Dispersion stabilizer for suspension polymerization and method for producing vinyl polymer using same
US11434310B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 6, 2018 |
| Grant date | Sep 6, 2022 |
| Priority date | — |
| Expiry date | Nov 22, 2038 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L29/04
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention provides a dispersion stabilizer for suspension polymerization that, when used for suspension polymerization of a vinyl compound, provides excellent polymerization stability, and can produce a vinyl polymer having a reduced number of coarse particles, and a reduced number of fisheyes when molded into a sheet form. The present invention also provides a method therewith. The present invention relates to a dispersion stabilizer for suspension polymerization of a vinyl compound, the dispersion stabilizer comprising a vinyl alcohol polymer (A) having a viscosity-average degree of polymerization of more than 400 and less than 1,000, a degree of saponification of more than 67 mol % and less than 78 mol %, 0.02 mol % to 1.0 mol % of a group having an ethylenic double bond in its side chain, and an absorbance (x) at 280 nm of more than 0.17 and less than 0.65 in an ultraviolet absorption spectrum of a 0.1 mass % aqueous solution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.