US 7,504,347 B2
Fibers made from copolymers of propylene/α-olefins
Benjamin C. Poon, Pearland, Tex. (US); Yunwa W. Cheung, Lake Jackson, Tex. (US); Shih-Yaw Lai, Pearland, Tex. (US); Ashish Sen, Lake Jackson, Tex. (US); Hongyu Chen, Lake Jackson, Tex. (US); Yuen-Yuen D. Chiu, Pearland, Tex. (US); Rajen M. Patel, Lake Jackson, Tex. (US); Andy C. Chang, Houston, Tex. (US); Antonios K. Doufas, Lake Jackson, Tex. (US); and Hong Peng, Lake Jackson, Tex. (US)
Assigned to Dow Global Technologies Inc., Midland, Mich. (US)
Filed on Mar. 15, 2006, as Appl. No. 11/377,725.
Application 11/377725 is a continuation in part of application No. PCT/US2005/008917, filed on Mar. 17, 2005.
Claims priority of provisional application 60/717863, filed on Sep. 16, 2005.
Claims priority of provisional application 60/553906, filed on Mar. 17, 2004.
Prior Publication US 2006/0199006 A1, Sep. 07, 2006
This patent is subject to a terminal disclaimer.
Int. Cl. D04H 1/00 (2006.01); B32B 25/02 (2006.01)
U.S. Cl. 442—361  [442/327; 428/296.7] 21 Claims
 
1. 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:
Tm>−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:
ΔT>−0.1299(ΔH)+62.81 for ΔH greater than zero and up to 130 J/g,
ΔT≧48° C. for ΔH 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.