| 摘要 |
FIELD: chemistry. ^ SUBSTANCE: mixture of polypropylenes basically contains a first homopolypropylene and a second homopolypropylene. MFR of the first homopolypropylene is higher than that of the second homopolypropylene. The weight fraction of the second homopolypropylene in the mixture of polypropylenes ranges from at least 3 wt % to a maximum of 25 wt %, wherein the remaining portion of the mixture of polypropylenes is basically composed of the first homopolypropylene. The second homopolypropylene has MFR, according to ISO 1133, from 0.7 to 14 g/10 min (230C/2.16 kg). The difference between the MFR of the second homopolypropylene and the MFR of the first homopolypropylene is at least 10 g/10 min, and the upper limit of the MFR of the first homopolypropylene is 55 g/10 min (230C/2.16 kg), according to ISO 1133. The mixture 'basically' contains only these two homopolypropylenes as polymers. The mixture can be added to a dopant or other additives except polymers. The mixture is obtained by separately feeding the first and second homopolypropylenes into an extruder. ^ EFFECT: invention enables to obtain high-expandability spunbonded nonwoven material from the corresponding mixture of polypropylenes. ^ 26 cl, 4 dwg, 9 tbl |
