Impact resistant polymer blends of crystalline polypropylene and partially crystalline, low molecular weight impact modifiers
US7109269B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 2, 2004 |
| Grant date | Sep 19, 2006 |
| Priority date | — |
| Expiry date | Aug 21, 2024 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K2200/062
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Polymer blends that exhibit good impact resistance comprise a crystalline polypropylene matrix and a partly crystalline copolymer impact modifier with a molecular weight lower than that of the matrix polymer. The matrix polymer can comprise any crystalline propylene homo- or copolymer. The impact modifying copolymers are characterized as comprising at least about 60 weight percent (wt %) of units derived from propylene and, in certain embodiments, as having at least one, preferably two or more, of the following properties: (i) 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity, (ii) a B-value greater than about 1.4 when the comonomer content of the copolymer is at least about 3 wt %, (iii) a skewness index, Six, greater than about −1.20, (iv) a DSC curve with a Tme that remains essentially the same and a Tmax that decreases as the amount of comonomer in the copolymer is increased, and (v) an X-ray diffraction pattern that reports more gamma-form crystals than a comparable copolymer prepared with a Ziegler-Natta (Z-N) catalyst.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.