Production process for hydrophilic polymer
US6207796A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 9, 1999 |
| Grant date | Mar 27, 2001 |
| Priority date | — |
| Expiry date | Nov 9, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F6/008
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention provides a production process to obtain a hydrophilic polymer, having a low residual monomer content, with good productivity while keeping the properties of a hydrogel polymer resultant from polymerization. In a drying process for a hydrogel polymer, the hydrogel polymer is dried under normal pressure at a material temperature of not higher than 90.degree. C. until the water content of the hydrogel polymer reduces to 15.about.40 weight %, and then the hydrogel polymer is kept for not shorter than 10 minutes either in a state where the change of the water content of the hydrogel polymer is within 5 weight % and where the material temperature is in the range of 70.about.120.degree. C. or in a state where the water content of the hydrogel polymer is in the range of 15.about.40 weight % and where the material temperature is in the range of 70.about.120.degree. C., and then the hydrogel polymer is finish-dried.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.