Patent ID: 7504347

Claim:
A fiber obtainable from or comprising a propylene/α-olefin interpolymer, wherein the propylene/α-olefin interpolymer is characterized by one or more of the following properties: (a) a Mw/Mn from about 1.7 to about 3.5, at least one melting point, Tm, in degrees Celsius, and a density, d, in grams/cubic centimeter, wherein the numerical values of Tm and d correspond to the relationship: T m >−2002.9+4538.5( d )−2422.2( d ) 2 ; or (b) a Mw/Mn from about 1.7 to about 3.5, and a heat of fusion, ΔH in J/g, and a delta quantity, ΔT, in degrees Celsius defined as the temperature difference between the tallest DSC peak and the tallest CRYSTAF peak, wherein the numerical values of ΔT and ΔH have the following relationships: Δ T >−0.1299(Δ H )+62.81 for Δ H greater than zero and up to 130 J/g, Δ T≧ 48° C. for Δ H greater than 130 J/g, wherein the CRYSTAF peak is determined using at least 5 percent of the cumulative polymer, and if less than 5 percent of the polymer has an identifiable CRYSTAF peak, then the CRYSTAF temperature is 30° C.; or (c) a Mw/Mn from about 1.7 to about 3.5 and an elastic recovery, Re, in percent at 300 percent strain and 1 cycle measured with a compression-molded film of the propylene/α-olefin interpolymer, and a density, d, in grams/cubic centimeter, wherein the numerical values of Re and d satisfy the following relationship when propylene/α-olefin interpolymer is substantially free of a cross-linked phase: Re> 1481−1629( d ); or (d) a Mw/Mn from about 1.7 to about 3.5 and a molecular fraction which elutes between 40° C. and 130° C. when fractionated using TREF, characterized in that the fraction has a molar comonomer content of at least 5 percent higher than that of a comparable random propylene interpolymer fraction eluting between the same temperatures, wherein said comparable random propylene interpolymer comprises the same comonomer(s) and has a melt index, density, and molar comonomer content (based on the whole polymer) within 10 percent of that of the propylene/α-olefin interpolymer.