Polyvinyl alcohol and method for producing polyvinyl alcohol
US11261270B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jul 11, 2018 |
| Grant date | Mar 1, 2022 |
| Priority date | — |
| Expiry date | Feb 19, 2039 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F18/08
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A polyvinyl alcohol has a number-average molecular weight (Mn) from 4,400 to 440,000, a molecular weight distribution (Mw/Mn) from 1.05 to 1.70, a degree of saponification from 80 to 99.99 mol %, wherein the polyvinyl alcohol contains an end group represented by a formula (I) below, and a molar ratio (X) of the end group based on total monomer units and the number-average molecular weight (Mn) satisfy a formula (1) below. Such a polyvinyl alcohol has a narrow molecular weight distribution and a high number-average molecular weight with hue good. (In the formula, R1 denotes an optionally substituted aromatic group having a carbon number from 6 to 20, and R2 denotes a hydrogen atom, an alkyl group having a carbon number from 1 to 20, or an optionally substituted aromatic group having a carbon number from 6 to 20.) X·Mn/44≥0.5 (1)
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.