RU2574975C2 - Absorbent structural element for absorbent products - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to an absorbent structural element for an absorbent product. The absorbent structural element (13) comprises an absorbent layer (17) with an absorbent material (50) containing superabsorbent polymeric particles, and carried by a support sheet (16), and has the first and second substantially longitudinal canals (26) free from the above superabsorbent polymeric particles, and containing one or more adhesive materials for immobilising the above absorbent material (50).

EFFECT: canals can provide better adhesion of the product, and/or better fluid intake and transfer, and/or higher efficacy of the element on the whole.

13 cl, 18 dwg

Description

Application area

The present invention relates to an absorbent component for an absorbent article, such as a diaper, containing an absorbent layer with an absorbent material containing particles of a superabsorbent polymer supported by a support sheet, and having first and second substantially longitudinal channels not containing particles of said superabsorbent polymer, and comprising one or more adhesive materials for immobilizing said absorbent material on said supporting sheet. The channels can be permanent, that is, their structural integrity is at least partially preserved both in the dry and in the wet state, and such channels provide an improved fit of the product on the body, and / or an improved reception / transfer of liquids, and / or a higher overall the efficiency of the absorbent structural element.

State of the art

Disposable absorbent articles for receiving and retaining body excretions, such as urine and feces, are well known. Examples of such products include disposable diapers, training panties and adult urinary incontinence products. Disposable diapers typically comprise a liquid-permeable topsheet facing the wearer's body, a liquid-impervious backsheet facing the wearer's clothes, and an absorbent core located between the topsheet and the backsheet.

Since their introduction into the market, manufacturers have continued to develop disposable diapers to make them better fit, more comfortable to wear and more functional.

An important component of disposable absorbent articles is an absorbent core (absorbent structural component). The absorbent core (absorbent structural component) typically includes a superabsorbent polymer material, for example, a hydrogel-forming polymer material, also referred to as absorbent gelling material (AGM). The superabsorbent polymeric material absorbs large amounts of body fluids, such as urine, by an absorbent product during its use, and in addition, it blocks absorbed fluids, ensuring minimal re-wetting and, therefore, sufficiently dry skin condition.

A superabsorbent polymeric material is typically incorporated into the structure of the absorbent core by means of a pulp of cellulose fibers. However, in recent years significant efforts have been made to develop thinner absorbent elements, which nevertheless could absorb and store large quantities of fluid secretions of the body, in particular, urine. Designs are proposed in which the absorbent core contains small amounts or does not contain cellulosic fibers at all.

In some cases, to maintain the mechanical strength of the elements of the absorbent cores, small amounts of a thermoplastic adhesive material, for example, a fibrous thermoplastic adhesive material, can be added to stabilize the absorbent polymer material. For this purpose, absorbent structural elements have been developed that have the required permeability / porosity, a reduced tendency of the gel to self-lock and have sufficient mechanical strength when using or transporting the product.

However, it was found that some types of structural elements of absorbent cores with a reduced content of cellulose fibers, being very thin before absorbing fluid secretions of the body, can have increased stiffness, being partially or completely filled, especially in areas in which the main absorbent capacity of the absorbent article is concentrated, such as, for example, the front region and the crotch area of the diaper. The increased rigidity of these areas is undesirable, since it impairs the ability of the absorbent product to fit snugly against the body when worn. Therefore, there remains a need for absorbent products having increased flexibility throughout the entire wearing cycle of the product, in particular, characterized by a better fit to the body in a wet state (at the same level of absorbent and retention capacity).

The inventors have found that in the presence of a certain type of permanent channels that do not contain particles of a superabsorbent polymer or a superabsorbent polymer material, improved liquid transfer characteristics are achieved, and therefore faster reception and more efficient absorption of the liquid throughout the absorbent structural element; even though a smaller amount of absorbent material can be used, significantly greater efficiency of the absorbent structure can be achieved. Due to the immobilization of the absorbent material or channels (by means of adhesive), the channels are permanent, that is, they retain their shape when using the product, despite the fact that the absorbing structural element is affected, for example, by friction from the side of the body, or despite what happens the expansion of the absorbent material when wet absorbent structural element. In addition, the inventors have found that in the presence of such channels, for example, in the front region of the absorbent core (absorbent structural element) and / or in the crotch region of the absorbent core (absorbent structural element), a diaper of increased flexibility can be provided while maintaining its effectiveness during the entire time of its use.

SUMMARY OF THE INVENTION

The present invention provides an absorbent structure (13) for an absorbent article, such as a diaper (1), comprising a support sheet (16) and an absorbent layer supported by it (17); wherein the absorbent layer (17) contains an absorbent material (50) containing at least a superabsorbent polymeric material and, optionally, a cellulosic material (in essence, it may contain only superabsorbent polymeric material and not contain cellulosic material); wherein said absorbent structure (13) and absorbent layer (17) have a longitudinal direction and an average length, a transverse direction and an average width, and a height; wherein said absorbent layer (17) has a longitudinal axis and a transverse axis perpendicular to it; and wherein said absorbent layer (17) has a first longitudinally extended side portion (20) located on one side of said longitudinal axis, and a second longitudinally extended side portion (20) located on the other side of said longitudinal axis ; wherein said absorbent structural element (13) and its said absorbent layer (17) have a front region, a rear region and a crotch region located between them, arranged in series in said longitudinal direction;

wherein said absorbent layer (17) has at least a first substantially longitudinally extended channel (26) formed in said first lateral part (20) and a second substantially longitudinally extended channel (26) made in said the second side part (20), wherein said channels (26) are essentially free of said superabsorbent polymer material, for example, are free of absorbent material (50), and are extended along said height of said absorbent layer (17); and wherein said absorbent structural member (13) contains one or more adhesive materials (40; 60), for at least partially immobilizing the absorbent layer (17) on said supporting sheet (16).

The absorbent layer (17) has a transverse direction and an average width W, a longitudinal direction and an average length L; and typically, each of the channels (26) has an average width W ′ of at least 4% to 25% of the average width W of said absorbent layer (17); and each of the channels (26) has an average length L ′ of 5% L to 80% L; for example, W ′ is at least 7% of W, and preferably up to 20%, or up to 15% of W; and / or W ′ is from at least 5 mm to, for example, 20 mm.

In order to prevent fluid flowing to the sides, the side channels (26) are not extended to any of the longitudinal side edges (18), the transverse front edge (19) or the trailing edge (19) of said absorbent layer (17). So, for example, for better fit of the product and better fluid transfer, said channels (26) may be present in said crotch region and anterior region, and possibly also in said posterior region.

In some embodiments, none of the channels (26) coincides with the longitudinal axis. In some embodiments, the smallest distance between the two channels (26) in the transverse direction is at least 5% W, preferably at least 10% W.

In some preferred embodiments of the present invention, said one or more adhesive materials include a first adhesive material (40) deposited on said absorbent layer (17) or a part thereof, if said layer is on said supporting sheet (16), said first adhesive material preferably is a thermoplastic fibrous adhesive material.

Alternatively, or in addition to this, in some preferred embodiments of the present invention, said one or more adhesive materials include a second adhesive material (60) present between said supporting sheet (16) and said absorbent layer (17), and a second adhesive material preferably applied to said supporting sheet (16) or a part thereof before applying said absorbent layer (17) or absorbent material (50) to said supporting sheet (16).

So, for example, said one or more adhesives (40; 60) are present in at least said channels (26), while said supporting sheet (16) is laid in said channels (26), or parts thereof, and said the backing sheet (16) is adhered to the absorbent material (50), which essentially forms the longitudinal walls of said channels (26), or part of said walls.

The present invention also relates to an absorbent core (7) containing an absorbent structural element (13) in accordance with the present invention, which is the first absorbent structural element (13), and containing additional material located in close proximity to said absorbent layer (17) and selected from i) an additional support sheet (16) and / or ii) a layer (70) of the receiving material; iii) a second absorbent structural member (13; 13 ′) comprising a second support sheet (16 ′) and a second absorbent layer (17 ′), said second absorbent layer (17 ′) and said absorbent layer (17) of the first element ( 13) are layered between said supporting sheet (16) of the first element and said second supporting sheet (16 ′), with the optional second absorbent structure (13) being the same as in any of the embodiments mentioned above.

The second absorbent structural element (13) may also be an absorbent structural element (13) without channels (26) (as shown, for example, in FIGS. 2B, 9, 10 and 11), or it may be an absorbent structural element (13 ) in accordance with the present invention; wherein said channels (26) of said second absorbent structure (13) may, for example, be substantially identical to said channels (26) of said first absorbent structure (13) and substantially overlap with them.

In some embodiments, the support sheet (16) of the first element and / or said second support sheet (16; 16 ′) are laid in or part of said channels (26), and said one or more adhesive materials are present in at least said channels (26) ), or parts thereof, and wherein said supporting sheets (16; 16 ′) are glued to each other in said channels (26) by said one or more adhesive materials.

Pressure may be applied to said support sheet of the absorbent structure, or to additional material, or to the additional support sheet (16 ′) of the second absorbent structure, or a combination thereof. So, for example, pressure can be selectively applied to one or more portions of the backing sheet (16 ′ 16 ′) corresponding to said channels (26), for (additionally) laying said backing sheet (16) into said channels (26), and, it is also possible to more firmly fix said supporting sheet (16) inside said channels (26) to their walls, or to additional material / second supporting sheet (16 ′).

The present invention also relates to an absorbent article, such as a diaper (1) comprising an absorbent structure (13) or an absorbent core (7) according to any of the above embodiments.

Brief Description of the Drawings

Figure 1. View of the diaper (1) in accordance with the present invention, in a straightened state.

Figa. Axonometric view of an absorbent structural element (13) in accordance with the present invention.

Figv. Axonometric view of an alternative embodiment of the absorbent layer (17) in accordance with the present invention.

Figs. Axonometric view of an absorbent structure (13) in accordance with the present invention in combination with an absorbent layer (17) in accordance with the present invention.

Figa. Axonometric view of an alternative embodiment of the absorbent layer (17) in accordance with the present invention.

Figv. Axonometric view of an alternative embodiment of an absorbent structural element (13) in accordance with the present invention.

Figa. Axonometric view of an alternative embodiment of the absorbent layer (17) in accordance with the present invention.

Figv. Axonometric view of an alternative embodiment of the absorbent layer (17) in accordance with the present invention.

Figure 5. Cross section of an absorbent core (7) in accordance with the present invention.

6. Cross section of an alternative embodiment of an absorbent core (7) in accordance with the present invention.

7. Cross section of an alternative embodiment of an absorbent core (7) in accordance with the present invention.

Fig. 8. Cross section of an alternative embodiment of an absorbent core (7) in accordance with the present invention.

Fig.9. Cross section of an alternative embodiment of an absorbent core (7) in accordance with the present invention.

Figure 10. Cross section of an alternative embodiment of an absorbent core (7) in accordance with the present invention.

11. Cross section of an alternative embodiment of an absorbent core (7) in accordance with the present invention.

Fig. 12. Cross section of an alternative embodiment of an absorbent core (7) in accordance with the present invention.

Fig.13. Cross section of an alternative embodiment of an absorbent core (7) in accordance with the present invention.

Fig.14. A method and apparatus for forming an absorbent core (7) in accordance with the present invention, containing two absorbent structural elements in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Definitions

The term "absorbent article" means devices that absorb and retain body excreta, and in particular means devices that are worn on the wearer's body or located in close proximity to the wearer's body to absorb and retain various body excretions. Absorbent products may include diapers (1) for children and adults, including diapers, for example, training panties for children and underwear for adults with urinary incontinence, feminine hygiene products, for example, sanitary pads, panty liners, urological pads , breast pads, sanitary napkins, baby bibs, wound dressings and the like. Absorbent products may include products for mopping, products for the food industry, and others. In the context of the present description, the term "fluid discharge" includes, but is not limited to, urine, blood, vaginal discharge, breast milk, sweat and feces.

In the context of the present description, the term "diaper (1)" means devices located in close proximity to the skin of the user and designed to absorb and hold various secretions of the body. Diapers are worn by infants and incontinent persons in the lower part of the body, so that the diaper surrounds the wearer's waist and legs. Examples of diapers (key 1) include conventional type diapers for infants and adults, and panty diapers, including training panties. In the context of the present description, the term "training panties" means a disposable underwear with an opening for the waist and openings for the legs, and intended for small children. Panty-shaped diapers may also be available for adult users. Such panty diapers can be worn on the user by threading the user's legs into the leg openings and then pulling them up to the desired position around the bottom of the user’s body. The diaper-panties are given the finished shape in the process of their production by any suitable means, including, but not limited to: fastening to each other parts of the product by various fastening methods, allowing for single and / or multiple fastening (for example, thermal bonding, welding, adhesive, cohesive bonding , fasteners and other types of fastening). The fastening of the parts of the diaper-panties can be performed in any part of the circumference of the waist opening (for example, on the sides, on the front waist part and in other areas).

In the context of the present description, the term “disposable” is used to describe products that are generally not intended to be washed, otherwise restored or reused, that is, it is understood that such products should be discarded after initial use, and preferably recycled, composted or removed in another way that is friendly to the environment.

In the context of the present description, the term "absorbent structural element (13)" means a three-dimensional element that can be used to absorb and retain liquids, such as urine. The absorbent structure (13) may be an absorbent structure (13) of an absorbent article, or may only be part of an absorbent core (7) of an absorbent article, for example, an absorbent component of an absorbent core (7), as will be described in more detail below.

In the context of the present description, the term “superabsorbent polymer material” means essentially a water-insoluble polymer material that can absorb 0.9% saline in demineralized water in an amount of at least 10 times (and usually at least 15 times or at least 20 times) exceeding its own weight, when measuring the absorbing capacity by centrifugation method (EDANA 441.2-01).

In the context of the present description, the term "nonwoven material" means a fabric made from directional or randomly oriented fibers, excluding paper and products that are woven, knitted, combed, stitched fibers or threads, or felted wet, with or without additional fleece . Non-woven materials and methods for their manufacture are well known in the art. In general, nonwoven fabrication processes include the steps of laying fibers on a forming surface, and may include methods such as spinning with styling, melt blowing, carding, aerodynamic styling, wet styling, co-molding, and combinations thereof. The fibers can be of natural or artificial origin, and can be staple fibers, continuous filaments or formed at the site of formation of the fabric.

Absorbent Feature (13)

The absorbent structure (13) in accordance with the present invention comprises a support sheet (16) with an absorbent layer (17) of absorbent material (50). The absorbent material (50) contains at least a superabsorbent polymer material and, as further possible, a cellulosic material, for example cellulose, cellulose pulp or modified cellulose.

The absorbent structural element (13) also contains one or more adhesive materials, which will be described in more detail below. The absorbent layer (17) is three-dimensional and contains the first essentially longitudinal channel (26) and the second essentially longitudinal channel (26), which are essentially free of the aforementioned superabsorbent polymer material. Other materials may be present in said channels (26), as will be described in more detail below, for example, one or more adhesive materials (40; 60).

The absorbent structural element (13) and the absorbent layer (17) have a longitudinal direction and an average length L, measured respectively in the longitudinal direction of the element or layer, and a transverse direction and an average width W, measured respectively in the transverse direction of the element or layer. The absorbent structural element (13) and the absorbent layer (17) have a front region located when the product is carried in front of the user, a rear region located when the product is worn behind the user, and a crotch area located between them. Each of these areas is extended over the entire width of the element / layer measured in the transverse direction, and each of them has a length of 1/3 of the average length of the element / layer.

The absorbent structural element (13) and the absorbent layer (17) have a central longitudinal axis X and a central transverse axis Y perpendicular to said central longitudinal axis X; said absorbent layer (17) and said absorbent structural element (13) have a pair of opposing longitudinal side edges (18) extended in the longitudinal direction of the element or layer, and a pair of opposing transverse edges (19), namely the front transverse edge located in front of the user when wearing the product, and the rear transverse edge located in the back of the user when wearing the product. The longitudinal side edges (18) and / or the transverse edges (19) of the absorbent structure (13) or the absorbent layer (17) may be parallel to the central longitudinal axis and / or the central transverse axis, or one or more of them may be curved, for example, the element / layer may have a smaller size in the crotch region. As a rule, the longitudinal lateral edges are a mirror image of each other relative to the longitudinal axis X.

The central longitudinal axis X of the absorbent layer (17) defines the first and second longitudinal side parts (20) of the absorbent layer (17), respectively, collectively referred to as the longitudinal side parts (20). Each of these longitudinal side portions is present in said front region, crotch region, and posterior region, and accordingly, there is a front region of the first longitudinal portion and a front region of the second longitudinal portion, and so on. In some embodiments, said longitudinal portions of the absorbent layer (17) are mirror images of each other with respect to the axis X of the layer.

The absorbent layer (17) contains at least a first channel (26) and a second channel (26), essentially free from (for example, not containing at all) said particles of a superabsorbent polymer, said channels (26) being extended through a thickness (height) ) of the absorbent layer (17) (It is hereby understood that a small, negligible number of particles of superabsorbent polymer material may be incidentally present in the channels, which, however, does not affect their general functionality). If the absorbent layer (17) contains cellulose or cellulosic materials, in some embodiments it may be preferable that said first and second channels (26) also not contain cellulose / cellulosic material.

The first channel (26) is located in said first longitudinal side part of the absorbent layer (17), and the second channel (26) is located in said second longitudinal side part of the absorbent layer (17).

The first and second channels (26) are essentially extended in the longitudinal direction, which means that each of these channels (26) is more extended in the longitudinal direction than in the transverse direction, and as a rule, at least twice as long in the longitudinal direction than in the transverse direction.

This, in particular, includes channels (26) that are completely longitudinally longitudinal and parallel to the longitudinal direction of said absorbent layer (17) (i.e., parallel to said longitudinal axis), and also includes channels (26) that may be curved provided that their radius of curvature is generally at least equal to the average size of the absorbent layer in the transverse direction (and preferably at least 1.5 times or even at least 2.0 times the average size of the absorbent of the layer in the transverse direction); and this includes channels (26) that are straight but angled (e.g., from 5 ° to 30 °, or to 20 °, or to 10 °), to a line parallel to the longitudinal axis. This may also include channels in the form of a broken line, the angle between the parts of which is at least 120 °, preferably at least 150 °; but in any case, provided that the length of the channel in the longitudinal direction exceeds its length in the transverse direction.

In some embodiments, there may be no channels extending completely or essentially completely in the transverse direction, at least in said crotch region, or such channels may be completely absent.

The first and second channels (26) may have an average width W ′, which is at least 4% of the average width W of said absorbent layer (17), or, for example, at least 7% W; and / or, for example, up to 25% W, or up to 15% W; and / or, for example, at least 5 mm; or for example, up to 25 mm, or, for example, up to 15 mm.

Each of the aforementioned first and second channels (26) may have an average length L ′, which may be, for example, up to 80% of the average length L of the said absorbent layer (17); if the channels (26) are located only in the front region, or only in the crotch region, or only in the posterior region, then L ′ can be, for example, up to 25% L, or up to 20% L, and / or L ′ can be at least 5% L, or at least 10% L; and / or L ′ may be at least 10 mm, or at least 20 mm; if the channels (26) are extended in said crotch region and anterior region, and as an additional possibility, in the posterior region, L ′ may be up to 80% L, or up to 70% L, and / or L ′ may be at least 40% L, or at least 50% L. In case the channel is not parallel to the longitudinal axis, the length L ′ of the channel is defined as the length of its projection onto the longitudinal axis.

Channels (26), as a rule, are the so-called “permanent”. By “permanent” it is meant that the structural integrity of the channels (26) is at least partially preserved both in a dry and in a wet state, including during friction of the product against the user's body. To determine whether the channels are permanent, the test for structural integrity of the channels in the wet state described below can be used, which allows one to determine how much the structure of the channels is preserved during swelling from a moist environment.

Permanent channels (26) can be obtained by using one or more adhesive materials immobilizing said absorbent material (50) and / or said channels (26) and / or said absorbent layer (17) and / or said supporting sheet (16) in said channels (26), or parts thereof. The absorbent cores (7) in accordance with the present invention may, in particular, comprise permanent channels formed by bonding the first supporting sheet (16) and the second supporting sheet (16 ′) inside the channels, as shown as examples in FIG. 7 and 13. Glue is usually used in order to bond both supporting sheets in the channels, but it is also possible to bond them to each other by other known methods, such as, for example, ultrasonic bonding or thermal bonding. The support sheets may be bonded to each other in a continuous or discontinuous manner along the length of the channels.

The inventors have found that such channels provide quick fluid intake, which reduces the risk of leaks. Permanent channels help to avoid saturation of the absorbent layer in the area adjacent to the places where fluids are released from the body (saturation increases the risk of leaks). Moreover, which is rather unexpected, the inventors have found that although the total amount of superabsorbent polymer material in the absorbent structural element is reduced (due to the presence of channels not containing such material), the properties of the absorbent structural element, or the entire diaper, in relation to interaction with fluids are improving. Additional advantages of the permanent channels are that in the wet state the absorbent material cannot move inside the core and remains in the desired position, and thus provides better fit to the body, on the one hand, and better absorption of fluids, on the other hand.

So, for example, the inventors compared the loss volumes of absorbent gelling material in the wet state according to the WAIIT test for a core having two absorbent layers with permanent channels shown in Fig. 4A, compared with a similar core containing the same amount of absorbent gelling material and glue, but without channels.

The essence of the WAIIT test is that it allows you to determine the amount of non-immobilized absorbent material in the form of particles with a core in wet conditions. In this test, the core is allowed to get wet at 73% of its capacity, after which it is cut in the middle in the transverse direction and dropped from a certain height. Then measure the loss of material. Details of the test are given in US patent publication 2008/0312622 A1.

The results showed that the core in accordance with the present invention has a wet immobilization rate of absorbent gelling material of 87% (standard deviation 5%) compared with a wet immobilization rate of 65% (standard deviation = 5%) for a comparative core sample not containing channels. In this example, the channels were made permanent by adhesive bonding of two support sheets in the channels using two layers of Fuller 1151 thermoplastic fiber adhesive applied in an amount of 5 g / m ² each and one layer of Fuller 1358 hot-melt adhesive applied in an amount of 5 g / m ² .

Test for structural integrity of the channels in the wet state

This test is intended to verify the structural integrity of the channel after it is saturated with a moist environment. The test can be carried out directly with an absorbent structure or with an absorbent core containing an absorbent structure. The test was carried out as follows.

1. Measured the length of the channel (in millimeters) in the dry state. If the channel is not straight, the length of the curve of the line passing through the middle of the channel was measured.

2. The absorbent structural element or absorbent core was immersed in 5 liters of synthetic urine substitute, which was a solution of sodium chloride in distilled water with a concentration of 9.00 g of NaCl per 1000 ml of solution. The temperature of the solution should be 20 ± 5 ° C.

3. After 1 minute after immersion in saline, the absorbent structure or absorbent core was removed from the solution and held vertically at one end for 5 seconds to swell the solution, and then straightened down on a flat horizontal surface with the side facing the garment, if this the side was recognizable. If the absorbent structure or absorbent core contains constricting elements, then the absorbent structure or absorbent core must be stretched tight in both directions: X and Y, so that no contraction is observed anywhere. After that, the edges of the absorbent structural element or absorbent core were fixed on a horizontal surface so as to prevent its possible contraction.

4. The absorbent structural element or absorbent core was coated with a rigid plate having a suitable weight and the following dimensions: the length was equal to the length of the absorbent structural element or absorbent core in the expanded state, and the width was equal to the maximum width of the absorbent structural element or absorbent core in the transverse direction.

5. A pressure of 18.0 kPa was applied to the portion of the test sample under the rigid plate for 30 s. Pressure is calculated based on the total area of said rigid plate. The pressure was created by installing additional weights in the geometric center of the rigid plate, that is, the total weight of the rigid plate and additional weights should provide a pressure of 18.0 kPa over the entire area of the rigid plate.

6. After 30 s, additional weights and a rigid plate were removed.

7. After that, the total length (in millimeters) of the channel sections that retained their structure was immediately measured. If the channel is not straight, the length of the curve of the line passing through the middle of the channel was measured. If none of the channel sections has retained its structure, then the channel is not permanent.

8. The structural integrity of the permanent channel in percent was calculated by dividing the total length of the channel sections that retained their integrity by the length of the channel in the dry state and multiplying by 100%.

According to the results of this test, the permanent channel in accordance with the present invention should maintain structural integrity by at least 20%, or 30%, or 40%, or 50%, or 60, or 70%, or 80% , or 90%.

As shown, for example, in FIGS. 5 and 9, one or more adhesive materials (60) may be present between said supporting sheet (16) and said absorbent layer (17) or between their parts (in the context of the present description, such adhesive materials referred to as "second adhesive material"). So, for example, adhesive material can be applied to parts of said supporting sheet (16) at locations coinciding with the locations of the channels (26), whereby in said channels the supporting layer can be attached by said adhesive to the walls of the channel, or to a part thereof, or other material, as will be described below; and / or the adhesive may be applied to portions of the backing sheet (16) that correspond to the locations of the absorbent material (50) to immobilize said material and to prevent its excessive migration into said channels; the adhesive can be applied in essence to the entire area of the backing sheet (16), i.e., in essence, in a continuous or homogeneous manner. The adhesive may be, for example, hot melt adhesive applied by printing, crevice or spraying methods.

In addition, or alternatively, the absorbent structural element (13) may contain one or more adhesive materials (40) deposited on said absorbent layer (17) or part thereof already supported by said supporting sheet (16) (in the context of the present description this adhesive material is referred to as the “first adhesive material”, for example, after bonding said absorbent material (50) with said supporting sheet (16) (or applying it to said supporting sheet (16)) to form the absorbent layer (17). This adhesive material may be, for example, a thermoplastic fibrous adhesive, as will be described below. In some embodiments, it may be continuously applied to the absorbent layer (17), that is, over the absorbent material (50) and in the channels (26), for immobilizing the absorbent layer (17), and possibly also for bonding it with the backing sheet in said channels, as described above, as shown, for example, in FIGS.

It is understood that the first and second adhesive materials can be adhesives of the same type, for example, thermoplastic hot-melt adhesive, and the difference between the first and second adhesives may lie in the places of their application.

In some embodiments, said one or more adhesive materials are present in at least channels (26), for example at least said first material, or both, that is, first and second adhesive materials. In particular, they can be present on the longitudinal walls of the channels (26) (being extended to the height of the absorbent layer (17) and its length). If the supporting sheet (16) is laid in said channels (26), or in parts thereof, for example, forms waves in said channels (26) or parts thereof, then said waves can be attached to said walls or parts thereof, which will ensure ( at least partial) maintaining the structure of the channels (26) during use of the product. Such examples are shown in FIGS. 10 and 11.

The first and second channels (26) can be mirror images of each other relative to the central longitudinal axis X of the absorbent layer (17) / absorbent structural element.

In some embodiments, some of which are shown in the drawings, there is no channel (26) that matches the central longitudinal axis of said absorbent layer (17). Channels (26) can be spatially spaced from each other along their entire length. The smallest distance D between them can be, for example, at least 5% of the average size W of the layer in the transverse direction, or at least 10% W, or at least 15% W; or at least 5 mm, or at least 8 mm.

In addition, to reduce possible leakage of fluid, the longitudinal channels (26), as a rule, are not extended to any of the transverse edges (19) and / or longitudinal edges (18) of the absorbent layer (17), which is also shown in the drawings. Typically, the smallest distance I ′ between the channel (26) and its closest longitudinal edge is at least 5% W, or at least 10% W. In some embodiments, the distance is at least 10 mm. The smallest distance F between the channel and the nearest transverse edge (19) of the absorbent layer (17) may, for example, be at least 5% of the average length L of the layer.

The absorbent structural element may contain only two channels, for example, only in the front region, as shown in FIG. 2B, or, for example, in the central (crotch) region, which may be extended to the front and / or rear region, as shown on figa.

The absorbent structural element (13) may contain two or more such channels, for example at least 4, or at least 5, or at least 6. Some or all of these channels can be essentially parallel to each other, for example, all of them can be straight and extended exactly in the longitudinal direction, and / or two or more of them can be mirror images of each other relative to the longitudinal axis, and / or two or more of them can be straight, broken or curved (with different radii curvature), and n of them may be mirror images of each other relative to the longitudinal axis. Examples of such channels are shown in FIGS. 3A and 3B.

So, for example, the front region of the absorbent layer (17) may contain two or more channels (26), which, as a rule, are mirror images of each other relative to the longitudinal axis of the layer, and the crotch region may contain two or more channels (26), which , as a rule, are mirror images of each other relative to the longitudinal axis of the layer, as shown, for example, in Fig. 4A, and the latter can be additionally extended to the front region and / or the rear region and have any of the dimensional or other characteristics indicated op ponents above. In the back region, additional channels can be made, for example, two, as shown in FIG.

The first and second channels (26), and possibly also additional channels (26), can be located in said absorbent layer (17) so that there will be a central longitudinal strip that does not contain any channels (26); wherein said absorbent material (50) is preferably substantially continuously positioned in said strip. So, for example, said strip may have a minimum width D of at least 5% of W, or at least 10% of W, and / or at least 5 mm, or at least 10 mm, or at least 15 mm, and / or even up to 40 mm.

In some embodiments, in the said central longitudinal strip between two adjacent channels (26), the average specific gravity of the absorbent material (50), or said superabsorbent material, may be from 350 to 1000 g / m ² , or, for example, from 450 g / m ² up to 750 g / m ² .

In some preferred embodiments, in the immediate vicinity of each of the first and second channels, and also, as an additional feature, in the immediate vicinity of said one or more additional channels, said absorbent material (50) is substantially continuously arranged in a continuous manner.

The absorbent structural element (13) typically contains one or more additional materials (for example, an additional material layer) covering the absorbent layer (17). To avoid ambiguity, we note that such a layer of additional material is not a layer consisting of adhesive material, however, the additional material may be a layer containing adhesive, for example, on a surface that should be in contact with the absorbent layer (17) of the absorbent structural element (13 ) in accordance with the present invention. That is, the additional material may contain adhesive material on its surface, which should be placed in close proximity to the absorbent layer (17) of the absorbent structural element (13).

The resulting construction is referred to in the present description as “absorbent core (7)”. Examples thereof are shown in FIGS. 5-13.

This additional material may be an additional absorbent structural element (13 ′) containing a second absorbent layer (17 ′) and a second support layer (16 ′), as a result of which both absorbent layers (17, 17 ′) will be located between the said supporting sheets ( 16; 16 ′); it may be an additional absorbent structural member (13 ′) in accordance with the present invention with two or more channels (26 ′) described above, as shown in FIGS. 5, 6, 7, 8; or may be an absorbent structural element in accordance with the present invention, but not containing channels, as shown, for example, in Fig. 9, and / or it may be an absorbent structural element in accordance with the present invention, but without adhesive.

The second absorbent structural element (13 ′) may be identical to the first absorbent structural element (13), or both of them can be absorbent structural elements with channels (26; 26 ′) in accordance with the present invention, but may differ, for example, in the shape of the channels, the number of channels (as, for example, in FIG. 8), the use of various adhesives, various methods of applying adhesives, or a combination of these characteristics.

The channels (26), or some of them, of the first absorbent structural element (13) and the channels (26 ′) of the second absorbent structural element (13 ′), or some of them, can coincide or overlap with each other, for example, completely, or coincide only partially, or overlap only partially; or some or all of the channels (26; 26 ′) may not even coincide or overlap with each other. In some embodiments, the channels are practically identical to each other, and the channels (26) of one absorbent structural element are essentially identical and overlap with the channels (26) of the second absorbent structural element. An example of such a construction is shown in FIG.

In some embodiments, the additional material may be part of a backing sheet (16) wrapped around the absorbent layer (17) and then secured at the peripheral edges so that it completely covers the absorbent layer (17).

In some embodiments, the additional material is an additional support sheet (16 ′), that is, the absorbent structure (13) is covered with an additional support sheet (16 ′), whereby the absorbent layer is located between the two support sheets.

In some embodiments, the additional material may be a layer (70) of the receiving material and / or the receiving sheet (12), which may, for example, be attached to said supporting sheet (16). In some embodiments, the additional material includes an additional absorbent structural element, for example, any of the above, or an additional support sheet (16 ′) that connects to the material receiving layer (70), and an optional additional receiving sheet (12). An example of such a construction is shown in FIG.

The additional material may also be a receiving material layer (70) located in close proximity to said absorbent layer (17), wherein the receiving material layer (70) preferably contains cellulose fibers with chemically formed cross-bonds and can be supported by a second supporting layer (16 ′ ) Thus, the absorbent layer (17) and the layer (70) of the receiving material can be layered between said supporting sheet (16) of the first element and said second supporting sheet (16 ′), as shown in FIG. The layer (70) of the receiving material may also further comprise channels (26 ′), in particular, substantially overlapping with the channels (26) of said first absorbent structural element (13), as shown in FIG. 13.

The supporting sheet (16) of the first element and / or the second supporting sheet (16 ′) of the receiving material layer (70) can be laid in the channels (26) of the first absorbent structural element (13), and / or as an additional feature, in the channels ( 26 ′) of the receiving material layer (70), if any, or to a part of these channels (26, 26 ′). One or more adhesive materials may be present in at least the channels (26, 26 ′), or in parts thereof, and the supporting sheets (16; 16 ′) may be glued to each other in the said channels (26, 26 ′) one or more from these adhesive materials. Between the second support sheet (16 ′) and the layer (70) of the receiving material, there may be a second adhesive material (60 ′). Another adhesive (not shown) can be applied between the layer (70) of the receiving material and the absorbent layer (17), in addition to the thermoplastic adhesive (40), to improve the adhesion of these layers to each other.

In any of these embodiments, additional material may be attached to the support sheet (16) at its peripheral edges, as a result of which it will completely cover the absorbent layer (17) and the optional absorbent layer (17 ′).

In any of these embodiments, the backing sheet (16) or the receiving layer / sheet can be laid (in waves) in said channels (26) or part thereof. This is shown, for example, in FIGS. 6, 7, 8.

The additional material may be adhered to the support sheet (16) of the absorbent structure (13) in accordance with the present invention in said channels (26), for example, with adhesive material, as described above. Alternatively, or in addition to this, it can be attached to the walls of the channels (26 and / or 26 ′) or to their parts.

In some embodiments, the absorbent structure (13) comprises such additional material covering said absorbent layer (17), and pressure is selectively applied to said supporting sheet (16) and / or said additional material, namely, those parts that fall onto said channels (26 and / or 26 ′) in order to feed these parts of said supporting sheet (16) and / or said additional material into said channels of an absorbent structural element (13) and / or into a channel l of the additional (second) absorbent structural element (13 ′), if any (that is, into the channels 26 and / or 26 ′, if any), for the formation of the said waves and / or for better bonding with each other the said additional material and said supporting sheet (16) in said channels (26 and / or 26 ′) if the adhesive material described above is used.

The means for applying pressure may be a pressure roller containing reliefly protruding parts, essentially having a size, shape, pattern of said channels (26 and / or 26 ′), and coinciding (mating) with said parts of the supporting sheet (16) or additional material matching with said channels (26 and / or 26 ′).

In some embodiments, the additional (eg, second) support sheet (16 ′) may be wider than the absorbent structure, which allows the second support sheet (16 ′) to be laid in channels (26 and / or 26 ′), or in part thereof, and stick it to the first support sheet (16). Examples of such embodiments are shown in FIGS. 6, 7 and 8.

In embodiments in which the absorbent core (7) comprises two or more absorbent structural members (13; 13 ′) containing channels (26; 26 ′) in accordance with the present invention, there may be one, two, or more, or all of the channels (26) of one absorbent structural element (13) are essentially superimposed on the channels (26 ′) of an adjacent absorbent structural element (13 ′). In this case, the absorbent core (7) is a laminate of absorbent structural elements (13 ′; 13 ′) with channels (26; 26 ′), while the channels (26; 26 ′) are essentially extended through the entire thickness of the absorbent layers ( 17; 17 ′). Such an embodiment is shown in FIG.

In addition, or alternatively, embodiments are possible in which one, two, or more, or all of the channels (26) of one absorbent structure (13) are not superimposed on the channels (26 ′) of an adjacent absorbent structure (13'); they can be, for example, mated with respect to the channels of an adjacent absorbent structural element. By conjugate is meant that the channels (26 ′) of the second absorbent structural element (13 ′) form a continuation of the channels of the first absorbent structural element (13).

In some embodiments, the absorbent core (7) may comprise two or more absorbent structural elements (13), one of which is an element in accordance with the present invention, and another is an absorbent structural element (13) with a support sheet (16 ′), which is coated with an absorbent layer (17 ′) (with a superabsorbent polymer material) without channels and / or without adhesive.

If a second absorbent component (13) is present in the absorbent core (7), it may contain one or more adhesives, as described above, and for the reasons described above.

So, for example, the adhesive can be located so that its location will coincide with at least the channels (26) of the first absorbent structural element (13), and / or with the channels (26 ′), if any.

Absorbent Material (50)

The absorbent layer (17) contains absorbent material (50), which in turn contains a superabsorbent polymeric material (e.g., in the form of particles), possibly in combination with cellulosic material (including, for example, cellulose or chopped wood pulp in the form of fibers). The additional material described above (for example, the additional (second) absorbent structural element (13 ′)) may also include absorbent material, and may also include the following.

In one embodiment, the absorbent material (50) may contain at least 60%, or at least 70%, of a superabsorbent polymer material (by weight), and a maximum of 40%, or even a maximum of 30%, of cellulosic material.

In some embodiments, the absorbent layer (17) comprises an absorbent material (50) consisting essentially of absorbent polymeric materials, for example, in the form of particles, for example, less than 5% cellulosic material by weight (based on the weight of the absorbent material ( fifty)); and said absorbent layer (17) / absorbent structure (13) may not contain cellulosic materials.

Typically, a superabsorbent polymer material is present in particulate form. Suitable for use in the composition of the absorbent layer (17) are any particles of superabsorbent polymeric materials described in the relevant literature, for example, in the publication ModernSuperabsorbentPolymer Technology (F.L. Buchholz, A.T. Graham, Wiley 1998). Particles of absorbent polymers can be spherical, close to spherical, irregularly shaped particles, wiener-shaped particles or ellipsoid-shaped particles, usually obtained in polymerisation reactions in phase reversal suspensions. Particles can also be partially agglomerated into larger particles of irregular shape.

In some embodiments, the absorbent material (50) as a whole and / or at least the particulate superabsorbent polymer material has a high absorption capacity, for example, has a retention capacity (measured by centrifugation) of at least 20 g / g, or at least 30 g / g. The upper limit may be, for example, 150 g / g, or 100 g / g.

In some embodiments, an absorbent material (50) may be used, comprising (or consisting of) superabsorbent polymer particles c4jurmed from acrylic acid polymers (polyacrylate polymers), for example, having a degree of neutralization of from 60% to 90%, or about 75%, for example containing sodium counterions.

As superabsorbent polymers, polyacrylates and polyacrylic acid polymers having internal and / or surface cross-linking can be used. Suitable materials are described in patent publications WO 07/047598, WO 07/046052, WO 2009/155265 and WO 2009/155264. In some embodiments, absorbent polymer particles can be obtained using processes currently used in the art, in particular using the process described in detail in WO 2006/083584. Superabsorbent polymers should preferably contain internal cross-bonds, that is, their polymerization should be carried out in the presence of compounds having two or more polymerizable groups that allow free radical copolymerization into the polymer chain. Suitable crosslinking compounds include ethylene glycol dimethacrylate, diethylene glycol diacrylate, allyl methacrylate, trimethylolpropane triacrylate, triallylamine, tetraallyloxyethane as described in EP-A 530438, di- and triacrylates as described in EP-A-547947, -A 632068, WO 93/21237, WO 03/104299, WO 03/104300, WO 03/104301 and in DE-A 10331450, mixed acrylates that, along with acrylate groups, include ethylene unsaturated groups as described in DE-A 10331456 and DE-A 10355401, or mixtures of substances for crosslinking, as described in DE-A 19543368, DE-A 19646484, WO 90/15830 and WO 02/32962, as well as crosslinking agents described in WO 2009/155265. Superabsorbent polymer particles can have cross-bonds made on the surface (the so-called post-cross-bonds). Suitable compounds for forming such bonds include compounds having two or more groups capable of forming covalent bonds with the carboxylate groups of the polymers. Suitable compounds of this type include, for example, alkoxysilyl compounds, polyaziridines, polyamines, polyamidoamines, di- or polyglycidyl compounds as described in EP-A 083022, EP-A 543303 and EP-A 937736, polyols, as described in DE-C 3314019, cyclic carbonates, as described in DE-A 4020780, 2-oxazolidone and its derivatives, such as N- (2-hydroxyethyl) -2-oxazolidone, as described in DE-A 19807502, bis- and poly-2- oxazolidones, as described in DE-A 19807992, 2-oxotetrahydro-1,3-oxazine and its derivatives, as described in DE-A 19854573, N-acyl-2-oxazolidones, as described in DE-A 19854574 cyclic ureas as described in DE-A 10204937; bicyclic amide acetals as described in DE-A 10334584; oxetane and cyclic ureas as described in EP-A 1199327; and morpholine-2,3-dione and its derivatives as described in WO 03/031482.

Superabsorbent polymers or their particles can be surface modified, for example, they can be applied fully or partially. Examples of absorbent coated polymer particles are described in WO 2009/155265. The coating material can make absorbent polymer particles more hydrophilic. For example, such a substance may be hydrophilic (e.g. pyrogenic) silica, such as Aerosils. The substance applied in the form of a coating can be a polymer, for example, an elastic polymer, a film-forming polymer, or simultaneously an elastic and film-forming polymer, forming an elastic (elastomeric) coating on the particles in the form of a film. The coating may be a homogeneous and / or uniform coating on the surface of the absorbent polymer particles. The coating agent may be applied in an amount of from 0.1% to 5%.

Superabsorbent polymer particles may have a size in the range of 45 μm to 4000 μm, more preferably in the range of 45 μm to about 2000 μm, or from about 100 μm to about 1000, or up to 850 μm. The particle size distribution of the particulate material can be determined by methods known in the art, for example, by dry sieving (EDANA 420.02).

In some embodiments of the present invention, a superabsorbent material in the form of particles with a weight average particle size of up to 2 mm, or from 50 μm to 2 mm, or up to 1 mm, or preferably from 100, 200, 300, 400 or 500 μm, up to 1,000, 800 is used or 700 microns; measured by the method described, for example, in EP-A-0691133. In some embodiments of the present invention, a particulate superabsorbent polymeric material is used, with at least 80% of the particles by weight having a size of between 50 μm and 1200 μm, and the mass-median particle size is in any of the ranges indicated above. In addition, in one embodiment of the invention, said particles are essentially spherical. In yet another embodiment of the present invention, the superabsorbent polymer material has a relatively narrow particle size distribution range, for example, most (e.g. at least 80%, preferably at least 90% or even at least 95% by weight) particles are from 50 μm to 1000 μm, preferably from 100 μm to 800 μm, and more preferably from 200 μm to 600 μm.

Support Sheet (16: 16 ′)

The absorbent structural element (13) in accordance with the present invention contains a support sheet (16) supporting and immobilizing absorbent material (50). The additional material may be a backing sheet (16 ′), or may include such a sheet, therefore, the following also applies to such a backing sheet (16 ′).

Such a supporting sheet (16) may be made of a sheet or web that is divided into separate absorbent structural elements (13). Examples of starting webs include paper, films, woven or non-woven materials, or laminates from any of the listed materials.

In some embodiments, the backing sheet (16) is a nonwoven fabric, for example, a nonwoven fabric, for example a carded nonwoven fabric, a spunbond nonwoven fabric, or a meltblown nonwoven fabric, or a laminate of any of the aforementioned nonwoven fabrics.

The fibers may be of natural or artificial origin, and may be staple fibers, continuous fibers, or fibers that are formed in place. Commercially available fibers have a diameter in a wide range, from less than about 0.001 mm to more than about 0.2 mm, and come in various forms: short fibers (called staple or cut), continuous single fibers (filaments or monofilaments) non-twisted bundles of continuous fibers (tow) and twisted bundles of continuous fibers (yarn). The fibers can be two-component fibers, for example, shell-core configurations, in which the shell and core are formed from various polymers. Nonwoven webs can be made using various processes, such as melt blowing, spunbond, spinning from a solution, electrospinning and carding. The proportion of non-woven fabrics is usually expressed in grams per square meter (g / m ² ).

In the context of the present description, the nonwoven material may be made of hydrophilic fibers. Hydrophilic fibers are called fibers or surfaces of fibers that are wetted by water-based fluids (e.g., body fluids having a water base) deposited on such fibers. Hydrophilicity and wettability are determined, as a rule, by the angle of contact and the time of passage of the fluid through the non-woven fabric. These concepts are discussed in detail in the publication of the American Chemical Society "Contact angle, wettability and adhesion" edited by Robert F. Gould (1964). A fiber or fiber surface is considered to be wettable by the fluid (i.e. hydrophilic) if the contact angle between the fluid and the fiber, or its surface, is less than 90 °, or if the fluid tends to spontaneously spread across the fiber surface (usually both phenomena take place simultaneously). Conversely, a fiber or fiber surface is considered hydrophobic if the contact angle exceeds 90 °, and the fluid does not spontaneously propagate over the fiber surface.

The support sheet (16) in accordance with the present invention may be breathable. The materials from which it can be made may contain micropores. For example, breathable nonwoven webs may be used. The support sheet (16) may, for example, have a breathability of 40 or 50, up to 300 or 200 m ³ / (m ² × min), determined according to the EDANA method 140-1-99 (differential pressure 125 Pa, sample area 38.3 cm ² ). Alternatively, the backing sheet (16) may have lower breathability or be completely airtight, which, for example, allows it to be better held on a moving surface by vacuum.

In preferred embodiments, the backing sheet (16) is a non-woven laminate, for example a non-woven laminate, for example, an SMS or SMMS web.

To facilitate the formation of the waves described above, the support sheet (16) may have a specific gravity of less than 60 g / m ² , less than 50 g / m ² , for example, from 5 g / m ² to 40 g / m ² , or up to 30 g / m ² .

The support sheet (16) may be extensible in the CD direction or in the MD direction.

In one embodiment of the present invention, the support sheet (16) has waves laid in the aforementioned first and second channels, and possibly in the above-mentioned additional channels, or in parts thereof. For example, waves can be extended along the entire length of the channel in the longitudinal direction, can be extended to the entire average height of the absorbent layer (17) / channel, or only 75% of the height, or only 50% of the average height of the absorbent layer (17) / channel. This contributes to better immobilization of the absorbent material (50) located in close proximity to the said channels (26) and the said channels (26) of the said layers.

The waves can be glued by said one or more adhesive materials, for example, a second adhesive material, to said walls of said channels (26). In addition to this, or alternatively, the backing sheet (16) can be glued in said channels (26) to said additional material, for example, to the second backing sheet (16) that was described above, for example, the first and / or a second adhesive.

Adhesive material

The absorbent structural element (13) may contain one or more adhesive materials. In some embodiments, it comprises a first adhesive material and / or a second adhesive material described above, and thus, as described above.

The absorbent core in accordance with the present invention may further comprise a second absorbent structural element (13 ′), which may also contain one or more adhesive materials, therefore, the information below may equally apply to it.

Any suitable adhesive may be used, for example, so-called hot-melt adhesives may be used. In particular, spray hot melt adhesives such as HL-1620-B manufactured by N.V. can be used. FullerCo. (St. Paul, Minnesota, USA).

The one or more adhesive materials used can not only help immobilize the absorbent material on the backing sheet, but can also help maintain the structural integrity of the channels of the absorbent core of the absorbent core during storage and / or use of a disposable absorbent article. Adhesive material can inhibit the migration of significant amounts of absorbent material into the channels. Moreover, when applying the adhesive material to the channels or to portions of the supporting sheet matching the channels, the adhesive may help to adhere the supporting sheet of the absorbent structural element to said walls and / or to additional material, as will be described in more detail below.

In some embodiments, the first adhesive (40) and / or the second adhesive (60) may be a thermoplastic adhesive material.

In some embodiments, the first adhesive (40) can be applied in the form of fibers, as a result of which it forms a fibrous network immobilizing the absorbent material on the backing sheet. Thermoplastic adhesive fibers may be partially in contact with the support sheet of the absorbent structure; if the adhesive is also applied to the channels, it further fixes the absorbent layer relative to the support sheet.

The thermoplastic adhesive material may, for example, allow swelling of the absorbent polymer in such a way that it will not burst and will not exert too much compressive force on the polymer that would prevent the swelling of the particles of the absorbent polymer. Thermoplastic adhesive materials (40; 60) suitable for use in the present invention include hot-melt adhesives containing at least a thermoplastic polymer in combination with plasticizer and other additives, for example, thermoplastic diluents, tackifying resins and antioxidants. Examples of suitable adhesive materials (40; 60) of the “hot melt” type are described in EP 1447067 A2. In some embodiments, the thermoplastic polymer has a molecular weight of more than 10,000 and a glass transition temperature T _g lower than room temperature, typically in the range −6 ° C <T _g <16 ° C. In some embodiments, the polymer concentration in the hot melt is from about 20% to about 40% by weight. In some embodiments, thermoplastic polymers may be water insensitive. Examples of such polymers are styrene block copolymers, including three-block structures of type ABA, two-block structures of type AB and block copolymers with a radial structure (AB) _n , where A denotes non-elastomeric polymer blocks, typically containing polystyrene, and blocks B are their unsaturated conjugated diene or (partially) hydrogenated derivatives. Typical examples of block B are isoprene, butadiene, ethylene / butylene (hydrogenated butadiene), ethylene / propylene (hydrogenated isoprene), and mixtures thereof.

Other suitable thermoplastic polymers are metallocene polyolefins, which are ethylene polymers prepared using a single point or metallocene catalyst. In this manner, at least one comonomer can be polymerized with ethylene to form a higher order copolymer, terpolymer or polymer. Amorphous polyolefins or amorphous α-polyolefins, which are homopolymers, copolymers or terpolymers of C ₂ -C ₈ α-olefins, are also suitable .

As mentioned above, a thermoplastic adhesive material, usually hot melt adhesive, is applied in the form of fibers, for example, it can be applied in a fluffed form. In some embodiments, the thermoplastic adhesive material forms a fibrous network over the particles of the absorbent polymer. The fibers can typically have an average thickness of from about 1 micron to about 100 microns, or from about 25 microns to about 75 microns, and an average length of from about 5 mm to about 50 cm. In some embodiments, a thermoplastic adhesive material is applied to the backing sheet (16) in an amount of from 0.5 to 30 g / m ² , or from 1 to 15 g / m ² , or from 1 to 10 g / m ² , or even from 1.5 to 5 g / m ² .

For an adhesive suitable for use in the present invention, the separation angle tangent at 60 ° C (tgΔ) should be lower than 1, or even lower than 0.5. The tangent of the angle of separation of the adhesive at 60 ° C (tgΔ) shows how close the state of the adhesive is to the liquid at an elevated temperature. The smaller the tgΔ, the sooner the adhesive resembles a solid, rather than the liquid, and the less its tendency to flow or migrate, and the less the tendency of the secondary structure of the adhesive in embodiments of the present invention to gradually break or even break over time. Therefore, this indicator is especially important if the absorbent product is used in a humid climate.

From the point of view of ease of processing in the manufacture of the product, or the effectiveness of the finished product, the thermoplastic adhesive material should preferably have a viscosity of from 800 to 4000 MPa · s, or from 1000 MPa · s, 1,200 MPa · s or 1,600 MPa · s to 3,200 MPa · s, 3000 MPa · s, 2 800 MPa · s or 2,500 MPa · s at 175 ° C, measured according to ASTMD3236-88, at a cartridge rotation speed of 2720 rpm, after preheating for 20 minutes and stirring within 10 minutes

The thermoplastic adhesive component may have a softening point of 60 ° C to 150 ° C, or 75 ° C to 135 ° C, or 90 ° C to 130 ° C, or 100 ° C to 115 ° C, measured according to ASTME28- 99 (Herzog method using glycerin).

In one embodiment, the thermoplastic adhesive component may be hydrophilic and have a contact angle of less than 90 °, less than 80 °, less than 75 °, or less than 70 °, measured according to ASTMD 5725-99.

Absorbent products (e.g. diapers)

The absorbent core (13) of the absorbent core (7) in accordance with the present invention can be used in absorbent products, examples of which were given above and in particular in the diaper (1), including fastened diapers (1) and panty diapers, which can used for children or adults, as well as in absorbent pads, for example, sanitary towels for women or underwear pads for adults with urinary incontinence.

In addition to the absorbent structural element (13) or the absorbent core (7) in accordance with the present invention, the absorbent article may include a top sheet and a back sheet, as well as one or more side strips (cuffs). The topsheet, cuffs or side planks may contain a skin care composition, for example, lotion or powder, known in the art, examples of which are described in US Pat. Nos. 5,607,760; 5,609,587; 5,635,191; 5643588.

Preferred products in accordance with the present invention comprise a top sheet facing the wearer when used, for example, a non-woven sheet, and / or a perforated sheet, for example, made of a perforated molded film as is known to those skilled in the art, and a back sheet.

The back sheet may be liquid impermeable, as is known to those skilled in the art. In preferred embodiments, the liquid impervious back sheet comprises a thin plastic film, for example, a thermoplastic film, having a thickness of from about 0.01 mm to about 0.05 mm. Suitable back sheet materials typically contain a “breathable” material that allows air to escape from the diaper (1), but prevents fluid from the body from passing through the back sheet. Suitable films for the manufacture of the back sheet include films XI5306, XI0962 and XI0964 manufactured by Tredegarlndustrieslnc. (Ter-Ot, Indiana, USA).

The back sheet, or any of its sections, can be elastically extensible in one or more directions. The back sheet may be attached or attached to the top sheet, an absorbent structural element (absorbent core), or any other diaper element (1), by any attachment methods known in the art.

The diapers of the present invention may comprise leg cuffs and / or barrier cuffs. The side planks and / or foot cuffs and / or barrier cuffs are arranged in pairs opposite each other along the longitudinal edges of the absorbent structure / absorbent core, being longitudinally extended along said absorbent structure / absorbent core, and are typically mirror images of each other relative to the longitudinal axis of the product. If there are both foot cuffs and barrier cuffs, then the foot cuffs are usually located outside with respect to the barrier cuffs. Leg cuffs can be extended in the longitudinal direction by at least 70% of the length of the product. The cuffs may have a loose longitudinal edge extending from the X-Y plane (formed by the longitudinal and transverse directions of the product), that is, extended in the Z direction. The cuffs may contain elastic material.

The diaper in accordance with the present invention may comprise a waistband, for example, a front waistband and a back waistband, which may comprise elastic material.

The diaper (1) may contain side panels (so-called "ears"). The diaper (1) may include fastening means for fastening the front and rear parts of the product to each other, for example, for fastening the front and rear waist belts to each other. Preferred attachment systems comprise petals and attachment zones, with the petals usually attached to the rear region of the diaper (1) and the attachment zones are part of the front region of the diaper (1).

The absorbent structural element (13) can be used in combination with the receiving layer (12) and / or with the layer (70) of the receiving material (and accordingly the absorbent core (7) or the diaper (1) may contain them). Such a component system may contain chemically formed cross-linked cellulose fibers. Such cross-linked cellulosic fibers may have the desired absorption properties. Examples of chemically formed crosslinked cellulosic fibers are described in US Pat. No. 5,137,537. In some embodiments, the crosslinked cellulosic fibers are made using from about 0.5 mol% to about 10.0 mol%, or from about 1.5 mol% to about 6.0 mol% of a substance based on a glucose unit that induces the formation of polycarboxy cross bonds C ₂ -C ₉ . An example of a suitable crosslinker is citric acid. In some embodiments, polyacrylic acids may be used. In some embodiments, cross-linked cellulosic fibers have a water retention rate of from about 25 to about 60, or from about 28 to about 50, or from about 30 to about 45. A method for determining water retention coefficient is described in patent 5137537. In some embodiments, cellulosic fibers with cross-linking can be wavy, twisted or twisted, or have any combination of the listed features.

In some embodiments, the upper and / or lower receiving layers may comprise a non-woven fabric, which may be hydrophilic. In addition, in some embodiments, the upper and / or lower receiving layers may contain chemically formed cross-linked cellulose fibers that may or may not form part of the non-woven fabric. In one embodiment, the upper receiving material may comprise non-woven material without cross-linked cellulosic fibers, and the lower receiving layer may comprise chemically formed cross-linked cellulosic fibers. In addition, in one embodiment, the lower receiving layer may comprise chemically formed cross-linked cellulosic fibers mixed with other types of fibers, such as, for example, natural or synthetic polymer fibers. In various embodiments, those mentioned as other, natural or synthetic polymer fibers may include fibers with a large surface area, thermoplastic binder fibers, polyethylene fibers, polypropylene fibers, PET fibers, viscose fibers, regenerated cellulose fibers, and mixtures thereof. Suitable nonwoven materials for the upper and lower receiving layers include, but are not limited to, SMS type materials (comprising a spunbond fabric layer, a meltblown fiber layer, and another spunbond fiber fabric layer). In some embodiments, it is advisable to use stably hydrophilic nonwoven webs, in particular nonwoven webs with persistent hydrophilic coatings. In another suitable embodiment, a web of SMMS structure is used. In some embodiments, the nonwoven materials are porous.

The diaper (1) may include a sublayer located between the top sheet and the absorbent structural element (13) / absorbent core (7), which can receive, distribute and / or immobilize fluid secretions of the body. Suitable sublayers include receiving layers, buffer layers, which quench the influx of large volumes of bodily fluids, and / or feces storage layers known to those skilled in the art. Suitable materials that can be used in sublayers can include large open cell foams, large particle foams, open or closed cell foams (macro- or micro-porous foams), non-woven fabrics with increased airiness, polyolefin, polystyrene, polyurethane foams or particles, structures containing many vertically oriented, preferably loop-shaped, filaments or fibers, or, preferably, perforated, formed films. In the context of the present description, the term "microporous" means materials that can carry fluids due to capillary forces, but containing pores with an average size of more than 50 microns. The term "macroporous" means materials in which the pore size is too large to allow capillary transfer of fluids, and usually more than (on average) 0.5 mm in diameter, usually more than (on average) 1 , 0 mm in diameter, but less than 10 mm or even less than 6 mm (average).

Possible methods for assembling the diaper (1) in accordance with the present invention include traditional methods for the manufacture of disposable absorbent articles. So, for example, the back sheet and / or top sheet can be attached to the absorbent structural element (13) / absorbent core (7) or to each other by means of a uniform and continuous adhesive layer, or by drawing a pattern from separate lines, spirals or adhesive points . It was determined that adhesives HL-1258 or H-2031 manufactured by N.V. are satisfactory for this purpose. FullerCompany (St. Paul, Minnesota, USA). Although the top sheet, back sheet and absorbent structure (13) / absorbent core (7) can be assembled with each other in various conventionally applied configurations, preferred diaper configurations (1) are described in US Pat. a stretchable elastic-like film with many zones ″ (Roe et al., issued September 10, 1996), 5569234 ″ Disposable diaper panties ″ (Buell et al., issued October 29, 1996); and 6004306 ″ Absorbent article with side panels expandable in several directions ″ (Robles et al., issued December 21, 1999).

A method of manufacturing an absorbent structural element (13)

The absorbent structural element (13) in accordance with the present invention can be manufactured by any method comprising the step of applying the absorbent material (50) to the support sheet (16), for example, first by placing said support sheet (16) above the raised portions, in shape and the dimensions corresponding to the formed channels (26), and then by applying said absorbent material (50) onto it, as a result of which the absorbent material (50) does not remain on the above raised areas, but Xia only on the remaining parts of the supporting sheet (16).

In some embodiments, the absorbent structure (13) with an absorbent layer (17) containing two or more channels (26) substantially free of absorbent material (50) can, for example, be obtained by a method comprising the steps of:

a) providing a feeding device, for example a hopper, for supplying said absorbent material (50) to a first infinite moving surface;

b) providing means for transferring the backing sheet (16) to a second endless moving surface;

c) providing a first infinite moving surface having one or more reservoirs for forming an absorbent layer (17) having a longitudinal direction and an average length perpendicular to its transverse direction and an average width, and a depth direction and an average depth perpendicular to both of them and a cavity volume for receiving said absorbent material (50) therein, wherein said reservoirs contain one or more raised strips, essentially extended in the longitudinal direction and in the place of which there is no empty space lifting, each of them having an average width W of at least 4% or at least 5% of the average width of the tank, and an average length L of at least 5% and a maximum of 30% of the average size of the tank in the longitudinal direction; wherein said one or more reservoirs are for transferring said absorbent material (50) onto said second endless moving surface.

d) providing a second infinite moving surface having an outer shell having one or more breathable or partially breathable sockets for receiving said supporting sheet (16) in or on them, with a receiving region and with one or more substantially longitudinally mating surfaces strips which may be airtight and each having an average width W ′ of at least 2.5 mm, preferably between 0.5 × W and 1.2 × W, and an average length L ′ of from about 0.8 × L to 1.2 × L;

while the breathable outer shell is connected with one or more secondary vacuum systems that ensure the retention of the supporting sheet (16) and / or said absorbent material (50) on it, and

at the convergence point, said first infinite moving surface and said second infinite moving surface are at least partially in close proximity to each other during the transfer of said absorbent material (50), and each of the mating strips is in close proximity to raised strip during transfer of said absorbent material (50);

e) supplying said absorbent material supply device (50) to said first endless moving surface in at least one or more of said reservoirs thereof;

f) as an additional possible step, removing the absorbent material (50) from said one or more protruding strips;

g) at the same time, transferring said supporting sheet (16) to said second infinite moving surface, to said one or more slots, or to them;

h) selectively transferring at said convergence point of said absorbent material (50) from said first endless moving surface only onto said part of the backing sheet (16) which is located on or in said receiving region of said socket; and

i) 1) applying an adhesive material (for example, a first adhesive material (40)) onto said absorbent structure (13) in step g; and / or

i) 2) applying an adhesive material (for example, a second adhesive material (60)) to said support sheet (16), before step f, or simultaneously with it, but in any case before step g).

Step i) 1) may include spraying said first adhesive material in a fiber bed onto said absorbent layer (17), or onto a part thereof, for example, in a substantially continuous manner, so that it is also applied to said channels (26).

Step i) 2) may include applying to the support sheet (16) a slit or spray coating, in a continuous manner, or, for example, in the form of a structure corresponding to the structure of the channels (26).

Said reservoirs may be formed in the form of a plurality of grooves and / or cavities having an “empty” volume and receiving absorbent material (50). In some embodiments, the average width W (of each) of the strip is at least 6 mm, or at least 7 mm, and / or at least 7%, or at least 10% of the average width of the respective reservoir.

Each of these cavities and / or grooves may have a maximum dimension in the transverse direction of at least 3 mm, and the shortest distance between adjacent cavities and / or grooves in the essentially transverse direction is less than about 5 mm. Cavities and / or grooves adjacent to a raised strip may have a volume exceeding the volume of one or more, or all of their adjacent grooves or cavities that are not adjacent to a given strip or other strip (i.e., are farther from the strip )

Said reservoirs of the first infinite moving surface may be at least partially breathable, wherein said first infinite moving surface may be a cylindrical surface with said reservoirs rotating around a stator containing a vacuum chamber; wherein said outer shell of the second infinite moving surface may be a cylindrical surface rotating around a stator containing a secondary vacuum chamber associated with said secondary vacuum system.

In one embodiment of the method, it is possible to manufacture an absorbent core (7) comprising two or more of the absorbent structural members described above (13; 13 ′); for example, two layers superposed in such a way that the absorbent material (50) of the first layer and the absorbent material (50) of the outer second layer will be located in close proximity to each other between the supporting sheet (16) of the first layer and the supporting sheet (16 ) of the second layer.

The method may include providing a means of applying pressure, for example, a pinch roller, which can exert pressure on the absorbent structural element (13), especially in those embodiments in which the absorbent material (50) is located between the supporting sheet (16) and the additional material; pressure may be applied to said supporting sheet (16) or to any additional material or layer laid over the absorbent layer (17) as described above. The pressure should preferably be applied selectively, namely, only to the channels (26 and / or 26 ′) of the absorbent structural element (13), for example, to the sections of the supporting sheet (16) corresponding to the channels (26), and which accordingly do not contain ( on the opposite surface) of the absorbent material (50), in order to avoid compression of the absorbent material (50) and / or portions of additional material, for example, a backing sheet (16 ′), corresponding to the channels (26 ′), and accordingly not containing (on the opposite surface sti) of absorbent material (50) to prevent compression of the absorbent material (50).

The pressure applying means may have a structure of protrusions corresponding to said structure of one or more raised strips and / or said mating strips, preferably a structure of mating strips.

The dimensions and their values contained in this document should not be construed as strictly limited to the exact values given. On the contrary, unless otherwise specified, a given value is understood to mean this value in accuracy and all values located in a functionally equivalent neighborhood. So, for example, a value designated as 40 mm should be considered as “approximately 40 mm”.

All documents cited in the detailed description of the present invention, in part related to the present invention, are mentioned only for reference. The citation of any document should not be construed as an admission that the cited document should be included in the prior art in relation to the present invention. If any meaning or definition of a concept in this document does not coincide with the meaning or definition of a given concept in a referenced document, one should be guided by the meaning or definition of a given concept contained in this document.

Although specific embodiments of the present invention are illustrated and described herein, one skilled in the art will appreciate that other changes and modifications are possible without violating the idea and purpose of the invention. For this purpose, it was intended in the appended claims to represent all possible similar changes and modifications within the scope of the present invention.

Claims (12)

1. An absorbent structural element (13) for an absorbent article, comprising a support sheet (16) and an absorbent layer supported by it (17); wherein the absorbent layer (17) contains an absorbent material (50) consisting essentially of particulate superabsorbent polymeric material; wherein said absorbent structure (13) and absorbent layer (17) have a longitudinal direction and an average length, a transverse direction and an average width, and a height; wherein said absorbent layer (17) has a longitudinal axis and a transverse axis perpendicular to it; and wherein said absorbent layer (17) has a first longitudinally extended side part (20) located on one side of said longitudinal axis, and a second longitudinally extended side part (20) located on the other side of said longitudinal axis; wherein said absorbent structural element (13) and its said absorbent layer (17) have a front region, a rear region and a crotch region located between them, arranged in series in said longitudinal direction; wherein said absorbent layer (17) has at least a first substantially longitudinally extended channel (26) in said first lateral part, and a second substantially longitudinally extended channel (26) in said second lateral part, with wherein said channels (26) are essentially free of said superabsorbent polymer material and are extended along said height of said absorbent layer (17); and wherein said absorbent structural element (13) comprises one or more adhesive materials (40; 60) configured to at least partially immobilize the absorbent layer (17) on said support sheet (16), wherein said one or the more adhesive material includes a first thermoplastic fibrous adhesive material (40) forming a fiber network immobilizing the absorbent material on the backing sheet (16), and said channels (26) are not extended to any length o from the longitudinal side edges (18), the transverse front edge (19), or the rear edge (19) of said absorbent layer (17). 2. The absorbent structural element (13) according to claim 1, characterized in that the absorbent layer (17) has a transverse direction and an average width W, a longitudinal direction and an average length L; and each of the channels (26) has an average width W ′ of at least 4% to 25% of the average width W of said absorbent layer (17); and each of the channels (26) has an average length L ′ of 5% L to 80% L. 3. The absorbent structural element (13) according to claim 2, characterized in that W ′ is at least 7% of W and preferably up to 20%, or up to 15% of W; and / or W ′ is from at least 5 mm to, for example, 20 mm. 4. The absorbent structural element (13) according to claim 2, characterized in that the smallest distance D in the transverse direction between the two channels (26) is at least 5% of W, preferably at least 10% W.
5 An absorbent structural element (13) according to claim 1, characterized in that the said one or more adhesive materials include a second adhesive material (60) existing between said supporting sheet (16) and said absorbent layer (17), and wherein the second the adhesive material is preferably applied to said supporting sheet (16) or a part thereof before applying said absorbent layer (17) or its absorbent material (50) to said supporting sheet (16). 6. The absorbent structural element (13) according to claim 1, characterized in that said one or more adhesives (40; 60) are present in at least said channels (26), and wherein said supporting sheet (16) is laid in said channels (26), or parts thereof, and wherein said supporting sheet (16) is adhered to an absorbent material (50), which essentially forms the longitudinal walls of said channels (26), or a part of said walls. 7. The absorbent core (7) containing the absorbent structural element (13) according to any one of the preceding paragraphs, which is the first absorbent structural element (13), and containing additional material located in close proximity to the said absorbent layer (17) and selected from i ) an additional support sheet (16 ′); ii) a layer (70) of the receiving material; iii) a second absorbent structure (13 ′) comprising a second support sheet (16 ′) and a second absorbent layer (17 ′), said second absorbent layer (17 ′) and said absorbent layer (17) of the first absorbent structure ( 13) are layered between said supporting sheet (16) of the first element and said second supporting sheet (16 ′), wherein the optionally mentioned second absorbent structural element (13 ′) is an absorbent structural element according to any of the preceding claims. 8. The absorbent core (7) according to claim 7, characterized in that the additional material located in close proximity to the absorbent layer (17) is a layer (70) of the receiving material, while said layer (70) of the receiving material preferably contains chemically formed cross-linked cellulosic fibers, wherein said receiving material layer is supported by a second support sheet (16 ′), while the absorbent layer (17) and the receiving material layer (70) are located between a wrinkled support sheet (16) of the first element and a second support sheet (16 ′). 9. The absorbent core (7) according to claim 8, characterized in that the layer (70) of the receiving material contains channels (26 ′), essentially completely overlapping with the channels (26) of the aforementioned first absorbent structural element (13), and preferably wherein the first and second supporting sheets are fastened in the channels. 10. An absorbent core (7) according to claim 7, characterized in that said second absorbent structural element (13 ′) is an absorbent structural element according to any one of paragraphs. 1-6, wherein said channels (26) of said second absorbent structural element (13 ′) are essentially identical to said channels (26) of said first absorbent structural element (13) and essentially overlap with them. 11. The absorbent core (7) according to claim 7, characterized in that said supporting sheet (16) of said first element and / or said second supporting sheet (16 ′) are laid in said channels (26 and / or 26 ′) of the first absorbent structural element (13) and / or, optionally, the second mentioned element (13 ′) of the receiving material layer (70), if any, or to part of said channels (26, 26 ′), and said one or more adhesive materials are available, at least in said channels (26, 26 ′), or in part thereof, and mentioned supporting sheets (16; 16 ') are glued to each other in said channels (26, 26'), said one or more adhesive materials. 12. The absorbent structural element (13) according to any one of paragraphs. 1-6 or an absorbent core (7) according to any one of paragraphs. 7-11, in which the channels at least partially retain their structural integrity both in the dry and in the wet state, in particular, in which each channel retains the structural integrity of at least 20%, or 30%, or 40 %, or 50%, or 60, or 70%, or 80%, or 90% according to the test results for the structural integrity of the channel in the wet state. 13. An absorbent product containing an absorbent structural element (13) according to any one of paragraphs. 1-6 or an absorbent core (7) according to any one of paragraphs. 7-11, wherein the absorbent article is a diaper (1).

Images