US2317750A - System of improving photographic layers - Google Patents

Description

April 27, 1943; -w. FERMAZIN 4 2,317,750

SYSTEM OF IMPROVING PHOTOGRAPHIC LAYERS Filed Nov. 27, 1939 l/lIl/(l/ 4 Jnwnfar:

walkr )Emrazm Attorney Patented Apr. 27, 1943" SYSTEM OF IMPROVlNg- PHOTOGRAPHIC LAYER Walter Fermazin, Berlin-Grunau,

Germany;

vested in the Alien Property Custodian Application November 27, 1939, Serial No. 306,272 In Germany August 11, 1939 3 Claims. (01. 95-88) This invention relates to methods and treating baths for the improvement of photographic records or pictures.

It is an object of the present invention to 7 improve the photographic pictures during the photographic treatment of the same in the photographic baths, for example, during the development and fixation, during the action of tanning' and dyeing liquids, toning baths or the like.

Another object of the invention is to form .a smooth surface layer on the rough surface of the image layer by solidified colloids, for avoiding any difiusion of light and for rendering the photographic image more brilliant.

Still another object of the invention is to provide a protective layer for the sensitive silvercontaining gelatine layer which is present for in stance on cinematographic films.

With these and further objects in view which will be apparent from the within disclosures the process according to the invention comprises introducing dispersed colloids into some of the baths following each other in the manufacturing process and coagulating the colloids adhering to the photographic layer in one or more of the subsequent baths, for example, by coagulating substances admixed thereto or by changing the pH value thereof, more particularly by diiferent electrolytic polarity. Advantageously, the treating baths contain softening agents which preferably are not dissociated or gelatinizi ng agents for the gelatinizing colloids contained in the rether swelling said layers after the same have left the baths, by action of heat, to such an extent that the deposited colloidallayer penetrates entirely or partly into the porous photographic image layer, whereby the transparency is substantially increased due to elimination interior dispersion of light.

Hitherto, in order to improve cinematographic V films and the like, the photographic layer has been subjected to a separate improving treat merit after the photographic process. On the the drawback occurs that in a contact printing process the two photographic layers which shall bein direct contact with each other are spaced by the protective layer whereby the sharpness of the printis reduced. This drawback would be still more considerable if photographic positive films and more particularly cinematographic filmswhich. are most liable to scratchingwould be providedv with a protective layer applied on the raw film, since the spacing in the printing process would be further increased thereby. Further drawbacks occur by the reflection produced by such protective layers. Moreover, the development process is retarded and rendered non-uniform unless the layer is of a uniform thickness and very homogeneous.

The said drawbacks of thefexisting methods are avoided by my novel method above pointed out. In case of layers of silver halides, both the developer'and the fixing "bath and in some in stances also 'the intermediate or watering bath may contain the above mentioned colloids in the form of a dispersion. Advantageously, the colloids are admixed to the first or developing bath since the photographic layer when introduced this invention to admix colloids which are soluble other hand if protective layers are applied on the photographic raw material in order to prevent the same from being damaged in the camera, which layers are not dissolved in the developer,

Fig. lis a section through a film developed in known manner.

Fig. 2 is asection through a film developed in Y accordance with the invention in a developingbath containing colloids.

, Fig. 3 is a section through the film shown in Fig. 2, after a swelling treatment in a drying chamber.

In the figures, item I represents the photographic layer and item 2 is the support therefor i of Celluloid or the like. As shown in Fig. 1,'the known process results in'a rpugh surfaces of the photographic layer while injFig. 2, acolloidal layer 4 is formed on the photographic layer l by the process according to the inventionfthus forming a smooth surface 5.- While the saidcolloidal layer is at first of athickness which might causethe above mentioned disadvantages pro-f dispersed colloids may be admixed to the toning 50 grs. sulfite of sodium. 2 grs. soda.

Where the photographic picture is produced by treatment in a toning or dye-stuff bath, the

or dyeing bath while coagulating agents are admixed to the clarifying bath. Photographic layers containing dye-stuff producing agents in addition to silver-halide or dye-stuff liable to destruction or decomposition by the formation of metal in a reducing reaction may be treated in acetone, for coagulation.

a similar manner. For example, if the photographic material treated in a developer as above described is acted upon by acidfied liquids (pH less than 6.5) such as, intermediate or fixing baths',a coagulating effect occurs with respect to the colloids and the dispersions solidify due to the swelling together of their boundaries, thus forming solid'layers which are inseparably'connectedwith, or anchored in, the photographic layer. j d

The colloids may be admixed to the chemical V substances forming the developing, fixing and like baths. However, it is also possible as pointed out above, to introduce the colloids in the form of a layer applied to the exposed raw film for being intimately anchored in the image layers by coagulation. a Advantageously, softening agents or gelatinizing agents are admixed to the baths containing the colloids which agents act upon the protective layer already existing or formed in the baths as well as upon the image layer and'if desired upon the'colloids forming the support of the image layer. Such agents shall not be dissociated or only slightly dissociated in order to avoid interference with the developing process. In this respect, organic estersof the fatty acids are very suitable.

Example 1.-An embodiment of a developing bath in accordance with the invention; film is developed in a developing bath compris ing: w

Grams Water .1000 S u l f a t e of monomethyl-para-amidophenol .T' 4 Hydrochinone 7 2 Y Sodium sulfite 80 Acid case I v, 10-30 Borax 8 Potassium bromide 0.25

The casein is used in the form of commercial pure acid casein which can be dispersed in water at pH=6.5 but is precipitated in the form of a free acid casein when approximating the iso- V electric point pH=4.6 7

Example 2.--The filmis developed in a de-' velopingbath comprising: V V 7 01 an u slightly amrnoniacal' dispersion of polymerization products,,e. g.,

of acryl or methacryl acid, t t 4 grs. sulfate of monoethyl-para-amido phenol,.

The

partly V incorporated in dispersed gelatine. After the fixing and prior to the watering the film is immersed in an i V Per cent Dyestufi 5 Gelatine 2 Hydrate of chloral in an aqueous solution 1 After the dyeing bath and prior to the clarifying bath'the film is immersed in an aqueous bath containing 50% of a mixture of alcohol and The baths according to the above examples are advantageously provided with 25-10% of softening agents which are soluble in water, such as, for example, lactic acid ethyl ester, glycerinated fatty acid ester or the like. The above percentages are-by weight. t

It will be understood that the invention is not restricted tothe examples hereinbefore stated, but comprises any formation of a layer within the bath for the image production which is based on dispersion or coagulation of colloids by difierentproperties of the-baths. I

I The so-called hardening-fixing baths may now be used in a concentration acting sufliciently rapidly without interfering with the photographic image layer of layers. The drawbacks occurring usually with hardening baths, such as,

to slowly growing resistivity against mechanical attacks or hornifying of' the layer occurring very soon and brittleness thereby caused are avoided in thiscmanner. V f' The treating baths and methods of the present invention have. been described in detail with reference to specific embodiments. It is tovbe understood, however, that the invention isrnot limited by such specific reference but is'broader in scopeand capable of other embodiments than those specifically described'an'd illustrated in thedrawing. v

I claim: f f V 1 In the art of finishing photographic layers by subjecting the layers to a fixing bathand at least one further treating bath in succession, the steps of admixing to said fixing bath a disproducea smooth protective surface upon the final layers by the solidified colloid. V

2. In the art of finishing photographic layer by subjecting the layers to a dyeing bath and at;

least one further treating bath, in succession, the steps of admixing to said dyeing bath a dispersed colloid and causing coagulation of said colloid in said further treating bath. so as to produce, a smooth protective surface upon the layers by the solidified colloid.

3.; In the art'offinishing photographic layers by subjecting the layers to different treating baths in succession,;the stepsof admixing to at least one of said treating baths a dispersed 1 colloid, and causing coagulation of said colloid inat least one of the subsequent, treating baths,

thereafter heat treating the. layers'upon leaving saidllast bathto form a smooth protective layer;

bythe solidifiedlcolloid upon and being at least the final 1ayers. WALTER FERMAZIN;

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