Method for producing amido-methylated vinyl-aromatic bead polymers

Abstract

The invention relates to a process for preparing amidomethylated vinylaromatic bead polymers.

Claims

1. A process for preparing amidomethylated vinylaromatic bead polymers, comprising the steps of reacting at least one vinylaromatic bead polymer with at least one compound of formula (I) or salts thereof ##STR00003## where R.sub.1=—CH—(C.sub.1-C.sub.6-alkyl) or —CH.sub.2— and R.sub.2=—CH—(C.sub.1-C.sub.6-alkyl) or —CH.sub.2— or R.sub.1 and R.sub.2 are two carbon atoms of an aromatic C.sub.6 ring optionally substituted by one or two C.sub.1-C.sub.6-alkyl radicals, or R.sub.1 and R.sub.2 are each —CH═, and at least one condensed formaldehyde in the presence of at least one protic acid and in the presence of at least one compound of the formula (II)
H.sub.(3-n)C(Br).sub.nR.sub.3  (II) where R.sub.3=C.sub.1-C.sub.4-alkyl, Br, H or C.sub.1-C.sub.4-bromoalkyl and n may be 0 or 1, where, if n=0, R.sub.3=C.sub.1-C.sub.4-bromoalkyl or Br.

2. The process as claimed in claim 1, wherein the compounds of the formula (II) used are dibromomethane, 1,3-dibromopropane or mixtures thereof.

3. The process as claimed in claim 1, wherein the protic acid used is sulfuric acid.

4. The process as claimed in claim 1, wherein the condensed formaldehyde used is paraformaldehyde or trioxane or mixtures of these compounds.

5. The process as claimed in claim 1, wherein the vinylaromatic bead polymer is a styrene/divinylbenzene copolymer.

6. The process as claimed in claim 1, wherein the compound of the formula (I) used is phthalimide or salts thereof.

7. The process as claimed in claim 1, wherein the vinylaromatic bead polymer used is a monodisperse vinylaromatic bead polymer.

8. The process as claimed in claim 1, wherein the vinylaromatic bead polymer used is a macroporous monodisperse vinylaromatic bead polymer.

9. The process as claimed in claim 1, wherein the molar ratio of the compounds of the formula (II) to the compounds of the formula (I) is 3.5:1 to 10:1.

10. The process as claimed in claim 1, wherein the molar ratio of the aromatic groups in the vinylaromatic bead polymer to the compounds of the formula (I) is 0.5:1 to 1.8:1.

11. The process as claimed in claim 1, wherein the molar ratio of compounds of the formula (I) to condensed formaldehyde is 0.95:1 to 1.1:1.

12. The process as claimed in claim 1, wherein the molar ratio of the compounds of the formula (I) to the protic acid used is 10:1 to 1:10.

13. The process as claimed in claim 1, wherein the reaction temperature for the conversion of the vinylaromatic bead polymers to the amidomethylated vinylaromatic bead polymers is between 10° C. and 80° C.

Description

EXAMPLE 1

1.1 Preparation of the Monodisperse Macroporous Bead Polymer Based on Styrene, Divinylbenzene and Ethylstyrene

[0074] A 10 l glass reactor is charged with 3000 g of demineralized water, and a solution of 10 g of gelatin, 16 g of disodium hydrogenphosphate dodecahydrate and 0.73 g of resorcinol in 320 g of deionized water is added and mixed in. The mixture is equilibrated to 25° C. Subsequently, while stirring, a mixture of 3200 g of microencapsulated monomer droplets having a narrow particle size distribution, composed of 3.1% by weight of divinylbenzene and 0.6% by weight of ethylstyrene (used in the form of a commercial isomer mixture of divinylbenzene and ethylstyrene with 80% divinylbenzene), 0.4% by weight of dibenzoyl peroxide, 58.4% by weight of styrene and 37.5% by weight of isododecane (technical isomer mixture having a high proportion of pentamethylheptane) is added, the microcapsule consisting of a formaldehyde-hardened complex coacervate composed of gelatin and a copolymer of acrylamide and acrylic acid, and 3200 g of aqueous phase having a pH of 12 is added.

[0075] The mixture is stirred and polymerized to completion by increasing the temperature in accordance with a temperature program commencing at 25° C. and terminating at 95° C. The mixture is cooled, washed through a 32 μm sieve and then dried at 80° C. under reduced pressure.

[0076] This gives 1893 g of a bead polymer with narrow particle size distribution.

1.2. Preparation of a Phthalimidomethylated Monodisperse Macroporous Bead Polymer with the Swelling Agent Dibromomethane

[0077] A round-bottom flask is charged with 1522 g of dibromomethane. To this are added 105.7 g of bead polymer from example 1.1, 150.1 g of phthalimide and 31.9 g of paraformaldehyde, and then the mixture is left to stir at room temperature for 30 min. 375.1 g of sulfuric acid (96%) is added within 30 min. This is followed by stirring at room temperature for 24 h, then the beads are separated off on a sieve and washed with water, acetone and water.

[0078] Volume yield: 670 ml

[0079] Nitrogen content (after drying): 5.3%

1.3. Preparation of a Phthalimidomethylated Monodisperse Macroporous Bead Polymer with the Swelling Agent 1,3-Dibromopropane

[0080] A round-bottom flask is charged with 1206 g of 1,3-dibromopropane. To this are added 105.7 g of bead polymer from example 1.1, 150.1 g of phthalimide and 31.9 g of paraformaldehyde, and then the mixture is left to stir at room temperature for 30 min. 375.1 g of sulfuric acid (96%) is added within 30 min. This is followed by stirring at room temperature for 24 h, then the beads are separated off on a sieve and washed with water, acetone and water.

[0081] Volume yield: 690 ml

[0082] Nitrogen content (after drying): 5.2%

EXAMPLE 2

Comparative Example (Noninventive)

2.1 Preparation of a Phthalimidomethylated Monodisperse Macroporous Bead Polymer with the Swelling Agent Dichloroethane

[0083] A round-bottom flask is charged with 625 g of 1,2-dichloroethane. To this are added 103.6 g of bead polymer from example 1.1, 147.1 g of phthalimide and 31.3 g of paraformaldehyde, and then the mixture is left to stir at room temperature for 30 min. 363.3 g of sulfuric acid (96%) is added within 30 min, and then the mixture is stirred at room temperature for 24 h. Thereafter, the beads are separated off on a sieve and washed with water, acetone and water.

[0084] Volume yield: 605 ml

[0085] Nitrogen content (after drying): 5.1%

EXAMPLE 3

Comparative Example (Noninventive)

3.1 Preparation of a Phthalimidomethylated Monodisperse Macroporous Bead Polymer with the Swelling Agent Bromotrichloromethane

[0086] A round-bottom flask is charged with 1209 g of bromotrichloromethane. To this are added 105.7 g of bead polymer from example 1.1, 150.1 g of phthalimide and 31.9 g of paraformaldehyde, and then the mixture is left to stir at room temperature for 30 min. 375.1 g of sulfuric acid (96%) is added within 30 min. This is followed by stirring at room temperature for 24 h, then the beads are separated off on a sieve and washed with water, acetone and water.

[0087] Volume yield: 540 ml

[0088] Nitrogen content (after drying): 3.5%

[0089] Example 1 demonstrates that, when dibromomethane and 1,3-dibromopropane are used as swelling agents, higher degrees of substitution by amidomethyl groups can be achieved in the bead polymer (see nitrogen content) than by comparison with swelling agents known from the prior art.