Method for the suspension polymerization of vinyl chloride monomer
US4694055A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 1985 |
| Grant date | Sep 15, 1987 |
| Priority date | — |
| Expiry date | Jun 25, 2005 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F14/06
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The invention provides an improvement in the suspension polymerization of vinyl chloride or a monomer mixture mainly composed of vinyl chloride in an aqueous medium containing a nonionic surface active agent and in the presence of a monomer-soluble polymerization initiator, according to which the aqueous polymerization medium is admixed with a crosslinked copolymer having carboxyl groups such as a copolymer of acrylic acid and diethyleneglycol bisallyl or bismethallyl ether at a moment when the percentage of the monomer conversion is in the range from 1 to 20% so that a polyvinyl chloride resin product of high quality can be obtained having an outstandingly high bulk density and plasticizer absorptivity but still containing an extremely small number of fish eyes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.