Abstract: The present invention relates to spherical solid components of catalysts for the polymerization of olefins comprising, supported on a magnesium dihalide in active form, a titanium compound containing at least one Ti-halogen bond and one OR group, said OR group being bonded to Ti in an amount such that the OR/Ti molar ratio is greater than or equal to 0.5; optionally the component also comprises an electron donor compound. The spherical solid components of the invention are characterized by having a porosity comprised between 0.35 and 0.7 cm.sup.3 /g and by a pore size distribution such that at least 50% of the porosity is due to pores having an average radius greater than 800 .ANG..

Abstract: The present invention relates to spherical solid components of catalysts for the polymerization of olefins comprising, supported on a magnesium dihalide in active form, a titanium compound containing at least one Ti-halogen bond, and optionally an electron donor compound. The spherical solid components of the invention are characterized by porosity values higher than 1 cm.sup.3 /g and a pore size distribution such that at least 30% of their pores have an average radius greater than 10000 .ANG..

Abstract: Crystalline polymers and copolymers of propylene in the form of spherical particles having a porosity (expressed in percentage of voids) greater than 15%. These polymers are useful in the preparation of masterbatch containing significant quantities of additives and/or pigments.

Abstract: Crystalline olefin polymers and copolymers in the form of spherical particles having porosity (expressed in percentage of voids) higher than 15%, with more than 90% of the pores having a pore diameter greater than one micron. These polymeric particulate materials find many applications, including, e.g., the preparation of masterbatches containing significant quantities of additives and/or pigments.

Abstract: Spherical catalyst components for the polymerization of olefins comprising a titanium compound and optionally an electron-donor supported on anhydrous magnesium chloride, characterized by a surface area between 20 and 250 m.sup.2 /g, porosity between 0.25 and 0.5 cc/g, and an X-ray spectrum where the magnesium chloride reflections are present at 2 .nu. of 35.degree. and 14.95.degree., or where the reflection at 35.degree. is substituted by a halo with the maximum intensity between 33.5.degree. and 35.degree. and the reflection of 2 .nu. at 14.95.degree. is absent.