Process method for improving yield of 1, 2-benzisothiazolin-3-one

Abstract

The invention discloses a process method for improving the yield of 1, 2-benzisothiazolin-3-one, which comprises the following steps: S1, injecting benzene metering equipment into a reaction kettle with a stirring mechanism, and then adding sodium diacid liquid and a catalyst into the reaction kettle; s2, adding thionyl chloride into the reaction kettle through metering equipment, heating, and carrying out acylating chlorination reaction; s3, after the acylating chlorination reaction is finished, cooling to normal temperature, then adding a proper amount of bromine into the reaction kettle through metering equipment, stirring and mixing through a stirring mechanism, and carrying out bromination reaction; s4, adding a proper amount of ammonia water into the reaction kettle through metering equipment, and stirring through a stirring mechanism to carry out cyclization reaction; and S5, after the reaction is finished, carrying out evaporation treatment until crystals are separated out. The method is suitable for industrial production, chlorine is not needed, compared with chlorine, bromine greatly reduces higher danger and difficulty in the operation process, and corrosivity to equipment is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of 1,2-benzisothiazolin-3-one preparation, and in particular to a process method for improving the yield of 1,2-benzisothiazolin-3-one. Background Art

[0002] Abstract: 1,2-Benzisothiazoline-3-one (BI) has been widely used in papermaking, adhesives, chemical fibers, coatings (latex paints), pigment polyurethane products, inks, latex products, leather products, and is also used in cosmetics, detergents, pharmaceuticals, food packaging materials, water treatment agents, oilfield water injection, industrial cooling circulating water and other industrial production fields.

[0003] The prior art publication number is CN116943590B, which is a process for improving the yield of 1,2-benzisothiazolin-3-one, belonging to the technical field of 1,2-benzisothiazolin-3-one processing. The invention is used to solve the technical problem in the prior art that the synthesis yield and purity of 1,2-benzisothiazolin-3-one need to be further improved. The process for improving the yield of 1,2-benzisothiazolin-3-one comprises the following steps: step 1, adding o-methylmercaptobenzonitrile, chlorobenzene and hydrochloric acid to a stirring kettle, stirring evenly, and reducing the temperature of the stirring kettle to 15-25°C; step 2, rotating a transfer pump to transport the clear liquid in the stirring kettle to a reaction kettle with a temperature of 15-25°C.

[0004] The above-mentioned prior art has the disadvantage that the use of chlorine will bring greater danger and difficulty to the operation process than bromine, and is more corrosive to the equipment; therefore, the present application proposes a process method for improving the yield of 1,2-benzisothiazolin-3-one. Summary of the invention

[0005] The purpose of the present invention is to solve the above technical problems and to propose a process for improving the yield of 1,2-benzisothiazolin-3-one.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A process for improving the yield of 1,2-benzisothiazolin-3-one comprises the following steps:

[0008] S1, injecting the benzene metering device into a reactor with a stirring mechanism, and then adding sodium diacid solution and catalyst into the reactor;

[0009] S2, adding thionyl chloride into the reaction kettle through a metering device and heating it to carry out chlorination reaction;

[0010] S3, after the acyl chloride reaction is completed, the reaction vessel is cooled to room temperature, and then an appropriate amount of bromine is added to the reaction vessel through a metering device and stirred and mixed by a stirring mechanism to perform a bromination reaction;

[0011] S4, adding an appropriate amount of aqueous ammonia to the reaction kettle through a metering device, and stirring the reaction kettle through a stirring mechanism to perform a cyclization reaction;

[0012] S5, after the reaction is completed, evaporation treatment is performed until crystals are precipitated, and then filtration is performed to obtain 1,2-benzisothiazolin-3-one.

[0013] Preferably, the method for preparing the sodium dicarboxylate solution comprises the following steps:

[0014] A1, adding a sodium nitrite solution at 0-5°C into a diazotization kettle for diazotization reaction to generate a diazonium salt solution;

[0015] A2, adding the diazonium salt solution into the disulfide reaction kettle to carry out disulfide reaction to generate sodium disulfide solution.

[0016] Preferably, the conditions of the disulfide reaction are: diazonium salt solution 0-5°C, reaction time 30min, denitrification gradually warming to room temperature for 1.5-2h.

[0017] Preferably, the catalyst is potassium oxide.

[0018] Preferably, the temperature of the bromination reaction in S3 is 16-20 degrees Celsius, and the reaction time is 11-15 minutes.

[0019] Preferably, the temperature of the cyclization reaction is 62-70 degrees Celsius, and the reaction time is 30 minutes.

[0020] Preferably, a mixed gas of hydrogen chloride and sulfur dioxide will escape during the acyl chlorination reaction, and the mixed gas of hydrogen chloride and sulfur dioxide that escapes is led out through a refrigerated separator to a water flushing pump system for absorption, and the obtained absorption liquid is discharged after being neutralized with alkaline solution.

[0021] Preferably, the reactor with a stirring mechanism comprises a reactor body, an upper cover is installed on the upper end of the reactor body, a metering device is installed on the upper cover, the metering device comprises a metering pump, a liquid inlet pipe is installed at the liquid inlet end of the metering pump, a liquid outlet pipe is installed at the liquid outlet end of the metering pump, the liquid outlet pipe is arranged through the upper cover, a motor is installed on the upper cover, the output end of the motor is fixedly connected to a shaft rod, the shaft rod passes through the upper cover and is rotatably connected thereto, a plurality of groups of stirring mechanisms are installed on the shaft rod, the stirring mechanism comprises a first stirring plate and a second stirring plate fixed on the shaft rod and distributed up and down, a first inclined groove is arranged through the first stirring plate, a second inclined groove is arranged through the second stirring plate, and the inclination directions of the first inclined groove and the second inclined groove are arranged in opposite directions.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] The present invention is suitable for industrial production and does not require the use of chlorine. Compared with chlorine, bromine greatly reduces the greater danger and difficulty of the operation process and reduces the corrosion to equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the structure of a reaction kettle in a process for improving the yield of 1,2-benzisothiazolin-3-one proposed by the present invention;

[0025] Figure 2 The invention discloses a side cross-sectional view of a first stirring plate and a second stirring plate in a reaction kettle in a process for improving the yield of 1,2-benzisothiazolin-3-one proposed by the invention.

[0026] In the figure: 1 kettle body, 2 upper cover, 3 motor, 4 metering pump, 5 liquid outlet pipe, 6 liquid inlet pipe, 7 first stirring plate, 8 second stirring plate, 9 first chute, 10 second chute. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0028] Reference Figure 1-Figure 2 , a process for improving the yield of 1,2-benzisothiazolin-3-one, comprising the following steps:

[0029] S1, injecting the benzene metering device into a reactor with a stirring mechanism, and then adding sodium diacid solution and catalyst into the reactor;

[0030] S2, adding thionyl chloride into the reaction kettle through a metering device and heating it to carry out chlorination reaction;

[0031] S3, after the acyl chloride reaction is completed, the reaction vessel is cooled to room temperature, and then an appropriate amount of bromine is added to the reaction vessel through a metering device and stirred and mixed by a stirring mechanism to perform a bromination reaction;

[0032] S4, adding an appropriate amount of aqueous ammonia to the reaction kettle through a metering device, and stirring the reaction kettle through a stirring mechanism to perform a cyclization reaction;

[0033] S5, after the reaction is completed, evaporation treatment is performed until crystals are precipitated, and then filtration is performed to obtain 1,2-benzisothiazolin-3-one.

[0034] In the present invention, the preparation method of the sodium dicarboxylate solution comprises the following steps:

[0035] A1, adding a sodium nitrite solution at 0-5°C into a diazotization kettle for diazotization reaction to generate a diazonium salt solution;

[0036] A2, adding the diazonium salt solution into the disulfide reaction kettle to carry out disulfide reaction to generate sodium disulfide solution.

[0037] In the present invention, the conditions of the disulfide reaction are: diazonium salt solution 0-5°C, reaction time 30min, denitrification gradually heated to room temperature for 1.5-2h.

[0038] In the present invention, the catalyst is potassium oxide.

[0039] In the present invention, the temperature of the bromination reaction in S3 is 16-20 degrees Celsius, and the reaction time is 11-15 minutes.

[0040] In the present invention, the temperature of the cyclization reaction is 62-70 degrees Celsius, and the reaction time is 30 minutes.

[0041] In the present invention, a mixed gas of hydrogen chloride and sulfur dioxide will escape during the acyl chlorination reaction. The mixed gas of hydrogen chloride and sulfur dioxide escaped is led out through a refrigerated separator to a water flushing pump system for absorption, and the obtained absorption liquid is discharged after being neutralized with alkali solution.

[0042] In the present invention, a reaction kettle with a stirring mechanism comprises a kettle body 1, an upper cover 2 is installed at the upper end of the kettle body 1, and an addition port can be set on the upper cover 2; a metering device is installed on the upper cover 2, and the metering device comprises a metering pump 4, a liquid inlet pipe 6 is installed at the liquid inlet end of the metering pump 4, and a liquid outlet pipe 5 is installed at the liquid outlet end of the metering pump 4, and the liquid outlet pipe 5 is arranged through the upper cover 2; a motor 3 is installed on the upper cover 2, and the output end of the motor 3 is fixedly connected to a shaft rod, and the shaft rod passes through the upper cover 2 and is rotatably connected thereto; multiple groups of stirring mechanisms are installed on the shaft rod, and the stirring mechanism comprises a first stirring plate 7 and a second stirring plate 8 fixed on the shaft rod and distributed up and down, a first chute 9 is penetrated on the first stirring plate 7, and a second chute 10 is penetrated on the second stirring plate 8, and the inclination directions of the first chute 9 and the second chute 10 are arranged in opposite directions.

[0043] When in use, the raw materials for producing 1,2-benzisothiazolin-3-one are added into the kettle body 1, and then the motor 3 is started. The motor 3 drives the shaft to rotate, and the rotation of the shaft drives the first stirring plate 7 and the second stirring plate 8 to rotate. The raw materials can be mixed and stirred by the first stirring plate 7 and the second stirring plate 8 to make them fully react. When the first stirring plate 7 and the second stirring plate 8 are stirring, the liquid raw materials pass through the first chute 9 and the second chute 10. Through the guidance of the first chute 9 and the second chute 10, the liquid raw materials collide with each other, so that the liquid raw materials react more fully.

[0044] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A process for improving the yield of 1,2-benzisothiazolin-3-one, characterized in that: The following steps are involved: S1, injecting the benzene metering device into a reactor with a stirring mechanism, and then adding sodium diacid solution and catalyst into the reactor; S2, adding thionyl chloride into the reaction kettle through a metering device and heating it to carry out chlorination reaction; S3, after the acyl chloride reaction is completed, the reaction vessel is cooled to room temperature, and then an appropriate amount of bromine is added to the reaction vessel through a metering device and stirred and mixed by a stirring mechanism to perform a bromination reaction; S4, adding an appropriate amount of aqueous ammonia to the reaction kettle through a metering device, and stirring the reaction kettle through a stirring mechanism to perform a cyclization reaction; S5, after the reaction is completed, evaporation treatment is performed until crystals are precipitated, and then filtration is performed to obtain 1,2-benzisothiazolin-3-one.

2. A process for improving the yield of 1,2-benzisothiazolin-3-one according to claim 1, characterized in that: The preparation method of the sodium dicarboxylate solution comprises the following steps: A1, adding a sodium nitrite solution at 0-5°C into a diazotization kettle for diazotization reaction to generate a diazonium salt solution; A2, adding the diazonium salt solution into the disulfide reaction kettle to carry out disulfide reaction to generate sodium disulfide solution.

3. A process for improving the yield of 1,2-benzisothiazolin-3-one according to claim 2, characterized in that: The conditions of the disulfide reaction are: diazonium salt solution 0-5°C, reaction time 30min, denitrification gradually warming to room temperature, 1.5-2h.

4. A process for improving the yield of 1,2-benzisothiazolin-3-one according to claim 1, characterized in that: The catalyst is potassium oxide.

5. A process for improving the yield of 1,2-benzisothiazolin-3-one according to claim 1, characterized in that: The temperature of the bromination reaction in S3 is 16-20 degrees Celsius, and the reaction time is 11-15 minutes.

6. A process for improving the yield of 1,2-benzisothiazolin-3-one according to claim 1, characterized in that: The temperature of the cyclization reaction is 62-70 degrees Celsius, and the reaction time is 30 minutes.

7. A process for improving the yield of 1,2-benzisothiazolin-3-one according to claim 1, characterized in that: During the acyl chlorination reaction, a mixed gas of hydrogen chloride and sulfur dioxide will escape. The mixed gas of hydrogen chloride and sulfur dioxide escaped is led out through a refrigerated separator to a water flushing pump system for absorption, and the obtained absorption liquid is discharged after being neutralized with alkaline solution.

8. A process for improving the yield of 1,2-benzisothiazolin-3-one according to claim 1, characterized in that: The reaction kettle with a stirring mechanism comprises a kettle body (1), an upper cover (2) is installed at the upper end of the kettle body (1), a metering device is installed on the upper cover (2), the metering device comprises a metering pump (4), a liquid inlet pipe (6) is installed at the liquid inlet end of the metering pump (4), a liquid outlet pipe (5) is installed at the liquid outlet end of the metering pump (4), the liquid outlet pipe (5) is arranged through the upper cover (2), a motor (3) is installed on the upper cover (2), the output end of the motor (3) is fixedly connected to a shaft rod, the shaft rod passes through the upper cover (2) and is rotatably connected thereto, a plurality of groups of stirring mechanisms are installed on the shaft rod, the stirring mechanism comprises a first stirring plate (7) and a second stirring plate (8) which are fixed on the shaft rod and distributed up and down, a first inclined groove (9) is penetrated through the first stirring plate (7), a second inclined groove (10) is penetrated through the second stirring plate (8), and the first inclined groove (9) and the second inclined groove (10) are arranged in opposite directions.

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