Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
  • G03C1/00—Photosensitive materials
  • G03C1/52—Compositions containing diazo compounds as photosensitive substances
  • G03C1/60—Compositions containing diazo compounds as photosensitive substances with macromolecular additives

Definitions

• the manufacture of light-sensitive diazotype materials involves the application to a suitable base of a sensitizing solution comprising one or ore stabilized light-sensitive diazonium compounds.
• a sensitizing solution comprising one or ore stabilized light-sensitive diazonium compounds.
• the latter are characterized in that upon exposure to actinic radiation they undergo a photolytically induced decomposition being thus rendered incapable of coupling with an azo dye coupling component.
• a pattern e.g., photographic transparency, line drawing or the like, whereby the light-sensitive diazonium compound is decomposed imagewise in accordance with the light transmitted by the pattern.
• a positive dye image is formed by subjecting the element thus exposed to an alkaline environment, preferably an ammonia atmosphere, to initiate the coupling reaction by the undecomposed diazonium and coupler.
• Two-compartment diazotype materials are in general preferred since the requirement for the use of an aqueous, coupler-containing developer composition is obviated. This, of course, presents several processing advantages including, for example, the elimination of the manifold problems associated with loss of sensitizing component, stabilizer, etc.,'via diffusion into the aqueous de veloper solution. Accordingly, the two-component process makes possible the obtension of reproductions characterized by superior dye density, brightness, image quality and the like.
• two-component diazo sensitizing solutions are prepared in an aqueous media maintained under an acid pH.
• a considerable number of the coupling components conventionally employed exhibit a somewhat limited solubility in the aqueous sensitizing media with the consequence that the range of selection of available coupling components is correspondingly circumscribed.
• the problem of limited water solubility has likewise been encountered in connection with the lightsensitive diazo compound as well, and particularly the paraaminobenzene diazonium salts which contain oleophilic substituents such as alkyl.
• xanthine compounds of the aforementioned type function not only to abate considerably the above described solubility problems, but in addition, in many instances function as stabilizers, i.e., enhance the keeping quality of the two-component diazotype materials probably by retardation of premature coupling.
• a primary object of the present invention resides in the provision of solubilizing synergists for twocomponent diazo sensitizing compositions wherein the problems associated with difiicultly soluble diazo and/or coupling components are eliminated or at least mitigated to a substantial extent.
• Another object of the present invention resides in the provision of diazo sensitizing compositions characterized by outstanding capacity to yield photographic images having improved image dye density, brightness, contrast and the like.
• a further object of the present invention resides in the .provision of diazotype photoprinting elements having exceptional resistance to pre coupl-ing.
• R R R and R are independently selected from the group consisting of hydrogen, lower alkyl of 1-4 carbon atoms, e.g., methyl, ethyl, propyl, isobutyl, etc., aryl, e.g., phenyl, naphthyl, etc., aralkyl, e.g., benzyl, alkaryl, e.g., tolyl, xylyl, etc, and cycloalkyl, e.g., cyclohexyl, cyclopentyl, etc., and the like; the foregoing groups may, of course, contain further substituents the nature of which is not particularly critical with the obvious qualification that the coupling reaction mechanism be not adversely aifected.
• the compounds included by the above formula should be devoid of such groups as NO NH and SO H.
• Two-component diazo sensitizing compositions modified in accordance with the present invention are found to be characterized not only by a mere uniform dispersion of the involved ingredients but in addition by a marked increase in resistance to pre-coupling.
• a particularly surprising discovery relates to the fact that the above described combination of solubilizing synergists can be employed in any two-component diazo sensitizing composition, i.e., regardless of the solubility of the diazo coupler, stabilizer, etc., whereby there is provided a more compatible sensitizer media having exceptional stability even under high humidity storage conditions.
• the solubility-promoting effects are particularly beneficial in connection with two-component diazo sensitizing compositions containing one or more difficulty soluble coupling and/ or diazo components.
• Hydantoin 5,5-dimethyl hydantoin l-ethyl hydantoin 1,5-dimethyl hydantoin, etc.
• the above compounds may be added to the sensitizing medium in a wide range of proportions so long as sufficient amounts be present to impart the desired degree of solubilization.
• optimum realization of improvements provided herein is obtained when utilizing the imidazoledione compound in amounts ranging from about 0.5% to about 3.0% and preferably from about 1% to about 2% by weight based on the total weight of sensitizing solution.
• the proportions selected will be infiuenced, of course, by a number of factors in addition to the solubility of the coupling component.
• the water solubility of the remaining components e.g., diazo compound, stabilizer, etc.
• the relative concentrations of each of such ingredients e.g., optimum concentrations in a particular circumstance can be readily ascertained by routine laboratory experimentation. It will be understood, of course, that mixtures of two or more of the imidazoledione compounds may likewise be employed to advantage.
• hydantoin can be prepared by simple hydrolysis of glycollic acid; l-methyl-lhydantoin can be prepared by the partial hydrolysis of ereatinine.
• the xanthine compounds found to be eminently suitable for use in the present invention include, for example, caffeine, theophylline, theobromine, and the like; caffeine is particularly preferred since it appears to possess a relatively high activity, i.e., solubilizing potential.
• the concentration of the xanthine is critical solely from the standpoint of its being present in amounts sufficient to impart the desired degree of solubilization, etc. In general, it is found that the foregoing results can be obtained by employing the xanthine compound in amounts ranging from about 0.5% to about 2.5% by Weight based on the total weight of sensitizing solution with a range of from about 1% to about 2% being preferred.
• the xanthine and imidazoledione components may be preliminarily provided in the form of a compatible solution or conversely, may be added separately to the diazo sensitizing composition.
• any combination of diazo and coupling component may be employed which is suitable for the preparation of two-component diazotype layers, i.e., dry development papers which upon development yield the shade desired for the final image.
• Diazo compounds which are suitable for such two-component materials are known to be those which are derived from 1,2- and 2,1- aninonaphthols, 1,4-aminonaphthols and aromatic p-diamines of the benzene series, particularly p-phenylene diamines which are monoor disubstituted on one of the two amino groups.
• diazo compounds which are commonly used in the production of diazotype images there may be mentioned the diazo derivatives of the following compounds:
• the diazo derivatives of the above mentioned compounds may be employed in the form of their stabilized salts, as exemplified by p-diphenylamine diazonium sulfate or in the form of zinc chloride or boron trifluoride double salts, etc.
• stabilized double salts there may be mentioned the zinc chloride or boron trifiuoride double salts of:
• diazo compound may be employed in the form of the anhydride as exemplified by:
• 2-amino-l-hydroxynaphthalene-4-sulfodiazonium anhydride 2-amino-1-hydroxynaphthalene-S-sulfodiazonium anhydride 1-amino-2-hydroxynaphtha1ene-4-sulfodiazonium anhydride 1-amino-2-hydroxynaphthalene-5-sulfodiazoninum anhydride and their water soluble alkali metal salts.
• Resorcinol- Phloroglucinol 3-hydroxyphenylurea 3-(N-3-aminobenzoyl) aminophenol 3-(N-4-aminobenzoyl) aminophenol 2,3-dihydroxynaphthalene 2,7-dihydroxynaphthalene 2,3-dihydroxynaphthalene-6-sulfonic acid 1-hydroxynaph-thalene-4-sulfonic acid 2-hydroxynaphthalene-3,6-disulfonic acid 1-hydnoxynaphthalene-3,8-disu1fonic acid 2-amino-8-hydroxynaphthalene-3,6-disulfonic acid 2,3-dihydroxynaphthalene-G-carboxylic acid 1-amino-7-hydroxynaphthalene 1-amino-8-hy droxynaphthalene-3,6-disulfonic acid 4-hydroxybenzimidazole hydrochloride 2-hydroxy-7,-8-naphthimidazole hydrochloride S-
• the sensitizing composition may also contain the various adjuncts conventionally employed in the manufacture of light-sensitize diazotype materials including hygroscopic agents, e.g., propylene glycol, one of more acid materials, e.g., citric acid, tartaric acid, tricarballylic acid, phosphoric acid and the like; suitable stabli-lizing or anti-oxidizing agents such as thiourea, allyl, isothiocyanate and the like which function to retard background discoloration on the finished print.
• suitable stabli-lizing or anti-oxidizing agents such as thiourea, allyl, isothiocyanate and the like which function to retard background discoloration on the finished print.
• Metal salts for intensification of the dyestulf image may also be added including zinc chloride, ammonium sulfate, nickel sulfate and the like.
• Suitable wetting agents include without limitation, saponin, lauryl sulfonate, keryl benz
• composition thus formulated may be applied to any suitable base material including paper, metal, as well as materials derived from film-forming synthetic resins, e.g., polyethylene terephthalate.
• suitable base materials include cellulose acetate, cellulose acetate butyrate and the like; textiles including fabrics derived from cotton, cellulose acetate, batiste, regenerated cellulose of the xanthate or viscose type, balloon cloth, knitted rayon jersey, mixed cotton and rayon or other absorbent fabrics, and woven or felted materials which can be impregnated with the diazo solution.
• Example I A two-component diazo sensitizing composition is prepared consisting of:
• the above solution is coated on a paper base and exposed to actinic light under a density step wedge and developed with ammonia vapors in a commercial model of an ammonia developing machine.
• the print obtained shows .a considerable enhancement in dye density and brightness When compared to prints made on paper similarly treated with the above coating solution but containing no caffeine and hydantoin.
• Example II High grade-sulfite bond paper is coated with a sensitizing solution of the following com-position:
• Ethylene glycol mls 5.0 Isopropanol mls 1.0 Citric acid gms 4.0 C-afieine gms 2.0 Thiourea gms 5.0 2,3dihydroxynaphthalene-6-sulf0nic acid gms 4.0
• Example III A diazotype paper stock made of rag paper is coated with an aqueous solution having the following composition:
• Example IV An aqueous solution of the following composition is prepared and applied to a starch-sized cotton cloth:
• Zinc chloride double salt of p-diethyl-amino-2- me'thylbenzenediazoninm chloride 5.0 2,3-dihydroxynaphthalene 8.0
• Citric acid 50.0
• Hydan-toin 10.0
• Zinc chloride 45.0 Saponin 0.1
• Caffeine 10.0
• Example V A solution having the following composition is prepared and coated on a diazotype paper stock made of rag paper:
• Example VI A coating solution having the following composition is coated on diazo stock paper:
• Example V II Example I is repeated except that the caffeine is replaced by theobromine in the same amount.
• the print obtained upon exposure and development reveals similar improvement when compared to the control sample.
• Example VIII Example I is repeated except that the hydantoin is replaced by 1,5-dimethylhydantoin. The prints obtained indicate a like improvement in image reproduction quality.
• a two-component light-sensitive diazo composition comprising a compatible aqueous solution of a lightsensitive diazo compound and a coupling component, said solution further containing as essential ingredients (a) a xanthine compound and (b) an imidazoledione compound of the formula:
• R R R and R are independently selected from the group consisting of hydrogen, lower alkyl, aryl, aralkyl, alkaryl, and cycloalkyl.
• composition according to claim 1 wherein said imidazoledione compound comprises hyd'antoin.
• composition according to claim 1 wherein said imidazoledione compound comprises 1,5-dimethylhydantoin.
• composition according to claim 1 wherein said xanthine compound comprises caffeine.
• composition according to claim 1 wherein said xanthine compound comprises theobromine.
• a two-component light-sensitive diazo composition comprising a compatible aqueous solution of a light-sensitive diazo compound, a diflicu-ltly soluble coupling component, said solution containing as essential ingredients (a) from about 0.5% to about 2.5% by weight based upon the total weight of sensitizing solution of a xanthine compound and (b) from about 0.5% to about 3.0% by weight based upon the total weight of sensitizing solution of an imidazoledione compound of the formula:
• R R R and R are independently selected from the group consisting of hydrogen, lower alkyl, aryl, aralkyl, alkaryl, and cycloalkyl.
• composition according to claim 6 wherein said imidazoledione compound comprises hyd antoin.
• composition according to claim 6 wherein said imidazoledione compound comprises 1,5-dimethylhydantoin.
• composition according to claim 6 wherein said xanthine compound comprises caffeine.
• composition according to claim 6 wherein said xanthine compound comprises theobromiue.
• a diazotype photoprinting material comprising a References Cited daiml p e p 7 2,270,756 1/11942 Kern 96--911XR 12.
• a di-azotype ph'otoprinting material according to 5 $419,296 5010mm 96-91XR claim 11 wherein said base comprises paper. 2,617,726 2" Kessels 3 9675 '13.

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• Spectroscopy & Molecular Physics (AREA)
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• General Physics & Mathematics (AREA)
• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)

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Citations (4)

• 1965
  • 1965-10-19 US US498110A patent/US3386828A/en not_active Expired - Lifetime
• 1966
  • 1966-09-15 CH CH1333966A patent/CH483656A/de not_active IP Right Cessation
  • 1966-09-20 GB GB41881/66A patent/GB1152477A/en not_active Expired
  • 1966-09-26 DE DE19661547913 patent/DE1547913A1/de active Pending
  • 1966-09-28 NL NL6613652A patent/NL6613652A/xx unknown
  • 1966-10-04 SE SE13403/66A patent/SE327627B/xx unknown

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