Abstract: The present invention relates to a solid catalyst component for the polymerization of olefins CH.sub.2 .dbd.CHR in which R is hydrogen or a hydrocarbyl radical with 1-12 carbon atoms, comprising a titanium compound, having at least a Ti-halogen bond and an electron donor compound supported on a Mg halide, in which said electron donor compound is selected from esters of malonic acids of formula (I): ##STR1## wherein R.sub.1 is a C.sub.5 -C.sub.20 linear or branched alkyl, a C.sub.5 -C.sub.20 cycloalkyl, a C.sub.7 -C.sub.20 arylalkyl or alkylaryl group; R.sub.2 and R.sub.3, equal to or different from each other, are C.sub.1 -C.sub.3 alkyl, cycloalkyl. Said catalyst components when used in the polymerization of olefins, and in particular of propylene, are capable to give high yields and polymers having high insolubility in xylene.

Abstract: The thermal stability of alpha-substituted acrylate graft copolymers can be improved by (a) making a graft copolymer comprising a backbone of a propylene polymer material having graft polymerized thereto monomers comprising (i) a 1-3 C alkyl-substituted acrylic acid and (ii) an ester of a 1-3 C alkyl-substituted acrylic acid, wherein the total amount of polymerized monomers is about 20 to about 240 parts per hundred parts of the propylene polymer material and the amount of (i) is about 1 to about 20%, based on the total weight of monomers, and (b) removing any unreacted grafting monomer from the resulting grafted propylene polymer material, decomposing any unreacted initiator, and deactivating any residual free radicals in the material.

Abstract: Elastomeric ethylene/propylene or ethylene/propylene/-polyene copolymers containing small amounts of one or more .alpha.-olefins are prepared by a slurry process wherein the polymerization reaction is carried out in a mixture of liquid propylene and alpha-olefin. Problems due to fouling phenomena in the reactor are avoided.

Abstract: A process is disclosed for preparing bis-cyclopentadienyl compounds bridged by a single carbon atom by reacting a carbonyl compound with a cyclopentadienyl compound in the presence of a base and of an oxygen-containing solvent having an atomic ratio carbon/oxygen not higher than 3. The compounds obtainable in high yields with this simple single-step process can be used to prepare ansa-metallocenes which are active as catalyst components in the polymerization of olefins.

Abstract: Disclosed is a polypropylene composition useful for making solid state oriented film. The composition comprises two predominantly isotactic polypropylenes with the melting point temperature of one of the polypropylenes being substantially lower than the melting point temperature of the other. In one embodiment of the composition the higher melting point polypropylene is made by Ziegler-Natta catalysis, while the lower melting point polypropylene is made by metallocene catalysis. Compared to polypropylene with similar melt flow rate and made by Ziegler-Natta catalysis, and solid state oriented film thereof, the composition provides a better balance of elevated temperature draw characteristics and physical properties of oriented film made therefrom. Thus, at the same or lower elevated temperature yield stress, oriented film of the composition exhibits improved properties such as stiffness, elongation-at-break, dimensional stability, and oxygen barrier.

Abstract: Copolymers of ethylene with comonomers selected from (a) alpha-olefins, (b) cycloolefins and/or (c) dienes, characterized by the fact that:the molar percentage of the comonomer (% .alpha.) and the density of the copolymer (D) satisfy the relation % .alpha.+150D.ltoreq.141.

Abstract: Process for repairing plastic coatings of metal pipes that allows one to make the repair using only a flame as a source of heat, including the application of protective shields during specific operating phases of the process.

Abstract: Homopolymers or copolymers obtained by a multistage process of olefins having the formula CH.sub.2 .dbd.CHR, in which R is hydrogen or R has from 1 to 10 carbon atoms and is an alkyl, cycloalkyl or aryl group, the process comprising:(A) a first stage of polymerization in which one or more of the olefins are polymerized in the presence of a titanium or vanadium catalyst;(B) a treatment stage in which the product obtained in the first stage of polymerization (A) is brought into contact with a compound capable of deactivating the catalyst present in the stage (A); and also brought into contact with a compound of a transition metal M selected from the group consisting of Ti, Zr, V, or Hf containing at least one M-.pi. bond and optionally with an alkyl-Al compound; and(C) a second stage of polymerization in which one or more of the olefins are polymerized, in one or more reactors, in the presence of the product obtained in treatment stage (B).

Abstract: Embossed sheets having improved grain retention can be made from a polyolefin composition containing a propylene polymer material and a partially crosslinked thermoplastic olefin elastomer composition. Large parts such as automobile door and instrument panels can be formed from these sheets.

Abstract: A radiation-resistant polyolefin composition which includes (i) a polyolefin; and (ii) a radiation-stabilizing amount of at least one aliphatic, unsaturated compound having at least one unsaturation site, the compound having a molecular weight of at least 200 and an iodine number of at least 25. Suitable aliphatic, unsaturated compounds include soybean oil, safflower oil, squalene, polybutadiene, a tertiary amine having at least one aliphatic, unsaturated fatty-acid-derived substituent, oleamide, calcium oleate, erucyl erucamide and glycerol monooleate. A saturated mobilizing compound is preferably included in the composition, which can advantageously be used in the manufacture of fibers, films, and medical devices such as syringes, tube assemblies, tissue culture flasks, and packaging film.

Abstract: A polymer composition for making molded parts including (1) a thermoplastic olefin, (2) a propylene polymer material, and (3) an oxidized polyethylene wax having an acid number of .gtoreq.15 mg KOH/g, a high molecular weight ethylene polymer, or mixtures thereof, wherein (2)+(3) equals at least 22.5 parts per hundred parts of the thermoplastic olefin, has a good paint adhesion/durability balance. Injection molded parts made from this composition have a unique morphology characterized by a continuous matrix phase and discrete particles of a dispersed phase having a specific aspect ratio near the surface of the part and a specific particle size in the core of the part.

Abstract: Stretchable multilayer films in which at least one layer (A) thereof comprises a copolymer (I) of ethylene with one or more .alpha.-olefins CH.sub.2 .dbd.CHR, having a density of between 0.88 and 0.945 g/cm.sup.3, a melt index of from 0.1 to 10 g/10' and containing up to 20 mol % of .alpha.-olefin CH.sub.2 .dbd.CHR (LLDPE), and at least one layer (B) comprises a heterophasic polyolefin composition having:(a) 20-100 parts by weight of a fraction which is insoluble in xylene at room temperature, comprising a propylene homopolymer or a copolymer of propylene with ethylene and/or another .alpha.-olefin CH.sub.2 .dbd.CHR.sup.I, this fraction containing more than 85% by weight of units derived from propylene; and (b) 30-80 parts by weight of a fraction which is soluble in xylene at room temperature, comprising an amorphous copolymer of ethylene with propylene and/or another .alpha.-olefin CH.sub.2 .dbd.CHR.sup.

Abstract: A ductile, gamma radiation resistant olefin polymer composition, including (a) an olefin in polymer, (b) an amount of N,N-dialkylhydroxylamine which is effective to increase the ductility of the composition, and (c) a polysiloxane which contains sterically hindered piperidino groups and which is present in an amount effective to increase the gamma radiation resistance of the composition. The composition may be used to manufacture sterilizable articles including food packaging and medical articles.

Abstract: Process for the production of a high tenacity propylene polymer fiber which comprises:spinning fiber from a molten propylene polymer composition consisting essentially of 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; said 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: Stretchable multilayer films in which at least one layer comprises:a) a linear low density polyethylene (LLDPE),b) a copolymer of propylene with ethylene and/or with one or more .alpha.-olefins CH.sub.2 .dbd.CHR.sup.I, in which R.sup.I is an alkyl radical having from 2 to 10 carbon atoms, this copolymer being of relatively high insolubility in xylene; andc) a low density polyethylene (LDPE).The said films, which have improved optical and mechanical properties, are particularly suitable for use in the packaging sector.

Abstract: It is possible to prepare in high yield and purity the racemic and meso forms of bridged chiral metallocenes with a stereoselective method, by synthesizing the sylil-, germyl- or stannyl-substituted ligands. These compounds can be prepared in their racemic and meso forms, and then selectively transformed in the corresponding metallocenes.

Abstract: Directly paintable polymer compositions contain (1) a thermoplastic olefin, (2) a propylene homopolymer or propylene copolymer with ethylene or a 4-8 C alpha-olefin, grafted with an anhydride of an aliphatic .alpha., .beta.-unsaturated dicarboxylic acid, (3) an oxidized polyethylene wax having a melting point of less than 116.degree. C. and an acid number of less than 40, (4) a functionalized polymer that reacts with the anhydride groups of the grafted polymers, and, optionally, (5) a polyolefin rubber grafted with an anhydride of an aliphatic .alpha., .beta.-unsaturated dicarboxylic acid, and (6) an ethylene polymer grafted with an anhydride of an aliphatic .alpha., .beta.-unsaturated dicarboxylic acid. The compositions are particularly useful for making injection molded parts such as automobile bumpers, and exhibit excellent paint adhesion and durability.

Abstract: Directly paintable polymer compositions contain (1) a thermoplastic olefin, (2) a maleic anhydride-grafted propylene homopolymer or random copolymer, (3) a maleic anhydride-grafted olefin polymer material, (4) a functionalized polymer that reacts with the maleic anhydride groups of the grafted polymers, and, optionally, (5) a maleic anhydride-grafted ethylene polymer. The amount of (2)+(3) or (2)+(3)+(5) is at least 16 parts but less than 27 parts per hundred parts of the thermoplastic olefin.

Abstract: Embossed sheets having improved grain retention can be made from a polyolefin composition containing a propylene polymer material and a partially crosslinked thermoplastic olefin elastomer composition that includes (1) 20-80 parts by weight of a thermoplastic elastomer containing (a) from 20 to 70% of a propylene homopolymer having an isotactic index greater than 90, or a crystalline propylene copolymer with ethylene and/or a 4-8 C alpha-olefin having a polymerized propylene content greater than 85% and an isotactic index of greater than 85%; (b) from 30 to 75% of an amorphous ethylene-propylene or ethylene-butane-1 copolymer, which is xylene soluble at room temperature and contains from 30 to 70% polymerized ethylene, and (c) from 3 to 30% of a semi-crystalline ethylene-propylene or ethylene-butene-1 copolymer that is xylene insoluble at room temperature and contains greater than 90% polymerized ethylene, and (2) 80-20 parts by weight of an ethylene/propylene/diene terpolymer rubber containing 1 to 10% of a

Abstract: Flame retarding additives prepared by way of reaction of:A) one or more nitrogenous organic compounds of a defined formula;B) P.sub.2 O.sub.5 ;C) H.sub.2 O.