Abstract: A polymer composition and fiber, film or sheet prepared therefrom, which contains (i) an olefin polymer containing an acid neutralizing agent other than a metallic salt of a saturated or unsaturated fatty acid, and ii) a stabilizer system distributed throughout the polymer, the stabilizer system including (a) a phosphite selected from 2,2',2"-nitrilo?triethyl-tris(3,3',5,5'-tetra-tert.butyl-1,1-biphenyl-2,2' -diyl)phosphite! and tris(2,4-di-tert-butylphenyl) phosphite; and (b) a N,N-dialkylhydroxylamine. Also disclosed is a method for preparing a polyolefin fiber, film or sheet, which includes adding the above stabilizer to an olefin polymer containing an acid neutralizing agent other than a metallic salt of a saturated or unsaturated fatty acid, thereby producing a stabilized olefin polymer; and extruding the stabilized olefin polymer through a die.

Abstract: A propylene homopolymer having a stick-point of 30 cm or less during melt spinning, an oligomer content of less than 1500 ppm without postpolymerization treatment to remove oligomers, and a melt flow rate greater than 300 dg/min is prepared by radiation visbreaking in a multistage fluidized bed reactor. The polymer is subjected to irradiation in the substantial absence of oxygen, followed by a multistage treatment in the presence of a controlled amount of oxygen. The radiation visbreaking process can also be applied to other propylene polymer materials. The propylene polymer materials produced by this radiation visbreaking process can be used, for example, for extrusion coating, film production, and injection molding.

Abstract: Disclosed is a process for coating the inner surface of metal containers by deposition of specific polyolefin compositions on the separate parts of the containers, subsequent assembly of the parts and melting of the polyolefin compositions.

Abstract: A graft copolymer of a propylene polymer material is prepared by (1) making an oxidized propylene polymer material by (a) irradiating a porous particulate propylene polymer material in the substantial absence of oxygen, (b) exposing the irradiated propylene polymer material to a controlled amount of oxygen of greater than 0.004% but less than 15% by volume at a temperature of 40.degree. C. to 110.degree. C., and (c) heating the irradiated polymer material to a temperature of at least 110.degree. C. in the presence of a controlled amount of oxygen within the same range as is used in the previous step, (2) dispersing the resulting oxidized propylene polymer material in water in the presence of a surfactant at a temperature of 30.degree. C.-90.degree. C., (3) adding (a) a primary reducing agent, (b) a chelating agent, and (c) a secondary reducing agent, (4) adding at least one vinyl monomer, and (5) recovering the graft copolymer from the reaction mixture.

Abstract: A propylene homopolymer having a stick-point of 30 cm or less during melt spinning, an oligomer content of less than 1500 ppm without postpolymerization treatment to remove oligomers, and a melt flow rate greater than 300 dg/min is prepared by radiation visbreaking in a multistage fluidized bed reactor. The polymer is subjected to irradiation in the substantial absence of oxygen, followed by a multistage treatment in the presence of a controlled amount of oxygen. The radiation visbreaking process can also be applied to other propylene polymer materials. The propylene polymer materials produced by this radiation visbreaking process can be used, for example, for extrusion coating, film production, and injection molding.

Abstract: An embrittlement-resistant polymer composition, including: (a) a visbroken polymer composition comprising a crystalline, random copolymer of propylene and either ethylene or C.sub.4 -C.sub.10 1-olefins, and (b) an amount of polymethyl propyl 3-oxy-?4-(2,2,6,6-tetramethyl)piperidinyl! siloxane which is effective to improve the radiation resistance of the composition. Optional components include an acid neutralizing agent, and a sorbitol-based clarifier compound. The composition may be used to manufacture medical articles and food packaging material which must be sterilized, either by irradiation or by autoclaving.

Abstract: Process for the production of a high tenacity propylene polymer fiber which includes:spinning fiber from a molten propylene polymer composition which essentially includes an olefin polymer (I) and a high molecular weight propylene polymer (II) having a branching index less than 1 and melt strength from 5 to 40 cN; the propylene polymer (II) being present in a concentration from 0.1 to 10% by weight with respect to the total weight of the composition; anddrawing the solid fiber thus obtained with a draw ratio greater than 4.5 when the spinning step is continuous and greater than 5 when the spinning step is discontinuous.

Abstract: Laminar articles are manufactured by slush molding polyolefin compositions in powder form composed of:A) 10-40 parts by weight of a propylene homopolymer or copolymer;B) 0-20 parts by weight of a copolymer fraction containing ethylene, propylene and/or a CH.sub.2 .dbd.CHR .alpha.-olefin, the copolymer fraction being insoluble in xylene at ambient temperature and having an ethylene content equal to or greater than 80% by weight;C) 50-80 parts by weight of a copolymer fraction containing ethylene, propylene and/or a CH.sub.2 .dbd.CHR .alpha.-olefin, the copolymer fraction being soluble in xylene at ambient temperature and having an intrinsic viscosity in tetrahydronaphthalene at 135 C ranging from 1 to 1.4 dl/g.

Abstract: Disclosed is a multilayered cast film which has an elongation at break greater than 100%. It comprises:A) at least one layer of a crystalline homopolymer of a C.sub.3 -C.sub.6 .alpha.-olefin, or a random copolymer of propylene with ethylene and/or a C.sub.4 -C.sub.10 .alpha.-olefin, or a composition of crystalline random copolymers of propylene with ethylene and/or a C.sub.4 -C.sub.8 .alpha.-olefin (Component A); andB) at least one layer of a propylene homopolymer, or a propylene copolymer with ethylene or a C.sub.4 -C.sub.10 .alpha.-olefin, or a propylene copolymer with ethylene and a C.sub.4 -C.sub.10 .alpha.-olefin, having an elongation at break lower than 30% (Component B).

Abstract: Disclosed is a normally solid, high molecular weight, gel-free, amorphous to predominantly crystalline, propylene polymer 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, and thermoforming.

Abstract: Gas-phase process for the preparation of polymers and copolymers of olefins CH.sub.2 .dbd.CHR, carried out in at least 2 fluidized or mechanically agitated bed gas-phase reactors operating under different reaction conditions so as to obtain different polymers in the different reactors; the process is characterized in that the polymer is at least partially recycled among the different reactors by using ratios of the flow rate of circulation among the different reactors to the discharge flow rate comprised between 2 and 6.

Abstract: Process for the preparation of a solid catalyst component for olefins polymerization including (1) a magnesium halide in active form, (2) a titanium compound, and (3) an electron-donor compound selected from particular 1,3-diethers, the process being carried out by reaction between the compounds from (1) to (3), and including at least two additions of electron-donor (3) in the following order:a) one addition prior to or during a reaction with the titanium compound or with a halogenated compound, and thenb) one addition prior to or during a further reaction with the titanium compound.

Abstract: Essentially atactic cross-linked propylene homopolymer or amorphous cross-linked random copolymer of propylene with ethylene and/or at least one C.sub.4 -C.sub.10 .alpha.-olefin. Polymer composition comprising the above mentioned cross-linked atactic or amorphous polymers and other olefin polymers. Foamed polymer or polymer composition obtained by foaming said cross-linked atactic or amorphous polymers or said polymer composition.Process for the preparation of said polymer or foamed polymer composition.

Abstract: Disclosed is a method for removing oligomers from substantially crystalline, .alpha.-olefin polymer particles without having to melt the particles. The method comprises fluidizing a bed of the particles with a gas in which the oligomers are soluble, which bed is at a temperature at which the particles are not sticky, but at least lower molecular weight oligomers will evaporate therefrom, and maintaining the particles in the fluidized bed until a substantial portion of the oligomers have evaporated and have been removed from the bed by the fluidizing gas. By regulatng the bed temperature and the residence time of the particles in the bed the proportion and chain length of the oligomers removed can be controlled.

Abstract: A process for preparing thermal bondable fibers including exposing molten fiber grade polymer to electromagnetic radiation at the one or more orifices of the spinneret and the upper portion of the spin line, and the fibers prepared therefrom.

Abstract: Disclosed are functionalized polyolefins prepared by mixing a polyolefin with a concentrate and extruding the resulting blend, where the concentrate is in the form of olefin polymer particles coated with a mixture of additives including:A) from 0.05 to 30% by weight, based on the total weight of the concentrate, of one or more nonpolymerizable polar vinyl monomers;B) from 0.05 to 30% in moles, with respect to (A), of a free radical generating initiator which is not active at temperatures lower than or equal to 70.degree. C., and optionally,C) from 0.1 to 5% by weight, based on the total weight of the concentrate, of a coating substance.

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: 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.