Uniform polymer beads and ion exchange resins therefrom prepared by post-crosslinking of lightly crosslinked beads
US4192920A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 24, 1978 |
| Grant date | Mar 11, 1980 |
| Priority date | — |
| Expiry date | Jul 24, 1998 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F8/44
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Polymer beads of uniform size are prepared by (a) forming linear polymer beads of a vinyl aromatic polymer containing about 0.8-2.0 chloromethyl groups per aromatic nucleus, (b) removing off-sizes from the linear polymer beads to leave beads of a desired size, (c) recycling the off-sizes into the formation of the linear polymer beads, as required to obtain higher counts of uniform beads, and (d) lightly crosslinking the desired size beads by a thermal treatment to stabilize the beads. Strong base anion exchange resins are produced from the lightly crosslinked beads by swelling the beads in an organic solvent, post-crosslinking the swollen beads with a Friedel-Crafts catalyst, and aminating the post-crosslinked beads. Suitable starting monomers are vinylbenzyl chloride, bis(chloromethyl)styrene and vinyltoluene.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.