Method for the preparation of a polyvinyl chloride resin powder with improved flowability
US5132382A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 7, 1991 |
| Grant date | Jul 21, 1992 |
| Priority date | — |
| Expiry date | Feb 7, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08K5/103
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
An improvement is proposed for decreasing triboelectric static charging of a polyvinyl chloride resin powder so as to improve the flowability of the powder and prevent a decrease in the bulk density of the powder due to static electricity. The improvement comprises, in the polymerization process of vinyl chloride monomer in an aqueous medium, adding, to the aqueous polymerization mixture, a specified amount of an aqueous dispersion containing a salt of a long-chain carboxylic acid with a divalent metal and an ester of sorbitan with a long-chain carboxylic acid in a specified weight proportion and in a specified total concentration at a moment when conversion of the monomer to polymer is at least 70%.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.