US3708299A

US3708299A - Photographic developing method

Info

Publication number: US3708299A
Application number: US00079335A
Authority: US
Inventors: I Shimamura; Y Iijima; H Iwano
Original assignee: Fuji Photo Film Co Ltd
Current assignee: Fujifilm Holdings Corp
Priority date: 1969-10-08
Filing date: 1970-10-08
Publication date: 1973-01-02
Anticipated expiration: 1990-01-02
Also published as: JPS4828295B1; FR2065100A5; GB1275375A; DE2049502A1

Abstract

A METHOD AND COMPOSITION FOR PROCESSING A SILVER HALIDE BLACK AND WHITE PHOTOGRAPHIC MATERIAL WHEREIN THE SILVER HALIDE GRAINS ARE LESS THAN 0.3 MICRON WHICH COMPRISES DEVELOPING THE PHOTOGRAPHIC MATERIAL WITH A DEVELOPING SOLUTION HYDROQUINONE (SUBSTITUTED OR UNSUBSTITUTED) AS THE MAIN DEVELOPING AGENT AND IMIDAZOLE IN A MINOR AMOUNT.

Description

United States Patent Office 3,708,299 Patented Jan. 2, 1973 U.S. Cl. 96-663 8 Claims ABSTRACT OF THE DISCLOSURE A method and composition for processing a silver halide black and white photographic material wherein the silver halide grains are less than 0.3 micron which comprises developing the photographic material with a developing solution comprising hydroquinone (substituted or unsubstituted) as the main developing agent and imidazole in a minor amount.

BACKGROUND OF THE INVENTION This invention relates to the processing of silver halide photographic materials and more particularly to developing solution for fine grained photographic materials.

Description of prior art The desirable properties of processing procedures for silver halide, Black and White photographic materials reside in increased speed, high rate of development and fine grained silver image. The well known development accelerators are amine compounds, such as alkylamines (U.S. Pat. No. 2,196,037), aralkylamines (U.S. Pat. No. 2,496,903; 2,515,147; 2,541,889), phenoxyalkylamines (U.S. Patent No. 2,482,546), heterocyclic alkylamines (U.S. Pat. 2,605,183), morpholine and piperidine (U.S. Pat. No. 1,086,681). These amines, however, are poisonous, odoriferous and volatile, thus necessitating careful handling. Furthermore, their concentration in developing solution is often diificult to keep constant. The increase in rate of development is observed to some extent by an addition of these compounds to the developing solution, but this effect is often negated by the increase in fog formation. Furthermore, the deterioration in the granularity of the developed silver is often observed.

SUMMARY OF THE INVENTION Therefore, the principal object of this invention is to provide an improved accelerator for the developing solution, which is easily handled, capable of increasing the rate of development and increasing the effective speed of the photographic material without undesirable increase in fog and the deterioration in the granularity of the developed silver.

Still another object of this invention is to provide a process for accelerating the developing of the fine grained photographic materials without deterioration in the granularity of the developed silver.

The developing solution of this invention is applied to the black-and-white photographic materials, especially to low sensitivity silver halide photographic materials which require fine granularity and is generally used for the oflice works, documentary works, industrial works, or reprographic works.

The present invention can be applied to telephotographic materials; lithographic materials (used for producing dots), phototypesetting materials, microfilms, microplates, materials for facsimile, materials for prints of scanned dots, materials for production of integral circuit master and photographic materials for astronomical study; these photographic materials are composed of extremely fine grained silver halide and contain very small amounts of silver halide.

Therefore, these two features of the photographic materials provide different ways of development from that for the ordinary photographic materials.

For these materials, the granularity of the developed silver image should be adequately low throughout the development in the development of, e.g., fine grain silver halide emulsions as in the developing acceleration of this invention.

Detailed description of the invention Accordingly, the present invention provides a method of treating a photographic material which comprise developing the materials with the developer containing imidazole and hydroquinone (substituted or unsubstituted) thus increasing the rate of development or shortening the developing time, inhibiting the fog formation, increasing the effective sensitivity and making fine the developed silver particles.

It has already been shown in U.S. Pat. No. 3,126,282 to add an imidazole to the first developer for the reversible color film Whose emulsion contains non-diifusible color coupler to increase the speed of the film.

However, the increase in speed of the black-and-white photographic material to which this invention is applied by the imidazole is much greater than that of the reversible color film described in the U.S. lPat. 3,126,282. From the examples of the specification, the reversible color film of this is considered to be composed of an emulsion of coarse silver iodobromide particles, while the emulsion of the Black and White photographic materials used in this invention contains finely divided silver halide particles.

That is to say, the process for developing the photographic material containing fine grain silver halides according to this invention has been made on a discovery that the increase in speed by an imidazole depends on the size of the silver halide grain.

The fact that the developing of the photographic material with fine grain silver halides is accelerated by the imidazole when added to the developing solution in an amount contemplated herein has been unknown and have not been heretofore shown in the prior art. The expression fine grained denotes a particle size of from 0.1 to 0.3 micron.

Preferred embodiments The developing solution exhibiting the aforesaid advantageous effects with the addition of the imidizole contains at least 120 parts/liter hydroquinone as the main developing agent and, in addition, a conventional developer such as 1-phenyl-3-pyrazolidone or N-methyl-paminophenol. If necessary, an oxidation inhibitor, such as Na sulfite or ascorbic acid, a suitable pH buffer, such as boric acid, sodium hydroxide, sodium carbonate or sodium phosphate, a developing inhibitor such as potassium iodide or potassium bromide, an organic fog inhibitor such as 6-nitro-benzimidazole or benzotriazole, and an aldehyde such as formaldehyde or glutaraldehyde can be added to the developing solution. The pH of this developing solution may be adjusted in a range between 8.5 and 12.0 and preferably 10 to 11. The amounts of the imidazole to be added to the developing solution vary with the type of the photographic material employed and the pH of the developing solution, but favorably in the range of between 0.5 part/liter and parts/liter. The finely divided silver halide is present in a concentration of from 10-70 mg./100 cm. and preferably 20-50 mg./crn.

A better understanding of the present invention will be had from the following examples which are merely illus- 4 trative and not limitative in nature. All parts are by weight Parts unless otherwise stated. N-methyl-p-aminophenol 5.0 Sodium sulfite 70.0 EXAMPLE 1 Hydroquinone 2.0 The 8 types of photographic films (I)-(VIII) were ex- Sodium carbonate monohydrate 41.0 posed to light by sensitometer and subjected to process of Potass um bromide 4.0 this invention; (I) commercial direct X-ray film, (II) Po assium thlocyanate 1.6 high speed black and white negative film (ASA 100) for Potassium 1od1de (0.1% aq. solution) amateur use, (III) reversal color film (ASA 100) for (by vol.) 10.0 amateur use, (IV) color negative film (ASA 100) for 10 Water to make 1 liter. amateur use (V) black and white fine grain posifilm for (d) The develo 1 ping so ution for the photographic film the cinematography, (VI) resographic film for photo- (IV) (developer for the color negative film). mechanical use, (VII) telephotographic film, (VIH) m1- Parts crofilm' Sodium hexamethaphosphate 1.4

The process of this invention was not effective for the Benzylalcohol VOL)" films (I)-(IV), but the test results were shown to be Sodium sulfite 30 compared with those of the films (V)(VII). The mean Sodium carbonate 4L0 diameter of the silver halide grains in each of the photo- Sodium hydroxide L0 graphlc films were as follows: 4-amino 3 methyl-N-ethyl-N-methane sulfon- Mean diameter of the amidethylaniline sulfate 5.0 Photographic film: silver particle, microns Potassium bromide 0.5

I 1.4 Water to make 1 liter.

H (e) The developing solution for the photographic films III 0.9

W 10 (V)-(VIII):

""""""""""""""""""""""" D-l6 developing solution for the black and white VI 0 2 posifilm (Eastman Kodak).

This D-16 developer was also applied to the films VII 0 2 VIII (I) and (II), though they were processed by the developers (a) and (b), too. In the first series of the developing Each of the photographic film (I)-(VII) was subsolutions (a)-(e) imidazole was not added and the secjected to the developing treatment with the suitable deond series 2.0 parts/liter added. veloping solution below. The test results were shown in the following table:

Addition Relative of lmidasensitivity Photographic Developing conditions zole, (logarithmic films (developer, temp, time) g./l. sensitivity) Notes I Rendol, 24 C., 5min 0 2. 60 .I 2.0 2.65 Increase in iog, deterioration of the silver image.

II D76, 24 0., 6min 0 2. 20 11.... do 2.0 2.30 Deterioration oi the silver image. III (0), 24 0., 6min 0 2. m dn 2. o 2. Do. 111 (c) 1 24 0., 6min 2.0 2. 45 IV ((1), 24 0., 10 min 0 2. 05 Iv o 2.0 2.10 I D-IG, 24 0., 5 min 0 2. 45 T 2.3 22 Increase in tog, deterioration of the silver image.

2.0 2:45 Deterioration oi the silver image.

1 (c) is a developing solution same as the (0) except for the lack of potassium thiocyanate.

(a) The developing solution for the photographic film Parts Mono-methyl-p-amino phenol 4.0 Sodium sulfite (anhydride) Hydroquinone 10 Sodium carbonate (anhydride) 53 Potassium bromide 2.5

Water to make one liter.

*Rendol developing solution (produced by Fuji Photo Film Co., Ltd.)

(b) The developing solution for the photographic film D-76 developing solution (produced by Eastman Kodak Co., Ltd.).

(c) The developing solution for the photographic film (III) (first developer for the reversal color film):

*Mono-methyl-p-amino phenol-4.0 parts; sodium sulfite- (unhydride)60 parts; hydr0quinone-10 parts; sodium carbonate(anhydride)-53 parts potassium bromide2.5 parts water to makeoue liter.

It is apparent from this table that the addition of imidazole is very efiective for the emulsion of fine grained silver halide.

EXAMPLE 2 Commercial fine grain positive film for the cinematography composed of grained silver bromochloride-gelatinemulsion was subjected to development with solution having following composition at 27 C.

Developing solution A: Parts Water (by vol.).. N-methyl-p-aminophenol sulfate 2.0 Sodium sulfite Hydroquinone 5 Borax 2 Water to make 1 liter.

TABLE 1 TABLE 3 Developing time Developin In 4 min. required to obtain time (min. Adding developing relative sensirequired to amounts relative tivity of 100 Adding In 4 min. obtain the (g./l.) sensitivity Fog 7 (min) 5 amounts relatige Develgprelative S9610- ar s sensi ivi in o sitivit 1 Control 100 0. 04 1. 30 4 p y g g 7 y Imidazole 1 180 0. 04 1. 33 2. Control. 0 100 0. 19 4. 00 4 D0 4 300 0 05 l. 36 1. 6 Imidazo1e 1 140 0. 20 4.06 3 Do 4 250 0. 21 4. 08 2 10 Said results have been attained wherein the silver halide EXAMPLE 3 contains fine grained silver chlorobromide and less than A high resolution plate, comprising a support with ultra-fine grain silver iodobromide gelatin emulsion coated thereon was subjected to development at 20 C. with developing solution having following composition.

Developing solution C: Parts Water (by vol.) 800 l-phenyl-B-pyrazolidone 0.5 Sodium sulfite 50 Hydroquinone 12 Sodium carbonate (NaCO H O) 60 Potassium bromide 2.0 Benzotriazole 0.2 Water to make 1 liter.

This developing solution required 6 min. to develop the dry plate, but the imidazole added developing solution shortened the developing time as shown in Table 2. On the other hand, 6 min. of development with the imidazole containing developing solution exhibited high sensitivity on the dry plate.

Commercial microfilm comprising a support with a fine grain silver chlorobromide, gelatin emulsion coated thereon, was subjected to development at 20 C. with a developing solution having following composition.

Developing solution B: Parts Water (by vol.) 80 N-methylp-aminophenol sulfate 1.0 Sodium sulfite 75 Hydroquinone 9.0 Sodium carbonate (NaCO .H 'O) 29 Potassium bromide 6.0

Water to make 1 liter.

The developing solution of E required 4 minutes to develop the microfilm, but the addition of the imidazole to the developing solution shortened the developing time as shown in Table 3. On the other hand, a development time of 4 minutes with the imidazole added to the developing solution produced a high sensitivity on the microfilm. Furthermore, the developed silver grains in the picture were favorably fine and uniform according to the process of this invention using the imidazole containing developing solution.

1% of silver iodide, the particle size being smaller than 0.2 micron.

As this invention has been particularly illustrated with reference to the examples, it will be clearly understood to one skilled in the art that the scope of this invention is not to be restricted to the examples and claims but that various alterations and modifications may be made without departing from the spirit of this invention.

Similar results have also been achieved using substituted hydroquinones and specifically, chloro, bromo, methyl, dimethyl, phenyl and methyl phenyl.

What is claimed is:

1. A method for processing an exposed silver halide black-and-white photographic material, wherein the silver halide grains are less than 0.3 micron which comprises developing the photographic material with a developing solution comprising at least 1.0 part of hydroquinone as the main developing agent and at least 0.5 part of imidazole per one liter of the developing solution.

2. The method of claim 1, wherein the concentration of hydroquinone and imidazole respectively is 1.0-20 grams/l. and 0.5-10.0 grams/l. by weight.

3. The method of claim 2, wherein the concentration of imidazole is from 1.0-6.0 grams/l.

4. The method of claim 1, wherein the size of the silver halide particles is less than 0.2 micron.

5. The method of claim 1, wherein the pH range is between 8.5 and 12.

6. The method of claim 5, wherein the pH ranges from 10-11.

7. The method as claimed in claim 1, wherein said silver halide contains fine grain silver chlorobromide and less than 1% of silver iodide, particle size of said silver halide being smaller than 0.2 micron.

8. The method of claim 5, wherein the silver halide is present in a range of from 10-70 mg./ 100 cm.

References Cited UNITED STATES PATENTS 2,324,123 7/1943 Weissberger 9666.5 2,605,183 7/1952 Runyan 96-663 3,046,130 7/ 1962 Dersch et al. 96-67 3,086,863 4/1963 Hunt et a1. 96-408 3,126,282 3/1964 Hunt 96-59 3,271,154 9/1966 Dersch et al. 96-66 3,335,009 8/ 1967 Rasch et a1. 96-61 3,353,956 11/1967 Rogers et al. 96-29 3,397,987 8/1968 Luckey et al. 96109 3,576,633 4/1971 Henn et al 96-665 J. TRAVIS B ROWN, Primary Examiner M. F. KELLEY, Assistant Examiner U.S. Cl. X.R.