POLYPROPYLENE FIBRES SUITABLE FOR SPUNBONDED NON-WOVEN FABRICS

摘要

A fibre for spunbonded fabrics comprising a propylene polymer composition (A ) having an MFR (1) value from 6 to 150 g/10 min and being selected from (i) a crystalline propylene random copolymer or crystalline propylene polymer composition containing at least 0.8% by weight of ethylene and having a melting temperature of 153~ C or higher, a content of fraction soluble in xylene at room temperature lower than 10% by weight, and a value of the rati o of the polymer fraction collected at the temperature range from 25~ to 95~ C to the xylene soluble fraction at room temperature higher than 4; and (ii) a crystalline propylene polymer composition having a melting temperature of 15 3~ C or higher, a content of fraction soluble in xylene at room temperature low er than 10% by weight; the said composition containing at least 0.64 wt% of ethylene or a C4-C10 a-olefin recurring unit and comprising: (1) 20-80 wt% o f a crystalline propylene polymer containing up to 1.5 wt% of ethylene and/or C4- C10 a-olefin; and (II) 20-80 wt% of a crystalline propylene random copolymer selected from (IIa) a copolymer of propylene with 0.8 to 10 wt% of ethylene and/or (IIb) a copolymer of propylene with 1.5 to 18 wt% of a C4-CIO a-olefi n. Said polymer composition (A) is obtainable by way of chemical degradation of a precursor polymer composition (A) having MFR values (MFR (2)) of from 0.5 to 50 g/10 min, provided that the ratio of MFR (1) to MFR (2) be from 1.5 to 60 . Propylene polymer composition (ii) as described above and non-woven fabrics that are prepared with the said fibres. The said fabric is useful for coverstock and diapers.