Abstract: This invention is concerned with a butadiene-based polymer having a high cis-1,4 bond content, a low vinyl bond content and a molecular weight distribution of a specified range, and more particularly a butadiene-based polymer having a 1,3-butadiene monomer unit, characterized in that a cis-1,4 bond content and a vinyl bond content in the 1,3-butadiene monomer unit as measured by a Fourier transform infrared spectroscopy (FT-IR) is not less than 98.0% and not more than 0.3%, respectively, and a ratio (Mw/Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) is 1.6-3.5.

Abstract: A method for the continuous production of polydienes, the method comprising the steps of (a) charging a mixture of one or more monomer, catalyst system, and less than 50% weight percent organic solvent based on the total weight of the monomer, catalyst and solvent, into first vessel, (b) polymerizing the monomer to a conversion of up to 20% by weight of the monomer to form a mixture of reactive polymer and monomer, (c) removing the mixture of reactive polymer and monomer from the vessel, and (d) terminating the reactive polymer prior to a total monomer conversion of 25% by weight.

Abstract: Metal complexes, catalyst compositions containing the metal complexes, and processes for making the metal complexes and the catalyst compositions are described for the manufacture of polymers from ethylenically unsaturated addition polymerizable monomers. The metal complexes have chemical structures corresponding to one of the following formulae: (Ia) (Ib) (VII) wherein MI. and MII. are metals; T is nitrogen or phosphorus; P is a carbon, nitrogen or phosphorus atom; groups R1, R2 and R3 may be linked to each other; Y is a divalent bridging group; X, X1, and X2 are anionic ligand groups with certain exceptions; D is a neutral Lewis base ligand; and s, o, k, i, ii, p, m, a, b, c, d, e, t, and y are numbers as further described in the claims.

Abstract: There is disclosed a process for producing a conjugated diene-containing polymer wherein a stream comprising conjugated diene monomer and a specified catalyst, that includes a lanthanide compound and an aluminoxane, is passed through an orifice into the reaction zone of a polymerization vessel, maintained under specific pressure conditions to form a cement having a viscosity that allows the cement to be conveyed through a devolatilization zone, where desired.

Abstract: A catalytic system usable for the copolymerization of at least one conjugated diene and at least one monoolefin, a process for preparing this catalytic system, a process for preparing a copolymer of a conjugated diene and at least one monoolefin using said catalytic system, and said copolymer are described.

Abstract: Promoters are described for vanadium-based catalysts used in the (co)polymerization of olefins and, in particular, in the production of ethylene/propylene (EPR) or ethylene/propylene/diene (EPDM) elastomeric copolymers. The promoters of the present invention belong to the group of compounds having general formula I: wherein: “X” represents a (—CO—) carbonyl or (—SO2—) sulfonyl group; “n” is 0 or 1; R? is an alkyl or alkylaryl group having from 1 to 20 carbon atoms; R?=R?, H.

Abstract: The invention relates to a pneumatic tire having excellent mechanical properties by using a rubber composition containing a polybutadiene rubber having a high cis-1,4 bond content, a low vinyl bond content and proper number average molecular weight and molecular weight distribution, and more particularly to a pneumatic tire characterized in that a rubber composition including a polybutadiene with a cis-1,4 bond content of not less than 99.0% and a vinyl bond content of not more than 0.3% as measured by a Fourier transform infrared spectroscopy is used in any one of tire members.

Abstract: A process is described for obtaining a 1,3-butadiene homopolymer by the reaction of a catalytic system in the presence of 1,3-butadiene and one or more monoolefin(s) with 4 carbon atoms. This catalytic system is based on at least: a conjugated diene monomer, an organic phosphoric acid salt of one or more rare earth metals, said salt being in suspension in at least one inert, saturated and aliphatic or alicyclic hydrocarbon solvent, an alkylating agent of the formula AlR3 or HAlR2, where R is an alkyl group, and an alkylaluminum halide halogen donor.

Abstract: A method for preparing a diene elastomer, such as a butadiene homopolymer or copolymer, in particular, a polybutadiene, with a high level of cis-1,4 linkages that has both a Mooney viscosity greater than or equal to 40 and a polydispersity index of less than 2.1. The method comprises a reaction of a catalyst system with at least one conjugated diene monomer to be polymerized and the catalyst system is based on at least: optionally one preforming conjugated diene; one salt of one or more rare earth metals; an inert hydrocarbon-based solvent; an alkylating agent comprising an allyl derivative of aluminum of formula R?nAlR?3-n, where R? is a saturated or unsaturated alkyl group or else a hydride, where R? is an allyl group and where n is an integer inclusively between 1 and 3; and a halogen donor that belongs to the family of alkylaluminum halides, excluding alkylaluminum sesquihalides.

Abstract: The present invention discloses a metallocene catalyst component based on a Group IIIb metal of the periodic Table and a bridged heteroatom-fluorenyl ligand. It also discloses its method of preparation and its use in polymerisation.

Abstract: The present invention provides 1) a complex comprising a mono-anionictridentate ligand, represented by the following general formula (I); 2) a polymerization catalyst composition, comprising the complex; and 3) a cis-1,4-isoprene polymer, a cis-1,4-butadiene polymer, a cis-1,4-isoprene-styrene copolymer, a cis-1,4-butadiene-styrene copolymer, a cis-1,4-butadiene-cis-1,4-isoprene copolymer, and a cis-1,4-butadiene-cis-1,4-isoprene-styrene copolymer, each of which has high-cis-1,4 content in a micro structure and a sharp molecular-weight distribution.

Abstract: A method for the continuous production of polydienes, the method comprising the steps of (a) charging a mixture of one or more monomer, catalyst system, and less than 50% weight percent organic solvent based on the total weight of the monomer, catalyst and solvent, into first vessel, (b) polymerizing the monomer to a conversion of up to 20% by weight of the monomer to form a mixture of reactive polymer and monomer, (c) removing the mixture of reactive polymer and monomer from the vessel, and (d) terminating the reactive polymer prior to a total monomer conversion of 25% by weight.

Abstract: The present invention discloses a metallocene catalyst component of the formula (I) [(Flu-R?-Cp)2M]?[Li(ether)4]+, wherein Cp is a cyclopentadienyl, substituted or unsubstituted, Flu is a fluorenyl, substituted or unsubstitutted, M is a metal Group III of the Periodic Table, and R? is a structural bridge between Cp and Flu imparting stereorigidity to the component. It further discloses a process for preparing said metallocene catalyst component and its use in controlled polymerisation.

Abstract: Disclosed herein are a method for preparing a cis-1,4-polybutadiene with a controlled molecular weight distribution, comprising polymerizing butadiene monomers using a rare-earth catalyst system comprising: (a) at least one aliphatic hydrocarbon-soluble organometallic compound comprising at least one metal element chosen from the elements of atomic numbers 51-71 in the periodic table; (b) at least one organoaluminum compound of the formula: AlR1R22, (c) at least one aliphatic hydrocarbon-soluble halogen-containing compound; (d) optionally at least one alkylaluminum alkoxide; and (e) at least one conjugated double bond-containing organic compound, and methods of preparing the rare-earth catalyst system.

Abstract: The present invention discloses a metallocene catalyst component of formula (Flu-R?-Cp)M(?3-C3R?5)(ether)n (I) wherein Cp is a cyclopentadienyl, substituted or unsubstituted, Flu is a fluorenyl, substituted or unsubstitutted, R? is a structural bridge between Cp and Flu imparting stereorigidity to the component, M is a metal Group III of the Periodic Table, each R? is the same or different and is hydrogen or a hydrocarbyl having from 1 to 20 carbon atoms and n is 0, 1 or 2. It further discloses a process for preparing said catalyst component and its used in the controlled polymerisation of polar or non polar monomers.

Abstract: A polymerisation catalyst comprising (1) a transition metal compound of Formula A, and optionally (2) an activating quantity of a Lewis acid activator. Z is a five-membered heterocyclic group containing at least one carbon atom, at least one nitrogen atom and at least one other hetero atom selected from nitrogen, sulphur and oxygen, the remaining atoms in the ring being nitrogen or carbon; M is a metal from Group 3 to 11 of the Periodic Table or a lanthanide metal; E1 and E2 are divalent groups from (i) aliphatic hydrocarbon, (ii) alicyclic hydrocarbon, (iii) aromatic hydrocarbon, (iv) alkyl substituted aromatic hydrocarbon (v) heterocyclic groups and (vi) heterosubstituted derivatives of groups (i) to (v); D1 and D2 are donor groups; X is an anionic group, L is a neutral donor group; n=m=zero or 1; y and z are zero or integers. The catalysts are useful for polymerising or oligomerising 1-olefins.

Abstract: A catalyst composition for polymerization of a conjugated diene or copolymerization of a conjugated diene and an aromatic vinyl compound, which comprises the following components: (A) a metallocene-type complex of a rare earth metal compound (samarium complex etc.), and (B) an ionic compound composed of a non-coordinate anion and a cation (triphenylcarbonium tetrakis(pentafluorophenyl)borate etc.) and/or an aluminoxane. The catalyst composition is useful for producing a polymer having a high cis-1,4-configuration content in the microstructure and a narrow molecular weight distribution.

Abstract: The present invention relates to a process for the preparation random copolymers of butadiene and isoprene, essentially consisting of reacting a catalytic system in the presence of butadiene and isoprene and using, as catalytic system, a system based on at least:—a conjugated diene monomer,—an organic phosphoric acid salt of one or more rare earth metals,—an alkylating agent consisting of an alkylaluminium of the formula AlR3 or HAlR2, and—a halogen donor consisting of an alkylaluminium halide, said salt being in suspension in at least one inert, saturated and aliphatic or alicyclic hydrocarbon solvent, which is included in said catalytic system, and the “alkylating agent:rare earth salt” molar ratio falls within a range of from 1 to 8, and performing the copolymerization reaction in an inert hydrocarbon polymerisation solvent or without solvent. These copolymers are in particular such that the butadiene and isoprene units which they comprise each have an elevated content of cis-1,4 linkages.

Abstract: A process is described for obtaining from an “FCC” initial C5 fraction which is enriched with isoprene and purified and usable for the selective polymerization of isoprene. A process is also described for obtaining an isoprene homopolymer from a polymerization medium comprising isoprene and at least one methyl butene, such as said “FCC” C5 fraction which is enriched with isoprene and purified. The process of obtaining the final fraction from the initial C5 fraction includes: a catalytic hydrogenation reaction of said initial C5 fraction by a palladium-based catalyst, which produces an intermediate C5 fraction comprising n-pentenes in a mass ratio which is less than 0.

Abstract: The subject invention relates to a process for preparing a catalyst system that comprises the sequential steps of (I) reacting an organometalic compound that contains a metal from Group III-B of the Periodic System with an organoaluminum compound at a temperature which is within the range of 50° C. to 100° C.

Abstract: The present invention relates to a method for preparing neodymium-carbon-nanotube and a process for preparing 1,4-cis-polybutadiene utilizing the same and more particularly, neodymium-carbon-nanotube. Neodymium is introduced by coordination with carboxylic acid, which is formed on the surface of carbon nanotube. In 1,3-butadiene polymerization with the neodymium-catalyst comprising the neodymium-carbon nanotube, a particular halogen compound, and a particular organometallic compound in an appropriate ratio, high 1,4-cis polybutadiene having molecular weight of 10,000 to 2,000,000 is produced, which exhibits excellent mechanical properties such as elasticity and durability.

Abstract: The present invention relates to a catalyst for polymerization of a conjugated diene or the like, which is composed of a metallocene-type cation complex of a gadolinium compound. Examples of such catalyst include a metallocene-type cation complex of a trivalent gadolinium compound represented by the general formula (I): RaGdXb (wherein, Gd represents gadolinium; R represents a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group, a substituted indenyl group, a fluorenyl group, or a substituted fluorenyl group; X represents an anion; “a” represents an integer of 1 or 2; and “b” represents an integer of 1 or 2). The present invention provides a catalyst by which polymerization of a conjugated diene or copolymerization of a conjugated diene and an aromatic vinyl compound can be carried out efficiently and inexpensively.

Abstract: A transition metal complex having the following Formula (A): wherein the monovalent groups R1 and R2 are —Ra, —ORb, —NRcRd, and —NHRe; the monovalent groups Ra, Rb, Rc, Rd and Re, and the divalent group R3 are (i) aliphatic hydrocarbon, (ii) alicyclic hydrocarbon, (iii) aromatic hydrocarbon, (iv) alkyl substituted aromatic hydrocarbon (v) heterocyclic groups and (vi) heterosubstituted derivatives of said groups (i) to (v); M is a Group (3) to (11) or lanthanide metal; E is phosphorus or arsenic; X is an anionic group, L is a neutral donor group; n is (1) or (2), y and z are independently zero or integers, such that the number of X and L groups satisfy the valency and oxidation state of the metal M. n is preferably (2) and the two resulting R1 groups are preferably linked.

Abstract: A family of novel hetrocyclic-amide type catalyst precursors useful for the polymerization of olefins, such as ethylene, higher alpha-olefins, dienes, and mixtures thereof.

Abstract: The present invention relates to a process for the preparation random copolymers of butadiene and isoprene, essentially consisting of reacting a catalytic system in the presence of butadiene and isoprene and using, as catalytic system, a system based on at least:—a conjugated diene monomer,—an organic phosphoric acid salt of one or more rare earth metals,—an alkylating agent consisting of an alkylaluminium of the formula AlR3 or HAlR2, and—a halogen donor consisting of an alkylaluminium halide, said salt being in suspension in at least one inert, saturated and aliphatic or alicyclic hydrocarbon solvent, which is included in said catalytic system, and the “alkylating agent:rare earth salt” molar ratio falls within a range of from 1 to 8, and performing the copolymerisation reaction in an inert hydrocarbon polymerisation solvent or without solvent. These copolymers are in particular such that the butadiene and isoprene units which they comprise each have an elevated content of cis-1,4 linkages.

Abstract: A process for the preparation of low branch content polybutadiene comprising: (a) a first butadiene polymerisation stage; (b) treatment of the polymer solution obtained upon completion of stage (a) with a coupling agent selected from: (i) polyunsaturated natural oils; (ii) butadiene and/or isoprene oligomers; (iii) butadiene and/or isoprene co-polymers with vinylarene monomers; the unsaturations present in compounds (i)–(iii) being at least partially substituted with groups selected from epoxides, anhydrides and esters; (c) recovery of the low branch content polybutadiene obtained upon completion of stage (b).

Abstract: A method of producing cis-1,4-polydienes, the method comprising the step of contacting conjugated diene monomer with a lanthanide-based catalyst system in the presence of less than 20% by weight of organic solvent based on the total weight of monomer, organic solvent, and resulting polymer, where the lanthanide-based catalyst system is the combination of or reaction product of (a) a lanthanide compound, (b) an organoaluminum hydride, (c) a trihydrocarbylaluminum, and (d) a halogen-containing compound.

Abstract: Disclosed are ethylene and butadiene copolymers and a catalytic system usable for the synthesis of these copolymers. The copolymers have a molar content of units resulting from butadiene of ?8%, said units comprising trans-1,2 cyclohexane linkages, and a number-average molecular mass Mn of ?40,000 g/mol. The catalytic system includes: (i) an organometallic complex represented by one of the following formulae A or B: where Ln represents a lanthanide and X a halogen, where, in the formula A, two ligand molecules Cp1 and Cp2 each consisting of a fluorenyl group, are attached to Ln, where, in the formula B, a ligand molecule consisting of two fluorenyl groups Cp1 and Cp2, joined together by a bridge P of formula MR2, where M is an element of column IVa and R is an alkyl with 1 to 20 carbon atoms, is attached to Ln, and (ii) a co-catalyst selected from an alkylmagnesium, an alkyllithium, an alkylaluminium, a Grignard reagent, or a mixture of these constituents.

Abstract: A process is described for the preparation of polydienes with a low vinyl content and having a branched structure effected by means of the polymerization of conjugated dienes in the presence of catalysts based on rare-earth compounds. The resulting polymers are characterized in that they have a cis content varying from 80 to 96% and prove to be branched with consequent low viscosity values in solution.

Abstract: 1-butene based polymer satisfying following requirements (1?) to (4?) provides formed product having low stickiness, superior flexibility and transparency. (1?) Crystalline resin having melting point (Tm?P), not observed or in the range of 0 to 100° C., wherein said melting point defined as the peak top of the peak observed in the highest temperature zone of the melting heat absorption curve obtained by heating a sample of said polymer at a rate of 10° C./minute using Differential Scanning Calorimeter (DSC), after melting said sample in advance at 190° for 5 minutes under nitrogen atmosphere, followed by cooling it to ?10° C. at a rate of 5° C./minutes, and keeping it at ?10° C. for 5 minutes. (2?) Stereoregularity index {(mmmm)/(mmrr+rmmr)} is at most 20. (3?) Molecular weight distribution (Mw/Mn) measured by Gel Permeation Chromatography (GPC) method is at most 4.0. (4?) Weight average molecular weight (Mw) measured by GPC method is in the range of 10,000 to 1,000,000.

Abstract: The present invention relates to a catalytic system usable for the preparation of polybutadienes by polymerisation, to a process for the preparation of said catalytic system and to a process for the preparation of polybutadienes by means of this catalytic system. A catalytic system according to the invention is based on at least: a conjugated diene monomer, an organic phosphoric acid salt of one or more rare earth metals, said salt being in suspension in at least one inert, saturated and aliphatic or alicyclic hydrocarbon solvent, an alkylating agent consisting of an alkylaluminium of formula AlR3 or HAlR2, the “alkylating agent:rare earth salt” molar ratio being greater than 5, and a halogen donor which belongs to the family of alkylaluminium halides with the exception of alkylaluminium sesquihalides, and, according to the invention, said catalytic system comprises said rare earth metal(s) in a concentration equal to or greater than 0.005 mol/l.

Abstract: The present invention relates to a catalyst composition for polymerization of a conjugated diene, comprising: (A) a metallocene-type complex represented by a general formula (I): (C5R1R2R3R4R5)aMXb.Lc (where, M represents a rare earth metal; C5R1R2R3R4R5 represents a substituted cyclopentadienyl group; R1 to R5 represent the same or different hydrocarbon groups (except when R1=R2=R3=R4=R5=a methyl group); X represents a hydrogen atom, a halogen atom, an alkoxide group, a thiolate group, an amide group, or a hydrocarbon group having 1 to 20 carbon atoms; L represents a Lewis basic compound; “a” represents an integer of 1, 2, or 3; “b” represents an integer of 0, 1, or 2; and “c” represents an integer of 0, 1, or 2); and (B) an ionic compound composed of a non-coordinating anion and a cation, and/or an aluminoxane.

Abstract: Process for the preparation of polybutadiene with a low branching degree which comprises: (a) a first polymerization step of butadiene in the presence of organic solvents and in the presence of a catalytic system comprising (a1) a derivative of neodymium; (a2) an aluminum alkyl having general formula (I) AlR1R2R3; (a3) an organo aluminum derivative containing at least one halogen atom, preferably chlorine; the above first step being carried out up to a conversion of butadiene >98% to give a linear polybutadiene (gm=1) with a content of 1,4-cis units greater than 93% and a Mw/Mn ranging from 2.2 to 2.9; (b) treatment of the polymeric solution obtained at the end of step (a) with a peroxide, (c) recovery of the polybutadiene with a low branching degree obtained at the end of step (b).

Abstract: The subject invention relates to a technique for synthesizing rubbery non-tapered, random, copolymers of 1,3-butadiene and isoprene. These rubbery copolymers exhibit an excellent combination of properties for utilization in tire sidewall rubber compounds for truck tires. By utilizing these isoprene-butadiene rubbers in tire sidewalls, tires having improved cut growth resistance can be built without sacrificing rolling resistance. Such rubbers can also be employed in tire tread compounds to improve tread wear characteristics and decrease rolling resistance without sacrificing traction characteristics.

Abstract: A catalyst composition that is the combination of or the reaction product of ingredients comprising (a) a lanthanide compound, (b) an organoaluminum hydride, and (c) a tin halide compound.

Abstract: The present invention provides synthetic polyisoprenes having a high cis-1,4 linkage content and a process for their preparation. The synthetic polyisoprenes according to the invention have a cis-1,4 linkage content, measured by carbon-13 nuclear magnetic resonance and/or medium-wave infrared radiation analysis, of greater than 99.0%. The process for the preparation of these synthetic polyisoprenes involve polymerizing, at a temperature of 0° C. or lower, isoprene in the presence of a catalytic system based on: a) a conjugated diene monomer, b) an organic phosphoric acid salt of one or more rare earth, c) an alkylaluminium alkylating agent of the formula AlR3 or HAlR2, and d) a halogen donor consisting of an alkylaluminium halide, wherein the salt is suspended in at least one inert, saturated aliphatic or alicyclic hydrocarbon solvent and the alkylating agent:rare earth salt molar ratio ranges from 1 to 5.

Abstract: A catalyst system comprising at least one metallocene, at least one cocatalyst, at least one support material and, if desired, further organometallic compounds is described. The catalyst system can advantageously be used for the polymerization of olefins and displays a high catalyst activity and gives a good polymer morphology without it being necessary to use aluminoxanes such as methylaluminoxane (MAO), which usually has to be used in high excess, as cocatalyst.

Abstract: 1-butene based polymer satisfying following requirements (1?) to (4?) provides formed product having low stickiness, superior flexibility and transparency. (1?) Crystalline resin having melting point (Tm?P), not observed or in the range of 0 to 100° C., wherein said melting point defined as the peak top of the peak observed in the highest temperature zone of the melting heat absorption curve obtained by heating a sample of said polymer at a rate of 10° C./minute using Differential Scanning Calorimeter (DSC), after melting said sample in advance at 190° for 5 minutes under nitrogen atmosphere, followed by cooling it to ?10° C. at a rate of 5° C./minutes, and keeping it at ?10° C. for 5 minutes. (2?) Stereoregularity index {(mmmm)/(mmrr+rmmr)} is at most 20. (3?) Molecular weight distribution (Mw/Mn) measured by Gel Permeation Chromatography (GPC) method is at most 4.0. (4?) Weight average molecular weight (Mw) measured by GPC method is in the range of 10,000 to 1,000,000.

Abstract: The present invention relates to a method for preparing a high 1,4-cis polybutadiene having a controlled cold flow and, more particularly, to a novel method for preparing a high 1,4-cis polybutadiene having a controlled cold flow that involves initiating polymerization of a 1,3-butadiene in the presence of a non-polar solvent using, as a polymerization catalyst, a complex prepared by mixing a neodymium compound with or without a conjugated diene compound, a halogenated organoaluminum compound or a halogenated organic compound, and an organoaluminum compound irrespective of the addition order of the catalyst; and adding an organoborane compound as a cold flow controller of 1,4-cis polybutadiene after a predetermined time of the polymerization. Accordingly, a high 1,4-cis polybutadiene having an efficiently controlled cold flow can be prepared without causing a significant increase in the Mooney viscosity (molecular weight), an odor (bad smell), and a reduction in 1,4-cis content and polymerization yield.

Abstract: A continuous process for producing conjugated diene polymers comprising the steps of contacting, within an hydrocarbon solvent and within a continuous reactor, conjugated diene monomer and a catalyst composition prepared by combining: (a) a lanthanide compound, (b) an alkylating agent, and (c) a halogen-containing compound, and maintaining a non-ideal flow pattern within the continuous reactor so that 10% of the reagents entering the reactor at a reference time t0 are still present within the continuous reactor at a time t0+xtrt, where trt is the residence time corresponding to ideal flow within the continuous reactor and x is a numeral greater than 1.5.

Abstract: A cationic Group 3 or Lanthanide metal complex for coordination polymerization of olefins is disclosed. The precursor metal complex is stabilized by an anionic amidinate ancillary ligand. Upon reaction with an activator, the complex becomes an active olefin-polymerization catalyst. Some invention processes give narrow polymer polydispersities.

Abstract: The present invention relates generally to the chemistry of inorganic reduction catalysts, and more particularly to the composition and use of dihalogenated lanthanides catalysts, for example TmI2 or DyI2, to facilitate reduction reactions such as the preparation of alkylated hydrocarbons and/or organic polymers.

Abstract: The present invention relates to a process for obtaining a polyisoprene having a high cis-1,4 linkage content, from a steam-cracked C5 naphtha fraction enriched with isoprene. The process of the present invention comprises reacting a steam-cracked C5 naphtha fraction in the presence of a catalytic system, wherein the C5 fraction is enriched with isoprene such that the mass fraction of isoprene in said enriched fraction lies within a range of from 30% to 95%, and the catalytic system is based on at least (a) a conjugated diene monomer, (b) an organic phosphoric acid salt of one or more rare earth metals, (c) an alkylating agent consisting of an alkylaluminum of the formula AlR3 or HAlR2, and (d) a halogen donor consisting of an alkylaluminum halide, said salt being suspended in at least one inert saturated hydrocarbon solvent of aliphatic or alicyclic type which is included in said catalytic system, and the molar ratio of alkylating agent:rare earth salt is in a range of from 1 to 5.

Abstract: The present invention provides a catalytic system that can be used to prepare by polymerization diene elastomers comprising polyisoprenes and polybutadienes. The invention also provides a process for the preparation of the catalytic system and to a process using the catalytic system to prepare diene elastomers comprising polyisoprenes having a high cis-1,4 linkage content and polybutadienes. The catalytic system according to the invention is based on (a) a conjugated diene monomer, (b) an organic phosphoric acid salt of a rare earth metal, (c) an alkylating agent consisting of an alkylaluminium of the formula AlR3 or HAlR2, and (d) a halogen donor consisting of an alkylaluminium halide, and is such that said salt is suspended in at least one inert and saturated aliphatic or alicyclic hydrocarbon solvent and, the “alkylating agent:rare earth salt” molar ratio ranges from 1 to 5.

Abstract: The present invention provides to a catalytic system, its method for preparation, and a method for preparation of a copolymer of ethylene and a conjugated diene, which uses this catalytic system. A catalytic system according to the invention comprises: an organometallic complex compound, which is represented by one formula A or B: in which Ln represents a metal of a lanthanide, the atomic number of which is between 57 and 71; X represents a halogen, which can be chlorine, fluorine, bromine or iodine; and Cp1 and Cp2 each comprise a cyclopentadienyl or fluorenyl group, which is or is not substituted, and P is a bridge corresponding to the formula MR2, in which M is an element of column IVA of Mendeleev's periodic classification, and R is an alkyl group comprising from 1 to 20 atoms of carbon; and a co-catalyst selected from among a magnesium alkyl, a lithium alkyl, an aluminium alkyl, or a Grignard's reagent, and mixtures thereof.

Abstract: The subject invention relates to a technique for synthesizing rubbery non-tapered, random, copolymers of 1,3-butadiene and isoprene. These rubbery copolymers exhibit an excellent combination of properties for utilization in tire sidewall rubber compounds for truck tires. By utilizing these isoprene-butadiene rubbers in tire sidewalls, tires having improved cut growth resistance can be built without sacrificing rolling resistance. Such rubbers can also be employed in tire tread compounds to improve tread wear characteristics and decrease rolling resistance without sacrificing traction characteristics.

Abstract: The production of a protein free synthetic polyisoprene which has both low levels of chemical impurities and good physical properties has yet to be realized. It has now been envisioned that the use of neodymium catalyzed polyisoprene will offer the combined advantages of both a clean, as well as, high cis-1,4 polymer. Synthesis of polyisoprene rubber using a neodymium based catalyst system is described. Characterization of the material shows the absence of an ultra high molecular weight fraction and the presence of very high cis-1,4-microstructure. Gum stock and black filled compound studies comparing neodymium polyisoprene with natural rubber, titanium polyisoprene, and lithium polyisoprene have been performed. Results indicate that polyisoprene rubber synthesized using a neodymium catalyst system (Nd—PI) has similar stress-strain and tear properties as synthetic titanium polyisoprene.

Abstract: The neodymium catalyst system prepared by the technique of this invention can be used in the polymerization of isoprene monomer into polyisoprene rubber that is clear (transparent) and of high purity. This invention more specifically discloses a process for the synthesis of polyisoprene rubber which comprises polymerizing isoprene monomer in the presence of a neodymium catalyst system, wherein the neodymium catalyst system is prepared by (1) reacting a neodymium carboxylate with an organoaluminum compound in the presence of isoprene for a period of about 10 minutes to about 30 minutes to produce neodymium-aluminum catalyst component, and (2) subsequently reacting the neodymium-aluminum catalyst component with a dialkyl aluminum chloride for a period of at least 30 minutes to produce the neodymium catalyst system.

Abstract: Novel conjugated diene polymers having good wear resistance, mechanical properties, storage stability, processability and a reduced cold flow are produced by polymerizing a conjugated diene compound with a catalyst of rare earth element compound and reacting the resulting polymer just after the polymerization with at least one compound selected from the group consisting of a halogenated organometallic compound, a halogenated metal compound, an organometallic compound, a heterocumulene compound, a hetero three-membered-ring containing compound, a halogenated isocyano compound, a carboxylic acid, an acid halide, an ester compound, a carbonic ester compound, an acid anhydride and a metal salt of a carboxylic acid as a modifying agent.

Abstract: The present invention relates to a method for preparing a high 1,4-cis polybutadiene having a controlled cold flow and, more particularly, to a novel method for preparing a high 1,4-cis polybutadiene having a controlled cold flow that involves initiating polymerization of a 1,3-butadiene in the presence of a non-polar solvent using, as a polymerization catalyst, a complex prepared by mixing a neodymium compound with or without a conjugated diene compound, a halogenated organoaluminum compound or a halogenated organic compound, and an organoaluminum compound irrespective of the addition order of the catalyst; and adding an organoborane compound as a cold flow controller of 1,4-cis polybutadiene after a predetermined time of the polymerization. Accordingly, a high 1,4-cis polybutadiene having an efficiently controlled cold flow can be prepared without causing a significant increase in the Mooney viscosity (molecular weight), an odor (bad smell), and a reduction in 1,4-cis content and polymerization yield.