阅读说明：本技术 一种间苯二胺的提纯方法 (Method for purifying m-phenylenediamine ) 是由 刘勇 祁咏梅 翟志宇 于 2021-10-25 设计创作，主要内容包括：本发明涉及染料技术领域,具体为一种间苯二胺的提纯方法。该方法利用静态结晶器,通过控制静态结晶器中物料温度、结晶板降温速度、结晶板最终温度和发汗温度等关键工艺条件,从间苯二胺、邻苯二胺和对苯二胺的混合物中提纯得到间苯二胺。与传统的间苯二胺提纯方法对比,该方法具有安全性高、更环保、低投资和低能耗的优势。本发明产品间苯二胺主要用于染料的合成,也用于树脂固化剂和阻聚剂。(The invention relates to the technical field of dyes, in particular to a method for purifying m-phenylenediamine. The method utilizes a static crystallizer, and obtains m-phenylenediamine by purifying from a mixture of m-phenylenediamine, o-phenylenediamine and p-phenylenediamine by controlling key process conditions such as material temperature in the static crystallizer, cooling speed of a crystallization plate, final temperature of the crystallization plate, sweating temperature and the like. Compared with the traditional m-phenylenediamine purification method, the method has the advantages of high safety, environmental protection, low investment and low energy consumption. The m-phenylenediamine product is mainly used for synthesizing dye, and is also used for a resin curing agent and a polymerization inhibitor.)

1. A method for purifying m-phenylenediamine is characterized in that: the method comprises the following steps:

s1: preparing a mixture, wherein the mixture comprises the following components in parts by weight: more than or equal to 80 percent of m-phenylenediamine 85 percent, less than or equal to 15 percent of o-phenylenediamine 12 percent, and less than or equal to 5 percent of p-phenylenediamine 3 percent;

s2: adding the mixture prepared in the step S1 into a static crystallizer, and controlling the temperature of the material in the static crystallizer until the material is completely melted;

s3: controlling the cooling speed of the crystallization plate to enable the final temperature of the crystallization plate to be 42-43 ℃, and discharging the mother liquor from a valve at the bottom of the static crystallizer;

s4: controlling the temperature of the crystallization plate to be 55-57 ℃, keeping the temperature for 10-30 minutes, and discharging sweat from a valve at the bottom of the static crystallizer;

s5: collecting the solid on the crystallization plate, namely the m-phenylenediamine.

2. A purification method of m-phenylenediamine according to claim 1, wherein in said mixture of m-phenylenediamine, o-phenylenediamine and p-phenylenediamine, the content of m-phenylenediamine is 85%; 12% of o-phenylenediamine; the content of p-phenylenediamine is 3 percent.

3. The method for purifying m-phenylenediamine according to claim 1, wherein the temperature of the material in said static crystallizer is 59 to 61 ℃.

4. The method for purifying m-phenylenediamine according to claim 1, wherein the cooling rate of said crystallization plate of said static crystallizer is 3 to 6 ℃/hr.

5. The method for purifying m-phenylenediamine according to claim 1, wherein the temperature increase rate of said sweating process by said static crystallizer crystallization plate is 1 to 2 ℃/hr.

Technical Field

The invention relates to the technical field of dyes, in particular to a method for purifying m-phenylenediamine.

Background

M-phenylenediamine is mainly used for synthesis of dyes, resin curing agents and polymerization inhibitors, is an intermediate of azo dyes and azine dyes, is mainly used for manufacturing dyes such as direct suntan RN, basic orange, basic brown G, direct suntan G and the like, and is used as a fur dye, and in Japan, the m-phenylenediamine consumed by the azo dyes accounts for 90% of the total consumption. Also used as an accelerator for cement, and used in hair dyeing water, mordant, developer, etc.

According to the reports of relevant documents, the current methods for synthesizing m-phenylenediamine include two methods:

the method comprises the following steps:

the method takes nitrobenzene as a raw material, obtains a mixture of m-dinitrobenzene, o-dinitrobenzene and p-dinitrobenzene through nitration reaction, and obtains the m-dinitrobenzene through sodium sulfite and liquid caustic soda refining; then, m-phenylenediamine is obtained by hydrogenation reduction. The purification method generates a large amount of waste water and has great pollution to the environment; with greater security risks.

The second method comprises the following steps:

the method comprises the steps of taking nitrobenzene as a raw material, obtaining a mixture of m-dinitrobenzene, o-dinitrobenzene and p-dinitrobenzene through nitration reaction, obtaining a mixture of m-phenylenediamine, o-phenylenediamine and p-phenylenediamine through hydrogenation reduction without purification, and finally obtaining the m-phenylenediamine through rectification. Although the purification method avoids the disadvantages of waste water and safety risk in the first method, the equipment investment and energy consumption are large when the m-phenylenediamine is purified by rectification.

Disclosure of Invention

The invention aims to provide a method for purifying m-phenylenediamine, which solves the technical problems in the prior art.

The technical scheme of the invention is as follows:

the invention relates to a method for purifying m-phenylenediamine, which comprises the following steps:

s1: preparing a mixture, wherein the mixture comprises the following components in parts by weight: more than or equal to 80 percent of m-phenylenediamine 85 percent, less than or equal to 15 percent of o-phenylenediamine 12 percent, and less than or equal to 5 percent of p-phenylenediamine 3 percent;

s2: adding the mixture prepared in the step S1 into a static crystallizer, and controlling the temperature of the material in the static crystallizer until the material is completely melted;

s3: controlling the cooling speed of the crystallization plate to enable the final temperature of the crystallization plate to be 42-43 ℃, and discharging the mother liquor from a valve at the bottom of the static crystallizer;

s4: controlling the temperature of the crystallization plate to be 55-57 ℃, keeping the temperature for 10-30 minutes, and discharging sweat from a valve at the bottom of the static crystallizer;

s5: collecting the solid on the crystallization plate, namely the m-phenylenediamine.

Furthermore, in the mixture of the m-phenylenediamine, the o-phenylenediamine and the p-phenylenediamine, the content of the m-phenylenediamine is 85 percent; 12% of o-phenylenediamine; the content of p-phenylenediamine is 3 percent.

Further, the temperature of the material in the static crystallizer is 59-61 ℃.

Further, the cooling speed of the crystallization plate of the static crystallizer is 3-6 ℃/h.

Further, the temperature rising speed of the sweating process of the crystallization plate of the static crystallizer is 1-2 ℃/h.

The invention has the advantages and beneficial effects that:

compared with the traditional m-phenylenediamine process, the purification method has the following advantages;

1. the purification method avoids purification in a mixture of m-dinitrobenzene, o-dinitrobenzene and p-dinitrobenzene, and has higher safety;

2. compared with rectification, the purification method has the advantages of low investment, low operation temperature and low energy consumption;

3. the purification method does not need to add a new solvent, so that no waste liquid is generated, and the method has the advantage of environmental protection.

Drawings

FIG. 1 is a nuclear magnetic spectrum of m-phenylenediamine according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

In the specific implementation process, in order to obtain the m-phenylenediamine with simplicity, high safety, environmental protection, low investment and low energy consumption, the method for purifying the m-phenylenediamine of the invention comprises the following steps:

the method utilizes the static crystallizer, and obtains m-phenylenediamine by purifying from the mixture of m-phenylenediamine, o-phenylenediamine and p-phenylenediamine by controlling key process conditions such as material temperature in the static crystallizer, crystallization plate cooling speed, crystallization plate final temperature and sweating temperature, and has the advantages of high safety, environmental protection, low investment and low energy consumption.

The present invention will be described in further detail below with reference to examples.

Example 1

200 g of a mixture of m-phenylenediamine, o-phenylenediamine and p-phenylenediamine (85% of m-phenylenediamine, 12% of o-phenylenediamine and 3% of p-phenylenediamine) are introduced into a static crystallizer, hot oil is introduced into the jacket of the static crystallizer, and the mixture is heated to 59 ℃ until the mixture is completely melted.

Hot oil with the same temperature as the jacket of the crystallizer is introduced into the jacket of the crystallization plate, the oil bath is controlled to be cooled to 42 ℃ at the speed of 3 ℃/hour, and the mother liquor is discharged from a valve at the bottom of the static crystallizer.

The oil bath was controlled to raise the temperature to 55 ℃ at a rate of 1 ℃/hour for 10 minutes, and the perspiration was discharged from the valve at the bottom of the static crystallizer. The solid on the crystallization plate was collected in about 99% yield of about 71%.

As shown in FIG. 1, m-phenylenediamine was obtained in this example, and its nuclear magnetic spectrum was taken.

Example 2

The difference between this example and example 1 is: in the example, the mixture of m-phenylenediamine, o-phenylenediamine and p-phenylenediamine accounts for 83 percent of the m-phenylenediamine, 12 percent of the o-phenylenediamine and 5 percent of the p-phenylenediamine, hot oil is introduced into a static crystallizer jacket, and the material is heated to 60 ℃ until the material is completely melted; controlling the cooling speed of the crystallization plate to be 3 ℃/hour in the step S3, and enabling the final temperature of the crystallization plate to be 42 ℃; and in the step S4, controlling the temperature of the crystallization plate to be 55 ℃, keeping the temperature for 10-30 minutes, wherein the temperature rise speed of the sweating process of the crystallization plate of the static crystallizer is 1 ℃/hour, and the sweating liquid is discharged from a valve at the bottom of the static crystallizer. Finally, the solid on the crystallization plate is collected, namely the m-phenylenediamine with the content of about 99 percent and the yield of about 68 percent.

Example 3

The difference between this example and example 1 is: in the embodiment, the mixture of m-phenylenediamine, o-phenylenediamine and p-phenylenediamine is 85 percent, 12 percent and 3 percent of the p-phenylenediamine, the material is heated to 61 ℃ until the material is completely melted, hot oil with the same temperature as that of a jacket of a crystallizer is introduced into a jacket of a crystallization plate, the temperature of the material in the static crystallizer is controlled to be 61 ℃ in the step S2, the cooling speed of the crystallization plate is controlled to be 5 ℃/h in the step S3, and the final temperature of the crystallization plate is controlled to be 42 ℃; controlling the temperature of a crystallization plate to be 56 ℃ in the step S4, keeping the temperature for 20 minutes, wherein the temperature rising speed of the sweating process of the crystallization plate of the static crystallizer is 1 ℃/hour, and releasing the sweating from a valve at the bottom of the static crystallizer; finally, the solid on the crystallization plate was collected in about 99% yield.

Example 4

The difference between this example and example 1 is: in the example, the mixture of m-phenylenediamine, o-phenylenediamine and p-phenylenediamine is 85%, 12% and 3% of o-phenylenediamine, and the material is heated to 61 ℃ in a static crystallizer controlled in the step S2 until the material is completely melted; controlling the cooling speed of the crystallization plate to be 3 ℃/hour in the step S3, and enabling the final temperature of the crystallization plate to be 42 ℃; controlling the oil bath to raise the temperature to 55 ℃ at the speed of 2 ℃/hour in the step of S4, and keeping the temperature for 10 minutes; discharging the perspiration from a valve at the bottom of the static crystallizer; finally, the solid on the crystallization plate was collected in about 99% yield of about 69%.