US2518686A - Aldehyde antistain baths for developed color photographic material - Google Patents

Description

Patented Aug. 15,1950

UNITE-D sra'r ss PATENT OFFICE 2,518,686 x lemmas ANTI'STAIN BATHS FOR DEVEL- OPED COLOR PHOTOGRAPHIIC MATERIAL h Harold C. Harsh and James Bates, Bingham i ton, N, ..Y.', assignors to General Aniline. & Fil'mC'orporation', New York, N. Y., a corpora- 'tion of Delaware .No Drawing.

This invention relatestojphotographic anti stain baths, to' antistain baths employed in multi-color photography, and especially to nonstaining baths for the washing of multi-color photographic material following the fixing treatment.

It is known that in, the'processing of multicolor reversible film and multi-color reversible white opaque the exposed film or exposed white opaque, is first developedwi'th a normal black and white developer toproduce a negative image. After development, the black and white negative material, without being fixed, is exposed to general illumination, followed by asecond development with a color-forming developer. During the first and second development the silver-halides in all the layers are reduced to metallic silver. After the second development, the material is cleared in running watenhardened in an aqueous solution consisting of either chrome or potassium alum, and then washed in running: water. After the latter treatment, thesilver present. in

all the layers formed during thefirst and second development is converted into a, saltby anyot and bleach solutions be removed, otherwise stains will be formed during-the-drying operation,

which are particularly noticeable in.;the white.

area. In order to prevent this staining, an extended final washing time in running water of from fifteen minutes to two hours hasbeen proposed. Even if this proposalbe adopted, stains are nevertheless formed afterv the drying operation, It is believed that the staining results from the oxidation of traces of the color developer retained in the layers of the material'following color-forming development, which then react with the unused color-former.

An object of the present invention is to eliminate excessive washing time of color developed mul ti-color photographic material while preventing the formation of stain.

A further object of the invention is a final Application November 8, 1945, a Serial No. 627,532

7 '4 Claims. (Cl. 88)

, 2 rinse' bath which clears undesirable matter from a multi-color photographic material in a short time while avoiding staining.

Other objects and features ofthe invention will become more apparent as the description proceeds.

Wehave found that the above objects are ac-- complished by employing, as a final rinse bath, an aqueous solution containing a small quantity of an aliphatic aldehyde, such as formaldehyde, paraformaldehyde (trioxymethylene), acetaldehyde (p'araldehyde), aldol, crotonaldehyde, propionaldehyde, and the like. makes it possible to considerably reduce the final washing time. The, concentration of the aliphatic aldehyde required may vary considerably. For instance, as little as 1 cc. of an aliphatic aldehyde per liter of water has been found to eliminate stain for the most part, but as much as cc. per liter. may be used if one wishes to take the greatest precaution to ensure freedom from stain.

Amounts higher than 20 cc. per liter give little improvement in stain prevention from a practical standpoint, and accordingly, concentrations ranging from between 10 cc. and 20 cc. per liter are most desirable.

v The photographic multi-layer materials, which may beprocessed with the anti-stain bath of the present invention, are color reversible film, color negative film, color reversiblewhite printing material coated on an opaque base, and color positive" printing material coated on paper, irrespective of Whether the dyestuff images are produced with color-formers present in the emulsion, or by a selective second exposure followed by color development.

The color reversible film consists of an integral tripack emulsion coated on the usual clear cellulose acetate or nitrate film base. Each of the emulsions are sensitized to one of the primary colors of light; namely, blue, green, and red. The top layer is blue sensitive. A filter layer, yellow in color and blue absorbing, lies under the top layer. Below this filter layer, lies a green sensitive emulsion layer, and below this is a red sensitive'emulsion layer. Each of the three silverhalide emulsion layers contain dye-forming compounds which unite during the development of a silver image in an aromatic amine developing This discovery agent to form a dye with the oxidation product of the developing agent, or may be free from colorformers in which case the film is processed with the color-formers in the color developers by the selective second exposure and color development method as described in United States Patents 1,897,866; 1,900,870; 1,928,709 and 1,980,941. The color negative film is made up in the same manner as the color reversible film with the exception that it may contain a layer of clear gelatin between the red, sensitive layer and the green sensitive layer. The color reversible white opaque material is prepared in the same manner as color reversible film and the color negative film with the exception that the base consists of an opaque white film. The color paper is also constructed in the same manner as the color reversible film and the color negative with the exception that the emulsion is coated on a baryta coated paper base.

As silver is formed during development, it must be removed after color development by treatment in a bleach, followed by treatment in a bath of sodium thiosulfate, according to usual practice. A yellow dye is formed in the blue sensitive emulsion; a magenta dye is formed in the green sensitive emulsion; and a cyan dye is formed in the red sensitive emulsion. Combinations of these three printing primaries will produce all of the other colors in the finished film or print. Suitable methods for the preparation of photographic multilayer materials have been described in the literature relating to color photography, and are, therefore, not described here.

The following examples describe in detail methods for accomplishing the above objects, but it is to be understood that they are inserted merely for purposes of illustration and are not to be construed as limiting the scope of the invention.

Example I A 4" x 5" full color transparency sheet of color film was printed by contact on two 4"" x 5 sheets of color reversible White opaque film.

The two sheets of 4" x 5" color reversible white opaque film were first developed for twelve minutes at 68 F. in a developer of the following composition:

Water to make up 1 liter.

Short stopped for 3 minutes at 68 11, in a 5% aqueous solution Of sodium bisulfite.

,Washed for 2 minutes in running water at. 68 F.

Color developed for 15. minutes at 681 R, in a developer of the following composition:-

Water to make up 1 liter.

Rinsed for 4 minutes in running water at 68 F.

Hardened for 5 minutes in a 3% aqueous solution of potassium chrome alum Washed for 5 minutes. in runnin Water at '4 68 F. The washed material was then treated with a bleach bath of the following composition:

Water to make up 1 liter.

Washed for 5 minutes. at. 68. F., and then fixed for 5 minutes in a solution of the following composition:

Grams Hypo 200 Borax 10 Water to make up 1 liter.

After fixing, the material was washed for 10 minutes in running water at 68 F.

After the final wash, one print was allowed to dry while the other was rinsed for two minutes in a solution containing 10 cc. of formalin per liter of water and then allowed to dry. At this point the prints appeared identical. After normal drying, the print rinsed in the formalin solution showed brighter colors and more brilliant highlights than the print given only a water wash for 15-20 minutes.

When the drying was carried out under conditions of high humidity so that. the drying time was extended for several hours, the water rinsed print showed even greater highlight stains while the print rinsed; in formalin solution did not change.

Example II Example I was repeated with the exception that the colored material employed was a color paper and the final rinse contained ZO cc. of acetaldehyde instead of formalin. The color print washed in water showed objectionable stains after drying while the print treated with the solution containing ac'etal'dehyde was clear and unstained.

Example III plain water shows marked staining upon drying of said material. This staining occurs especially under slow drying conditions and is probably" due to the coupling of the slow oxidation product of the color developer with a residual color-coupler present. in one or more layers.

In place of aliphatic al'd'ehydes referred to above, organic. hardening agents such as the hydroxy' aldehydes. described in Sheppard and Houch, United States Patent 2,059,817, and thedialkyl diketones described. in Stand and Briggs, United: States Patent 2,663,351, mayalso be em- Dloyed.

The abovespecifi'c examples are to be regarded as merely illustrative ofi'the-invention, and not inany sense restrictive. It. willbe obvious to any one skilled: in the. art that many modifications suchassubstitntingequivalent material and varythe oportions of materials used are within the spirit and scopeot the invention asdefined' in the appended claims.

We claim:

1. In a process of producing color photographic images selected from the class consisting of indophenol and azomethine dyes in a multilayer color film by exposing the film, color-forming developing the same, bleaching, fixing and washing, the improvement which comprises avoiding the formation of stain, after the bleaching, fixing, and washing operation, by rinsing the said film with an aqueous solution consisting of water and a carbonyl compound selected from the class con.- sisting of aliphatic aldehydes and. di-ketones.

2. In a process of producing color photographic images selected from the class consisting of indophenol and azomethine dyes in a multilayer color film by exposing the film,.colorforming develop ing the same, bleaching, fixing and washing, the improvement which comprises avoiding the formation of stain, after the bleaching, fixing, and washing operation, by rinsing the film with an aqueous solution consisting of water and formaldehyde.

3. In a process of producing color photographic images selected from the class consisting of indophenol and azomethine dyes in a multilayer color film by exposing the film, color-forming developing the same, bleaching, fixing and washing, the improvement which comprises avoiding the formation of stain, after the bleaching, fixing, and washing operation, by rinsing the film with an .aqueous solution consisting of water and acetaldehyde.

4. In a process of producing color photographic images selected from the class consisting of indophenol and azomethine dyes in a multilayer color film by exposing the film, color-forming developing the same, bleaching, fixing and washing, the

6 improvement which comprises avoiding the formation of stain, after the bleaching, fixing, and washing operation, by rinsing the film with an aqueous solution consisting of water and crotonaldehyde.

HAROLD C. HARSH.

JAMES E. BATES.

REFHERENCES CITED The following references are of record, in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Neblette, The Glazing of Prints, Camera Craft, vol. 32, March 1925, pages 116, 118 and 120 (Copy in Library of Congress; Photostat in 95-8$ A.)

Ankersmit, "Rapid Drying of Plates and Films, Eastman Kodak 00., Monthly Abstract Bulletin, vol. XIV, No. 5, May 1928, page 239. (Copy in Scientific Library (Abstract of Photofreund, vol. 8, Feb. 20, 1928, pages -1).)

Case, Drying Prints and Negatives, Amateur Photographer, 68, October 23, 1929, page 375. (Copy in U. S. National Museum; Photostat in -88 A.)

Claims (1)

1. IN A PROCESS OF PRODUCING COLOR PHOTOGRAPHIC IMAGES SELECTED FROM THE CLASS CONSISTING OF INDOPHENOL AND AZOMETHINE DYES IN A MULTILAYER COLOR FILM BY EXPOSING THE FILM, COLOR-FORMING DEVELOPING THE SAME, BLEACHING, FIXING AND WASHING, THE IMPROVEMENT WHICH COMPRISES AVOIDING THE FORMATION OF STAIN, AFTER THE BLEACHING, FIXING, AND WASHING OPERATION, BY RINSING THE SAID FILM WITH AN AQUEOUS SOLUTION CONSISTING OF WATER AND A CARBONYL COMPOUND SELECTED FROM THE CLASS CONSISTING OF ALIPHATIC ALDEHYDES AND DI-KETONES.