Manufacture of Prepared Sensitised Leather for Photographic Purposes.
Year: 1897

page_text: Date of Application, 15th Mar., 1807
Complete Specification Left, 15th Dec., 1897-Accepted, 12th Feb., 1898
Complete Specification Left, 15th Dec., 1897-Accepted, 12th Feb., 1898
PROVISIONAL SPECIFICATION.
Manufacture of Prepared Sensitised Leather for Photographic
Purposes.
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 (as communicated to me by The Farbwerke vormals Meister Lucius
and Brüning, of Hoechst "/Main, in the German Empire, Chemical Manufacturers),
to be as follows:-
Photographs on leather have hitherto been produced either by copying on
transfer paper or by the pigment process and final fixing on leather by transferring.
This method is not only troublesome and uncertain but also too expensive to be
practically employed.
When ordinary leather is prepared directly with a sensitised emulsion, the
emulsion soon decomposes. In the same way the gold salts of the toning baths
decompose, that is to say, the leather treated with them becomes spotty and finally
turns black by the gold &c. separating out. This is due to the chemical action
which the substances contained in leather exercise by their reducing properties
upon gold and silver salts.
My foreign correspondents have succeeded in avoiding this injurious reducing
action by preparing the leather, before it is treated with a sensitised emulsion, with
a substance such for instance as collodion, which protects the silver salts of the
emulsion, as well as the gold-salts of the toning baths against reduction.
The following is an example of the process. The leather intended for copying
is put on a frame and saturated on both sides with a solution of collodion of one half
to one per cent. strength. After 24 hours the leather, upon which the collodion
apart from its mechanical protection evidently has a chemical oxidising influence,
may be covered with any sensitised emulsion and then treated in the same way as
prints and plates.
1007
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SIMULTICATION.
Manufacture of Prepared Sensitised Leather for Photographic
Purposes.
I, OLIVER IMRAY, of Birkbeck Bank Chambers, Southampton Buildings,
Chancery Lane, in the County of London, but formerly of No. 28, Southampton
Buildings, Chartered Patent Agent, do hereby declare the nature of this invention
TD 077

page_text: (as communicated to me by The Farbwerke vormals Meister Lucius and Brüning,
of Hoechst /Main, in the German Empire, Chemical Manufacturers), and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
Photographs on leather have hitherto been produced either by copying on
transfer paper or by the pigment process and final fixing on leather by transferring.
This method is not only troublesome and uncertain but also too expensive to be
practically employed.
When ordinary leather is prepared directly with a sensitised emulsion, the
emulsion soon decomposes. In the same way the gold salts of the toning baths
decompose, that is to say, the leather treated with them becomes spotty and finally
turns black by the gold &c. separating out. This is due to the chemical action
which the substances contained in leather exercise by their reducing properties
upon gold and silver salts.
My foreign correspondents have succeeded in avoiding this injurious reducing
action by preparing the leather, before it is treated with a sensitised emulsion,
with a substance such for instance as collodion, which protects the silver salts of
the emulsion, as well as the gold-salts of the toning baths against reduction.
The following is an example of the process. The leather intended for copying
is put on a frame and saturated on both sides with a solution of collodion of one half
to one per cent. strength. After 24 hours the leather, upon which the collodion
apart from its mechanical protection evidently has a chemical oxidising influence,
may be covered with any sensitised emulsion and then treated in the same way as
prints and plates.
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 sensitised leather for photographic purposes by preparing
the leather, before it is treated with a sensitised emulsion, with a substance such for
instance as collodion, which does not attack the gold or silver salts of the toning
baths, substantially as described.
2. Sensitised leather prepared as above set forth.