Melt-blown nonwoven fabric, process for producing same and the uses thereof

Abstract

The disclosure relates to a melt-blown non-woven fabric based on cellulose esters, with fibers of mean diameter less than about 10 microns. The fabric contains 0-10 wt. % extractable softener, has a reflection factor determined according to DIN 53 145 Part I (1992) of more than 60% and the cellulose ester has a degree of substitution DS of about 1.5-3.0. The softener is preferably water-extractable. A melt-blown non-woven fabric is produced with the cellulose ester as follows: a cellulose ester, cellulose acetate, with a DS of about 1.5-3.0, in particular 1.7-2.7, is mixed with softener in a weight ratio of about 2:1 to 1:4 and simultaneously heated and melted. The mixture of softener and cellulose ester has a melting index MFI (210/2.16) according to DIN 53 735 of about 400 to 5 g/10 min., in particular 300 to 50 g/10 min. The melt is worked in a melt-blown spinning device into a melt-blown non-woven fabric and the softener is then extracted with a softener solvent to leave a proportion of 0-10 wt. %. The melt-blown non-woven fabric is especially suitable as a filter material.

Dependencies are inferred from the claim text.