DD298320A5 - METHOD FOR PRODUCING RHODIUM-DOTTED GELATINE-CONTAINING SILVER HALOGENIDE EMULSIONS - Google Patents

Abstract

The invention relates to a process for the preparation of rhodium-doped gelatin-containing silver halide emulsions, which are particularly suitable for photographic materials. Rhodium-doped silver halide emulsions according to the inversion method are prepared by adding the rhodium hexane chlorocomplex salt in the presence of alkanols having 1 to 3 hydroxyl groups and 2 to 3 carbon atoms of the halide solution, the alkanol occupying 1 to 15% of the total volume of the halide solution rhodium-doped; rhodium; Inversfaellung; Doppeleinlauffaellung; Rhodiumhexachlorokomplexsalz; alkanol}

Description

The invention relates to a process for the preparation of rhodium-doped gelatin-containing silver halide emulsions according to the inverse precipitation method for photographic film materials.

Characteristic of the known state of the art

The doping of silver halide photographic emulsions with rhodium-III ions causes desensitization associated with an increase in gradation. The amounts of rhodium-III-ions are usually in the order of 10 ^"7 to 10" ⁸ MoI Rh ³⁺ ions per mol of silver halide. This, received as Rhodiumeffekt in the literature method (after publication of the FIAT Final Report FIAT Final Report No.360 Report on Agfa Photo Paper Plant at Leverkusen) has become a widely used practice in the photographic industry, particularly in the production of silver halide emulsions for use in the photographic film sector and in the production of steeply graduated photographic papers Effect can only be detected in the presence of the hexachlororhodate III complex (H. Welzel, Z. Wiss., Phot 58 (1964) 58, MT Beck, P. Kiesz J. Signal AM [1976] 131) Use of the sodium hexachlororhodate-III complex (Na ₃ RhCl) In aqueous systems, the sodium hexachlororhodate III complex forms mixed ligand complexes in which chloride ions are separated by Wa be replaced (W.Preetz; E.BIasiusZ. anorg. Gen. Chem. 333 [196511]. Possible variants are: (RhCIe) ³ "; (RhCl ₆ (H ₂ O) ² -; (RhCl ₄ (H ₂ O) ₂ ) -; (RhCl ₃ (H ₂ O) ₃ ); (RhCl ₂ (H ₂ O) ₄ ) *; (RhCl (H ₂ O) ₆ ²⁺ and (Rh (H ₂ O) ₆ ) ³ *, where the sensitomeric activity of the complexes decreases in the given order All complex solutions were stored and used in acidified 4.3 M sodium chloride solutions (FIAT Final Report No. 360 Report on Agfa-Photo Paper Plant at Leverkusen).

In gelatin-containing media, as applied to the synthesis of photographic silver halide emulsions, similar ligand exchange reactions occur between chloride, water and gelatin, the kinetics of which are affected by the terms gelatin concentration, gelatin type, pH, halide ion concentration, temperature and presence of foreign ions.

For this reason, in the production of the silver halide emulsions by the single-jet method in which the silver nitrate solution is added to the agitated halide-containing gelatin solution in one or more run-in, the addition of the sodium hexachlororhodate-III complex is usually carried out one minute before the silver halide precipitation (P. Glafkides Chimie Photographique Paul Montel-Verlag 1957).

When using inverse precipitation in which the silver nitrate solutions are made in mostly acidified gelatin solutions, the sodium hexachlororhodate III complex is usually added together with the halide solution. These dilute halide salt solutions undergo a clearly detectable aquolysis of the complex. Similar conditions are in Doppeleinlauffällungen. Here, at a defined pAg value, halide and silver nitrate solutions are added simultaneously to the gelatin solution.

The sodium hexchlorochloroiodate-III complex is added to the halide solution. During in-run times, which are rarely less than 30 minutes, chloride-water ligand exchange occurs and equilibrium forms between the hexachloro and chloroquoic species, which has reduced sensitometric activity. For optimum gradation Sensitivity Directorate customary photo technical Lith-Line materials of rhodium from 10 to ~ ⁷ to 10 ^"6 MoI Rh ³⁺ ions per mol of silver halide At substantially higher amounts of rhodium, as are customary for direct positive or overhead materials., It affects the Aquolysis of the Natriumhexachlororhodat-III complex particularly disturbing on the achievement of optimal sensitometric properties.

In the known patents, which involve the use of rhodium in photographic silver halide emulsions, no solutions to increase the stability of the Natriumhexachlororhodat-ill complex during the Silberhalogenidfällungen are shown, but only variants for improving the storage stability and usually in combination with other metal ions Improvement of Short-Time Reciprocity Error (GBPS 775197; FR-PS 1546184; Japanese Patent 49-33781; SU-PS 334906; OS 2226877; OS 2632202; Jap-K 53-39120; FR-PS 2406228; DE-PS 312S921; US-PS 4332887; DE-PS 3340323).

Object of the invention

The aim of the invention is a photo-technical film material with optimal sensitometric properties.

-2- 298 320 Explanation of the essence of the invention

The invention is based on the object of providing a process for producing rhodomoted emulsions after the inverse precipitation process.

or the double-feed method for photographic film materials, the high gradation values at low

Have addition of rhodium-III complexes. According to the invention, the object is achieved in a process for producing rhodium-doped gelatin-containing Silver halide emulsions by preparation of silver nitrate and rhodium complex halide solutions, I η ve rs- or Double-jet precipitation, physical ripening and desalting are achieved by dissolving the rhodium hexachloro-complex salt in Presence of alkanols having 1 to 3 hydroxyl groups and 2 to 3 carbon atoms of the halide solution, wherein the Alkenol is 1 to 15% of the total volume of the halide solution. The alkanol can be added with both the rhodium hexachloro complex salt and the halide solution as well

the halide solution prior to the addition of the complex salt.

Particularly advantageous are 3 to 8% of an alkanol having a hydroxyl group and 2 to 3 carbon atoms or 1 to

5% of an alkanol having 2 to 3 hydroxyl groups and 2 to 3 carbon atoms relative to the total volume d6r

Halide solution proved. The combined use of monohydric and polyhydric alkanols is also possible. It has surprisingly been found that significantly improved by Alkanolzusatz according to the invention, the rhodium effect

becomes. With small amounts of Rhodiumkomplexsalz a clear increase in the gradation in photo-technical

Materials. The invention can be applied to chemically unripened emulsions for light-room materials and chemically matured Emulsions for conventional photographic film materials are successfully applied. Spectroscopic investigations confirm the presumption that by the presence of 1 to 15% of alkanols with 1 to

3 hydroxyl groups and 2 to 3 carbon atoms based on the total volume of the halide solution, the kinetics of

Ligand exchange of the rhodium hexachloro complex with water, which takes place in dilute halide solutions,

is slowed down considerably. The sensitometrically effective rhodium hexachloro complex can be used during the

Silver halide precipitation longer effective. embodiments example 1 Spectroscopic measurements of rhodium hexahalogeno or rhodium haloquo complexes with inventive Addition of different amounts of alkanols, alkanediols and alkanetriols. The measurements are in the visual field

between 400 and 700nm with the Specord UV-VIS.

(Küvettenstärke: 10mm; recording time: 2min; Einstellboreich: Transparenz75-125% Measurement temperature: 30 ⁰ C)

The rhodium concentration is 3.55 x 10 ~ ⁴ (added as Na ₃ (RhCIg)), the halide ion concentration 1.2 M / I. According to W. Preetz and E. Blasius, the rhodium complexes have the following absorption maxima: RhCl ₆ ³ "(RhCl ₅ (H ₂ O)) '- (RhCl ₄ (H ₂ O) ₂ )"

514.7 nm 503.5 nm 489.7 nm

The existence of the different rhodium complex species is demonstrated by a decrease in the individual absorption maxima or formation and increase in the new maxima

 Table 1 demonstrates the results.

Medium duration of detectability of the

Rhodium complex species in minutes with the league: η in equilibrium

6Cl (predominantly) (6CI: 5CIH ₂ O 5CIH ₂ O: 4CI (H ₂ O) ₂

Water S 2 2-10> 10

1% by volume of ethanol S3 3-12> 15

5 vol .-% ethanol §4 4-20> 20

10% by volume of ethanol S7 7-30> 30

15% by volume of ethanol S10 10-30> 30

5% by volume ethanol S 5 5-15> 15

5% by volume propanetriol S5 5-15> 15

From the results in Table 1 it can be seen that by addition of the alkanols of the ligand exchangers chloride-water of the rhodium hexachloro complex in 1.2 molaror Nair ^! chloride solution is significantly slowed down. With extended life of the complex species with a higher chloride ligand egg number, according to the invention, an increased sensitometric activity is shown. The spectroscopic results, taking into account the diversity of spectroscopic and sensitometric measuring methods, correlate with the achieved sensitometric data of the silver halide emulsions prepared according to the invention, as demonstrated by Examples 2 and 3.

Example 2 Using the solutions indicated, silver chloride emulsions are subjected to a potential-controlled Double inlet process produced.

Solution I: 100 OmiH ₂ O; 20 g low-content gelatin; pH 2 solution: 50 ml of H ₂ O; 10OgAgNO ₃

Solution: 50 ml of H ₂ O; 35gNaCl, 0.366mgRh ³⁺ (as Na ₃ RhCl _e )

For solution III various amounts of water are replaced by alkanol according to the invention.

Emulsion a Solution III a OmI Alkanol 50OmIH ₂ O

Emulsion b solution IHb 5 ml ethanol 495 ml H ₂ O

Emulsion C solution 25 ml of ethanol 475 ml of H ₂ O.

Emulsion d solution HId 50 ml ethanol 45OmIH ₂ O

Emulsion e solution IH 75 ml ethanol 425 ml H ₂ O

Emulsion f solution HIf 25 ml ethanol 475 ml H ₂ O

Emulsion g solution IHg 25mlPropanetriol 475 ml H ₂ O

To the temperature-controlled at 32 ° C Solution I heated to 24 ⁰ C the solutions II and III (ag) at a constant rate are added over a period of 40 minutes simultaneously., The Ag ρ-value during the precipitation process is constant at 6.4 ± 0.05 regulated.

After removal of the soluble salts by a conventional flocculation process, the emulsions are added with simultaneous increase in pH to 6, b with 90 g of low-profile gelatine and 2-methyl-4-hydroxy-1,3,3a, 7-tetraazaindene added as a stabilizer.

Characteristics of the finished emulsions:

Halide composition: 100% silver chloride

Silver content: 30 gAg / kg emulsion

Rhodium doping: 6-10 "" MRh ³ VMAg

pH value: 6.5

pAg value: 6.6

Viscosity (4O ⁰ C): 8.5 mPas

Gelatin content: 60 g / kg emulsion

Average grain size: 0.13 μπι log σ0.06

The resulting emulsions are cast on acetylcellulose backing using standard wetting and curing agents as well as conventional filter dyes having a silver content of 4.0 g / m ² . The exposure is carried out with a mercury high-pressure lamp (500 W) with a time of 4 seconds behind a step wedge with the increase in density \ / ~ 2. The development takes place according to ORWO regulation 1111 (ORWO recipe book edition 1983). The sensitometric results are shown in Table 2.

emulsion Sensitometric results D _m t " gradation 0.04 a 6.6 0.04 b 7.6 0.04 C 7.8 0.04 d 8.0 0.04 e 8.2 0.04 f 8.0 0.04 G 8.0

In the case of the emulsions prepared according to the invention, this formulation shows a clear increase in the gradation as a result of the rhodium hexachloro complex, which is more effective.

Example 3

Using the solutions indicated, emulsions are prepared by the inverse precipitation method.

Solution I: 100 OmiH ₂ O; 20g low-gelatin; pH 3.0 solution: 50 mmol of O ₂ ; 10OgAgNO ₃

Solution: 50 ml of H ₂ O; 25gNaCl; 4,3gKBr; 0,732mgRh ³⁺ (asNa ₃ RhCI ₈ )

According to the invention, different amounts of alkanol are added to solution IH, and the corresponding amount of water is substituted.

Emulsion h Solution IHh OmlAlkanol 50OmIH ₂ O Emulsion i Solution Uli 25mlEthanol 475 ml H ₂ O Emulsion k Solution IHk 50 ml of ethanol 45OmIH ₂ O Emulsion I Solution III I 20mlEthandiol 48OmIH ₂ O

To the tempered to 32 ° C solution I is added to the likewise 32 ⁰ C tempered solution Il. After stirring for 2 minutes, the tempered to 24 ⁰ C solution Il (hl) is added within 10 minutes. After 10 minutes of digestion and removal of the soluble salts by a conventional flocking process, 90 g of low-added gelatin are added to the emulsion while the pH is raised to 7.0, and the emulsion is added with 2-methyl-4-hydroxy-1,2,3a, 7 tetraazaindene stabilized. Characteristics of the finished emulsion:

Halide composition: Ag CIo.m Br _Oi oa Silver content: 30 g / kg emulsion Rhodium doping: 1.2-10 " ⁶ MRh ³ VMAg

pH value: 7.0

pAg value: 6.8

Viscosity (4O ⁰ C): 8.5 mPas Gelatin content: 50 g / kg emulsion Average grain size: 0.14 μιη log σ0.08

The resulting emulsions are cast onto acetyl cellulose pad using standard wetting and curing agents, as well as conventional filter dyes having a silver content of 5.0 g / m ² . The exposure and processing are carried out analogously to Example 2. The sensitometric results are shown in Table 3.

emulsion Sensitometric results 0.04 gradation 0.04 H 4.3 0.04 i 5.7 0.04 k 5.9 I 5.7

This formula also clearly shows the effect of increasing the gradation in the emulsion synthesis according to the invention.

Claims (1)

A process for preparing rhodium-doped gelatin-containing silver halide emulsions by preparing silver nitrate and rhodium complex-containing halide solutions, inverse fission precipitation, physical ripening and desalting, characterized by adding the rhodium hexachloro-complex salt in the presence of alkanols having 1 to 3 hydroxyl groups and 2 to 3 carbon atoms of the halide solution wherein the alkanol is 1 to 15% of the total volume of the halide solution. Field of application of the invention