Production of a Blue Dyestuff suitable for Dyeing Wool.
Year: 1896

page_text: Date of Application, 29th Oct., 1896
PROVISIONAL SPECIFICATION.
Production of a Blue Dyestuff 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 & Co., of Frankfort-on-Main in the Empire of
Germany) to be as follows:--
The diazo derivatives of the peri-amido-naphtolsulpho acids are very sensitive
to the action of alkalies, they can however be used in weak acid solutions for the
formations of azo dyestuffs.
A technically useful dyestuff of a violet shade has been obtained by for
instance combining the diazotised 1.8 amidonaphtol 3.6 disulpho acid with
monoalkylnaphtylamine (British application for Patent No. 12556).
The study of the combinations with amidonaphtols which are formed in acid
solutions, has demonstrated the fact, that one of them--the 1.5 amidonaphtol-
yields in combination with the diazotised periamidonaphtolsulpho acid a pure blue
dyestuff which is distinguished from all known blue azo dyestuffs by its great
fastness to light and on account of its dyeing level very easily. It furthermore
possesses the advantageous property of dyeing in a strongly acidulated boiling bath
without being decomposed in the least. The method of production is illustrated
by the following example, the parts being by weight: 32 parts of 1.8
amidonaphtol 3.6 disulpho acid are diazotised with 35 parts of hydrochloric
acid and 7 parts of nitrite of soda; the diazo compound which separates is
filtered off, washed with salt water, and then distributed in 500 litres water.
Thereto 16 parts of 1.5 amidonaphtol dissolved in 15 parts of hydrochloric acid
and 300 parts of water, are added, and then a solution of 30 parts of acetate of
soda. After a short time a clear dark blue solution is obtained. This is
neutralized with 20 parts of carbonate of sola, whereby a portion of the dyestuff
is separated, and finally the solution is entirely precipitated by means of common
salt.
001
1900
Production of a Blue Dyestuff 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 & Co., of Frankfort-on-Main, in the Empire of
Price 8d.1

page_text: Germany) and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:-
The diazo derivatives of the peri-amido-naphtolsulpho acids are very sensitive
to the action of alkalies, they can however be used in weak acid solutions for the
formations of azo dyestuffs.
A technically useful dyestuff of a violet shade has been obtained by for
instance combining the diazotised 1.8 amidonaphtol 3.6 disulpho acid with
monoalkylnaphtylamine (British application for Patent No. 12556%).
The study of the combination with amidonaphtols which are formed in acid
solutions, has demonstrated the fact, that one of them-the 1.5 amidonaphtol-
yields in combination with the diazotised periamidonaphtolsulpho acid a pure blue
dyestuff which is distinguished from all known blue azo dyestuffs by its great
fastness to light and on account of its dyeing level very easily. It furthermore
possesses the advantageous property of dyeing in a strongly acidulated boiling bath
without being decomposed in the least. The method of production is illustrated
by the following example, the parts being by weight:-32 parts of 1.8
amidonaphtol 3.6 disulpho acid are diazotised with 35 parts of hydrochloric
acid and 7 parts of nitrite of soda; the diazo compound which separates is
filtered off, washed with salt water and then distributed in 500 litres water.
Thereto 16 parts of 1.5 amidonaphtol dissolved in 15 parts of hydrochloric acid
and 300 parts of water, are added, and then a solution of 30 parts of acetate of
soda.
After a short time a clear dark blue solution is obtained. This is
neutralized with 20 parts of carbonate of soda, whereby a portion of the dyestuff
is separated, and finally the solution is entirely precipitated by means of common
salt.
In the place of the 1.8 amidonaphtol 3.6 disulpho acid other sulpho acids of the
periamidonaphtol may be used such as the 4.6, 3.5, 5.7 disulpho acid or the
4 monosulpho acid. Analogous colouring matters are further obtained if instead
of 1.5 amidonaphtol the 1.5 amidonaphtol 6 sulpho acid and the 1.5 amidonaphtol
7 sulpho acid are employed in the described process.
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 blue azo coloring matters by combining the diazo derivatives of
periamidonaphtolsulpho acids with 1.5 amidonaphtol or sulpho acids thereof
substantially as described.
2. The new coloring matters hereinbefore described.