Abstract: Polypropylene sheet for thermoforming having at least one layer comprises a propylene polymer containing at least 0.8% by weight of ethylene and, optionally, one or more C4-C10 &agr;-olefins, or a propylene polymer composition containing at least 0.8% by weight of one or more comonomers selected from the group consisting of ethylene and C4-C10 &agr;-olefins, and having I) a melting temperature of 155° C. or higher; and II) a xylene soluble fraction at room temperature lower than 4% by weight, and a value of the ratio of the polymer fraction collected at 25° C. to 95° C. to the xylene soluble fraction higher than 8.

Abstract: The present invention discloses methods for enhancing the wear-resistance of polymers, the resulting polymers, and in vivo implants made from such polymers. One aspect of this invention presents a method whereby a polymer is irradiated, preferably with gamma radiation, then thermally treated, such as by remelting of annealing. The resulting polymeric composition preferably has its most oxidized surface layer removed. Another aspect of the invention presents a general method for optimizing the wear resistance and desirable physical and/or chemical properties of a polymer by crosslinking and thermally treating it. The resulting polymeric compositions is wear-resistant and may be fabricated into an in vivo implant.

Abstract: Long-chain, branched, propylene-based polymers, of which the melt index and the molecular weight distribution and the melt tension and the limiting viscosity both satisfy specific requirements, have good physical properties that are comparable to or better than those of conventional propylene-based polymers. They have good melt workability and are favorable to large-size blow molding and extrusion foaming. They are favorably used as miscibility improvers for propylene homopolymers and propylene-based copolymers.

Abstract: The propylene polymer of the invention is transparent and has good low-temperature heat-sealability and scratch resistance, and is favorable to wrapping and packaging films. (1) The polymer has a melting point, Tm (° C.), measured through differential scanning calorimetry, of 110≦Tm≦140; (2) its heat of fusion &Dgr;H (J/g) and melting point Tm (° C.) satisfy &Dgr;H≧0.45×Tm+22; (3) the half-value width Th (° C.) of the peak top of its elution curve obtained in programmed-temperature fractionation is Th≦5; and (4) its intrinsic viscosity [&eegr;] (dl/g) measured in a solvent of tetralin at 135° C. falls between 0.5 and 5.

Abstract: Olefin polymers produced using components of catalysts obtained by contacting a Ti compound of formula Ti(OR)n-yXy, where n is the valence of titanium and y is a number between 1 and n, with a pre-polymer having a porosity higher than 0.3 cc/g and containing from 0.5 to 100 g of polymer per g of solid catalyst component, the pre-polymer being obtained by (co)polymerizing an olefin or a diolefin in the presence of a catalyst comprising a Ti, V, Zr or Hf compound supported on a Mg dihalide having a mean crystallite dimension lower than 30 nm.

Abstract: The present invention provides a polyolefin resin for hot melt adhesives containing [I] a propylene polymer in an amount of 20 to 99 mass %, and [II] an adhesive capacity applying resin in an amount of 80 to 1 mass %, wherein [I] the propylene polymer satisfies the requirements of (1) a meso pentad fraction (mmmm) is from 0.2 to 0.6; and (2) a racemic pentad fraction (rrrr) and (1−mmmm) satisfy the relation: [rrrr/(1−mmmm)]≦0.1. The polyolefin resin for hot melt adhesives is superior in thermostability or flowing ability at high-temperature, easy for coating, environmentally friendly with little fear of generating toxic gas in the disposal and incineration, superior in adhesive property to lowly polar substances and in heat resistance of the adhesion face.

Abstract: Provided are a propylene homopolymer in which a melt tension (MT), a Z average molecular weight (Mz) and a melt index (MI) (g/10 minutes) are specifically related and in which a difference in eluting temperatures and a maximum eluting temperature in programmed temperature fractional chromatography and a propylene copolymer in which a comonomer is specific &agr;-olefin and a content thereof falls in a specific range and in which a melt tension (MT), a Z average molecular weight (Mz) and a melt index (MI) (g/10 minutes) are specifically related. The propylene homopolymer or the propylene copolymer of the present invention has physical properties equivalent to or not lower than those of conventional propylene polymers, and it can be controlled in a melt tension and is suited to foaming molding, sheet molding and blow molding.

Abstract: The invention refers to a linear, isotactic polymer which has a structure of one or several C2 to C20 olefins, of which the isotacticity, due to a statistic distribution of stereoscopic errors in the polymer chain, is within the range of from 25 to 60% of [mmmm] pentad concentration with the proviso that an arbitrary or rather regular sequence of isotactic and atactic blocks is excluded, the polymer having a mean molecular weight Mw within the range of from 100,000 to 800,000 gms/mol and a TG of from −50 to +30.

Abstract: A process for preparing olefinic living polymers having a molecular weight distribution (Mw/Mn) of 1 to 1.3, comprising polymerizing an olefinic monomer having 2 to 20 carbon atoms at low temperatures in the presence of a catalyst comprising (A) a hafnium or zirconium-containing compound having one or two cyclopentadienyl backbones, (B) a triphenyl boron compound or a tetraphenyl borate compound and optionally (C) a specific mono-, di- or trialkylaluminum compound. When the catalyst comprising the zirconium-containing compound is prepared by further using a titanium-containing compound (D), the polymerization temperature can be raised.

Abstract: Bis(salicylaldiminato)titanium complex with optionally substituted phenyl or cyclohexyl on nitrogen catalyzes highly syndiospecific polymerization of propylene. Syndiotactic polypropylene with defects of the type rmr having [rrrr] content greater than 0.70 and block copolymer containing block(s) of the syndiotactic polypropylene and block(s) of poly(ethylene-co-propylene) and/or poly(alpha-olefin-co-propylene) are obtained. Certain of the catalysts provide living polymerization. Living olefin polymers and olefin terminated oligomers and polymers are also products.

Abstract: Embodiments of the present invention include a polypropylene homopolymer synthesized from a metallocene catalyst system and methods of forming the homopolymer, the homopolymer having an aluminum and chlorine recoverables value of less than 25 ppm and a xylene solubles of less than 1 wt % relative to the total weight of the homopolymer. The resulting homopolymer has other desirable properties such as a heat deflection temperature at 0.45 MPa of from 90° C. to 110° C., and a MWD value of from 1.7 to 5.0. These properties make embodiments of the homopolymer desirable for films, and in particular for capacitor films.

Abstract: This invention relates to propylene homopolymer compositions obtained from metallocene catalysis wherein the polymer has a molecular weight distribution (Mw/Mn) in the range of from 4.0 to 20.0. The propylene homopolymer composition may be prepared in a multiple stage polymerization process using the same metallocene component in at least two stages. The composition may comprise isotactic homopolymer in one embodiment, and have a hexane extractables of less than 2 wt % in one embodiment. The composition is useful in making films.

Abstract: An object of the present invention is to provide a novel propylene-based polymer capable of providing a propylene-based polymer with a good adhesion and coatability.

Abstract: Industrial polyolefin piping system with improved stiffness, impact strength for use at high service temperature, comprising single or multilayer pipes, fitting, chambers, valves and vessels, consisting of &bgr;-nucleated propylene homopolymers with an IR&tgr;≧0.98 having a tensile modulus ≧1500 MPa, a Charpy impact strength, notched, at +23° C.≧30 kJ/m2 and a Vicat B temperature >90° C. and a Heat Distortion Temperature >100° C. The industrial polyolefin piping system is suitable for chemical plant constructions comprising single or multilayer pipes, fittings, chambers, valves and vessels with improved stiffness, impact strength and high service temperature, preferred for conveyance of natural gas, dangerous liquids and/or toxic liquids.

Abstract: The invention relates to a thermoplastic vulcanizate comprising four components (A, B. C, D), notably: a thermoplastic (A); a substantially non-cross-linked polyethylene (B); an at least partially vulcanized rubber (C); a softener (D); as well as standard blend ingredients (E). The above mixture contains between 5 and 20% by weight thermoplastic (A), in relation to the sum of the four components (A, B, C, D). The invention also relates to advantageous material parameters and process steps.

Abstract: A process for preparing olefin homopolymers or copolymers by polymerization of at least one olefin in a hydrocarbon (mixture) in the presence of a molar mass regulator, a mixed catalyst and a substance which increases the electrical conductivity of the hydrocarbon (mixture) and is soluble in the hydrocarbon or the mixture of hydrocarbons or which reacts with components of the mixed catalyst, wherein the mixed catalyst is obtainable by reaction of a magnesium alkoxide with titanium(IV) halide and comprises titanium in the oxidation states four and three and also an organic aluminum compound, where the molar ratio of Ti(IV) to Ti(III) is from 100:1 to 1:100.

Abstract: The present invention relates to a transition metal compound represented by the general formula (I), and a olefin polymerization catalyst comprising above transition metal compound and activating co-catalyst as the main components. (wherein, M represents a metal element in the groups 3 to 10 of the periodic table or in the lanthanoide series, X represents a &sgr; bonding ligand bonded to M, Y represents a Lewis base, A represents a cross-linking group, p is an integer of 1 to 20, q is an integer of 1 to 5 and represents [(valence of M)−2], r is an integer of 0 to 3. R1 represents a group in above R2 to R9 except hydrogen atom). The present invention provides a transition metal compound useful for olefin polymerization catalyst, and olefin polymerization catalyst using above compound.

Abstract: A new class of methylene-bridged metallocenes of formula (I), wherein M is a transition metal of group 3, 4, 5, 6, lanthanide or actinide; X is a monoanionic sigma ligand; R1 can be alkyl, cycloalkyl, aryl, alkylaryl or arylalkyl radicals; R2 can be halogen, alkyl, cycloalkyl, aryl, alkylaryl or arylalkyl radical; p is 0-3; m is 0-2; and n is 0-4. Furthermore, the corresponding ligands, a new process for their preparation and catalysts systems containing said methylene-bridged metallocenes are described.

Abstract: This invention relates to a polymer comprising one or more C3 to C40 olefins, optionally one or more diolefins, and less than 15 mole % of ethylene, where the polymer has:

Abstract: Propylene polymers containing from 0 to 2.5% by weight of C2-C10-olefin comonomers have an Mw of from 350,000 to 1,000,000 g/mol, an Mw/Mn of from 4 to 10, a proportion by weight of the polymer fraction having a viscosity number of from 500 to 1400 ml/g of from 20 to 80% of the total polymer and a proportion by weight of a polymer fraction having a viscosity number of from 200 to 400 ml/g of from 80 to 20% of the total polymer and an isotactic sequence length of from 50 to 100.

Abstract: A process for polymerizing olefins using a catalyst system comprising a conventional Ziegler-Natta catalyst and an external election donor selected from the group consisting of diethers and combinations thereof. The catalyst system comprises a Ziegler-Natta catalyst having a transition metal compound generally represented by the formula: MR′x where M is a transition metal, R′ is a halogen or a hydrocarboxyl, and x is the valence of the transition metal. The transition metal compound can be TiCl4. The Ziegler-Natta catalyst may comprise an internal electron donor, such as phthalate. The catalyst system further includes an external electron donor selected from the group consisting of diethers and a co-catalyst selected from the group of organoaluminum compounds. In one embodiment, the external electron donor is 2,2-diisobutyl-1,3-dimethoxypropane, and the co-catalyst is triethylaluminum.

Abstract: A propylene polymer is characterized by satisfying the following (1) to (5): (1) a melt flow rate (MFR) measured at 230° C. under a 2.16 kg load of from 0.1 to 1000 g/10 min; (2) an isotactic triad traction (mm) measured by 13C-NMR of 99.0 % or above; (3) a Q value measured by gel permeation chromatography (GPC) of from 2.0 to 6.0; (4) a relation between melt flow rate (MFR: g/10 min) measured at 230° C. under a 2.16 kg load and a memory effect (ME) measured at 190° C. at an orifice diameter of 1.0 mm satisfying the following formula (I): 1.75≧(ME)+0.26×log(MFR)≧1.40  (I); and (5) a relation of the cold xylene solubles at 23° C. (CXS) satisfying the following formula (II) CXS≦0.5×[C2]+0.2×log(MFR)+0.5  (II) wherein [C2] represents the ethylene unit content (% by weight) in the polymer.

Abstract: The invention is directed to a polypropylene resin which has a Mw/Mn of less than 5, a melt flow rate of less than 7 g/10 min., a 1% secant flexural modulus of greater than 300,000 psi and less than 2 wt. % xylene solubles.

Abstract: Shear-thinning ethylene/&agr;-olefin and ethylene/&agr;-olefin/diene monomer interpolymers that do not include a traditional branch-inducing monomer such as norbornadiene are prepared at an elevated temperature in an atmosphere that has little or no hydrogen using a constrained geometry complex catalyst and an activating cocatalyst.

Abstract: A polyolefin plaque is made by hot compaction of an assembly of fibres of the oriented polymer. It has been found to be beneficial to subject the fibres to a prior crosslinking process. Hot compaction is then less temperature-sensitive and produces plaques with excellent hot strength properties. Preferably the fibres have been subjected to prior stages of irradiation and annealing, both in a non-oxidising environment, for example acetylene.

Abstract: A method of preparing ultra high melt flow polypropylene having reduced xylene solubles is provided. The method utilizes a diether internal donor-containing Ziegler-Natta catalyst system to polymerize propylene. The polypropylene produced is characterized by having a melt flow of at least about 300 g/10 min and a xylene solubles of not more than about 3.5% and no peroxide residue. The catalyst system may also include an internal phthalate donor. The method of the invention allows the amount of external donors to be reduced, or even eliminated, without significant increases in xylene solubles.

Abstract: New ligands, compositions, metal-ligand complexes and arrays with pyridyl-amine ligands are disclosed that catalyze the polymerization of monomers into polymers. Certain of these catalysts with hafnium metal centers have high performance characteristics, including higher comonomer incorporation into ethylene/olefin copolymers, where such olefins are for example, 1-octene, isobutylene or styrene. Certain of the catalysts are particularly effective at polymerizing propylene to high molecular weight isotactic polypropylene in a solution process at a variety of polymerization conditions.

Abstract: Certain specific embodiments of the inventions will now be discussed. For example, a process of preparing a copolymer composition that includes a diene-modified polypropylene copolymer is described, which process includes: contacting a metallocene catalyst compound with a polymerization medium that includes at least a propylene monomer and an &agr;, internal non-conjugated diene monomer; and conducting polymerization of the monomers in the presence of the metallocene catalyst compound for a time sufficient to provide a diene-modified polypropylene random copolymer that includes monomeric units derived from each of the monomers, and having from 0.0 wt % to 2.0 wt % ethylene and a heat of fusion of 25 J/g or more.

Abstract: Branched crystalline polypropylene compositions and methods for the preparation of branched crystalline polypropylene compositions are provided. For example, described herein is a process of preparing branched crystalline polypropylene composition that comprises contacting a supported metallocene catalyst compound with a polymerization medium that comprises propylene monomers; and conducting polymerization of the propylene monomers at a temperature greater than 70° C. for a time sufficient to provide branched crystalline polypropylene that has from 0.0 wt % to 2.0 wt % ethylene and a heat of fusion of 70 J/g or more.

Abstract: The present invention concerns high-stiffness polymer composition and a process for producing a polymer composition by nucleated with a polymeric nucleating agent containing vinyl compound units. The method comprises modifying a catalyst by polymerizing a vinyl compound in the presence of said catalyst and a strongly coordinating donor in a medium, which does not essentially dissolve the polymerized vinyl compound, and by continuing the polymerization of the vinyl compound until the concentration of unreacted vinyl compounds is less than about 0.5 wt-%. The thus obtained modified catalyst composition is used for polymerizing propylene optionally together with comonomers in the presence of said modified catalyst composition. Modification of the catalyst according to the present invention will reduce production costs and provide highly reliable catalyst activity and polymers of high stiffness.

Abstract: A process for producing a polyolefin-based resin composition comprises, in the first polymerization stage, polymerizing an &agr;-olefin having 4 to 20 carbon atoms, a styrene or a cyclic olefin in the presence of a specific catalyst and, in the second polymerization stage, copolymerizing the obtained polymer with an &agr;-olefin having 2 to 20 carbon atoms, a styrene or a cyclic olefin in the presence of a polyene. A polypropylene composition has a branching parameter a and a branching index g in specific ranges. The curve showing the change in viscosity under elongation with time, the degradation parameter D or the content of a high molecular weight component is specified. The polyolefin-based resin composition exhibits excellent uniformity and improved workability in melting due to improved tension in melted condition. The polypropylene composition exhibits excellent melting elasticity and secondary workability and provides foamed molded articles, sheets and blow molded articles.

Abstract: Disclosed herein are processes for polymerizing ethylene, acyclic olefins, and/or selected cyclic olefins, and optionally selected olefinic esters or carboxylic acids, and other monomers. The polymerizations are catalyzed by selected transition metal compounds, and sometimes other co-catalysts. Since some of the polymerizations exhibit some characteristics of living polymerizations, block copolymers can be readily made. Many of the polymers produced are often novel, particularly in regard to their microstructure, which gives some of them unusual properties. Numerous novel catalysts are disclosed, as well as some novel processes for making them. The polymers made are useful as elastomers, molding resins, in adhesives, etc.

Abstract: Substantially linear olefin polymers having a melt flow ratio, I10/I2, ≧5.63, a molecular weight distribution, Mw/Mn, defined by the equation: Mw/Mn≦(I10/I2)−4.63, and a critical shear stress at onset of gross melt fracture of greater than about 4×106 dyne/cm2 and their method of manufacture are disclosed. The substantially linear olefin polymers preferably have at least about 0.01 long chain branches/1000 carbons and a molecular weight distribution from about 1.5 to about 2.5. The new polymers have improved processability over conventional olefin polymers and are useful in producing fabricated articles such as fibers, films, and molded parts.

Abstract: The invention relates to catalyst components, suiitable for the sprtion of homnopolymats and copolymene of ethylene having a broad molecular weight distribution (MWD), which comprise Ti, Mg, Cl, and are characterized by the following properties: surface area, determined by BET method, of lower than 100 m2/g, a total poroslty, measured by the mercury method, of higher than 0.25 cm3/g, a pore radius distribution such that at least 45% of the total porosity is due to pores with radius up to 0.1 &mgr;m.

Abstract: A polypropylene-based calendered or injection-molded article satisfying the requirements of (1) having a tensile modulus TM of 5 MPa or higher and (2) having, when measured by a differential scanning calorimeter (DSC), no melting point or a melting point Tm (° C.) satisfying the formula: TM≧5×Tm−450, is less tacky and excellent in flexibility and transparency. Such a polypropylene-based calendered or injection-molded article is produced from a propylene polymer satisfying the requirements of (1) having a component soluble in a 25° C. hexane in a content H25 of 0 to 80% by weight; (2) having, when measured by a differential scanning calorimeter (DSC), no melting point or a melting point Tm (° C.) satisfying the formula: &Dgr;H≧6×(Tm−140) wherein &Dgr;H is a melting endotherm (J/g); and (3) having an intrinsic viscosity [&eegr;] of 1 to 3 dl/g as measured at 135° C. in tetralin.

Abstract: Provided is a catalyst for the polymerisation of olefins of general formula:

Abstract: A process for producing substantially amorphous propylene (co)polymers, comprising contacting propylene optionally in the presence of one or more olefins under polymerization conditions with a catalyst system comprising: A) a half sandwich titanium complex wherein the cyclopentadienyl is substituted with one or two heterocyclic rings, according to formula (I): cf formula (I) in claim 1: wherein X is N or P; Z is C, Si or Ge; Y1 is an atom selected from the group consisting of NR7, O, PR7 or S; Y2 is selected from the group consisting of CR8 or Y1 and m is 0 or 1 and B) an activating cocatalyst. The above titanium complex and the ligand useful as intermediates in their synthesis are also described.

Abstract: Use of isotactic polypropylene homopolymers or copolymers in processes in which the polypropylene solidifies from a melt, wherein for enhanced speed of solidification of the polypropylene the polypropylene has a melt temperature and a crystallisation temperature not more than 50° C. less than the melt temperature resulting from the polypropylene having been produced using a metallocene catalyst component having the general formula: R″(CpR1R2R3)(Cp′Rn′)MQ2. Cp and Cp′ are a substituted cyclopentadienyl ring, and a sybstituted or unsubstituted fluorenyl ring, respectively. R″ is a structural bridge; R1 is a substituent on the cyclopentadienyl ring distal to the bridge. The distal substituent comprises a bulky group of the formula XR*a; X is chosen from Group IVA. M is a Group IVB transition metal or vanadium and each Q is hydrocarbyl having 1 to 20 carbon atoms or is a halogen.

Abstract: Process for the polymerization of olefins CH=CHR, in which R is hydrogen or a hydrocarbon radical with 1-12 carbon atoms, carried out in the presence of a catalyst component (A) comprising Mg, Ti and halogen as essential elements and of a catalyst component (B) capable to produce, under the same polymerization conditions, a polymer with an average particle size lower than that obtainable with the said catalyst component A. The said process provides polymers with increased bulk density.

Abstract: A block copolymer having structural formula A-B or A-B-A, wherein A is a crystallizable isotactic polypropylene block segment and B is an amorphous olefin elastomeric block segment; the novel crystallizable block copolymer may be used as it is as a molding material, or as a compatibilizer, a surfactant, a mechanical property improvement agent and the like for other polyemers.

Abstract: A polymerization process and a catalyst delivery system are provided. For example, a polymerization process is described, including providing a conduit having a catalyst inlet, a first propylene stream inlet located downstream of the catalyst inlet, and a second propylene stream inlet located downstream of the first propylene stream inlet, the conduit being operably connected to a polymerization vessel, introducing a catalyst to the conduit through the catalyst inlet, and passing the catalyst through the conduit to the polymerization vessel. The process may further include introducing a first propylene stream to the conduit to provide a mixed catalyst stream downstream of the catalyst inlet. The process may additionally include stopping the flow of the catalyst passing through the conduit, introducing a second propylene stream to the conduit through the second propylene stream inlet, removing a section of the conduit, and replacing the removed section of the conduit with a different conduit section.

Abstract: A polymerization process is provided. For example, a polymerization process is described, including contacting olefin monomers with a supported metallocene catalyst to polymerize the olefin monomers and form a product mixture that includes polyolefins macromers or polymers, unreacted or partially reacted olefin monomers, alcohols and organohalides. The polymerization process further includes removing a portion of the product mixture to form a recycle stream and passing the recycle stream through a removal device comprising zeolite particles having pore size of from 6 to 16 Å to transfer at least a portion of the alcohols and organohalides from the recycle stream to the removal device providing a purified recycle stream having alcohols and organohalides in an amount of 1 ppm or less. The polymerization process may further include contacting at least a portion of the purified recycle stream with the supported metallocene catalyst to form polyolefins.

Abstract: The present invention relates to a method for the prepolymerization of &agr;-olefin in the presence of a catalyst system which comprises (a) a magnesium supported solid complex titanium catalyst and (b) an organometallic compound of metal of Group I or III of the Periodic Table, characterized in that an inert solvent having high viscosity with molecular weight of 300 g/mole or more is used as a reaction medium.

Abstract: Disclosed are polypropylene homopolymers, copolymers and mono and polyfunctional polypropylene derivatives as well as methods of preparing them. These polymers are prepared in the èresence of a metallocene catalyst and are isotactic. Applications using these polymers include but are not limited to, electrophotography toners, melt facture reduction agents, and compatibilizers.

Abstract: The present invention relates to a polymerizable composition comprising a) at least one ethylenically unsaturated monomer and b1) at least one multifunctional triazinyl based 2,2,6,6 tetramethylpiperidine-1-oxyl and a free radical initiator or b2) at least one multifunctional triazinyl based 2,2,6,6 tetramethylpiperidine-1-oxyl-ether. Further aspects of the present invention are a process for polymerizing ethylenically unsaturated monomers, the (co)polymers obtainable by this process and the use of multifunctional triazinyl based 2,2,6,6 tetramethylpiperidine-1-oxyls in combination with a free radical initiator, or a multi-functional triazinyl based 2,2,6,6 tetramethylpiperidine-1-oxyl-ethers for controlled polymerization. In a particularly preferred embodiment at least one additional heating step at a temperature from 140 to 280° C. is applied after polymerization is completed.

Abstract: This process for preparing a catalyst support for the homopolymerization or copolymerization of ethylene and &agr;-olefins is characterized in that at least one organochlorine compound and a premix of at least one alkylmagnesium and of at least one organoaluminum compound chosen from aluminoxanes, aluminosiloxanes and alkylaluminums are reacted together, in the presence of at least one aliphatic diether as electron donor.

Abstract: It has been discovered that using n-butylmethyldimethoxysilane (BMDS) as an external electron donor for Ziegler-Natta catalysts can provide a catalyst system that may prepare polypropylene films with improved properties. The catalyst systems of the invention provide for controlled chain defects/defect distribution and thus a regulated microtacticity. Consequently, the curve of storage modulus (G′) v. temperature is shifted such that the film achieves the same storage modulus at a lower temperature enabling faster throughput of polypropylene film through a high-speed tenter.

Abstract: A process for the preparation of an olefin polymerization catalyst component containing a magnesium dihalide, a titanium tetrahalide, and a dicarboxylic acid di- oligo- or polyester as internal electron donors is disclosed. A catalyst component and its use for the polymerization of &agr;-olefins such as propene are also disclosed.

Abstract: A process for preparing propylene polymer comprising contacting, under polymerization conditions, propylene and optionally ethylene, with a catalyst system comprising a bridged metallocene and a suitable activating cocatalyst, said process being characteized by reducing the concentration of hydrogen formed during the polymerization reaction.

Abstract: The present invention relates to methods of producing syndiotactic polypropylene articles through high performance nucleation via the presence of certain novel nucleating agents within molten syndiotactic resins, and subsequently permitting the resultant molten mixture to cool into a selected shape or configuration. Such novel nucleating agents are new classes of hyper-nucleators that promote crystallization within such target syndiotactic resins at levels well above any previously disclosed nucleators. This invention thus also encompasses the articles and compositions of such nucleated syndiotactic polypropylene as well.