Process for the mass polymerization of vinyl chloride
US4460754A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 1, 1982 |
| Grant date | Jul 17, 1984 |
| Priority date | — |
| Expiry date | Jun 1, 2002 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F14/06
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A process is described for the two-stage mass polymerization of vinyl chloride, in which 0.1 to 3% by weight, relative to the monomer employed, of one or more of the following compounds which are known as heat stabilizers for polyvinyl chloride: monoalkyltin-IV or dialkyltin-IV compounds in which the residual valencies of the tin are attached to organic radicals via sulfur atoms, and/or aminocrotonic acid esters, are added to the polymerization mixture when a conversion of 65 to 85% has been reached. After thorough removal of the unreacted vinyl chloride from the resulting polymer, preferably at temperatures above the glass transition point of the polymer, products are obtained which have an improved color in comparison with polyvinyl chloride produced by conventional mass polymerization.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.