Polypropylene interior parts for autocars
US4638030A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jun 25, 1985 |
| Grant date | Jan 20, 1987 |
| Priority date | — |
| Expiry date | Jun 25, 2005 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60R13/02
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
Polypropylene interior parts for autocars having overcome the drawback of their permanent bulge or secondary deformation due to high temperature exposure is provided, which parts are obtained by molding a material comprising a propylene-ethylene block copolymer prepared by polymerizing propylene at a first stage so that the resulting propylene homopolymer can have a relation between its isotactic pentad ratio (P) and MFR of EQU 1.00.gtoreq.P.gtoreq.0.015 log MFR+0.955 and can occupy 70 to 95% by weight of the total polymerization quantity, followed by polymerizing ethylene or ethylene and propylene in 30 to 5% by weight of the total polymerization quantity at at least one stage, so as to give an ethylene content occupying 3 to 12% by weight of the total polymerization quantity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.