Abstract: 2-alkyl-4-(2,6-dialkylphenyl) indenes, methods for the synthesis thereof, methods for converting such indenes to bridged metallocene ligands, methods for converting such ligands to bridged metallocenes and olefin polymerization processes in which such metallocenes are used as a catalyst or as a component of a catalyst system are described.

Abstract: In the polymerization of C3-C12-&agr;-olefins, the activity of the catalyst and the isotacticity and molecular weight of the polymer product can be adjusted and improved in a controlled manner by a new process wherein A) a catalyst system is prepared by bringing a support which comprises magnesium chloride, a derivative thereof or a reagent forming it into contact with at least titanium tetrachloride or a reagent forming it, in order to produce a titanated support; by bringing the titanated support into contact with at least a group 1, 2 or 13 metal compound which contains a C1-C10-alkyl and activates titanium tetrachloride to a catalytically active titanium group, in order to produce an activated support; and by bringing a substance selected from among the said support, titanated support and activated support into contact with at least one donor or a reagent forming it, in order to produce a catalyst system B) polymerization is carried out using the catalyst system by bringing it into contact with at least

Abstract: Microspheres comprise a polymer including one or more of 1) a plurality of C3 or larger alpha-olefin units wherein the C3 or larger alpha-olefin units are incorporated into the polymer so as to give an average number of less than one branch point per C3 or larger alpha-olefin unit, 2) a plurality of C2 alpha-olefin units wherein the C2 alpha-olefin units are incorporated so as to give an average number of branch points greater than 0.01 per C2 alpha-olefin unit, and 3) cyclopentene or substituted cyclopentene, the microspheres having an average diameter in the range of 1 to 300 micrometers. Optionally, the polymer of the microspheres can be crosslinked. The microspheres can be prepared by suspension or dispersion polymerization processes using aqueous or organic reaction media. Powder coatings can be prepared from the microspheres.

Abstract: Disclosed are a propylene polymer having a high crystallinity of a boiled heptane-insoluble component contained therein, a high stereoregularity and an extremely long mesochain (continuous propylene units wherein directions of &agr;-methyl carbons are the same as each other), and a process for preparing said polymer. Further disclosed is a propylene polymer composition comprising the above propylene polymer and at least one stabilizer selected from a phenol type stabilizer, an organophosphite type stabilizer, a thioether type stabilizer, a hindered amine type stabilizer and a metallic salt of higher aliphatic acid. The propylene polymer of the invention is excellent in rigidity, heat resistance and moisture resistance, and can be favorably used for sheet, film, filament, injection molded product, blow molded product, etc.

Abstract: The present invention relates to a solid catalyst component for the polymerization of olefins CH2═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): wherein R1 is a C1-C20 linear or branched alkyl, C3-C20 alkenyl, C3-C20 cycloalkyl, C6-C20 aryl, arylalkyl or alkylaryl group; R2 is a C1-C20 linear alkyl, C3-C20 linear alkenyl, C6-C20 aryl, arylalkyl or alkylaryl group; R3 and R4 are independently selected from the group consisting of C1-C3 alky, cyclopropyl, with the proviso that when R1 is C1-C4 linear or branched alkyl or alkenyl, R2 is different from R1. 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: An organic aluminoxy compound which shows 27Al nuclear magnetic resonance spectrum (27Al-NMR spectrum) having an A1/A2 ratio of at most 0.1, wherein A1 is area of a region encompassed by a segment of a line which connects a local minimum point existing between a continuous curve “a” containing a peak appearing at around 150 ppm and a continuous curve “b” containing a peak appearing at around 60 ppm to the point where the above curve “b” comes into contact with the base line and also by the above curve “b” and A2 is area of a region encompassed by the above curves “a” and “b” and also by the base line; an organic aluminoxy compound containing at least 5%, expressed in terms of aluminum atom, of a portion insoluble in a mixed solvent of toluene and hexane in a ratio by volume of 2:5 at 30° C. or lower; and a catalyst for producing a polymer comprising any of the above organic aluminoxy compounds and a transition metal compound.

Abstract: Process for the manufacture of a composition comprising ethylene polymers, in at least two polymerization reactors connected in series, according to which, in a first reactor, from 30 to 70% by weight with respect to the total weight of the composition of an ethylene homopolymer (A) having a melt flow index MI2 of 5 to 1000 g/10 min is formed and, in a subsequent reactor, from 30 to 70% by weight with respect to the total weight of the composition of a copolymer of ethylene and of hexene (B) having a melt flow index MI5 of 0.01 to 2 g/10 min is formed. The compositions obtained by this process exhibit a good compromise between the processing properties and the mechanical properties, which renders them capable of being used in the manufacture of articles shaped by extrusion and extrusion blow-molding, such as films and pipes.

Abstract: A class of bridged or unbridged metallocene compounds is disclosed, wherein the cyclopentadienyl ligands have two or four adjacent substituents forming one or two alkylenic cycles of from 4 to 8 carbon atoms.

Abstract: It is disclosed a new class of bridged metallocene compounds of formula (I): wherein R1 and R2 can be hydrogen, alkyl, cycloalkyl, aryl, alkylaryl or arylalkyl radicals; R3 and R4 form a condensed, 5- to 8-membered, aliphatic, aromatic or heterocyclic ring; M is a transition metal of groups 3, 4, 5, lanthanide or actinide; X is hydrogen, halogen, —R, —OR, —OSO2CF3, —OCOR, —SR, —NR2 or PR2, wherein R is an hydrocarbon substituent; and p is 0-3. Furthermore, a catalyst system for olefin polymerization based on the above bridged metallocene compounds and the ligands for their preparation are disclosed.

Abstract: A propylene polymeric composition with elastic character that is soluble in at least one nonpolar organic solvent selected from the group consisting of toluene, xylene, heptane, and hexane, comprises greater than 3 weight percent and up to 45 weight percent homotactic sequences each having only r or m diads, all of which homotactic sequences have a helical length in the range of 20 to 150 Å, and in the range of 55 to 97 weight percent of the sum of homotactic sequences of less than 20 Å in helical length, each homotactic sequence having only r or m diads and having fewer than 10 repeat units with mmmm pentads being present in the range of 0 to 35 weight percent of the total composition, and heterotactic sequences having r and m diads of unequal number, the polymer having a molecular weight (Mw) of at least 70,000.

Abstract: A C1 symmetric metallocene compound of general formula R″(CpRb)CP′R′m) MQp for use as a catalyst component in the production of short sequence syndiotactic/isotactic block polyolefins, where Cp is a substituted cyclopentadienyl; each R is independently aryl or hydrocarbyl having 1 to 20 carbon atoms, at least position 3 of Cp is substituted with aryl, at least one other position of Cp is substituted with a non-bulky substituent, and n is an integer in the range from 2 to 4; Cp′ is substituted or unsubstituted fluorenyl; each R′ is independently hydrocarbonyl having 1 to 20 carbon atoms and m is O or an integer in the range from 1 to 8; R″ is a structural bridge to impart stereorigidity between Cp and Cp′; M is a metal from Group IIIB, IVB, VB or VIB; Q is a hydrocarbyl radical having 1 to 20 carbon atoms or a halogen; and p is the valence of M minus 2.

Abstract: A polymerizable composition comprises an alpha-olefin hydrocarbon monomer, an effective amount of an organometallic catalyst of a Group VIII metal, preferably Ni or Pd, and at least one of water and air. Novel catalysts for polymerizing alpha-olefin hydrocarbon monomers provide improved processes and products. Methods of the invention include polymerizing the composition in open air and in the presence of water to provide novel polymers.

Abstract: Disclosed are a thermoplastic elastomeric polypropylene (and other olefin homopolymerized polymers) made using a metallocene catalyst and a single olefin monomer, and a method of preparing the same to produce a chain of alternating stereo regular crystallizable segments and stereo-irregular non-crystallizable polymerized segments, the former acting as physical crosslinks between tee non-crystallizable segments to form a thermoplastic elastomeric material having good elastomeric properties.

Abstract: A catalyst composition comprises at least two different polymerization catalysts of which a) at least one is a polymerization catalyst based on an early transition metal component and b) at least one is a polymerization catalyst based on a late transition metal component.

Abstract: The invention enables solution modification of a polyolefin with an unsaturated anhydride, unsaturated acid, or unsaturated ester, with high efficiency without the formation of undesirable impurities resulting from the competing reaction of the solvent with the unsaturated anhydride, unsaturated acid, or unsaturated ester. The process entails combining a polyolefin; a solvent; an unsaturated anhydride, unsaturated acid or unsaturated ester and a free-radical initiator to form a reaction mixture. The solvent is selected from the group consisting of substituted aromatic solvents which do not contain benzylic hydrogens and mixtures thereof. This reaction mixture is reacted under suitable conditions to produce a modified polyolefin.

Abstract: A process for preparing homopolymers and copolymers of addition polymerizable monomers, or mixtures of such monomers, and the resulting polymer, wherein the process comprising contacting said monomer or mixture under high monomer conversion polymerization conditions with a catalyst composition comprising: a) a catalyst system comprising a Group 3-10 metal complex; and c) a silane, or hydrocarbylsilane corresponding to the formula: JjSiH4−j or AnJjSiH4-(n+j)  wherein: J is C1-40 hydrocarbyl, A is a C2-20 alkenyl group, n is 1 or 2, and j is 0 or 1; wherein the polymer comprises from 0.1 to 100 long chain branches per 10,000 carbons, and at least some of which comprise a silane branching center.

Abstract: There is provided a catalyst containing a transition metal precursor having the formula (C5R15)MX3, an alcohol, a substituted bulky phenol, an aluminoxane, and optionally a support or spray drying material. There is also provided a polymerization process employing the catalyst composition, a polymer produced using the catalyst, and a cable produced therefrom.

Abstract: This invention is for a process for the polymerization of propylene to a minimum level of xylene solubles by use of the molar ratio of co-catalyst to external electron donor (selectivity control agent). Using a conventional supported heterogeneous Ziegler-Natta catalyst component with an trialkyl aluminum co-catalyst and an cycloalkylalkyldialkoxysilane external electron nor (selectivity control agent) in a Al/Si molar ratio of about results in the minimum amount of xylene solubles.

Abstract: A process for polymerizing addition polymerizable monomers using hafnocenes catalysts/catalyst precursors having a selected symmetry condition under condensed polymerization conditions where the symmetry condition is such that the resulting polymer has varying degrees of tactioselectivity or copolymers having regions of varying degrees of tactioselectivity. Preferred classes of the haflocenes are capable of generating near pure isospecific and syndiospecific polymers in solution or in bulk polymerization conditions.

Abstract: The invention relates to novel Thermoplastic Olefin compositions comprising polypropylene, and ethylene-alpha olefin elastomer and a compatabilizer comprising an ethylene-propylene copolymer having a propylene content of greater than 80 weight percent. The ethylene-propylene copolymer compatabilizer imparts a greater degree of compatibility between the polypropylene and elastomer phases yielding improved physical properties.

Abstract: The invention provides a metallocene catalyst for use in preparing syndiotactic/isotactic block polyolefins. The catalyst comprises a bridged metallocene in which one of the cyclopentadienyl rings is substituted in a substantially different manner from the other ring and the cyclopentadienyl rings have lack of bilateral or pseudo-bilateral symmetry.

Abstract: Provided is polyolefin composition, the majority of which is highly isotactic polypropylene, comprising the property of heat of melting (&Dgr;Hm) greater than or equal to about 89 J/g.

Abstract: The invention relates to metallocenes of formula (I), in which M is a metal from the Ti, Zr, Hf, V, Nb, Ta group or an element from the lanthanide group, X1 and X2 stand for an alkyl-, aryl-, alkenyl-, arylalkyl-, alkylaryl- or arylalkenyl group and L1 and L2 are hydrocarbon capable of forming a sandwich structure with M. R stands for C, Si, Ge or Sn, A and B are ferrocenyl-substituted radicals, or B is optionally a radical X1 of X2. The metallocenes are preferably used as catalysts in the polymerization of olefins.

Abstract: Polymers of alkenes are prepared by suspension polymerization in the presence of catalyst systems by a process in which the catalyst systems used are supported catalyst systems obtainable by

Abstract: Ionic catalyst compositions can be prepared by combining two components. The first component is a bis(cyclopentadienyl) Group IV-B metal complex containing at least one ligand which will combine irreversibly with the second component or at least a portion thereof such as a cation portion thereof. The second component comprises a cation which will irrevesibly react with at least one ligand on the Group IV-B metal complex and a non-coordinating anion. The combination of the two components produces an ionic catalyst composition comprising a cationic bis(cyclopentadienyl) Group IV-B metal complex which has a formal coordination number of 3 and a 4+ valence charge and the aforementioned non-coordinating anion.

Abstract: Porous particles of MgCl2 having the form of essentially regular polyhedrons with six or eight faces in which the paired symmetrically opposite faces are essentially parallel, two of which faces are large and elongated and form the too face and the bottom face of a polyhedron such that on each of them the longest diagonal (D) is larger than the shortest distance (d) separating two opposite sides, which large elongated faces are surrounded essentially perpendicularly by the other essentially rectangular faces that form the sides of the said polyhedron, the length of the smaller side (e) of each of the said essentially rectangular faces being less than the shortest distance (d) separating the two opposite sides of the large elongated faces, catalytic components supported on the particles, catalyst systems utilizing the catalytic products, process for making the particles, and polyolefins obtained utilizing the catalytic systems.

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: Process for the gas-phase polymerization of olefins of the formula CH2═CHR where R is hydrogen or an alkyl or aryl radical with 1 to 8 carbon atoms carried out in one or more reactors having a fluidized or mechanically agitated bed, using a catalyst obtained by reaction of a titanium halide or haloalcoholate and optionally an electron-donor compound supported on an active Mg-dihalide with an Al-trialkyl compound and optionally an electron-donor compound, comprising the steps of: a) contacting the catalyst components in the absence of polymerizable olefin or optionally in the presence of said olefin in an amount to from up to 3 g per g of solid catalyst component; b) prepolymerizing propylene or mixtures of propylene with ethylene or an alpha-olefin to form a propylene polymer having an insolubility in xylene of at least 60% by weight, in an amount of from 5 g of polymer per g of solid catalyst component to 10% by weight of the final catalyst yield; and c) polymerizing one or more CH2═CHR olefins

Abstract: Branched polypropylene compositions which have improved melt strength and good processability are provided. The branched polypropylene compositions of the present invention have a polydispersity of less than 4.0 and a melt point greater than 90° C. Further, the weight average branching index g of the polypropylene compositions is less than 0.95. Additionally, a novel process is provided for efficiently producing a branched polypropylene composition comprising: a) contacting propylene monomers in a reactor with an inert hydrocarbon solvent or diluent and a catalyst composition comprising one or more single site catalyst compounds capable of producing stereospecific polypropylene at a temperature from about 40° C. to about 120° C., wherein the ratio in the reactor of the propylene monomers to the inert hydrocarbon solvent or diluent is less than 9.

Abstract: Syndio-isoblock polymers of 1-olefins having molecular chains which contain syndiotactic and isotactic sequences are obtained if the polymerization of the 1-olefins is carried out using a catalyst which is composed of a bridge chiral metallocene of the formula I an an aluminoxane. The polymers have some rubber-like properties.

Abstract: Process for the manufacture of a composition comprising ethylene polymers, in at least two polymerization reactors connected in series, according to which, in a first reactor, from 30 to 70% by weight with respect to the total weight of the composition of an ethylene homopolymer (A) having a melt flow index MI2 of 5 to 1000 g/10 min is formed and, in a subsequent reactor, from 30 to 70% by weight with respect to the total weight of the composition of a copolymer of ethylene and of hexene (B) having a melt flow index MI5 of 0.01 to 2 g/10 min is formed. The compositions obtained by this process exhibit a good compromise between the processing properties and the mechanical properties, which renders them capable of being used in the manufacture of articles shaped by extrusion and extrusion blow-molding, such as films and pipes.

Abstract: Amorphous copolymers of ethylene with propylene, and optionally with minor amounts of polyenes, have the following characteristics: (A) the % content by mole of propylene in the copolymer (%P) and the triads ratio EPE/(EPE+PPE+PPP) satisfy the following relationship: 0.01%P+EPE/(EPE+PPE+PPP)≧1 (B) less than 2% of the CH2 groups in the chain are in sequences (CH2)n, wherein n is an even number. These copolymers are obtainable by operating in the presence of particular metallocene catalysts having two fluorenyl groups joined together through a bridging group.

Abstract: The present invention relates to a solid catalyst component for the polymerization of olefins, making it possible to obtain polymers or copolymers exhibiting a high Mz/Mw, generally higher than 3, and a high Mw/Mn, generally higher than 5.5. In the solid component according to the invention, titanium is present in a proportion of at least 2.5% by weight and a diester of phthalic acid is present in a proportion of less than 7% by weight.

Abstract: The invention is a polymerization process for ethylene copolymers having a density less than 0.915 comprising contacting ethylene, one or more &agr;-olefin monomer, and optionally one or more diene monomer, with a catalyst composition comprising the reaction product of at least one organometallic Group 4 metallocene compound derived from a bridged, fused-ring ligand containing biscyclopentadienyl hafnocene, said bridge being a substituted or unsubstituted carbon or silicon atom connecting the biscyclopentadienyl ligands, and a salt of a Group 13 element anionic complex having halogenated aromatic ligands in an essentially tetrahedral structure wherein the aromatic groups are polycyclic fused or pendant aromatic rings. The process is particularly suitable for the preparation of high comonomer content and high molecular weight ethylene-&agr;-olefin plastomers and ethylene-propylene or ethylene-propylene-diene monomer elastomers.

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: A system for pressurizing a propylene polymerization reactor includes: a pressurization vessel including an internal heat exchanger; a pressure sensor for monitoring the pressure in the vessel, the pressure sensor providing a signal indicative of the pressure in the vessel; a control valve for supplying heated gas to a first region of the vessel in response to signals from the pressure sensor, the first region of the vessel being maintained above the critical temperature and pressure of propylene; a temperature sensor for monitoring the temperature in a second region of the pressurization vessel, the temperature sensor providing a signal indicative of the temperature in the second region of the vessel; and a control valve for supplying a cooling medium to the internal heat exchanger to cool propylene in the second region below the critical temperature of propylene at the pressure in the pressurization vessel.

Abstract: The present invention teaches the use of particular soluble metallocene catalysts to produce stereoregular polymers in gas phase polymerizations wherein the catalysts are fed into a particular lean zone in the reactor. The metallocene catalysts are bridged bis(substituted indenyl) compounds.

Abstract: The invention provides a process for commercial production of syndiotactic polyolefins using a metallocene catalyst supported on silica treated with MAO. The invention includes contacting the supported metallocene catalyst with an aluminum alkyl and aging the catalyst prior to polymerization. In addition, the catalyst is prepolymerized in a tubular reactor prior to being introduced into the polymerization reaction zone. The treated silica is produced by removing water to a level of 0.5-1.08%, slurrying in a nonpolar solvent, adding an alumoxane, heating to reflux, cooling the slurry, and separating the solid product.

Abstract: A novel composition is disclosed comprising about 80 to about 99 weight percent based on the composition, of a linear ultra low density polyethylene (LULDPE) and about 1 to about 20 weight percent of a propylene polymer comprising 0 to about 40 weight percent olefin comonomer units having 2 to 10 carbon atoms and from about 60 to about 100 weight percent propylene, based on the propylene polymer, the propylene polymer having a Brookfield Thermosel viscosity of about 1 to about 30,000 mPa·s at 190° C. and a needle penetration of about 5 to about 300 dmm at 23° C. Also disclosed are films produced from the composition, both blown and cast, and both monolayer and multilayer. Also disclosed are processes for stretch wrapping and forming blown and cast film.

Abstract: Modified polypropylenes of improved processability are produced by a continuous method by absorptively charging polypropylene particles at 20° to 120° C. with a gas mixture, which contains oxygen and bifunctional, unsaturated monomers, and melting the mixture. The modified polypropylenes of improved processability as well as mixtures with unmodified polypropylenes are suitable for the production of films, sheets, fibers, panels, coatings, pipes, hollow objects and foamed materials.

Abstract: A propylene polymer made using a magnesium halide-supported, titanium-containing solid catalyst component having a broad processing window is produced by incorporating into the polymerization catalyst system a selected alkyl methyldimethoxysilane, preferably isobutylmethyl-dimethoxysilane. Useful articles made from such resin include OPP film.

Abstract: A polyolefin composition is provided which consists essentially of isotactic polypropylene and, optionally, repeating units of one or more comonomers, wherein the total comonomer repeating unit content of the polyolefin composition is from 0 to 20 mole percent, and further, wherein the weight average branching index g′ for the lower molecular weight region of the polyolefin composition is less than 0.93. Additionally, a process is provided for producing a polyolefin composition comprising: a) contacting, in solution, at a temperature from about 90° C. to about 120° C.

Abstract: Multiphase homo- or copolymers of C2-C10-alk-1-enes are prepared by a process in which polymerization is effected in the presence of two different catalyst systems in one reaction zone, one of the catalyst systems containing, as active components, a metallocene complex of the general formula (I) or (II) where M1 is a metal of group IVb, Vb or VIb of the Periodic Table, R1 and R2 are identical or different and are each hydrogen, C1-C10-alkyl, C1-C10-alkoxy, C6-C10-aryl, C6-C10-aryloxy, C2-C10-alkenyl, C7-C40-arylalkyl, C7-C40-alkylaryl, C8-C40-arylalkenyl or halogen, R3 and R4 are identical or different and are each hydrogen, halogen, C1-C10-alkyl which may be halogenated, C6-C10-aryl or an —NR210, —SR10, —OSiR310, —SiR310 or —PR210 radical, where R10 is halogen, C1-C10-alkyl or C6-C10-aryl, and R5 and R6 are identical or different and have the meanings stated for R3 and R4, with the proviso that R5 and R6 are not hydrogen.

Abstract: A novel composition is disclosed comprising about 85 to about 99 weight percent based on the composition of a polymeric ethylenic containing component having a density no greater than 0.94 g/cc, and about 1 to about 15 weight percent based on the composition, of a propylene polymer comprising 0 to less than about 1 weight percent based on the polymer, of olefin comonomer units and from about greater than 99 to 100 weight percent propylene, based on the polymer, the propylene polymer having a viscosity of about 1 to about 2,000 mPa.s at 190° C. and a needle penetration of about 5 to about 50 dmm at 23° C. Also disclosed are films produced from the composition, both blown and cast, and both monolayer and multilayer. Also disclosed are processes for stretch wrapping and forming blown film.

Abstract: An olefin polymer characterized by having (A) a density of from 0.850 to 0.940 g/cm3, (B) a melt flow rate (MFR) of from 0.1 to 200 g/10 minutes, and (C) a relation between the melt flow rate (MFR) and an intrinsic viscosity [&eegr;] measured in tetralin at 135° C. satisfying the range of the following equation (1): −4.04 log [&eegr;]+0.6≦log MFR≦−4.04 log [&eegr;]+0.96  (1) and its a film or sheet, and a method for producing an olefin polymer characterized by homopolymerizing an olefin or copolymerizing two or more olefins, with a catalyst for olefin polymerization, comprising: (A) a transition metal complex represented by the general formula [I] below; (B) at least one aluminum compound selected from (B1) to (B3); and/or (C) at least one boron compound selected from (C1) to (C3), at a temperature of at least 130° C. under a pressure of at least 300 kg/cm2G.

Abstract: The invention provides for highly crystalline syndiotactic polypropylene comprising a high percentage of racemic (r) dyads. The high crystallinity may be due to the polymerization mechanism of metallocene catalysts of a particular structure which appear to produce syndiotactic polypropylene of a new microstructure.

Abstract: There are provided a propylene-based polymer characterized in that (1) the xylene-extraction insoluble portion (XI) is 99.0 wt % or greater, (2) the isotactic pentad ratio (IP) is 98.0% or greater as measured by 13C nuclear magnetic resonance spectroscopy, (3) the isotactic average chain length (N) is 500 or greater, and (4) the total amount of each of the fractions obtained by column separation of the xylene insolubles whose average chain length (Nf) is 800 or greater accounts for 10 wt % or more of the entirety, and a method for its production, as well as a propylene-based polymer composition prepared by combining with this propylene-based polymer at least a nucleating agent in the range of 0.05-15 wt %. In addition, there are provided a polymerization catalyst component allowing the production of such a propylene-based polymer, and a method for its production.

Abstract: A thermoplastic elastomer is provided comprising a branched olefin polymer having crystalline sidechains and an amorphous backbone wherein at least 90 mole percent of the sidechains are isotactic or syndiotactic polypropylene and at least 80 mole percent of the backbone is atactic polypropylene. Additionally, a process is provided for producing a thermoplastic elastomer composition comprising: a) contacting, in solution, at a temperature from about 90° C. to about 120° C., propylene monomers with a catalyst composition comprising a chiral, stereorigid transition metal catalyst compound capable of producing isotactic or syndiotactic polypropylene; b) copolymerizing the product of a) with propylene and, optionally, one or more copolymerizable monomers, in a polymerization reactor using an achiral transition metal catalyst capable of producing atactic polypropylene; and c) recovering a branched olefin polymer.

Abstract: A process for the preparation of (i) polyethylene or (ii) polypropylene, which is essentially isotactic or a mixture of atactic and isotactic polypropylenes comprising contacting ethylene or propylene per se, or in admixture with one or more alpha-olefins, under polymerization conditions, with a catalyst system comprising: (a) a precatalyst comprising a mixture of racemic and meso stereoisomers of a metallocene catalyst containing two cycloalkadienyl ligands joined by a bridging linkage, said ligands complexed to a metal atom; and (b) (1) to obtain polyethylene catalyzed by the rac epimer only, a cocatalyst selected from the group consisting of tris(perfluorophenyl)borane and isobutyl alumoxane;  (2) to obtain polyethylene catalyzed by both the rac and the meso epimers, a cocatalyst selected from the group consisting of dimethylanilinium tetrakis(perfluorophenyl)borate and triphenylmethyl tetrakis(perfluorophenyl)borate;  (3) to obtain polypropylene, which is essentially isotactic, a cocatalyst

Abstract: The novel metallocenes of the formula I in which, preferably, M1 is Zr or Hf, R1 and R2 are alkyl or halogen, R3 and R4 are hydrogen, R5 and R6 are alkyl or haloalkyl, —(CR8R9)m—R7—(CR8R9)n— is a single- or multi-membered chain in which R7 may also be a (substituted) hetero atom, m+n is zero or 1, and R10 is hydrogen, form, together with aluminoxanes as cocatalysts, a very effective catalyst system for the preparation of polyolefins or high stereospecificity and high melting point. Polyolefins with unique or improved properties are obtained by polymerizing an olefin in the presence of a metallocene combined with a cocatalyst, wherein the metallocene is preferably a zirconocene or a hafnocene, and the Zr or Hf central atom is coordinated with two ligands which are derivatives of 2-substituted indenyl nuclei and which are substituted with at least one and up to four groups (e.g. aliphatic or aromatic groups) on the six-member rings of the indenyl nuclei.