Nonwoven fabric, process for producing the same, sanitary material and sanitary supply

Abstract

Polyolefin resin-based non-woven fabric characterized by containing a fatty acid amide compound, and by having a static friction coefficient of 0.1 to 0.4. Production of such non-woven fabric is achieved by subjecting, for example, non-woven fabric containing 0.05 to 1 wt. % erucamide to an aging treatment at 30 to 60° C. for 5 to 50 hours.

Description

[0001] The present invention relates to polyolefin resin-based non-woven fabric and a method for the production thereof, particularly to fabric suitable as a material of sanitary articles such as disposable diapers because of its excellent hand and touch feeling.DESCRIPTION OF THE RELATED ART[0002] The filament non-woven fabric such as spunbonded non-woven fabric has been widely used in many applications because it has excellent mechanical properties such as high tensile strength and air permeability, as well as ensures the efficient production of fabric based on continuously spun fibers. The thermoplastic resin which has been mainly used as a material of such filament non-woven fabric includes polyamide resins and polyester resins because they give excellent fiber characteristics, and are easily melt into a fiber easily yielding to spinning (spinning easiness). However, currently, an increasingly larger amount of polyolefin resins such as polypropylene, polyethylene, etc., or the r...

AI Technical Summary

Benefits of technology

[0091] This invention provides a method for producing polyolefin resin-based non-woven fabric excellent in hand and touch feeling. That fabric can be suitably used as sanitary articles such as disposable diapers, or as a material of such sanitary articles.

Problems solved by technology

If it is made of a resin having a high crystallizing activity, it will be excellent in spin easiness, but poor in softness and problematic in hand.

If a polypropylene-based resin of which the isotactic pentad fraction (which serves as an index representing the crystallizing activity of the resin) is about 90 mol %, or a resin most often used as a material of non-woven fabric, is employed, the fiber will be comparatively good in spin easiness but the fabric based thereon will not always have a sufficient hand and touch feel to be effectively applied for the production of sanitary articles such as disposable diapers, sanitary napkins, incontinence pads, etc.

In the material of this fabric, however, the features characteristic with a propylene-based homopolymer such as high thermal resistance, high mechanical strength, etc are absent, and a comparatively large amount of a hydrocarbon compound with a low molecular weight and low melting point must be added to the propylene-based random copolymer.

The coexistence of such a hydrocarbon lubricant may prove to be problematic: the heat seal and adhesiveness of the non-woven fabric will be degraded as a result of the brittleness introduced by the lubricant.

Namely, the resin has a crystallizing activity different from that of the resin commonly used as a material of a polypropylene resin-based non-woven fabric; but the fabric based on the resin does not always give a good softness, hand and touch feel.

%, it will be difficult for the fabric to have a static friction coefficient of 0.1 to 0.4, depending on the aging condition.

%, its deposition on the fiber surface will become considerable, which may result in the development of whiteness on the fiber surface, degrading its appearance, or cause the lowered thermal adhesiveness of fibers.

If the aging condition is milder than above, the lowering speed of the static friction coefficient of the fabric may become so low as to interfere with the productivity.

On the contrary, if the aging condition is sterner than above, the fabric may give a higher static friction coefficient than specified, which is undesirable.

However, in certain cases, it is possible to overlap a layer of the polyolefin resin-based non-woven fabric with another layer of different fabric, and then to submit the resulting layered fabric complex to aging.