Abstract: The present disclosure relates to poly(alpha-olefin)s and methods for making poly(alpha-olefin)s. A poly(alpha-olefin) may include about 95 wt % or greater C10-C18 alpha-olefin content and have a weight average molecular weight of from about 1,000,000 g/mol to about 10,000,000 g/mol. A method for forming a poly(alpha-olefin) may include introducing one or more C10-C18 alpha-olefins to a catalyst system comprising a catalyst compound and an activator. The method may include obtaining poly(alpha-olefin)s comprising about 95 wt % or greater C10-C18 alpha-olefin content and having a weight average molecular weight of from about 1,000,000 g/mol to about 10,000,000 g/mol.

Abstract: A process for the preparation of an ethylene polymer including the step of polymerizing ethylene or copolymerizing ethylene and one or more other olefins in the presence of a Phillips-type chromium catalyst in a gas-phase polymerization reactor containing a reactor bed of particulate polymer, wherein the gas-phase polymerization reactor is equipped with a cycle gas line, wherein the reactor gas returned to the polymerization reactor through the cycle gas line has been condensed in part and the amount of liquid in the returned reactor gas is from 0.5 wt. % to 10 wt. % based upon the total weight of the reactor gas/liquid composition, the polymerization is carried out at from 108° C. to 125° C., and an aluminum alkyl is fed into the polymerization reactor in an amount in the range of from 0.0025 mole to 0.1 mole per ton of dosed ethylene.

Abstract: An ISBM article is disclosed wherein the ISBM article is made from an HDPE resin having a MI2 of 0.1 to 5.0 dg/min as measured by ASTM D-1238; 190° C./2.16 kg, a density of from 0.940 to 0.970 g/cc as measured by ASTM D792, a peak molecular weight of greater than 40,000 g/mol and a zero shear viscosity between 15,000 and 250,000 Pa·sec.

Abstract: A method comprising contacting an olefin in the presence of a catalyst and a melt index modifier (MIM) under conditions suitable to form a polyolefin and recovering the polyolefin, wherein the polyolefin melt index is increased by at least about 25%, wherein the normalized catalyst activity is decreased by less than about 10%, and wherein the MIM is characterized by the general formula R1—HC?CH—R2 or R3R4C?CH2 where R1, R2, R3, R4 are each selected from the group consisting of a non-aromatic organyl group.

Abstract: Systems and methods for the maintenance of active chromium-based catalysts and their use in polymerization processes are described. In one embodiment, a system for the introduction of multiple polymerization components to activate a chromium based catalyst within a mix tank is described. Other described features may include materials and methods to purify the liquid medium of a catalyst slurry so that the catalyst slurry maintains a high level of activity. The active chromium-based catalyst may provide polyolefins with a number of desirable properties in a reliable, consistent, and predictable manner.

Abstract: Systems and methods for the maintenance of active chromium-based catalysts and their use in polymerization processes are described. In one embodiment, a system for the introduction of multiple polymerization components to activate a chromium based catalyst within a mix tank is described. Other described features may include materials and methods to purify the liquid medium of a catalyst slurry so that the catalyst slurry maintains a high level of activity. The active chromium-based catalyst may provide polyolefins with a number of desirable properties in a reliable, consistent, and predictable manner.

Abstract: Disclosed herein are various methods and systems for gas and liquid phase polymer production. In certain embodiments, the methods comprise manipulating properties of polymers produced by adjusting the hydrogen feed rate.

Abstract: A gas phase polymerization process for producing a polyethylene polymer including polymerizing ethylene and optionally at least one ?-olefin comonomer in a fluidized bed reactor under condensed mode operating conditions using a Cr+6-based supported catalyst and a catalyst initiation enhancing agent is provided. The catalyst initiation enhancing agent is an aluminum alkyl solution that is present in the fluidized bed reactor at effective Al/Cr ratios between 0.2 to 1.5. A catalyst initiation enhancing system including at least one aluminum alkyl and at least one hydrocarbon solvent wherein the aluminum alkyl is present in the solvent at concentrations of less than about 0.03 molar.

Abstract: Disclosed herein is a polyolefin polymer having improved properties wherein the polymer is produced using a chromium based catalyst in combination with aluminum alkyl activators and co-catalysts. Also disclosed is a pipe comprising the inventive polymer and a film comprising the inventive polymer, each having improved properties over those known in the art.

Abstract: The present invention discloses the use of a chromium-based catalyst system in two serially connected loop reactors for copolymerising ethylene and a comonomer, at reduced productivity, the final polyethylene having a reduced amount of gel.

Abstract: Methods of making supported chromium catalyst systems and processes of polymerizing ethylene using the supported chromium catalyst systems are disclosed. A method of forming a catalyst system in a polymerization reactor includes contacting a supported chromium catalyst and a metal alkyl cocatalyst by cofeeding the catalyst and cocatalyst to the reactor or feeding the catalyst and cocatalyst separately to the reactor, to form a catalyst system. The catalyst and cocatalyst are not pre-contacted prior to the feeding or cofeeding step. The catalyst system can be contacted with ethylene and optional alpha-olefin comonomer to form polyethylene.

Abstract: The present invention is directed to the use of aluminum alkyl activators and co-catalysts to improve the performance of chromium-based catalysts. The aluminum alkyls allow for the variable control of polymer molecular weight, control of side branching while possessing desirable productivities, and may be applied to the catalyst directly or separately to the reactor. Adding the alkyl aluminum compound directly to the reactor (in-situ) eliminates induction times.

Abstract: The present invention is directed to the use of aluminum alkyl activators and co-catalysts to improve the performance of chromium-based catalysts. The aluminum alkyls allow for the variable control of polymer molecular weight, control of side branching while possessing desirable productivities, and may be applied to the catalyst directly or separately to the reactor. Adding the alkyl aluminum compound directly to the reactor (in-situ) eliminates induction times.

Abstract: Methods of preparing a polymerization catalyst are provided that include contacting a support comprising alumina with a sulfating agent and with chromium. In an embodiment in which the chromium is provided from a chromium compound such as chromium oxide, the support may be calcined after loading the sulfating agent and the chromium on the support. Alternatively, the sulfating agent can be loaded on the support while calcining it. In another embodiment in which the chromium is provided from an organochromium compound, the support may be calcined after contacting it with the sulfating agent and before contacting it with the organochromium compound. Catalysts compositions formed by the foregoing method are provided. In an embodiment, catalyst compositions comprise chromium and a sulfate treated alumina support. The catalyst compositions have an activity for ethylene polymerization that is at least about 25% greater than an activity of the same catalyst without sulfate.

Abstract: The present invention relates to a process for the gas-phase (co-)polymerization of olefins in a fluidized bed reactor using a chromium oxide catalyst characterized in that the polymerization is performed in the presence of a polymer structure modifier.

Abstract: The invention relates to a gel based on poly-?-1,4-D-glucan and, optionally, on starch as well as on a swelling agent, to a method for the production thereof, and to the use of a gel of this type.

Abstract: A continuous vapor-phase fluidized-bed process for the preparation of ethylene homopolymers and copolymers having a density of from 0.87 to 0.97 g/cm3 in which ethylene or mixtures of ethylene and C3-C8 a-monoolefins are (co)polymerized in the presence of a supported chromium catalyst in the polymerization zone of a vapor-phase fluidized-bed reactor under pressures ranging from 1 to 100 bar and at temperatures ranging from 30° to 125° C. in the vapor phase in an agitated bed of bulk material comprising particulate polymer, the resultant heat of polymerization is removed by cooling the recirculated reactor gas and the resulting (co)polymer is removed from the vapor-phase fluidized-bed reactor, wherein, for the preparation of a (co)polymer of a specific density d, the (co)polymerization is carried out at a temperature which is in a range restricted by an upper envelope defined by equation I T H = 171 + 6 ? ? ? d ? 0.

Abstract: A polymerization catalyst is disclosed, wherein the catalyst comprises: (a) a metallocene of Ti, Zr or Hf, (b) an organoaluminum compound, and (c) a treated solid oxide support which comprises fluorine and chromium.

Abstract: Methods of making supported chromium catalyst systems and processes of polymerizing ethylene using the supported chromium catalyst systems are disclosed. A method of forming a catalyst system in a polymerization reactor includes contacting a supported chromium catalyst and a metal alkyl cocatalyst by cofeeding the catalyst and cocatalyst to the reactor or feeding the catalyst and cocatalyst separately to the reactor, to form a catalyst system. The catalyst and cocatalyst are not pre-contacted prior to the feeding or cofeeding step. The catalyst system can be contacted with ethylene and optional alpha-olefin comonomer to form polyethylene.

Abstract: A continuous vapor-phase fluidized-bed process for the preparation of ethylene homopolymers and copolymers having a density of from 0.87 to 0.97 g/cm3 in which ethylene or mixtures of ethylene and C3-C8 a-monoolefins are (co)polymerized in the presence of a supported chromium catalyst in the polymerization zone of a vapor-phase fluidized-bed reactor under pressures ranging from 1 to 100 bar and at temperatures ranging from 30° to 125° C.

Abstract: The invention relates to a method for producing an ethylene polymer, comprising performing polymerization of ethylene in co-presence of hydrogen using a trialkylaluminum compound-carried chromium catalyst, wherein the chromium catalyst is obtained by calcination-activating a chromium compound that is carried on an inorganic oxide carrier in a non-reducing atmosphere to convert chromium atoms in the chromium compound into hexavalent chromium atoms for at least a portion thereof, and treating with a trialkylaluminum compound in an inert hydrocarbon solvent to carry thereon and removing to dry the solvent so that the chromium atoms are not over-reduced by the trialkylaluminum compound, and to an ethylene polymer suitable for blow molded articles obtained by the production method. The ethylene polymer of the invention have improved environment stress crack resistance (ESCR) and impact resistance in a good balance and are suitable for molded blow articles, in particular large size blow molded articles.

Abstract: A process for the gas-phase (co-)polymerization of olefins in a fluidized bed reactor using a chromium oxide catalyst. The polymerization is performed in the presence of a process aid additive.

Abstract: The invention relates to a process for preparing a support material having an increased number of reactive groups and to a process for preparing coreactive surfaces that may have catalytic or cocatalytic properties.

Abstract: Ths invention provides a process for the preparation of a polyethylene, in particular an HDPE suitable for blow moulding of HIC, which comprises polymerizing ethylene and, optionally an ethylenically unsaturated comonomer copolymerizable therewith, in the presence of a catalyst comprising a first silica-supported chromium catalyst having a pore volume of at least 2 mL/g, a surface area of at least 350 m2/g and a chromium content of 0.1 to 1.0% by weight and a second silica-supported chromium catalyst having a pore volume of at least 2 mL/g, a surface area of at least 450 m2/g and a chromium content of 0.1 to 1.0% by weight, wherein the silica support of said first catalyst also comprises alumina and the silica support of said second catalyst also comprises titanium, and preferably a co-catalyst.

Abstract: A process for preparing pillared chromium phyllosilicate clay &agr;-olefin catalysts is disclosed. This process utilizes palygorskite and sepiolite clays. The pillaring of said clays comprises the steps of: (a) preparing a hydrolyzed first solution by dissolving a chromium salt and a base in water, heating said first solution to a temperature in the range of about 20° C. to about 100° C. while stirring continuously until the solution reaches a pH in the range of about 1.5 to about 2.5 and thereby producing a master batch; (b) diluting said master batch with water to produce a diluted second solution and heating said diluted second solution to produce a heated second solution; (c) adding a solid clay selected from the group consisting of sepiolites and palagorskites to said heated second solution, and continuing heating; (d) recovering said pillared chain silicate clay; and (e) drying said pillared chain silicate clay to form first product.

Abstract: This invention relates to a method for purifying and drying a polymer hydrogel. This invention is based in part upon the discovery that rapid drying of polymer hydrogels can eliminate the problem of unacceptable levels of soluble oligomers caused by prolonged thermal treatment. Rapid drying techniques allow drying hydrogels containing more water than was previously considered possible without a loss in product quality. Furthermore, it was discovered that slurries comprising polymer hydrogels and large quantities of water can be spray dried and that spray drying can be conducted with only minimal oligomer formation.

Abstract: A polyethylene produced by the homopolymerisation of ethylene or copolymerisation of ethylene with &agr;-olefins in the presence of a catalyst, characterized in that the fraction of low molecular weight polymers having MW<5000 g/mole is lower than 12% by weight of the produced polymer, and that the produced polyethylene has a measured melt strength expressed by a haul-off (HO) value satisfying the expression: HO>K1·&eegr;0.05+K2, wherein K1 is 9.10−5 and K2 is 0.4.

Abstract: An olefin polymerization process is provided comprising contacting an olefin monomer with chromium oxide on a titanium containing silica support having less than about 3 weight percent titanium in combination with an organoboron promoter. Polymers thus produced are useful for blow molding applications.

Abstract: A process for producing a polyethylene resin having a monomodal molecular weight distribution in a single polymerisation reactor using a chromium-based catalyst system, by copolymerising ethylene and an alpha-olefinic-comonomer having from 3 to 8 carbon atoms, the polyethylene resin comprising a blend of a higher molecular weight fraction polymerised by a first chromium-based catalyst of the system and a lower molecular weight fraction polymerised by a second chromium-based catalyst of the system, wherein the comonomer incorporation in the higher molecular weight fraction is greater than the comonomer incorporation in the lower molecular weight fraction is greater than the comonomer incorporation in the lower molecular weight fraction whereby the higher and lower molecular weight fractions differ in density by from 0.01 to 0.03 g/cc.

Abstract: A process for producing high density polyethylene having a bimodal molecular weight distribution, the process comprising pre-contacting a chromium-based catalyst with an alkyl metal oxane, the chromium-based catalyst comprising chromium oxide on a silica-containing support, to form a catalyst system wherein the atomic ratio of the metal of the oxane to the chromium is less than 1, and polymerising ethylene or copolymerising ethylene and an alpha-olefinic comonomer comprising from 3 to 10 carbon atoms in the presence of the catalyst system. A catalyst system for polymerising ethylene or copolymerising ethylene and an alpha-olefinic comonomer comprising from 3 to 10 carbon atoms to produce high density polyethylene, the catalyst system comprising in combination a chromium-based catalyst comprising chromium oxide on a silica-containing support and an alkyl metal oxane with which the chromium-based catalyst has been precontacted whereby the atomic ratio of the metal of the oxane to the chromium is less than 1.

Abstract: A process for producing high density polyethylene suitable for blow molding and having high environmental stress cracking resistance and rigidity copolymerizing ethylene and an alpha-olefinic comonomer comprising from 3 to 10 carbon atoms, in the presence of a chromium-based catalyst, having an alumina-containing support, and an organoboron compound, wherein the atomic ratio of boron in the organoboron compound to the chromium in the chromium-based catalyst is from around 0.2 to around 0.4.

Abstract: An improved chromium oxide-based catalyst supported on a granular or microspherical refractory oxide for the gas phase polymerization of at least one alpha olefin containing from 2 to 12 carbon atoms, wherein the supported chromium oxide-based catalyst has been subjected to a sole calcination/activation step consisting of a single thermal treatment performed at a temperature ranging from 200° to 450° C. under an oxygen containing atmosphere, and an olefin polymerization process employing such catalyst.

Abstract: The invention relates to a method for producing an ethylene polymer, comprising performing polymerization of ethylene in co-presence of hydrogen using a trialkylaluminum compound-carried chromium catalyst, wherein the chromium catalyst is obtained by calcination-activating a chromium compound that is carried on an inorganic oxide carrier in a non-reducing atmosphere to convert chromium atoms in the chromium compound into hexavalent chromium atoms for at least a portion thereof, and treating with a trialkylaluminum compound in an inert hydrocarbon solvent to carry thereon and removing to dry the solvent so that the chromium atoms are not over-reduced by the trialkylaluminum compound, and to an ethylene polymer suitable for blow molded articles obtained by the production method. The ethylene polymer of the invention have improved environment stress crack resistance (ESCR) and impact resistance in a good balance and are suitable for molded blow articles, in particular large size blow molded articles.

Abstract: An olefin polymerization process is provided comprising contacting an olefin monomer with chromium oxide on a titanium containing silica support having less than about 3 weight percent titanium in combination with an organoboron promoter. Polymers thus produced are useful for blow molding applications.

Abstract: A process for producing high density polyethylene suitable for blow molding and having high environmental stress cracking resistance and rigidity, comprising copolymerizing ethylene and a C.sub.3 -C.sub.10 alpha-olefinic comonomer in the presence of a chromium-based catalyst having an alumina-containing support, and an organoboron compound, wherein the atomic ratio of boron in the organoboron compound to the chromium in the chromium-based catalyst is from around 0.2 to around 0.4.

Abstract: An ethylene base polymer and a preparation method of an ethylene base polymer characterized in use of a catalyst comprising a chromium amide compound, a solid inroganic oxide calcined at 100 to 500.degree. C. and alumoxane. According to the present invention, an ethylene base polymer with a wide molecular weight distribution, excellent shock and environmental stress cracking resistances, causing no melt fracture, and suitable for film forming and blow molding can be effectively prepared.

Abstract: A process to control the heat transfer coefficient in slurry olefin polymerization processes comprising shocking the polymerization reactor is provided. This shock comprises quickly decreasing and then restoring to normal operating conditions, the higher alpha-olefin comonomer to ethylene monomer weight feed ratio.

Abstract: A catalyst system for olefin polymerization, including a catalytic solid based on chromium deposited on a support containing silica, alumina and aluminium phosphate and a cocatalyst chosen from organoaluminium compounds. One of the essential characteristics of the invention is the combination of an organoaluminium compound as cocatalyst with a catalytic solid based on chromium deposited on a support containing silica, alumina and aluminium phosphate.

Abstract: Catalyst compositions are provided that comprise (a) discrete silica particles; (b) chromium; and (c) a support comprising silica. These composition are useful in polymerizing ethylene or copolymerizing ethylene with a comonomer and provide better control over the molecular weight and the molecular weight distribution of a resulting polymer.

Abstract: Chromium catalyst compositions are provided. These chromium catalyst compositions comprise at least two chromium catalyst systems that have a certain amount of chromium and a support that comprises silica and titania. the supports have certain pore volumes and surface areas. These catalyst compositions are useful for homopolymerizing ethylene or copolymerizing ethylene with a comonomer. The resins produced are useful in film applications.

Abstract: This invention provides a chromium catalyst system that comprises[a] a support that comprises silica, wherein said support has a surface area to pore volume relationship as follows0.5.ltoreq.Pore volume.ltoreq.f(SA)wherein said f(SA) is(1.14.times.10.sup.-7)(SA).sup.3 -(1.19.times.10.sup.-4)(SA).sup.2 +(3.19.times.10.sup.-2)(SA)+0.20;and[b] a hexavalent chromium compound;wherein the surface concentration of said hexavalent chromium on said support is from 0.25 to 1 hexavalent chromium atoms per square nanometer.Another embodiment of this invention provides a process to homopolymerize ethylene, or copolymerize ethylene with a comonomer, said process comprises polymerizing ethylene with the above chromium catalyst composition.

Abstract: A novel Phillips catalyst for the copolymerization of ethylene with .alpha.-olefins, contains, as a catalytically active component, a finely divided, aluminum silicate-supported, phosphorus-containing chromium catalyst. This can be prepared by applying at least one organic phosphorus(III), (IV) and/or (V) compound and at least one chromium(III) compound which does not react with said phosphorus compounds under the reaction conditions used, in succcession in any order or simultaneously, to a finely divided aluminum silicate hydrogel or xerogel with formation of a catalyst intermediate and activating the catalyst intermediate at elevated temperatures in an oxidizing atmosphere, with the result that the chromium catalyst is formed. The novel Phillips catalyst gives ethylene/.alpha.-olefin copolymers in which the comonomers are more uniformly distributed over the copolymer chains than is the case with ethylene/.alpha.-olefin copolymers which have been prepared with the aid of conventional Phillips catalysts.

Abstract: Olefins can be polymerized in the presence of a catalyst system composition comprising chromium oxides supported on a inorganic oxide support, a pyrrole-containing compound and a non-hydrolyzed metal alkyl. The use of this type of polymerization catalyst in a polymerization process can produce an olefin comonomer in-situ, resulting in polymers having decreased density and increased branching.

Abstract: A process to produce a polyethylene composition that has less than 2 weight percent fines, based on the weight of said polyethylene composition, and a fluff bulk density greater than 25 pounds per cubic foot, said process comprising polymerizing ethylene in the presence of a trialkylaluminum compound, and a diluent that is essentially saturated with ethylene under slurry polymerization conditions that comprise a polymerization temperature from 104.degree. C. to 116.degree. C., with an activated catalyst system comprising (a) a catalyst support that comprises a silica compound, wherein said catalyst support has a pore volume less than 2 cubic centimeters per gram, (b) a catalyst that comprises a chromium compound, wherein the amount of chromium in said catalyst system is from about 0.1 to about 20 weight percent, wherein said weight percent is based on the total weight of said catalyst and catalyst support, and (c) a fluorine compound, wherein the amount of fluorine used is from about 0.

Abstract: Supported olefin polymerization catalyst systems can be produced using waste chromium compounds. Olefin polymers can be prepared using a catalyst system composition comprising a waste chromium compound and an alkyl aluminum compound, both supported on an inorganic oxide support, wherein at least a portion of the waste chromium compound is in a hexavalent state.

Abstract: Olefins can be polymerized in the presence of a catalyst system composition comprising chromium supported on an inorganic oxide support, a pyrrole-containing compounds, and a metal alkyl. The use of this type of polymerization process can produce an olefin comonomer in-situ, resulting in polymers having decreased density and increased branching.

Abstract: A novel Phillips catalyst for the homopolymerization of ethylene and the copolymerization of ethylene with .alpha.-olefins contains as catalytically active components a specific chromium catalyst on an aluminum phosphate support and cocatalysts of the formula I to IV, ##STR1## where M is lithium, sodium and potassium,M.sup.1 is magnesium and zinc,M.sup.2 is boron and aluminum,R is C.sub.1 -C.sub.10 -alkyl and C.sub.6 -C.sub.20 -aryl,R.sup.1 is R and C.sub.1 -C.sub.10 -alkoxy and C.sub.6 -C.sub.20 -aryloxy,X is chlorine, bromine and iodine,n is 0, 1 and 2The chromium catalyst on an aluminum phosphate support can be obtained by applying chromium compounds to a finely divided aluminum phosphate with a P:A1 molar ratio near to or equal to 1 and a pore volume of >1 cm.sup.3 /g and activating the resulting intermediate at elevated temperatures in an oxidizing atmosphere. The novel Phillips catalyst has an exceptionally long duration of activity and its productivity can be increased further by adding hydrogen.

Abstract: An ethylene polymerization catalyst system is provided. This catalyst system is produced by the process comprising forming an activated and reduced composition that is substantially free of titania and that comprises a fluorine compound, a chromium compound, and a catalyst support that consists essentially of silica.An ethylene polymerization process is provided. This process uses the ethylene polymerization catalyst system above. This catalyst system is contacted with ethylene, in the presence of hydrogen and trialkylaluminum, under polymerization conditions, to produce a polyethylene resin.

Abstract: The present invention relates to a process for the polymerization of ethylene or copolymerization of ethylene and at least one other alpha-olefin, in the gas phase in a fluidized bed reactor, in the presence of a catalyst comprising chromium compounds associated with a granular support comprising a refractory oxide and activated by thermal treatment, which process is characterized in that the catalyst is used in the form of active particles of prepolymer, obtained by bringing the said catalyst in contact with ethylene, alone, or in a mixture with at least one higher alpha-olefin, in such a way that the prepolymer contains from 4.times.10.sup.-5 to 3 milligram atoms of chromium in the catalyst per gram.

Abstract: The present invention relates to a process for the polymerisation of ethylene or copolymerisation of ethylene and at least one other alpha-olefin, in the gas phase in a fluidised bed reactor, in the presence of a catalyst comprising chromium compounds associated with a granular support comprising a refractory oxide and activated by thermal treatment, which process is characterised in that the catalyst is used in the form of active particles of prepolymer, obtained by bringing the said catalyst in contact with ethylene, alone, or in a mixture with at least one higher alpha-olefin, in such a way that the prepolymer contains from 4.times.10.sup.-5 to 3 milligram atoms of chromium in the catalyst per gram.