CA2355525C - Absorbent article with surface member of continuous filaments - Google Patents

Absorbent article with surface member of continuous filaments Download PDF

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Publication number
CA2355525C
CA2355525C CA002355525A CA2355525A CA2355525C CA 2355525 C CA2355525 C CA 2355525C CA 002355525 A CA002355525 A CA 002355525A CA 2355525 A CA2355525 A CA 2355525A CA 2355525 C CA2355525 C CA 2355525C
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Canada
Prior art keywords
continuous filaments
surface member
lower layer
upper layer
filaments
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CA002355525A
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French (fr)
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CA2355525A1 (en
Inventor
Kodai Furuya
Hiroo Hayashi
Takamitsu Igaue
Shinya Kaneko
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Unicharm Corp
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Unicharm Corp
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Publication of CA2355525A1 publication Critical patent/CA2355525A1/en
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Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00Bandages or dressings; Absorbent pads
    • A61F13/15Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/51Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators characterised by the outer layers
    • A61F13/511Topsheet, i.e. the permeable cover or layer facing the skin

Abstract

Disclosed is an absorbent article including: a liquid permeable surface member; a backing sheet; and an absorbent layer interposed between the surface member and the backing sheet. The surface member includes an upper layer located at a liquid-receiving side surface and a lower layer located adjacent to the absorbent layer. The upper layer is formed of first continuous filaments. The lower layer is formed of second continuous filaments. The first and second continuous filaments individually extend over the entire length of the surface member. Hydrophilicity of the lower layer is higher than that of the upper layer.

Description

ABSORBENT ARTICLE WITH SURFACE MEMBER Of CONTINUOUS FILAMENTS
BACKGROUND OF THE INVENTION
Field of the Invention The present invention relates to an absorbent article, such as sanitary napkin, disposable diaper or the like, which has a surface member formed of continuous filaments.
Description of the Related Art Absorbent articles, such as sanitary napkins, disposable diapers or the like are generally constructed such that a liquid impermeable backing sheet is stacked on the back side of an absorbent layer, and a liquid permeable surface member is stacked on the surface side as a liquid-receiving side.
As functions of the surface member of the absorbent article, it is required to have superior liquid permeability for permitting liquid to flow toward the absorbent layer, and to achieve high effect in preventing liquid from flowing back.
Here, the phenomenon where liquid once absorbed in absorbent layer flows back toward the surface side is often referred to as ~~rewet~~ .
For example, in Japanese Unexamined Patent Publication No. 5-176954, there is disclosed a surface member, in which a spun bonded non-woven fabric formed of hydrophobic continuous filaments and a thin paper formed of pulp fibers are stacked and the continuous filaments and the pulp fibers are entangled by action of water flow. In this prior art, by contacting the hydrophobic spun bonded non-woven fabric and the hydrophilic thin paper on the entire surface, body fluid is easily absorbed and passed by absorbing force of the pulp fibers forming the thin paper.
However, since this conventional surface member requires a process step of applying water flow, production cost becomes high. Also, since water flow is applied, basis weight becomes high and bulkiness becomes low to lack soft feeling as a surface member.
On the other hand, in Japanese Unexamined Patent Publication No. 9-510374, there is disclosed a surface member in which a first sheet and a second sheet are stacked in spaced apart relationship via a spacer to exhibit capillary effect by a gap defined between the first and second sheets to easily pass the body fluid.
However, since this conventional surface member employs complicate structure for requiring placing two sheets in spaced apart relationship by the spacer, difficulty is encountered in manufacturing and this is less practical.
On the other hand, as other prior art, there is a surface member in which a hydrophilic non-woven fabric is stacked below a hydrophobic non-woven fabric and these two kinds of non-woven fabric are adhered. In this surface member, permeability of body fluid is improved by liquid absorbing ability of the lower hydrophilic non-woven fabric.
However, in this conventional surface member, since the hydrophobic non-woven fabric and the hydrophilic non-woven fabric are adhered with a hot melt type adhes ive or the 1 ike, the adhesive is inherently present on the interface between the non-woven fabrics to serve to block flow of the liquid.
On the other hand, Japanese Unexamined Utility Model Publication No. 57-13609, Japanese Unexamined Utility Model Publication No. 56-141612 and so forth, disclose absorbent articles, in which a layer of hydrophobic continuous filaments is provided on the surface side of the absorbent layer. In these absorbent articles employing the continuous filament layer as a surface layer, the surface layer has a low filament density and a high bulkiness . Therefore, it can provide soft contact feeling on the skin of a wearer. In addition, since the relatively bulky, hydrophobic filament layer is present between the absorbent layer and the skin of a wearer, flowing back of liquid once absorbed in the absorbent layer (i.e., rewet) can be easily prevented.
However, since the relatively bulky, hydrophobic filament layer is present on the surface of the absorbent layer, body fluid is difficult to penetrate into the absorbent layer to cause a defect that the body fluid may be retained in the filament layer.
SUMMARY OF THE INVENTION
The present invention has been worked out in view of the problem in the prior art set forth above. It is, therefore, a feature of one embodiment of the present invention to provide an absorbent article having a surface member which provides soft contact feeling on the skin of a wearer, high liquid permeability and high rewet-preventing property, and which is easy to manufacture.
In accordance with an embodiment of the present invention there is provided an absorbent article comprising:
a liquid permeable surface member; a backing sheet; and an absorbent layer interposed between the surface member and the backing sheet, the surface member having at least two layers including an upper layer located at a liquid-receiving side surface and a lower layer located adjacent to said absorbent layer, the upper layer being formed of first continuous filaments, the lower layer being formed of second continuous filaments, the first and second continuous filaments individually extending over an entire length of the surface member, wherein the first continuous filaments are prepared by applying at least one compound selected from the group consisting of PEG modified polyester, polyoxyethylene alkyl sulfate, alkyl phosphoric ester K
salt, polyoxyethylene alkyl ester, and alkylsulfonate Na salt on surfaces of hydrophobic filaments, and the second - 4a -continuous filaments are prepared by applying at least one compound selected from the group consisting of polyether ester, ether nonion, polyether modified silicon, sulfo succinate, polyoxyethylene amide ether, alkyl imidazoline type ration, and polyglycerol polyester an surfaces of hydrophobic filaments so that a hydrophilicity of said lower layer is higher than a hydrophilicity of the upper layer.
For example, the first and second continuous filaments may be respectively prepared by applying a hydrophilic oil solution on surfaces of hydrophobic filaments, and durability of a hydrophilic oil solution applied to the second continuous filaments may be higher than that of a hydrophilic oil solution applied to the first continuous filaments.
In an alternative, the first and second continuous filaments may be respectively prepared by applying a hydrophilic oil solution on surfaces of hydrophobic filaments, and the application amount of the hydrophilic oil solution to the second continuous filaments may be greater than the application amount of the hydrophilic oil solution to the first continuous filaments.
In another alternative, the first continuous filaments may be hydrophobic filaments and the second continuous filaments may be hydrophilic filaments. In still another alternative, the first continuous filaments may be hydrophobic filaments not treated to be hydrophilic and the second continuous filaments may be hydrophobic filaments treated to be hydrophilic.
Preferably, a density of the first continuous filaments in the upper layer is different from a density of the second continuous filaments in the lower layer. More preferably, a density of the second continuous filaments in the lower layer is higher than a density of the first continuous filaments in the upper layer. In this case, number of crimp in the first continuous filaments and number of crimp in the second continuous filaments may be respectively in a range of 5 to 30 per 1 inch, but may be different from each other so that the difference in density is caused by the difference in number of crimp, and/or crimp modulus of elasticity of the first continuous filaments and crimp modulus of elasticity of the second continuous filaments may be respectively greater than or equal to 70%, but may be different from each other so that the difference in density is caused by the difference in crimp modulus of elasticity.
In the present invention, since the surface member is formed of the continuous filaments to have a low density and a high bulk, it provides soft contact feeling to the skin of a wearer. Especially, since the individual continuous filaments extend over the entire length of the surface member to have no fiber end appearing on the surface, the surface is made so smooth.
Moreover, since a difference in hydrophilicity is provided between the upper layer and the lower layer in the surface member of the continuous filaments, liquid permeability of the surface member is improved and the rewet-preventing effect is enhanced.
Still moreover, the surface member having the layers of different hydrophilicities can be easily manufactured by continuously feeding the continuous filaments of different hydrophilicities and by partially fixing them.

BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be understood more fully from the detailed description given hereinafter and from the accompanying drawings of the preferred embodiment of the present invention, which, however, should not be taken to be limitative to the invention, but are for explanation and understanding only.
In the drawings:
Fig. 1 is a perspective view showing an absorbent article according one embodiment of the present invention;
Fig. 2 is a partial plan view of a surface member of the absorbent article shown in Fig. 1;
Fig. 3A is a partial section showing a condition where continuous filaments of an upper layer is stacked on continuous filaments of a lower layer;
Fig. 3B is a partial section showing a condition where stacked continuous filaments are partially fusion bonded for forming the surface member;
Fig. 4 is a partial section showing a surface member according to another embodiment of the present invention; and Fig. 5 is a partial section showing the absorbent article and the surface member.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention will be discussed hereinafter in detail in terms of the preferred embodiment of the present invention with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be obvious, however, to those skilled in the art that the present invention may be practiced without these specific details. In other instance, well-known structure are not shown in detail in order to avoid unnecessary obscurity of the present invention.
Fig. 1 is a perspective view showing an absorbent article according to one embodiment of the present invention, Fig. 2 is a partial plan view of a surface member of the absorbent article shown in Fig. 1, Fig. 3A is a partial section showing a condition where continuous filaments of an upper layer is stacked on continuous filaments of a lower layer, Fig. 3B is a partial section showing a condition where stacked continuous filaments are partially fusion bonded for forming the surface member, Fig. 4 is a partial section showing a surface member according to another embodiment of the present invention, and Fig. 5 is a partial section showing the absorbent article and the surface member.
An absorbent article 1 shown in Fig. 1 is a sanitary napkin, in which a width direction is defined as X direction and a longitudinal direction is defined as Y direction. The absorbent article 1 has an intermediate portion 2, and front _ _9_ and rear portions 3 and 4 lying opposite one another in the longitudinal direction and having the intermediate portion 2 located therebetween. At two lateral sides of a main body of the absorbent article 1, side leakage preventing walls 5 and 5 extending in the longitudinal direction (Y direction) are provided. To the leakage preventing walls 5 and 5, elastic members for exhibiting elastic contracting force in the longitudinal direction are provided. By the elastic contracting force, the main body of the absorbent article 1 is curved in the longitudinal direction, and the leakage preventing walls 5 and 5 are three-dimensionally raised from the liquid-receiving face of the main body, mainly at the intermediate portion 2.
As shown in the section of Fig. 5, the main body of the absorbent article 1 is constructed to include a liquid impermeable backing sheet 7, an absorbent core (absorbent layer) 8 stacked on the backing sheet 7, and a liquid permeable surface member 10 stacked over the absorbent core 8. The surface member 10 is formed of at least two kinds of continuous filaments having different hydrophilicities.
The absorbent core 8 is provided from the intermediate portion 2 to part of the front and rear portions 3 and 4. The surface member 10 is provided between the leakage preventing walls 5 and 5 to extend over the entire length of the main body of the absorbent article 1 (i.e., from end edge of the front _ 10' portion 3, through the intermediate portion 2, to the end edge of the rear portion 4). Each leakage preventing wall 5 is formed of a sheet such as non-woven fabric, which is joined to the surface member 10 at a position inside of the leakage preventing wall 5, and is extended outwardly of the leakage preventing wall 5 and joined to the backing sheet 7 with a hot melt adhesive or the like, at a flap portion 6 outside of the leakage preventing wall 5.
In the embodiment shown, the surface member 10 is provided over the entire length of the main body of the absorbent article 1, but should not be limited thereto. For example, the surface member 10 may be provided only at the intermediate portion 2, especially only at the center portion of the liquid-absorbing region where the absorbent core 8 is present.
The backing sheet 7 is impermeable to liquid, and is formed of a moisture permeable (breathable) resin film, a non-woven fabric or a laminate of a resin film and a non-woven fabric. The absorbent core 8 is formed of a mixture of crushed pulp and SAP (superabsorbent polymer) wrapped in liquid permeable paper, air laid pulp formed into a sheet form by binder process, absorbent paper, a non-woven fabric primarily consisted of hydrophilic fibers, or the like.
The aforementioned sheet forming the leakage preventing wall 5 (also forming the flap port~.on 6 together with the backing sheet 7 ) may be formed of a non-woven fabric, such as through-air .. -11' bonded non-woven fabric, point bonded non-woven fabric, spun bonded non-woven fabric, spun laced non-woven fabric, melt blown non-woven fabric or air laid non-woven fabric, which is preferably hydrophobic or water repellent.
As shown in Fig. 3B, the surface member 10 is formed with an upper layer 10a appearing on a liquid-receiving side surface, and a lower layer lOb positioned adjacent to the absorbent core 8. The upper layer 10a and the lower layer lOb are formed of first continuous filaments lla and second continuousfilaments 11b, respectively. These individual continuous filaments lla and llb extend in the Y direction without any interruption.
In other words, the individual continuous filaments 11a and llb extend over the entire length of the surface member 10.
Here, the continuous filaments lla and llb are crimped.
As described in detail hereinafter, the upper layer 10a is formed of a filament bundle (generally called as "tow"), in which the crimped continuous filaments lla are bundled.
Similarly, the lower layer lOb is also formed of a filament bundle (generally called as "tow"), in which the crimped continuous filaments llb are bundled. These filament bundles (i.e., tows) are opened, spread into a predetermined width, and joined to each other to form the surface member 10. These continuous filaments lla and llb are occasionally referred to as tow filaments.
The continuous filaments lla and llb are made of heat-fusible, hydrophobic synthetic resin. For example, the continuous filaments lla and llb may be mono-fibers, such as those of PE (polyethylene), PP (polypropylene), PET
(polyethylene terephthalate)or the like, conjugatedsynthetic fibers of core-sheath structure, such as those of PE/PET, PE/PP
or the like, or conjugated synthetic fibers of side-by-side structure, such as those of PE/PET, PE/PP or the like. The continuous filaments lla and llb preferably contain inorganic filler for whitening, such as titanium oxide or the like, in the content of 0.5 to 10% by weight. By whitening process, the menstrual blood absorbed in the absorbent core 8 can be easily concealed from external view. The individual continuous filaments may have a circular or modified cross-section.
Crimping is provided for continuous filaments upon production by means of crimper, and number of crimp is increased by pre-heating calender or hot air treatment. In the alternative, through pre-heating calender, drawing and relaxing are repeated to cause strain in orientation of resin forming continuous filaments to cause crimp in coil form.
Opening of a bundle of crimped continuous filaments can be performed as following. While the bundle is transported between transporting rolls, tension force is applied in the direction along which the filaments extend, and then the tens ion force is released. These processes are repeated to separate individual continuous filaments from each other for opening.

In the alternative, it is also possible to perform opening of the bundle by urging sliding plates onto the bundle from opposite sides. In thismethod, the bundle transported between transporting rolls is slidingly contacted with the sliding plates, and individual filaments are separated from each other by sliding contact force for opening. The latter method employing the sliding plates has been disclosed in commonly owned co-pending U. S. Patent Application for "METHOD AND
APPARATUS FOR OPENING CONTINUOUS FILAMENTS" (claiming priority based on Japanese Patent Application No. 2000-265458). The disclosure of the above-identified commonly owned co-pending U. S. Patent Application is herein incorporated by reference.
The bundle of continuous filaments thus opened has a small filament density and a large apparent width.
Furthermore, the opened filament bundle is spread (widened) in the width direction to have a uniform bulkiness and to have a width substantially matching with the width of the surface member 10 shown in Fig. 1.
As described above, the bundle of the continuous filaments lla for forming the upper layer 10a and the bundle of the continuous filaments llb for forming the lower layer lOb are opened and spread, respectively, and then stacked as shown in Fig. 3A. The upper layer 10a and the lower layer lOb thus stacked are clamped by weldi-ng rolls, at least one of which contains a pattern of protrusions for embossing on the peripheral surface, for forming fixing lines 12. At respective fixing lines 12, the continuous filaments lla of the upper layer 10a and the continuous filaments llb of the lower layer lOb are heat fused or welded by induction heating with ultrasonic wave to thereby form the layers 10a and lOb into a sheet.
In the embodiment shown in Figs. 1 and 2, the individual fixing lines 12 extend across the surface member 10 in the X
direction in the form of continuous line approximated to trigonometric curve. In the Y direction along which the individual continuous filaments lla and llb extend, the fixing lines 12 are spaced apart from each other by a given pitch P.
The pitch P of the fixing lines 12 is in a range of 20 to 50 mm. However, fixing lines should not be limited to the shown wavy shape but may extend in various forms, for example, in the form of straight line or V-shaped line. It is also possible to provide a plurality of short fixing lines intermittently arranged at a given interval in the X direction, so long as consideration is given to prevention of falling out of filaments.
Various alternation of the short fixing line patterns are disclosed in commonly owned co-pending U. S. patent application, for "ABSORBENT ARTICLE EMPLOYING SURFACE LAYER WITH CONTINUOUS
FILAMENT AND MANUFACTURING PROCESS THEREOF" (claiming priority based on Japanese Patent Application No. 2000-265467). The disclosure of the above-identified commonly owned co-pending U. S. patent application will be herein incorporated by reference. Of course, it is possible to replace the short fixing lines with circular dot-shaped fixing portions or the like.
The surface member 10, which consists of the upper layer 10a and the lower layer 10b, has a total basis weight in a range of 5 to 100 g/m~, and preferably in a range of 10 to 60 g/m2.
The upper layer 10a and the lower layer lOb preferably have the same basis weight, but may have different basis weights.
Here, the filament weight ratio of the upper layer 10a to the lower layer lOb is in a range of 5:95 to 95:5, and preferably in a range of 30:70 to 70:30. In the surface member 10, in which the upper layer 10a and the lower layer lOb are combined, the average filament density is in a range 0.002 to 0.01 g/cm'.
The individual continuous filaments lla and llb of the respective upper and lower layers 10a and lOb have a fineness in a range of 1.1 to 20 dtex, and preferably in a range of 1.1 to 11 dtex.
In the individual continuous filaments lla and 11b, number of crimp is in a range of 5 to 30 per inch, and preferably in a range of 15 to 30, and crimp modulus of elasticity is preferably greater than or equal to 70%.
Number of crimp is based on JIS L-1015 and crimp modulus of elasticity is based on JIS L-1074. In case of the filament of a fineness less than 5.5 dte~, an initial load of 0.49 mN
is applied in pulling direction, and in case of the filament of a fineness greater than or equal to 5.5 dtex, an initial load of 0.98 mN is applied in pulling direction. Number of crimp referred to is number of threads ( peaks ) per 1 inch ( 25 mm) when the initial load is applied.
On the other hand, the crimp modulus of elasticity is expressed by:
~(b - c)/(b - a)} x 100 (%) wherein a is a length of filament when the initial load is applied, b is a length when the crimp is stretched by applying a tension force of 4.9 mN per 1.1 dtex for 30 seconds, and c is a length as applied the initial load again after 2 minutes from releasing the tension force.
In the surface member 10, the continuous filaments lla of the upper layer 10a and the continuous filaments llb of the lower layer lOb have different hydrophilicities with each other, such that the lower layer lOb has a higher hydrophilicity than that of the upper layer 10a. In addition, the upper layer 10a and the lower layer lOb have different filament densities with each other, such that lower layer lOb has a higher filament density than that of the upper layer 10a. However, the upper layer 10a may have a higher filament density than that of the lower layer 10b, if desired.
Here, a difference in hydrophilicity represents a difference in interfacial chemical nature on the filament surface, and hydrophilicity becomes higher at lower contact angle of water, in case of hydrophobic filament.
As set forth, the continuous filaments lla of the upper layer 10a and the continuous filaments llb of the lower layer lOb are hydrophobic filaments, such as core-sheath type conjugated fiber of PE/PP or PE/PET. In the case where these hydrophobic continuous filaments lla and llb are both treated to be hydrophilic by applying a hydrophilic oil solution onto the surfaces of the continuous filaments, a difference in hydrophilicity can be provided by using hydrophilic oil solutions having different durabilities against liquid.
For example, onto the continuous filaments lla of the upper layer 10a, applied is an initial hydrophilic oil solution, namely a hydrophilic oil solution which can relatively easily drop off as contacting with water or other liquid. This kind of initial hydrophilic oil solution may be PEG modified polyester, polyoxyethylene alkyl sulfate, alkyl phosphoric ester K salt, polyoxyethylene alkyl ester, alkylsulfonate Na salt and so forth. On the other hand, onto the continuous filaments llb of the lower layer 10b, applied is a durable hydrophilic oil solution which is difficult to drop off by water or other liquid in comparison with the initial hydrophilic oil solution. The durable hydrophilic oil solution may be polyether ester, ether nonion, polyether modified silicon, sulfo succinate, polyoxyethylene amide ether, alkyl imidazoline type cation, polyglycerol polyester and so forth.
With the hydrophilic oil solutions being thus selected to make the durability of hydrophilic oil solution against liquid higher in the lower layer lOb than in the upper layer 10a, the lower layer lOb is permitted to have a higher hydrophilicity than that of the upper layer 10a.
In an alternative, a difference in hydrophilicity may be provided by applying the same hydrophilic oil solution onto both the continuous filaments lla and llb of the upper and lower layers 10a and 10b, such that an application amount of hydrophilic oil solution per unit fineness (1 dtex) of continuous filaments is greater in the lower layer lOb than in the upper layer 10a.
In another alternative, a difference in hydrophilicity may also be provided such that only the hydrophobic continuous filaments llb of the lower layer lOb are treated to be hydrophilic by applying a hydrophilic oil solution onto the filaments or by kneading a hydrophilic oil solution into the filaments, while the hydrophobic continuous filaments lla of the upper layer 10a are not processed by the hydrophilic treatment.
Moreover, it is also possible to provide a difference in hydrophilicity by utilizing hydrophilic fibers.
Hydrophilic fibers can draw moisture by hydrophilic group on the surface thereof. Here, examples of the hydrophilic fibers include hydrophilic continuous filaments, such as those of cellulose acetate, and hydrophilic short fibers, such as natural cellulose fibers. The hydrophilic continuous filaments, such as those of cellulose acetate, may be mixed with the hydrophobic continuous filaments llb to form the lower layer 10b, while the upper layer 10a being formed only of the hydrophobic continuous filaments 11a. Alternatively, the hydrophilic continuous filaments may be mixed with the hydrophobic continuous filaments lla and 11b, respectively, to form the upper layer 10a and lower layer 10b, in which a content of the hydrophilic continuous filaments is higher in the lower layer 10b. Of course, it is possible to prepare the lower layer lOb only of the hydrophilic continuous filaments, if desired. On the other hand, the hydrophilic short fibers, such as natural cellulose fibers, may be bonded to the hydrophobic continuous filaments llb of the lower layer lOb with an adhesive or the like, for enhancing hydrophilicity of the lower layer 10b.
Next, a difference in density can be adjusted by varying the fineness of the continuous filaments. For example, by making the fineness of the continuous filaments llb of the lower layer lOb smaller that of the continuous filaments lla of the upper layer 10a, the density of trhe lower layer lOb can be made higher than the density of the upper layer 10a.

Alternatively, a difference in density may also be provided between the upper and lower layers 10a and lOb by varying number of crimp of the continuous filaments and/or by varying crimp modulus of elasticity. For example, by providing greater number of crimp for the continuous filaments llb of the lower layer lOb than that of the continuous filaments lla of the upper layer 10a, the density of the lower layer lOb can be made higher. On the other hand, by making the crimp modulus of elasticity of the continuous filaments llb of the lower layer lOb higher than the crimp modulus of elasticity of the continuous filaments lla of upper layer 10a, the density of the lower layer lOb can be made lower.
Here, it is preferred to provide a difference in number of crimp greater than or equal to 10 per inch between the upper layer 10a and the lower layer 10b, and it is also preferred to provide a difference in crimp modulus of elasticity in the extent greater than or equal to 10% between the upper layer 10a and the lower layer 10b. Also, a difference in density between the upper layer 10a and the lower layer lOb is preferably in the extent greater than or equal to 0.003 g/cm3.
On the other hand, as shown in Fig. 4, the surface member 10 may further comprise a liquid permeable non-woven fabric sheet 15 formed of hydrophilic fibers. In this construction, the continuous filaments llb o~ the lower layer lOb and the continuous filaments lla of the upper layer 10a are stacked on the non-woven fabric sheet 15, and the non-woven fabric sheet 15, the lower layer lOb and the upper layer 10a are fixed together at the fixing lines 12.
Also, it is possible to provide one or more intermediate layers of continuous filaments between the upper layer 10a and the lower layer 10b. In other words, the surface member 10 may be formed with three or more layers of mutually different continuous filaments. In this case, it is preferred to gradually increase hydrophilicity toward the lower layer.
In the absorbent article 1 as has been described above, the surface member 10 as a portion to contact the skin of a wearer, is formed of the continuous filaments. Therefore, no fiber end appears on the surface to thereby provide smooth contact feeling to theskin. Furthermore, since the continuous filaments can move independently to follow movement of the skin, the surface member 10 becomes less irritative to the skin. Also, the surface member 10 is so bulky as to provide superior cushioning characteristics.
Furthermore, in the surface member 10 composed of the upper layer 10a and the lower layer 10b, the lower layer lOb has a higher hydrophilicity. Therefore, the liquid applied on the surface of the surface member 10 is drawn to the lower layer 10b and thus supplied to the absorbent core 8. This results in reducing an amount of residual liquid in the upper layer 10a. If the density of the lower layer lOb is made higher than that of the upper layer 10a, the body fluid can be drawn to the lower layer lOb by capillary effect. In this case, too, an amount of residual liquid in the upper layer 10a can be reduced. Furthermore, since the upper layer 10a serves for preventing the liquid from flowing back from the absorbent core 8, the liquid absorbed in the absorbent core 8 hardly flows back toward the skin of a wearer ( i. e. , rewet hardly occurs ) .
If the density of the upper layer 10a is made higher than the density of the lower layer 10b, on the other hand, rewet-preventing property can be enhanced by the high density of the continuous filaments lla of the upper layer 10a.
On the other hand, since the individual continuous filaments lla and llb extend in the longitudinal direction (Y
direction) of the absorbent article 1, the liquid applied to the surface member 10 is easily guided in the longitudinal direction to thereby reduce or eliminate side leakage in the width direction (X direction). Furthermore, since the continuous filaments lla and llb are fixed at the fixing lines 12 spaced apart from each other by the given pitch P in the longitudinal direction, spreading or propagation of the liquid in the longitudinal direction in the surface member 10 can be restricted. Thus, the liquid can be easily guided to the absorbent core 8.
Since the upper layer 10a and the lower layer lOb having different hydrophilicities and densities can be formed by simply stacking and fixing opened tows of continuous filaments, manufacturing process becomes quite simple. Furthermore, since no adhesive is disposed between the upper and lower layers 10a and lOb for fixing them at the fixing lines 12, migration of liquid toward the absorbent core may not be interfered by adhesive.
As set forth above, in the present invention, the surface member of the absorbent article may have good liquid permeability with prevention of flowing back of the liquid.
Moreover, the surface member may provide soft contact feeling on the skin of a wearer and superior cushioning characteristics .
Still moreover, the surface member having a difference in hydrophilicity can be easily manufactured with simple process of stacking two opened bundles of continuous filaments.
Although the present invention has been illustrated and described with respect to exemplary embodiment thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omission and additions may be made therein and thereto, without departing from the spirit and scope of the present invention. Therefore, the present invention should not be understood as limited to the specific embodiment set out above but to include all possible embodiments which can be embodied within a scope encompassed and equivalent thereof with respect to the feature set out in the appended claims.

For instance, while the surface member is formed over entire surface of at least the central portion of the absorbent article, it is also possible to form the surface member into a plurality of strips arranged in parallel in spaced apart relationship. Such construction has been disclosed in commonly owned co-pending U. S. Patent Application, for "ABSORBENT ARTICLE HAVING FIBROUS LAYER ON SURFACE" (claiming priority based on Japanese Patent Application No.2000-265476).
The disclosure of the above-identified commonly owned co-pending U. S. Patent Application is herein incorporated by reference.
J

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An absorbent article comprising:
a liquid permeable surface member;
a backing sheet; and an absorbent layer interposed between said surface member and said backing sheet, said surface member having at least two layers including an upper layer located at a liquid-receiving side surface and a lower layer located adjacent to said absorbent layer, said upper layer being formed of first continuous filaments, said lower layer being formed of second continuous filaments, said first and second continuous filaments individually extending over an entire length of said surface member, wherein said first continuous filaments are prepared by applying at least one compound selected from the group consisting of PEG modified polyester, polyoxyethylene alkyl sulfate, alkyl phosphoric ester K salt, polyoxyethylene alkyl ester, and alkylsulfonate Na salt on surfaces of hydrophobic filaments, and said second continuous filaments are prepared by applying at least one compound selected from the group consisting of polyether ester, ether nonion, polyether modified silicon, sulfo succinate, polyoxyethylene amide ether, alkyl imidazoline type cation, and polyglycerol polyester on surfaces of hydrophobic filaments so that a hydrophilicity of said lower layer is higher than a hydrophilicity of said upper layer.
CA002355525A 2000-09-01 2001-08-22 Absorbent article with surface member of continuous filaments Expired - Fee Related CA2355525C (en)

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JP2000265496A JP3875009B2 (en) 2000-09-01 2000-09-01 Absorbent articles using continuous filament surface material
JP2000-265496 2000-09-01

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CA2355525A1 CA2355525A1 (en) 2002-03-01
CA2355525C true CA2355525C (en) 2006-05-09

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EP (1) EP1184020B1 (en)
JP (1) JP3875009B2 (en)
KR (1) KR100796225B1 (en)
CN (1) CN1222264C (en)
AT (1) ATE481071T1 (en)
BR (1) BR0103837B1 (en)
CA (1) CA2355525C (en)
DE (1) DE60143068D1 (en)
MY (1) MY127547A (en)
SG (1) SG101459A1 (en)
TW (1) TW565439B (en)

Families Citing this family (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1292729B1 (en) * 2000-04-18 2004-07-14 Lohmann GmbH & Co. KG Non woven textile structure incorporating stabilized filament assemblies
JP3875008B2 (en) * 2000-09-01 2007-01-31 ユニ・チャーム株式会社 Method for producing absorbent article having fiber layer on surface
EP1632207B1 (en) * 2001-07-26 2012-08-29 The Procter & Gamble Company Absorbent articles with elastic topsheets
AR034469A1 (en) * 2002-06-11 2004-02-25 Freudenberg S A A TRANSFER LAYER OF LIQUID FLUIDS AND ABSORBENT ARTICLE THAT INCLUDES IT.
JP3878085B2 (en) * 2002-08-09 2007-02-07 ユニ・チャーム株式会社 Disposable body fluid absorbent article
EP1417945B1 (en) * 2002-11-08 2008-12-31 The Procter & Gamble Company Disposable absorbent articles with masking topsheet
DE60209613T2 (en) * 2002-11-08 2006-10-05 The Procter & Gamble Company, Cincinnati Absorbent disposable with improved upper layer
JP4140835B2 (en) * 2003-09-19 2008-08-27 大王製紙株式会社 Absorbent articles
JP4282428B2 (en) * 2003-09-30 2009-06-24 花王株式会社 Composite sheet
ATE473718T1 (en) * 2003-10-02 2010-07-15 Procter & Gamble ABSORBENT ARTICLE WITH ELASTOMERIC MATERIAL
US20050215965A1 (en) * 2004-03-29 2005-09-29 The Procter & Gamble Company Hydrophilic nonwovens with low retention capacity comprising cross-linked hydrophilic polymers
KR101148537B1 (en) * 2004-04-15 2012-05-23 가오 가부시키가이샤 Topsheet for absorbent article
JP4566051B2 (en) * 2004-04-15 2010-10-20 花王株式会社 Absorbent article surface sheet
JP4593986B2 (en) * 2004-06-30 2010-12-08 大王製紙株式会社 Absorber
JP4518906B2 (en) * 2004-10-20 2010-08-04 花王株式会社 Top sheet for absorbent articles
ATE472308T1 (en) * 2004-12-29 2010-07-15 Sca Hygiene Prod Ab ABSORBENT ARTICLE WITH IMPROVED PROPERTIES FOR HANDLING LOW VISCOSE FECAL MATERIAL
US20080167634A1 (en) * 2005-03-23 2008-07-10 Takuya Kouta Absorbent Article
CN101378714A (en) * 2006-02-01 2009-03-04 宝洁公司 Absorbent article with urine-permeable coversheet
JP5133639B2 (en) * 2007-09-21 2013-01-30 大王製紙株式会社 Absorbent articles
JP5421720B2 (en) * 2009-10-09 2014-02-19 ユニ・チャーム株式会社 Non-woven
WO2012043546A1 (en) * 2010-09-28 2012-04-05 住友精化株式会社 Water absorbent sheet structure
DE102011018985A1 (en) 2011-04-28 2012-10-31 Evonik Industries Ag Elastic, absorbent hygiene product for absorption of body fluids
JP6005019B2 (en) * 2013-09-30 2016-10-12 大王製紙株式会社 Absorbent articles
CN104873335A (en) * 2014-02-27 2015-09-02 金红叶纸业集团有限公司 Absorption product and surface layer thereof
BR112018003750A2 (en) * 2015-08-24 2018-09-25 Kao Corporation non-woven fabric and absorbent article supplied with it.
ES2746375T3 (en) 2016-08-02 2020-03-05 Fitesa Germany Gmbh System and process for the preparation of polylactic acid nonwoven fabrics
US11441251B2 (en) 2016-08-16 2022-09-13 Fitesa Germany Gmbh Nonwoven fabrics comprising polylactic acid having improved strength and toughness
WO2018129701A1 (en) * 2017-01-13 2018-07-19 The Procter & Gamble Company Nonwoven and absorbent articles having same
CN110573668B (en) * 2017-03-15 2020-10-02 花王株式会社 Laminated nonwoven fabric, method for producing same, absorbent article, and sweat-absorbing sheet

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3949130A (en) * 1974-01-04 1976-04-06 Tuff Spun Products, Inc. Spun bonded fabric, and articles made therefrom
JPS56141612A (en) 1980-04-07 1981-11-05 Hitachi Ltd Elastic surface wave equipment
JPS5713609A (en) 1980-06-28 1982-01-23 Toshiba Electric Equip Illuminator
JPH05176954A (en) 1991-09-04 1993-07-20 Oji Paper Co Ltd Surface material of sanitary material, such as disposable diaper
US5997989A (en) * 1992-02-03 1999-12-07 Bba Nonwovens Simpsonville, Inc. Elastic nonwoven webs and method of making same
CA2107170A1 (en) * 1993-05-20 1994-11-21 Kimberly-Clark Worldwide, Inc. Lightweight nonwoven web laminates with improved comfort and barrier properties
US5500270A (en) 1994-03-14 1996-03-19 The Procter & Gamble Company Capillary laminate material
CA2199535A1 (en) * 1994-09-09 1996-03-14 Bernard Cohen Z-direction liquid transport medium
JP3012475B2 (en) * 1995-01-26 2000-02-21 ユニ・チャーム株式会社 Liquid permeable composite nonwoven fabric for body fluid absorbent articles
US5752945A (en) * 1997-04-25 1998-05-19 Fibertech Group, Inc. Absorbent article with liquid transfer layer
SE516777C2 (en) * 1997-12-03 2002-02-26 Sca Hygiene Prod Ab Absorbent articles with layers of continuous fibers
SE514391C2 (en) * 1997-12-03 2001-02-19 Sca Hygiene Prod Ab Absorbent articles
EP0953323A1 (en) * 1998-05-02 1999-11-03 The Procter & Gamble Company Disposable absorbent article having an improved topsheet
SE516036C2 (en) * 2000-03-27 2001-11-12 Sca Hygiene Prod Ab Fiber-based material layer comprising at least two continuous fibers webs, so-called tow, method of making it, and absorbent articles containing the layer
US6488670B1 (en) * 2000-10-27 2002-12-03 Kimberly-Clark Worldwide, Inc. Corrugated absorbent system for hygienic products

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BR0103837B1 (en) 2009-08-11
CN1222264C (en) 2005-10-12
ATE481071T1 (en) 2010-10-15
JP3875009B2 (en) 2007-01-31
SG101459A1 (en) 2004-01-30
EP1184020A3 (en) 2004-09-08
EP1184020A2 (en) 2002-03-06
JP2002065738A (en) 2002-03-05
US6646178B2 (en) 2003-11-11
EP1184020B1 (en) 2010-09-15
DE60143068D1 (en) 2010-10-28
KR100796225B1 (en) 2008-01-21
KR20020018599A (en) 2002-03-08
US20020029024A1 (en) 2002-03-07
BR0103837A (en) 2002-05-07
MY127547A (en) 2006-12-29
CN1349787A (en) 2002-05-22
TW565439B (en) 2003-12-11
CA2355525A1 (en) 2002-03-01

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