Method for the Production of Monodispersed Ion Exchangers Containing Pores

Abstract

The present invention relates to a method for the production of monodisperse pore-containing ion exchangers, and also of monodisperse pore-containing bead polymers having a particle size of 10-500 μm.

Description

EXAMPLES

Example 1

1a) Production of Seed Polymer 1a

2400 g of n-butanol and 180 g of polyvinylpyrrolidone (Luviskol® K30) were stirred for 60 min in a 4 liter three-necked flask, a homogeneous solution being obtained. The reactor was then flushed with a nitrogen stream of 20 l/h and 300 g of styrene were added in the course of a few minutes with further stirring at 150 rpm. The reactor was heated to 80° C. When a temperature of 71° C. was reached, a solution of 3 g of azodiisobutyronitrile and 117 g of n-butanol heated to 40° C. was added all at once. The stirring speed was increased to 300 rpm for 2 min. After return to 150 rpm, the nitrogen stream was shut off. The reaction mixture was kept at80° C. for 20 h. Thereafter, the reaction mixture was cooled to room temperature, the resultant polymer was isolated by centrifugation, washed twice with methanol and twice with water. This produced in this manner 2970 g of an aqueous dispersion of seed polymer 1a having a solids content of 10% by weight. The particle size was 2.9 μm, Ø(90)/Ø(10) was 1.29.

1b-1) Production of Seed Polymer 1b-1

In a plastic vessel, a finely divided emulsion-I was produced from 300 g of styrene, 9.24 g of 75% strength by weight dibenzoyl peroxide, 500 g of water, 3.62 of ethoxylated nonylphenol (Arkopal® N060), 0.52 g of isooctyl sulfosuccinate sodium salt and 2 g of 3,3′,3″,5,5′5″-hexa-tert-butyl-alpha, alpha′, alpha″-(mesitylene-2,4,6-triyl)tri-p-cresol (Irganox® 1330 inhibitor) using an Ultraturrax (3 min at 13 500 rpm).

A solution of 10 g of methylhydroxyethylcellulose in 2245 g of deionized water, 400 g of aqueous dispersion from 1a) (40 g of solid) and 500 g of water was charged into a 4 l three-necked flask which was flushed with a nitrogen stream of 20 l/h. At room temperature, with stirring, the finely divided emulsion-I was pumped in at constant rate in the course of 3 hours. The batch was left to stand for a further 13 hours at room temperature and then heated to 80° C. for 9 hours. Thereafter, the reaction mixture was cooled to room temperature, the resultant polymer isolated by centrifugation, washed twice with methanol and twice with water and dispersed in water. This produced in this manner 1438 g of an aqueous dispersion having a solids content of 18.95% by weight. The particle size was 6.6 μm, the Ø(90)/Ø(10) value was 1.33.

1b-2) Production of Seed Polymer 1b-2

Step 1a) was repeated, but together with the solution of 10 g of methylhydroxyethylcellulose in 2245 of deionized water, 211 g of the dispersion from 1b-1) (40 g of solid) and 700 g of water were charged.

The resultant polymer was isolated by centrifugation, washed twice with methanol and twice with water and dispersed in water. This produced in this manner 1403 g of an aqueous dispersion having a solids content of 13.3% by weight. The particle size was 13.1 μm, the Ø(90)/Ø(10) value was 1.33.

1c) Production of Pore-Containing Bead Polymer 1

In a plastic vessel, a finely divided emulsion-II was produced from 101.7 g of technical grade divinylbenzene (approximately 80% by weight divinylbenzene content), 22.9 g of styrene, 203.4 g of toluene, 2 g of dibenzoyl peroxide, 515 g of water, 4.6 g of ethoxylated nonylphenol (Arkopal® N060), 0.80 g of isooctyl sulfosuccinate sodium salt and 2 g of 3,3′,3″5,5′5″-hexa-tert-butyl-alpha,alpha′,alpha″-(mesitylene-2,4,6-triyl)tri-p-cresol (Irganox 1330 inhibitor) using an Ultraturrax (3 min. at 10 000 rpm).

A solution of 10 of methylhydroxyethylcellulose in 2245 of deionized water, 100 g of aqueous dispersion from 1b-2) and 410 g of deionized water was charged into a 4 l three-necked flask which was flushed by a nitrogen stream of 20 l/h. At room temperature, with stirring, the finely divided emulsion-II was pumped in at constant rate in the course of 3 hours. The batch was left to stand at room temperature for a further 13 hours and then heated to 80° C. for 12 hours. Thereafter the reaction mixture was cooled to room temperature, the resultant polymer decanted off twice in methanol and subsequently copiously washed with water on a vacuum filter. After drying for 24 in the vacuum drying cabinet, this produced 89 g of finely divided porous beads having apparent density 0.29 g/cm³. The yield was 65%, the particle size was 28 μm, the Ø(90)/Ø(10) value was 1.31. The bead polymers had a BET pore surface area of 37.8 m²/g and a mean pore diameter of 100 nm.

Example 2

2c) Production of Pore-Containing Bead Polymer 2

The procedure was followed as in 1c), but for production of emulsion-II, 203.4 g of cyclohexane were used instead of toluene.

This produced 68 g of finely divided porous beads. The yield was 50%, the particle size was 28 μm, the Ø(90)/Ø(10) value was 1.28. The bead polymers had a BET surface area of 54 m²/g and a mean pore diameter of 79 nm.

2d) Production of Strongly Acidic Cation Exchanger 2

39.7 g of the pore-containing bead polymer from 2c) and 414 g 98% strength sulfuric acid were charged into a 1 liter 4-necked flask equipped with intensive cooler and agitator. The agitator was switched on (agitator speed 150 rpm), the mixture was heated 115° C. and held at 115° C. with stirring for 8 hours. Subsequently, the reactor contents were cooled to room temperature and, on a vacuum filter, successively washed with 500 ml in each case of 78% strength, 50% strength and 20% strength sulfuric acid. Subsequently the product was washed with demineralized water until the pH of the effluent was virtually neutral (pH 6 to 8).

This produced approximately 150 g of brown pore-containing cation exchanger beads having a mean diameter of 33 μm and a solids content of 30.5% by weight. The number of whole, round, undamaged beads was more than 90% of the total number of particles. The content of strongly acidic groups was 1.28 mmol per milliliter of moist resin in the H form.

Example 3

3a) Production of Seed Polymer 3a

A polystyrene seed polymer was produced as in 1a).

This produced 2985 g of an aqueous dispersion of seed polymer 3a having a solids content of 9.1% by weight. The particle size was 3.8 μm.

3b-1) Production of Seed Polymer 3b-1

The procedure was followed as in 1b-1) based on seed polymer 3a. This produced 1565 g of an aqueous dispersion of seed polymer 3b-1 having a solids content of 16.1% by weight. The particle size was 7.4 μm, the yield was 75%.

3b-2) Production of Seed Polymer 3b-2

The procedure was followed as in 1b-2) based on seed polymer 3b-1. This produced 1062 g of an aqueous dispersion of seed polymer 3b-2 having a solids content of 15.3% by weight. The particle size was 15 μm, the yield was 48%.

3b-3) Production of Seed Polymer 3b-3

The procedure was followed as in 1b-2) based on seed polymer 3b-2. This produced 1050 of an aqueous dispersion of seed polymer 3b-3 having a solids content of 31.1% by weight. The particle size was 25 μm.

3c) Production of Seed Polymer 3

The procedure was followed as in 1c) based on seed polymer 3b-3. This produced 46 g of finely divided porous beads. The particle size was 59 μm, the Ø(90)/Ø(10) value was 1.21.

Claims

1-8. (canceled)

9. A method of producing a monodisperse pore-containing ion exchanger, comprising: a) producing a noncrosslinked monodisperse seed polymer having a particle size of 0.5 to 20 μm by free-radical initiated polymerization of a monoethylenically unsaturated compound in the presence of a nonaqueous solvent;b) adding to an aqueous dispersion of the noncrosslinked monodisperse seed polymer at least one monomer feed (A), said monomer feed (A) comprising0.1 to 5% by weight of initiator and95 to 99.9% by weight of monomer,

10. The method according to claim 9, wherein the adding step c) is performed in the presence of a dispersant.

11. The method according to claim 10, wherein the dispersant comprises at least one water-soluble cellulose derivative.

12. A monodisperse pore-containing ion exchanger produced according to the method of claim 9.

13. The monodisperse pore-containing ion exchanger according to claim 12, wherein said functionalizing step d) is carried out so that the monodisperse pore-containing ion exchanger is an anion exchanger.

14. The monodisperse pore-containing ion exchanger according to claim 12, wherein said functionalizing stop d) is carried out so that the monodisperse pore-containing ion exchanger is a cation exchanger.

15. A method of producing a monodisperse pore-containing bead polymer comprising: a) producing a noncrosslinked monodisperse seed polymer having a particle size of 0.5 to 20 μm by free-radical initiated polymerization of a monoethylenically unsaturated compound in the presence of a nonaqueous solvent;b) adding to an aqueous dispersion of the noncrosslinked monodisperse seed polymer at least one monomer feed (A), said monomer feed (A) comprising0.1 to 5% by weight of initiator and95 to 99.9% by weight of monomer

16. The method according to claim 15, wherein the adding step c) is performed in the presence of a dispersant.

17. The method according to claim 16, wherein the dispersant comprises at least one water-soluble cellulose derivative.

18. A monodisperse pore-containing bead polymer produced according to the method of claim 15.

19. A process for removing a anion from a substance or mixture, said substance or mixture being in liquid, solid, or gaseous form, comprising: contacting the monodisperse pore-containing anion exchanger according to claim 15 with the substance or mixture.

20. A process for removing a cation from a substance or mixture, said substance or mixture being in liquid, solid, or gaseous form, comprising: contacting the monodisperse pore-containing cation exchanger according to claim 15 with the substance or mixture.