CH96885A

CH96885A - Photographic film with a water-permeable support and process for its manufacture.

Info

Publication number: CH96885A
Authority: CH
Inventors: Cellophane Societe Anonyme La
Original assignee: Cellophane Sa
Priority date: 1920-04-19
Filing date: 1921-01-14
Publication date: 1922-11-16

Description

Pellicule photograpliique ä Support permeable ä: 1'eau et procede pour sa fabricatiou. La presente invention se rapporte ä une pellicule photographique ä Support permeable ä feau, et ä un procede pour sa. fabrication. Water-permeable carrier photographic film and process for its manufacture. The present invention relates to photographic film on a water-permeable support, and to a process for the same. manufacturing.

La pellicule photographique ne presente 1e sel sensible que d'un cöte seulement <B>du</B> Sup port permeable ä 1'eau. The photographic film presents the sensitive salt on only one side of the water-permeable support.

Suivant 1e procede pour la fabrication de ladite pellicule, an forme une couche sensible d'un cötg seulement du Support permeable. According to the process for the manufacture of said film, a sensitive layer is formed on one side only of the permeable Support.

Les pellicules photographiques ä Support permeable ä 1'eau, employees jusqu'ici en Photographie, etaient obtenues en trempant, Jans certaines conditions, les Supports per m6ables ä feau, tels que ceux en cellulose et autres, Jans differents ba.ins, en vue de de- velopper, au sein meme des Supports, 1e sel sensible. Ce dernier comme an 1e voit se trou- vait, de cette faQon, concentre vers les deux faces du Support, sa concentration allant en diminuant vers 1'intgrieur du Support. Au point de vue photographique, cette double conceniration du sel sensible, Sur les faces du Support, peut donner lieu ä. certains incon- v6nients, quant ä la finesse de 1'image. La pellicule photographique qui Fait 1'objet de 1'invention ne presentant 1e sel sensible quo d'un cöte seulement du Support permeable ä 1'eau, evite ces inconvenients. Poux la former, an peut se servir dune emulsion photogra- phiqu.e ä, base de .ge1atine, que Von etend Sur Tune des faces d'un Support permeable ä 1'eau, Support en viscose, par exemple, prealablement mouille ä fond et dopt an ex- prime 1'exces d'eau avant d'eteudre ladite emulsion. Apres sa coagulation, cette emulsion se trouve repartie träs r6guliere- ment Sur ladite face du Support. The photographic films on a water-permeable support, hitherto used in photography, were obtained by soaking, under certain conditions, the water-permeable supports, such as those made of cellulose and the like, in different baths, in view to develop, within the Supports themselves, the sensitive salt. The latter as we see it was, in this way, concentrated towards the two faces of the Support, its concentration decreasing towards the interior of the Support. From the photographic point of view, this double concentration of the sensitive salt, on the faces of the Support, can give rise to ä. certain drawbacks, as regards the sharpness of the image. The photographic film which is the subject of the invention presenting the sensitive salt on only one side of the water-permeable support avoids these drawbacks. To form it, one can use a photographic emulsion based on gelatine, which is spread on one side of a water-permeable support, a viscose support, for example, previously thoroughly wetted. and dopt an expresses the excess water before the said emulsion is diluted. After its coagulation, this emulsion is distributed very regularly On the said face of the Support.

0n peut ggalement proceder de la ma- niere suivante: Des Supports permeables ä 1'eau sont Passes au travers d'un Premier bain qui a pour objet de dilater les pores des Supports et de les impregner en meme temps de 1'un des produits des'tines ä reagir ulte- rieurement. Cela Fait, an applique deux -Sup ports 1'un contre 1'autre et an les fait passer ainsi, accoles 1'un ä 1'autre, entre des roti- leaux exprimeurs, qui ont pour effet d'ex- primer l'exces de liquide, provenant du Pre mier bain precite, se trouvant Jans lesdits Supports. 0n obtient apres cela un Support double, qui est soumis ä 1'action d'un second bain, qui a pour effet de produire, Sur les deux faces dudit Support double, 1e sel sen-. sible. Cette operation terminee, an separe les deux Supports 1'un de 1'autre et Fon ob- tient deux Supports dans lesquels 1e sel sen sible se trouve concentre Sur l'une des faces seulement. It is also possible to proceed in the following manner: Water-permeable Supports are passed through a First bath, the object of which is to dilate the pores of the Supports and to impregnate them at the same time with one of the products intended to react later. This done, an applies two -Sup ports one against the other and an makes them pass in this way, side by side, between the expressor rollers, which have the effect of expressing the excess of liquid, coming from the first aforesaid bath, being Jans the aforesaid Supports. After that, a double support is obtained, which is subjected to the action of a second bath, which has the effect of producing, on both sides of said double support, the sensing salt. possible. This operation completed, the two Supports are separated from each other and two Supports are obtained in which the sensitive salt is concentrated On one of the faces only.

L'accolage des deux Supports 1'un ä 1'au- tre, au lieu d'etre effectue entre 1e Premier et 1e second bain, pourrait aussi bien etre fait avant 1e Passage dans 1e Premier bain ou Pendant leur Passage dans ce Premier bain. The joining of the two Supports to one another, instead of being carried out between the First and the second bath, could just as well be done before the Passage through the First bath or During their Passage through this First bath. .

Cette fagon de proceder donne, chaque fois, deux pellicules photographiques ä Sup port permeable. 0n pourrait egalement, si Fon veut sacrifier -1e rendement, fixer cha- que Support permeable Sur un Support non permeable aux bains, par exemple une surface en verre, plane ou cylindrique, et detacher apres fraitement, 1e Support permeable de son Support non permeable. 0n obtsendra de cette fagon 1e meme resultat que celui in- dique ei-dessus, c'est-ä-dire des pellicules pho- tographiques ä Support permeable ne presen- tant 1'emulsion sensible que Sur l'une de leurs faces. This way of proceeding gives, each time, two photographic films with a permeable support. One could also, if one wishes to sacrifice -1e efficiency, fix each permeable Support On a Support not permeable to baths, for example a glass surface, plane or cylindrical, and detach after treatment, the 1st Permeable Support from its non-permeable Support. . In this way, the same result as indicated above will be obtained, that is to say photographic films with a permeable support presenting the sensitive emulsion only on one of their faces.

Claims

CLAIM I: A water-permeable support photographic film characterized in that it presents the sensitive salt on only one side of the water-permeable support. CLAIM II: Process for the manufacture of 1a. A water-permeable support photographic film according to claim 1, wherein a sensitive layer is formed on one side only of the permeable support. SUB-CLAIMS: 1 Manufacturing process according to claim 11, according to which an extends, on one of the faces of a support permeable to water, previously wetted thoroughly and then dop an has then expresses the excess of water, a layer of a gelatin-based photographic emulsion which is allowed to coagulate on said face of the Support.

2 Manufacturing process according to claim II, according to which an passes through a first bath, two supports permeable to water, to dilate their pores and impregnate them with one of the products intended to react subsequently , then joined, by one of their faces, -these two Supports, which are thus passed side by side into a second bath in which the sensitive salt is formed on the free face of each of the two Supports, which one then separate one from the other.

3 Manufacturing process according to claim II, according to which an adjoins by one of their faces, two Water-permeable supports, and passes them through baths so that the RTI ID="0002.0267" WI= "5" HE="4" LX="1647" LY="1329"> sensitive salt is formed on the free face of each of the two supports, which are then separated from one another.

4 Manufacturing process according to claim II, characterized in that it consists in fixing, by one of its faces, a support permeable to water, on a new permeable support and in detaching after passing them through two sensitization baths, 1st permeable support of its non-permeable support.

5 A method of manufacture according to claim II and sub-claim 4, wherein the non-permeable Support is of glass.