Initiated scale-free formation of vinyl chloride polymers using washing liquid at temperature affecting initiator half-life
US5100988A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 1990 |
| Grant date | Mar 31, 1992 |
| Priority date | — |
| Expiry date | Mar 16, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F14/06
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A method for preparing vinyl chloride polymers which comprises polymerizing vinyl chloride monomer or a vinylic monomer mixture mainly composed of vinyl chloride in an aqueous medium in the presence of a polymerization initiator, characterized by washing a piping and an opening of a polymerizer, for charging the polymerization initiator into the polymerizer, with water, steam or a washing liquid capable of lowering the half-life of the polymerization initiator to not more than 30 minutes after introducing the initiator into the polymerizer. The method makes it possible to eliminate the formation of polymer scales on the piping and the opening for charging the polymerization initiator into a polymerizer and, therefore, the yield of the vinyl chloride polymers can greatly improved and the production cost can be substantially saved. Moreover, the polymer product does not include any materials used for washing said portions and thus polymer product of high quality can be provided in a high yield.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.