Abstract: The present invention relates to a solid catalyst suitable for polymerizing olefins in a heterogeneous process, the catalyst consisting of spheroidal particles having a narrow particle size distribution and comprising (i) a support containing magnesium dichloride and an electron-donor free from labile hydrogene, (ii) a zirconium metallocene, and (iii) optionally an organoaluminium compound which is an aluminoxane preferably. The solid catalyst may be used in the form of a prepolymer comprising a polyethylene or a copolymer of ethylene and an active zirconium metallocene catalyst essentially consisting of atoms of Zr, Mg, Cl and Al, preferably in the form of spheriodal particles. The solid catalyst or the prepolymer may be used for producing polyethylene or copolymer of ethylene having from 0.5 to 20 ppm of Zr and a molecular weight distribution from 2 to 5, in the form of a powder having a bulk density from 0.3 to 0.55 g/cm.sup.3, preferably consisting of spheroidal particles.

Abstract: Solution and RIM polymerization of cycloolefins containing at least one norbornene moiety is carried out in the presence of a methathesis catalyst system and an activator, particularly a chlorosilane activator, to obtain faster reaction with higher conversions at lower mold temperatures. The methathesis catalyst system includes an organoammonium molybdate or tungstate catalyst and an alkylaluminum or an alkylaluminum halide cocatalyst. The chlorosilane activator is used at a level of 0.05 to 10 millimoles per mole of the cycloolefin monomers. The polymers of cycloolefins can be impact modified and/or flame-retarded.

Abstract: An olefin polymerization catalyst formed from (A) a solid titanium catalyst component containing magnesium, titanium and halogen as essential ingredients, (B) an organoaluminum compound, and (C) an organosilicon compound containing a cyclopentyl group, a cyclopentenyl group, a cyclopentadienyl group or a derivative derived from any of these groups.A polymerization process which comprises polymerizing or copolymerizing olefins in the presence of the olefin polymerization catalyst to form a homopolyolefin having high stereoregularity or a copolyolefin having a narrow composition distribution.

Abstract: A process for the polymerization of propylene or a mixture comprising propylene and one or more alpha-olefins and, optionally, one or more diolefins comprising contacting the propylene or the mixture of olefins in at least one reaction zone, under polymerization conditions, with a catalyst system comprising (i) a solid catalyst precursor, which includes magnesium; titanium; a halogen which is chlorine, bromine, or iodine, or mixtures thereof; and a mono- or polycarboxylic acid ester; (ii) a hydrocarbylaluminum cocatalyst; and (iii) a mixture of selectivity control agents comprising a mono- or polycarboxylic acid ester and a silicon compound containing at least one silicon-oxygen-carbon linkage with the proviso that (a) the atomic ratio of aluminum to titanium is in the range of about 5 to about 300; and (b) the molar ratio of the ester to silicon compound in the mixture of selectivity control agents is at least about 1.5:1.

Abstract: A method for preparing a propylene (co)polymer having a substantially high syndiotactic structure and a desired molecular weight which comprises the step of (co)polymerizing propylene or propylene and a small amount of another olefin by the use of a transition metal compound catalyst having asymmetric ligands in the presence of a specific internal olefin.

Abstract: A novel polymerization catalyst system comprising a diluent, a substrate, a nickel compound wherein the nickel is in a zero oxidation state and picolinic acid and a method for making such catalyst system is described. The polymerization catalyst system can be used in a process for the polymerization of polymerizable olefins.

Abstract: Ziegler polymerization of .alpha.-olefins is disclosed which is characterized by a solid catalyst component and an organoaluminum component used in the Ziegler catalyst, and also by the temperature used which is 150.degree. to 300.degree. C. The solid catalyst component, Component (A), comprises Sub-component (i) which is a solid catalyst component for Ziegler catalysts comprising Ti, Mg and a halogen; Subcomponent (ii) which is a silicon compound represented by a formula:R.sup.1.sub.m X.sub.n Si(OR.sup.2).sub.4-n-mwherein R.sup.1 indicates a hydrocarbyl group, R.sup.2 which may be the same as or different from R.sup.1 indicates a hydrocarbyl group, X is a halogen atom, and m and n are each a number satisfying equations 0.ltoreq.m.ltoreq.3, 0.ltoreq.n.ltoreq.3 and 0.ltoreq.m+n.ltoreq.3; and Sub-component (iii) which is an organometal compound of a metal of Groups I to IV of the Periodic Table. The organoaluminum component (B) is an organoaluminum compound which is a mixture of the following Sub-component (B.

Abstract: A catalyst for producing styrene-based polymers, containing (A) a titanium compound, (B) a contact product of an organoaluminum compound and water, and (C) an organic polyhydroxy compound, or (A) a titanium compound and (B) a contact product of an organoaluminum compound, water and a organic polyhydroxy compound, and a process for producing styrene-based polymers by the use of the above catalyst.

Abstract: In the case of Ziegler catalysts based on a metallocene as the transition metal component and an aluminoxane as the activator, preactivation of the metallocene with the aluminoxane results in a considerable increase in the activity of the catalyst system. Furthermore, 1-olefin polymers of a high degree of isotacticity and having compact, spherical particles, a very narrow particle size distribution and a high bulk density are obtained by means of a catalyst system of this type.

Abstract: A polyethylene, having 1 to 60 methyl branches and 1 to 60 hexyl or higher branches per 1000 carbon atoms, a g-value of 0.5 to 0.8, and a limiting viscosity [.eta.] of 0.005 to 20.0 dl/g as measured at 140.degree. C. in o-dichlorobenzene, and a method for producing the same by polymerizing ethylene using a catalyst system comprising a coordination nickel compound of zero- or two-valent nickel and an aminobis(imino)phosphorane represented by a general formula (I): ##STR1## where R.sub.1, R.sub.2, R.sub.3 and R.sub.4 may be the same as or different from each other and are respectively n-alkyl, isoalkyl, aryl or trialkylsilyl, in the presence of .alpha.-olefin.

Abstract: A polymer supported catalyst comprises Ziegler-Natta catalysts immobilized on a magnesium-modified polymer support. The catalyst support is prepared by (1) dissolving a carboxyl group-containing polymer in a solvent and precipitating the polymer in a polar non-solvent, (2) wet-grinding the precipitated polymer, and (3) mixing the ground polymer with an organomagnesium compound or a complex of an organomagnesium compound and an organoaluminum compound to give a magnesium-modified polymer support. Optionally, the resulting magnesium-modified support is treated with a halogen-containing silicon compound. The catalysts may be loaded onto the support by reacting the magnesium-modified support with a transition metal compound to form a catalyst constituent, and then combining the catalyst constituent with an appropriate organo-metallic compound.

Abstract: A process for producing an ethylene polymer comprising bringing ethylene or ethylene and an .alpha.-olefin having 3 to 10 carbon atoms into contact with a catalyst comprising the following components (A) and (B):component (A): a solid component for a Ziegler type catalyst obtained by bringing a solid product obtained by sequentially contacting the following components (A-1), (A-2) and (A-3) and then washing the contact product formed into contact with the component (A-4):component (A-1): a solid catalyst component comprising the following components (i), (ii) and (iii) wherein component (i) is a magnesium dihalide; component (ii) is a titanium tetraalkoxide and/or a polytitanic acid ester;and component (iii) is a polymeric Si compound represented by the formula: ##STR1## (R.sup.1 : a hydrocarbyl group) component (A-2) which is an organoaluminum compound; component (A-3) which is a silicon halide; and component (A-4) which is an organoaluminum halide; and component (B) which is an organoaluminum compound.

Abstract: Multimodal high-density ethylene polymers or copolymers (HDPE) of broad molecular weight distribution suitable for blow-molding and films are prepared with a chromium oxide catalyst mixed with a MgO-supported Ziegler catalyst, modified with an alkene and with alkyl aluminum hydride, and with an MgO additive.

Abstract: A polymerization catalyst is formed by producing a solution of a halide of scandium, yttrium, or a rare earth metal and an alcohol; contacting the solution with an organometallic compound to form a soluble complex; and contacting the soluble complex with a halide ion exchanging source. Optionally an ester or an anhydride can also be combined with the halide solution or the soluble complex. The catalyst thus produced can be combined with an organometallic cocatalyst.

Abstract: A catalyst for .alpha.-olefin polymerization which comprises the following components (A) and (B):component (A), which is a transition metal compound represented by the formulaQ(C.sub.5 H.sub.4-m R.sup.1.sub.m)(C.sub.5 H.sub.4-n R.sup.2.sub.n)MeXYwherein (C.sub.5 H.sub.4-m R.sup.1.sub.m) and (C.sub.5 H.sub.4-n R.sup.2.sub.n) respectively represent a conjugated five-membered ring ligand coordinating to a metal Me; R.sup.1 and R.sup.

Abstract: Ziegler polymerization of C.sub.3 or higher .alpha.-olefins is disclosed which is characterized by a solid catalyst component and an organoaluminum component used in the Ziegler catalyst, and also by the temperature used which is 150.degree. to 300.degree. C. The solid catalyst component, Component (A), comprises Sub-component (i) which is a solid catalyst component for Ziegler catalysts comprising Ti, Mg and a halogen; Sub-component (ii) which is a silicon compound represented by a formula: R.sup.1.sub.m X.sub.n Si(OR.sup.2).sub.4-n-m wherein R.sup.1 indicates a hydrocarbyl group, R.sup.2 which may be the same as or different from R.sup.1 indicates a hydrocarbyl group, X is a halogen atom, and m and n are each a number satisfying equations 0.ltoreq.m.ltoreq.3, 0.ltoreq.n.ltoreq.3 and 0.ltoreq.m+n.ltoreq.3; and Sub-component (iii) which is an organometal compound of a metal of Groups I to IV of the Periodic Table. The organoaluminum component (B) is an organoaluminum compound represented by a formulaR.sup.3.

Abstract: A highly crystalline semi-rigid random 1-butene/ethylene copolymer consisting of 1-butene and ethylene, said copolymer having the following characteristics (A) to (K);(A) it consists of 99 to 90 mole % of the 1-butene component and 1 to 10 mole % of the ethylene component,(B) it has an intrinsic viscosity (.eta.), measured in decalin at 130.degree. C., of from 0.5 to 6 dl/g,(C) it has a DSC melding point (Tm) measured by a differential scanning calorimeter, of from 100.degree. to 120.degree. C.,(D) it has a crystallinity, measured by X-ray diffractometry, of from 20 to 58%,(E) the amount (W.sub.1 in % by weight) of that portion of it which is soluble in boiling methyl acetate is not more than 2%,(F) the amount (W.sub.2 in % by weight) of that portion of it which is soluble in a 1:1 by volume mixture of acetone and n-decane at 10.degree. C. is less than 5.times.(.eta.).sup.-1.2,(G) it has a yield strength of 30 to 180 kg/cm.sup.2,(H) it has a tensile strength at break of 200 to 800 kg/cm.sup.

Abstract: A liquid catalyst component which can be used as a component of a catalyst system in combination with an organoaluminum compound (B) for producing ethylene-.alpha.-olefin copolymers.

Abstract: A catalyst and process for the polymerization of cyclic olefins, such as dicyclopentadiene, are disclosed. The catalyst includes a transition metal compound, a co-catalyst and a boron halide promoter. Polymerization can be carried out in a reaction injection molding process to prepare a thermoset molded article having high Tg and superior flexural strength.

Abstract: Suspensions, in oils, of particles containing a transition metal compound, which are spheroidal and of narrow particle size distribution.These suspensions can be employed in processes for the polymerization of alpha-olefins, carried out in the presence of an organoaluminium activator.