Abstract: Disclosed are catalyst components for the polymerization of olefins which include magnesium halide in active form, and, supported thereon, a titanium halide or titanium halogen alcoholate and an electron-donor compound selected from the group diamines of formula ##STR1## wherein the radicals R.sub.1 to R.sub.10 are the same or different and are hydrogen or C.sub.1 -C.sub.18 hydrocarbon radicals, with the proviso that at least one of the R.sub.7 and R.sub.8 radicals and at least one of the R.sub.9 and R.sub.10 radicals are not hydrogen. Also, disclosed are catalysts obtained from the catalyst components and an Al-alkyl compound, as well as catalysts obtained by reaction of an Al-alkyl compound and a diamine of formula (I) with a solid catalyst component including a titanium halide or a titanium halogen alcoholate, and an electron-donor compound having particular characteristics of extractability with Al-triethyl, supported on magnesium halide in active form.

Abstract: Disclosed is a catalyst for the polymerization of olefins, which includes the product of the reaction between an Al-alkyl compound and a solid catalyst component containing a magnesium halide in active form, a titanium compound and an electron-donor selected from the 1,3-diketones of formula: ##STR1## wherein the radicals R are the same or different, the radicals R.sup.I are the same or different, and R and R.sup.I are C.sub.1 -C.sub.20 alkyl, C.sub.3 -C.sub.20 cycloalkyl, C.sub.6 -C.sub.12 aryl, C.sub.7 -C.sub.20 arylalkyl or alkylaryl radicals or hydrogen, with the proviso that at least one of the R radicals is not hydrogen and can be bonded with the other R radical to form a cyclic structure, and at least one of the R.sup.I radicals, which are not bonded to one another to form a cyclic structure, is a branched alkyl, cycloalkyl or aryl radical, or is bonded to one or both R radicals to form a cyclic structure.

Abstract: Disclosed are solid catalyst components for the polymerization of olefins comprising a titanium halide or titanium alkoxy halide, and an electron-donor compound selected from silicon compounds of the formula ##STR1## where R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are hydrocarbyl radicals, supported on a magnesium halide in active form.Also disclosed are catalysts obtained from said catalyst components and from an Al-alkyl compound, as well as catalysts obtained by the reaction of an Al-alkyl compound and a silicon compound of the formula above with a solid catalyst component comprising a titanium halide or halogen alcoholate and an electron-donor compound having specific characteristics of extractability with Al-triethyl, supported on an active magnesium halide.

Abstract: Catalyst components for the polymerization of olefins comprising a titanium halide or alkoxyhalide and an electron-donor compound selected from ethers having two or more ether groups and containing at least one heteroatom selected from the group consisting of N, S, P, Si, non-ether O and halogen atoms or at least one double bond, or both at least one heteroatom and at least one double bond, supported on a magnesium halide in active form.Catalysts obtained from said catalyst components and an Al-alkyl compound, as well as catalysts obtained by the reaction of an Al-alkyl compound and an ether having the above defined characteristics with a solid catalyst component comprising a titanium halide or alkoxyhalide and an electron-donor compound having particular characteristics of extractability with Al-triethyl, supported on activated magnesium halide.

Abstract: Catalysts for the polymerization of olefins, particularly alpha-olefin of the formula CH.sub.2 .dbd.CHR in which R is an alkyl radical with 1-6 carbon atoms or an aryl radical, obtained by the reaction of:(a) an Al-alkyl compound;(b) an ether containing at least two ether groups which can form complexes with anhydrous magnesium dichloride, under standard conditions of reaction, in an amount less than 60 mmol per 100 g Mg dichloride; and(c) a solid catalyst component comprising an anhydrous magnesium dihalide in active form and having supported thereon a titanium compound containing at least a Ti-halogen bond and an electron-donor compound which is at least 70 mole % extractable with Al-triethyl, under standard conditions of extraction, component wherein the solid, after extraction, has a surface area of more than 20 m.sup.2 g.

Abstract: Solid catalyst components for the polymerization of olefins and modified with electron-donor compounds, comprising a titanium halide supported on a magnesium dihalide in active form and containing as an electron-donor compound a di- or other polyether having specific reactivity characteristics towards MgCl.sub.2 and TiCl.sub.4.