as a Substitute for Lithographic Stones.
Year: 1885

page_text: as a Substitute for Lithographic Stones.
I, HERBERT JOHN HADDAN, of 67 Strand, in the City of Westminster, Civil
Engineer, do hereby declare the nature of said invention for A PROCESS FOR
PRODUCING ON METAL PLATES A LAYER OF MATERIAL AS A SUBSTITUTE FOR
LITHOGRAPHIC STONES, a communication to me from abroad by Julius Wezel,
of the firm of Wezel and Naumano, Manufacturers of Rendnitz-Leipzig, in the
kingdom of Saxony, to be as follows:-
Lithographic stone, chalk, marble, lime &c, are dissolved by means of sulphuric
and muriatic acid, and from this solution chalk combined with resinous or fatty
acid is precipitated by means of resin or good soft soap.
After the superfluous acid has been removed by filtration, the residuum is dried
to a powder which forms a mixture of lime in combination with fatty or resinous
acid and sulphate of lime.
The dry powder is distributed mechanically in a weak solution of soda, and
blown on to the hot metal plate by a steam injector or other suitable contrivance.
HERBERT & Co.,
Agents, 67, Strand.

page_text: as a Substitute for Lithographic Stones.
I, HERBERT JOHN HADDAN, of 07 Strand, in the County of Middlesex, Civil
Engineer, do hereby declare the nature of this invention a communication to
me from abroad by Julius Wezel, of the firm of Wezel and Naumann, Manu-
facturers of Rendnitz-Leipzig in the kingdom of Saxony, and in what manner
the same is to be performed, to bo particularly described and ascertained in and
by the following statement :—
• The processes hitherto known for producing on metal plates a layer of litho-
graphic stone or a substitute for the same, do not give a perfectly satisfactory
result, chiefly owing to the facts, that they have always employed calcic carbonate,
which is not suitable or sufficient for this purpose.
The process hereinafter described has for its object to produce lithographic plates,
which possess exactly the same qualities as ordinary lithographic stone, but are
much more easily manipulated.
The process of preparing these plates is as follows:
Lithographic stone, chalk, marble, lime-stone etc. are dissolved in sulphuric
and hydrochloric acid, and combinations of lime with resinous or fatty acids are
precipitated from this solution by means of resin-soap or good oil soap.
3. After the removal of the superfluous acid by filtration, the residue is dried to
form a powder which is a mixture of calcic sulphate with a combination of lime.
and resinous acid, or with a combination of lime and fatty acid.
The dried powder is mechanically suspended in diluted solution of sodic
carbonate and applied upon the hot metal plate in the form of a spray or jet
by means of a steam injector or other suitable contrivance.
In order to impart to the layer, thus produced, a certain measure of elasticity
and to increase its adhesion upon the metallic plate, a small quantity of asphalte,
dissolved in turpentine, may be added to the dissolved stone at the time of its
being mixed with soap.
Having now particularly described, and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I-elaim, is
.
The process for producing on metal-plates a layer of lithographic stone or a
substitute for the same, which consists in forming a mixture of calcic sulphate with
a combination of lime and resinous or fatty acid, with or without the addition of
asphalte, dissolved in turpentine, and fixing the mixture on the metal plate, in a
fine state of division.