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Method to extract silver from photographic developer

A developing solution and silver halide technology, applied in chemical instruments and methods, photography, photographic technology, etc., can solve problems such as damage, frequent maintenance and cleaning operations of silver precipitation, shortening the service life of the developing solution, etc.

Inactive Publication Date: 2002-10-02
EASTMAN KODAK CO
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

These silver deposits then require more frequent maintenance and cleaning operations
Also, the presence of silver-containing slurries in the developer bath shortens the useful life of the developer
Eventually, silver-containing slurries can deposit on the processed film, whereby they form black spots or fog, which can destroy the developed image

Method used

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  • Method to extract silver from photographic developer

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] Example 1-Preparation of aluminosilicate polymer

[0031] Add 16.7mmol tetraethyl orthosilicate Si(OR) to 1000mL deionized water 4 . The reaction mixture was stirred at room temperature for 1 hour, and then 31.2 mmol of AlCl was added 3 .6H 2 O is dissolved in 1000 mL of pure water. The resulting mixture was stirred for 20 minutes, and then the pH was adjusted to 4.5 by means of 1M sodium hydroxide. The solution became cloudy. When the solution became clear, 1M sodium hydroxide was added until the pH reached 6.8. A white gel was obtained, which was centrifuged at 2000 rpm for 20 minutes. The gel was taken out and re-dissolved in 5 mL of a mixture of 1M hydrochloric acid and 2M acetic acid. The volume is made up to 2 liters with water. The solution contained 30 mmol Al, 16.6 mmol Si, 5 mmol HCl, and 10 mmol acetic acid. Store the solution at 5°C.

[0032] Then, the solution was diluted with deionized water, and as a result, an Al concentration of 10 mmol / liter was obtained. ...

Embodiment 2

[0036] 21.1g / l

[0037] The developer is aged, that is, used, it contains 0.11 mg / l of silver derived from the development of photographic products. The developer is sent through the pipe 14 to the cassette 16, in which is placed a container 18, which contains 100 mg of the polymer prepared in Example 1. The wall of the container 18 allows the developer to permeate. After flowing through the cassette 16, the developer is fed back into the tank 12. The flow rate in this circulation loop is 0.5 liters / minute. The amount of silver is measured by inductively coupled plasma mass spectrometry (ICPMS) per liter of developer after the cycle. No trace of silver was detected. The concentration of the main component of the developer did not change.

Embodiment 3

[0039] Put 3 liters of aged Graphic Arts developer in the tank, the composition of which is the same as that in Example 2, except that the developer contains 0.8 mg of silver per liter. In the developer solution, a bag made of a polypropylene cover containing 100 mg of the polymer prepared in Example 1 was placed. The silver concentration is measured by ICPMS at regular intervals.

[0040] The following results are obtained:

[0041] Contact time

[0042] The concentration of other organic or inorganic components in the developer has not changed.

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PUM

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Abstract

This invention relates to the development of silver halide photographic products. Silver-containing slurry builds up in the developing bath. These silver-containing slurries can be eliminated by contacting the developing bath with sulfur group modified aluminosilicate polymers. For example, the developing tank (12) is provided with a circuit for delivering the bath liquid through the cassette (16) containing a developing bath-permeable element (18) containing a polymeric aluminosilicate modified with sulfur groups. thing.

Description

Invention field [0001] The present invention relates to a method for removing the silver contained in a used photographic silver halide developer. Background of the invention [0002] In the photographic industry, silver halide film (and photographic paper) is exposed and placed in several treatment baths, especially at least one developing bath for processing. Such washing methods are well known (see, for example, "Chimie et Physique Photographiques", P. Glafkidès, Vol Chapter XL, pages 947-967, fifth edition, 1987). A known problem encountered in the development of silver halide photographic films is the accumulation of metallic silver in the development bath in the form of a silver-containing slurry. The accumulation of silver-containing slurry causes silver deposits to adhere to the walls of the developing tank, the conveying rollers, and all parts of the washing line. As a result, these silver deposits require more frequent maintenance and cleaning operations. Also, the pres...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G03C5/00C01B33/26C02F1/62C22B3/24C22B7/00C22B11/00G03C5/31
CPCC01B33/26G03C5/31G03C2200/40
Inventor O·J·C·庞赛莱特J·罗斯赫D·M·H·维特林
Owner EASTMAN KODAK CO