Process for preparing vinyl chloride polymer improved in plasticizer take-up by two-stage addition of dispersion stabilizers
US5204421A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 1990 |
| Grant date | Apr 20, 1993 |
| Priority date | — |
| Expiry date | Jul 31, 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 of the present invention comprises initiating suspension polymerization by suspending a vinyl chloride monomer in an aqueous medium in the presence of a first dispersion stabilizer and adding a second dispersion stabilizer at a specified time after the initiation of polymerization. Here, as the first dispersion stabilizer, (A) a partially saponified polyvinyl alcohol with a high saponification degree and (B) a hydroxypropylmethyl cellulose are used in combination, and as the second dispersion stabilizer, (C) a partially polyvinyl alcohol with a low saponification degree is used. According to the process, it is possible to prepare a vinyl chloride polymer with excellent characteristics such as plasticizer take-up, etc.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.