US2167732A

US2167732A - Photographic material

Info

Publication number: US2167732A
Application number: US142660A
Authority: US
Inventors: Verkinderen Honore
Original assignee: Gevaert Photo Producten NV
Current assignee: Gevaert Photo Producten NV
Priority date: 1936-05-19
Filing date: 1937-05-14
Publication date: 1939-08-01
Anticipated expiration: 1956-08-01
Also published as: DE679336C; GB481702A

Description

Patented Aug. 1,1939

umrso STATES amuse I l rnorooaarmo MATERIAL Honor- Verkinderen, Hortael, near Antwerp, Bel-- glam, assignor to Gemrt Photo-Promoters Application May 14, 1931. Serial No. use w msmcramsylaiase I Asaruleeachottheselayersistora different part of the spectrum. Such multi-layer material is produced by pouring one layer on top oi the other. It is however known that the separation oi the w rmed layers encounters ditilculties which could hitherto not be overcome entirely. It has already been suggested to arrange between adjoining layers a thin intermediate support, which can readily be stripped. However in view of the fact that such intermediate support must a certain thickness, one or the other or the light-sensitive layers, when the material is exposed in the camera, will be out focus and in consequence thereof an indistinct image will be produced. One has also suggested to insert between the light-sensitive layers very thin layers of coliodium or similar material, sincesuoh lay- .ers, similarly as the intermediate supports men! tioned above, are adapted to facilitate the stripping of the light-sensitive layers and, in contrast negative from teing damaged and deformed when the part negatives are stripped Inthe photographic material aomrding to the present invention a plurality of layers are superposed in such manner that the light-sensitive layers each consisting of a binder such as gelatine and a light-sensitive substance such as a silver halide suspended therein are arranged in closest superposition, so that the production oi sharp and distinct images is guaranteed. Moreover these layers can be separated easily and without any danger of a negative being damaged.

In accordance with this invention the new material comprises, intermediatebetween the lightsensitive layers, fusible intermediate layers, the

,melting temperature of which lies within a and below the temperature at which the lightsensitive layers'and/or their support would be may also (01.. es-zl a damaged or the multi-layer material were exposed to thistemperature for a short part oftime.

I prefer pr intermediate layers melting at diiierent temperatures and arranging the intel-mediate layers in such manner that the melting temperatures rise in the direction from the top layertowards the support or carrier, 1. e. an intermediate layer farther remote from the supmedlate layers may for instance be wax, paratfln, fatty substances. natural or artificial resins, etc.

. I have found that the intermediate layers may be poured with extreme thinness (below microns and preferably about-24 microns), and will still be able to serve my purpose.

port will have a lower melting point than an in-' termediate layer nearer to the support.

The material constituting the fusible inter-j I may choose the material for the intermediate layers in such manner that the refractive index I of the intermediate layer: and that of the binder forming part of the light sensitive layers are about the same so that in this manner the optical contact between the light-sensitive layers is assured.

In the drawing photographic material embodying my invention is illustrated diagrammatically by way of example in cross section, drawn to a greatly enlarged scale. The material here shown is a negative material of a kind adapted for use in three-color photography. I

ierring to the drawing, l is the support, which may be glass, Celluloid, cellulose acetate, w ,9 or some other suitable material and 2, 3 and t are three light-sensitive layers. The layer 2 is sensitised for red, layer 3 for green-yellow.

r I is not sensitlzedand therefore only bluetivei Between the layers 2 and 3 is arranged a very thin parai'nn layer 5 melting at about 70 C. Between the layers 3 and! is arranged a similarly very thin paramn layer C, which melts already at about t0 C. In order to prevent blue rays from reaching the light-sensitive layers 3 and I, the intermediate layer 8 and/or the light sensitive layer I may contuin a yellow color illter-dyestuff. In order to prevent certain rays from penetrating the layer 3 and reaching the layer 2, the'layers 3 and/or I contain corresponding color fllter dyestufls.

The light-sensitive layer 2 may be replaced by a panchromatic emulsion sensitized for the entire "spectrum and in that case a red color filter dyestuii in the intermediate layer 5 may prevent other than red rays from reaching the light-sensitive layer 2.

Obviously the light-sensitive layers may be supposed in different sequence than shown in the drawing and it is also powble to so form the new material that it is able to satisfy the many differ- 5 ent conditions to be fulfilled by a color photogra- I phy material. Thus for instance the layer 2, which is sensitive for blue and red, may be arranged on top and in this case the sensitivity of this layer for blue may be reduced by well-known means. It is however also possible to obtain a copy from the red part-negative without reducing separately on transparent supports which may for instance be coated with a gelatine layer to which may be admixed substances adapted to facilitate the pasting-on of the light-sensitive layer. Instead of gelatine also other substances facilitating the fixing of the-light-sensitive layers may be used. In the case, where the material is designed for use in cinematography, it is preferable to use, for the individual layers, supports possessing the same properties (shrinkage limits etc.) as the support of the multi-layer material.

I have also found it advantageous to use in- 5 dividual supports having perforations of the same dimensions as the support of the multilayer material in order that on transferring the individual layers onto their individual supports the perforations of these layers and oftheir 44) supports are in exact register. In' view of the necessity of providing perforations of identical dimensions -in the original support and in the supports for the individual layers it appears desirable that the manufacturer who produces the 45 multi-layer material, provide his customer also with the corresponding number of supports for.

the part-layers. These part-supports should, if possible, be formed from the same batch as the multi-layer support in order to possess the same properties as this support. Therefore when selling a material such as shown onthe drawing, this material shall preferably be accompanied by two transparent supports designed to take While up the light-sensitive layers I and 4. these layers are then transferred onto these new supports, the light-sensitive layer 2 remains on the original support I.

The light-sensitive layers may be separated from each other and transferred onto their in- 50 dividual supports in the following manner:

In order to transfer the layer 4 onto one of the individual transparent supports provided for s this purpose, the gelatine layer, which may be arranged on this support, is moistened and the layer 4 pressed onto the gelatine layer in such manner as to firmly adhere to it. Now the multilayer negative as a wholetogether with the transparent individual support adhering to it is heated to'about 45-50 0., whereby the paramn layer 8 is caused to melt. The transparent individual support may now be removed together with thelight-sensitive layer 4. I thus obtain the original negative material, from which the top layer 4 is removed, and on the other hand the combination of this layer with a transparent support. As a rule a thin layer of paraffin adheres to both. As far as such fusible layers still adhering to the articles are soluble, they are now removed by means of appropriate solvents, wellknown in the art, which, whiledissolving the 5 fusible substance, are unable to exert an ob noxious influence on the light-sensitive layers or on their support. Similarly as the layer 4 also layer 3 is separated from the multi-layer material and transferred onto a transparent support. 10 However in order to cause the paraffin layer I to melt the multi-layer material must be heated to about 75-80 C. Since the light-sensitive layer 2 remains on the original support I, there re- 5 sult at the end of the separating operation three separate supports carrying the light-sensitive layers 2, 3 and 4 respectively, each of which can new photographic material may also comprise only two such layers arranged in superposition on a common support. The third light-sensitive layer may be arranged on a separate support and go may be used together with the two-layer material as a bi-paclr. When using such negative materials, after exposure only one of the two superposed light-sensitive layers must be transferred onto a transparent support. However op- '5 erating with a bi-pacln involves the disadvantages, that the light-sensitive layers must be exposed across a support, that the contact between the light-sensitive layers is not satisfactory and that a special kind of camera is re-. 0 quired for the exposure.

Obviously in photographic material according to this invention a greater or lesser number of light-sensitive layers th'anthree may be provided. Any such different material is used for producing more or less than three part-negatives.

The process according to this invention may readily be adapted to any material. For instance if four part negatives shall be obtained, 0 the four light sensitive layers may either be arranged on a common support or, as in a bi-pack for three-color photography, be distributed on two supports in such manner, that three layers are arranged on one support, the fourth layer 5 on another support. Alternatively the layers may be arrangedin pairs on two supports.

Various changes may be made in the details disclosed in the foregoing specification without departing from the invention or sacrificing the advantages thereof.

.1 claim:

l. A photographic material comprising in combination, a plurality of superposed light-sensitive layers and a fusible intermediate layer beas tween adjoining light-sensitive layers, the melting temperatureof the fusible layer being above the temperature which enables a light-sensitive layer to be arranged on the intermediate layer, and below the temperature at which the light- 70 sensitive layers would be damaged if exposed to this temperature for a short time.

2. A photographic material comprising in combination, a support, a plurality of superposed light-sensitive layers arranged on said support and a fusible intermediate layer between adjoining light-sensitive layers, the melting temperature of the fusible layer being above the temperature which enables a light-sensitive layer to be arranged on the intermediate layer, and below the temperature at which the light-sensitive layers and said support would be damaged if exposed to this temperature for a short time.

3. The photographic material of claim 1, in which a plurality of fusible intermediate layers is provided, diiferent layers having diflerent melting points.

4. The photographic material of claim 2, in which a plurality of more than two light-sensitive layers is arranged in super-position with a fusible layer between every two adjoining lightsensitive layers, the melting point of the fusible layer nearest to the support being higher than the melting point of a layer farther away from the support. l

5. The photographic material of claim 2, in which a plurality of more than two light-sensitive layers is arranged in superposition with a fusible layer between every two adjoining lightsensitive layers, the melting points of the layers farther away from the support being lower than those of the layers nearer to the support.

6. The photographic material of claim 1, in which each light-sensitive layer comprises a binder and a light-sensitive substance suspended in said binder, the binder and the fusible layer having refractive indexes of the same order.

'7. The method of producing part images for color photography with the aid of a photographic multi-layer material which is a combination of a plurality of superposed light-sensitive layers and a fusible layer between adjoining light-sensitive layers, the melting temperature of the fusible layer being lower than the temperature at which the adjacent light-sensitive layers would be damaged if exposed to this temperature for a short time, which comprises placing an auxiliary transparent support, coated with a binder, onto the topmost light-sensitive layer of the multilayer material, heating the multilayer material together with the auxiliary support resting thereon to a temperature slightly above the melting point of said fusible intermediate layer and removing the auxiliary support together with the topmost light-sensitive layer adhering to it.

8. The method of claim 7 as applied to a photographic multilayer material being a combination of a plurality of light-sensitive layers with a fusible intermediate layer between each two adjacent light-sensitive layers, these fusible intermediate layers having different melting points, which comprises placing an auxiliary transparent support, coated with a binder, onto the topmost light-sensitive layer of the multilayer material, heating the multilayer material together with the auxiliary support resting thereon to a temperature slightly above the melting point of the fusible intermediate layer adjoining the topmost light-sensitive layer, removing the auxiliary support together with the topmost light-sensitive layer adhering to it, placing another auxiliary transparent support, coated with a binder, onto the light-eensitive layer uncovered by the removal of the topmost layer, heating the multilayer material together with said other auxiliary support slightly above the melting point of the fusible intermediate layer adjoining said uncovered light-sensitive layer and removing said other auxiliary support together with the uncovered light-sensitive layer adhering to it.

9. The process of claim 7, in which the multi-