Unine Rd

page_text: acids, forming dyestuffs, the shades of which, ranging between orange and red, are
changed by the influence of acids to violet. For this reason these combinations
are not useful for dyeing purposes. Another circumstance which prevents their
industrial application, is their relatively inferior fastness to light. Tests have
proved that by introducing a hydroxyle group at a certain portion of the nucleus
of the diazonaphtalene-sulpho acid brought into reaction, an essential alteration of
the before mentioned azo bodies is effected. If for instance the diazo derivatives
of periamidonaphtolsulpho acids are allowed to react upon secondary alpha-
naphtylamine, violet dyestuffs are obtained which are stable against alkalis and
acids and which possess a remarkable fastness to light. In order to obtain easily
soluble combinations, it is advisable to start from the diazotised periamidonaphtol-
disulpho acids.
Example.-32 parts by weight of amidonaphtoldisulpho acid H are diazotised at
10° 15° C. with 7 parts by weight of nitrite of soda. Then a solution, having a
temperature of about 60° C., of the chlorhydrate of 18 parts by weight of
monoethyl-alpha-naphtylamine is introduced. The formation of the dyestuff is
terminated in about 12 hours. The solution is neutralized with soda and the
dyestuff precipitated with common salt. It dyes wool a violet shade in an acid
bath.
Dyestuffs of quite similar properties are obtained for instance from the 2.4 or
from the 4.6-disulpho acid of 1.8. amidonaplitol or by using the monomethyl base
instead of monoethylnaphtylamine.
If the diazo derivatives of periamidonaphtolmonosulpho acids are employed, as
for instance such of 1.8.4 amidonaphtolsulpho acid, coloring matters of nearly the
same shades result, which are only somewhat less soluble than those above
described.
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. Producing azo coloring matters by the combination of diazotised periamido-
naphtolsulpho acids with monoalkylated alpha naphtylamine, substantially as set
2. The new dyestuffs which may be obtained as above set forth.
forth.