Improvements in the Manufacture of Transparent Flexible Films for Photographic and other Purposes
Year: 1890

page_text: Date of Application, 26th June, 1890
Complete Specification Left, 27th Apr., 1891-Accepted, 30th May, 1891
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Transparent Flexible Films for
Photographic and other Purposes.
We, JOSEPH WILSON SWAN, of Lauriston, Bromley, Kent, and JAMES LESLIE
of 2 Somerset Terrace, University Street, Belfast, in the County of Antrim,
Chemists, do hereby declare the nature of this invention to be as follows:-
Whereas it has hitherto been customary in forming rollable films of nitro-
cellulose or celluloid for photographic purposes, to produce them by coating glass
or other rigid material with the nitro-cellulose or celluloid solution; and whereas
the use of such rigid surfaces for forming the film upon is attended with incon-
veniences such as limitation of length, we have invented a means of obviating these
inconveniences, and our invention consists in the use of a flexible instead of a rigid
support to form the film upon, and in the employment of means to render such a
method of manufacture practicable; and in connection with films so formed com-
bining with their formation the subsequent coating of the same with sensitive
photographic emulsion.
In carrying out our invention we spread or distribute the nitro-cellulose solution
upon or over a surface of paper, linen, cotton, silk, or any suitable flexible sheet,
suitably prepared with a surface unacted upon by the nitro-cellulose solution, from
which it may be stripped after drying. Such suitable coating may consist for
example of gelatine, but we do not confine ourselves to the use of this surfacing
material, but may modify it by the use of other substances either alone or combined
with the gelatine.
Previous to stripping the nitro-cellulose film from its support, it may be coated
with sensitive photographic emulsion.
Dated this Twentieth dow of Tun 1900
J. WILSON SWAN.
JAMES LESLIE.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Transparent Flexible Films for
Photographic and other Purposes.
We JOSEPH WILSON SWAN of Lauriston Bromley in the County of Kent
and JAMES LESLIE of Orrington House, Eglantine Avenue in the City of Belfast
and County of Antrim, Chemists, 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:-
Whereas it has hitherto been customary in forming rollable films of nitro-
cellulose or celluloid to produce them by coating glass or other rigid material with
the nitro-cellulose or celluloid solution, and whereas the use of such rigid surface
is attended with inconveniences, such as limitation of length, we have invented a
means of obviating these inconveniences, and our invention consists in the use of
a flexible instead of a rigid support to form the film upon; and in the employment
of means to render such a method of manufacture practicable and in connection
with films so formed, combining with their formation the subsequent coating of the
same with sensitive photographic emulsion.
:
In carrying out this invention we spread or distribute the nitro-cellulose solution
equally by means of a paper coating machine, such as is used in coating bromide
paper, or other suitable device, upon or over a surface of paper, linen, cotton,
silk, or any suitable flexible sheet which has been previously prepared with a surface
Price 4d 1

page_text: .
impervious to and unacted upon by the celluloid solution or any of its constituents,
and from which it may be stripped after drying.
Such suitable coating may consist for example, of gelatine or isinglass applied in
solution in a similar manner to that already described: but, we do not limit our-
selves to the use of these surfacing materials, but may modify them by using other
substances either alone or combined with them.
Previous to being coated with the celluloid solution, the gelatined support when
dry, is passed through rollers or calenders in order to give it a perfectly smooth
surface and is then polished with talc or other suitable substance to facilitate the
subsequent stripping of the film.
When coated with the celluloid solution the supporting paper or other fabric must
be kept level until the film sets, when it may be hung up to dry.
When dry, the film if intended for photographic purposes may be coated in the
same manner with sensitive collodion, or emulsion, before or after being stripped
from its support.
A solution of nitro-cellulose of a suitable consistency for distribution by the
before described method may be prepared by dissolving one part of the nitro-
cellulose compound known as celluloid or xylonite in six to eight parts of a
volatile solvent, such as the methyl, ethyl, or amyl alcohols, acetates, or ketones
or a mixture of either of them; but we do not limit ourselves to the use of these
or of any particular solvents or to the above stated proportions all of which
may be modified according to requirements and to the means of distribution
employed.
The quantity of this solution to be distributed upon the supporting material
depends on the thickness of film required; but, twenty four fluid ounces to each
square yard of surface produces a film of weight and thickness suitable for roll
holders.
We are aware that flexible photographic films have been prepared by distributing
a solution of celluloid on a rigid surface of glass or other material, and by coating
the same with sensitive emulsion.
Also that collodion and gelatine films have been spread on paper and coated with
sensitive emulsion, but in this case, the paper remains until the picture is developed
and fixed.
We are also aware that collodion and gelatine films have been spread upon paper
prepared with an india rubber surface, and coated with emulsion. In this case, the
gelatine adheres to the celluloid film, is stripped with it from its support, and
remains part of the film throughout all subsequent operations.
We make no claim to either of the above referred to methods of producing
photographic films but,
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. The hereinbefore described improvements in the art of making transparent
flexible celluloid films for photographic and other purposes, which consists in
spreading a solution of nitro-cellulose or celluloid, upon a flexible support having a
prepared surface, coating the same when dry with sensitive collodion or emulsion if
required, and stripping the film so prepared from its support.
2. A flexible celluloid film for photographic and other purposes, made in con-
tinuous or long lengths upon a flexible support having a prepared surface,
substantially as hereinbefore described.
Dated this 22nd day of April 1891.
JAMES STEVENSON,
Grays Inn Chambers, 20, High Holborn, W.C., Agent for Applicants.