US495458A - Process of treating films - Google Patents

Description

UNITED STATES PATENT OFFICE.

EDI/VARD WILLIAM FOXLEE, OF LONDON, ENGLAND, ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE EASTMAN KODAK COMPANY, OF ROCHESTER, NEW

YORK.

PROCESS OF TREATING FILMS.

SPECIFICATION forming part of Letters Patent No. 495,458, dated April 11, 1893. Application filed June 25.1887- Serial No. 242,524. (No specimens.) Patented in England December 1, 1886, No. -727- To all whom it may concern:

Be it known that I, EDWARD WILLIAM FoXLEE, a subject of the Queen of England, residing at Acton, in the county of Middlesex,

5 England, have invented new and useful Improvements in or Relating to the Treatment of Photographic Dry Plates or Films, (for which I have obtained a patent in Great Britain, No. 15,727, bearing date December 1,

TO 1886,) of which the following is a specification.

This invention relates to that class of flexible films from which the paper or other backing is ultimately stripped. Films of this description vary in construction considerably;

: 5 in some the stripping of the back is done in a wet state, in others in a dry state and in others not stripped at all. Some of the films are made with a paper backing an insoluble gelatine film to receive the image and a soluble 2o gelatine layer interposed between the two; some makers do not use gelatine at all but a gelatinous or mucilaginous compound instead. In all cases however the film is supported by a backing generally of paper which is subsequently stripped off and to most if not to all of these the present invention is applicable. I will however describe it as applied to a plate made according to the Eastman patent, No. 306,594, and consisting of the paper backing the insoluble gelatine film and the interposed layer of soluble gelatine.

I shall use the word negative to indicate the insoluble film with the image on it,whether that image happens to be a negative or aposi- 3 5 tive picture as it may be either.

An advantage of my invention is that whereas the negatives as ordinarily prepared are subject to the attacks of damp and other atmospheric influences my improved o negatives are when required coated on both sides with collodion or varnish which is impervious to atmospheric influences.

In carrying out my invention I take a plate of glass or equivalent material and coat it with plain or normal collodion such as that employed by photographers but without being iodized. Before the collodion is poured upon the plate the latter is treated in the usual way with wax or india rubber dissolved in one of their solvents or powdered talc (French chalk) or some similar material to prevent the permanent adhesion of the collodion. When the collodion is set the plate is immersed in a dish of cold water until the ether and alcohol are washed out. This operation may be accelerated by washing under a tap. When the solvents have been removed from the collodion it is ready for the reception of the negative. This having been fixed and washed is laid face downward upon the collodion. An india. rubber squeegee is now employed with somepressure to insure close contact and expel the superfluous water and air bubbles but before the squeegee is applied asheet of india rubber or paper is laid on the plate in order to prevent abrasion of any exposed portions of the collodion film. Blotting paper is now placed upon the paper backing of the negative with a light pressure where it is allowed to remain for a suitable time rarely exceeding half an hour. Next the plate with the adherent negative is placed without previous drying in warm or hot water. In a short time the paper will be easily removed owing to the solution of the soluble substratum or interposed layer of gelatine leaving the negative firmly attached to the collodion. The plate is now removed from the water and a thin sheet or pelicle of gelatine which has previously been thoroughly softened in water-or a mixture of water and glycerine-is laid upon the negative and pressedinto close contact bya squeegee a sheet of india rubber being interposed to prevent abrasion. The whole is now allowed to dry or instead of applying this sheet in a firm state it may be run on in aliquid state. When the gelatine is dry it is coated with collodion or with a varnish. When this coating is dry the negative is stripped from the glass when it will bring the collodion film which was applied to the glass away with it firmly attached so that the negative and the gelatine are protected front and back with afilm of collodion or with one of collodion and one of varnish.

To facilitate the stripping a sharp knife may be run round the negative cutting the collodion to prevent tearing.

In some cases where it is not desired to remove the negative at all from the glass plate as when an inverted or reversed negative is required it is not necessary to prepare the surface of the glass with talc before running on the collodion. In these cases when the negative has been attached to the glass and the backing stripped off it is only necessary to coat the exposed surface with oollodion or varnish.

I claim The hereinbefore described improvement in the art of photography which consists in exposing and developing the image in the sensitized coating or film while attached to a flexible support; applying the developed negative or image bearing film to a prepared film of collodion and stripping off the flexible support; and finally coating the surface exposed by the removal of the flexible support with a film or layer of gelatine and the latter with a film of collodion or varnish; substantially as described.

In testimony whereof I have hereto set my hand in the presence of the two subscribing witnesses.

EDWARD \VILLIAM FOXLEE.

WVitnesses:

H. B. BRIDGE, H. WADE.