Abstract: A process for preparing high density polyethylene in the gas phase comprising contacting a mixture comprising ethylene and one or more alpha-olefins with the supported reaction product of a bis-hydrocarbylsilyl chromate and a hydrocarbylaluminum compound or a hydrocarbyl boron compound in a fluidized bed reactor having a recycle gas line, under particularly defined polymerization conditions, including, but not limited to, the following provisos:(i) oxygen and/or another catalyst poison is introduced into the reactor in the range of about 0.005 to about 0.5 part by volume of catalyst poison per million parts by volume of ethylene; and(ii) a relatively low boiling inert hydrocarbon is introduced into the recycle gas line in an amount sufficient to raise the dew point of the recycle gas, which is comprised of alpha-olefins and other reactor gases, and the recycle gas is partially condensed and recycled to the reactor where it promotes cooling by evaporation.

Abstract: A composition comprising:(i) a mixture of about 40 to about 80 percent by weight of a copolymer of ethylene and an alpha-olefin having a melt index in the range of about 0.1 to about 10 grams per 10 minutes and a density in the range of 0.870 to 0.930 gram per cubic centimeter and about 20 to about 60 percent by weight of a copolymer of ethylene and ethyl acrylate having a melt index in the range of about 0.1 to about 50 grams per 10 minutes and an ethyl acrylate content in the range of about 10 to about 40 percent by weight, and for each 100 parts by weight of said mixture,(ii) about 30 to about 150 parts by weight of a mixture of talc and calcium carbonate wherein the weight ratio of talc to calcium carbonate is in the range of about 0.3:1 to about 1.2:1; and(iii) about 1 to about 20 parts by weight of an organopolysiloxane having a kinematic viscosity in the range of about 0.06 to about 2 meters per second as measured at 23 degrees C.

Abstract: A process for the devolatilization of a thermoplastic polymer containing gaseous impurities in an apparatus having a melting zone, a mixing zone, and a reduced pressure zone, comprising:(a) (i) adding a granular blowing agent directly or via a masterbatch to the polymer prior to the introduction of the polymer into the melting zone, said blowing agent being added in an amount of about 1 to about 4 percent by weight based on the weight of the polymer or (ii) adding a gaseous blowing agent to the mixing zone;(b) melting the polymer in the melting zone;(c) mixing the molten polymer and blowing agent in the mixing zone under sufficient pressure to maintain the blowing agent in the mixture;(d) at a temperature sufficient for decomposition or expansion, (i) decomposing the granular blowing agent in the mixing zone and/or in the reduced pressure zone or (ii) expanding the gaseous blowing agent in the reduced pressure zone wherein the blowing agent in its decomposed or expanded state develops froth cells in the molte

Abstract: A film comprising a blend of (i) a linear low density polyethylene and (ii) an in situ blend of copolymers of ethylene and one or more alpha-olefins having 3 to 8 carbon atoms wherein (a) the weight ratio of component (i) to component (ii) is in the range of about 0.01:1 to about 6:1; (b) the blend has been extruded, under extrusion conditions, at a die rate in the range of about 6 to about 20 pounds per hour per inch of die circumference and at a die gap in the range of about 0.020 to about 0.075 inch; and (c) the film exhibits essentially no melt fracture.

Abstract: A cable comprising one or more electrical conductors or a core of one or more electrical conductors, each conductor or core being surrounded by an insulating composition comprising a mixture of(i) about 20 to about 50 percent by weight of a homogeneous polyethylene having a polydispersity in the range of about 1.5 to about 3.5 and an essentially uniform comonomer distribution; and(ii) about 50 to about 80 percent by weight of a homopolymer of ethylene made by a high pressure process.

Abstract: A cable comprising one or more electrical conductors or communications media, or a core of two or electrical conductors or communications media, each electrical conductor, communications medium, or core being surrounded by a composition comprising:(A) about 40 to about 93 percent by weight of at least one resin selected from the group consisting of ethylene/vinyl acetate copolymer, ethylene/ethyl acrylate copolymer, and an ethylene/alpha-olefin copolymer having a density equal to or less than 0.915 gram per cubic centimeter.(B) about 5 to about 50 percent by weight of a linear ethylene/alpha-olefin copolymer produced by using a single-site metallocene catalyst and having a melt flow rate of about 0.5 to about 50 grams per 10 minutes; a density of 0.86 to 0.91 gram per cubic centimeter; and an Mw/Mn ratio equal to or less than about 3.

Abstract: A cable having one or more electrical conductors or a core of electrical conductors, each electrical conductor or core being surrounded by an insulating composition, essentially free from water tree growth inhibitors, having(i) a polyethylene having a density in the range of 0.860 to 0.940 gram per cubic centimeter; and, based on 100 parts by weight of component (i),(ii) about 0.2 to about 1 part by weight of a homopolymer of propylenewith the proviso that the insulating composition is extruded at a temperature below the melting point of the homopolymer of propylene.

Abstract: A cable construction comprises the following components: (i) a plurality of insulated electrical conductors having interstices therebetween, said insulation comprising (a) one or more polyolefins selected from the group consisting of polyethylene, polypropylene, and mixtures thereof, and, blended therewith, (b) a mixture containing one or more alkylhydroxy-phenylalkanoyl hydrazines and one or two functionalized hindered amines; (ii) hydrocarbon cable filler grease within the interstices; and (iii) a sheath surrounding components (i) and (ii) wherein said hindered amines have the following structural formulae: ##STR1## wherein n is about 2 to about 12; R is CxHyOz wherein x is about 2 to about 6, y is about 4 to about 16, and z is zero to about 3; ##STR2## wherein m is about 2 to about 30; n is about 2 to about 30; and x is about 1 to about 30; or ##STR3## wherein n is about 2 to about 20.

Abstract: A cable construction comprising the following components: (i) a plurality of insulated electrical conductors having interstices therebetween, said insulation comprising (a) one or more polyolefins selected from the group consisting of polyethylene, polypropylene, and mixtures thereof, and, blended therewith, (b) a mixture containing one or more alkylhydroxy-phenylalkanoyl hydrazines and one or two functionalized hindered amines; (ii) hydrocarbon cable filler grease within the interstices; and (iii) a sheath surrounding components (i) and (ii) wherein said hindered amines have the following structural formulae in which n is about 2 to about 10: ##STR1##

Abstract: A blend comprising a mixture of two ethylene/alpha-olefin copolymers, said blend having a flow index in the range of about 5 to about 50 grams per 10 minutes; a melt flow ratio in the range of about 10 to about 50; a density in the range of 0.900 to 0.940 gram per cubic centimeter; a molecular weight in the range of about 98,000 to about 190,000; and an Mw/Mn ratio in the range of about 2 to about 8, said blend having been prepared by mixing first and second copolymers having about equal molecular weights, each copolymer being a copolymer of ethylene and an alpha-olefin having 3 to 8 carbon atoms, the first copolymer having a flow index in the range of about 5 to about 75 grams per 10 minutes; a melt flow ratio in the range of about 10 to about 50; a density in the range of 0.860 to 0.

Abstract: A sheet such as a geomembrane consisting essentially of an extruded in situ blend of two copolymers of ethylene and one or more alpha-olefins having 3 to 8 carbon atoms, said blend having a flow index in the range of about 3 to about 100 grams per 10 minutes; a melt flow ratio in the range of about 50 to about 200; a density in the range of 0.905 to 0.943 gram per cubic centimeter; an Mw/Mn ratio in the range of about 10 to about 50; and a weight average molecular weight in the range of about 180,000 to about 465,000.

Abstract: A shrink film comprising a blend of copolymers of ethylene and one or more alpha-olefins having 3 to 12 carbon atoms formed in situ, said blend having a melt index in the range of about 0.2 to about 3.5 grams per 10 minutes; a melt flow ratio in the range of about 50 to about 175; a molecular weight in the range of about 90,000 to about 225,000; a Mw/Mn ratio of at least about 8; and a density in the range of 0.910 to 0.940 gram per cubic centimeter, said shrink film being formed at a blow up ratio in the range of about 2:1 to about 6:1 and having the following properties:(i) at about 135 degrees C., a shrinkage of at least about 50 percent in the machine direction and zero or positive shrinkage in the transverse direction;(ii) melt stress is zero or positive kilopascals; and(iii) a cooled stress of at least about 0.35.times.10.sup.3 kilopascals.

Abstract: A cable comprising one or more electrical conductors or a core of one or more electrical conductors, each conductor or core being surrounded by a layer of insulation comprising a multimodal copolymer of ethylene and one or more alpha-olefins, each alpha-olefin having 3 to 8 carbon atoms, the copolymer having a broad comonomer distribution as measured by TREF with a value for the percent of copolymer, which elutes out at a temperature of greater than 90 degrees C., of greater than about 5 percent; a WTGR value of less than about 20 percent; a melt index in the range of about 0.1 to about 30 grams per 10 minutes; and a density in the range of 0.880 to 0.950 gram per cubic centimeter, and being prepared by a low pressure process.

Abstract: A process for the extrusion of polyethylene having a broad molecular weight distribution wherein the polyethylene is prepared in pellet form, said extrusion taking place in a pelletizing extruder having one or more zones essentially filled with polyethylene and two or more zones partially filled with polyethylene including(i) introducing the polyethylene into the extruder at a temperature sufficient to melt the polyethylene; (ii) introducing a mixture of an inert gas and oxygen into each partially filled zone wherein the mixture contains about 1 to about 21 percent by volume oxygen based on the volume of the gaseous mixture; (iii) passing the molten polyethylene through each zone at melt temperature; and (iv) extruding the polyethylene into pellets and cooling same.

Abstract: A cable comprising one or more communications media or electrical conductors, or a core of two or more communications media or electrical conductors, each communications medium, electrical conductor, or core being surrounded by at least two layers, an inner insulating layer and an outer jacketing layer, is disclosed. The jacketing layer comprises an in situ blend of two copolymers of ethylene and one or more alpha-olefins having 3 to 12 carbon atoms. The blend has an Mw/Mn ratio in the range of about 8 to about 22; a melt index in the range of about 0.2 to about 3.5 grams per 10 minutes; a melt flow ratio in the range of about 55 to about 135; a molecular weight in the range of about 90,000 to about 250,000; and a density of at least 0.915 gram per cubic centimeter.

Abstract: A process for the co-extrusion of an outer layer, a middle layer, and an inner layer, each layer including a thermoplastic resin, around a conductive medium in three extruders, one extruder for each layer, connected by a triple crosshead, each of said extruders having an extrusion zone comprising a die plate and, downstream of the die plate, a die, and, downstream of the extrusion zone, a common crosslinking zone, comprising passing the thermoplastic resins through the extrusion zones, under extrusion conditions including an extrusion temperature in the range of at least 150 degrees C. to below the decomposition temperature of the organic peroxide referred to hereinafter, and passing the extrudate into the crosslinking zone, under crosslinking conditions, the improvement comprising introducing an organic peroxide having a half life of one minute at a temperature of about 150 to about 200 degrees C.

Abstract: A cable comprising one or more electrical conductors or communications media, or a core of two or more electrical conductors or communications media, each electrical conductor, communications medium, or core being surrounded by a composition, which is essentially halogen free, comprising 100 parts by weight of a mixture of resins and 5 to 250 parts by weight of a flame retardant compound, which is either magnesium hydroxide, coated or uncoated, or aluminum trihydrate, wherein the resins in the mixture are as follows:(i) a polyethylene made using a metallocene single site catalyst system, said polyethylene having an Mw/Mn ratio of no greater than about 3;(ii) a polyethylene made using a transition metal catalyst system other than a metallocene single site catalyst system, said polyethylene having an Mw/Mn ratio greater than about 4;(iii) optionally, a copolymer of ethylene and an unsaturated ester or a very low density polyethylene having a density no greater than 0.

Abstract: A cable comprising one or more electrical conductors or communications media, or a core of two or more electrical conductors or communications media, each electrical conductor, communications medium, or core being surrounded by a composition, which is essentially halogen and antimony free, comprising:(a) a copolymer of ethylene and an unsaturated ester comonomer selected from the group consisting of:(i) an alkyl acrylate;(ii) an alkyl methacrylate; and(iii) a vinyl carboxylatewherein (A) the alkyl group has 1 to 8 carbon atoms and the carboxylate group has 2 to 8 carbon atoms;(B) the copolymer is, optionally, modified with an anhydride of an unsaturated aliphatic diacid having 4 to 20 carbon atoms;(C) the copolymer has an ester content in the range of about 5 to about 50 percent based on the weight of the copolymer and a melt index in the range of about 0.

Abstract: A gas phase process for the production of an in situ polyethylene blend comprising contacting ethylene and at least one alpha-olefin comonomer having 3 to 8 carbon atoms with a magnesium/titanium based catalyst system including an activator and a cocatalyst in each of two fluidized bed reactors corrected in series, under polymerization conditions, with the provisos that:(a) the mixture of ethylene copolymer matrix and active catalyst formed in the first reactor in the series is transferred to the second reactor in the series;(b) other than the active catalyst referred to in proviso (a) and the cocatalyst referred to in proviso (f), no additional catalyst is introduced into the second reactor;(c) in the first reactor in which a relatively high molecular weight copolymer is made:(1) the alpha-olefin is present in a ratio of about 0.01 to about 0.4 mole of alpha-olefin per mole of ethylene; and(2) optionally, hydrogen is present in a ratio of about 0.001 to about 0.

Abstract: A process comprising contacting ethylene and at least one alpha-olefin comonomer having 3 to 8 carbon atoms with a transition metal based catalyst system in two fluidized bed reactors connected in series, in the gas phase, under polymerization conditions, with the provisos that:(a) the first reactor is operated at a temperature at or above the dew point of the mixture of monomers, but no higher than about 5 degrees C. above said dew point;(b) the mixture of ethylene copolymer matrix and active catalyst formed in the first reactor in the series is transferred to the second reactor in the series;(c) other than the active catalyst referred to in proviso (b), no additional catalyst is introduced into the second reactor;(d) in the reactor in which a low melt index copolymer is made:(1) the alpha-olefin is present in a ratio of about 0.01 to about 0.4 mol of alpha-olefin per mol of ethylene; and(2) optionally, hydrogen is present in a ratio of about 0.001 to about 0.