Process for preparing vinyl chloride polymer with two-stage addition of dispersion stabilizers
US5096988A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 1990 |
| Grant date | Mar 17, 1992 |
| Priority date | — |
| Expiry date | Aug 8, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F14/06
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A process for preparing a vinyl chloride polymer comprises initiating suspension polymerization with a monomer, etc. being suspended previously in an aqueous medium by used of (A) a particular partially saponified polyvinyl alcohol with high saponification degree and (B) a particular hydroxypropylmethyl cellulose as the first dispersion stabilizer, and adding further the partially saponifice polyvinyl alcohol (A) into the polymerization system at a predetermined timing after the initiation of polymerization. A vinyl chloride polywer with a high bulk density can be obtained, and yet from said polymer, a molded or formed product of high quality with a very small number of fish eyes can be obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.