Improvements in and in the Manufacture of Pigments, Printing-inks,. or Paint Mixtures.
Year: 1897

page_text: Date of Application, 22nd Mar., 1897-Accepted, 8th May, 1897'
COMPLETE SPECIFICATION.
Improvements in and in the Manufacture of Pigments, Printing-inks,.
or Paint Mixtures.
We, ERIC OSCAR STANISLAUS GENTELE, Chemist, and HERRMANN
RICHARD GENTELE, Paint Dealer, both of 25, Kommendörsgatan, Stockholm, in
the Kingdom of Sweden, 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 :-
In the preparation of pigments, printing inks or paint mixtures, the method
employed often consists in precipitating the colouring matter on another substance,
the so called substratum, which is more or less indifferent to the colouring matter,
such substances being kaoline, plaster of Paris, starch, sugar of lead or hydrate of
alum. These substances, however, are heavy, and some of them are injurious.
This invention consists in the use, for preparation of pigments, etcetera, of wood
pulp, cellulose or wood in the shape of powder or dust, the pigments, etcetera, thus
prepared gaining in covering qualities as compared with pigments prepared by the
use of other substances; an unnecessary increase in the weight of the
pigments, etcetera, being moreover avoided. The improved covering qualities are
due to the fact that the powdered wood absorbs the colouring matter more readily
than other substrata, a given quantity of colouring matter being thus distributed
over a larger quantity of the substratum, and a larger quantity of pigment, etcetera,
being obtained than heretofore. As a result of this more complete distribution or
mingling of the colouring matter, the percentage of the arsenic which may be
present is reduced to such a degree that the pigment, etcetera, may be regarded as
free from arsenic.
The powder or dust of wood, wood-pulp, or cellulose of fibrous materials, may
be produced by grinding in a dry or a wet state. Chemical or mechanical wood-
pulp or cellulose is suitably ground in a wet state so as to give the powder the
fineness desired. On this powder or dust, or even on the washed cellulose, the
colouring matter is then precipitated by means of suitable chemical agents; aniline
or coal tar colours being suitable for the process. The precipitation of the colouring
matter on the cellulose may thus take place either before or after grinding the
latter to powder.
For transferring an aniline colour to the powder or dust, the latter may be
mixed, for instance, with a solution of the aniline colour, as in water soluble
eosine, all the colouring matter then passing directly over to the powder or dust.
Another method for transferring the colouring matter to the powder or dust
consists in precipitating the dissolved colouring matter, for instance, an aniline
colour, by the addition of an acid (as sulphuric acid) or a solution of a salt (as sugar
of lead or a tin salt) on the powder or dust previously mixed with the solution of
colouring matter.
The depth of the colour, or the covering quality of the pigment, etcetera,
depends on the quantity of colouring matter added to a given amount of powder.
The powder thus treated may be used in the same manner as the ordinary
powdered colours for the preparation of pigments, etcetera.
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 improvement in the manufacture of pigments, printing inks or paint

page_text: mixtures, which consists in distributing the colouring matter over a substratum of
powder or dust of wood, wood pulp or cellulose either before or after the grinding
of the said substratum material substantially as herein before set forth for the
purpose of improving the covering qualities of the pigments and the like by
the use of a substratum which readily absorbs the colouring matter, and of
rendering harmless any arsenic which may be present, by reducing the percentage
of the latter.
2. Pigments, printing-inks or paint mixtures, having the colouring matter
distributed over a substratum of powder or dust of wood, wood pulp, or cellulose,
substantially as and for the purpose set forth.
Dated this 20th day of March 1897.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicants.