AU740658B2 - Stabilized absorbent material for personal care products and method for making - Google Patents

Description

WO 99/56687 PCT/US99/09404 STABILIZED ABSORBENT MATERIAL FOR PERSONAL CARE PRODUCTS AND METHOD FOR MAKING FIELD OF THE INVENTION The present invention relates to a material structure in an absorbent article for personal care products like diapers, training pants, absorbent underpants, adult incontinence products, bandages and feminine hygiene products.

BACKGROUND OF THE INVENTION Personal care absorbent articles include such items as diapers, training pants, feminine hygiene products such as sanitary napkins, panty-liners and tampons, incontinence is garments and devices, bandages and the like. The most basic design of all such articles typically includes a bodyside liner, an outercover and an absorbent core disposed between the bodyside liner and the outercover. Generally, the bodyside liner and the outercover are sealed about the periphery so as to encapsulate the absorbent core and thus make it possible to entrap and retain any fluids contained within the absorbent core. Depending upon the design of the particular personal care absorbent article, other components also may be included. Thus, the product may include such things as elastic side panels, fluid containment flaps, fastening devices and other layers of fluid transfer or retention materials.

Previous personal care products have been constructed of materials made separately and then joined together to produce a laminate. In such cases, the boundary between adjacent layers is relatively crisp, often marked by the presence of an adhesive which is used to hold the layers together to produce the laminate. The separate production of each layer and the adhesive joining together to form the laminate is an expensive procedure requiring many different pieces of production equipment. This method of production results in a material for personal care products having crisp definition between each layer at the interface or boundary which may result in decreased fluid transfer between adjacent layers.

2 It is an object of this invention, therefore, to produce a material for use in personal care products which does not require the multiple of production steps to make. It is a further object of this invention to produce a material for personal care products in which adjacent fibrous layers have indistinct boundaries, with intermingled and entangled fibers, so as to improve fluid transfer between adjacent layers.

Summary of the Invention According to a first aspect, the present invention consists in a material for personal care products comprising: a body side layer having a basis weight of from about 10 to about 100 gsm, a o density of from about 0.05 to about 0.5 g/cc and comprising synthetic fibers and binder in a ratio of from about 90/10 to about 0/100; a fluid retention layer having a basis weight of from about 50 to about 250 Igsrn, a density of from about 0.05 to about 0.5 g/cc and comprising synthetic fibers and natural fibers in a ratio of from about 0/100 to about 50/50 and binder in an effective 1 5 amount; wherein a boundary between any two adjacent fibrous layers is indistinct in that fibers at or near the surfaces of such adjacent layers are significantly intermingled.

According to a second aspect, the present invention consists in a material for personal care products comprising sequentially: a body side layer having a basis weight of from about 10 to about 100 gsm, a density of from about 0.05 to about 0.5 g/cc and comprising synthetic fibers and binder fibers in a ratio of from about 50/50 to about 20/80; a fluid transfer layer having a basis weight of from about 10 to about 100 gsmn, a density of from about 0.05 to about 0.5 g/cc and comprising synthetic fibers and natural fibers in a ratio of from about 40/60 to about 10/90 and binder in an effective amount; a fluid retention layer having a basis weight of from about 50 to about 250 gsm, a density of from about 0.05 to about 0.5 g/cc and comprising synthetic fibers and natural fibers in a ratio of from about 10/90 and 20/80 and binder in an effective amount; a garment side liner layer adjacent said fluid retention layer on a side away from said body side layer, selected from the group consisting of films and a fibrous layer having a basis weight of from about 10 to about 100 gsm and comprising synthetic fibers and binder fibers in a ratio of from about 50/50 to about 0/100; R:\LI3BIFF]O4256.doc:mrnrr 2a wherein a boundary between any two adjacent fibrous layers is indistinct in that fibers at or near the surfaces of such adjacent layers are significantly intermingled and wherein said product is embossed with a pattern selected from the group consisting of sine waves and shells.

According to a third aspect, the present invention consists in a personal care product selected from the group consisting of diapers, training pants, absorbent underpants, adult incontinence products, bandages and feminine hygiene products comprising the material of the second aspect.

I According to a fourth aspect, the present invention consists in a material for personal care products comprising sequentially: a body side layer having a basis weight of from about 10 to about 100 gsm, a density of from about 0.05 to about 0.05 g/cc and comprising synthetic fibers and binder fibers in a ratio of about 30/70; a fluid transfer layer having a basis weight of from about 10 to about 100 gsm, a density of from about 0.05 to about 0.5 g/cc and comprising synthetic fibers and natural fibers in a ratio of from about 40/60 to about 10/90 and binder in an effective amount; a first fluid retention layer having a basis weight of from about 50 to about •ooo• 20 250 gsm, a density of from about 0.05 to about 0.5 g/cc and comprising synthetic fibers and natural fibers in a ratio of about 4/60 and binder in an effective amount; S. a second fluid retention layer comprising natural fiber, superabsorbent fiber, and binder in an effective amount; a garment side liner layer selected from the group consisting of films and a 25 fibrous layer having a basis weight of from about 10 to about 100 gsm and comprising synthetic fibers and binder fibers in a ratio of from about 50/50 to about 0/100; wherein a boundary between any two adjacent fibrous layers is indistinct in that fibers at or near the surfaces of such adjacent layers are significantly intermingled and wherein said product is embossed with a pattern selected from the group consisting of sine waves and shells.

I R:AI I FFj]04256.doc:mrr 2b The invention provides a material for personal care products having a body side layer with a basis weight of from about 10 to about 100 gsm, a density of from about 0.05 to about 0.5 g/cc and comprising synthetic fibers and/or binder, and a fluid retention layer having a basis weight of from about 50 to about 250 gsm, a density of from about 0.05 to about 0.5 g/cc and comprising synthetic fibers, binder and/or natural fibers, where a boundary between any two adjacent fibrous layers is indistinct in that fibers at or near the surfaces of such adjacent layers are significantly intermingled.

The material may optionally include a fluid distribution layer and a fluid transfer layer and a garment side liner. Other optional components include superabsorbents and o0 odor control compounds and the layers may be embossed for aesthetic and fluid control reasons.

Brief Description of the Drawings Figure 1 shows an embossing pattern for a personal care product which is a sine wave pattern.

s 5 Figure 2 shows an embossing pattern for a personal care product which is a shell e: pattern.

J: Definitions "Disposable" includes being disposed of after use and not intended to be washed and reused.

2 "Front" and "back" are used throughout this description to designate relationships relative to the garment itself, rather than to suggest any position the garment assumes "when it is positioned on a wearer.

[R:\LIBFF]04256.doc:mrr WO 99/56687 PCT/US99/09404 "Hydrophilic" describes fibers or the surfaces of fibers which are wetted by the aqueous liquids in contact with the fibers. The degree of wetting of the materials can, in turn, be described in terms of the contact angles and the surface tensions of the liquids and materials involved. Equipment and techniques suitable for measuring the wettability s of particular fiber materials can be provided by a Cahn SFA-222 Surface Force Analyzer System, or a substantially equivalent system. When measured with this system, fibers having contact angles less than 900 are designated "wettable" or hydrophilic, while fibers having contact angles equal to or greater than to 900 are designated "nonwettable" or hydrophobic.

"Inward" and "outward" refer to positions relative to the center of an absorbent garment, and particularly transversely and/or longitudinally closer to or away from the longitudinal and transverse center of the absorbent garment.

"Layer" when used in the singular can have the dual meaning of a single element or a plurality of elements.

"Liquid" means a non-particulate substance and/or material that flows and can assume the interior shape of a container into which it is poured or placed.

"Liquid communication" means that liquid is able to travel from one layer to another layer, or one location to another within a layer.

"Longitudinal" and "transverse" have their customary meaning. The longitudinal axis lies in the plane of the article when laid flat and fully extended and is generally parallel to a vertical plane that bisects a standing wearer into left and right body halves when the article is worn. The transverse axis lies in the plane of the article generally perpendicular to the longitudinal axis. The article as illustrated is longer in the longitudinal direction than in the transverse direction.

"Particles", in the context of this invention, refers to any geometric form such as, but not limited to, spherical grains, fibers or strands, flat surfaces or roughened surfaces, sheets, ribbons, strings, strands, or the like.

"Spray" and variations thereof include forcefully ejecting liquid, either as a stream or, such as swirl filaments, or atomized particles through an orifice, nozzle, or the like, by means of an applied pressure of air or other gas, by force of gravity, or by centrifugal force. The spray can be continuous or non-continuous.

"Conjugate fibers" refers to fibers which have been formed from at least two polymers extruded from separate extruders but spun together to form one fiber. Conjugate fibers are also sometimes referred to as multicomponent or bicomponent fibers. The WO 99/56687 PCT/US99/09404 polymers are usually different from each other though conjugate fibers may be monocomponent fibers. The polymers are arranged in substantially constantly positioned distinct zones across the cross-section of the conjugate fibers and extend continuously along the length of the conjugate fibers. The configuration of such a conjugate fiber may be, s for example, a sheath/core arrangement wherein one polymer is surrounded by another or may be a side by side arrangement, a pie arrangement or an "islands-in-the-sea" arrangement. Conjugate fibers are taught in US Patent 5,108,820 to Kaneko et al., US Patent 5,336,552 to Strack et al., and US Patent 5,382,400 to Pike et al. For two component fibers, the polymers may be present in ratios of 75/25, 50/50, 25/75 or any other lo desired ratios. The fibers may also have shapes such as those described in US Patents 5,277,976 to Hogle et al., and 5,069,970 and 5,057,368 to Largman et al., hereby incorporated by reference in their entirety, which describe fibers with unconventional shapes.

"Biconstituent fibers" refers to fibers which have been formed from at least two polymers extruded from the same extruder as a blend. The term "blend" is defined below.

Biconstituent fibers do not have the various polymer components arranged in relatively constantly positioned distinct zones across the cross-sectional area of the fiber and the various polymers are usually not continuous along the entire length of the fiber, instead usually forming fibrils or protofibrils which start and end at random. Biconstituent fibers are sometimes also referred to as multiconstituent fibers. Fibers of this general type are discussed in, for example, US Patent 5,108,827 to Gessner. Bicomponent and biconstituent fibers are also discussed in the textbook Polymer Blends and Composites by John A.

Manson and Leslie H. Sperling, copyright 1976 by Plenum Press, a division of Plenum Publishing Corporation of New York, IBSN 0-306-30831-2, at pages 273 through 277.

"Airlaying" is a well known process by which a fibrous nonwoven layer can be formed. In the airlaying process, bundles of small fibers having typical lengths ranging from about 3 to about 19 millimeters (mm) are separated and entrained in an air supply and then deposited onto a forming screen, usually with the assistance of a vacuum supply. The randomly deposited fibers then are bonded to one another using, for example, hot air or a spray adhesive. Airlaying is discussed in, for example, US Patents 4,005,957, 4,388,056, 4,592,708, 4,598,441,4,674,996, 4,761,258, 4,764,325, 4,904,440, 4,908,175, and 5,004,579, German Patent DE3508344 Al, European Patent Application 85300626.0 and British Patent Application 2,191,793.

WO 99/56687 PCT/US99/09404 "Personal care product" means diapers, training pants, absorbent underpants, adult incontinence products, bandages and feminine hygiene products.

"Feminine hygiene products" means sanitary napkins or pads.

"Target area" refers to the area or position on a personal care product where an insult is normally delivered by a wearer.

TEST METHODS Material caliper (thickness) The caliper of a material is a measure of thickness and is measured at 0.05 psi with a Starret-type bulk tester, in units of millimeters.

Den.si The density of the materials is calculated by dividing the weight per unit area of a sample in grams per square meter (gsm) by the bulk of the sample in millimeters (mm) at 68.9 Pascals and multiplying the result by 0.001 to convert the value to grams per cubic centimeter (glcc). A total of three samples would be evaluated and averaged for the density values.

DETAILED DESCRIPTION OF THE INVENTION Personal care absorbent articles include such items as diapers, training pants, feminine hygiene products such as sanitary napkins, panty-liners and tampons, incontinence garments and devices, bandages and the like. The most basic design of all such articles typically includes a bodyside liner, an outercover and an absorbent core disposed between the bodyside liner and the outercover. Generally, the bodyside liner and the outercover are sealed about their peripheries so as to encapsulate the absorbent core and thus make it possible to entrap and retain any fluids contained within the absorbent core. Depending upon the design of the particular personal care absorbent article, other components also may be included. Thus, the product may include such things as elastic side panels, fluid containment flaps, fastening devices and other layers of fluid transfer or retention materials.

A discussion of materials for personal care products may be found in a co-assigned patent application, filed the same day as this application, under attorney docket number 13303.10. A discussion of methods of manufacturing the materials of case 13303.10 may be found in a co-assigned copending patent application, under attorney docket number 13817.

WO 99/56687 PCT/US99/09404 This invention is a material for use in personal care products, which has been made in such a way as to produce indistinct boundaries or interfaces between adjacent fibrous layers. Previous personal care products have been constructed of materials made separately and then joined together to produce a laminate. In such cases, the boundary between adjacent fibrous layers is relatively crisp and distinct, often marked by the presence of an adhesive which is used to hold the layers together to produce the laminate.

The material of this invention is preferably made according to an airlaying process in which fibers are suspended and transported in a gas stream, preferably air, and deposited onto a substrate to produce a layer. The material of this invention is made from a number of layers which are sequentially deposited. Such a sequential deposition of materials is possible with a multi-bank airlaying process. In this process, the fibrous layers are not made separately, individually stabilized, and brought together to produce a laminate, but are produced one on top of the other. While the entire material must, of course, be stabilized in some manner, the individual layers of the instant invention, need not be. Stabilization is achieved through the use of a binder, which, if thermally activated, obviously requires heat treatment of the material after fiber deposition.

The individual fibrous layers of the material of this invention have fibers which intermix and entangle with the fibers of the adjacent layer as a consequence of the airlaying process. This aspect of airlaying, and the usual absence of an adhesive between adjacent layers, results in a boundary or interface between adjacent layers which is not crisp and distinct but which is indistinct.

The production of a material through the multi-bank airlaying process is much more cost effective than producing separate layers and then joining them to produce a laminate, thus permitting the lowering of costs to the ultimate consumer.

The material of this invention has a body side layer, optionally a fluid transfer layer, a fluid retention layer and a garment side layer. The material may also have a distribution layer or other optional layers to provide specialized functions.

The body side layer is sometimes referred to as a bodyside liner or topsheet. In the thickness direction of the article, the liner material is the layer against the wearer's skin and so the first layer in contact with liquid or other exudate from the wearer. The liner further serves to isolate the wearer's skin from the liquids held in an absorbent structure and should be compliant, soft feeling and non-irritating.

WO 99/56687 PCT/US99/09404 The body side liner can have a basis weight, for example, ranging from about 10.0 grams per square meter (gsm) to about 100 gsm, and a density between about 0.05 grams per cubic centimeter (g/cc) and about 0.5 g/cc. The body side liner is comprised of synthetic fibers and binder in a ratio of from about 90/10 to about 0/100, more particularly s from about 50/50 to about 20/80 and still more particularly about 30/70. It should be noted that binder fibers, not liquid binder, are preferred, especially for those cases having more than 10 percent binder.

The body side liner can be surface treated with a selected amount of surfactant, such as about 0.28% Triton X-1 02 surfactant, or otherwise processed to impart the desired level of wettability and hydrophilicity. If a surfactant is used, it can be an internal additive or applied to the layer by any conventional means, such as spraying, brush coating and the like, prior to the deposition of the next layer.

The fluid retention layer used in this invention must absorb liquid from the adjacent body side layer in a controlled manner such that liquid may be stored away from contact with the body. Suitable retention materials for this application should have a basis weight of from about 50 to about 250 gsm, a density of from about 0.05 to about 0.5 g/cc. The retention material comprises binder, synthetic fibers and natural fibers. The binder must be present in an effective amount, generally between about 3 and 15 weight percent or more particularly about 10 weight percent. The synthetic and natural fibers, excluding the binder, may be present in a ratio of from about 0/100 to about 50/50, more particularly between about 10/90 and 20/80, and still more particularly about 40/60. While any of the layers of this invention may optionally contain a superabsorbent, the fluid retention layer is the most logical layer to contain such a component. This layer may contain 0 to 85 weight percent of superabsorbent, which should be included as natural fiber in the calculation of the ratio of materials present.

Any number of layers may be made according to this invention, though a particularly useful additional layer is a second retention layer. Such a second retention layer would be interposed between the first retention layer and the garment side liner and could contain binder in an effective amount, and exclusive of the binder, about 75 percent natural fibers and about 25 percent superabsorbent fibers. As noted above, superabsorbent should be considered a natural fiber in the calculation of the ratio of fibers in the layer, making the ratio of synthetic to natural fiber in this layer 0/100, exclusive of binder.

WO 99/56687 PCT/US99/09404 The garment side liner layer, also referred to as a backsheet or outer cover is the farthest layer from the wearer. The outer cover has traditionally been formed of a thin thermoplastic film, such as polyethylene film, which is substantially impermeable to liquid.

The outer cover functions to prevent body exudates contained in an absorbent structure from wetting or soiling the wearer's clothing, bedding, or other materials contacting the personal care product. While the outer cover may be, for example, a polyethylene film having an initial thickness of from about 0.5 mil (0.012 millimeter) to about 5.0 mil (0.12 millimeter), it is preferred that the outer cover be produced as an integral part of the material of this invention. In this case, it is preferred that the garment liner or outer cover lo have a basis weight of from about 10 to about 100 gsm, and comprise synthetic fibers and binder in a ratio of from about 50/50 to about 0/100.

The outer cover may be embossed and/or matte finished to provide a more aesthetically pleasing appearance. Other alternative constructions for outer cover include woven or nonwoven fibrous webs that have been constructed or treated to impart the desired level of liquid impermeability, or laminates formed of a woven or nonwoven fabric and thermoplastic film. The outer cover may optionally be composed of a vapor or gas permeable, microporous "breathable" material, that is permeable to vapors or gas yet substantially impermeable to liquid. Breathability can be imparted in polymer films by, for example, using fillers in the film polymer formulation, extruding the filler/polymer formulation into a film and then stretching the film sufficiently to create voids around the filler particles, thereby making the film breathable. Generally, the more filler used and the higher the degree of stretching, the greater the degree of breathability. Backings may also serve the function of a mating member for mechanical fasteners, in the case, for example, where a nonwoven fabric is the outer surface.

The optional fluid transfer layer, also referred to as a surge layer, is most typically interposed between and in intimate, liquid communicating contact with the bodyside liner and another layer such as a fluid distribution or retention layer. The fluid transfer or surge layer allows fluid movement through itself generally in the Z-direction, i.e. away from the body side and towards the garment side. The surge layer is generally subjacent the inner (unexposed) surface of bodyside liner. Its preferred that the surge have a density between about 0.05 g/cc to about 0.5 g/cc and a basis weight between about 10 and about 100 gsm. The surge layer may be a layer composed of synthetic fibers, binder, and natural fibers where the binder is present in an effective amount and, exclusive of the binder, the synthetic and natural fibers are present in a ratio of from about 40/60 to about 10/90.

WO 99/56687 PCT/US99/09404 An optional distribution layer may be interposed above (toward a wearer) the fluid retention layer and must be capable of moving fluid from the point of initial deposition to where storage is desired. The fluid distribution layer, therefore, in addition to allowing fluid movement through itself in the Z-direction, also moves fluid in the X and Y directions.

s Distribution must take place at an acceptable rate such that the target insult area, generally the crotch area, is ready for the next insult. The time between insults can range from just a few minutes to hours, generally depending on the age of the wearer and the personal care product in question. In order to achieve this transportation function, a distribution layer must have a high capillary tension value. Capillary tension in distribution materials is measured simply by the equilibrium vertical wicking of a 8.5 g/ saline solution and should be above 15 cm. The wicking test is performed by placing an end of the material vertically into the saline solution, waiting until the solution has reached equilibrium, and measuring the height it has reached. Materials from which the distribution layer may be made from synthetic and natural fibers, with a small amount of binder.

Synthetic fibers include those made from nylons, polyethylene terephthalate, rayon, polyolefins like polypropylene, Lyocel regenerated cellulose and any other suitable synthetic fibers known to those skilled in the art. Such synthetic fibers may include conjugate, biconstituent and homopolymer fibers of staple or other lengths and mixtures of such fibers with other types of fibers. Synthetic fibers may also include kosmotropes for product degradation as discussed below.

Natural fibers include cellulose, e.g. wood pulp, cotton etc. Pulps include standard soft-wood fluffing grade such as Kimberly-Clark Corporation's Coosa Mills CR-1654, high bulk additive formaldehyde free pulp (HBAFF) available from the Weyerhaeuser Corporation of Tacoma, WA, and is a which is a crosslinked southern softwood pulp fiber with enhanced wet modulus, and a chemically cross-linked pulp fiber such as Weyerhaeuser NHB416. HBAFF has a chemical treatment which sets in a curl and twist, in addition to imparting added dry and wet stiffness and resilience to the fiber. Another suitable pulp is Buckeye HP2 pulp and still another is IP Supersoft from International Paper Corporation. Suitable rayon fibers are 1.5 denier Merge 18453 fibers from Courtaulds Fibers Incorporated of Axis, Alabama.

Binders include fiber, liquid or other binder means which may be thermally activated. Exemplary binders include conjugate fibers of polyolefins and/or polyamides, and liquid adhesives. One suitable binder is a sheath core conjugate fiber available from WO 99/56687 PCT/US99/09404 Trevira Inc. (formerly Hoechst-Celanese), PO Box 4, Salisbury, NC 28145-0004 under the designation T-255, though many suitable binder fibers are known to those skilled in the art, and are made by many manufacturers such as Chisso and Hercules Inc. Another suitable binder fiber is from Danaklon a/s, located at Engdraget 22, KD-6800 Varde, s Denmark, and is 2 denier conjugate PE/PP sheath/core fibers cut into 6 mm lengths. A suitable liquid binder is Kymene® 557LX binder available from Hercules Inc. of Wilmington, DE.

Superabsorbents include AFA-94-21-5 from The Dow Chemical Company of Midland MI, Dow's AFA-130-53C, Stockhausen's W77553 or Stockhausen's Favor 870, io and Sanwet IM 1500 superabsorbent from Trevira Inc.

It is becoming of increasing concern to produce personal care products which are "flushable" or which may be disposed of in a conventional toilet, and which are safe for septic or municipal waste treatment systems. One method of increasing the biodegradability of personal care products is to produce products which will fall apart rapidly under the conditions present in such systems. There are a number of mechanisms to produce this result, though most are unsuitable or unreliable, resulting in product failure at inappropriate times or in inordinate time requirements before the product falls apart.

One mechanism which can be used to trigger water-degradability in an acceptable time frame is ion sensitivity, where the term "ion" is given its conventional meaning of an atom or molecularly bonded group of atoms, which has gained or lost one or more electrons and consequently has a negative or positive electrical charge. Certain polymers contain acid-based (R-COO-) components which are held together by hydrogen bonding. In a dry state, these polymers remain solid. In an aqueous solution which has a relatively high ion concentration, such as urine, the polymer still will remain relatively intact. However, when the same polymer is later exposed to larger quantities of water with reduced ion content, such as can be found in a toilet bowl, the ion concentration will decrease and the hydrogen bonding will begin to break apart. As this happens, the polymer, itself, will begin to break apart in the water. Materials having these characteristics are known as kosmotropes. See for example, U.S. Patent No. 4,419,403 to Varona which is incorporated herein by reference in its entirety.

In a conjugate fiber, for example, first component polymers that are stable in high ion concentration solution environments (for example, baby or adult urine and menses) could be sulfonated polyesters coded AQ29, AQ38, or AQ55, as supplied by the Eastman Chemical WO 99/56687 PCT/US99/09404 Company of Kingsport, Tennessee. The Eastman AQ38 polymer is composed of 89 mole percent isophthalic acid, 11 mole percent sodium sulfoisophthalic acid, 78 mole percent diethylene glycol and 22 mole percent 1, 4 -cyclohexanedimethanol. It has a nominal molecular weight of 14,000 Daltons, an acid number less than two, a hydroxyl number less than 10 and a glass transition temperature of 38 0 C. Other examples could be blends of poly(vinyl alcohol) or copolymers of poly(vinyl alcohol) blended with polyacrylic or methacrylic acid, or polyvinylmethyl ether blended with polyacrylic or methacrylic acid. The Eastman polymers are stable in high ionic solution environments, but will break-up rapidly in toilet water during the flushing process (excess water) thus reducing ion concentration. The l0 Eastman polymers can be matched with a higher melting temperature range second component polymer such as polyethylene.

Other first component polymers that are stable in high ion concentrations include "triggered, water-dispersible polymers." By this it is meant that when the first component of the conjugate fiber is exposed to a trigger component, such as, for example, the sulfate ion is or chloride ion, at a first concentration level found in normal tap water, the polymer forming the first component disperses or disintegrates in no more than 30 minutes. However, when the first component of a conjugate fiber is exposed to the same trigger component at a second, higher concentration level typically found in body fluids, such as infant or adult urine or menses, the polymer forming the first component remains stable and does not disperse.

Suitable examples of such first component include water-dispersible polyester or polyamide polymers, or copolymers, such as copolyester polymers available from National Starch and Chemical Company under the product designations 70-4395 and 70-4442. Conjugate fibers having a first component comprising a triggered, water-dispersible polymer are insensitive to the presence of a particular trigger component at a concentration level found in urine or menses, yet are highly sensitive to and disperse in a period not exceeding 30 minutes in the presence of the same trigger component at a different, lower concentration level typically found in excess tap water, such as is found in toilet bowls. Thus, fibrous webs formed from or incorporating the triggered, water-dispersible polymers are unaffected in terms of dispersibility when insulted with body fluids, such as urine or menses, yet when disposed of in normal tap water tend to break apart as the first component of the conjugate fiber disperses.

Further, it is preferred that the entire material be embossed, preferably from the body liner side. The embossing could be light enough to emboss only the body side liner or could include the optional fluid transfer and distribution layers and the fluid retention WO 99/56687 PCT/US99/09404 layer as well. The embossing pattern could be chosen to maximize material densification, which enhances fluid intake and dispersion throughout the product, and fluid distribution along the front to back axis. Embossing can also provide visual signals to the wearer that the product capacity is approaching full and should be discarded, and can be used to give an aesthetic benefit as well. Examples of suitable embossing patterns are given in the drawings. Figure 1 is an embossing pattern for a personal care product referred to as a sine wave pattern and Figure 2 is an embossing pattern for a personal care product referred to as a shell pattern.

Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. In the claims, means plus function claims are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures.

It should further be noted that any patents, applications or publications referred to herein are incorporated by reference in their entirety.

Claims (17)

1. 2. The material for personal care products of claim 1 further comprising a garment side liner layer adjacent said fluid retention layer on a side away from said body i side layer, selected from the group consisting of films and a fibrous layer having a basis S is5 weight of from about 10 to about 100 gsm, and comprising synthetic fibers and binder in a ratio of from about 50/50 to about 0/100.
2. 3. The material for personal care products of claim 1 or 2 further comprising a fluid transfer layer interposed between said body side layer and said fluid retention layer and having a basis weight of from about 10 to about 100 gsm, a density of from about o o 20 0.05 to about 0.5 g/cc and comprising synthetic fibers and natural fibers in a ratio of from about 40/60 to about 10/90 and binder in an effective amount.
3. 4. The material for personal care products of any one of claims 1 to 3 further comprising a fluid distribution layer adjacent said fluid retention layer on the body side °°oO S" and having an equilibrium vertical wicking of an 8.5 g/l saline solution above 15 cm. 25 5. The material of any one of claims 1 to 4 further comprising an odor absorbing compound.
4. 6. The material of any one of claims 1 to 5 further comprising superabsorbent particles.
5. 7. The material of any one of claims 1 to 6 further comprising a peripheral seal.
6. 8. The material of any one of claims 1 to 7 further comprising an embossing pattern.
7. 9. The material of any one of claims 1 to 8 wherein at least a portion of said A synthetic fibers comprises a kosmotrope. A material for personal care products comprising sequentially: R:\LI B FFO4256.doc.m rr 14 a body side layer having a basis weight of from about 10 to about 100 gsm, a density of from about 0.05 to about 0.5 g/cc and comprising synthetic fibers and binder fibers in a ratio of from about 50/50 to about 20/80; a fluid transfer layer having a basis weight of from about 10 to about 100 gsm, a density of from about 0.05 to about 0.5 g/cc and comprising synthetic fibers and natural fibers in a ratio of from about 40/60 to about 10/90 and binder in an effective amount; a fluid retention layer having a basis weight of from about 50 to about 250 gsm, a density of from about 0.05 to about 0.5 g/cc and comprising synthetic fibers and Io natural fibers in a ratio of from about 10/90 and 20/80 and binder in an effective amount; a garment side liner layer adjacent said fluid retention layer on a side away firom said body side layer, selected from the group consisting of films and a fibrous layer having a basis weight of from about 10 to about 100 gsm and comprising synthetic fibers and binder fibers in a ratio of from about 50/50 to about 0/100; 5. I wherein a boundary between any two adjacent fibrous layers is indistinct in that fibers at or near the surfaces of such adjacent layers are significantly intermingled and wherein said product is embossed with a pattern selected from the group consisting of sine waves and shells.
8. 11. The material of claim 10 further comprising an odor absorbing compound. °oolo 20 12. The material of claim 10 or 11 further comprising superabsorbent particles.
9. 13. The material of claim 10, 11 or 12 further comprising a peripheral seal.
10. 14. The material of any one of claims 10 to 13 further comprising an embossing a pattern. °15. The material of any one of claims 10 to 14 wherein at least a portion of said 2 synthetic fibers comprises a kosmotrope.
11. 16. A personal care product selected from the group consisting of diapers, training pants, absorbent underpants, adult incontinence products, bandages and feminine hygiene products comprising the material of any one of claims 10 to
12. 17. The personal care product of claim 16 which is a diaper. 3) 18. The personal care product of claim 16 which is a training pant.
13. 19. The personal care product of claim 16 which is an absorbent underpant. The personal care product of claim 16 which is a bandage.
14. 21. The personal care product of claim 16 which is a feminine hygiene product.
15. 22. The feminine hygiene product of claim 21 which is a sanitary napkin. 3 23. A material for personal care products comprising sequentially: I R.\Li BFFJO4256.doc:mlrr a body side layer having a basis weight of from about 10 to about 100 gsm, a density of from about 0.05 to about 0.05 g/cc and comprising synthetic fibers and binder fibers in a ratio of about 30/70; a fluid transfer layer having a basis weight of from about 10 to about 100 Sgsmn, a density of from about 0.05 to about 0.5 g/cc and comprising synthetic fibers and natural fibers in a ratio of from about 40/60 to about 10/90 and binder in an effective amount; a first fluid retention layer having a basis weight of from about 50 to about 250 gsm, a density of from about 0.05 to about 0.5 g/cc and comprising synthetic fibers I0 and natural fibers in a ratio of about 4/60 and binder in an effective amount; a second fluid retention layer comprising natural fiber, superabsorbent fiber, and binder in an effective amount; a garment side liner layer selected from the group consisting of films and a fibrous layer having a basis weight of from about 10 to about 100 gsm and comprising 1. i synthetic fibers and binder fibers in a ratio of from about 50/50 to about 0/100; wherein a boundary between any two adjacent fibrous layers is indistinct in that fibers at or near the surfaces of such adjacent layers are significantly intermingled and wherein said product is embossed with a pattern selected from the group consisting of sine waves and shells. 20 24. Material for personal care products, substantially as hereinbefore described with reference to any one of the examples and/or any one of the accompanying drawings. A process for preparing a material for personal care products, substantially as hereinbefore described with reference to any one of the examples and/or any one of the "accompanying drawings. 25 26. A material for personal care products prepared by the process of claim
16. 27. A material for personal care products according to any one of claims 1 to 23, 24 or 26 when used in a personal care product.
17. 28. A material when used according to claim 27 wherein the personal care product is a diaper, training pant, absorbent underpant, adult incontinence product, bandage, feminine hygiene product or sanitary napkin. Dated 14 September, 2001 Kimberly-Clark Worldwide, Inc. Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON I R:\LIBF3F104256.doc mr