A tyre for wheels of vehicles, in particular motor vehicles, is described. The tyre has a tread with at least one copolymer of (iso-styrene/trans-butadiene): diene-terminated copolymers. The tread has less sensitivity to the effects of temperature, with less weakness, better consistancy of performances, and improved characteristics in terms of grip and/or resistance to laceration.

The present invention relates to a polyolefin-polystyrene multi-block copolymer having a structure comprising a polyolefin block and polystyrene blocks bonded to both ends of the polyolefin block, to an organozinc compound for preparing the same, and a method for preparing the polyolefin-polystyrene multi-block copolymer.

A heterophasic propylene polymerization material, including a propylene polymer component (I) and an ethylene--olefin copolymer component (II), the heterophasic propylene polymerization material satisfying features (i) to (v): (i) the heterophasic propylene polymerization material contains a xylene-soluble content by 20 wt % or more; (ii) xylene-soluble content in the heterophasic propylene polymerization material has a limiting viscosity [].sub.CXS not less than 5 dL/g; (iii) a melt flow rate of the propylene polymer component (I) is 70 g/10 min or more; (iv) MFR of the heterophasic propylene polymerization material is not less than 5 g/10 min; and (v) the number of gels of 100 m or more in diameter on a sheet for counting gels, including the heterophasic propylene polymerization material, is 1000 or less per 100 cm.sup.2 of the sheet.

A composition comprising (A) from 10 wt % to 90 wt % of a polymeric ethylene ionomer; (B) from 10 wt % to 40 wt % of a propylene component including at least one propylene based polymer having a propylene content of at least 50.0 wt %, based on the total weight of the propylene based polymer, and a melt flow rate from 0.5 g/10 min to 200.0 g/10 min (according to ASTM D-1238 at 230 C./2.16 kg); and (C) from 5 wt % to 20 wt % of a crystalline block composite.

The present invention relates to a polypropylene resin comprising a propylene/ethylene copolymer; an elastomer as impact modifier based on polypropylene or polyethylene and additives. The resin of the present disclosure is characterized by a flow index between 2 g/10 min to 10 g/10 min measured at 230 C.; density between 0.89 kg/m3 and 0.91 kg/m.sup.3; elongation percentage between 11% and 15%; flexural modulus between 792.9 MPa to 1034.2 MPa; tensile strength between 24.13 MPa and 27.58 MPa and Izod impact between 210 J/m and 350 J/m, making it useful in the manufacture of a wide range of products for the food, automotive, nautical, chemical, furniture and equipment, household appliances and sporting goods industries, among others.

Provided is a novel olefin polymer which is excellent in lightness and moldability, has high rigidity and yields molded products excellent in flexural elasticity. The olefin polymer includes a propylene initial polymerization product formed in the presence of an olefin polymerization catalyst which is a contact reaction product of an olefin polymerization solid catalyst component containing a titanium atom, a magnesium atom, a halogen atom and an internal electron donating compound, at least one organoaluminum compound selected from the compounds of the general formula (I), and a first external electron donating compound; and a polypropylene part formed of a propylene polymerization product formed in the presence of the olefin polymerization catalyst and a second external electron donating compound higher in adsorption to the surface of the olefin polymerization solid catalyst component than the first external electron donating compound.

Provided is a novel olefin polymer which is excellent in lightness and moldability, has high rigidity and yields molded products excellent in flexural elasticity. The olefin polymer includes a propylene initial polymerization product formed in the presence of an olefin polymerization catalyst which is a contact reaction product of an olefin polymerization solid catalyst component containing a titanium atom, a magnesium atom, a halogen atom and an internal electron donating compound, at least one organoaluminum compound selected from the compounds of the general formula (I), and a first external electron donating compound; and a polypropylene part formed of a propylene polymerization product formed in the presence of the olefin polymerization catalyst and a second external electron donating compound higher in adsorption to the surface of the olefin polymerization solid catalyst component than the first external electron donating compound.

The present invention relates to a polyethylene composition comprising a base resin comprising a low molecular weight ethylene polymer component and a high molecular weight ethylene polymer component, wherein the high molecular weight ethylene polymer component has a higher weight average molecular weight than the low molecular weight ethylene polymer component, wherein the base resin has a density of at least 958.0 kg/m.sup.3, and the polyethylene composition a melt flow rate MFR.sub.2 (190 C., 2.16 kg) of from 0.50 to 0.80 g/10 min and a molecular weight distribution being the ratio of the weight average molecular weight and the number average molecular weight, Mw/Mn, of from 10.0 to 15.0, a process for producing said polyethylene composition, an article comprising said polyethylene composition and the use of said polyethylene composition for the production of a film.

The present disclosure provides a foam bead. The foam bead contains at least one of the following components: (A) a block composite; and/or (B) a crystalline block composite. The present disclosure also provides a sintered foam structure formed from a composition comprising at least one of the following components: (A) a block composite; and/or (B) a crystalline block composite.

The present disclosure relates to an olefin polymerization catalyst system for use in forming a multi-block copolymer, said copolymer containing therein two or more segments or blocks differing in chemical or physical properties, a polymerization process using the same, and the resulting polymers, wherein the catalyst system comprises: (A) a first olefin polymerization procatalyst, (B) a second olefin polymerization procatalyst capable of preparing polymers differing in chemical or physical properties from the polymer prepared by procatalyst (A) under equivalent polymerization conditions, and (C) a chain shuttling agent.