US 12,291,628 B2
Propylene polymer fibers
Roberto De Palo, Ferrara (IT); Jaume Marti Porqueres, Reus (ES); Renaud Lemaire, Brussels (BE); and Claudio Cavalieri, Ferrara (IT)
Assigned to Basell Poliolefine Italia S.r.l., Milan (IT)
Appl. No. 17/616,854
Filed by BASELL POLIOLEFINE ITALIA S.R.L., Milan (IT)
PCT Filed May 18, 2020, PCT No. PCT/EP2020/063778
§ 371(c)(1), (2) Date Dec. 6, 2021,
PCT Pub. No. WO2020/244912, PCT Pub. Date Dec. 10, 2020.
Claims priority of application No. 19179084 (EP), filed on Jun. 7, 2019.
Prior Publication US 2022/0306848 A1, Sep. 29, 2022
Int. Cl. C08L 23/12 (2006.01); B29C 48/00 (2019.01)
CPC C08L 23/12 (2013.01) [B29C 48/022 (2019.02); C08L 2203/12 (2013.01)] 8 Claims
 
1. A process for preparing a fiber comprising:
extruding a propylene homopolymer to form a fiber, wherein the polypropylene homopolymer has:
(i) a melting point ranging from 150° C. to 164° C.;
(ii) a fraction soluble in xylene at 25° C. between 6.0 wt. % and 2.0 wt. %,
(a) wherein the fraction soluble in xylene at 25° C. contains a fraction soluble in acetone at 25° C. and a fraction insoluble in acetone at 25° C.,
(b) wherein the fraction soluble in acetone at 25° C. between 0.5 wt. % and 2.0 wt. %, based on the total weight of the polypropylene homopolymer;
(c) wherein the fraction soluble in xylene at 25° C. contains a ratio of the fraction soluble in acetone at 25° C. to the fraction insoluble in acetone 25° C. between 0.30 and 0.60;
(iii) a polydispersity index ranges from 2.8 to 4.5; and
(iv) a melt flow rate (ISO 1133, 230° C./2.16 kg) between 2 to 40 g/10 min.