Acrylonitrile-based cation exchangers

Patent metadata

Field	Value
Publication number	US-12359031-B2
Application number	US-202217573682-A
Country	US
Kind code	B2
Filing date	Jan 12, 2022
Priority date	Jan 13, 2021
Publication date	Jul 15, 2025
Grant date	Jul 15, 2025

Abstract

The invention relates to acrylonitrile-based cation exchangers, to a process for the production thereof and to the use thereof for decationization and/or softening of aqueous or organic solutions.

First claim

What is claimed is:

1. A cation exchanger produced by hydrolysis of a polymer produced based on 80% to 95% by weight of acrylonitrile as monomer and 5% to 20% by weight of triallyl isocyanurate as crosslinker, wherein the parts by weight of acrylonitrile and triallyl isocyanurate sum to at least 98% by weight based on the total amount of employed monomers and crosslinkers.

2. The cation exchanger according to claim 1 , wherein 91% to 93% by weight of acrylonitrile and 7% to 9% by weight of triallyl isocyanurate are employed, wherein the parts by weight of acrylonitrile and triallyl isocyanurate sum to at least 98% by weight based on the total amount of employed monomers and crosslinkers.

3. The cation exchanger according to claim 1 , wherein the parts by weight of acrylonitrile and triallyl isocyanurate sum to at least 99% by weight based on the total amount of the employed monomers and crosslinkers.

4. The cation exchanger according to claim 1 , wherein the cation exchanger has a gel-like structure and has a BET surface area <25 m 2 /g.

5. A process for producing a cation exchanger, comprising the steps:
polymerizing, in the presence of water and at least one initiator, 80% to 95% by weight of acrylonitrile as monomer and 5% to 20% by weight of triallyl isocyanurate as crosslinker, wherein the parts by weight of acrylonitrile and triallyl isocyanurate sum to at least 98% by weight based on the total amount of the employed monomers and crosslinkers,
optionally in the presence of at least one protective colloid,
thereby forming a polymer and
hydrolyzing the polymer to afford the cation exchanger in the presence of at least one base or at least one acid.

6. The process for producing the cation exchanger according to claim 5 , wherein the at least one initiator is selected from peroxy compounds, dibenzoyl peroxide, dilauroyl peroxide, bis(p-chlorobenzoyl) peroxide, dicyclohexyl peroxydicarbonate, tert-butyl peroctoate, tert-butyl peroxy-2-ethylhexanoate, 2,5-bis(2-ethylhexanoylperoxy)-2,5-dimethylhexane, tert-amylperoxy-2-ethylhexane, azo compounds, 2,2′-azobis(isobutyronitrile), and 2,2′-azobis(2-methylisobutyronitrile).

7. The process for producing the cation exchanger according to claim 5 , wherein the protective colloid is employed and is selected from gelatine, starch, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, polymethacrylic acid and copolymers of (meth)acrylic acid and (meth)acrylic acid esters, cellulose derivatives, cellulose, esters, cellulose ethers, carboxymethylcellulose, methylhydroxyethylcellulose, methylhydroxypropylcellulose, hydroxyethylcellulose, naphthalenesulfonic acid-formaldehyde condensate and the Na salt thereof.

8. The process for producing the cation exchanger according to claim 7 , wherein the protective colloid is naphthalenedisulfonic acid-formaldehyde condensate and/or the Na salt thereof.

9. The process for producing the cation exchanger according to claim 5 , wherein the pH of the aqueous phase is adjusted to 8 to 10 by addition of a base.

10. The process for producing the cation exchanger according to claim 9 , wherein the weight ratio of acrylonitrile and triallyl isocyanurate to the aqueous phase is 0.5 to 1.0.

11. The process for producing the cation exchanger according to claim 5 , wherein an acid hydrolysis is performed by addition of sulfuric acid.

12. The process for producing the cation exchanger according claim 11 , wherein acids are employed in a molar ratio of 0.5:1 to 5:1 based on the molar amount of nitrile groups in the polymer.

13. A process for decationization and/or softening of aqueous or organic solutions, for decationization and/or softening of process streams in the chemical industry and for removal of heavy metal and/or noble metal ions from aqueous solutions, comprising contacting the cation exchanger produced according to claim 5 with the aqueous or organic solutions and/or the process streams in the chemical industry to be treated.

14. A polymer produced based on 91% to 93% by weight of acrylonitrile as monomer and 7% to 9% by weight of triallyl isocyanurate as crosslinker, wherein the parts by weight of the acrylonitrile and the triallyl isocyanurate sum to at least 98% by weight based on total amount of the employed monomers and crosslinkers.

Assignees

• Lanxess Deutschland Gmbh

Inventors

• Reckziegel Aurelia

Classifications

• C08F220/70

  Nitriles; Amides; Imides · CPC title

• C08F8/12 Primary

  Hydrolysis · CPC title

• C02F2001/425

  using cation exchangers · CPC title

• C02F1/42

  by ion-exchange (ion-exchange in general B01J) · CPC title

• B01J20/261

  obtained by reactions only involving carbon to carbon unsaturated bonds (macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds per se C08F) · CPC title