A New or Improved Process for Separating Photographic Gelatine Films from Celluloid Supports or Bases.
Year: 1893

page_text: Date of Application, 20th Oct., 1893
Complete Specification Left, 20th July, 1894-Accepted, 8th Sept., 1894
PROVISIONAL SPECIFICATION.
A New or Improved Process for Separating Photographic Gelatine
Films from Celluloid Supports or Bases.
We, ALFRED ALLEN BARRATT, Clerk in Holy Orders, of Cleygate Vicarage,
Esher, and ALBERT JOHN EVES HILL, Manager of the Cresco-fylma Company,
Brighton Road, Surbiton, both in the County of Surrey, do hereby declare the
nature of this invention to be as follows:-
This invention relates to a new or improved process for separating photographic
gelatine films from celluloid supports or bases.
Celluloid supports or bases, coated with sensitised gelatine films, are, for certain
purposes, preferable to similarly coated glass plates, inasmuch as they are light,
extremely thin, and practically unbreakable, but a serious objection to them is that
the nature of the celluloid renders them inconvenient to print from, or as
transparencies, owing to the celluloid not retaining its flat form, and it has hitherto
been impossible to float the film off the celluloid support or base on to a glass plate
by reason of the close union of the celluloid with the gelatine film.
Now the object of the present invention is to provide means of readily separating
the negative or other gelatine film from the celluloid support or base and floating it
on to a glass plate so that it may be employed in the ordinary manner.
For this purpose, we place the celluloid negative in a solution of acetone, or
amyl acetate, and water combined in suitable proportions, such as, for example,
of about
One part of amyl acetate or acetone
Six parts of water.
This compound penetrates the gelatine film and attacks the surface of the
celluloid beneath the same, thereby loosening such film which may then be stripped
or floated off the celluloid support or base, on to a glass plate and dried.
When it is desired to enlarge the film, a vegetable acid, such, for example, as
citric, tartaric or glacial acetic, is applied to the film in combination with the acetone
and water.
Or, the stripped film may be steeped in a solution of the vegetable acid until it
becomes saturated therewith, when it should be transferred to a water bath, in which
the enlargement will take place.
In combination with the process above described, we may employ suitable chemicals
either to preserve the density of the film or to increase the same.
For the first of these purposes, we prefer to employ sulphate of iron, and for the
second bi-chloride of mercury followed by ammonia, as in ordinary photographic
procedure, but any of the usual methods employed for like purposes may be
adopted.
Dated this 20th day of October 1893.
VAUGHAN & SON,
Agents for the Applicants.

page_text: COMPLETE SPECIFICATION.
A New or Improved Process for Separating Photographic Gelatine
Films from Celluloid Supports or Bases.
We, ALFRED ALLEN BARRATT, Clerk in Holy Orders, of Cleygate Vicarage,
Esher, and ALBERT JOHN EVES HILL, Manager of the Cresco-fylma Company,
Brighton Road, Surbiton, both in the County of Surrey, 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 :-
Our said invention relates to a new or improved process for separating photographic
gelatine films from celluloid supports or bases.
Celluloid supports or bases, coated with sensitised gelatine films are, for certain
purposes, preferable to similarly coated glass plates, inasmuch as they are light,
extremely thin, and practically unbreakable, but a serious objection to them is that
the nature of the celluloid renders them inconvenient to print from, or as
transparencies, owing to the celluloid not retaining its flat form, and it has hitherto
been impossible to float the film off the celluloid support or base on to a glass plate
by reason of the close union of the celluloid with the gelatine film.
Now, the object of the present invention is to provide means of readily separating
the negative or other gelatine film from the celluloid support or base and floating it
on to a glass plate so that it may be employed in the ordinary manner.
For this purpose, we place the celluloid negative in a solution of acetone or
amyl acetate and water combined in suitable proportions, such as, for example,
of about :-
One part of amyl acetate or acetone
Three to six parts of water.
This compound penetrates the gelative film and attacks the surface of the
celluloid beneath the same, thereby loosening such film which may then be stripped
or floated off the celluloid support or base, on to a glass plate and dried.
When it is desired to enlarge the film, sulphuric or hydrochloric acid or
preferably a vegetable acid, such, for example, as citric, tartaric or glacial acetic,
is applied to the film in combination with the acetone and water in the proportion
of about one ounce of the former to about three ounces of the latter.
Or, for the same purpose the stripped film may be steeped in a solution of the
vegetable acid until it becomes saturated therewith, when it should be transferred
to a water hath, in which the enlargement will take place.
In combination with the process above described, we may employ suitable
chemicals either to preserve the density of the film or to increase the same.
For the first of these purposes, we prefer to employ sulphate of iron and for the
second bi-chloride of mercury followed by ammonia, as in ordinary photographic
procedure, but any of the usual methods employed for like purposes may be
adopted.
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 berein described process for separating photographic gelatine films from
celluloid supports or bases, consisting in soaking the celluloid negative in a solution
of acetone or amyl acetate and water combined in suitable proportions, substantially
as herein described.

page_text: 2. In the separation of photographic gelatine films from celluloid supports or bases,
the employment of a solution consisting of amyl acetate or acetone and water in or
in about the proportions herein stated.
Dated this 20th day of July 1894.
VAUGHAN & SON,
Agents for the Applicants.