Refining method of n-butyl isocyanate

A technology of n-butyl isocyanate and butyl isocyanate, which is applied in the field of n-butyl isocyanate refining, and can solve the problems of high free acid, n-butyl isocyanate turbidity and difficulty in removal

Active Publication Date: 2016-10-05
HUNAN GOFAR FINE CHEM IND TECH CO LDT
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Based on this, it is necessary to provide a refining method for n-butyl isocyanate aimed at the problems of turbidity, high free acid and difficulty in removing n-butyl isocyanate produced by the traditional n-butyl isocyanate synthesis method

Method used

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  • Refining method of n-butyl isocyanate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] Provide 500L of n-butyl isocyanate solution to be refined. After analysis, the mass content of n-butyl isocyanate is 99.1%, the mass content of free acid is 0.69%, and there are a large amount of white flocs inside.

[0045] At -8°C, add aluminum trichloride and dropwise 0.2mol / L sodium hydroxide solution to the n-butyl isocyanate solution to be refined while stirring, and react for 1 hour to obtain a mixed solution, in which n-butyl isocyanate to be refined The mass ratio of base isocyanate solution, aluminum trichloride and sodium hydroxide solution is 1:0.05:5.5.

[0046] The above mixed solution was left to stand for 60 minutes, and the upper organic layer was taken for vacuum distillation, and fractions were collected to obtain a 480L sample. After analysis, the mass content of n-butyl isocyanate in the sample is 99.63%, the mass content of free acid is 0.09%, and the appearance is clear and transparent; after the sample is placed for 7 days, the mass content of n-...

Embodiment 2

[0048] Provide 1000L of n-butyl isocyanate solution to be refined. After analysis, the mass content of n-butyl isocyanate is 99.21%, the mass content of free acid is 0.75%, and there are a large amount of white flocs inside.

[0049] At -10°C, add aluminum trichloride and dropwise 0.23mol / L sodium hydroxide solution to the n-butyl isocyanate solution to be refined while stirring, and react for 1 hour to obtain a mixed solution, in which n-butyl isocyanate to be refined The mass ratio of base isocyanate solution, aluminum trichloride and sodium hydroxide solution is 1:0.05:5.

[0050]The above mixed solution was left to stand for 30 minutes, the upper organic layer was taken for vacuum distillation, and fractions were collected to obtain a 985L sample. After analysis, the mass content of n-butyl isocyanate in the sample was 99.7%, the mass content of free acid was 0.06%, and the appearance was clear and transparent; after the sample was placed for 14 days, the mass content of n...

Embodiment 3

[0052] Provide 1500L of n-butyl isocyanate solution to be refined. After analysis, the mass content of n-butyl isocyanate is 99.23%, the mass content of free acid is 0.72%, and there are a large amount of white flocs inside.

[0053] At -7°C, add aluminum trichloride and dropwise 0.25mol / L sodium hydroxide solution to the n-butyl isocyanate solution to be refined while stirring, and react for 1 hour to obtain a mixed solution, in which n-butyl isocyanate to be refined The mass ratio of base isocyanate solution, aluminum trichloride and sodium hydroxide solution is 1:0.05:5.5.

[0054] The above mixed solution was left to stand for 45 minutes, and the upper organic layer was taken for vacuum distillation, and fractions were collected to obtain a 1480L sample. After analysis, the mass content of n-butyl isocyanate in the sample is 99.78%, the mass content of free acid is 0.04%, and the appearance is clear and transparent; after standing for 28 days, the mass content of n-butyl i...

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Abstract

The invention provides a refining method of normal-butyl isocyanate. The method comprises the following steps: providing normal-butyl isocyanate solution to be refined, adding alchlor and dropwise adding a sodium hydroxide solution to the normal-butyl isocyanate solution to be refined at minus 10 to minus 5 DEG C while stirring, ensuring that reaction is performed for 0.5 to 1 hour, so as to obtain mixed liquor, ensuring that the mixed liquor is subjected to standing and layering, and separating and purifying an organic layer in the upper layer, so as to obtain the normal-butyl isocyanate. According to the refining method for normal-butyl isocyanate, impurity acid and a poly (normal-butyl isocyanate) floccule in the normal-butyl isocyanate to be refined are neutralized by using by the sodium hydroxide under the action of alchlor, then standing and layering are carried out, and the organic phase in the upper layer is separated and purified to obtain the normal-butyl isocyanate; according to the method, the product quality is improved.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a method for refining n-butyl isocyanate. Background technique [0002] n-Butyl isocyanate is an important pesticide intermediate. When preparing sulfonylurea herbicides by phosgene method, n-butyl isocyanate is used as a catalyst, which can make the reaction stable and increase the yield; n-butyl isocyanate is also used in the synthesis of pesticide fungicide benomyl. Benomyl is a high-efficiency broad-spectrum, systemic fungicide with protective, eradicating and therapeutic effects, and can prevent and control a variety of crop diseases. However, the n-butyl isocyanate produced by the traditional n-butyl isocyanate synthesis method has problems such as turbidity, high free acid and difficulty in removal, which does not meet the quality requirements, short-term storage, that is, self-polymerization to form flocs, and the subsequent reaction yield. Reduced, affecting product qu...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C265/04C07C263/20
Inventor 黎辉良陈南方张敦河沈方勇李勇利
Owner HUNAN GOFAR FINE CHEM IND TECH CO LDT
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