TH40159A - The process for producing heterophatic polymer components and the components obtained by this method. - Google Patents

Abstract

DC60 (08/09/42) Process for the preparation of heterophatic polyolefins composed of: (i) a step in which (a) polymerization of propylene to form crystalline propylene or ethylene with C3-C10 alpha-olefins to form an elastomeric copolymer; this step is performed in the presence of a Ziegler-Natta catalyst; (ii) a treatment step in which the polymer obtained in step (i) is exposed to: a) a compound capable of deactivating the catalyst present in step (i); and b) the catalyst (2) obtained by exposure of (I) a compound containing a transition metal M, and at least one ligand coordinated with metal M by a pi bond, and (II) a co-catalyst; (iii) The copolymerization step in which ethylene and C3-C10 alpha-olefin are polymerized in the presence of the polymers treated in step (ii), and the catalyst (2) mentioned above. The process for preparing heterophasic polyolefins consists of: (i) a step in which (a) polymerization of propylene to form crystalline propylene or ethylene with C3-C10 alpha-olefins to form an elastomeric copolymer; this step is carried out in the presence of the Ziegler-Natta catalyst; (ii) a treatment step in which the polymers obtained in step (i) are exposed to: a) a compound capable of deactivating the catalyst present in step (i); and b) the catalyst (2) obtained by contacting (I) a compound containing the transition metal M, and at least one ligand that coordinates with the metal M by a pi bond, and (II) the co-catalyst; (iii) the copolymerization step in which ethylene and C3-C10 alpha-olefin are polymerized in the presence of the polymers treated in step (ii), and the aforementioned catalyst (2).

Claims (8)

1. The process for preparing heterophatic polyolefins consisting of: i) steps which occur, in any order, a) polymerization of propylene to produce at least 80% by weight of crystalline propylene polymer that is insoluble in xylene at ambient temperature, or of propylene with ethylene and/or C4-C10 alpha-olefin. a) Copolymerization of ethylene to form a propylene copolymer containing more than 85% by weight of propylene, or polymerization of ethylene to form an ethylene homopolymer, or of ethylene with C3-C12 alpha-olefin, to form an ethylene copolymer containing up to 20% mol of C3-C12 alpha-olefin, and b) Copolymerization of ethylene and C3-C10 alpha-olefin, and possibly diin, to form a partially soluble elastomeric copolymer in ambient xylene, containing up to 70% by water of ethylene in the soluble fraction in ambient xylene; these steps were performed in the presence of a contact-acquired Ziegler-Natta catalyst (1). The following components are involved: - A catalyst component containing a titanium compound and an electron-donating compound, both supported on MgCl2; - Organometallic compounds, and possibly - electron-donating compounds; ii) A treatment step in which the polymer obtained in step polymerization (i) is exposed in any order to: a) a compound capable of deactivating the catalyst present in step (i); and b) the catalyst (2) obtained by exposure (I) to a compound containing the transition metal M, and at least one ligand coordinated to the metal M by a pi bond, and (II) at least one co-catalyst selected from aluminoxane, for example; iii) The copolymerization step in which ethylene and C3-C10 alpha-olefin are polymerized in the presence of the polymers treated in step (ii), and the catalyst (2) as described. 2. The process of claim 1 in which, in the copolymerization step (iii), the molar ratio between ethylene and the total amount of monomer fed is in the range of 0.5 to 0.7. 3. The process of claim 1 or 2 in which the fraction of the elastomeric copolymer (1) (b) that is soluble in xylene contains up to 40% by weight of ethylene. 4. The process of any one of claims 1-3, where C3-C10 alpha-olefin is propylene or I-butene. 5. Polymer composition obtained from the processes of claims 1-5. 6. Polymer composition of claim 5 consisting of (% by weight): 1) 10-45%, ideally 15-40%, of the selected crystalline polymer fraction from propylene homopolymer with xylene solubility greater than 80% at ambient temperature, ideally greater than 90%, copolymer of propylene with ethylene or C4-C10 alpha-olefin, or a mixture of such comonomers; such copolymer contains more than 85% propylene, and is insoluble in xylene at ambient temperature greater than 80%; or homopolymer or copolymer of ethylene with C3-C12 alpha-olefin, such copolymer contains up to 20% mol of C3-C12 alpha-olefin; 2) From 16 to 55%, ideally from 16 to 50% of the fraction that Partially soluble in xylene at ambient temperature, composed of a copolymer of ethylene with C3-C10 alpha-olefin; such fractions consist of an elastomeric copolymer of ethylene with C3-C10 alpha-olefin, and may contain a small amount of diene, soluble in xylene at ambient temperature, and from 1 to 15%, compared to the positive results of such fractions (1) and (2), of crystalline copolymer of ethylene with C3-C10 alpha-olefin that are insoluble in xylene at ambient temperature; such elastomeric copolymer contains up to 40% of ethylene; 3) 15-60% optimal 20-60%, of the elastomeric copolymer selected from the copolymers. For ethylene-to-C3-C10 alpha-olefin copolymers with ethylene molar content ranging from 30 to 75%, such copolymers have a proportion (formula) less than 4; such polymer composition has a ratio between the amount of xylene-soluble fraction at such ambient temperature of the fraction copolymer (2) and the amount of fraction polymer (1) equal to or less than 1.5. 7. Component of claim 6 in which elastomeric copolymer (3) has an internal viscosity greater than 1.5 dL/g. 8. Items obtained from the elements of claims 6 and 7.