US2397864A - Color yielding photographic elements - Google Patents

Description

Patented Apr. 2, 1946 I UNITED STATES PATENT OFF-ICE coma YmLnmG rngrooaarmo poration of Delaware No Drawing. Application March 31, 1944,- Serial No. 528,942

9 Claims.

' polymer containing a plurality of hydroxyl groups and having a plurality of color-former; structural components and. in addition, containing light-sensitive silver salts. The invention also relates to methods of making such elements and to processes for preparing dye images utilizing such layers.

Various types of elements for color photography using color-formers or dye intermediates which couple with the oxidation products of aromatic primary amino developing agents during the deveiopment of silver images have been proposed. Among the proposed elements are those which consist of a gelatin-silver halide emulsion layer containing a dye intermediate capable of color coupling development which is immobile or fast to diffusion. The intermediate may be substantive to gelatin by reason of a group which lends substantivity to a dye-forming component, or the dye components may have a high molecular weight group attached thereto which renders the entire molecule fast to diffusion. Other proposed elements use, in gelatino silver halide layers, color-formers which are dispersed in particles of water-permeable resins. In a variation, the resin particles may also contain silver halide grains. These elements, however, have poor definition and, on enlargement or projection, color grains appear.

This invention has for an object the production of photographic elements which contain synthetic color-formers which are hydrophilic and have the ability to disperse, and prevent coagulation and sedimentation of silver salts. Another object is to provide a photographic element for color photography which can be made in a simple and economical manner. Another object is to provide photographic elements which are free from gelatin binding agents. Still other objects will be apparent from the following description of the inventlon.

It has been found that useful photographic compositions for the production of dye images which can be made by incorporating light-sensi-- tive silver salts into hydrophilicfilm-forming synthetic polymers containing as a part of their molecular structure, color-former nuclei or components capable oi forming indophenol or ammethine dyes. The light-sensitive silver salts can be incorporated by admixing dispersed, preformed reducible silver salts with the hydrophilic synthetic polymer color-formers, or the 511- ver salts may be formed .or precipitated in the hydrophilic synthetic polymer color-formers. The compositions comprising the hydrophilic filmtorming synthetic polymer color-formers and light-sensitive silver salts can be deposited on a base or support to form an element suitable for photographic exposure and development. BY hydrophilic film-forming synthetic color-torming polymers" in this application is meant synthetic organic polymeric color-formers which contain a plurality of non-phenolic hydroxyl groups as the predominant hydrophilic group and which include in their molecular structure nuclei which are capable of forming an azo-inethine or indophenol dye on color-coupling development and which, in the form of thin layers, e. g., .1 to 10 microns in thickness, are insoluble in water at 30 C; but are freely water-permeable. They should, moreover, be soluble to the extent of at least 5 parts by weight in 100 parts of a boiling aqueous solution containing less' than 50%, and preferably less than 25% of ethanol.

In accordance with the invention, the hydrophilie light-sensitivelayers and compositions are composed of hydrophilic synthetic linear hydroxyl-polmer color-formers which contain a plurality of free hydroxyl groups and a plurality of color-. former nuclei capable of forming indophenol or azomethine dyes. as a part of their molecular structure. The polymers of this aspect contain a plurality of non-phenolic hydroxyl groups as the predominant hydrophilic group. The hydroxyl polymers in general should contain at least 1 aliphatic hydroxyl group to every 8 carbon atoms of the poh'mer chain, 1. e., 12.5 hydroxyl groups for every chain atoms, and preberably, 1 to 2 hydroxyl groups for every 5 chain atoms 1. e., between 25 and 50 hydroxyl groups per each 100 chain atoms. The color-former nucleu or groups are attached to the polymer chain either directly or indirectly. It is preerred that for every 100 chain atoms, between 1 and 35 color former nuclei be present. These 5; preferred hydroxyl polymer color-formers, moreover, have a polymer chain containing more than 200 atoms.

Suitable synthetic hydroxyl polymers that may be connected to color-forming nuclei to produce the hydrophilic color-forming hydroxyl polymers of the present invention include hydrolyzed polyvinyl esters, i. e., polyvinyl alcohols, hydrolyzed interpolymers of vinyl esters, e. g., vinyl acetate, vinyl propionate, and vinyl butyrate, etc., with olefins, e. g., ethylene, propylene, butane-l, and other vinyl compounds, e. g., acrylic acid, acrylic acid alkyl esters, alkyl methacrylates, vinyl chloride, vinyl cyanide, and maleic anhydride, and also the partial esters, ethers, and acetals of such polymers. These polymers may be connected to the colorformer nuclei by various chemical groupings or linkages, such as, for example, carbonamide, sulfonamide, amino groups, acetal, ester, ether linkages, etc.

The color-former nuclei or components of the above synthetic polymers have as active coupling groups a structure, which may be repre sented as no-(o=cli) 11:

where n is 0 or 1. This structure is found in color formers which contain a reactive acyclic or intracyclic methylene group and in aromatic hydroxyl compounds. These groups occur in phenols (including haphthols), acylacetarylides. cyanoacetarylides, beta-k'eto-esters, pyrazolones, N-homophthalylamines, coumaranones, indoxyls, thioindoxyls, etc. The reactive groups may also be termed reactive methylene, reactive ethenol and reactive 4-hydroxy-1,3-butadienyl groups. In all of the color-former nuclei the hydrogen atoms in the coupling position may be replaced by groups which are readily eliminated in the coupling reaction, e. g., halogen, e. g., C1 and Br, sulfonic acid, carbox'ylic acid, etc.

Suitable compositions for the radiation-sensitive layers of photographic elements can be made by precipitating the silver halide in the hydrophilic synthetic polymer color-formers of the above described type. They can be advantageously made by mixing a viscous aqueous solution of the hydrophilic color formers with an aqueous solution of a water-soluble metal halide and subsequently with an aqueous solution of a soluble silver salt. As a resu1t,, silver halides are precipitated and the resulting silver halide dispersions, after suitable treatment such as coagulation, ripening, washing and digesting, are coated from an aqueous solution which may contain methyl or ethyl alcohol onto a suitable support, such as a film base or support which may be paper, glass, metal or a cellulose ether or ester or a synthetic resin, e. g., polyvinyl acetals, superpolyamides, e. g., nylon, etc. sensitizing dyes can be incorporated into the compositions before coating or the resulting layers can be bathed or impregnated with a solution are sensitizing dye, e. g., an acetone or alcohol solution.

The hem-sensitive color-yielding elements 0! this invention constitute a novel type of. photo graphic article in that they contain but two constituents in the light-sensitive layers or strata, (l) light-sensitive silver salts and (2) the hydrophilic synthetic polymer color-former, which acts as a dispersing and protective colloid binding agent for the silver salts.

Multilayer elements tor-color photography can be similarly made by ccatingsuccessively on a film support similar hydroplaiic color-tamer silver halide layers. The silver salts and sensitizing dyes should be so chosen with respect to the hydrophillc synthetic polymer color formers that the layers, when arranged in the element. are sensitive to different regions of the spectrum and yield dyes of different spectral absorption. Filter layers can be used to control the selective action of the layers to light.

In the case of multilayer elements for threecolor photography, the light-sensitive colorforming layers and a yellow filter layer may be arranged and sensitized in the same manner as the gelatino silver halide color-former layers described in U. s. P. 2,179,234 but utilizing three diflerent hydrophilic synthetic polymer colorformers of the above type. One of the polymers may contain color former groups which form a blue-green indophenol or azomethine dye upon color coupling development of a silver salt image formed in the layer, e. g., with a primary aromatic amino color developing agent. A sensitizing dye which confers red sensitivity thereto is added and the resulting composition is coated onto a transparent film base and dried. A second layer composed of a hydrophilic synthetic polymer color former of the above type which is capable of forming a magenta indophenol or azomethine dye upon-color coupling development of a silver salt image for-med in the layer containing a sensitizing dye which renders it sensitive to the green region of the spectrum, is coated on the first layer. On the second layer is coated a water permeable colloid, e. g., polyvinyl alcohol, etc., containing a removable yellow filter dye. On this layer may be coated a layer of a hydrophilic synthetic polymer color-former of the above type capable of forming a yellow indophenol or azomethine dye upon color coupling development of light-sensitive silver salts contained in such layer which are sensitive to the blue region of the spectrum.

The invention will be further illustrated but is not intended to be limited by the following examples wherein all parts are by weight, all temperatures centlgrade, and all solutions aqueous unless otherwise indicated, and all radiations which will expose or fog the light-sensitive silver halides are excluded.

Example I A mixture of 106 parts of polyvinyl alcohol having a viscosity of 18-28 centipoises in a 4% aqueous solution at 20, 200 parts of salicylaldehyde, 500 parts of dioxan, and 10 parts or phosphoric acid is stirred at 85 for five hours. diluted with 1000 parts of acetone, and filtered. The white powder is washed by decantation in moo-part portions of acetone 6 times for 1 hour each, then filtered and dried to give 140 parts of a fine white powder. Ten parts of this powder isdissolved by stirring in parts of 40% ethanolwater at 80 for hour. To 40 parts of this solution is added 40 parts of water, 5 parts of 1% aqueous sodium dodecyl sulfate, and 5 parts of concentrated ammonia water. The mixture is stirred at 45 while adding 20 parts of 3N silver nitrate and 23 parts of 3N ammonium bromidel/lON potassium iodide simultaneously during five minutes. After stirring a total of 15 minutes, the silver halide dispersion is allowed to cool and mixed with 106 parts or acetone which precipitates the binding agent containing dispersed light-sensitive silver halides. After pouring on the liquid, soft rubbery polymer mass is washed for one -half hour in running water to remove the soluble salts, then the remaining 60 parts of the original polymer solution is added, together withparts of ethanol and 1 part of 10% aqueous potassium bromide, and the whole mixture stirred at 58 for one-half hour, after which it may be used directly or stored. This light-sensitive dispersion is coated on paper or a film base and exposed to a colored object. It is then developed in the following solution:

Parts p-Aminodiethylaniline hydrochloride 2 Sodium sulfite 3 Sodium carbonate 20 Water To make 1,000

made by dissolving the constituents in 500 parts of water and dilution of the solution to 1000 parts. It is then washed, bleached in 4% potassium ferricyanide, and fixed whereby a strong blue-green negative image is obtained.

Example II A coating composition was prepared by compounding the following solution:

Acetal of polyvinyl alcohol with allylsalicylaldehyde and phthalaldehydic acid (U. S. P. 2,310,943, Example X) g 5 Dlmethyl formamide cc Sodium hydroxide (5 N.) cc 1.5 Water cc 250 The solution was heated to 85 F. and 25 cc. of

water containing 1.5 g. of ammonium bromide added. To the resulting solution in darkness were added with stirring 25 cc. of water containing 2.5

g. of silver nitrate and Just enough ammonium p-Amino-N-diethylaniline grams 2 Sodium carbonate (anhydrous) do d Sodium sulfite (anhydrous) do 1 Potassium bromide do 2 Water to make -c- 1,000

A blue-green positive dye image formed in situ with the metallic silver. Upon removal of the silver and silver salts by treatment of the element in 4% potassium ierricyanide and hypo solutions, a blue-green dye image remained.

Example III A dye forming coating composition of the following composition was prepared:

The modified acetal of Example VI of U. S. P.

2,310,943 g 5 Ethanol cc 15 Water c 15 Sodium hydroxide (5 N aqueous) cc 1.5

The solution was heated to 80 F. and '75 cc. of water containing 1.5 g. of ammonium bromide added. To the resulting solution maintained under conditions of darkness were added 25 cc. of water containing 2.5 g. of silver nitrate and just enough ammonium hydroxide to make it basic, while stirring. The resulting composition was digested for 20 minutes at about 100 F. and then coated on a gelatin subbed cellulose acetate film base. The film was exposed through a negative and developed in a solution of the type described in Example I and then the silver and silver salts were removed in like manner tothat example whereby a yellow dye image remained.

The elements can be developed by a reversal process, it desired. Thus, an exposed element can be treated for a period 01. five minutes with intermittent agitation in a non-color forming developer of the formula:

N-methyl-p-aminophenol /2 sulfate grams 5.0 Hydroquinone do 7.5 Sodium sulfite do 60.0 Potassium bromide do 4.5 Water to cc 1,000.0

After washing in the dark for ten minutes, the film is exposed to light and developed for ten minutes in a color-developer of the following composition:

p-Amino-N-diethylaniline hydrochloride grams 2.0 Sodium carbonate (anhydrous) do 20.0 Sodium sulfite do 0.5 Water to cc 1,000.0

After washing for 15 minutes in running water the film is bleached in neutral potassium ferricyanide, rinsed, fixed in plain hypo, washed and dried. A reversed dye image remains at the points where the reversed silver image was formed.

Example IV A mixture of 100 parts of polyvinyl alcohol of medium viscosity, 200 parts of salicylaldehyde, 500 parts of dioxan, and ten parts of phosphoric acid is stirredat 85" for five hours, diluted with 1000 parts of acetone, and filtered. The white powder is washed by decantation in 1000-part portions of acetone six times for one hour each, then filtered and dried togive 140 parts of a fine white powder which is a salicylaldehyde acetal of polyvinyl aldehyde containing in excess of one acetal group per 20 hydroxyl groups. Ten parts of this powder is dissolved by stirring in parts of 40% ethanol-water at 80 for one-half hour. To 40 parts of this solution is added 40 parts of water and 5 parts of concentrated ammonia water. The mixture is stirred at 45 C. while adding 20 parts of 3N silver nitrate and 23 parts of 3N ammonium bromide-l/ION potassium iodide simultaneously during five minutes. After stirring a total of 15 minutes, the silver halide dispersion is allowed to cool and mixed with parts of acetone which precipitates the binding agent containing dispersed light-sensitive silver halides. After pouring of! the liquid, the soft rubbery polymer mass is washed for one-half hour in running water to remove the soluble salts, then the remaining 60 parts of the original polymer solution, in which was incorporated 0.01 part of allyl thiourea, is added, together with '70 parts of ethanol and one part of 10% potassium bromide, and the whole mixture stirred at 58 for one-half hour, after which it may be used directly or stored. This light-sensitive solution is coated on paper or film base and exposed to a colored object. It is then followed by washing, bleaching. in 4% potassium ferricyanide, and fixing, and yields a strong blue- (5' greennegative image.

Eaxzmple V Ten parts of the material described and used in Example III, U. S. P. 2,320,422 (saponified polyglycerol treated with o-hydroxy-phenvl acetaldehyde) is dissolved in 100 parts of dilute alkali. Five grams of light-sensitive silver halide precipitated directly in the polymer and coated onto a film base yields a blue image when the resulting element is exposed and developed in primary aromatic amino developing agent as in Example 1.

Example VI Ten parts of the condensate obtained from polyvinyl alcohol acetalized with m-aminobenzaldehyde and condensed with phenylmethylpyrazolone carboxylic acid (described in U. S. P. 2,320,422, Example VIII) is dissolved in 200 parts of dilute alkali solution and silver bromide precipitated within the polymer. A layer of this material yields a magenta dyestufl image in a primary aromatic amino developing solution.

Example VII Fifteen g. of the product obtained from polyvinyl alcohol acetalized with aminobenzaldehyde and condensed with acetoacetaminophenyl carboxylic acid (described in Example IX of U. S. P. 2,320,422) is dissolved in 250 parts of mild alkali solution. To this are added 20 parts of 3N KBr followed by parts of ammoniacal 3N AKNO in darkness. A layer of the material when exposed and developed in a primary aromatic amino developing solution yields a yellow dyestufl' image.

Example VIII A multilayer three-color film may be prepared as follows: Coat in order thin layers from aqueous ethano1 solutions of the following compositions:

1. The light-sensitive color-former dispersion of Example I sensitized to red with 1,l'-diethyl- 2,2'-naphthcarbo-cyanine iodide.

2. Hardened polyvinyl alcohol.

3. The light-sensitive composition of Example VI sensitized to green with l,1'-diethyl-2,2'- cyanine iodide.

4. Hardened polyvinyl alcohol containing a yellow filter dye or pigment or colloidal silver.

5. The light-sensitive composition of Example VII sensitive to blue only.

This film when exposed to colored objects can be developed to a color image in a primary aromatic amino developing solution of Example I to give a three-color picture in complementary colors upon removal of the silver and silver salts. Alternatively, the film may be processed by a reversal method as in Example III whereby a reproduction of the original scene is obtained.

Example IX A hydrophilic film-forming acetal of a hydroxyl polymer is prepared as in Example I using a hydrolyzed ethylene/vinyl acetate lnterpolymer oi mol ratio of about 0.1 of ethylene to 1 of vinyl acetate, prepared by interpolymerizing ethylene and vinyl acetate as described in Example V of application Serial No. 446,116 followed by alkali catalyzed methanolysis as described in Example XI of application Serial No. 446,114 and continuation application thereof Serial No. 577,736, filed February 13, 1945, now United States Patent 2,386,437, in place of the alcohol. Ten parts of the resulting color-forming polymer is dissolved by stirring in 90 Parts of 40% ethanol-water at 80 C. for one hour. To this is added 80 part: of

water, five parts of 1% sodium lauryl sulfate, five parts of concentrated ammonia, 45 parts of 3N ammonium bromide-l /10N potassium iodide and the solution stirred at 45 while adding 40 parts of 3N silver nitrate containing 40 parts of water and five parts of 1% sodium lauryl sulfate during ten minutes. After stirring a total of 20 minutes, the silver halide dispersion is allowed to cool and mixed with 200 parts of acetone which precipitates the binding agent containing dispersed light-sensitive silver halide. To this, after washing in water for one half hour and draining, is added a solution of ten parts of the polymer dissolved in parts of 50% ethanol water and two parts of 10% potassium bromide solution and the mixture stirred at 58 C. for one-half hour. This coating composition is employed in place of the corresponding material in Example 1, and strong blue-green negative images are obtained by photographic processing in the same way as in that example.

A multilayer film can be made by coating compositions of the type disclosed and a yellow filter layer in order onto a cellulose acetate film base after adding suitable sensitizers as described above so that the layers of the resulting element are disposed and sensitized so that each layer records the light from about one-third of the visible spectrum. Such multilayer film elements free from gelatin-color-former layers can be processed to a color picture after the manner described in U. S. P. 2,179,234.

In place of the specific hydrophilic synthetic polymer color-formers described above, can be substituted various other high molecular weight hydrophilic film-forming synthetic polymer coloriormers having the general characteristics set forth above. The suitable color-formers have as an integral part of their molecular structure, color-former nuclei either as links in the main polymer chain or as lateral substituents bonded to recurring atoms or groups of the molecule. The color-former nuclei may contain phenolic hydroxyl groups or intracyclic or acyclic reactive methylene groups which render them capable of coupling with the oxidation products of an aromatic primary amino color developing agent to form an indophenol or azomethine dye. They are further characterized by having a softening point above 40 C., being insoluble in' water and photographic developing and fixing solutions at 25 C. and below but being soluble to the extent of at least 5% in boiling water or boiling water containing less than 50% of ethanol and permeable to water and photographic processing solutions. In addition, the polymeric colorformers are essentially colorless but are capable of forming coherent, transparent, supported nontacky films and are free from adverse action on light-sensitive silver halides.

Suitable additional hydrophilic synthetic polymer color-formers having such characteristics are disclosed in U. S. Patents 2,310,943 and 2,320,422 and may be utilized in the single layer or mutilayer elements of this invention.

Various other hydroxy1 polymers can be used as a source of the hydrophilic color-forming hydroxy'l formers. The materials in general should have at. least 30% of the weight thereof represented by CHOH or CH2OH groups. Suitable materials include polyvinyl alcohol, hydro lyzed inter-polymers of vinyl acetate with acrylates, methacrylates, and other vinyl compounds, e. g., vinyl chloride or vinyl cyanide; also any of the above compounds having up to 40% of the hydroxyl groups converted to ethers, e. g., methyl. ethyl, hydroxyethyl, etc., or to esters, e. g., acetate, propionate, butyrate, etc., or to acetals, e. g., formals, acetals, propionals, butyrals, benzals, etc., or any other suitable group. Of all these materials, however. the preferred binding agents of this invention are prepared from the vinyl type polymer in which th polymer chain consists essentially of carbon to carbon linkages. These are desirable because the'polymers are more stable and resist degradation or breaking of the polymer chain in the reaction involving linkage of the color formers and because color-forming hydroxyl polymers of this type form thin fihns of great toughness.

A high water solubility of the original polymer does not prevent its use in the preparation of the hydrophilic color former of the present invention since the introduction of dye intermediate nuclei usually decreases the cold water solubility to the point Where the coated films are no longer softened excessively in water. However, if the binding agent has undesirably high water sensitivity, this can be controlled by the introduction of other groups such as esters, e. g., acetates. propionates, benzoates, ether groups, or metal groups, etc. Similarly, if the binding agent does not have sufficiently high water sensitivity or so]- ubility, this can be improved by the introduction of solubilizing groups. For example, the carboxylic or sulfonlc acid groups can be introduced by acetal formation with phthalaldehydic acid, o-sulfobenzaldehyde, or acids of the type cno (cm) .coon

or by partial esterification with phthalic or succinic acid, or by etheriflcation with glycolic acid. or by use of a dye intermediate nucleus containing such solubilizing groups. Any of the above groups can be introduced either before or after introduction of the color-forming groups into the polymer.

In addition to the color-former groups or components of the above polymeric color-formers, other of such groups may be employed. Thus, the dye intermediate nucleus may be any aromatic phenolic compound having a coupling position available ortho or para to the activating group or any active methylene compound, 1. e., a compound having a CH:-- group activated by two unsaturated groups taken from the class of be utilized as a direct taking stock in the colordevelopment process as described in the above examples, but they are useful in duplicating or copying. For instance, the multilayer film of Example VIII may be processed as in Example I to a color negative, then printed onto a similar film with white light or by exposure with blue, green, and red light controlled by suitable filters adjusted to the spectral qualities of the dyes and color sensitizers and the printed material again Processed as in Example I to a color positive. A number of color positives may be produced from a single color negative. Similarly, by using reversal processing as in Example VIII for both taking and printing steps, color positives can be produced. In this way also any number of color print can b produced. The colo negatives or positives produced according to this invention can also be employed in securing separation negatives or positives by known processes of color separation.

The invention is obviously not limited to the use of the specific color coupling developing agents of the above examples. On the contrary, various other developing agents of this type may be substituted in like manner. A number of useful color developing agent are disclosed in the patents listed in the preceding paragraphs.

Various materials may be added to the novel hydrophilic synthetic polymer color-former silver salt dispersions such as general emulsion or sulfur sensitizers, e. g., allyl thiourea, allyl isothiocyanate, sodium thiosulfate, etc.; optical sensitizers such as cyanine, 1,1-diethyl-4,4'-cyanine iodide, 1,1'-diethyl-s,4'-cyanine iodide, 1,1'-diethyl-2,2'-carbocyanine iodide, l',3-diethylthia- 4'-carbocyanine iodide and other methine and polymethine cyanine dyes, kryptocyanines, merocyanines, pseudo-cyanines, etc.

The hydrophilic'film forming synthetic polymer color-formers of this invention possess a number of useful properties, among which can be mentioned (1) ability to disperse, prevent coagulation and sedimentation of silver salts, (2) freedom from adverse action on radiation-sensitive silver salts, (3) adequate solubility in solvents, e. g., water,'ethanol, etc., for coating, (4) a relatively high softening point, (e. g., above 50 C.), (5) transparency and freedom from color, (6) insolubilityand freedom from softening in water at moderate temperatures, (e. g., below' 20 0.), ('7) ready permeability to water and photographic processing solutions at temperatures in the neighborhood of 20 C., and (8) ability to form a strong, coherent, supported film.

An important advantage of the invention resides in the fact that the hydrophilic color-former layers produce the maximum color densities obtainable from the amount of silver salt reduced by. development. This admits of a decided saving in silver halides without sacrificing the quality of the dye image. Thinner coatings can be used which is of major importance in multilayer elements, because the innermost layers are substantiallyin thesame plane as the outermost layers The less, silver halide the outer layers contain, the less scattering of light there is, and the more light passes through to the innermost layers. This results in more sensitive films. hav-- ing a higher degree .of definition and resolution than is obtainable by the use of immobile or non-diffusing color-formers in gelatin layers.

In contrast to gelatin, which is non-uniform and varies from lot to lot in respect to the sensitizing action on silver halides, the present hydrophilicsynthetic pclymerf color -formers are uniform and-the sensitivity -to light of the silver haiides'dispersedthereincan be accurately controlled by; adii n tmeasured amounts of sensitizing agents f ,Inggdgiitiomthe color-yielding silver salt compositions-in -the present invention are much more stable than gelatin solutions and can be stored for longer periods of time without bein adversely afl'ectedi Inaddition, they are not sub- UCGI Lil HUUHI 6 asoasea.

ject to bacterial putrefaction as are gelatin-silver halide compositions. Still other advantages will be apparent from the above description of the invention.

As many apparently widely diflerent embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.

What is claimed is:

1. A photographic element comprising a support bearing at least one layer composed of a hydrophilic, essentially colorless, synthetic polymer color-former containing a plurality of aliphatic alcohol hydroxyl groups as the predominant hydrophilic groups and having as an integral part of its molecular structure color-former nuclei containing a structure of the formula came where n is a number from the group consisting of and 1, said layer containing light-sensitive silver halides.

2. A photographic element comprising a support bearing at least one layer composed of a hydrophilic, essentially colorless, synthetic polymer color-former having at least 12.5 aliphatic aicohol hydroxyl groups as the predominant hydrophilic groups and at least one color-former component containing an active dye coupling structure of the formula where n is a. number from the group consisting of 0 and 1 for every 100' chain atoms, said layer containing light-sensitive silver salts".

3. A photographic element comprising a support bearing at least one layer composed of a hydrophilic, essentially colorless; synthetic polymer color-former having at least. 260 chain atoms at least 12.5 aliphatic alcohol hydroxyl groups as the predominant hydrophilic groups and at least one-color-former component containing an active dye coupling structured thliormola where n is a number from the group consisting of 0 and 1, for every 100 chain atoms and being soluble to the extent. of at. least five parts by weight in water containing from I to of ethanol said layer containing light-sensitive silver halides.

4. A multilayer photographic element comprising a support bearing a yellow filter layer and three color-yielding layers composed of a hydropl'rilic', essentially colorless, synthetic polymer color-former containing a plurality of aliphatic hydroxyl groups as the predominant hydrophilic groups and having as an integral part of its molecular structure color-former nuclei containing a structure of the formula where n is a number from the group consisting of 0 and 1, said color-yielding layers being different and containing light-sensitive silver halides and being so sensitized and arranged that they each'record about onn4hird or the visible spectrum and form a colordevelopedf dye which is complementary in color to the utilized sensitivity of the respective layers.

5. A photographic element comprising a support hearing at least one layer composed of a hydrophilic, essentially colorless, synthetic vinyl alcohol polymer color-former having at least 200 chain atoms, at least 12.5 hydroxyl groups, and at least one color-former component containing an active dye coupling structure of the formula where n is a number from the group consisting of 0 and 1, for every chain atoms and being soluble to the extent of at least five parts by weight in water containing from 1 to 10% of ethanol, said layer containing light-sensitive silver halides.

6. A photographic element comprising a support bearing at least one layer composed of a hydrophilic, essentially colorless, synthetic vinyl alcohol polymer color-former having at least 200 chain atoms, at least 12.5 hydroxyl groups, and at least one color-former component containing an active dye coupling structure of the formula lal-e where n is a number from the group consisting of 0 and 1, for every 100' chain atoms and being soluble to the extent of at least five parts by weight in water containing from I to 10% of ethanol, said component being connected through acetal linkages to carbon atoms of the vinyl alcohol polymer chain and said layer containing lightsensitive silver halides.

7. A photographic element comprising a support bearing at least one layer composed of a hydrophilic, essentially colorles acetal of salicyl aldehyde with polyvinyl alcohol having at least 200 carbon atoms, at least 12.5 aliphatic hydroxyl groups, and at least one salicyl' aldehyde radical for every 100 chain atoms and being solubleto the extent of at least five parts by weight in water containing from 1 to 10% of ethanol, said layer containing light-sensitive silver halides.

8. A photographic element comprising a support hearing at least one layer composed of a hydrophillc, essentially colorless acetal of o-acetoacetamidobenzaldehyde with polyvinyl alcohol having at least 200 carbon atoms, at least 12.5

aliphatic hydroxyl groups, and at least oneo-acetoacetamidobenzaldehyde radical for every 100 chain atoms and being soluble to the extent of at least five parts by weight'in water containing from 1 to 10% of ethanol, said layer containing light-sensitive silver halides.

9. A photographic element comprising a support hearing at least one layer composed of a hydrophilic, essentially colorless acetal of m phenylmethylpyrazolonoyiamidobenzaldehyde with polyvinyl alcohol having at least 200 carbon atoms, at least 12.5 aliphatic hydroxyl groups, and at least one m-phenylmethylpyrazolonylamidobenzaldehyde radical for every 100 chain atoms and being soluble ,to the extent'ef at least five parts by weight in'water containingfrom 1 to 10 of ethanol, said. layer containing light-sensitive silver halides.

ANDREW B. JENNINGS. OTIS WILLARD MURRAY- F. A. WHITE.