MXPA01005814A - Mel-bondable polypropylene/ethylene polymer fiber and composition for making the same - Google Patents

Abstract

The subject invention is directed to fibers and polymer blend compositions having improved bonding performance. In particular, the subject invention pertains to a multiconstituent fiber comprising a blend of a polypropylene polymer and a high molecular weight (that is, low melt index or melt flow) ethylene polymer. The subject invention further pertains to the use of the fiber and polymer blend composition which has improved bonding performance in various end-use applications, especially woven and nonwoven fabrics such as, for example, disposable incontinence garments and diapers. The fibers have good spinnability and provide fabrics having improved bond strength and elongation.

Description

-, 1 POLYMER FIBER PROPÍ LE N O / ETI LE NO THAT JOINS THROUGH MEL AND COMPOSITION TO MAKE THE SAME DESCRIPTION OF THE INVENTION This invention relates to polymer compositions having improved bonding performance. In particular, the present invention relates to a polymer composition comprising the mixture of a polypropylene polymer and an ethylene polymer with high molecular weight (ie, low melt index or melt flow). The present invention also relates to the use of the The polymer blend composition, which has improved binding performance in various end-use applications, especially fibers, nonwovens and articles made from fibers (eg, incontinence garments and disposable diapers). The fibers have good flexibility or spinnability and provide a fabric that has good bond strength and good elongation. The fiber is typically classified according to its diameter. Monofilament fiber is generally defined as having an individual fiber diameter greater than 15 denier, usually greater than 30 denier per filament. Fine denier fiber is usually refers to a fiber that has a diameter less than 15 denier per filament. The microdenier fiber is generally defined as a fiber that has less than 100 microns in diameter. The fiber can also be classified by the process through which it is made, such as monofilament, fine filament continuous winding, fiber discontinuous or cut, fiber filaments linked together and ^^? & ji blown by fusion. A variety of fibers and fabrics have been made from thermoplastics, such as polypropylene, highly polyethylene • low density branching (LDPE) typically made in a high pressure polymerization process, heterogeneously branched linear polyethylene (eg, linear low density polyethylene using Ziegler catalysts), mixtures of polypropylene and heterogeneously branched linear polyethylene, mixtures of linear polyethylene heterogeneously branched and • 10 ethylene / vinyl alcohol copolymers. Of the various polymers known to be extrudable to fibers, low density, highly branched polyethylene (LDPE) has not been successfully melt spun to a fine denier fiber. The heterogeneously branched line polyethylene has been made to a monofilament, as described in the patent of E.U.A. No. 4,076,698 (Anderson et al.). The linearly heterogeneously branched polyethylene has also been successfully made to a fine denier fiber, as described in the U.S. patent. No. 4,644,045 (Fowells), patent of E.U.A. No. 4,830,097 (Sawyer et al.), Patent of E.U.A. No. 4,909,975 (Sawyer et al.), And US patent. No. 4,578,414 (Sawyer et al.). Mixtures of said heterogeneously branched polymer have also been successfully made to a fiber and fine denier fabrics as described in the U.S. patent. No. 4,842,922 (Krupp et al.), US patent. Do not. 4,990,686 (Krupp et al.) And US patent. No. 5,112,686 (Krupp .- -. * -... aiuafc ^ ta MMHÉÍriteilki and others). The patent of E.U.A. No. 5,068,141 (Kubo et al.) Also discloses the formation of non-woven fabrics from continuous heat-bonded filaments of certain heterogeneously branched LLDPEs, which have specific melting heats. Although the use of heterogeneously branched polymer blends produces an improved fabric, the polymers are more difficult to spin without breaking the fiber or dripping or spinning on the spinner die or both. The patents of E.U.A. Nos. 5,294,492 and 5,593,768 (Gessner) describe a multi-constituent fiber having improved thermal bonding characteristics composed of a blend of at least two different thermoplastic polymers, which form the continuous polymer phase and at least one polymer phase Does not continue. In the claims, Gessner describes that at least one phase does not continue to occupy a substantial portion of the surface made of the mixture. But although it is believed that the claims in the patents of E.U.A. Nos. 5,294,492 and 5,593,768 specify, for example, a core-sheath configuration with respect to the polymer phases, the photomicrograph (Figure 1 therefrom) shows an island-sea type phase configuration for the fiber cross-section. In addition, it is believed that it is the continuous polymer phase (not the non-continuous phase) that occupies a substantial portion of the illustrated fiber surface, (but not reclaimed) by Gessner. Also, all the examples (and mainly Figure 1 from there) consist of polypropylene polymer blended with the ASPUN ™ fiber of LLDPE-grade resin having an L2 melt index of 12 or 26 g / 10 minutes as supplied by The Dow Chemical Company The illustrative polypropylene polymer used by Gessner was described as a PP "controlled rheology" (ie, a PP of reduced viscosity) having a melt flow rate of 26 and at least 90% by weight of isotacticity. The patent of E.U.A. No. 5,549,867 (Gessner et al.) Discloses the addition of a low molecular weight polyolefin (ie, high melt index or melt flow) to a polyolefin with a molecular weight (Mz) of 400,000 to 580,000 to improve spinning. The examples set forth in the Gessner et al. Patent are all directed to mixtures of 10 to 30% by weight of a metallocene polypropylene with a lower molecular weight of 70 to 90% by weight of a higher molecular weight polypropylene. produced using a Ziegler-Natta catalyst. The patent of E.U.A. No. 4,839,228 (Jezic et al.) Discloses biconstituent fibers having improved tenacity and being hand-compounded of a highly crystalline polypropylene polymer with LDPE, HDPE or preferably LLDPE. It is disclosed that polyethylene resins have a modern high molecular weight where their melt index, 12, is on the scale of 12 to 120 g / 10 minutes. Also, fibers made from mixtures of reduced viscosity polypropylene polymer and high density polyethylene homopolymer (HDPE) having a melt index, 12, equal to or greater than 5 g / 10 minutes are known. It is believed that such mixtures . -. *. * * I "- ***. *. **. »* *. m a, Aaaaa »^ function in the water immiscible capacity base of olefin polymers. WO 95/32091 (Stahl et al.) Discloses a reduction in bonding temperatures using blends of fibers produced from polypropylene resins having different melting points and produced through different fiber manufacturing processes, for example, meltblown and spunblown fibers. Stahl et al. Claim a fiber comprising a mixture of an isotactic propylene copolymer with a thermoplastic polymer of higher melting point. WO 96/23838, patent of E.U.A. No. 5,539,056 and US patent. No. 5,516,848 teach mixtures of an amorphous poly-α-olefin with Mw > 150,000 (produced through individual site catalysis) and a crystalline poly-α-olefin with Mw > 300,000, (produced through individual site catalysis), wherein the molecular weight of amorphous polypropylene is greater than the crystalline polypropylene molecular weight. Preferred blends comprise from 10 to 90% amorphous polypropylene, the blends described are said to exhibit unusual elastomeric properties, mainly an improved balance or mechanical strength and rubber recovery properties. The patent of E.U.A. No. 5,483,003 and EP 643100 teach mixtures of a semicrystalline propylene homopolymer having a melting point of 125 to 165 ° C and a propylene homopolymer. semicrystalline having a melting point below 130 ° C or a ^ len ^ a ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ These blends are said to have improved mechanical properties, notably impact resistance. It has been reported that crystalline polypropylenes produced by individual site catalysis are particularly suitable for the production of fibers. Due to the narrow molecular weight distributions and low amorphous contents, higher spin speeds and higher tenacities have been reported. But, isotactic PP fibers, in general, (and particularly when they are produced using individual site catalysis) exhibit poor binding performance. The patent of E.U.A. No. 5,677,383 (Lai et al.) Discloses mixtures of (A) at least one homogeneously branched ethylene polymer having a high strain hardening coefficient slope and (B) at least one ethyl polypropylene polymer having a high density of polymer and a certain amount of a linear high density polymer fraction. The examples set by Lai and others, are directed to substantially linear ethylene interpolymers blended with heterogeneously branched ethylene polymers. Lai and others describe the use of their blends in a variety of end-use applications, including fibers. The compositions described preferably comprise a substantially linear ethylene polymer having a density of at least 0.89 g / cm 3. But Lai and áÉ ^ UlkÉ others describe manufacturing temperatures only above 165 ° C. In contrast, to preserve the integrity of the fiber, the fabrics are often bonded at temperatures less than 165 ° C so that all the crystalline material does not melt before or during the bonding step of the fiber. Although various olefin polymer compositions have been successful in a number of fiber and fabric applications, fibers made from such compositions could benefit from an improvement in bond strength, which can lead to more fabrics. strong, and therefore, a high value for manufacturers of non-woven fabrics and articles, as well as for the final consumer. But any benefit in bond strength should not be at the cost of a damaging reduction in the spinning capacity and elongation of the fiber, nor a harmful increase in adhesion of the fibers or fabrics to the equipment during processing. It has been found that the inclusion of a high molecular weight ethylene polymer has a polypropylene polymer provides a multi-constituent fiber and calendered fabric having improved bonding performance, while simultaneously maintaining excellent fiber spinning and elongation performance . Accordingly, the present invention provides a fiber having a diameter on the scale of 0.1 to 50 denier and comprising: (A) from 0.5% to 25% by weight (by weight of the fiber) of at least one polymer of ethylene having: (i) a melt start, 12 less than or equal to 10 grams / 10 minutes, preferably less than 5 grams / 10 minutes, preferably less than or equal to 3 g / 10 minutes, most preferably less than or equal to 1.5 g / 10 minutes, and especially less than or equal to 0.75 g / 10 minutes, and (ii) a density of 0.85 to 0.87 grams / centimeters3, as measured in accordance with ASTM D792, (or a corresponding percentage of crystallinity in the range of 12 to 81 weight percent, as determined using differential scanning calorimetry (DSC)), and (B) a polypropylene polymer, preferably a polypropylene polymer having a melt flow rate (MFR) in the scale from 1 to 1000 grams / 10 minutes, as measured according to ASTM D 1238 at 230 ° C / 2.16 kg, most preferably on the scale of 5 to 100 grams / 10 minutes, provided that when the ethylene polymer is an ethylene / α-olefin interpolymer having a melt index, 12, on the scale from 5 to 10 g / 10 minutes, the density of the ethylene / α-olefin polymer is greater than 0.87 g / cm3, preferably greater than or equal to 0.90 g / cm3, and most preferably greater than or equal to 0.94 g / cm3. cm3, as measured in accordance with ASTM D792, provided that when the ethylene polymer is an ethylene homopolymer or ethylene / α-olefin interpolymer, having a density greater than or equal to 0.94 g / cm3, as measured in accordance with ASTM D792 , the melting index 12 of the ethylene polymer is less than 5 g / 10 minutes, preferably less than or equal to 3 g / 10 minutes, preferably less than or equal to 1.5 g / 10 minutes, most preferably less than or equal to at 0.75 g / 10 minutes, and where the fiber can be thermally bonded to 6069 kilograms / meter (kg / m) and a tempera Bonding surface area on the scale from 127 to 137 ° C. In a particular aspect, the present invention provides a fiber having a diameter on the scale of 0.1 to 50 denier, a continuous polymer phase and at least one discontinuous polymer phase, comprising: (A) as the phase of discontinuous polymer of 0.1% 30% by weight (by weight of the fiber) of at least one ethylene polymer having: (i) a melt index, 12 less than or equal to 10 grams / qO minutes, and (ii) ) a density of 0.85 to 0.97 grams / centimeters3, and (B) as the continuous polymer phase, a polypropylene polymer, provided that when the polypropylene polymer is an ethylene / α-olefin interpolymer with a melt index, , on a scale of 5 to 10 g / 10 minutes, the density of the ethylene / α-olefin polymer is greater than 0.87 g / cm 3 (or has a crystallinity of DSC percentage greater than 13% by weight), preferably higher that or equal to 0.90 g / cm3 (or has a percentage crystallinity greater than 33% by weight) and very preferably you greater than or equal to ^ U | ri | ßj ^^^^^^^ a | teÉMttMMHU. 0. 94 g / cm3 (or has a crystallinity in percentage of DSC greater than 60% by weight), provided that when the ethylene polymer is an ethylene homopolymer or ethylene / α-olefin interpolymer having a density greater than or equal to 0.94 g / cm3 the melt index, 12, of the ethylene polymer is less than 5 g / 10 minutes, where, before any bonding operation, the continuous polymer phase constitutes more than 50% of the surface area of the fiber and the two polymer phases transversely providing an island-sea configuration, and wherein the fiber can be thermally bonded at 6069 kilograms / meter and at a joint roll surface temperature in the range of 127 to 137 ° C. In specific embodiments, the discontinuous phase constitutes a quantity of the surface area of the fiber, which is within or less than 50%, preferably 25%, most preferably 10% of the amount contained in the blend composition. That is, in such embodiments, the percentage of surface area of the discontinuous phase polymer is non-substantial as it closely approximates the total weight percentage of the discontinuous phase polymer composition, as determined using an electron microscope technique, which It may include selective staining to improve resolution. Preferably, the fiber of the invention will be prepared from a polymer blend composition comprising: (A) at least one homogeneously branched ethylene polymer, most preferably at least one substantially linear ethylene / α-olefin interpolymer which has: i. a melt flow ratio, l10 / l2, = 5.63, • ii. a molecular weight distribution, Mw / Mn, defined by the equation: Mw / Mn, < (l10 / l2) * 4.63, and iii. a critical shear rate at the beginning of the melt fracture of the surface of at least 50% greater than the critical shear rate at the beginning of the fracture • 10 by melting the surface of a linear ethylene polymer having approximately the same 12 and Mw / Mn, and constituting the discontinuous polymer phase, and (B) at least one isotactic polypropylene-propylene. The present invention further provides a method for improving the bond strength of a fine denier fiber composed of at least one polypropylene polymer, the method comprising providing an intimate blend therewith of less than or equal to 22% by weight, preferably less than or equal to 17% by weight, most preferably less than or equal to 12% by weight of at least one ethylene polymer having a density of 0.85 to 0.97 g / cm3 and a melt index, 12, from 0.01 to 10 g / 10 minutes, provided that when the ethylene polymer is an ethylene / α-olefin interpolymer having a melt index of l2, on the scale of 5 to 10 g / 10 minutes, the density of the ethylene polymer / α-olefin is greater than 0.87 g / cm3, and provided that when the ethylene polymer is an ethylene homopolymer or ethylene / α-olefin interpolymer having a density greater than or equal to 0.94 g / cm3, the melt index, 12, of the ethylene polymer is less than 5 g / 10 minutes. The present invention also provides a polymer composition having an improved bond strength, comprising: (A) from 0.1 to 30% by weight (by weight of the composition) of at least one ethylene polymer having: . a melt index, 12, less than or equal to 10 grams / 10 • 10 minutes, and ii. a density of 0.85 to 0.97 grams / centimeters3, and (B) a polypropylene polymer, provided that when the ethylene polymer is an ethylene / α-olefin interpolymer having a melt index, 12, on the 15 5 scale at 10 g / 10 minutes, the density of the ethylene / α-olefin polymer is greater than 0.87 g / cm 3 and provided that when the ethylene polymer is an ethylene homopolymer or ethylene / α-olefin interpolymer • having a density greater than or equal to 0.94 g / cm3, the melt index, 12, of the ethylene polymer is less than 5 g / 10 minutes. The present invention further provides a polymer composition of the invention, in the form of a fiber, fabric, nonwoven or woven article, rotomolded article, film layer, injection molded articles, thermoformed articles, blow molded articles, articles blow molded and injection molded, or an extrusion coating composition.

. * - .. ** *. * - ~ * ^ ***** ^ *. The fibers and fabrics of the invention can be produced by conventional fiber or synthetic fabric processes (e.g., carded, spin-spun, melt-blown, and spin-spin) and can be used to produce fabrics having a high elongation and tensile strength, without a major sacrifice in the spinning capacity of the fiber. As an unexpected surprise, the polymer blend exhibits excellent fiber spinning capacity although the ethylene polymer is characterized as having a high molecular weight. In fact, the excellent spinnability of the polymer blend is achieved even when the same ethylene polymer is not capable of being soluble to fine denier fibers (ie, diameters less than or equal to 50 denier) when They use alone. It is also surprising that improved bond strength is obtained without significant reductions in performance or elongation performance. It is also surprising that in relation to known PP / HDPE blends, improved strengths are obtained for binding to relatively low polymer densities and crystallinity. It is yet another surprise that blends of the invention based on high molecular weight ethylene / vinyl aromatic interpolymer provide dramatically improved bond strengths relative to comparative mixtures based on ethylene / α-olefin interpolymers with crystallinity and melt indexes comparable. As another surprise, the invention when the polypropylene polymer (B) is manufactured using a metallocene or catalyst system of individual or restricted site geometry results in substantially stable bond strengths to 6069 • kilograms / meter on the junction temperature scale from 127 to 5 137 ° C. These and other embodiments are described more fully in the detailed description with the following drawings. Figure 1 is a photomicrograph of transmission electron microscope of the cross section of a fiber of the invention (example of the invention 1) showing a continuous phase of polypropylene polymer and a discontinuous phase of ethylene polymer (in dark color). Figure 2 is a photomicrograph of transmission electron microscope of the cross section of a fiber of the invention (Example 3 of the invention) showing a continuous phase of polypropylene polymer and a discontinuous phase of ethylene polymer (dark colored). Figure 3 is a photomicrograph of transmission electron microscope of the cross section of a fiber of the invention (Example 9 of the invention) showing a continuous phase of polypropylene polymer and a discontinuous phase of ethylene polymer (particles with dark colored peripheries). Figure 4 is a photomicrograph of transmission electron microscope of the cross section of a comparative fiber (Comparative example 7) showing a continuous phase of polypropylene polymer and a discontinuous phase of ethylene polymer (dispersed particles dyed in dark). Figure 5 is a transmission electron microscope (TEM) photomicrograph of the cross section of a comparative fiber (comparative example 12) showing a continuous phase of the polymer and a discontinuous phase (highly stained dark colored particles). Figure 6 is a bar diagram illustrating the thermal bond strength of the fabric of examples 1-3 of the invention and comparative example 4. Figure 7 is a bar graph illustrating the thermal bond strength of the fabric of examples 1,5 and 6 of the invention and comparative example 4. Figure 8 is a bar graph illustrating the thermal bond strength of the fabric of examples 1, 8 and 9 of the invention and comparative examples 4, 7, 10, 11 and 12. Figure 9 is a bar graph illustrating the thermal bond strength of the fabric of examples 1 and 2 of the invention and comparative examples 4, 13 and 14. Figure 10 is a bar graph illustrating the thermal bond strength of the fabric of examples 1 and 6 of the invention and comparative examples 4 and 15. Figure 11 is a bar graph illustrating the thermal bond elongation of the fabric of examples 1-3 of the invention and comparative example 4.

Figure 12 is a bar graph illustrating the thermal bond elongation of the fabric of examples 1, 5 and 6 of the invention and comparative example 4. Figure 13 is a bar graph illustrating the thermal bond elongation of the fabric of examples 1, 8 and 9 of the invention, and comparative examples 4, 7, 10, 11 and 12. Figure 14 is a bar graph illustrating the thermal bond elongation of the fabric of examples 1 and 2 of the invention and comparative examples 4, 13 and 14. Figure 15 is a bar graph illustrating the thermal elongation of the fabric of examples 1 and 6 of the invention and comparative examples 4 and 15. Figure 16 is a bar graph illustrating the thermal bond strength of the fabric of examples 16 and 17 of the invention and comparative examples 18 and 19. Figures 17a-d are electron microscope photomicrographs of firing of thermally bonded fibers of the invention (example 1 of the invention) and comparative fibers (comparative example 4) at a magnification of 25x and 200x. Figures 18a-d are electron microscope photomicrographs of thermally bonded fibers of the invention (example 1 of the invention) and comparative fibers (comparative example 4) at an amplification of 50 μm to 20 μm. Figure 19 is a transmission electron microscope (TEM) photomicrograph at a 15,000x amplification of the joined cross section of thermally bonded fibers of the invention (example 1 of the invention) showing a continuous polypropylene polymer phase and a phase of discontinuous ethylene polymer (dyed in dark). Figure 20 is a transmission electron microscope (TEM) photomicrograph at a 15,000x amplification of the joined cross section of several thermally bonded comparative fibers (comparative example 4) showing stress cracking (dark dyeing) within the matrix continuous polymer • 10 polypropylene. The term "joint" as used herein refers to the application of force or pressure (separate from or in addition to that required or used to stretch fibers less than or equal to 50 denier) to melt melted or co-melted fibers, way that a bond strength greater than or equal to 1.500 grams is present. The term "thermal bonding" as used herein, refers to the reheating of short fibers and the application of force or pressure (separate from or in addition to that or used to stretch fibers less than or equal to 50 denier) to effect melting (or softening) and melting of fibers so that a bond strength greater than or equal to 2,000 grams is present. The operations that stretch and fuse fibers together in a single operation or simultaneously, or before any roll work (for For example, a guide pulley) such as, for example, spinning, are not considered to be a thermal bonding operation, although the fiber of the invention may have the shape of or result from a spinning operation and manufacturing operations. of fibers • Similar. The terms "reduced viscosity" and "cracked viscosity" are used herein in their conventional sense to refer to a reactor grade or polypropylene polymer product that is subsequently cracked or divided by chain before, during or through extrusion to provide a flow velocity of substantially higher melting. In the present invention, a polypropylene polymer of cracked viscosity will show a change of RMF of 3: 2, especially 5: 1 and most especially 7: 1 with respect to the ratio of its MFR subsequent to the initial MFR. For example, but the invention is not limited to this, a polymer of reactor grade polypropylene having an MFR of 4 can be used in the present invention where it is of reduced viscosity or cracked viscosity at an MFR greater than 20 (i.e., having a MFR of relative viscosity of> 20) before of, during or by extrusion (for example, in an extruder immediately before a spinner) in a conventional fiber manufacturing operation. In the present invention, to facilitate viscosity reduction, an initiator, such as a peroxide (for example, but not limited to, Lupersol ™ 101) and optionally an antioxidant can be combined with the polypropylene polymer of MFR. initially low before the manufacture of the fiber. In one embodiment, the polypropylene polymer is provided in powder form and the peroxide, antioxidant and ethylene polymer are mixed through a side arm extrusion in the • polypropylene polymer manufacturing facility. The polypropylene polymers having a reduced viscosity melt flow rate are also referred to in the art as "controlled rheology polypropylene" (see, for example, Gessner in US Patent No. 5,593,768) and degraded polypropylene aided with initiator (see, for example Polypropylene • 10 Handbook, Hanser Publishers, New York (1996)). The term "reactor grade" is used herein in its conventional sense to refer to a virgin polypropylene polymer or modified with additive, which is not cracked or divided by chain after its initial production and as such its MFR does not will be substantially changed during or by extrusion (for example, in an extruder immediately before spinning). In the present invention, a reactor grade polypropylene will have a • change of MFR during extrusion of less than 3: 1, especially less than or equal to 2: 1, more especially less than or equal to 1.5: 1 and very especially less than or equal 1.25: 1, with respect to the ratio of the subsequent MFR of the polymer to its initial MFR (before extrusion). In the present invention, the reactor grade polypropylene polymers are characterized as having a subsequent to initial MFR ratio of less than or equal to 1.25: 2, typically contain an effective thermal stabilizer system such as, for example, but not limited to, 1% by total weight of the phenolic antioxidant Irganox ™ 1010 or the phosphite stabilizer lrgafox ™ 168, or both. Reactor grade polypropylene polymers characterized by having a relatively low initial to initial MFR ratio are referred to in the art as "constant rheology polypropylene" (see Jezic et al., U.S. Patent No. 4,839,228). The term "excellent spinning capacity" as used herein, refers to the ability to produce high quality fine denier fibers using at least one semi-commercial equipment (if not a commercial equipment) at least at speeds of semi-commercial production (but it is at commercial production speeds). Representative examples of excellent spinnability is the production of end denier fiber at more than or equal to 750 m / minute without any drop using the spinnability test described by Pinoca et al. In the U.S. patent. No. 5,631,083. The term "stable bond strength" as used herein, means that the thermal bond strength for the manufactured article (eg, fiber) is on the scale of 4000a 6000 grams as determined at 6069 kilograms / meter and joining temperatures in the range of 127-37 ° C. The term "fine denier fiber" as used herein, refers to fibers having a diameter less than or equal to 50 denier.

The polymer blend composition used to make the fiber and fabric of the present invention comprises at least one polypropylene polymer, preferably a polymer of • crystalline polypropylene. The polypropylene polymer may be coupled, branched, reduced viscosity or a reactor grade resin. The composition of the invention comprises from 70 to 99.9% by weight of at least one polypropylene polymer. In certain embodiments, the composition of the invention comprises equal to or greater than 78% by weight, especially equal to or greater than 83% • 10 by weight and more especially equal to or greater than 88% by weight of at least one polypropylene polymer. A crystalline polypropylene polymer is a polymer with at least 90 mol% of its repeating units derived from propylene, preferably at least 97%, most preferably at minus 99%. The term "crystalline" as used herein means isotactic polypropylene having at least 93% isotactic triads as measured by 13 C NMR, preferably • at least 95%, most preferably at least 96%. The polypropylene polymer comprises either as a polymer of polypropylene or propylene polymerized with one or more other addition monomers polymerizable with propylene. The other monomers are preferably olefins, preferably alpha-olefins, and most preferably ethylene or an olefin having a structure RCH = CH2 wherein R is aliphatic or aromatic and has At least two, and preferably less than 18 carbon atoms. ... **,. *. **. * i The hydrocarbon olefin monomers within the skill in the art, include hydrocarbons having one or more double bonds at least one of which is polymerizable with the • alpha-olefin monomer. The alpha-olefins suitable for polymerization with propylene include 1-butene, 1-pentene, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-unidecene, 1-dodecene, and the like as well as 4- methyl-1-pentene, 4-methyl-1-hexen, 5-methyl-hexene, vinylcyclohexene, styrene, and the like. Preferred alpha-olefins include ethylene, 1- • 10 butene, 1-hexene and 1-octene. Optionally, but not the most preferred embodiment of the present invention, the polypropylene polymer comprises monomers having at least 2 double bonds, which preferably are dienes and triphenyls. The diene comonomers and Suitable trienes include 7-methyl-1, 6-octadiene, 3,7-dimethyl-1, 6-octadiene, 5,7-dimethyl-1,6-octadiene, 3,7, 11 -tri meti I-1, 6, 10-octatriene, 6-methyl-1,5-heptadiene, 1 -3-butadiene, 1,6-heptadiene, • 1, 7-octadiene, 1, 8-nonadiene, 1, 9-decadiene, 1, 10-undecadiene, norbornene, tetracyclododecene, or mixtures thereof, Preferably, butadiene, hexadienes, and octadienes, and most preferably 1,4-hexadiene, 1, 9-decadiene, 4-methyl-1,4-hexadiene, 5-methylene-1,4-hexadiene, dicyclopentactiene, and the like. -eti liden-2- norborneno. Suitable polypropylenes are formed through media Within the skill in the art, for example, using individual site catalysts or Ziegler-Natta catalysts. The polypropylene and optional alpha-olefin monomers are polymerized under conditions within the art, for example, as described by Galli et al., Anqew. 5 Macromol. Chem., Vol. 120, 73 (1984), or by E. P. Moore et al., In Polypropylene Handbook, Hanser Publishers, New York, 1996, particularly pages 11-98. The polypropylene polymer used in the present invention is conveniently any molecular weight distribution. • 10 (MWD). Polypropylene polymers of broad or narrow molecular weight distribution are formed through means within the skill in the art. For fiber applications, a narrower molecular weight distribution is generally preferred (e.g., a ratio of Mw / Mn or polydispersity). less than or equal to 3). Polypropylene polymers having a narrow molecular weight distribution can advantageously be provided by viscosity reduction or by degrees • of manufacturing reactor (without viscosity reduction) using individual site catalysis, or both. The polypropylene polymers for use in the present invention preferably have a weight average molecular weight as measured by gel permeation chromatography (GPC) greater than 100,000, preferably greater than 115,000, preferably greater than 150,000 and most preferably higher what 250,000 to obtain a desirably high mechanical strength in the final product. Preferably the polypropylene polymer has a melt flow rate (MFR) on the scale at 1 to 1000 grams / 10 minutes, • very preferably on the scale of 5 to 100 grams / 10 minutes, 5 as measured according to ASTM D1238 at 230 ° C / 2.16 kg. In general, for making fibers, especially fiber spinning, the melt flow rate of the polypropylene polymer is preferably greater than or equal to 20 g / 10 minutes, preferably greater than or equal to 25 g / 10 minutes, and especially in • 10 the scale from 15 to 50 g / 10 minutes, more specifically from 30 to 40 g / 10 minutes. But specifically for staple or staple fibers, the melt flow rate (MFR) of the polypropylene polymer preferably is in the range of 10 to 20 g / 10 minutes. For 15 spunbond fibers, the melt flow rate (MFR) of the polypropylene polymer is preferably in the range of 20 to 40 g / 10 minutes. For melt blown fibers the flow velocity • Melting (MFR) of the polypropylene polymer is preferably in the range of 500 to 1500 g / 10 minutes. For fibers spun by gel, the melt flow rate (MFR) of the polypropylene polymer is preferably less than or equal to 1 g / 10 minutes. The polypropylene polymer used in the present invention may be branched or coupled to provide high regimes or rates of nucleation and crystallization. The term "Coupled" is used herein to refer to polypropylene polymers that are modified in the rheology, so as to exhibit a change in the strength of the molten polymer to flow during the fiber forming operation (eg, in the extruder immediately before going to the spinner in a 5 operation of fiber spinning). While "reduced viscosity" is in the direction of chain splitting "coupled" is in the direction of entanglement or network formation. An example of coupling is when a coupling agent (eg, an azide compound) is added to a melt flow rate polypropylene polymer.

• Relatively high, so that after extrusion, the resulting polypropylene polymer composition achieves a melt flow rate substantially lower than the initial melt flow rate. For the coupled or branched polypropylene used in the present invention, the ratio of MFR Subsequent to initial MFR preferably is less than or equal to 0.7: 1, most preferably less than or equal to 0.2: 1. The branched polypropylene suitable for use in the • This invention is commercially available, for example, from Montell North America for the trade names of Profax PF-20 611 and PF-814. Alternatively, suitable branched or coupled polypropylene can be prepared through means within the skill in the art, such as through treatment with peroxide or electron beam, for example, as described by DeNicola et al., In the USA No. 5,414,027 (the use of high-energy radiation (ionization) in an atmosphere with a reduced oxygen content); EP 1 190 889 by Himont (irradiation of isotactic polypropylene electron beam at lower temperatures); patent of E.U.A. No. 5,464,907 (Akzo Nobel NV); EP 0 754 • 711 Solvay (peroxide treatment); and patent application of 5 E.U.A. No. 09 / 133,576, filed August 13, 1998 (azide coupling agents). All references herein to elements or metals belonging to a certain group refer to the Periodic Table of the Elements published and registered by CRC Press, Inc., 1989. ^ ßf 10 Also any reference to the group or groups should be to the group or groups presented in this Periodic Table of the Elements using the IUPAC system to list groups. The preparation of crystalline polypropylene polymers is within the skill in the art. Advantageous catalysts for use in the preparation of polypropylene narrow molecular weight distribution polymers useful in the practice of the invention are preferably derivatives of any transition metal including lanthanides, but preferably Group 3, 4 or lanthanide metals which are in the state of oxidation formal +2, +3 or +4. Preferred compounds include metal compounds containing from 1 to 3 linked anionic or neutral ligand groups by which they are delocalized anionic ligand groups, optionally cyclic or non-cyclic linked. Examples of such anionic ligand groups bound by p are conjugated or non-conjugated, cyclic or non-cyclic dienyl groups and allyl groups. By the term "attached by p" is meant that the ligand group is attached to the transition metal through its delocalized p-electrons. • Each atom in the group attached by delocalized p optionally and independently is substituted with a radical selected from the group consisting of hydrogen, halogen, hydrocarbyl, halohydrocarbyl, hydrocarbyl substituted metalloid radicals, wherein the metalloid is selected from group 14 of the Periodic Table of the Elements, and said metalloid radicals • 10 substituted with hydrocarbyl or hydrocarbyl, further substituted with a heterogeneous atom of group 15 or 16 containing a portion. Included within the term "hydrocarbyl" are alkyl radicals of 1 to 20 carbon atoms, straight, branched and cyclic, aromatic radicals of 6 to 20 carbon atoms.

Carbon, alkyl substituted aromatic radicals of 7 to 20 carbon atoms and substituted aryl alkyl radicals of 7 to 20 carbon atoms. In addition, 2 or more of these adjacent radicals • together they can form a fused ring system, a hydrogenated fused ring system, or a metallocycle with the metal. Suitable hydrocarbyl substituted organometaloid radicals include mono-, di-, and tri-substituted organometaloid radicals of the group 14 elements, wherein each of the hydrocarbyl groups contains from 1 to 20 carbon atoms. Examples of organometaloid radicals substituted with Advantageous hydrocarbyl include, trimethylsilyl, triethylsilyl, ethyldimethylsilyl, methyldiethylsilyl, trif in ilgermyl, and trimethylgermyl groups. Examples of the heterogeneous atom of group 15 or 16 containing portions include amine, phosphine, ether or thioether portions or their Monovalent derivatives, for example, amide, phosphide, ether or thioether groups attached to the transition metal or metal of lanthanides, and attached to the hydrocarbyl group or to the group containing a hydrocarbyl substituted metalloid. Examples of groups linked by delocalized, anionic, advantageous p include cyclopentadienyl, indenyl, fluorenyl, tetrahydroindenyl, tetrahydrofluorenyl, octahydrofluorenyl, pentadienyl, cyclohexadienyl, dihydroanthracenyl, hexahydroanthracenyl, and decahydroanthracenyl, as well as their hydrocarbyl substituted derivatives of 1 to 10 carbon atoms or substituted with silyl and substituted with hydrocarbyl from 1 to 10 carbon atoms. Preferred anionic p-linked groups with cyclopentadienyl, pentamethylcyclopentadienyl, tetramethylcyclopentadienyl, • teramethylsilylcyclopentadienyl, indenyl, 2,3-dimethylindenyl, fluorenyl, 2-methylindenyl, 2-methyl-4-phenyltindenyl, Tetrahydrofluororenyl, octahydrofluorenyl, and tetrahydroindenyl. A preferred class of catalysts are transition metal complexes corresponding to formula A: LTMXG? X 'nX "P, or a dimer thereof wherein: L is a group attached by delocalized, anionic p, which is M-linked, containing up to 50 non-hydrogen atoms, optionally two L groups can be linked together forming a bridge structure, and optionally a group L is attached to X; • M is a metal of group 4 of the Periodic Table of the 5 Elements in the formal oxidation state +2, +3, or +4; X is an optional divalent substituent of up to 50 non-hydrogen atoms that together with L forms a metallocyl with M; X 'in each occurrence is an optional neutral Lewis base having up to 20 non-hydrogen atoms and optionally a • 10 of X 'and one of L' may be joined together; X "in each occurrence is an anionic, monovalent moiety, having up to 40 non-hydrogen atoms, optionally two X groups" are covalently linked together to form a divalent dianionic moiety both having valencies attached to M, u, optionally, the X groups "are covalently bound together to form a conjugated or unconjugated, neutral diene that is attached by pa M (where M is in the oxidation state • + 2), and optionally also one or more of the groups X "and one or more of the groups X 'are joined together, thus forming a portion that is both covalently linked to M and coordinated to it through a Lewis base functionality, I is 0, 1 or 2, m is 0 or 1, n is a number from 0 to 3, 25 p is an integer from 0 to 3, and the sum, I + m + p, is equal to the formal oxidation state of M, except that when two groups X "together form a neutral conjugated or unconjugated diene that is joined by pa M, where the sum of I + m equals the formal oxidation state of M. Preferred complexes include those containing either one or both of the L groups. The latter examples include those which contain a bridge group linking the two L groups. The preferred bridge groups are those corresponding to the formula (ER * 2) X where E is silicon, germanium, tin or carbon, • 10 R * independently of each occurrence is hydrogen or a selected group of silyl, hydrocarbyl, hydrocarbyloxy and combinations thereof, wherein R * has up to 30 carbon or silicon atoms and x is from 1 to 8. Preferably R * independently of The occurrence is methyl, ethyl, propyl, benzyl, tert-butyl, phenyl, methoxy, ethoxy or phenoxy. Examples of complexes containing two L groups are compounds corresponding to the formula: • where: M is titanium, zirconium or hafnium, preferably zirconium or hafnium, in the formal oxidation state +2 or +4; R3 is each occurrence independently is selected from • group consisting of hydrogen, hydrocarbyl, silyl, germyl, cyano, halogen and combinations thereof, R3 having up to 20 non-hydrogen atoms, or adjacent R3 groups together form a divalent derivative (e.g., a hydrocarbaryl group, germadiil) thus forming a fused ring system, and B independently of each occurrence is an anionic ligand group • 10 of up to 40 atoms that are not hydrogen, or two X 'groups together form a divalent anionic ligand group of up to 40 atoms that are not hydrogen or together are a conjugated diene having from 4 to 30 non-hydrogen atoms, forming a complex a with M, so M is in the formal oxidation state +2, and R *, E, and x are like were previously defined. The above metal complexes are especially suitable for the preparation of polymers having a • stereoregular molecular structure. In said capacity, it is preferred that the complex possess a Cs symmetry or possess a stereorigid, chiral structure. Examples of the first type are compounds possessing different p-linked, delocalised systems, such as a cyclopentadienyl group and a fluorenyl group. Similar systems based on Ti (IV) or Zr (IV) were described for the preparation of syndiotactic olefin polymers by Ewen et al., 25 J. Am. 6255-6256 (1980). Examples of chiral structures include rae bis-indenyl complexes. Similar systems based on Ti (IV) or Zr (IV) were described for the preparation of isotactic olefin polymers by Wild et al., J.

• Organomet. Chem., 232, pp. 233-47 (1982). Suitable bridge ligands containing two groups attached by p are: (dimethylsilyl-bis (cyclopentadienyl)), (dimethylsilyl bis (methylcyclopentadienyl)), (dimethylsilyl-bis (ethylcyclopentadienyl)), (dimethylsilyl-bis (t-butylcylpentadienyl)) ), (dimethylsilyl-bis (tetramethylcyclopentadienyl)), (dimethylsilyl- • 10 bis (indenyl)), (dimethylsilyl-bis- (tetrahydroindenyl)), (dimethylsilyl-bis (fluorenyl)), (dimethylsilyl-bis (tetrahydrofluorenyl)), (dimethylsilyl-bis (2-methyl-4-phenylindenyl)), (dimethylsilyl-bis (2-methylindenyl)), (dimethylsilyl-cylcopentadienyl-fluorenyl), (dimethylsilyl-cyclopentadinenyl-octahydrofluorenyl), (dimethyl-silyl-cyclopentadienyl-15-tetrahydrofluorenyl), (1,1-2,2-tetramethyl-1,1-disilyl-bis-cyclopentadienyl), (1 , 2-bis (cyclopentadienyl) ethane, and (isopropyldienyl-cyclopentadienyl-fluorenyl) • Preferred X groups are selected from hydride, hydrocarbyl, silyl, germyl, halohydrocarbyl, halosilyl, Silylhydrocarbyl and aminohydrocarbyl, or two X groups "together form a divalent derivative of a conjugated diene or together form a conjugated diene, attached by p, neutral.The highly preferred groups X are hydrocarbyl groups of 1 to 20 carbon atoms, including those optionally formed from two groups X "together.

An additional class of metal complexes corresponds to the preceding formula, LiMX2X 'nX ", or a dimer thereof, wherein X is a divalent substituent of up to 50 non-hydrogen atoms that together with L forms a metallocycle with M. Substituents Preferred divalent X include groups containing up to 30 non-hydrogen atoms comprising at least one atom which is oxygen, sulfur, boron, or a member of group 14 of the Periodic Table of the Elements directly attached to the group attached by p, delocalized , and a different atom • selected from the group consisting of nitrogen, phosphorus, oxygen or sulfur that is covalently bound to M. A preferred class of such metal coordination complexes of group 4 corresponds to the formula: wherein: M is titanium, zirconium or hafnium in the formal oxidation state + 2, +3, or +4; 20 X "and R3 are as previously defined for the formulas Al and All; Y is -O-, -S-, -NR * -, -NR * 2-, or -PR-; and Z is SiR * 2, CR * 2, SiR * 2SiR * 2, CR * 2CR * 2, CR * = CR *, Cr * 2SR * 2, or GeR * 2, where R * is as defined previously. Illustrative group 4 metal complexes that are optionally used as catalysts include: cyclopentadienyl trimethyl cyclopentadienyl titanium, cyclopentadienyl cyclopentadienyl titanium, cyclopentadienyl triisopropyl titanium, cyclopentadienyl triphenyl titanium, cyclopentadienyl tribencyl titanium, titanium 2,4 -cyclopentadienyl dimethylpentadienyl, cyclopentadienyl cyclopentadienyl 2,4-dimethylpentadienyl titanium, cyclopentadienyl cyclopentadienyltrimethylphosphine 2,4-dimethylpentadienyl titanium, cyclopentadienyl titanium dimethyl methoxy, cyclopentadienyl titanium methyl chloride, pentamethylcyclopentadienyltrimethyl titanium, trimethyl indenyl titanium , Indenyl triethyl titanium, triphenyl indenyl titanium, triphenyl indenyl titanium, tetrahydroindenyl tribenzyl titanium, pentamethylcyclopentadienyl triisopropyl titanium, pentamethylcyclopentadienyl tribenzyl titanium , Pentamethylcyclopentadienyl dimethyl pentamethyl cyclopentadienyl, pentamethylcyclopentadienyl dimethyl chloride, bis (p5-2,4-dimethylpentadienyl) titanium, bis (p5-2,4-dimethylpentadienyl) titanium of trimethylphosphine, titanium bis (p5-2) , 4-dimethylpentadienylco) of triethylphosphine, trimethyl octahydrofluorenyl titanium, trimethylenitrile tetrahydroindenyl titanium, trimethyl tetrahydrofluorenyl titanium, dimethyl titanium of (tert-butylamido) (1,1-dimethyl-2, 3, 4, 9, 10- 1.4,? 5, 6, 7, 8-hexahydronaphthalenyl) dimethylsilane, dimethyl titanium of (tert-butylamido) (1,1, 2, 3-tetramethyl-2,3, 4, 9, 10-1, 4, 5, 6, 7, 8-hexahydronaphthalenyl) dimethylsilane, dibenzyl titanium (tert-butylamido) (tetramethyl-? 5-cyclopentadienyl) dimethylsilane, dimethyl (tert-butylamido) titanium (tetramethyl) -n5-cyclopentadienyl) dimethylsilane, dimethyl titanium of (tert-butylamido) (tetramethyl-,? 5- cyclopentadienyl) -1,2-ethanediyl, dimethyl titanium of (tert-butylamido) (tetramethyl-? 5-indenyl) dimethylsilane, titanium (III) 2- (dimethylamine) benzyl (tert-butylamido) (tetramethyl-? 5-cyclopentadienyl) dimethylsilane; titanium (lll) allyl (tert-butylamido) (tetramethyl-? 5-cyclopentadienyl) dimethylsilane titanium (III) 2, 4-dimetilpentadienílíco of (tert-butylamido) (tetramethyl-? 5-cyclopentadienyl) dimethylsilane titanium (lll) 1, 4-d if il-1, 3-butadienílico of (tert-butylamido) (tetramethyl,? 5-cyclopentadienyl) dimethyl silane titanium (II) 1, 3-pentadienílico of (tert-butylamido) (tetramethyl -? 5-cyclopentadienyl) dimethylsilane titanium (II) 1, 4-difeni I- 1, 3-butadienílico of (tert-butylamido) (2-methylindenyl) dimethylsilane titanium (II) 2, 4-hexadienílico of (ter- butylamido) (2-methylindenyl) dimethylsilane titanium (IV) 2, 3-dimethyl-1, 3-butadienílico of (tert-butylamido) (2-methylindenyl) dimethylsilane titanium (IV) isoprenílico of (tert-butylamido) (2 -metilindenil) dimethylsilane titanium 1, 3-butadienílico of (tert-butylamido) (2-methylindenyl) dimethylsilane titanium (IV) 2, 3-dimethyl-1, 3-butadienílico of (tert-butylamido) (2,3- dimethylindenyl) dimethylsilane, titanium (IV) isopren (tert-butylamido) (2,3-dimethylindenyl) dimethylsilane; titanium (IV) dimethyl (tert-butylamido) (2,3-dimethylindenyl) dimethylsilane; titanium (IV) dibenzyl of (tert-butylamido) (2,3-dimethylindenyl) dimethylsilane; titanium 1, 3-butadienyl (tert-butylamido) (2,3-dimethylindenyl) dimethyl silane, . - * *, ****. * ..,. titanium (II) 1, 3-pentadienyl of (tert-butylamido) (2,3-dimethylindenyl) dimethylsilane, titanium (II) 1,4-d if eni I-1,3-butadienyl of (terbutylamido) (2,3 - • dimethylindenyl) dimethylsilane, 5-titanium (II) 1, 3-pentadienyl (tert-butylamido) (2-methylindenyl) dimethylsilane, titanium (IV) dimethyl (tert-butylamido) (2-methylindenyl) dimethylsilane, titanium (IV ) dibenzyl of (tert-butylamido) (2-methylindenyl) -10-dimethylsilane, titanium (II) 1,4-d if enyl-1,3-butadienyl of (tert-butylamido) (2-methyl-4-phenylindenyl) dimethylsilane, titanium (II) 1, 3-pentadienyl of (tert-butylamido) (2-methyl-4-phenylindenyl) dimethylsilane, 15 titanium (II) 2,4-hexadienyl of (tert-butylamido) (2-methyl-4-phenyl-indenyl) ) dimethylsilane, 1, 3-butadienyl titanium (tert-butylamido) (tetramethyl-5-cyclopentadienyl) dimethylsilane, titanium (IV) 2,3-dimethyl-1,3-butadienyl (tert-butylamido) 20 (tetramethyl) il5-cyclopentadienyl) dimethylsilane, titanium (IV) isoprene (tert-butylamido) (tetramethyl-5-cyclopentadienyl) dimethylsilane, titanium (II) 1,4-dibenzyl-1,3-butadienyl (tert-butylamido) (tetramethyl-5-cyclopentadienyl) d -methylsilane, Titanium (II) 2,4-hexadienyl of (tert-butylamido) (tetramethyl-,? 5- cyclopentadienyl) dimethylsilane, titanium (II). 3-Methyl-1, 3-pentadienyl of (tert-butylamido) (tetramethyl-? 5-cyclopentadienyl) dimethylsilane, dimethyl titanium of (tert-butylamide) (2,4-dimethylpentadiene-3-yl) dimethylsilane, dimethyl titanium of ( tert-butylamido) (6,6-dimethylcyclohexadienyl) dimethylsilane, dimethyl titanium (tert-butylamido) (1,1-dimethyl-2,3,4,9,10,1,4,5,6,7,8- hexahydronaphthalen-4-yl) dimethylsilane, dimethyl (tert-butylamido) titanium (1,1,3,3-tetramethyl-2,3,4,9,10,1,4,5,6,7,8-hexahydronaphthalene) -4-yl) dimethylsilane, titanium (IV) dimethyl (tert-butylamido) (tetramethyl-? 5-cyclopentadienyl methyl nyl nyl silane, titanium (II) 1,4-d if eni I-1,3-butadienyl ether -butylamido) (tetramethyl-? 5-cyclopentadienylmethyl nyl silane, titanium (IV) dimethyl of 1- (tert-butylamido) -2- (tetramethyl-? 5-cyclopentadienyl-ethanediyl, and titanium (II) 1,4-d if and I-1, 3-butadienyl of (tert-butylamido) -2- (tetramethyl-? 5-cyclopentadienyl) ethanediyl. The complexes containing two L groups incluy endo bridge complexes, include: bis (cyclopentadienyl) dimethyl zirconium, bis (cyclopentadienyl) dibenzyl zirconia, bis (cyclopentadienyl) methylbenzyl zirconia, bis (cyclopentadienyl) methylphenyl zirconium, - * »- * ^ -. diphenylic acid bis (cyclopentadienyl) zirconium, bis (cyclopentadienyl) allyl titanium, bis (cyclopentadienyl) zirconium methyl methoxide, bis (cyclopentadienyl) zirconium methyl chloride, bis (pentamethylcyclopentadienyl) dimethyl zirconium, dimethyl titanium bis (pentamethylcyclopentadienyl), bis (indenyl) methyl zirconium, (2-dimethylamino) benzyl) bis (indenyl) zirconium, bis (indenyl) zirconium methyltrimethylsilyl, bis (tetrahydroindenyl) methyltrimethylsilyl zirconium, bis benzyl zirconium (pentamethylcyclopentadienyl), bis (pentamethylcyclopentadienyl) dibenzyl zirconia, bis (pentamethylcyclopentadienyl) zirconium methyl methoxide, bis (pentamethylcyclopentadienyl) zirconium methyl chloride, bis (methylethylcyclopentadienyl) dimethyl zirconium, • bis (butylcyclopentadienyl) dibenzyl zirconium, bis (t-butylcyclopentadienyl) dimethyl zirconium, bis (ethyltetramethylcyclopentadienyl) dimethyl zirconium, bis (methylpropylcyclopentadienyl) dibenzyl zirconium, bis (trimethylsilylcyclopentadienyl) zirconium dibenzyl, dimethylsilyl-bis dimethyl zirconium (cyclopentadienyl), titanium- (III) of dimethylsilyl-bis (tetramethylcyclopentadienyl), zirconium dimethylsilyl-bis (t-butylcyclopentadienyl) dichloride, zirconium dimethylsilyl-bis ([beta] -butylcyclopentadienyl) dichloride, titanium ( lll) 2- (dimethylamino) benzyl of (methylene-bis (tetramethylcyclopentadienyl), titanium (III) -2- (dimethylamino) benzyl of (methylene-bis (γ-butylcyclopentadienyl), benzyl chloride of dimethylsilyl-bis (indenyl) zirconium, dimethylsilyl-bis (2-methylindenyl) dimethyl zirconium, dimethyl zirconium of dimethylsilyl-bis (2-methyl-4-phenylindenyl), zirconium-1, 4-d if eni I-1,3-dimethylsilyl-bis (2-methylindenyl) -butadienyl, zirconium (II) 1, 4-d if in il-1, dimethylsilyl-bis (2-methyl-4-phenylindenyl) -3-butadienyl, zirconium (II) 1,4-d if in dimethylsilyl-bis (tetrahydroindenyl) -l, 1,3-butadienyl, methyl chloride of dimethylsilyl-bis (fluorenyl) zirconium, dimethylsilyl-bis (tetrahydrofluorenyl) bis (trimethylsilyl) zirconium, and dimethylsilyl (tetramethylcyclopentadienyl) (fluorenyl) dimethyl zirconium Other catalysts, especially catalysts containing other group 4 metals, of course will be apparent to those skilled in the art.Preferred metalic species include complexes of restricted geometry metal, including titanium complexes and - ..-.-..., ** ...... methods for their preparation as described in the patent application of E.U.A. No. 545,403, filed July 3, 1990 (EP-A-416,815); patent application of E.U.A. No. 967,365, filed October 28, 1992 (EP-A-514,828); and patent application of E.U.A. series No. 876,268, filed on 1st. May 1992, (EP-A-520,732), as well as the patent of E.U.A. No. 5,055,438; patent of E.U.A. No. 5,057,475;; patent of E.U.A. No. 5,096,867; patent of E.U.A. No. 5,064,802;; patent of E.U.A. No. 5,096,867; patent of E.U.A. No. 5,132,380;; patent of E.U.A. No. 5,132,380; patent of • 10 E.U.A. No. 5,470,993;; patent of E.U.A. No. 5,486,632; patent of E.U.A. No. 5,132,380; and patent of E.U.A. No. 5,321,106. Metallocene catalysts are advantageously made catalytically active through the combination with one or more activating cocatalysts, through the use of an activation technique or a combination thereof. Advantageous co-catalysts are those co-catalysts containing boron within the skill in the art. Among the co-catalysts that • boron contains the compounds of tri (h idroca rbil) boron and halogenated derivatives thereof, advantageously having from 1 to 10 carbons in each hydrocarbyl or halogenated hydrocarbyl group, more especially perfluorinated tri (aryl) boron compounds, most especially tris (pentafluorophenyl) borane), amine, phosphine, aliphatic alcohol mercaptan adducts or trí compounds (hydrocarbyl 1) to 10 carbon atoms) halogenated boron, Especially adducts of perfluorinated tri (aryl) boron compounds.

Alternatively, the co-catalyst includes borates such as tetraphenyl borate, having as counterions, ammonium ions, such as ^ k is within the experience in the art and as described by European patent EP 672,688 (Canich, Exxon), published on 20 September 5, 1995. The co-catalyst can be used in combination with a tri (hydrocarbyl) aluminum compound having from 1 to 10 carbons in each hydrocarbyl group or an oligomeric or polymeric alumoxane. It is possible to employ these aluminum compounds for their ability • 10 beneficial for sweeping impurities such as oxygen, water and aldehydes from the polymerization mixture. Preferred aluminum compounds include tpalkylaluminium compounds having from 2 to 6 carbons in each alkyl group, especially those wherein the alkyl groups are ethyl, propyl, isopropyl, n-butyl, isobutyl, pentyl, neopentyl or isopentyl, and methylalumoxane, modified by methylalumoxane (ie methylalumoxane modified through the action with aluminum triisobutyl) (MMAO) and diisobutyl alumoxane. The • molar ratio of the aluminum compound to the metal complex preferably is from 1: 10,000 to 1000: 1, preferably from 1: 5000 to 100: 1, and most preferably from 1: 100 to 100: 1. The co-catalysts are used in amounts and under conditions within the skill in the art. Its use is applicable to all processes within the experience in the art, including, solution polymerization, grout, bulk (especially propylene) and processed gas phase. Such processes include those totally referred to in the references cited above. The molar ratio of catalyst / co-catalyst or activator • employed, preferably ranges from 1: 10,000 to 100: 1, preferably 5 from 1: 5000 to 10: 1, and most preferably from 1: 1000 to 1: 1. When such strong Lewis acid co-catalysts are used to polymerize higher α-olefin, especially propylene it has been found especially desirable to also contact the catalyst / co-catalyst mixture with a small one.

• Amount of ethylene or hydrogen (preferably at least 1 mole of ethylene or hydrogen per mole of metal complex, conveniently 1 to 100 moles of ethylene or hydrogen per mole of metal complex). This contact may occur before, after or simultaneously with contact with the higher α-olefin. If the above Lewis acid activated catalyst compositions are not treated in the manner described, either extremely long induction periods or no polymerization at all are encountered. • all results. The ethylene or hydrogen can be used in a suitably small amount, so that no significant effect on the properties of the polymer is observed. In most cases, the polymerization advantageously presents conditions known in the prior art for polymerization reactions of the Ziegler-Natta or Kaminsky-Sinn type, ie, temperatures of 0-250 ° C and atmospheric pressures to 3000 atmospheres If desired, suspension phase, solution, slurry, gas or high pressure may be employed, if employed in an intermittent or continuous manner or under other process conditions, including the recirculation of condensed monomers or solvent. Examples of such processes are well known in the art, for example, WO 988/02009-AI or patent of E.U.A. No. 5,084,534, describes conditions that are advantageously employed with the polymerization catalysts. A support, especially silica, alumina, or a polymer (especially polytetrafluoroethylene or polyolefin) is optionally employed, and desirably used when the catalysts are used in a gas phase polymerization process. Such supported catalysts are advantageously not affected by the presence of liquid aliphatic or aromatic hydrocarbons such as those optionally present under the use of condensation techniques in a gas phase polymerization process. The methods for the preparation of supported catalysts are described in numerous references, examples of which are patents of E.U.A. Nos. 4,808,561; 4,912,075; 5,008,228; 4,914,253, and 5,086,025 and are suitable for the preparation of supported catalysts. In said process, reagents and catalysts are optionally added to the solvent, sequentially, and in any order, or alternatively one or more of the reactants or components of the catalyst system are premixed with solvent or material preferably miscible therewith, then mixed together or in more solvent, optionally containing the other reagents or catalysts. The preferred process parameters depend on the monomers used and the polymer • wanted. The propylene added to the reaction vessel in previously determined amounts to achieve predetermined ratios, advantageously in gaseous form using a joint mass flow controller. Alternatively, propylene or other liquid monomers are added to the reaction vessel in amounts previously determined to result in desired relationships in the final product. Optionally they are added together with the solvent (if any), α-olefin and functional comonomer, or alternatively they are added separately. The pressure in the reactor is a function of the temperature of the mixture and the relative amounts of propylene or other monomers used in the reaction, or both. Advantageously, the polymerization process is carried out at a pressure of 70 to 7,000 kPa, most preferably of 980 to 3,790 kPa. The polymerization is then conducted at a temperature of 25 to 200 ° C, preferably at 50 to 100 ° C and most preferably at 60 to 80 ° C. The process is advantageously continuous, in which case the reagents are added continuously or at intervals, and the catalyst and, optionally the co-catalyst are added as necessary to maintain the reaction or develop loss or both. Polymerization of bulk solution or polymerization is preferred. In the latter case, the liquid polypropylene is the reaction medium. Preferred solvents include mineral oils and the various hydrocarbons, which are liquid at reaction temperatures. Illustrative examples of useful solvents include straight and branched chain hydrocarbons such as alkanes, for example, isobutane, butane, pentane, isopentene, hexane, heptane, octane and nonane, as well as mixtures of alkane including kerosene and Isopar E, available from Exxon Chemicals , Inc.; cyclic and alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclohexane, methylcyclooctane, and mixtures thereof; and aromatics and alkyl substituted aromatics such as benzene, toluene, xylenes, ethylbenzene, diethylbenzene and the like; and perfluorinated hydrocarbons such as perfluorinated 4- to 10-carbon alkanes. Suitable solvents may include liquid olefins, which may act as monomers or comonomers. Mixtures of the above are also suitable. At all times, the individual ingredients, as well as the recovered catalyst components, are protected from oxygen and moisture. Therefore, the catalyst components and catalysts are prepared and recovered in an atmosphere free of oxygen and moisture. Preferably, therefore, the reactions are carried out in the presence of an inert, dry gas such as, for example, nitrogen. Without limiting the scope of the invention in any way, a means to perform said polymerization process is as follows.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ J ^^^ - ^^^^^^ j ^ gfe == iíig ^ In a reactor of stirred tank, the olefin monomer is continuously introduced together with the solvent and the polyene monomer. The reactor contains a liquid phase composed substantially of monomers together with any additional solvent or diluent. It is continuously introduced into the catalyst and co-catalyst in the liquid phase of the reactor. The temperature and pressure of the reactor can be controlled by adjusting the solvent / monomer ratio, the rate of catalyst addition, as well as cooling and heating coils, liners, or both. The polymerization rate is controlled through the rate of catalyst addition. The molecular weight of the polymer product is controlled, optionally, by controlling other polymerization variables such as temperature, monomer concentration or through a stream of hydrogen introduced to the reactor, as is well known in the art. The effluent from the reactor is contacted with a catalyst killing agent such as water or an alcohol. The polymer solution is optionally heated, and the polymer product is recovered by vaporizing gaseous monomers as well as residual solvent or diluent at reduced pressure, and, if necessary, conducting further de-volatilization in the equipment such as a devolatilization extruder. In a continuous process, the average residence time of the catalyst and polymer in the reactor is generally from 5 minutes to 8 hours, and preferably from 10 minutes to 6 hours. Preferably, the polymerization is conducted in a continuous solution polymerization system, optionally comprising more than one reactor connected in series or in series or in parallel. The ethylene polymer used in the polymer blend composition for making the fiber or fabric of the present invention is characterized as having a high molecular weight. Suitable ethylene polymers include, for example, high density polyethylene (HDEP), low density polyethylene, heterogeneously branched, linear (LLDPE), ultra low density polyethylene, heterogeneously branched (ULDPE), linear, homogeneously branched ethylene polymers, polymers substantially linear, homogeneously branched ethylene, long branched chain, homogeneously branched ethylene polymers, and ethylene, vinyl or vinylidene aromatic monomer interpolymers. But homogenously branched ethylene polymers and ethylene vinyl or vinylidene aromatic monomer interpolymers are preferred, and substantially linear, homogeneously branched ethylene polymers and substantially random aromatic ethylene vinyl interpolymers are highly preferred. The substantially linear, homogeneously branched ethylene polymers used in the polymer blend compositions described herein may be interpolymers of ethylene with at least one α-olefin of 3 to 20 carbon atoms. The term "interpolymer" and "ethylene polymer" as used herein, indicates that the polymer may be a co-polymer or a terpolymer. Monomers usefully copolymerized with ethylene to be homogeneously branched linear or substantially linear ethylene polymers include the α-olefins of 3 to 20 carbon atoms, especially • 1-pentene, 1-hexene, 4-methyl-1-pentene, and 1-octene. The 5 especially preferred comonomers include 1-pentene, 1-hexene and 1-octene. Copolymers of ethylene and an α-olefin of 3 to 20 carbon atoms are especially preferred. The term "substantially linear" means that the base structure of the polymer is substituted with 0.01 branches of • 10 long chain / 1000 carbons, to 3 long chain branches / 1000 carbons, preferably 0.01 long chain branches / 1000 carbons to a long chain branch / 1000 carbons, and specifically 0.05 long chain branches / 1000 carbons to 1 branches of long chain / 1000 15 carbons. The long chain branching is defined herein as a branching having a chain length greater than that • of any short chain branching, which results in the incorporation of comonomers. The long chain branch 20 can be as long as about the same length as the length of the base structure of the polymer. The long chain branching can be determined using 13C nuclear magnetic resonance (NMR) spectroscopy and quantified using the method of Randall (Rev. 25 Macromol. Chem. Phvs., C29 (2 &3), pp. 275-287) .

In the case of substantially linear ethylene ethylene polymer, such polymers can be characterized as having: a) a melt flow ratio, l? 0 / l2, = 5.63, b) a molecular weight distribution, Mw / Mn, defined by the equation: Mw / Mn < (l10 / l2) - 4.63, and c) a critical shear stress at the beginning of the raw melt fracture greater than 4 x 106 dynes / cm2 or a critical shear rate at the beginning of the melt surface fracture at least 50% greater than the critical shear rate at the beginning of the surface fracture by melting any homogenously or heterogeneously branched linear ethylene polymer, having approximately the same l2 and Mw / Mn or both. In contrast to the substantially linear ethylene polymers, the linear ethylene polymers lack long chain branching, ie they have less than 0.01 long chain branches / 1000 carbons. The term "linear ethylene polymers" in this manner does not refer to high pressure branched polyethylene, ethylene / vinyl acetate copolymers, or ethylene / vinyl alcohol copolymers, which are known to those skilled in the art to have numerous long chain branches. Linear ethylene polymers include, for example, traditional linear, heterogeneously branched, low density polyethylene polymers or high density polyethylene polymers made using Ziegler polymerization processes (e.g., U.S. Patent No. 4,076,698 (Anderson et al. others)), or homogeneous linear polymers (for example, U.S. Patent No. 3,645,992 (Elston)). The homogeneous linear and substantially linear ethylene polymers used to form the fibers have homogeneous branching distributions. The term "homogeneous branching distribution" means that the comonomer is • 10 randomly distributed within a given molecule and that substantially all of the copolymer molecules have the same ethylene / monomer ratio. The homogeneous ethylene / α-olefin polymers used in this invention essentially lack a measurable "high density" fraction, as measured by the TREF technique (ie, the homogeneous branched ethylene / α-olefin polymers are characterized by typically have less than 15% by weight, preferably less than 10%, and most preferably less than • 5% by weight of a polymer fraction with a degree of branching less than or equal to 2 methyl / 1000 carbons). 20 The homogeneity of the branching distribution can be measured in a variety of ways, including measuring the Short Chain Branch Distribution Index (SCBDI) or the Composition Distribution Branch Index (CDBI). The SCBDI or CDBI is defined as the percentage by weight of the polymer molecules having a comonomer content within 50% of the content of -.- - «. > ,.? * J ^^ as ^ n ... average total molar comonomer. The CDBI index of a polymer is easily calculated from data obtained from techniques known in the art, such as, for example, fractionation of • circumvention of temperature rise (abbreviated as "TREF") as described in, for example, Wild et al., Journal of Polvmer Science, Polv. Phvs. Ed .. Vol. 20, p. 441 (1982), patent of E.U.A. No. 5,008,204 (Stehling). The technique for calculating the CDBI index is described in the patent of E.U.A. No. 5,322,728 (Davey et al.) And in the US patent. No. 5,246,783 (Spenadel et al.). The index • 10 SCBDI or CDBI for homogeneously branched and substantially linear linear ethylene polymers is typically greater than % and preferably is greater than 50%, preferably greater than 60%, preferably 70% and most preferably greater than 90%. The homogeneous branched ethylene polymers used to make the fibers of the present invention preferably will have an individual melting peak, as measured using differential scanning calorimetry (DSC) in contrast to linear, heterogeneously branched ethylene polymer, which have 2 or more melting peaks, due to the wide distribution of branching of the heterogeneously branched polymer. Substantially linear ethylene polymers exhibit a highly unexpected flow property wherein the ho / l2 value of the polymer is essentially the polydispersity index (ie, Mw / Mn of the polymer). This is in contrast polymers of homogeneous linear homogeneous ethylene and linear, heterogeneously branched polyethylene resins for which the polydispersity index must be increased in order to increase the value of H 2 O The substantially linear ethylene polymers also exhibit good processability and low pressure drop to through a spinner package, even when high shear filtration is used. The homogeneous linear ethylene polymers useful for making the fabrics and fibers of the invention are a known class of polymers, which have a linear polymer base structure, without long chain branching and a narrow molecular weight distribution. Said polymers are interpolymers of ethylene and at least one α-olefin comonomer of 3 to 20 carbon atoms, and preferably are copolymers of ethylene with an α-olefin of 1 to 20 carbon atoms, and most preferably copolymers of ethylene with propylene 1-butene, 1-hexene, 4-methyl-1-pentene or 1-octane. This kind of polymer is described, for example, by Elston in the US patent. No. 3,645,992 and subsequent processes for producing such polymers using metallocene catalysts have been developed, as shown in, for example, EP 0 129 368, EP 0 260 999, U.S. No. 4,701,432; patent of E.U.A. No. 4,937,301; patent of E.U.A. No.4, 937, 301; patent of E.U.A. No. 4,935,397; patent of E.U.A. No. 5,055,438; and WO 90/07526, and others. The polymers can be made through conventional polymerization processes, (e.g., gas phase, slurry, solution, and high pressure).

• • •• • ••• • • Another useful measurement for characterizing the molecular weight of ethylene polymers is conveniently indicated using a melt index measurement according to ASTM D-1238, condition 190 ° C / 10 kg (previously known as "condition (N)" and also known as ho) The ratio of these two terms of melting index is the melt flow ratio and is designated as ho / l2 For the substantially linear ethylene polymers used in polymer compositions useful for making the fibers of the invention, the ho / l2 ratio indicates the degree of long chain branching, that is, the higher the ho / l2 ratio the greater the long chain branching in the polymer. substantially linear ethylene can have variable ho / l2 ratios, while maintaining a low molecular weight distribution (ie, Mw / Mn from 1.5 to 2.5) In general, the ratio of ho l2 of the po substantially linear ethylene labels are at least 5.63, preferably at least 6, preferably at least 7, and especially at least 8. In general, the upper limit of the ho / l2 ratio for ethylene polymers is substantially linear, homogeneously branched is 50 or less, preferably 30 or less and especially 20 or less. Additives such as antioxidants (for example, hindered phenolics (eg, Irganox ™ made by Ciba-Geigy Corp.), phosphites (eg, Irgafos ™) 168 made by Ciba-Geigy Corp.), adhesion additives (eg, polyisobutylene (PIB), antiblock additives) , pigments, may also be included in the first the polymer, the second polymer, or the entire polymer composition useful for making the fibers and fabrics of the invention, to the extent that they do not interfere with the improved fiber and fabric properties discovered by the The molecular weight distributions of ethylene polymers are determined through gel penetration chromatography (GPC) in a Waters 150C high temperature chromatographic unit equipped with a differential refractometer and three columns of mixed porosity. Polymer Laboratories and are commonly packaged with pore sizes of 103, 104, 105 and 106 A. The solvent is 1, 2,4-trichlorobenzene, from which, around 0. 3% by weight of solutions of the samples are prepared for injection. The flow rate is about 1.0 ml / minutes, the unit operating temperature is about 140 ° C and the injection size is about 100 microliters. The determination of molecular weight with respect to the polymer base structure is deduced using narrow molecular weight distribution polystyrene standards (from Polymer Laboratories) together with their elution volumes. Equivalent polyethylene molecular weights are determined using appropriate Mark-Houwink coefficients for polyethylene and polystyrene (as described by Williams and Ward in Journal of Polvmer Science Polvmer Letters, Vol. 6, page 621, 1968), to derive the following equation: "" polypropylene - 3 (M po | ístireno) • In this equation, a = 0.4316 and b = 1.0. The weight average molecular weight, Mw, is calculated in the usual way according to the following formula: Mj = (Dw, (M, ')) J; where w is the fraction of the weight of molecules with molecular weight M, eluting from the GPC column in fraction i and j = 1 when calculating Mw and j = 1 when calculating Mn. The novel composition has Mw / Mn less than or equal to 3.3, preferably less than or equal to 3, and especially in the range of 2.4 to 3. The Mw / Mn ratio of homogeneously branched, substantially linear ethylene polymers is defined by the equation: Preferably, the ratio of Mw / Mn for the ethylene polymers is from 1: 5 to 2: 5, and especially from 1: 8 to 2: 2. An apparent shear stress plot against apparent shear rate to identify the phenomenon of fusion fracture. According to the Journal of Rheoloqy. 30 (2), 337-357, 1986, above a certain critical flow velocity, the observed extrusion irregularities can be broadly classified into two main types: surface melt fracture and raw melt fracture. The surface melt fracture occurs under seemingly stable flow conditions and varies in detail from spectacular loss of brightness to the more severe form of "shark skin". In this description, the onset of the surface melt fracture is characterized at the beginning of the extrusion gloss loss where the roughness of the extrusion surface can only be detected at a magnification of 40x. The critical shear stress rate at the beginning of the surface melt fracture for a substantially linear ethylene polymer is at least 50% greater than the critical shear rate at the beginning of the surface melt fracture of a polymer. homogenous linear ethylene that has the same l2 and Mw / Mn. • 10 Raw fusion fracture occurs at unstable flow conditions and varies in detail from regular deformations (alternating roughness and smoothness, helical, etc.) to random deformations. For commercial acceptability (for example, in blown film products), the surface defects must be minimal, if not than absent. The critical shear rate at the beginning of the surface melt fracture (OSMF) and at the beginning of the raw melt fracture (OGMF) will be used here based on • in the roughness changes and configurations of the products extracted through GER. 20 The gas extrusion rheometer is described by M Shida, R. N. Shroff and L.V. Cando in Polvmer Engineering Science, Vo. 17, no. 11, p. 770 (1977), and in Rheometers for Molten Plastics by John Delay, published by Van Nostrand Reinhold Co. (1982) on page 97. All the GER experiments were performed at a temperature of 190 ° C, at nitrogen pressures of between 368,075 to 35.15 kg / cm2 using a L-D die of 20: 1 with a diameter of 0.075184 cm. A graph of apparent shear stress versus apparent shear rate is used to identify the phenomenon of • fusion fracture. According to Ramamurthy in Journal of 5 Rheologv. 30 (2), pp. 337-357, 1986, above a certain critical flow velocity, the irregularities of the extracted product observed can be broadly classified into two main types: surface melt fracture and raw melt fracture. For the polymers described herein, the Pl is the Apparent viscosity (in Kpoise) of a material measured through GER at a temperature of 190 ° C, at a nitrogen pressure of 175.75 kg / cm2 using a given LD of 20: 1 with a diameter of 0.75184 cm, or tension of corresponding apparent shear stress of 2.15 x 106 dynes / cm2. 15 The processing index is measured at a temperature of 190 ° C at a nitrogen pressure of 175.155 kg / cm2 using an L-D die of 20: 1 with a diameter of 0.075184 cm, having an entry angle of 180 °. The restricted geometry catalysts illustrative for used in the polymerization of substantially linear, homogeneously branched ethylene polymers, preferentially used to make the novel fibers and other articles of the present invention preferably include those of restricted geometry described in the application E.U.A. series No. 545,403, filed July 3, 1990; 758,654, now US patent. No. 5,132,380; 758,660, now abandoned, filed on September 12, 1991; and 720,041, now abandoned, filed June 24, 1991, and the US patent. No. 5,272,236 and patent of E.U.A. No. 5,278,272. As indicated above, substantially random ethylene / vinyl aromatic interpolymers are especially preferred ethylene polymers for use in the present invention. Representatives of substantially random ethylene / vinyl aromatic interpolymers are substantially random vinyl / styrene interpolymers, preferably containing at least, preferably equal to or greater than 30, and most preferably equal to or greater than 50% by weight of interpolymerized styrene monomer. substantially random interpolymer comprises in polymerized form, (i) one or more α-olefin monomers, (ii) one or more vinyl or vinylidene aromatic monomers; one or more vinyl or vinylidene monomers aliphatic or cycloaliphatic, sterically hindered, or both; and optionally (iii) other polymerizable ethylenically unsaturated monomers. The term "interpolymer" as used herein, denotes a polymer wherein at least two different monomers are polymerized to make the interpolymer. The term "substantially random" in the substantially random interpolymer resulting from the polymerization of (i) one or more α-olefin monomers and (ii) one or more vinyl or vinylidene aromatic monomers; or one or more vinylidene or vinylidene monomers aliphatic or cycloaliphatic, sterically hindered, or both; and optionally (iii) other ethylenically monomers • Unsaturated, polymerizable, as used herein, 5 generally means that the distribution of the monomers of said interpolymer can be described by the Bernoulli statistical model or by a first or second order statistical model, as described by Polvmer Sequence Determination. Carbon-13 NMR Method, Academic Press New cork, 1977, pp. 71-78. Preferably, the substantially random interpolymer resulting from the polymerization of one or more α-olefin monomers and one or more vinyl or vinylidene aromatic monomers, and optionally other polymerizable ethylenically unsaturated monomers, does not contain more than 15% of the amount The total vinyl aromatic monomer or vinylidene in aromatic vinyl or vinylidene monomer blocks of more than 3 units. Most preferably, the interpolymer is not characterized by a high degree of either isotacticity or syndicality. This means that in the carbon-13 NMR spectrum of the interpolymer When substantially randomized, the peak areas corresponding to the methylene carbons and the main chain methine representing either meso diad sequences or racemic diad sequences should not exceed 75% of the total peak area of the methylene carbons and the main chain methine. By the term subsequently used, "substantially random interpolymer" is meant to mean a substantially random interpolymer produced from the aforementioned monomers. Suitable α-olefin monomers which are useful for preparing the substantially random interpolymer include, for example, α-olefin monomers containing from 2 to 20, preferably from 2 to 12, most preferably from 2 to 8 carbon atoms. Preferred monomers include ethylene, propylene, butane-1,4-methyl-1-pentene, hexene-1, and octeto-1. Most preferred are ethylene or a combination of ethylene with α-olefins of 3 to 8 carbon atoms. These α-olefins do not contain an aromatic portion. Suitable vinyl or vinylidene aromatic monomers which can be used to prepare the substantially random interpolymer include, for example, those represented by the following formula I: Ar (CH2) n R1-C = C (R2) 2 (formula 1) in wherein R1 is selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; each R2 independently is selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; Ar is a phenyl group, or a phenyl group substituted by 1 to 5 substituents; selected from the group consisting of halogen, alkyl of 1 to 4 carbon atoms, and haloalkyl of 1 to 4 carbon atoms; and n • has a value of 0 to 4, preferably 0 to 2, very preferably 0. Such particularly suitable monomers include styrene, and its derivatives substituted with lower alkyl or halogen. Illustrative monovinyl or monovinylidene aromatic monomers include styrene, vinyl toluene, α-methyl styrene, t-butyl styrene or chlorostyrene, including all isomers of these • 10 compounds. Preferred monomers include styrene, α-methyl styrene, derivatives substituted with lower alkyl of 1 to 4 carbon atoms or the phenyl ring of styrene, such as, for example, ortho-, meta-, and para-methylstyrene, styrenes halogenated in the ring, para-vinyl toluene or mixtures thereof. A preferred aromatic vinyl monomer is styrene. By the term "aliphatic or cycloaliphatically sterically hindered vinylidene or vinylidene monomers", it represents polymerizable vinylidene or vinylidene addition monomers corresponding to the formula: A1 A1 R1 - C = C (R2) 2 wherein A1 is a spherically bulky aliphatic or cycloaliphatic substituent of up to 20 carbons, R1 is selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, preferably hydrogen _¡ | | u C • I 1"- * - '" - • - "> • * • * -' **» * - "*» "- or methyl; each R2 is independently selected from the group of radicals consisting of hydrogen and alkyl radicals containing from 1 to 4 carbon atoms, preferably hydrogen or methyl; or • alternatively R1 and A1 together form a ring system. By the term "sterically bulky" is meant that the monomer carrying this substituent is normally incapable of addition polymerization through standard Ziegler-Natta polymerization catalysts at a rate comparable to ethylene polymerizations. The α-olefin monomers containing from 2 to 20 carbon atoms and having a linear aliphatic structure such as propylene, butane-1, hexene-1 and octet-1 are not considered as sterically hindered aliphatic monomers. Aliphatic or cycloaliphatic vinylidene or vinylidene compounds, sterically hindered are monomers in which one of the carbon atoms carrying the ethylenic unsaturation is substituted in tertiary or quaternary form. Examples of such substituents include aliphatic groups and rings such as cycloexilo, cyclohexenyl, cyclooctenyl, or ring-substituted derivatives with alkyl or aryl of the , ter-butyl or norbornyl. Preferred sterically hindered aliphatic or cycloaliphatic vinylidene or vinylidene compounds are the various isomeric vinyl ring substituted derivatives of cyclohexene and substituted cyclohexene, and 5-ethylidene-2-norbornene. Especially suitable are 1-, 3-, and 4-25-vinylcyclohexene.

Substantially random interpolymers usually contain from 0.5 to 65, preferably from 1 to 55, most preferably from 2 to 50 mol% of at least one aromatic vinyl or vinylidene sorbent; or a sterically hindered aliphatic or cycloaliphatic vinyl or vinylidene monomer; or both, and from 35 to 99.5, preferably from 45 to 99, and most preferably from 50 to 98 mole% of at least one aliphatic α-olefin having from 2 to 20 carbon atoms. Other optionally polymerizable, ethylenically unsaturated monomers include ring-restricted olefins such as norbornene and alkyl-substituted norbones of 1 to 10 carbon atoms or with aryl of 6 to 10 carbon atoms, with a substantially random interpolymer being ethylene / styrene no / norbornene. The highly preferred substantially random interpolymers are interpolymers of ethylene and styrene and interpolymers of ethylene, styrene and at least one α-olefin, containing from 3 to 8 carbon atoms. The number average molecular weight (Mn) of the substantially random interpolymers is usually greater than 5000, preferably from 20,000 to 1,000,000, most preferably from 50,000 to 500,000. The glass transition temperature (Tg) of the substantially random interpolymers preferably is from -40 ° C to + 35 ° C, preferably from 0 ° C to + 30 ° C, and most preferably from + 10 ° C to +25 ° C, measured according to the differential mechanical exploration (DMS). Substantially random interpolymers can be modified through typical grafting, hydrogenization, functionalization, or other reactions well known to those skilled in the art. The polymers can be easily sulfonated or chlorinated to provide derivative functionalized according to established techniques. Substantially random interpolymers can also be modified through various chain extension or entanglement processes, including, but not limited to, peroxide, silane, sulfur, radiation or azide-based curing systems. A complete description of the various entanglement technologies is described in the patent applications of E.U.A. co-pending Nos. 08 / 921,641 and 08 / 921,642, both filed on August 27, 1997. Dual healing systems, which utilize a combination of heat, moisture, and radiation steps, can also be effectively employed . The dual cure systems are described and claimed in the patent application of E.U.A. series No. 536,022, filed on September 29, 1995 in the names of K.L. Walton and S.V. Karande For example, it may be desirable to employ peroxide crosslinking agents together with silane crosslinking agents, peroxide crosslinking agents together with sulfur-containing crosslinking agents, radiation together with silane crosslinking agents, etc. '** ..., t. *, ...- * ....

Substantially random interpolymers can also be modified through various entanglement processes that include but are not limited to the incorporation of a component of • diene as a thermonomer in its preparation and subsequent entanglement through the aforementioned methods and additional methods that include vulcanization through the vinyl group using sulfur, for example, as the entanglement agent. A method for manufacturing aromatic interpolymers of Substantially random ethylene / vinyl includes polymerizing a mixture of polymerizable monomers in the presence of one or more metallocene catalysts or restricted geometry in combination with various co-catalysts, as described in EP-A-0,416,815 by James C. Stevens et al. and US patent No. 5,703,187 of French J. Timmers. Preferred operating conditions for such polymerization reactions include atmospheric pressures of up to 3000 atmospheres and temperatures of -300 ° C to 200 ° C. Polymerizations and removal of unreacted monomers at temperatures above the self-polimerization temperature of The respective monomers may result in the formation of some amounts of homopolymer polymerization products resulting from the free radical polymerization. Examples of suitable catalysts and methods for preparing substantially random interpolymers are described in the application of E.U.A. No. 702,475, filed May 20, 1991 (EP-A-514,828); as well as in the patents of E.U.A. Nos .: 5, 055,438; 5,055,475; 5,096,867; 5,064,802; 5,132,380; 5,189,192; 5,321,106; 5,347,024; 5,350,723; 5,374,696; 5,399,635; 5,470,993; 5,703,187; and 5,721,185. The substantially random ethylene / vinyl aromatic interpolymers can also be prepared by the methods described in JP 07/278230 using compounds shown by the general formula: R wherein Cp1 and Cp2 with cyclopentadienyl groups, indenyl groups, fluorenyl groups, or substituents thereof, independently of one another; R1 and R2 are hydrogen atoms, halogen atoms, hydrocarbon groups with carbon numbers of 1-2, alkoxy groups, or alkyloxy groups, independently of one another; M is a group IV metal, preferably Zr or Hf, most preferably Zr; and R3 is an alkylene group or a silanodiyl group used to crosslink Cp1 and Cp2. The substantially random ethylene / vinyl aromatic interpolymers can also be prepared by the methods described by John G. Bradfute et al. (W.R. Grace &Co.) in WO 95/32095; by R.B. Pannell (Exxon Chemical Patents, inc.) In WO 94/00500; and in Plastics Technology p. 25 (September 1992). Also suitable are substantially random interpolymers comprising at least one triad of α-olefin / vinyl aromatic / vinyl aromatic / α-olefin described in the application of E.U.A. 08 / 708,869, filed September 4, 1996, and WO 98/0999, both by Francis J. Timmers et al. These interpolymers contain additional signals in their carbon-13 NMR spectra with intensities greater than 3 times the peak-to-peak noise. These signals appear on the chemical shift scale of 43.70 - 44.25 ppm and 38.0 ppm. Specifically, peaks greater than 44.1, 43. 9 and 38.2 ppm are observed. A proton test NMR experiment indicates that the signals in the chemical shift region 43.70-44. 25 ppm with methine carbons and the signals in the 38.0-38.5 ppm region are methylene carbons. It is believed that these new signals are due to sequences involving two vinyl aromatic monomer insertions from head to tail preceded and followed by at least one α-olefin insert, eg, an ethylene / styrene / styrene / ethylene triad. , wherein the styrene monomer insertions of said triads occur exclusively in a form of 1.2 (head to tail). It should be understood by one skilled in the art that for such triads involving a vinyl aromatic monomer other than styrene and an α-olefin other than ethylene, that the triad of ethylene / vinyl aromatic monomer / vinyl aromatic monomer / ethylene will give emergence to similar peaks of carbon-13 NMR but with chemical shifts • slightly different These interpolymers can be prepared by conducting the polymerization at temperatures from -30 ° C to 250 ° C in the presence of such catalysts as those represented by the formula: • / \ Wherein each Cp is independently, in each occurrence, a substituted cyclopentadienyl group, joined by p to M; E is C or Si; M is a group IV metal, preferably Zr or Hf, most preferably Zr; each R is independently, of each Occurrence, H, hydrocarbyl, silahydrocarbyl or hydrocarbylsilyl, containing up to 30, preferably 1 to 20, most preferably 1 to 10 carbon atoms or silicon; each R1 is independently, of each occurrence, H, halogen, hydrocarbyl, hydrocarbyloxy, silahydrocarbyl, id rbi rock Isi I ilo containing up to 30, preferably 1 to 20, most preferably 1 to 10 carbon atoms or silicon, or 2 R 1 groups together can be a 1,3-butadiene substituted with hydrocarbyl of 1 to 10 carbon atoms; M is 1 or 2; and optionally, but preferably in the presence of an activating cocatalyst. Particularly, suitable substituted cyclopentadienyl groups include those illustrated by the formula: wherein each R is independently, of each occurrence, H, hydrocarbyl, silahydrocarbyl, or hydrocarbylsilyl, containing up to 30, preferably 20, most preferably 1 to 10. • carbon or silicon atoms, or two R groups together form a divalent derivative of said group. Preferably, R independently of each occurrence is (including where all isomers are appropriate) hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, benzyl, phenyl or silyl or (where appropriate) 2 R groups are bonded together forming a fused ring system such as indenyl, fluorenyl, tetrahydroindenyl, tetrahydrofluorenyl, or octahydrofluorenyl. • Particularly preferred catalysts include, for example, racemic (dimethylsilanediyl) -bis- (2-methyl-4-phenylindenyl) zirconium dichloride, 1,4-diphen-l, 3-butadiene (dimethylsilanediyl) -bis - racemic (2-methyl-4-phenylindenyl) zirconium, dialkyl of 1 to 4 carbon atoms of racemic (dimethylsilanediyl) -bis- (2-methyl-4-phenylindenyl) zirconium, dialkoxide of 1 to 4 carbon atoms of racemic (dimethylsilanediyl) -bis- (2-methyl-4-phenylindenyl) zirconium, or any combination thereof, and the like.

It is also possible to use the following restricted geometry catalysts based on titanium, [? - (1, 1 -di met i leti I) -1,1-dimethyl-1 - [1, 2, 3,4,5 -? ) -1, 5,6, 7-tet rahid ro-s-indacen-1- • il] silanaminate (2 -) -?] Titanium dimethyl; (1 -indenyl) (tert-butylamido) 5-dimethylsilane titanium dimethyl; ((3-tert-butyl) (1, 2,3,4, 5-γ) -1-indenyl) (tert-butylamido) dimethylsilane titanium dimethyl; and ((3-α-propyl) (1, 2,3,4, 5-γ) -1-indenyl) (tert-butylamido) dimethylsilane titanium dimethyl, or any combination thereof, and the like. Other preparative methods for the interpolymers used in the present invention have been described in the literature. Longo and Gras (Makromol, Chem. Vol. 191, pages 2387 to 2396 [1990] and D'Aniello et al. (Journal of Applied Polvmer Science, volume 58, pages 1701-1706 [1995]) reported the use of a catalytic system based on methylaluroxane (MAO) and cyclopentadienyl-15 titanium trichloride (CpTiCI3) to prepare an ethylene-styrene copolymer Xu and Li (Polvmer Prepints, Am. Chem. Soc, Div. Polym. Chem.) Volume 35, pages 685,687 [1994]) have reported copolymerization using a MgCl 2 / TiCl / NdCl 3 / AI (iBu) 3 catalyst to give random copolymers of styrene and propylene. Lu and others (Journal of Applied Polvmer Science, volume 53, pages 1453 to 1460 [1994]) have described the copolymerization of ethylene and styrene using a TiCl4 / NdCI3 / MgCl2 / al (Et) 3 catalyst. Sernetz and Mulhaupt, (Macromol. Chem. Phvs. V. 197, pp. 1071-1083, 1997) have described the influence of polymerization conditions on the copolymerization of styrene with ethylene using the catalysts of Me2Si (Me4Cp) (? -ter-butyl) TiCl2 / Methylaluminoxane Ziegler-Natta. Ethylene-styrene copolymers produced through bridged metallocene catalysts have been described by Arai, Toshiaki and Suzuki (Polvmer Preprints Am. Chem. Soc, Div. Polym. Chem.) Volume 38, pages 349, 350 [1997] , and in the US patent No. 5,652,315, issued to Mitsui Toatsu Chemicals Inc. The manufacture of α-olefin / aromatic vinyl monomer interpolymers, such as propylene / styrene and butane / styrene are described in US Pat. No. 5,244,996, issued to Mitsui Petrochemical Industries, Ltd. or US patent. No. 5,652,315 also issued to Mitsui Petrochemical Industries Ltd. or as described in DE 197 11339 Al to Denki Kagaku Kogyo KK. Also, although of high isotacticity and therefore not "substantially random", random copolymers of ethylene and styrene as described in Polvmer Preprints, Vol. 39, no. 1, March 1998, by Toru Aria and others, may also be employed as the ethylene polymer of the present invention. Although in preparing the substantially random polymer, e can form an amount of atactic vinyl aromatic homopolymer due to the homopolymerization of the vinyl aromatic monomer at elevated temperatures. The presence of vinyl aromatic homopolymer in general is not dangerous for the purposes of the present invention and can be tolerated. The aromatic vinyl homopolymer can be separated from the interpolymer, if desired, through extraction techniques such as selective precipitation from solution with a non-solvent either for interpolymer or for the aromatic vinyl homopolymer. However, for the purposes of the present invention, it is preferred • not more than 30% by weight, preferably less than 20% by weight 5 (based on the total weight of the interpolymers) of the atactic vinyl aromatic homopolymer is present. The polypropylene and ethylene polymers can be produced through a controlled continuous polymerization process (as opposed to an intermittent one), using at least one reactor for • 10 each polymer. But the same polymer blend composition of the invention (or a mixture comprising the polypropylene polymer or a separate mixture comprising the ethylene polymer or both) can also be produced using multiple reactors (e.g., using a reactor configuration). multiple as described in the patent of E.U.A. No. 3,914,342 (Mitchell)), with the polypropylene polymer being manufactured in a reactor and the ethylene polymer being manufactured in at least one other reactor. Multiple reactors can be operated in series or in parallel, at least with a geometry catalyst Restricted one employed in at least one of the reactors at a polymerization temperature and sufficient pressure to produce the polypropylene polymer or the ethylene polymer (or both) having the desired properties. According to a preferred modality of the process of In present, polymers are produced in a continuous process, as opposed to an intermittent process. Preferably, the polymerization or interpolymerization temperature of ethylene is from 20 ° C to 250 ° C, using catalyst technology of restricted geometry. If a • narrow molecular weight distribution polymer (Mw / Mn from 5 1.5 to 2.5) having a higher ratio of Mw / Mn (for example, Mw / Mn of 7 or more, preferably of at least 8, especially at least 9) if desired, the concentration of ethylene in the reactor is preferably not more than 8% by weight of the contents of the reactor, especially not more than 4% by weight of the contents of the reactor. reactor. Preferably, the polymerization is carried out in a solution polymerization process. In general, the manipulation of ho / I2 while maintaining Mw / Mn relatively low to produce the substantially linear polymers described herein, is a function of reactor temperature or ethylene concentration or both. The The reduced ethylene concentration and the higher temperature generally produce h0 / l2 higher. The polymerization conditions for the manufacture of homogeneous or substantially linear linear ethylene polymers used to make the fibers of the present invention are generally those useful in the solution polymerization process, although the application of the present invention is not limited thereto. It is believed that slurry and gas phase polymerization processes are also useful, provided that appropriate catalysts and polymerization conditions are employed. 25 A technique for the polymerization of ethylene polymers .... **., .... homogeneous linear ** useful herein is disclosed in the U.S. patent. No. 3,645,992 (Elston). In general, polymerization continues to be useful for • ethylene polymers used in the present invention can be achieved at conditions well known in the art for Ziegler-Natta or Kaminsky-Sinn type polymerization reactions, ie, temperatures from 0 to 250 ° C and atmospheric pressures at 1000 atmospheres (100 MPa). The compositions described herein can be formed through • 10 of any convenient method, including mixing the dried individual and subsequent components by melt mixing or mixing prior to melting in a separate extruder (e.g., a Banbury mixer, a Haake mixer and an internal Brabender mixer, or a double screw extruder (or individual) including pellet extrusion). Preferably, the composition of the invention is formed by melt mixing in a double screw co-rotation extrusion. • Another suitable technique for making the composition is in situ polymerization as provided in the patent of E.U.A. pending No. 08 / 010,958, entitled "Ethylene Interpolvmerizations ", (Interpolymerizations of Ethylene), which was filed on January 29, 1993, in the names of Brian W. S. Kolthammer and Robert S. Cardwell, US Patent No. 08 / 010,958 describes, inter alia, interpolymerizations of ethylene and α-olefins of 3 to 20 carbon atoms using a «. a homogeneous catalyst in at least one reactor and a heterogeneous catalyst in at least one other reactor and this method can be adapted to employ a polypropylene polymerization reactor • as a substitute for the heterogeneous catalyzed ethylene polymerization reactor 5 or as an additional reactor. That is, in situ polymerization can comprise at least 3 reactors, wherein, at least two of the reactors provide the ethylene polymer (as a polymer blend composition) and at least one reactor provides the polypropylene polymer of grade of reactor. For in situ polymerizations, the multiple reactors can be operated sequentially or in parallel, but preferably, when the in situ polymerization is used, it is only used to provide suitable ethylene polymers (or ethylene polymer blend compositions) and not the same composition of the invention. Preferably, the fiber of the invention will be a fiber of multiple constituents or of multiple components. The multi-constituent fiber of the invention can be short fibers, spunbond fibers, meltblown fibers (using, by For example, the systems described in the U.S.A. No. 4,340,563 (Appel et al.), Patent of E.U.A. No. 4,663,220 (Wisneski et al.), Patent of E.U.A. No. 4,668,566 (Braun), patent of E.U.A. No. 4,322,027 (Reba), patent of E.U.A. No. 3,860,369), fibers spun by gel (e.g., the system described in the patent of E.U.A. No. 4,413,110 (Kavesh et al.)), And fibers spun by vaporization (e.g., the system described in U.S. Patent No. 3,860,369). As defined in The Dictionarv of Fiber & Textile • Technology, by Hoechst Celanese Corporation, 5-gel spinning refers to "[a] spinning process wherein the primary mechanism of solidification is the gelation of the polymer solution by cooling to form a gel filament consisting of a polymer and solvent precipitated.The removal of the solvent is achieved after solidification by washing the liquid. The resulting fibers can be extracted to give a product with high tensile strength and modulus. "As defined in The Nonwoven Fabrics Handbook, by John R. Starr, Inc., produced by INDA, Association of the Nonwoven Fabrics Industry, Spraying spinning refers to "a method of modified spinning where a polymer solution is extruded and rapid evaporation of the solvent occurs, so that the individual filaments are separated or divided into a highly fibrillar form and are collected in a sieve to form a band. "20 The fibers short can be spunbond (can be extruded to the final fiber diameter directly without further extraction), or can be spun by fusion to a larger diameter and subsequently drawn in hot or cold to the desired diameter using conventional fiber stretching techniques .

The novel fibers described herein can also be used as binding fibers, especially when the novel fibers have a lower melting point than the surrounding matrix fibers. In a fiber-bonding application, the bonding fiber • it is typically mixed with other matrix fibers and the entire structure is subjected to heat, where the bond fiber is melted and attached to the surrounding matrix fiber. Typical matrix fibers that benefit from the use of novel fibers include, but are not limited to: polyethylene terephthalate fibers; cotton fibers; nylon fibers; other polypropylene fibers; other fibers of heterogeneously branched polyethylene; and linear polyethylene homopolymer fibers. The diameter of the matrix fiber may vary depending on the end-use application. The multi-constituent fibers of the invention can also be used to provide a two-component fiber cover / core (ie, one where the cover concentrically surrounds the core). The polymer blend of the invention can be either the shell or the core. Different polymer blends of the invention can also be used independently as the shell and the core in the same fiber and especially where the shell component has a melting point lower than that of the core component. Other types of two-component fibers are within the scope of the invention as well, and include structures such as collateral fibers (e.g., fibers having separate regions of polymers, in Wherein the polymer blend of the invention comprises at least Bj || rijaHa | UH¡ | faith_ ^ a portion of the fiber surface). One embodiment is a two-component fiber, wherein the polymer blend composition described herein is provided on the shell, and a fusion polymer • higher, such as polyester terephthalate or a different polypropylene 5 is provided in the core. The shape of the fiber is not limited. For example, the typical fiber has a circular cross-sectional shape, but sometimes the fibers have different shapes, such as a three-lobed shape, or a flat (ie, "ribbon") shape. The fiber described herein is not limited by the shape of the fiber. The diameter of the fiber can be measured and reported in a variety of ways. Generally, the diameter of the fiber is measured in denier x filament. Denier is a textile term, which is defined as the grams of fiber per 9,000 meters of the length of that fiber. Monofilament generally refers to an extruded strand having a denier per filament greater than 15, usually greater than 30. Fine denier fiber generally refers to a fiber having a denier of 15 or less. Microdenier (also referred to as "microfiber") generally refers to fibers that have a diameter no greater than 100 micrometers. For the novel fibers described herein, the diameter can be widely varied. But the denier of the fiber can be adjusted to suit the capabilities of the finished article and as such, preferably it can be from 0.5 to 30 denier / filament for meltblowing; from to 30 denier / filament for spinning; and from 1 to 20,000 denier / filament for continuous winding filament. Fabrics made from the fibers of the invention include both woven and non-woven fabrics. Non-woven fabrics can • made in a variable form, including fine cord fabrics (or hydrodynamically entangled) as described in the patent of E.U.A. No. 3,485,706 (Evans) and US patent. No. 4,939,016 (Radwanski et al.), Cardando and thermally bonding short fibers; spinning continuous fibers in a continuous operation; or blowing by melting fibers to a fabric and subsequently calendering or binding thermally the resulting band. These various nonwoven fabric manufacturing techniques are well known to those skilled in the art and the description is not limited to any particular method. Other structures made from such fibers are also included within the scope of the invention, including, for example, blends of these novel fibers with other fibers (e.g., polyethylene terephthalate (PET) or cotton). Optional additive materials for use in the present invention include pigments, antioxidants, stabilizers, surfactants, for example, as described in the patent of E.U.A. No. 4,486,552 (Niemann), patent of E.U.A. No. 4,578,414 (Sawyer et al.) Or patent of E.U.A. No. 4,835,194 (Bright et al.). In preferred embodiments of the invention, at binding temperatures lower than the peak elongation temperature (where the peak elongation temperature is the temperature of the elongation Maximum), the fabrics prepared from the fibers of the invention will exhibit a fabric elongation, which is at least 20% preferably at least 50%, and most preferably at least 100% greater than that of the fabric prepared with fibers prepared • starting from the unmodified polypropylene used as the second polymer. In preferred embodiments of the invention, at bonding temperatures of at least 10 ° C lower than the peak strength bonding temperature (ie, the bonding temperature of the maximum strength (tenacity)), fabrics prepared from the fibers of the The invention will exhibit a fabric strength, which is at least 25%, preferably at least 50% and most preferably at least 70% greater than a fabric prepared from the prepared fiber of the unmodified polypropylene polymer as the second polymer. The improvement is particularly important since the Obtaining a tenacity given to a comparatively lower thermal bond invariably promotes the highly desired performance property of the fabric softness • improved. In preferred embodiments of the invention, the fibers of the The present invention will exhibit a spinning capacity (maximum stretch, rpms) that is not greater than 25% less than, most preferably not more than 15% less than the spinnability (maximum stretch, rpms) of the fiber prepared from the unmodified polypropylene polymer used as the second polymer. Stretching, rpms can also be correlated with the stretching pressure in a spinning process.

Useful articles that can be made from the polymer compositions described herein include films, fibers, thermoformed articles, molded articles (e.g., blow molded articles, injection molded articles and rotomolded articles), and coated articles (e.g. coatings by extrusion). Other useful articles include woven and nonwoven articles such as those described in the U.S.A. Issued No. 5, 472,775 (Obijeski and others). The present invention is particularly useful in the preparation of fabrics bonded by calendering rolls such as short carded fabrics or spunbond fabrics. Examples of end-use items include, but are not limited to, diapers and other items of personal hygiene items, disposable clothing (such as hospital garments), durable clothing (such as insulated outer clothing), disposable wipes, kitchen rags, and filtration media. The present invention is also usefully employed in the joining of carpet or upholstery components, and in the bonding or reinforcement of other bands (such as industrial shipping sacks, crimp and rope, wood wraps, house / building wraps, covers for pool, geotextiles and canvas). The present invention also finds utility in adhesive formulations, optionally in combination with one or * ^, ** ^ - * - more thickeners, plasticizers, or waxes. EXAMPLES In an evaluation to determine the effect of polymers of • ethylene on spinning properties, binding and elongation fiber 5 of the polymers polypropylene, a lesser amount of various ethylene polymers are mixed separately with an isotactic polypropylene polymer catalysed by Ziegler, INSPIRE H500-35 ™, supplied by The Dow Chemical Company. The polypropylene polymer was supplied with a melt flow rate • 10 reduced viscosity of 35 g / 10 minutes at 230 ° C / 2.16 kg. The various ethylene polymers used in the evaluation are listed in Table 1. In this evaluation polypropylene / ethylene polymer blends were prepared by dry mixing by stirring followed by extrusion under melting and pellet formation. To the dry mixes, 1000 ppm of Irgafos 168 was added through a 5% by weight masterbatch concentrate comprising • INSPIRE ™ H500-35 as the carrier resin. Melt extrusion and pelletization were performed using a double extruder Werner Pflieder ZSK-30 co-rotating screw (30 mm) at a melting temperature of approximately 190 ° C. The extruder was equipped with positive transportation elements and non-negative transportation elements. The resulting polymer blends and INSPIRE ™ H500-35 polypropylene polymer control (comparative example 4) were all spun by fusion to a fiber.

Table 2 provides the percent weight information for the various examples.

TABLE 1 Resin Type / designation l2, index Density, g / cmj product melting, g / 10 min EP1 ENGAGE 8150 * 0.5 0.87 EP2 ENGAGE 8100 * 1 0 87 EP3 ENGAGE 8200 * 5 0.87 EP4 AFFINITY PL 1280 * 6 0.90 EP5 ESI 5 < 15% by Weight EP6 ENGAGE 8400 0.87 30 * SLEP EP7 30 EP8 ASPUN 0913 6811 27 0941 Rather than density, the reported value is percent crystallinity as determined using differential scanning calorimetry (DSE). Except for ENGAGE elastomers, all of the above ethylene polymers are available from The Dow Chemical Company. ESI denotes a substantially random ethylene / styrene interpolymer, which contains about 30% by weight of styrene interpolymerized with ethylene. SLEP denotes an ethylene / 1-octene substantially linear homogeneously branched manufactured using a system constrained geometry catalyst in a reaction system continuous polymerization. ENGAGE is a trademark of Dupont-Dow Elastomers for ethylene elastomers. AFINITY is a trademark of The Dow Chemical Company for ethylene elastomers. Both AFINITY and ENGAGE resins are manufactured in a continuous polymerization reaction system. ASPUN is a trademark of The Dow Chemical Company for fiber grade, linear, low density polyethylene resins.

• (LLDPE) manufactured using a Ziegler titanium catalysis system. The spinning of the fiber was conducted in a laboratory scale spinning apparatus Alex James Laboratory available from (Alex James, Inc.). The various compositions of the example were fed separately to a single screw extruder of • 10 2.54 cm x 60.96 cm, with a melting temperature varying from 195 ° C to 220 ° C. The compositions of the melted example were advanced to a Zenith gear pump at 1752 cc / rev, and through a triple sieve configuration (20/400/20 mesh). TABLE 2 Example Ethylene polymer Percentage by weight d < Ethylene polymer Inv. 1 EP1 5 Inv. 2 EP1 1 Inv. 3 EP1 20 • Inv. 5 EP2 2 Inv. 6 EP2 10 Comp. 7 EP3 5 Inv. 8 EP4 5 Inv. 9 EP5 5 Comp. 10 EP6 5 comp. 11 EP7 5 Comp. 12 EP8 5 comp. 13 EP3 1 comp. 14 EP6 1 comp. 15 EP6 10 15 - • "* •• * •" í "The compositions of Example melted then left through a spinner containing 108 holes, each with a diameter of 400 .mu.m, wherein the L / D of the holes was 4/1 . The • molten example compositions were drawn at 0.37 g / minute 5 from each hole and cooled with air through an extinguishing chamber. The drawn fibers were moved 3 meters to a feed guide pulley with a diameter of 15.24 cm, then to a guide pulley of a winder with a diameter of 15.24 cm. The guide pulleys were set at 2000-2200 rotations per minute (rpm), no cold stretching was imparted and fibers were supplied having diameters in the range of 3.0 to 3.5 denier. The fiber samples were collected for 2 minutes on the second guide pulley for each example composition and then cut from the pulley guide Each example was then cut into sections of 2.54 to 3.81 cm known as short fibers and allowed to relax for a minimum of 24 hours to promote consistency with the laboratory. All example compositions were spun well, providing short fibers of fine denier. However, the good The performance or spinning performance of the examples of the invention (all comprising an ethylene polymer having a melt index, 12, less than or equal to 5 g / 10 minutes) was surprising, since the various ethylene polymers used as the mixing component for the compositions of the invention is not rotated in the spinning apparatus described above when . i. «> ^ ".

They used alone. That is, as taught by Jezic and others in the U.S. patent. No. 4,839,228, for a successful spinning of fiber, ethylene polymers having a melt index, l2 greater than or • equal to 12 g / 10 minutes, typically are used and not the type of high molecular weight ethylene polymers required in the present invention. The short fibers of each example composition were weighed as 1.25 g specimens, typically 4-8 specimens per sample. The specimens of 1.25 g were fed to a • 10 SpinLab Rotor Ring 580 device set at a maximum speed for 45 minutes to carder the fibers and provide an initial band. After the first carding, the fibers were removed, re-fed to the SpinLab Rotor Ring 580, and re-charged for another 45 seconds. After the second After the carding, a fiber band of 8.89 cm was removed for each example, and placed in a metal feed tray of 8.89 cm by 30.48 cm.

• A photomicrograph of the cross section of carded short fibers of the example of the invention 1 was taken (Figure 1). Before After taking the photomicrograph the carded short fibers were stained with RuCI3 / hypochlorite and mounted with Epofix ™. The same photomicrograph shows, before thermal bonding, the transverse configuration of the polypropylene polymer (continuous polymer phase) and the ethylene polymer (the discontinuous phase) which is of the island / sea type with the polypropylene polymer constituting more than 50% of the surface of the carded short fiber. That is, the discontinuous phase did not occupy a substantial portion of the surface of the fiber prior to thermal bonding. The same result and characteristic are shown in ^ p Figures 2 and 3 for examples of the invention 3 and 9, 5 respectively. In addition to indicating that the discontinuous phase is distinct, it is not highly dispersed (relatively larger particles) and occupies approximately as much as the surface of the fiber as the percentage by weight of the amount contained there (ie, there is no preferential migration or concentration • substantially larger on the surface), Figure 3 also shows that the discontinuous, substantially random ESI phase has at least 2 components. This discontinuous phase of multiple components is shown as substantially circular particles with darkly colored peripheries, which can relate to the amount of atactic polymer present in the interpolymer. In contrast to Figure 1-3, Figure 4 and Figure 5 indicate that the comparative examples are characterized by a • substantially higher degree of dispersion (smaller discontinuous phase particles) and miscible capacity between phases (less discontinuous phase distinction). Figures 1-5 were all taken at an amplification of 15,000x. The carded short fibers of each example composition were joined using a two roll thermal bonding unit (i.e., a Belait Wheeler Model 700 Laboratory apparatus).

Calendar). The top roller has a diameter of 12.7 cm and a face of 30.48 cm and consists of hardened chromed steel enhanced in a square pattern to a coverage of 20%. The lower roller is the same, except that it is not highlighted. For thermal bonding, the bonding rolls were fixed at 70.3 kg / cm2. which is equivalent to 6.069 kg / m (kg / m) for this unit. The conversion calculation was as follows: 70.3 kg / cm2-28.12 kg / cm2 so that the lower roller exceeds the spring force = 42.18 kg / cm2 by 12.85 cm2 cylinder area / 3.5 cm band width = 6069 kg / meter . The temperatures of the bonding rollers were set to maintain approximately at a differential of 3 ° C, with the upper roller always being colder to minimize stickiness. The bonding rollers were also set at a temperature range of 118 ° C to 137 ° C (top roll temperature) and 115 ° C to 134 ° C (lower roll temperature). The rolls were rotated at 7,193 m / minute. The fiber webs were then passed between the two rollers and removed from the opposite side to the feeding area. The resulting woven embossed fabrics, which had a nominal basis weight of 33. p grams / m2, were then cut to 2.54 x 10.16 cm fabric specimens. Before testing the operation, each cloth specimen was weighed and the weight entered into a computer program. The 2.54 x 10.16 cm specimens were placed over the entire length in a Sintech 10D tensiometer equipped with a 90.8 kg load cell, so that 2.54 cm at each end of the specimen were clamped in the upper and lower fasteners. The specimens were then pulled, one at a time, to 12.7 cm / minute to their breaking point. The computer then used the dimensions of the specimen and the force exerted to calculate the percentage of resistance (elongation) experienced by the specimen and the force normalized to the rupture (rupture to tension, which was taken as the resistance to union for the example) in grams. Four measurements were taken at each junction temperature for each example. Table 3 provides the results of operation of thermal bond strength for the various examples of carded short fabric. Table 4 gives the performance results of thermal bond elongation for the various examples of carded short fabric. Figures 6-15 provide several comparisons between the examples of the invention 1, 2, 3, 5, 6, 8 and 9 and comparative examples 4, 5, 7, 10, 11, 12, 13, 14 and 15. • ^^^ to ^ ^ TABLE 3 Resistance to bonding, grams Roller • upper, raised, 118 120 123 127 130 133 137 temperatijra, ° C. Ex. Inv. 1 ND ND 2769 3272 3251 4075 4457 Ex. Inv. 2 1842 19828 2150 2756 2704 3578 3975 Ex. Inv. 3 3509 4039 4337 4551 4289 4133 4329 Ex. Comp. 4 1843 2028 1831 2332 2464 3278 3431 Ex. Inv. 5 2051 2100 3387 2784 2909 4080 4491 Ex. Inv. 6 3240 3367 3558 3936 4110 4897 4574 • Ex. Comp 7 1781 1809 2171 2545 2403 2965 3610 Ex. Inv. 8 1992 2129 2009 2626 2672 3454 4389 Ex. Inv. 9 3029 3307 3344 3886 4468 4497 3646 Ex. Comp 10 1780 1774 1819 2092 2764 3542 3560 Ex. Comp. 11 1651 1625 1695 2043 2507 3125 3970 Ex. Comp. 12 1692 1738 1961 2161 2488 3301 3772 Ex. Comp. 13 2095 2054 2037 2275 2251 3295 4311 Ex. Comp. 14 1528 1630 2146 1965 2083 3047 3659 Ex. Comp. 15 1914 2198 2111 2493 2882 3167 3745 Table 3 and Figures 6-20 show all the examples of the invention, at an enhanced roll temperature of 127- • 130 ° C, and are generally characterized as having good bond strengths greater than or equal to 2, 500 grams and examples of the invention, 1, 3, 6 and 9 are preferentially characterized as having dramatically improved bond strengths to more than or equal to 3,250 grams. That is, the joining strengths of the examples of the invention 1, 3, 6 and 9 were greater than 36% more (and up to 84%) than the bond strength than the polypropylene polymer at a higher embossed roll temperature from 127-130 ° C. Table 3 and Figures 6-10 also show when the melt index 12 of the ethylene polymer is relatively high (ie, greater than or equal to 5. g / 10 minutes) and the ethylene polymer is an ethylene interpolymer. α-olefin (for example, when the α-olefin is 1-hexene, 1-butene or 1-octene), the composition of the invention will be characterized as comprising an ethylene polymer, which has a polymer density greater than 0.87. g / cm3, preferably greater than or equal to 0.90 g / cm3, and most preferably greater than or • 10 equal to 0.94 g / cm3. TABLE 4 Elongation percentage Upper roll, raised, 118 120 123 127 130 133 137 temperature, ° C. Ex. Inv. 1 ND ND 20 23 27 36 37 Ex. Inv. 2 11 12 12 17 18 24 28 Ex. Inv. 3 42 56 53 60 55 50 54 Ex. Comp. 4 11 11 12 14 14 19 23 Ex. Inv. 5 13 12 18 21 20 33 39 • Ex. Inv. 6 24 27 27 30 35 44 41 Ex. Comp 7 11 12 13 14 17 22 25 Ex. Inv. 8 15 15 13 19 19 25 36 Ex. Inv. 9 55 66 106 127 107 105 60 Ex. Comp 10 69 73 69 83 90 75 45 Ex Comp. 11 13 14 14 16 20 27 30 Ex. Comp. 12 11 11 11 13 16 22 32 Ex Comp. 13 11 11 12 14 16 25 32 Ex. Comp. 14 15 14 14 15 18 24 36 Ex. Comp. 15 9 10 11 11 12 19 24 El. Comp. 16 16 16 18 19 21 26 30 In addition, Table 3 and Figures 6-10 also show that in addition to the ethylene / α-olefin interpolymers (examples of the invention 1,3 and 6), other weight ethylene polymers high molecular weight, such as ethylene / styrene interpolymers of high molecular weight • (example of the invention 9) can dramatically improve the bond strength of the fabric of the isotactic polypropylene polymers. These data also suggest that the same result can be obtained as high molecular weight ethylene homopolymers (HMW-HDPE). Figures 11-15 and Table 4 show that in addition to the • Improved bond strength The composition of the invention also provides improved fiber elongation; that is to say at a thermal bonding temperature of 127-130 ° C, all the compositions of the invention had elongations greater than 15% and the preferred compositions of the invention (examples of the invention 3, 6 and 9) had larger elongations than or equal to 30% at a thermal bonding temperature of 127-130 ° C. This result is surprising and unexpected since the improvements of • Bond strength tend to reduce elongation performance (and vice versa). For example, Comparative Example 10 had a bond strength lower than 127 ° C than the polypropylene polymer, while this comparative example also had a higher percentage elongation than the polypropylene polymer at 127 ° C. In another evaluation, the effect of mixing a minor amount of a high molecular weight ethylene polymer in a polypropylene polymer catalyzed by Ziegler and a polypropylene polymer -.,.,. **.-... »**. - Catalyzed with metallocene, was investigated. The Ziegler catalyzed polypropylene polymer and the high molecular weight ethylene polymer (EP2) were the same as those used in the example of the previous invention. The reactor-grade metallocene-catalyzed polypropylene polymer in the evaluation had an MFR of 22 g / 10 minutes, melt flow rate (ASTM D-1238, condition 230 ° C / 2.16 kg) and was sold under the name of ACHIEVE 3904 by Exxon Chemical Corporation. This evaluation consisted of 4 different compositions of polymer; each polypropylene polymer was evaluated as a control resin and for the other two examples, each polypropylene polymer was mixed / extruded under melting with 1000 ppm Irgafos 168 and 5% by weight elastomer ENGAGE Elastomer 8100 (an ethylene / interpolymer). 1 -octene supplied by Dupont-dow Elastomers) using the master intermittent concentrate described above and the ZSK-30 extruder at approximately 190 ° C. Each control propylene polymer was also mixed / extruded under melting with 1000 ppm of Irgafos 168 using the master intermittent concentrate described above and the ZSK-30 extruder a approximately 190 ° C. The polypropylene / ethylene polymer blend comprising the Ziegler-catalyzed polypropylene polymer was designated as the example of the invention 16. The polypropylene / ethylene polymer blend comprising the catalysed polypropylene polymer with metallocene was designated as the example of the invention 17. The rf ^ M ^ ißUllÉ Ziegler-catalyzed polypropylene polymer was designated as comparative example 18 and the metallocene-catalyzed polypropylene polymer ACHIEVE 3904 was designated as comparative example 19. Each polymer composition was spun into short fine denier fibers as described above for the example of the invention 1, and was also carded as described above. The carded short fibers were tested for binding function using the same methods and procedures described above for the example of the invention 1. Figure 16 graphically shows thermal bonding performance results for the four example compositions. The results in Figure 12 indicate that a polymer of high molecular weight ethylene at nominal amounts can dramatically improve the thermal bonding performance of both metallocene-polypropylene and isotactic polymers and that the improvements are especially substantial and surprising and stable through a wide variety of binding temperature with the metallocene-polypropylene polymer. Figures 17-20 are photomicrographs of thermally bonded fibers. Figure 17 shows that a small shrinkage or tension is associated with the fiber of the invention (Figure 17b relative to the comparative fiber (Figure 17d) Figure 18 shows that substantially more melt and fluid is associated with the fiber of the invention (Figure 18a and b) in relation to the comparative fiber (Figure 18c and d) Figure 19 shows at least four different fibers of the invention at different perspectives in a 15,000x thermally amplified linked site The different perspectives show, for the fiber of the invention (example of the invention 1), the discontinuous ethylene polymer phase (dark stained areas) which does not occupy a substantial portion of a respective fiber surface after thermal bonding. Figure 20 shows some cracking associated with polypropylene polymers In another evaluation to investigate thermal bonding performance, a smaller amount of several high molecular weight ethylene polymers were mixed separately with a Ziegler-catalyzed polypropylene polymer of reduced viscosity and compared to the Ziegler-catalyzed polypropylene polymer with reduced net viscosity, a reactor-grade metallocene-catalyzed polypropylene polymer net and a Ziegler-catalyzed polypropylene polymer of net reactor grade. The Ziegler-catalyzed polypropylene polymer of reduced viscosity (comparative example 18) was the same as that used in the example of the previous invention 1. The reactor-grade metallocene-catalyzed polypropylene polymer (comparative example 19) was the same as above; that is, it had an MFR of 22 g / 10 minutes, melt flow rate (ASTM D-1238, condition 230 ° C / 2.16 kg) and was sold under the trade name of AVHIEVE 3904 Exxon Chemical Corporation. The reactor-grade Ziegler-catalyzed polypropylene polymer (comparative example 20) had an MFR . *., -t.s. i 25g / 10 minutes, melt flow rate (ASTM D-1238, condition 230 ° C / 2.16 kg). The various polymers of high molecular weight polypropylene used in this evaluation are listed in Table 5 below: TABLE 5 Resin Type / designation l2, Density index, g / cmz melt product, g / 10 min. EP9 HDPE 05862 5 0.962 EP10 SLEP 0.7 0.960 EP11 ESI OF 100 0.5 30% by weight? EP12 ESI DS 100 0.5 70% in pesof EP13 ENGAGE * 8180 0.5 0.863 t Instead of density, the reported value is a percentage by weight of styrene. Except for ENGAGE 8180, all of the above ethylene polymers are available from The Dow Chemical Company. ESI denotes a substantially random ethylene / styrene interpolymer. SLEP denotes a substantially linear, homogeneously branched ethylene / 1-ketene interpolymer, manufactured using a constrained geometry catalyst system in a continuous polymerization reaction system. ENGAGE is a trademark of Dupont-Dow Elastomers for ethylene elastomers. ENGAGE elastomers are manufactured in a continuous polymerization reaction system using a constrained geometry catalyst system. HDPE 05862 was manufactured using a Ziegler catalysis system. Table 6, presented below, provides the «- • - • * - < - - percentage information by weight of the polymer for the examples investigated in this evaluation. TABLE 6 Example Polymer of Percent in ethylene weight of ethylene polymer Ej Comp. 21 EP9 5 Ex Inv. 22 EP10 5 Ex Comp. 23 EP11 5 Ex Inv. 24 EP12 5 Ex Inv. 25 EP10 / EP13 2.5 / 2.5 Ex Comp. 26 EP9 8 Each of the ethylene polymer / polypropylene polymer blends were mixed / extruded by melting with 1000 ppm Irgafos 168 in a twin screw co-rotating extruder ZSK-30 at approximately 190 ° C. Comparative example 18, a control propylene polymer, was also mixed / extruded by melting with 1000 ppm of Irgafos 168, the extruder ZSK-30 at approximately 190 ° C. Each polymer composition was spun into short fine denier fibers as described above for the example of the invention 1 and was also carded as described above. The carded short fibers were tested for binding performance using the same methods and procedures described above for the example of the invention 1. Table 7 . t * * - «« provides the performance results of bond strength of the thermal bond (tenacity) at 33.9 g / m2 for the various examples of carded short fabric. Table 8 provides the • results of thermal bond elongation operation at 33.9 g / m2 for the various examples of carded short fabric. TABLE 7 Bond strength, grams Top roll, raised, 120 123 127 130 133 137 140 temperature, ° C. Ex. Comp. 18 1608 1553 1836 1813 2112 3165 3725 Ex. Comp. 19 ND 2080 1825 2288 2361 3263 3573 Ex. Comp. 20 ND 1816 1776 2024 2043 2559 2839 Ex. Comp. 21 1608 1643 2025 2001 2532 3113 3981 Ex. Inv. 22 2545 2709 3157 3872 4693 4872 4644 Ex. Comp. 23 1965 2237 2249 2479 2899 3452 4231 Ex. Inv. 24 2117 2521 2829 3100 3637 3836 5048 Ex. Inv. 25 2288 2792 3383 3851 4092 4780 4329 Ex. Comp. 26 ND 1817 2217 2492 2709 3312 4640 TABLE 8 Percentage of Elongation Upper roller, raised, 120 123 127 130 133 137 140 temperature, ° C. Ex. Comp. 18 8 8 9 11 13 18 27 Ex. Comp. 19 ND 10 8 11 12 19 24 Ex. Comp. 20 ND 8 9 10 10 13 15 Ex. Comp. 21 9 9 11 14 17 23 37 Ex. Inv. 22 24 26 34 53 85 80 59 Ex. Comp. 23 12 14 13 18 22 27 38 E. Inv. 24 15 18 19 23 30 35 54 E. Inv. 25 24 30 40 55 70 80 52 Ex. Comp. 26 ND 10 12 15 18 23 40 Table 7 shows all the examples of the invention, at an enhanced roller temperature of 127-130 ° C, generally characterized by having strengths greater than or equal to 2,500 grams. That is, at this junction temperature scale, the bonding resistances of the examples of the invention 22, 24 and 26 were 26 to 114% greater than the bonding strengths of the net propylene polymer compositions (comparative examples). , 19, 20) and the composition comprising 5 g / 10 minutes of HDPE catalyzed with Ziegler with an I2 of 5 g / 10 minutes (comparative example 21). Table 7 also shows interpolymer / styrene comprising 30% by weight of styrene or less, the melt index 12, must be in the scale of more than 0.5 g / 10 minutes of or equal to 10 g / 10 minutes to ensure a tenacity substantially improved.

Table 8 shows that the composition of the invention provides even more dramatic improvements with respect to elongation. Specally, at an enhanced roll temperature • upper of 127-130 ° C, the elongation percentages of the examples of the invention 22, 24 and 25 were 28% up to 450% higher than the percentage of the elongations of the comparative examples 18, 19, 20, and 21 . • 10 • ai? ^? -? ß m

Claims (39)

1. CLAIMS 1. A fiber having a diameter in the range of 0.1 to 50 denier and comprising: (A) from 0.1% to 30% by weight (in fiber weight) of at least one ethylene polymer having: (i) a melt index l2, less than or equal to 10 grams / 10 minutes, and (ii) a density of 0.85 to 0.97 grams / centimeters3, and (B) a polypropylene polymer, provided that when the ethylene polymer is an ethylene / α-olefin interpolymer having a melt index l2 in the range of 5 to 10 g / 10 minutes, the density of the ethylene / α-olefin polymer is greater than 0.87 g / cm 3, and provided that when the Ethylene polymer is an ethylene homopolymer or ethylene / α-olefin interpolymer having a density greater than or equal to 0.94 g / cm 3, the melt index 12 of the ethylene polymer is less than 5 g / 10 minutes, and where the fiber is characterized in that it can be thermally bonded to 6069 kilograms / linear meter (kg / m) and a surface temperature of uni roll n in the range of 127-137 ° C. The fiber according to claim 1, wherein the fiber comprises from 0.5 to 22% by weight of the ethylene polymer. The fiber according to claim 1, wherein the ethylene polymer is an interpolymer of ethylene and at least one α-olefin of 3 to 20 carbon atoms. 4. The fiber according to claim 1, wherein the ethylene polymer has a density of 0.855 to 0.880 grams / centimeters3. 5. The fiber according to claim 1, wherein in ethylene polymer it has a melt index of 0.01 to 10 grams / 10 minutes. 6. The fiber according to claim 1, wherein the ethylene polymer has a melt index of less than 5 grams / 10 minutes. The fiber according to claim 1, wherein the ethylene polymer is a substantially linear ethylene / α-olefin interpolymer which has: a. a melt flow ratio (110 / l 2) > .5.63, b. a molecular weight distribution, Mw / Mn, defined by the equation: Mw / Mn < (I10 / I2) - 4.63, and c. a critical shear rate at the beginning of the melt surface fracture, which is at least 50% greater than the critical shear rate at the beginning of the melt surface fracture of an ethylene / α-olefin interpolymer linear having approximately the same l2 and Mw / Mn. The fiber according to claim 1, wherein the polypropylene polymer is a reactor grade polypropylene and has an MFR at 230 ° C / 2.16 kg greater than or equal to 20 g / 10 minutes 9. The fiber according to claim 1, wherein the polypropylene polymer is a polypropylene of reduced viscosity and has a melt flow rate at 230 ° C / 2.16 kg greater than or equal to 20 g / 10 minutes. The fiber according to claim 1, wherein the polypropylene polymer has a melt flow rate coupled at 230 ° C / 2.16 kg greater than or equal to 20 g / 10 minutes. 11. The fiber according to the claim 1, wherein the polypropylene polymer is manufactured using a single-site restricted geometry or metallocene catalyst system. The fiber according to claim 1, wherein the polypropylene polymer is characterized as having at least 96% by weight of isotacticity. The fiber according to claim 1, wherein the fibers are prepared through a melt spinning process, such that the fibers are meltblown fibers, spunbonded fibers, carded short fibers or spunbond fibers. vaporization. 14. A fiber having a diameter in the range of 0.1 to 50 denier, a continuous polymer phase and at least one discontinuous polymer phase, and comprising: (A) as at least one discontinuous polymer phase, of 0.1 % to 30% by weight (in fiber weight) of at least one ethylene polymer having: (i) a melt index l2, less than or equal to 10 grams / 10 minutes, and (ii) a density of 0.85 to 0.97 grams / centimeters3, and (B) as the continuous polymer phase, a polypropylene polymer that has a melt flow rate (MFR) at 230 ° C / 2.16 kg higher than or equal to 12 grams / 10 minutes, provided that when the ethylene polymer is an ethylene / α-olefin interpolymer having a melt index, 12, on a scale of 5 to 10 g / 10 minutes, the polymer density of ethylene / α-olefin is greater than 0.87 g / cm 3, provided that when the ethylene polymer is an ethylene homopolymer or ethylene / α-olefin interpolymer having a density greater than or equal to 0.94 g / cm 3, where, before of any joining operation, the continuous polymer phase constitutes more than 50% of the surface area of the fiber and at least two polymer phases transversely provide an island-sea configuration, and wherein the fiber is characterized in that it can be thermally bond to 6.069 kg / linear meter (kg / m) and a temperatur a of surface of roller joined in the scale of 127 to 137 ° C. The fiber according to claim 14, wherein the discontinuous phase constitutes an amount of the fiber surface area, which is within or less than 50% of the amount of the discontinuous phase polymer contained throughout the fiber. 16. A method for improving the bond strength of a fine denier fiber composed of at least one polypropylene resin, the method comprising providing an intimate blend ?? - j.j ^ j_fcj > ^ Mi? with the same of less than or equal to 22% by weight of at least one ethylene polymer having a density of 0.85 to 0.97 g / cm3 and a melt index, 12, of 0.01 to 10 grams / 10 minutes, provided that when the ethylene polymer is an ethylene / α-olefin interpolymer having a melt index, 12, on the scale of 5 to 10 g / 10 minutes, the density of the ethylene / α-olefin polymer or ethylene homopolymer is higher 0.87 g / cm3 and provided that when the ethylene polymer is an ethylene / α-olefin homopolymer or interpolymer having a density greater than or equal to 0.94 g / cm3, the melt index, 12, of the ethylene polymer is lower than 5 g / 10 minutes. 17. A polymer composition having improved strength to the bond comprising: (A) from 0.1% to 30% by weight (by weight of the fiber) of at least one ethylene polymer having at least: ( i) a melt index, l2, less than or equal to 10 grams / 10 minutes, and (ii) a density of 0.85 to 0.97 grams / centimeters3, and (B) a polypropylene polymer, provided that when the ethylene polymer either an ethylene / α-olefin interpolymer or an ethylene homopolymer having a melt index of l2, on a scale of 5 to 10 g / 10 minutes, the density of the ethylene / α-olefin polymer or ethylene homopolymer is greater than 0.87 g / cm3, and with the proviso that when the ethylene polymer is an ethylene homopolymer or ethylene / α-olefin interpolymer having a density greater than 0.935 g / cm3, the melt index, 12, of the ethylene polymer is less than 5 g / 10 minutes. 18. A process for making the composition of claim 17, comprising at least two polymerization reactors operated sequentially or in parallel. 19. The process according to claim 18, wherein the ethylene polymer is manufactured in at least two polymerization reactors. The process according to claim 18, wherein the ethylene polymer is manufactured in at least one of the two polymerization reactors and the polypropylene polymer is manufactured in another reactor of at least two polymerization reactors. 21. The process according to claim 18, wherein the ethylene polymer is manufactured in the first of at least two polymerization reactors and the polypropylene polymer is manufactured in the second of at least two polymerization reactors, in where at least two polymerization reactors are operated sequentially. 22. The process according to claim 18, wherein the polypropylene polymer is manufactured in the first of at least two polymerization reactors and the ethylene polymer is manufactured in the second of at least two polymerization reactors, in where at least two polymerization reactors are operated sequentially 23. The polymer composition according to claim 17, in the form of a fiber, rotomolded article, film layer, injection molded article, blow molded article, blow molded article and injection, or 5 extrusion coating composition. The fiber according to claim 1, or claim 14, or the composition of claim 17, wherein the ethylene polymer has a melt index, 12, less than 5 g / 10 minutes. 25. The fiber according to claim 1, or claim • 10 14, or the composition of claim 17, wherein the ethylene polymer is a homogeneously branched ethylene polymer having a branching ratio of composition distribution (CDBI) greater than 50%. 26. The fiber or composition according to claim 25, wherein the homogeneously branched ethylene polymer has a long chain branching. 27. The fiber or composition according to claim 25, • wherein the homogeneously branched ethylene polymer is a homogenously branched linear ethylene polymer. 28. The fiber or composition according to claim 25, wherein the homogeneously branched ethylene polymer is a homogeneously branched substantially linear ethylene polymer. 29. The fiber according to claim 1 or claim 25 14, or the composition of claim 17, wherein the ethylene polymer is an ethylene / vinyl or vinylidene aromatic interpolymer. 30. The fiber or composition according to claim 29, wherein the interpolymer is an ethylene / styrene interpolymer. • The fiber according to claim 1 or claim 5, or the composition of claim 17, wherein the ethylene polymer is a substantially random ethylene / vinyl or vinylidene aromatic interpolymer. 32. The fiber or composition according to claim 29, wherein the interpolymer is an ethylene / styrene interpolymer. • 10 substantially random. The fiber or composition according to claim 30 or claim 32, wherein the interpolymer contains more than or equal to 25% by weight (based on the total weight of the interpolymer) of interpolymerized or copolymerized styrene. 34. The fiber or composition according to claim 30 or claim 32, wherein the interpolymer contains more than or equal to 50% by weight (based on the total weight of interpolymer) of interpolymerized or copolymerized styrene. 35. The fiber according to claim 1, or claim 20, or the composition of claim 17, wherein the fiber or composition further comprises at least one other olefin polymer. 36. The fiber or composition according to claim 35, wherein at least the other olefin polymer is a polymer of 25 ethylene high density that has a density greater than or equal to 0. 94 g / cm3. 37. The fiber or composition according to claim 36, wherein the high density ethylene polymer is a polyethylene of • homopolymer. 5 38. A fiber having a diameter in the range of 0.1 to 50 denier, and comprising: (A) from 0.1% to 30% by weight (by weight of the fiber) of at least one ethylene polymer having : (i) a melt index, 12, less than or equal to 10 grams / 10 • 10 minutes, and (i) a density of 0.85 to 0.97 grams / centimeters3, and (B) a crystalline, coupled or branched polypropylene polymer, provided that when the ethylene polymer is an ethylene / α-olefin interpolymer having a melt index, 12, on a scale of 5 to 10 g / 10 minutes, the density of the ethylene / α-olefin polymer is greater than 0.87 g / cm 3, provided that when the ethylene polymer is an ethylene homopolymer or ethylene / α-olefin interpolymer having a density greater than 0.94 g / cm 3, the melt index, 12 20, of the ethylene polymer is less than 5 g / 10 minutes, and wherein the fiber is characterized because it can be thermally bonded at 6,069 kilograms / meters (kg / m) and a joint roll surface temperature in the range of 127 to 137 ° C. 39. A fiber having a diameter in the range of 0.1 to 50 denier, and comprising: (A) from 0.1% to 30% by weight (in fiber weight) of at least one ethylene polymer having (i) a melt index, l2, less than or equal to 10 grams / 10 minutes, and (ii) a density of 0.85 to 0.97 grams / centimeters3, and (B) a crystalline polypropylene polymer, made using a system of restricted geometry or metallocene catalyst, single-site, provided that when the ethylene polymer is an ethylene / α-olefin interpolymer having a melt index, 12, on a scale of 5 to 10 g / 10 minutes, the The density of the ethylene / α-olefin polymer is greater than 0.87 g / cm3, provided that when the ethylene polymer is an ethylene homopolymer or ethylene / α-olefin interpolymer having a density greater than 0.94 g / cm 3, the fusion, 12, of the ethylene polymer is less than 5 g / 10 minutes, and wherein the fiber is characterized because it can be r thermally bonded to 6,069 kilograms / meter (kg / m) and a roll surface »joining temperature in the range of 127 to 137 ° C.