Abstract: An autodepositing liquid composition comprises dispersed non-film-forming polymer particles in addition to the dispersed film forming polymer characteristic of all autodepositing liquid compositions. Preferably, the non-film-forming polymer particles are gas-tight microballoons filled with a gas such as air and have an average particle size less than 1 &mgr;m. Such particles act in the autodepositing liquid compositions and in the dried coatings formed from them as opaque white pigments, unless the coatings are heated above about 130° C., if so heated, the coatings, unless they contain other heat stable pigment, become irreversibly transparent.

Abstract: Herein is disclosed a blend of a neat oxygen scavenging polymer and a second polymer. The blend can be prepared by extrusion of a neat formulation of the oxygen scavenging polymer and the second polymer. Also disclosed are methods for preparing the neat formulation of the oxygen scavenging polymer, and packaging articles prepared from the blend. In addition, compositions comprising a branched oxygen scavenging polymer and a second polymer are disclosed, as well as packaging articles prepared from such compositions.

Abstract: The invention consists of a bitumen/resin composite emulsion for a road surface protection layer against the attacks of petroleum derivates, realised by mixing a first emulsion comprising at least one resin with a second emulsion comprising a bituminous binder and a resin crosslinking agent. A pigmentary preparation and/or a load made of a filler or sand or a fine sand or their combinations, can be incorporated to the first emulsion, the second emulsion or into the composite emulsion resulting from the mixture of both emulsions. The loaded composite emulsion enables the realisation of thin film-type surface coatings made of one or several layers.

Abstract: A flame resistant composition comprises (a) a polymer; (b) a synergistic mixture comprising(i) from about 0.6 to about 3 percent of a non-halogenated flame retardant compound; and (ii) at least about 0.06 percent of a compatible additive; wherein said percentages are based on weight percent of (a) plus (b), wherein (a) plus (b) equals 100 percent. A method of rendering a polymer flame resistant comprises compounding said polymer with a synergistic mixture comprising (i) from about 0.6 to about 3 percent of a non-halogenated flame retardant compound; and (ii) at least about 0.06 percent of a compatible additive; wherein the percentages are based on weight percent of polymer plus the synergistic mixture, and wherein polymer plus synergistic mixture equals 100 percent.

Abstract: The present invention relates to a method of making improved polyolefinic elastic articles from cured, irradiated or crosslinked amorphous ethylene interpolymers. In particular, the invention relates to a method of making a shaped article (e.g. film or fiber) characterized by improved elevated temperature elasticity as well as washability and dryability. The inventive elastic article comprises a substantially cured, irradiated, or crosslinked (or curable, irradiated or crosslinkable) homogeneously branched ethylene interpolymer characterized as having a density less than 0.90 g/cm3 and containing at least one nitrogen-containing stabilizer. The improved elastic article of the present invention is particularly suitable for use in applications where good elasticity must be maintained at elevated temperatures and after laundering such as, for example, elastic waist bands of undergarments and other clothing.

Abstract: A rubber composition and method of making a rubber composition which is improved in a dispersibility of silica into rubber, a heat generating property and an abrasion property.

Abstract: A charging member is provided, in which the electrical resistance is controlled with ease, the electrical resistances are uniform, and the electrical resistance, chemical properties, mechanical properties, etc., are suppressed to change with time so as to exhibit superior durability. The charging member primarily contains 100 parts by weight of at least one kind of polar rubber including at least a nitrile rubber, and further contains at least 0.01 parts by weight or more and 5 parts by weight or less of diazabicycloamine compound and 0.01 parts by weight or more and 10 parts by weight or less of weakly acidic compound.

Abstract: Bicyclic nucleator compounds that provide highly versatile nucleation benefits for different polyolefins are provided. Such nucleator compounds provide very high peak crystallization temperatures and significantly reduced crystallization cycle time for certain thermoplastic formulations with or without the presence of other calcium stearate and/or peroxide components within the same type of formulation. Furthermore, such inventive nucleator compounds exhibits very little if any fugitivity from such thermoplastic formulations thereby providing excellent processing characteristics as well as excellent nucleation capabilities for a variety of different thermoplastic resins, independent of the presence of different, potentially necessary, additives (such as calcium stearate). Thermoplastic compositions as well as thermoplastic additive packages comprising such inventive nucleator compounds are also contemplated within this invention.

Abstract: Polyvinyl butyral resin and sheet having a hydroxyl content less than 19.5, preferably about 17 to 19 weight %, calculated as polyvinyl alcohol, plasticized with a compatible amount of triethylene glycol di-2-ethylhexanoate.

Abstract: Monoesters of fatty acids containing at least 12 carbon atoms may replace a considerable percentage of conventional plasticizers based on phthalic acid esters, alkyl sulfonic acid esters of phenol or other known plasticizers in plastisol compositions. The methyl and/or ethyl esters of fatty acids of renewable fats and oils, such as tall oil fatty acids, rapeseed oil fatty acids, linseed oil fatty acids or safflower oil fatty acids, are preferably used for these secondary plasticizers. These plastisols are preferably used as adhesives, sealing materials or coatings in automobile construction.

Abstract: Halogen-containing polymer compositions comprising a latent mercaptan-containing heat stabilizer composition substantially free from the offensive odor typically associated with mercaptans are protected during processing by the degradation products of the latent (i.e., blocked) mercaptan which include a free mercaptan. Other products of the degradation are believed to include carbocations of the blocking moiety which are stabilized by a molecular structure in which the electron deficiency is shared by several groups. The latent mercaptan may be the sole heat stabilizer additive but the free mercaptan released during processing may also synergize the activity of metal-based heat stabilizers such as metal salts and organometallic stabilizers such as organotin carboxylates and mercaptides in the polymer composition. The odor of primary mercaptan-containing heat stabilizers in halogenated polymer compositions is masked by a small amount of a latent mercaptan.

Abstract: This invention is a composition comprising (a) an oligomer or polymer dispersible in an organic solvent, having a low dielectric constant, or being curable to form a material having a low dielectric constant, (b) at least one organic solvent and (c) less than 1000 parts by weight of a polymeric coating additive per million parts by weight of total composition (ppm). The polymeric additive is characterized in that it is miscible with component (a) and the solvent system but becomes incompatible with the mixture of component (a) and solvent during the coating process.

Abstract: Novel ultraviolet absorbing compounds that are liquid in nature, are extremely low in color (and thus permit use without the concomitant necessity of adding large amounts of other coloring agents to combat such discoloring), and are highly effective in providing protection in wavelength ranges for which previous attempts at low-color ultraviolet absorbers have failed are provided herein. Such compounds provide such excellent, inexpensive, and beneficial protection from ultraviolet exposure within various media, including, but not limited to, clear thermoplastics. The particular compounds are generally polymeric in nature including various chain lengths of polyoxyalkylenes thereon and are liquid in nature to facilitate handling and introduction within the target media. In addition, such ultraviolet absorbers also exhibit extremely low migratory properties thereby providing long-term protective benefits to the target media as well.

Abstract: The invention provides a process for the preparation of polymer particles having a mode particle size of at least 50 &mgr;m which process comprises (a) obtaining a first particulate polymer seed material having a mode particle diameter of no more than 50 &mgr;m; (b) using said first seed material, performing a suspension polymerization involving the steps: (i) forming an aqueous dispersion comprising a polymer seed material, an organic compound (e.g. a polymerization initiator) which has a molecular weight of less than 5000 Daltons and a water solubility of less than 10−2 g/L at 25° C., a stabilizer and optionally an organic solvent (e.g. acetone or a portion of the monomer mentioned below); (ii) allowing said organic compound to diffuse into the seed material to produce an activated seed material; and (iii) contacting said activated seed material with a monomer (e.g.

Abstract: A phenol resin composition for forming pulleys used in motor vehicles is disclosed. The composition comprises 35 to 45 wt % of resol, 35 to 45 wt % of glass fiber, 5 to 15 wt % of one or more inorganic powders selected from the group consisting of calcium carbonate, clay, and wallastonite, and 1 to 3 wt % of polyvinyl butyral. The phenol resin pulley for motor vehicles is almost free from swelling or shell cracking on the surface at a high temperature of 250° C. or more and exhibits high mechanical strength and superior thermal shock resistance.

Abstract: A rubber composition of the invention comprises [1] a cross inked rubber particle component whose toluene-insolubles is 50% by weight or more and whose number mean particle size is 3 to 1000 nm and [2] a non-crosslinked rubber component whose toluene-insolubles is less than 20% by weight. This crosslinked rubber particle component is a polymer comprising at least one selected from (1) a conjugated diene unit, (2) a conjugated diene unit and an &agr;,&bgr;-unsaturated nitrile unit and (3) a conjugated diene unit and an acrylate unit as well as a monomer unit having at least 2 polymerizable unsaturated groups. The non-crosslinked rubber component described above is a polymer co rising at least one selected from (a) a conjugated diene unit, (b) (a) plus an aromatic vinyl unit, (c) (a) plus an &agr;,&bgr;-unsaturated nitrile unit, (d) (a) plus an acrylate unit and (e) an ethylene unit and an &agr;-olefin unit having 3 to 12 carbon atoms.

Abstract: The invention relates to the preparation of a water-dilutable stone impact protection and of a compensation paint and its use and processes for their production, especially in the automobile industry. The water-dilutable stone impact protection paint contains 20 to 60 wt % binder and 2 to 10 wt % pigments and possibly uncoagulated overspray of water-soluble base paints and the compensation paint contains 40 to 80 wt % binder.

Abstract: An aqueous polymer dispersion, wherein the dispersion contains from 0.0001 to 1 mol of a hydrolyzable silicon group and from 0.0001 to 1 mol of a urea or thiourea group, based, in each case, on 100 g of the polymer present in the dispersion.

Abstract: An aqueous polymer dispersion comprising a polymer substantially free of cationic polymerizable groups and a cationic photoinitiator, wherein the polymer is capable of being precipitated by an acid or base generating photoinitiator upon exposure to radiation and is optionally an energy curable polymer.

Abstract: Forming graft copolymers in water using labeling of water soluble polymers with photoinitiators. Water soluble polymers can form environmentally responsive hydrophobically stimulated cages. The cages, which contain initiating radicals after irradiation, may be “opened” or “closed” by changes in environmental conditions. When the cage is closed, the radicals are trapped inside and thus do not cause substantial polymerization of water soluble monomers in the same solution. When the cage is closed, the radicals escape and cause polymerization. In another variation, hydrogels and graft copolymers are formed by covalently linking phototoinitiator groups to water soluble polymers that do not form cages. Thus, monomers may form grafts to the polymer, allowing formation of physical hydrogels.

Abstract: In order to easily and effectively polymerize an organosiloxane and produce a polyorganosiloxane latex from which the organosiloxane monomer does not emerge and which has a weight-average diameter controlled to under 0.4 &mgr;m, a paste is polymerized which contains at least a cyclic organosiloxane, a surface active agent, an initiator, and water, and which is an emulsified dispersion of the cyclic organosiloxane, in which the water content is in a proportion of 1 to 66 parts by weight with respect to 100 parts by weight of the cyclic organosiloxane. A latex obtained by diluting the thus-obtained polymerized paste has excellent liquid stability. The above paste, which is an emulsified dispersion of the cyclic organosiloxane, can be produced by mixing the organosiloxane, the surface active agent, the initiator, and the water together in an emulsifying and dispersing machine, and dispersing therein.

Abstract: This invention relates to binders for aqueous coatings, to a process for the production thereof and to the use thereof for lacquers and coatings.

Abstract: The present invention provides golf balls having a cover, a core, and optionally one or more intermediate layers between the cover and the core, wherein at least one of the cover, the core and, if present, the intermediate layer or layers, includes an anionic polymer. The anionic polymer has at least one of a neutralizable hydroxyl or dealkylable ether group, at least a portion of which are neutralized or dealkylated by a metal ion to provide anionic moieties. The anionic polymer compositions of the present invention can be used to provide improved characteristics to golf balls made therefrom.

Abstract: Disclosed is a process for producing a powdered water-soluble polymer comprising hydrolyzing a copolymer comprising an N-vinylamide unit and a vinyl acetate unit while dispersed in water under a basic condition and then washing the resulting powdered water-soluble polymer with at least one washing liquid selected from an alcohol, water at 20° C. or lower, and salt water.

Abstract: There is a vinyl 4-hydroxybenzal-vinylalcohol-vinyl acetate copolymer, a 4-t-butoxycarbonyloxybenzal-vinyl alcohol-vinyl acetate copolymer and a vinyl 4-t-butoxycarbonyloxybenzal-vinyl 4-hydroxybenzal-vinyl alcohol-vinyl acetate copolymer suitable for photoresist and methods for preparing the same. The latter two polymers contain 4-hydroxybenzal groups all or parts of which are protected with t-butoxycarbonyl group. Superior in transparency, thermal stability, mechanical strength, and adhesiveness to silicon wafer, the photoresists prepared from the protected copolymers can enhance the resolution of fine circuit by virtue of low weight loss upon the thermal treatment after exposure.

Abstract: The blends comprise (a) thermoplastic polyurethane having a Shore hardness of from 60 A to 50 D and (b) ethylene-propylene (EPM) rubbers and/or modified ethylene-propylene (EPM) rubbers, where the weight ratio of (a):(b) is from 3:1 to 999:1.

Abstract: Safety glass interlayers are prepared from a composition comprising: A. A homogeneously linear or substantially linear ethylene/&agr;-olefin interpolymer, e.g., ethylene/1-octene; B. A coagent containing at least two vinyl groups, e.g., trimethyol propane tri(meth)acrylate; and C. A peroxide, e.g., Luperox™ 101. The interlayer films exhibit an excellent combination of tear strength and clarity.

Abstract: The present invention relates to a curing type water base resin composition comprising: (I) a copolymer obtained by copolymerizing an ethylenically unsaturated monomer (a) having a maleimide group, an ethylenically unsaturated monomer (b) having a carbonyl group and other ethylenically unsaturated monomer (c) and (II) a compound having two or more groups per molecule which are the same or different and selected from a hydrazide group, a semicarbazide group and hydrazone group and further comprising, if necessary, as an additional component: (III) a copolymer having a carbonyl group and/or (IV) a water base polyurethane resin having a carbonyl group or a hydrazine group.

Abstract: The present invention provides a thermoplastic resin composition comprising (a) 100 parts by weight of a resin selected from the group consisting of polypropylenes and copolymers composed mainly of propylene, (b) 5 to 350 parts by weight of a resin selected from the group consisting of polyethylenes and copolymers composed mainly of ethylene, the resin having been prepared using a single site catalyst, and (c) 5 to 200 parts by weight of an ionomer resin or its ester. The present thermoplastic resin composition is excellent in mechanical properties and heat bonding property to various resins, and causes no bleeding out of softening agents, thereby the softness of the shaped articles obtained from the composition can be easily controlled. The present invention also provides a laminated article comprising a layer of the resin composition.

Abstract: A subject of the present invention is an aqueous composition combining at least one block copolymer (A) comprising, in the pH and temperature conditions of the composition, at least two polyionic blocks of the same charge and at least one non-charged block, with at least one ionic or polyionic (B) type with an opposite charge to that of the said polyionic blocks, in the pH conditions of the composition; type (B) being chosen from among ions carrying at least two charges, surfactants carrying at least one charge, oligomers and/or polymers carrying at least two charges and/or mineral particles carrying at least two charges; the block copolymer (A) content being such that the viscosity of the composition is at least greater than three times that of an aqueous solution of block copolymer (A) and to that of an aqueous solution of type (B), in the same temperature, pH and concentration conditions. The present composition, before its use or during its use, is in the form of a gel.

Abstract: The present invention firstly provides a novel olefin/styrene/diene type cross-copolymer having excellent physical properties and mechanical properties, and a novel, efficient and economically excellent process for its production. Further, it provides an efficient and economically excellent process for producing various cross-copolymers such as an olefin/diene type cross-copolymer. The present invention secondly provides various resin compositions or processed products containing cross-copolymers, having problems of various conventional resin compositions or processed products solved and improved, as applications of cross-copolymers of the present invention.

Abstract: Porous polyolefins are especially efficiently free-radically grafted using (fluorinated alkyl)olefins, vinylsilanes or certain carboxylic acids or their esters as the grafting molecules. The use of a solvent to swell the porous polyolefin is sometimes advantageous.

Abstract: Process for the preparation of aqueous dispersions of (co)polymerizates using a polymer with cationic functionality, optionally accompanied by the use of conventional additives, the polymer with cationic functionality being obtained by (co)polymerization in an aqueous medium of olefinically unsaturated (co)monomers, in which at least one (co)monomer has a cationic functionality, further (co)monomers are added and polymerization takes place in the presence of suitable initiators, wherein the polymers and/or (co)monomers are so chosen and the process is so controlled that a (co)polymerizate particle with heterogeneous morphology is formed and the dispersed (co)polymerizate obtained has a glass transition temperature Tg of more than about 50° C. The invention also relates to a process in which the polymer with cationic functionality is formed in situ in the presence of a seed. Redispersible powders and the use thereof are also described.

Abstract: Disclosed are sulfonated aromatic perfluorocyclobutane polymers meeting a condition selected from: a) the equivalent weight of the polymer is 5000 or less, and b) the proton conductivity of the polymer at 25° C. is 0.

Abstract: Melt-fabricable thermoplastic fluoropolymer having pendant functional groups is thermally cross-linked in the presence of polyfunctional nucleophile.

Abstract: Liquid-absorbent polymers are prepared by a process for the gel and/or surface postcrosslinking of water-absorbent polymers by the polymer being treated with a surface postcrosslinking solution and being postcrosslinked and dried during and after the treatment by raising the temperature, wherein the surface postcrosslinking solution comprises as crosslinker a compound of the formula I where R1, R2, R3 and R4 are independently hydrogen, C1-C12-alkyl, C1-C12-alkenyl, C6-C12-aryl or C1-C12-alkoxy, R5 is C1-C16-alkyl, C1-C4-hydroxyalkyl, C6-C12-aryl, C1-C16-alkenyl or a group of the formula —(CH2)n—COOH or —(CH2)n—SO3H in the form of the acid or a respective metal salt, ammonium salt or triethanolammonium salt thereof or —(CH2—CH2—O—)m—R6, R6 is hydrogen or C1-C16-alkyl, n is from 1 to 10, m is from 1 to 20 dissolved in an inert solvent, and are used in hygiene articles, packaging materials and nonwovens.

Abstract: Rubbery polymers made by anionic polymerization can be coupled with both tin halides and silicon halides to improve the characteristics of the rubber for use in some applications, such as tire treads. In cases where the rubbery polymer is synthesized by anionic polymerization utilizing a polar modifier it is difficult to attain a high level of coupling.

Abstract: A hydrogenated polymer is prepared by a method comprising: hydrogenating a polymer having carbon—carbon double bonds and a hydroxy group and/or a functional group which is convertible into a hydroxy group or into a hydroxymethyl group in the presence of a catalyst of palladium on a base activated carbon and/or platinum on a base activated carbon.

Abstract: An aqueous immersion bath contains a water-soluble peroxide compound and a transition metal salt and is used to activate the surface of a thermoplastic olefin prior to the application of a coating thereon. After immersion of the thermoplastic olefin material in the aqueous immersion bath, an improved adhesion between the coating and the surface of the thermoplastic olefin material is obtained.

Abstract: The present invention relates to glyoxylic compound comprising one or more active ingredient. By the present invention, a delayed release of the active ingredient is provided upon contact of the compound with an aqueous medium.

Abstract: A processable poly(hydroxy acid) composition which has been stabilized by adding to the polymer during the melt processing stage 0.05-3% by weight of a peroxy compound the degradation of which produces one or more acid radicals, and which has good melt strength and elasticity. The melt strength is high enough to produce films with conventional methods as the film blowing method.

Abstract: A photoimageable, aqueous acid soluble polyimide polymer comprising an anhydride, including a substituted benzophenone nucleus, a diamine reacted with the anhydride to form a photosensitive polymer intermediate, and at least 60 Mole % of solubilizing amine reacted with the photosensitive polymer intermediate to form the photoimageable, aqueous acid soluble polyimide polymer. An emulsion for electrophoretic deposition of a coating of a photoimageable, aqueous acid soluble polyimide polymer comprises a dispersed phase, including the photoimageable aqueous acid soluble polyimide polymer, dissolved in an organic solvent and a dispersion phase including a coalescence promoter and water. The emulsion may be applied, by electrophoretic deposition, to a conductive structure to provide a photoimageable coating on the conductive structure.

Abstract: A primer composition comprising (A) a diorganopolysiloxane having an average degree of polymerization of 500-2,000 and alkenyl groups at both ends of its molecular chain in an amount of 0.001-0.005 mol per 100 g of the diorganopolysiloxane, (B) an organohydrogenpolysiloxane having at least two SiH groups in a molecule, (C) a platinum base curing catalyst, and (D) a retarder is effective for improving the adhesion between various plastic films and silicone pressure-sensitive adhesives and thus forming satisfactory pressure-sensitive adhesive tapes.

Abstract: A process and apparatus for passing a polymerization effluent, comprising solid polymer, unreacted monomer, diluent and minor amounts of contaminants, to a high pressure flash where most of the fluid components are flashed and wherein a slip stream comprising diluent and minor amounts of monomer is separated from the bulk of the flashed fluid components. The slip stream is subjected to olefin removal to give an essentially olefin-free stream for recycle to a catalyst mud preparation area. The bulk of the flashed fluid components are recycled directly back to the polymerization zone without expensive olefin removal, although treatment to remove other contaminants can optionally be performed. The polymer and entrained fluid is passed to a low pressure flash zone where the fluids are flashed off, compressed and joined with the flash from the high pressure flash tank.

Abstract: Disclosed is a method of purifying olefin containing oxygenate contaminants. The method incorporates the use of extractive distillation. Under the appropriate conditions, olefins containing very low levels of oxygenate contaminants can be recovered.

Abstract: The present invention provides a catalyst for producing an ultra high molecular weight polyethylene and also a method for preparation of an ultra high molecular weight polyethylene with the use of said catalyst. The catalyst of the present invention is prepared by a process comprising: (i) producing a magnesium compound solution by contact-reacting a magnesium compound and an aluminum or boron compound with alcohol; (ii) contact-reacting the said solution with an ester compound containing at least one hydroxy group and a silicon compound containing an alkoxy group; and (iii) producing of a solid titanium catalyst by adding a mixture of a titanium compound and a silicon compound thereto. The catalyst prepared by the present invention has excellent catalytic activity, and it helps to produce an ultra-high molecular weight polyethylene with large bulk density and narrow particle distribution without too large and minute particles.

Abstract: The present invention relates to a method of homo- or co-polymerization of &agr;-olefin by means of using a catalyst system which comprises the following components: (1) a solid complex titanium catalyst produced by means of a production method comprising the following steps: (a) preparing a magnesium compound solution by dissolving a magnesium halide compound and a compound of Group IIIA of the Periodical Table in a solvent of mixture of cyclic ester, one or more types of alcohol, a phosphorus compound, and an organic silane; (b) precipitating the solid particles by reacting said magnesium compound solution with a transitional metal compound, a silicon compound, a tin compound, or the mixture thereof; and (c) reacting said precipitated solid particles with a titanium compound and electron donors; (2) an organometallic compound of metal of Group IIIA of the Periodical Table; and (3) external electron donors comprising three or more types of organo-silicon compounds, wherein the melt flow rates of the homopoly

Abstract: A process for making ethylene copolymers is disclosed. Ethylene copolymerizes with an &agr;-olefin in the presence of a catalyst system comprising an activator and a silica-supported, bridged indenoindolyl metal complex having “open architecture.” The supported complex incorporates comonomers with exceptional efficiency, and the process gives ethylene copolymers having high molecular weights (Mw>100K) and very low densities (<0.910 g/cm3). Open architecture catalysts that include bridging through the indolyl nitrogen of the indenoindolyl framework are also described.

Abstract: Catalysts for the polymerization of olefins are disclosed, which comprise the product obtained by contacting: (A) a bridged and/or substituted cyclopentadienyl compound of titanium, zirconium or hafnium; (B) an organometallic aluminium compound of the formula: Al(CH2—CR4R5—CR6R7R8)wR9qHz wherein R4 is a C1-C10 alkyl, alkenyl, or arylalkyl group; R5 is hydrogen or a C1-C10 alkyl, alkenyl, or arylalkyl group; R6 and R7 are C1-C10 alkyl, alkenyl, aryl, arylalkyl or alkylaryl groups; R8 is hydrogen or a C1-C10 alkyl, alkenyl, aryl, arylalkyl or alkylaryl group; R9 is a C1-C10 alkyl, alkenyl, or arylalkyl group, a carbon atom in the compound of formula (II) being optionally replaced by a Si or Ge atom; w is 1-3, z is 0 or 1, q=3−w−z, and (C) water; the molar ratio (B)/(C) being comprised between 1:1 and 100:1. These catalysts show an improved activity with respect to known catalysts, wherein different aluminium compounds are used.

Abstract: The invention is directed to olefin polymerization processes using bridged hafnocene catalyst complexes comprising highly substituted noncoordinating anions that are surprisingly stable under high temperature olefin polymerization processes such that olefin copolymers having significant amount of incorporated comonomer can be prepared with high molecular weights. More specifically, the invention is a polymerization process for ethylene copolymers having a melt index of about 0.87 to about 0.930 comprising contacting, under homogeneous polymerization conditions at a reaction temperature at or above 140° C. to 225° C.