High bulk density rigid poly(vinyl chloride) resin powder composition and preparation thereof
US4239679A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 1979 |
| Grant date | Dec 16, 1980 |
| Priority date | — |
| Expiry date | Jun 27, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2327/06
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Completely free flow characteristics are provided to a densified rigid poly(vinyl chloride) resin powder composition as prepared in a high shear mixer at an elevated temperature, by withholding at least a portion of the total filler requirement from the composition during the initial mixing cycle, and thereafter adding the remainder of the filler requirement to the composition after it has been cooled to a temperature of 175.degree. F. or less. The total filler requirement of the composition may likewise be added after cooling the blend to 175.degree. F. or less. The resulting rigid resin powder composition exhibits the optimum free flow characteristics required for satisfactory processing in multi-screw extruders.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.