Abstract: The useful life of SO.sub.X additives having a SO.sub.2 .fwdarw.SO.sub.3 oxidation catalyst component and a SO.sub.3 absorption component can be extended by employing each of these components as separate and distinct physical particles, pellets, etc., with each component having large proportions of certain ingredients and having small proportions of certain other ingredients.

Abstract: A particulate phyllosilicate mixture comprising a mixture containing a phyllosilicte belonging to the smectite group and a phyllosilicate belogning to the mica group, the phyllosilicate particle having a content of the phyllosilicate belonging to the smectite group of 0.1 to 50% by weight and optionally satisfying the following requirements (a) to (c):(a): the average particle diameter is 20 to 1000 .mu.m with not more than 20% of the total number of particles being accounted for by particles having a particle diameter of not more than 10 .mu.m;(b): the crushing strength of the particle is not less than 0.5 MPa as measured with a microcompression tester and(c): the bulk density of the particle of not less than 0.6 g/cm.sup.3.Polymerization of olefins with catalyst comprising the particulate phyllosilicate mixture as a carrier or support for the catalysts is also disclosed.

Abstract: The present invention relates to a solid catalyst component for the polymerization of olefins CH.sub.2 .dbd.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): ##STR1## wherein R.sub.1 is a C.sub.5 -C.sub.20 linear or branched alkyl, a C.sub.5 -C.sub.20 cycloalkyl, a C.sub.7 -C.sub.20 arylalkyl or alkylaryl group; R.sub.2 and R.sub.3, equal to or different from each other, are C.sub.1 -C.sub.3 alkyl, cycloalkyl. 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: Polyesters are prepared by the reaction of a dicarboxylic acid, preferably an aromatic acid such as terephthalic acid, or an ester or ester-forming derivative thereof with a dihydroxy compound such as 1,4-butanediol in the presence of a catalyst composition comprising the combination of a titanium-based compound such as tetra-n-butyl titanate, a zirconium-based compound such as zirconium tetrakis(2,4-pentanedionate) and a phosphate-forming compound such as sodium dihydrogen phosphate. This catalyst composition affords polyesters having relatively low melt viscosities in short reaction times and does not produce an excessive level of undesirable reaction by-products.

Abstract: Disclosed is a novel catalyst for use in producing a carboxylic ester from an aldehyde, an alcohol and molecular oxygen, which comprises a carrier having supported thereon Pd and Pb in a Pd/Pb atomic ratio (S) of 3/0.7.ltoreq.S.ltoreq.3/1.3, and which exhibits a maximum intensity peak at a diffraction angle (2.theta.) in the range of from 38.55.degree. to 38.70.degree. in a powder X-ray diffraction pattern thereof, wherein the peak is ascribed to the (111) crystal face diffraction of a Pd--Pb intermetallic compound.

Abstract: By subjecting an aromatic compound of the formula (I), which is an inexpensive raw material, to a vapor-phase intramolecular cyclodehydrogenation reaction, fluorenes of the formula (II) can be obtained industrially advantageously in a high yield. Fluorenes (II) are expected to be used as raw materials for heat-resistant epoxy resins, polycarbonates or polyesters. wherein R.sub.1 and R.sub.2 each represent a hydrogen atom, a methyl group or an ethyl group, or R.sub.1 and R.sub.2 represent .dbd.O at the same time; and R and R' each represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms.

Abstract: Linear, thermoplastic, elastomneric copolymers of carbon monoxide and olefinically unsaturated compounds have an alternating sequence of repeating units and an average molecular weight Mw of the copolymers of from 80,000 to 1,200,000, binary, linear, alternating carbon monoxide/ethylene copolymers being excluded.

Abstract: Novel, chiral diarsine compounds, which are present in the (R)- or (S)- or (rac)-form, of the formula ##STR1## wherein R signifies an optionally substituted aryl from the group of phenyI, naphthyl, furyl and thienyl; C.sub.3-8 -cycloalkyl or C.sub.1-8 -alkyl;R.sup.1, R.sup.2, R.sup.3 each independently signify C.sub.1-8 -alkyl, C.sub.1-8 -alkoxy, aryloxy, F or Cl,R.sup.2 and R.sup.3 each independently also signify hydrogen orR.sup.1 and R.sup.2 together signify tetramethylene or a benzo or benzofuro system or dioxymethylene on the respective benzene ring; orR.sup.2 and R.sup.3 together signify dioxymethylene,and the manufacture of the diarsine compounds of formula I, as well as complexes of the compounds of formula I with Group VIII metal and their use for enantioselective reactions.

Abstract: The invention provides non-antimony containing polymerization catalysts for the condensation of polyesters. The catalyst is in the form of a clear chlorine and/or bromine containing solution of a metal glycoxide and a metal glycolate having a pH in the range of from 0 to about 1, and containing chlorine and/or bromine atoms at a number ratio of chlorine and/or bromine to total metal cations in the catalyst ranging from about 0.5:1 to about 3:1. Polyesters produced with this catalyst have improved melt elasticity, and higher melt viscosity. The former property is desirable for the preparation of large and complex shaped polyester containers, and the latter property is desirable for melt spinning of industrial grade fibers and tire cords.

Abstract: The invention relates to a process for the preparation of a high activity procatalyst for the production of ethylene polymers. The process according to the present invention comprises the following steps:(a) contacting the inorganic support with an alkyl metal chloride which is soluble in non-polar hydrocarbon solvents, and has the formula(R.sub.n MeCl.sub.3-n).sub.m (1)wherein R is a C.sub.1 -C.sub.20 aklyl group, Me is a metal of group III(13) of the periodic table, n=1 or 2 and m=1 or 2, to give a first reaction product,(b) contacting said first reaction product with a compound or mixture containing hydrocarbyl and hydrocarbyl oxide linked to magnesium which is soluble in non-polar hydrocarbon solvents, to give a second reaction product, and(c) contacting said second reaction product with a titanium compound which contains chlorine, having the formulaCl.sub.x Ti(OR.sup.IV).sub.4-x (2)wherein R.sup.IV is a C.sub.2 -C.sub.20 hydrocarbyl group and x is 3 or 4, to give said procatalyst.

Abstract: The present invention relates, inter alia, to methodologies for the synthesis, screening and characterization of organometallic compounds and catalysts (e.g., homogeneous catalysts). The methods of the present invention provide for the combinatorial synthesis, screening and characterization of libraries of supported and unsupported organometallic compounds and catalysts (e.g., homogeneous catalysts). The methods of the present invention can be applied to the preparation and screening of large numbers of organometallic compounds which can be used not only as catalysts (e.g., homogeneous catalysts), but also as additives and therapeutic agents.

Abstract: The sugar alcohols mentioned as title compounds can be prepared from the corresponding sugar in equimolar amounts by catalytic hydrogenation with hydrogen in aqueous solution, the hydrogenation being carried out continuously at an H.sub.2 pressure of 100 to 400 bar and a reaction temperature of 20 to 80.degree. C. using fixed-bed support-free molded bodies composed of compacted powders of alloys of the elements of the iron subgroup of group VIIIA of the periodic table with elements of group IVB and VA. The molded bodies have a compressive strength of 20 to 220 N and an internal surface area of 10 to 95 m.sup.2 /g.

Abstract: The present invention relates to a polyester polymerization catalyst, comprising a solution containing an aluminum compound and an alkali compound, with water or an organic solvent or a mixture consisting of water and an organic solvent as the medium, a production method thereof, and a polyester production method, in which the product obtained by the esterification reaction or ester interchange reaction between an aromatic dicarboxylic acid or any of its ester forming derivative and a diol is polycondensed, to produce a polyester, comprising the use of said polymerization catalyst containing an aluminum compound.The present invention can provide a polyester excellent in processability and can overcome such problems as spinneret contamination, filtration pressure rise, filament breaking, film breaking and foreign matter production in the production process of products such as fibers, films, resins and bottles.

Abstract: An olefin polymerization catalyst system comprising a complex having the general formula I or II: ##STR1## wherein in formula (I) M is V, Nb or Ta and in formula (II) M is Cr, Mo or W; R is selected from alkyl and aryl, and in formula II the R groups may be the same or different; X is an organic group containing a cyclopentadienyl nucleus, Y is a univalent anionic ligand, the Y groups may be the same or different; n is 0 or 1; the complex of formula (I) or (II) being supported on a substrate comprising a polyaminostyrene or a copolymer of styrene and aminostyrene.

Abstract: A process for the preparation of heterogeneous zirconium based catalyst for polymerization of alpha-olefins to super high molecular weight poly (alpha-olefins). The process comprises in mixing zirconium alcholate or phenolate with anhydrous magnesium chloride in the presence of a solvent. The mixture is heated, then cooled and an organoaluminum compound is added. Optionally, an electron donor compound is added and heated to obtain a black slurry, which is cooled and then washed with a hydrocarbon diluent.

Abstract: The invention comprises a curable composition comprising: (i) a blocked reactive component wherein the blocked reactive component is a blocked isocyanate or a blocked isothiocyanate; (ii) a functional compound reactive with the blocked reactive component, the functional compound containing reactive hydrogen; (iii) a catalyst for promoting the reaction of the reactive component with the blocked functional compound, wherein said catalyst is based on the reaction product of manganese, cobalt, nickel, copper, zinc, germanium, antimony, or bismuth, or the oxides thereof with a mercaptan, or an organic acid, wherein said organic acid is hexanoic, oxalic, adipic, lactic, tartaric, salicylic, thioglycolic, succinic, or mercapto succinic acid, or the reaction product of copper or germanium, or the oxides thereof with a lower aliphatic acid.

Abstract: A catalyst having a high pore volume, high surface area porous silica support and a non-metallocene, Ziegler-Natta catalytic component incorporated on the silica support is provided for the production of polyolefins from .alpha.-olefins. The porous silica support is made up of silica gel particles having an average surface area of about 600 to about 800 m.sup.2 /g of silica and an average pore volume of about 2.5 to about 4.0 ml/g of silica. Preferably, the silica particles have an average surface area of about 650 to about 750 m.sup.2 /g of silica and an average pore volume of about 2.75 to about 3.25 ml/g of silica. Even more preferably, the silica particles have an average surface area of about 700 m.sup.2 /g of silica and an average pore volume of about 3.0 ml/g of silica. The catalytic component comprises a complex product of a transition metal halide and a metal alkyl which excludes cyclopentadienyl rings.

Abstract: The invention provides a catalytic composition which is based on a cerium oxide and on at least one other oxide chosen from iron, manganese and praseodymium oxides, which controls H.sub.2 S emissions in the catalysis of treatment of automobile exhaust gas.

Abstract: Methods of making substantially phase-pure and thermally stable crystalline alumina compositions stabilized with an oxide of silicon, germanium, phosphorus, arsenic or a mixture thereof. Also provided are crystalline alumina compositions and catalyst supports made using these methods.

Abstract: A catalyst for the production of vinyl acetate by reaction of ethylene, oxygen and acetic acid comprising a porous support on the porous surfaces of which is deposited metallic copper in a zone surrounded by deposits of catalytically effective amounts of metallic palladium and gold, neither of which is substantially intermingled with said copper. Methods for preparing the catalyst and for synthesizing vinyl acetate utilizing the catalyst are also disclosed.

Abstract: A method of making a solid, substantially dry olefin polymerization procatalyst precursor is disclosed whereby a solid precursor containing magnesium and titanium is formed in a slurry or solution, the solid then is separated from the solution and then dried at a temperature above 50.degree. C. for over an hour. Solid, substantially dry olefin polymerization procatalyst precursors made by the method also are disclosed, whereby the precursors are easier to handle, have better flowability, reduced clumpness and provide catalysts that can be used to produce polymers having improved extrudability, less filter clogging, less "talc"-like polymer particles of <10 micron in size and reduced polymer product segregation in storage.

Abstract: A process for polymerizing a gaseous conjugated diene by bringing it in contact with a catalyst consisting of a rare earth allyl compound, an organic aluminum compound, an inorganic support and optionally, the same or a different conjugated diene. The resulting polymers possess elevated proportions of cis-1,4 units.

Abstract: The present invention relates to a catalyst for purifying an exhaust gas, and in particular provides a catalyst for purifying an exhaust gas using a complex oxide, which is not deteriorated in its purifying performance even in a lean atmosphere containing sulfur dioxide SO.sub.2 at temperatures as high as at least 1,000.degree. C., comprising at least one of the noble metals and one or at least two elements selected from the group consisting of alkaline earth metals and Group IIIA elements, and at least one member selected from the group consisting of iron, nickel and cobalt is supported in the surface portion of the catalyst, the catalyst further comprising, as a constituent element of the complex oxide, at least one element selected from the group consisting of iron, nickel and cobalt.

Abstract: Disclosed is an alkylating agent that contains an aluminum reagent Alk.sub.3-m AlL.sub.m, in which Alk means a methyl, ethyl, n- or i-propyl, n-, i- or tert-butyl, pentyl, hexyl, heptyl or octyl group, which all can also be branched, L means an ethoxy group, a chlorine or bromine atom, and m is equal to 1 or 2, as an alkyl source or else zinc dimethyl as a methyl source, which contains in addition catalytic amounts of one or more copper(I) and/or copper(II) compounds and one (or more) silyl reagent(s) of general formula IIIR.sup.1 R.sup.2 R.sup.3 SiZ (III),in whichR.sup.1, R.sup.2 and R.sup.3 are as defined herein, as well as a process for 1,4-addition of an alkyl group to an .alpha.,.beta.-unsaturated ketone or an .alpha.,.beta.-double unsaturated ketone or to an .alpha.,.beta.-unsaturated aldehyde with use of the agent according to the invention.

Abstract: A catalyst composition for use in the preparation of a polyester or copolyester is disclosed. The catalyst composition comprises the combination of (a) a titanium-based compound or zirconium-based compound, and (b) a lanthanide series compound or hafnium. Various titanium-based compounds and lanthanide-based compounds are described. Moreover, in some embodiments, the catalyst composition may further comprise a phosphate-forming compound. Another aspect of this invention is an improved method for preparing a polyester, based, for example, on the two-stage process of ester interchange and polycondensation. The method is carried out in the presence of the catalyst composition described above.

Abstract: A soluble mono-alkyl Stannoic Acid/glycol liquid phase catalyst produced from the reaction of a mono-alkyl Stannoic Acid and a glycol at a temperature of from at least 180.degree. C., and its use in preparing high molecular weight polyester polymers.

Abstract: Rhenium oxide catalysts carried on aluminium silicates, if required with added boric oxide, tungsten oxide, molybdenum oxide or vanadium oxide for the metathesis of olefins and functionalised olefins, in particular of carboxylic acid esters, are provided, whereby the carrier material was hydrothermally treated.

Abstract: Esters of unsaturated fatty acids or mixtures thereof can be hydrogenated by a catalysed liquid-phase hydrogenation with hydrogen to give saturated or partially saturated esters of fatty acids or ester mixtures of fatty acids by carrying out the hydrogenation continuously at a pressure of 50 to 350 bar and a reaction temperature of 40 to 150.degree. C. on oxygen-free and support-free shaped bodies which are arranged in a fixed bed and made of pressed powders of elements of the iron subgroup of subgroup VIII of the Periodic Table of the Elements or their alloys with each other or their alloys with elements of subgroup VI; in addition, hydrogenation-inert elements can be present. The shaped bodies have a compressive strength of 20 to 250N on the curved shaped body surface and have an internal surface area of 10 to 90 m.sup.2 /g.

Abstract: Catalysts consisting ofA) an alcoholate of the rare earths, a carboxylate of the rare earths, a complex compound of the rare earths with diketones and/or an addition compound of the halides of the rare earths with an oxygen or nitrogen donor compound,B) an aluminium trialkyl, a dialkyl aluminium hydride and/or an alumoxane,C) another Lewis acid andD) an inert, particulate inorganic solid with a specific surface of greater than 10 m.sup.2 /g (BET) and a pore volume of 0.3 to 15 ml/gare eminently suitable for the polymerization of conjugated dienes, more particularly butadiene, in the gas phase.

Abstract: A cationic metallocene complex with trisperfluorobiphenyl borate for use as a polymerization catalyst.

Abstract: A trityl perfluorophenyl alumninate such as tris(2,2',2"-nonafluorobiphenyl) fluoroaluminate (PBA.sup.-) and its role as a cocatalyst in metallocene-mediated olefin polymerization is disclosed.

Abstract: A catalyst composition for the polymerization of olefins is provided, comprising a bis(hydroxy aromatic nitrogen ligand) transition metal catalyst precursor and an activating cocatalyst.

Abstract: A supported catalyst component comprising (a) a support material, an organometal compound, and (b) an activator compound comprising b.1) a cation which is capable of reacting with a transition metal metallocene compound to form a catalytically active transition metal complex, and b.2) a compatible anion having up to 100 nonhydrogen atoms and containing at least one substituent comprising an active hydrogen moiety; a supported catalyst comprising the supported catalyst component and a transition metal compound; process for making the same; an addition polymerization process using the supported catalyst; complex compounds, and a method for preparing the same.

Abstract: A catalyst for the (co)polymerization of ethylene is obtained by a process comprising the contact of the following components (A), (B), (C) and (D) in the respective molar ratios (1):(0.5-2):(0-25):(0-15):(A): a bivalent arene of titanium having the formulaTi (.eta..sup.6 -arene)(AlR.sub.x X.sub.4-x).sub.2 ;wherein: "arene" indicates benzene, or benzene substituted with from 1 to 6 C.sub.1 -C.sub.10 alkyl groups;each X independently represents a chlorine, bromine or fluorine atom;R is a C.sub.1 C.sub.10 alkyl group, linear or branched; "x" is a number varying from 0.5 to 2.

Abstract: A catalyst for olefin polymerization obtainable by contacting:(a) a transition metal compound containing a transition metal of the Group 4 of the Periodic Table,(b) an organometallic compound, and(c) a solid catalyst component comprising a carrier and an ionized ionic compound capable of forming a stable anion on reaction with a transition metal compound, wherein the ionized ionic compound comprises a cationic component and an anionic component and the cationic component is fixed on the surface of the carrier. The catalyst system of the invention enables production of olefin polymers with excellent physical properties at good productivity without causing contamination of a polymerization vessel.

Abstract: The present invention provides new catalyst formats which comprise a supported catalyst tethered to a second and different catalyst by a suitable tethering ligand. A preferred system comprises a heterogeneous supported metal catalyst tethered to a homogeneous catalyst. This combination of homogeneous and heterogeneous catalysts has a sufficient lifetime and unusually high catalytic activity in arene hydrogenations, and potentially many other reactions as well, including, but not limited to hydroformylation, hydrosilation, olefin oxidation, isomerization, hydrocyanation, olefin metathesis, olefin polymerization, carbonylation, enantioselective catalysis and photoduplication. These catalysts are easily separated from the products, and can be reused repeatedly, making these systems very economical.

Abstract: The invention relates to a procatalyst for the production of ethylene polymers, which procatalyst comprises an inorganic support, a chlorine compound carried on said support, a magnesium compound carried on said support, a titanium compound carried on said support, whereby the chlorine compound can be different from or the same as the magnesium compound and/or the titanium compound. The activity balance AB of the procatalyst in specified polymerization conditions, isAB>3.2wherein AB=?(A+A'):2!.multidot.?log (MFR.sub.2 ':MFR.sub.2):(A-A')!, A means polymerization activity expressed an kg PE/g cat .multidot.h, MFR.sub.2 means the melt flow rate in g/min units at a load of 2,16 kg, according to the standard ISO 1133, the absence of the upper index ' means low melt flow rate polymerization and the presence of the upper index ' means high melt flow polymerization. This means that the catalyst activity is relatively independent of the presence of chain transfer agents.

Abstract: Catalyst support containing an .alpha.-olefin polymer which is in the form of particles of mean size from 5 to 350 .mu.m in which the pore volume generated by the pores of radius from 1,000 to 75,000 .ANG. is at least 0.2 cm.sup.3 /g.Catalyst usable for the polymerization of .alpha.-olefins, including a compound containing at least one transition metal belonging to groups IIIb, IVb, IVb and VIb of the Periodic Table, bound in or on this support.

Abstract: A process for the preparation of a copolymer of carbon monoxide with an olefinically unsaturated compound, comprising copolymerizing the monomers in the presence of a Group VIII metal containing catalyst composition and in the presence of an olefinically unsaturated compound (A) which contains in its molecular structure an organic group imparting steric hindrance on the vinyl group. A copolymer obtainable by the said process.

Abstract: The present invention concerns new catalysts based on compounds containing both rhenium and aluminum, which are deposited on an organic or inorganic support. The compounds of rhenium and aluminum correspond to the general formula:O.sub.3 Re--O--?Al(OR)(L).sub.x --O!.sub.n --ReO.sub.3in which R is a hydrocarbyl residue, for example alkyl, cycloalkyl, alkenyl, aryl, and aryl or cycloalkyl which are substituted, containing from 1 to 40 carbon atoms, which residue can be substituted by alkoxy groups or by halogens, L is the synthesis solvent, x is equal to 0 or 1 and n is an integer of from 1 to 10. The invention also concerns the preparation of such catalysts and the use thereof for the metathesis of olefins.

Abstract: A process for the copolymerization of carbon monoxide with ethene and optionally another olefinically unsaturated compound in which process the monomers are copolymerized in the presence of a liquid diluent and a catalyst composition which is based on(a) a Group VIII metal compound,(b) an anion of an acid which is obtainable by combining a Br.o slashed.nsted acid with a Lewis acid, and(c) an organic oxidant in a quantity of less than 30 moles per mole of Group VIII metal.

Abstract: The present invention relates to a process for the preparation of a solid catalytic component of a catalyst of Ziegler-Natta type, comprising contacting (i) at least one compound (A) of a transition metal (TM) with (ii) a solid product (B) comprising a magnesium compound and having a reducing power for the transition metal (TM), in the presence of (iii) at least one olefin under conditions such that the olefin at least partially polymerizes during the contacting. The solid catalytic component is particularly useful for producing ethylene (co-)polymers in a gas phase process and for improving the statistical distribution of the comonomer in the copolymer structure.

Abstract: A process for the preparation of alternated linear copolymers based on carbon monoxide and one or more compounds having an unsaturation of the alkenylic type comprises, reacting in a halogenated aromatic or aliphatic solvent the carbon monoxide and one or more compounds having an alkenylic unsaturation in the presence of a catalyst having general formula (I)?Pd(chel)(chel')!.sup.+ ?A.sup.- !wherein: chel represents a non-charged bidentate chelating agent, chel' represents the anion of an organic compound containing a double carbon--carbon bond co-ordinated via .pi. bond to palladium (Pd) and a carbanion bound via .sigma. bond to palladium which is co-ordinated to the metal as a bidentate chelating agent and A.sup.- is an anion of a non-esterifiable or almost non-esterifiable and non-coordinating acid.

Abstract: This invention relates to a conventional supported heterogeneous Ziegler-Natta catalyst for the polymerization of olefins. It has been found that adding a lithium compound to a transition metal catalyst component and then adding an organoaluminum co-catalyst and an organosilicon electron donor produces a catalyst which yields polymer with increased molecular weight. The lithium compound is of the general formula LiCp wherein Cp is a cyclopentadienyl or substituted cyclopentadienyl and is preferably lithium cyclopentadienide or lithium indene. Preferably, the molar ratio of lithium compound/transition metal is at least 0.2.

Abstract: Linear alternating copolymers of carbon monoxide and at least one compound containing an alkenyl unsaturation are obtained by reaction between carbon monoxide and at least one compound containing an alkenyl unsaturation, in a solvent which is liquid under the operating conditions, in the presence of a preformed bischelated catalyst having general formula (I) active without cocatalysts:?Pd(chel)(chel')!.sup.++ ?A.sup.- !.sub.2 (I)wherein: chel and chel', the same or different, represent a nitrogenated or phosphorated bidentate chelating agent, and A.sup.- represents an essentially non-co-ordinating, non-esterifiable and non-labile anion selected from (3,5-(CF.sub.3).sub.2 -C.sub.6 H.sub.3).sub.4 B.sup.-, tetra(perfluorophenyl)borate B(C.sub.6 F.sub.5).sub.4.sup.- and Al(C.sub.6 F.sub.5).sub.4.sup.-.

Abstract: A high surface area oxidative catalyst smoke suppressive composition, smoke suppressive articles, and method of making such compositions and articles are disclosed. The smoke suppressive composition is a solid solution comprising a mixture of iron (Fe) and magnesium (Mg) that promotes efficient combustion, articles treated with such compositions, and methods for making such smoke suppressive compositions and articles. The smoke suppressive composition is made by co-precipitating Fe and Mg from an aqueous solution in the presence of a base. The iron-magnesium composition demonstrates high surface area and efficient combustion for embodiments having iron in an amount from approximately 3 mol % to approximately 30 mol % and magnesium in an amount from approximately 97 mol % to approximately 70 mol %. The compositions provide superior smoke suppression for items such as cigarettes and smoke suppressive articles.

Abstract: Siloxy-aluminoxane compositions which are the reaction products of hydrocarbylsiloxanes substantially-free of Si--OH groups, and aluminoxanes and which have improved solubility and stability in solution even at up to 60 weight percent when compared to the original aluminoxane. The compositions in combination with metallocenes of transition lanithanide and actinide metals form catalysts which can be used in the polymerization of olefins such as ethylene.

Abstract: Process for the preparation of crystalline vinylaromatic polymers with a predominantly syndiotactic structure which comprises polymerizing vinylaromatic monomers, alone or mixed with at least one other monomer, in the presence of a catalytic system essentially consisting of:a) a complex of titanium or zirconium selected from those having general formula:MR.sub.1 R.sub.2 R.sub.3 R.sub.4, A.sub.1 MR.sub.1 R.sub.2 R.sub.3, A.sub.1 A.sub.2 MR.sub.1 R.sub.2 (I)b) a co-catalyst selected from an alkylalumoxane and a compound of boron having formula (II):BX.sub.1 X.sub.2 X.sub.3 (II)or one of its salts;c) a derivative of tin having general formula:SnR.sub.5 R.sub.6 R.sub.7 R.sub.

Abstract: A method for preparing polyester by use of a catalyst. The method comprises the steps of: esterifying either a terephthalic acid, a dicarboxylic acid containing terephthalic acid or derivatives thereof with either ethylene glycol or a glycol containing ethylene glycol, or derivatives thereof to produce an esterification product containing either bis(.beta.-hydroxyethyl) terephthalate, its low molecular weight polymer, or a combination of .beta.-hydroxyethyl terephthalate and its low molecular weight polymer; and continuously polycondensing the obtained esterification product to prepare a polyester, wherein in the said polycondensing step, a composite polymerization catalyst dissolved in an ethylene glycol or an ethylene glycol-containing solution, consisting of a compound of antimony, a compound of titanium, and a compound of tin is used.

Abstract: There are disclosed a transition metal compound of the general formula RMX.sub.a-1 L.sub.b (R is a .pi. ligand, a fused polycyclic cyclopentadienyl group in which at least one of many-membered rings to which cyclopentadienyl groups are fusedly bonded is a saturated ring, M is a transition metal, X is a .sigma. ligand, L is a Lewis base, a is the valency of M, and b is 0, 1 or 2); a polymerization catalyst for styrene, etc. comprising the above transition metal, preferably further comprising an oxygen atom containing compound ionic compound or organoboron compound and optionally a Lewis base; and a process for producing a polymer of a compound containing an ethylenically unsaturated double bond or an acetylenic polymer, especially a syndiotactic polystyrene by using the above polymerization catalyst. The catalyst is particularly effective for producing highly syndiotactic polystyrene minimized in residual metals amounts at a low cost in enhanced efficiency.