Process for the preparation of cation exchangers in gel form
OwnerWolfgang Podszun, Ulrich Schnegg +2inventors
InventorsWolfgang Podszun, Ulrich Schnegg, Reinhold Klipper, Claudia Schmid
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Abstract
Spherical copolymers prepared by a seed/feed process with a feed comprising vinylaromatic compounds, divinylbenzene, methyl acrylate, and free-radical initiator can be converted into cation exchangers in gel form having high stability and purity by sulfonation in the absence of a swelling agent.
Claims12
A process for the preparation of monodisperse cation exchangers in gel form which have high stability and purity comprising
- (a) forming a suspension of seed polymer in a continuous aqueous phase,
- (b) allowing the seed polymer to swell in an activated monomer mixture consisting essentially of
- (i) 71 to 95.95% by weight of a vinylaromatic compound,
- (ii) 3 to 20% by weight of divinylbenzene,
- (iii) 1 to 6% by weight of methyl acrylate, and
- (iv) from 0.05 to 1% by weight of free-radical initiator,
- (c) polymerizing the monomer mixture in the seed polymer, and
- (d) functionalizing the resulting copolymer by sulfonation in the absence of a swelling agent.
A monodisperse cation exchanger in gel form obtained by
- (a) formation of a suspension of seed polymer in a continuous aqueous phase,
- (b) swelling of the seed polymer in an activated monomer mixture consisting essentially of
- (i) 71 to 95.95% by weight of a vinylaromatic compound,
- (ii) 3 to 20% by weight of divinylbenzene,
- (iii) 1 to 6% by weight of methyl acrylate, and
- (iv) from 0.05 to 1% by weight of free-radical initiator,
- (c) polymerization of the monomer mixture in the seed polymer, and
- (d) functionalization of the resultant copolymer by sulfonation in the absence of a swelling agent.
A cation exchanger obtained by converting a monodisperse cation exchanger from the acidic form into the sodium form by charge exchange.
Dependencies are inferred from the claim text.