An Improved Process of Decorating or Protecting Articles of Aluminium.
Year: 1894

page_text: Date of Application, 6th Feb., 1894-Accepted, 10th Mar., 1894
COMPLETE DIECIFICATION.
An Improved Process of Decorating or Protecting Articles of
Aluminium.
I, WILHELM GRÜNE, of 130 Alte Jacob-str. Berlin S.W. in the Empire of
Germany, Chemist, 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 bas for its object a new or improved process of decorating and
protecting the surfaces of objects made of aluminium by colouring or shading the
same in suitable patterns.
Aluminium, when heated, combines in a solid manner with carbon, a peculiarity
not heretofore known. I make use of this quality for colouring and decorating
aluminium surfaces.
In order to easily attach the carbon to the aluminium I apply liquid hydro-
carbons or solutions of hydrocarbons by painting or printing or by any other means
in the desired pattern upon the surface to be decorated or protected, which I after-
wards expose to heat. When the aluminium has been heated to a dark red, the
hydrogen escapes, and the carbon remains very finely distributed upon the
aluminium, with which it very intimately combines. According to the thickness
of the remaining layer of carbon particles the colouring of the pattern will be light
dark or coal-black, thus the shading may be made according to the pattern by
using more or less thick solutions of carbon.
For the practical application of my invention I make use of solutions of fat, oil,
resin or other hydrocarbons. Olive-oil, shellac, wax, mutton-tallow, asphalt and
the like are for instance very suitable hydrocarbons, when dissolved in alcohol,
benzene, strong oil-varnish, turpentine-oil and the like. Such solutions are painted
or printed or put upon the blank aluminium in any other suitable manner. It is
not necessary to clean the surface to be decorated by acids or lyes, as even washing
with benzene or rubbing it with a clean rag will suffice.
The aluminium after it has been provided with the desired pattern, is heated to
dark red by any suitable means as for instance by gas, spirit, coal-fire or the like.
The colouring appears during the heating and cannot be removed after cooling,
not even by hydrofluoric acid and soda-lye which are the best means for dissolving
aluminium.
The hydrocarbons may be applied in combination with metallic salts, which are
decomposed by heat and leave the pure metal. In this case in addition to the
layer of carbon there also remains a metallic layer upon the aluminium.
Metallic salts, which cannot be dissolved in hydrocarbons or which from any
other reason should not be combined with the same, can be applied after the carbon
layer is fixed upon the aluminium, as the carbon layer will not be destroyed by
heating.
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:
:-
First. The process of decorating or protecting aluminium surfaces by covering
the same with a layer of hydrocarbons and then heating the same to a dark red-
heat, substantially as described.
Second. The process of decorating or protecting aluminium surfaces by covering
the same with a layer of hydrocarbons mixed with suitable solutions of metallic
salts and then heating the same to a dark red-heat, substantially as described.

page_text: Third. The process of decorating or protecting aluminium surfaces by covering
the same with a layer of hydrocarbons, then heating the same to a dark red-heat
and finally heating the same again with solutions of metals substantially as set
forth.
Dated this 6th day of February 1891
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.