Propylene-ethylene copolymer composition and process for producing the same
US6005034A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Apr 30, 1997 |
| Grant date | Dec 21, 1999 |
| Priority date | — |
| Expiry date | Apr 30, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F210/16
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A propylene-ethylene copolymer composition is obtained which has good moldability and an excellent balance of rigidity, toughness, and impact-strength. The composition has a melt flow rate of 10 to 300 g/10 minutes and is obtained by producing 60 to 95% by weight, based on the weight of whole polymer, of a propylene polymer having a melt flow rate (ASTM D1238) in the range of 100 to 1,000 g/10 minutes and having a ratio (Cf) of integrated values of the propylene polymer dissolved in o-dichlorobenzene at a temperature of lower than 112.degree. C., and a temperature of 112.degree. C. or higher, respectively, of 0.5 or less, by carrying out polymerization of propylene in the presence of a highly stereoregular catalyst and hydrogen in a polymerization step (I), and then producing 5 to 40% by weight, based on the weight of whole polymer, of an ethylene-propylene copolymer by feeding ethylene and propylene to the propylene polymer to react so that the content of ethylene becomes 30 to 80% by weight. Also provided is a propylene-ethylene copolymer composition comprising the composition mentioned above and a .alpha.-crystal and/or .beta.-crystal nucleator added therewith.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.