Abstract: The present invention relates to components of catalysts for the polymerization of olefins comprising a metallocene compound and a magnesium halide which have particular values of porosity and surface area. In particular the components of the invention have surface area (BET) greater than about 50 m.sup.2 /g, porosity (BET) greater than about 0.15 cm.sup.3 /g and porosity (Hg) greater than 0.3 cm.sup.3 /g, with the proviso that when the surface area is less than about 150 m.sup.2 /g, the porosity (Hg) is less than about 1.5 cm.sup.3 /g. The components of the invention are particularly suitable for the preparation of catalysts for the gas-phase polymerization of .alpha.-olefins.

Abstract: Process for gas-phase polymerization carried out in two interconnected polymerization zones, to which one or more .alpha.-olefins CH.sub.2 .dbd.CHR are fed in the presence of catalyst under reaction conditions and from which the polymer product is discharged. The process is characterized in that the growing polymer flows through a first polymerization zone under fast fluidization conditions, leaves said first zone and enters a second polymerization zone through which it flows in a densified form under the action of gravity, leaves said second zone and is reintroduced into the first polymerization zone, thus establishing a circulation of polymer around the two polymerization zones. The novel process allows olefins to be polymerized in the gas phase with high productivity per unit volume of the reactor without incurring the problems of the fluidized-bed technologies of the known state of the art.

Abstract: A gas phase process for producing olefin polymer graft copolymers, including providing a reaction apparatus having first and second reaction zones operatively connected to each other into which particles of an olefin polymer and a free-radical polymerizable monomer are fed while maintaining free-radical polymerization conditions and a substantial non-oxidizing environment in said zones and from which the grafted copolymer product is discharged. An apparatus suitable for practicing this process is also disclosed.

Abstract: Multi-layer heat-shrinkable films in which at least one layer (A) is based on a polyolefin composition comprising a propylene copolymer and having particular crystallinity characteristics, and at least one layer (B) comprises a linear compolymer of ethylene with one or more .alpha.-olefins (LLDPE). The films are characterized by an optimum balance of physicomechanical properties, processability and sealability at low temperatures.

Abstract: Polyolefin fibers, suitable for the preparation of nonwoven fabrics, prepared by using a spinneret or extruder with dies having a real or equivalent output diameter of the capillaries or holes greater than 0.4 mm, with the proviso that for fibers having a denier greater than or equal to 4 dtex, the ratio of the output capillary or hole diameter to the denier is greater than or equal to 0.06 mm/dtex.

Abstract: Polyolefin compositions, capable of developing substantial dielectric heat including (percent by weight):(I) 85-97% of a heterophasic olefin polymer optionally modified with polar monomers in amount from 0.3 to 0.03% of the heterophasic olefin polymer; and(II) 3-15% of at least one polymer having a dielectric heat loss factor greater than or equal to 0.01.

Abstract: Disclosed are graft copolymers of polyolefins and a method of preparing the graft copolymers. The method includes irradiating a mass of olefin polymer particles and thereafter treating the mass of particles with a vinyl monomer in liquid form. A nonoxidizing environment is maintained throughout the process while free radicals produced in the olefin polymer by the irradiation are present, thereby preventing degradation of the polymer. In a final step, residual free radicals are deactivated, and any unreacted monomer is removed.

Abstract: Multistage process for the polymerization of one or more olefins of the formula CH.sub.2 .dbd.CHR, in which R is hydrogen or an alkyl, cycloalkyl or aryl group having from 1 to 10 carbon atoms, comprising:(A) a first stage of polymerization, in which a first olefin polymer is prepared in the presence of titanium catalyst or vanadium catalyst;(B) a treatment stage in which the catalyst used previously is deactivated and in which a metallocene compound is supported on the olefin polymer produced in stage (A); and(C) a second stage of polymerization in which one or more olefins are polymerized in the presence of the product obtained from stage (B).

Abstract: Disclosed is a blown film or sheet material comprising a broad molecular weight distribution propylene polymer material having a molecular weight distribution M.sub.w /M.sub.n of about 4 to about 60, a melt flow rate of about 0.5 to about 50 dg/min, and xylene insolubles at 25.degree. C. of greater than or equal to 94%. A mixture of the broad molecular weight distribution propylene polymer material and a heterophasic olefin polymer composition can also be used.

Abstract: Disclosed is a drawn, polyolefin fiber useful for nonwoven fabrics, the thermobonding index of said fiber being 4.5-9 Newtons, and the flexibility index thereof being 1020-1500. The fiber is composed of a blend of specified polymers. Also disclosed is a process for making the fiber by spinning the blend from a die hole having at the output end a diameter less than 0.5 mm, and drawing the resulting fiber at a draw ratio of 1.1 to 1.8.

Abstract: Isospecific and/or syndiospecific catalysts and processes for the propagation of an isotactic and/or syndiotactic polymer chain derived from an ethylenically unsaturated monomer which contains 3 or more carbon atoms or is a substituted vinyl compound. The catalysts comprise a stereorigid, stereodirected and stereolocked metallocene and/or metallocene cation catalysts, characterized by having .beta. stereodirecting substituents and .alpha. stereolocking substituents such that the catalysts have overall either C.sub.s or C.sub.2 (or pseudo-C.sub.s or C.sub.2) symmetry and such that the substituents define the orientation of the growing polymer chain end and resulting in tactioselectivity of successive monomer additions. Methods are also described for the preparation and use of these unique catalysts.

Abstract: Apparatus for coating the interior surfaces of metal containers by electrostatic deposition of specific polyolefin compositions on the separate parts of the containers prior to assembly of the containers and melting of the polyolefin compositions, which includesa first spray booth containing at least one electrostatic powder spraying device for spraying a polyolefin composition powder, the first spray booth being adapted for spraying the bottoms and lids of the containers,means for conveying the bottoms and lids of containers in the first spray booth,a second spray booth containing at least one electrostatic powder spraying device for spraying a polyolefin composition powder, the second spray booth being adapted for spraying the bodies of the containers,means for conveying the bodies of containers in the second spray booth, andat least one electrostatic generator connected to the spraying devices.

Abstract: The carbon monoxide contained in .alpha.-olefins and saturated hydrocarbons, in particular .alpha.-olefins and C.sub.2-4 saturated hydrocarbons, is removed, by contacting such .alpha.-olefins and saturated hydrocarbons, at a temperature ranging from 0.degree. to 150.degree. C., with a catalyst system comprising a mixture and/or the reaction product of:A) one or more oxides of metals selected from the group consisting of Cu, Fe, Ni, Co, Pt, Pd; andB) one or more oxides of metals selected from the group consisting of metals of groups V B, VI B, or VII B of the Periodic Table;thus reducing the content of carbon monoxide to values lower than 0.03 ppm.

Abstract: Saxony carpet containing a pile yarn comprising propylene polymer yarn of increased resiliency and shrinkage, compared to crystalline propylene homopolymer yarn, having a continuous strand of multiple monofilament fibers, said fibers consisting essentially of certain propylene polymer blends and materials.

Abstract: Disclosed are a crystalline propylene copolymer composition, film, sheet and plate made therefrom and laminates wherein at least one layer is made therefrom, having low seal initiation temperature and good ink adhesion properties. The composition comprises (percent by weight):A) 20-60% of a crystalline copolymer of propylene with 1 to 5% ethylene; andB) 40-80% of a crystalline copolymer of propylene with 1 to 5% ethylene and 6 to 15% C.sub.4 -C.sub.8 .alpha.-olefin.In the composition the total content of ethylene being 1% to 5% and of C.sub.4 -C.sub.8 .alpha.-olefin being 2.4% to 12%.

Abstract: Shaped articles for biomedical use characterized by a good transparency and flexibility also at low temperatures are prepared starting from elastomeric copolymers of ethylene with propylene and/or other alpha-olefins having a unique set of mechanical properties and thermoplastic processability. Of particular interest are devices for containing, administering, draining and transport of blood and biological and physiological fluids, syringe seals and similar applications.

Abstract: Disclosed are catalysts for the polymerization of alpha-olefins which comprise the reaction product of:(a) an Al alkyl compound;(b) a silicon compound containing at least a Si--OR or Si--OCOR or Si--NR.sub.2 bond, R being a hydrocarbyl radical;(c) a solid comprising, as essential support, a Mg dihalide in active form and, supported thereon, a Ti halide or a halo-Ti-alcoholate and a particular, selected type of electron-donor compound.

Abstract: A process for polymerizing olefins using a fluidized bed, in which the monomer entry point is located at a point above the bed height. A pre-polymerization step can be conducted using a Z/N catalyst along with an alkane diluent, and resultant liquid phase is introduced into the fluidized bed above the bed height. The process may use several reactors in series arrangement.

Abstract: Disclosed is a piperidinyl phosphite composition consisting of a piperidinyl phosphite compound and an additive having a melting point of greater than 155.degree. C. selected from the group consisting of (i) sorbitol compounds, (ii) phosphite compounds and (iii) sterically hindered phenolic compounds, and polyolefin compositions containing them.

Abstract: Disclosed is a normally solid, high molecular weight, non-linear, substantially gel-free, propylene polymer material characterized by high melt strength due to strain hardening which is believed to be caused by free-end long chain branches of the molecular chains forming the polymer.Also disclosed is a process for making the polymer by high energy radiation of a normally solid, high molecular weight, linear, propylene polymer in a reduced active oxygen environment, maintaining the irradiated material in such environment for a specific period of time, and then deactivating free radicals in the material.Further disclosed is the use of the strain hardening polymer in extensional flow operations such as, for example, extrusion coating, film production, foaming and thermoforming.