Abstract: A new class of heterocyclic metallocenes, a catalytic system containing them and a process for polymerizing addition polymerizable monomers using the catalytic system are disclosed; the heterocyclic metallocenes correspond to the formula (I): YjR?iZjjMeQkPl wherein Y is a coordinating group containing a six ? electron central radical directly coordinating Me, to which are associated one or more radicals containing at least one non-carbon atom selected from B, N, O, Al, Si, P, S, Ga, Ge, As, Se, In, Sn, Sb and Te; R? is a divalent bridge between the Y and Z groups; Z is a coordinating group, optionally being equal to Y; Me is a transition metal; Q is halogen or hydrocarbon substituents; P is a counterion; i is 0 or 1; j is 1-3; jj is 0-2; k is 1-3; and l is 0-2.

Abstract: A catalyst system obtained by reacting at least one chiral transition metal compound and at least one cocatalyst, where the chiral transition metal compound is a transition metal compound of formula (Ia) or one of its enantiomers of the formula (Ia*), where M is an element of Group 4, Z are each halogen, hydrogen, C1-C10-alkyl, C6-C14-aryl, alkylaryl or arylalkyl having from 1 to 4 carbon atoms in the alkyl part and from 6 to 10 carbon atoms in the aryl part, n1 and n2 are each 0 or 1, R1 and R2 are each a C1-C40 radical, or R1 and R2 together with the atoms connecting them form a cyclic or polycyclic ring system, R5 and R6 are each hydrogen or a C1-C40 radical, R10, R11 are each hydrogen, t-butyl or phenyl, R12 are each t-butyl or phenyl, and R13 are each hydrogen or a C1-C40 radical.

Abstract: The present invention relates to organometallic transition metal compounds of the formula (I), a catalyst composition comprising at least one of the organometallic transition metal compound and an olefin polymerization process in the presence of one of the catalyst composition.

Abstract: The present invention provides a method for varying the melting points and molecular weights of polyolefins by changing the structure of the catalyst used in the polymerization. The catalysts that are useful in the present invention are chiral, stereorigid metallocene catalyst of the formula R?(C5R?m)2MeQ. The catalysts include a bridge structure between the (C5R?m) groups and may contain substituents on the groups. It has been discovered that the melting points and molecular weights of the polymers produced by such catalysts are influenced by the bridge and substituents added to the (C5R?m) groups. Thus, the present invention provides a method for varying the melting points of the polymer product and a method of varying the molecular weights of the product by changing the components and structure of the metallocene catalysts. The present invention also provides a process for polymerizing olefins in which the melting points and/or molecular weights of the product may be controlled.

Abstract: A new class of heterocyclic metallocenes, a catalytic system containing them and a process for polymerizing addition polymerizable monomers using said catalytic system are disclosed; the heterocyclic metallocenes correspond to the formula (I): YjR?iZjjMeQkPl wherein Y is a coordinating group containing a six ? electron central radical directly coordinating Me, to which are associated one or more radicals containing at least one non-carbon atom selected from B, N, O, Al, Si, P, S, Ga, Ge, As, Se, In, Sn, Sb and Te; R? is a divalent bridge between the Y and Z groups; Z is a coordinating group, optionally being equal to Y; Me is a transition metal; Q is halogen or hydrocarbon substituents; P is a counterion; i is 0 or 1; j is 1–3; jj is 0–2; k is 1–3; and l is 0–2.

Abstract: The present invention provides a method for varying the melting points and molecular weights of polyolefins by changing the structure of the catalyst used in the polymerization. The catalysts that are useful in the present invention are chiral, stereorigid metallocene catalyst of the formula R?(C5R?m)2MeQ. The catalysts include a bridge structure between the (C5R?m) groups and may contain substituents on the groups. It has been discovered that the melting points and molecular weights of the polymers produced by such catalysts are influenced by the bridge and substituents added to the (C5R?m) groups. Thus, the present invention provides a method for varying the melting points of the polymer product and a method of varying the molecular weights of the product by changing the components and structure of the metallocene catalysts. The present invention also provides a process for polymerizing olefins in which the melting points and/or molecular weights of the product may be controlled.

Abstract: The present invention provides a method for varying the melting points and molecular weights of polyolefins by changing the structure of the catalyst used in the polymerization. The catalysts that are useful in the present invention are chiral, stereorigid metallocene catalyst of the formula R″(C5R″m)2MeQ. The catalysts include a bridge structure between the (C5R′m) groups and may contain substituents on the groups. It has been discovered that the melting points and molecular weights of the polymers produced by such catalysts are influenced by the bridge and substituents added to the (C5R′m) groups. Thus, the present invention provides a method for varying the melting points of the polymer product and a method of varying the molecular weights of the product by changing the components and structure of the metallocene catalysts. The present invention also provides a process for polymerizing olefins in which the melting points and/or molecular weights of the product may be controlled.

Abstract: A class of metallocene compounds is disclosed having general formula (I) wherein Y is a moiety of formula (II) wherein A, B, and D, same or different from each other, are selected from an element of the groups 14 to 16 of the Periodic Table of the Elements (new IUPAC version), with the exclusion of nitrogen and oxygen; R1, R2, R3, R4 and R5 are hydrogen or hydrocarbon groups, Z is selected from a moiety of formula (II) as described above and from a moiety of formula (III) wherein R6, R7, R8 and R9, are hydrogen or hydrocarbon groups; L is a divalent bridging group; M is an atom of a transition metal selected from those belonging to group 3, 4, 5, 6 or to the lanthanide or actinide groups in the Periodic Table of the Elements (new IUPAC version), X, same or different, is hydrogen, a halogen, a R10, OR10, OSO2CF3, OCOR10, SR10, NR102 or PR102 group, wherein the substituents R10 are hydrogen or alkyl groups; p is an integer of from 1 to 3, being equal to the oxidation state of the metal M minus 2.

Abstract: The present invention provides a method for varying the melting points and molecular weights of polyolefins by changing the structure of the catalyst used in the polymerization. The catalysts that are useful in the present invention are chiral, stereorigid metallocene catalyst of the formula R″(C5R″m)2MeQ. The catalysts include a bridge structure between the (C5R′m) groups and may contain substituents on the groups. It has been discovered that the melting points and molecular weights of the polymers produced by such catalysts are influenced by the bridge and substituents added to the (C5R′m) groups. Thus, the present invention provides a method for varying the melting points of the polymer product and a method of varying the molecular weights of the product by changing the components and structure of the metallocene catalysts. The present invention also provides a process for polymerizing olefins in which the melting points and/or molecular weights of the product may be controlled.

Abstract: A class of metallocene compounds is disclosed having the general formula (I): wherein Y is a moiety of formula (II) wherein A, B and D, same or different from each other, are selected from an element of the groups 14 to 16 of the Periodic Table of the Elements (new IUPAC version), with the exclusion of nitrogen and oxygen; R1, R2, R3, R4 and R5 are hydrogen or hydrocarbon groups, Z is selected from a moiety of formula (II) as described above and from a moiety of formula (III): wherein R6, R7, R8 and R9, are hydrogen or hydrocarbon groups; L is a divalent bridging group; M is an atom of a transition metal selected from those belonging to group 3, 4, 5, 6 or to the lanthanide or actinide groups in the Periodic Table of the Elements (new IUPAC version), X, same or different, is hydrogen, a halogen, a R10, OR10, OSO2CF3, OCOR10, SR10, NR102 or PR102 group, wherein the substituents R10 are hydrogen or alkyl groups; p is an integer of from 0 to 3, being equal to

Abstract: The present invention provides a method for varying the melting points and molecular weights of polyolefins by changing the structure of the catalyst used in the polymerization. The catalysts that are useful in the present invention are chiral, stereorigid metallocene catalyst of the formula R″(C5R′m)2MeQ. The catalysts include a bridge structure between the (C5R′m) groups and may contain substituents on the groups. It has been discovered that the melting points and molecular weights of the polymers produced by such catalysts are influenced by the bridge and substituents added to the (C5R′m) groups. Thus, the present invention provides a method for varying the melting points of the polymer product and a method of varying the molecular weights of the product by changing the components and structure of the metallocene catalysts. The present invention also provides a process for polymerizing olefins in which the melting points and/or molecular weights of the product may be controlled.

Abstract: New metallocene compounds are described where the ligand contains at least one open-pentadienyl containing radical characterized by a cyclic or acyclic, six &pgr; electron, delocalized, five atomic center structure. These metallocenes can advantageously be used in catalyst systems for the polymerization of olefins to generate a wide variety of different polymers including HDPE, LLDPE, ethylenelpropylene/(diene) elastomers, tactiospecific C3+&agr;-olefin polymers, intimate mixture thereof and the like.

Abstract: This invention is for a metallocene compound which can be used in a catalyst system to produce hemiisotactic polymer. The compound is a bridged metallocene compound having dissimilar cyclopentadienyl groups and no bi-lateral symmetry. One example of the compound is isopropylidene(3-methylcyclopentadienyl-1-fluorenyl) zirconium dichloride. The catalyst of this invention can be converted to an ionic metallocene catalyst by an ionizing agent, such as methylaluminoxane. The polymer produced with this catalyst is characterized by having an isotactic structure effecting only every other asymmetric carbon atom. In the case of polypropylene, every other methyl group is on the same side of the principal polymer chain as represented by a Fisher projection. The remaining methyl groups can be either on the same side or on the opposite side of the principal polymer chain. The polymer produced with the catalyst of this invention can be used as a plasticizer.

Abstract: The present invention provides a method for varying the melting points and molecular weights of polyolefins by changing the structure of the catalyst used in the polymerization. The catalysts that are useful in the present invention are chiral, stereorigid metallocene catalyst of the formula R″(C5R′m)MeQ. The catalysts include a bridge structure between the ((C5R′m) groups and may contain substituents on the groups. It has been discovered that the melting points and molecular weights of the polymers produced by such catalysts are influenced by the bridge and substituents added to the (C5R′m) groups. Thus, the present invention provides a method for varying the melting points of the polymer product and a method of varying the molecular weights of the product by changing the components and structure of the metallocene catalysts. The present invention also provides a process for polymerizing olefins in which the melting points and/or molecular weights of the product may be controlled.

Abstract: This invention is for a metallocene catalyst component comprising a bridged metallocene in which the two substituted indenyl rings are complexed to a metal hydrocarbyl or metal halide. This metallocene catalyst component is useful for polymerizing olefins having three or more carbon atoms to produce a polymer with a isotactic stereochemical configuration. The catalyst component is a stereorigid metallocene described by the formula: R″(CpR2C4R4)(CpR′2C4R′4)MeQk wherein (CpR2C4R4) and (CpR2C4R4) are substituted indenyl rings; each R and R′ is a hydrogen or a hydrocarbyl radical having 1-20 carbon atoms; R″ is a structural bridge between the two indenyl rings imparting stereorigidity to the indenyl rings; Me is a transition metal; and each is a hydrocarbyl radical or is a halogen. Further, one R and R′ is a hydrocarbyl radical having 1-20 carbon atoms in a proximal position adjacent to the bridgehead carbon of the indenyl rings.

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 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: 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 &bgr; stereodirecting substituents and &agr; stereolocking substituents such that the catalysts have overall either Cs or C2 (or pseudo-Cs or C2) 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: A process for polymerizing addition polymerizable monomers using titanocenes 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 titanocenes are capable of generating near pure isospecific and syndiospecific polymers in solution or in bulk polymerization conditions.

Abstract: A process for polymerization of olefins having increased molecular weight and melting point uses a catalyst formed by combining a chiral, stereorigid metallocene compound with an organoaluminum compound. The metallocene compound has a silicon hydrocarbyl radical as an interannular bridge between two cyclopentadienyl or substituted cyclopentadienyl rings which are coordinated with a metal which is bonded to a hydrocarbon radical or a halogen. The cyclopentadienyl rings are described by the formula (C.sub.5 R'.sub.m) wherein R' is hydrogen or hydrocarbyl radical having from 1-20 carbon atoms, each R' being the same or different. The metal is a group 4b, 5b or 6b metal as designated in the Periodic Table of Elements.