Production process for vinylpyrrolidone polymer
US6391994B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 31, 2001 |
| Grant date | May 21, 2002 |
| Priority date | — |
| Expiry date | Jan 31, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F226/10
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention provides a production process for a vinylpyrrolidone polymer which process prevents the polymerization reaction of N-vinylpyrrolidone from being hindered by by-products (as formed by nucleomethylation of N-vinylpyrrolidone) or &ggr;-butyrolactone, and therefore enables to obtain a vinylpyrrolidone polymer that has a desired molecular weight and involves only a small amount of residual monomers, wherein the vinylpyrrolidone polymer can display excellent properties even if the vinylpyrrolidone polymer is, for example, crosslinked to convert it into a water-absorbent resin. The production process for a vinylpyrrolidone polymer comprises the step of polymerizing a polymerizable monomer component or components which include N-vinylpyrrolidone, wherein: the N-vinylpyrrolidone as used is N-vinylpyrrolidone having a &ggr;-butyrolactone content of not more than 500 ppm; and/or the N-vinylpyrrolidone as used is N-vinylpyrrolidone obtained without using acetylene as a raw material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.