KR20000069675A - Disposable absorbent article for topical adhesive attachment to the skin of a wearer providing odour control - Google Patents

Abstract

The present invention relates to disposable absorbent products, in particular sanitary napkins, panty liners, adult incontinence products or sweat pads. In particular, the present invention relates to such disposable absorbent articles as are worn by attaching directly to the wearer's skin in areas where absorption of body fluid is desired and where an odor suppression system is provided.

Description

DISPOSABLE ABSORBENT ARTICLE FOR TOPICAL ADHESIVE ATTACHMENT TO THE SKIN OF A WEARER PROVIDING ODOUR CONTROL}

Conventional prior art in the field of disposable absorbent products for topical application to the wearer's skin has been developed in particular in the fields of disposable bands, plasters and bandages. However, these products are usually applied in emergencies where the skin of the wearer is cut and trying to absorb the fluids secreted from the wound. In this case, the performance aspects of absorbent products such as comfort and ease of use and application, pain-free removal, odor suppression and separation are neglected according to criteria such as wound sterility, maintenance of treatment, mechanical protection. In addition, such wound covering absorbent products are mainly used in areas of the skin where hair removal is possible or little or no growth of hair is present prior to application of the absorbent product.

The present invention does not relate to absorbent articles for wound coating, but to absorbent articles for body fluid absorption which are naturally secreted from the body without a wound. Such products are for example sanitary napkins or pantyliners used in the genital area. In addition, for example, a device for incontinence worn in the genital area or a sweat pad worn on a person's armpit is also a subject of the present invention. These products are generally used to separate and absorb liquids that otherwise adversely affect the social status of users of these products. However, odors emitted from such products can have the same adverse effect or at least be recognized by themselves.

The product is applied to the wearer's skin in areas where there is typically a significant amount of hair growth, in which easy and painless removal of the product is the most important criterion. Such direct applied products are generally disclosed in US legislation H1602 or International Patent Publication No. WO 96/33683 on the invention registration. Some of the more detailed descriptions of these products are given in WO 95/16424. This document discloses a sanitary napkin in which an adhesive is applied along the entire circumference of the sanitary napkin's wearer facing surface. The problem of this document primarily addresses the problem of safe attachment to the skin, but also of the need to remove the product after use without causing severe pain to the wearer.

International Publication No. WO 95/16424 discloses a more detailed analysis of the criteria for body adhesives in terms of rheological criteria. However, the rheological criteria taught include commercially available hair loss (ie, hair removal) compositions, such as STREP MIELE®, available from Laboratori Vaj SpA, Italy. The literature rarely considers the problem of removing the product painlessly. Topical adhesives mentioned in WO 95/16424 also include current pressure sensitive adhesives used to attach sanitary napkins to undergarments. In addition, the document only confirms the static rheological properties of the body adhesive and does not mention its dynamic rheological behavior.

International Patent Publication No. WO 96/13238 discloses a body adhesive model that is frequency dependent. However, for example, all measurements disclosed on page 9 are performed at temperatures between -60 and + 120 ° C. and actual frequencies between 0.1 and 100 rad / sec. The Williams-Landel-Ferry (hereinafter WLF) equation was used to obtain the required data at the application temperature (typical bathroom, ie storage temperature of about 20 ° C).

These WLF equations are experimental and valid only at certain limits and therefore cannot be used to extrapolate to temperatures below the glass transition temperature of the polymeric adhesive and also WLF cannot be used based on values obtained below the glass transition temperature. A detailed description of the WLF equation and its applicability can be found in Z. Tadmor and CG Gogos, "Principles of Polymer processing", published by John Wiley & Sons, or JD Ferry. " Viscoelastic Properties of Polymers, "published by John Wiley & Sons. This is not described in WO 96/13238, so the applicability of the disclosed data cannot be evaluated. In addition, this document does not relate to absorbent articles with odor suppressing means.

EP 638 303 discloses the use of a body adhesive on the side cuff of a sanitary napkin to hold the cuff in an upright position. Swiss Patent No. CH-643730 discloses the use of very long sanitary napkins with rounded outer edges in which body adhesive is applied at the four corners of the outer edge to provide a body adhesive region sufficiently outside of the hair growth region.

It is an object of the present invention to provide a body-adhesive absorbent product, in particular a sanitary napkin and a pantyliner, with odor suppressing means for reducing or eliminating odors emitted from the product. If the product is applied in close proximity to the wearer's skin, the perceived real need for odor suppression is high. In addition, application to the skin provides odor closure properties that allow the odor of the absorbed liquid or the odor formed from the absorbed liquid to accumulate in the absorbent product. Thus, the odor feeling upon removal of the product increases if no relative active means are performed.

In addition, it is an object of the present invention to provide a disposable product for absorption of naturally secreted liquid from the wearer's body, which also adheres to the wearer's skin while also providing pain-free removal of the absorbent product. Still another object of the present invention is to ensure that the absorbent product is removed such that no residue of adhesive is present on the wearer's hair or skin. It is another object of the present invention to provide a disposable absorbent article that is worn very close to the wearer's body fluid secretion area to minimize or reduce the loss of liquid out of the absorbent article. In the case of disposable absorbent products worn in the crotch region of the wearer, this will improve the safety of contamination around the skin and clothing.

Summary of the Invention

The present invention relates to disposable absorbent articles for topical adhesive attachment to wearers of articles comprising odor suppression systems. The product typically has an outer surface which is the wearer facing surface and also the so-called garment facing surface in the product worn under the garment. The article includes an absorbent core structure between the wearer facing surface and the garment facing surface to absorb the naturally secreted liquid from the wearer. Disposable absorbent articles according to the invention comprise an adhesive for topical adhesive attachment of the product to the skin of the wearer on at least a portion of the wearer's opposing face, and the product also includes an odor suppression system to provide odor suppression benefits.

In a preferred embodiment according to the invention, the absorbent core comprises an odor suppression system, preferably the odor suppression system comprises a granular odor inhibitor. Most preferably, the particulate odor inhibitor is a particle selected from zeolite, absorbent gelling material (AGM), activated carbon, silica and mixtures thereof.

In a particularly preferred embodiment according to the invention, the garment facing surface of the absorbent article is generally provided by a backsheet which should be liquid impermeable, and in a preferred embodiment it must be at least water vapor permeable to provide breathability of the absorbent article. This is particularly desirable because it has been found that the combination of a breathable absorbent product and an odor suppression system can increase the effectiveness of the odor suppression system. This is particularly desirable in products attached to the wearer's skin as provided by the present invention.

In general, any body adhesive acceptable to the wearer of the product according to the invention can be used. However, it is particularly preferable that the adhesive has the following properties.

This adhesive is characterized in particular by having an elastic modulus at 37 ° C. (100 ° F.) abbreviated as G ′ ₃₇ and a viscous modulus at 37 ° C. (100 ° F.) abbreviated as G ″ _{37. The} adhesive is also 100 rad / sec. or less G difference _"37 and 1rad / sec G in frequency, between ₃₇ ΔG than 150% of the" ₃₇ is G at 1rad / sec frequency _'37, preferably at least 80% of the frequency, less preferably 10000Pa than The adhesive is additionally selected to have a kinetic elastic behavior that is less than. The adhesive additionally has a difference ΔG ″ ₃₇ between G ″ ₃₇ at 100 rad / sec frequency and G ″ ₃₇ at 1 rad / sec frequency of 10000 Pa or less, preferably 5000 Pa or less, Most preferably selected to have a kinetic viscous behavior to be less than or equal to 1000 Pa.

Products according to the invention is from 1 to 100rad / the entire frequency range of sec G _'37 / G "value of ₃₇ ratio is 1 or less, preferably 1.6 or less, and most preferably 3.3 or less is particularly preferred.

At least 1 to in the frequency range of _{100rad / sec G '37 / G} " value of ₃₇ ratio, but may be varied in accordance with the increase of the frequency, but is not necessarily proportional to the frequency change. G' ₃₇ / G" ₃₇ ratio It should not change within the frequency range by more than 3 times, preferably 2 times, and most preferably it should remain constant.

At 1 rad, a preferred value of G ′ ₃₇ is less than 20000 Pa, preferably less than 15000 Pa, most preferably less than 10000 Pa. On the other hand, at a frequency of 1 rad / sec, the value of G ″ ₃₇ should not exceed 15000 Pa, which is preferably less than 10000 Pa and most preferably less than 5000 Pa. The rheological criterion is a plastic compound which is liquid at 20 ° C. Or 51% to 99.5% of the composition, 0.5 to 20% of the polymeric compound or composition which can be dissolved or swelled in the plastic compound or the composition, preferably 5 to 15%, 0 to 600% by weight of the adhesive resin (weight of the polymeric compound) Plastic compound or composition is preferably from the group consisting of water, alcohols, preferably glycerol, glycols, polyglycols, liquid polybutenes, oils, and combinations thereof. And the polymeric compound or composition is preferably a block copolymer-thermoplastic elastomer, a styrene-block copolymer and hydrogen Selected from the group consisting of styrene-block copolymers.

Very generally, preferred body adhesives are at least partially hydrophobic, wherein 60% by weight of the adhesive, more preferably 80% by weight, consists of a hydrophobic component and none of the materials in the adhesive are hydrophilic, ie the adhesive is completely hydrophobic. Most preferably made of.

In a particularly preferred embodiment according to the invention the adhesive comprises less than 20%, more preferably less than 10% of the wearer facing surface of the absorbent article. The present invention is most advantageously applied in the field of sanitary napkins or pantyliners.

The present invention relates to disposable absorbent products, in particular sanitary napkins, panty liners, adult incontinence products or sweat pads. In particular, the present invention relates to disposable absorbent products that are worn by attaching directly to the wearer's skin in areas where body fluid is to be absorbed and providing an odor suppression system.

The present invention relates to disposable absorbent articles that can be applied and modified directly on the skin of a user. It exhibits absorption into body fluids, prevents user's garments from becoming dirty, provides odor suppression benefits, improves physical comfort for the user, and is easy to manufacture and package. Disposable absorbent articles are described below with respect to sanitary napkins or sanitary articles, but panty liners, adult incontinence products or sweat pads are also included in the term disposable absorbent articles. As used herein, the term “physiological zone” is intended to absorb and contain various body fluids (eg, vaginal discharge, menstrual blood and / or urine) that are worn by the woman adjacent to the vulva region and secreted from the body, and after one use Refers to a product that is intended to be discarded. Disposable absorbent articles are preferably thin, most preferably 1 mm to 5 mm thick, and may be present in a substantially flat or pre-shaped state prior to use.

As used herein, the term “connected” or “fixed” refers to a structure in which the first member is directly coupled to the second member and to an intermediate member in which the first member is coupled to the second member such that the first member is coupled to the second member. It includes a structure that is indirectly coupled to.

In a preferred embodiment, the sanitary napkin of the present invention comprises a liquid permeable topsheet, a liquid impermeable backsheet connected to the topsheet and an absorbent core positioned between the topsheet and the backsheet. The sanitary napkin has two major surfaces: a body contact surface or a wearer facing surface and a garment facing surface or a garment contact surface.

The topsheet is compliant, soft to the touch and non-irritating to the wearer's skin. The topsheet may also have elastic properties that allow it to extend in one or two directions at a portion thereof or through the entirety of its extension. In addition, the topsheet allows fluid (eg, menstrual and / or urine) permeation to readily permeate through its thickness. Suitable topsheets include woven and nonwoven fabrics; Polymeric materials such as perforated thermoplastic films, perforated plastic films, and hydroformed thermoplastic films; And thermoplastic scrims. Suitable fabrics and nonwovens can be natural fibers (eg wood or cotton fibers), synthetic fibers (eg polymeric fibers such as polyester, polypropylene or polyethylene fibers) or mixtures of natural and synthetic fibers or bicomponent / multicomponent fibers It may be made of.

Preferred topsheets used in the present invention are usually selected from high loft nonwoven topsheets and perforated film topsheets. Perforated shaped films are particularly desirable for topsheets because they pass through body feces but are nonabsorbent and reduce the tendency for the fluid to pass back through to wet the wearer's skin again. Thus, the surface of the molded film in contact with the wearer remains dry, thereby reducing body soiling and providing more comfort to the wearer. Suitable molding films are described in US Pat. No. 3,929,135, US Pat. No. 4,324,246, US Pat. No. 4,342,314, US Pat. No. 4,463,045 and US Pat. No. 5,006,394. Particularly preferred microperforated molded films are disclosed in US Pat. Nos. 4,609,518 and 4,629,643. Preferred topsheets for this invention are moldings described in one or more of the above patents and marketed as sanitary napkins as "DRI-WEAVE" by The Procter & Gamble Compony, Cincinnati, Ohio. It includes a film.

Also contemplated by the present invention is a topsheet that does not have a uniform liquid passage except for a portion of the topsheet that includes the liquid passage. Typically, such topsheets will have liquid passages oriented such that they are permeable in the central direction to the liquid and impermeable in the circumferential direction.

The wearer facing surface of the formed film topsheet may be hydrophilic to aid in the transfer of liquid through the topsheet faster than if the body facing surface is not hydrophilic. In a preferred embodiment, the surfactant is incorporated into the polymeric material of the film topsheet formed as described in WO 93/09741. The wearer facing surface of the topsheet can also be hydrophilized by treatment with a surfactant as described in US Pat. No. 4,950,254.

Another alternative is called hybrid topsheets incorporating fibrous and film-like structures, and particularly useful embodiments of hybrid topsheets are disclosed in WO 93/09744, WO 93/11725 or WO 93/11726. It is described in.

When referred to as topsheet, a multilayer structure or a single layer structure is considered. The hybrid topsheet is also contemplated as other multilayer topsheets, such as multilayer designs or primary and second topsheet designs.

Odor suppression systems according to the invention may also be provided on the topsheet. For example, if the odor suppression system includes an odor masking agent (eg perfume), these masking agents may be sprayed, for example, on the surface of the topsheet. In addition, microencapsulated odor inhibitors protected from preconsumption may be provided on the topsheet. Activated forms, for example microcapsules following crushing or heat or dissolution, have a high possibility of activation only when they are needed. However, it is generally desirable to provide an odor suppression system having an absorbent core.

The absorbent structure or absorbent core may comprise the following components: (a) optionally, a first fluid distribution layer, preferably together with a second optional fluid distribution layer; (b) a fluid storage layer; (c) optionally a fibrous (“dusting”) layer beneath the storage layer; And (d) any other optional ingredient.

a. First / second fluid distribution layer

One optional component of the absorbent structure according to the present invention is a first fluid distribution layer and a second fluid distribution layer. The first distribution layer is typically under the topsheet and in fluid communication. The topsheet delivers the captured fluid to this first distribution layer for final distribution to the storage layer. The transfer of fluid through this first distribution layer takes place not only in thickness but also along the length and width of the absorbent article. Also an optional but preferred second distribution layer is typically below the first distribution layer and in fluid communication. The purpose of this second distribution layer is to easily capture fluid from the first distribution layer and quickly transfer it to the underlying storage layer. This helps to make full use of the fluid retention capacity of the underlying storage layer. The fluid distribution layer can be made of any material typical for such distribution layers. In particular, a fibrous layer that holds capillaries between fibers even when wet is useful as a distribution layer.

b. Fluid storage layer

The fluid storage layer is located in fluid communication and is typically below the first or second distribution layer. The fluid storage layer may comprise any common absorbent material or mixtures thereof. It preferably comprises an absorbent gelling material generally referred to as a "hydrogel", "superabsorbent", "hydrocolloid" material in combination with a suitable carrier.

Absorbent gelling materials can absorb large amounts of aqueous body fluid and can also retain such absorbed fluid under moderate pressure. The absorbent gelling material may be uniformly or heterogeneously dispersed in a suitable carrier. Suitable carriers can also be used alone if they are absorbent on their own.

Suitable gelling materials for use herein will often include substantially water insoluble, slightly crosslinked, partially neutralized, polymeric gelling materials. This material forms a hydrogel upon contact with water. Such polymeric materials can be prepared from polymerizable, unsaturated, acid containing monomers known in the art.

Suitable carriers include materials commonly used in absorbent structures, such as natural, modified or synthetic fibers, especially modified or unmodified cellulose fibers, in fluff and / or tissue forms. Suitable carriers can be used with the absorbent gelling material, but they can also be used alone or in combination. Tissue or tissue laminate is most preferred in sanitary napkins / panty liners.

An aspect of an absorbent structure made in accordance with the present invention includes a bilayer tissue laminate formed by folding the tissue itself. These layers may be combined with each other. Absorbent gelling material or other optional material may be included between the layers.

Modified cellulose fibers such as reinforcing cellulose fibers can also be used. Synthetic fibers can also be used and include cellulose acetate, polyvinylidene fluoride, polyvinylidene chloride, acrylics (eg Orlon), polyvinyl acetate, insoluble polyvinyl alcohol, polyethylene, polypropylene, polyamides (eg Nylons), polyesters, bicomponent fibers, ternary fibers, mixtures thereof, and the like. Preferably, the fiber surface is treated to be hydrophilic or hydrophilic. The storage layer may also include filler materials such as perlite, diatomaceous earth, vermiculite and the like to improve liquid retention.

Even if the absorbent gelling material is unevenly dispersed in the carrier, the storage layer can be locally uniform, ie have a distribution gradient in one or several directions within the dimensions of the storage layer. Heterogeneous distribution also refers to a laminate of carriers that partially or wholly contain the absorbent gelling material.

c. Optional fibrous ("dusting") layer

An optional component for inclusion in the absorbent core according to the present invention is a fibrous layer adjacent to the storage layer and usually underlying the storage layer. This underlying fibrous layer is commonly referred to as the "dusting" layer because it provides a substrate on which the absorbent gelling material is deposited in the storage layer during the manufacture of the absorbent core. Indeed, when the absorbent gelling material is in the form of a macrostructure, such as a fiber, sheet or strip, this fibrous "dusting" layer need not be included. However, these "dusting" layers provide additional fluid handling capability, such as rapid suction of fluid along the length of the pad.

d. Other optional ingredients

The absorbent core according to the present invention may comprise other optional components generally present in the absorbent web. For example, the reinforcing scrim can be placed in each layer of the absorbent core or between each layer. Such reinforcing scrims should have a structure such that they do not form interfacial barriers to fluid transfer. If structural integration occurs, which generally occurs as a result of thermal bonding, reinforcing scrims are generally not needed for thermally bonded absorbent structures.

Odor suppression system

According to the invention, the absorbent article comprises an odor suppression system as an essential feature. Any odor inhibitor or mixtures thereof known in the art for this purpose can be used herein. There is a wealth of description in the art of various odor inhibitors for use in absorbent products to address the problem of malodor formation, which can be usefully employed in the present invention. These inhibitors can typically be classified according to the type of odor the inhibitor is intended to suppress. Odors can be classified chemically as acidic, basic or neutral.

Acidic odor inhibitors have a pH greater than 7 and typically include sodium carbonate, sodium bicarbonate, sodium phosphate, particularly zinc sulfate and copper sulfate. Basic odor inhibitors have a pH of less than 7 and include compounds such as carboxylic acids such as citric acid, lactic acid, boric acid, adipic acid and maleic acid.

The neutral odor inhibitor has a pH of about 7. Examples of these types of compounds include activated carbon, clays, zeolites, silicas, absorbent gelling materials (AGMs) and starches. Neutral odor inhibitors and systems are described, for example, in European Patent Nos. EPO 348 978, EPO 510 619, WO 91/12029, WO 91/11977, WO 91/12030, WO 81/01643 and WO 96/65089. Cyclodextrins and derivatives thereof can also be used as described in US Pat.

Alternatively, the odor suppression system can be classified as to the mechanism by which malodor detection is reduced or prevented. Such odor inhibitors typically inhibit odor detection by absorption mechanisms.

Thus, an odor suppression system may also be used herein which chemically reacts with a compound that produces malodorous compounds or malodorous degradation products resulting in compounds that are odorless or have a odor that is acceptable to the consumer. Suitable inhibitors include chelating agents, for example amino carboxylates such as for example ethylenediamine-tetraacetate, amino such as ethylenediaminetetrakis (methylene-phosphonate), as described in US Pat. Phosphonates, aromatic chelating agents substituted with polyfunctional groups as described in US Pat. No. 38,120,44, and mixtures thereof. Without wishing to be bound by theory, the benefits of these materials are due in part to their specific ability to remove iron, copper, calcium, magnesium and manganese present in fluids absorbed by the formation of chelates and their degradation products. I think.

Other odor inhibitors suitable for use herein include buffer systems such as citric acid and sodium bicarbonate, sodium phosphate and sorbic acid buffer systems. In addition, buffer systems having a pH of 7 to 10 as described, for example, in WO 94/25077 may be used herein.

Other odor suppression systems use ion exchange resins such as those described in US Pat. Nos.

Masking agents such as perfumes can also be used as odor inhibitors herein. Preferably, the masking agent is used in admixture with further odor inhibitors such as zeolites as described in WO 94/22500. As indicated above, such masking agents in odor suppression systems may be defined as "schmiegsam (translated into English or flexible) as defined in European Patent Application EP-A-333773." It may be provided in encapsulated, preferably microencapsulated form, providing additional benefits that do not adversely affect the ability to ".

Preferred odor suppression systems for use herein include the following mixtures: i) preferably 5: 1: 1 to 1: 1: 5, most preferably 3: 1: 1 to 1: 1: 3 Ratios of silica, AGM and zeolites; ii) zeolite, activated carbon and AGM; iii) preferably silica and AGM in a ratio of 5: 1 to 1: 5, more preferably 3: 1 to 1: 3; iv) zeolite and AGM; v) preferably silica and zeolite in a ratio of 1: 5 to 5: 1, more preferably 1: 3 to 3: 1; vi) chelating agents, in particular ethylenediamine-tetraacetate; vii) A chelating agent mixed with an odor suppression system in a ratio of preferably 1:10 to 10: 1, more preferably 1: 5 to 5: 1, most preferably 1: 3 to 3: 1.

According to the invention, the amount of odor suppression system incorporated into the absorbent article can be readily determined by one skilled in the art and also depends on the intended use of the absorbent article in view of the dimensions of the absorbent article. Typically, the absorbent article is 5 g / m ² to 400 g / m ² , more preferably 100 g / m ² to 300 g / m ² , most preferably 150 g / based on the weight of the odor suppression system. m ² to 250 g / m ² . For example, a sanitary napkin or pantyliner may comprise 0.25 g to 5 g, preferably 0.4 g to 3 g, most preferably 0.5 g to 2.5 g of the odor suppression system.

If the absorbent product element and the absorbent product itself meet the specific needs described herein, the odor suppression system can be incorporated into the product by any method disclosed in the art. For example, the odor suppression system can be stacked on the core of the absorbent material or mixed in the fibers of the absorbent core. The odor suppression system is preferably incorporated between the two layers of cellulose tissue in the fluid storage layer. Optionally, the odor suppression system can be coupled, for example, with a hot melt adhesive, a polyethylene particle binder or any other bonding system between the two cellulose tissue layers.

The backsheet is absorbed by the absorbent core so that the contained secretions do not wet the materials in contact with the absorbent product, such as underpants, trousers, pajamas and undergarments. Preferably the backsheet is preferably made from a thin plastic film impermeable to liquids (eg, menstrual blood and / or urine), although other flexible liquid permeable materials may also be used. As used herein, the term "flexible" means a material that is compliant and easily conforms to the general shape and contour of the body. The backsheet may also have elastic properties that stretch in one or two directions.

The backsheet typically extends throughout the absorbent core and extends to the topsheet and then folded around the absorbent core to form part of the topsheet. As such, the topsheet form described in US Pat. No. 4,342,314, column 16, lines 47-62, can be obtained without the need to selectively perforate the topsheet.

The backsheet may comprise a woven material or a nonwoven material, a polymeric film such as a thermoplastic film of polyethylene or polypropylene, or a composite material such as a film coated nonwoven material. Preferably the backsheet is a polyethylene film having a thickness of about 0.012 mm (0.5 mil) to about 0.051 mm (2.0 mil).

Examples of polyethylene films are the trade name P18-1401, manufactured by Clofei Corporation, Cincinnati, Ohio, and the trade name XP-39385, manufactured by Bisquin Division, Ethyl Corporation, Tere Haute, IN. Preferably the backsheet is embossed and / or matted to provide a more garment-like appearance.

Preferably, the backsheet can also provide breathability to the absorbent article by making it at least water vapor permeable, preferably air permeable, without compromising the main function of the backsheet. The backsheet may be a laminate material, such as a combination of microporous film and / or nonwoven and / or perforated molded film. If desired, breathability may be defined around or in the center of the backsheet, or may exist over the entire backsheet. Preferably, the backsheet may also be a microporous film comprising an odor suppressing material suitable as an inert filler to create a microporous structure upon stretching while providing malodor blocking.

Topical Adhesive

The product according to the invention described above is applied directly to the skin of a user. In particular, sanitary napkins are applied around the liquid discharge zone, typically in the genital area of female users. As used herein, the term “skin” refers not only to the specific derma of a user, but also to mucosal tissue and body hair typically observed in the genital area of a sanitary napkin user.

In order to provide fixability to the user's skin of the product according to the invention, it is necessary to provide a topical attachment adhesive, referred to as a body adhesive, in a specific area on the topsheet side of the product opposite the wearer.

Various designs are contemplated in this respect, but preferably a body adhesive is provided along the distal end of the topsheet such that the central area of the product is an adhesive free margin. Most suitably facilitates the installation of a product that places the liquid permeable topsheet of the adhesive member adjacent to the body fluid secretion organ so that the liquid is delivered into the absorbent structure of the absorbent product as soon as the liquid flows out without the possibility of leakage or spillage.

However, the body adhesive need not be provided within the closure circumference around the topsheet, but provided in an incremental area, such as a dot or discontinuous line, to provide additional comfort for the wearer to the product, while cushioning between different attachment locations. Can be.

It is particularly preferred to meet the following considerations even when any body adhesive acceptable to the wearer of the product according to the invention can be used:

Desirable physical, rheological and adhesive properties of body adhesives

Even when body adhesives are used as pressure sensitive adhesives on the hair and mucosal tissues of human skin, the body adhesive compositions are referred to as typical pressure sensitive adhesives (hereinafter referred to as PSAs) based on the most characteristic flowable aspect that identifies the substance. I understand that there is a difficulty in regard to this.

Indeed, as those skilled in the art of adhesives know, the most distinguishing factor that distinguishes PSA from other materials that can temporarily stick objects (e.g. water between two glass plates) is their rheological parameters, in particular elasticity. It is a fact that the modulus (G ′) varies greatly depending on the frequency of the stress applied. More particularly, the G 'of the PSA may increase by several orders of magnitude while the frequency of the stress applied varies from the normal binding frequency to the normal resolution frequency, ie 1 rad / sec to 100 rad / sec as described below.

As a first result, it is concluded that it is unacceptable to define a material to be used as a "body adhesive" by providing a rheological variable value, in particular a G 'value at a fixed frequency. This may be misjudged as it will include materials that have no practical value in the absence of other features. Therefore, rheological properties should be based on dynamic considerations.

This applies not only to the elastic modulus G 'but also to the viscous modulus G "and thus also to tan (δ) = G" / G'. A typical PSA not only has a high variation of G 'across the frequencies considered, but also closer to or much higher than the G' value (ie, especially tan (δ) is about 1 or much greater than 1 in the typical frequency of the solution sum). It is well known to have a greater G " than).

While not based on theory, this is largely due to the fact that much of the energy applied to the solution solution dissipates in the adhesive (and therefore is not effective in generating solution solution). Can be.

To provide good bonding conditions at a frequency of about 1 rad / sec, the absolute value of the elastic modulus should not be too high, otherwise the adhesive will be too hard and cannot be bonded or molded immediately to the surface to be bonded. It is also important to have a low G " absolute value in order for the material to be flexible and properly adhered to the skin while having good adhesion which is particularly useful for use in menstrual convection.

Finally, those skilled in the art will also recognize that the glass transition temperature of the PSA is a useful parameter to more fully define a useful group of PSA materials.

As mentioned above, the material useful as the body adhesive according to the present invention has a rheological property mainly measured at a reference temperature of 37 ° C. (general human body temperature) and a range of frequencies. In the application of absorbent products (eg sanitary napkins) comprising body adhesives, it has been found that the contact of the adhesive is formed at a low frequency while the solution bond occurs at the rate of tearing off the product. This rate was expressed in 100 rad / sec frequency while the low frequency of adhesive bond was found to be on the order of 1 rad / sec. Thus, the frequency range for use according to the invention is 1 to 100 rad / sec. The following set of characteristics must be satisfied:

- in the frequency range, and the elastic modulus G 'rate of change (%) of ₃₇ G in 1rad / sec' up to 150% of _37, preferably less than 100%, more preferably less than 80%, the variance is a value based on Less than 10,000 Pa. This is met by the body adhesive, but to be illustrative, Pro meon (Promeon) RG-63B, quoted in the prior art represents a variance of an unacceptable 331% of the G _'37, if according to the invention in the same frequency range.

In the frequency range, the percent change in viscosity modulus G ″ ₃₇ is 10,000 Pa or less, preferably 5,000 Pa or less, 5,000 Pa or less, most preferably 1,000 Pa or less.

At least one to the value of G _'37 / G _"37 in the frequency range of 100rad / sec is preferably one should be the same as or greater, more preferably 1.6 or more, and most preferably at least 3.3, preferably from about 150 It should not exceed.

In the application frequency of 1 rad / sec, G 'and G "are to be understood as values taken at a temperature of 37 ° C. In practical use of the product according to the invention, the actual storage temperature of the product and the temperature of the body adhesive in subsequent application are For example, it can reach up to about 37 ° C when stored in a hot bathroom near a radiator, but can reach temperatures near 0 ° C when stored in a storage room or bathroom with no winter heating and in an open window. The product according to the invention is used directly on the skin and the user does not want to wear an overly cold product, so the actual temperature of the body adhesive will reach 37 ° C. very quickly and may be warmed by the wearer before wearing. Is considered to be the best choice for body temperature.

As mentioned above, the rheological behavior is also related to the value of the glass transition temperature Tg. In the body adhesive according to the invention, the Tg should be below -15 ° C, more preferably below -20 ° C and most preferably below -25 ° C.

Chemical and Compositional Properties of Body Adhesives

The following formulation criteria may further be used to meet the above rheological and physical property requirements of body adhesives. It should be appreciated that most of the compositions useful as body adhesives have a substantially gel-like structure and are preferably gels. This is derived from the following facts.

The main component is a plasticizer which is a liquid substance at room temperature.

Macromolecular or polymeric components are present in small amounts relative to the plasticizer. They form, in a preferred embodiment, three-dimensional networks generated by physical or chemical bonds between molecules. Particularly useful are the physical bonds present in systems containing block thermoplastic elastomers.

More particularly, the composition typically comprises the following components.

0.5 to 20% by weight, preferably 5 to 15% by weight macromolecular polymeric material or mixtures thereof soluble or swellable in the plasticizer (s) mentioned below. By way of non-limiting example, macromolecules or polymeric materials include natural and / or synthetic products, such as natural rubbers or derivatives such as natural rubbers and gelatins, derivatives and alginates thereof; Polyacrylic; Polyvinyl alcohol; Polyethylene oxide; Polyvinylpyrrolidone (PVP) or polyvinyl ether, copolymers and derivatives thereof; Cellulose derivatives; Block copolymer thermoplastic elastomer, preferably styrenic block copolymer, more preferably hydrogenated styrol / ethylene-butylene / styrene (SEBS), styrene / isoprene / styrene (SIS) and styrol / ethylene-propylene / styrene ( SEPS).

51 to 99.5% by weight of plastic substances or mixtures thereof which are liquid at room temperature. By way of non-limiting example, the plasticizer can be water, various alcohols (particularly glycerol), glycols, polyglycols, liquid polybutenes, natural or synthetic oils such as vegetable oils, mineral oils or combinations thereof.

0 to 600% by weight of macromolecular polymeric material of the tacky resin, whose main range is particularly adapted to the glass transition temperature in systems containing synthetic polymers (based on synthetic polymers).

0 to 10% by weight, more preferably 0 to 5% by weight, for the promotion and stabilization of the gel forming process of both hydrophilic or hydrophobic liquid plasticizers. These include, for oily systems, for example fatty acids having C ₈ -C ₂₂ carbon atoms, metal salts thereof and polyoxo-derivatives thereof; Lanolin derivatives; Silica; Bentonite, montmorillonite and derivatives thereof; Polyamides, waxes or mixtures thereof.

Additives commonly known in the art, such as preservatives, antioxidants, ultraviolet (UV) inhibitors, pigments, inorganic fillers, rheology modifiers, may each be included in amounts of up to 10%.

When chemical crosslinks are formed in the system, the crosslinkers may be present in an amount of preferably up to 5% by weight. Chemical crosslinkers can be formed by mutual neutralization of polymers with different functional groups, such as in the reaction between acid polyacryl and polysaccharide.

Product compositions for body adhesives can be classified into the following three groups depending on the nature of the main component, namely the liquid plasticizer (s).

(1) A hydrophobic composition wherein the plasticizer is typically an oil derived from a vegetable or mineral source or a blend thereof and the polymer is generally a soluble or swellable polymer in the oil (s), preferably an elastomer.

(2) Mixed-phase compositions wherever possible in both the plasticizer and the polymer, wherein both the hydrophobic and hydrophilic components form two or more separate phases. In this case the emulsifier / surfactant is preferably present in an amount suitable to form a stable emulsion between the immiscible phases. In the case of the body adhesive according to the present invention, it is preferable to include the hydrophobic component as a main component as compared to the hydrophilic component;

(3) Hydrophilic compositions, typically wherein the plasticizer is water / glycerol / glycol and / or mixtures thereof and the like and the polymer phase originates from a synthetic (eg polyacrylic) or natural (eg natural rubber) source or mixtures thereof.

In contrast to the foregoing prior art and medicinal fields, it is emphasized that the hydrophobic and mixed phase compositions (1) and (2) above are preferred for use in the present invention, while hydrophilic compositions are not preferred.

This depends, in part, on technical reasons in that many hydrophilic compositions used in the medical field exhibit too low elastic properties and adhesion for use in the present invention. Another reason for favoring hydrophobic or mixed phase compositions is that the application of the present invention, particularly in the field of sanitary napkins, involves the possibility of contacting the liquid with which the body adhesive will be absorbed. Since liquids are all common aqueous types, contact with hydrophilic body adhesives can partially absorb body fluids into body adhesives.

This results in a change in rheological properties and thus an unsanitary appearance which results in the maintenance of direct contact with the skin for an extended period of body fluid, which is not intended by any of the disposable absorbent articles according to the invention. . In addition, some hydrophilic compositions are potentially good culture media for the growth of a large number of microorganisms, including pathogens, which may result in potential diseases for the wearer.

Additional hydrophilic body adhesives can also be perceived as cold or wet conditions that do not meet typical consumer expectations when applying new sanitary napkins or underarm sweat pads. A further problem arises due to the fact that body adhesives, especially those comprising water as plasticizers, tend to be dehydrated if they are not sealed as an impermeable package.

Absorbent articles according to the invention can be prepared by methods customary in the art. Application of the adhesive to the topsheet of the absorbent article may be provided by similar techniques commonly used for panty anchoring adhesives and therefore should not cause major problems for those skilled in the art. The total area of the wearer facing surface of the absorbent article occupied by the body adhesive should be 20% or less, preferably 10% or less. Preferably the adhesive is close to the periphery of the absorbent article and in the case of the film topsheet (or when the backsheet is folded over the topsheet) the adhesive is preferably on a portion of the film which is liquid impermeable.

Body adhesives on products (used with panty fixed adhesives) need to be protected before use. Such protection may be provided by a release liner, such as a siliconized or surfactant treated paper, provided that the paper has a good release surface for a specially selected body adhesive.

In principle, the absorbent article according to the invention is supported by the body adhesive to the wearer and does not require an additional support for fixing. However, a non-slip coating may be provided on the backsheet side of the sanitary napkin for the purpose of preventing the sanitary napkin form from slowly deviating from its position. In addition, even if panty anchoring adhesives are not intended and thus undesirable for the present invention, they are not strictly excluded from the present invention.

Example 1

The oil-based compositions useful in the present invention are 9.9% by weight of Kraton G-1651, Witko, a styrene / ethylene-butylene / styrene block copolymer sold from Shell Co. and containing 33% by weight of styrene. It is formulated using 59.3% by weight of Kaidol, a paraffinic mineral oil commercially available from Witco Co. Moreover, the composition contains 301 parts of the tacky resin per 100 parts of the Kraton polymer. The adhesive resin is Ewcorez 5300, a hydrogenation resin commercially available from Exxon Co.

Magnesium Stearate, available from Carlo Erba S.p.A., is used as an auxiliary gelling agent for oils at a concentration of 0.7% by weight.

The antioxidant Irganox 1010, available from Ciba-Geigy, is added at a concentration of 0.3% by weight.

Thus, the final blend has the following weight percentages:

Kraton G-1651 9.9% by weight

Kaidol 59.3% by weight

Escorts 5300 29.8% by weight

Magnesium Stearate 0.7% by weight

Aganox 1010 0.3 wt%

The composition exhibits the following rheological properties at 37 ° C .:

a) Elastic Modulus at 1rad / sec G _'37 = 6876Pa

b) non-G _'37 / G "of the elastic modulus and the viscous modulus at 1rad / sec ₃₇ = 12.49

In 100rad / sec of the elastic modulus and viscous modulus ratio _{G '37 / G "37 =} 7.01

c) a ratio of 'G in 100rad / sec for _37' at ₃₇ G 1rad / sec: 1.308

Comparative Example

7.1% by weight of Kraton G-1651, a styrene / ethylene-butylene / styrene block copolymer sold by Shell Company and containing 33% by weight of styrene, and 41.9% by weight of kaidol, a paraffinic mineral oil marketed by Witko Company. Comparative oil-based composition is blended. Moreover, the composition contains 704 parts of the tacky resin per 100 parts of the Kraton polymer. The adhesive resin is Regalerez 3102, a hydrocarbon resin commercially available from Hercules Co.

Magnesium stearate, available from Carlo Erva S.P.A, is used as an auxiliary gelling agent for oils at a concentration of 0.7% by weight.

The antioxidant Aganox 1010, available from Ciba-Geigy, is added at a concentration of 0.3% by weight.

Thus, the final blend has the following weight percentages:

Kraton G-1651 7.7% by weight

Kydol 41.9% by weight

Regalez 3102 50.0% by weight

Magnesium Stearate 0.7% by weight

Aganox 1010 0.3 wt%

The composition exhibits the following rheological properties at 37 ° C .:

a) Elastic Modulus at 1rad / sec G _'37 = 3059Pa

b) 1rad / sec in G ratio of the elastic modulus and the viscous modulus' ₃₇ / G _"37 = 2.53

Ratio _{G '37 / G "37 =} 0.74 for the elastic modulus and the viscous modulus at 100rad / sec

c) a ratio of 'G in 100rad / sec for _37' at ₃₇ G 1rad / sec: 4.944

The combination is considered very inconvenient when applied to forearm skin. Sensitive body hair cannot be tolerated when applied to many skins.

Claims (10)

A disposable absorbent article having a wearer facing surface and a garment facing surface and comprising an absorbent core between the wearer facing surface and the garment facing surface, An adhesive for topical adhesive attachment of the absorbent article to at least a portion of the wearer facing surface, Comprising an odor suppression system to provide an odor suppression benefit, Disposable absorbent products that adhere to the wearer with a topical adhesive. The method of claim 1, The absorbent product comprises an odor suppression system, preferably the odor suppression system comprises a granular odor inhibitor, and most preferably the granular odor inhibitor is selected from zeolites, absorbent gelling materials, activated carbon, silica and mixtures thereof. Disposable absorbent product comprising a. The method according to claim 1 or 2, Disposable absorbent article wherein the garment facing surface is provided by the breathable backsheet. The method according to any one of claims 1 to 3, An adhesive for topical adhesive attachment having a viscous modulus G _"37 at 37 ℃ (100 ℉) elastic modulus G _'37, and 37 ℃ (100 ℉) in, Adhesive 1rad / sec of frequency (frequency) in the G _'37 and 100rad / G at frequencies of sec _"37 variation ΔG' ₃₇ is G at the 1rad / sec frequency 'up to 150% of _37, preferably Selected to have a kinetic elastic behavior of less than 10,000 Pa, The kinematic viscosity behavior of the adhesive having a deviation ΔG " ₃₇ of G" ₃₇ at a frequency of 1 rad / sec and G " ₃₇ at a frequency of 100 rad / sec is 10,000 Pa or less, preferably 5,000 Pa or less, and most preferably 1000 Pa or less. Disposable absorbent product selected to have. The method according to any one of claims 1 to 4, G _'37 is less than 20,000Pa in frequency of 1rad / sec, preferably less than 15,000Pa, most preferably less than 10,000Pa product. The method according to any one of claims 1 to 5, G " ₃₇ is less than 15,000 Pa, preferably less than 10,000 Pa, most preferably less than 5,000 Pa at a frequency of 1 rad / sec. The method according to any one of claims 1 to 6, 51-99.5% by weight of the plastic compound or composition, wherein the adhesive is liquid at 20 ° C., 0.5-20% by weight of the polymeric compound or composition soluble or swellable in the plastic compound or composition, and 0-600% by weight of the polymeric compound or composition An absorbent article that is a composition of a material comprising a phosphorous adhesive resin. The method of claim 7, wherein The plastic compound or composition is selected from the group consisting of water, alcohols, glycols, oils and combinations thereof, wherein the polymeric compound or composition is a block copolymer-thermoplastic elastomer, a styrene-block copolymer and a hydrogenated styrene-block copolymer An absorbent product selected from the group consisting of: The method according to any one of claims 1 to 8, Absorbent article wherein the adhesive is at least partially hydrophobic, preferably 80% by weight of the adhesive consists of hydrophobic components, and most preferably all components of the adhesive are hydrophobic. The method according to any one of claims 1 to 9, Product wherein the adhesive comprises less than 20%, preferably less than 10%, of the wearer's facing surface.