Division of a polyarylene ether solution

Abstract

Process for producing polyarylene ether beads from a polyarylene ether solution, comprising the steps of i) dividing the polyarylene ether solution into droplets, ii) transferring the droplets into a precipitation bath to form polyarylene ether beads in the precipitation bath which (A) comprises at least one aprotic solvent (component (1)) and at least one protic solvent (component (2)), (B) has a temperature of 0° C. to T.sub.c, where the critical temperature T.sub.c in [° C.] can be determined by the numerical equation T.sub.c=(99−c)/0.61 in which c is the concentration of component (1) in the precipitation bath in [% by weight] and (C) has component (1) in concentrations of 5% by weight to c.sub.c, where the critical concentration c.sub.c in [% by weight] can be determined by the numerical equation c.sub.c=99−0.61*T in which T is the temperature in the precipitation bath in [° C.], where
the percentages by weight are each based on the sum of the percentages by weight of component (1) and of component (2) in the precipitation bath.

Claims

1. A process for producing polyarylene ether beads from a polyarylene ether solution, comprising: i) dividing the polyarylene ether solution into droplets; and ii) transferring the droplets into a precipitation bath to form polyarylene ether beads in the precipitation bath which (A) comprises an aprotic solvent (component (1)) and a protic solvent (component (2)), and (B) has a temperature of 0° C. to T.sub.c, where the critical temperature T.sub.c in [° C.] is determined by the numerical equation T.sub.c=(99−c)/0.61 in which c is the concentration of component (1) in the precipitation bath in [% by weight], wherein the percentages by weight are each based on the sum of the percentages by weight of component (1) and of component (2) in the precipitation bath, wherein the precipitation bath comprises water or alcohol as component (2), the polyarylene ether solution has a concentration of 5 to 50% by weight of polyarylene ether in the aprotic solvent, where the percentages by weight are based on the sum of the percentages by weight of the polyarylene ether and the aprotic solvent, the polyarylene ether solution on division has a temperature of 15 to 250° C., the aprotic solvent is selected from the group consisting of dimethyl sulfoxide, dimethylformamide, sulfolane, diphenyl sulfone, 1,2-dichlorobenzene, hexamethylphosphoramide and mixtures thereof, and wherein, in the polyarylene ether beads formed from the precipitation bath in (ii), a content of particles having a particle size of less than or equal to 1000 μm is less than 8.15% by weight.

2. The process according to claim 1, wherein the precipitation bath is agitated.

3. The process according to claim 1, wherein the polyarylene ether solution on division has a temperature of 20 to 120° C.

4. The process according to claim 1, wherein the polyarylene ether solution after leaving the division apparatus covers a full distance from the exit point to the precipitation bath surface of 0.10 m to 1.20 m.

5. The process according to claim 1, wherein the division apparatus used comprises a capillary and/or die plate.

6. The process according to claim 5, wherein the capillary and/or die plate has a diameter of 0.1 to 5.0 mm.

7. The process according to claim 1, wherein the polyarylene ether solution and the precipitation bath comprise the same aprotic solvent.

8. The process according to claim 1, wherein the precipitation bath comprises 12 to 50% by weight, of component (1), where the percentages by weight are each based on the sum of the percentages by weight of component (1) and component (2) in the precipitation bath.

9. The process according to claim 1, wherein a concentration of component (1) in the precipitation bath is from 5 to 70% by weight.

10. The process according to claim 1, further comprising stirring the precipitation bath when transferring the droplets into the precipitation bath.

11. The process of claim 1, wherein, in the polyarylene ether beads precipitated from the precipitation bath in (ii), the content of particles having a particle size of less than or equal to 1000 μm is 0.68% by weight or less.

12. The process according to claim 1, wherein the polyarylene ether beads are individual beads which are not agglomerated.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows samples from example 1.

(2) FIG. 2 shows samples from example 6.

(3) FIG. 3 shows samples from example 37.

(4) FIG. 4 shows samples from example 42.

EXAMPLES

(5) Examples 1 to 36: Variation of precipitation bath temperature and precipitation bath composition in water/sulfolane

(6) Experiments 1 to 36 were conducted successively, each with an illustrative polyarylene ether solution, with optimization of the precipitation behavior.

(7) Solution 1: A solution comprising a polyarylene ether having elements of the structure I (formula II) was dissolved in sulfolane and the respective concentration was set (see tables, polyarylene ether solution). The polyarylene ether used, having elements of the structure I, had a viscosity number of 56 ml/g. The viscosity number determination was conducted to ISO1628 from a 0.01 g/ml solution in phenol/1,2-dichlorobenzene (1:1) at 25° C.

(8) ##STR00004##

(9) Solution 1, of set concentration, was run from a reservoir vessel at a constant delivery rate of 1000 g/h through a capillary for division to form droplets. The experiments were conducted with a capillary as the die. The capillary diameter and the fall distance from exit from the capillary to the precipitation bath surface are specified in the tables below. After the division, the droplet of the respective polymer solution fell into a precipitation bath. The precipitation bath composition (component 1.1 sulfolane, component 1.2 DMSO, component 2.1 water) was varied as specified in the tables. The temperature of the precipitation bath was kept constant during an experiment. The beads formed in the process were separated off using a screen and examined further.

(10) The experiment was conducted at different precipitation bath temperatures.

(11) The sulfolane content in the precipitation bath was controlled with the aid of a refractometer at 25° C. The instrument used was an Abbe refractometer from Leo Kübler GmbH (model: Atago). A drop of the water/sulfolane mixture was taken from the precipitation medium to measure the refractive index. Using a calibration curve of sulfolane/water composition versus refractive index, it was possible to control or measure the precipitation bath composition.

(12) Sulfolane solvent, solution 1

(13) Variation of the sulfolane content of the precipitation bath at precipitation bath temperature 20° C.:

(14) TABLE-US-00001 Precipitation bath Polyarylene ether solution Sulfolane Conc. Die Precipitation content Solution [% by T diameter height T [% by Precipitation Ex. number wt.] [° C.] [mm] [cm] [° C.] wt.] characteristics 1 1 18 76 1 70 20 20 Individual beads 2 1 18 76 1 70 20 40 Individual beads 3 1 18 76 1 70 20 60 Individual beads 4 1 18 76 1 70 20 80 Individual beads 5 1 18 76 1 70 20 85 Individual beads 6 1 18 76 1 70 20 90 Beads which agglomerate in the precipitation bath

(15) Photos of the samples from examples 1 and 6 were taken for illustration and are shown in FIGS. 1 and 2.

(16) Variation of the sulfolane content of the precipitation bath at precipitation bath temperature 30° C.:

(17) TABLE-US-00002 Precipitation bath Polyarylene ether solution Sulfolane Conc. Die Precipitation content Solution [% by T diameter height T [% by Precipitation Ex. number wt.] [° C.] [mm] [cm] [° C.] wt.] characteristics 7 1 18 76 1 70 30 20 Individual beads 8 1 18 76 1 70 30 40 Individual beads 9 1 18 76 1 70 30 60 Individual beads 10 1 18 76 1 70 30 70 Individual beads 11 1 18 76 1 70 30 75 Individual beads 12 1 18 76 1 70 30 81 Beads which agglomerate in the precipitation bath

(18) Variation of the sulfolane content of the precipitation bath at precipitation bath temperature 40° C.:

(19) TABLE-US-00003 Precipitation bath Polyarylene ether solution Sulfolane Conc. Die Precipitation content Solution [% by T diameter height T [% by Precipitation Ex. number wt.] [° C.] [mm] [cm] [° C.] wt.] characteristics 13 1 18 76 1 70 40 20 Individual beads 14 1 18 76 1 70 40 40 Individual beads 15 1 18 76 1 70 40 60 Individual beads 16 1 18 76 1 70 40 70 Individual beads 17 1 18 76 1 70 40 75 Beads which agglomerate in the precipitation bath

(20) Variation of the sulfolane content of the precipitation bath at precipitation bath temperature 50° C.:

(21) TABLE-US-00004 Precipitation bath Polyarylene ether solution Sulfolane Conc. Die Precipitation content Solution [% by T diameter height T [% by Precipitation Ex. number wt.] [° C.] [mm] [cm] [° C.] wt.] characteristics 18 1 18 76 1 70 50 20 Individual beads 19 1 18 76 1 70 50 40 Individual beads 20 1 18 76 1 70 50 60 Individual beads 21 1 18 76 1 70 50 65 Individual beads 22 1 18 76 1 70 50 70 Beads which agglomerate in the precipitation bath

(22) Variation of the sulfolane content of the precipitation bath at precipitation bath temperature 60° C.:

(23) TABLE-US-00005 Precipitation bath Polyarylene ether solution Sulfolane Conc. Die Precipitation content Solution [% by T diameter height T [% by Precipitation Ex. number wt.] [° C.] [mm] [cm] [° C.] wt.] characteristics 23 1 18 76 1 70 60 20 Individual beads 24 1 18 76 1 70 60 40 Individual beads 25 1 18 76 1 70 60 50 Individual beads 26 1 18 76 1 70 60 60 Individual beads 27 1 18 76 1 70 60 65 Beads which agglomerate in the precipitation bath

(24) Variation of the sulfolane content of the precipitation bath at precipitation bath temperature 70° C.:

(25) TABLE-US-00006 Precipitation bath Polyarylene ether solution Sulfolane Conc. Die Precipitation content Solution [% by T diameter height T [% by Precipitation Ex. number wt.] [° C.] [mm] [cm] [° C.] wt.] characteristics 28 1 18 76 1 70 70 20 Individual beads 29 1 18 76 1 70 70 40 Individual beads 30 1 18 76 1 70 70 50 Individual beads 31 1 18 76 1 70 70 55 Individual beads 32 1 18 76 1 70 70 59 Beads which agglomerate in the precipitation bath

(26) Variation of the sulfolane content of the precipitation bath at precipitation bath temperature 80° C.:

(27) TABLE-US-00007 Precipitation bath Polyarylene ether solution Sulfolane Conc. Die Precipitation content Solution [% by T diameter height T [% by Precipitation Ex. number wt.] [° C.] [mm] [cm] [° C.] wt.] characteristics 33 1 18 76 1 70 80 20 Individual beads 34 1 18 76 1 70 80 40 Individual beads 35 1 18 76 1 70 80 50 Individual beads 36 1 18 76 1 70 80 53 Beads which agglomerate in the precipitation bath

(28) Examples 37 to 72: Variation of precipitation bath temperature and precipitation bath composition in water/DMSO

(29) Experiments 37 to 72 were conducted successively, with an illustrative polyarylene ether solution, with optimization of the precipitation behavior.

(30) Solution 2: A solution comprising a polyarylene ether having elements of the structure II (formula III) was dissolved in DMSO and the respective concentration was set (see tables, polyarylene ether solution). The polyarylene ether used, having elements of the structure II, had a viscosity number of 63 ml/g. The viscosity number determination was conducted to ISO1628 from a 0.01 g/ml solution in phenol/1,2-dichlorobenzene (1:1) at 25° C.

(31) ##STR00005##

(32) Solution 2, of set concentration, was run from a reservoir vessel at a constant delivery rate of 1000 g/h through a capillary for division to form droplets. The experiments were conducted with a capillary as the die. The capillary diameter and the fall distance from exit from the capillary to the precipitation bath surface are specified in the tables below.

(33) After the division, the droplet of the respective polymer solution fell into a precipitation bath. The precipitation bath composition was varied as specified in the tables. The temperature of the precipitation bath was kept constant during an experiment. The beads formed in the process were separated off using a screen and examined further.

(34) The experiment was conducted at different precipitation bath temperatures.

(35) The DMSO content in the precipitation bath was controlled with the aid of a refractometer at 25° C. The instrument used was an Abbe refractometer from Leo Kübler GmbH (model: Atago). A drop of the water/DMSO mixture was taken from the precipitation medium to measure the refractive index. Using a calibration curve of DMSO/water composition versus refractive index, it was possible to control or measure the precipitation bath composition.

(36) DMSO solvent, solution 2

(37) Variation of the DMSO content of the precipitation bath at precipitation bath temperature 20° C.:

(38) TABLE-US-00008 Precipitation bath Polyarylene ether solution DMSO Conc. Die Precipitation content Solution [% by T diameter height T [% by Precipitation Ex. number wt] [° C.] [mm] [cm] [° C.] wt.] characteristics 37 2 18 75 1 70 20 20 Individual beads 38 2 18 75 1 70 20 40 Individual beads 39 2 18 75 1 70 20 60 Individual beads 40 2 18 75 1 70 20 80 Individual beads 41 2 18 75 1 70 20 85 Individual beads 42 2 18 75 1 70 20 92 Beads which agglomerate in the precipitation bath

(39) Photos of the samples from examples 37 and 42 were taken for illustration and are shown in FIGS. 3 and 4.

(40) Variation of the DMSO content of the precipitation bath at precipitation bath temperature 30° C.:

(41) TABLE-US-00009 Precipitation bath Polyarylene ether solution DMSO Conc. Die Precipitation content Solution [% by T diameter height T [% by Precipitation Ex. number wt.] [° C.] [mm] [cm] [° C.] wt.] characteristics 43 2 18 75 1 70 30 20 Individual beads 44 2 18 75 1 70 30 40 Individual beads 45 2 18 75 1 70 30 60 Individual beads 46 2 18 75 1 70 30 80 Individual beads 47 2 18 75 1 70 30 85 Beads which agglomerate in the precipitation bath

(42) Variation of the DMSO content of the precipitation bath at precipitation bath temperature 40° C.:

(43) TABLE-US-00010 Precipitation bath Polyarylene ether solution DMSO Conc. Die Precipitation content Solution [% by T diameter height T [% by Precipitation Ex. number wt.] [° C.] [mm] [cm] [° C.] wt.] characteristics 48 2 18 75 1 70 40 20 Individual beads 49 2 18 75 1 70 40 40 Individual beads 50 2 18 75 1 70 40 60 Individual beads 51 2 18 75 1 70 40 70 Individual beads 52 2 18 75 1 70 40 74 Individual beads 53 2 18 75 1 70 40 78 Beads which agglomerate in the precipitation bath

(44) Variation of the DMSO content of the precipitation bath at precipitation bath temperature 50° C.:

(45) TABLE-US-00011 Precipitation bath Polyarylene ether solution DMSO Conc. Die Precipitation content Solution [% by T diameter height T [% by Precipitation Ex. number wt.] [° C.] [mm] [cm] [° C.] wt.] characteristics 54 2 18 75 1 70 50 20 Individual beads 55 2 18 75 1 70 50 40 Individual beads 56 2 18 75 1 70 50 60 Individual beads 57 2 18 75 1 70 50 68 Individual beads 58 2 18 75 1 70 50 73 Beads which agglomerate in the precipitation bath

(46) Variation of the DMSO content of the precipitation bath at precipitation bath temperature 60° C.:

(47) TABLE-US-00012 Precipitation bath Polyarylene ether solution DMSO Conc. Die Precipitation content Solution [% by T diameter height T [% by Precipitation Ex. number wt] [° C.] [mm] [cm] [° C.] wt.] characteristics 59 2 18 75 1 70 60 20 Individual beads 60 2 18 75 1 70 60 40 Individual beads 61 2 18 75 1 70 60 60 Individual beads 62 2 18 75 1 70 60 62 Individual beads 63 2 18 75 1 70 60 68 Beads which agglomerate in the precipitation bath

(48) Variation of the DMSO content of the precipitation bath at precipitation bath temperature 70° C.:

(49) TABLE-US-00013 Precipitation bath Polyarylene ether solution DMSO Conc. Die Precipitation content Solution [% by T diameter height T [% by Precipitation Ex. number wt.] [° C.] [mm] [cm] [° C.] wt.] characteristics 64 2 18 75 1 70 70 20 Individual beads 65 2 18 75 1 70 70 40 Individual beads 66 2 18 75 1 70 70 50 Individual beads 67 2 18 75 1 70 70 55 Individual beads 68 2 18 75 1 70 70 61 Beads which agglomerate in the precipitation bath

(50) Variation of the DMSO content of the precipitation bath at precipitation bath temperature 80° C.:

(51) TABLE-US-00014 Precipitation bath Polyarylene ether solution DMSO Conc. Die Precipitation content Solution [% by T diameter height T [% by Precipitation Ex. number wt.] [° C.] [mm] [cm] [° C.] wt.] characteristics 69 2 18 75 1 70 80 20 Individual beads 70 2 18 75 1 70 80 40 Individual beads 71 2 18 75 1 70 80 50 Individual beads 72 2 18 75 1 70 80 55 Beads which agglomerate in the precipitation bath

(52) Examples 73 and 74 show the influence of the sulfolane concentration in the precipitation bath on the formation of fines. “Fines” are understood here to mean polyarylene ether beads having a particle size of ≦1000 μm.

(53) For this purpose, a solution 3 of polyarylene ether in sulfolane was prepared. The polyarylene ether used was Ultrason® E2020 from BASF SE. The concentration of the polyarylene ether was 16.0% by weight.

(54) The polyarylene ether was precipitated by means of dropletization and then extracted. For the dropletization, solution 3 was introduced into the reservoir vessel and adjusted to the desired temperature. By means of a gear pump, solution 3 was dropletized through a capillary. The precipitation was effected in a precipitation bath with an overflow to an agitated screen which removed the beads. The precipitation bath solution was collected in a buffer vessel and then sent back to the precipitation bath.

(55) The concentration of sulfolane in the precipitation bath was monitored by means of refractive index and balanced by addition of demineralized water. After dropletization had ended, the beads/lenses were filtered off with suction, washed with demineralized water and then extracted.

(56) The conditions during the dropletization are specified in the following table.

(57) TABLE-US-00015 Conc. in Conc. solv. in the Precipitation Temp. of solution 3 Fall solution 3 precipitation bath bath temp. on dropletization height Exp. Solvent [% by wt.] [%] [° C.] [° C.] [cm] 73 Sulfolane 16.0 <1 40 80 60 74 Sulfolane 16.0 40 40 80 60

(58) The conditions in the extraction with water were as follows:

(59) TABLE-US-00016 Temp. in the extraction: 95° C. Extractant throughput: 2000 ml water/h Extractant temp.: 90-95° C. Extraction period: 24 h

(60) The particle size distribution was determined as follows:

(61) The extracted moist beads/lenses were dried in a drying cabinet at 60° C. and then the distribution was determined by means of manual screening in a screening tower. The results are reported in the table which follows.

(62) TABLE-US-00017 Particle size [μm] 73 74 3150 99.16 100.0 2800 97.49 99.89 2500 92.48 99.21 2000 27.69 30.51 1600 8.88 2.94 1250 5.33 0.45 1000 4.28 0.23 650 3.87 0.45 Sum ≦ 8.15 0.68 1000 = fines

(63) Examples 73 and 74 show that, within the inventive concentration range of aprotic solvent in the precipitation bath, polyarylene ether beads having a distinctly smaller fines fraction are obtained.