Propylene polymer composition having good transparency and improved impact resistance
US5298561A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 11, 1992 |
| Grant date | Mar 29, 1994 |
| Priority date | — |
| Expiry date | Sep 11, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L2314/02
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Propylene polymer compositions having good transparency and improved impact resistance at low temperature comprising: PA0 a) 70 to 98% by weight crystalline copolymer of ethylene with propylene and/or with an alpha olefin of the formula H.sub.2 C=CHR where R is a C.sub.2-8 linear or branched alkyl radical and b) 2 to 30% by weight of an elastomeric propylene-ethylene copolymer. The portion of said copolymer b) soluble in xylene at room temperature has an intrinsic viscosity (I.V. 2) which satisfies the following relation: EQU 0.2.ltoreq.(I.V. 2/I.V. 1).times.(C.sub.2.sup.-).ltoreq.0.6 where I.V. 1 is the intrinsic viscosity of the crystalline propylene copolymer, (C.sub.2.sup.-) is the ethylene weight content of b). The ratio between the ethylene weight content in b) and the weight of the xylene soluble portion is equal to or less than 1.5. The compositions are prepared by sequential polymerization of the monomers in the presence of Ziegler-Natta stereospecific catalysts which include a titanium compound supported on a magnesium dihalide in active form.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.