Improvements in the Manufacture of Pigments.
Year: 1894

page_text: Date of Application, 3rd Jan., 1894-Accepted, 10th Mar., 1894
COMILELE
SPECIFICATION.
[Communicated from abroad by JOSEPH SACHS, of 14, Dey Street, in the City of
New York, Merchant, CHARLES EMIL MEIER, of 406, Pearl Street, in the City
of New York, Merchant, and MAX GERSTENDÖRFER, of 17, Barclay Street, in
the City of New York, Merchant, all in the United States of America.]
Improvements in the Manufacture of Pigments.
I, OLIVER IMRAY, of No. 28, Southampton Buildings, Chancery Lane, in the
County of London, Chartered Patent Agent, 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 :-
My invention relates to the manufacture of pigments for decorating purposes by
dyeing pulverised minerals, such for instance finely powered mica, with organic dyes,
such as aniline-dyes, wood extracts or other soluble dyes, in such manner that the
colour thus produced will resist washing with cold or hot water or with weak acids
or alkalies.
Minerals of the kind referred to are quite insoluble in water and cannot be
coloured by simply bringing them into contact with solutions of colouring matter
containing adhesive material. It is a well known fact that certain vegetable fibres,
such as cotton or linen readily absorb and retain certain colours, but do not absorb
others, but when these fibres are treated with albuminoid substances they readily
receive and retain colours which without such treatment they repel. This treatment
of fibre is technically called "animalizing. My foreign correspondents have
discovered that some minerals may similarly be animalized, or made to receive
colours as dyes, and the method of dyeing pulverized minerals according to the
present invention is based upon this animalizing process.
It is also a well known fact that finely divided amorphous or gelatinous substances,
such as sulphur, hydroxyde of alumina, oxyde of tin, starch, etc., are capable
of taking up colour from certain colour solutions their particles becoming dyed.
But by the mere use of these mordants a solid dyeing of mica or similar minerals
can not be effected while the surface lustre is destroyed.
My correspondents have found that by subjecting finely divided mica or the like
to the combined action of the so called animalizing substances, such as albumen,
casein, etc., and the above mentioned mordants, the mica is brought into such
condition as to readily receive colours applied as dyes retaining at the same time its
surface lustre.
The practical manufacture of the pigments is carried on as follows: Finely
divided mica or similar mineral matter is thoroughly washed and is then introduced
into a bath of egg albumen, and the mixture is thoroughly stirred to bring the
particles into close contact. The mineral is then separated by filtration and dried
and when dry is introduced into a closed vessel, provided with agitators and while
well stirred is subjected to the action of steam at a temperature a little above 100° C.
The drying process above referred to may be effected in the following manner: The
mineral is placed in thin layers on suitable frames, that are brought into a suitable
drying apparatus, and therein subjected to a current of heated air, until perfectly
dry. The drying apparatus, is, of course, provided with an outflow, for the
discharge of the moistened air. Any other suitable drying method may be used
with the same result.
After the steaming treatment whereby a thin coating of coagulated albumen
is deposited on the particles of the mica, the mineral is introduced into a cold or hot
aqueous solution of any suitable soluble dye stuff. Aniline colours readily fix unon

page_text: it no other mordant being required; but when wood extracts are used, small
quantities of soluble mineral mordants, such as neutral sulphate of alumina, chloride
or subchloride of tin are added, so as to obtain a thorough dyeing of the mica. The
product thus dyed is then thoroughly washed and dried. Instead of effecting the
coagulation of the albumen by means of steam it may be effected in the known
manner by means of vapors of acetic acid, or of solutions of acetic, phosphoric,
or carbolic acids, or of certain metal salts, but it is preferred to perform the
coagulation by steam. According to a modification, the finely divided mica is
introduced into 8 or 10 times its weight of warm water at a temperature of
about 50° to 70° C., and to the mixture while thoroughly stirred is added a solution
of casein slightly ammoniacal.
There are then added a suitable quantity of dissolved dyestuff and finally a
solution of neutral alumina or tin salt. The solution of casein instead of being
added before the colour may be added after it.
in
The relative proportions of the several materials employed in the process, have
many cases to be determined by experiment. It is found that generally
a quantity of casein not exceeding 2 to 3 per cent. of the weight of the mica, yields
good results.
The dyed mica has a beautiful lustre, under reflected light. In order to obtain a
pronounced metallic lustre the thoroughly dried dyed mica is mixed with well
polished metallic powders such as bronze powder, brocade, or other similar
substances possessing metallic lustre as for instance bisulphide of tin, and the
like care being taken that the tint of the dyed mica is well matched with that of
the metallic addition.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The manufacture of pigments by treating finely divided mineral substances
such as mica with animalizing and other mordants and soluble dyes substantially as
described.
2. The manufacture of pigments having metallic lustre by mixing the pigments
produced as set forth in the preceding claim with metallic powders, substantially as
described.
3. Pigments consisting of mineral powders dyed as set forth in the first claim.
4. Pigments having metallic lustre produced by mixing metallic powders with
powdered minerals dyed as set forth in the first claim.
Dated this 3rd day of January 1894.
ABEL & IMRAY,
Agents for the Applicant.