阅读说明：本技术 一种邻苯二胺母液的脱氨工艺 (Deamination process of o-phenylenediamine mother liquor ) 是由 罗利忠 胡孝明 朱玉梅 孙曹玖 于 2021-08-06 设计创作，主要内容包括：本发明公开了一种邻苯二胺母液的脱氨工艺,属于邻苯二胺生产技术领域。该脱氨工艺包括以下步骤：步骤一、将邻苯二胺母液经过换热器换热；步骤二、将氮气通入脱氨罐中5-8min后,再加入热邻苯二胺母液,打开风扇,氮气气流带走氨气,从气体出口排出,邻苯二胺母液从母液出口排出；步骤三、重复步骤一和步骤二的操作,直至邻苯二胺母液中氨浓度≤3g/L,得完成脱氨的邻苯二胺母液。且本发明通过换热器和脱氨罐的设置,可对邻苯二胺母液进行重复脱氨,且在氨气、风扇的作用下,氨气脱除更加充分和彻底,且在风扇表面喷涂一层防腐层,避免风扇被邻苯二胺母液腐蚀。(The invention discloses a deamination process of o-phenylenediamine mother liquor, belonging to the technical field of o-phenylenediamine production. The deamination process comprises the following steps: firstly, exchanging heat of o-phenylenediamine mother liquor through a heat exchanger; step two, introducing nitrogen into a deammoniation tank for 5-8min, then adding hot o-phenylenediamine mother liquor, opening a fan, taking ammonia gas away by nitrogen airflow, discharging the ammonia gas from a gas outlet, and discharging the o-phenylenediamine mother liquor from a mother liquor outlet; and step three, repeating the operation of the step one and the operation of the step two until the ammonia concentration in the o-phenylenediamine mother liquor is less than or equal to 3g/L, and obtaining the deamination o-phenylenediamine mother liquor. In addition, the invention can repeatedly deaminate the o-phenylenediamine mother liquor through the arrangement of the heat exchanger and the deamination tank, the ammonia gas can be removed more fully and thoroughly under the action of the ammonia gas and the fan, and the surface of the fan is sprayed with an anticorrosive coating to prevent the fan from being corroded by the o-phenylenediamine mother liquor.)

1. A deamination process of o-phenylenediamine mother liquor is characterized by comprising the following steps: the method comprises the following steps:

step one, heat exchange is carried out on o-phenylenediamine mother liquor by a heat exchanger (40) to obtain hot o-phenylenediamine mother liquor;

introducing nitrogen into the deammoniation tank for 5-8min, adding hot o-phenylenediamine mother liquor, opening a fan (20), taking ammonia gas away by nitrogen airflow, discharging the ammonia gas out of the deammoniation tank from a gas outlet (60), and discharging the o-phenylenediamine mother liquor out of the deammoniation tank from a mother liquor outlet (70);

and step three, repeating the operation of the step one and the operation of the step two until the ammonia concentration in the o-phenylenediamine mother liquor is less than or equal to 3g/L, and obtaining the deamination o-phenylenediamine mother liquor.

2. The deamination process of o-phenylenediamine mother liquor according to claim 1, wherein the deamination process comprises the following steps: in the first step, the temperature of the hot o-phenylenediamine mother liquor is 90-100 ℃.

3. The deamination process of o-phenylenediamine mother liquor according to claim 1, wherein the deamination process comprises the following steps: in the second step, the pressure at the nitrogen inlet is 0.06-0.2 MPa.

4. The deamination process of o-phenylenediamine mother liquor according to claim 1, wherein the deamination process comprises the following steps: and in the second step, the ammonia removal tank is a heat preservation tank.

5. The deamination process of o-phenylenediamine mother liquor according to claim 1, wherein the deamination process comprises the following steps: and the outer surface of the fan (20) is sprayed with a layer of anticorrosive coating.

6. The deamination process of o-phenylenediamine mother liquor according to claim 5, wherein the deamination process comprises the following steps: the anticorrosive coating is a modified epoxy resin powder coating and comprises the following components: epoxy resin powder, block modified epoxy resin powder, a curing agent, an organic silicon flatting agent, titanium dioxide, pigment and an aluminate coupling agent.

7. The deamination process of o-phenylenediamine mother liquor according to claim 6, wherein the deamination process comprises the following steps: the block modified epoxy resin powder is prepared by the following steps:

under the protection of nitrogen, 3- (trimethoxysilyl) propyl methacrylate, a fluorine-containing monomer, an epoxy unsaturated monomer, an initiator, a chain transfer agent, di-n-butyltin dilaurate and a solvent are uniformly stirred, stirred and reacted for 5 hours at the temperature of 95-105 ℃, cooled to room temperature, filtered, dried, precipitated and ground to obtain the block modified epoxy resin powder.

8. The deamination process of o-phenylenediamine mother liquor according to claim 7, wherein the deamination process comprises the following steps: the fluorine-containing monomer is prepared by the following steps:

under the stirring state, adding p-toluenesulfonic acid and acrylic acid into an isopropanol solution of perfluorooctyl diol, heating to 56 ℃, reacting for 1h, adding hydroquinone, and continuing to react for 4h to obtain the fluorine-containing monomer.

9. The deamination process of o-phenylenediamine mother liquor according to claim 7, wherein the deamination process comprises the following steps: the epoxy unsaturated monomer is one of allyl glycidyl ether and glycidyl acrylate.

Technical Field

The invention belongs to the technical field of production of o-phenylenediamine, and particularly relates to a deamination process of an o-phenylenediamine mother liquor.

Background

The synthesis of o-phenylenediamine comprises two steps: firstly, synthesizing o-nitroaniline by o-nitrochlorobenzene and ammonia water (45%) at 185 ℃ and 4.8 MPa; and secondly, reducing the o-nitroaniline into o-phenylenediamine by using sodium sulfide to obtain o-phenylenediamine mother liquor. The o-phenylenediamine mother liquor is cooled, crystallized, centrifuged and packaged to obtain a crude o-phenylenediamine. It can be known that the o-phenylenediamine mother liquor contains a large amount of ammonia water, and if the o-phenylenediamine mother liquor is not subjected to deamination treatment, direct crystallization and centrifugal operation can cause serious ammonia odor in a workshop, pollute the workshop environment, easily cause occupational hazards, and simultaneously cause the increase of ammonia consumption and increase of cost.

Therefore, it is necessary to develop a deamination process for o-phenylenediamine mother liquor, which reduces the ammonia content in the o-phenylenediamine mother liquor and improves the environment of a centrifugal workshop for the o-phenylenediamine mother liquor.

Disclosure of Invention

The invention aims to provide a deamination process of o-phenylenediamine mother liquor.

The technical problems to be solved by the invention are as follows: how to reduce the ammonia content of the o-phenylenediamine mother liquor.

The purpose of the invention can be realized by the following technical scheme:

a deamination process of o-phenylenediamine mother liquor comprises the following steps:

step one, passing the o-phenylenediamine mother liquor through a heat exchanger to obtain hot o-phenylenediamine mother liquor;

secondly, introducing nitrogen into the ammonia removal tank for 5-8min, driving away air in the ammonia removal tank, introducing o-phenylenediamine mother liquor, opening a fan, spraying the o-phenylenediamine mother liquor through a liquid spray head, spraying nitrogen through a gas spray head, enabling the o-phenylenediamine mother liquor to move downwards and the nitrogen to move upwards under the action of gravity, enabling ammonia in the o-phenylenediamine mother liquor to be taken away by nitrogen airflow, increasing airflow strength of the nitrogen under the action of the fan, enabling the ammonia to be taken away more thoroughly, continuously providing heat for ammonia volatilization in the mother liquor by the hot o-phenylenediamine mother liquor, enabling the ammonia to continuously volatilize, enabling the volatilized ammonia to be taken away by the nitrogen airflow, achieving the effect of deamination of the o-phenylenediamine mother liquor, finally discharging the o-phenylenediamine mother liquor out of the ammonia removal tank from a mother liquor outlet, and discharging mixed gas of the nitrogen and the nitrogen out of the ammonia removal tank from a gas outlet;

and step three, repeating the operation of the step one and the operation of the step two until the ammonia concentration in the o-phenylenediamine mother liquor is less than or equal to 3g/L, and obtaining the deamination o-phenylenediamine mother liquor.

Further, the heating temperature of the o-phenylenediamine mother liquor in the first step is 90-100 ℃.

Furthermore, the ammonia removal tank in the step two is a heat preservation tank, so that the loss of heat of the o-phenylenediamine mother liquor is avoided, and the volatilization of ammonia supplied by heat is ensured.

Further, the pressure at the nitrogen inlet in the second step is 0.06-0.2 MPa.

And further, in the second step, the mixed gas of the nitrogen and the nitrogen is discharged from the ammonia removal tank and then passes through an ammonia recovery tank and a drying tank, and the dried nitrogen is obtained again and can be repeatedly used.

Furthermore, the outer surface of the fan is sprayed with a layer of anticorrosive coating to protect the fan from being corroded by the o-phenylenediamine mother liquor, so that the service time of the fan is prolonged, and the maintenance cost of the ammonia removal tank is reduced.

Further, the anticorrosive layer is a modified epoxy resin powder coating and comprises the following raw materials in parts by weight: 50-80 parts of epoxy resin powder, 12-22 parts of block modified epoxy resin powder, 12-19 parts of curing agent, 1.5-5.5 parts of organic silicon leveling agent, 4.5-7.5 parts of titanium dioxide, 0-5 parts of pigment and 1-3 parts of aluminate coupling agent.

Further, the epoxy resin powder is one of E-12, E-20 and E-14.

Further, the aluminate coupling agent is one of isopropoxy distearoyl acyloxy aluminate, tristearoyl acyloxy aluminate and triacetyl acetone aluminium.

Further, the block-modified epoxy resin powder is prepared by the following steps:

under the protection of nitrogen, uniformly stirring 3- (trimethoxysilyl) propyl methacrylate, a fluorine-containing monomer, an epoxy unsaturated monomer, an initiator, a chain transfer agent, di-n-butyltin dilaurate and a solvent, then stirring and reacting at 95-105 ℃ for 5 hours, cooling to room temperature, filtering, drying, precipitating and grinding to obtain block modified epoxy resin powder, wherein the molar ratio of the 3- (trimethoxysilyl) propyl methacrylate to the fluorine-containing monomer to the epoxy unsaturated monomer is 1.1-1.2: 1: 1.1-1.3, the adding mass of the initiator is 2-5% of the mass of the fluorine-containing monomer, and the adding mass of the di-n-butyltin dilaurate is 1-5% of the mass of the fluorine-containing monomer.

Further, the solvent is a mixed solvent which is prepared by mixing xylene and n-butanol according to a mass ratio of 1.2-1.5: 1 are mixed to form the composition.

Further, the initiator is one of azobisisobutyronitrile and azobisisovaleronitrile.

Further, the epoxy unsaturated monomer is one of allyl glycidyl ether and glycidyl acrylate.

Further, the molecular structural formula of the fluorine-containing monomer is as follows:

in the reaction for obtaining the block modified epoxy resin powder, the polymerization reaction of double bonds in 3- (trimethoxysilyl) propyl methacrylate, double bonds at two ends in a fluorine-containing monomer and double bonds in an epoxy unsaturated monomer is utilized to form a polymer with three molecular chains, and the molecular structure of the polymer is as follows:

according to the structural formula, the octafluoro-alkane chain and the siloxane chain are introduced into the block modified epoxy resin, the block modified epoxy resin is endowed with high acid-base resistance and waterproof performance due to the low surface energy and the mobility of the octafluoro-alkane chain, and the block modified epoxy resin is endowed with good compatibility with the main epoxy resin due to the flexibility and the mobility of the siloxane chain, so that the block modified epoxy resin chain is uniformly dispersed in a composite material system, and the acid-base resistance and the waterproof performance of the whole composite material are further improved.

Further, the fluorine-containing monomer is prepared by the following steps:

s1, mixing perfluorooctyl iodoalkane and allyl acetate, heating to 97 ℃, keeping for 1min, adding benzoyl peroxide, continuing to react for 30min after the reaction rapidly releases heat and is heated to 150 ℃, adding n-octane and potassium hydroxide when the reaction temperature is reduced to 80 ℃, reacting for 6h, cooling, filtering, washing and distilling to obtain 3-perfluoro-n-octyl-1, 2-epoxypropane, wherein the dosage ratio of perfluorooctyl iodoalkane, allyl acetate and n-hexane is 0.1 mol: 0.1-0.13 mol: 100mL of 100-200mL of the mixture, wherein the adding mass of the benzoyl peroxide is 0.1-0.3% of the adding mass of the perfluorooctanoic iodoalkane, and the adding mass of the potassium hydroxide is 1-5% of the adding mass of the perfluorooctanoic iodoalkane;

s2, under a sealed condition, stirring 3-perfluoro-n-octyl-1, 2-epoxypropane, methanol and 23% ammonia water by mass for 24h, removing the ammonia water and the methanol by rotary evaporation, adding the 3-perfluoro-n-octyl-1, 2-epoxypropane and the methanol again, continuing to react for 12h, dissolving a reaction crude product with diethyl ether, washing, separating liquid, taking an organic layer, drying, suction filtering, rotary evaporation, recrystallization and cooling to obtain perfluoro-octyl dihydric alcohol, and performing ring-opening reaction by using an epoxy group and ammonia, wherein the dosage ratio of the 3-perfluoro-n-octyl-1, 2-epoxypropane, the methanol and the ammonia water is 0.1 mol: 20-40 mL: 80-150mL, the amount of the 3-perfluoro-n-octyl-1, 2-epoxypropane added again is equal to the amount of the 3-perfluoro-n-octyl-1, 2-epoxypropane added for the first time, and the amount of the methanol added again is one tenth of the amount of the methanol added for the first time;

s3, adding p-toluenesulfonic acid and acrylic acid into an isopropanol solution of perfluorooctyl diol under the stirring state, heating to 56 ℃, reacting for 1h, adding hydroquinone, and continuing to react for 4h to obtain a fluorine-containing monomer, wherein the molar ratio of the perfluorooctyl diol to the acrylic acid is 1: 2.1-2.3, the adding mass of the p-toluenesulfonic acid is 3-6% of that of the perfluorooctyl dihydric alcohol, and the adding mass of the hydroquinone is 2-4% of that of the perfluorohexyl dihydric alcohol.

In step S3, a fluorine-containing monomer having double bonds at both ends is obtained by reacting a carboxyl group in acrylic acid with a hydroxyl group in perfluorooctyl diol.

The invention has the beneficial effects that:

according to the invention, through the arrangement of the heat exchanger and the deamination tank, ammonia in the o-phenylenediamine mother liquor can be repeatedly deaminated, and the ammonia can be removed more fully and thoroughly under the action of ammonia and a fan. The explanation is as follows: through the arrangement of the heat exchanger, the o-phenylenediamine mother liquor is heated and enters the ammonia removal tank, the o-phenylenediamine mother liquor is heated to volatilize ammonia in the solution to generate ammonia, the ammonia is more easily exposed through the liquid sprayed by the liquid spray head and is separated from the wrapping of the liquid, the ammonia is fully contacted with the nitrogen airflow, and the ammonia is separated from the o-phenylenediamine mother liquor by the nitrogen airflow, moreover, under the action of the fan, the flowing of the gas in the ammonia removal tank is enhanced, the volatilization of the ammonia is promoted, the nitrogen airflow is stronger, the ammonia is more easily separated from the o-phenylenediamine mother liquor, and the deamination of the o-phenylenediamine mother liquor is promoted;

in addition, in order to apply the fan in the environment of brushing the o-phenylenediamine mother liquor for a long time, the invention sprays a layer of anticorrosive coating on the surface of the fan, so that the fan is prevented from being corroded by the o-phenylenediamine mother liquor (the o-phenylenediamine mother liquor has the characteristic of high ammonia content and strong basicity), the service time of the fan is prolonged, and the maintenance cost of an ammonia removal tank is reduced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a flow chart of a deamination process of an o-phenylenediamine mother liquor according to the present invention;

FIG. 2 is a schematic view of the structure of a deammoniation tank used in the present invention.

In the drawings, the components represented by the respective reference numerals are listed below:

10. a gas shower; 20. a fan; 30. a liquid ejection head; 40. a heat exchanger; 50. an ammonia concentration meter; 60. a gas outlet; 70. and (4) a mother liquor outlet.

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. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, the deamination process of the o-phenylenediamine mother liquor provided by the present invention includes the following steps:

step one, passing the o-phenylenediamine mother liquor through a heat exchanger 40 to obtain hot o-phenylenediamine mother liquor;

step two, introducing nitrogen into the ammonia removal tank for 5-8min, adding hot o-phenylenediamine mother liquor, opening a fan 20, taking ammonia gas away by nitrogen airflow, discharging the ammonia gas out of the ammonia removal tank from a gas outlet 60, and discharging the o-phenylenediamine mother liquor out of the ammonia removal tank from a mother liquor outlet 70;

and step three, repeating the operation of the step one and the operation of the step two until the ammonia concentration in the o-phenylenediamine mother liquor is less than or equal to 3g/L, and obtaining the deamination o-phenylenediamine mother liquor.

Referring to fig. 2, the deamination tank used in the present invention includes a tank body, a liquid nozzle 30 is disposed at the top end inside the tank body, a plurality of fans 20 are disposed on the inner wall of the tank body, a gas nozzle 10 is disposed at the bottom end inside the tank body, a gas outlet 60 is disposed at the top of the tank body, a mother liquor outlet 70 is disposed at the bottom of the tank body, the liquid nozzle 30 is communicated with a heat exchanger 40 through a water pipe, an ammonia concentration meter 50 is disposed at the mother liquor outlet 70, the ammonia concentration meter 50 is used for measuring the ammonia content in the discharged o-phenylenediamine mother liquor, the mother liquor outlet 70 is communicated with the heat exchanger 40 through a water pipe, so as to facilitate the cyclic deamination of the o-phenylenediamine mother liquor, the gas outlet 60 is communicated with an ammonia gas collection tank through a gas pipe, the ammonia gas collection tank is used for collecting ammonia gas in mixed gas, the ammonia gas collection tank is communicated with a drying cabinet through a gas pipe, and the drying cabinet is used for drying nitrogen gas, so as to facilitate the reuse of nitrogen gas.

Introducing nitrogen into the ammonia removal tank for 5-8min, driving away air in the ammonia removal tank, introducing o-phenylenediamine mother liquor, opening a fan 20, spraying the o-phenylenediamine mother liquor through a liquor spray nozzle 30, spraying the nitrogen through a gas spray nozzle 10, enabling the o-phenylenediamine mother liquor to move downwards under the action of gravity, enabling the nitrogen to move upwards, enabling ammonia in the o-phenylenediamine mother liquor to be taken away by nitrogen airflow, increasing airflow intensity of the nitrogen under the action of the fan 20, enabling the ammonia to be taken away more thoroughly, continuously providing heat of ammonia volatilization in the mother liquor by the hot o-phenylenediamine mother liquor, enabling the ammonia to continuously volatilize, enabling the volatilized ammonia to be taken away by the nitrogen airflow, achieving the effect of deamination of the o-phenylenediamine mother liquor, finally discharging the ammonia removal tank from a mother liquor outlet 70, and discharging mixed gas of the nitrogen and the ammonia removal tank from a gas outlet 60.

Example 1:

the fluorine-containing monomer is prepared by the following steps:

s1, mixing 0.1mol of perfluorooctyl iodoalkane and 0.1mol of allyl acetate, heating to 97 ℃, keeping for 3min, adding benzoyl peroxide with the mass of 0.1% of that of the perfluorooctyl iodoalkane, continuing to react for 30min after the temperature is raised to 150 ℃ due to rapid heat release of the reaction, adding 100mL of n-octane and potassium hydroxide with the mass of 1% of that of the perfluorooctyl iodoalkane when the reaction temperature is reduced to 80 ℃, reacting for 6h, cooling and filtering, washing with the n-octane, distilling the filtrate under reduced pressure, and collecting 82 ℃/40mmHg fraction to obtain 3-perfluoro-n-octyl-1, 2-epoxypropane;

s2, adding 0.1mol of 3-perfluoro-n-octyl-1, 2-epoxypropane, 20mL of methanol and 80mL of ammonia water with the mass fraction of 24%, stirring for 12h, removing the ammonia water and the methanol by rotary evaporation, then adding 0.1mol of 3-perfluoro-n-octyl-1, 2-epoxypropane and 2mL of methanol again, continuing to react for 8h, dissolving the reaction crude product with diethyl ether, washing with distilled water, separating liquid, taking an organic layer, drying with anhydrous sodium sulfate, performing suction filtration, removing the methanol by rotary evaporation, recrystallizing with chloroform, and cooling to obtain perfluorohexyl diol;

s3, adding 0.1mol of perfluorohexyl diol and 50mL of isopropanol into a three-neck flask with a thermometer, a stirrer and a condenser, adding p-toluenesulfonic acid with the mass of 2% of the perfluorohexyl diol, 0.21mol of acrylic acid and hydroquinone with the mass of 2.5% of the perfluorohexyl diol into the three-neck flask under stirring, heating to 56 ℃, and reacting for 10 hours to obtain the fluorine-containing olefin monomer.

Example 2:

the fluorine-containing monomer is prepared by the following steps:

s1, mixing 0.1mol of perfluorooctyl iodoalkane and 0.13mol of allyl acetate, heating to 97 ℃, keeping for 3min, adding benzoyl peroxide with the mass of 0.3% of that of the perfluorooctyl iodoalkane, continuing to react for 30min after the temperature is raised to 150 ℃ due to rapid heat release of the reaction, adding 200mL of n-octane and potassium hydroxide with the mass of 5% of that of the perfluorooctyl iodoalkane when the reaction temperature is reduced to 80 ℃, reacting for 6h, cooling and filtering, washing with the n-octane, distilling the filtrate under reduced pressure, and collecting 82 ℃/40mmHg fraction to obtain 3-perfluoro-n-octyl-1, 2-epoxypropane;

s2, adding 0.1mol of 3-perfluoro-n-octyl-1, 2-epoxypropane, 40mL of methanol and 50mL of ammonia water with the mass fraction of 28% into a completely sealed flask, stirring for 12 hours, removing the ammonia water and the methanol by rotary evaporation, then adding 0.1mol of 3-perfluoro-n-octyl-1, 2-epoxypropane and 2mL of methanol again, continuing to react for 8 hours, dissolving a reaction crude product by using diethyl ether, washing by using distilled water, separating liquid to obtain an organic layer, drying by using anhydrous sodium sulfate, carrying out suction filtration, removing the methanol by rotary evaporation, recrystallizing by using chloroform, and cooling to obtain perfluorohexyl dihydric alcohol;

s3, adding 0.1mol of perfluorohexyl diol and 50mL of isopropanol into a three-neck flask with a thermometer, a stirrer and a condenser, adding p-toluenesulfonic acid with the mass of 4% of the perfluorohexyl diol, 0.23mol of acrylic acid and hydroquinone with the mass of 8.5% of the perfluorohexyl diol into the three-neck flask under stirring, heating to 56 ℃, and reacting for 10 hours to obtain the fluorine-containing olefin monomer.

Example 3:

the block modified epoxy resin powder is prepared by the following steps:

under the protection of nitrogen, 3- (trimethoxysilyl) propyl methacrylate, the fluorine-containing monomer prepared in example 1, the epoxy unsaturated monomer, the initiator, a chain transfer agent of di-n-butyltin dilaurate and a solvent are uniformly stirred, stirred and reacted at 95 ℃ for 5 hours, cooled to room temperature, filtered, dried, precipitated and ground to obtain block modified epoxy resin powder, wherein the molar ratio of the 3- (trimethoxysilyl) propyl methacrylate to the fluorine-containing monomer to the epoxy unsaturated monomer is 1.1: 1: 1.1, the adding mass of the initiator is 2 percent of the mass of the fluorine-containing monomer, and the adding mass of the di-n-butyltin dilaurate is 1 percent of the mass of the fluorine-containing monomer. Wherein the solvent is a mixed solvent which is a mixture of xylene and n-butanol according to a mass ratio of 1.2: 1, mixing the components; the initiator is azobisisobutyronitrile, and the epoxy unsaturated monomer is allyl glycidyl ether.

Example 4:

the block modified epoxy resin powder is prepared by the following steps:

under the protection of nitrogen, 3- (trimethoxysilyl) propyl methacrylate, the fluorine-containing monomer prepared in example 2, the epoxy unsaturated monomer, the initiator, a chain transfer agent of di-n-butyltin dilaurate and a solvent are uniformly stirred, stirred and reacted at 105 ℃ for 5 hours, cooled to room temperature, filtered, dried, precipitated and ground to obtain block modified epoxy resin powder, wherein the molar ratio of the 3- (trimethoxysilyl) propyl methacrylate to the fluorine-containing monomer to the epoxy unsaturated monomer is 1.2: 1: 1.3, the adding mass of the initiator is 5 percent of the mass of the fluorine-containing monomer, and the adding mass of the di-n-butyltin dilaurate is 5 percent of the mass of the fluorine-containing monomer. Wherein the solvent is a mixed solvent which is a mixture of xylene and n-butanol according to a mass ratio of 1.5: 1, mixing the components; the initiator is azobisisovaleronitrile, and the epoxy unsaturated monomer is glycidyl acrylate.

Example 5:

the modified epoxy resin powder coating comprises the following raw materials in parts by weight: 50 parts of epoxy resin powder, 12 parts of block modified epoxy resin powder prepared in example 3, 12 parts of curing agent, 1.5 parts of organic silicon flatting agent, 4.5 parts of titanium dioxide, 0 part of pigment and 1 part of aluminate coupling agent, wherein the epoxy resin powder is E-12; the aluminate coupling agent is isopropoxy distearoyl acyloxy aluminate.

The preparation method comprises the following steps: fully and uniformly mixing the components in a high-speed mixer; then melt-extruding through a screw extruder, and controlling the temperature of a feeding section to be 65 ℃, the temperature of a melting section to be 102 ℃ and the temperature of a discharging section to be 115 ℃; and tabletting the molten material by a tabletting machine, controlling the thickness to be 2mm, crushing the molten material, feeding the crushed molten material into a grinding mill for crushing, and sieving the crushed molten material by a 200-mesh sieve to obtain the corrosion-resistant epoxy resin powder coating.

Example 6:

the modified epoxy resin powder coating comprises the following raw materials in parts by weight: 60 parts of epoxy resin powder, 16 parts of block modified epoxy resin powder prepared in example 4, 17 parts of curing agent, 2 parts of organic silicon flatting agent, 6 parts of titanium dioxide, 2 parts of pigment and 2 parts of aluminate coupling agent, wherein the epoxy resin powder is E-20; the aluminate coupling agent is tristearate acyloxy aluminate.

The preparation method comprises the following steps: the same procedure was used to prepare example 5.

Example 7:

the modified epoxy resin powder coating comprises the following raw materials in parts by weight: 80 parts of epoxy resin powder, 22 parts of block modified epoxy resin powder prepared in example 5, 19 parts of curing agent, 5.5 parts of organic silicon flatting agent, 7.5 parts of titanium dioxide, 5 parts of pigment and 3 parts of aluminate coupling agent, wherein the epoxy resin powder is E-14; the aluminate coupling agent is aluminum triacetylacetonate.

The preparation method comprises the following steps: the same procedure was used to prepare example 5.

Comparative example 1:

epoxy resin powder coating of Shandong Bishan special coating science and technology Limited is sold in the market.

Comparative example 2:

in contrast to example 5, no block-modified epoxy resin powder was added.

Example 8:

the epoxy resin powder coatings obtained in examples 5 to 7 and comparative examples 1 to 2 were sprayed on a fan 20 and, after curing, a fan 20 with an anticorrosive layer was obtained, and examples 8-1, 8-2, 8-3, 8-4, and 8-5 were respectively labeled corresponding to examples 5 to 7 and comparative examples 1 to 2.

Example 9:

the fan 20 obtained in example 8 is installed in a deammoniation tank, the obtained fan 20 is applied to deammoniation for 8 months, the deammoniation process is carried out according to the following two methods, the corrosion condition of the fan 20 in each month is recorded, and the measured data is shown in a table 1-2;

the method comprises the following steps: the deamination process comprises the following steps:

step one, passing the o-phenylenediamine mother liquor through a heat exchanger to obtain hot o-phenylenediamine mother liquor, wherein the temperature of the hot o-phenylenediamine mother liquor is 90 ℃;

step two, introducing nitrogen into a deammoniation tank for 5min, driving away air in the deammoniation tank, introducing o-phenylenediamine mother liquor, opening a fan 20, spraying the o-phenylenediamine mother liquor through a liquid spray head 30, spraying nitrogen through a gas spray head 10, finally discharging the o-phenylenediamine mother liquor out of the deammoniation tank from a mother liquor outlet 70, and discharging mixed gas of nitrogen and nitrogen out of the deammoniation tank from a gas outlet 60, wherein the pressure at a nitrogen inlet is 0.06 MPa;

and step three, repeating the operation of the step one and the operation of the step two until the ammonia concentration in the o-phenylenediamine mother liquor is less than or equal to 3g/L, and obtaining the deamination o-phenylenediamine mother liquor.

The second method comprises the following steps: the deamination process comprises the following steps:

step one, passing the o-phenylenediamine mother liquor through a heat exchanger to obtain hot o-phenylenediamine mother liquor, wherein the temperature of the hot o-phenylenediamine mother liquor is 100 ℃;

step two, introducing nitrogen into a deammoniation tank for 8min, driving away air in the deammoniation tank, introducing o-phenylenediamine mother liquor, opening a fan 20, spraying the o-phenylenediamine mother liquor through a liquid spray head 30, spraying nitrogen through a gas spray head 10, finally discharging the o-phenylenediamine mother liquor out of the deammoniation tank from a mother liquor outlet 70, and discharging mixed gas of the nitrogen and the nitrogen out of the deammoniation tank from a gas outlet 60, wherein the pressure at a nitrogen inlet is 0.2 MPa;

and step three, repeating the operation of the step one and the operation of the step two until the ammonia concentration in the o-phenylenediamine mother liquor is less than or equal to 3g/L, and obtaining the deamination o-phenylenediamine mother liquor.

TABLE 1 Corrosion of fans in method one

TABLE 1 Corrosion of the fans in method two

As can be seen from the data in tables 1-2, the coating of application examples 5-7, which is sprayed on the surface of the fan 20, has the function of protecting the fan 20, preventing the fan 20 from being corroded by the o-phenylenediamine mother liquor, and prolonging the service life of the fan.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing is merely exemplary and illustrative of the principles of the present invention and various modifications, additions and substitutions of the specific embodiments described herein may be made by those skilled in the art without departing from the principles of the present invention or exceeding the scope of the claims set forth herein.