DE4240869A1 - Color photographic processing method - Google Patents

Description

The invention relates to a process for the continuous union processing imagewise exposed, farbfotogra fischer materials based on hochchloridhaltiger silver halide emulsions with at least the processing steps (a) color development, (b) bleaching and fixing or bleach-fixing, (c) watering or Stabili Sieren and (d) Drying, wherein the color developer is regenerated with a recovery rate of less than 160 ml / m ² .

It makes economic and ecological sense that continuous development of photographic materials always lower regeneration rates are applied, which the chemical activity of developers, bleaching baths, Bleach-fix baths and fixer baths in continuous operation maintained.

For example, in the Kodak EP-2 process, regeneration rates of 325 ml / m ^{2 were} used.

For the 1986 introduced Kodak RA 4 process 160 ml / m ^{2 were} prescribed. For this process exist since 1991 process variants, which provide a regeneration of only 90 to 100 ml / m ² .

The lower the recovery rate, the higher but the equilibrium concentration of reaction products that are used in photographic processing ent stand, z. As the concentrations of the halide ions, the be released from the emulsions.

While the EP-2 process had an equilibrium concentration of 0.7 g KBr at a recovery rate of 325 ml / m ² , the concentration of KBr at 160 ml / m ^{2 increased} to 1.4 g / l and already required a developer temperature from 38 ° C instead of 33 ° C to compensate for the loss of activity.

A recovery rate of 80 ml / m ² has not been realized in this system and would have led to a KBr concentration of about 2.8 g / l.

The concentration of KCl in the RA 4 process is usually between about 0.8 and 2 g / l at a regeneration rate of 160 ml / m ² , with a regeneration rate of 80 ml / m ² between about 1.6 and 4 g / l wherein the lower value results from the photographic process of reduction of silver chloride by the developing agent.

Will you lower the recovery rate again, z. B. to less than 40 ml / m ² , it is to be expected even higher KCl concentrations Kon, which is very detrimental to the development kinetics of the yellow layer, so that the maximum densities yellow are no longer achieved and the gamma 2 values for Decrease yellow severely.

A compensation of the loss of activity due to temperature increase is insufficient, so that more chemical measure such as pH increase and concentration increase Developer substance required.

But that contradicts the desired goal, the process to lead ecologically.

Object of the present invention was, despite vermin derter Regenerierquoten and thus increased Halogenidkon maintain the activity of the developer received and thus typge in the specified target time to obtain sensitometric results.

It has now surprisingly been found that this task, although the developer at least 2 g KCl / l, preferably 4 to 10 g KCl / l, from the Reduction of AgCl originates, by at least one-time, preferably two to twenty times Be elimination or significant reduction in the Interface of the material adhering diffusion layer can be solved.

Among high chloride silver halide emulsions are to understand those whose silver halides too little at least 90 mole% of AgCl, preferably 95 mole% AgCl exist. The difference to 100 mol% AgBr and / or AgI.  

To eliminate or significant reduction in the Interface of the material adhering diffusion a number of methods are available, z. As the guiding of the material via wiper lips, by Squeegee rolls, over rotating, preferably gegenläu fig for material transport rotating foam rollers or the multiple redirecting of the material over one large number of transport shafts.

example 1

A commercial color paper for processing in the RA-4 process, whose silver halide emulsions contain AgCl _0.995 Br _0.005 , was processed as follows:

Developer: | 45 s, 35 ° C Bleach-fixing: 45 s, 35 ° C Water: 4 × 22.5 s, 30 to 35 ° C dry

developer Developer substance CD 3 | 5 g diethylhydroxylamine 5 g potassium carbonate 30 g Ethylenediaminetetraacetic acid (EDTA) 2 g diethylene glycol 30 ml pH 10.2

Bleach Fix Ammonium iron EDTA | 35 g (NH ₄ ) ₂ S ₂ O ₃ 70 g potassium 5 g pH 6.5

The recovery rate of the developer was 160 ml / m ² . Veil, gamma 1, gamma 2 and maximum density were determined. The results are shown in Table 1.

Example 2

The procedure was as in Example 1, but were the Developer 10 g KCl / l was added.

Example 3

The procedure was as in Example 2, but the tempera The developer's temperature has been increased to 38 ° C.

Example 4

The procedure was as in Example 2, but the material was passed after leaving the developer bath through two pairs of rollers, the roles of front and back of the material touched and exerted on the material, a pressure of 150 p / cm ² . On the material between the two roller pairs 50 ml of water / m ² material were applied.

Example 5

The procedure was as in Example 2, but the material in the developer bath passed through 5 pairs of rollers, all of which exerted a pressure of 150 p / cm ² on the material.

Example 6

The procedure was as in Example 5, but it went through the material after leaving the developer bath additional  Lich 2 pairs of rollers according to Example 4, wherein the Ma material between the two roller pairs 50 ml water / m² Material were applied.

The results of Examples 2 to 6 are also in Table 1 listed.

Claims (3)

A process for the continuous processing of imagewise exposed color photographic materials based on high chloride silver halide emulsions with at least the steps of (a) developing color, (b) bleaching and fixing or bleaching, (c) watering or stabilizing and (d) drying, wherein the color developer with a Rege nerierquote of less than 160 ml / m ^{2 is} regenerated, characterized in that the developer contains at least 2 g KCl / l from the chemical reduction of the AgCl emulsions and from the che mix reduction of the AgCl emulsions the boundary surface of the material adhering diffusion layer at least once, preferably two to twenty times significantly reduced or completely removed. 2. The method according to claim 1, characterized in that the Regenerierquote less than 80 ml / m ² be wearing and the developer contains 4 to 10 g KCl / l. 3. The method according to claim 1, characterized in that the Regenerierquote less than 40 ml / m ² be wearing.