Propylene block copolymer compositions
US6355736B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Oct 23, 2000 |
| Grant date | Mar 12, 2002 |
| Priority date | — |
| Expiry date | Oct 23, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F210/06
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A propylene block copolymer composition is disclosed which comprises (A) a propylene-&agr;-olefin random copolymer with a propylene content of 99.4 to 99.9 mol % and (B) a propylene-&agr;-olefin random copolymer with a propylene content of 35 to 60 mol %, &agr;-olefin contained in the random copolymer (A) being ethylene and/or 1-butene, wherein the intrinsic viscosity ([&eegr;B]) of the propylene-&agr;-olefin random copolymer (B) ranges from 0.5 to 2.0 dl/g, the ratio ([&eegr;B]/[&eegr;A]) of the intrinsic viscosity ([&eegr;B]) of the propylene-&agr;-olefin random copolymer (B) to the intrinsic viscosity ([&eegr;A]) of the propylene-&agr;-olefin random copolymer (A) ranges from 0.3 to 1.2 and the product (([&eegr;B]/[&eegr;A])×(WA/WB)) of the intrinsic viscosity ratio ([&eegr;B]/[&eegr;A]) and the weight ratio (WA/WB) of both copolymers ranges from 1.0 to 3.0. The propylene block copolymer composition is suitable as a raw material for molded article having excellent see-through property, transparency, stress-whitening resistance, stiffness and heat resistance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.