US3776731A

US3776731A - Developer for photographic negatives used for printing

Info

Publication number: US3776731A
Application number: US00211756A
Authority: US
Inventors: H Iwano; K Hayashi; Y Iijima; I Shimamura
Original assignee: Fuji Photo Film Co Ltd
Current assignee: Fujifilm Holdings Corp
Priority date: 1970-12-24
Filing date: 1971-12-23
Publication date: 1973-12-04
Anticipated expiration: 1990-12-04
Also published as: DE2162335A1; JPS4839171B1; GB1351629A

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:

WHEREIN R1 and R3 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, and R2 and R4 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.

Description

NEGATIVES USED FOR PRINTING [30] 3 Foreign Application Priority Data Dec. 24, 1970 Japan 45/118087 [52] US. Cl 96/66.4, 96/66.3, 96/66 R [51] Int. Cl .L G031: 5/30 [58] Field of Search 96/66, 33, 38, 45

[56] 1 References Cited UNITED STATES PATENTS 1,482,613 2/ 1924 John 96/66 R 2,837,430 6/1958 Goldberg 96/66 R 2,877,116 3/1959 Dickersonm. 96/66.3 3,128,180 4/1964 Henn et a1. 96/66.4 3,453,109 7/1969 Lee 96/66 R 3,490,905 1/ 1970 Blake 96/33 3,557,696 1/1971 Hoover et a1. 96/33 3,649,281 3/1972 Iwano et a1. 96/66.5

Assignee:

Filed:

Appl. No.: 211,756

Inventors: Haruhiko lwano; Katsumi Hayashi;

Yoo lllljima; Isao Shimamura, all of Minami Ashigara-Machi, Japan Fuji Photo Film Co., Ltd., Minami tates atent 1 [1 11 337769731 lwano et al. 51 4, i973 DEVELOPER FOR PHOTOGRAPHICQ Primary Exa miner Norrna n G.- Torchin AssistantExaminer-M. F. Kelley AttorneyRichard C. Sughrue et a1.

[57] 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:

wherein 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, and 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.

8 Claims, No Drawings DEVELOPER FOR PHOTOGRAPHIC NEGATIVES USED FORPRINTING BACKGROUND OF THE INVENTION 1. Field 'ofthe Invention The present inventionrelates 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.

2. Description of the Prior Art Light sensitive photographic elements used in graphic arts for making half-tone or line images are known (hereafter merely called 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.

In order to divide the image into meshed dots, 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. However, no matter how high a contrast the sensitive element has, intermediate density areas which are called fringe are always formed around the meshed dots, and have an intermediate density.

Fringe should not occur during plate making'because the quality of the printing images deteriorates remarkably. Since a line drawing is regarded as a continuation of meshed dot images, intermediate density areas should not of course, occur on the litholine film or plate.

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.

ln infectious developers of this kind, the preservability of the developer is inferior to that of common blackwhite developers since the sulfite ions in the free state are present in a low amount. In a developer having a low free sulfite ion concentration'the life of the activated hydroquinone is kept for a long time, and an in fectious development with hydroquinone is successively carried out, by which process rapid development isachieved and images having a high contrast and small fringe are obtained. In infectious developers having a high free sulfi te ion concentration, since activated hydroquinone is short-lived and is not accumulated, rapid development is not possible and images having low contrast and large fringe are obtained. There is thus a reciprocal relationship between'the free sulfite ion concentration and-the quality of the photographic films used for-printing.

It'is'essential 'thatan infectious developer have good preservability. Accordingly, it has been proposed to improve preservability by adding antioxidants other than the sulfites, e.g., it is known to add ascorbic acid to infectious developers (Jap. Pub. No. 28673/69). However, ascorbic acid is unstable and easily decomposes, especially when metal ions such as copper ions and iron ions exist in the developer, andthus the preservability of the developer is poor. Ascorbic acid has the further drawbacks that 'itdelays the progress of development and*the quality of the meshed dots deteriorates if it is added in a large amount. Summary of the Invention 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:

wherein 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, and 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.

In the case that 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. However, in the case of an infectious developer containing more than 0.008 mol of sulfite, the preservability of the developer is remarkably improved by a synergistic effect with the compounds of the present invention. In this point of view, 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. On the other hand, 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. However, 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.

As will be clear from the following examples, the effect of the present invention is very large. Although the mechanism of the resorcinol derivatives is not clear, it is believed to be as follows. 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. Though 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. Further, 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. Thus a sulfite ion buffer such as formaldehyde-sodium hydrosulfite addition product is generally used. Usually, by adding 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. In general, 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. However, as shown above, such a degree of preservability is insufficient. However, preservability can be remarkably improved by the compounds of the present invention.

In the present invention, not only one but two or more of the compounds of the present invention can be used together.

Although 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. 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. In the case of using a liquid 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. It is also possible to improve the preservability of the used developer by adding the compounds of the invention during or after developing photographic films used for printing, e.g., after adding the compound to a developer, 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.

As the emulsion of the photographic negative used for printing, common 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. Furthermore, 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.

The following examples illustrate the present invention in great detail.

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.

TABLE 1 Developer Additive Time of Quality Sensitivity developof dots Fresh Elapsed ment solution solution (minutes) A 2% a l00 34 B S-methyl resorcinol 2% a 100 90 C Sodium sulfitc 3 c 100 52 D Lascorbic acid 3 a 100 50 The time of development was that time required to reach the sensitivity obtained with developing by Developer A for 2 A minutes (this sensitivity was set as 100). The quality of the dots is represented by a, b and c, in which a means excellent, b means good and c means bad. Objective measurement of the dot quality are impossible. Therefore, it is usually measured by sight. The term excellent shows dot images having no fringe and term goodshowsdot images having low fringe, as these measurements are understood by the art. 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.

As shown in Table l, in control Developer A deterioration with lapse of time is large, Deterioration of the sensitivity by lapse of time of Developer C, in which 20 g of sodium sulfite was added for comparison purposes, is smaller than that of the Developer A but is still large. Deterioration of the sensitivity by lapse of'time of Developer D, in which 1.0 g of L-ascorbic acid was added for comparison purposes, is the same asthatof the Developer C and is insufficient. Deterioration of the sensitivity of lapse of time of Developer B, in which 1.0 g of S-methyl resorcinol was added, is the lowest and deterioration of the quality of dots by the fresh solution was not observed. The solution does not easily fatigue by treatment, and the quality of dots after treatment of a number of sensitive elements does not lower greatly.

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.

The results obtained upon development are shown in Table 2.

It will be seen that the deterioration of sensitivity of developers containing the compounds of the present invention is small as compared with that of developers not containing the compounds.

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.

The results are shown in Table 3.

TABLE 3 Developer Amount of hydroquinone remaining (7%) Developer E 87 Developer F Developer G 98 From the above results the amount of hydroquinone in the Solution l, which contains resorcinol and 4-chloro resorcinol does not greatly decrease by the lapse of time, and the developer can endure long periods of preservation.

REFERENCE EXAMPLE.

The same procedure as in Example 1 was carried out but using Developer L instead of Developer A.

Developer L Sodium carbonate (monohydrate) 50 g Formaldehyde-sodium hydrogensulfite addition product l5 g Potassium bromide 2 g S-Methyl resorcinol l g Hydroquinone 18 g Sulfuric acid (added so pH agreed with that of Developer A) Water to make 1 liter Upon developing, the quality of the dots was found to be in class c, and the sensitivity of the elapsed solution deteriorated to such a degree that it could not be used practically. Accordingly, when the sulfite ion concentration is very low, the resorcinol derivatives of the present invention do not exhibit a good effect.

What is claimed is:

1. 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.

2. The developer of claim 1 wherein from 0.01 to 0.08 mole of said free sulfite ions are present per liter of said 'developer.

3. The developer of claim 1 wherein said aldehydealkali hydrogensulfite addition product is present in an amount of from 30 to 60 grams per liter of developer.

4. The developer of claim 1 containing from 2 mg to 10 grams per liter of the developer of said compound.

5. The developer of claim 1 containing from 10 mg to 4 grams per liter of the developer of said compound.

6. The developer of claim 1 wherein 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.

7. 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:

Ra --O H wherein 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.

8. The developer of claim 2 wherein said compound is present in said developer in an amount of from 2 milligrams to 10 grams per liter of developer.

Claims

2. The developer of claim 1 wherein from 0.01 to 0.08 mole of said free sulfite ions are present per liter of said developer.
3. The developer of claim 1 wherein said aldehyde- alkali hydrogensulfite addition product is present in an amount of from 30 to 60 grams per liter of developer.
4. The developer of claim 1 containing from 2 mg to 10 grams per liter of the developer of said compound.
5. The developer of claim 1 containing from 10 mg to 4 grams per liter of the developer of said compound.
6. The developer of claim 1 wherein said compound is selected from the group consisting of resorcinol, 2-methylresorcinol, 5-methylre-sorcinol, 4-chlororesorcinol, 4-methoxy resorcinol, Alpha -resorcylic acid, Beta -resorcylic acid, gamma -resorcylic acid, 4-bromoresorcinol, 2,4-dihydroxybenzene sulfonic acid, 1,3,5-trihydroxybenzene, 4-n-propyl resorcinol, 4,6-di-tert-butylresorcinol, o-hydroxyethyl resorcinol, 2,4-dihydroxy acetophenone and 2,6-dihydroxy acetophenone.
7. 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:
8. The developer of claim 2 wherein said compound is present in said developer in an amount of from 2 milligrams to 10 grams per liter of developer.