PROCESS FOR PRODUCING POLYARYLENE ETHER NITRILE WITH EFFICIENTLY RECOVERING N-METHYLPYRROLIDONE SOLVENT

Abstract

A process for producing polyarylene ether nitrile, in which an N-methylpyrrolidone solvent can be efficiently recovered. The process includes the following steps: mixing N-methylpyrrolidone, potassium carbonate, 2,6-dichlorobenzonitrile, dihydric phenol and toluene, and carrying out a dehydration reaction and a polymerization reaction in sequence to obtain a high-viscosity polyarylene ether nitrile solution; then pelletizing and conveying polyarylene ether nitrile particles together with methanol to a primary vibrating screen to complete a primary replacement of N-methylpyrrolidone; then using a secondary vibrating screen to complete a secondary replacement of the solvent; subsequently, grinding the polyarylene ether nitrile particles and carrying out an extraction with methanol, and then centrifuging, washing with water and drying to obtain purified polyarylene ether nitrile powder; and finally distilling replacement liquid and centrifugation liquid to separate methanol from N-methylpyrrolidone.

Claims

1. A process for producing polyarylene ether nitrile with efficiently recovering an N-methylpyrrolidone solvent, comprising the following steps: S1: adding potassium carbonate and 2,6-dichlorobenzonitrile to N-methylpyrrolidone to obtain a first mixture, and mixing the first mixture well to obtain a reaction solution; and then adding dihydric phenol and toluene to the reaction solution to obtain a second mixture, mixing the second mixture well and then carrying out a dehydration reaction and a polymerization reaction on the second mixture in sequence to obtain a high-viscosity polyarylene ether nitrile solution; S2: carrying out a pelletizing treatment on the high-viscosity polyarylene ether nitrile solution obtained in 51 to obtain polyarylene ether nitrile particles; S3: conveying the polyarylene ether nitrile particles obtained in S2 together with methanol to a primary vibrating screen for a first vibration to obtain a third mixture, and carrying out a primary replacement and recovery of N-methylpyrrolidone, wherein a volume ratio of the methanol used to the N-methylpyrrolidone used during a synthesis of the high-viscosity polyarylene ether nitrile solution is 1-1.5:1; S4: conveying the third mixture after the first vibration of the primary vibrating screen to a secondary vibrating screen, and supplementally adding methanol for a second vibration, and carrying out a secondary replacement and recovery of N-methylpyrrolidone, wherein a volume ratio of the supplementally added methanol to the methanol added to the primary vibrating screen is 0.6-0.9:1; and then separating the polyarylene ether nitrile particles from a replacement liquid; S5: mixing the polyarylene ether nitrile particles after a treatment in S4 and methanol in a mass ratio of 1:1.5-3 to obtain a fourth mixture, and then sending the fourth mixture to a grinding device for grinding to obtain a polyarylene ether nitrile powder slurry; S6: carrying out an extraction on the polyarylene ether nitrile powder slurry with methanol, then performing a centrifugation to separate the polyarylene ether nitrile powder slurry from a centrifugation liquid, and then carrying out water washing and drying treatments on the polyarylene ether nitrile powder slurry in sequence to obtain purified polyarylene ether nitrile powder; and S7: combining the replacement liquid and the centrifugation liquid to obtain a fifth mixture, distilling the fifth mixture to remove methanol and completing a recovery of the N-methylpyrrolidone solvent.

2. The process according to claim 1, wherein a molar ratio of the 2,6-dichlorobenzonitrile, the dihydric phenol, the potassium carbonate, the N-methylpyrrolidone and the toluene used in S1 is 1:1:1.1-1.8:2.5-3:0.5-1.25.

3. The process according to claim 2, wherein the molar ratio of the 2,6-dichlorobenzonitrile, the dihydric phenol, the potassium carbonate, the N-methylpyrrolidone and the toluene is 1:1:1.5:2.5:1.

4. The process according to claim 1, wherein the dihydric phenol is at least one selected from the group consisting of: ##STR00007##

5. The process according to claim 1, wherein in S1, a reaction temperature of the dehydration reaction is 140-170° C., reaction time of the dehydration reaction is 2-4 h; and a reaction temperature of the polymerization reaction is 180-200° C., and reaction time of the polymerization reaction is 3-5 h.

6. The process according to claim 1, wherein the polyarylene ether nitrile particles are cylindrical particles with a length of 0.2-0.5 mm and a diameter of 0.2-0.45 mm.

7. The process according to claim 1, wherein a particle size of the purified polyarylene ether nitrile powder is 150-300 mesh.

8. The process according to claim 1, wherein the extraction and the centrifugation are repeated three times in S6.

9. The process according to claim 1, wherein an extraction temperature is 20-25° C., extraction time is 10-30 min; and a centrifugation rate is 800-1200 rpm, and centrifugation time is 8-15 min.

10. The process according to claim 1, wherein in S7, a distillation temperature is 75-80° C., and distillation time is 3-5 h.

11. The process according to claim 2, wherein the dihydric phenol is at least one selected from the group consisting of: ##STR00008##

12. The process according to claim 3, wherein the dihydric phenol is at least one selected from the group consisting of: ##STR00009##

13. The process according to claim 8, wherein an extraction temperature is 20-25° C., extraction time is 10-30 min; and a centrifugation rate is 800-1200 rpm, and centrifugation time is 8-15 min.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] The following embodiments are intended to illustrate the present invention in detail, which are preferred embodiments and are not used for limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts shall fall with the protection scope of the present invention.

Embodiment 1

[0034] A continuous process for producing polyarylene ether nitrile with efficiently recovering an N-methylpyrrolidone solvent includes the following steps:

[0035] S1: adding 150 mol of potassium carbonate and 100 mol of 2,6-dichlorobenzonitrile to 250 mol of N-methylpyrrolidone, and mixing well to obtain a reaction solution; and then adding 100 mol of dihydric phenol as shown in formula I and 100 mol of toluene to the reaction solution, and after mixing well, carrying out a dehydration reaction at 140° C. for 2 h, and then carrying out a polymerization reaction at 180° C. for 3 h, to obtain a high-viscosity polyarylene ether nitrile solution;

##STR00002##

[0036] S2: introducing the high-viscosity polyarylene ether nitrile solution obtained in S1 into an autoclave, wherein the discharge port of the autoclave is provided with a casting head, a pelletizing cutter head and a cooling spray device, starting the pelletizing cutter head and the cooling spray device, and under the action of a pressure pump, conveying the high-viscosity polyarylene ether nitrile solution to the casting head of the discharge port, and cutting it into cylindrical particles with a length of about 0.5 mm and a diameter of about 0.3 mm to obtain polyarylene ether nitrile particles;

[0037] S3: conveying the polyarylene ether nitrile particles obtained in S2 together with methanol to a primary vibrating screen for vibration, and carrying out a primary replacement and recovery of N-methylpyrrolidone, wherein a volume ratio of the methanol used to the N-methylpyrrolidone used during synthesis of polyarylene ether nitrile is 1:1;

[0038] S4: conveying a mixture after the vibration treatment of the primary vibrating screen to a secondary vibrating screen, and supplementally adding methanol for vibration, and carrying out a secondary replacement and recovery of N-methylpyrrolidone, wherein a volume ratio of the supplementally added methanol to the methanol added to the primary vibrating screen is 0.8:1; and then separating the polyarylene ether nitrile particles from a replacement liquid;

[0039] S5: mixing the polyarylene ether nitrile particles after the treatment in S4 and methanol in a mass ratio of 1:2, and then sending the mixture to a colloid mill for grinding and crushing; and after triple crushing by a three-stage colloid mill, obtaining a polyarylene ether nitrile powder slurry;

[0040] S6: conveying the polyarylene ether nitrile powder slurry obtained in S5 to a centrifuge via a pipeline, extracting with methanol at 25° C. for 10 min, and then centrifuging at 800 rpm for 8 min to separate the polyarylene ether nitrile powder from a centrifugation liquid; repeating the above operations three times; and then carrying out water washing and drying treatments on the polyarylene ether nitrile powder in sequence to obtain purified polyarylene ether nitrile powder, wherein the drying temperature is 50° C. and the drying time is 20 min; and

[0041] S7: combining the replacement liquid in S4 and the centrifugation liquid in S6, distilling at 80° C. for 3 h to remove methanol and completing the recovery of N-methylpyrrolidone.

Embodiment 2

[0042] A continuous process for producing polyarylene ether nitrile with efficiently recovering an N-methylpyrrolidone solvent includes the following steps:

[0043] S1: adding 180 mol of potassium carbonate and 100 mol of 2,6-dichlorobenzonitrile to 300 mol of N-methylpyrrolidone, and mixing well to obtain a reaction solution; and then adding 100 mol of dihydric phenol as shown in formula II and 50 mol of toluene to the reaction solution, and after mixing well, carrying out a dehydration reaction at 150° C. for 2.5 h, and then carrying out a polymerization reaction at 185° C. for 3.5 h, to obtain a high-viscosity polyarylene ether nitrile solution;

##STR00003##

[0044] S2: introducing the high-viscosity polyarylene ether nitrile solution obtained in S1 into an autoclave, wherein the discharge port of the autoclave is provided with a casting head, a pelletizing cutter head and a cooling spray device, starting the pelletizing cutter head and the cooling spray device, and under the action of a pressure pump, conveying the high-viscosity polyarylene ether nitrile solution to the casting head of the discharge port, and cutting it into cylindrical particles with a length of about 0.2 mm and a diameter of about 0.2 mm to obtain polyarylene ether nitrile particles;

[0045] S3: conveying the polyarylene ether nitrile particles obtained in S2 together with methanol to a primary vibrating screen for vibration, and carrying out a primary replacement and recovery of N-methylpyrrolidone, wherein a volume ratio of the methanol used to the N-methylpyrrolidone used during synthesis of polyarylene ether nitrile is 1.5:1;

[0046] S4: conveying a mixture after the vibration treatment of the primary vibrating screen to a secondary vibrating screen, and supplementally adding methanol for vibration, and carrying out a secondary replacement and recovery of N-methylpyrrolidone, wherein a volume ratio of the supplementally added methanol to the methanol added to the primary vibrating screen is 0.6:1; and then separating the polyarylene ether nitrile particles from a replacement liquid;

[0047] S5: mixing the polyarylene ether nitrile particles after the treatment in S4 and methanol in a mass ratio of 1:1.5, and then sending the mixture to a colloid mill for grinding and crushing; and after triple crushing by a three-stage colloid mill, obtaining a polyarylene ether nitrile powder slurry;

[0048] S6: conveying the polyarylene ether nitrile powder slurry obtained in S5 to a centrifuge via a pipeline, extracting with methanol at 24° C. for 15 min, and then centrifuging at 900 rpm for 10 min to separate the polyarylene ether nitrile powder from a centrifugation liquid; repeating the above operations three times; and then carrying out water washing and drying treatments on the polyarylene ether nitrile powder in sequence to obtain purified polyarylene ether nitrile powder, wherein the drying temperature is 55° C. and the drying time is 22 min; and

[0049] S7: combining the replacement liquid in S4 and the centrifugation liquid in S6, distilling at 75° C. for 5 h to remove methanol and completing the recovery of N-methylpyrrolidone.

Embodiment 3

[0050] A continuous process for producing polyarylene ether nitrile with efficiently recovering an N-methylpyrrolidone solvent includes the following steps:

[0051] S1: adding 110 mol of potassium carbonate and 100 mol of 2,6-dichlorobenzonitrile to 250 mol of N-methylpyrrolidone, and mixing well to obtain a reaction solution; and then adding 100 mol of dihydric phenol as shown in formula III and 125 mol of toluene to the reaction solution, and after mixing well, carrying out a dehydration reaction at 160° C. for 3 h, and then carrying out a polymerization reaction at 190° C. for 4 h, to obtain a high-viscosity polyarylene ether nitrile solution;

##STR00004##

[0052] S2: introducing the high-viscosity polyarylene ether nitrile solution obtained in S1 into an autoclave, wherein the discharge port of the autoclave is provided with a casting head, a pelletizing cutter head and a cooling spray device, starting the pelletizing cutter head and the cooling spray device, and under the action of a pressure pump, conveying the high-viscosity polyarylene ether nitrile solution to the casting head of the discharge port, and cutting it into cylindrical particles with a length of about 0.5 mm and a diameter of about 0.2 mm to obtain polyarylene ether nitrile particles;

[0053] S3: conveying the polyarylene ether nitrile particles obtained in S2 together with methanol to a primary vibrating screen for vibration, and carrying out a primary replacement and recovery of N-methylpyrrolidone, wherein a volume ratio of the methanol used to the N-methylpyrrolidone used during synthesis of polyarylene ether nitrile is 1.5:1;

[0054] S4: conveying a mixture after the vibration treatment of the primary vibrating screen to a secondary vibrating screen, and supplementally adding methanol for vibration, and carrying out a secondary replacement and recovery of N-methylpyrrolidone, wherein a volume ratio of the supplementally added methanol to the methanol added to the primary vibrating screen is 0.9:1; and then separating the polyarylene ether nitrile particles from a replacement liquid;

[0055] S5: mixing the polyarylene ether nitrile particles after the treatment in S4 and methanol in a mass ratio of 1:2, and then sending the mixture to a colloid mill for grinding and crushing; and after triple crushing by a three-stage colloid mill, obtaining a polyarylene ether nitrile powder slurry;

[0056] S6: conveying the polyarylene ether nitrile powder slurry obtained in S5 to a centrifuge via a pipeline, extracting with methanol at 22° C. for 20 min, and then centrifuging at 1000 rpm for 12 min to separate the polyarylene ether nitrile powder from a centrifugation liquid; repeating the above operations three times; and then carrying out water washing and drying treatments on the polyarylene ether nitrile powder in sequence to obtain purified polyarylene ether nitrile powder, wherein the drying temperature is 60° C. and the drying time is 26 min; and

[0057] S7: combining the replacement liquid in S4 and the centrifugation liquid in S6, distilling at 75° C. for 4 h to remove methanol and completing the recovery of N-methylpyrrolidone.

Embodiment 4

[0058] A continuous process for producing polyarylene ether nitrile with efficiently recovering an N-methylpyrrolidone solvent includes the following steps:

[0059] S1: adding 150 mol of potassium carbonate and 100 mol of 2,6-dichlorobenzonitrile to 300 mol of N-methylpyrrolidone, and mixing well to obtain a reaction solution; and then adding 100 mol of dihydric phenol as shown in formula IV and 100 mol of toluene to the reaction solution, and after mixing well, carrying out a dehydration reaction at 170° C. for 3.5 h, and then carrying out a polymerization reaction at 195° C. for 4.5 h, to obtain a high-viscosity polyarylene ether nitrile solution;

##STR00005##

[0060] S2: introducing the high-viscosity polyarylene ether nitrile solution obtained in S1 into an autoclave, wherein the discharge port of the autoclave is provided with a casting head, a pelletizing cutter head and a cooling spray device, starting the pelletizing cutter head and the cooling spray device, and under the action of a pressure pump, conveying the high-viscosity polyarylene ether nitrile solution to the casting head of the discharge port, and cutting it into cylindrical particles with a length of about 0.5 mm and a diameter of about 0.45 mm to obtain polyarylene ether nitrile particles;

[0061] S3: conveying the polyarylene ether nitrile particles obtained in S2 together with methanol to a primary vibrating screen for vibration, and carrying out a primary replacement and recovery of N-methylpyrrolidone, wherein a volume ratio of the methanol used to the N-methylpyrrolidone used during synthesis of polyarylene ether nitrile is 1:1;

[0062] S4: conveying a mixture after the vibration treatment of the primary vibrating screen to a secondary vibrating screen, and supplementally adding methanol for vibration, and carrying out a secondary replacement and recovery of N-methylpyrrolidone, wherein a volume ratio of the supplementally added methanol to the methanol added to the primary vibrating screen is 0.9:1; and then separating the polyarylene ether nitrile particles from a replacement liquid;

[0063] S5: mixing the polyarylene ether nitrile particles after the treatment in S4 and methanol in a mass ratio of 1:3, and then sending the mixture to a colloid mill for grinding and crushing; and after triple crushing by a three-stage colloid mill, obtaining a polyarylene ether nitrile powder slurry;

[0064] S6: conveying the polyarylene ether nitrile powder slurry obtained in S5 to a centrifuge via a pipeline, extracting with methanol at 20° C. for 25 min, and then centrifuging at 1100 rpm for 13 min to separate the polyarylene ether nitrile powder from a centrifugation liquid; repeating the above operations three times; and then carrying out water washing and drying treatments on the polyarylene ether nitrile powder in sequence to obtain purified polyarylene ether nitrile powder, wherein the drying temperature is 65° C. and the drying time is 28 min; and

[0065] S7: combining the replacement liquid in S4 and the centrifugation liquid in S6, distilling at 80° C. for 4 h to remove methanol and completing the recovery of N-methylpyrrolidone.

Embodiment 5

[0066] A continuous process for producing polyarylene ether nitrile with efficiently recovering an N-methylpyrrolidone solvent includes the following steps:

[0067] S1: adding 150 mol of potassium carbonate and 100 mol of 2,6-dichlorobenzonitrile to 250 mol of N-methylpyrrolidone, and mixing well to obtain a reaction solution; and then adding 50 mol of dihydric phenol as shown in formula I, 50 mol of dihydric phenol as shown in formula III and 100 mol of toluene to the reaction solution, and after mixing well, carrying out a dehydration reaction at 140° C. for 2 h, and then carrying out a polymerization reaction at 180° C. for 3 h, to obtain a high-viscosity polyarylene ether nitrile solution;

##STR00006##

[0068] S2: introducing the high-viscosity polyarylene ether nitrile solution obtained in S1 into an autoclave, wherein the discharge port of the autoclave is provided with a casting head, a pelletizing cutter head and a cooling spray device, starting the pelletizing cutter head and the cooling spray device, and under the action of a pressure pump, conveying the high-viscosity polyarylene ether nitrile solution to the casting head of the discharge port, and cutting it into cylindrical particles with a length of about 0.5 mm and a diameter of about 0.3 mm to obtain polyarylene ether nitrile particles;

[0069] S3: conveying the polyarylene ether nitrile particles obtained in S2 together with methanol to a primary vibrating screen for vibration, and carrying out a primary replacement and recovery of N-methylpyrrolidone, wherein a volume ratio of the methanol used to the N-methylpyrrolidone used during synthesis of polyarylene ether nitrile is 1:1;

[0070] S4: conveying a mixture after the vibration treatment of the primary vibrating screen to a secondary vibrating screen, and supplementally adding methanol for vibration, and carrying out a secondary replacement and recovery of N-methylpyrrolidone, wherein a volume ratio of the supplementally added methanol to the methanol added to the primary vibrating screen is 0.8:1; and then separating the polyarylene ether nitrile particles from a replacement liquid;

[0071] S5: mixing the polyarylene ether nitrile particles after the treatment in S4 and methanol in a mass ratio of 1:2, and then sending the mixture to a colloid mill for grinding and crushing; and after triple crushing by a three-stage colloid mill, obtaining a polyarylene ether nitrile powder slurry;

[0072] S6: conveying the polyarylene ether nitrile powder slurry obtained in S5 to a centrifuge via a pipeline, extracting with methanol at 25° C. for 10 min, and then centrifuging at 800 rpm for 8 min to separate the polyarylene ether nitrile powder from a centrifugation liquid; repeating the above operations three times; and then carrying out water washing and drying treatments on the polyarylene ether nitrile powder in sequence to obtain purified polyarylene ether nitrile powder, wherein the drying temperature is 50° C. and the drying time is 20 min; and

[0073] S7: combining the replacement liquid in S4 and the centrifugation liquid in S6, distilling at 80° C. for 3 h to remove methanol and completing the recovery of N-methylpyrrolidone.

[0074] Result Analysis

[0075] For the polyarylene ether nitrile product prepared in Embodiment 1, its thin film sample has a tensile strength of about 98 MPa, a thermal decomposition temperature (T.sub.5%) of 505° C., a glass transition temperature (T.sub.g) of 180° C., and a potassium ion content (specified purity) of 130 ppm, and the recovery rate of the N-methylpyrrolidone solvent is 85%.

[0076] For the polyarylene ether nitrile product prepared in Embodiment 2, its thin film sample has a tensile strength of about 102 MPa, a thermal decomposition temperature (T.sub.5%) of 515° C., a glass transition temperature (T.sub.g) of 185° C., and a potassium ion content (specified purity) of 132 ppm, and the recovery rate of the N-methylpyrrolidone solvent is 88%.

[0077] For the polyarylene ether nitrile product prepared in Embodiment 3, its thin film sample has a tensile strength of about 93 MPa, a thermal decomposition temperature (T.sub.5%) of 512° C., a glass transition temperature (T.sub.g) of 181° C., and a potassium ion content (specified purity) of 127 ppm, and the recovery rate of the N-methylpyrrolidone solvent is 82%.

[0078] For the polyarylene ether nitrile product prepared in Embodiment 4, its thin film sample has a tensile strength of about 99 MPa, a thermal decomposition temperature (T.sub.5%) of 510° C., a glass transition temperature (T.sub.g) of 184° C., and a potassium ion content (specified purity) of 129 ppm, and the recovery rate of the N-methylpyrrolidone solvent is 80%.

[0079] For the polyarylene ether nitrile product prepared in Embodiment 5, its thin film sample has a tensile strength of about 108 MPa, a thermal decomposition temperature (T.sub.5%) of 519° C., a glass transition temperature (T.sub.g) of 186° C., and a potassium ion content (specified purity) of 134 ppm, and the recovery rate of the N-methylpyrrolidone solvent is 86%.

[0080] For the polyarylene ether nitrile products prepared in Embodiments 1 to 5 described above, the tensile strength of the thin film sample indicates that a high molecular weight polyarylene ether nitrile is obtained, the thermal decomposition temperature and glass transition temperature indicate that the molecular structure is relatively regular and defect-free, and the structure is regular; and the potassium ion content indicates that the final product is high-purity polyarylene ether nitrile, and the recovery rate of the N-methylpyrrolidone solvent indicates that the process can realize the efficient recovery of the solvent.

[0081] Although the specific implementation of the present invention has been described in detail in conjunction with the embodiments, it should not be construed as limiting the protection scope of the present invention. Within the scope described in the claims, various modifications and variations made by those skilled in the art without creative efforts still fall within the protection scope of the present patent.