Crystallization of polypropylene using a semi-crystalline, branched or coupled nucleating agent
US6927256B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 5, 2002 |
| Grant date | Aug 9, 2005 |
| Priority date | — |
| Expiry date | Nov 5, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K2200/062
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A method of nucleating a propylene homo- or copolymer, the method comprising contacting the propylene polymer with a semi-crystalline branched or coupled polymeric nucleating agent under nucleation conditions. In one embodiment, the propylene homopolymer is characterized as having 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity. In another embodiment, the copolymer is characterized as comprising at least about 60 weight percent (wt %) of units derived from propylene, and as having at least one 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, i.e., the units derived from ethylene and/or the unsaturated comonomer(s), 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, i.e., the units derived from ethylene and/or the unsaturated comonomer(s), in the copolymer is increased, and (v) an X-ray diffracti…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.