Abstract:
The invention relates to a process for the preparation of porous ethylene polymers and to a specific group of ethylene polymers therefrom obtained. In particular, the present invention relates to a process for the preparation of ethylene (co)polymers characterized by: prepolymerizing propylene in the presence of a Mg, Ti, and halogen containing solid catalyst component having a porosity, higher than 0.25 cc/g up to producing from 0. 1 to 15 g of propylene pre-polymer per g of catalyst component; and polymerizing ethylene in the presence of the propylene pre-polymer obtained in step (i) up to an amount of ethylene polymer ranging from 10g to 2.5 kg per g of propylene prepolymer.
Abstract:
An olefin polymer composition comprising (ppm with respect to the polymer): a lactone of the furan-2-one type, a phenol in amounts of 50 to 200 ppm, a sterically hindered amine in amounts of 50 to 300 ppm, and an organic phosphite and/or organic phosphonite in amounts of 50 to less than 280 ppm. The polymer composition contains the unsubstituted furan-2-one moiety in amounts ranging from 11 to 49 ppm with respect to the polymer. Staple fibres with high tenacity and elongation at break and non-woven fabrics are prepared from such an olefin polymer composition.
Abstract:
A continuous process for the olefin polymerization in a fluidized bed reactor, said process comprising continuously passing a gaseous stream comprising one or more α-olefin monomers through the fluidized bed in the presence of a polymerization catalyst under reactive conditions, withdrawing polymeric product and unreacted fluids from the reactor, cooling part of said unreacted fluids below the dew point to form a two-phase mixture of gas and condensed liquid and reintroducing said two-phase mixture into the reactor, the process being characterized in that said twophase mixture is reintroduced under the distribution plate of the reactor so that a part of condensed liquid is separated from the gas and is successively fed above the fluidized bed through an external pipe connecting the bottom of the reactor to a point situated above the upper limit of the fluidized bed of polymer particles.
Abstract:
Olefin polymer composition comprising (by weight, unless otherwise specified): A) 60 - 95% of a propylene homopolymer or copoloymer having a Polydispersity Index (P.I.) value of from 4.6 to 10 and a content of isotactic pentads (mmmm), measured by 13C NMR on the fraction insoluble in xylene at 25 °C, higher than 98 molar; B) 5 - 40% of a copolymer of ethylene containing from 40% to 70% of propylene or C 4 -C 10 α-olefins) or of combinations thereof, and optionally minor proportions of a diene; said composition having a Temperature Rising Elution Fractionation (TREF) profile, obtained by fractionation in xylene and collection of fractions at temperatures of 40 °C, 80°C and 90 °C, in which the ethylene content Y of the fraction collected at 90 °C satisfies the following relation (I): Y≤ -0.8 + 0.035X + 0.0091X 2 wherein X is the ethylene content of the fraction collected at 40 °C and both X and Y are expressed in percent by weight, and a value of intrinsic viscosity [η] of the fraction soluble in xylene at 25 °C of from 1.8 to 4.2 dl/g.
Abstract:
A masterbatch composition comprising (percent by weight): A) 50%-90% of a crystalline polypropylene component comprising: A I ) from 25% to 75% of a fraction having a melt flow rate MFR I of from 0.1 to 10 g/10 min.; and A II ) from 75% to 25% of a fraction having a melt flow rate value MFR II equal to or lower than 100 g/10 min.; wherein the ratio MFR I /MFR II is from 5 to 60; and B) 10%-50% of a copolymer component of ethylene and at least one C 3 -C 10 α-olefin, containing from 15% to 50% of ethylene; said masterbatch composition having a value of the intrinsic viscosity [η] of the fraction soluble in xylene at room temperature equal to or higher than 3.5 dl/g, is added to polyolefin materials to obtain final compositions suitable for injection molding.
Abstract:
A compatible blend of an engineering thermoplastic such as a polyamide and an olefin . polymer material is prepared by (1) making an oxidized olefin polymer material containing carboxylic acid groups or derivatives thereof, (2) extruding a mixture of (a) the oxidized olefin polymer material from step (1), (b) an engineering thermoplastic, (c) optionally, an inorganic base, and (d) optionally, a non-oxidized olefin polymer material, and (3) recovering a blend of the engineering thermoplastic, the oxidized olefin polymer material or an ionomer thereof, which acts as a compatibilizer, and, optionally, the non-oxidized olefin polymer material. The oxidized olefin polymer material can be made by treating the olefin polymer material with an organic peroxide initiator while adding a controlled amount of oxygen.
Abstract:
Irradiated, oxidized olefin polymer coupling agents for use in the manufacture of non-halogenated flame retardant-containing and filler-containing olefin polymer compositions and coupling agent-containing olefin polymer concentrates.
Abstract:
A fibre for spunbonded fabrics comprising a propylene polymer composition (A) having an MFR (1) value from 6 to 150 g/10 min and being selected from (i) a crystalline propylene random copolymer or crystalline propylene polymer composition containing at least 0.8% by weight of ethylene and having a melting temperature of 153° C or higher, a content of fraction soluble in xylene at room temperature lower than 10% by weight, and a value of the ratio of the polymer fraction collected at the temperature range from 25° to 95° C to the xylene soluble fraction at room temperature higher than 4; and (ii) a crystalline propylene polymer composition having a melting temperature of 153° C or higher, a content of fraction soluble in xylene at room temperature lower than 10% by weight; the said composition containing at least 0.64 wt% of ethylene or a C 4 -C 10 a-olefin recurring unit and comprising: (1) 20-80 wt% of a crystalline propylene polymer containing up to 1.5 wt% of ethylene and/or C 4 -C 10 a-olefin; and (II) 20-80 wt% of a crystalline propylene random copolymer selected from (IIa) a copolymer of propylene with 0.8 to 10 wt% of ethylene and/or (IIb) a copolymer of propylene with 1.5 to 18 wt% of a C4-CIO a-olefin. Said polymer composition (A) is obtainable by way of chemical degradation of a precursor polymer composition (A) having MFR values (MFR (2)) of from 0.5 to 50 g/10 min, provided that the ratio of MFR (1) to MFR (2) be from 1.5 to 60. Propylene polymer composition (ii) as described above and non-woven fabrics that are prepared with the said fibres. The said fabric is useful for coverstock and diapers.
Abstract:
Propylene polymers having a content of isotactic pentads (mmmm) higher than 97%, molecular weight distribution, expressed by the formula (a) ratio, equal to or higher than 6 and a value of formula (b) ratio equal to or lower than 5.5. The said polymers are prepared in the presence of a particular combination of Ziegler-Natta solid catalyst components and highly stereoregulating electron-donor compounds. Laminated articles, in particular bi-axially oriented films and sheets, can be prepared with the said polymers.
Abstract:
A solid catalyst component for the polymerization of olefins, comprising: an inert porous support, Mg, Ti, halogen and an electron donor selected from succinates of formula (I) wherein the radicals R 1 and R 2, equal to or different form each other, are hydrocarbon groups, the radicals R 3 , R 4 , R 5 and R 6 , equal to or different from each other, are hydrogen or hydrocarbon groups.