An embrittlement-resistant polyolefin composition, including: (a) at least 80% by weight, based on the total weight of the polyolefin composition, of a crystalline polymer comprising either a propylene homopolymer having an isotactic index greater than 90 or a random copolymer of propylene and either ethylene or C.sub.4 -C.sub.10 1-olefins, (b) an elastomeric copolymer of ethylene and either propylene or butene-1, where the elastomeric copolymer is present in an amount sufficient to enhance the flexibility of the polyolefin composition, without adversely affecting the clarity of the polyolefin composition, and where the polyolefin composition has a heat distortion temperature of at least 60.degree. C. Optional components include a stabilizing amount of a hindered amine light stabilizer, an acid neutralizing agent, and a sorbitol-based compound. The composition may be used to manufacture medical articles and food packaging material which must be sterilized, either by irradiation or by autoclaving.
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); 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.
Propylene polymers contain a) from 50 to 95 parts by weight of a propylene homopolymer having a melt flow index of from 0.1 to 100 g/10 min., at 230.degree. C. and under a weight of 2.16 kg, according to ISO standard 1133, and an isotacticity index of at least 98%, b) from 5 to 50 parts by weight of an ethylene copolymer containing from 4 to 40% by weight of polymerized C.sub.4 -C.sub.20 -alk-1-ene and having a density of from 0.865 to 0.920 g/cm.sup.3 and c) from 0 to 1.5 parts by weight of a nucleating agent, the sum of the parts by weight of the propylene homopolymer a) and of the ethylene copolymer b) always being 100 parts by weight. The propylene polymers are distinguished in particular by high rigidity and little tendency to white fracture.
A polypropylene composition comprises an isotactic polypropylene homopolymer resin that is suitable to form an injected molded article exhibiting less than about 60% haze, as determined by ASTM D1003, at a thickness of 0.05 inch without clarity-enhancing agents. The polypropylene composition has particular application to injection molded articles and may have a melt flow rate of from about 0.1 g/10 min to about 150 g/10 min as determined by ASTM D-1238, Procedure B. The resin may be prepared using a metallocene catalyst, and the composition may include clarity-enhancing agents for even greater clarity improvements.
A stabilizer mixture containing (A) a sterically hindered amine compound, and (B) two different compounds selected from the group consisting of an organic salt of Zn, an inorganic salt of Zn, an organic salt of Mg and an inorganic salt of Mg; the weight ratio of the two different compounds being 1:10 to 10:1; with the provisos that (1) the stabilizer mixture is essentially free of perchloric acid, and (2) the two compounds in component (B) are different from the combination ZnO and Zn stearate and the combination ZnO and hydrotalcite; is useful for stabilizing an organic material, in particular a polyolefin, against degradation induced by light, heat or oxidation.
Unique copolymers comprising propylene, ethylene and/or one or more unsaturated comonomers are characterized as having: at least one, preferably more than one, of the following properties: (i) .sup.13 C 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, S.sub.ix, greater than about -1.20, (iv) a DSC curve with a T.sub.me that remains essentially the same and a T.sub.max 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 catalyst. These polypropylene polymers are made using a nonmetallocene, metal-centered, heteroaryl ligand catalyst. These polymers can be blended with other polymers, and are useful in the manufacture of films, sheets, foams, fibers and molded articles.