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Industrialized preparation method of 1,8-diaminonaphthalene

A technology of diaminonaphthalene and dinitronaphthalene, which is applied in the field of preparation of 1,8-diaminonaphthalene, can solve the problems of inapplicability, high requirements for reaction raw materials, and failure to give full play to the advantages of the hydrazine hydrate reduction method, so as to ensure complete the effect of ensuring safety

Active Publication Date: 2014-03-26
九江常宇化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The raw material used in this method is refined 1,8-dinitronaphthalene, which has high requirements for the reaction raw material and does not give full play to the advantages of the hydrazine hydrate reduction method; due to the limitation of the reaction raw material, this method is not suitable for industrial production of 1,8 -Diaminonaphthalene

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1）

[0025] The industrialized preparation method of 1,8-diaminonaphthalene of the present embodiment comprises the following steps:

[0026] ① Add 70kg of prefabricated catalyst and tidal dinitronaphthalene (the mass of dinitronaphthalene is 700kg) to the 5000L enamel reaction kettle with agitator, thermometer, reflux condenser and high-level dripping storage tank and solvent ethanol 2500L, then turn on the agitator, after the material in the kettle is warmed up to 65 ° C ~ 75 ° C (70 ° C in this embodiment) under stirring, slowly add 80.1% ~ 100% (in this embodiment) dropwise at this temperature 100%) of hydrazine hydrate 520kg, dripping time is 5 hours, after the hydrazine hydrate is added dropwise, the material in the reactor continues to be warmed up to 75 ° C ~ 90 ° C (75 ° C in this embodiment), at this temperature insulation reaction 3 The reaction was stopped after ~8 hours (5 hours in this example).

[0027] The added tidal dinitronaphthalene was detected by high-perform...

Embodiment 2）

[0046] All the other of the industrialized preparation method of 1,8-diaminonaphthalene of the present embodiment are identical with embodiment 1, and difference is:

[0047] The solvent added to the reactor in step ① is methanol, and the dosage is 2500L.

[0048] In step ②, methanol is used to wash the catalyst obtained by pressure filtration.

[0049] Step 3. the solvent recovered is methanol.

[0050] Step ④ rectification to obtain: 463kg of 1,8-diaminonaphthalene finished product at the top of the tower (the content of 1,8-diaminonaphthalene in HPLC is 99.5%), 20kg of 1,5-diaminonaphthalene by-product at the bottom of the tower (1,5-diaminonaphthalene The detection content of diaminonaphthalene into HPLC is 92.3%).

Embodiment 3）

[0052] All the other of the industrialized preparation method of 1,8-diaminonaphthalene of the present embodiment are identical with embodiment 1, and difference is:

[0053] ①Add 700Kg of dry dinitronaphthalene (1 ， 8 The content of dinitronaphthalene was 98.5% by HPLC), 70kg of prefabricated catalyst and a mixed solvent composed of 2000L ethanol and 500L toluene, and the stirring was started to raise the temperature of the materials in the kettle to 70°C. At this temperature, 610 kg of 85% hydrazine hydrate was added dropwise to the reactor, and the time for adding was 4 hours. After the addition of hydrazine hydrate was completed, the temperature of the materials in the kettle was continued to rise to 79° C., and the reaction was stopped after 4 hours of heat preservation.

[0054] ② Cool the reacted material in step ① to 45°C, press filter to recover the catalyst, wash the catalyst obtained by press filtration with a small amount of ethanol, combine the washing liquid and...

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Abstract

The invention discloses an industrialized preparation method of 1,8-diaminonaphthalene, which comprises the following steps: sequentially adding a catalyst, dinitronaphthalene and a solvent into a reaction kettle, stirring and heating materials in the reaction kettle to a temperature of 65-75 DEG C, slowly dripping hydrazine hydrate, then continuously heating materials in the reaction kettle to the temperature of 75-90 DEG C and keeping the temperature for 3-8 hours until the end of the reaction; cooling the materials after the reaction to the temperature of 40-45 DEG C for pressure filtration, washing and recovering the catalyst obtained through pressure filtration, and mixing the washing liquid and the filtering liquid to obtain a feed liquid; conducting decompression and desolvation on the feed liquid to recover the solvent; adding hot water with the temperature of 50-80 DEG C into the desolventized feed liquid for water washing stratification, wherein the upper layer is water phase and the lower layer is feed liquid phase; feeding the feed liquid phase obtained through stratification into a rectifying tower for rectification, and obtaining 1,8-diaminonaphthalene, wherein the purity of 1,8-diaminonaphthalene at the top of the rectifying tower is equal to or larger than 99.5%. The dinitronaphthalene raw materials comprise water and an organic solvent, wherein the organic solvent comprises an organic solvent used by a naphthaline-nitrified product in refining.

Description

technical field [0001] The invention relates to a preparation method of 1,8-diaminonaphthalene, in particular to an industrial preparation method of 1,8-diaminonaphthalene. Background technique [0002] Diaminonaphthalene mainly includes 1,5-diaminonaphthalene and 1,8-diaminonaphthalene, which are important pigment intermediates; among them, 1,8-diaminonaphthalene is an important intermediate for the manufacture of oil-soluble pigments, mainly used for synthesis C.I. Oil-soluble orange 60# and oil-soluble red 135#. These two pigments are widely used in the coloring of polystyrene, plexiglass, rigid polyvinyl chloride and ABS. [0003] The reduction of dinitronaphthalene is an important way to prepare diaminonaphthalene. The methods for preparing diaminonaphthalene by reduction of dinitronaphthalene include iron powder reduction method, electrochemical reduction method, catalytic hydrogenation reduction method and hydrazine hydrate reduction method, etc. Although the prepa...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C211/58C07C209/36C07C209/84
Inventor 陆益周武勇付强周应剑
Owner 九江常宇化工有限公司
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