Superabsorbent acrylic powders having low residual monomer content
US5373066A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 12, 1993 |
| Grant date | Dec 13, 1994 |
| Priority date | — |
| Expiry date | Aug 12, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F6/006
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Particulates of a superabsorbent partially, neutralized acrylic polymer, e.g., polyacrylic acid, having a mean particle size ranging from 100 to 500 .mu.m, essentially monodisperse and essentially devoid of fines having a particle size of less than 100 .mu.m, having a nonuniformly surfaced spheroidal particle morphology and containing less than 50 ppm of residual monomer, well suited for a variety of hygienic applications, are prepared by (i) polymerizing a suspension of an acrylic monomer charge I in an organic medium and producing a suspension of acrylic polymer gel particles, (ii) next absorbing a second acrylic monomer charge II into the gel particles, (iii) polymerizing in the gel particles the second acrylic monomer charge II, (iv) azeotropically dehydrating the acrylic polymer particulates thus obtained, (v) then treating the dehydrated particulates with hydrogen peroxide, and (vi) drying the superabsorbent particulates thus treated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.