Absorbent article having improved bonding.

FIELD OF THE INVENTION

The invention relates to an article having improved bonding of a superior canvas material to an absorbent material. More particularly, this invention relates to an article having improved bonding of an upper canvas material to an absorbent material in such a way that dismantling or tearing of the upper canvas is prevented during normal use of the article.

BACKGROUND OF THE INVENTION

Absorbent items such as sanitary napkins, panty liners, tampons, absorbent interlabial devices, disposable diapers, incontinence products, and bandages are designed to absorb and retain fluid and other discharges from the human body and to prevent soiling of both the body and the body. clothing. In the manufacture of absorbent articles it is generally necessary to join the components that will make up said absorbent article to form the finished product. For example, the topsheet materials can be bonded to an absorbent layer, such as, for example, a secondary layer, to provide added strength and reinforcement to the topsheet.

Some premium canvas materials, such as low-cost premium canvas materials that are soft and silky to the touch, have weak material strength in the cross direction. It has been observed in typical use that the use of bonding methods, such as, for example, fusion bonding, to bond such materials to a layer

INSTITUTO MEXICANO absorbents can result in destruction of the integrity of the binding site. A solution for joining these types gives matariaicc inHnya adding glue to the binding sites; However, gluing the layers together results in a stiffer, less comfortable and more integrated laminate of materials. Therefore, the desire and need in the art persists to develop an article that has a sufficient bond between the upper and absorbent canvas materials, particularly, when a low-cost superior canvas material with weak material strength is used. in the transverse direction, so that tearing of the weft material during use is prevented, without inconveniently increasing the rigidity of the article.

BRIEF DESCRIPTION OF THE INVENTION

An absorbent article is provided. The absorbent article includes a liquid-permeable film topsheet having a body-facing surface and a garment-facing surface; a bottom canvas having a body-facing surface and a garment-facing surface; an absorbent core having a body-facing surface and a garment-facing surface, the absorbent core is provided between the upper canvas and the lower canvas; and a tie layer having a body-facing surface and a garment-facing surface. The body-facing surface of the tie layer has a fibrous matrix comprising cellulosic fibers and thermoplastic fibers, and the body-facing surface of the upper canvas is directly bonded to the body-facing surface of the point tie layer. adhesive-free bonding systems.

Further provided is an absorbent article comprising a canvas

IMPI

INSTITUTO MUKANO HEARD INDUSTRIAL PROPERTY

<img file="MX345441B_D0001.tif" />

top of liquid permeable film having a surface area facing the garment; a lower canvas having a body-facing surface and a garment-facing surface; and an absorbent core having a body-facing surface and a garment-facing surface, the absorbent core is provided between the upper canvas and the lower canvas; and a tie layer having a body-facing surface and a garment-facing surface. The body-facing surface of the tie layer has a fibrous matrix comprising cellulosic fibers and thermoplastic fibers, and the body-facing surface of the tie layer is different from the body-facing surface of the tie layer. The body-facing surface of the top canvas is directly bonded to the body-facing surface of the tie layer at separate tie points.

Further provided is an absorbent article comprising a liquid permeable film topsheet having a body-facing surface and a garment-facing surface, the topsheet comprising a plurality of distinct projecting extensions extending only from one first surface of the precursor web and macroapertures; a bottom canvas having a body-facing surface and a garment-facing surface; an absorbent core having a body-facing surface and a garment-facing surface, the absorbent core is provided between the upper canvas and the lower canvas; and a tie layer having a body-facing surface and a garment-facing surface. The body-facing surface of the tie layer has a fibrous matrix comprising cellulosic fibers and thermoplastic fibers. The body-facing surface of the top canvas is directly bonded to the body-facing surface of the tie layer at separate adhesive-free bonding points.

<img file="MX345441B_D0002.tif" />

IMPI

ΙΝΤΓΠνΤΟ MEXICAN PROPERTY, INDUSTRIAL

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 is a perspective view of one embodiment of a sanitary napkin.

Figure 2 is a cross-sectional view of the sanitary napkin of Figure 1, taken through line 2-2.

Figure 3 is a perspective view of one embodiment of a sanitary napkin.

Figure 4 is a cross-sectional view of the sanitary napkin of Figure 1, taken through line 2-2.

Figure 5 is a schematic illustration of a top canvas material suitable for use in one embodiment of the description.

DETAILED DESCRIPTION OF THE INVENTION

An absorbent article is provided comprising a topsheet, such as, for example, an inexpensive topsheet that is soft and silky to the touch, a tie layer, and an absorbent core. The tie layer includes a matrix of a fibrous matrix comprising cellulosic and thermoplastic fibers that is in direct contact with and directly bonded to the upper canvas. This configuration surprisingly results in an article having an improved bond between the topsheet and the tie layer, without undesirably increasing the stiffness of the article.

The invention can be used on a variety of disposable absorbent articles, but is particularly useful in feminine hygiene products such as sanitary napkins and panty liners. The modalities of an absorbent article

<img file="MX345441B_D0003.tif" />

INSTITUTO MEXICANO DE LA PROPIEDAD disposable using the invention are the sanitary pads 10 qUBPWthuesTireft-in Figure 1, Figure 2, Figure 3, and Figure 4. --------------- -—........... -.

The illustrated sanitary napkin 10 has a body-facing top side 11 that is in contact with the wearer's body during use. The lower opposite side 13 facing the garment is in contact with the wearer's clothing.

A sanitary napkin 10 may have any shape known in the art for feminine hygiene items, including the generally symmetrical "hourglass" shape as shown in Figure 1, as well as pear-shaped, bicycle seat shapes, trapezoidal shapes, wedge shapes, or other shapes that have one end wider than the other. Sanitary napkins and panty liners may additionally be provided with side extensions known in the art as "flaps" or "wings" 15. Such extensions can serve a number of purposes including, but not limited to, preventing panty briefs from the user get dirty and keep the sanitary napkin in place.

The top side of a sanitary napkin generally has a liquid-permeable top sheet 14. The bottom side generally has a liquid-impervious bottom sheet 16 that meets the top sheet 14 at the edges of the product. An absorbent core 18 is positioned between the top sheet 14 and the bottom sheet 16. A secondary top sheet can be provided on top of the absorbent core 18, below the top sheet.

The upper canvas 14, the lower canvas 16, and the absorbent core 18 can be assembled in a variety of known configurations, including so-called "tube" or side flap products, such as, for example, the configurations generally described. in US Patent No. 4,950,264, "Thin and Flexible Sanitary Napkin" issued to Osborn on August 21, 1990, US Patent⁶

INSTITUTE MEXíCAHC. ......... „„ „..... ... nu.vwp'KR '* US num. 4,425,130, Composite sanitary napkin grantedⁿúT) esMarcns ^ r January 10, 1984; US Patent No. 4,321 ^ 02,1) "Beaded disposable bUHTC absui item" granted to Ahr on March 30, 1982; US Patent No. 4,589,876, and "Flap Shaped Sanitary Napkin" issued to Van Tilburg on August 18, 1987. Each of these patents is incorporated herein by reference.

The lower canvas 14 and the upper canvas 16 can be secured together in a variety of ways. The adhesives manufactured by Η. B. Fuller Company of St. Paul, Minn. with the designation HL-1258 or H-2031 are considered satisfactory. Alternatively, the upper canvas 16 and the lower canvas 14 can be joined together by thermal bonding, pressure bonding, ultrasonic bonding, dynamic mechanical bonding, or a crimp seal. A fluid impervious crimp seal 24 can resist lateral migration ("wicking") of fluid across the edges of the product, which inhibits soiling of the side of the wearer's underwear.

As is typical for sanitary napkins and the like, the sanitary napkin 16 of the present invention may have an adhesive for attaching to the undershirt disposed on the garment-facing side of the lower canvas 10. Underwear can be any known adhesive that is used in the art for this purpose and can be covered prior to use by a release paper, as is well known in the industry. If fins or wings are present, the adhesive for attaching to the garment can be applied to the side facing the garment so as to contact and adhere to the underside of the wearer's undergarment.

For the purpose of describing the present invention, the important parts of the sanitary napkin 10 are the topsheet 14, the absorbent core 18, and optionally the secondary topsheet. Each of these components is

<img file="MX345441B_D0004.tif" />

describe in turns.

IMPI

MEXICAN IIWmWTO

OF THE RSOriSDAL

INDUSTRIAL

The top canvas 14 is attached to the tie layer 20. such as, for example, a secondary top canvas as shown in Figure 2.

Alternatively, the topsheet may be attached to tie layer 20, which is part of absorbent core 18, as shown in Figure 4.

Bonding layer

The upper canvas 14 is attached to a tie layer 20 which has an undergarment facing side and a wearer facing side and is formed of a fibrous matrix comprising cellulosic fibers and thermoplastic fibers. In certain embodiments, the fibrous matrix is ​​thermally bonded, such as, for example, a thermally bonded air-laid web. The tie layer 20 can function as a secondary topsheet or can be considered part of the absorbent core; however, the upper canvas and the fibrous matrix are directly bonded to each other without the intervention of any material or layer, such as, for example, an adhesive or other material provided between the upper canvas and the bonding layer 20 at the points of attachment. . In certain embodiments, tie layer 20 may include additional materials on the garment-facing side, such as, for example, a carrier weft, but these materials will not be directly attached to the upper canvas. This provides a softer and more comfortable absorbent article.

In certain embodiments, tie layer 20 is lopsided, meaning that the wearer-facing side and the garment-facing side are different. For example, the wearer-facing side is typically adjacent to the upper canvas and will comprise the fibrous matrix, while the garment-facing side may be a material other than the fibrous matrix, such as, for example, a weft.

<img file="MX345441B_D0005.tif" />

INSTmiTO Mf.HCAHO Πί LA nOHED * · carrier, such as a non-woven fabric, tissue paper or any other mHreflShadeTOaSer ^

The fibrous matrix may comprise cellulosic and fibrous fibers in any amount, such as, for example, in a ratio of basis weight of cellulosic fibers to basis weight of thermoplastic fibers of about 1.5: 1, about 1.7: 1, about 2 .Ί, about 2.3: 1, about 2.5: 1, about 2.7: 1, about 3: 1, about 3.3: 1, about 3.5: 1, about 4: 1 or more. In certain embodiments, the fibrous matrix comprises more cellulosic fibers than thermoplastic fibers.

The tie layer may comprise cellulosic fibers and thermoplastic material, including thermoplastic fibers and / or thermoplastic powder, in any suitable amount, such as, for example, in a ratio of basis weight of cellulosic material to basis weight of thermoplastic material greater than about 1: 1, greater than about 1.1: 1, or greater than about 1.5: 1, such as, for example, about 1.1: 1, about 1.2: 1, about 1.3: 1, about 1.4: 1, about 1.5: 1, about 1.7: 1, about 2: 1, about 2.5: 1, or more. In certain embodiments, the tie layer comprises more cellulosic material than thermoplastic material.

Generally, the topsheet is attached to the bonding layer 20 at multiple different bonding points, such as, for example, by pressing the topsheet into the fibrous matrix to form the bonding points. In certain embodiments, the thermoplastic fibers are plastically deformed during the bonding process to form the bond. Additionally, the fibrous matrix is ​​capable of dissipating the bond and wear force throughout the web, which decreases the likelihood of bond destruction or breakage during bond formation or wear.

The tie layer 20 has a fibrous web or matrix of cellulosic fibers and

<img file="MX345441B_D0006.tif" />

INSTITUTO MEXICANO jk thermoplastic fibers. This fibrous matrix or web provides the met ^ printspiEp ^ to handle the aqueous fluids and, particularly, the corpercriee-aeHOfios fluids discharged ™ · ». This matrix or web typically provides a capillary structure to handle such fluids. In certain embodiments, the fibrous web is a bonded network of fibers, such as, for example, an air-laid web that is heated to thermally bond the fibers.

Many cellulosic materials can be used to make the matrix or weft, including both unmodified cellulosic fibers of natural origin, such as cotton, esparto grass, bagasse, hemp, flax, wood pulp and jute, as well as modified cellulosic fibers such as chemically modified wood pulp, rayon and the like. Such fibers can be stiffened by chemical means.

In certain embodiments, cellulosic fibers are hydrophytic. As used herein, the term "hydrophilic" describes fibers or fiber surfaces that can be wetted by aqueous fluids (eg, aqueous body fluids) that are deposited on these fibers. Hydrophilicity and wettability are typically defined in terms of the contact angle and surface tension of the participating fluids and solids. This is discussed in detail in the American Chemical Society publication Contact Angle, Wettability and Adhesion, edited by Robert F. Gould (Copyright 1964). It is said that a fiber or the surface of a fiber is wetted by a fluid (that is, it is hydrophytic) when the contact angle between the fluid and the fiber or its surface is less than 90 degrees or when the fluid tends to disperse spontaneously over the entire surface of the fiber, normally coexisting under both conditions. In contrast, a fiber or fiber surface is considered to be hydrophobic if the contact angle is greater than 90 degrees and the fluid does not spontaneously disperse across the fiber surface.

The tie layer 20 further comprises thermoplastic material. The fibers

INSTITUTO MEXICANO or thermoplastic particles can be used for this purpose ^ í ^ VmaíSBH ^ Particularly, thermoplastic fibers can be made from dft.una ^_T_ thermoplastic polymers including polyolefins such as polyethylene (eg, PULPEX.RTM.) and polypropylene, polyesters, copolyesters and copolymers of any of those mentioned above.

Depending on the characteristics desired for the resulting thermally bonded matrix, suitable thermoplastic materials include hydrophobic turned hydrophilic fibers, such as surfactant-treated or silica-treated thermoplastic fibers derived from, for example, polyolefins such as polyethylene or polypropylene, polyacrylics, polyamides, polystyrenes, polyurethanes and the like. The surface of the hydrophobic thermoplastic fiber can be rendered hydrophilic by treatment with a surfactant, such as a nonionic or anionic surfactant, for example, by spraying the fiber with a surfactant, dipping the fiber in a surfactant, or incorporating the surfactant as part of the polymer melted during the production of the thermoplastic fiber. Once melted and resolidified, the surfactant will tend to remain on the surfaces of the thermoplastic fiber. Suitable surfactants include nonionic surfactants such as Brij 76 manufactured by ICI Americas, Inc. of Wilmington, Del, and various surfactants available from Pegosperse.RTM trademark of Glyco Chemical, Inc. of Greenwich, Conn. In addition to nonionic surfactants, anionic surfactants can also be used. These surfactants can be applied to thermoplastic fibers at levels, for example, from about 0.2 to about 1 gram per square centimeter of thermoplastic fiber.

Suitable thermoplastic fibers can be made from a single polymer (monocomponent fibers) or from more than one polymer (eg, bicomponent fibers). As used herein, the term "bicomponent pounds" refers to thermoplastic fibers that comprise a fiber from a polymer encapsulated in a thermoplastic sheath made from a different polymer. The polymer comprising the shell frequently melts at a different temperature, typically lower, than the polymer comprising the core 18. Consequently, these bicomponent fibers provide thermal bonding as a result of the melting of the shell polymer and the same. time they maintain the desirable strength characteristics of the core polymer.

Bicomponent fibers suitable for use in the present invention may include sheath / core fibers having the following polymer combinations: polyethylene / polypropylene, polyethylvinyl acetate / polypropylene, polyethylene / polyester, polypropylene / polyester, copolyester / polyester, and the like. Particularly suitable bicomponent thermoplastic fibers for use herein are those with a polypropylene or polyester core and a copolyester, polyethylvinyl acetate o r polyethylene sheath (eg, bicomponent fibers from DANAKLON.RTM., CELBOND.RTM. or CHISSO.RTM.) of less fusion. These bicomponent fibers can be concentric or eccentric. As used in the present description, the terms "concentric" and "eccentric" refer to the uniform or non-uniform thickness of the sheath in the cross-sectional area of ​​the bicomponent fiber. Eccentric bicomponent fibers can be practical to offer more compressive strength at smaller fiber thicknesses. The bicomponent fibers suitable for use in the present invention can be un crimped (ie, not kinked) or crimped (ie, kinked). The bicomponent fibers can be crimped by typical textile means such as, for example, a spin box method or the sprocket method to achieve predominantly two-dimensional crimp or "flat" crimp.

The length of the bicomponent fibers may vary depending on the

<img file="MX345441B_D0007.tif" />

particular properties desired for the fibers and the weft-forming process. Typically, in an air-laid weft, these thermoplastic fibers are from about 2mm to about 12mm in length, preferably from about 2.5mm to about 7.5mm in length, and most preferably from about 3.0mm to about approximately 6.0mm in length. The properties of these thermoplastic fibers can be further adjusted by varying the diameter (gauge) of the fibers. The diameter of these thermoplastic fibers is typically defined in terms of denier (grams per 9000 meters) or decitex (grams per 10,000 meters). Suitable bicomponent thermoplastic fibers as used in an airlaid manufacturing machine can have any suitable decitex range, such as, for example, from about 1.0 to about 20 decitex, from about 1.4 to about 10 decitex, from about 1.7 to about 7 decitex, or from about 2 to about 10 decitex, such as, for example, about 2 decitex, about 4 decitex, about 6 decitex, about 8 decitex, or any other suitable decitex range.

Furthermore, the compression modulus of these thermoplastic materials and, especially, those of thermoplastic fibers can be important. The modulus of compression of thermoplastic fibers is affected not only by their length and diameter, but also by the composition and properties of the polymer or polymers from which they are made, the shape and configuration of the fibers (e.g. ., concentric or eccentric, curly or non-curly), and similar factors. Differences in the modulus of compression of these thermoplastic fibers can be used to alter the properties, and especially the density characteristics, of the respective thermally bonded fibrous matrix.

In certain embodiments, tie layer 20 may further include fibers I

IMPI

INSTITUTO MEXICANO Synthetic fibers that do not typically function as binder fibersVáhWus' ^ áío

<img file="MX345441B_D0008.tif" />

mechanical properties of fibrous webs. This can include. for example Hn polyester fibers such as polyethylene terephthalate (eg, DACRON.RTM. and KODEL.RTM.), high melt crimped polyester fibers (eg, KODEL.RTM. 431 manufactured by Eastman Chemical Co .), hydrophilic nylon (HYDROFIL.RTM.), and the like. Suitable fibers can further hydrophilize hydrophobic fibers such as surfactant-treated thermoplastic fibers or silica derived from, for example, polyolefins such as polyethylene or polypropylene, polyacrylics, polyamides, polystyrenes, polyurethanes and the like. In the case of non-bonding thermoplastic fibers, their length can vary according to the particular properties desired for these fibers. They typically have a length of about 0.3 to 7.5 cm, preferably about 0.9 to about 1.5 cm. Suitable non-bonding thermoplastic fibers may have decitex in the range of about 1.5 to about 35 decitex, more preferably about 14 to about 20 decitex.

The secondary top canvas

In certain embodiments, the sanitary napkin 10 includes a secondary topsheet that can function as the tie layer 20. The secondary topsheet can be interposed between the absorbent core 18 and the topsheet 14 and serves to rapidly extract discharged body fluids. , particularly, menstrual fluids, through the permeable upper (primary) canvas 14. This allows the surface of the primary topsheet 14 adjacent to the wearer of the article protector to remain relatively clean and dry.

The secondary top canvas can have any suitable basis weight, such as, for example, a basis weight of less than 125 grams per square meter, a ¹⁴ tNSTmne MEXICAN

O £ LA r »OWDAD basis weight less than 100 grams per square meter, or a weight ^ T ^ se¹ less than 80 grams per square meter. The second-hand sanitary and polished upper canvas has a basis weight of approximately 59 grams per square meter. It has a gauge thickness of approximately 0.75mm, a density of approximately 0.08 grams / cubic centimeter, and a permeability of approximately 80 darcy.

In the secondary topsheet used in the described sanitary napkin 10, the cellulosic fibers contribute approximately 34 grams per square meter to the basis weight of the secondary topsheet, and the bicomponent fibers contribute approximately we achieved per square meter to the basis weight of the secondary topsheet. In certain embodiments, the secondary topsheet may include superabsorbent material, such as, for example, fibrous superabsorbent material, such as, for example, material that is 6mm in length with a decitex of 10. Suitable material can be purchased from Technical UK absorbent as Oasis type 111.

In certain embodiments, it is preferred to use less than about 3.5 grams per square meter of superabsorbent material, such as, for example, between 0.3 and 3.5 grams per square meter of superabsorbent material, more preferably use between 0.3 and 2.5 grams per square meter. of such material and, most preferably, use between 0.3 and 1.5 grams per square meter of such material. In the secondary topsheet used in the polished sanitary napkin, the fibrous superabsorbent material contributes 0.6 grams per square meter to the basis weight of the secondary topsheet.

The Upper Canvas 14

To provide softness close to the body, the upper canvas 10 of the illustrated sanitary napkin 14 is formed from a soft, soft, flexible and

INSTITUTO MKXICANC porous that does not cause irritation to the skin of the user. In certain mSyáiií ^ Kíé, superior 14 is considered soft, flimsy and weak compared to the commercially available superior canvases currently available. The top canvas 14 must be permeable to body fluids that the article will collect and therefore, for a sanitary napkin, must be permeable to vaginal discharge.

Shaped film topsheets suitable for absorbent articles can be made from a wide range of materials such as hole-formed thermoplastic films, hole-formed plastic films, and hydroformed thermoplastic films; cross-linked thermoplastic films; thermoplastic gauze; and film and / or non-woven fabric laminates. In certain embodiments, the top canvas can be hydrophobic. Hydrophobic topsheets have a reduced tendency to allow fluids to flow back through and rewet the wearer's skin. In this way, the surface of the shaped film that is in contact with the body remains dry, thereby reducing the possibility of the body getting dirty, and creating a more comfortable feel for the wearer.

The topsheets for use in the present invention may be hydrophobic topsheets selected from two-dimensional or three-dimensional film tops with holes. In addition, top formed film canvases with high holes, with appreciable top canvas texture (bumps, micro-texture or with filament-like prominences on the body-facing surface that can trap body discharges and prevent fluid from low flow into the body) which can be hydrophobic or hydrophilic in natural origin. Orifice formed films are especially preferred for the topsheet 14 because they are permeable to body exudates and nonabsorbent.

In certain embodiments, the top canvas can be a weft material

<img file="MX345441B_D0009.tif" />

INSTITUTO MEXICANO low cost, soft and silky to the touch, such as, for example, LOS ^ ipr ^ wros rnSMaJ ^ of weft suitable for use in the article of confnrmiaaH mn mortality Ha the description are materials of advantageously lower cost than the materials typical top canvas materials, such as, for example, the commercially available top canvas material such as the soft, dry woven cover used in ALWAYS ULTRATHIN (Procter &amp; Gamble) protectors. However, such weft materials tend to adhere to the wearer's skin during use and have low yield points, which can cause tearing of the weft between attachment points when such weft materials are incorporated into an article. absorbent. For example, compared to the commercially available soft dry woven cover used in ALWAYS ULTRATHIN protectors, the first weft material exhibits significantly increased adhesion to the skin and decreased performance resistance.

Suitable first screen materials are described in US Patent No. 7,521,588 and US Patent Publication Nos. 2010/0230857, 2010/0230858, 2010/0230866 and 2010/0230867, the descriptions of which are incorporated in their entirety in this description. The first frame includes a precursor frame, which may include, for example, a plurality of distinct protruding extensions that extend only from a first surface of the precursor frame. The first frame may also include macroapertures. In one embodiment, the first frame includes macroapertures and does not include distinct outgoing extents.

Examples of screens suitable for use as a precursor screen include low density polyethylene (LDPE) films, linear low density polyethylene (LLDPE), and blends of low density polyethylene and Linear Low Density Polyethylene (LDPE / LLDPE). The

<img file="MX345441B_D0010.tif" />

Precursor material can have a thickness of from about 10 microns to about 25 microns. For example, the grits of the suitable precursor flame include about 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25 microns. A suitable material for use as the precursor web is DOWLEX 2045A polyethylene resin, available from The Dow Chemical Company, Midland, Mich., USA. A film of this material having a thickness of 20 microns can have a tensile strength of at least 12 MPa; a maximum tensile of at least 53 MPa; an ultimate elongation of at least 635%; and a tensile modulus (2% secant modulus) of at least 210 MPa (each of the above measurements were determined in accordance with ASTM D 882).

The protruding extensions have side walls that define an open proximal portion and a closed distal portion. The distinct protrusions may form hair-like fibrils extending from a first surface of the web. The distinct protrusions impart a soft feel to the weft material, which makes it more convenient for use in an absorbent article, and particularly, for use as a top canvas material in an absorbent article. The protruding extensions can be formed integrally with the film, and can be formed by permanent local plastic deformation of the film. The protruding extensions have a height that is measured from a minimum width between adjacent protruding extensions to a maximum width at the closed distal portion. The protruding extensions may have a diameter, which for a generally cylindrical structure is the outer diameter at a lateral cross section. "Lateral" generally means parallel to the plane of the first surface of the raster. For non-uniform lateral sections and / or non-cylindrical structures, the diameter is measured as the average dimension in lateral cross-section at half the height of the

<img file="MX345441B_D0011.tif" />

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DE LA NONEDAD INDUSTRIAL outgoing section. Thus, an aspect ratio can be determined for each projecting extension, defined as height / diameter. Outgoing extents can have a ^ aspect ratio of at least 0.5. Other suitable aspect ratios include, for example, about 0.5, 1.1.5, 2, 2.5, and 3.

The diameter of the protruding extensions may remain constant or may decrease with increasing amplitude (the amplitude increases to a maximum at the closed distal end). For example, the diameter, or average lateral cross-sectional dimension of the projecting extensions may be a maximum in the proximal portion and the lateral cross-sectional dimension decreases steadily to the distal end. The protruding extensions can have an average cross-sectional diameter of from about 50 microns to about 130 microns, from about 60 microns to about 120 microns, from about 70 microns to about 110 microns, and from about 80 microns to about 100 microns. Other suitable average cross-sectional diameters include about 50, 60, 70, 80, 90, 100, 110, 120, and 130 microns.

The areal density of the protrusions, which is the number of protrusions per unit area of ​​the first surface of the web, can be optimized for use in absorbent articles. Generally, center-to-center spacing can be optimized to provide adequate tactile impression, while reducing inter-fiber fluid occlusion. Currently, it is considered optimal to use a center spacing of about 100 microns to 250 microns on sanitary napkins. Reducing the occlusion of the menstrual flow between the fibers improves the cleanliness of the surface of the sanitary napkin, which in turn improves the cleanliness and health of the wearer's skin.

<img file="MX345441B_D0012.tif" />

The first web may further include a plurality of openings to allow the first web to be permeable to liquids. For example, the apertures can be macro-apertures that are formed by means of multiple interconnecting members, such as fiber-like elements, that interconnect with each other to define a first surface of the weft. The macro-openings can be of any suitable shape. For example, macroapertures can be shaped like a polygon. In one embodiment, the macroapertures are shaped like a hexagon. The

<td>macroapertures</td><td>can have a diameter in a range</td><td>from</td><td>approximately</td>

<td>300 micrometers</td><td>at about 1000 microns,</td><td>from</td><td>approximately</td>

<td>400 micrometers</td><td>at about 900 microns,</td><td>from</td><td>approximately</td>

<td>500 micrometers</td><td>at about 800 microns, or</td><td>from</td><td>approximately</td>

600 microns to about 700 microns. In one embodiment, the first frame includes separate macroopenings and overhangs. The apertures may extend from the first surface of the weft to a second surface of the weft, to extend in an opposite direction, since the projecting extensions and the distinct projecting extensions can be located only on the first surface of the weft. Referring to Figure 5, in one embodiment, the first frame 40 may include macroapertures 46 with distinct protruding extensions 48 that extend only from an upper surface 42 (ie, the first) of the frame. The side walls 44 of the macro-openings 46 remain without protruding extensions 48.

Suitable formed film topsheets are described in US Pat. 3,929,135 (Thompson), issued December 30, 1975; US Patent No. 4,324,246 (Mullane, et al.), Issued Apr. 13, 1982; US Patent No. 4,342,314 (Radel. Et al.), Issued Aug. 3, 1982; US Patent No. 4,463,045 (Ahr et al.), Issued Jul 31, 1984; and the

<img file="MX345441B_D0013.tif" />

2nd 1ΜΡΙ:

US Patent No. 5,006,394 (Baird), issued April 9, 1991. All of these patents are incorporated by reference into the present invention. Other orifice formed film top canvases are disclosed in US Pat. 4,609,518 (Curro et al.), Issued September 2, 1986 and US Patent No. 4,629,643 (Curro et al.), Issued December 16, 1986, which are incorporated by reference. Other top canvases are described in, for example, US Patent Nos. 7,172,801; 7,270,861; 7,410,683; 7,507,459; 7,553,532; 7,648,752; 7,670,665; 7,682,686; 7,718,243; and US Patent Application Nos. 2005/0281976; 2005/0283129; 2008/0119807; 2009/0030390; 2009/0030391. A preferred topsheet in the present invention is the shaped film described in one or more of the above patents and sold on sanitary napkins from The Procter &amp; Gamble Company of Cincinnati, Ohio as "DRI-WEAVE."

The absorbent core 18

The absorbent core 18 of a sanitary napkin serves to store body fluids discharged during use. Core 18 can be made in a wide variety of sizes and shapes and can be profiled to have different thicknesses, hydrophilic gradients, superabsorbent gradients, densities, or average basis weights at different positions along the face of the product. In certain embodiments, tie layer 20 can be part of absorbent core 18.

An absorbent core 18 may have a fluid distribution layer as well as a fluid storage layer. The fluid distribution layer transfers the received fluid downward and sideways and generally has higher permeability and less capillarity than the fluid storage layer.

In addition to conventional absorbent materials such as cotton wadding

<img file="MX345441B_D0014.tif" />

folded cellulose, fluff cellulose fiber, also known wood pulp fibers. Like air felt and textile fibers, the fluid storage layer often includes superabsorbent material that absorbs fluids and forms hydrogels. These materials are typically capable of absorbing large amounts of body fluids and holding them under moderate pressure. The fluid storage layer of the absorbent core 18 may be made solely of superabsorbent material, or may include such materials dispersed in a suitable carrier such as cellulose fibers in the form of fluff or stretched fibers. In addition, synthetic fibers including cellulose acetate, polyvinyl fluoride, polyvinylidene chloride, acrylics (such as Orion), polyvinyl acetate, insoluble polyvinyl alcohol, polyethylene, polypropylene, polyamides (such as nylon), polyesters, can be used. bicomponent fibers, tricomponent fibers, mixtures of these and the like. The fluid storage layer may further include fillers, such as pearlite, diatomaceous earth, vermiculite, or other suitable materials, which reduce wetting problems.

However, structured, the total absorbent capacity of absorbent core 18 should be compatible with the design load and the intended use of the article. Therefore, the size and absorbent capacity of the absorbent core 18 can be varied to accommodate different uses such as incontinence pads, panty liners, common sanitary napkins, or nighttime sanitary napkins. The absorbent core 18 in the polished sanitary napkin is made of cellulose fibers and absorbent gelling material such as, for example, described in International Patent Application Publication No. 00/59438 (Walker), herein incorporated by reference.

The absorbent core 18 may further include other optional components sometimes used in absorbent webs. For example, you can²² ΙίΜΡΙά ^

MEXICAN INSTITUTE

I7E LA MOMIDAO V&gt; »-. ....,. . x _, __x _ _ _x. ______x. industrial ^ -_ r —__ place a lightweight reinforcing fabric within or between the respective layers of the absorbent core 18. - ------ '

Bottom canvas 20 covering the underside of absorbent core 18 prevents fluids in absorbent core 18 from wetting items that are in contact with sanitary napkin 16, such as panties, pajamas, and underwear. Accordingly, the bottom canvas 16 is preferably made of a liquid-impervious thin film or non-woven sheet / vapor-permeable film, a microporous film, orifice formed film, or other polymeric film that is vapor-permeable or provided for be permeable to vapor, but practically impervious to fluid.

Super absorbent material

Absorbent gelling materials suitable for use in the invention may comprise a polymeric gelling material, practically insoluble in water, slightly cross-linked and partially neutralized. When this material comes into contact with water, it forms a hydrogel. These polymeric materials can be prepared from polymerizable, unsaturated, acid-containing monomers. Suitable acidic unsaturated monomers for use in preparing the absorbent polymeric gelling material used in this invention include those listed in US Pat. 4,654,039 (Brandt et al.), Issued March 31, 1987, and granted as RE 32,649 on April 19, 1988, which are incorporated herein by reference. Preferred monomers include acrylic acid, methacrylic acid, and 2-acrylamido-2-methyl propane sulfonic acid. Acrylic acid itself is the one that is especially preferred for the preparation of the polymeric gelling material. The polymeric component formed from unsaturated acid-containing monomers can be grafted onto other types of

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u RíOPieoxn polymeric entities, such as starch or cellulose. The grafted starch materials of

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Polyacrylates of this type are particularly preferred. Preferred absorbent gelling polymeric materials, which can be prepared from conventional monomer types, include hydrolyzed acrylonitrile grafted starch, polyacrylate grafted starch, polyacrylates, maleic anhydride-based copolymer, and combinations thereof. Especially preferred are polyacrylates and polyacrylate grafted starch.

Whatever the nature of the basic polymeric components of the hydrogel-forming polymeric absorbent gelling materials such materials will generally be slightly cross-linked. Crosslinking serves to render hydrogel-forming polymeric gelling materials practically insoluble in water, and crosslinking therefore, in part, determines the gel volume and extractable polymeric characteristics of the hydrogels formed from these polymeric gelling materials. Suitable crosslinking agents are known in the art and include, for example, those described in greater detail in US Pat. 4,076,663 (Masuda et al.); issued Feb. 28, 1978, which is incorporated by reference to the present invention. Preferred crosslinking agents are unsaturated mono- or polycarboxylic acid di- or polyesters with polyols, bisacrylamides and di- or triallylamines. Other preferred crosslinking agents are N, N'methyleneobisacrylamide, trimethylolpropane triacrylate, and triallylamine. The crosslinking agent may generally constitute from about 0.001 mole percent to 5 mole percent of the resulting hydrogel shaped polymeric material. More preferably, the crosslinking agent will constitute from about 0.01 mole percent to 3 mole percent of the hydrogel-forming polymeric gelling material.

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INSTITUTO MEXICANC JR

OF THE PROPERTY

Polymeric gelling materials conforlYféOSVés ce ^ hrorogel slightly cross-linked are generally used in their foiTOT pal ulali i leí i le¹1 iculi aliiaüe. For purposes of the present invention, such materials are considered partially neutralized when at least 25 mole percent and preferably at least 50 mole percent of the monomers used to form the polymer are monomers that contain an acid group and that have been neutralized with a salt-forming cation. Suitable salt-forming cations include alkali metal, ammonium, substituted ammonium, and amines. This percentage of the total monomers used that are monomers containing neutralized acid groups is referred to as "degree of neutralization" in the present description.

While these absorbent gelling materials are typically in particulate form, it is further contemplated that the absorbent gelling material may be in the form of macrostructures such as fibers, canvases or strips. These macrostructures are typically prepared by forming the particulate absorbent gelling material into an aggregate, treating the aggregate material with a suitable crosslinking agent, compacting the treated aggregate to densify it into a coherent mass, and then curing the compact aggregate to make it the crosslinking agent reacts with the particulate absorbent gelling material to form a composite porous absorbent macrostructure. Porous absorbent macrostructures are described, for example, in US Patent Ull. no. 5,102,597 (Roe et al.), Issued Apr. 7, 1992, which is incorporated by reference to the present invention.

Bonding layer formation

The mixtures of fibers, thermoplastic material and, optionally, material

<img file="MX345441B_D0017.tif" />

INSTITUTO MEXICANO DE LA PROPERTY superabsorbent, can be formed in layers by any of the methods, including air-laid methods.

In certain embodiments, tie layer 20 may be formed by airlaying the mixture of fibers and thermoplastic material. Generally, air laying can be achieved by measuring an air flow containing the fibers and thermoplastic material, in a practically dry condition, over a typically horizontally moving wire forming mesh. Apparatus and systems suitable for airlaying blends of fibers and thermoplastic material are described in, for example, US Pat. 4,157,724 (Persson), issued June 12, 1979, and granted December 25, 1984 as Re. 31,775; US Patent No. 4,278,113 (Persson), issued Jul 14, 1981; US Patent No. 4,264,289 (Day), issued Apr. 28, 1981; US Patent No. 4,352,649 (Jacobsen et al.), Issued Oct. 5, 1982; US Patent No. 4,353,687 (Hosler et al.), Issued Oct. 12, 1982; US Patent No. 4,494,278 (Kroyer et al.), Issued Jan. 22, 1985; US Patent No. 4,627,806 (Johnson), issued December 9, 1986; US Patent No. 4,650,409 (Nistri et al.), Issued Mar 17, 1987; and US Patent No. 4,724,980 (Farley), issued February 16, 1988, which have been incorporated by reference into the present invention.

A particularly preferable system for airlaying blends of fibers and thermoplastic material in accordance with the present invention is described in US Pat. 4,640,810 (Laursen et al.), Issued Feb. 3, 1987, which is incorporated by reference.

In certain embodiments, tie layer 20 can be formed as a secondary topsheet by air-laying cellulose, thermoplastic material, and, ²⁶

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optionally, fibrous superabsorbent material on a nonwoven fabric carrier, such as, for example, a nonwoven fabric carrier made from thermally consolidated pullUIUTins, such as, for example, thermally consolidated polypropylene. The resulting fibrous matrix can be heated to create a bonded network of fibers within the fibrous web, such as, for example, in the form of a heat-bonded airlaid web. Additionally, in certain embodiments, latex can be sprayed onto one or both sides of tie layer 20.

There are different ways of combining tie layer 20 and absorbent core 18. Tie layer 20 can be formed separately from absorbent core 18 and then combined after densification / thermal bonding. Alternatively, the tie layer 20 and all or parts of the absorbent core can be formed together or one on top of the other.

Union

The top canvas and tie layer 20 can be joined in any way or configuration. In certain embodiments, the topsheet and tie layer 20 can be joined by a plurality of different tie points that can be formed by any known means. For example, the bonding points can be formed by fusing the top canvas and the bonding layer 20 at different bonding points. Suitable examples of methods of attachment can be found in US Pat. US no. 7,056,404 and 4,854,984. In certain embodiments, the bonding points are adhesive free, this means that no adhesive is provided between the top canvas and the bonding layer 20.

The top canvas and tie layer 20 can be joined in any suitable pattern. In certain embodiments, the bonding pattern may adhere together at least one of the first end regions of the upper canvas and the bonding layer 20 and / or the

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INSTITUTO MEXICANO ÓTTfcfe OE LA MKWIEDAO Second end regions of upper canvas and layer of ^ JfflW^v20 / tTT Certain modalities, the pattern of union may include a separation din iui iblonaUá between Ιό “adjacent points of union sufficient to have inscribed in it a circle having a diameter of from about 1mm to about 12mm. The circle may be inscribed so that it is tangent to the adjacent junction points. Other suitable diameters include from about 2mm to about 10mm, from about 3mm to about 10mm, and from about 4mm to about 8mm. For example, the dimensioned spacing may be sufficient to have inscribed on it a circle having a diameter of approximately 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10 mm, 11 mm and 12 mm. As used in the present description, the term "adjacent points of attachment" refers to two points of attachment, which may be connected through a straight line that does not intersect or otherwise touch another point of attachment. Adjacent junction points are further located in the same end region (the first end region or the second end region).

The bonding pattern can cover from about 10% to about 20%, from about 15% to about 20%, from about 12% to about 18%, or from about 14% to about 16% of the total surface area of ​​the former. or second end regions 10 and 12, respectively, of the first and second frames. For example, bonding pattern 18 can cover approximately 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20% of the total surface area of the first and second end regions, respectively.

The dimensions and values ​​described in this description should not be construed as strictly limited to exact numerical values.

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1.1 LA MWFitBAO mentioned. Instead, unless specified in WS ^ ttfer oucnform, each of those dimensions will mean both the value meneie ^ do · wrnurafflBléh υ'Γ ”functionally equivalent interval comprising that value. For example, a dimension described as "40mm" refers to "about 40mm."

All documents cited in the present description, including any cross-references or related applications or patents, are incorporated in their entirety in the present description by reference unless they are expressly excluded or limited in any other way. If any document is mentioned, it should not be construed as being admitted to constitute prior art with respect to any invention described or claimed in the present description, or that independently or in combination with any other reference or references, instructs, suggests or describes such an invention. In addition, to the extent that any meaning or definition of a term in this document contradicts any meaning or definition of the term in a document incorporated by reference, the meaning or definition assigned to the term in this document shall govern.

While particular embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the industry that various other changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, all changes and modifications that are within the scope of this invention are intended to be encompassed in the appended claims.