Abstract: A packaging material according to the present invention includes an electret material having a surface part mutually different polarized electric charges on a front surface and a rear surface thereof. A method of packaging according to the present invention includes covering at least a portion of an object using the packaging material.

Abstract: This invention relates to an electret material having thermal stability and capable having high trapped charge quantity and stably existing for a long period of time and a process for preparing the electret material. The electret material is characterized in that it comprises 100 parts by weight of polypropylene, 0.01 to 2 parts by weight of a least one stabilizer selected from among hindered amine, nitrogen-containing hindered phenol, and metal-containing hindered phenol stabilizer and that at least part of the propylene has such a molecular weight distribution that the M(w)/M(n) ratio wherein M(w) is a weight-average molecular weight is 5.5 or less. The electret material can be widely used for various applications and, e.g., is best suited for use in, e.g., various filter materials, wiper materials, absorption materials, masking materials, and dust-proof materials.

Abstract: This invention relates to a melt-blow water-absorbing fiber webs whose main component is block-copolyetheresters having polyester and polyether segments in the molecules, wherein the amount the polyether component is 5 to 80 wt % base on the block-copolyetheresters.The water-absorbing web of this invention shows high chlorine fastness and consequently shows excellent water absorption performances after repeated washing. They are available as good batting (urine absorber) for diapers, as well as bed pads, towel materials and sports underpants, and applicable to a wide range of disposal products which require high water absorption performances and durability.