Improvements in the Treatment of Gelatinous Matter and the Production of Photographic Films.
Year: 1894

page_text: Date of Application, 30th Jan., 1894
Complete Specification Left, 29th Oct., 1894-Accepted, 1st Dec., 1894
PROVISIONAL SPECIFICATION.
Improvements in the Treatment of Gelatinous Matter and the
Production of Photographic Films.
I, AUGUST ZIMMERMANN, of 6 and 7 Cross Lane, St. Mary-at-Hill in the City
of London, Merchant, (a communication to me from abroad by The Chemische
Fabrik auf Actien vorm. E. Schering of 170 Müllerstrasse, Berlin), do hereby
declare the nature of this invention to be as follows:-
According to this invention gelatinous matters such as glue, gelatine, and
isinglass, are transformed by the action of formic aldehyde (CH,O) into a
substance insoluble in water. Such substance is extremely flexible, tough, and
transparent and suitable for transparent skins films or plates.
The invention relates also to the production and utilization of such insoluble dry
adhesive agents and insoluble flexible skins films or plates, in photography. They
are intended as carriers for the sensitive mass or film as explained in the following
examples.
1. In the wet collodion process and collodion emulsion process adhesion of the
sensitive film to the glass plate, was formerly obtained by the application of chrome-
gelatine to the glass plate prior to pouring on the sensitive collodion emulsion.
According to this invention, instead of chrome-gelatine being employed, the
colourless and extremely resistant formic-aldehyde gelatine can be used with
advantage.
For instance, a solution of 1 gramme gelatine in 250 ccm. of warm water is
made and after cooling, a few drops of aqueous formic-aldehyde solution (36%
formalin) are added. The plates to be treated after first having been damped
with water, are then painted once or twice with the formic aldehyde gelatine
solution, drained and allowed to dry. The plates thus treated are then fit for use
in the wet collodion and collodion emulsion processes.
2. The formic aldehyde gelatine can further be used with great advantage in
making flexible, resistant or sensitive dry films or plates intended to replace the
beavy glass plates and celluloid emulsion films hitherto in use.
A well cleaned plate of glass or metal is first covered with a thin film of
collodion and after drying a solution of gelatine is poured on containing a certain
amount of formic-aldehyde according to the desired toughness and brittleness of the
film.
Upon drying of the formic-aldehyde gelatine film, thus made, the sensitive
gelatine is then poured on, i.e. either the halogen silver gelatine emulsion (bromide
of silver emulsion) or gelatine sensitized by the use of chromic salts.
After drying, the formic aldehyde gelatine film coated with the sensitive emulsion,
may be stripped from the glass or metal plate with ease, coming off in the form of a
skin or film.

page_text: These films or skins, can now be used in the same manner as the ordinary bromide
of silver emulsion dry plates and films or like pigment papers.
Dated this Thirtieth day of January 1894.
COMPLETE SPECIFICATION.
Improvements in the Treatment of Gelatinous Matter and the
Production of Photographic Films.
I, AUGUST ZIMMERMANN, of 6 and 7 Cross Lane, St. Mary-at-Hill, in the City
of London, Merchant, (a communication to me from abroad by the Chemische
Fabrik auf Actien vorm. E. Schering, of 170 Müllerstrasse, Berlin,) 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 :-
According to this invention gelatinous matters such as glue, gelatine, and isinglass,
are transformed by the action of formic aldehyde (CHO) into a substance
insoluble in water. Such substance is extremely flexible, tough, and transparent
and suitable for transparent skins films or plates.
For example if 100 grammes of warm 20 % gelatinous solution be mixed with
3 cubic centimetres of a 36 % solution of formic aldehyde the gelatine sets into a
insoluble and non-fusible jelly. This result also occurs when dry gelatine is dipped
into a formic aldehyde solution.
When very small quantities of formic aldehyde are added to a warm gelatine
solution the gelatine will set on cooling and can easily be remelted but when spread
on a surface it will after drying form a flexible skin which is perfectly insoluble in
water.
The invention relates to the production and utilization of such insoluble dry
adhesive agents and insoluble flexible skins films or plates, in photography. They
are intended as carriers for the light and colour sensitive coating or film as explained
in the following examples.
1. In the wet collodion process and collodion emulsion process adhesion of the
sensitive film to the glass plate, was formerly obtained by the application of chrome
gelatine to the glass plate prior to pouring on the sensitive collodion emulsion.
According to this invention instead of chrome-gelatine being employed, the colour-
less and extremely resistant formic-aldehyde gelatine can be used with advantage.
For instance, a solution of 1 gramme gelatine in 250 ccm. of warm water is made
and after cooling, a few drops of aqueous formic-aldehyde solution (36% formalin)
are added. The plates to be treated after first having been damped with water,
are then painted once or twice with the formic aldehyde gelatine solution, drained
and allowed to dry. The plates thus treated are then fit for use in the wet collodion
and collodion emulsion processes.
2. The formic aldehyde gelatine can further be used with great advantage in
making flexible, resistant or sensitive dry-films or plates intended to replace the
heavy glass plates and celluloid emulsion films hitherto in use.
On a well cleaned plate of glass or metal is poured a solution of gelatine contain-
ing a certain amount of formic aldehyde according to the desired toughness and
brittleness of the film, but not enough to prevent the gelatine solution from being
conveniently poured.
The following solution would answer the purpose.

page_text: Such a solution sets on cooling but is easily reliquified by warming. If however
it is allowed to dry it becomes an elastic skin which is totally insoluble in water.
Upon a dry film of formic-aldehyde gelatine thus made, the light and colour
sensitive gelatine is then poured on, i.e. either the halogen silver gelatine emulsion
(bromide of silver emulsion) or gelatine sensitized by the use of chromic salts.
After drying, the formic aldehyde gelatine film coated with the sensitive emulsion,
may be stripped from the glass or metal plate with ease, coming off in the form of a
skin or film.
These compound films or skins can now be used in the same mauner as the
ordinary bromide of silver emulsion dry plates and films or like pigment papers or
plates.
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 :-
--
1. Preparing a plate for use in the wet collodion and collodion emulsion processes
by covering it with formic aldehyde gelatine substantially as described.
2. A compound photographic film consisting of a foundation of insoluble formic
aldehyde gelatine and a sensitive face spread thereon substantially as described.
3. The production of photographic films substantially as described.
Dated this 29th day of October 1894.
AUG. ZIMMERMANN.