Process for producing vinyl chloride polymer, with iron chelates in coated vessel
US6022932A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 29, 1997 |
| Grant date | Feb 8, 2000 |
| Priority date | — |
| Expiry date | Apr 29, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J2219/00081
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
In a process for producing vinyl chloride polymers including polymerization of vinyl chloride or a monomer mixture containing it in an aqueous medium using a polymerization initiator, the polymerization is carried out in the presence of a chelating agent, The chelating agent is capable of chelating iron (II) and iron (III). This process makes it possible to prevent polymer scales from adhering to, e.g. baffle surfaces facing inner walls of the polymerization vessel, which has been hitherto difficult to do so, and less cause initial discoloration of polymer products to improve quality. It is more effective to use a polymerization vessel previously provided with coating films of a polymer scale preventive agent on the inner walls of the polymerization vessel and the other portions with which monomers come into contact in the course of polymerization.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.