39144 results about "Polypropylene" patented technology

A universal, surgical prosthesis for hernia repair is provided in the form of a foldable sheet. The prosthesis includes a barrier layer formed of a material adapted to prevent biological adherence thereto, such as polytetrafluoroethylene, and a second surface layer formed of a material adapted to promote biological tissue adherence thereto, such as polypropylene. The second surface may be formed of a series of spaced projections. The prosthesis is adapted to be manipulated into an operative position to exhibit an appropriate exterior when in the operative position. In this manner, the universal, surgical prosthesis can be utilized for a wide range of surgical procedures.

A medical device having a contact surface exposed repeatedly to bodily tissue is disclosed. The contact surface is coated with a silicone polymer and one or more non-silicone hydrophobic polymers. The preferred medical device is a surgical needle, and the preferred coating is a polydimethylsiloxane and polypropylene wax hydrocarbon mixture. The incorporation of the non-silicone hydrophobic polymer increases the durability of the coating on the device without sacrificing lubricity.

Unique copolymers comprising propylene, ethylene and / or one or more unsaturated comonomers are characterized as having: at least one, preferably more than one, of the following properties: (i) 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity, (ii) a B-value greater than about 1.4 when the comonomer content of the copolymer is at least about 3 wt %, (iii) a skewness index, Six, greater than about −1.20, (iv) a DSC curve with a Tme that remains essentially the same and a Tmax that decreases as the amount of comonomer in the copolymer is increased, and (v) an X-ray diffraction pattern that reports more gamma-form crystals than a comparable copolymer prepared with a Ziegler-Natta catalyst. These polypropylene polymers are made using a nonmetallocene, metal-centered, heteroaryl ligand catalyst. These polymers can be blended with other polymers, and are useful in the manufacture of films, sheets, foams, fibers and molded articles.

A liquid acquisition material for use in an absorbent article. The liquid acquisition material having first fibers and second fibers. The first fibers are chemically cross-linked cellulose fibers and the second fibers are selected from the group consisting of: polyethylene, polypropylene, polyester, rayon, lyocell, and mixtures thereof. The liquid acquisition material has a total dry weight, the first fibers have a first dry weight, and the second fibers have a second dry weight. The first dry weight is from 30 to 95 percent of the total dry weight and the second dry weight is from 5 to 70 percent of the total dry weight.

A new polypropylene terephthalate composition is provided. The polypropylene terephthalate is comprised of 1,3-propanediol and terephthalate. The 1,3-propanediol is produced by the bioconversion of a fermentatble carbon source, preferable glucose. The resulting polypropylene terephthalate is distinguished from petrochemically produced polymer on the basis of dual carbon-isotopic fingerprinting which indicates both the source and the age of the carbon.

Polymer blends comprises 1) at least one ethylene / α-olefin interpolymer and 2) at least one polyolefin, or at least one styrenic block copolymer, or a combination thereof. Such polyolefins include, but are not limited to, high melt strength high density polyethylene and high melt strength polypropylene. The ethylene / α-olefin interpolymers are random block copolymers comprising at least a hard block and at least a soft block. The polyolefins can be homopolymers or interpolymers. The resulting polymer blends can be used to make flexible molded articles.

A filler rod for occupying space in a stranded optical fiber communications cable having at least one buffer tube containing at least one optical fiber is disclosed. The filler rod comprises an elongated rod extruded from a polypropylene homopolymer, a polypropylene-polyethylene copolymer (i-PP) resin material, or preferably, from a polypropylene-polyethylene copolymer having a nucleating agent disbursed therein. The resin material is foamed during extrusion so as to have a plurality of void spaces therein and a relative density which is less than 1 relative to the unfoamed resin material. As compared to rods made from high density polyethylene, the i-PP filler rods show a greater foaming efficiency, more efficient use of material, an improved combination of mechanical properties and density, reduced post-extrusion shrinkage and a substantial reduction in the sticking of the filler rods to the outer jacket that is experienced with high density polyethylene filler rods.

The present invention relates to a device and method which may be used to reinforce the native annulus during spinal surgery. The device is a catheter based device which is placed into the inter-vertebral space following discectomy performed by either traditional surgical or endoscopic approaches. The distal end of the catheter is comprised of an expansile loop which may be increased in diameter by advancement of a portion of the catheter via its proximal end, such proximal end remaining external to the body. The expansile loop may be formed of a woven or braided material and may be made of a polymer such as nylon, polyurethane, polyester, polyethylene, polypropylene or any of the well known and biocompatible polymers. Alternatively the expansile portion of the catheter may be formed from a metallic braid of stainless steel, elgiloy, Nitinol, or other biocompatible metals. The expansile loop may be formed such that when the loop is diametrically contracted the loop feeds into its other end, similar to a snake eating its own tail. Stabilization of the outer portion of the loop and pulling out the inner portion will thereby increase the overall diameter of the loop while maintaining it as a closed loop or torus. The present invention comprises four embodiments and can be used to 1) facilitate disk fusing, 2) perform an artificial replacement of the nucleus, 3) perform an artificial replacement of the annulus, or 4, perform an artificial replacement of both the nucleus and annulus.

This invention relates to rapid prototyping systems, specifically, a composition for a release film comprising one or more base materials selected from the group consisting of silicone, polycarbonate, polyethylene, and polypropylene; and one or more free-radical inhibitors.

This invention relates to hetero-phase polyolefin compositions comprising: a) 30 to 99.7 wt % of a polypropylene-based TPO comprising at least 50 wt % propylene and at least 10 wt % ethylene, and b) 0.1 to 20 wt % of one or more non-functionalized plasticizer, and c) 0.2 to 50 wt % of one or more filler; based upon the weight of the composition, and having: i) an MFR of 5 dg / min or more, and ii) a flexural modulus of 500 MPa or more, and iii) a notched Charpy impact strength at −30° C. of 1 kJ / m2 or more or a notched Izod impact strength at −18° C. of 50 J / m or more.These compositions are especially useful in applications such as automotive parts that demand both high stiffness and high impact toughness, as well as good processibility during fabrication.

A filler rod for occupying space in a stranded optical fiber communications cable having at least one buffer tube containing at least one optical fiber is disclosed. The filler rod comprises an elongated rod extruded from a polypropylene homopolymer, a polypropylene-polyethylene copolymer (i-PP) resin material, or preferably, from a polypropylene-polyethylene copolymer having a nucleating agent disbursed therein. The resin material is foamed during extrusion so as to have a plurality of void spaces therein and a relative density which is less than 1 relative to the unfoamed resin material. As compared to rods made from high density polyethylene, the i-PP filler rods show a greater foaming efficiency, more efficient use of material, an improved combination of mechanical properties and density, reduced post-extrusion shrinkage and a substantial reduction in the sticking of the filler rods to the outer jacket that is experienced with high density polyethylene filler rods.

Compositions having good impact performance can be made from a thermoplastic (e.g., a polyolefin such as polypropylene or HDPE) and an ethylene multi-block copolymer. The compositions are easily molded and often have particular utility in making, for example, automotive facia, parts and other household articles.

An integral gasketed filtration cassette structure of a type comprising a filtration cassette fully or partially overcoated by a gasket layer, forming a fluid-tight seal between the filtration cassette and the filtration cassette holder to which the filtration cassette is to be affixed. The filtration cassette comprises filter sheets arranged in a multilaminate, peripherally bonded array, wherein the filter sheets alternate with permeate and retentate sheets. The gasket layer comprises an elastomeric material with suitable hardness and temperature resistance for sealing, such as silicone, ethylenepropylenedienemonomer (EPDM), viton, polyurethane, polypropylene, polyethylene, polyvinylchloride, polyester, epoxy, ethylvinylacetate, bunnas, and styrene butadiene. The filtration cassettes and filter of the invention may be advantageously employed for dewatering of aqueous biomass suspensions, desalting of proteins, removal of secreted metabolites from cellular suspensions, and the like.

New ligands, compositions, metal-ligand complexes and arrays with bridged bis-aromatic ligands are disclosed that catalyze the polymerization of monomers into polymers. These catalysts with metal centers have high performance characteristics, including higher comonomer incorporation into ethylene / olefin copolymers, where such olefins are for example, 1-octene, propylene or styrene. The catalysts also polymerize propylene into isotactic polypropylene.

A composite structural panel includes a cover sheet laminated onto a three-layered substrate including a thermoplastic foam core sandwiched between two composite outer layers. Each composite outer layer includes natural fibers embedded in a thermoplastic matrix. The thermoplastic material of all layers is preferably polypropylene, and the core consists of an expanded cellular polypropylene rigid foam. In a method for forming the composite structural panel, a first preheated outer layer is laminated and molded onto the foam core in a first molding step, and then the second preheated outer layer and the cover sheet are laminated and molded onto the foam core in a second molding step, with a cooling-down time allowed between the two molding steps. In this manner, each preheated outer layer provides enough heat to thermally fuse the outer layer onto the foam core, without overheating the foam core to the point of softening or melting the foam core. The low density foam core provides a spacing distance between the strong composite outer layers, and therefore the finished composite structural panel has a high strength and rigidity, and a high strength-to-weight ratio. The structural panel can be molded into any desired three-dimensional contoured configuration during the molding process.

A process for polymerizing propylene is provided. The process comprises contacting propylene and optionally one or more monomers with a catalyst system comprising a bis-indenyl Group 4 metallocene compound supported on silica, the silica treated with one or more organoaluminum compounds and one or more heterocyclic compounds, under slurry conditions in the presence of hydrogen at a temperature of about 50° C. to about 160° C. and a pressure of from about 3 MPa to about 5 MPa to provide a catalyst activity of greater than 30,000 pounds of product per pound of catalyst; and then recovering isotactic polypropylene having a melt flow rate of 20 dg / min or less as measured according to ASTM D-1238 at 230° C. and 2.16 kg.

An improved composite structural member comprising a complex profile structural member, made of a composite comprising a polypropylene polymer and a wood fiber. The material is useful in conventional construction applications. The complex profile, in the form of an extruded thermoplastic composite member can be used in residential and commercial structures as described. Preferably, the structural member is used in the manufacture of the fenestration components such as windows and doors. Such linear members are designed with specifically configured cross-sectional shapes to form structural elements in the fenestration units. Structural elements must possess sufficient strength, thermal stability and weatherability to permit the manufacture of a structurally sound window unit that can be easily installed into a rough opening but can maintain its attractive appearance and structural integrity over the life of the window unit often twenty years or more. The structural member comprises a hollow complex cross-section with at least one structural web or one fastener web formed within the component. The exterior of the extruded component has a visible capstock layer and is shaped and adapted for installation in rough openings. The exterior also contains shape and components capable of supporting the elements of the fenestration unit such as a window, sash or movable door unit. The improved polypropylene structural members have unique advantages and can be assembled in thermoplastic weld processes.

The present invention relates to fibers and nonwovens made from plasticized polyolefin compositions comprising a polyolefin, a non-functionalized hydrocarbon plasticizer and a slip agent.

The invention relates to a composite comprising a weight fraction of single-wall carbon nanotubes and at least one polar polymer wherein the composite has an electrical and / or thermal conductivity enhanced over that of the polymer alone. The invention also comprises a method for making this polymer composition. The present application provides composite compositions that, over a wide range of single-wall carbon nanotube loading, have electrical conductivities exceeding those known in the art by more than one order of magnitude. The electrical conductivity enhancement depends on the weight fraction (F) of the single-wall carbon nanotubes in the composite. The electrical conductivity of the composite of this invention is at least 5 Siemens per centimeter (S / cm) at (F) of 0.5 (i.e. where single-wall carbon nanotube loading weight represents half of the total composite weight), at least 1 S / cm at a F of 0.1, at least 1×10−4 S / cm at (F) of 0.004, at least 6×10−9 S / cm at (F) of 0.001 and at least 3×10−16 S / cm (F) plus the intrinsic conductivity of the polymer matrix material at of 0.0001. The thermal conductivity enhancement is in excess of 1 Watt / m-° K. The polar polymer can be polycarbonate, poly(acrylic acid), poly(acrylic acid), poly(methacrylic acid), polyoxide, polysulfide, polysulfone, polyamides, polyester, polyurethane, polyimide, poly(vinyl acetate), poly(vinyl alcohol), poly(vinyl chloride), poly(vinyl pyridine), poly(vinyl pyrrolidone), copolymers thereof and combinations thereof. The composite can further comprise a nonpolar polymer, such as, a polyolefin polymer, polyethylene, polypropylene, polybutene, polyisobutene, polyisoprene, polystyrene, copolymers thereof and combinations thereof.

The present invention relates to a device and method which may be used to reinforce the native annulus during spinal surgery. The device is a catheter based device which is placed into the inter-vertebral space following discectomy performed by either traditional surgical or endoscopic approaches. The distal end of the catheter is comprised of an expansile loop which may be increased in diameter by advancement of a portion of the catheter via its proximal end, such proximal end remaining external to the body. The expansile loop may be formed of a woven or braided material and may be made of a polymer such as nylon, polyurethane, polyester, polyethylene, polypropylene or any of the well known and biocompatible polymers. Alternatively the expansile portion of the catheter may be formed from a metallic braid of stainless steel, elgiloy, Nitinol, or other biocompatible metals. The expansile loop may be formed such that when the loop is diametrically contracted the loop feeds into its other end, similar to a snake eating its own tail. Stabilization of the outer portion of the loop and pulling out the inner portion will thereby increase the overall diameter of the loop while maintaining it as a closed loop or torus. The present invention comprises four embodiments and can be used to 1) facilitate disk fusing, 2) perform an artificial replacement of the nucleus, 3) perform an artificial replacement of the annulus, or 4, perform an artificial replacement of both the nucleus and annulus.

Extensible nonwoven fabrics having improved elongation, extensibility, abrasion resistance and toughness. In particular, embodiments of the invention are directed to extensible spunbond fabrics comprising a polymeric blend of a metallocene catalyzed polypropylene, polyethylene, and a third polymer component.

The thermoplastic resin composition (Xi) of the present invention comprises (A1), (B1), (C1), and optionally (D1) below: 1 to 90 wt % of an isotactic polypropylene (A1); 9 to 98 wt % of a propylene / ethylene / α-olefin copolymer (B1) containing 45 to 89 mol% of propylene-derived structural units, 10 to 25 molt of ethylene-derived structural units, and optionally, 0 to 30 mol% of C4-C20 α-olefin-derived structural units (a1); 1 to 80 wt % of a styrene-based elastomer (C1); and 0 to 70 wt % of an ethylene / α-olefin copolymer (D1) whose density is in the range of 0.850 to 0.910 g / cm3, wherein (A1)+(B1)+(C1)+(D1)=100 wt %.

New ligands, compositions, metal-ligand complexes and arrays with pyridylamine ligands are disclosed that catalyze the polymerization of monomers into polymers. Certain of these catalysts with hafnium metal centers have high performance characteristics, including higher comonomer incorporation into ethylene / olefin copolymers, where such olefins are for example, 1-octene, isobutylene or styrene. Certain of the catalysts are particularly effective at polymerizing propylene to high molecular weight isotactic polypropylene in a solution process at a variety of polymerization conditions.

Polypropylene block-copolymer resin exhibiting high melt tension and improved moldability with balanced stiffness and impact resistance may be molded at high speed into large-sized articles, including, stretched films, with good appearance and resistance to deformation. The block copolymer includes a higher molecular weight polypropylene segment, a lower molecular weight polypropylene segment and an ethylene alpha-olefin copolymer segment. When subjected to dissolution fractionation m paraxylene, a large proportion is insoluble at 23° C. but soluble at 135° C., and a smaller portion is soluble at 23° C. The block copolymer has a melt flow rate of 0.01 to 5 g / 10 min at 230 C. (2.16 kg) and a molecular weight distribution Mw / Mn of 6-20 and Mz / Mw of at least 3.5. A continuous multistage polymerization may be used to form the block copolymer.

The present invention concerns a high melt strength propylene polymer or copolymer suitable for manufacturing foams and thermoformed product exhibiting a melt strength of at least 3 g and comprising a high molar mass portion and a low or medium molar mass portion. The polymers are produced by subjecting propylene and optionally other olefins to polymerization in a plurality of polymerization reactors connected in series, employing different amounts of hydrogen as a molar mass modifier in at least two of the reactors, and carrying out the polymerization reaction in the presence of a catalyst system capable of catalyzing the formation of a high molar mass polymerization product having a MFR2 of less than 0.1 g / l0 min and a low or medium molar mass polymerization product having a MFR2 of more than 0.5 g / 10 min.

A method of making a composite material part, in particular a wind turbine blade of great length, consists in placing a thickness of a cloth made up of threads comprising a mixture of polypropylene threads or fibers and of glass fibers or threads in two mold portions having the shape of the part that is to be made, placing an inflatable envelope on the cloth inside one of the mold portions, in closing the mold, in placing it in an enclosure fed with hot gas under pressure to melt the polypropylene of the cloth, thereby embedding the glass fibers or threads, then in allowing it to cool, and in unmolding.