Process for production of granular material for water treatment
US4915884A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 1988 |
| Grant date | Apr 10, 1990 |
| Priority date | — |
| Expiry date | Mar 14, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W10/10
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A granular water treatment material and a process for the production thereof, the material being in the form of spherical granules, each having a thermoplastic polymeric matrix (1) and a more dense adjuvant in the form of micro-grains (3) dispersed in the matrix; each granule has on the surface a porosity in the form of micro-cavities (4) and cationic hydrophilic sites distributed on the surface; the process includes providing a mixture of an oxidizable thermoplastic resin and an adjuvant in powdered form, heating the mixture to make it plastic, extruding the plastic material to a diameter corresponding to the size of the granules to be obtained and cutting the extrusions to a length equal to this diameter, achieving a beading of the extruded pieces, oxidizing the surface of the spherical granules thus obtained, then ionically grafting a cationic polyelectrolyte to the surface of said granules.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.