MXPA01001555A - Improved adhesive composition for a strainable composite laminated structure - Google Patents

Abstract

The present invention relates to an adhesive composition for use in a composite laminated structure comprising a substrate and an apertured layer joined together by means of the adhesive composition. The laminated structure is extensible at least in designated zones and the adhesive composition provides both an effective connection of the layers forming the composite laminated structure and an improved resistance of the adhesive bonding to straining of the laminated structure. The composite laminated structure preferably constitutes side flaps in a disposable absorbent article such as a sanitary napkin.

Description

IMPROVED ADHESIVE COMPOSITION FOR A DEFORMABLE LAMINATED COMPOSITE STRUCTURE FIELD OF THE INVENTION The present invention relates to an adhesive composition for use in a laminated composite structure comprising a substrate and a layer with openings joined together by means of the adhesive composition. The laminated structure is extensible at least in several areas. designated and constitutes of preference the side flaps in a disposable absorbent article such as a sanitary napkin.

BACKGROUND OF THE INVENTION LOI articles < abso > benfes such as the ioaüas -.fipitarias, i. i f .. < pt: p? ottors,. Incontinence pads are devices that have become typical in the region of interspersing? of an undergarment. These devices are taught to absorb and retain fluid and other discharges from the body humar ?? Y to avoid staining the body and clothes. The sanitary napkins are a tioo of absorbent article carried by women within a pair of panties and is normally placed between the legs of the wearer, adjacent to. perianal area of the body Sanitary towels in oarticular are lateral wrapping elements, frequently also referred to as lateral fins or wings, are disclosed in the literature and are available commercially. Sanitary napkins having side wings or fins of 5 different types are disclosed in United States Patent No. 4,687,478, United States Patent.

No. 4,608,047, United States Patent No. 4,589,876, patent of Reexamination No. B1 4,589,876, United States Patent No. 4,285,343. Sanitary towels that have wings are commonly seen as providing good protection against staining. However, some women find that the application of sanitary napkins that have side flaps is inconvenient for several reasons. For example, some women find it difficult to attach the lateral flaps to the underside of the crotch of their panties. This may be due to factors such as difficulties in bending the side flaps appropriately in place and attaching them to the inner garment. As a result, some women still prefer a sanitary napkin without side flaps. In addition, some women who generally prefer a sanitary pad with side flaps, occasionally (such as during periods of light flow) prefer a sanitary pad without fins. Therefore, there is a need for a sanitary towel that provides an alternative sanitary napkins that have • conventional side wings while still providing similar protection. Several variations of sanitary napkins that have conventional side wings have been suggested. For example, U.S. Patent No. 4,911,701 discloses a sanitary napkin having elastic threads to provide a greater convex shape to the body-facing portion of the central absorbent and to allow the adhesive-free placement of the fins. laterals in the panties. U.S. Patent No. 4,940,462 discloses a sanitary napkin with longitudinally sxpandible fins. The fins are designed to fold over the outside of the wearer's panties and then expand to conform to the contour of the panties. Further enhancements of the wraparound side elements with extensible zones have been disclosed in U.S. Patent Application Serial No. 08/124180 of September 17, 1993; and 08/277733 of July 20, 1994 and in the European application No. 94202252. 6 of August 3, 1994.

In these disclosures the extension capacity is provided by a number of different processes. For example, extensible zones can be created by mechanically deforming, corrugation, "ring rolling", warming and deforming, subjecting portions of the wrapping side elements or fins to compression between matching plates, and the like. In particular, high speed mechanical deformation such as corrugated or ring rolling is desirable due to manufacturing efficiency allowing high production speeds. Also, the rolled areas with an extension capacity ring can have an angled extension capacity in relation to to the address of the machine (transport direction of the process). Suitable methods for ring rolling, typically by means of two tooth rollers and interlocked slots, are described in United States Patent No. 4, 107,364, United States Patent No. 4,834,741, United States No. 5,143,679, United States Patent No. 5 156,793 and United States Patent No. 5,143,679; 'T, United States No. 5,167,897.; Particularly preferred wrapping side elements or fins comprise at least two layers of material! but sometimes more, for example. four layers of material that are joined together forming a laminated composite structure that is made extensible only after being formed into a laminate. In In particular, the prior art sanitary napkins with wraparound side elements having extensible zones are constructed such that the side wrapping elements are formed by extending portions laterally of the upper layer of the sanitary napkin (typically called the topsheet) and the lower layer of the sanitary napkin (typically referred to as the backsheet). 5 The laminate formed in the laterally external area of the main portion of the sanitary napkin is subjected to stress by mechanical processes such as rolling with ring previously mentioned in the production speed of these articles. For the laminate showing the uniform behavior during the mechanical deformation, the individual layers need to be properly joined together at least in the areas of mechanical deformation. The adhesives typically, especially the thermal fusion adhesives have been suggested and used for that purpose. The development of a wide variety of adhesives has been developed and continues for the different situations that occur within the manufacturing process of the disposable absorbent articles. Preferred adhesives of the type of thermal melt which are used to join layers of the laminated structures comprised in the disposable absorbent articles typically have a low viscosity at a relatively low application temperature, in order to facilitate the application and at the same time avoid the damage of the sensitive paterials! heat commonly used in the manufacture of these desired absorbent articles. Alternative joining methods include soda which is used -between plastic materials of a similar type allowing the creation of an area where the materials melt together to create permanent connections, or pleating which is a local mechanical deformation of the layers. way that the layers bind locally. A problem applied when deformation is applied, for example, mechanical deformation, to a laminated composite structure comprising a layer. with openings attached by means of an adhesive to a substrate, is related to the exposure of the adhesive on the outer side of the laminated structure through the openings of the apertured layer. In the case of mechanical deformation imparted to such a structure, for example, by means of a ring rolling process, in order to provide the designated areas of the extending structure, it is that the parts of the machinery, typically the vertices of the metal teeth of one of The rollers used in the ring rolling process come into direct contact with the adhesive layer through the openings of the apertured layer. The layer with openings can be non-woven, or, preferably, a three-dimensional polymeric film with openings, for example constituting the upper sheet of a sanitary napkin, and the substrate can be a polymeric film impermeable to the liquid, preferably a wet vapor permeable layer, impervious to liquid, such as a breathable microporous film, comprised in a preferably breathable back sheet. The adhesives used in the field of disposable absorbent articles are tacky to show the adhesive characteristics over a wide range of temperatures. These are usually still tacky at room temperature and therefore during the mechanical deformation stage by means of, for example, rolling with a ring, these can still stick to the teeth of a ring rolling roller through the openings <; Je the layer with openings. It is particularly undesirable during the process of deformation if the adhesive is exposed on the outer side of any of the iodinated * 1 amines to which the adhesive accumulates, in particular the sticky adhesive accumulates on the rapidly moving parts of the machinery leading quickly to the unstable conditions of the process. As a minimum, the occurrence of these conditions requires frequent cleaning but can even cause the disastrous destruction of the material! leading to machine shutdowns and reduced efficiency. Particularly, when the ring rolling process is carried out and one of the layers of the laminated structure has openings the adhesive that sticks on the apexes of the teeth of one of the rollers can pull the portions of the layer attached to the layer with openings, that is, the substrate, through openings in the layer with openings, up to the limit that ruptures and holes are created in this substrate. This is detrimental to the integrity of the substrate, and also to the liquid impermeability of the substrate, when, as preferred, it is it constitutes at least part of a backsheet structure in a disposable absorbent article, and therefore breaks the substrate finely which may cause leakage of liquid during the use of the product. This tensile action is even more effective in the case of a laminated composite structure comprising a thermoplastic polymeric film with three-dimensional openings such as the apertured layer and a breathable microporous film as the substrate, since the presence of the micropores in the microporous film It makes the film a little weaker and more prone to breakage due to the tensile action of the adhesive glued, for example, to the teeth of a ring roll. Adhesives that Due to be exposed through openings of a layer with openings on the outer side of a composite structure in an absorbent article of paper are also highly undesirable for the consumer. Adhesives that are sticky at the temperature of use of these products or have no contact with the skin or garment of the wearer will usually cause the adhesive residue on the garments or the skin of the wearer. These undesirable effects can also be increased by the mechanical deformation itself, for example a rolling process with annulus and a laminated structure comprising a three-dimensional apertured film bonded to a substrate, for example, a breathable microporous film, since the induced mechanical stress By e! ring rolling increases the size of the apertures in the three-dimensional film with apertures, and at the same time at least partially destroys the three-dimensional structure of the film with apertures themselves, thereby reducing its thickness. This means that the adhesive is exposed through enlarged openings on the outer side of said laminate, and is also closer to the outer surface, and therefore. it is more likely that it will come into contact, for example, with the wearer's skin or garment. It has been found that an alternative method for joining the materials of a laminated composite structure, which is called welding, can be used in the process of mechanical deformation of the laminated structure. This method as iai is known from the technique of joining metals, but it has also been applied in e! field of disposable absorbent articles, as described in patent application EP-A-707841 and EP-A-7 I0470. A welder, as described in the cited application, is an adhesive that exhibits adhesive behavior when applied at its process temperature, which also preferably has a relatively low application temperature and a low viscosity at that temperature, but is not sticky at room temperature. Therefore during the step of mechanical deformation for example by ring rolling a laminated composite structure comprising a substrate joined to a layer with openings by means of a soldering iron, the adhesive used as the tiler can not stick to the parts of the machine, and nothing else aurapí? the subsequent use of the laminate, while e! Tiler (adhesive) has been maintained at room temperature. A problem with laminated composite structures comprising an apertured layer bonded to a substrate by means of the known adhesives used as welders is that these adhesives, while not tacky at room temperature, and therefore able to prevent both formation adhesive on the parts of the machinery, and the subsequent damage to the laminated structure due to the adhesion between the laminated structure itself and the loaves of the machinery on which the adhesive can be glued, and the possible stickiness of the laminated structure during use of the structure itself, for example, in absorbent products disposable, does not have sufficient extension capacity to withstand deformation for example in a mechanical deformation process. The known adhesives used as welders in these laminated structures for their preferred behavior in terms of low viscosity at the relatively high application temperature and the lack of tack at room temperature have a relatively high hardness and a low elongation at break, and therefore make the laminated composite structure rigid. This causes the adhesive layer joining the layers of the laminated composite structure break into small pieces when subjected to the laminated structure for example to mechanical deformation, for example by rolling ring, which is provided with ia extensibility in the designated areas. The union between the layers of the laminated composite structure can therefore fail and cause the delamination of the structure ie the repair of the layers on at least part of! united area. It is therefore an object of the present invention to provide an adhesive composition for use in bonding the component layers of a laminated composite structure comprising an abatement and an apertured layer, wherein e. adhesive is simple to apply at a process temperature that is not harmful to the layers intended to be in contact with the adhesive, it avoids the problems related to the exposure of the adhesive outside the structure, for example the direct contact of the adhesive with 'as parts! to machinery through the openings of the layer with openings, and also provides a secure connection 'as layers when the structure is extended or deformed, for example deformed mechanically during manufacturing to provide it with areas of capacity designated extension. Said adhesive composition is also advantageous for joining layers of laminated composite structures comprising a substrate and a layer with openings which are intended to be extended, for example, when at least one of the layers The components are stretchable, or also elastically stretchable, during use, for example being incorporated into a disposable absorbent product that can be deformed before or during the time of use, wherein the bond provided by the adhesive composition is not damaged by the elongation of the adhesive. the laminated composite structure. At the same time, the adhesive exposed on the outside of the composite structure laminated through the openings of the apertured layer is not tacky at room temperature, thereby providing the other advantages of lack of stickiness of the structure towards other components of the structure. disposable absorbent product, or to the wearer's undergarments, or in addition to the wearer's skin. It is another object of the present invention to provide a disposable absorbent article comprising the adhesive composition in a composite structure. It also has extensible zones, wherein the substrate is a backsheet impermeable to liquid, but preferably permeable to wet vapoi, and the layer with openings is a sheet. liquid permeable upper Preferably the absorbent article is a sanitary jacket, side flaps, and the fins comprise the laminated composite structure bonded by the adhesive composition and having zones of extension capacity to facilitate bending of the fins.

BRIEF DESCRIPTION OF THE INVENTION An adhesive composition that. has a viscosity of less than 10000 mPa-s at a temperature not higher than 160 ° C, and a separation force on steel of less than 10 g at a temperature of 23 ° C as measured in accordance with the steel separation strength test described herein, and comprising: a microcrystalline wax, and a polymer that has an elongation at break of at least 400% according to ASTM D 638M-91a where the thickness of the sample is 4 mm. The adhesive composition of the present invention is preferably comprised of a laminated composite film comprising a sub-layer and a layer with openings attached thereto, which is intended to be extended, for example by means of mechanical deformation which is provided with a capacity of extension in at least the designated areas. The laminated composite structure is preferably comprised in a disposable absorbent article.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is an exploded view of a sanitary napkin having lateral fins comprising a laminated composite structure worked according to the present invention. Figure 2 shows a top view of a sanitary napkin having extension areas rolled with a ring in the lateral atlases. The zones are indicated by the lines shaded with lines that symbolize that these are angled with respect to the longitudinal axis.

DETAILED DESCRIPTION OF THE INVENTION In accordance with the present invention there is provided an adhesive composition for use in a laminated composite structure which comprises a subsurface and an apertured layer bonded by the adhesive composition; The laminated structure has areas that can be extended, for example extensible zones provided by means of mechanical deformation. The laminated composite structure comprising The adhesive composition of the present invention is preferably used in a disposable absorbent article such as a sanitary towel having side flaps as illustrated in Figures 1 and 2, the fins comprising the laminated composite structure. The absorbent article has a surface that gives the body typically provided by a layer of fibers or a liquid-like film-like structure; a surface that gives the garment preferably provided by a layer impervious to the liquid, but breathable, and a structure absorbenle placed enire the surface that gives the body and the surface that gives the garment. He The absorbent article has a longitudinal axis 10 and a transverse axis 11 as shown in the figures and may comprise any of the components or features common in the art, including in particular the components of the lateral flap and any type of exlensibility or elasticity characteristic. known op technique. The preferred sanitary napkin or pantiliner made in accordance with the present invention has a pair of wrapping layered elements (or "components that cover the undergarment") that provide protection to the wearer's panlaleias to reduce lateral staining (it is say, stained the edges of the crotch of the panties) without the use of conventional fins. The preferred sanitary or panty protection device comprises a major body portion! comprising a liquid-permeable upper sheet, a liquid-impermeable back sheet bonded to the upper sheet, and an absorbent core positioned facing the top sheet and the back sheet. The side wrapping elements are either integrally formed with the main body portion which is preferred or attached to the side that gives the garment of the main body portion along the longitudinal side edges thereof. In the preferred embodiment of the present invention discussed in the Figures 1 and 2 the lateral wrapping elements of the sanitary navel comprise a structure laminated composite formed by the upper sheet as the layer with openings and by the rear sheet as the substrate both extending laterally from the main body portion of the article, outside the longitudinal side edges thereof, and being joined together by a layer of an adhesive composition made in accordance with the present invention, which is not shown in Figure 1. The composite composition laminated to each of the laminar wrapping elements is provided with at least one extension capacity, preferably two extension capacities. separated apart as shown in Figure 2, which are symmetrically placed with respect to the longitudinal centerline of the absorbent article. The zones of extension capacity are regions of the composite structure laminated in the lateral wrapping elements that have a greater extension interval than the adjacent regions of the structure compile? laminated The disposable article for absorbing liquids is written off by reference to a sanitary napkin or pantyhose. However, such products as baby or adult diapers or incontinence inserts for adults comprising zones of extension capacity may similarly benefit from the laminated composite shape of the present invention. If the side wrapping elements are formed integrally with the main body portion of the absorbent article, as is preferred, indentation regions are formed which extend around the intersection between the perimeter of the laminar wrapping elements and the longitudinal side edge of the wrapping. main body portion wherein the lateral wrapping elements extend beyond the longitudinal side edge of the main body portion. For these integral designs of the lateral wrapping element is preferable when at least a symmetric pair of zones of capacity of The extension extends into the notch regions, i.e., each extendable zone extends from the longitudinal side edge of the main body portion. Alternately for the lateral wrapping elements that are provided as separate elements and which are fixed to the side that gives the garment (and which are loose outward from where they are fixed) the distance between the punches laterally towards inside the zones of extension capacity and the longitudinal center line is preferably within the range of 40 mm to 50 mm. Generally, the area of extension capacity may be primarily stress-sensitive in the longitudinal direction or mainly in the transverse direction or in any direction that falls between them. For the integrally formed side wrapping elements the zone of extension capacity is most preferably exiensible in a direction which follows as close as possible to the adjacent outer perimeter of the absorbent article. Preferably, the zones'; of extension capacity are provided with corrugations that have fold lines. The sanitary napkins of the present invention provide an alternative for conventional sanitary napkins having side flaps. In one embodiment, the lateral wrapping elements do not require action by a! user to fold them under their panties or to fix them to the panialetas The lateral wrapping elements remain in the place fo enough to cover the lateral edges of the wearer's panties without fixing them under the wearer's panties. In an alternative embodiment, particularly for the side wrapping elements extending further outward from the main body portion, the sanitary napkin may be provided with a fastener, such as with a pressure sensitive adhesive. The adhesive fastener can be provided on the side that the garment of the main body portion and also extend on the side that gives the garment the side wrapping elements. In this modality, particularly in the crotches With narrow margins, the side wrapping elements can fold around the side edge of the crotch of the wearer's panties in such a way that portions of the wrapping side elements still overlap. This forms a novel structure that tightens the side edge of the panels to the folded portion of the side wrapping elements.

Top sheet The upper sheet 2 is flexible, soft feeling, and non-irritating to the wearer's skin. The upper sheet may also have elastic characteristics that allow it to be stretched in one or two directions in portions of the upper sheet or in its entire extension. In addition, the upper sheet is permeable to leakage allowing the fluids (eg, menstruation and / or urine) to easily penetrate through its thickness. A suitable top sheet can be manufactured from a wide variety of materials such as woven and non-woven materials; physical materials such as thermoplastic films formed with openings, plastic films with openings, and hydroformed hydrolyzed films; porous foams; cross-linked foams; thermoplastic reticulated films; and thermoplastic canvases. Suitable woven and nonwoven materials may be composed of natural fibers (e.g., wood or cotton fibers), synthetic fibers (e.g., polymer fibers such as polyester, polypropylene, or polyethylene fibers) or a combination thereof of natural and synthetic fibers. The preferred top sheets for use in the present invention are selected from higher nonwoven webs of high fluffiness and upper sheets of film formed with openings. Films formed with openings are especially preferred for the top sheet because they are permeable to exudates from the body and still not absorbent and have a reduced tendency to allow fluids to pass back through and re-wet the wearer's skin. Therefore, the surface of the formed film that is in contact with the body remains dry thus reducing the soiling of the body and creating a more comfortable feeling for the wearer. Suitable formed films are described in United States Patent No. 3,929,135; U.S. Patent No. 4,324,246; U.S. Patent No. 4,342,314; U.S. Patent No. 4,463,045; and in United States Patent No. 5,006,394. Top sheets of film formed with particularly preferred micro apertures are disclosed in U.S. Patent No. 4,609,518 and U.S. Patent No. 4,629,643. A preferred top sheet for the present invention comprises the formed film described in one or more of the above patents and which sanitary napkins are marketed by he Procter & Gamble Company of Cincinnati Onio, as "CRI-. WEAVE". . The upper sheets which do not have a homogeneous distribution of liquid passages but only a portion of the upper sheet comprising passages of liquid are also contemplated by the present invention. Typically, these upper sheets would have the liquid passages oriented such that they result in a centrally permeable upper sheet and peripherally impervious to liquids. The body surface of the formed film top sheet can be hydrophilic to help transfer the liquid through the upper sheet faster than if the body surface were not hydrophilic. In a preferred embodiment, surfactant is incorporated into the polymeric materials of the upper film sheet formed tai as described in PCT publication 93/09741. Alternatively, the body surface of the upper sheet can be made hydrophilic by treating it with an agent ions as described in U.S. Patent No. 4,950,254.

Another alternative are so-called hybrid top sheets which incorporate fibrous and film-like structures particularly the useful embodiments of these hybrid top sheets are disclosed in PCT disclosures WO 93/09744; WO 93/11725 or WO 93/11726. In the preferred embodiment of the present invention the topsheet 2 comprises a three-dimensional thermoplastic film with openings and typically extends through the tolality of the absorbent structure 4 and outwardly from the coextensive area with the absorbent structure 4. As indicated in the Figure 1 the top sheet 2 extends and forms all of the preferred side alleles as shown and designated 52 in the. Figure 1, and constitutes the apertured layer of the laminated composite structure comprising the adhesive composition of the present invention. When referring to the top sheet, a multi-layer structure or a mono-layer structure is also contemplated. If the various layers of the multi-ply topsheet are bonded together they are also susceptible to forming a laminated composite structure having designated zones of extension capacity provided by means of mechanical deformation, the structure being joined by a composition adhesive according to the present invention. The hybrid top sheet mentioned above is said multi-layer design but other multi-layer top sheets such as the primary and secondary top sheet designs susceptible to forming a laminated composite structure according to the present invention are also considered.

Absorbent structure The absorbency structure is shown as a simple entity 4 in ia Figure 1. This may include the following components; (a) optionally a layer primary fluid dissipation preferably June with a secondary layer of fluid distribution; (b) a fluid storage layer; (c) optionally a fibrous layer ("time-off") underlying the storage layer; and (d) other optional components. a) Primary / secondary layer of fluid distribution An optional component of the absorber solution according to the present invention is a primary fluid distribution layer and a secondary fluid distribution layer. The primary dissipation layer is typically below the top sheet and is in fluid communication therewith. The top sheet transfers the acquired substance to this primary layer of distribution for the final distribution to the storage layer. This transfer of fluid through the primary layer of distribution occurs not only within the thickness, but also along the length and width directions of the absorbent product. The also optional but preferred secondary distribution caps are typically below the primary distribution layer and are in fluid communication with it. The purpose . This secondary layer of distribution is that of easily acquiring the fluid from the primary distribution layer and transferring it rapidly to the underlying storage layer. This helps to fully utilize the fluid capacity of the underlying storage layer. b) Fluid storage layer Placed in fluid communication with, and typically underlying the primary or secondary distribution layers, it is a fluid storage layer.

The fluid storage layer may comprise any common absorbent material or combinations thereof. Esla preferably comprises gelling absorbent materials commonly referred to as "hydrogel", "superabsorbent", "hydrocolloid" materials in combination with suitable carriers. The gelling absorbent materials are capable of absorbing large quantities of aqueous fluids from the body, and are also capable of retaining these absorbed fluids under moderate pressures. The absorbent gelling materials can be dispersed homogeneously or non-homogeneously in a suitable carrier. The right carriersAs long as they are absorbent as well as they can be used alone. Suitable gelling absorbent materials to be used herein will frequently comprise a slightly interlaced, partially neutralized, gelling polymeric material susriably insoluble in water. This matter! • * form a hydroge! when getting in contact with water. These polymeric materials can be prepared from polymerized, unsaturated, acid-containing mcromers. The unsaturated acid monomers for use in preparing the polymeric gelling absorbent material used in this invention include those that are disabled in US Pat. No. 4,654,039 reissued as RE 32,649. Preferred monomers include acrylic acid, methacrylic acid. and 2-acrylamido-meityl propane sulfonic acid. The acrylic acid itself is especially preferred for the preparation of the polyacrylic gelling material. Suitable carriers include materials that are used in a conventional manner in the absorbent materials such as cellulose fibers, in the form of lint and / or tissue. Suitable carriers can be used in June with the gelling absorbent material, however these can also be used alone or in combinations. Very favorite are the tissues or laminates of deniro tissue! context of sanitary / pantiprotective towels. In an embodiment made in accordance with the present invention the absorbent structure 4 comprises a double-layer tissue laminate formed by folding the tissue on itself. Modified cellulose fibers such as hardened cellulose fibers can also be used. Synthetic fibers can also be used and include those made from cellulose acetate, polyvinyl fluoride, vinylidene chloride, acrylics (such as Orion), polyvinyl acetate, insoluble polyvinyl alcohol, pcyethylene, polypropylene, polyamides (such as nylon) , polyesters, two-component fibers, three-component fibers, mixtures thereof and the like. Preferably, the surfaces of the fihra are hydrophobic or are treated to be hydrophobic. The storage layer may also include filling materials, such as peruta, diatomacea earth, vermiculite, ele, which reduce the problems of rewetting. If the absorbent material is dispersed in a non-homogeneous manner in the carrier, the storage layer can nevertheless be locally homogeneous, that is, have a distribution gradient in one or more directions within the dimensions of the carrier. storage layer. The inhomogeneous distribution can also refer to the laminates of carriers that enclose partially or allially absorbent gelling materials. c) Optional fibrous layer ("dedusting") An optional component for inclusion in the absorbent structure according to the present invention is a fibrous layer adjacent to, and typically underlying the storage layer. This underlying fibrous layer is typically referred to as a "dedusting" layer as it provides a subsurface over which the absorbent gel material is deposited in the storage layer during the manufacture of the absorbency structure. In fact, in those examples where the material absorbs gelling is in the form of macrostruments such as fibers, leaves or lyres, this fibrous "dedusting" layer does not need to be included.

However, this "dedusting" layer provides some additional fluid handling capabilities such as rapid capillary action of the fluid along the length of the pad. d) Other optional components of the absorbent structure The absorbent structure according to the present invention can include other components normally normally present in the absorbent webs. For example, a reinforcing fabric may be placed within the respective layers, or between the respective layers of the absorbent structure. These reinforcing canvases should be of such configuration so as not to form interfacial barriers to the transfer of the fluid, especially if they are placed between the respective layers of the absorbent structure. Given the structural integrity that normally occurs as a result of thermal bonding, reinforcement canvases are not commonly required for absorbent films according to the present invention. Another component that can be included within the absorbent structure according to the invention and preferably is provided near or as part of the primary or secondary fluid distribution layer are the odor control agents. Typically activated carbon coated with or in addition to other odor control agents, in particular zeolites or suitable clay materials, are optionally incorporated into the absorbent structure. These components can be incorporate in any desired form but are often included as discrete particles. Back sheet The backsheet 3 mainly prevents the exudates absorbed and contained in the absorbent structure from wetting the articles that are in contact with the absorbent product such as underpants, briefs, pajamas and undergarments. The backsheet 3 is preferentially impermeable to liquids (for example, menstruation and / or urine) and can be manufactured from a thin plastic film, although other flexible liquid impervious materials can also be used. As used herein, the term "flexible" refers to materials that are flexible and that will easily conform to the figure and general contour of the human body. The posture as well. it can have elastic characteristics that allow stretching "* in one or two directions. Er. the preferred embodiment of the present invention illustrated in Figures 1 and 2, the back sheet 3 comprises two layers: a first layer comprising a ': film layer formed with openings permeable to! 3A gas and a second layer .. comprising a breathable microporous film layer 3B. Preferably, the apertured film of the first layer 3A comprises a layer having discrete apertures extending beyond the horizontal plane of the garment facing surface to the absorbent core 4 thereby forming frills. Each protuberance has a hole located at its terminal end. Preferably, the projections are funnel-shaped or conical, similar to those described in US Pat. No. 3,929,135. The openings located in the plane of the layer and the holes located in the terminal end of the protuberances themselves can be circular or non-circular. In any case, the cross-sectional area or dimension of the hole in the termination of the pro -uberance is smaller than the dimension or cross-sectional area of the aperture located in the plane of the layer. The first layer 3A of the backsheet 3 can be made from any material known in the art, but is preferably manufactured from commonly available polymeric materials. The first layer 3A may also comprise any type of formed films that can be used for a topsheet as described above. The second layer 3B of the backing sheet 3 preferably comprises a breathable microporous film composed of an iron-plaster resin and inorganic re-binders dispersed in the phosprospinal resin. Suitable thermoplastic polymers include polyolefins, such as polyethylenes, including linear low density polyethylene (LLDPE), low density polyethylene (LDPE), ultra low density polyethylene (ULOPE), high density polyethylene (HDPE), or polypropylene and blends. of the same ones with the previous ones or other materials. ' Examples of other suitable thermosetting polymers that may also be used include but are not limited to, polyesters, polyurethanes, polymers capable of composting or 'Hodegradabl * s, thermoplastic elastomers, and polymers based on metallocene catalyst (eg, INSITE® available from Dow Chemical Company and Exxací® available from Exxon). Matter! Inorganic or filler may comprise talc, silica, calcium carbonate, clay, titanium dioxide, barium sulfate, with the preferred inorganic filler being calcium carbonate. The inorganic filler may be coated with fatty acid esters, fatty acids or its metal salts to improve the dispersion of the filler particles in the thermoplastic polymer and to obtain higher charges in the polymer. The inorganic filler and the thermoplastic polymer are mixed together to form a homogeneous mixture in a suitable mixing extruder, or in a separate combined preliminary stage. The mixture is then emptied or blown into a film. The obtained film is stretched at least in one direction to impart breathability over the area basically the movie. The step of drawing a film to impart respirability can be done in a different place before the manufacturing process of the absorbent articles. Alternatively, the stretch step can be made in the same place, ie, the same manufacturing process, before assembling a breathable microporous film with other elements of the absorbent articles. In any case, the film is imparted with respirability over the substantially total area of the film before the respirable microporous film is assembled to result with other absorbent article elements. The top sheet, the back sheet, and the absorbent core can be assembled in a variety of configurations known in the art (including layered or "sandwich" configurations and wrapped or "tube" configurations).

Figures 1 and 2 show a preferred embodiment of the sanitary napkin 1 assembled in imr. sandwich construction in which the upper sheet 2 and the microporous film * resμNX'ble 38 have dimensions of length and width generally greater than the absorbent core 4 The upper sheet 2 and the film, picroporous respiraole 3B extend beyond the original the absorber 4 to form portions of the periphery. The sanitary bag 1 shown in FIGS. 1 and 2 also comprises a pair of fins 52 that are attached to the main body portion along a joint. The fins 52 extend laterally outwardly beyond the longitudinal lateral edges of the main body portion from their proximal edges to their distant edges (or "free ends"). The alleles 52 comprise an upper wing sheet and a rear wing sheet. In the embodiment shown in Figures 1 and 2, the fins 52 are integral with the main body portion, that is, the upper fin sheet and the posterior leaf of the aleia comprise integral extensions of the upper sheet 2 and the microporous film. Breathable 3B, respectively.

The film formed with openings 3A of the backing sheet is approximately the same shape as the absorbent core 4 to cover at least the region where the absorbent core 4 lies as shown in Figure 1. Ally, this may have a shape a little larger than the absorbent core 4, or it may have the same shape as the main body portion of the sanitary layer 1.

In any case, preferably, the film formed with openings 3A does not extend towards the fins 52 as shown in Figure 1. Alternately, but less preferably, the formed film with openings 3A may extend toward the fins 52 of the form the formed film with openings constitutes a part of the fins 52. The upper sheet 2 and the breathable microporous film 3B can be joined by any suitable manner known in the art for this purpose. Preferably, in the mosired embodiment, portions of the topsheet 2 and the microporous breathable film 3B are bonded using adhesives on the liner portions extending beyond the edges of the absorbent core 4, and therefore over the entire region. of the flakes 52. In the embodiment shown in Figure 1, the first layer 3A is located adjacently to the absorbent core 4 and the back layer 3B of the backsheet is typically located farther away from the absorbent core 4. The bottom sheet 3 may be also understand additional layers. All of the layers of the backsheet 3 can be substantially in intimate and direct contact with each other. The function of the fins, also called lateral wrapping elements, if they are integral or attached to the article after they are formed separately, is further improved by making them extendible in one or both directions parallel to the longitudinal axis 10 or the lateral axis 11. The extension capacity can be provided through iodine or only part of the lateral wrapping elements and it can be achieved by folding or rolling with ring those parts that are going to be made extensible. The layered structure formed by the upper sheet 2 (layer with openings) and by the breathable microporous film 3B (substring) of the back sheet extending beyond the longitudinal edges of the absorbent article to form the layered aliases 52, also comprise the adhesive layer of the present invention joining the layer with openings and the substrate, constituting a laminated composite structure which is intended to be provided with extension capacity in the selected areas designated 56 by means of mechanical deformation preferably imparted by ring rolling . The laminated composite structure comprising the adhesive composition of the present invention eliminates the problems associated with the build-up of sticky adhesive on parts of the adhesive. high-speed deformation equipment such as the rollers used to roll with ring, together with the problem of a-laminated composite structure stiffness that can lead to the breakage of the adhesive layer and consequently the at least partial delarination of the layers during mechanical deformation, preferably achieved by ring rolling. In the preferred sanitary / pantiprotechlorine made in accordance with the present invention shown in Figure 2, the lateral wrapping elements each comprise laminated composite structures having two sections of extension capacity 56 therein. The extension capacity of the entire extension capacity zone 56 on the side wrapping elements may extend in the same direction. In a different way. one or more extension capacity zones 56 may be extendable in a different direction. Also, the extension capacity in each zone 56 may vary if desired.

The extension capacity zones 56 are preferably made capable of extending by 20% and 90%, more preferably 50% and 80%, and most preferably 70% and 80% by the forces associated with the use of the barrier. sanilaria in a couple of panlaleías. The extension capacity zones 56 are also preferably extensible without being elastic. In addition, any inherent elasticity in the zones of extension capacity 56 (ie, any tendency of the material comprising the zones of extension capacity to return to its original dimension) is generally relatively low to nonexistent.

Adhesive composition according to the present invention The laminated composite structure comprising the adhesive composition according to the present invention comprises a substrate and an apertured layer, respectively, corresponding to the breathable microporous film 3B and the upper surface 2 in the intended embodiment illustrated in Figs. 1 and ?, joined together by a layer of adhesive of the present invention. The adhesive is considered useful to provide permanent connections between the materials since the formed composite laminates typically have to be adhesive. The adhesive should preferably resist at least at a separation resistance of 0.4 N / 2.5 cm. The resistance to separation is the resistance required to separate The materials attached to each other in a strip of 2.5 cm wide sample. A full description of the test is included below. The adhesive strength can of course exceed the strengths of the material of the bonded materials. Therefore an alternative for the test against 0.4 N / 2.5 cm may be the internal cohesion test. In this test an adhesive connection is dismantled. The adhesive connection satisfies the test if one of the materials desiruye.

According to the present invention, the adhesive has a low viscosity at a low relative application temperature, in order to make the application of the simple adhesive with the common techniques employed with known thermal fusion adhesives., such as, for example, coater coating, roller coating, curtain coating, sprinkling. Typically an adhesive composition according to the present invention has a viscosity comprised between 1500 mPa-s and 10000 nnPa-s at an application temperature in the range of I 10 ° C to 160 ° C, preferably less than 5000 mPa-s at a temperature of not more than 160 ° C, more preferably comprised between 3000 mPa s and 5000 rnPa-s at a temperature not higher than 130 ° C. According to the present invention, the adhesive composition comprised in the laminated composite structure also has a force of clamping force on steel at a temperature of 23 ° C, indicative of a standard temperature, less of 10 g, preferably less than 1 g, according to or with? Test of the separation force on steel described below. This involves that the laminated composite structure is subjected to mechanical deformation, for example ring rolling, and provided at the temperature of the adhesive at this stage which is the ambient temperature, at or less than the typical application temperature. of the adhesive composition, the parts of the machinery that are in direct contact with the adhesive layers through the openings of the apertured layer during mechanical deformation, typically the apexes of the teeth of a ring rolling roller, not they stick to the adhesive. This prevents the adhesive from forming on the parts of the machinery on which the adhesive otherwise adheres, and consequently pulls the substrate layer through the apertures of the apertured layer through the teeth of the roller, with damage possible of the substrate itself. This in general means that the adhesive composition of the invention is present on the outside of the structure The laminated composite comprising the apertured layer is not tacky at room temperature, and therefore can not stick through the openings of the apertured layer of the composite structure. In the preferred use of the laminated composite structure according to the present invention in the field of disposable absorbent articles such as sanitary napkins, another typically critical temperature is the temperature of the wearer's body of disposable absorbent articles since any tackiness of the adhesive The skin of the user can also preferably be avoided. Including a safety margin of 40 ° C is considered to be an adequate upper limit where preferably the adhesive comprised in the laminated composite structure of the present invention should have a separation force on the steel of less than 10 g, preferably less than 10 g. 1 g. As already mentioned, mechanical deforming is applied to the laminated composite structure comprising the adhesive composition. to form the designated designated areas of the extensible structure. As discussed above, mechanical deformation can be provided by any of the methods known in the art. However, the most preferred method is ring rolling according to the prior art publications identified above. In the step of rolling with a ring, two tooth rollers and intermeshing grooves close and the force is forced through the rollers to extend perpendicular to the direction of the groove. The adhesive composition according to the present invention comprised in the laminated composite structure must have a lower hardness and a sufficient extension capacity to be able to resist the deformation of the structure, for example the deformation imparted by the mechanical deformation process, without break or in any case cause the layers of the structure Laminated composite delaminate. This is achieved by an adhesive composition which meets the aforementioned requirements in terms of viscosity and low or preferably zero tack on the steel at room temperature (23 ° C), and which comprises in the composition a microcrystalline wax and a polymer , the polymer being selected from those having an elongation at break of at least 400%, as measured according to the standard Test Method for the tensile properties of plastics ASTM D 638-91 A, wherein the thickness of the sample has a standard value of 4 mm. Such an adhesive composition specifically has the preferred performance of known thermal melt adhesives in terms of viscosity and low tack and preferably zero at room temperature, and further provides high elongation at break and high smoothness. In addition, these compositions also have excellent adhesion to plastics and especially poholefins at their application temperatures, even when they are not in contact with tackifying resins. - Preferably the adhesive compositions of the present invention have such elongation at break of at least 35%, preferably at least 50%, as measured according to the same test method as specified above. If the laminated composite construction comprising an adhesive composition of the present invention has to be mechanically deformed by means of ring rolling, the adhesive composition preferably shows an elongation at break of at least equal to the highest deformation that is induced in the adhesive. the composite structure laminated during rolling with a ring, for example 100%. Preferred compositions of the adhesive composition of the present invention comprise, in percent weight, from 30% to 80% of a microcrystalline wax, from 5% to 70% of a polymer having a rupture elongation of at least 400. % in accordance with ASTM D 638-91 a, where the thickness of the samples has the standard value of 4mm, and optionally 25% of a paraffinic oil. Preferably, the adhesive composition comprises from 30% to 70%, preferably from 40% to 60% by weight of the microcrystalline wax, and from 30% to 70% by weight of the polymer, wherein the polymer is a copolymer of ethylene and acetyl. of viniio having a melt flow index (MFI), evaluated by the method ASTM D 1238-5 under conditions 190 / 2.16, of at least 150 g / 10 min, and a vinyl acelaio content of at least minus 14% by weight. More preferably, the polymer is a polymer which also contains an acid monomer, for example acrylic acid, in an amount such that the acid number of the polymer is comprised of 1 and 100 mg of KOH per gram of the polymer. Alternatively, the adhesive composition of the invention comprises, in percent by weight, from 50% to 80% of the microcrystalline wax, and from 5% to 25% of the polymer having an elongation to the rupture. of at least 400% by weight S1 MD 638 -91 a as defined above, wherein the polymer is a c-polymer of styrenic block having a styrene content comprised between 14% and 35% in this case. Preferred optional components in the adhesive compositions of the present invention are up to 10% by weight of a paraffin wax, or a mixture of paraffin waxes, up to 25% by weight of an atactic poly-alpha-epinephrine, or a mixture of atactic poly-alpha-olefins, and up to 40% by weight of a tackifying resin or a mixture of tackifying resins. Preferred tackifying resins are hydrocarbon resins, aliphatic, or aromatic or aliphatic-aromatic resins, partially or partially hydrogenated resins, or mixtures thereof, wherein the resin or mixture of resins preferably has a softening point no greater than 100 ° O The adhesive composition according to the present invention which is comprised in the laminated composite composition can also have the characteristics of a welder material such as those disclosed in the two prior art publications EP-A-7Q7841 and EP-A-710470 mentioned. above, as long as they also have the required characteristics disclosed above. The joining of the materials by welding requires applying a solder to one or both surfaces that are going to join and bring the surfaces in contact before the solder cools down below its solidification temperature. In order to apply the weld, it is heated to a temperature above its solidification temperature and applied in a similar manner or in the same way as the adhesives are applied. Actually the same equipment currently used to apply adhesives can be adapted to apply the solder to the respective surface where it is needed. Methods such as spot coating, roller coating, pro coating sprinkled in random patterns or designed as a spiral coating can all be used to apply the weld according to the present invention. When the surfaces to be joined join the weld makes contact on both surfaces intimately at a temperature above its solidification temperature. This creates a permanent connection after cooling below the solidification temperature. Incorporated into the world of welding according to the present invention are the methods in which in the technique of mela! they are referred to as brass where the weld forms bonds between the material through the contact surface. Although not wishing to be bound by theory, it is believed that the weld forms a thin layer of internal connections in the material where the upper molecular layers of the materials to be welded become involved. In order to customize the welding of the generic adhesives, discloses a tack test to define a weld in the aforementioned EP-A-710470 patent application. During the deformation, particularly the mechanical deformation, preferably applied by ring rolling, of the laminated composite structure comprising the adhesive composition of the present invention, the rupture of the adhesive layer joining the substrate and the apertured layer was prevented by mediation. extension capacity of the adhesive composition. The adhesive agglomerates on the parts of the machinery that are in direct contact with the adhesive layer through the openings of the layer with openings, and possibly pulls the sub-layer decided for this purpose, is otherwise avoided due to the absence of tackiness from the adhesive to steel at room temperature. The selective principle of non-tacky adhesive materials in combination with steel but sticky on "other" surfaces is contemplated in accordance with the present invention. From then on it is preferred that an adhesive used in a composite structure laminated according to IP priinvention is not pegeiuos at room temperature on any material. Furthermore, not all the layers of material comprised in the laminated composite structures according to the present invention are subjected to mechanical deformation, but, of course, excluding the adhesive layer, it needs to be deformable. By "deformable" it is implied that e! material is subjected to permanent deformation without the removal of its integrity. However, the combination of non-deformable with the deformable material can be deformed. For example, the non-woven non-woven material with the deformable polymeric film, bonded by an adhesive having the extension capacity required in terms of elongation at the break, can be deformed. In this case, the film is permanently deformed (and provides the zone of desired extension capacity) while the non-woven material would be localized. destroyed (breaking Abras fibers or bonds) but otherwise remain firmly adhered to the film recognizing the adhesive's extension capacity that does not break under mechanical deformation. The adhesive composition according to the present invention has been as described herein with reference to its preferred use in laminated composite structures comprising a substrate and a layer with openings that are subjected to mechanical deformation, for example by means of a rolling process with ring, in order to be provided with extension capacity at least in the designated areas. However, the adhesive composition of the present invention can also be used to bond a substrate to a layer with openings in laminated composite materials that can be spread differently during use. For example, a laminated composite structure comprising a sub-stack and a layer with openings by an adhesive composition in accordance with the present invention can be incorporated into a disposable absorbent article, for example a < 3 sanitary napkin wherein the composite structure can be extended during use for example by the user, or due to the movement of the user. The adhesive composition of the present invention provides the advantage of low or preferably zero tack to the openings of the apertured layer of the laminated composite structure, and at the same time allows the laminated structure to be elongated or stretched without imparting the encased bond. layers forming the structures, recognizing the expandability and softness characteristics of the adhesive composition.

Test methods All tests conducted with respect to the present invention require the test conditions of 23 ° C plus minus 1 ° C and a relative humidity of 50% unless stated in a different way. Unless otherwise stated, all test materials are conditioned at this temperature and humidity for at least 4 hours before the test itself. Each result is averaged over ten test samples.

Separation force test The separation force or separation resistance test analyzes the force required to delaminate a connection between the materials when a material. it is separated from the other material at a 180 degree angle according to the ASTM D 1876-72 test method. but driven with a head speed of the tension testing machine of 100 mm / min. With respect to the definition of a? permanent connection, it has been found very sensitive to create a real sample of the laminated composite structure joined by a layer of an adhesive composition. according to the present invention and analyzing the resistance to the separation between the actual materials that are to be joined together instead of releasing the materials or applying the adhesive. The test is conducted on a 2.5 cm wide sample strip that has enough end tabs to apply the separation force equally across the total width of the sample to be tested. The resistance to separation of a connection by means of an adhesive layer according to the present invention from the materials forming a laminated composite is sufficient if the force required to delaminate the joined connection is at least 0.4 N / 2.5. cm or if the connection can withstand retention of a 0.4 N load without delamination. As the materials already indicated have a bond strength less than the required 0.4 N / 2.5 cm, they are still considered permanently connected by the adhesive composition of the present invention if the material undergoes the glide failure instead of the adhesive connection. Obviously, this test is substantially easier to execute than a force measurement of the separation resistance. This can also be used on materials that have a superior adhesion strength of 0.4 N / 2.5 cm providing one of the materials and the adhesive connection is not drawn. Therefore, in the general desirucción of one of the materials joined together implies that the adhesive connection was permanent.

Proof of the separation force on steel The test of the resistance to separation or force of separation on steel. measures the tack on a steel surface at 23 ° C, which is considered As a standard ambient temperature, an adhesive according to the present invention. The measurement of the separation force is performed in the same way as in the separation resistance method or separation force described above. (force of separation at 180 degrees with a head speed of ICO mm / min), but the samples are prepared and handled as described hereinafter. The adhesive composition is applied to a substrate according to the supplier's instructions in an amount of 80 g / m2. For the current test method it has been found that using a Nordson slot coater with a 50 mm wide nozzle available from Nordson, Lüneburg, Germany is useful. The adhesive is applied for this test in a width of at least 2.5 cm of the coating of the surface area at a speed of the first sub-surface of at least 0.5 m / s in relation to the coating equipment. Wider coatings are acceptable while coatings of smaller width or only fractions of! Width that is coated (for example, spiral coating) are not acceptable in the context of that test.

Of course, these coating patterns can be used to apply the denor adhesive of the particular application context according to the present invention. The iongitude of the adhesive layer in the individual test sample should not be less than 10 cm. The test sample has a sufficient end tab to allow the application of the separation force equally across the full width of the adhesive coating on the sample to be tested. The substrate is constituted by the polyethylene terephthalate (PET) film having a thickness between 20 and 30 μm. Typically the adhesives used within the context of the present invention are thermal fusion adhesive compositions which are applied in a molten state at a temperature according to the manufacturers.

A polyethylene terephthalate film as a substrate is able to withstand the application of these adhesives over a broad spectrum of application temperatures, which is typical in the case of the absorbent absorbent articles. After the adhesive has been applied to the substrate, it is allowed if it is necessary to cool to the temperature at which the measurements are to be taken, while ensuring that the open side of the sample remains untouched and is only exposed to clean air. The substrate is then placed on a 5 x 5 cm horizontal steel plate that has a smooth, flat surface, according to what is specified in? STM D 3380, with the iolai surface of the sample coated with the adhesive layer that is in contact with the steel plate A pressure is applied with a compression roller weighing 200 g, rolling once over the total length of the sample at a speed of 300 mm / min. After the application of the pressure the samples are left for 30 seconds. The measurement of the separation force at 180 degrees is conducted as described above, with a head speed of 100 mm / min of the machine of tension test with the steel plate connected to the fixed staple and with the subtraction connected to the moving staple in its free eximetry tongue. Since it is preferred that the separation force on the steel be as low as possible, it is possible, with particularly preferred adhesives, that this be virtually zero. In this case, no force measurement is detected during delamination, or, alternatively, the film sub-film can delaminate from the steel plate under its own weight when the steel plate is placed vertically to be connected to the staple staple of the film. dynamometer. It is considered that in these cases the adhesive satisfies the test.

Elongation test to rupture The elongation at rupture is measured according to the standard test method for the tensile properties of plastics ASTM D 638M-91 á, where the samples prepared for the test have a standard thickness of 4 mm Examples Two laminated composite structures have been prepared comprising both as the substrate a breathable polymeric microporous film produced by Mitsui under the commercial name Espoir Microporous PG-01 with a basis weight of 40 g / m2, and as the layer with openings a polymeric film with openings produced by Tredegar threedimensional under the trade name Dri-Wave The substrate and the layer with openings are joined together by a layer of an adhesive composition comprised therein and applied by curtain coating in an amount of 11 g / m2.

In the reference sample the laminated composite structure comprises a layer of an adhesive composition designated Fuller HS350, available from H.B. Fuller Company The adhesive composition made in accordance with the present invention comprised in the second laminated composite has the following composition in weight percent: Elvax 4310 (Ethylene vinyl acetate terpolymer available from Dupont) 59 7% Wiícodur 236 (available microcrystalline wax from Witco Company) 40% Irganox 1010 (antioxidant available from Ciba Geigy) 0.03% Both laminated composite materials satisfy the separation strength test, and both adhesive compositions show virtually no adhesion to steel at 2 ° C (no separation force was measured in the separation force test on steel). The two laminated composite structures are subjected to a mechanical deformation by rolling with anil'c in order to be provided with a 75% extension. In the reference sample the adhesive layer broke causing delamination of the laminated composite structure. The failure of the adhesive connection can be determined for example by carrying out a second separation force test on the deformed structure; the requirement of at least 0.4 N / 2.5 cm of separation force are never satisfied anymore. The structure comprising the adhesive composition according to the present invention on the contrary shows a satisfactory resistance of the adhesive composition to mechanical deformation, and the effectiveness of the adhesive connection can be demonstrated by a second separation force test on the structure deformed, where the requirement of 0.4 N / 2.5 cm of separation force is satisfied.

Claims (10)

1. An adhesive composition having a lower viscosity of 10000 mPa-s at a temperature no greater than 160 ° C, and a separation force on steel less than 10 g at a temperature of 23 ° C as measured according to the Steel Separation Test described herein, the adhesive composition comprising : a microcrystalline wax, a polymer that has a rupture elongation of at least 400% according to ASTM D-638-91a where the thickness of the sample is 4 mm.

An adhesive composition according to claim 1, wherein the viscosity is less than 5000 mPa-s at a temperature not higher than 160 ° C:

3. An adhesive composition according to claim 2, wherein the viscosity is comprised from 3000 mPa-s to 5000 rriPa at a temperature not exceeding 130 ° C:

4. An adhesive composition according to any preceding claim, wherein the adhesive composition comprises: from 30% to 80% by weight of the microcrystalline wax , from 5% to 70% by weight of said polymer, from 0% to 25% by weight of a plasticizing paraffinic oil. from 0% to 10% by weight of a paraffin wax, or of a mixture of paraffin waxes, from 0% to 25% by weight of an atactic poly-alpha-olefin, or of a mixture of alpha-olefin polysaccharides, from 0% to 40% by weight of a tackifying resin or mixtures of tackifying resins.

5. An adhesive composition according to claim 4, wherein the adhesive composition comprises: from 30% to 70%, preferably from 40% to 60% by weight of the micro-islamine wax, and from 30% to 70% by weight of the polymer, said polymer being a copolymer of ethylene and vinyl acetate having a melt flow index of at least 150 g / 10 min and a vinyl acetate content of at least 14% by weight.

6. An adhesive composition according to claim 5, wherein the polymer is a terpolymer also containing an acid monomer in an amount such that the acid number of the polymer is comprised between 1 and 100 mg KOH per gram of said polymer. polymer.

7. An adhesive composition according to any of claims I to 4, wherein the adhesive composition comprises: from 50% to 80% by weight of the microcrystalline wax, from 5% to 25% by weight of the polymer, the polymer being a styrene block copolymer having a silyrene content comprised of 14% and 35% by weight.

8. An adhesive composition according to any of claims 4 to 7, wherein the tackifying resin is a hydrocarbon resin, or an aliphatic, or aromatic, or aliphatic-aromatic resin, a partial resin or hydrogenated ional, or mixtures of them, said resin or resin mixtures preferably with a softening point not higher than 100 ° C.

9. A laminated composite structure comprising a sub-layer, an apertured layer bonded to said substrate by means of a layer of an adhesive composition comprised therein, said adhesive composition comprising: In accordance with any preceding claim, said laminated composite structure having extensible zones.

10. A disposable absorbent article comprising a laminated composite structure according to claim 9.