Fabric (woven – knitted – or nonwoven textile or cloth – etc.) – Nonwoven fabric – Including a foamed layer or component
Patent
1995-11-06
1998-09-08
Bell, James J.
Fabric (woven, knitted, or nonwoven textile or cloth, etc.)
Nonwoven fabric
Including a foamed layer or component
4283159, 442373, 442398, 604369, 604372, 604378, A61F 1315, B32B 326
Patent
active
058045180
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to an absorbent article. More particularly, it relates to an absorbent article comprising a porous sheet which exhibits excellent tensile strength and high molding productivity as well as excellent moisture permeability and resistance to water pressure.
BACKGROUND ART
Porous sheets for absorbent articles have conventionally been produced by a process comprising molding a molten mixture of a polyolefin, such as polyethylene or polypropylene, and 40% by weight or more of an inorganic filler into a sheet and monoaxially or biaxially stretching the resulting sheet.
Porous sheets obtained by the above process are excellent in air- and moisture-permeability and cause no moisture condensation and are therefore useful as wall paper and wrapping paper. Addition of softness to these excellent properties makes the porous sheet suitable for use as an element of absorbent articles such as a back sheet of disposable diapers. In order to obtain soft porous sheets, it has been proposed to use linear low-density polyethylene as a polyolefin.
However, the conventional porous sheet has the following disadvantages for use as an element of absorbent articles such as disposal diapers.
For example, commonly employed disposal diapers are fabricated from an absorbent-member for absorbing excreta such as urine, a topsheet which covers the surface of the absorbent member and is directly applied to the skin, and a back sheet which covers the back side of the absorbent member and prevents leakage, these three parts being adhered together into a unitary body. The top and bottom ends and side edges of the diaper corresponding to the waist portion and a crotch portion are made stretchable for tight-fit to prevent leakage. The disposable diapers also have a fastening means such as tapes, with which the diaper is fitted to a wearer's body in use. The above-mentioned porous sheet is used as the back sheet.
The above-mentioned tapes provided for fastening (so-called fastening tapes) mostly have a width of about 25 to 35 mm for convenience of handling. However, when the fastening tape is unfastened to adjust the position of the diaper for a better fit or to see if urine has been discharged or not, the tape cannot be peeled without tearing the soft back sheet due to lack of strength. This being the case, the diaper must be changed with a new one. In order to avoid this, it has been proposed to provide wide tapes having a release surface (so-called landing tapes or target tapes) on the front side back sheet, on which fastening tapes may be removably adhered.
However, many problems are posed by the use of landing tapes. That is, the kinds of diaper constituting members and processes of production of diapers increase. A landing tape is more costly than any other diaper constituting members, so that use of the landing tape with a sufficient width increases the cost. In addition, even with a wide landing tape, cases are sometimes met with depending on the body size of a wearer, in which a fastening tape is adhered to the back sheet outside the landing tape area and cannot be stripped off.
Japanese Patent Application Laid-open 5-98057 discloses a high strength porous sheet obtained by blow molding a composition comprising a specific polyolefin, a filler, a specific plasticizer and a radical generator, and monoaxially stretching the blown film in the machine direction.
Although the sheet disclosed has nearly twice as much strength as a porous sheet obtained by a conventional process (a molten mixture of a polyolefin and an inorganic filler is molded into a sheet followed by stretching), such a degree of improvement is still insufficient for eliminating the necessity of landing tapes. In addition, since the use of the radical generator makes melt flow properties of the molded resin composition different from those of the composition before molding, it is difficult to recycle inevitably produced in the course of the production, resulting in reduced productivity.
Further, Japanese Patent Application Laid-open 5
REFERENCES:
patent: 4206980 (1980-06-01), Krueger
patent: 4539256 (1985-09-01), Shipman
patent: 4609584 (1986-09-01), Cutler et al.
patent: 4726989 (1988-02-01), Mrozinski
patent: 4813950 (1989-03-01), Branch
patent: 4820293 (1989-04-01), Kamme
patent: 5043209 (1991-08-01), Boisse et al.
patent: 5085654 (1992-02-01), Buell
patent: 5106383 (1992-04-01), Mulder et al.
patent: 5151091 (1992-09-01), Glaug et al.
patent: 5169712 (1992-12-01), Taff
patent: 5246432 (1993-09-01), Suzuki et al.
patent: 5260360 (1993-11-01), Mrozinski et al.
Kumamoto Yoshiaki
Maeda Katsushi
Odajima Shingo
Sakai Yoshihiro
Bell James J.
Copenheaver Blaine R.
Kao Corporation
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