US20050268442A1

US20050268442A1 - Mechanically extensible substrates

Info

Publication number: US20050268442A1
Application number: US11/137,676
Authority: US
Inventors: Ralph Moody; Jennifer Mayhorn; Nick Carter
Original assignee: Polymer Group Inc
Current assignee: PGI Polymer Inc; Avintiv Specialty Materials Inc
Priority date: 2004-05-26
Filing date: 2005-05-25
Publication date: 2005-12-08
Also published as: EP1749124A2; WO2005118929A2; WO2005118929A3

Abstract

The present invention is directed to mechanically extensible substrates, and more specifically relates to engineered substrates that exhibit functionality upon application of an external force, which in turn actuates the substrate, optionally releasing an underlying functional agent that assists a specific task or exposing an underlying layer. In accordance with the present invention, the mechanically extensible substrates exhibit a degree of controlled regional disentanglement, an expandable and retractable valve system, a limited degree of rupture, or a combination thereof.

Description

TECHNICAL FIELD

The present invention relates to mechanically extensible substrates, and more specifically relates to engineered substrates that exhibit functionality upon application of an external force, which in turn actuates the substrate, optionally releasing an underlying functional agent that assists a specific task or exposing a dissimilar underlying surface.

BACKGROUND OF THE INVENTION

Nonwoven fabrics and polymeric films are used in a wide variety of applications where the engineered qualities of the fabrics and films can be advantageously employed. The use of selected thermoplastic polymers in the construction of the fibrous and filamentary fabric components, selected treatment of the fibrous or filamentary components (either while in fibrous form or in an integrated structure), and selected use of various mechanisms by which the fibrous or filamentary components are integrated into a useful substrate, are typical variables by which to adjust and alter the performance of the resultant nonwoven fabric.
Various substrates, including apertured or non-apertured films, nonwoven staple fiber substrates, filamentary substrates, and the combinations thereof, which have been thermally bonded, entangled, or consolidated by other bonding techniques known in the art, have been employed in the disposable wipes market for performing a specific function. Use of single layer and multi-layered constructs are known in the art, wherein multi-layered constructs have been known to incorporate a first substrate that exhibits a first performance and a second substrate that exhibits a second performance.
Disposable wiping substrates are known in the home care market for cleaning hard surfaces, such as kitchen and bathroom counters, sinks, and floors. The personal hygiene market uses hand held disposable wiping substrates for facial cleansing, body cleansing, baby wipes, and the application of sun screen or insect repellent. Still other disposable wiping substrates are utilized in the automotive industry for applying cleaning agents to interior car surfaces, the medical industry to administer disinfectants and antimicrobials, and the industrial industry to dissipate static charge for instance.
In recent years, disposable wiping substrates have been impregnated, submersed, or coated with a functional agent to assist with a specific chore, such as dusting or dish washing. Functional agents are selected from aqueous solutions, powders, and gels that render the substrate ready to use directly out of the packaging or after being activated by the introduction of water. Further, such wiping substrates have been used in combination with a cleaning implement, such as a mop or hand held duster, wherein various wiping substrates can be affixed to the cleaning implement and discarded after use.
Additional disposable wiping substrate enhancements include imparting a three-dimensional profile into the surface of an otherwise planar substrate. A three-dimensional profile is often desired to assist with particulate capture and entrainment of particulate matter. Three-dimensionality is also often imparted into a substrate for aesthetic purposes only. Aperturing is also utilized alone or in combination with a three-dimensional profile to enhance the performance or aesthetic quality of a substrate.
The aforementioned substrates are often inextensible, as the end-use product didn't necessarily warrant the need for extensibility; however, it has been contemplated that incorporating mechanically activated extensibility into such substrates may further enhance disposable wiping articles, as well as other end-use articles including disposable absorbent hygienic articles, such as feminine hygiene articles, diapers, and incontinence garments. An unmet need exists for extensible substrates that are mechanically actuated, wherein such actuation may optionally release a functional agent or expose an underlying surface to enhance the performance or aesthetic nature of the end-use article.

SUMMARY OF THE INVENTION

The present invention is directed to mechanically extensible substrates, and more specifically relates to engineered substrates that exhibit functionality upon application of an external force, which in turn actuates the substrate, optionally releasing an underlying functional agent that assists a specific task or exposing an underlying layer.
In accordance with the present invention, the mechanically extensible substrates exhibit a degree of controlled regional disentanglement, an expandable and retractable valve system, a limited degree of rupture, or a combination thereof. In one embodiment, the mechanically extensible substrate is an entangled continuous filament nonwoven fabric as disclosed in co-pending application Ser. No. 09/287,673, hereby incorporated by reference. As disclosed, the entangled filaments are inter-engaged by a matrix of packed continuous complex loops or spirals, with the filaments being substantially free of any breaking, wrapping, knotting, or severe bending. The continuous filament fabric can exhibit controlled, regional disentanglement upon extension by varying degrees of inter-engaged loops or spirals so as to create zones of high inter-engaged filaments and low inter-engaged filaments, affecting the bulk and porosity across the fabric. Once the continuous filament fabric is subjected to external forces, the filaments begin to disentangle. Accordingly, the zones of high inter-engaged filaments disentangle less than those zones of low inter-engaged filaments. Subsequently, the extensibility of the entangled continuous filament fabric can be regionally controlled.
In another embodiment, the mechanically extensible substrate is a nonwoven fabric with a stretch and recovery performance comprising one or more three-dimensional profile elements. Exemplary fabrics are taught in U.S. Pat. No. 6,306,234 to Barker, et al., hereby incorporated by reference. In this embodiment, the one or more three-dimensional profile elements imparted in the substrate comprise one or more apertures, which perform as a regulator system upon extension of the substrate. Such mechanically extensible substrates can act as a valve between the interior environment to the exterior environment, or between two interior environments, or alters the presentation/exposure of an underlying treated surface.
In yet another embodiment, the mechanically extensible substrate is a film comprised of a series of weakened points which are predisposed to rupture upon exertion of an external force. Similar to those films described in U.S. Pat. No. 4,381,326 to Kelly, hereby incorporated by reference, the film of the present invention is produced utilizing “partial depth reticulation”. A film is affected by partial depth reticulation when a film substrate comes in contact with an embossing roll and a smooth roll, wherein the embossing roll preferably is rotating at a slightly higher peripheral speed than the smooth roll. There is a wiping action at the nip which forces a portion of the molten substrate into the grooves of the embossing roll imparting weakened areas into the film substrate. The resultant film can be utilized in a laminate construct where upon mechanical extension of the substrate ruptures the weakened areas exposing an underlying surface that may optionally be treated with a functional agent.
The aforementioned mechanically extensible substrates are suitable for various cleaning and cleansing applications. Such substrates can be used alone or in combination with existing home care products so as to enhance such products. The mechanically extensible substrates are suitable either by themselves or in laminate form as cleaning sheets, whereby the substrates can be impregnated or coated with one or more functional agents that are activated upon mechanical extension of the substrate. Further, the extensible cleaning sheet may have one or more three-dimensional profiled elements imparted into the substrate surface, thereby creating a foreground surface and background surface. It has been contemplated that such an extensible cleaning sheet may comprise regionally imprinted functional agents, wherein a first functional agent is regionally imprinted on or impregnated into the foreground of the substrate and a second functional agent is regionally imprinted or impregnated into the background of the substrate.
Such mechanically extensible substrates can also be used in combination with existing home care products. For instance, the aforementioned extensible substrate may comprise a specific functional agent, such as a bleaching agent, and extend over the face of a dish washing wand to assist in removing unsightly stubborn stains caused by tea or coffee from porous surfaces, such as sinks and the inside of mugs. In addition to dish washing wands, the mechanically extensible nonwoven substrate may be utilized in combination with mops and brushes, such as toilet brushes, wherein the substrate extends over the mop or brush to assist in the cleaning process.
The extensible aforementioned substrates are suitable for cleansing applications as well, such as hygienic face and body cleansing sheets, wherein the extensible sheet may be impregnated or coated with one or more emollients, organic extracts, vitamins, or other skin wellness agents. Regionally controlled extensible substrates also benefit cleansing applications due to the exchange of air through the substrate which promotes lathering to assist with the cleansing process.
It's also in the purview of the present invention to incorporate the extensible substrates as one or more components within disposable hygienic absorbent articles, including, but not limited to feminine care products, diapers, and incontinence garments. The extensible substrates may be utilized, either alone or in laminate form, as topsheets. Such topsheets may comprise localized regions of controlled mechanically extensibility that release a scent when actuated. Further, the extensible substrates may act as a valve system between the interior environment to the exterior environment of an absorbent article, as well as cleaning or cleansing applications, or act as a valve system between two interior environments of such applications, or alters the presentation of such applications by exposing an underlying surface.
Other features and advantages of the present invention will become readily apparent from the following detailed description, the accompanying drawings, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an apparatus suitable for manufacturing a mechanically extensible substrate in accordance with the present invention;
FIG. 2 is a schematic view of an apparatus suitable for manufacturing a mechanically extensible substrate in accordance with the present invention;
FIG. 3 is a schematic view of an apparatus suitable for manufacturing a mechanically extensible substrate in accordance with the present invention;
FIG. 4 a is a diagrammatic view of a mechanically extensible substrate made in accordance with the present invention;
FIG. 4 b is a diagrammatic view of a mechanically extensible substrate made in accordance with the present invention in an extended state;
FIG. 5 a is a diagrammatic view of a mechanically extensible substrate made in accordance with the present invention; and
FIG. 5 b is a diagrammatic view of a mechanically extensible substrate made in accordance with the present invention in an extended state.

DETAILED DESCRIPTION

While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment of the invention, with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiment illustrated.
The present invention is directed to mechanically extensible substrates that exhibit a degree of controlled regional disentanglement, an expandable and retractable valve system, a limited degree of rupture, or a combination thereof, upon application of an external force. Mechanical actuation of the substrates may subsequently result in the release of an underlying functional agent, such as a cleaning agent or exposure of an underlying layer.
Substrates
Referring to the drawings, FIG. 1 illustrates an apparatus for the manufacture of a mechanically extensible, entangled continuous filamentary nonwoven fabric substrate of the invention. Continuous filaments 2 are melt-extruded, drawn, and then deposited by beam 4 on moving porous support wire 6 winding on rollers 7 to form an unbonded filament web 8. As filaments 2 are continuously extruded, they are substantially endless. Deposited, unbonded filament web 8 is relatively fragile, thin, and easily disturbed. Web 8 may be comprised of more than one layer of filaments 2. The dominant orientation of filaments 2 is in the machine-direction, with some degree of overlap in the cross-direction. If desired, a variety of techniques may be employed to encourage further separation of individual filaments 2 and greater randomness in the cross-direction. These techniques may include, but are not limited to, impinging filaments 2 with air currents, electrostatic charging, or contact with solid objects. Also, as is well-known in the art, vacuum may be drawn through support wire 6 in the area of depositing filaments 2.
Web 8 is continuously and substantially without interruption advanced to pre-entangling station 10 for pre-entanglement with a plurality of individual pre-entangling jets 12 that direct water streams of a hydraulic pressure onto web 8. Preferably, pre-entangling station 10 comprises from one to four sets of pre-entangling jets 12, with one to three most preferred. The number of individual jet streams per jet 12 will vary with the width of web 8; jet 12 will extend substantially across the width of web 8, with individual jet streams at a density of 10 to 50 per inch. The pressures of individual pre-entangling jets 12 may vary as desired depending on fabric basis weight.
During pre-entanglement, web 8 is supported on moving support 14, which may comprise a forming drum, or as illustrated, a single or dual wire mesh rotating about rollers 15. Because filaments 2 are substantially endless and of considerable denier, support 14 need not be of fine mesh as may be required for shorter or finer fibers of the prior art. For high pre-entanglement hydraulic pressures associated with heavier basis weight fabrics, supporting web 8 on a rotating forming drum is preferred. The purpose of pre-entanglement is to create some cohesiveness in web 8 so that web 8 can be transferred and will not be destroyed by the energy of subsequent high pressure hydroentanglement. After pre-entangling, web 8 is observed to have minimal entanglement and low strength values.
Subsequently, the continuously moving web 8 is next subjected to high pressure hydroentangling. High pressure hydroentangling may be achieved at a hydro-entanglement station that comprises a plurality of sets of water jets 16.
It's also in the purview of the present invention to regionally entangle the filamentary web. Regionally entangled webs comprise one or more zones that are highly entangled and one or more zones that are less than highly entangled or not entangled at all. Achieving zones of variable entanglement within a substrate involve utilizing dissimilar jet pressures from one orifice to the next or preferably not utilizing a select number of orifices. The resultant substrate can have zones that exhibit highly inter-engaged loops and spirals, increased bulk, and decreased porosity, as well as zones that exhibit scarcely inter-engaged loops and spirals, decreased bulk, and increased porosity.
FIG. 2 illustrates an apparatus for the manufacture of a mechanically extensible and recoverable substrate comprised of one or more three-dimensional profile elements imparted into the surface. In this embodiment, the one or more three-dimensional profile elements imparted in the substrate comprise one or more apertures, which can act as a valve between the interior environment to the exterior environment, or between two interior environments, or alters the presentation/exposure of an underlying treated surface.
In accordance with the method disclosed in U.S. Pat. No. 6,306,234, previously incorporated by reference, a precursor web is formed utilizing conventional carding and crosslapping techniques prior to subjecting the web to hydroentanglement, and a binder application. The binder composition, comprising an elastomeric emulsion, may have the following formulation, of or about 0.2% Tween 20 (Wetting Agent), 0.025% Anti-foam Y-30 (Silicone Defoamer), 0.3% of 10% Aqua Ammonia, 0.7% San Cure 861 (Polyurethane), a variable amount of Hystretch V-29 (Acrylic Binder), and water, which can be employed in the bath of the binder application station. Tween 20 is commercially available from ICI Chemicals, while Antifoam Y-30 is commercially available from Dow Chemical. Aqua Ammonia is commercially available from Ashland Chemical, while San Cure 861 is available from B.F. Goodrich Company. Hystretch V-29 acrylic binder is commercially available from the B.F. Goodrich Company. This acrylic binder is soft and elastic, and exhibits solvent resistance, excellent U.V. stability, dirt resistance, and low temperature flexibility.
The aforementioned nonwoven fabric has been particularly configured to exhibit elastic characteristics, that is, extensibility and recovery, in the cross-direction of the fabric. The cross-direction (CD) is transverse or perpendicular to the machine-direction (MD) of the fabric, that is, the direction in which the fabric is manufactured and processed, typically extending along the longitudinal axis of the fabric. By configuring the present fabric to exhibit cross-direction elasticity, the fabric can be employed in those applications in which such elastic characteristics are desirable.
In yet another embodiment, the mechanically extensible substrate is a partial depth reticulated film comprised of a series of weakened points which are predisposed to rupture upon exertion of an external force. Referring to FIG. 3, therein is illustrated an apparatus for forming a partial depth reticulated film. The reticulated film of the invention is preferably produced by extruding a thin film of a mixture comprising an olefin polymer directly onto a forming apparatus (described below). Conventional extrusion apparatus can be employed. In some cases it has been found that mixing is enhanced by cooling the extruding screw. Extruder screws that are specifically designed for effective mixing are available, and may be preferred for efficient commercial operation.
The extruded film is formed into a partial depth reticulated substrate. A preferred way to do this is to form the partial depth reticulated substrate directly from the extruded film without collecting the film as an intermediate product. This can be done by the process which is schematically illustrated in the drawing.
As shown in FIG. 3, a mixture comprising an olefin polymer is extruded in the form of a thin sheet 12 of molten material through a conventional slot die 14. The olefin polymer may optionally be combined with staple length fibers prior to extrusion, wherein the composition of the staple length fibers are of a higher melt temperature than that of the polymeric base resin. The still molten substrate 12 is collected on a heated rotating roll 16 having a smooth surface. The heated smooth roll 16 has a predetermined peripheral speed. The temperature of the heated smooth roll 16 is such that the substrate 12 is molten and formable when the substrate 12 reaches the nip 17 between the roll 16 and a second roll 18. The second (embossing) roll 18 is in contact with the smooth roll 16 at the said nip 17 between the two rolls. The embossing roll 18 is cooled, and has a resilient engraved surface. The engraving is in the form of continuous recessed areas 20 surrounding discontinuous raised areas 21. For instance, a preferred engraved pattern has a first series of grooves running circumferentially around the surface of the embossing roll 18, and a second series of grooves running perpendicular to and intersecting the first series of grooves. The said second series of grooves are parallel to the longitudinal axis of the embossing roll 18. They are shown in cross-section and exaggerated form as 20 in the drawings.
The sheet 12 transfers from the smooth roll 16 to the embossing roll 18 at the nip 17 between the two rolls. The embossing roll 18 is cooled and preferably is rotating at a slightly higher peripheral speed than the smooth roll 16. In some cases, the two rolls 16, 18 can rotate at the same speed, and in others, the embossing roll 18 can be slightly slower than the smooth roll 16. There is a wiping action at the nip 17 which forces a portion of the molten substrate 12 into the grooves 20, to form localized thinned areas throughout the substrate. The sheet begins to solidify in the form of a partial depth reticulated substrate 22 while it is in contact with the embossing roll 18. The substrate will have the same structure or pattern as the engraved grooves on the roll 18. When actuated by an external force, the localized thinned areas rupture; however when staple length fibers have been incorporated into the base resin, the fibers can remain relatively intact.
The aforementioned substrates of the present invention may be combined with one or more similar or dissimilar substrates to form a laminate construct. Such substrates include, but are not limited to wovens, continuous and discontinuous filamentary nonwovens, carded nonwovens, various films, such as monolithic or microporous films, a supportive member, such as a spunbond or mesh scrim, or a barrier layer of sorts. Continuous filamentary substrates are manufactured utilizing the spunbond process. A process for the formation of spunbond involves supplying a molten polymer, which is then extruded under pressure through a large number of orifices in a plate known as a spinneret or die. The resulting continuous filaments are quenched and drawn by any of a number of methods, such as slot draw systems, attenuator guns, or Godet rolls. The continuous filaments are collected as a loose web upon a moving foraminous surface, such as a wire mesh conveyor belt. When more than one spinneret is used in line for the purpose of forming a multi-layered fabric, the subsequent webs is collected upon the uppermost surface of the previously formed web. The web is then at least temporarily consolidated, usually by means involving heat and pressure, such as by thermal point bonding. Using this bonding means, the web or layers of webs are passed between two hot metal rolls, one of which has an embossed pattern to impart and achieve the desired degree of point bonding, usually on the order of 10 to 40 percent of the overall surface area being so bonded.
A process related to the formation of spunbond is the meltblown process, which involves the formation of discontinuous filaments. Again, a molten polymer is extruded under pressure through orifices in a spinneret or die. High velocity air impinges upon and entrains the filaments as they exit the die. The energy of this step is such that the formed filaments are greatly reduced in diameter and are fractured so that microfibers of finite length are produced. This differs from the spunbond process whereby the continuity of the filaments is preserved. The process to form either a single layer or a multiple-layer fabric is continuous, that is, the process steps are uninterrupted from extrusion of the filaments to form the first layer until the bonded web is wound into a roll. Methods for producing these types of fabrics are described in U.S. Pat. No. 4,043,203. The meltblown process, as well as the cross-sectional profile of the spunbond filament or meltblown microfiber, is not a critical limitation to the practice of the present invention.
A nano-fiber of finite or infinite length may also be utilized in the present invention, wherein the average fiber diameter of the nano-fiber is in the range of less than or equal to 1000 nanometers, and preferably less than or equal to 500 nanometers. Formation of substrates from nano-fibers, particularly when a light basis weight nano-fiber barrier layer is preferred, is either coated or “dusted” onto a substrate layer. The present invention may utilize a nano-fiber layer of less than about 2 grams per square meter.
In addition, one or more of the substrates may be imparted with one or more surface asperities, such as three-dimensional profiled elements, apertures, or a combination thereof. Three-dimensional profiled elements may be imparted into a substrate surface by way of a forming apparatus, wherein the forming surface may be a profiled continuous surface, a plurality of linked profiled plates, and the combinations thereof. Further still, the forming surface may be circular in formation (i.e. drum-like), as well as planar, and follow a pre-determined continuous path. In one embodiment, the forming surface is such as that described in U.S. Pat. No. 5,244,711 and No. 5,098,764, and incorporated herein by reference.
Functional Agents
Cleaning compositions suitable for use in the various end-use applications include those that are described in U.S. Pat. No. 6,103,683 to Romano, et al., No. 6,340,663 to Deleo, et al., No. 5,108,642 to Aszman, et al., and No. 6,534,472 Arvanitidou, et al., all of which are hereby incorporated by reference. Selected cleaning compositions may also include surfactants, such as alkylpolysaccharides, alkyl ethoxylates, alkyl sulfonates, and mixtures thereof; organic solvent, mono- or polycarboxylic acids, odor control agents, such as cyclodextrin, peroxides, such as benzoyl peroxide, hydrogen peroxide, and mixtures thereof, thickening polymers, aqueous solvent systems, suds suppressors, perfumes or fragrances, and detergent adjuvants, such as detergency builder, buffer, preservative, antibacterial agent, colorant, bleaching agents, chelants, enzymes, hydrotropes, and mixtures thereof. The aforementioned compositions preferably comprise from about 50% to about 500%, preferably from about 200% to about 400% by weight of the dual sided nonwoven cleaning article.
The single or multi-layered extensible substrates embodying the principles of the present invention is also suitable for personal cleaning or cleansing articles. Non-limiting examples of such applications include dry or wet facial wipes, body wipes, and baby wipes. Suitable methods for the application of various aqueous and non-aqueous compositions comprise aqueous/alcoholic impregnates, including flood coating, spray coating or metered dosing. Further, more specialized techniques, such as Meyer Rod, floating knife or doctor blade, which are typically used to impregnate cleansing solutions into absorbent sheets, may also be used. The following compositions preferably comprise from about 50% to about 500%, preferably from about 200% to about 400% by weight of the dual sided nonwoven article.
The extensible substrates may incorporate an alpha-hydroxycarboxylic acid, which refers not only the acid form but also salts thereof. Typical cationic counterions to form the salt are the alkali metals, alkaline earth metals, ammonium, C₂-C_-8trialkanolammonium cation and mixtures thereof. The term “alpha-hydroxycarboxylic acids” include not only hydroxyacids but also alpha-ketoacids and related compounds of polymeric forms of hydroxyacid.
Amounts of the alpha-hydroxycarboxylic acids may range from about 0.01 to about 20%, preferably from about 0.1 to about 15%, more preferably from about 1 to about 10%, optimally from about 3 to about 8% by weight of the composition which impregnates the substrate. The amount of impregnating composition relative to the substrate may range from about 20:1 to 1:20, preferably from 10:1 to about 1:10 and optimally from about 2:1 to about 1:2 by weight.
Further, a humectant may be incorporated with the aforementioned alpha-hydroxycarboxylic compositions. Humectants are normally polyols. Representative polyols include glycerin, diglycerin, polyalkylene glycols and more preferably alkylene polyols and their derivatives. Amounts of the polyol may range from about 0.5 to about 95%, preferably from about 1 to about 50%, more preferably from about 1.5 to 20%, optimally from about 3 to about 10% by weight of the impregnating composition.
A variety of cosmetically acceptable carrier vehicles may be employed although the carrier vehicle normally will be water. Amounts of the carrier vehicle may range from about 0.5 to about 99%, preferably from about 1 to about 80%, more preferably from about 50 to about 70%, optimally from about 65 to 75% by weight of the impregnating composition.
Preservatives can desirably be incorporated protect against the growth of potentially harmful microorganisms. Suitable traditional preservatives for compositions of this invention are alkyl esters of para-hydroxybenzoic acid. Other preservatives which have more recently come into use include hydantoin derivatives, propionate salts, and a variety of quatenary ammonium compounds. Preservatives are preferably employed in amounts ranging from 0.01% to 2% by weight of the composition.
The cosmetic composition may further include herbal extracts. Illustrative extracts include Roman Chamomile, Green Tea, Scullcap, Nettle Root, Swertia Iaponica, Fennel and Aloe Vera extracts. Amount of each of the extracts may range from about 0.001 to about 1%, preferably from about 0.01 to about 0.5%, optimally from about 0.05 to about 0.2% by weight of a composition.
Additional cosmetic additives may also include vitamins such as Vitamin E Acetate, Vitamin C, Vitamin A Palmitate, Panthenol and any of the Vitamin B complexes. Anti-irritant agents may also be present including those of steviosides, alpha-bisabolol and glycyhrizzinate salts, each vitamin or anti-irritant agent being present in amounts ranging from about 0.001 to about 1.0%, preferably from about 0.01 to about 0.3% by weight of the composition.
These impregnating compositions of the present invention may involve a range of pH although it is preferred to have a relatively low pH, for instance, a pH from about 2 to about 6.5, preferably from about 2.5 to about 4.5.
In addition to cosmetic compositions, lotions may be incorporated into the extensible substrates. The lotion preferably also comprises one or more of the following: an effective amount of a preservative, an effective amount of a humectant, an effective amount of an emollient; an effective amount of a fragrance, and an effective amount of a fragrance solubilizer.
As used herein, an emollient is a material that softens, soothes, supples, coats, lubricates, or moisturizes the skin. The term emollient includes, but is not limited to, conventional lipid materials (e.g. fats, waxes), polar lipids (lipids that have been hydrophylically modified to render them more water soluble), silicones, hydrocarbons, and other solvent materials. Emollients useful in the present invention can be petroleum based, fatty acid ester type, alkyl ethoxylate type, fatty acid ester ethoxylates, fatty alcohol type, polysiloxane type, mucopolysaccharides, or mixtures thereof.
Humectants are hygroscopic materials that function to draw water into the stratum corneum to hydrate the skin. The water may come from the dermis or from the atmosphere. Examples of humectants include glycerin, propylene glycol, and phospholipids.
Fragrance components may be utilized, such as perfumes, include, but are not limited to water insoluble oils, including essential oils. Fragrance solubilizers are components which reduce the tendency of the water insoluble fragrance component to precipitate from the lotion. Examples of fragrance solubilizers include alcohols such as ethanol, isopropanol, benzyl alcohol, and phenoxyethanol; any high HLB (HLB greater than 13) emulsifier, including but not limited to polysorbate; and highly ethoxylated acids and alcohols.
Preservatives prevent the growth of micro-organisms in the liquid lotion and/or the substrate. Generally, such preservatives are hydrophobic or hydrophilic organic molecules. Suitable preservatives include, but are not limited to parabens, such as methyl parabens, propyl parabens, and combinations thereof.
The lotion can also comprise an effective amount of a kerotolytic for providing the function of encouraging healing of the skin. An especially preferred kerotolytic is Allantoin ((2,5-Dioxo-4-Imidazolidinyl)Urea), a heterocyclic organic compound having an empirical formula C₄H₆N₄O₃. Allantoin is commercially available from Tri-K Industries of Emerson, N.J. It is generally known that hyperhydrated skin is more susceptible to skin disorders, including heat rash, abrasion, pressure marks and skin barrier loss. An extensible substrate according to the present invention can include an effective amount of allantoin for encouraging the healing of skin, such as skin which is over hydrated.
The lotion can further comprise between about 0.1 and about 3 percent by weight Allantoin, and about 0.1 to about 10 percent by weight of an aloe extract, such as aloe vera, which can serve as an emollient. Aloe vera extract is available in the form of a concentrated powder from the Rita Corporation of Woodstock, Ill.
Further, latherants may be incorporated within the single or multi-layered extensible substrates. Non-limiting examples of anionic lathering surfactants useful in the compositions of the present invention are disclosed in McCutcheon's, Detergents and Emulsifiers, North American edition (1986), published by allured Publishing Corporation; McCutcheon's, Functional Materials, North American Edition (1992); and U.S. Pat. No. 3,929,678, to Laughlin et al., issued Dec. 30, 1975, all of which are incorporated by reference herein in their entirety. A wide variety of anionic lathering surfactants are useful herein. Non-limiting examples of anionic lathering surfactants include those selected from the group consisting of sarcosinates, sulfates, isethionates, taurates, phosphates, lactylates, glutamates, and mixtures thereof.
Non-limiting examples of nonionic lathering surfactants and amphoteric surfactants for use in the compositions of the present invention are disclosed in McCutcheon's, Detergents and Emulsifiers, North American edition (1986), published by allured Publishing Corporation; and McCutcheon's, Functional Materials, North American Edition (1992); both of which are incorporated by reference herein in their entirety.
Non-ionic lathering surfactants useful herein include those selected from the group consisting of alkyl glucosides, alkyl polyglucosides, polyhydroxy fatty acid amides, alkoxylated fatty acid esters, lathering sucrose esters, amine oxides, and mixtures thereof.
The term “amphoteric lathering surfactant,” as used herein, is also intended to encompass zwitterionic surfactants, which are well known to formulators skilled in the art as a subset of amphoteric surfactant.
A wide variety of amphoteric lathering surfactants can be used in the compositions of the present invention. Particularly useful are those which are broadly described as derivatives of aliphatic secondary and tertiary amines, preferably wherein the nitrogen is in a cationic state, in which the aliphatic radicals can be straight or branched chain and wherein one of the radicals contains an ionizable water solubilizing group, e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate. Non-limiting examples of amphoteric or zwitterionic surfactants are those selected from the group consisting of betaines, sultaines, hydroxysultaines, alkyliminoacetates, iminodialkanoates, aminoalkanoates, and mixtures thereof.
Additional compositions utilized in accordance with the present invention can comprise a wide range of optional ingredients. The CTFA International Cosmetic ingredient Dictionary, Sixth Edition, 1995, which is incorporated by reference herein in its entirety, describes a wide variety of nonlimiting cosmetic and pharmaceutical ingredients commonly used in the skin care industry, which are suitable for use in the compositions of the present invention. Nonlimiting examples of functional classes of ingredients are described at page 537 of this reference. Examples of these functional classes include: abrasives, anti-acne agents, anti-caking agents, antioxidants, binders, biological additives, bulking agents, chelating agents, chemical additives, colorants, cosmetic astringents, cosmetic biocides, degreasers, denaturants, drug astringents, emulsifiers, external analgesics, film formers, fragrance components, humectants, opacifying agents, plasticizers, preservatives, propellants, reducing agents, skin bleaching agents, skin-conditioning agents (emollient, humectants, miscellaneous, and occlusive), skin protectants, solvents, foam boosters, hydrotropes, solubilizing agents, suspending agents (nonsurfactant), sunscreen agents, ultraviolet light absorbers, and viscosity increasing agents (aqueous and nonaqueous). Examples of other functional classes of materials useful herein that are well known to one of ordinary skill in the art include solubilizing agents, sequestrants, and keratolytics, and the like.
The aforementioned classes of ingredients are incorporated in a safe and effective amount. The term “safe and effective amount” as used herein, means an amount of an active ingredient high enough to modify the condition to be treated or to deliver the desired skin benefit, but low enough to avoid serious side effects, at a reasonable benefit to risk ratio within the scope of sound medical judgment.
In addition to home care and personal care end uses, the extensible substrates may be used in industrial and medical applications. For instance, the extensible substrates may be useful in paint preparation and cleaning outdoor surfaces, such as lawn furniture, grills, and outdoor equipment. Aqueous or non-aqueous functional industrial solvents which may be utilized in the present invention include, oils, such as plant oils, animal oils, terpenoids, silicon oils, mineral oils, white mineral oils, paraffinic solvents, polybutylenes, polyisobutylenes, polyalphaolefins, and mixtures thereof, toluenes, sequestering agents, corrosion inhibitors, abrasives, petroleum distillates, and the combinations thereof.
The extensible substrates may incorporate an antimicrobial composition, including, but not limited to iodines, alcohols, such as such as ethanol or propanol, biocides, abrasives, metallic materials, such as metal oxide, metal salt, metal complex, metal alloy or mixtures thereof, bacteriostatic complexes, bactericidal complexs, and the combinations thereof.
Additional compositions utilized in accordance with the present invention can comprise a wide range of optional ingredients. The CTFA International Cosmetic ingredient Dictionary, Sixth Edition, 1995, which is incorporated by reference herein in its entirety, describes a wide variety of nonlimiting cosmetic and pharmaceutical ingredients commonly used in the skin care industry, which are suitable for use in the compositions of the present invention. Nonlimiting examples of functional classes of ingredients are described at page 537 of this reference. Examples of these functional classes include: abrasives, anti-acne agents, anticaking agents, antioxidants, binders, biological additives, bulking agents, chelating agents, chemical additives, natural additives, colorants, cosmetic astringents, cosmetic biocides, degreasers, denaturants, drug astringents, emulsifiers, external analgesics, film formers, fragrance components, humectants, opacifying agents, plasticizers, preservatives, propellants, reducing agents, skin bleaching agents, skin-conditioning agents (emollient, humectants, miscellaneous, and occlusive), skin protectants, solvents, foam boosters, hydrotropes, solubilizing agents, suspending agents (nonsurfactant), sunscreen agents, ultraviolet light absorbers, and viscosity increasing agents (aqueous and nonaqueous). Examples of other functional classes of materials useful herein that are well known to one of ordinary skill in the art include solubilizing agents, sequestrants, and keratolytics, and the like.
End-Use Applications
The extensible substrates of the present invention are suitable for home and personal care cleaning and cleansing applications, which can be utilized in the form of a standard hand sheet, glove, mitt, puff, or pad. Such substrates may be used by themselves or in combination with a cleaning implement. The extensible substrates are affected by an external force by way of disentangling, as shown in FIGS. 4 a and 4 b, stretching, as shown in FIGS. 5 a and 5 b, or rupturing, as shown in FIGS. 6 a and 6 b. The extensible substrates may comprise an internal and/or external functional agent for a specific end-use. Extension of the substrates may activate a functional agent or expose an underlying layer.
One particular application for the mechanically extensible substrates is a hygienic body wipe when wash water is not available, for example when traveling. Wipes are commonly used for human cleansing and wiping such as face and hand cleansing. Wipes may also be used for application of substances to the body including removing and applying of make-up, skin conditioners and medications. Another application of wipes is during diaper changes and also for the treatment of adult and baby dermatitis partly caused by the use of diapers and incontinence devices. In addition, wipes are also applicable for wiping and or cleaning other surfaces or for the application of compositions to surfaces, for example kitchen and bathroom surfaces, eyeglasses, shoes and surfaces which require cleaning in industry for example surfaces of machinery or automobiles. Wipes also include articles used for the cleaning or grooming of pets.
The extensible substrates of the present invention are suitable for disposable absorbent article applications, wherein the mechanically extensible substrates may be used as a single or multi-layer topsheet, surge layer, core wrap, core layer, and/or backsheet component of the absorbent article, such as a sanitary napkin, a panty liner, a panty shield, diaper, and incontinent garment. The extensible substrates may act as a valve system between the interior environment to the exterior environment of an absorbent article, as well as cleaning or cleansing applications, or act as a valve system between two interior environments of such applications, or alters the presentation of such applications by exposing an underlying surface.
Additional end-uses include industrial applications, such as single or multi-layer tapes, tarpaulins, agricultural cover, and car cover. Further, medical applications may benefit from the extensible substrates for use as bandages, wraps, surgical drapes, and gowns.
From the foregoing, it will be observed that numerous modifications and variations can be affected without departing from the true spirit and scope of the novel concept of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated herein is intended or should be inferred. The disclosure is intended to cover, by the appended claims, all such modifications as fall within the scope of the claims.

Claims

1. A method of making a mechanically extensible substrate exhibiting regionally controlled disentanglement upon extension comprising the steps of:

providing a continuous filament substrate;

a. providing an entanglement apparatus comprising jets that extend the width of said substrate;

b. advancing said substrate onto said apparatus; and

c. variably entangling said substrate, whereby one or more jets exhibit dissimilar jet pressures.

2. A method of making a mechanically extensible substrate comprising one or more three-dimensional profiled elements and a stretch and recovery performance comprising the steps of:

a. providing a nonwoven web comprising staple length fibers;

b. hydroentangling said nonwoven web, wherein said web is imparted with one or more three-dimensionally profiled elements; and

c. applying a polymeric binder composition substantially uniformly to said nonwoven web, wherein said binder composition comprising between about 17% and 31%, by weight, of acrylic binder.

3. A method of making a mechanically extensible partial depth reticulated film substrate with one or more localized thin areas prone to rupture upon exerting an external force comprising the steps of:

a. providing a conventional extrusion apparatus;

b. providing a polymeric melt;

c. extruding said melt from said apparatus;

d. collecting said melt as a formable substrate onto a heated surface; and

e. embossing said substrate so as to impart localized thinned areas into said substrate.

4. A method of making a mechanically extensible substrate as in any one of the aforementioned claims, wherein said substrate comprises an internal functional agent, topical functional agent, or a combination thereof.