Polypropylene resin hollow molded foam article and a process for the production thereof
US7014801B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 23, 2003 |
| Grant date | Mar 21, 2006 |
| Priority date | — |
| Expiry date | Jan 30, 2024 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1352
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The present invention relates to a hollow molded foam article in which a plurality of polypropylene resins are used as the base resin, and to a process for the production of this hollow molded foam article. More particularly, the present invention relates to a polypropylene resin hollow molded foam article having a foam layer, in which the base resin comprises (a) a polypropylene resin with a melt tension of at least 98 mN and a melt flow rate of 0.5 to 15 g/10 minutes, (b) a polypropylene resin with a melt tension of less than 30 mN (excluding O) and a melt flow rate of 2 to 30 g/10 minutes, and (c) a polypropylene resin with a melt tension of at least 30 mN and less than 98 mN and a melt flow rate of 2 to 15 g/10 minutes, formed by positioning in a mold a softened cylindrical foam having a foam layer obtained by extruding from the die of an extruder a foamable molten resin composition containing a foaming agent, wherein the melt tension at 230° C. of the polypropylene resin that forms the foam layer is at least 10 mN and less than 49 mN, and the apparent density of the foam layer is no more than 0.3 g/cm3.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.