Polymerization of vinyl chloride with hydroxycarboxylic acids, inhibitors and Fe ions
US6455646B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 2001 |
| Grant date | Sep 24, 2002 |
| Priority date | — |
| Expiry date | Nov 20, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F14/06
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Vinyl chloride or a monomer mixture containing it transported over a long distance or stored for a long period usually contains a polymerization inhibitor and Fe ions. If this kind of vinyl chloride or monomer mixture is polymerized, stirring torque during the polymerization increases, and heat removal by the cooling jacket of a polymerization vessel tends to become insufficient, making the polymer quality subject to bad influences. In the present invention, a hydroxycarboxylic acid compound is added to the polymerization mixture in an amount of 50-1000 ppm relative to the monomer or monomer mixture. As a result, an increase in stirring torque during polymerization is suppressed, and heat removal by the cooling jacket of the polymerization vessel can be performed effectively, making it possible to obtain vinyl chloride of good quality.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.