Novel polyvinyl alcohol and process for producing polyvinyl alcohol by hydrolysis catalyzed by acids
US5047469A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 9, 1989 |
| Grant date | Sep 10, 1991 |
| Priority date | — |
| Expiry date | Feb 9, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F8/12
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The polyvinyl alcohol of the present invention is a partially saponified polyvinyl alcohol having a saponification degree of 70 to 98 mol % and containing a larger amount of methanol-soluble substances than that contained in polyvinyl alcohols having the same saponification degree obtained by known processes, and is novel. And, the process for producing polyvinyl alcohol of the present invention comprises saponifying polyvinyl esters in a solvent of a polyoxyalkylene ether having in the molecule thereof a structural unit represented by the general formula [I]: EQU --O).sub.l (R.sup.1 --O).sub.m (R.sup.2 --O).sub.n [I] wherein R.sup.1 and R.sup.2 each represents an alkylene group having 2 to 5 carbon atoms in the main chain thereof, which may be substituted with a lower alkyl group or lower alkoxy group; l is an integer of 0 or 1; m and n each represents 0 or an integer of 1 to 10; and l+m+n.gtoreq.2; with the catalyst of an aliphatic or aromatic sulfonic acid at an elevated temperature in the presence of water. The process can produce polyvinyl alcohol having a higher saponification degree at a higher reaction rate than conventional hydrolysis processes catalyzed by acids.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.