US3856531A

US3856531A - Photographic compositions and processes

Info

Publication number: US3856531A
Authority: US
Inventors: P Grisdale; B Babb
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1971-08-02
Filing date: 1973-06-04
Publication date: 1974-12-24
Anticipated expiration: 1991-12-24

Abstract

Photographic compositions including a radiation-sensitive complex of a triorganophosphine, e.g. a triarylphosphine, with an organoazide such as an arylazide are radiation-sensitive and can be imagewise exposed to activating rays to yield a species that can react with a dye-forming coupler to form an image dye, e.g. an azo dye. Optionally, such compositions can include a polymeric binder and/or a dye-forming coupler. In another aspect, imageforming compositions are presented which include the organoazide and a precursor to the triorganophosphine, a phosphonium salt for example, that yields triorganophosphine on treatment with base. With such an embodiment, the composition is relatively lightinsensitive prior to alkaline treatment which activates the composition by forming the phosphine-azide complex in situ, and shelf life is desirably extended. When these compositions are present on a support, photographic or image-forming elements are formed. Once the azide-phosphine complex is present in a composition or element of this invention, imagewise exposure to activating rays for the complex and subsequent or concomitant treatment with a dye-forming coupler or the like produces a photographic image in exposed regions, i.e., a negative image of the original exposure. If a leuco compound, dye forming coupler, etc., is present in the composition, then a visible image generally forms on exposure. After production of the image, it can be stabilized by overall heating. In certain cases, heat fixation also produces intensification of a low density or substantially latent photographic image. If desired, positive images can be formed by thermophotographic means. Once the phosphineazide complex is present in the composition, imagewise exposure to heat desensitizes the complex in heated regions and a subsequent overall exposure to activating rays for the complex produces either a visible or an intensifiable photographic image. No heat fixation is required, but image intensification can be accomplished by heat. Lithographic printing surfaces can be prepared when a hydrophilic polymeric azide is used to form the phosphine azide complex or when hydrophilic polymeric couplers are used to form the dye image.

Description

United States Patent [191 Grisdale et al.

[111 3,856,531 [451 Dec. 24, 1974 [5 1 PHOTOGRAPHIC COMPOSITIONS AND PROCESSES [75] Inventors: Patrick J. Grisdale; Bruce E. Babb,

both of Rochester, N.Y.

[73] Assignee: Eastman Kodak Company,

Rochester, N.Y.

22 Filed: June 4,1973 21 Appl. No.: 366,884

Related US. Application Data [62] Division of Ser. No. 168,392, Aug. 2, 1971, Pat. No.

[52] U.S.Cl 96/91 N, 96/33, 96/35.1, 96/36.49, 96/75, 96/90 R, 96/115 R,

[51] Int. Cl. G03c 1/52, G03c l/58, G03c 1/72 [58] Field of Search.. 96/91 N, 90 R, 115 R, 115 P, 96/75, 33, 35.1, 36; 260/349 OTHER PUBLICATIONS Van Allan et al., Journal of Heterocyclic Chemistry, Vol. 5, 1968, p.471-476.

Leffler et al., Journal of Organic Chemistry, Vol. 26,1961, p. 48104814.

Primary Examiner-Charles L. Bowers, Jr. Attorney, Agent, or FirmD. M. Schmidt [57] ABSTRACT Photographic compositions including a radiationsensitive complex of a triorganoph-osphine, e.g. a triarylphosphine, with an organoazide such as an arylazide are radiation-sensitive and can be imagewise exposed to activating rays to yield a species that can react with a dye-forming coupler to form an image dye, e.g. an azo dye. Optionally, such compositions can include a polymeric binder and/or a dye-forming coupler. In another aspect, image-forming compositions are presented which include the organoazide and a precursor to the triorganophosphine, a phosphonium salt for example, that yields triorganophosphine on treatment with base. With such an embodiment, the composition is relatively light-insensitive prior to alkaline treatment which activates the composition by forming the phosphine-azide complex in situ, and shelf life is desirably extended. When these compositions are present on a support, photographic or imageforming elements are formed. Once the azidephosphine complex is present in a composition or element of this invention, imagewise exposure to activating rays for the complex and subsequent or concomitant treatment with a dye-forming coupler or the like produces a photographic image in exposed regions, i.e., a negative image of the original exposure. If a leuco compound, dye forming coupler, etc., is present in the composition, then a visible image generally forms on exposure. After production of the image, it can be stabilized by overall heating. In certain cases, heat fixation also produces intensification of a low density or substantially latent photographic image. If desired, positive images can be formed by thermophotographic means. Once the phosphineazide complex is present in the composition, i'magewise exposure to heat desensitizes the complex in heated regions and a subsequent overall exposure to activating rays for the complex produces either a visible or an intensifiable photographic image. No heat fixation is required, but image intensification can be accomplished by heat. Lithographic printing surfaces can be prepared when a hydrophilic polymeric azide is used to form the phosphine azide complex or when hydrophilic polymeric couplers are used to form the dye image.

6 Claims, No Drawings PHOTOGRAPHIC COMPOSITIONS AND PROCESSES This is a division of application Ser. No. 168,392, filed Aug. 2,1971, now US. Pat. No. 3,767,409.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to photography and particu larly to new photographic and image-forming compositions and elements that can be negative-working, as well as to photographic processes that are useful in pro ducing stable images that can be formed in the substantial absence of moisture or noxious developing agents.

2. Description of the Prior Art Photographic compositions designed for dry or substantially dry processing are known. Widely used such formulations are two-component diazotype compositions that include a diazonium salt and a coupler that, under alkaline conditions, can react with the diazonium salt to form an azo dye. A broad description of diazotype elements appears in Kosar, Light-Sensitive Systems, John Wiley & Sons, Inc., New York (1965), especially at Chapter 6. On exposure to light, the lightsensitive diazonium salt is destroyed and subsequent treatment with an alkaline developer like ammonia promotes a dye-forming reaction in unexposed areas to produce a positive reproduction of an original line transparency or the like. Diazotype-compositions, however, have certain disadvantages in that they tend to suffer background printup on storage. This tendency can be diminished by inclusion of an acidic precoupling inhibitor, but the addition of such a material slows development rate since the inhibitor must be neu tralized before coupling can occur. Additionally, well known developing agents like ammonia are generally either toxic and/or noxious.

Another type of diazotype photographic element uses diazosulfonates which, on exposure to light, form diazonium salts that can couple in the normal fashion. These elements are negative-working since they produce image dye in regions of exposure. However, they suffer the disadvantage that image stabilization usually requires a washout step to remove remaining sensitive components.

Still another well-known type of negative-working photographic element uses organic azides and dye precursors. See, for example, US. Pat. No. 3,062,650. Such elements yield a printout image directly on exposure. However, an inconvenient washout step to remove unreacted components is generally necessary to stabilize background areas against subsequent printout.

The desirability of providing new photographic elements that do not use silver as the light-sensitive agent (it being in short supply) and that produce stable images without substantial moisture, stabilization washes, or noxious or toxic developing agent is widely acknowledged. Additionally, widespread contemporary apprehension relative to organic pollutants and their effect on the environment has stimulated activity designed to inhibit the flow of contaminants into the environment. Such goals are also of deep concern to those skilled in the photographic arts.

Accordingly, it is an object of this invention to provide new photographic compositions.

It is another object of this invention to provide novel photographic compositions including a radiationsensitive complex of a triorganophosphine with an organoazide.

Still another object of the present invention is to provide new image forming compositions that include an organoazide and a triorganophosphine precursor.

Yet an additional object of the instant invention is to provide novel photographic .and image-forming ele ments that include the present photographic and image-forming compositions.

Another object of this invention is to provide new photographic processes for preparing stable images.

An additional object of this invention is to provide novel photographic processes for preparing stable images by means of light and heat in the substantial absence of moisture.

Still another object of this invention is to provide new thermophotographic processes for preparing stable images. I

STATEMENT OF THE INVENTION The objects of this invention are: accomplished, with radiation-sensitive phosphineazide complexes. In one aspect, the invention relates to new photographic compositions that include a radiation-sensitive complex of a triorganophosphine with anorganoazide'. In another aspect, the present invention includes novel imageforming compositions containing suitable precursors to the light-sensitive complex and from which the aforementioned complex can be released conveniently. Optionally, such photographic and image-forming compositions can include a dye precursor, e.g. a dye-forming coupler.

The photographic compositions yield an image directly on exposure to activating radiation for the complex. No external processing agents are required. The

background regions can then be stabilized against printup by simple heat fixation. In certain cases, this heating step also produces an intensification of the image. As used herein, the term photographic image refers to visible and latent photographic images. The image-forming compositionscan be exposed and developed with similar convenience, but require liberation of the radiation-sensitive complex from the precursors prior to exposure. This can be done, for example, by contacting the image-forming composition with base. Additionally, .if a particular photographic or image forming composition or element does not contain a coupler, exposure is advantageously followed by treatment with a coupler solution. If desired, positive images can be prepared by thermophotographic means, using an imagewise thermal exposure followed by an overall exposure to activating radiation for the complex (i.e. radiation to which the phosphineazide complex is sensitive). Heat fixation is not required but heating can be used to effect image intensification if desired. Additionally, where the azide of the complex is a polymeric azide or where the coupler is a polymeric coupler, lithographic surfaces can be prepared.

DESCRIPTION OF PREFERRED EMBODIMENT(S) In accordance with the present invention, there are presented new photographic compositions including radiation-sensitive complexes of a triorganophosphine with an organoazide. As used herein, the term radiation sensitive described sensitivity to electromagnetic rays including X-rays, ultraviolet rays, visible light and the like. The phosphine-azide complexes described herein are chemical complexes that; on exposure to activating rays for the complex, yield a species that can react with a coupler to form an image dye.

A wide variety of triorganophosphines (i.e. phosphines having three organic chemical substituent groups) are useful in forming radiation-sensitive complexes of the present type. In general, any triorganophosphine that will form such a complex with an organoazide is useful. Determination of such utility can be accomplished conveniently by simple screening. For example, any triorganophosphine can be codissolved with an organoazide of the types recited elsewhere herein (i.e. p-morpholinophenylazide and/or 4- azidobenzenesulfonamide) usually in equivalent molar quantities or with a slight excess of phosphine and with a fi-naphthol dye-forming coupler, e.g. 2-naphthol, 2,3- naphthalenediol, etc., to form a solution which can be coated onto a support, dried in a layer and thereafter exposed to activating radiation (i.e. rays to which the complex is sensitive) to form a photographic image which is visible or is intensifiable to a visible image. If this image, when visible, is different in color and/or intensity from the photographic image that is formed wherein:

each of R, R and R independently represents one of either an alkyl group and preferably lower alkyl, an alkoxy group and preferably lower alkoxy, an aryl group and preferably phenyl, or an amino group having the formula wherein:

R represents one of either an alkyl group or an aryl group, and R additionally represents a group having the formula wherein:

n represents a positive integer having a value of from 1 to about 18 and each of R and R is as previously defined.

As used herein the term alkyl group includes substituted or unsubstituted, straight and branched chain alkyl groups having from 1 to about 8 carbon atoms in the aliphatic chain used as a basis for establishing the nomenclature for such group. Representative alkyl groups include. for example methyl groups, ethyl groups, 2-chlorocthyl groups, n-propyl groups, isopropyl groups, n-butyl groups, tert-butyl groups, pentyl groups. hexyl groups, heptyl groups, n-octyl groups, tert-octyl groups, etc. The term alkoxy group as herein defined, includes alkoxy groups the alkyl moiety of which has from 1 to about 8 carbon atoms and corresponds to the alkyl groups recited immediately hereinabove. The term lower alkyl group or lower alkoxy group refers to such alkyl or alkoxy groups having from 1 to 4 carbon atoms in the aliphatic chain used as a basis for establishing the chemical nomenclature for any such group.

Aryl group, as herein defined, includes substituted or unsubstituted mono and polycyclic aromatized carbocyclic groups having, from 6 to 14 atoms in the nucleus, e.g., phenyl, p-chlorophenyl, 4-methylphenyl, naphthyl, anthryl, etc., with phenyl being preferred.

Especially desirable triorganophosphine compounds include triphenylphosphine tris(3-methylphenyl)phosphine P,P-diphenyl-P-methylphosphine tris(4-methylphenyl)phosphine trimethylphosphine P,P-diphenyl-P-ethoxyphosphine P,P-dimethyl-P-phenylphosphine P-pentafluorophenyl-P,P-diphenylphosphine butyldimethoxyphosphine tris(n-butyl)phosphine tris(dimethylamino)phosphine tris(n-octyl)phosphine tris(diphenylamino)phosphine P-methyl-P,P-diphenylphosphine tris(4-chlorophenyl)phosphine tris(4-methoxyphenyl)phosphine triethoxyphosphine l,2-bis(diphenylphosphino)ethane l,4-bis(di-n-butylphosphino)butane l,8-bis(di-4-chlorophenylphosphino)octane According to this invention, at least one triorganophosphine is chemically combined with an organoazide to form radiation-sensitive phosphine-azide complexes. Such complexes form under ambient conditions when the triorganophosphine and organoazide are brought into intimate contact such as by codissolving them in a suitable solvent. As with the triorganophosphine, a wide range of organoazides are useful, and the operability of any particular azide can be established by the convenient procedure outlined hereinabove with respect to the screening of triorganophosphines. In this instance, however, an operator would codissolve the azide in question with a phosphine that is known to operate in the present compositions, elements and processes, e.g. triphenylphosphine.

Desirable organoazides (i.e. organic azides) include a large variety of radiation-sensitive compounds that have been used heretofore in photographic printout compositions of the type that includes the azide and a dye-former that reactswith the azide upon exposure to activating rays to form a dye in exposed regions. Certain such azides include most of the aryl azides, aminoarylazides, and heterocyclyl azides described in U.S. Pat. No. 3,062,650 and U.S. Pat/No. 3,282,693. Azides useful as photosensitizers for polymers are also useful herein. Such photosensitizers can be the same as or different from the azides useful in printoutmaterials and they are described in some detail in Kosar, Light- Sensitive Systems," John Wiley & Sons, Inc, New York 1965) especially at pp 330-336 (including footnotes). Still other descriptions of useful organic azides appear in U.S. Pat. Nos. 2,940,853; 3,061 ,435, and 3,143,417. With regard to heterocyclyl azides, it is preferred that the azido group is not substituted on the heterocylic ring at a position ortho to a hetero ring atom. Other advantageous azides include polymeric azides such as those described in US. Pat. Nos.

3,002,003 and 3,096,311.

Particularly useful organoazides include such materials as the following;

4-azidobenzenesulfonamide ethyl 4-azidobenzoate ethyl 2-azidobenzoate 4-azidobenzoate 3-azidobenzoic acid 4-azidobenzenearsonic acid 4-azidobenzamide 4-azido-N-methylacetanilide 4-azidobenzophenone 2-(4-azidophenyl)-6-methylbenzothiazole 3-azido-a,a,a-trifluorotoluene 3-azido-4-chloro-a,a,a,-trifluorotoluene 4-azidobenzonitrile 3-hydroxypropyl 4-azidobenzoate phenyl 4-azidobenzoate 2-(3-hydroxynaphthyl)4-azidobenzoate 4-methyl-N-phenyl-4-azidobenzamide N-( 2,6-dimethylphenyl)-4-azidobenzamide 4-azidobenzopiperidide N-( l-naphthyl)-4-azidobenzamide N-(pentatluorophenyl)-4-azidobenzamide phenyl 4-azidophenylsulfonate 2,4,6-trichlorophenyl 4-azidophenylsulfonate N-(4-azidophenylsulfonyl)phthalimide 4-azidobenzophthalimide N-phenyl-N-methyl-4-azidophenylsulfonamide N-(4-azidophenylsulfonyl)-piperidine N-(2,6-dimethylphenyl)-4-azidophenylsulfonamide N-(4-azidophenylsulfonyl)succinimide N-(6-azido-2-naphthylsulfonyl)piperidine N-methyl-N-phenyl-2-azidonaphthalene-6- sulfonamide phenyl 6-azidonaphthalene-2sulfonate N-(6-azido-Z-naphthylsulfonyl)succinimide N-(6-azido-2-naphthylsulfonyl)phthalimide l-azido-2,4,6-trichlorobenzene 2-azido-3-nitrobenzene 4-azidobenzoic acid 3-azidophthalic anhydride 4-azidocinnamic acid 3-azidobenzenesulfonamide 2-azido-9-fluorenone l-azido-5-methoxynaphthalene 2-(4-azidophenyl)-5-phenyloxazole 4'-azido-4-chlorochalcone 2-(4-azidophenyl)benzoxazole l-azidonaphthalene 2-phenyl-5-(4-azidophenyl)oxazole 2-(4-azidobenzylidene)-3,4-dihydro-2H-1- naphthone 4-azidochalcone I N-(4-azidobenzylidene)-4-chloroaniline 2-(4-azidophenyl)benzimidazole l-azido-2,4-dichlorobenzene 2-(3*azidophenyl)-5-phenyloxazole 4,4'-diazido-3,3'-dimethoxybiphenyl 2-azidophenetole 4-azidophenetole trimethylene bis(4-azidobenzoate) bis(4azidophenyl)disulfide b 4-azido-3,S-diethoxybenzanilide: N-methyl-4-azidoacetanilide 4-azidophenyl sulfide 4-azido-3-nitroanisole N-(3-azidophenylsulfonyl)succinimide 4-azido-3,5-dimethoxyphenylmorpholine 3-azidoquinoline Z-azidocarbazole 2-azidobenzoic acid 4-azidophenoxyacetic acid N-methyl-N-octadecyl-4-azidoaniline l azido-4-bromonaphthalene bis(4-azidophenyl)ether 4-azidoazobenzene N-(4-azidophenyl)-N-methylmo:rpholinium tetrafluoroborate 4-azido 4-toluenesulfonanilide 4-azidobenzenesulfonic acid l-azido-4-methoxynaphthalene 4-azidostyryl l-naphthyl ketone 3-(4-azidophenyl)coumarin l,2,3,4,5,6,-hexa(4-azidobenzoxy)hexane 4,4-diazidodibenzalacetone 1azido-2,4,6-tribromobenzene 4-azidoacetanilide 2-azidodiphenyl ether 2,5-bis(4-azidophenyl)oxazole 2-(4-azidophenethyl)-5-phenylo:xazole 2-(4-azidophenethyl)benzoxazole 4,4'-diazido-2,2-stilbenedi(N,N-dibutylsulfonamide 2,6-di(4azidobenzal)-4-methylcy'clohexanone poly(vinyl acetate-co-4-azidobenzoate) l-azido-3-cyano-4-methoxybenzene l-azido-3-cyano-4-morpholinobenzene N-(4azido-2-cyanophenyl)piperidine N-butyl -4-azido-2-cyanoaniline N,N-diethyl'4-a2ido-2-cyanoaniline N,N-dibutyl-4-azido-Z-cyanoaniline N'-hydroxyethyl-4-azido-2-cyanoaniline N,N-diethyl-4-azido-2-chloroaniline 4-azidodiphenylamine 4-azido-Z-cyanodiphenylamine 4-azido-2-cyano-4'-methoxydiphenylamine 4-azido-2-cyano-4-dimethylaminodiphenylamine 1-azido-2-methoxy-4-morpholinobenzene l-azido-3-methoxy-4-morpholinobenzene N-methyl-4-(4-azidophenyl)-2,6-diphenylpyridinium perchlorate N-methyl-4-(4-azidostyryl)-2,6diphenylpyridinium perchlorate, and 2,5-bis-(4-azidophenyl) oxadiazole In another aspect of the present invention, the trimganophosphine can be replaced by a precursor for such phosphine to prepare stable image forming compositions. Image-forming compositions and elements of this invention are distinguished from the subject photographic compositions and elements in that the imageforming counterparts do not contain the radiationsensitive phosphine-azide complex as prepared, it being formed therein at a subsequent time as desired. Especially desirable phosphine precursors are those which, on chemical treatment, e.g. on treatment with base,

yield a triorganophosphine that can form a radiationsensitive complex with an azide such as those described herein. since these image-formingcompositions are not substantially radiation-sensitive prior to liberation of the phosphine, their sensitivity being limited to that of the low speed azide, they enjoy an extremely high storage stability. Once the phosphine is released, such as by means of chemical treatment, the radiation-sensitive phosphine-azide complex forms spontaneously in situ and the activated composition can be used to prepare photographic images according to the procedures described herein.

A preferred class of phosphine precursors are phosphonium salts from which the corresponding triorganophosphine is easily released by treatment with base, e.g.

fuming with ammonia. A wide range of. useful phosphonium salts include those described in a patent application of Reynolds entitled Image-Forming Compositions Including Phosphonium Salts, filed concurrently as U.S. Ser. No. 168,395, now abandoned the complete disclosure of which is incorporated by reference. Exemplary phosphonium salts useful herein include cyclohexanon-3yltriphenylphosphonium chloride 2-methylcyclohexanon-3-yltriphenylphosphonium tetrafluoroborate cyclohexanon-3-yltri-p-tolylphosphonium chloride 2-methylcyclohexanon-3-yltri-p-tolylphosphonium perchlorate 2-ethoxycarbonylethyltriphenylphosphonium tetrafluroborate 2-ethoxycarbonylethyltri-p-tolylphosphonium bromide 3-oxobutyltriphenylphosphonium tetrafluoroborate 4-oxopent-2-yltriphenylphosphonium chloride 3-oxo-l-phenylbutyltriphenylphosphonium perchlorate 3-oxobutyltri-p-tolylphosphonium chloride 4-oxopent-2-yltri-p-tolylphosphonium bromide 3-oxo-l-phenylbutyltri-p tolylphosphonium bromide a-benzoylmethylbenzyltriphenylphosphonium tetrafluoroborate a-benzoylmethylbenzyltri-p-tolylphosphonium chloride Another preferred class of phosphine precursors from which triorganophosphine can be released by treatment with base are certain stable transition metal complexes of triorganophosphines. They are described in detail in a patent application of Nelson entitled -Image Forming Compositions Including Transition Metal Complexes," filed concurrently and now U.S. Pat. No. 3,764,335.

The photographic and image-forming compositions can, if desired, contain a polymeric carrier vehicle. Advantageous carriers include film-forming, substantially hydrophobic polymers that can be coated using organic solvents, but which are sufficiently permeable to bases including gasses and liquids so as not to restrain either convenient phosphine release from a precursor or image dye development. Especially useful such carrier or binder vehicles include polymers like, for example, cellulosic compounds such as ethyl cellulose, butyl cellulose, as well as cellulose esters like cellulose acetate, cellulose triacetate, cellulose butyrate, cellulose acetate butyrate, etc; vinyl polymers such as poly(vinyl acetate), poly(vinylidene chloride), poly(vinyl butyral), copolymers of vinyl chloride and vinyl acetate, polystyrenes, poly(methyl methacrylate) homopolymers or copolymers of acrylamides, copolymers of alkylacrylates and acrylic acid, etc., such as poly(N-isopropylacrylamide) poly(diacetone acrylamide) copoly(diacetone acrylamide/N- isopropylacrylamide) copoly(methacrylamide/N-isopropylacrylamide) copoly(N-isopropylacrylamide/1-vinyl-2- pyrrolidone) copoly(methyl methacrylate/methacrylic acid) copoly(butyl acrylate/acrylic acid) as well as additional polymers such as poly(phenylene oxides), terpolymers of ethylene glycol, isophthalic acid and terephthalic acid, terpolymers of pcyclohexanedicarboxylic acid, isophthalic acid and cyclohexylenebismethanol, copolymers of pcyclohexanedicarboxylic acid and 224,4-

tetramethylcyclobutane-l,3-diol, and additional polymers such as, for example, the condensation product of epichlorohydrin and bisphenol-A.

The photographic or image-forming compositions of this invention can also'include a dye-forming coupler which, it is theorized, reacts with a photolytic product of the phosphine-azide complex to form a dye in exposed regions. If used, the coupler is usually present in a molar amount substantially equivalent to the amount of phosphine-azide complex, or in a slight excess, e.g. 5-10% molar, to insure maximum dye formation.

Couplers that are advantageous herein include couplers of the type used in two-component diazotype compositions. Such couplers are described in the literature, for example in Kosar Light-Sensitive Systems,John Wiley & Sons, New York (1965), especially at pp 220-240. Especially desirable couplers are recited in U.S. Pat. No. 3,573,052, especially at column. 6, line 17 to column 7,line 20. Representative couplers of this type include 2,3-naplithalene diol 2-hydroxy-3-naphthanilide 2-hydroxy-2-methyl-3-naphthanilide 2-hydroxy-2',4-dimethoxy-5'-chloro-3- naphthanilide 2-hydroxy-2,4'-dimethoxy-3-naphthanilide 2-hydroxy-2,5'-dimethoxy-4'-chloro-3- naphthanilide 2-hydroxy-l '-n aph thyl-3-naphthanilide 2-hydroxy-2'-naphthyl-3-naphthanilide 2-hydroxy-4-ch loro-3-naphthanilide 2-hydroxy-3-naphthanilide 2-hydroxy-2',5 -dimethoxy-3anaphthanilide 2-hydroxy-2,4'-dimethyl-3-naphthanilide l-hydroxy-Z-naphthamide N-methyll -hydroxy-2-naphthamide N-butyl-l -hydroxy-2-naphthamide N-octadecyl- 1 -hydroxy-2-naphthamide N-phenyll -hydroxy-2-naphthamide N-methyl-N-phenyl-l-hydroxy-2-naphthamide N-(2-tetradecyloxyphenyl)-l-hydroxy-2- naphthamide N-[4-(2,4-di-tert-amylphenoxy)butyl]-lhyclroxy-2- naphthamide l-hydroxy-2-naphthopiperidide N-(3,S-dicarboxyphenyl)-N-ethyl-l-hydroxy-2- naphthamide N,N-dibenzyl-l-hydroxy-Z-naphthamide N-(2-chlorophenyl)-l-hydroxy-2-naphthamide N-(4-methoxyphenyl)-l-hydroxy-2-naphthamide l-hydroxy-2-naphthopiperizide l,3-bis( l -hydroxy-2-naphthamido)benzene 2-acetamido-5-methylphenol Z-acetamido-S-pentadecylphenol 2-butyramido-5-methylphenol 2-(2,4-di-tert-amylphenoxyacetamido)-5- methylphenol 2-benzamido-5-methylphenol Still other useful couplers include those which contain a reactive methylene or methine group, such as those described in U.S. Pat. No. 3,062,650, especially at column 4, line 8 to column 4, linee 27. This type of coupler, e.g. 3-methyl-l-phenyl-5-pyrazolone, is particularly useful when the organoazide has an amino group substituted on the organic residue, as in the case of an aminoarylazide. Preferably, such aminoarylazides are 4-amino-l-azidobenzene compounds or derivatives.

The photographic compositions of this invention are conveniently prepared, for example, by codissolving at least one triorganophosphine and at least one organoazide. Desirable solvents include a wide range of organic media such as methyl ethyl ketone, methylene chloride, acetone, lower alkanols, dichloroethane, tetrahydrofuran, toluene, etc., either alone or in combination. In the solution, the ratio of phosphine to azide can be varied widely, but it is preferred that the phosphine be included in a slight molar excess, e.g. from 5-l0%, to in-' sure that substantially all azide is complexed. Without substantially complete azide complexing background stabilization is impaired. Image-forming compositions are prepared in a like manner except that the phosphine precursor is included in lieu of the triorganophosphine.

Photographic and image-forming elements utilizing the photographic and image-forming compositions of this invention are conveniently prepared by coating such compositions onto a support material. Advantageous support materials include conventional photographic film base materials like cellulose esters such as cellulose acetate, cellulose triacetate, cellulose acetate butyrate, etc.; poly-a-olefins typically having from 2to carbon atoms like polyethylene, polypropylene, and polystyrene; polyesters such as poly(ethylene terephthalate); polycarbonates as well as metals such as zinc and aluminum and paper including polyethylene and polypropylene coated papers. Other support materials that are suitably used herein are known in the art.

Coating is typically by solvent coating means, since t off rs t e. qten lfqtraizis .wn n snt Continuous operation. Coating is effected by first dissolving components of the photographic or image-forming composition in a suitable solvent, such as those described herein, along with a matrix polymer if desired. Exemplary matrix polymers are described hereinabove. The coating solution conventionally contains from about 5 to about 20 weight percent solids, and preferably from about 8 to about percent solids. In that solution, if a matrix polymer is utilized, the image-forming components are typically included in an amount of from about to about 50 parts of weight per 100 parts of polymeric binder, with concentrations in the range of from about to about parts per 100 parts of matrix polymer eing preferred. Wider variations are possible where desired, but the above-mentioned ratios are typical for most conventional preparations. After coating by such means as immersion, whirler coating, brushing, doctor blade coating, hopper coating or the like, typically at a wet thickness of from about 0.001 inches to about 0.02 inches, the coated material is dried to prepare a composite photographic or image-forming element of this invention. The subject photographic elements are radiation-sensitive and, without further treatment, can be imagewise exposed to activating rays for purposes of image preparation. The selection of appropriate exposing rays will depend on the spectral response for the particular phosphine-azide complex. Characterization of appropriate exposing rays can be readily determined by preparation of wedge spectrograms for the phosphine-azide complex in question. Generally, however, the region of spectral response will include ultraviolet and other actinic rays so that exposure by means of a mercury arc lamp, which is rich in U.V. rays, or a similar exposure source is appropriate. Numerous diazo copiers and other commercially available photocopying apparatus incorporate exposure stations which include radiation sources emitting in the U.V. As a general rule these are quite satisfactory for exposing compositions and elements of this invention.

It is noted that the radiation-sensitivity of the phosphine-azide complexes described herein should not be equated to the known sensitivity of aryl azides such as those used in vesicular photography or other photographic systems. Such compounds are known to exhibit low photoreactivity, whereas the radiation-sensitive complexes of this invention exhibit a relative photographic speed about ten times that of a comparable non-complexed azide.

As noted herein, the subject image-forming compositions and elements are activated to yield a triorganophosphine and form the phosphine-azide complex by chemical treatment including treatement with base. Generally, any of the bases useful :ln initiating coupling in diazotype reproduction media, eg. ammonia, organic amines and other organic nitrogen bases, are suitable herein to release the phosphine from its precursor. A range of such bases is described in Kosar, cited hereinabove, as well as in the patent literature, for example U.S. Pat. No. 3,578,452, Canadian Patent No. 772,109, etc. It is preferred that the base have a pH of at least about 8 so that activation is obtained rapidly. Treatment can be accomplished by immersion in a solution of the base, by fuming with vapors of the base, etc.

When the sensitive phosphine-azide complex of a photographic composition or element or suitably activated image-forming composition or element is exposed to activating rays, and if a coupler is included in the composition or element that is so exposed, an image forms in exposed regions. Usually, this is a readily visible dye image which can vary in optical density depending on the particular formulation. ln certain cases, the image may be a latent image that is not easily visible or is not visible at all. It is theorized that the dyeforming reaction is promoted by the imagewise release of hydroxyl ions and ammonium hydroxide on exposure of the phosphine-azide complex. It is theorized further that this liberation is due to reaction of a phosphinimine anion that is formed on exposure with water that is inherently present in the composition or element.

Subsequent to an image-defining exposure, the composition or element is preferably heated to a temperature sufficient to stabilize non-image regions against printup (i.e. to stabilize the photographic image). It is theorized that on heating, the phosphine-azide complex rearranges to form a stable, substantially colorless phosphinimine. Where the image after exposure either is of low optical density or is a latent image, the heat stabilization treatment simultaneously effects an image intensification such that it is readily viewable by eye. Stabilization heating is generally accomplished at temperatures of at least about 60C, with temperatures up to about 130C being useful for most situations. It will be recognized that the support or any components should not be deliteriously affected by heating, but higher temperatures require shorter fixation times. The duration of the heat fixing step is variable, depending on factors like fixation temperature, etc. Usually, times of from about seconds to 2 minutes are sufficient. Heating'can be carried out conveniently, such as by contact with a suitably heated surface, insertion into a heated chamber or the like.

In cases where no coupler is present in the composition or element, exposure of the phosphine-azide complex is desirably followed by treatment of the composition or element with one or more couplers of the types described herein to promote image formation. A dense dye image will then form spontaneously, or an intensifiable image of the type noted herein will result. As an example of useful treatment methods, a coupler solution can be contacted against the composition or element by such means as immersing the composition or element therein, swabbing or spraying the solution over the composition or element, or by a similar means. After such treatment, the composition or element can be washed and/or dried or drying can be accomplished simultaneously with heat stabilization.

In one embodiment of the invention, a base can be included in an image-forming composition or element, in lieu of the phosphine precursor. Useful bases include, for example N,N,N',N'-tetramethylethylene diamine, as well as a wide variety of other organic amines and nitrogen containing organic compounds. Activation to form the phosphine-azide complex is then accomplished by treatment with a phosphine precursor such as those described herein. Treatment is easily carried out by using a solution of the precursor according to methods like those discussed previously with reference to coupler treatment.

In yet another embodiment of this invention, an image'forming composition that includes a phosphine precursor, a radiation-sensitive azide of the type described in U.S. Pat. NO. 3,062,650wherein an amino group is present thereon, e.g. a p-disubstitutedaminophenylazide, and a coupler that is reactive with such an azide, multiple images such as two-color dye images can be prepared as follows: The composition is given a first imagewise exposure with activating radiation for the azide, i.e., radiation to which the azide is sensitive. A visible dye image forms on exposure. The composition is then activated by chemical treatment such as by contact with base (eg by fuming with ammonia vapor) to release triorganophosphine from the precursor and form the phosphine-azide complex and thereafter is given a second imagewise exposure with activating radiation for the complex, i.e., radiation to which the complex is sensitive. Since the complex is a different chemical species from the azide, it can have a different spectral absorption envelope. Accordingly, each exposure may require the use of a different radiation source, although ultraviolet rays will generally suf- I fice. On the second exposure, an image forms in exposed regions. It will be appreciated that this second dye image may, in certain cases, be intensifiable as discussed herein. This second image, when'visible, is preferably of a different color from the image formed on the first exposure. Heat stabilization is then accomplished, and this also effects image intensification of the second dye image if it is of a low optical density. If the concentration of azide is sufficient, and the first exposure is not so intense that all azide is photolized in regions of exposure, then remaining azide in such regions will complex with the phosphine on activation with base and the second exposure will produce a second dye in areas that are common to each exposure.

As discussed previously, the compositions and elements of this invention are useful in preparing negative images, i.e. images corresponding to regions of irradiation. They can also be processed by thermophotographic techniques to prepare positive images. i.e. images corresponding to non-irradiated regions. A photographic composition or element, or an image-forming composition or element which has been activated to form a phosphine-azide complex therein, is given an imagewise thermal exposure -to stabilize such regions against printup. Thereafter, it is overall exposed to activating radiation for the complex to prepare a visible or intensifiable dye image. If no coupler is present in the element, image development will also include treatment with a coupler solution as described elsewhere herein.

In still another embodiment of this invention, lithographic surfaces are prepared in exposed regions when the azide used is a hydrophilic polymeric azide like those described in U.S. Pat. No. 3,002,003 and other references cited therein. Lithographic surfaces can also be prepared when the coupler is a hydrophilic, polymeric coupler such as a polymeric pyrazolone. Desirably, the azide used with the polymeric coupler is a his azide. After exposure and subsequent process steps as described herein, the developed surface is wet with water which is accepted in unexposed areas. Greasy printing inks are transferable from exposed regions which comprise the printing surface.

The following examples are included for a further understanding of the invention.

EXAMPLE 1 A solution of l-azido-4-morpholinobenzene (0.2 g), 4-methoxy-l-naphthol (0.2 g) and triphenylphosphine (0.25 g) is prepared in 20 ml of a 4% solution of poly(- vinyl butyral) in methyl ethyl ketone. This solution is whirl coated on aluminum and exposed imagewise to the ultraviolet rich rays of a 250 Watt high pressure mercury vapor lamp, yielding a purple printout image. The unexposed areas are then stabilized by heating the plates to C for 1 minute.

EXAMPLE 2 A solution of 4-azidobenzenesulfonamide (0.2 g), 2,3-naphthalenediol (0.2 g), and cyclohexanon-3-yltriphenylphosphonium chloride (1.0 6) in 30 ml of a 10% cellulose acetate butyrate solution in methylene chloride is doctor blade coated at a thickness of 0.006 inch on poly(ethylene terephthalate) support and dried. The resultant element is then exposed to NH vapor. Thereafter, the image-forming element is exposed through a silver negative at 20 ft./minute in the exposing unit of a Model 22,000 Ozalid machine marketed by Ozalid Corporation. The machine contains a 1200 Watt high pressure mercury-vapor lamp as an exposure source. The resulting yellow-orange image is heated at C for 10 seconds to produce a stable, fixed print.

EXAMPLE3 A solution of l-azido-4-(2-benzimidazolyl)benzene (0.05 g) triphenylphosphine (0.10 g) and 4- methoxynaphthol (0.05 g) is poured onto a filter paper and dried. The paper is then exposed imagewise to a 500 Watt infrared lamp for 10 seconds through and in contact with a silver negative. The entire sheet is then irradiated with UV. light to produce a dye image in the thermally unexposed areas.

EXAMPLE 4 A solution of p-morpholinophenyl azide (0.15 g), a coupler, 2,4-dichloro-6-(2,4-dipentylphenoxyacetamido)-3 methylphenol (0.2 g) and P-(2-acetyll-phenylethyl)P,P,P-triphenylphosphonium tetrafluoroborate (0.8 g) is prepared in 15 ml of acetone. This is added to 15 ml of a 10 percent solution of cellulose acetate butyrate in dichloroethane and the mixture is doctor blade coated on poly(ethylene terephthalate) film support at a wet thickness of 0.006 inch. The resulting image-forming element is first exposed on a Model 22,000 Ozalid machine at ft./minute to form a blue dye image in exposed areas. The element is then contacted with moist ammonia vapor at 50C for seconds to liberate phosphine from the phosphonium salt precursor, and reexposed in the Ozalid copier at ft./minute to produce an orange dye image in the newly exposed areas. The background regions are stabilized by heating to 110C for 5 seconds, producing a pale pink background. Other useful bases that can be used to liberate the phosphine and activate thecomposition include aqueous solutions of an organic base such as those described in US. Pat. No. 3,578,452.

Using techniques as described in Example 4, but coating a radiation-sensitive layer on each side of a transparent support which has a substantially colorless U.V. absorber contained in the support or in a separate layer or otherwise positioned between the support and one of the radiation-sensitive layers, it is possible to form four-color elements that can be viewed conveniently. Processing is as in Example 4, except that the appropriate exposures are desirably doubled to expose separately the radiation-sensitive materials present on each side of the support.

EXAMPLE 5 A coating solution is prepared from 0.15 g of 4-4- bis(azido)-3,3-dimethoxybiphenyl, 0.3 g of 2,3- naphthalenediol, 10 drops of N,N,N, N-tetramethylethylenediamine, 3 drops of formaldehyde, 15 ml of an 8.8 percent solution of copoly(N-isopropylacrylamideacrylamide-Z-acetoacetoxyethyl methacrylate) (Mole ratio 2:7:0.5) in a 1:1 by volume mixture of acetone and ethanol, and 15 ml of acetone. The mixture is doctor blade coated on poly(ethylene terephthalate) film support at a wet thickness of 0.006 inch and dried. A portion of the resultant element is dipped in a 10 percent solution of cyclohexanon-3-yltriphenylphosphonium chloride in water. The coating dipped portion is then dried, exposed at a setting of 3 on a Model Brunning Copier, marketed by the Charles Bruning Division, Addressograph Multigraph Corporation, and heated at l 10C to stabilize the winecolored dye image. The portion of the coating not dipped into the phosphonium salt solution produces no image at all when exposed and heated in a like manner.

The invention has been described in detail with paraticular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

There is claimed:

1. An image-forming composition comprising in admixture a radiation-sensitive organoazide which is one of either an aryl azide or a heterocyclyl azide and a triorganophosphine precursor which, on treatment with base, liberates a triorganophosphine that can form a radiation-sensitive complex with the azide.

2. An image-forming composition as described in claim 1 and further comprising a polymeric binder material.

3. An image-forming element comprising a support having coated thereon a layer comprising an imageforming composition as described in claim 1.

4. An image-forming element as described in claim 3 and further comprising a binder material in said imageforming composition.

5. An image-forming composition comprising a radiation-sensitive organoazide which is one of eitherv an aryl azide or a heterocyclyl azide and a triorganophosphine precursor which, on treatment with base, yields a triorganophosphine that can form a radiationsensitive complex with the azide, the triorganophosphine that is yielded by said precursor being one that, when codissolved with p-morpholinophenylazide and- /or 4-azidobenzenesulfonamide and a ,B-naphthol azodye-forming coupler, forms a composition which can be dried in a layer and imagewise exposed to activating radiation to form a photographic image, that, when visible, is different in color and/or intensity from the photographic image that is formed when a similar composition, but without the triorganophosphine, is dissolved, dried and exposed in the same manner.

6. An image-forming element comprising a support having coated thereon a layer comprising an image-

Claims

1. AN IMAGE-FORMING COMPOSITION COMPRISING IN ADMIXTURE A RADIATION-SENSITIVE ORGANOAZIDE WHICH IS INE OF EITHER AN ARYL AZIDE OR A HETEROCYCLYL AZIDE AND A TRIORGANOPHOSPHINE PRECURSOR WHICH, ON TREATMENT WITH BASE, LIBERATES A TRIORGANOPHOSPHINE THAT CAN BE FORM A RADIATION-SENSITIVE COMPLEX WITH THE AZIDE.

3. An image-forming element comprising a support having coated thereon a layer comprising an image-forming composition as described in claim 1.

4. An image-forming element as described in claim 3 and further comprisinG a binder material in said image-forming composition.

5. An image-forming composition comprising a radiation-sensitive organoazide which is one of either an aryl azide or a heterocyclyl azide and a triorganophosphine precursor which, on treatment with base, yields a triorganophosphine that can form a radiation-sensitive complex with the azide, the triorganophosphine that is yielded by said precursor being one that, when codissolved with p-morpholinophenylazide and/or 4-azidobenzenesulfonamide and a Beta -naphthol azodye-forming coupler, forms a composition which can be dried in a layer and imagewise exposed to activating radiation to form a photographic image, that, when visible, is different in color and/or intensity from the photographic image that is formed when a similar composition, but without the triorganophosphine, is dissolved, dried and exposed in the same manner.

6. An image-forming element comprising a support having coated thereon a layer comprising an image-forming composition as described in claim 5.