JPH0251898B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a 1,3-diaminopropane-tetraacetic acid iron diammonium salt which can be used, for example, as an oxidizing agent in color photographic printing.

[Prior art] Conventional oxidizing agents (hereinafter simply referred to as oxidizing agents) for color photographic printing include EDTA/FeNa (ethylenediaminetetraacetic acid iron sodium salt) and
EDTA/FeNH ₄ (ethylenediaminetetraacetic acid iron diammonium salt) is used.

[Problems to be Solved by the Invention] When using the above compound as an oxidizing agent, aqueous ammonia is added to an aqueous solution of the compound to adjust the pH. It is thought that the oxidizing effect is exerted by changing it to Fe(NH ₄ ) ₂ . That is, EDTA.Fe(NH ₄ ) ₂ exists only in a solution form and has not been obtained as a solid. For that reason
The physical and chemical properties of EDTA/Fe(NH ₄ ) ₂ have not been fully elucidated, nor has it been developed into other fields where it can be applied as an oxidizing agent. The present invention was made in view of these circumstances, and as a result of giving up on the crystallization of EDTA/Fe(NH ₄ ) ₂ itself and attempting crystallization research on closely related compounds, color photographic printing has been developed. The present invention was completed by discovering a new crystalline compound that can be used as an oxidizing agent in the process.

[Structure of the invention] 1,3-diaminopropane-tetraacetic acid iron 2 of the present invention
Ammonium salt [1,3-PDTA・Fe
(NH ₄ ) ₂ OH] is represented by the following formula.

An example of the method for synthesizing this new compound is as follows.

First, 1,3-PDTA (1,3-diaminopropane tetraacetic acid) is reacted with aqueous ammonia and Fe ₃ O ₄ . As shown in the following formula, Fe (divalent) NH ₄ salt and Fe (3
Produce a mixture of _NH4 salts.

1,3-PDTA+NH ₄ OH + Fe ₃ O ₄ → 1,3-PDTA・Fe (bivalent) (NH ₄ ) +1,3-PDTA・Fe (trivalent) (NH ₄ ) This reaction has a pH of 3 to 6, More preferably 3-5
It will be held in 1,3- if PH is less than 3
There is a risk that PDTA, Fe, and H will precipitate and the reaction will not proceed, and if the pH exceeds 6, the reaction rate will slow down. By mixing equimolar amounts of each raw material and reacting them, the pH can be adjusted to the above-mentioned preferred range.

The reaction rate is preferably 50 to 100°C. If it is less than 50℃, the reaction rate will be slow, while if it exceeds 100℃, there is a risk of decomposition reaction.
It is 80℃.

Although the reaction time is not particularly limited, it is usually carried out within a range of 5 to 20 hours.

As shown in the reaction formula above, the Fe complex compound produced in this reaction contains a mixture of divalent and trivalent iron, so the reaction solution can be further oxidized to convert divalent iron to trivalent iron. is necessary. The oxidation time varies depending on the oxidation conditions, but in order to improve the yield, it is preferable to check for divalent iron and oxidize until the amount of divalent iron is 0.1% or less. everything about 1,3-PDTA・Fe (trivalent) (NH ₄ ) represented by
become.

The oxidation method is not particularly limited, but oxidation using O ₂ or air, which is less likely to cause side reactions, is preferred. The oxidation temperature is 40-80°C, more preferably 40-60°C. If it exceeds 80°C, there is a strong tendency for decomposition reactions to occur, and if it is less than 40%, the oxidation rate becomes slow. It is necessary to adjust the pH of the reaction solution during oxidation to 4 to 7, more preferably 4 to 6; if the pH is too high, the oxidation rate will be slow. Next, the reaction solution is filtered to remove unreacted iron oxide, but filtration may be performed before the oxidation step.

Next, aqueous ammonia was applied to the reaction solution to give 1,3
−PDTA·Fe(trivalent)OH(NH ₄ ) ₂ is obtained. That is, 1,3-PDTA・Fe (trivalent) (NH ₄ )NH ₄ OH ― ― ― ― ― ― → 1,3-PDTA・Fe (trivalent) ・OH (NH ₄ ) ₂ In this case, the pH is 8 It is preferable to set it to ~8.5,
The pH can be maintained within the above range by adding 1,3-PDTA.Fe (trivalent) (NH ₄ ) and equimolar ammonia water. In this case, the reaction temperature is preferably 40 to 60°C from the viewpoint of maintaining the reaction rate and suppressing the decomposition reaction.

After the reaction is completed, the reaction solution is concentrated under reduced pressure.
By removing evaporated moisture and precipitating crystals, washing the obtained crystals with methanol etc. and drying them, crystals of 1,3-PDTA・Fe (trivalent) (NH ₄ ) ₂ OH are obtained. It will be done. The pressure at the time of decompression is preferably 50 to 150 mmHg from the viewpoint of suppressing decomposition reactions and maintaining concentration efficiency.

Although examples of the synthesis method in the present invention have been described above,
As another example, 1,3-PDTA・(NH ₄ ) ₃・H
A method of reacting FeCl ₃ and further adding NH ₄ OH,
In other words, 1,3-PDTA・(NH ₄ ) ₃・H+FeCl ₃ → 1,3-PDTA・Fe (trivalent)・H+3NH ₄ Cl 1,3-PDTA・Fe (trivalent)・H+2NH ₄ OH→ 1,3 -PDTA・Fe (trivalent) (NH ₄ ) ₂ OH + H ₂ O reaction is also available.

Examples will be described below, but the present invention is not limited to the following examples, and it is within the technical scope of the present invention to make appropriate design changes in accordance with the spirit described above and below.

[Example] 1,3-PDTA: 1000g 25% ammonia: 218g Water: 1300g Fe ₃ O ₄ (Fe content 71% by weight): 238g After mixing and reacting each raw material, the reaction solution was cooled and then Subjected to air oxidation. The reaction conditions in this step were reaction temperature: 70°C, pH: 3.5, reaction time: 16 hours, cooling temperature: 40-50°C, and air oxidation time: 10 hours.

Next, the reaction solution was filtered to remove unreacted substances. The reaction rate was 95%.

Further, 210 g of 25% ammonia water was added to this reaction solution to adjust the pH to 8.2, and the mixture was concentrated under a reduced pressure of 100 mmHg. Approximately 1100 g of evaporated water was extracted, and the precipitated crystals were filtered and washed with methanol.
526 g of dark red crystals of 1,3-PDTA.Fe (trivalent) (NH ₄ ) _2.OH were obtained. The yield was 39%, and the physical properties were as follows.

Molecular weight: 411 5% solution PH: 8.16 Solubility (25℃): 52% by weight Melting point: 178℃ (decomposition) Characteristic infrared absorption (KBr): Figure 1 Iron content: 13.8% The above iron content is the theoretical value. It was 101.51% of the value calculated from the molecular weight, and the Zn-XO content was also 101.8% of the theoretical value, and the error was within the experimental error range.

[Effects of the Invention] Since the present invention is configured as described above, a new crystalline compound, 1,3-diaminopropane-tetraferric acetate diammonium, which can be used as an oxidizing agent, etc. during color photographic printing You can get salt.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the infrared absorption spectrum of the new substance according to the present invention.

Claims (1)

[Claims] 1 formula An iron diammonium salt of 1,3-diaminopropane-tetraacetate, characterized by the following: