Abstract:
A process for the preparation of propylene polymer compositions comprising from 50 to 90 % by weight of a propylene (co)polymer fraction insoluble in xylene at 25°C, and from 10 to 50% by weight of an ethylene copolymer fraction soluble in xylene at 25°C, said process comprising: (i) a first step of polymerizing propylene in the optional presence of ethylene and/or C 4 -C 10 alpha olefins, to produce a propylene (co)polymer being for at least 85% by weight insoluble in xylene at 25°C; and (ii) a successive step, carried out in gas-phase, in the presence of the product coming from step (i), of copolymerizing a mixture of ethylene with one or more ±-olefins CH 2 =CHR in which R is a hydrocarbon radical having 1-10 carbon atoms, to produce an ethylene copolymer; the process being carried out in the presence of a catalyst system comprising: the product obtained by contacting: (a) a solid catalyst component comprising a magnesium halide, a titanium compound having at least a Ti-halogen bond and at least two internal electron donor compounds one of which being present in an amount from 35 to 90% by mol with respect to the total amount of donors and being selected from succinates and the other being selected from 1,3-diethers, the total amount of internal electron donor compounds being lower than 14.0% by weight with respect to the total weight of the solid catalyst component; with (b) an aluminum hydrocarbyl compound, and optionally with (c) an external electron donor compound.
Abstract:
A polymer composition comprising (per cent by weight): a) 70-84% of a crystalline propylene polymer having an amount of isotactic pentads (mmmm), measured by 13C-MNR on the fraction insoluble in xylene at 25° C., higher than 97.5 molar %; b) 8-15% of an elastomeric copolymer of ethylene and propylene, the copolymer having an amount of recurring units deriving from ethylene ranging from 25 to 50 wt % and being partially soluble in xylene at ambient temperature; the polymer fraction soluble in xylene at ambient temperature having an intrinsic viscosity value ranging from 2.5 to 3.5 dl/g; and c) 8-15% of ethylene homopolymer having an intrinsic viscosity value ranging from 1.5 to 4 dl/g; said composition having a value of melt flow rate ranging from 55 to 90 g/10 min, and the amount of hexane extractables lower than 3.5 wt %.
Abstract:
Process for the preparation of a porous propylene carried out in the presence of a catalyst system comprising (a) a Ziegler-Natta catalyst containing at least two electron donor compounds one of which being present in an amount from 50 to 90% by mol with respect to the total amount of donors and selected from succinates and the other being selected from 1,3 diethers, (b) an aluminum alkyl and comprising the following steps: i) contacting the catalyst components (a) and (b) for a period of time ranging from 1 to 60 minutes, at a temperature ranging from 35 to 55°C; optionally, ii) pre-polymerizing with one or more olefins of formula CH2=CHR, where R is H or a C1-C10 hydrocarbon group, up to forming amounts of polymer from about 0.1 up to about 1000 g per gram of solid catalyst component (a); and iii) polymerizing propylene in the optional presence of minor amounts of ethylene and/or C4-C10 alpha olefins producing said porous propylene (co)polymer.
Abstract:
A process for the preparation of propylene polymer compositions comprising from 50 to 90 % by weight of a propylene (co)polymer fraction insoluble in xylene at 25°C, and from 10 to 50% by weight of an ethylene copolymer fraction soluble in xylene at 25°C, said process comprising: (i) a first step of polymerizing propylene in the optional presence of ethylene and/or C 4 -C 10 alpha olefins, to produce a propylene (co)polymer being for at least 85% by weight insoluble in xylene at 25°C; and (ii) a successive step, carried out in gas-phase, in the presence of the product coming from step (i), of copolymerizing a mixture of ethylene with one or more ±-olefins CH 2 =CHR in which R is a hydrocarbon radical having 1-10 carbon atoms, to produce an ethylene copolymer; the process being carried out in the presence of a catalyst system comprising: the product obtained by contacting: (a) a solid catalyst component comprising a magnesium halide, a titanium compound having at least a Ti-halogen bond and at least two internal electron donor compounds one of which being present in an amount from 35 to 90% by mol with respect to the total amount of donors and being selected from succinates and the other being selected from 1,3-diethers, the total amount of internal electron donor compounds being lower than 14.0% by weight with respect to the total weight of the solid catalyst component; with (b) an aluminum hydrocarbyl compound, and optionally with (c) an external electron donor compound.
Abstract:
A process for the preparation of high purity propylene polymers carried out in the presence of a catalyst comprising the product obtained by contacting: (a) a solid catalyst component comprising Mg, Ti and at least a first internal electron donor compound (HD) selected among the succinates and a second internal electron donor compound (2ID) selected among the 1,3-diethers, wherein the molar ratio of first internal donor over second internal donor 1ID:2ID is comprised between 4:6 and 9:1, with (b) an organo-aluminium compound, and optionally with (c) an external electron donor compound, said process being carried out at a temperature equal or higher than 78° C. and by employing a molar ratio of organo-aluminum compound over solid catalyst component (b):(a) of lower than 5.