Abstract: Polyacetylene having an apparent density at 20.degree. C. greater than 0.6 g/ccm and a surface area below 60 m.sup.2 /g is prepared by polymerizing gaseous acetylene in the presence of a catalytic system consisting of:(a) an oxygenized compound of Ti or V, containing at least one metal-oxygen bond;(b) an organometallic compound of aluminum containing at least one hetero-atom, of the formula: ##STR1## wherein: ##STR2## while R=a hydrocarbon radical with 1-18 carbon atoms, and where R'.dbd.R, or halogen or alcoxyl.

Abstract: Disclosed are catalysts for the polymerization of ethylene and of mixtures thereof with olefins, comprising the product obtained by reacting the following components:(a) an Al-alkyl compound;(b) an electron-donor compound containing at least a nitrogen atom, said compound being reactive towards MgCl.sub.2, but not towards Al-triethyl; and(c) the reaction product between a titanium compound containing at least a titanium-halogen bond and an anhydrous magnesium halide.The obtained (co)polymers have a very narrow molecular weight distribution which renders them particularly suitable for some applications, such as injection molding.

Abstract: Catalyst components for the polymerization of olefins and in particular of ethylene and of mixtures thereof with alpha-olefins comprising a tetravalent titanium halide supported on Ti trichloride or tribromide having a surface area greater than 50 m.sup.2 /g are disclosed, as are catalysts prepared from said components.

Abstract: Catalysts for the polymerization of alpha-olefins, which comprise the product of the reaction between:(a) a metalorganic compound of Al;(b) an electron-donor compound reactive towards MgCl.sub.2 but which is not completely complexed with AlEt.sub.3, at the equivalent point of a potentiometric titration under standard conditions;(c) a solid comprising a halogenated Ti compound and an electron-donor belonging to particular classes of compounds and being extractable with AlEt.sub.3 for at least 70% by mols from the solid, the surface area of which after extraction is higher than 20 m.sup.2 /g.The present invention refers to new supported components of catalysts for the polymerization of olefins CH.sub.2 .dbd.CHR, in which R is an alkyl with 1-14 carbon atoms or an aryl, and of mixtures of such olefins with each other and/or with ethylene, and to the catalysts obtained from such components.

Abstract: Catalysts for the polymerization of olefins, comprising the product of the reaction between:(a) an Al-alkyl compound;(b) an electron-donor compound capable of reacting with MgCl.sub.2 but which is not completely complexed with Al-triethyl at the equivalent point of a potentiometric titration under standard conditions and belonging to particular classes of compounds; and(c) a solid comprising a Ti compound having at least a Ti-halogen bond and an electron-donor compound belonging to particular classes of esters, both supported on a Mg halide in active form.

Abstract: Catalysts for the polymerization of alpha-olefins, comprising the product of the reaction between:(a) a metalorganic Al compound;(b) an electron-donor compound reactive towards MgCl.sub.2 but which results not to be completely complexed with Al-triethyl at the equivalent point of the potentiometric titration under standard conditions;(c) a solid comprising a halogenated Ti compound supported on an anhydrous Mg halide and at least one of the following activators:(1) an Al, Fe, Mn, Sb or Zn compound containing at least one metal-halogen bond;(2) a complex between an electron-donor compound and a Lewis acid chosen among the halides of the metals of Groups II-VIII of the Periodic System other than Ti;(3) a compound or composition, inert towards the Mg halide, having a dielectric constant at 20.degree. C. higher than 2;compounds (1), (2) and (3) being extractable from the solid for at least 30% by mols by treatment with toluene at 80.degree. C.

Abstract: Components of catalysts for polymerizing olefins having the general formula:VCl.sub.n (OR).sub.min which R=a hydrocarbon radical having 1-18 C; or R.sub.p.sup.1 Si(OH).sub.3-p, in which R.sup.1 =a hydrocarbon radical, 1.ltoreq.p.ltoreq.3; 1.5.ltoreq.n.ltoreq.3, m=3-n; with X-ray powder spectrum, in which maximum intensity diffraction lines, which in the spectrum of normal VCl.sub.3 appear at d=5.75 .ANG., d=2.67 .ANG. and d=1.74 .ANG., exhibit a broadening of the half peak breath of at least three times for the diffraction line at d=5.75 .ANG. and of at least four times for the diffraction lines appearing at d=2.67 .ANG. and d=1.74 .ANG., or said diffraction lines disappear.

Abstract: Catalyst-forming components are prepared from(a) a halogenated Ti compound containing at least a Ti-halogen bond;(b) an electron-donor compound free of active hydrogen atoms;and(c) the solid product of the reaction between at least one electron-donor compound containing active hydrogen atoms and a Mg dihalide or a complex thereof with an electron-donor compound free of active hydrogen atoms, obtained by decomposing organic Mg compounds containing at least one Mg-R or Mg-OR group, in which R is an alkyl, aryl, cycloalkyl or alkenyl radical having 1 to 20 carbon atoms, by means of a halogenating agent different from (a).Catalysts for polymerizing olefins and prepared by mixing the aforesaid catalyst-forming components with an organometallic compound of Al are also disclosed.

Abstract: New components of catalysts for the polymerization of alpha-olefins, e.g., olefins containing three or more carbon atoms, and mixtures thereof with ethylene, are disclosed, said catalysts comprising a Mg dihalide and, chemically fixed thereto, a Ti compound and an electron-donor compound.

Abstract: A new crystalline form (beta form) of MgCl.sub.2 is disclosed, as are methods for obtaining it by reaction of SOCl.sub.2 with hydrated MgCl.sub.2 at a temperature comprised between room temperature and the boiling point of SOCl.sub.2.

Abstract: Catalyst components which comprise the reaction product of a Ti compound and a Mg dihalide and which are in the form of spherical particles having an average diameter of 1 to 100 microns, a surface area of 300 to 500 m.sup.2 /g, and a porosity of 0.3 to 0.4 cc/g are disclosed, as are catalysts also in the form of spherical particles prepared therefrom and useful in the polymerization of ethylene and of alpha-olefins CH.sub.2 .dbd.CHR in which R is alkyl radical having from 1 to 6 carbon atoms, and the polymerization of the alpha-olefins therewith.

Abstract: New and improved catalysts for polymerizing alpha-olefins of formula CH.sub.2 .dbd.CHR in which R is a C.sub.1 to C.sub.6 alkyl, more particularly propylene, mixtures of the alpha-olefins, and mixtures thereof with ethylene are disclosed. The catalysts are prepared from Al alkyl compounds and a solid product including a Mg dihalide and reaction products of said halide with at least one Ti compound and an electron donor compound which is an ester of an organic or inorganic oxygenated acid.

Abstract: A process for preparing components of catalysts for the polymerization of alpha-olefins and mixtures thereof with ethylene is disclosed. The process comprises reacting a Ti compound having at least oe Ti-halogen linkage with either (1) a mixture of a hydrocarbyl electron-donor compound ED which does not contain active H atoms and an adduct (a) of a Mg dihalide with at least one hydrocarbyl electron-donor compound AH containing active H atoms, or (2) with an adduct (b) of at least a Mg dihalide with a compound AH and ED defined in (1), adducts (a) and (b) being obtained without co-grinding of the Mg dihalide with compounds AH and ED.

Abstract: There are disclosed new solid catalyst-forming components for use in preparing catalysts for the stereoregular polymerization of alpha-olefins containing at least 3 carbon atoms, mixtures of alpha-olefins with one another and/or with ethylene, said components being obtained by reacting(a) at least one hydrocarbon-soluble halogenated Ti compound;(b) a product comprising a Mg dihalide obtained by decomposition of an adduct of at least a Mg dihalide and an electron-donor compound present in the adduct in an amount of at least 0.5 mole per mole of Mg dihalide, the decomposition product being characterized in that, in its X-rays powder spectrum, instead of the diffraction line of maximum intensity which appears in the X-rays powder spectrum of the normal Mg dihalide, a halo appears whose intensity maximum is shifted with respect to said line, and(c) an electron-donor compound which does not contain active hydrogen atoms.

Abstract: There are disclosed new starting components for use in preparing catalysts for the polymerization and copolymerization of olefins. The new starting components are compounds having the general formulae R.sub.2 AlOR" and/or RAl(OR").sub.

Abstract: New catalysts for the polymerization and copolymerization of olefins are described. The catalysts are prepared from new components which are complexes of the metals Mg, Mn and/or Ca with the transition metals Ti, V and/or Zr, plus an electron-donor compound.

Abstract: New catalysts for the polymerization and copolymerization of olefins are disclosed. The catalysts are prepared from (1) a new class of metal compounds containing at least one atom of Mg, Mn or Ca and at least one atom of Ti, V or Zr and (2) organometallic compounds of metals belonging to one of Groups I to III of the Mendelyeev Periodic Table.

Abstract: There are disclosed new solid catalyst-forming components for use in preparing catalysts for the stereoregular polymerization of alpha-olefins containing at least 3 carbon atoms, mixtures of alpha-olefins with one another and/or with ethylene, said components being obtained by reacting(a) at least one hydrocarbon-soluble halogenated Ti compound;(b) a product comprising a Mg dihalide obtained by decomposition of an adduct of at least a Mg dihalide and an electron-donor compound present in the adduct in an amount of at least 0.5 mole per mole of Mg dihalide, the decomposition product being characterized in that, in its X-rays powder spectrum, instead of the diffraction line of maximum intensity which appears in the X-rays powder spectrum of the normal Mg dihalide, a halo appears whose intensity maximum is shifted with respect to said line, and(c) an electron-donor compound which does not contain active hydrogen atoms.

Abstract: New catalysts for the polymerization and copolymerization of olefins are disclosed. The catalysts are prepared from (1) a new class of metal complexes of general formula M.sub.m M'X.sub.2m Y.nE, in which M is Mg, Mn and/or Ca; m is a number from 0.5 to 2.0; M' is Ti, V and/or Zr; X is Cl, Br or I; Y is one or more atoms or groups of atoms of various kinds in an amount such as to satisfy the valence of M'; n is a number from 0.5m to 20m; and E is an electron-donor compound; and (2) organometallic compounds of metals belonging to one of Groups I to III of the Mendelyeev Periodic Table.

Abstract: There are disclosed new starting components for use in preparing catalysts for the polymerization and copolymerization of olefins. The new starting components are compounds having the general formulae R.sub.2 AlOR" and/or RAl (OR").sub.