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
  • G03C5/00—Photographic processes or agents therefor; Regeneration of such processing agents
  • G03C5/26—Processes using silver-salt-containing photosensitive materials or agents therefor
  • G03C5/29—Development processes or agents therefor
  • G03C5/305—Additives other than developers

Definitions

• ABSTRACT A developer for photographic films used for half-tone printing which contains at least one compound represented by the following formula in combination with more than 0.008 mols of sulfite ions:
• R and R each represent a hydrogen atom, an alkyl group having one to two carbon atoms, a carboxyl group, an acetyl group having one to two carbon atoms or a hydroxyl group
• R and R each represent a hydrogen atom, a halogen atom, an alkyl group having one to six carbon atoms, a carboxyl group, a sulfo group, an alkoxy group having one to two carbon atoms, an acetyl group having one to two carbon atoms or a hydroxyalkyl group having one to two carbon atoms.
• the present invention relates to an infectious developer for producing photographic films used for printing, and particularly to an infectious developer having excellent preservability for producing photographic films used for printing.
• Photographic films used for printing are produced, in general, by infectious development using a lithe-type sensitive element for producing dot images (hereafter often referred to as meshed dots) or line drawings, or a hard sensitive element having very high contrast and excellent sharpness.
• the litho-type sensitive elements used include litho-films or litho-prin'ting plates. These materials are used for recording images on an original having a density of continuous gradation by dividing the images into meshed dots which change the variation of density into a variation of area.
• Litholine film or litholine printing plates are also used for printing an original having line drawings.
• a glass cross line screen or a contact screen is used.
• a halftone negative can be produced by printing images of the original onto the litho-type sensitive element through these screens and carrying out development.
• the ideal half tone negative consists of meshed dots having maximum density and a background having minimum density.
• intermediate density areas which are called fringe are always formed around the meshed dots, and have an intermediate density.
• the developer for producing photographic films used for printing using litho-type sensitive elements or other high-contrast sensitive elements is usually an alkaline.
• infectious developer which contains a dihydroxybenzene type developing agent and an aldehyde-alkali hydrogensulfite addition product as a preservative.
• One object of the present invention is to provide a developer for photographic films used for printing which does not have a harmful influence upon the quality of the resulting images and which has excellent preservability.
• the present inventors have discovered that the preservability of infectious developers is improved without injury to photographic properties of the infectious developer by the presence of a compound represented by the following formula with more than 0.008 mol of dissociated sulfite ion in the infectious developer per one liter of developer:
• R, and R each represent a hydrogen atom, an alkyl group having one to two carbon atoms, a carboxyl group, an acetyl group having one to two carbon atoms or a hydroxyl group
• R and R each represent a hydrogen atom, a halogen atom, an alkyl group having one to six carbon atoms, a carboxyl group, a sulfo group, an alkoxy group having one to 'two carbon atoms, an acetyl group having one to two carbon atoms or a hydroxyalkyl group having one to two carbon atoms.
• Examples of compounds represented by the above formula used in the present invention include resorcinol, Z-methylresorcinol, S-methylresorcinol, 4- chlororesorcinol, 4-methoxy resorcinol, a-resorcylic acid, B-resorcylic acid, 'y-resorcylic acid, 4- bromoresorcinol, 2,4-dihydroxybenzene sulfonic acid, 1,3,5-trihydroxybenzene, 4-n-propyl resorcinol, 4,6-ditert-butylresorcinol, o-hydroxyethyl resorcinol, 2,4- dihydroxy acetophenone and 2,6-dihydroxy acetophenone. These compounds are commonly available.
• the dissociated sulfite ion is not included or is included only in a very small amount, good results are not obtained by adding the compounds of the present invention.
• the preservability of the developer is remarkably improved by a synergistic effect with the compounds of the present invention.
• the compounds of the present invention are believed to accelerate the preserving function of the sulfite ions. This function deteriorates with an increase of the sulfite ion concentration and it is not observed with best results in the high sulfite ion concentration of 0.2 mole to 1.0 mole whichis used for common developers for blackwhite films.
• the decrease in effect might be acceptable to some users, however, especially at value closer to the 0.2 mol figures.
• the degree of acceleration of the preserving function of the sulfite ions by the compounds of the invention increases with a decrease in the sulfite ion concentration.
• the preservability of the solution itself lowers because of the absolute decrease in the sulfite ion concentration.
• the cooperative effect is very effective in the 0.008 to 0.1 mole range of sulfite ion concentration with a more preferred range being 0.01 to 0.08 mole. Therefore, in solutions in which the sulfite ion concentration is low, such as in the infectious developer of the invention, the cooperative effect of the sulfite ions and the compounds of the present invention is most effective.
• the effect of the present invention is very large.
• the aldehyde-alkali hydrogensulfite addition product included in the infectious developer releases aldehyde by oxidation of the developer with a lapse of time and the exhaustion of the developer during development.
• the aldehyde reacts with hydroquinone as the developing agent to form a compound which deteriorates the infectious developing characteristics
• the compounds of the present invention react with this aldehyde to change it into a photographically harmless material.
• the compounds of the present invention thus have the function of accelerating the rate of development while keeping the infectious developing property without delaying the progress of development.
• the compounds of the present invention can thus be seen to have a peculiar effect. Namely, when the compounds of the present invention are used in an infectious developer, not only is coloring of the solution by oxidation and subsequent deterioration of the treating ability during storage or in automatic developing apparatus prevented, but hardening of half-tone gradation by fatigue of the treating solution and increased fatigue can be prevented.
• the developers for photographic films used for printing to which the compounds of the present invention are added are the common infectious developers which contain hydroquinone as the developing agent, preferably in an amount offrom about 5 to about 25 g per liter of developer, water soluble acids, alkalis and salts such as sodium carbonate, sodium hydroxide, acetic acid and boric acid as the alkali agent or a pH buffer agent, an aldehyde-alkali hydrogensulfite addition product, ketone-alkali hydrogensulfite addition products, sulfites or two or more thereof as antioxidants, and halogenated alkalis as the developing controller.
• hydroquinone as the developing agent
• water soluble acids, alkalis and salts such as sodium carbonate, sodium hydroxide, acetic acid and boric acid as the alkali agent or a pH buffer agent
• an aldehyde-alkali hydrogensulfite addition product ketone-alkali hydrogensulfite addition products, sulfites or two or more
• organic antifogging agents such as benzotriazole and l-phenyl-5-mercapto-tetrazole, polyalkylene oxides, amino compounds and organic solvents such as triethyleneglycol, dimethylformamide, methyl alcohol and cellosolve may be added, if desired, in an amount of O to 300 ml per 1 liter of the developer.
• the most preferred developer comprises hydroquinone, an addition product and a compound ofthe indicated formula.
• the presence of sulfite ion is extremely preferred (with a range of 0.008 to 0.2 mole being preferred).
• the preferred amount of hydroquinone is 5 to 25 g per one liter of developer, and the preferred range of the addition product is 30 to 60 g per one liter of the developer.
• Sulfite salts may be added, if necessary, to provide a sulfite ion concentration greater than 0.008 mole.
• a characteristic of the infectious developer is that the free sulfite ion concentration is low.
• a sulfite ion buffer such as formaldehyde-sodium hydrosulfite addition product is generally used.
• a alkali sulfite such as sodium sulfite in an amount of less than 5 g per liter of the developer'to the sulfite buffer, the free sulfite ion concentration is controlled.
• up to 3 g of sulfite is added, by which the preservability of the developer is somewhat improved, though the quality of meshed dots deteriorates.
• preservability can be remarkably improved by the compounds of the present invention.
• the amount of the compound of the present invention in the developer depends on the composition of the developer and the types of compounds present it is usually used in the amount of 2 mg to 10 g per liter of the developer, and 10 mg to 4 g is most preferred.
• the compounds of the present invention are generally added at the preparation of the developer.
• the developer When the developer is prepared as a liquid or powdery composition and diluted or dissolved at use, it is effective to add the compounds to the liquid or powdery composition.
• addition to the liquid composition is especially effective because the preservability of the liquid composition is remarkably improved by the addition.
• Common liquid developer compositions consists of two liquid parts, one part of which contains a developing agent and the other part .of which contains an alkali agent.
• the compounds of the invention may be added to either part, but it is more effective to add to the part containing the developing agent.
• photographic elements may be developed with the developer, or photographic elements may be developed with a developer while adding the compound to the developer. Otherwise, after any photographic elements are developed with a developer containing no compound of the invention, the other photographic elements are developed with the developer containing the compound.
• the preservability of the liquid developer is thus superior, and the stability of the developer after preparation of the infectious developer by diluting is remarkably improved.
• silver halide photographic emulsions are used, e.g., those containing silver chloride, silver bromode, silver bromochloride, silver iodobromide and silver iodobromochloride.
• Silver bromochloride is particularly suitable.
• These silver halides are dispersed in gelatin or a mixture of gelatin and a synthetic high molecular weight polymer to form an emulsion.
• the emulsion may be chemically sensitized by compounds containing unstable sulfur such as sodium thiosulfate and allyl thiourea, gold compounds such as complex salts of monovalent gold and thiocyanate, or mixtures thereof.
• the emulsion may be optically sensitized by adding color sensitizing agents such as cyanine dyes and merocyanine dyes.
• the emulsion may also contain polyalkylene oxides, amino compounds and organic antifogging agents such as benzotriazole.
• the emulsion' may be hardened by hardeners such as formaldehyde and mucochloric acid, ormay contain surface active agents such as saponin in order to facilitate application. These materials are well knownto the art and are merely added to serve their art recognized function.
• EXAMPLE l Commercially available litho films were used and after photographing with an exposure wedge for sensitometry through a 150 line magenta contact screen, the films were developed at 20C using 4 kinds of developers having the following compositions.
• Developer A Sodium carbonate (monohydrate) Formaldehyde-sodium hydrogensulfite addition product Potassium bromide Hydroquinone Sodium sulfite Water to make 1 Developer B That obtained by adding g of S-methyl resorcinol to Developer A. Developer C That obtained by adding 2 g of sodium sulfite additionally to Developer -A. Developer D That obtained by adding 1 g of L-ascorbic acid to Developer A. The values of the photographic properties of the developed films are shown in Table 1.
• Elapsed solution is that which is subjected to deterioration by contacting 500 ml of the developer with the air for 5 hours in a cm X cm vat.
• EXAMPLE 2 Availa blelithofilms were used. After photographing with an exposure wedge for sensitometry through a 150 line magenta contact screen, the films were developed at 20C using developers prepared from 2 kinds of compositions having the following compositions.
• Developer E Solution 1 Distilled water 60 ml Triethylene glycol 30 ml Formaldehyde-sodium hydrogensulfite addition product 45 g Sodium sulfite l 'g 'Hydroquinone l6 g Distilled water to make 125 ml Solution ll Distilled water l00 ml Sodium carbonate (monohydrate) 30 g Sodium hydroxide 5 g Boric acid 3 g Sodium bromide 2 g Distilled water to make 125 ml At use, Solution 1 was added to 750 ml of water and then Solution II was added thereto to make 1 liter.
• -Developers F,G,H,.l and K are prepared by adding the following compounds to Developer E.
• EXAMPLE 3 The reduction in the amount of hydroquinone in the developers was determined by charging each solution I of Developers E, F and G into an air constant temperature bath at 50C for 20 days.
• Example 1 The same procedure as in Example 1 was carried out but using Developer L instead of Developer A.
• An infectious developer for a light-sensitive silver halide element comprising from about 5 to about 25 grams per liter of developer of a hydroquinone compound as the only developing agent, an effective amount of a buffering agent comprising an aldehydealkali hydrogen sulfite addition product, from 0.008 to 0.1 mole, per liter of developer, of free sulfite ion and at least one compound representing by the formula:
• R W wherein R, andR each represents a hydrogen atom, an alkyl group having one to two carbon atoms, a carboxyl group, an acetyl group having one to two carbon atoms or a hydroxyl group, and R and R, each represents a hydrogen atom, a halogen atom, a sulfo group, an alkoxy group having one to two carbon atoms, an acetyl group having one to two carbon atoms, or a hydroxyalkyl group having one to two carbon atoms.
• the developer of claim 1 containing from 2 mg to 10 grams per liter of the developer of said compound.
• the developer of claim 1 containing from 10 mg to 4 grams per liter of the developer of said compound.
• said compound is selected from the group consisting of resorcinol, 2- methylresorcinol, S-methylre-sorcinol, 4- chlororesorcinol, 4-methoxy resorcinol, a-resorcylic acid, B-resorcylic acid, 'y-resorcylic acid, 4- bromoresorcinol, 2,4-dihydroxybenzene sulfonic acid, 1,3,5-trihydroxybenzene, 4-n-propyl resorcinol, 4,6-ditert-butylresorcinol, o-hydroxyethyl resorcinol, 2,4- dihydroxy acetophenone and 2,6-dihydroxy acetophenone.
• An infectious developer for a light-sensitive silver halide photographic element consisting essentially of from about 5 to about 25 grams per liter of developer of hydroquinone as the only developing agent, from 30 to 60 grams per liter of developer of a buffering agent consisting essentially of an aldehyde-alkali hydrogensulfite addition product, from 0.008 to 0.1 mole per liter of developer of free sulfite ion and at least one compound represented by the formula:
• R and R each represents a hydrogen atom, an alkyl group having one to two carbon atoms, a earboxyl group, an acetyl group having one to two carbon atoms or a hydroxyl group, and R and R each represents a hydrogen atom, a halogen atom, a sulfo group, an alkoxy group having one to two carbon atoms, an acetyl group having one to two carbon atoms, or a hydroxyalkyl group having one to two carbon atoms.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=14727659

Family Applications (1)

Country Status (4)

Cited By (2)

• 1970
  • 1970-12-24 JP JP45118087A patent/JPS4839171B1/ja active Pending
• 1971
  • 1971-12-15 DE DE19712162335 patent/DE2162335A1/de active Pending
  • 1971-12-16 GB GB5857271A patent/GB1351629A/en not_active Expired
  • 1971-12-23 US US00211756A patent/US3776731A/en not_active Expired - Lifetime

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