Polymer composition containing processing aid
US3991135A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 4, 1975 |
| Grant date | Nov 9, 1976 |
| Priority date | — |
| Expiry date | Jun 4, 1995 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L51/003
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A process is disclosed for preparing a polyacrylate-modified polyvinyl chloride processing aid for polyvinyl chloride by sequentially polymerizing the vinyl chloride and the desired acrylate ester monomer. Thus, a conventional vinyl chloride suspension polymerization is conducted at a controlled rate of agitation and in the presence of a specified concentration of suspending agent and is then halted at or near its completion; unreacted vinyl chloride monomer is removed, a minor proportion of an acrylate ester monomer, e.g., methyl methacrylate, which has been pre-mixed with a fresh supply of a free radical initiating catalyst is added and polymerization is resumed and continued until the acrylate ester monomer polymerizes in and/or on the particles of the previously polymerized polyvinyl chloride. The polyacrylate-modified PVC thereby recovered is an effective aid for processing conventional PVC, or it can be processed per se since it is suitable for calendering or extruding.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.