Highly crystalline polypropylene
US6162887A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 1998 |
| Grant date | Dec 19, 2000 |
| Priority date | — |
| Expiry date | Mar 30, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31938
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A highly crystalline polypropylene having a degree of crystallinity of at least 50.5% calculated from the heat of melting; and a relationship between a proportion f(R)of R-lamella with respect to spherulites and a weight-average molecular weight Mw which satisfies the following Formula (II). The above-mentioned proportion f(R) of R-lamella spherulites is calculated using the following Formula (I) from the birefringence .DELTA.n of crystallized spherulites obtained by melting said highly crystalline polypropylene at 230.degree. C. for 5 minutes, cooling to a temperature of 132.degree. C. at a cooling rate of 20.degree. C./minute, and then maintaining said temperature for 90 minutes. Molded articles obtained using the above-mentioned highly crystalline polypropylene or a resin composition containing the above-mentioned highly crystalline polypropylene resin are superior in rigidity, heat resistance, scratch resistance, dimensional stability, and low production of odor during molding, and can be widely used in various applications. EQU f(R)=(-.DELTA.n+0.0351).times.100/0.0528 Formula (I) EQU f(R)>-2.5.times.(log{Mw}-4).sup.2 +88.9 Formula (II).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.