Propylenic random copolymer and composition comprising it, and film comprising the copolymer or composition

Abstract

Provided are a propylenic random copolymer of propylene and ethylene satisfying the following (1) to (5), a composition comprising the copolymer, a film and a stretched film of the copolymer or its composition, and a laminate film and a stretched laminate film comprising at least one layer of the copolymer or its composition. (1) The ethylene unit content (x, wt. %) of the copolymer is from 0.2 to 10 wt. %. (2) The copolymer has a melt index (MI, g/10 min) of from 0.1 to 4 g/10 min. (3) The relation between the boiling diethyl ether extraction (E, wt. %) of the copolymer and x satisfies the following (I) or (II); E≦0.253x+1.1 (0.2≦x<6)  (I) E≦2.6 (6≦x≦10)  (II) (4) The relation between the melting point (Tm, ° C.) of the copolymer as measured with a differential scanning calorimeter and x satisfies the following (III): Tm≦165−5x  (III) (5) The isotactic triad fraction (mm, mol %) in the PPP sequence of the copolymer, as measured in 13C-NMR, is not smaller than 98.0 mol %. The films have good stiffness, low-temperature heat-sealability, heat-shrinkability, hot-slipping ability, anti-blocking ability and cold-slipping ability, and are favorably used as wrapping or packaging shrink films.

Dependencies are inferred from the claim text.