International Dyestuff Industry - ColorantsHistory.Org

against Simpson, Maule & Nicholson to make free the arsenic acid process for aniline red,
and after 1865 his business grew rapidly. This also assisted Ivan Levinstein, from Berlin,
who in 1865 began the manufacture of magenta at Blackley, Manchester; Levinstein’s
factory was a forerunner of the present ICI Specialties.
Litigation and the outcomes of patent disputes were also spurs to new innovative activities.
Since routes based on the oxidations of aniline with arsenic acid were held up in Britain
(except at Nicholson’s firm) until early 1865, because of injunctions, phenol-based colors,
naphthalene colors, modifications of mauve, and exploitation of Peter Griess’s discovery,
what was later called the diazo reaction, were all investigated. Heinrich Caro, a German
colorist at Roberts, Dale & Co. in Manchester, the main rival of Simpson, Maule & Nicholson,
was instrumental in directing research that led to all these colors. [15]
Heinrich Caro, colorist, chemist and technical leader, at BASF,
from 1868-1888. Edelstein Collection, Hebrew University.
Aniline Black
Caro invented a process for mauve in 1860, whereby copper salts were used as oxidants. It
became the sole competitor to Perkin’s dichromate reaction and the Manchester-made
mauve was used in Lancashire and Scotland from around 1862. From the residue of the
reaction, Roberts, Dale & Co. extracted a black colorant suited to cotton printing. However,
in 1862 it was used only to a limited extent by printers in Britain because of the corrosive
action on printing machinery. It was more widely applied on the mainland of Europe, where
wooden block printing was still popular.
The original discovery of aniline black was made in 1859 by John Lightfoot of Accrington,
north of Manchester. He established that the direct application of aniline in the presence of
an oxidizing agent to cotton, using the engraved copper plates of cylinders of printing
machinery, gave a fast and brilliant black, but, again, this was not wholly satisfactory
because of the corrosion problem. Lightfoot eventually patented his process early in 1863.
For mainland Europe and the United States patent rights were assigned to J.J. Muller- Pack
of Basle.
In 1864 Charles Lauth in Paris came out with the first of the improvements that were to
make aniline black printing possible with machinery. This was through the use of insoluble
copper salts. For the remainder of the nineteenth century, aniline black printing and dyeing
was carried out on a vast scale. [16]
Alkylation and phenylation of aniline
Since the Renards retained exclusive control over the production of aniline red, blue and
violet, chemists in Paris and Lyon also sought out new reactions on coal tar products. In
addition, the Renards, which became Societe La Fuchsine in 1864 (backed by the Credit
Lyonnais bank), had problems with pollution from large scale arsenic acid oxidation (from
around 1862). For these reasons, amino group hydrogens of aniline and toluidine were
replaced by phenyl and alkyi groups prior to oxidation. This work, inspired by Hofmann’s
publications on the constitutions of aniline colors, led to the introduction of reactions carried
out at high pressures and temperatures by Poirrier in Paris (alkylation, 1866), which
enabled the Renards’ patents to be circumvented. It also led to the introduction of less