公开(公告)号：CA2155936A1

公开(公告)日：1994-08-18

申请号：CA2155936

申请日：1994-01-31

Applicant: HOECHST AG

Inventor： BREKNER MICHAEL-JOACHIM ,  DECKERS HELLMUTH ,  OSAN FRANK

IPC: G02B6/00 ,  C08F4/42 ,  C08F4/642 ,  C08F4/646 ,  C08F4/659 ,  C08F4/6592 ,  C08F4/68 ,  C08F4/72 ,  C08F8/00 ,  C08F32/00 ,  C08F210/00 ,  C08F232/00 ,  C08F232/08 ,  D01F8/06 ,  G02B1/04

Abstract: A process for the preparation of a cycloolefin copolymer (COC) having low melt viscosity by copolymerization of from 0.1 to 99.9% by weight, based on the total amount of the monomers, of at least one monomer ¢lacuna! in which R1, R2, R3, R4, R5, R6, R7 and R8 are identical or different and are a hydrogen atom or a C1-C8-alkyl radical or an aryl radical, where identical radicals in the various formulae can have different meanings, from 0 to 99.9% by weight, based on the total amount of the monomers, of a cycloolefin of the formula V in which n is a number from 2 to 10, and from 0.1 to 99.9% by weight, based on the total amount of the monomers, of at least one acyclic 1-olefin of the formula VI, in which R9, R10, R11 and R12 are identical or different and are a hydrogen atom or a C1-C8-alkyl radical, in solution, in suspension, in the liquid cycloolefin monomer or cycloolefin monomer mixture or in the gas phase, at a temperature of from -78 to 150.degree.C, at a pressure of from 0.5 to 64 bar, in the presence of a catalyst comprising a metallocene as transition-metal component and an aluminoxane of the formula VII for the linear type and/or of the formula VIII for the cyclic type, where, in the formulae VII and VIII, R13 is a C1-C6-alkyl group or phenyl or benzyl, and n is an integer from 2 to 50, where the polymerization is carried out in the presence of a catalyst whose transition-metal component is at least one compound of the formula IX in which M1 is titanium, zirconium, hafnium, vanadium, niobium or tantalum, R14 and R15 are identical or different and are a hydrogen atom, a halogen atom, a C1-C10-alkyl group, a C1-C10-alkoxy group, a C6-C10-aryl group, a C6-C10-aryloxy group, a C2-C10-alkenyl group, a C7- C40-arylalkyl group, a C7 - C40 - alkylaryl group or a C8 - C40 -arylalkenyl group, and m may be one or two, depending on the valency of the central atom M1, R18 is =BR19, =AIR19, -Ge-, -Sn-, -O-, -S-, =SO, =SO2, =NR19, =CO, = PR19 or =P(O)R19, where R19, R20 and R21 are identical or different and are a hydrogen atom, a halogen atom, a C1-C10-alkyl group, a C1-C10-fluoroalkyl group, a C6-C10-fluoroaryl group, a C6-C10-aryl group, a C1-C10-alkoxy group, a C2-C10-alkenyl group, a C7 - C40 - arylalkyl group, a C8-C40-arylalkenyl group or a C7-C40-alkylaryl group, or R19 and R20 or R19 and R21, in each case with the atoms connecting them, form a ring, M2 is silicon, germanium or tin, R16 and R17 are different and are a monocyclic or polycyclic hydrocarbon radical which can form a sandwich structure with the central atom M1, wherein the metallocene of the formula IX has C8-symmetry with respect to the ligands R16 and R17 and with respect to the central atom M1 connecting them.

公开(公告)号：AU693083B2

公开(公告)日：1998-06-25

申请号：AU5972494

申请日：1994-01-31

Applicant: HOECHST AG

Inventor： BREKNER MICHAEL-JOACHIM ,  DECKERS HELLMUTH ,  OSAN FRANK

IPC: G02B6/00 ,  C08F4/42 ,  C08F4/642 ,  C08F4/646 ,  C08F4/659 ,  C08F4/6592 ,  C08F4/68 ,  C08F4/72 ,  C08F8/00 ,  C08F32/00 ,  C08F210/00 ,  C08F232/00 ,  C08F232/08 ,  D01F8/06 ,  G02B1/04

Abstract: PCT No. PCT/EP94/00263 Sec. 371 Date Aug. 10, 1995 Sec. 102(e) Date Aug. 10, 1995 PCT Filed Jan. 31, 1994 PCT Pub. No. WO94/18251 PCT Pub. Date Aug. 18, 1994Thermoplastic cycloolefin copolymers (COCs) having low melt viscosity and low optical attenuation, a process for their preparation, and their use as optical waveguides (optical fibers).

公开(公告)号：CA1338649C

公开(公告)日：1996-10-15

申请号：CA600855

申请日：1989-05-26

Applicant: HOECHST AG

Inventor： CHERDRON HARALD ,  DECKERS HELLMUTH ,  HEROLD FRIEDRICH ,  HESS REINER

IPC: B29C47/00 ,  B29C43/00 ,  B29C45/00 ,  C08G69/32 ,  C08G69/40 ,  C08G69/42 ,  D01F6/82

Abstract: Aromatic copolyether amide which can be processed as a thermoplastic, process for its preparation and its use for the production of moldings The structure of the aromatic copolyether amide which can be processed as a thermoplastic comprises recurring units of the formulae -CO-Ar1-CO- (A), -NH-Ar1-O-Ar1-X-Ar1-O-Ar1-NH (B) and -NH-Ar2-NH- (C) in which Ar1 denotes a divalent, unsubstituted or substituted aromatic radical having 6 carbon atoms which is linked in the p-position, X represents a 2,2-propylidene link and Ar2 is identical with Ar1 or is Ar1 which is linked in the m-position, or is the -Ar1-Z-Ar1- group in which Z is a direct bond or is a radical -CH2-, -C(CH3) 2-, -SO2-, -CO-, -O-, -CH=CH-, -CO-NH- or -O-Ar1-O- or the radical in which R represents hydrogen or a branched or unbranched alkyl radical having 1-4 carbon atoms. The proportion of units (A) and of the sum of units (B) and (C) is each 100 mol-%, the proportion of units (C) being up to 50 mol-% and, if Z represents -SO2-, up to 75 mol-%. The Staudinger index ¢?! of the copolyether amide is in the range from 50 to 1000 cm3/g, and the value of the glass transition temperature is above 200.degree.C. The copolyether amide is prepared by a low-temperature solution, solid, interface or melt condensation process. The moldings produced therefrom in the form of filaments, wires, films and other moldings are obtained by processing the pulverulent copolyether smides or their solutions.

公开(公告)号：CA1329299C

公开(公告)日：1994-05-03

申请号：CA600856

申请日：1989-05-26

Applicant: HOECHST AG

Inventor： CHERDRON HARALD ,  DECKERS HELLMUTH ,  HEROLD FRIEDRICH ,  HESS REINER

IPC: C08G69/26 ,  C08G69/28 ,  C08G69/32 ,  C08G69/40

Abstract: A thermoplastically processible aromatic polyetheramide, in which the structure comprises the repeating units of the formulae -CO-Ar-CO- (A) and -NH-Ar-O-Ar-X-Ar-O-Ar-NH- (B) in which Ar signifies a bivalent unsubstituted or substituted aromatic radical having 6 carbon atoms, and whose linkages are in the p-position and X denotes a 2,2propylidene linkage, the polyetheramide having an intrinsic viscosity ¢.pi.! in the range of 50 to 750 cm3/g, and a glass transition temperature of above 200.degree.C, and a process for its production. The production of the polyetheramide is carried out by a low temperature solution condensation process, a solid phase condensation process, an interfacial condensation process or a melt condensation process. The polyetheramide is used for the production of molded articles in the form of filaments, wires, films and other moldings, which are produced by extrusion, press-molding or injection molding of the dry polyetheramide in powder form or by processing of solutions of the polyetheramide.

公开(公告)号：CA2155936C

公开(公告)日：2006-05-30

申请号：CA2155936

申请日：1994-01-31

Applicant: HOECHST AG

Inventor： BREKNER MICHAEL-JOACHIM ,  DECKERS HELLMUTH ,  OSAN FRANK

IPC: C08F232/08 ,  G02B6/00 ,  C08F4/42 ,  C08F4/642 ,  C08F4/646 ,  C08F4/659 ,  C08F4/6592 ,  C08F4/68 ,  C08F4/72 ,  C08F8/00 ,  C08F32/00 ,  C08F210/00 ,  C08F232/00 ,  D01F8/06 ,  G02B1/04

Abstract: A process for the preparation of a cycloolefin copolymer (COC) having low melt viscosity by copolymerization of from 0.1 to 99.9% by weight, based on the total amount of the monomers, of at least one monomer [lacuna] in which R1, R2, R3, R4, R5, R6, R7 and R8 are identical or different and are a hydrogen atom or a C1-C8-alkyl radical or an aryl radical, where identical radicals in the various formulae can have different meanings, from 0 to 99.9% by weight, based on the total amount of the monomers, of a cycloolefin of the formula V in which n is a number from 2 to 10, and from 0.1 to 99.9% by weight, based on the total amount of the monomers, of at least one acyclic 1-olefin of the formula VI, in which R9, R10, R11 and R12 are identical or different and are a hydrogen atom or a C1-C8-alkyl radical, in solution, in suspension, in the liquid cycloolefin monomer or cycloolefin monomer mixture or in the gas phase, at a temperature of from -78 to 150.degree.C, at a pressure of from 0.5 to 64 bar, in the presence of a catalyst comprising a metallocene as transition-metal component and an aluminoxane of the formula VII for the linear type and/or of the formula VIII for the cyclic type. where. in the formulae VII and VIII, R13 is a C1-C6-alkyl group or phenyl or benzyl, and n is an integer from 2 to50, where the polymerization is carried out in the presence of a catalyst whose transition-metal component is at least one compound of the formula IX in which M1 is titanium, zirconium, hafnium, vanadium, niobium or tantalum, R14 and R15 are identical or different and are a hydrogen atom, a halogen atom, a C1-C10-alkyl group, a C1-C10-alkoxy group, a C6-C10-aryl group, a C6-C10-aryloxy group, a C2-C10-alkenyl group, a C7-C40-arylalkyl group, a C7-C40-alkylaryl group -32- or a C8-C40-arylalkenyl group, and may be one or two, depending on the valency of the central atom M1, is =BR19, =AIR19, -Ge-, -Sn-, -O-, -S-, =SO, =SO2, =NR19, =CO; - PR19 or =P(O)R19, where R19, R20 and R21 are identical or different and are a hydrogen atom, a halogen atom, a C1-C10-alkyl group, a C1-C10-fluoroalkyl group, a C6-C10-fluoroaryl group, a C6-C10-aryl group, a C1-C10-alkoxy group, a C2-C10-alkenyl group, a C1-C40-arylalkyl group, a C8-C40-arylalkenyl group or a C7-C40-alkylaryl group, or R19 and R20 or R19 and R21, in each case with the atoms connecting them, form a ring, is silicon, germanium or tin, and R17 are different and are a monocyclic or polycyclic hydrocarbon radical which can form a sandwich structure with the central atom M1, wherein the metallocene of the formula IX has C s-symmetrywith respect to the ligands R16 and R17 and with respect to the central atom M1 connecting them.

公开(公告)号：BR9405833A

公开(公告)日：1995-12-26

申请号：BR9405833

申请日：1994-01-31

Applicant: HOECHST AG

Inventor： BREKNER MICHAEL-JOACHIM ,  DECKERS HELLMUTH ,  OSAN FRANK

IPC: G02B6/00 ,  C08F4/42 ,  C08F4/642 ,  C08F4/646 ,  C08F4/659 ,  C08F4/6592 ,  C08F4/68 ,  C08F4/72 ,  C08F8/00 ,  C08F12/00 ,  C08F32/00 ,  C08F210/00 ,  C08F212/00 ,  C08F232/00 ,  C08F232/08 ,  G02B1/04

Abstract: A process for the production of cyclo-olefin copolymers (COC) with high tenacity by the copolymerisation of 0.1 to 99.9 wt %, in relation to the total quantity of monomers, of at least one monomer in which R , R , R , R , R , R , R and R are the same or different and represent a hydrogen atom or a C1-C8 alkyl radical or C6-C16 aryl radical, where identical radicals may have a different significance in the various formulae, 0 to 99.9 wt %, in relation to the total quantity of monomers, of a cyclo-olefin in which n is a number from 2 to 10, and 0.1 to 99.9 wt %, in relation to the the total quantity of monomers, of at least one acyclic 1-olefin in which R , R , R and R are the same or different and signify a hydrogen atom or a C1-C8 alkyl radical or C6-C16 aryl radical, in solution, in suspension, in the liquid cyclo-olefin monomer or cyclo-olefin monomer mixture or in the gas phase, at a temperature of -78 to 150 DEG C, at a pressure of 0.5 to 64 bar, in the presence of a catalyst consisting of a metallocene as the transition metal component and an aluminoxane for the linear type and/or for the cyclic type. In formulae VII and VIII, R is a C1-C6 alkyl group or phenyl or benzyl and n is a whole number from 2 to 50. Polymerisation is conducted in the presence of a catalyst, the transition metal component of which is at least one compound of formula IX, in which: M is titanium, zirconium, hafnium, vanadium, niobium or tantalum; R and R are the same or different and signify a hydrogen atom, a halogen atom, a C1-C10 alkyl group, a C1-C10 alkoxy group, a C6-C10 aryl group, a C6-C10 aryloxy group, a C2-C10 alkenyl group, a C7-C40 arylalkyl group, a C7-C40 alkylaryl group or a C8-C40 arylalkenyl group, and m may be one or two depending on the valency of the central atom M , R is =BR , =AlR , -Ge-, -Sn-, -O-, -S-, =SO, =SO2, =NR , =CO, =PR or =P(O)R , where R , R and R are the same or different and signify a hydrogen atom, a halogen atom, a C1-C10 alkyl group, a C1-C10 fluoroalkyl group, a C6-C10 fluoroaryl group, a C6-C10 aryl group, a C1-C10 alkoxy group, a C2-C10 alkenyl group, a C7-C40 arylalkyl group, a C8-C40 arylalkenyl group or a C7-C40 alkylaryl group or R and R or R and R form a ring with the atoms bonding them, M is silicon, germanium or tin, R and R are the same or different and signify a mono or multi-nuclear hydrocarbon radical which can form a sandwich structure with the central atom M . The metallocene of formula IX exhibits C2 symmetry if R and R are the same and, if R and R are different, a C1 symmetry in relation to the ligands R and R and the central atom M bonding them.

公开(公告)号：CA2155937A1

公开(公告)日：1994-08-18

申请号：CA2155937

申请日：1994-01-31

Applicant: HOECHST AG

Inventor： BREKNER MICHAEL-JOACHIM ,  DECKERS HELLMUTH ,  OSAN FRANK

IPC: G02B6/00 ,  C08F4/42 ,  C08F4/642 ,  C08F4/646 ,  C08F4/659 ,  C08F4/6592 ,  C08F4/68 ,  C08F4/72 ,  C08F8/00 ,  C08F12/00 ,  C08F32/00 ,  C08F210/00 ,  C08F212/00 ,  C08F232/00 ,  C08F232/08 ,  G02B1/04

Abstract: A process for the preparation of a copolymer of cycloolefin copolymer (COC) having high tear strength by copolymerization of 0.1 to 99.9% by weight, based on the total amount of the monomers, of at least one monomer in which R1, R2, R3, R4, R5, R6, R7 and R8 are identical or different and are a hydrogen atom or a C1-C8-alkyl radical or a C6-C16-aryl radical, where identical radicals in the various formulae can have different meanings, from 0 to 99.9% by weight, based on the total amount of the monomers, of a cycloolefin in which n is a number from 2 to 10, and from 0.1 to 99.9% by weight, based on the total amount of the monomers, of at least one acyclic 1-olefin in which R9, R10, R11 and R12 are identical or different and are a hydrogen atom or a C1-C8-alkyl radical or a C6-C16-aryl radical, in solution, in suspension, in a liquid cycloolefin monomer or cycloolefin monomer mixture or in the gas phase, at a temperature of from -78 to 150.degree.C, at a pressure of from 0,5 to 64 bar, in the presence of a catalyst comprising a metallocene as transition-metal component and an aluminoxane for the linear type and/or for the cyclic type, where, in the formulae VII and VIII, R13 is a C1-C6-alkyl group or phenyl or benzyl, and n is an integer from 2 to 50, where the polymerization is carried out in the presence of a catalyst whose transition-metal component is at least one compound of the formula IX in which M1 is titanium, zirconium, hafnium, vanadium, niobium or tantalum, R14 and R15 are identical or different and are a hydrogen atom, a halogen atom, a C1-C10-alkyl group, a C1-C10-alkoxy group, a C6-C10-aryl groups a C6-C10-aryloxy group, a C2-C10-alkenyl group, a C7-C40-arylalkyl group, a C7-C40-alkylaryl group or a C8-C40-arylalkenyl group, and m may be one or two, dependigng on the valency of the central atom M1, R18 is =BR19, =AIR19, -Ge-, -Sn-, -O-, -S-, =SO, =SO2, =NR19, =CO, = PR19 or =P(O)R19, where R19, R20 and R21 are identical or different and are a hydrogen atom, a halogen atom, a C1-C10-alkyl group, a C1-C10-fluoroalkyl group, a C6-C10-fluoro-aryl group, a C6-C10-aryl group, a C1-C10-alkoxy group, a C2-C10-alkenyl group, a C7-C40-arylalkyl group, a C8-C40-arylalkenyl group or a C7-C40-alkylaryl group, or R19 and R20 or R19 and R21, in each case with the atoms connecting them, form a ring, M2 is silicon, germanium or tin, R16 and R17 are identical or different and are a mono cyclic or polycyclic hydrocarbon radical which can form a sandwich structure with the central atom M1, wherein the metallocene of the formula IX has C2symmetry with respect to the ligands R16 and R17 and with respect to the central atom M1 connecting them in the case where R16 and R17 are identical and has C1-symmetry in the case where R16 and R17 are different.

公开(公告)号：CA2155937C

公开(公告)日：2007-06-19

申请号：CA2155937

申请日：1994-01-31

Applicant: HOECHST AG

Inventor： BREKNER MICHAEL-JOACHIM ,  DECKERS HELLMUTH ,  OSAN FRANK

IPC: C08F232/08 ,  G02B6/00 ,  C08F4/42 ,  C08F4/642 ,  C08F4/646 ,  C08F4/659 ,  C08F4/6592 ,  C08F4/68 ,  C08F4/72 ,  C08F8/00 ,  C08F12/00 ,  C08F32/00 ,  C08F210/00 ,  C08F212/00 ,  C08F232/00 ,  G02B1/04

Abstract: Cycloolefin copolymers having high tear strength and low optical attenuation A process for the preparation of a copolymer of cycloolefin copolymer (COC) having high tear strength by copolymerization of 0.1 to 99.9% by weight, based on the total amount of the monomers, of at least one monomer in which R1, R2, R3, R4, R5, R6, R7 and R8 are identical or different and are a hydrogen atom or a C1-C8-alkyl radical or a C6-C16-aryl radical, where identical radicals in the various formulae can have different meanings, from 0 to 99.9% by weight, based on the total amount of the monomers, of a cycloolefin in which n is a number from 2 to 10, and from 0.1 to 99.9% by weight, based on the total amount of the monomers, of at least one acyclic 1-olefin in which R9, R10, R11 and R12 are identical or different and are a hydrogen atom or a C1-C8-alkyl radical or a C6-C16-aryl radical, in solution, in suspension, in a liquid cycloolefin monomer or cycloolef in monomer mixture or in the gas phase, at a temperature of from -78 to 150.degree.C, at a pressure of from 0,5 to 64 bar, in the presence of a catalyst comprising a metallocene as transition-metal component and an aluminoxane for the linear type and/or for the cyclic type, where, in the formulae VII and VIII, R13 is a C1-C6- alkyl group or phenyl or benzyl, and n is an integer from 2 to 50, where the polymerization is carried out in the presence of a catalyst whose transition-metal component is at least one compound of the formula IX in which M1 is titanium, zirconium, hafnium, vanadium, niobium or tantalum, R14 and R15 are identical or different and are a hydrogen atom, a halogen atom, a C1-C10-alkyl group, a C1-C10-alkoxy group, a C6-C10-aryl group, a C6-C10-aryloxy group, a C2-C10-alkenyl group, a C7-C40-arylalkyl group, a C7-C40-alkylaryl group or a C8-C40-arylalkenyl group, and -32- m may be one or two, depending on the valency of the central atom M R18 is =BR19, =AIR19, -Ge-, -Sn-, -O-, -S-, =SO, =SO2, =NR19, =CO, = PR19 or =P (O) R19, where R19, R20 and R21 are identical or different and are a hydrogen atom, a halogen atom, a C1-C10-alkyl group, a C1-C10-fluoroalkyl group, a C6-C10-fluoro-aryl group, a C6-C10-aryl group, a C1-C10-alkoxy group, a C2-C10-alkenyl group, a C7-C40-arylalkyl group, a C8-C40-arylalkenyl group or a C7-C40-alkylaryl group, or R19 and R20 or R19 and R21, in each case with the atoms connecting them, form a ring, M2 is silicon, germanium or tin, R16 and R17 are identical or different and are a mono-cyclic or polycyclic hydrocarbon radical which can form a sandwich structure with the central atom M1, wherein the metallocene of the formula IX has C2--symmetry with respect to the ligands R16 and R17 and with respect to the central atom M1 connecting them in the case where R16 and R17 are identical and has C1-symmetry in the case where R16 and R17 are different.

公开(公告)号：BR9405831A

公开(公告)日：1995-12-26

申请号：BR9405831

申请日：1994-01-31

Applicant: HOECHST AG

Inventor： BREKNER MICHAEL-JOACHIM ,  DECKERS HELLMUTH ,  OSAN FRANK

IPC: G02B6/00 ,  C08F4/42 ,  C08F4/642 ,  C08F4/646 ,  C08F4/659 ,  C08F4/6592 ,  C08F4/68 ,  C08F4/72 ,  C08F8/00 ,  C08F32/00 ,  C08F210/00 ,  C08F232/00 ,  C08F232/08 ,  D01F8/06 ,  G02B1/04

Abstract: PCT No. PCT/EP94/00263 Sec. 371 Date Aug. 10, 1995 Sec. 102(e) Date Aug. 10, 1995 PCT Filed Jan. 31, 1994 PCT Pub. No. WO94/18251 PCT Pub. Date Aug. 18, 1994Thermoplastic cycloolefin copolymers (COCs) having low melt viscosity and low optical attenuation, a process for their preparation, and their use as optical waveguides (optical fibers).

公开(公告)号：AU6000094A

公开(公告)日：1994-08-29

申请号：AU6000094

申请日：1994-01-31

Applicant: HOECHST AG

Inventor： BREKNER MICHAEL-JOACHIM ,  DECKERS HELLMUTH ,  OSAN FRANK

IPC: G02B6/00 ,  C08F4/42 ,  C08F4/642 ,  C08F4/646 ,  C08F4/659 ,  C08F4/6592 ,  C08F4/68 ,  C08F4/72 ,  C08F8/00 ,  C08F12/00 ,  C08F32/00 ,  C08F210/00 ,  C08F212/00 ,  C08F232/00 ,  C08F232/08 ,  G02B1/04

Abstract: A process for the production of cyclo-olefin copolymers (COC) with high tenacity by the copolymerisation of 0.1 to 99.9 wt %, in relation to the total quantity of monomers, of at least one monomer in which R , R , R , R , R , R , R and R are the same or different and represent a hydrogen atom or a C1-C8 alkyl radical or C6-C16 aryl radical, where identical radicals may have a different significance in the various formulae, 0 to 99.9 wt %, in relation to the total quantity of monomers, of a cyclo-olefin in which n is a number from 2 to 10, and 0.1 to 99.9 wt %, in relation to the the total quantity of monomers, of at least one acyclic 1-olefin in which R , R , R and R are the same or different and signify a hydrogen atom or a C1-C8 alkyl radical or C6-C16 aryl radical, in solution, in suspension, in the liquid cyclo-olefin monomer or cyclo-olefin monomer mixture or in the gas phase, at a temperature of -78 to 150 DEG C, at a pressure of 0.5 to 64 bar, in the presence of a catalyst consisting of a metallocene as the transition metal component and an aluminoxane for the linear type and/or for the cyclic type. In formulae VII and VIII, R is a C1-C6 alkyl group or phenyl or benzyl and n is a whole number from 2 to 50. Polymerisation is conducted in the presence of a catalyst, the transition metal component of which is at least one compound of formula IX, in which: M is titanium, zirconium, hafnium, vanadium, niobium or tantalum; R and R are the same or different and signify a hydrogen atom, a halogen atom, a C1-C10 alkyl group, a C1-C10 alkoxy group, a C6-C10 aryl group, a C6-C10 aryloxy group, a C2-C10 alkenyl group, a C7-C40 arylalkyl group, a C7-C40 alkylaryl group or a C8-C40 arylalkenyl group, and m may be one or two depending on the valency of the central atom M , R is =BR , =AlR , -Ge-, -Sn-, -O-, -S-, =SO, =SO2, =NR , =CO, =PR or =P(O)R , where R , R and R are the same or different and signify a hydrogen atom, a halogen atom, a C1-C10 alkyl group, a C1-C10 fluoroalkyl group, a C6-C10 fluoroaryl group, a C6-C10 aryl group, a C1-C10 alkoxy group, a C2-C10 alkenyl group, a C7-C40 arylalkyl group, a C8-C40 arylalkenyl group or a C7-C40 alkylaryl group or R and R or R and R form a ring with the atoms bonding them, M is silicon, germanium or tin, R and R are the same or different and signify a mono or multi-nuclear hydrocarbon radical which can form a sandwich structure with the central atom M . The metallocene of formula IX exhibits C2 symmetry if R and R are the same and, if R and R are different, a C1 symmetry in relation to the ligands R and R and the central atom M bonding them.