Dispersing stabilizer for suspension polymerization of vinyl chloride
US5780547A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 1995 |
| Grant date | Jul 14, 1998 |
| Priority date | — |
| Expiry date | Mar 17, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F8/12
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A dispersing stabilizer suitable for suspension polymerization of vinyl chloride or a monomer mixture mainly composed of vinyl chloride which can be used in a hot water charging polymerization process without any problems, and which can produce vinyl chloride homopolymer or copolymers having a good porosity, a large bulk density, a very low content of coarse particles and good physical properties, the dispersing stabilizer comprising a polyvinyl alcohol having a degree of hydrolysis of 75 to 85% by mole, an absorbance of not less than 0.1 measured at a wavelength of 280 m.mu. with respect to the 0.1% by weight aqueous solution, a content of carboxyl group of 0.01 to 0.15% by mole and a cloud point of not less than 50.degree. C. measured with respect to the 0.1% by weight aqueous solution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.