JPH01167747A - Precursor for bleaching promotor - Google Patents

Abstract

PURPOSE: To obtain good results even if a photographic film is used in a different kind of bleaching or bleach fixing composition by incorporating a heavy metal salt of an acid-containing nonzwitter ionic organic thiol as the bleach promoter precursor. CONSTITUTION: The bleach promoter precursor contained in the color photographic element contains the heavy metal salt of the acid-containing nonzwitter ionic organic thiol. For practicable embodiment, this precursor is solubilized in the presence of one or more kinds of carboxylic acid or sulfate, thus permitting a residual silver concentration left after bleaching to be reduced, contrast to be lowered, and image quality and color saturation to be enhanced, and excellent effects to be exhibited on the color development processing using the precursor in the bleaching or bleach fixing processing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to color photographic materials. In one specific aspect, the invention relates to a color photographic material containing a bleach accelerator precursor.

[Conventional technology]

The action of silver halide development results in imagewise distribution of dyes to produce color images in color photographic elements. - For boat fishing, this color image is produced by the reaction between a coupler compound and an oxidized silver halide developing agent. However, colorless images can also be produced by other means such as imagewise diffusion of dyes or imagewise decomposition of dyes. Regardless of the means by which the dye image is produced, it is common practice to remove the silver halide produced by the phenomenon and any remaining silver halide in the unexposed areas of the element. This removal involves - after oxidizing the silver image with a suitable oxidizing agent, commonly referred to as a bleaching agent;
This is generally carried out by a bleaching process in which silver halide is dissolved in a silver halide solvent called a fixing agent. Alternatively, a bleaching agent and a fixing agent can be mixed to form a bleach-fix solution, which can be used to remove silver in step I.

In the past, various bleaching compositions have been used in silver halide materials. Bleaching compositions include, for example, those based on ferrocyanides, dichromates, permanganates, chlorides, quinones as well as aminocarboxylic acids and persulfate oxidizing agents. Representative examples of compositions containing such oxidizing agents for photographic image silver bleaching include U.S. Pat.
No. 1647.469, No. 3.689.272,
No. 3.706.561, No. 3.716.362,
No. 3.749.572, No. 3.772.020, No. 3.893.858, No. 4.163.669, 4.
No. 292.401, No. 4.293.639, No. 4.3
01.23 (No. i, No. 4.322.493, No. 4.4
No. 48.878, No. 4.458.010, No. 4.48
No. 1.290, No. 4.524.129, No. 4.546
．． Mention may be made of those mentioned or described in No. 070 and No. 4.596.764.

For more information on the composition and use of photographic silver bleach, see
Neblett's Handbo of Photography and Revrography, Materials, Broaches and Systems, published by Nostrand Reinhold Company.
ok of PIIOTOGR eight yen IY AN to Rε
PROGRAPIIY,Aterials,Pro
ce・5ses and Systems), 7th edition, pages 124 and 125 and published by Macmillan Publishing Company, Inc. (31ac!
The Theory of the Photographic Process (T1
1εTHεDRY OF T）IE PIIOTOGR
8 pH+ (:PROCESS), 4th edition, pages 447 and 450.

Various substituted thiols have been found to enhance bleaching when they are added directly to the bleach solution or introduced via a pre-bath before the bleaching step. In this regard, for example, 1
U.S. Patent No. 3.893.85, issued July 8, 975 [1]
It is stated in No. 8.

U.S. Patent No. 1.163.6, issued August 7, 1979
No. 69 suggests that while there are benefits to incorporating bleach accelerators directly into photographic film, the inclusion of free thiols can adversely affect the photographic properties of the film. . Also, this U.S. Patent No. 4.16
No. 3.669 discloses the inclusion of certain bleach accelerators in the form of salts of heavy metal ions. Among the bleach accelerators described are U.S. Pat.
There are organic thiols of the type described in No. 8.

Although the heavy metal salts described in the aforementioned U.S. Pat. No. 4,163,669 are effective in bleach compositions based on ferric ethylenediaminetetraacetate, they may This is not as effective as expected. Additionally, these compounds do not help reduce staining due to residual sensitizing dyes.

[Problem to be solved by the invention]

Photo Phil! - a bleaching accelerator which can be included in the film to provide good results when used in dissimilar bleaching and bleach-qualifying compositions and to reduce contamination of sensitizing dyes; Precursor compounds are desired.

[Means to solve the problem]

According to the present invention, the bleach accelerator precursor contained in the color photographic element contains a heavy metal salt of an acid-containing non-zwitterionic organic thiol.

According to one specific embodiment, the color photographic element of the invention includes a support and a silver halide emulsion layer.

In a preferred embodiment, the bleach accelerator precursor is solubilized by the presence of one or more carboxylic acid or sulfate groups. Although these compounds can contain amine groups, they must be non-basic amines to prevent the formation of zwitterionic components.

Preferably, the compound has relatively high solubility in both the alkaline developer composition and the acidic bleach or bleach fixer composition used during processing of the element.

In a particularly preferred embodiment of the invention, the bleach accelerator precursor comprises: 1) a color developer having a pH of 4.25 g/l and a bromide concentration of 4.25 g/l and ii) p
It has a solubility of greater than 10 g/i' in both H6 and bleach or bleach-fix solutions with a bromide concentration of 150 g/j7.

Compounds useful in the present invention include salts of heavy metals such as silver, iron, cobalt, nickel, copper, zinc, rhodium, palladium, cadmium, iridium, platinum, gold and lead. Among these, silver salts are particularly preferred.

Representative examples of precursor compounds useful in the present invention include those having the following structures.

Margin table 1 below 1 Ag5C2Hz, C0OH 2Pb (SC2H4Coo) ()2 ”3AgSC2H4S03H 4/145 (:2H4SC2H4COOHC2H4C0
2H By using such bleach accelerator precursors in photographic elements, the residual silver concentration, ie, the concentration of silver that is still present after bleaching, can be reduced. Reducing residual silver reduces contrast and improves image quality and color saturation. Additionally, the infrared density of the photographic element affected by residual silver can be reduced, which is beneficial when other infrared absorbers such as soundtracks and control markings form part of the photographic element. Instead of reducing the residual m concentration, it is also advantageous to shorten the time of the °C1 bleaching step if necessary.

The bleach accelerator precursors of this invention are preferably used with photographic elements containing dyes that are adsorbed to the developable silver halide surface. In particular, the Research Disclosure issued in January 1983
It is advantageous for use with photographic elements containing high concentrations of sensitizing dyes such as spectrally sensitized high aspect ratio tabular grains such as those described in Section 22543. This Research Disclosure was published by Bmsworth Studio Co., Ltd.
Published by h5tudios Inc.

A major source of color contamination in color photographic materials is sensitizing dyes remaining in the material after processing. Because the compounds of the present invention are soluble in high pH color developers, they help remove tough pigments by preventing readsorption onto developed silver, and thus are useful for cleaning from materials. The amount of dye delivered can be increased.

The bleach accelerator precursors of the present invention, one or more of which can be placed in the photographic element at any convenient location where active fragments released during bleaching can diffuse into the silver-containing emulsion layer. Thus, the compound may be incorporated directly into the silver halide emulsion layer in which the silver is bleached, or it may be incorporated into any of the bleach solution permeable layers of the photographic element on either side of the support, especially Silver may be included in any layer adjacent to the bleached emulsion layer. Bleaching of silver from the red-sensitive emulsion layer, which is usually the lowest layer in color photographic materials, can be improved by incorporating accelerator precursors into the underlying antihalation layer.

The bleach accelerator precursor compounds of this invention can be incorporated into photographic elements by a variety of methods.

A particularly preferred method is to homogenize or ball mill a slurry of the compound in the presence of a surfactant to produce finely divided particles, as disclosed in Swank et al., U.S. Pat. No. 4,006,025. forming, milling a mixture of a molten compound and a molten or liquid molecule f,'(agent) as described in Aida Patent No. 1.151.590, or as described in Belgian Patent No. 852.
Mechanical dispersion of the compound as described in No. 138 may be mentioned. U.S. Pat. No. 3.485.634 by Qwen et al. and Salminen (S.
U.S. Patent No. 3.551.157 by
Ultrasonic waves can be used to dissolve the compound prior to incorporation into the photographic coating composition, as described in the present invention. Also, Cheno (CBCN), Research Disclosure, Volume 159, July 1977, No. 1593
As explained in Section 0, the compound may be incorporated directly into a hydrophilic colloid such as gelatin, or the compound may be added to a latex and dispersed. Representative apparatus and procedures for introducing and formulating bleach accelerator precursors according to the present invention are described by Johnson et al. in U.S. Pat. 773.302 and 3.850.643;
US Pat. No. 3,342,605 to McCrossen et al.;
U.S. Patent No. 2.912.343 by Terwilliger et al.
It is described in No. 65.

The bleach accelerator precursors of the present invention can be applied to photographic elements that are, for example, otherwise conventional color photographic elements, preferably in the range of 0.01 to 10 g/m2 for typical silver concentrations.
Optimally it is present at a concentration in the range of 0.05 to 0.15 g/m''. For photographic elements with high silver concentrations, even higher concentrations of the compound are desirable.

A preferred application of the invention is bleaching silver from photographic materials that can produce multicolor dye images. Such photographic elements include a support having a plurality of color forming layer units coated thereon. The color forming layer units include at least one blue recording yellow dye image forming layer unit, at least one green recording magenta dye image forming layer unit and at least one red recording cyan dye image forming layer unit. Each color forming layer unit includes at least one silver halide emulsion layer. Dye image-providing substances, such as couplers, can be located in the emulsion layer or adjacent layers, or can be introduced during development. Emulsion layer in the blue recording layer (
- layers or more) may rely on their inherent blue-sensitivity or may contain a dye capable of absorbing blue light, i.e. a blue sensitizing dye, adsorbed onto the silver halide grains of the emulsion. good.

Sensitizing dyes capable of absorbing green light and red light are adsorbed on the silver halide grain surfaces in the green and red recording color forming layer unit Φ emulsion layers, respectively.

To prevent color contamination of adjacent color layer units, a scavenger for oxidized development products may be included at any location in the color layer unit or in an intermediate layer separating adjacent color layer units. can. As an effective scavenger, Lle issber
U.S. Patent No. 2,336,327 to Yutzy et al.
．． Alkyl-substituted aminophenols and hydroquinones disclosed in No. 086, Thirtl.
sulfoalkyl-substituted hydroquinones as exemplified in Yoneda Patent No. 2.701.197 by E) et al. and U.S. Patent No. 4.2 by Erikson et al.
Examples include sulfonamide-substituted phenols exemplified in No. 05.987.

Any conventional silver halide emulsion containing dye adsorbed to the surface of the silver halide grains can be used.

For color printing applications, silver chloride, silver bromide and silver chlorobromide emulsions are particularly preferred, while for camera speed photography silver bromoiodide emulsions are preferred. These silver halide emulsions may be direct positive emulsions, such as internal latent image desensitized emulsions, but in most applications, they are negative-acting. Specific types of silver halide emulsions and explanations about their production are given in Research Disclosure, Vol. 176, 1978, 12.
No. 17643, Baragraph I.

Particularly preferred silver halide emulsions include high aspect ratio tabular grain emulsions such as those described in Research Disclosure, Item 22534, supra.

Examples of dyes that are effective for adsorption to silver halide grain surfaces include those commonly used in silver halide emulsions to modify intrinsic sensitivity, expand spectral sensitivity, or both. The dyes used (these are sometimes collectively referred to as spectral sensitizing dyes) are mentioned. Such adsorbed dyes can be selected from a variety of polymethine dyes including cyanine, merocyanine, complexed cyanine and arsenic complexed merocyanine, oxonol, hemioxonol, styryl, merostyryl and streptocyanine.

Research Disclosure, December 1978, No. 17643, paragraph IV provides a more detailed explanation of the use of spectral sensitizing dyes in color photographic materials.

It was clearly recognized that dyes adsorbed on the surface of silver halide grains can inhibit bleaching of developed silver in photographic materials, but similar bleach-inhibiting effects can be imparted by other adsorbed additives. It seems possible. Thus, the advantages of the present invention are obtained when bleaching silver from photographic elements resulting from the development of silver halides with forming additives other than dyes.

The photographic element may include any conventional photographic support. Typical photographic supports include one or more layers of subbing (sub+ng) to improve properties such as adhesion, antistatic properties, dimensions, 1N resistance, hardness, friction properties, and antihalation properties on the surface of the support. Included are polymeric films provided, wood fibers, such as paper, metal sheets and foils, glass and ceramic support elements. Representative examples of useful supports are further described in Research Disclosure, Section 17643, December 1978, Paragraph XVII.
has been disclosed.

In addition to the features described above, the photographic element may have features known in the art as set forth in the above-referenced Research Closure, Item 17643. For example, a silver halide emulsion can be chemically sensitized as described in paragraph I11, contain a brightener as described in paragraph V, and contain a brightener as described in paragraph Vl. the emulsion layer and other layers contain a vehicle as described in paragraph IX; However, the hydrophilic colloid layer and other hydrophilic colloid layers may contain a hardening agent as described in paragraph X, and the layer may contain a coating aid as described in paragraph XI. The layers may contain plasticizers and lubricants as described in paragraph May contain matting agents. The listing of this representative additive and feature is not meant to be limiting or absent of other conventional photographic features that are compatible with the practice of the present invention.

The exposed photographic elements of this invention can be processed by conventional methods to produce color contrast images. Thereafter, the simultaneously developed silver image is removed by bleaching or bleach-fixing. Any undeveloped residual silver/silveride can be removed in a separate fixing step or simultaneously with bleaching.

Separately, it is also possible to stop the development before bleaching by using a pH lowering solution called a stop solution. Also, the stabilizing bath,
It can be used before drying. Conventional processing methods are described in Research Disclosure, Section 17643, Paragraph XIX.

Although the present invention has been described in terms of using one or more compounds to enhance bleaching, other suitable compounds may be used in combination to enhance bleaching, if desired. Such other compounds may be present in the photographic element or in the processing solution.

The salts according to the invention can be produced by methods well known in the field of organic compound synthesis.

As the starting thiol raw material, a commercially available product may be used, or it may be produced from a commercially available substance by a known method.

After reacting the thiol with a suitable water-soluble salt such as silver nitrate,
The resulting compound is purified to remove reaction products that may adversely affect the sensitometric properties of the silver halide emulsion.

The following is the preparation of blank precursor 1. 3-Mercaptopropionic acid (b) 30 g is mixed with water 1 β
The following margin was dissolved and treated with 56 ml of a 5 molar solution of silver nitrate (a). A white solid formed immediately. This was stirred at room temperature for 2 hours until mixed. After the addition of silver nitrate was complete, an exothermic reaction occurred and brown gas (lINO3) was evolved. A white solid was collected, washed with water 21 and then dried in a vacuum oven at room temperature.

Yield was 45 g (82%).

N OJ O CI2J 16. ! I II 1.5 2.4 S 10.9 15.1 Other compounds according to the invention can also be prepared by analogous methods.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to these. In this example, the bleach accelerator precursor compounds of the present invention are represented by the numbers assigned in Table 1 above. - On the other hand, it has the structure of a comparative bleach accelerator precursor.

Compound BAgsc4H9-n Example 1: Bleaching Performance A first control photographic element was prepared having the following structure. All numbers in parentheses here are coating amounts in g/lTl2.

V! t3 Cerafon (5,3) 82 Gelatin (3,7) - Red spectral sensitizing silver halide [silver coated fit (1,6)] - Spectral sensitizing dye A (0,
30) - Spectral sensitizing dye B (0°52) - Cyan dye-forming coupler (0,8 layer 1 Gelatin (2,6) - Gray colloidal silver (0,32) Transparent film support sensitizing dye,... anhydro-516'chloro-1-ethyl-3-(3-
Sulfobutyl”)-3'-(3-sulfopropyl)-
4°, 5′-benzobenzimidazolothiacarbo-cyanine hydroxide sensitizing dye B: Anhydro5. 5'-cyclo9-ethyl-3
, 3°-bis(3-sulfopropyl)thiacarbocyanine hydroxydocyanine dye-forming coupler: l-hydroxy-2-[4-(2,4-di-tert-
Photographic elements identical to the control photographic elements described above were further prepared, except that the bleach accelerators listed in Table 2 were each incorporated in layer l at a coating m of 0.1 g/m''. Bleaching The accelerator is blended into the coating composition by a dispersion method. For example, Precursor 1 is blended by the following procedure.

That is, 6 g of precursor l, 16 ml of 7% TX-200 surfactant solution (available from ROH & HAAS, Philadelphia), 130 g of distilled water. , a mixture consisting of 250 ml of 2 mm ceramic ZrO beads (
The mixture was shaken for 3 hours in a SWECO pulverizer (SWECO, Florence, KY). Next, 1
After adding 48 g of a 2.5% aqueous gelatin solution, the mixture was filtered through a coarse phase bag to remove ceramic beads to obtain a milky white dispersion.

Each strip of the photographic element described above was subjected to conventional color development treatments including bleaching (Treatment A) and bleach-fixing (Treatment B), respectively, after uniform exposure to white light.

Process A: Color development 3 minutes 15 seconds bleaching 1 minute/4 minutes washing ゛ 1 minute fixing 4 minutes drying Composition of processing solution: Color development liquid water 809 ml Potassium carbonate 37.5 g Sulfite) IJum (dried) 4.25 g Potassium iodide 1.2g Sodium bromide 1.3g Hydroxylamine sulfate 2. Og diaminopropanol tetra vinegar N? 2.5g
4-Amino-3-methoxy-N-ethyl-N-hydroxyethylaniline sulfate 4.75 g Potassium hydroxide (4
596 solution 6) Total volume after adding 0.65ml water
Ij7 pH 10.0 Bleach water 600ml Ammonium bromide 150gFeEDTA
175ml glacial acetic acid
10.5ml nitric acid
Total volume after adding 41.2g water 14
2 pH 6.0 fixing water 800ml
Ammonium thiosulfate (58% solution) 162ml ED
TA (sodium salt) 1.25g aqueous sodium sulfite (anhydrous) 12.4g sodium hydroxide
Complete appearance after adding 2.4g water &j
11p86.5 Processing B: Color development phenomenon 3 minutes 15 seconds bleach fixing
1 minute/4 minute wash
Composition of 4-minute drying solution: Color developing agent water 809ml
Potassium carbonate 37. 5g sodium sulfite (dry) 4.25g potassium iodide 1.2g sodium bromide
1.3g hydroxylamine sulfate 2.
0g diaminopropanol tetraacetic acid fV 22.5g 4-amino-3-methoxy-N-ethyl-N-hydroxyethylaniline sulfate 4.75g potassium hydroxide (45% solution) 0.65ml 1 Total volume after adding water "1 1β pH10.0 Bleach-fixing ammonium thiosulfate 104g Sodium sulfite 13g Ammonium Fc1Emouth T8 (0,18?J) 65.6 gE D T A
6.56 g ammonium hydroxide (28% solution) Total volume after adding 27.9 ml water &j
The amount of silver in the rice after I l1 pH 6,8 treatment was measured by X-ray fluorescence. Table 2 shows the amount of silver in g/g for bleaching times of 1 minute and 4 minutes. The data in Table 2 shows that the bleach accelerator precursors of the present invention exhibit excellent effectiveness in removing silver from color-developed photographic elements processed with either bleach or bleach-fix processing.

Margin table below 2 1 10.7? , 0 11.0 2 Δ 2DJ 7.2 G, 1 1.23 B
38. ll l11.382.374.64 C3
0,115,54,50,2514,000,60 G 2 16.8 :1.2 4.507 3 12
, lI 1.1 0.408 4 10.48.0 4
40 Example 2: Dye Stain Performance Photographic elements were prepared by the method described in Example 1 and processed by Process A as described in Example 1 after exposure through a graduated density test object. To determine possible contamination due to residual sensitized color chips, the maximum density in each blue, green, and red spectral region was measured using blue, green, and red filters (Status M).
) filter). From the result (determined density (DB, D(4 and DR)), calculate the ratio of the undesired blue or green density to the desired red density.

The lower this ratio, the less staining of the dye and therefore the higher the purity of the color and the better the separation of the colors. Table 3 shows the results.

Table 3 9. 32 43 10 A, 28. 27 11 B, 30. 29 12 G, 36. 35 13 1. 12. 15 14 2. 16. 18 15 3. 09. 15 16 4. 17. 20 17 5. 12. 16 From the data in Table 3, it can be seen that the bleach accelerator precursor of the present invention is highly effective in removing contaminants remaining on color photographic film after processing.

Claims (1)

[Claims] 1. A bleach accelerator precursor in color photographic elements characterized in that it contains a heavy metal salt of an acid-containing non-zwitterionic organic thiol.