Catalyst components and catalysts for the polymerization of alpha-olefins

• US 4,399,054 A
• Filed: 01/21/1981
• Issued: 08/16/1983
• Est. Priority Date: 08/22/1978
• Status: Expired due to Term

• Current Assignee: Montedison S.p.A. (Government of France)
• Original Assignee: Montedison S.p.A. (Government of France)
• Inventors: Albizzati, Enrico, Parodi, Sandro, Giannetti, Enzo, Motroni, Giuseppe, Ferraris, Mario, Rosati, Francesco
• Primary Examiner(s): Garvin, Patrick
• Application Number:
  US06/226,837
• Time in Patent Office: 937 Days
• Field of Search: 252/429 B, 252/429 C
• US Class Current: 502/125
• CPC Class Codes: C08F 10/00 Homopolymers and copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
• CPC Class Codes: C08F 110/06 Propene
• CPC Class Codes: C08F 2500/12 Melt flow index or melt flow ratio
• CPC Class Codes: C08F 2500/17 Viscosity
• CPC Class Codes: C08F 2500/24 Polymer with special particle form or size
• CPC Class Codes: C08F 4/022 Magnesium halide as support anhydrous or hydrated or complexed by means of a Lewis base for Ziegler-type catalysts
• CPC Class Codes: C08F 4/651 Pretreating with non-metals or metal-free compounds
• CPC Class Codes: C08F 4/6543 halides of magnesium
• CPC Class Codes: C08F 4/6557 and metals of C08F4/64 or compounds thereof

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 m² /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 CH₂ ═CHR in which R is alkyl radical having from 1 to 6 carbon atoms, and the polymerization of the alpha-olefins therewith.

Claims

1. Catalyst components for the polymerization of olefins, which comprise the reaction product of a Ti compound selected from the group consisting of Ti tetrahalides, Ti haloalcoholates and Ti halophenolates with a Mg halide, said catalyst components being in the form of spherical particles having an average diameter comprised within the range of from 1 to 100 micron, a surface area comprised between 300 and 500 m² /g and a porosity comprised between 0.3 and 0.4 cm³ /g, and being capable of forming, by reaction with Al-alkyl compounds, catalysts which, when used in a standard test for the polymerization of propylene, yield polymers in the form of spherical particles having a flowability lower than 16 seconds, determined according to ASTM 1895-79 (A), and a bulk density higher than 0.4 g/cm³.

2. Catalyst components according to claim 1, in which the polymers in the form of spherical particles have a flowability of from 12 to 15 seconds.

3. Catalyst components according to claim 1, containing in a combined form an electron-donor compound, in a molar ratio with the Ti compound of from 0.2 to 3.

4. Catalyst components according to claim 1, obtained by reaction of TiCl₄ with an adduct MgX₂.nROH, wherein ROH is an alcohol, obtained by causing a homogeneous mixture of the adduct, in molten form, and of a liquid that is immiscible and does not react with the adduct, to pass through a predetermined path under conditions of turbulent motion and in quenching the emulsion at the outlet of said path.

5. Carriers for catalysts for the polymerization of olefins, comprising a Mg dihalide, in the form of spherical particles having an average diameter comprised between 1 and 100 micron, a surface area higher than 500 m² /g and a porosity higher than 0.5 cc/g, the catalysts obtained from said carriers being characterized in that, when used in a standard polymerization test, they yield polymers in the form of spherical particles having a flowability lower than 16 seconds, determined according to ASTM 1895-79(A) and a bulk density higher than 0.4 g/cm³.

6. Carriers according to claim 5 the catalysts obtained from said carriers being characterized in that, when used in a standard polymerization test, they yield polymers having a flowability comprised between 12 and 15 seconds.