Method for increasing the low temperature water solubility and the sticking temperature of fully hydrolyzed polyvinyl alcohol
US4529775A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 3, 1983 |
| Grant date | Jul 16, 1985 |
| Priority date | — |
| Expiry date | Oct 3, 2003 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2329/04
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A method is provided for reducing the solvent content and increasing the sticking temperature of polyvinyl alcohol, which is prepared from the alcoholysis of polyvinyl acetate, charged to a dryer. The polyvinyl alcohol from the alcoholysis reaction, without prior vacuum drying at an elevated temperature, is slurried in a liquid medium comprising methanol, methyl acetate, water and, optionally, a nonsolvent for polyvinyl alcohol. The slurry is heated to at least 60.degree. C. for at least 5 minutes. The polyvinyl alcohol burnt particle count is reduced in the subsequent drying step and a product is afforded which has a reduced ash content and increased cold water solubility and low temperature solubility.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.