Abstract: Process for the imidization of vinyl-aromatic copolymers containing maleic anhydride, using as an imidizing agent an amide, the imidization being conducted in an anhydrous state and in the presence of a catalyst.

Abstract: The invention concerns a process for the imidization of copolymers of maleic anhydride with vinyl-aromatic monomers using an urea as the imidizing agent.

Abstract: Thermoplastic compositions based on polyphenylenether resins, endowed with improved mechanical, thermal and solvent-resistance characteristics, comprising, for 100 parts by weight of polyphenylenether resin:(a) from 0 to 90 parts by weight of a thermoplastic polymer other than polystyrene and incompatible with the polyphenylenether resin, and(b) from 1 to 90 parts by weight of a polymeric compatibility-promoting agent comprising one or more blocks of vinylacromatic monomeric units compatible with the polyphenylenether resin, and one or more blocks of monomeric units of the same nature as the thermoplastic polymer (a), or compatible with that polymer.

Abstract: Polymerization catalysts, more particularly catalysts for the polymerization of ethylene and mixtures thereof with other monomers copolymerizable therewith, are disclosed. The catalysts are prepared by mixing (A) an organometallic compound or hydride of a metal belonging to Groups I, II or III of the Mendelyeev Periodic Table, with (B) the reaction product of (1) a titanium compound of the type (NR.sub.4).sub.p Ti.sub.m X.sub.(n.m)+p, in which R.sub.4 is hydrogen and/or hydrocarbon radicals, X.sub.n.m represents halogen atoms or, in part, OR' groups in which R' is an organic radical; n represents the Ti valence, and m and p are the whole numbers 1, 2 or 3; and (2) a carrier comprising an anhydrous magnesium halide.

Abstract: New catalysts for the polymerization of olefins and more particularly of ethylene and mixtures thereof with higher alpha-olefins and/or diolefins, are disclosed. The catalysts are prepared by mixing (a) a hydride or an organo-metallic compound of a metal belonging to Groups I, II or III of the Mendelyeev Periodic Table with (b) the product obtained by contacting a titanium compound (1) with a mixture of an anhydrous magnesium halide (2) in a particular active form and an anhydrous compound of a metal belonging to Group I or II of said Periodic Table, (3). In the particular active form to which it is converted, during or prior to the contacting the anhydrous magnesium halide is characterized in that, in its X-ray spectrum, the diffraction line which is most intense in the X-ray spectrum of the normal, inactive magnesium halide shows a decreased intensity, and/or the active magnesium halide has a surface area greater than 3 m.sup.2 /g.

Abstract: Polymerization catalysts, particularly catalysts for the polymerization of olefins, are disclosed. The catalysts are prepared by mixing hydrides of organometallic compounds of metals belonging to Groups I to III of the Mendelyeev Periodic Table with products obtained by contacting (1) titanium compounds of the formulaMpTi.sub.m X.sub.(n. m) +pin which M is an alkaline metal or the group NR.sub.4 in which the valences of the quaternary nitrogen atom are satisfied by hydrogen and/or by hydrocarbon groups or is part of a heterocyclic ring; X.sub.n. m substituents are NR.sub.2 group in which the Rs represent hydrogen, and/or hydrocarbon groups or, in part, halogen atoms; n is the titanium valence; m is a whole number from 1 to 3 inclusive; and p is zero or a whole number from 1 to 3, inclusive; with (2) carriers consisting of anhydrous Mg halides which are in active form or converted to active form by the conditions under which the carriers are contacted with the titanium compounds.

Abstract: Highly active catalysts for the polymerization of olefins are disclosed. The catalysts are prepared by mixing a hydride or organometallic compound of a metal belonging to Groups I, II or III of the Mendelyeev Periodic Table with the product obtained by contacting an oxygenated Ti compound in which one or more Ti atoms are bound through oxygen atoms to organic radicals with an activated anhydrous Mg dihalide. The polymerization of ethylene by means of said catalysts is also disclosed.

Abstract: There is disclosed a process for the stereoregular polymerization of alpha-olefins or mixtures thereof with ethylene, conducted in the presence of highly active and stereospecific new catalysts. The catalysts are obtained from the reaction of a particular Al-alkyl compound which is at least in part in the form of a complex and/or a substitution reaction product with an ester of an oxygenated organic or inorganic acid, with a supported component characterized by having surface area exceeding certain values or showing a particular X-rays spectrum, and obtained by contacting a Ti halogenated compound, preferably in the form of a complex with an electron-donor compound, with a support comprising a Mg or Mn bihalide in an activated condition. In the catalysts the ratio between the Ti compound, expressed in Ti g-atoms, and the g moles of the ester and the electron-donor compound, when present, is lower than 0.3.

Abstract: New, highly active catalysts for the polymerization of ethylene and mixtures of ethylene with higher alpha-olefins and/or diolefins, are disclosed. The catalysts are prepared by mixing (a) hydrides or organometallic compounds of metals belonging to Groups I, II or III of the Mendelyeev Periodic Table with (b) the products obtained by contacting titanium compounds with activated anhydrous halides of magnesium or manganese, diluted with anhydrous compounds of metals belonging to Groups III or IV of said Periodic Table, and which are different from either (a) or the titanium compound of (b).

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, highly active catalysts for the polymerization of ethylene and mixtures of ethylene with higher alpha-olefins and/or diolefins, are disclosed. The catalysts are prepared by mixing (a) hydrides or organometallic compounds of metals belonging to Groups I, II or III of the Mendelycev Periodic Table with (b) the products obtained by contacting titanium compounds with activated anhydrous halides of magnesium or manganese, diluted with anhydrous compounds of metals belonging to Group III or IV of said Periodic Table, and which are different from either (a) or the titanium compound of (b).

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: There is disclosed a process for the stereoregular polymerization of alpha olefins or mixtures thereof with ethylene conducted in the presence of highly active and stereospecific new catalysts. The catalysts are obtained from the reaction of a particular Al-alkyl compound which is at least in part in the form of a complex and/or a substitution reaction product with an electron-donor compound free from ester groups of oxygenated organic and inorganic acids, with a supported component characterized by having surface area exceeding certain values or by showing a particular X-rays spectrum and which is obtained by contacting a halogenated Ti compound, preferably in the form of a complex with an electron-donor compound, with a support comprising a Mg or Mn dihalide in an active state. In the catalysts the ratio between the Ti compound expressed in Ti g-atoms and the g-moles of the electron donor compounds is lower than 0.3.

Abstract: There is disclosed a process for the stereoregular polymerization of alpha-olefins or mixtures thereof with ethylene, conducted in the presence of highly active and stereospecific new catalysts. The catalysts are obtained from the reaction of a particular Al-alkyl compound which is at least in part in the form of a complex and/or a substitution reaction product with an ester of an oxygenated organic or inorganic acid, with a supported component characterized by having surface area exceeding certain values or showing a particular X-rays spectrum, and obtained by contacting a Ti halogenated compound, preferably in the form of a complex with an electron-donor compound, with a support comprising a Mg or Mn bihalide in an activated condition.In the catalysts the ratio between the Ti compound, expressed in Ti g-atoms, and the g moles of the ester and the electron-doner compound, when present, is lower than 0.3.

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 is disclosed a process for the stereoregular polymerization of alpha olefins or mixtures thereof with ethylene, conducted in the presence of highly active and stereospecific new catalysts. The catalysts are obtained from the reaction of a particular Al-alkyl compound which is at least in part in the form of a complex and/or a substitution reaction product with an ester of an oxygenated organic or inorganic acid, with a supported component characterized by having surface area exceeding certain values or by showing a particular X-rays spectrum, and obtained by contacting a Ti halogenated compound, preferably in the form of a complex with an electron-donor compound, with a support comprising a Mg or Mn bihalide.In the catalysts the ratio between the Ti compound, expressed in Ti g-atoms, and the g moles of the ester and the electron-donor compound, when present, is lower than 0.3.

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 is disclosed a process for the stereoregular polymerization of alpha olefins or mixtures thereof with ethylene conducted in the presence of highly active and stereospecific new catalysts.The catalysts are obtained from the reaction of a component (A) which is a particular Al-alkyl compound that is at least in part in the form of an addition and/or a substitution reaction product with an electron-donor compound free from ester groups of oxygenated organic and inorganic acids, with a component (B) which is a supported component characterized by having surface area exceeding certain values or by showing a particular X-rays spectrum, and prepared by contacting a halogenated Ti compound, preferably in the form of a complex with an electron-donor compound, with a support comprising a Mg or Mn dihalide in an active state.In the catalysts the ratio between the Ti compound expressed in Ti g-atoms and the g-moles of the electron-donor compounds is lower than 0.3.