Abstract: The present invention provides a method for varying the melting points and molecular weights of polyolefins by changing the structure of the catalyst used in the polymerization. The catalysts that are useful in the present invention are chiral, stereorigid metallocene catalyst of the formula R″(C5R″m)2MeQ. The catalysts include a bridge structure between the (C5R′m) groups and may contain substituents on the groups. It has been discovered that the melting points and molecular weights of the polymers produced by such catalysts are influenced by the bridge and substituents added to the (C5R′m) groups. Thus, the present invention provides a method for varying the melting points of the polymer product and a method of varying the molecular weights of the product by changing the components and structure of the metallocene catalysts. The present invention also provides a process for polymerizing olefins in which the melting points and/or molecular weights of the product may be controlled.

Abstract: Provided is a metallocene catalyst component for use if preparing isotactic polyolefins, which component has the general formula (I): R″ (CpR1R2R3)(Cp′R′n) MQ2 wherein Cp is a substituted cyclopentadienyl ring; Cp′ is substituted or unsubstituted fluorenyl ring; R″ is a structural bridge imparting stereorigidity to the component; R1 is a substituent on the cyclopentadienyl ring which is distal to the bridge, which distal substituent comprises a bulky group of the formula XR*3 in which X is chosen from Group IVA, and each R* is the same or different and chosen from hydrogen or hydrocarbyl of from 1 to 20 carbon atoms, R2 is substituent on the cyclopentadienyl ring which is proximal to the bridge and positioned non-vincinal to the distal substituent, and is of the formula YR#3, in which Y is chosen from Group IVA, and each R# is the same or different and chosen from hydrogen or hydrocarbyl of 1 to 7 carbon atoms, R3 is a substituent on the cyclopentadienyl ring which is pro

Abstract: This invention relates to isotactic propylene homopolymer compositions obtained from metallocene catalysis wherein the polymer has a molecular weight distribution (Mw/Mn) in the range of from about 2.5 to about 20.0. The isototic propylene homopolymer composition may be prepared in a multiple stage polymerization process using the same metallocene component in at least two stages.

Abstract: A polymeric material suitable for fabrication into an article and particularly a polymeric material suitable for fabrication into an article suitable for receiving paint is provided. The polymeric material may be a blend of impact copolymer and plastomer. The impact copolymer includes between 95 and 78 wt % homopolypropylene and between 5 and 22 wt % of ethylene-propylene rubber, wherein ethylene propylene rubber may have less than about 50 wt % ethylene. The plastomer may be an ethylene/hexene plastomer. The ethylene/hexene plastomer may have a density in the range from 0.88 to 0.915 g/cc and a melt index (dg/min) from 0.8 to 10. The impact copolymer may be present in the blend in a range of 95 to 70 wt % and the ethylene/hexene plastomer may be present in the blend in a range from 5 to 30 wt %. The propylene, ethylene and hexene components may be present in the blend in respective ranges of 73.2 to 84.2 wt %, 14.3 to 23.1 wt % and 1.5 to 3.7 wt %.

Abstract: A hot melt pressure sensitive adhesive for use with oriented polypropylene films is provided. The adhesive composition comprises an elastomeric component which is a blend of styrene-isoprene block copolymers and styrene-butadiene block copolymers mixed with a tackifier component. The tackifier component is a blend of at least two hydrocarbon resins, the first being compatible with the styrene-isoprene block copolymer and the second being compatible with the styrene-butadiene block copolymer.

Abstract: This invention relates to metallocene catalyst compositions which are highly active for the polymerization of olefins, particularly prochiral &agr;-olefins. The catalyst compositions contain at least one metallocene, and least one activator and a support that has been fluorided using a fluoride containing compound.

Abstract: The present invention provides a method for varying the melting points and molecular weights of polyolefins by changing the structure of the catalyst used in the polymerization. The catalysts that are useful in the present invention are chiral, stereorigid metallocene catalyst of the formula R″(C5R′m)MeQ. The catalysts include a bridge structure between the ((C5R′m) groups and may contain substituents on the groups. It has been discovered that the melting points and molecular weights of the polymers produced by such catalysts are influenced by the bridge and substituents added to the (C5R′m) groups. Thus, the present invention provides a method for varying the melting points of the polymer product and a method of varying the molecular weights of the product by changing the components and structure of the metallocene catalysts. The present invention also provides a process for polymerizing olefins in which the melting points and/or molecular weights of the product may be controlled.

Abstract: This invention relates generally to articles formed from polypropylene polymer foams and desirably isotactic polypropylene polymer foams. The polypropylene polymers are obtained from metallocene catalysis. The polypropylene polymer has molecular weight distributions and densities that fall within broad ranges. The polypropylene polymer foam may be prepared in a multiple stage polymerization process using the same metallocene component in at least two stages.

Abstract: The present invention relates to polypropylene copolymer alloys which are especially suited for soft fiber and fabric applications. These alloys comprise an ethylene-propylene random copolymer having an ethylene content of from about 1.0 to 5.0% by weight, in an amount of from about 40 to 90% by weight of the alloy; and an ethylene-propylene bipolymer having an ethylene content of from about 10 to 30% by weight, in an amount of from about 10 to 60% by weight of the alloy. The present invention further relates to fiber and fabric articles made from such alloys.

Abstract: This invention relates to isotactic propylene homopolymer compositions obtained from metallocene catalysis wherein the polymer has a molecular weight distribution (Mw/Mn) in the range of from about 2.5 to about 20.0. The isotactic propylene homopolymer composition may be prepared in a multiple stage polymerization process using the same metallocene component in at least two stages.

Abstract: A process/apparatus is disclosed for continuously separating a liquid medium comprising diluent and unreacted monomers from a polymerization effluent comprising diluent, unreacted monomers and polymer solids, comprising a continuous discharge of the polymerization effluent from a slurry reactor through a discharge valve and transfer conduit into a first intermediate pressure flash tank with a conical bottom defined by substantially straight sides inclined at an angle to that of horizontal equal to or greater than the angle of slide of the slurry/polymer solids and an exit seal chamber of such diameter (d) and length (l) as to maintain a desired volume of concentrated polymer solids/slurry in the exit seal chamber such as to form a pressure seal while continuously discharging a plug flow of concentrated polymer solids/slurry bottom product of said first flash tank from the exit seal chamber through a seal chamber exit reducer with inclined sides defined by substantially straight sides inclined at an angle to t

Abstract: A polyolefin composition is provided which consists essentially of isotactic polypropylene and, optionally, repeating units of one or more comonomers, wherein the total comonomer repeating unit content of the polyolefin composition is from 0 to 20 mole percent, and further, wherein the weight average branching index g′ for the lower molecular weight region of the polyolefin composition is less than 0.93. Additionally, a process is provided for producing a polyolefin composition comprising: a) contacting, in solution, at a temperature from about 90° C. to about 120° C.

Abstract: A thermoplastic elastomer is provided comprising a branched olefin polymer having crystalline sidechains and an amorphous backbone wherein at least 90 mole percent of the sidechains are isotactic or syndiotactic polypropylene and at least 80 mole percent of the backbone is atactic polypropylene. Additionally, a process is provided for producing a thermoplastic elastomer composition comprising: a) contacting, in solution, at a temperature from about 90° C. to about 120° C., propylene monomers with a catalyst composition comprising a chiral, stereorigid transition metal catalyst compound capable of producing isotactic or syndiotactic polypropylene; b) copolymerizing the product of a) with propylene and, optionally, one or more copolymerizable monomers, in a polymerization reactor using an achiral transition metal catalyst capable of producing atactic polypropylene; and c) recovering a branched olefin polymer.

Abstract: This invention relates generally to foamable polypropylene polymer, and more particularly a foamable isotactic polypropylene homopolymer obtained from metallocene catalysis and to their methods of production and articles formed therefrom. The foamable polypropylene polymer has molecular weight distributions and densities that fall within broad ranges. The foamable polypropylene polymer may be prepared in a multiple stage polymerization process using the same metallocene component in at least two stages.

Abstract: This invention relates to an adhesive composition comprising a copolymer comprising units derived from one or more macromonomers and an unsaturated acid or an unsaturated anhydride wherein the weight average molecular weight of the copolymer is at least twice the weight average molecular weight of the macromonomer, the melt index of the copolymer is 1 dg/min or more, and wherein the macromonomer:(1) has a weight average molecular weight between 500 and 100,000;(2) has at least 30% terminal unsaturation; and(3) comprises a copolymer of ethylene and at least one .alpha.-olefin, and/or a copolymer of propylene and ethylene or an .alpha.-olefin.

Abstract: A method of forming a polymer that simultaneously provides an improved level of impact resistance and processability in which an .alpha.-olefin monomer is subjected to polymerization in the presence of a Ziegler-Natta catalyst system and a blend of electron donors including dicyclopentyldimethoxysilane (DCPMS) and propyltriethoxysilane (PTES). The polymer so formed will have a relationship between a first melt flow rate of a homopolymer formed by polymerizing an .alpha.-olefin monomer in the presence of a Ziegler-Natta catalyst system and a first electron donor (MFR (a)), and a second melt flow rate of a homopolymer formed polymerizing an .alpha.-olefin monomer in the presence of the Ziegler-Natta catalyst system and a second electron donor (MFR (b)), is defined by the equation:1.2.ltoreq.log [MFR(b)/MFR(a)].ltoreq.1.

Abstract: An absorbent structure containing an absorbent particle size gradient is disclose. The absorbent structure may also include a fiber size gradient. The absorbent structure may also include absorbent particles coupled to loosely distributed fibers and more particularly, the absorbent particles may be electrostatically couple to the loosely distributed fibers.

Abstract: A disposable, flexible shoe cover for receive a sole of a shoe or a foot is provided. The shoe cover includes cleats secured to an outside surface of the shoe cover, wherein some of the cleats are adapted to overlie the sole. The cleats may include a first portion and a second portion wherein, the second portion is thicker in cross-section than the first portion. The first and second portions of the cleats may eccentricly positioned. The shoe cover may also include elastic member secured to an inside surface of the body and adapted to contact the sole.

Abstract: A method for sterilizing an article supported in a housing is provided. The method includes placing an article in a housing, introducing pressurized steam and a sterilizing gas into the housing and closing the housing. The sterilizing gas may be mixture of ethylene oxide/carbon dioxide or ethylene oxide/nitrogen. The percent by volume of ethylene oxide in the housing at the conclusion of the sterilizing gas introducing step may range from at least about 2% to about 25% by volume. The present invention is particularly well suited for use with a form-fill-seal process.

Abstract: A multi-layered structure having improved liquid barrier properties is provided. The multi-layered structure includes a porous hydrophobic layer and a spacing layer adjacent to and in juxtaposition with the porous hydrophobic layer. The function of the spacing layer is to provide sufficient channels for a liquid while supporting all or substantially all of a compressive pressure exerted against the spacing layer. As such, when the spacing layer is contacted with a liquid, such as water, saline or a bodily fluid such as blood, and subjected to a compressive pressure, of at least 2 psi, applied generally perpendicularly to the spacing layer, the channels are available within the bulk of the spacing layer for such liquid to flow therein or therebetween, while all or substantially all of the compressive pressure is supported by the spacing layer. In this way, the liquid in contact with the spacing layer flows into these channels without passing through the porous hydrophobic layer.