CN1198547C - Disposable absorbent article with skin care composition on apertured top sheet - Google Patents

Abstract

The present invention relates to a disposable absorbent article such as a diaper (20). The disposable absorbent article is provided with a structural carrier (24), a bottom sheet (26) and an absorbent core (28), wherein the structural carrier (24) can be penetrated by liquid; at least the part periphery of the bottom sheet (26) is connected with the structural carrier (24); the bottom sheet (26) can not be penetrated by the liquid; the absorbent core (28) is positioned between the structural carrier (24) and the bottom sheet (26). When the disposable absorbent article is worn, the structural carrier (24) which can be penetrated by liquid has an inner surface which faces the inner orientation of the disposable absorbent article, and an outer surface which faces the skin orientation of a wearer. The structural carrier (24) has at least about 12% of an effective open area and a plurality of holes of which the effective sizes are larger than 0.1 square millimeter. The outer surface of the structural carrier (24) is provided with a skin protective composition of an effective amount. The composition is semisolid or solid below 20 DEG C and can be partially transferred on the skin of the wearer.

Description

Disposable absorbent article with skin care composition on porous topsheet

Technical field

The present invention relates to disposable absorbent articles, such as diapers and adult incontinence articles, and more particularly, to disposable absorbent articles capable of effectively disposing of urine and low viscosity feces.

Background technique

There are many commercially available high capacity disposable absorbent articles such as diapers for absorbing urine. Disposable articles of this type generally comprise a liquid permeable topsheet material, an absorbent core and a liquid impermeable backsheet material. While these types of absorbent structures are highly effective for absorbing liquids, they are not capable of absorbing faeces (ie, hereinafter referred to as "BM"). Typically, BM is trapped between the outer surface of the liquid permeable topsheet and the wearer's skin, and many adhere to the wearer's skin.

To prevent BM from sticking to the wearer's skin, caregivers often apply protective or "waterproof" products such as petrolatum or mineral oil to the buttocks or anal area before placing the absorbent article on the wearer's body superior. This procedure usually involves the caregiver pouring an oil or lotion on one of her hands, rubbing both hands to distribute the substance over the hands, and then rubbing the substance on the baby's skin. In order to eliminate this wasteful, tedious and forgettable step, many attempts have been made to produce absorbent articles containing protective or therapeutic skin care substances on the topsheet.

One substance that has been applied to absorbent products as a lotion to impart a soft, protective coating is mineral oil. Mineral oil (also known as liquid petrolatum) is a mixture of various liquid hydrocarbons obtained by distillation of the high boiling (ie, 300-390° C.) fraction of petroleum. Mineral oil is liquid at ambient temperature, eg 20-25°C. As a result, mineral oils are relatively fluid and runny, even when applied to the topsheet of an article.

Since mineral oil is fluid and mobile at ambient temperature, it tends not to remain fixed on the surface of the topsheet, instead it migrates through the topsheet into the interior of the diaper. Accordingly, relatively high levels of mineral oil need to be applied to the topsheet to provide the desired emolliency benefit of the therapeutic or protective coating. Not only does this increase the cost of these lotioned products, but it also has other deleterious effects.

One of these detrimental effects is a reduction in fluid handling performance, since high levels of mineral oil tend to clog the openings of the topsheet. Also, when mineral oil migrates to the interior of the article, it tends to act as a hydrophobic additive, thereby reducing the absorbency of the underlying absorbent core, if an article is used. The reduction in hygroscopicity will be more pronounced as the amount of mineral oil applied increases.

The tendency of mineral oils to migrate after application has other detrimental effects even without increasing their levels. For example, applied mineral oil can migrate to, into, and through the packaging material of a moisturizer-laden product. This may require barrier packaging films to prevent swelling or other leakage of mineral oil in the product.

In order to overcome the problems associated with mineral oil, lotions have been applied to absorbent products. Hygroscopic products with lotion: (1) have therapeutic or protective benefits, (2) do not require a relatively high level of coating (e.g., mineral oil) that is liquid at room temperature; and (3) contain no Requires special packaging or barrier material.

While lotioned absorbent products do solve the problems associated with mineral oil, care must be taken when applying lotions to absorbent products to prevent occlusion of the topsheet. This type of occlusion of previous topsheets prevents urine from penetrating through the topsheet, inevitably leading to leakage. To overcome this problem, lotions have been applied to the topsheet in a manner that does not coat the entire surface of the topsheet, thereby leaving certain portions of the topsheet free of lotion. An example of such an application technique is to apply the lotion in spaced apart strips. While lotion strips do allow urine to penetrate through the topsheet, they add to the complexity of the application method, may allow the lotion to be delivered unevenly to the skin and may contaminate untreated areas of the topsheet, thereby Absorbent elements that reduce the transfer of urine to the underlying layer.

It is therefore an object of the present invention to provide disposable absorbent articles having a structured carrier having excellent urine and BM disposal properties. As used herein, the term "structured carrier" refers to any two-dimensional or three-dimensional morphological structure designed to carry and then deliver a composition while still maintaining a pathway through which urine can pass.

Another object of the present invention is to provide a structured carrier for disposable absorbent articles having an effective open area and a plurality of open cells of sufficient effective size to allow urine and low-viscosity feces to Permeation through allows for relatively easy application of skin care compositions while eliminating occlusion problems with structured carriers. As used herein, the term "skin care composition" refers to any composition containing one or more agents which, when transferred from the article to the skin of the wearer, provide therapeutic and/or protective benefits to the skin. Exemplary materials are discussed in detail below.

Another advantage of the present invention is to provide an absorbent article having a skin care composition on the outer surface of the structured carrier that is transferable to the skin of the wearer and that is effective to produce the desired skin benefits and/or Reduces the adhesion of BM to the skin, thereby improving the ease of cleaning of BM without inhibiting the ability of the structured carrier to dispose of urine.

These and other objects are attainable by use of the present invention, which will become more apparent upon reading the following disclosure.

Contents of Invention

The present invention is a disposable absorbent article such as a diaper. The disposable absorbent article comprises a structured carrier, a liquid impermeable backsheet at least partially peripherally attached to the structured carrier, and an absorbent core positioned between the structured carrier and the backsheet. The structured carrier has an inner surface oriented towards the interior of the disposable absorbent article and an outer surface oriented towards the skin of the wearer when the disposable absorbent article is worn. The structured support has an effective open pore area of at least about 12% and a plurality of pores with an effective size greater than 0.1 square millimeters. The outer surface of the structured carrier contains an effective amount of a skin care composition which is semi-solid or solid at 20°C and which is partially transferable to the skin of the wearer.

Description of drawings

Although the specification concludes with claims pointing out and distinctly claiming the invention, it is believed that the invention will be better understood from the following drawings when read in conjunction with the accompanying description, wherein like parts have been given like numerals, wherein

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a plan view of the disposable absorbent article of the present invention, shown in partial cross-section.

Detailed ways

The term "absorbent article" as used herein means an article which absorbs and retains body exudates, and more particularly, an article which is placed against or near the body of the wearer to absorb and retain various exudates discharged from the body. The term "disposable" is used to describe absorbent articles that are not intended to be laundered or otherwise restored or reused as an absorbent article (i.e., tend to be discarded after one use and are preferably recycled, composted, or otherwise disposed of in an environmentally appropriate manner) be processed). "Unity"absorbent articles are absorbent articles that are composed of separate parts joined together to form a coherent whole so that they do not require separate operating parts such as separate casings and liners. A preferred embodiment of the absorbent article of the present invention is a unitary disposable absorbent article, such as the diaper 20 shown in FIG. As used herein, the term "diaper" refers to an absorbent article typically worn by infants and adult incontinent persons around their lower torso. The present invention is also applicable to other absorbent articles such as incontinence pants, incontinence underwear, absorbent pads, diaper covers and liners, feminine hygiene garments, and the like.

Figure 1 is a plan view of the diaper 20 of the present invention in its flattened, uncontracted state (i.e., pulled out of the contraction caused by the elastic), with portions cut away to more clearly show the construction of the diaper 20, wherein towards and The portion of the diaper 20 that contacts the wearer, ie, the inner surface, faces the viewer. As shown in Figure 1, the diaper 20 preferably comprises a liquid permeable structured carrier 24, a liquid impermeable backsheet 26 attached to the structured carrier 24, and an absorbent absorbent material positioned between the structured carrier 24 and the backsheet 26. Core 28. The diaper 20 may further include elasticized side panels (not shown), elasticated leg cuffs (not shown), elastic waist features (not shown) and a fastening system with tape tabs , and many places are generally represented by 36.

The diaper 20 shown in Figure 1 has a first waist region 27, a second waist region 29, a crotch region 31 between the first waist region 27 and the second waist region 29 and a perimeter defined by the outer edge of the diaper 20, when When wearing this diaper 20, the first waist region 27 is juxtaposed with the front of the wearer, and the second waist region 29 is opposite to the first waist region 27 and juxtaposed with the back of the wearer, wherein the longitudinal sides of the diaper Marked as 33, end marked as 35. The interior surface of the diaper 20 includes the portion of the diaper 20 that is adjacent to the wearer's body during use (ie, the interior surface is typically comprised of at least a portion of the structured carrier 24 and other components associated with the structured carrier 24). The outer surface comprises the portion of the diaper 20 that is positioned away from the wearer's body during use (ie, the outer surface is typically formed from at least a portion of the backsheet 26 and other components associated with the backsheet 26).

Figure 1 shows an embodiment of a diaper 20 in which the structured carrier 24 and backsheet 26 have length and width dimensions generally greater than the length and width dimensions of the absorbent core. The structured carrier 24 and backsheet 26 extend beyond the edges of the absorbent core 28 to form the perimeter of the diaper 20 . Although the structured carrier 24, backsheet 26 and absorbent core 28 can be assembled in a variety of well-known configurations, preferred diaper configurations are generally described in USP 3, issued January 14, 1975 to Kenneth B. Buell, 860,003, entitled "Contractible Sides of Disposable Diapers"; USP 5,151,092, issued September 29, 1992 to Kenneth B. Buell et al., entitled "Dynamic Elastic Waist Member with Preset Elastic Flexure Hinges" absorbent article"; the above two patents are incorporated herein by reference.

The absorbent core 28 can be any absorbent member that is generally compressible, conformable and non-irritating to the wearer's skin and capable of absorbing and retaining liquids such as urine and other body exudates. As shown in Figure 1, the absorbent core 28 has a garment side, a body side, side edges and a waist edge. The absorbent core 28 can be made in many different sizes and shapes (e.g., rectangular, hourglass, T-shaped, asymmetrical, etc.), and can be made of a variety of liquid-absorbent materials commonly used in disposable diapers and other absorbent articles. , such as comminuted wood pulp commonly known as airfelt. Examples of other suitable absorbent materials include creped cellulose wadding; melt blown polymers including coform; chemically stiffened, modified or crosslinked cellulose fibers; tissues, including tissue wraps and layers Pressed paper; absorbent foam; absorbent sponge; superabsorbent polymers; absorbent gelling material or any equivalent material or combination of materials.

The configuration and configuration of the absorbent core 28 can also be varied (for example, the absorbent core 28 can have zones of various thicknesses, gradients of hydrophilicity, gradients of superabsorbency, lower average density, and lower average basis weight zones; or can have Including one or more layers or one or more structures). However, the total absorbent capacity of the absorbent core 28 should be consistent with the design load and intended use of the diaper 20. In addition, the size and absorbent capacity of the absorbent core 28 can be varied to suit wearers from infants to adults.

Typical absorbent structures used as the absorbent core 28 were granted to Weisman et al., US Patent 4,610,678 entitled "High Density Absorbent Structure" on September 9, 1986; "U.S. Patent 4,673,402; 1989.12.19 granted to Angstadt entitled "Absorbent Core with a Backing Layer" US Patent 4,888,231; 1989.5.30 granted to Alemany et al. entitled "High Density Absorbent with Low Density and Low Weight Acquisition Area" described in US Patent 4,834,735, which is incorporated herein by reference.

The backsheet 26 is positioned adjacent the garment side of the absorbent core 28 and is preferably attached to the absorbent core by fasteners (not shown) such as those known in the art. The term "attached" as used in the present invention includes configurations in which one element is fixed directly to another element by fixing the element directly to the other element, as well as by first fixing an element to an intermediate element, the intermediate Components are in turn fixed to other components and one component is indirectly fixed to other components.

For example, the backsheet 26 may be secured to the absorbent core 28 by a uniform continuous layer of adhesive, a patterned layer of adhesive, or an array of discrete lines, spirals, or spots of adhesive. A satisfactory adhesive has been found to be that manufactured by H.B. Fuller Company of St. Paul, Minnesota, under the designation HL-1258. The attachment means preferably comprises an open pattern network of adhesive filaments, more preferably several coiled in a helical pattern, such as described in U.S. Patent 4,573,986, entitled "Disposable Waste - Retaining Garment" issued March 4, 1986 to Minetola et al. Adhesive filament thread, such as 1975.10.7 to Sprague, Jr.'s US Patent 3,911,173; 1978.11.22 to Ziecker et al. US Patent 4,785,996; 1989.6.27 to Werenicz's US Patent 4,842,666 shown in the device and method icon. The above patents are incorporated herein by reference. In another aspect, attachment means may include thermal bonding, pressure bonding, ultrasonic bonding, dynamic mechanical bonding, or any other suitable bonding means as known in the art, or a combination of these means.

The backsheet 26 is impermeable to liquids, such as urine, and is preferably made of a plastic film, although other flexible liquid impermeable materials may also be used. The term "flexible" as used herein means that the material is compliant and will readily conform to the general shape and contours of the human body.

The backsheet 26 prevents exudates absorbed and contained in the absorbent core 28 from wetting articles that contact the diaper 20, such as bed sheets and undergarments. Thus, the backsheet 26 may comprise a woven or nonwoven material; a polymeric film such as a polyethylene or polypropylene thermoplastic film; or a composite material such as a coated nonwoven material. Preferably, the backsheet 26 is a thermoplastic film having a thickness of about 0.012 mm (0.5 mil) to about 0.051 mm (2.0 mils). Particularly preferred materials for the backsheet 26 include RR8220 blown film and RR5475 cast film manufactured by Tredegar Industries, Inc. (Terre Haute, Indiana). The backsheet 26 is preferably embossed and/or matte finished to provide a more textile-like appearance. Additionally, the backsheet 26 may allow vapors to escape from the absorbent core 28 (ie, be breathable) while still preventing exudates from passing through the backsheet 26 .

The structured carrier 24 has a first or inner surface oriented towards the interior of the disposable diaper, particularly the absorbent core 28, and an opposite second or outer surface oriented towards the wearer's skin when the diaper is worn. .

The structured carrier 24 is juxtaposed with, but not necessarily adjacent to, the body surface of the absorbent core 28, and is preferably attached to the backsheet 26 or the absorbent core 28 by attachment means known in the art. Suitable attachment means are those described above for attaching the backsheet 26 to the absorbent core 28 . In a preferred embodiment of the present invention, the structured carrier 24 and the backsheet 26 are directly attached to each other at the periphery of the diaper.

The structured carrier 24 is compliant, soft feeling and non-irritating to the wearer's skin. Furthermore, the structured carrier 24 is liquid permeable, allowing liquids, such as urine, to readily pass through its thickness. A suitable structured carrier 24 can be made of many materials, such as porous foam, reticulated foam, perforated plastic film, or natural fibers (such as wood or cotton fibers), synthetic fibers (such as polyester or polypropylene fibers) or Woven or nonwoven webs with a combination of natural and synthetic fibers. Preferably, the structured carrier 24 is made of a hydrophobic material to isolate the wearer's skin from liquids contained in the absorbent core 28 . Alternatively, structured carrier 24 can be treated with a surfactant to render it hydrophilic.

Structured support 24 preferably has a plurality of pores having an effective size of at least 0.2 square millimeters, more preferably at least 0.5 square millimeters, still more preferably at least 1.0 square millimeters, most preferably at least 2.0 square millimeters. Valid wells are those with a gray level of 18 or lower on a standard gray scale scale of 0-255 under the image acquisition parameters described below.

The structured carrier 24 preferably has an active open area of at least 15%, more preferably at least 20%, further preferably at least 25%, most preferably at least 30%.

Effective pore size and effective open pore area were determined by the following procedure using the image analysis below. The procedure has three main steps: image acquisition, i.e. obtaining a representative image of the area on the surface of the structured support 24; image measurement, i.e. measuring the image for the percent open area and the area of the individual pores and their perimeter and data analysis, outputting the percent open area, area and perimeter measurements of individual holes to a spreadsheet where frequency distribution, sum of area distributions, and hydraulic radius calculations are performed.

An image analysis system with a frame grabber board, microscope, video camera and image analysis software is used. A frame grabber board, model DT2855, available from DataTranslation (Marlboro, Mass.) was provided. A VH5900 surveillance microscope, video camera with a VH50 lens with a contact head, available from Keyence Company (Fair Lawn, N.J.), was also provided to acquire images and store the images to a computer file. The Keyence microscope acquires the image, and the frame grabber board converts the analog signal of that image into a computer-readable digital format. Images are stored to a computer file and measurements are made using suitable software such as Optimas Image Analysis software, version 3.1, available from BioScan Company (Edmaons, Wash.). In order to use the Optimas Image Analysis software, the computer should have Windows software, version 3.0 or higher, available from Microsoft Corporation (Redmond, Wash.). Should also have a CPU at least equivalent to an Intel 80386. Any suitable desktop PC can be used and the 486DX33 model PC has been found to be particularly suitable. Images stored to and recalled from file were displayed on a Sony Trinitron monitor model PVM-1343MO at a final display magnification of approximately 50x.

The image acquisition procedure indicated above requires a representative structured carrier 24 sample from a particular type of diaper 20 or from 10 different areas of the sample material to be tested. Each area is a rectangle of approximately 5.8 mm x 4.2 mm. Place the sample on a black backing plate to increase the contrast between the well and the portion of the sample that defines the well. The average gray level and standard deviation of the black mat were 16 and 4, respectively.

Images were acquired with the room lights off using a Keyence monitor microscope mounted on a copystand directly above the sample. The Keyence light source that irradiated the sample was adjusted and monitored with Optimas software to measure the average gray level and standard deviation of a light split with a blackness of 0.3 on a Kodak Gray Scale purchased from Eastman Kodak Company (Rochester, New York). Adjust the control mechanism of the Keyence light source so that the average gray level of the irradiated light splitter is 111±1, and the standard deviation is 10±1. All images were acquired in a single time period, and the Keyence light source was monitored by measuring the average gray level and standard deviation of the beam splitter throughout the image acquisition.

When measuring individual holes, only the effective hole size is important. Measuring the effective pore size quantifies the pore size that is expected to contribute to the porosity of the structured support 24 and accounts for the contribution of fibers and fiber bundles across an area expected to be pores. A valid aperture is any aperture through structured support 24 that has a gray level of less than or equal to 18 using the image acquisition parameters described herein. Thus, a desired hole can be divided into a plurality of effective holes by the transverse fibers.

Calibrate the image analysis software in millimeters by the scale image acquired from the sample image. A 3×3 pixel averaging filter from the Optimas 3.1 Image menu was applied to each stored image to reduce noise. The detected hole gray scale range is 0-18. Holes not completely contained within the 5.8 x 4.2 viewing area were considered excluded from the respective area and perimeter measurements. Therefore, the mean values and distributions of area and perimeter are not affected by holes not completely contained within the viewing area.

However, individual holes in the image that cannot be fully observed will be included in the calculation of percent open area. This difference exists because the percent open area is simply the ratio of the number of pixels to the total number of pixels within the image with gray levels 0-18. Areas with a gray scale of 19 or greater are not included in the calculation of open area.

Optimas Image Analysis software was used to measure the average of the percent open area of 10 images of each structured support 24 . The percentage of open area is defined as the ratio of the number of pixels with a gray level of 0-18 to the total number of pixels in the image. The percent open area is measured for each image representing a particular region of the structured support sample. The percent open area for each of the 10 images was then averaged to obtain the percent open area for the entire sample.

Data analysis was performed by an Excel spreadsheet, also purchased from Microsoft Corporation (Redmond, Wash.). The Excel extension table organizes the measurements of percent open cell area, cell area, and cell perimeter obtained from the Optimas software. The sample mean and standard deviation for each pore area, size and frequency distribution, and the calculated hydraulic radius (area divided by perimeter) for each pore were obtained using this expanded table.

The distribution of individual pore areas was also calculated using an Excel spreadsheet. The holes are sorted into libraries with certain size ranges. The number of pore areas falling within certain size ranges of interest and the sum of the areas within each range are determined. Set the range in increments of 0.05 mm². These areas are expressed as a percentage of the total open area of the samples. The frequency and sum of the area distributions were obtained by combining the individual well measurements from all 10 images for each sample.

A number of production techniques are available to produce structured vectors24. For example, structured carrier 24 may be a nonwoven web of fibers such as spunbond, carded, wetlaid, meltblown, hydroentangled, combinations of the foregoing, or composite laminates. A preferred structured carrier 24 comprises a carded/carded composite material and a hydroentangled fibrous web that is hydroentangled on a forming wire and through-air bonded by means well known in the nonwovens art. . On the other hand, apertured formed films, woven meshes and woven apertured nettings are also suitable.

Although the specific composition delivered according to the method of the present invention (hereinafter referred to as "skin care composition" and "composition") is not an important factor in improving the skin condition of the area below the absorbent article, it is clear that the composition must Provides a protective, non-occlusive function (such as a relatively liquid-impermeable but vapor-permeable barrier) to prevent overhydration of the skin and exposure of the skin to substances contained in bodily waste, or it must contain direct or indirect Agents that provide skin care benefits. For example, indirect efficacy includes improved removal of skin irritants such as feces or urine. The composition can be in a variety of forms including, but not limited to, emulsions, lotions, creams, ointments, salves, powders, suspensions, capsules, gels, and the like.

As used herein, the term "an effective amount of a skin care composition" refers to an amount of a particular composition which, when applied to or migrated to one or more body-contacting surfaces of an absorbent article, will be effective to provide skin care through the skin over time. Absorbent articles deliver a protective barrier and/or provide skin care benefits. The effective amount of the composition applied to the article will, of course, depend largely on the particular composition used. However, the amount of the composition on at least a portion of the absorbent article which contacts the wearer's surface is preferably in the range of about 0.05 mg/in ² (0.0078 mg/cm ² ) to about 80 mg/in ² (12.4 mg/cm ² ), more preferably about 1 mg/in ² (0.16 mg/cm ² ) to about 40 mg/in ² (6.20 mg/cm ² ), more preferably about 4 mg/in ² (0.62 mg/cm ² ) to About 26 mg/in ² (4.03 mg/cm ² ). These ranges are provided as examples only, and those of ordinary skill in the art will recognize that the nature of the composition will determine the amount of composition that must be applied to achieve the desired skin care benefit, and such amounts can be determined from conventional Experiment to determine.

Although the amount of skin care composition applied to an absorbent article is an important aspect of the methods of the present invention, the amount of composition delivered to the wearer's skin during use of one or more treated articles is more important. as important. Although the amount that must be delivered to the skin to provide the desired skin care benefit will depend to some extent on the nature of the composition employed, applicants have found that relatively low amounts can be delivered while still providing the desired skin care benefits. skin effect. This is especially true for the preferred compositions.

Another benefit of the method of the present invention is to control the application of the skin care composition to provide the desired low but effective amount of the composition. This is in contrast to the typical sporadic manual application of skin care agents where the caregiver/user will often apply a much larger amount than required. Excessive material added by hand may also adversely affect the fluid handling properties of the absorbent article as a result of transport from the skin to the article. Indeed, with some materials, such as petrolatum, the amount applied by hand may actually result in an occlusive effect, thereby damaging the skin. One benefit of the method of the present invention is to provide a barrier to surface moisture while avoiding occlusion of the skin (ie, maintaining skin breathability). Thus, the method of the present invention controls the delivery of the composition throughout the wearing period, which will deliver an optimum amount of the composition to the skin to maintain and/or improve skin health.

For the amount of skin care composition delivered to the wearer during about 3 hours ⁽ typical daytime wear time) of a treated absorbent article, the preferred amount is at least about 0.01 mg/in during 3 hours of wear (0.0016 mg/cm ² ), more preferably at least about 0.05 mg/in ² (0.0078 mg/cm ² ), still more preferably at least about 0.1 mg/in ² (0.016 mg/cm ² ) of the composition is delivered to the skin. Typically, a treated article delivers the composition in an amount of about 0.01 mg/in ² (0.0016 mg/cm ² ) to about 5 mg/in ² (0.78 mg/cm ² ), more preferably is about 0.05 mg/in ² (0.0078 mg/cm ² ) to about 3 mg/in ² (0.47 mg/cm ² ), more preferably about 0.1 mg/in ² (0.016 mg/cm ² ) to about 2 mg/in in ² (0.31 millicharge/cm ² ).

For such cases where treated supplies are used continuously over a 24-hour period (in other words, where changes are made according to a regular pattern of use, which typically includes changing every 3 to 4 hours during the day and a new supply at night before going to bed) , preferably at least about 0.03 mg/in ² (0.0047 mg/cm ² ), more preferably at least about 0.1 mg/in ² (0.016 mg/cm ² ), more preferably at least about 0.3 mg/in ² ( 0.047 mg/cm ² ) of the composition is delivered to the skin of the wearer. Typically, the amount of composition delivered is from about 0.03 mg/in ² (0.0047 mg/cm ² ) to about 18 mg/in ² (2.79 mg/cm ² ), more preferably about 0.1 mg/in ² (0.016 mg/cm ² ) to about 10 mg/in ² (1.55 mg/cm ² ), still more preferably about 0.3 mg/in ² (0.047 mg/cm ² ) to about 6 mg/in ² (0.93 mg/cm ² ).

It will be appreciated that of the many materials used in skin care compositions that are delivered to the skin according to the methods of the present invention, those materials that are considered safe and effective skin care agents are reasonable materials for use in the present invention. This class of materials includes Class I active substances as defined in the U.S. Federal Food and Drug Administration's (FDA) interim final rule for over-the-counter skin protection drug products for human use, which currently includes: alantoin, aluminum hydroxide gel, zinc paste , cocoa butter, dimethicone, cod liver oil (blended), glycerin, kaolin, petrolatum, lanolin, mineral oil, shark liver oil, white petrolatum, talc, topical starch, zinc acetate, zinc carbonate, zinc oxide, etc. . Other materials that may be used are Class III active substances as defined in the U.S. Federal Food and Drug Administration (FDA) Interim Final Rule for Over-the-Counter Human Skin Protection Drug Products, which currently include: live yeast cell derivatives, aldioxa, Aluminum acetate, microporous cellulose, vitamin D ₃ , colloidal oat flour, cysteine hydrochloride, panthenol, Peruvian balsam oil, protein hydrolyzate, racemic methionine, sodium bicarbonate, vitamin A, etc.

Many FDA-regulated skin care ingredients are currently used in commercially available skin care products such as A+D® Ointment, Vaseline® Petroleum Jelly, Desitin® Diaper Rash Ointment and Daily Care Ointment, GoldBond® Medicated Baby Powder, Aquaphor® Treatment Ointment , Baby Magic® Baby Lotion, Johnson's Ultra Sensitive® Baby Balm, Johnson's Baby Lotion, Lip Balm, etc. These commercially available products can be applied to absorbent articles to produce treated articles for use in the methods of the present invention, with or without modifications to facilitate their delivery by the novel method.

As described below, the skin care compositions used in the methods of the present invention preferably, though not necessarily, have a melting point distribution such that the compositions are relatively immobilized and localized on the wearer-contacting surface of the article at room temperature and readily delivered at body temperature. to the wearer and, under extreme storage conditions, is still not completely liquid. Preferably the composition is readily transferable to the skin by normal contact, wearer movement and/or body heat. Because the composition is preferably substantially immobilized on the wearer-contacting surface of the article, relatively low levels of the skin care composition are required to impart the desired skin care benefit. Additionally, no special barrier or packaging material is required in packaging the treated articles used in the methods of the present invention.

In a preferred embodiment, the skin care compositions used in the present invention are solid, more usually semi-solid at 20°C, ie ambient temperature. "Semi-solid" means that the composition has the rheology of a pseudoplastic or plastic liquid. If no shear is applied, the composition has a semi-solid appearance, but as the shear rate is increased, the composition becomes fluid. This is because although the composition mainly includes solid components, it also includes some minor liquid components. Preferably, the compositions of the present invention have a zero shear viscosity of from about 1.0 x ¹⁰⁶ centipoise to about 1.0 x ¹⁰⁸ centipoise, more preferably from about 5.0 x ¹⁰⁶ centipoise to about 5.0 x ¹⁰⁷ centipoise. The term "zero shear viscosity" as used herein refers to the viscosity measured with a disk and cone viscometer at very low shear rates (e.g., 1.0 sec ^-1 ); a suitable instrument is TA Instruments from New Castle, DE The company purchased it as the CSL100 model. One of ordinary skill in the art will recognize that other components than high melting point components (described below) may be used to provide comparable measured viscosities for compositions containing such components, the zero shear viscosity being Determined by extrapolation of viscosity versus shear rate curves for such compositions to zero shear rate at about 20°C.

Preferred compositions are semisolid at least at room temperature to minimize migration of the composition. In addition, the final melting point (100% liquid) of the composition is preferably above the storage conditions (greater than 45°C) that may be "harsh" (eg, warehouse in Arizona, car body in Florida, etc.). Representative compositions having these melting point characteristics are described in detail in US Pat. Nos. 5,643,588 (Roe et al.), 5,607,760 (Roe et al.), 5,609,587 and 5,635,191, the disclosures of which are incorporated herein by reference. In particular, preferred compositions have the melting point distribution shown in the following table:

characteristic Preferred range Most preferred range % liquid at room temperature (20°C) 2-50 3-25 % liquid at body temperature (37°C) 25-95 30-90 Final melting point (°C) ≥38 ≥45

By being solid or semi-solid at ambient temperature, the preferred compositions have less tendency to run off and migrate into undesired areas of the absorbent article to which they are applied. This means that less skin care composition is required to impart the desired therapeutic, protective and/or conditioning benefits.

In order to increase the fixity of the preferred compositions, the viscosity of the formulated composition should be as high as possible to prevent flow to undesired areas within the article. Unfortunately, in some instances, high viscosity may inhibit the delivery of the composition to the wearer's skin. Accordingly, the viscosity should be balanced; high enough to anchor the composition on the surface of the article, but not so high that it impedes delivery to the wearer's skin. Suitable viscosities for compositions are generally about 5-500 centipoise, preferably about 5-300 centipoise, more preferably about 5-100 centipoise, as measured at 60°C using a rotational viscometer (a suitable viscometer is available from Melrose Lab Line Instruments, Park, IL, as model 4537). The viscometer was operated at 60 rpm using spindle number 2.

For compositions designed to provide skin smoothness benefits, a useful active ingredient in such compositions is one or more skin protectants and/or emollients. As used herein, an "emollient" is a material that prevents wetting or irritation, softens, softens, smoothes, coats, lubricates, moisturizes, protects and/or cleanses the skin. It should be recognized that the specified actives listed above are lubricants as defined herein. In a preferred embodiment, these lubricants have a plastic or liquid consistency at room temperature, ie 20°C. This particular emollient consistency imparts a soft, lubricious and lotion-like feel to the composition.

Representative lubricants useful in the present invention include, but are not limited to, the following lubricants: petroleum-based; polyol polyesters; sucrose fatty acid esters; polyethylene glycol and its derivatives; wetting agents; fatty acid esters; Alkyl ethoxylates; fatty acid ester ethoxylates; fatty alcohols; polysiloxanes; propylene glycol and its derivatives; glycerin and its derivatives (including glycerides, acetylglycerides and _{C12 -} Ethoxylated glycerides of _C28 fatty acids), triethylene glycol and its derivatives; spermaceti or other waxes; fatty acids; fatty alcohol ethers (especially substances with a fatty chain length of 12-28 carbon atoms , such as stearic acid); propoxylated fatty alcohols; other fatty esters of polyhydric alcohols; lanolin and its derivatives; kaolin and its derivatives; any of the prescribed skin care agents listed above; or these emollients mixture. Suitable petroleum-based lubricants include those hydrocarbons having a chain length of 16 to 32 carbon atoms, or mixtures of such hydrocarbons. Petroleum-based hydrocarbons with these chain lengths include mineral oil (also known as "liquid petrolatum") and petrolatum (also known as "ozokerite", "petroleum jelly" and "mineral jelly"). Mineral oil generally refers to a mixture of lower viscosity hydrocarbons having 16-20 carbon atoms. Petroleum jelly generally refers to a more viscous mixture of hydrocarbons with 16-32 carbon atoms. Petrolatum and mineral oil are particularly preferred lubricants for use in the compositions of the present invention.

Suitable fatty acid ester lubricants include those derived from C _12- C ₂₈ fatty acids, preferably C _16- C ₂₂ saturated fatty acids, and short chain (C _1- C ₈ , preferably C _1- C ₃ ) monohydric alcohols . Representative examples of such esters include methyl palmitate, methyl stearate, isopropyl laurate, isopropyl myristate, isopropyl palmitate, ethylhexyl palmitate, and mixtures thereof. Suitable fatty acid ester lubricants are also derived from esters of longer chain fatty alcohols ( _{C12- C28} , preferably _{C12- C16} ) and shorter chain fatty acids such as lactic acid, such as lauryl lactate and cetyl lactate .

Suitable alkyl ethoxylate-based lubricants include _{C12- C22} fatty alcohol ethoxylates having an average degree of ethoxylation of from about 2 to about 30. Preferred fatty alcohol ethoxylate lubricants are selected from the group consisting of lauryl, cetyl and stearyl ethoxylates having an average degree of ethoxylation of from about 2 to about 23, and mixtures thereof. Representative examples of the alkyl ethoxylates include: laureth-3 (lauryl ethoxylate with an average degree of ethoxylation of 3), laureth Ether-23 (lauryl ethoxylate with an average degree of ethoxylation of 23), ceteth-10 (cetyl alcohol ethoxylate with an average degree of ethoxylation of 10), Stearyl Ethoxylate-10 (stearyl alcohol ethoxylate with an average degree of ethoxylation of 10). When these alkyl ethoxylate lubricants are used, they are typically used in combination with petroleum-based lubricants such as petrolatum at a weight ratio of alkyl ethoxylate lubricant to petroleum-based lubricant of from about 1:1 to about 1:1: 5, preferably from about 1:2 to about 1:4.

Suitable fatty alcohol lubricants include C _12- C ₂₂ fatty alcohols, preferably C _16- C ₁₈ fatty alcohols. Representative examples include cetyl alcohol and stearyl alcohol, and mixtures thereof. When these fatty alcohol lubricants are used, they are typically used in combination with petroleum based lubricants such as petrolatum at a weight ratio of fatty alcohol lubricant to petroleum based lubricant of from about 1:1 to about 1:5, preferably from about 1:1 to about 1:2.

Other classes of lubricants suitable for use in the present invention include silicone compounds. Suitable polysiloxane materials generally useful in the present invention include those materials having monomeric siloxane units of the following structure:

In the formula, for each independent siloxane monomer unit, _R1 and _R2 can independently be hydrogen or any alkyl, aryl, alkenyl, alkaryl, aralkyl, cycloalkane groups, halogenated hydrocarbons, or other groups. Any of these groups may be substituted or unsubstituted. _R1 and _R2 in any particular monomeric unit may be different from the corresponding functional groups of the next linked monomeric unit. In addition, polysiloxane may be linear, branched, or have a cyclic structure. Additionally, the groups _R1 and _R2 may independently of each other be other silicon-containing functional groups such as, but not limited to, siloxanes, polysiloxanes, silanes, and polysilanes. The groups _R1 and _R2 may also comprise any organic functional groups including, for example, alcohol, carboxylic acid, phenyl and amine functional groups.

Exemplary alkyl groups are methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, octadecyl, and the like. Exemplary alkenyl groups are vinyl, allyl and the like. Exemplary aryl groups are phenyl, biphenyl, naphthyl and the like. Exemplary alkaryl groups are tolyl, xylyl, ethylphenyl, and the like. Exemplary aralkyl groups are benzyl, α-phenethyl, β-phenethyl, α-phenbutyl, and the like. Exemplary cycloalkyl groups are cyclobutyl, cyclopentyl, cyclohexyl, and the like. Exemplary halohydrocarbyl groups are chloromethyl, bromoethyl, tetrafluoroethyl, fluoroethyl, trifluoroethyl, trifluoromethylphenyl, hexafluoroxylyl, and the like.

The viscosities of useful silicones can vary as much as silicones typically vary in viscosity so long as the silicones flow or are made to flow when used in absorbent articles. This includes, but is not limited to, as low as 5 centistokes (measured by a glass viscometer at 37°C) to about 20,000,000 centistokes. Preferably the polysiloxane has a viscosity at 37°C of from about 5 to about 5,000 centistokes, more preferably from about 5 to about 2,000 centistokes, most preferably from about 100 to about 1000 centistokes. High-viscosity polysiloxanes that are inherently resistant to flow by methods such as emulsifying the polysiloxane in a surfactant, or providing a solution of the polysiloxane with the aid of a solvent such as hexane (for example only) Effective deposition on absorbent articles. Particular methods of adding silicone lubricants to absorbent articles are discussed in more detail below.

Preferred silicone compounds for use in the present invention are disclosed in US Patent 5,059,282, Ampulski et al., issued October 22, 1991, which is incorporated herein by reference. Particularly preferred silicone compounds useful as lubricants in the compositions of the present invention include: phenyl-functional polymethylsiloxane compounds (e.g., Dow Corning 556 Cosmetic-Grade Fluid: polyphenylmethyl siloxane) and cetyl or octadecyl functionalized polydimethylsiloxanes such as Dow 2502 and Dow 2503 polysiloxane fluids respectively. In addition to substituents with phenyl functions or alkyl groups, effective substituents are also amino, carboxyl, hydroxyl, ether, polyether, aldehyde, ketone, amide, ester and thiol groups. Of these available substituents, those containing phenyl, amino, alkyl, carboxyl, and hydroxy are preferred over others; most preferred is the phenyl function.

Suitable wetting agents include: glycerin, propylene glycol, sorbitol, trihydroxystearin, and the like.

The amount of emollient included in the composition will depend on various factors including the particular emollient involved, the emollient benefit desired, other components of the composition, and the like. The composition may contain a lubricant in an amount of about 0-100% by total weight. Preferably, the composition comprises from about 10-95% by weight lubricant, more preferably from about 20-80%, most preferably from about 40-75%.

An optional and preferred component of the skin treatment/protection/skin conditioning compositions used in the methods of the present invention is the ability to incorporate the composition (including preferably emollients and/or other skin conditioning/treatment/protection agents) ) An agent immobilized at a desired location in or on a treated article. Because certain preferred lubricants in the composition have a plastic or fluid consistency at 20°C, the lubricants tend to have a tendency to flow or migrate even when subjected to moderate shear. When the lubricant is applied to the wearer contacting surface or other portion of the absorbent article, especially in a molten or melted state, the lubricant will not remain primarily in or on the treated area. Instead, the lubricant will tend to migrate and flow into unwanted areas of the article.

In particular, if the lubricant migrates into the interior of the article, it may have an undesired effect on the absorbency of the article's absorbent core, as is the case with many lubricants and other skin care agents used in compositions used in the methods of the present invention. Due to the hydrophobic nature of the conditioner. This also means that much more lubricant needs to be applied to the article to obtain the desired skin smoothness benefits. Increased lubricant levels not only increase cost, but also exacerbate adverse effects on the absorbent core of the article and poor delivery of the composition during processing/reconstruction of the treated article.

The immobilizing agent counteracts this tendency of the lubricant to migrate or flow by primarily immobilizing the lubricant on the surface or within the area of the article to which the composition will be applied. This is believed to be due in part to the fact that the fixative raises the melting point and/or viscosity of the composition above that of the lubricant. Since the fixative is preferably miscible with (or soluble in) the lubricant with the aid of a suitable emulsifier, it also traps the lubricant on the wearer contacting surface of the article or in the area where the lubricant is to be applied.

It is also advantageous to "lock" the fixative onto the wearer-contacting surface or area of the article to which it is applied. This can be achieved by using a fixative that will "set" (or cure) quickly when applied to the article. In addition, external cooling of the treated article by means of blowers, fans, chill rolls, etc. can accelerate the crystallization of the fixative.

In addition to being miscible with (or soluble in) the lubricant, the fixative preferably has a melting point distribution that will provide a composition that is solid or semi-solid at ambient temperature. In this regard, preferred fixatives have a melting point of at least about 35°C. As such, the fixative itself will not have a tendency to migrate or flow. Preferred fixatives have a melting point of at least about 40°C. Typically, the fixative has a melting point in the range of from about 50°C to about 150°C.

When used in the present invention, suitable immobilizing agents may be selected from any of a number of agents so long as the preferred properties of the skin care composition provide the skin benefits described herein. Preferred immobilizing agents will include: selected from polyhydroxy fatty acid esters, polyhydroxy fatty acid amides, C _14- C ₂₂ fatty alcohols, C _12- C ₂₂ fatty acids and C 12-C 22 fatty acids with an average degree of ethoxylation of about _2-30. Fixative for _C22 fatty alcohol ethoxylates and mixtures thereof. Preferred fixatives include: _{C16- C18} fatty alcohols, most preferred crystalline high melting point substances are selected from: cetyl alcohol, stearyl alcohol, behenyl alcohol and mixtures thereof. The linear structure of these materials accelerates cure on treated articles. Mixtures of cetyl alcohol and stearyl alcohol are particularly preferred. Other preferred fixatives include: _{C16- C18} fatty acids, most preferably selected from: palmitic acid, stearic acid and mixtures thereof. Mixtures of palmitic and stearic acids are particularly preferred. Still other preferred fixatives include: _{C16- C18} fatty alcohol ethoxylates having an average degree of ethoxylation of from about 5 to about 20. Preferably the fatty alcohols, fatty acids and fatty alcohol ethoxylates are linear. Importantly, these preferred fixatives such as _{C16- C18} fatty alcohols increase the rate of crystallization of the composition, allowing the composition to crystallize rapidly on the surface of the substrate.

Other types of ingredients that can be used as fixatives, either alone or in combination with the above-mentioned fixatives, include waxes such as carnauba wax, ozokerite, beeswax, candelilla wax, paraffin wax, ozokerite, spanish wax , small crown coconut wax, rezowax, isoparaffin and other known mixed and mineral waxes. The high melting points of these materials can aid in anchoring the composition to the desired surface or location on the absorbent article. In addition, microcrystalline wax is also an effective fixative. Microcrystalline waxes help to "lock" low molecular weight hydrocarbons into skin care compositions. A preferred wax is paraffin. Another example of a particularly preferred fixative is paraffin such as Parrafin S.P. 434 (available from Strahl and Pitsch Inc. P.O. Box 1098 West Babylon, NY 11704).

Suitable polyhydroxy fatty acid esters for use in the present invention will have the formula:

In the formula, R is a C _5- C ₃₁ hydrocarbon group, preferably a straight-chain C _7- C ₁₉ alkyl or alkenyl, more preferably a straight-chain C _9- C ₁₄ alkyl or alkenyl, most preferably a straight-chain _{C11- C17} alkyl or alkenyl, or mixtures thereof; Y is a polyhydroxyhydrocarbyl moiety in which the hydrocarbyl chain has at least 2 free hydroxyl groups directly attached to the chain; n is at least 1. Suitable Y groups can be composed of polyols such as glycerol, pentaerythritol; sugars such as raffinose, maltose glucose, galactose, sucrose, glucose, xylose, fructose, maltose, lactose, mannose and erythrose; sugar alcohols such as erythrose Derived from sugar alcohols, xylitol, maltitol, mannitol, and sorbitol; and anhydrides of sugar alcohols such as sorbitan.

One class of suitable polyhydroxy fatty acid esters for use in the present invention includes certain sorbitan esters, preferably sorbitan esters of _{C16- C22} saturated fatty acids. Due to the typical method of preparation of these sorbitan esters, these sorbitan esters often comprise mixtures of mono-, di-, tri-, etc. esters. Representative examples of suitable sorbitan esters include sorbitan palmitate (e.g., SPAN 40), sorbitan stearate (e.g., SPAN 60), and sorbitan behenate, which comprise Monoesters, diesters and triesters of one or more of these sorbitan esters, for example sorbitan palmitate monoesters, diesters and triesters, sorbitan stearate monoesters, diesters and triesters, Sorbitan mono-, di-, and triester behenic acids, and mixed sorbitan mono-, di-, and triesters of tallow fatty acids. Alternatively, mixtures of different sorbitan esters may be used, such as a mixture of sorbitan palmitate and sorbitan stearate. A particularly preferred sorbitan ester is sorbitan stearate, usually a mixture of mono-, di-, and triesters (plus some tetra-esters) such as SPAN 60, and under the trade name GLYCOMUL-S (Lonza, Inc.) sorbitan stearate. Although these sorbitan esters generally contain mixtures of monoesters, diesters and triesters, plus some tetraesters, within these mixtures the monoesters and diesters predominate.

Another class of suitable polyhydroxy fatty acid esters for use in the present invention includes certain monoglycerides, preferably monoglycerides of _{C16- C22} saturated fatty acids, such as glyceryl monostearate, glyceryl monopalm Glyceryl mono(behenic acid) ester. Also, as with sorbitan esters, mixtures of monoglycerides will generally contain some di- and triesters. However, said mixture should mainly comprise monoglycerides to be used in the present invention.

Another class of suitable polyhydroxy fatty acid esters for use in the present invention includes certain sucrose fatty acid esters, preferably _{C12- C22} saturated fatty acid esters of sucrose. Sucrose mono- and diesters are particularly preferred and include sucrose mono- and diesters of stearic acid and sucrose mono- and diesters of laurate.

Suitable polyhydroxy fatty acid amides for use in the present invention have the formula:

In the formula, ^R is H, C _1- C ₄ hydrocarbon group, 2-hydroxyethyl, 2-hydroxypropyl, methoxyethyl, methoxypropyl or a mixture thereof, preferably C _1- C ₄ alkyl, Methoxyethyl or methoxypropyl, more preferably C _or C _alkyl or methoxypropyl, most preferably C _alkyl (i.e. methyl) or methoxypropyl; R ² is a C _5- C ₃₁ hydrocarbon group, preferably a straight-chain C _7- C ₁₉ alkyl or alkenyl group, more preferably a straight-chain C _9- C ₁₇ alkyl or alkenyl group, most preferably a straight-chain C _11- C ₁₇ Alkyl or alkenyl, or mixtures thereof; Z is a polyhydroxyhydrocarbyl moiety in which the linear hydrocarbyl chain has at least 3 hydroxyl groups directly attached to the chain. See US Patent 5,174,927, issued to Honsa on December 29, 1992 (hereby incorporated by reference), which discloses these polyhydroxy fatty acid amides and methods for their preparation.

The Z moiety is preferably derived from a reducing sugar in a reductive amination reaction; most preferred is glycidyl. Suitable reducing sugars include glucose, fructose, maltose, lactose, galactose, mannose and xylose. Dextrose-enriched corn syrup, fructose-enriched corn syrup, and maltose-enriched corn syrup can be used, as well as the various sugars listed above. These corn syrups can yield a mixture of sugar components for Part Z.

The moiety Z is preferably selected from _-CH2- (CHOH) _n - _CH2OH , -CH( _CH2OH )-[(CHOH) _n-1 ] _-CH2OH , _-CH2OH - _CH2- (CHOH) ₂ (CHOR ³ )(CHOH)-CH ₂ OH, wherein n is an integer of 3-5, and R ³ is H or a cyclic or aliphatic monosaccharide. Most preferred are glycidyl groups wherein n is 4, especially _-CH2- (CHOH) _{4- CH2OH} .

In the above formula, ^R can be, for example, N-methyl, N-ethyl, N-propyl, N-isopropyl, N-butyl, N-2-hydroxyethyl, N-methoxypropyl ^R can be selected to provide, for example, cocamide, stearamide, oleamide, lauramide, myristamide, capramide, palmitamide, tallowamide, and the like. The Z moiety can be 1-deoxyglucosyl, 2-deoxyfructosyl, 1-deoxymaltosyl, 1-deoxylactosyl, 1-deoxygalactosyl, 1-deoxymannosyl, 1-deoxymaltotriosyl wait.

The most preferred polyhydroxy fatty acid amides have the general formula:

In the formula, R ¹ is methyl or methoxypropyl; R ² is C _11- C ₁₇ linear alkyl or alkenyl. These substances include: N-Lauryl-N-methylglucamide, N-Lauryl-N-methoxypropylglucamide, N-cocoyl-N-methylglucamide, N-coco Oleyl-N-methoxypropyl glucamide, N-palmityl-N-methoxypropyl glucamide, N-tallow-N-methyl glucamide or N-tallow-N- Methoxypropyl Glucamide.

As noted previously, some fixatives require an emulsifier to aid in dissolution in the lubricant. This is especially true for certain glucamides such as N-alkyl-N-methoxypropyl glucamides having an HLB value of at least about 7. Suitable emulsifiers generally include those having an HLB value below about 7. In this regard, it has been found that previously described sorbitan esters, such as sorbitan stearate having an HLB value of about 4.9 or less, can be used to dissolve these glucosamide fixatives in petrolatum. Other suitable emulsifiers include: stearyl polyoxyethylene ether-2 (polyethylene glycol ether of stearyl alcohol corresponding to the formula CH ₃ (CH ₂ ) ₁₇ (OCH ₂ CH ₂ ) _n OH, where The average value of n is 2), sorbitan tristearate, isosorbide laurate and glyceryl monostearate. The emulsifier is used in an amount sufficient to dissolve the fixative in the lubricant so that a substantially homogeneous mixture is obtained. For example, when 20% of a 1:1 mixture of stearyl-2 and sorbitan tristearate is added as an emulsifier, the An approximately 1:1 mixture of N-cocoyl-N-methylglucamide and petrolatum will melt into a single phase mixture.

Other types of ingredients that can be used as fixatives, either alone or in combination with the above-mentioned fixatives, include waxes such as carnauba wax, beeswax, candelilla wax, paraffin wax, ozokerite, Spanish grass wax, coronet Coconut wax, rezowax and other known waxes. A preferred wax is paraffin. An example of a particularly preferred paraffin is Parrafin S.P. 434 (available from Strahl and Pitsch Inc. P.O. Box 1098 West Babylon, NY 11704).

The amount of optional fixative that should be added to the composition will depend on various factors including the actives involved (such as lubricants), the particular fixative involved (if present), other components in the composition , whether an emulsifier is needed to dissolve the fixative in other components, etc. If a fixative is used, the composition will generally comprise from about 5% to about 90% fixative. Preferably, the composition will comprise from about 5% to about 50%, most preferably from about 10% to about 40%, of a fixative.

Of course, it is highly desirable that at least a portion of the structured carrier of the article be made of a hydrophilic material to facilitate rapid transport of liquids, such as urine, through the structured carrier. Similarly, it is desirable that the composition should be sufficiently wettable to ensure rapid liquid transport through the structured carrier. Alternatively, hydrophobic skin care compositions may be used as long as they are applied such that the fluid handling properties of the structured carrier are adequately maintained. (For example, as discussed below, applying the composition unevenly to the structured carrier is one way to achieve this goal.) This reduces the amount of bodily exudates that will flow out of the composition-treated structured carrier, rather than the possibility of being guided through a structured carrier and absorbed by the absorbent core.

Where hydrophilic compositions are desired, a hydrophilic surfactant (or mixture of hydrophilic surfactants) may or may not be required to improve wettability, depending on the particular components used in the composition. For example, certain fixatives, such as N-coco-N-methoxypropylglucamide, have an HLB value of at least about 7 and are sufficiently wettable without the addition of hydrophilic surfactants. Other fixatives, such as _{C16- C18} fatty alcohols with HLB values less than about 7, may require the addition of hydrophilic surfactants to improve wettability when the composition is applied to the structured support of the article. Similarly, hydrophobic lubricants such as petrolatum may require the addition of a hydrophilic surfactant, if a hydrophilic surfactant is desired. Of course, when the surface in contact with the wearer is not the structured carrier of the article or when the fluid handling properties of the structured carrier can be adequately maintained by other means (such as non-uniform application), the wettability problem will not be - factor.

Suitable hydrophilic surfactants are preferably miscible with the other ingredients of the skin care composition to form a blended mixture. These surfactants should also be mild and non-irritating to the skin since use of the disposable absorbent product to which the composition is applied may sensitize the skin. Typically, these hydrophilic surfactants are non-ionic which are not only non-irritating to the skin but which will avoid adverse effects on any other structure within the article being treated. For example, reduction in tensile strength of tissue laminates, adequacy of adhesive bonds, etc.

Suitable nonionic surfactants are substantially non-migrating after the composition has been applied to the article and typically have an HLB value of from about 4 to about 20, preferably from about 7 to about 20. To be non-migratory, these nonionic surfactants will generally have a melting temperature above the temperatures encountered during storage, transport, trade and use of disposable absorbent articles, for example at least about 30°C. In this regard, these nonionic surfactants will preferably have melting points similar to the aforementioned fixatives.

Suitable nonionic surfactants for use in compositions to be applied to the article, at least in the liquid release zone of the diaper, include: alkyl glycosides; alkyl glycoside ethers, as described in 1977, incorporated herein by reference Disclosed in U.S. Patent 4,011,389 issued to Langdon et al. on March 8; alkyl polyethoxylated esters such as Pegosperse 1000MS (available from Lonza, Inc., Fair Lawn, New Jersey), with an average degree of ethoxylation ranging from about 2 to about 20, preferably from about 2 to about 10 ethoxylated sorbitan monoesters, diesters and/or triesters of C ₁₂ -C ₁₈ fatty acids, such as TWEEN 60 (average degree of ethoxylation approx. 20 sorbitan stearate), TWEEN 61 (sorbitan stearate with an average degree of ethoxylation of about 4), and condensation products of aliphatic alcohols with about 1 to about 54 moles of ethylene oxide . The alkyl chain of the aliphatic alcohol is generally in a straight (linear) configuration and contains from about 8 to about 22 carbon atoms. Particularly preferred are condensation products of alcohols containing alkyl groups of about 11 to about 22 carbon atoms with about 2 to about 30 moles of ethylene oxide per mole of alcohol. Examples of such ethoxylated alcohols include: the condensation product of myristyl alcohol with 7 moles of ethylene oxide per mole of alcohol, coconut alcohol (a mixture of fatty alcohols with alkyl chain lengths varying between 10 and 14 carbon atoms), ) is the condensation product of about 6 moles of ethylene oxide. A number of suitable ethoxylated alcohols are commercially available including TERGITOL 15-S-9 (a condensation product of a C ₁₁ -C ₁₅ linear alcohol with 9 moles of ethylene oxide), sold by Union Carbide; KYRO EOB (condensation product of a _C13 - _C15 linear alcohol with 9 moles of ethylene oxide), sold by The Procter & Gamble Co.; surfactants under the name NEODOL (sold by Shell Chemical Company), especially NEODOL 25-12 (Condensation product of C ₁₂ -C ₁₅ linear alcohol with 12 moles of ethylene oxide) and NEODOL 23-6.5T (C ₁₂ -C ₁₃ linear alcohol with 6.5 moles of ethylene oxide that has been distilled (topped) to remove certain impurities Condensation products of alkanes); especially the surfactants under the name PLURAFAC (sold by the company BASF), especially PLURAFAC A-38 (condensation product of C ₁₈ linear alcohol with 27 moles of ethylene oxide). (Certain hydrophilic surfactants, especially ethoxylated alcohols such as NEODOL 25-12 can also function as alkyl ethoxylated lubricants). Other examples of preferred ethoxylated alcohol surfactants include: Brij surfactants of the ICI class and mixtures thereof, wherein Brij 72 (i.e. stearyl polyoxyethylene ether-2) and Brij 76 (i.e. stearyl polyoxyethylene ether-2) Oxyethylene ether-10) is particularly preferred. Additionally, mixtures of cetyl and stearyl alcohols ethoxylated to an average degree of ethoxylation of from about 10 to about 20 are also useful as hydrophilic surfactants.

Another class of suitable surfactants for use in the composition includes: Aerosol OT, sodium dioctyl succinate sulfonate, sold by the American Cyanamid Company.

A further class of suitable surfactants for use in the compositions includes: silicone copolymers such as General Electric SF 1188 (a copolymer of polydimethylsiloxane and polyoxyalkylene ether) and General Electric SF 1228 (siloxane polyether copolymer). These silicone surfactants can be used in combination with the other classes of hydrophilic surfactants mentioned above, such as ethoxylated alcohols. These silicone surfactants have been found to be effective at concentrations as low as 0.1%, more preferably from about 0.25% to about 1.0%, by weight of the composition.

When a hydrophilic composition is desired, the amount of hydrophilic surfactant required to increase the wettability of the composition to the desired level will depend in part on the HLB value and amount of the fixative used, the surfactant used The HLB value and other factors. When desired to increase the wettability of the composition, the composition may contain from about 0.1 to about 50%, preferably from about 1 to about 25%, most preferably from about 10 to about 20%, of a hydrophilic surfactant.

The compositions also contain other ingredients normally present in such emulsions, creams, ointments, lotions, powders, suspensions and the like. These components include water, viscosity modifiers, fragrances, antiseptic actives, antiviral agents, vitamins, pharmaceutical actives, film formers, deodorants, sunscreens, astringents, solvents, preservatives, and the like. Additionally, stabilizers may be added to increase the shelf life of the composition, such as cellulose derivatives, proteins and lecithin. All of these materials are well known in the art for use as additives to such formulations and are used in suitable amounts in the compositions used in the present invention.

If water-based skin care compositions are used, preservatives are required. Suitable preservatives include, but are not limited to: propylparaben, methylparaben, benzyl alcohol, benzylkonnium chloride, tribasic calcium phosphate, butylated hydroxytoluene (BHT) or Acids such as citric acid, tartaric acid, maleic acid, lactic acid, malic acid, benzoic acid, salicylic acid, etc. Suitable viscosity increasing agents include agents which are useful in fixatives. Other suitable viscosity increasing agents include: alkyl galactomannans, silicon dioxide, talc, magnesium silicate, sorbitol, colloidal silicon dioxide, magnesium aluminum silicate, zinc stearate, lanolin alcohol, sorbitan Sorbiton, sesquioleate, cetyl hydroxyethyl cellulose and other modified celluloses. Suitable solvents include propylene glycol, glycerin, cyclomethicone, polyethylene glycol, hexylene glycol, glycols or polyhydric solvents. Suitable vitamins include A, D3, E, B5 and E acetate.

In preparing the products of the present invention, the lotion composition is applied to the outer surface (ie, the body-facing surface) of the structured carrier of the sample. Any coating method that evenly distributes the lubricating material having a molten or liquid consistency can be used. Suitable methods include: spraying, printing (such as offset printing), coating (such as gravure coating), extrusion or a combination of these coating techniques, such as spraying the skin care composition onto a rotating surface such as a roller, and then applying The composition is transferred to the outer surface of the structured carrier of the article.

Because the structured carrier has an effective open area and a plurality of pores of sufficient effective size, urine and low-viscosity feces can penetrate the structure regardless of the amount of skin care composition that has been applied to the structured carrier the carrier of transformation. Thus, even if a structured carrier is fully saturated with the skin care composition, urine and low-viscosity feces will easily penetrate through it because the structure of the carrier creates sufficient space between the areas where the skin care composition is applied. Separation allows fluid to permeate unhindered through the carrier. The problem of occlusion has been solved by providing a structured support with an effective open area and a plurality of pores of sufficient effective size.

An effective amount of the composition needs to be applied to the structured carrier to reduce the adhesion of the BM to the skin and/or to provide skin benefits to the wearer. The composition is preferably applied to the structured carrier of the article in an amount of about 0.1 mg/ ⁱⁿ² to about 35 mg/ ⁱⁿ² . This amount of composition is believed to be sufficient to impart the desired therapeutic and/or protective efficacy to the structured carrier.

Now that the problem of occlusion has been resolved, the composition can be applied to the outer surface of the structured carrier in any desired manner. For example, the composition can be applied to the entire exterior surface or only a portion thereof. The composition may also be applied non-uniformly to the outer surface of the structured carrier. "Non-uniform" means that the amount, location and pattern of distribution, etc., of the composition can vary across the surface of the structured support. For example, certain portions of the treated surface of the structured support may have greater or lesser amounts of the composition, including portions of the surface that do not have any composition thereon.

The composition can be applied to the article at any point during assembly. For example, the composition may be applied to the structured carrier of the finished disposable absorbent product prior to packaging of the disposable absorbent product. The composition may also be applied to a structured carrier before being combined with other materials to form the finished disposable absorbent product.

Typically the composition is applied in a molten state to the structured support of the article. Since the compositions melt at temperatures significantly above ambient temperature, the compositions are usually applied to the structured support in the form of a heated coating. Typically, the composition is heated to a temperature in the range of about 35-100°C, preferably about 40-90°C, prior to application to the structured support of the article. Once the molten composition has been applied to the structured support of the article, it is allowed to cool and solidify to form a cured coating or film on the surface of the structured support. The method of application is preferably designed to facilitate cooling/fixing of the composition.

The diaper 20 may further include elasticized leg cuffs (not shown) for improved containment of liquids and other body exudates. Each elasticized leg cuff may contain several different embodiments for reducing bodily leakage in the leg region. (The leg cuffs may be and are sometimes referred to as leg cuffs, side flaps, barrier cuffs, or elastic cuffs.) US Patent 3,860,003 describes a disposable diaper 20 that provides a collapsible diaper with side flaps and one or more elastic members. Leg openings to provide elasticated leg cuffs (sealed cuffs). Commonly assigned U.S. Patent 4,909,803, issued March 20, 1990 to Aziz et al., entitled "Disposable Absorbent Articles Having Elasticized Wings," describes having "upstanding" elasticated wings (barrier cuffs) Disposable diaper 20 for improved containment in the leg area. Commonly assigned US Patent 4,695,278, issued September 22, 1987 to Lawson, entitled "Absorbent Article Having Dual Closures," describes a disposable diaper 20 having dual closures including sealing and barrier cuffs.

The diaper 20 preferably further includes an elastic waist feature (not shown) to provide improved fit and containment. The elastic waist feature is the portion or area of the diaper 20 that is expected to elastically expand and contract to dynamically fit the wearer's waist. The elastic waist feature extends longitudinally outwardly from at least one waist edge of the absorbent core 28 and generally forms at least a portion of the ends of the diaper 20 . Disposable diapers are typically constructed with two elastic waist features, one disposed in the first waist region 27 and the other disposed in the second waist region 29, although the diaper may also be constructed with only one elastic waist feature. Moreover, although the elastic waist feature or any of its constituent elements may comprise separate elements secured to the diaper 20, the elastic waist feature is preferably constructed as an extension of other elements of the diaper 20 such as the backsheet 26 or structured carrier 24, preferably the backsheet 26 and structured carrier 24 both. The elasticated waistband 34 can be constructed in many different configurations, including USP 4,515,595 issued May 7, 1985 to Kievit et al. and above-referenced US Patent Application Serial No. 07/715,152, which are incorporated herein as refer to.

The diaper 20 also contains a side closure forming fastening system 36 which maintains the first waist region 27 and the second waist region 29 in an overlapping configuration thereby maintaining lateral tension at the periphery of the diaper 20 to hold the diaper 20 in a on the wearer. Typical fastening systems are disclosed in: U.S. Patent 4,846,815, issued Jul. 11, 1989 to Scripps, entitled "Disposable Diapers with Improved Fastening Means"; U.S. Pat. 4,894,060, entitled "Disposable Diapers Having Improved Hook Fastening Portions"; commonly assigned U.S. Patent 4,946,527, entitled "Pressure Sensitive Adhesive Fasteners and Methods of Making Same," issued Aug. 7, 1990 to Battrell; 1974 Commonly assigned U.S. Patent 3,848,594, issued November 19, 1987 to Buell, entitled "Tape Fastening System for Disposable Diapers"; commonly assigned U.S. Patent B1 4,662,875, issued May 5, 1987 to Hirotsu et al. Absorbent Article"; and US Patent Application Serial No. 07/715,152, previously referenced herein, each of which is incorporated herein by reference.

The diaper 20 is preferably applied to the wearer by placing a waist region, preferably the second waist region 29, on the back of the wearer and pulling the rest of the diaper 20 over the wearer's legs between them so as to place another waist region, preferably the first waist region 27, on the front of the wearer. The tape piece 26 of the fastening system is then removed from the release portion. The person applying the diaper then wraps the elasticized side panels around the wearer while still grasping the tape portion. The fastening system is secured to the outer surface of the diaper 20 to effect closure on both sides.

While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes can be made in the invention without departing from the spirit and scope of the invention. and change. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims (16)

1. Disposable absorbent articles (20), comprising: A liquid permeable structured carrier (24) comprising an inner surface oriented towards the interior of said absorbent article and an outer surface oriented towards the wearer's skin when the disposable absorbent article is worn, said structure A structured carrier having an effective open pore area of at least 12% and a plurality of pores with an effective size greater than 0.2 square millimeters, said outer surface of said structured carrier comprising an effective amount of a skin care composition that is semi-solid or solid, and which may partially transfer to the wearer's skin; a liquid-impermeable backsheet (26) at least partially peripherally attached to said structured carrier; and An absorbent core (28) positioned between said structured carrier and said backsheet. 2. The disposable absorbent article of Claim 1, wherein said structured carrier has an effective open area of at least 15%. 3. The disposable absorbent article of claim 1, wherein said structured carrier has an effective open area of at least 20%. 4. The disposable absorbent article of claim 1, wherein said structured carrier has an effective open area of at least 30%. 5. The disposable absorbent article of claim 1, wherein said pores in said structured carrier have a size greater than 0.5 square millimeters. 6. The disposable absorbent article of claim 1, wherein said pores in said structured carrier have a size greater than 1.0 square millimeters. 7. The disposable absorbent article of claim 1, wherein said pores in said structured carrier have a size greater than 2.0 square millimeters. 8. The disposable absorbent article of claim 1, wherein said skin care composition comprises a petroleum based lubricant selected from the group consisting of mineral oil, petrolatum, and mixtures thereof. 9. The disposable absorbent article of claim 1, wherein said skin care composition comprises a fixative, said fixative having a melting point of at least 40°C, wherein said fixative is selected from the group consisting of polyhydroxy fatty acid esters, polyhydroxy fatty acid Amides, C ₁₄ -C ₂₂ fatty alcohols, C ₁₂ -C ₂₂ fatty acids, C ₁₂ -C ₂₂ fatty alcohol ethoxylates with an average degree of ethoxylation of 2 to 30 and mixtures thereof. 10. The disposable absorbent article of claim 9, wherein said immobilizing agent comprises a _C16 - _C18 fatty alcohol selected from the group consisting of cetyl alcohol, stearyl alcohol and mixtures thereof. 11. The disposable absorbent article of claim 9, wherein said fixative comprises a polyhydroxy fatty acid ester having the formula:

Wherein, R is a C ₅ -C ₃₁ hydrocarbon group; Y is a polyhydroxy hydrocarbon moiety, and its hydrocarbon chain has at least 2 free hydroxyl groups directly connected to the chain; n is at least 1. 12. The disposable absorbent article of claim 9, wherein said immobilizing agent comprises a polyhydroxy fatty acid amide having the formula: In the formula, R ¹ is H, C ₁ -C ₄ hydrocarbon group, 2-hydroxyethyl, 2-hydroxypropyl, methoxyethyl, methoxypropyl or a mixture thereof; R ² is C ₅ -C ₃₁ hydrocarbon group ; Z is a polyhydroxyhydrocarbyl moiety having a linear hydrocarbyl chain with at least 3 hydroxyl groups directly attached to the chain. 13. The disposable absorbent article of claim 9, wherein said skin care composition further comprises paraffin wax as a fixative. 14. The disposable absorbent article of claim 1, wherein said skin care composition comprises a silicone lubricant having a plastic or fluid consistency at 20°C. 15. The disposable absorbent article of claim 1, wherein said structured carrier has an effective open area of at least 30% and said pores in said structured carrier have a size greater than 2.0 square millimeters. 16. The disposable absorbent article of Claim 1 wherein said skin care composition comprises a polyol polyester lubricant.