US3582333A - Method for reducing color fog in color emulsions coated on electron bombarded supports - Google Patents

Abstract

COLOR FOG FORMATION AND LOSS OF SPEED IN A COLOR-FORMER BEARING EMULSION LAYER COATED NEAREST TO A HYDROPHOBIC SURFACE THAT IS ELECTRON BOMBARDED JUST PRIOR TO COATING IS ADVANTAGEOUSLY REDUCED OR PREVENTED BY THE INCORPORATION OF A REDUCING AGENT IN SAID EMULSION LAYER, OR IN A NONLIGHT-SENSITIVE HYDROPHILIC COLLOID LAYER COATED BETWEEN SAID EMULSION LAYER AND THE ELECTRON BOMBARDED SUPPORT.

Description

United States Patent 3,582,333 METHOD FOR REDUCING COLOR FOG IN COLOR EMULSIONS COATED ON ELECTRON BOM- BARDED SUPPORTS Richard G. Yost, Spencerport, and Ronald L. Heidke,

Rochester, N.Y., assignors to Eastman Kodak Company, Rochester, NY. N0 Drawing. Filed Apr. 8, 1968, Ser. No. 719,691 Int. Cl. G03c 1/76, 1/34 U.S. Cl. 96-74 23 Claims ABSTRACT OF THE DISCLOSURE Color fog formation and loss of speed in a color-former bearing emulsion layer coated nearest to a hydrophobic surface that is electron bombarded just prior to coating is advantageously reduced or prevented by the incorporation of a reducing agent in said emulsion layer, or in a nonlight-sensitive hydrophilic colloid layer coated between said emulsion layer and the electron bombarded support.

This invention relates to photography and to improved color photographic materials and processes.

Multicolor photographic materials are well known in the art. These materials contain a support coated with dilferently sensitized silver halide emulsions usually a blue-sensitive emulsion that forms a yellow dye image, a green-sensitized emulsion that form a magenta dye image and a red-sensitized emulsion that forms a cyan dye image. Some of these materials have the blue-sensitive emulsion layer coated nearest the support then the green-sensitized layer with the red-sensitized emulsion layer outer most, while some materials have the blue-sensitive layer outer most and the red-sensitized layer nearest the support. Still other arrangements of the dilferently sensitized emulsion layers are also used. Some of these materials contain incorporated dye-forming couplers in the silver halide emulsion layers, usually with a phenolic or naphtholic cyan dye-forming coupler in the red-sensitized layer, a 5-pyrazolone magenta dye-forming coupler in the green-sensitized layer, and an open-chain ketomethylene yellow dye-forming coupler in the blue-sensitive layer. For those materials which do not contain incorporated couplers, the appropriate diffusible couplers are supplied in the color developing solutions. In another type of multicolor photographic material the ditferently sensitized silver halide emulsions, each with an appropriate incorporated coupler, are dispersed as packets in a single layer. The individual packets are insolated from each other by hydrophilic colloid.

It is known to coat photographic paper supports with poly-alpha-olefin layers and then coat the light-sensitive silver halide emulsion layer or layers over the poly-alphaolefin. In order to improve the adhesion of the light-sensitive layers to the poly-alpha-olefin, the outer surface of the poly-alpha-olefin is bombarded by electrons prior to coating. Processes for electron bombardment are also known as corona discharge treatment. Such processes are described in Alsup et al. British Patents 971,058 and 1,060,- 526 (polyolefin surfaces) and Carroll et al. U.S. Patent 3,220,842 [Poly(ethylene terephthalate)]. When color photographic silver halide emulsion layers are coated over hydrophobic surfaces, such as poly-alpha-olefin which have just been treated with electron bombardment, the silver halide emulsion layer closest to the support after light exposure and normal color processing exhibits an objectionably high level of stain and upon prolonged storage before exposure a loss of speed.

It is therefore an object of our invention to provide a novel photographic element which has a hydrophobic support that has been treated by electron bombardment and then immediately coated with at least one hydrophilic colloid layer containing a silver halide emulsion and an incorporated coupler which after light exposure and normal color processing exhibits little or no color stain and upon prolonged storage before exposure little or no loss in speed.

Another object is to provide a novel color photographic element comprising a paper support coated with a polyalpha-olefin layer that has been electron bombarded and then coated in succession with: (l) a blue-sensitive photographic gelatino silver halide emulsion layer containing a dispersion of a yellow dye-forming coupler, (2) a greensensitized gelatino silver halide emulsion containing a dispersion of a magenta dye-forming coupler, and (3) a redsensitized gelatino silver halide emulsion containing a dispersion of a cyan dye-forming coupler which after light exposure and normal color processing exhibits little or no color fog and upon prolonged storage before exposure little or no loss in speed.

Another object is to provide a novel method for reducing or eliminating color fog in multilayer color photographic elements caused by coating the light-sensitive layers over hydrophobic layers immediately after electron bombardment of the hydrophobic layer to improve the adhesion of the light-sensitive layers to the hydrophobic support layer.

Still other objects will become obvious from a consideration of the following specification and claims.

These and other objects are accomplished according to our invention by the preparation and use of our novel color photographic elements. In the simplest embodiment of our invention a support having a hydrophobic resin surface substantially immediately after it has been treated by electron bombardment is coated with a hydrophilic colloid layer containing a noncolor-forming reducing agent having an oxidation potential, E more negative than +0.3 volt and preferably more negative than +0.25 volt and incorporating either in this hydrophilic colloid layer a light-sensitive silver halide emulsion or coating over the reducing agent containing hydrophilic colloid layer a hydrophilic colloid layer containing a light-sensitive silver halide emulsion layer. Our silver halide emulsion containing hydrophilic colloid layer advantageously contains a dispersion of a color-forming coupler which upon color development couples with oxidized primary aromatic amine color developing agent to form a dye of the desired color. One or more additional hydrophilic colloid layers containing differently sensitized light-sensitive silver halide emulsions either with or without dispersions of other color-forming couplers are advantageously coated over the first coated silver halide containing hydrophilic colloid layer. One of our preferred multilayer elements comprises a paper support coated with a film of poly-alpha-olefin which has been treated by electron bombardment and this treated layer is coated in succession with (l) a hydrophilic colloid layer containing a blue-sensitive silver halide emulsion and a noncolorfouming reducing agent and a dispersion of a yellow dyeforming coupler, (2) a hydrophilic colloid layer containing a green-sensitized silver halide emulsion and a dis persion of a magenta dye-forming coupler and (3) a hydrophilic colloid layer containing a red-sensitized silver halide emulsion and a dispersion of a cyan dye-forming coupler. The reducing agent is advantageously contained in the dispersion of the yellow dye-forming coupler or in the hydrophilic colloid layer that contains the blue-sensitive silver halide emulsion or the reducing agent can be incorporated in both the dispersion and the hydrophilic colloid. In another preferred embodiment'of our invention the reducing agent is incorporated in a hydrophilic colloid layer between the electron-bombarded poly-alphaolefin layer and the hydrophilic colloid layer containing the blue-sensitive silver halide emulsion. Alternatively, the reducing agent can advantageously be incorporated in the nonlight-sensitive hydrophilic colloid layer, the bluesensitive hydrophilic colloid layer and the coupler dispersion in the blue-sensitive colloid layer. In still other preferred embodiments of our invention, the differently sensitized silver halide emulsions and the dispersed color-forming couplers used with them are arranged in other orders over a nonlight-sensitive hydrophilic colloid layer con taining a 3-pyrazolidone or coated directly over an electron bombardment treated poly-alpha-olefin surface of a support. Our photographic elements are characterized by having a reducing agent on the silver halide grains, and/ or in the hydrophilic colloid and/or in the coupler dispersion around the silver halide grains and/or between the silver halide grains in the first light-sensitive hydrophilic colloid layer coated on the electron bombardment treated hydrophobic surface.

In still other embodiments of our invention a paper support coated with electron bombarded poly-alpha-olefin film is coated with a hydrophilic colloid layer containing a reducing agent, a dispersion of a blue-sensitive silver halide emulsion containing a yellow dye-forming coupler, a dispersion of a red-sensitized silver halide emulsion containing a cyan dye-forming coupler and a dispersion of a green-sensitized silver halide emulsion containing a magenta dye-forming coupler. Alternatively, part or all of the reducing agent is advantageously incorporated in one or more of the dispersions.

Even when our light-sensitive photographic emulsion layers are coated on the hydrophobic resin surface imme diately after it has been treated with electron bombardment they have upon light exposure and the usual color processing no or very little color fog, and little if any loss in speed from storage. Furthermore, the elimination or reduction in color fog is acocmplished without any appreciable change in the sensitometric characteristics of the dye images.

The reducing agents employed in the practice of this invention can be characterized in terms of their polarographic half wave potential, i.e., their oxidation potentials, E determined by polarography. Anodic measurements can be made with 1 1O molar solution of the reducing agent in aqueous solvent solution at pH 6.0, e.g., a water or water plus organic solvent such as acetone or methanol, using a saturated silver/silver chloride reference electrode and a pyrolytic graphite electrode with the voltometric half peak potential for the negative anodic response being designated E Under these conditions, the reducing agents of our invention have an E value more negative than +0.3 volt and preferably more negative than +0.25 volt. The preferred reducing agents of our invention have a solubility in water at pH 6.0 and 20 C. greater than 1 l0* moles per liter and preferably greater than 0.01 mole per liter. Analytic chemical measurements of this type are known in the art and are described in New Instrumental Methods in Electro Chemistry, by Delahay, Interscience Publishers, New York, N.Y., 1954; Polarography, by Kolthofi and Lingane, Second Edition, Interscience Publishers, New York, N.Y., 1952; Analytical Chemistry, volume 36, 2426 (1964) by Elving; and Analytical Chemistry, volume 30, 1576 (1958) by Adams.

Reducing agents used to advantage according to our invention include:

the 3-pyrazolidones,

the amino hexose reductones,

the anhydro amino hexose reductones, ascorbic acids,

polyhydroxybenzenes, and p-aminophenols, N-substituted.

4 Particularly preferred are 3-pyrazo1idone reducing agents included in the formula:

in which R represents hydrogen, an alkyl group preferably having from 1 to 12 carbon atoms substituted or not (e.g., methyl, ethyl, butyl, amyl, hexyl, chloromethyl, bromoethyl, chloroethyl, chloropropyl, etc.), an aryl group such as a phenyl group (e.g., phenyl, 4-methylphenyl, 4-methoxyphenyl, etc.); R represents hydrogen, an alkyl group preferably having from 1 to 12. carbon atoms (e.g., methyl, ethyl, butyl, decyl, dodecyl, etc.), a heterocyclic group having from 5- to 6-atoms in the heterocyclic ring (e.g., a benzothiazolyl group, a benzoxazolyl group, a Z-pyridinyl group, etc.), an aryl group such as a phenyl group (substituted or not) or a naphthyl group (substituted or not) (e.g., phenyl, tolyl, ethylphenyl, chlorophenyl, methoxyphenyl, aminophenyl, acetamidophenyl, hydroxyphenyl, hydroxyethylphenyl, diphenyl, u-naphthyl, fl-naphthyl, 7-hydroxy-fi-naphthyl, 4- methyl-fi-naphthyl, 7-chloro-B-naphthyl, etc.); R R R and R can be the same or different and represent hydrogen, an alkyl group preferably having from 1 to 12 carbon atoms (e.g., methyl, ethyl, butyl, octyl, dodecyl, hydroxymethyl, hydroxyethyl, chloromethyl, ,S-bromoethyl, etc.), an aralkyl group (e.g., benzyl, phenethyl, etc.), an aryl group such as a phenyl group (substituted or not) or a naphthyl group (substituted or not) (e.g., phenyl, tolyl, ethylphenyl, chlorophenyl, methoxyphenyl, aminophenyl, acetamidophenyl, hydroxyphenyl, hydroxyethylphenyl, diphenyl, a-naphthyl, B-naphthyl, 7-hydroxyp-naphthyl, 4-methyl-[3-naphthyl, 7-chloro-fl-naphthyl, etc.).

The following compounds are representative of the 3- pyrazolidones useful according to our invention.

The amino hexose reductones and anhydro amino hexose reductones of our invention are derived from sugars, especially D-glucose, although other six carbon or hexose reducing sugars such as D-galactose, D-mannose, D-fructose, L-sorbose or the like can be used. A typical method for preparing these reductones comprises heating in a reaction medium substantially free of water a hexose reducing sugar and an aliphatic or cyclic secondary amine in the presence of an acidic reductone-forming catalytic wherein R and R can be an alkyl radical, preferably having 1 to 8 carbon atoms, or together the necessary atoms to make a heterocyclic radical with the nitrogen atom, preferably having a 5 or 6 atom nucleus and including a second nitrogen atom or an oxygen such as morpholino, piperazino, pyrrolino, pyridino, pyrimidino, piperidino and the like. Typical suitable reductone derivatives include:

dimethylamino hexose reductone, diallylamino hexose reductone, di-n-butylamino hexose reductone, di-n-hexylamino reductone, morpholino hexose reductone,

' piperazino hexose reductone,

pyrrolino hexose reductone,

piperidino hexose reductone,

piperidino di(heXose reductone),

anhydro dimethylamino hexose reductone, anhydro diallylamino hexose reductone, anhydro di-n-hexylamino reductone, anhydro morpholino hexose reductone, anhydro piperazino hexose reductone, anhydro pyrrolino hexose reductone, and anhydro piperidino hexose reductone.

These and other related suitable reductones and methods for preparing such are described in Hodges, U.S. Patent 2,936,308.

Ascorbic acids used to advantage include l-ascorbic acid, di-iso-ascorbic acid, etc.

Polyhydroxybenzene reducing agents used to advantage include those represented by the formula:

I Rs W wherein Y Y Y each represent the hydroxyl group or the hydrogen atom providing that at least two of Y Y and Y represent the hydroxyl group; R R and R each represent the same or different member such as hydrogen, alkyl, preferably having from 1 to 8 carbon atoms (e.g., methyl, ethyl, propyl, butyl, octyl, etc.), halogen (e.g., chlorine, bromine, etc.). Representative compounds include hydroquinone, methylhydroquinone, 2,6-dimethylhydroquinone, chlorohydroquinone, 2-methyl-3-chlorohydroquinone, chloro-2,6-dimethylhydroquinone, dichlorohydroquinone, bromohydroquinone, butylhydroquinone, amylhydroquinone, octylhydroquinone, dioctylhydroquinone, catechol, methylcatechol, chlorocatechol, etc.

N-substituted p-aminophenol reducing agents used to advantage include representative members such as N-methyl p aminophenol, p-B-hydroxyethylaminophenol, N- methyl-p-amino-2- (or 3) chlorophenol, N-ethyl-fl-aminophenol, etc.

The concentration of the reducing agents used can be varied widely and will depend upon the particular use and effects desired. The optimum concentration can be determined by methods well known in the art. In general, we have found that amounts of about 10 milligrams and above per mole of silver are used to advantage and amounts of from about 10 milligrams to about 20 grams are preferred, and from about 20 mg. to about 5 g. are especially preferred.

Supports having a hydrophobic surface used to advantage according to our invention include hydrophobic resins (i.e., resins which repel and do not absorb or adsorb water) which are electron bombarded to improve adhesion of hydrophilic colloid layers coated over them. The hydrophobic resin films are either self supporting or are coated over another support layer which can be a permanent or a temporary support. Specific supports having hydrophobic surfaces used to advantage include electron bombarded poly(ethylene terephthalate) films; e.g., those electron bombarded to have a contact angle less than 45, by the process described in Carroll et al. U.S. Patent 3,220,842, issued Nov. 30, 1965' (which disclosure is incorporated herein by reference); electron bombarded surfaces comprising a chromium halide complex, e.g., sterato chromic chloride electron bombarded by the process described by Crawford et a1. U.S. Patent 3,117,865, issued Jan. 14, 1964 (which disclosure is incorporated herein by reference); and electron bombarded hardened gelatin coatings, e.g., hardened gelatin coated papers electron bombarded by the process described by Crawford et al. U.S. Patent 3,411,910, Nov. 19, 1968, and corresponding Belgian Patent 671,661, Nov. 15, 1965 (which disclosure is incorporated herein by reference). Other hydrophobic surfaces which can be electron bombarded by processes and apparatus similar to that described in the cited references include poly-u-olefins, preferably derived from olefins containing from 2 to 10 carbon atoms (e.g., polyethylene, polypropylene, poly(3-methylbutene-1), poly- (octene-l poly(decene-l etc.) polyamides; polyacetals; polycarbonates; and cellulose esters and ethers, e.g., cellulose triacetate, cellulose acetate butyrate, ethyl cellulose, etc.

Included among the preferred supports are paper or other fibrous material coated with a hydrophobic film such as are mentioned above. The hydrophobic material, for example a poly-a-olefin, is coated on the paper by any of the methods commonly used such as by extrusion of a melt of the poly-a-olefin, coating of a solvent solution of the poly-a-olefin, etc. The paper support is advantageously provided with an antistatic material as described by Chu et al. U.S. Pat. 3,253,922.

The electron bombardment treatment used to advantage includes any of the corona discharge treatments used for activating hydrophobic polymer surfaces in a manner well known in the art. British Pats. 971,058 and 1,060,526, for example, describe some of these corona discharge treatments using apparatus such as is described by U.S. Pats. 2,864,755 and 2,864,756.

According to our invention at least one hydrophilic colloid layer containing light-sensitive silver halide and a color-forming coupler is coated onto a hydrophobic surface substantially immediately after it has been electron bombarded by corona discharge. In the specification and claims herein the term substantially immediately means in the range of time from a fraction of a second to about 30 minutes, preferably within a few seconds, i.e., from a fraction of a second up to about 30 seconds, that is required for the support material to be moved from the station in the apparatus where the corona discharge treatment is applied to the. hydrophobic surface to the station where the light-sensitive hydrophilic colloid silver halide emulsion containing color-forming coupler is applied to the corona discharge treated hydrophobic surface.

Hydrophilic colloids used to advantage include gelatin, colloidal albumin, a cellulose derivative, or a synthetic resin, for instance, a polyvinyl compound. Some colloids which may be used are polyvinyl alcohol or a hydrolyzed polyvinyl acetate as described in Lowe U.S. Pat. 2,286,215, issued June 16, 1942; a far hydrolyzed cellulose ester, such as cellulose acetate hydrolyzed to an acetyl content of 1926% as described in Lowe et al. U.S. Pat. 2,327,808, issued Aug. 24, 1943; a water-soluble ethanolamine cellulose acetate as described in Yutzy U.S. Pat. 2,322,085, issued June 15, 1943; a polyacrylamide having a combined acrylamide content of 30-60% and a specific viscosity of 0.25-1.5 on an imidized polyacrylamide of like acrylamide content and viscosity as described in Lowe et al. U.S. Pat. 2,541,474, issued Feb. 13, 1951; zein as described in Lowe U.S. Pat. 2,563,791, issued Aug. 7, 1951, a vinyl alcohol polymer containing urethane carboxylic acid groups of the type described in Unruh et al. U.S. Pat. 2,768,154, issued Oct. 23, 19 56, or containing cyano-acetyl groups, such as the vinyl alcohol-vinyl cyano-acetate copolymer as described in Unruh et al. U.S. Pat. 2,808,331, issued Oct. 1, 1957; or a polymeric material which results from polymerizing a protein or a saturated acylated protein with a monomer having a vinyl group as described in Illingworth et a1. U.S. 'Pat. 2,852,382, issued Sept. 16, 1958.

The silver halide emulsions employed in our elements can be spectrally sensitized or unsensitized. The usual spectral sensitizing dyes can be used, such as, the cyanines, merocyanines, complex (trinuclear) cyanines, complex (trinuclear) merocyanines, styryl, hemicyanines, etc. These dyes contain the usual basic nuclei, such as, thiazole, benzothiazole, naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, naphthoselenazole, quinoline, etc.; or in the case of the merocyanine dyes, such as, hydantoin, 2-thiohydantoin, oxazolidone, pyrazolones, etc. Such dyes, for example, are described in Brooker et a1. U.S. Pats. 2,185,182, 2,241,237; Carroll U.S. Pats. 2,635,961, 2,652,330; Heseltine and Brooker U.S. Pat. 2,666,761; Carroll and Jones U.S. Pat. 2,704,715, etc.

Our invention is primarily directed to ordinarily employed silver halide developing-out emulsions, e.g., gelation-silver-chloride, -chlorobromide, -chloroiodide, -chlorobromoiodide, bromide and -bromoiodide, developingout emulsions. Particularly useful results are obtained for the gelatino silver chlorobromide emulsions which are useful for preparing subtractive color reproductions on 'fibrous or paper supports. Emulsions which form the latent image mostly inside the silver halide grains, such as, the emulsions described in Knott et al. U.S. Pat. 2,456,956 are also used to advantage in our elements.

While our invention is particularly directed to the ordinarily employed gelatino silver halide emulsions, hydrophilic colloids other than gelatin, such as those described above are also used to advantage.

Photographic silver halide emulsions, such as those listed above, can also contain such addenda as chemical sensitizers, e.g., sulfur sensitizers (e.g., allyl thiocarbamide, thiourea, allylisothiocyanate, cystine, etc.), various gold compounds (e.g., potassium chloroaurate, auric trichloride, etc.) (see Baldsiefen U.S. Pat. 2,540,085; Damschroder U.S. Pat. 2,597,856; and Yutzy and Leermakers U.S. Pat. 2,597,915), various palladium compounds, such as palladium chloride (Baldsiefen et a1. U.S. Pat. 2,540,086), potassium chloropalladate (Stauifer et a1. U.S. Pat. 2,598,079), etc., or mixtures of such sensitizers; antifoggants, such as ammonium chloroplatinate (Trivelli and Smith U.S. Pat. 2,566,245), ammonium chloroplatinite (Trivelli and Smith U.S. Pat. 2,566,263), benoztriazole, nitrobenzimidazole, 5-nitroindazole, benzidine, mercaptans, etc. (see Mees, The Theory of the Photographic Process, Macmillan Pub., 1942, page 460), or mixtures thereof; hardeners, such as formaldehyde or chrome alum (Miller U.S. Pat. 1,763,533), glyoxal (Brunken U.S. Pat. 1,870,354), dibromacrolein (Bloch et al. British Pat. 406,750) etc.

Any of the color-forming couplers used in photographic elements are used to advantage in our photographic materials. Included among the phenol and naphthol cyan dye-forming couplers used to advantage are those described by the following U.S. Pats. 2,423,730, 2,474,293, 2,521,908, 2,725,291, 2,801,171, 3,253,294, etc. Included among the ketomethylene yellow dye-forming couplers used to advantage are those described in U.S. Pats. 2,298,443, 2,778,658, 2,801,171, 2,875,057, 3,253,924, 3,277,155, etc. Included among the 5-pyrazolone magenta dye-forming couplers used to advantage are those described in U.S. Pats. 2,600,788, 2,801,171, 3,252,924, etc.

Dispersing agents for color-forming couplers and the dispersing techniques used to advantage include those set forth in Jelley et a1. U.S. Pat. 2,322,027, Mannes et a1. U.S. Pat. 2,304,940, Fierke et al. U.S. Pat. 2,801,171, etc.

Any of the color-forming developing agents are used to advantage for the color development of our photographic materials. These include developers having two primary amino groups as well as those having one of the amino groups substituted, or having substituents in the ring such as alkylphenylenediamine and alkyltolucnediamines. These compounds are usually used in the salt form such as the hydrochloride and the sulfate Which are more stable than the amines themselves. Suitable developing agents are diethyl-p-phenylenediamine hydrochloride, monomethyl-p-phenylenediamine hydrochloride, dimethyl-p-phenylenediamine hydrochloride, 2-amino-5-diethylaminotoluene hydrochloride, N-ethyl-N-(B-methanesuL fonamidoethyl)-4-aminoaniline sulfate, N-ethyl N (13- methanesulfonamidoethyl) 3 methyl 4 aminoaniline sulfate, and 4-amino-N-ethyl-N-(p-methanesulfonamidoethyl) m toluidine sesquisulfate. Monohydrate. The p-aminophenols and their substitution products may also be used where the amino group is unsubstituted. All of these groups have unsubstituted amino groups which enable the oxidation products of the developer to couple with the color-forming compounds to form a dye image.

The following examples are included for further understanding of our invention.

EXAMPLE 1 A piece of polyethylene coated paper is electron bombarded by corona discharge such as described in British Pat. 971,058 and held for a minimum of one hour before coating photographic layers thereon. For convenience, this treated paper will hereinafter be referred to as prebombarded supports (PBS). Another piece of polyethylene coated paper is electron bombarded and immediately thereafter is coated with the desired photographic lightsensitive layers with a coating machine in-line with the electron bombarding means. For convenience, this treated material is referred to hereinafter as in-line bombarded supports (ILBS). Pieces of the PBS and ILBS supports described above are coated in succession over the bombarded polyethylene surface with (1) a gelatin layer containing an ordinary blue-sensitive gelatino silver chlorobromide emulsion and a dispersion of a yellow dyeforming coupler of the type described in McCrossen et a1. U.S. Pat. 2,875,057, (2) a gelatin interlayer, (3) a gelatin layer containing an ordinary green-sensitized gelatino silver chlorobromide emulsion, a dispersion of a magenta dye-forming coupler such as one of the couplers described in Loria et al. U.S. Pat. 2,600,788, (4) a gelatin layer, (5) a gelatin layer containing an ordinary red-sensitized gelatino silver chlorobromide emulsion, a dispersion of a cyan dye forming coupler such as is described in Fierke U.S. Pat. 2,801,171, and a red light absorbing dye of the type described in Saunders et a1. U.S. Pat. 2,865,752, and (6) a gelatin protective layer; with the addenda described by Table I. The photographic elements are exposed in an intensity scale sensitometer using 3000 K-SOO watt illumination from a projection incandescent lamp. The

exposed photographic elements are then developed for about 12 minutes in the following composition:

Water liter 1.0 Benzyl alcohol cc 12.6 Sodium hexametaphosphate (Calgon) grams 2.0 Sodium sulfite, anhydrous do 2.1 Sodium carbonate monohydrate do 26.8 Sodium bicarbonate do 2.9 Potassium bromide do 0.48 Sodium chloride do 0.7 'Hydroxylamine sulfate do 2.1 Color developer 1 do 4.2 pH at 75 F. 9.96

4n.min0 N ethy1-N(B-methanesmlfionamidoethyl) mrtoluidine sesqulsulfrate monohydrate.

The developed coatings are then immersed for about 2 minutes in a stop bath having the following composition:

The coatings are then washed in running water at about 73 to 77 F. for 2 minutes. The paper coatings are then treated for 4 minutes at 73 to 77 F. in a bleach bath having the following composition:

Water liter 1.0 Sodium nitrate grams 45.0 Potassium ferricyanide do 22.5 Potassium bromide do 8.2 Boric acid do 7.5 Borax do 0.97

The paper coatings are then washed in running water at 73 to 77 F. for 2 minutes and then fixed for 2 minutes in a hardener-fixing bath having the following composition:

The paper coatings are then washed in running water at 73 to 770 F. for 8 minutes and then treated for 3 minutes in a hardening bath at 73 to 77 F., the bath having the following composition:

Water liter 1.0 Sodium hexametaphosphate (Calgon) grams 0.75 Sodium carbonate monohydrate do 8.8 Formaldehyde (37% by water) ccs 25.5

The paper coatings are then washed for 2 minutes in running water and treated for 3 minutes in a buffer bath having the following composition:

Water liter 1.0 Citric acid grams 30.0 Borax do 20.4

The prints are then allowed to dry in the air or in a conventional drier.

Reflection densitometer measurements are made of the processed color prints in order to determine the relative blue speed and the yellow stain density. The yellow stain density measurements are made in the D-min. area of the processed prints. After these measurements are made, the processed prints are incubated for 3 days and densitometric measurements are made to determine the relative blue speed. The results obtained are summarized in Table I.

TABLE I Relative blue speed Yellow Addenda added to blue-sensitive 3 day stain Coating layer (mg/Ag mole) Fresh inc. density A Control (PBS) 82 13 B Control (ILBS) 97 16 C Control (ILBS) plus 1-phenyl-3- 115 107 .13

pyrazolidone (87 mg). D Control (ILBS) plus 1-pheuyl-3- 100 100 12 pyrazolidone (174. mg). E Control (ILBS) plus 1-phenyl-3- 102 96 13 pyrazolidone (261 mg).

The results show that coatings C, D and E which contain 87 milligrams, 174 milligrams, and 261 milligrams, respectively, per silver mole of 1-phenyl-3-pyrazolidone in the blue-sensitive emulsion layer have yellow stain densities that are as low as the control coating A coated on PBS while the control coating B coated on ILBS without the 1-phenyl-3-pyrazolidone (outside of our invention) has a substantially higher stain density. Coating D shows the lowest stain density and a relative blue speed which is unchanged by 3 days of incubation.

EXAMPLE 2 Coatings are made on in-line bombarded supports, exposed, processed and resulting densities measured with a reflection densitometer in the manner described in Example 1. The addenda used and the results obtained are described below in Table II.

1 Compounds of this general type are described in the prior art as conventional antifoggants.

The results show that coating H of our invention which contains 218 milligrams per mole of silver of l-phenyl-3- pyrazolidone in the blue-sensitive emulsion layer has a fresh relative blue speed of 102 compared to the control of 100 and a yellow stain density of only .12 as compared to the control of .18 density units. Coating G (outside of our invention) which contains an antifoggant reduces the fresh relative blue speed to 26 and even has increased the yellow stain density instead of decreasing it as though accomplished by our element of coating H. Pieces of coatings F and H are incubated for 3 and 5 months before exposing and processing as described in Example 1. The resulting color prints are measured with a reflection densitometer and the relative blue speeds determined. These results are summarized in Table III.

Coating H of our invention shows substantially no change in relative blue speed from 3 months incubation and only a small decrease in relative blue speed after 5 months while Coating F, outside of our invention, shows a very substantial decrease in relative blue speed even after 3 months incubation.

EXAMPLE 3 Coatings similar to those described in Example 1 except that only a single blue-sensitive emulsion layer is coated on the support are prepared and tested with the following results:

TABLE IV Yellow Addenda added to blue-sensitive layer stain Coating (mg/Ag mole) density I Control (PBS) 08 .T Control (ILB S) 24 K Contr)l (ILB S) plus l-phenyl-3-pyrazolid0ne (43.5 19

mg. L Control (ILB S) plus l-phenyl-E-pyrazolidone (174 10 mg. M Contr)ol (ILBS) plus Lphenyl-B-pyrazolidone (261 11 The results show that even as little as 43.5 mg./silver mole of l-phenyl 3 pyrazolidone in the blue-sensitive emulsion layer produces a very substantial decrease in yellow stain density from the stain density of control ILBS (coating J) and that increasing the concentration of l-phenyl 3 pyrazolidone to 174 milligrams per silver mole reduces the yellow stain density to a level approaching the control PBS, Coating I.

A comparison of the sensitometric curves for processed prints made on our coatings C, D and E with control coating B in Example 1, a comparison of the sensitometric curves for processed prints made from our coating H with control coating F in Example 2 and a comparison of the sensitometric curves for processed prints made on coatings K, L and M with control coating J in Example 3 show that the addition of 1-phenyl-3-pyrazolidone to the blue-sensitive gelatino silver chlorobromide emulsion layers coated next to the electron bombarded polyethylene support surface does not appreciably shift the sensitometric curves. The addition of l-phenyl-3- pyrazolidone to the silver halide emulsion layer coated next to the electron bombarded polyethylene support surface, however, is very effective in the reduction or elimination of color fog.

EXAMPLE 4 Example 1 is repeated using 1-phenyl-4,4-dimethyl-3- pyrazolidone in place of 1-phenyl-3-pyrazolid'one. The results show that the additions of 1-pheny1-4,4-dimethyl- 3-pyrazolidones to the blue-sensitive gelatino silver chlorobromide emulsion coated over the polyethylene support surface that has just been electron bombarded are etfective in reducing the formation of yellow stain and speed loss (after prolonged storage before exposure) without significantly shifting the sensitometric curves.

EXAMPLE 5 Example 1 is repeated using a different order of coating the light-sensitive layers so that the red-sensitive layer is coated next to the electron bombarded polyethylene with the green-sensitive layer and the blue-sensitive layers coated over the blue-sensitive layer. In this material the l-phenyl 3 pyrazolidone is added to the red-sensitive layer instead of the blue-sensitive layer. Upon exposure and processing as in Example 1 the addition of l-phenyl- 3-pyrazolidone is shown to be effective in reducing cyan stain density from that shown for the control ILBS.

EXAMPLE 6 Example 1 is repeated using a different order of coating the light-sensitive layers so that the green-sensitive layer is coated next to the electron-bombarded polyethylene with the red-sensitive and the blue-sensitive layers coated over the green-sensitive layer. In this material the 1- phenyl 3 pyrazolidone is added to the green-sensitive layer instead of the blue-sensitive layer. Upon exposure and processing as in Example 1, the addition of l-phenyl- 3-pyrazolidon'e is shown to be effective in reducing magenta stain from that shown for the control ILBS.

EXAMPLE 7 Example 3 is repeated but by incorporating the laphenyl- 3-pyrazolidone in the dispersion of the yellow dye-forming coupler instead of in the silver halide emulsion per se. Upon exposure and processing as described in Example 1 improvements are shown in the yellow stain density of the coatings that contain 1-phenyl-3-pyrazolidone.

EXAMPLE 8 Example 1 is repeated excepting that in place of the multilayer light-sensitive coatings, a single light-sensitive gelatin layer containing packets of blue-sensitive gelatino silver chlorobromide 'with a dispersion of yellow dyeforming coupler, packets of green-sensitized gelatino silver chlorobromide with a dispersion of magenta dyeforming coupler, and packets of a red-sensitized gelatino silver chlorobromide emulsion with a dispersion of a cyan dye-forming coupler is used. In this material the control ILBS coating has not only high yellow stain density but also high cyan and high magenta stain density compared to the control PBS. The addition of l-phenyl- 3-pyrazolidone to the gelatin layer containing the mixed packet dispersion is advantageous in reducing the stain densities and preventing speed loss (after storage before exposure) without changing the sensitometric curve shapes significantly.

EXAMPLE 9 Example 1 is repeated excepting that a gelatin layer is coated between the electron bombarded polyethylene surface anl the blue-sensitive gelatino silver chlorobromide emulsion layer and the 1-phenyl-3-pyrazolidone used in Example 1 is placed in the gelatin interlayer. The incorporation of 1-phenyl-3-pyrazolidone in the gelatin interlayer reduces the yellow stain.

EXAMPLE 10 Example 1 is repeated using 1-phenyl-4,4-dihydroxymethyl-3-pyrazolidone in place of l-phenyl-3-pyrazolidone. The results show the use of -1-phenyl-4,4-dihydroxymethyl-3-pyrazolidone reduces yellow stain.

EXAMPLE 11 Example 1 is repeated using l-phenyl-4-hydroxymethyl- 4-methyl-3-pyrazolidone in place of 1-phenyl-3-pyrazolidone. The results show the use of l-phenyl-4-hyd1'oxymethyl-4-methyl-3-pyrazolidone reduces the yellow stain.

Similar results are obtained when other 3-pyrazolidones of our invention as described by general Formula I such as are illustrated by compounds 1 through 25 are used in the above examples.

The following example illustrates the use of l-phenyl-3- pyrazolidone and other reducing agents such as hydroquinone, dioctylhydroquinone, l-ascorbic acid and piperidino hexose reductone according to our invention. Sodium formaldehyde bisulfite, dextrine, octadecyl-(3,5-dit-buty1- 4-hydroxy phenol)-acetate and 2,4,6-tri-t-pentyl phenol which are outside the invention, are included for comparison purposes.

EXAMPLE 12 A piece of polyethylene-coated paper is electron bombarded by a corona discharge and held for a minimum of one hour before coating photographic layers thereon (referred to hereinafter as PBS). Another piece of polyethylene-coated paper is electron bombarded and immediately thereafter is coated with the desired photographic lightsensitive layers (referred to hereinafter as ILBS). A series of silver chlorobromide gelatin emulsions, containing a yellow dye-forming coupler (Coupler 9 of Weissberger et al. US. Pat. 3,265,506) is coated on the PBS and ILBS supports at a coverage of approximately 460 mg. of silver, 193 mg. of gelatin, and 117 mg. of coupler per ft. as

described below. Over each emulsion layer is coated a gelatin protective layer at a coverage of 175 mg. of gelatin per ft. A sample of each coating is exposed on an intensity scale sensitimeter and processed through the process described in Example 1 at a development time of 12 minutes at 75 F. The background stain density of each coating is read using a Wratten (Eastman Kodak Trademark) 36B blue filter. The following results are obtained.

Type of electron Stain bombardment Reducing agents (mg/silver mole) density PB S None None 30 1-phenyl-3-pyrazolidine (Phenidone) (440)- 10 Hydroquinone (300) 12 ILBS Hydroquinone (650) 12 Di-octyl hydroquinone (880 18 Di-octyl hydroquinone (440) 22 Sodium formaldehyde bisulfite (440) l 28 Sodium formaldehyde bisulfite (4,400) 1 29 PB S None 10 None 36 Dextrine (440) 1 33 Dextrine (2,200) 1 29 Dextrine (11,000) 1 30 ILBS L-Ascorbic acid (440) 08 L-Ascorbic acid (2,200) 09 Octadecyl (3,5-di-tert1ary butyl-i-hydroxy 27 phenol acetate (1,300) Oetadccyl (3,5-di-tertiary butyl-4-hydroxy 41 phenol acetate (4,400)

PB S None 09 None z I 44 l-phenyl-3 pyrazolid1ne (Phenidone) (440) 09 2,4,6-tri-tert-pentyl phenol (440) 46 ILBS .1 2,4,ti tri-tert-pentyl phenol (880) L. 38 Piperidino hexose reduetone (440) 08 Piperidino hexose reductone (2,200) 08 Piperidino hexose reductone (11,000) 08 1 Other reducing agents for comparative purposes.

resentative reducing agents used to illustrate our invention.

Reducing agent: I E in volts 1-phenyl-3-pyrazolidine (Phenidone) +0.-12 Hydroquinone +0.20 Di-octyl hydroquinone +0.06 L-ascorbic acid +0.11 Piperidino hexose reductone +0.18

Sodium formaldehyde bisulfite, dextrine, octadecyl(3,5-dit-butyl-4-hydroxyphenol) and 2,4,6-tri-t-pentyl phenol outside our invention gave E values more positive than +0.33 volt.

Results similar to those described above are obtained when sheets of our hydrophobic resins, such as, polyethylene, polypropylene, polybutylene and other poly-alphaolefins, poly(ethylene terephthalate), polyamides, polyacetals, polycarbonates, cellulose esters and cellulose ethers of our invention are electron bombarded and coated substantially immediately with the light-sensitive coating layers described in the above examples. As mentioned before, the hydrophobic resin can be self supporting or coated over a paper support providing the resin coating is given electron bombardment treatment and then substantially immediately coated with light-sensitive hydrophilic colloid layers as described in the examples.

Although the examples shown use silver chlorobromide emulsions it is to be understood that any of the other silver halides are used advantageously in photographic elements according to our invention. Similarly, it can be shown that any of the hydrophilic colloid substitutes used 14 in place of gelatin are used advantageously in place of gelatin in elements made according to our invention.

The multicolor elements of our invention have been described as being processed in conventional color processes, but it should be realized that stabilization processes of the type described in Fassbender et al. US. Pat. 3,335,- 004 or the color diffusion transfer processes of the type described in Salminen US. Pat. 3,330,655 and in Whitmore US. Pat. 3,227,552 may also be used to advantage when appropriate.

The invention has been described in detail with particular embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

We claim:

1. The process for preparing a color photographic element which comprises electron bombarding the outer surface of a layer of hydrophobic resin to provide a good adhesion for a hydrophilic colloid layer and in the range of time from a fraction of a second to about 30 minutes thereafter coating on said electron bombarded surface at least one hydrophilic colloid layer containing a noncolorforming reducing agent having a polarographic halfwave potential E more negative than +0.3 volt, said =E,, measurement being made on a 1X10- molar solution of said reducing agent in aqueous solvent at a pH of 6.0 using a saturated silver/ silver chloride reference electrode and a pyrolytic graphite electrode, said reducing agent having a solubility greater than 1 10* moles per liter of water at a pH of 6.0 and 20 C. and at least one hydrophilic colloid layer containing a light-sensitive silver halide emulsion having dispersed therein a nondiffusing color-forming coupler that forms a dye when reacted with oxidized aromatic primary amine color developing agent, said reducing agent being present in at least one of (1) a first light-sensitive layer coated nearest to said support and (2) a layer between said first light-sensitive layer and said electron bormbarded surface in a suflicient quantity in the concentration range of from about 10 mg. to about 20 g. per mole of silver to prevent the formation of color fog during color development with an aromatic primary amine color developing agent.

2. A process for preparing a color photographic element as defined in claim 1 in which the said hydrophobic poly-a-olefin is a polyethylene.

3. The process for preparing a color photographic element which comprises electron bombarding the outer surface of a layer of hydrophobic resin to provide a good adhesion for a hydrophilic colloid layer and in the range of time from a fraction of a second to about 30 minutes thereafter coating on said electron bombarded surface at least one hydrophilic colloid layer containing a noncolor-forming reducing agent having a polarographic halfwave potential E more negative than +0.3 volt, said E measurement being made on a 1 10- molar solution of said reducing agent in aqueous solvent at a pH of 6.0 using a saturated silver/ silver chloride reference electrode and a pyrolytic graphite electrode, said reducing agent having a solubility greater than 1X 10* moles per liter of water at a pH of 6.0 and 20 C. and at least one hydrophilic colloid layer containing a light-sensitive silver halide emulsion having dispersed therein a nondiffusing color-forming coupler that forms a dye when reacted with oxidized aromatic primary amine color developing agent, said reducing agent being present in at least one of (1) a first light-sensitive layer coated nearest to said support and (2) a layer between said first light-sensitive layer and said electron bombarded surface in a sufiicient quantity in the concentration range of from about 10 mg. to about 20 g. per mole of silver to prevent the formation of color fog during color development with an aromatic primary amine color developing agent, said reducing agent being selected from the class consisting of an amino hexose reductone,

an anhydro hexose reductone, a polyhydroxybenzene, an ascorbic acid and a 3-pyrazolidone having the formula:

wherein R R R and R each represent a member selected from the class consisting of hydrogen, an alkyl group and an aryl group; and R represents a member selected from the class consisting of hydrogen, an alkyl group, a heterocyclic group having from 5 to 6 atoms in the heterocyclic ring and an aryl group.

4. The process for preparing a color photographic element as defined in claim 3 in which the said hydrophobic resin is selected from the class consisting of a poly-alphaolefin, a polyamide, a polyacetal, a polycarbonate, a cellulose ester, a cellulose ether and a hardened gelatin.

5. The process for preparing a color photographic element as defined in claim 3 in which the said reducing agent is a 3-pyrazolidone having the formula:

wherein R R R and R each represent a member selected from the class consisting of hydrogen, an alkyl group, and an aryl group; and R represents a member selected from the class consisting of hydrogen, and alkyl group, a heterocyclic group having from 5 to 6 atoms in the heterocyclic ring and an aryl group.

6. The process for preparing a color photographic element as defined in claim 5 in which the hydrophobic resin is selected from the class consisting of a poly-alpha-olefin,

a polyamide, a polyacetal, a polycarbonate, a cellulose ester, a cellulose ether and a hardened gelatin.

7. The process for preparing a color photographic element as defined in claim 3 in which the said reducing agent is a reductone derivative selected from the group consisting of an amino hexose reductone and an anhydro amino hexose reductone wherein the amino moiety of said reductone derivative has the formula:

RBN

it. where in R and R are selected from the group consisting of alkyl radicals and together with the nitrogen atom form a nitrogen containing heterocyclic ring.

8. The process for preparing a color photographic element as defined in claim 7 in which the said hydrophobic resin is selected from the class consisting of a poly-alphaolefin, a polyamide, a polyacetal, a polycarbonate, a cellulose ester, a cellulose ether and a hardened gelatin.

9. The process for preparing a color photographic element as defined in claim 3 in which the said reducing agent is an ascorbic acid.

10. The process for preparing a color photographic element as defined in claim 9 in which the said hydrophobic resin is selected from the class consisting of a poly-alphaolefin, a polyamide, a polyacetal, a polycarbonate, a cellulose ester, a cellulose ether and a hardened gelatin.

11. The process for preparing a color photographic element which comprises electron bombarding the outer surface of a layer of a hydrophobic poly-a-olefin to provide a good adhesion for a hydrophilic colloid layer and in the range of time from a fraction of a second to about 30 minutes thereafter coating on said electron bombarded surface at least one hydrophilic colloid layer containing a noncolor-forming reducing agent having a polargraphic halfwave potential E more negative than +0.3 volts, said E measurement being made on a 1 10- molar solution of said reducing agent in aqueous solvent at a pH of 6.0 using a saturated silver/ silver chloride reference electrode and a pyrolytic graphite electrode, said reducing agent having a solubility greater than 1 x 10* moles per liter of water at a pH of 6.0 and 20 C. and at least one hydrophilic colloid layer containing a light-sensitive silver halide emulsion having dispersed therein a nondiifusing color-forming coupler that forms a dye when reacted with oxidized aromatic primary amine color deyeloping agent, the said reducing agent being present in at least one of (1) a first light-sensitive layer coated nearest to said support and (2) a layer between said first lightsensitive layer and said electron bombarded surface in a sufiicient quantity in the concentration range of from about 10 mg. to about 20 g. per mole of silver to prevent the formation of color fog during color development with an aromatic primary amine color developing agent, said reducing agent being selected from the class consisting of an amino hexose reductone, an anhydro amino hexose reductone, an ascorbic acid, a polyhydroxybenzene and a 3-pyrazolone having the formula:

wherein R R R and R each represent a member selected from the class consisting of hydrogen, an alkyl group and an aryl group; and R represents a member selected from the class consisting of hydrogen, an alkyl group, a heterocyclic group having from 5 to 6 atoms in the heterocyclic ring and an aryl group.

12. The process for preparing a color photographic element as defined in claim 11 in which the hydrophobic poly-a-olefin is polyethylene.

13. The process for preparing a color photographic element as defined in claim 11 in which thesaid reducing agent is a polyhydroxybenzene.

14. The process for preparing a color photographic element which comprises electron bombarding the outer surface of a polyethylene layer coated on a paper support and in the range of time from a fraction of a second to about 30 minutes thereafter coating on the said bombarded polyethylene surface at least one gelatin layer containing a 1-phenyl-3-pyrazolidone and at least one gelatin layer containing a light-sensitive silver halide emulsion having dispersed therein a nonditfusing color-forming coupler that forms a dye when reacted with oxidized aromatic primary amine color developing agents, said l-phenyl-3- pyrazolidone being present in gelatin around grains of silver halide in a first light-sensitive layer coated nearest to said bombarded polyethylene surface in a suflicient quantity in the concentration range of from about 10 mg. to about 20 g. per mole of silver to prevent the formation of a color fog during color development.

15. A photographic element comprising a support having a hydrophobic resin surface that has been treated by electron bombardment and having coated over said treated surface in the range of time from a fraction of a second to about 30 minutes after said bombardment at least one hydrophilic colloid layer containing a noncolor-forming reducing agent having a polarographic halfwave potential E more negative than +0.3 volt, said E measurement being made on a 1X10" molar solution of said reducing agent in aqueous solvent at a pH of 6.0 using a saturated silver/ silver chloride reference electrode and a pyrolytic graphite electrode, said reducing agent having a solubility greater than 1 10- moles per liter of water at a pH of 6.0 and 20 C., and at least one hydrophilic colloid layer containing a light-sensitive silver halide emulsion having dispersed therein a nondiffusing color-forming coupler that forms a dye when reacted with oxidized aromatic primary amine color developing agent, the said reducing agent being present in at least one of (1) a first light sensitive layer coated nearest to said support and (2) a layer between said first light-sensitive layer and said hydrophobic resin surface treated by electron bombardment in a sufficient quantity in the concentration range of from about mg. to about g. per mole of silver to prevent the formation of color fog during color development with aromatic primary amine color developing agent, said reducing agent being selected from the class consisting of an amino hexose reductone, an anhydro hexose reductone, an ascorbic acid and a 3-pyrazolidone having the formula:

where in R R R ad R each represent a member selected from the class conisting of hydrogen, an alkyl group and aryl group; and R represents a member selected from the class consisting of hydrogen, an alkyl group, a heterocyclic group having from 5 to 6 atoms in the heterocyclic ring and an aryl group.

16. A photographic element comprising a support having a hydrophobic poly-u-olefin surface that has been treated by electron bombardment and having coated over said treated surface in the time range of from a fraction of a second to about minutes after said bombardment at least one hydrophilic colloid layer containing a noncolor-forming reducing agent having apolyographic halfwave potential E more negative than +0.3 volts, said E measurement being made on a 1X10- molar solution of said reducing agent in aqueous solvent at a pH of 6.0 using a saturated silver/ silver chloride reference electrode and a pyrolytic graphite electrode, said reducing agent having a solubility greater than 1 10 moles per liter of water at a pH of 6.0 and 20 C., said reducing agent being selected from the class consisting of an amino hexose reductone, an anhydro amino hexose reductone, an ascorbic acid and a 3-pyrazolidone having the formula:

wherein R R R and R each represent a member selected from the class consisting of hydrogen, an alkyl group and an aryl group; and R represents a member selected from the class consisting of hydrogen, an alkyl group, a heterocyclic group having from 5 to 6 atoms in the heterocyclic ring and an aryl group and at least one hydrophilic colloid layer containing a light-sensitive silver halide emulsion having dispersed therein a nondiffusing color-forming coupler that forms a dye when reacted with oxidised aromatic primary amine color developing agent, the said reducing agent being present in at least one of (1) a first light-sensitive layer coated nearest to said support and (2) alayer between said first light-sensitive layer and said hydrophobic poly-a-olefin surface that has been treated by electron bombardment in a sufiicient quantity in the concentration range of from about 10 mg. to about 20 g. per mole of silver to prevent the formation of color fog during color development with an aromatic primary amine color developing agent.

17. A photographic element of claim 16 in which the said reducing agent is a hydrophilic colloid coated in a layer separating the said treated hydrophobic POlY-a-OlefiH surface and the hydrophilic colloid layer containing the said silver halide emulsion and the said dispersion of nondifiusing color-forming coupler.

18. A photographic element of claim 16 in which the said reducing agent is incorporated with the said lightsensitive silver halide emulsion and the said nondilfusing color-forming coupler in the hydrophilic colloid layer coated on the said treated surface of the poly-alpha-olefin.

19. A photographic element of claim 16 in which the said hydrophobic poly-a-olefin surface is a polyethylene coated over paper.

20. A photographic element as described in claim 19 wherein the reducing agent is 1-phenyl-3-pyrazolidone in an amount in the range from about 10 milligrams to about 5 grams per mole of silver halide.

21. A photographic element as described in claim 16 wherein the reducing agent is L-ascorbic acid in an amount in the range from about 10 milligrams to about 5 grams per mole of silver halide.

22. A photographic element as described in claim 16 wherein the reducing agent is piperidino hexose reductone in an amount in the range from about 10 milligrams to about 5 grams per mole of silver halide.

23. A photographic element comprising a paper support having coated on at least one surface a film of a polyethylene whose outward facing surface has been treated by electron bombardment and coated in succession over the said treated surface in the range of time from a fraction of a second to about 30 minutes after said bombardment (1) a blue-sensitive gelatino-silver-chlorobromide emulsion containing in the range of from about 10 mg. to about 20 g. of 1-phenyl-3-pyrazolidone per mole of silver and a nondiffusing yellow dye-forming coupler, (2) a green-sensitive gelatino-silver-chlorobromide emulsion containing a nondiffusing magenta dye-forming coupler, (3) a gelatin layer and (4) a red-sensitive gelatinosilver-chlorobromide emulsion containing a nonditfusing cyan dye-forming coupler.

References Cited UNITED STATES PATENTS 2,403,721 7/1946 Jelley et al. 9674X 3,241,967 3/ 1966 De Marle et a1. 9666 3,243,294 3/1966 Barr 9674X 3,480,434 11/1969 Hanna 9674 FOREIGN PATENTS 1,460,174 11/1966 France. 1,134,211 11/1968 Great Britain 9685 J. TRAVIS BROWN, Primary Examiner J. WINKLEMAN, Assistant Examiner U.S. Cl. X.R.

PEI-W50 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,5 ,333 Dated June 1 1 97 Richard G. Yost and Ronald L. Heidke Inventor(s) It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In column H line 39, "bormbar'ded' should read --bombarded--.

In column 15, line 37, "the hydrophobic" should read --the said hydrophobic-.

In column 18, line 6, "reducing agent is a hydrophilic colloid" should read ---reducing agent is in a hydrophilic colloid--.

Signed and sealed this 27th day of June 1 972.

(SEAL) Attest:

ROBERT GOTTSCHALK EDWARD M .FLETCHER, JR.

Commissioner of Patents Attesting Officer