JP2002509737A - Layered absorbent structure with segmented basis weight and heterogeneous layer area - Google Patents

Abstract

(57) Abstract: A unique absorbent comprising an absorbent core having a plurality of absorbent layers, wherein the absorbent layers interact to preferentially place the liquid within a designated highly saturated guiding layer. The localization of the liquid in the guiding layer increases the ability of this layer to transfer liquid by capillary action by increasing the level of saturation and the amount of liquid available. The uptake capacity of the absorption system can be improved as much as or better than current systems by making the second layer of the absorption system a low saturation level by maximizing the liquid absorption of the product, Appropriate control of composite properties will provide optimal uptake performance. The low saturation level of this layer is also high absorbing so that it provides void volume for incoming liquid absorption, i.e., increases the uptake rate of the absorption system as a whole, while the low saturation layer reduces leakage generation. It is balanced to provide adequate high capillary forces to provide sufficient control of the liquid to prevent. This low saturation layer is used separately from the surge material and provides a different uptake function than that provided by the surge material. In certain aspects of the invention, the body-side layer of the absorbent core does not extend over the entire surface of the entire absorbent core, and thus is not used as a highly saturated guiding layer, but is used as an intake layer. This configuration also allows the intake layer to be in direct contact with the incoming liquid, thus allowing for even more immediate access and improved intake capabilities. In another aspect, the at least one main layer region has a non-uniform, selectively segmented basis weight distribution. The specific structure of at least one main layer region can constitute a target region of this main layer region having a basis weight smaller than that of the other non-target regions. Further, at least one main layer region can have a heterogeneous structure. In certain structures, at least one main layer region can include a plurality of two or more sub-layers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to a layered absorbent structure. More particularly, the present invention relates to a layered composite absorbent structure having individual layers configured and arranged to selectively cooperate to provide desired performance parameters in the composite layered structure.

[0002] on the performance goals of the disposable absorbent article, such as a background infant diaper of the invention, it is leak-free product, that there is a dry feel to the wearer, and that there is a pleasant perfect feeling through the product life included. Accordingly, absorbent articles typically include an absorbent core with liquid handling and other absorbent functions required to meet product performance goals. The absorbent core of an absorbent product generally consists of wood pulp fibers and, in many cases, superabsorbent materials dispersed in the absorbent core to enhance liquid absorption capacity. The absorbent core is usually formed in a configuration such as an hourglass or a T-shape in which the width of the absorbent material is reduced in the central crotch region for a perfect feeling and comfort for the wearer.

[0003] Absorbent articles often leak before the liquid absorbing capacity of the entire absorbent core is fully utilized. One of the problems that can cause leakage is the inability of the absorbent core to quickly and completely take up all of the liquid when it is discharged into the absorbent article. Another related problem that causes leakage is that during discharge, a sufficient amount of liquid is transferred, i.e. dispersed, from the target area of the absorbent article to the farther and farther end areas of the unused absorbent core. The inability of the absorbent core to do so. This saturates only the central target area of the absorbent core, resulting in poor performance, poor fit, and discomfort to the wearer. Results. Disadvantages of these absorbent cores are that the mass and capacity of the absorbent in the target area are reduced to improve the fit of the product.
This is particularly acute for thin, narrow crotch absorbent designs with crotch widths of less than 4 inches.

[0004] The current absorbent cores of absorbent articles do not adequately meet recent performance goals. The desirable absorbent core liquid uptake / dispersion function required for high efficiency absorbent article design in the upstream narrow section also exceeds current capabilities. In this way, while improving the ability to take up swooping liquids,
There is still a need for an absorbent structure that can improve the liquid dispersion ability to move liquid out of the target area during a liquid assault and maintain this desirable liquid uptake over the life of the product.

SUMMARY OF THE INVENTION The disclosed invention is an absorption system having a plurality of absorption layer regions. The two or more absorbent layer regions can advantageously interact with a method of preferentially positioning a given liquid in a selected layer region. Thus, by concentrating the liquid in this layer region, a higher saturation level and an increase in the amount of liquid that can be accepted are possible, whereby the capillary action caused by this layer region allows the liquid to move. Can be increased. The absorption capacity of the absorption system provides optimal uptake performance through proper control of complex properties while keeping the second layer area of the absorption system at a low saturation level through as much liquid assault on the product as possible This can be maintained or improved beyond the current system. The low saturation performance of this region, together with high permeability, provides void volume for incoming assault liquids, thereby increasing the uptake rate of the overall absorption system. The properties of this layer region can be advantageously balanced with a suitable high level of capillary tension that provides sufficient liquid control to substantially prevent unwanted leakage. This low saturation layer region can be used in addition to the surge control material layer, adding further uptake performance to the uptake performance provided by the surge material.

According to a particular aspect of the present invention, the bodyside layer of the absorbent structure does not extend over the entire surface of the absorbent system, and the intake layer as an additional part of the highly saturated (capillary) guiding layer area. Can be provided. This arrangement allows the area of the intake layer to be located in a position that is substantially in direct contact with the incoming liquid, thereby allowing more immediate access to the incoming liquid and improving the liquid intake function.

[0007] In another aspect, at least one main layer region can have a non-uniform, selectively zoned basis weight distribution. As a specific configuration relating to at least one main layer region, the basis weight of the target region of the main layer region can be configured to be smaller than the basis weight of another non-target portion in the main layer region. Furthermore, at least
One main region can have a heterogeneous structure. In certain configurations, at least one main layer region can include multiple, two or more auxiliary layers.

In another aspect of the invention, the layer area of the absorption system acts to provide a desired Liquid Wicking Potential Value, for example, a liquid guidance value of at least about 16%. Also, the present invention provides a flow control device having a desired flow conduction value.
ductance Value), for example, may Rukoto provide at least flow conductivity value of about 7 * 10 ^-6 cm ^3, a. In another aspect, the present invention is at least winning 14 * 10 ^-6 cm ^3,
The prepared Conductance-Wicking Value can be provided. According to a further aspect of the invention, a system can be provided that provides a desired flow conduction value and further comprises at least one layer region having a desired liquid guidance value. According to yet another aspect of the present invention, a superabsorbent polymer (SAP) material that exhibits a specific, controlled absorption can be provided. For example, a high-absorbent material with a desired control rate may have a specific absorption rate,
A Tau Value can be indicated, for example, a tau value of at least about 0.67 minutes (min). In another aspect, the invention can comprise a combination of superabsorbent materials with a particular tau value.

In its various forms, the present invention can provide articles having a low volume, thin, high absorption capacity, leak resistance, and a more effective absorption structure. According to the configuration of the present invention, the total retained absorption capacity of the absorption structure can be more fully utilized, and the obtained liquid can be
More efficient movement and distribution from the initial uptake area to a more remote area located proximate the distal area of the absorbent structure. In addition, the structure of the present invention can provide the ability to acquire and take up liquid at a high rate, maintaining the desired uptake rate even after the absorbent structure has been wetted and the critical portion has reached its retained total absorbent capacity. be able to. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more fully understood and further advantages will become apparent by reference to the following detailed description of the invention and the drawings.

[0010] Various aspects and embodiments of the invention are described in the context of a disposable absorbent article, such as a disposable diaper. However, it is quite apparent that the invention can also be used in other articles, such as children's training pants, women's care products, incontinence clothing, protective cover pads, etc., which can be configured to be disposable. Normal,
Disposable articles, such as disposable garments, are intended for limited use and are not intended to be washed or otherwise washed for reuse. For example, disposable diapers are discarded after being soiled by the wearer. In the context of the present invention, a mechanical fixation system is a system comprising a plurality of cooperating components that are mechanically constrained to provide a desired fixation.

The present invention provides an absorption system having a plurality of layer regions and having an absorption core that provides significantly improved void volume, permeability, and liquid uptake performance at a given target region. The absorption system, and in particular the absorption core of the system, can substantially regenerate the desired level of void volume through the transfer of liquid out of the target area, such as by capillary guidance or other mechanism. The liquid is advantageously concentrated in the layer area of the absorbent core selected to provide the desired relatively high liquid dispersion, while the layer area selected to provide void volume and uptake has a relatively low saturation. We can maintain state. In most cases, the basis weight of the relevant layer area, i.e. the concentration of superabsorbent material, is such that a suitable cooperating material with appropriate properties can function properly in the system and provide good performance, Can be placed. However, it has been discovered that certain combinations provide significant performance gains over others.
Also, the basis weight and other characteristics of the components optimize cost, other consumer attributes,
Or to promote a desired dispersion of the absorbed liquid, a specific area of the absorption structure (
It should be noted that changes can be made (e.g., front vs. back).

In the present invention, the absorbent layer regions are characteristically configured to cooperatively interact in a manner that preferentially positions the liquid within one or more designated or selected layer regions. it can. By concentrating the liquid within the designated layer area, this layer moves and disperses the liquid through relatively higher saturation and capillary action due to the increased amount of liquid that can be handled in the designated layer. Ability can be improved.

[0013] The uptake capacity of the absorption system, especially of the absorption core, allows the main intake layer area of the absorption system to be kept at a low saturation level through as much of the liquid as possible into the product, while providing adequate control of the composite properties. By providing optimal uptake performance through, maintenance or improvement over conventional systems. This relatively low level of liquid saturation in the area of the intake layer, together with high permeability, provides a void volume for incoming liquid assaults, thereby increasing the uptake rate of the overall absorption system. This intake layer region can be advantageously configured to provide an adequately high level of capillary tension to properly control liquid movement and substantially avoid unwanted leakage. This low saturation uptake layer region can desirably be used in addition to a separately provided surge control to provide an uptake function in addition to the uptake function provided by the surge layer material.

[0014] In certain configurations, the uptake layer region can be located on the body side of the absorbent structure and can be configured to not extend across the entire area of the total absorbent structure. Therefore, the main body side layer region is used as the intake layer region, not as the highly saturated guide layer region. This arrangement also allows the intake layer area to be in substantially direct contact with the incoming liquid, thereby providing more immediate access to the incoming liquid and a more efficient intake function. It is possible to do. The layer regions can be designed individually or in combination to improve the balance between the uptake and dispersion functions, in particular the uptake and dispersion of aqueous liquids. For example, improved performance can be provided by changing the physical and / or chemical composition of the component materials, or by changing the physical configuration of the component parts.

[0015] Composites of current fibers and superabsorbent polymers (SAPs) used in conventional designs of absorbent articles, such as diapers, can provide the usual combination of uptake, distribution, and retention functions. However, improved materials, improved systems, and systems that provide improved combinations with higher levels of uptake, distribution, and retention capabilities
There is a continuing need for structure. To provide improved leakage resistance, the present invention incorporates an improved material that exhibits improved properties in at least one functional area. As a result, it is possible to improve the overall performance of the system.

[0016] For example, the uptake function is the fiber and particle size of the material in the relevant layer area,
It can be adjusted by controlling such factors as the porosity of the layer region, the basis weight of the layer region, and the composition of the layer region. The distribution or distribution function is adjusted by controlling factors such as, for example, the fiber and particle size of the constituent materials, the liquid contact angle provided by the material, the liquid surface tension sunk by the liquid, and the basis weight of the material. it can. To further enhance the desired balance of absorption properties, a number of key factors have been identified that allow the layer regions to function better in combination, thereby improving the function of the overall system. . This includes the preferred flow conduction values and liquid guidance values provided by the absorption system. Another factor is the combined conduction and guidance values provided by the system.

[0017] Flow conduction is a value related to the uptake capacity provided by the absorbent core structure, based on the physical properties of the absorbent material, especially the absorbent material located in the target area of the absorption system. Desirably, the flow conduction value has a minimum value of about 2.5 * 10 ^-6 cm ³ or more. Alternatively, the flow conduction value is about 3 * 10 ^-6 cm ³ or more, optionally to improve performance,
It is about 3.5 * 10 ^-6 cm ³ or more. In another aspect of the invention, the flow conduction value is up to about
It can be 5 * 10 ^-6 cm ³ . Alternatively, the flow conduction value can be up to about 7 * 10 ^-6 cm ³ ,
And optionally, it can be up to about 9 * 10 ^-6 cm ³ or more for performance enhancement.

The liquid guiding ability value (liquid guiding value) is a performance parameter related to the amount of liquid moved from the target area of the absorbing structure in the course of the vertical guiding action. This value is
Representing the ability of the absorbent structure to move fluid from a target area during a liquid assault, at least one layer area of the absorbent system is configured to provide a desired liquid guiding capacity value. Desirably, at least one layer of the absorption system, particularly at least one main layer region of the absorption core, can provide a liquid guide value of at least about 10% or more. Alternatively, the provided liquid guidance value is about 15% or more, and optionally about 20% or more. In another form of the invention, the absorption system can provide a liquid guidance value of up to about 60%. Alternatively, the liquid guidance value provided is up to about 65%, and can optionally be up to about 70% or more for improved performance.

The combined conduction and guidance value (C) of the system can be at least about 14 * 10 ⁻⁶ cm ³ . Alternatively, the combined conduction and guidance value is at least about 17 * 10 ^-6 cm ³ for improved performance, and optionally about 20 * 1 for improved performance balance.
It can be 0 ^-6 cm ^3. In other desirable preparations, the combined conduction and guidance value can be at least about 15 * 10 ^-6 cm ³ , or alternatively, at least about 16 * 1
0 ^-6 can be cm ^3, Optionally, in order to provide a more desirable advantages, about
It can be 18 * 10 ^-6 cm ³ .

In a thin absorbent design with a narrow crotch, the target area of the product, in its dry state, typically does not have enough void volume to effectively absorb the initial assault of a liquid such as urine. This lack of void volume can be compensated for by incorporating a specially configured SAP in an amount sufficient to absorb the incoming liquid throughout the time of liquid absorption. The embedded SAP is configured to receive and hold the volume of fluid to be absorbed during a liquid assault to provide the desired leak resistance.

Although some of these parameters have been described individually above, it is difficult to provide an effective combination of these attributes in a single composite structure while maintaining desirable consumer attributes. It has been. The problems encountered in the past have generally arisen with the desire to have a relatively low SAP content in the entire structure or individual layers in order to increase the guiding capacity. If a low SAP concentration is used throughout the product, an excessively large product thickness may be required to provide the desired absorption capacity. Attempts have been made to provide one absorbent layer with a low SAP concentration to facilitate the guiding action, while maintaining a high SAP concentration in the other layer to achieve a thin product with the desired absorption capacity. . Such systems did not provide the desired level of performance because liquids preferentially migrate to areas containing higher SAP concentrations. In layer regions containing relatively low SAP concentrations, the amount of liquid retained is insufficient to provide the desired guiding action.

To overcome these shortcomings, certain aspects of the present invention include SAP control rates in absorption systems. By using an SAP control rate, such as a selected SAP depletion rate, the degree of concentration of the liquid within the fiber structure of a given dispersion layer region may be reduced if the dispersion layer region contains a selected amount of SAP. Can be kept as high as possible. In certain preparations, low SAP control is mainly provided in areas other than the dispersion layer. As a result, the low SAP layer can be selectively saturated while the overall absorption capacity in the thin product is maintained at the desired high level. It is contemplated that alternative mechanisms other than the incorporation of low SAP rates may be used to provide the desired distribution between the selected layer areas and different concentrations of liquid. For example, the desired distribution can be created by selectively configuring the corresponding wettability and / or density of the layer area.

Referring to FIGS. 1 and 2, the combined absorption system 26 of the present invention includes a surge controller 84 and an absorption pad or core structure 30. The absorbent core 30 has a plurality of absorbent layer regions, the characteristics of the individual layer regions being selected to provide improved leakage performance by balancing the uptake and guidance characteristics of the absorbent component. And adjusted. In general, the absorbent core 30 of the present description can be used to maintain the integrity of such layers during functional testing, along certain intermediate components (the innermost body-side surface of the article). From the first layer containing superabsorbent (as set in moving towards the outermost surface of the article). Such a first layer desirably comprises a minimum of about 5 wt% or more of superabsorbent. The absorbent core is substantially liquid selected to prevent leakage from the diaper (as set when moving from the innermost bodyside surface of the article toward the outermost surface of the article). Ends with the last absorbent layer located just before the permeable layer. Thus, the absorbent core 30 of the configuration shown,
The first main absorbent layer 48, the outermost layer of the wrap sheet 28 or 36, and the components sandwiched therebetween are provided. The absorbent core having the structure shown in the drawing is a surface sheet layer.
24, the surge control layer 84 that does not contain a high absorbent, and the back sheet layer 22 are not described.

The proper balance of intake and guiding properties depends on various determinants, such as flow conductance values, guiding capacity values, basis weight, density, particle size, fiber size, relative amounts of fibers, etc., and combinations thereof. Can be represented by The flow conductance value of the absorber is related to the effective void volume and permeability of the structure across the various saturation levels commonly encountered during normal use. In order to provide improved performance to the absorbent system, the liquid should be able to enter the absorbent structure at a speed as close as possible to the speed at which the liquid is dispersed on the absorbent composite structure. The flow conductance values can help characterize the uptake capacity of the overall absorption system 26, and in particular, can help characterize the uptake capacity of the absorbent core 30. In addition, for preservation, transfer the liquid from the inlet area to a more remote area of the absorption system, thereby restoring the state of the inlet area again to more effectively receive the next liquid absorption, It is important to prepare for it. The liquid guidance value can help characterize the ability of the absorbent structure to move liquid from the target area during a liquid raid.

Referring to FIGS. 2 and 2A, the absorbent core 30 has an overall composite core length 66, an overall composite core width 68, an overall composite core thickness 70, a crotch core width 58, and a predetermined foremost edge. . The foremost side edge is selected to be located on the front belt portion of the article. The entire composite assembly of absorbent core 30 extends over and covers the entire core area, as shown in FIG. Each core component layer and optional auxiliary layer can extend over the entire absorbent core area, or over selected portions of the core area as needed to provide the desired performance. . In addition, each of the individual layer regions has individual dimensions. In the arrangement shown, for example, the first layer 48 has a first thickness or height 72, a first length 7
3, and a first width 74. The second layer region has a second thickness or height 75, a second length 66, and a second width 68.

For the total length 66 of the absorbent core 30, the target intake / target area 52 in the absorbent structure is:
Beginning with a laterally extending transverse line located 24% of the absorbent composite core length 66, away from the leading edge at the end of the absorbent core, 59% of the absorbent composite length away from the leading edge of the absorbent core % Is a region of the absorbent core extending to the width direction line located at%. In the illustrated arrangement, for example, the target area of the absorbent core begins with a laterally extending line located about 3.5 inches (89 mm) from the leading edge of the distal end of the absorbent core and about 8.5 inches from the leading edge of the absorbent core. An absorbent structure area extending to a line extending in the width direction, which is located at an inch (216 mm) can be provided.

In articles having a narrow crotch width, it is not desirable to increase the flow conduction value by increasing the volume of the absorbent core structure due to the excessive thickness of the product. As a result, there is a continuing need for configurations that can provide the desired uptake performance, as represented by the flow conduction values, while maintaining the thin absorbent core 30 and thin absorbent system 26. Desirably, the total thickness of the dried absorbent core is:
Approximately 6 mm or less. Alternatively, the thickness of the absorbent core can be about 5.3 mm or less, and optionally, the thickness of the absorbent core can be about 5 mm or less to provide the desired advantage. In other embodiments of the present invention, the thickness of the dry absorbent core 30 can be no more than about 25% of the crotch article of the absorbent core. Alternatively, the dry absorbent core thickness can be no more than about 20% of the absorbent core crotch width, and optionally, the absorbent core crotch width to provide improved benefits. It can be about 15% or less.
For the purposes of this disclosure, the crotch width of the absorbent core is set to the narrowest (minimum) lateral dimension of the crotch region located within the target area 52 of the core.

Desirably, the total thickness of the dry absorption system 26 is less than or equal to about 8 mm; alternatively, the thickness of the absorption system may be less than or equal to about 7.3 mm; Can have a thickness of 7 mm to provide the desired advantage. In another aspect of the invention, the total thickness of the dry absorption system is about the crotch width of the absorption system.
It can be 30% or less. Alternatively, the thickness of the dry absorbent core can be no more than about 25% of the crotch width of the absorbent system, and optionally, the crotch of the absorbent system to provide improved benefits. It can be less than about 20% of the width. For purposes of the present invention, dry thickness is measured at a confined pressure of 0.2 psi (1.38 Kpa).

In another form of the invention, the low volume absorption system 26, and particularly the absorbent core 30, has the smallest (minimum) lateral dimension of the crotch region provided within the target area 52, which is the minimum crotch width. Such a crotch 54 may be positioned between the wearer's legs. Thus, an adult product (intended for use by persons older than 13 years) would have a crotch width of less than about 5.5 inches (about 14 cm) when the absorbent composite was dry. can do. Alternatively, the minimum crotch width 54 can be no more than about 4.5 inches (about 11.4 cm), and optionally about 3.5 cm (about 11.4 cm) to provide improved fit and comfort. 8.9 cm) or less. Minor products (intended for use by persons under the age of 13) shall have a crotch width of at least about 4 inches (about 10 cm) minimum lateral dimension when the absorbent composite is dry be able to. Alternatively, the minimum crotch width 54 can be about 3 inches (about 7.6 cm) or less, and optionally about 2 cm to provide improved fit and comfort for minors. (About 5
.1 cm) or less.

It is also important to move liquid from the target area 52 of the absorption system and to effectively prevent this area from becoming oversaturated and leaking from the article. The ability of the absorption system to move liquid away from the target area can be represented by the liquid guidance value provided by the system. This guidance capability value is for the amount of liquid that the system can move out of the target area if the target area has a liquid loading / saturation level in the target area of the absorbent complex of 1.0 grams liquid per square centimeter. Thus, the present invention provides a characteristic layered absorption system that is thin, narrow and low volume in the crotch region.

The layer regions in the absorption system include a body-side first layer region, which can be of various suitable configurations, but the size of this region is typically the outermost second layer region.
It is equal to or smaller than the size in the absorption layer region. This first upper layer region can maintain a low saturation level over use of the absorbent article and can maintain high flow conduction values when used in combination with the second lower layer region. The lower layer region can be of a selected shape, such as an hourglass or a T-shape, to disperse liquid outside the target area of the absorbent complex,
It is configured to move. In particular, the second lower layer region can provide a desired liquid guiding capability value, as can be determined by the liquid guiding capability value procedure described below.

Referring to FIGS. 1, 1A and 1B, the present invention can provide an absorbent garment article, such as a diaper 20, having a longitudinal length direction and a lateral width direction 88. The article has a first belt portion, such as a rear belt portion 40, a second belt portion, such as a front belt portion 38, and an intermediate portion 42 interconnected with the first and second belt portions. Front belt 38
Has a pair of side end regions 118 on the front side that are laterally opposed, and the rear belt portion 40 has a pair of side end regions 116 on the rear side that are laterally opposed, The intermediate portion 42 has a crotch region located between the wearer's legs.

FIG. 1 shows a representative disposable diaper 20 of the present invention in a flattened, uncontracted condition (ie, with substantially all of the shrink-inducing elastics removed). FIG. Parts of the structure have been partially cut away to more clearly show the internal structure of the diaper article, and the body-side surface of the diaper with which the wearer contacts is facing the viewer of this figure. The outer end of the diaper is defined by a longitudinally extending side edge 110 and a laterally extending distal edge 112. The side edges define the diaper leg opening and are optionally curved or contoured.
The terminal edges are shown as straight lines, but may optionally be curved.

The liquid-permeable front sheet layer 24 is overlaid in facing relationship with the back sheet layer 22, and the absorbent system can function between the back sheet layer 22 and the front sheet layer 24. Connected and fixed in the state. The configuration typically shown is a surge control unit 84,
And an absorption complex system 26 including a storage unit for holding and storing the liquid.
The storage part of the illustrated absorption system comprises an absorption core 30. In the structure shown, the surge control section 84 is a layer located between the absorbing core 30 and the front sheet layer 24. Also, other arrangements can be used. For example, the surge layer 84 can optionally be located between the absorbent core and the backsheet layer 22, or on the bodyside surface of the facesheet.

Typically, the article comprises elastic members such as leg elastics 34 and waist elastics 32,
And a surge control unit arranged in a state of being in liquid communication with the storage unit of the absorbent article. The surface sheet 24, the back sheet 22, the absorbent core 30, the surge control unit 84, and the elastic members 34 and 32 can be assembled together to form various known diaper configurations. Further, the diaper may additionally include a containment flap 82 and a retractable or otherwise elasticized side panel member 90.

An example of an article having telescopic side panels and selectively forming fastener tabs is entitled “Dynamic Fitting Diaper” by T. Rossier, December 1993.
It is described in US Patent Application No. 168,615, filed on the 16th (Attorney Docket No. 10,961). Various techniques for forming a desirable fastening system are described in T. Rossler et al., 1995, entitled "How to Make a Fastening System for Dynamically Fit Diapers".
U.S. Patent No. 5,399,219 filed on March 21 (Attorney Docket No. 11,186), U.S. Patent No. 5,5
U.S. Pat. Filed April 3, 1995, entitled "Laminate Tape Assembly Process" by D. Fries, issued as U.S. Patent No. 5,595,618.
11,950) in U.S. patent application Ser. No. 08 / 415,383. The disclosures of the above documents are hereby incorporated by reference herein in a consistent manner (to avoid interference).

As typically shown in FIG. 1, diaper 20 generally defines a longitudinally extending length direction 86 and a laterally extending width direction 88. The diaper can be in any desired shape, for example, rectangular, I-shaped, generally hourglass-shaped, or T-shaped. According to the T shape, the horizontal line of T can be constituted by the front belt portion of the diaper, and alternatively, can be constituted by the rear belt portion of the diaper.

The front side sheet 24 and the back side sheet 22 can be generally coextensive, are generally larger than the dimensions of the corresponding absorbent structure 26, and extend beyond that length and width. It has dimensions and extends beyond the terminal edge of the absorbent structure, creating corresponding side edges 110 and terminal edges 112. The front sheet 24 is associated with and superimposed on the back sheet 22 so that the circumference of the diaper 20 can be defined. The belt area, when it is worn, the waist or the lower center of the torso of the wearer,
It constitutes a diaper part which is entirely or partially covered or surrounded. Central crotch area 42
Is located between the belt regions 38 and 40, interconnecting them and, when worn, forms a diaper portion that is located between the feet of the wearer and covers the lower torso of the wearer. Thus, the central crotch region 42 typically corresponds to the area where the surge of liquid that occurs in a diaper or other disposable absorbent article is repeated.

The back sheet 22 can typically be provided along the outer side surface of the absorbent composite 26 and can be comprised of a liquid permeable material, but is substantially impermeable to liquids. It is desirable to configure. For example, a typical backing sheet can be made from a thin resin film, or other flexible, substantially liquid impermeable material. As used herein, the term "flexible" refers to a material that is compliant and readily deforms to the overall shape and irregularities of the wearer's body.
The back sheet portion 22 prevents exudates contained in the absorbent composite 26 from wetting articles in contact with the diaper 20, such as bed sheets and covers. In certain embodiments according to the present invention, the backing sheet 22 has a thickness of about
It may include 0.012 mm (0.5 mil) to about 0.051 mm (2.0 mil) film. For example, the backing sheet film can be about 1.25 mil thick.

[0040] An alternative structure of the backing sheet is a woven fabric that is wholly or partially constructed or treated to create a desired level of liquid impermeability to selected areas adjacent to or near the absorbent composite. It can be constituted by a fabric or a nonwoven web. For example, the backing sheet can include a gas-permeable nonwoven layer laminated to a gas-permeable or otherwise polymer film layer. Other examples of fibrous cloth-like backing sheet materials are thin stretch materials, ie, 0.6 mil (0.015 mm) thick polypropylene blown film, and 0.7 ounces per square yard (23.8 gsm) polypropylene spunbond material. (2 denier fiber) made of elastic thermal laminate material. This type of material forms the outer cover of the diaper HUGGIES SUPREME sold by Kimberly-Clark. Typically, the back sheet 22 comprises an outer cover of the article. However, optionally, the article can include a separate outer cover component that is added to the backing sheet.

Alternatively, the backing sheet 22 may include a microporous “breathable” material that allows gas, such as water vapor, to escape from the absorbent composite 26. On the other hand, it prevents liquid exudate from passing through the back sheet. For example, the breathable backing sheet can be comprised of a microporous polymer film or a nonwoven coated or otherwise modified to have a desired level of liquid impermeability. For example, a suitable microporous film is
It can be PMP-! Material sold by Mitsui Toatsu Chemicals with offices in Tokyo, or XKO-8044 sold by 3M Company of Minneapolis, Minnesota. Further, the back sheet may be embossed or the like having a pattern or a matte finish so as to show a more aesthetically pleasing appearance.

In various configurations of the present invention, if components such as the backing sheet 22 or the confinement flap 82 are configured to be gas permeable, but have resistance and limited permeability to liquids, The liquid resistance material may have a configuration capable of supporting a head of at least about 45 cm with substantially no leak therethrough. A suitable technique for measuring the resistance of a material to liquid penetration is US Federal Test Standard FTMS 191 Method 5514, December 31, 1968.

The size of the backing sheet 22 is typically determined by the size of the absorbent composite 26 and the particular diaper design selected. The backsheet 22 can be, for example, entirely T-shaped, entirely I-shaped, or a modified hourglass shape, and to create at least some side and end edges, A selected distance, such as a distance in the range of about 0.5 to 1.0 inches (about 1.3 to 2.5 cm), can extend beyond the ending edge of the absorbent composite 26.

The front sheet 24 is compliant, soft to the touch, and provides a body-facing surface that does not irritate the wearer's skin. Further, the front side sheet 24 is less porous than the absorbent composite 62 and is porous enough to allow the liquid to penetrate the liquid so as to easily penetrate the thickness thereof and reach the absorbent composite. is there. Suitable front side sheet layers 24 include porous foam, reticulated foam, perforated resin film, natural fibers (eg, wood or cotton fibers), synthetic fibers (eg, polyester or polypropylene fibers), or natural and synthetic fibers. Can be manufactured with a wide selection of webs, such as combinations. The face sheet layer 24 is typically used to help isolate the wearer's skin from the liquid retained within the absorbent composite 26.

A variety of woven and nonwoven fibers can be used for the face sheet 24. For example, the facing sheet may comprise a melt blown or spunbonded web of the desired fibers, and may be a bonded carded web, a hydroentangled web, and the like, and combinations thereof. Various woven fabrics can be composed of natural fibers, synthetic fibers, or combinations thereof. Optionally, the facing sheet can include a net material or a perforated film.

For the purposes of this description, the term “nonwoven” means a web of fibrous material formed without the aid of a weaving or braiding process of a woven fabric. The term "fabric" is used to refer to all of woven, knitted, and nonwoven fabric webs, as well as combinations thereof. The face sheet fabric is comprised of a substantially hydrophilic material, which is optionally treated with a surfactant or other process to have a desired level of wettability and hydrophilicity. be able to. In certain embodiments of the present invention, the face sheet 24 is a nonwoven, spunbond polypropylene fabric of about 2.8-3.2 denier formed into a web having a basis weight of about 22 gsm and a density of about 0.06 gm / cc. . The fabric is surface treated with about 0.28% Triton X-102 surfactant. The surfactant can be supplied in any conventional manner, such as by spraying, printing, plush coating, and the like.

The front side sheet 24 and the back side sheet 22 are connected by a functionable method, or
Associated. As used herein, the term `` associate '' refers to a configuration in which the front sheet 24 is directly fixed to the back sheet 22 so that the front sheet 24 is directly joined to the back sheet 22; Front sheet 24, then back sheet
A configuration in which the front side sheet 24 is indirectly joined to the back side sheet 22 by fixing to an intermediate member fixed to the rear side sheet 22 is included. The front sheet 24 and the back sheet 22 may be attached to each other by attachment means (not shown) such as, for example, adhesive bonding, sonic bonding, heat welding, pinning, suturing, or any other known method, and combinations thereof. ) Allows each to be fixed directly around the diaper. For example, a uniform continuous layer of adhesive, a patterned layer of adhesive, a sprinkled pattern of adhesive, or
Separate rows of arrays, swirls, or dots formed by an adhesive can be used to secure the face sheet 24 to the back sheet 22. It should be readily conceivable that the above-described attachment techniques could also be used for appropriate interconnection, assembly, and / or securing various other components of the articles described herein to one another.

The article typically shown includes a surge layer 84 and an absorbent system that includes a retainer for retaining and retaining absorbed liquids and other dirt material. In a particular form of the invention, the retention or retention is provided by the illustrated absorbent core structure 26, which consists of multiple layers of selected fibers and superabsorbent particles. The illustrated absorbent composite configuration is placed and sandwiched between the face sheet 24 and the back sheet 22 to form a diaper. Absorbent composites are generally structures that are compressible and deformable, do not irritate the wearer's skin, and have the ability to absorb and retain exudates from the body.

In various configurations of the present invention, many suitable types of hydratable, hydrophilic fabric materials can be used to form any of the various components of the absorbent article.
Examples of suitable fibers include naturally occurring organic fibers of inherently hydratable materials such as cellulose fibers, synthetic fibers of cellulose or cellulose derivatives such as rayon fibers, and inherently hydratable materials such as glass fibers. Inorganic fibers, synthetic fibers made from inherently hydratable thermoplastic polymers such as certain polyester or polyamide fibers, and synthetic fibers comprising non-hydratable thermoplastic polymers such as polypropylene fibers. These fibers may be non-hydratable, hydrophilic, for example, by treatment with silica, by treatment with materials that have suitable hydrophilic components and are not easily removed from the fiber, or during or after the fiber forming process. The fibers can be hydrophilized by shuffling with the hydrophilic polymer. It is foreseen that for the purposes of the present invention, the various types of selected blends described above can be used.

As used in this description, the term “hydrophilic” refers to a fiber or fiber surface that is humidified by an aqueous liquid that contacts the fiber. The degree of material wetting is then described in terms of the contact angle and surface tension of the material associated with the liquid. Apparatus and techniques suitable for measuring the wettability of a particular fiber material or blend of fiber materials can be provided by a Cahn SFA-222 surface force analysis system, or a substantially equivalent system. Fibers having a contact angle of less than 90 °, as measured by such a system, are designated as wettable, and fibers having a contact angle of 90 ° or more are:
Designated as non-wetting.

In particular, the absorbent core structure 30 can include one or more matrix fibers, such as natural fibers, synthetic fibers, and the like, and combinations thereof. Desirably, the fibers are hydrophilic, either naturally or by the effects of conventional hydrophilization treatments. In certain preparations, a fibrous matrix consisting of cellulosic wood pulp fluff can be included. It should be readily envisioned that each of the main layer regions 48 and 50 may include the same type of fiber matrix, or may include different types of fiber matrices.

In certain aspects of the invention, the fibers in one or more of the main layers 48 and 50 may be mixed with, or otherwise incorporated with, particles of superabsorbent material. The fibers in the selected layer or layers are disposed in an absorbent matrix, preferably
Each of the layers 48 and 50 can include fibers mixed with particles of a superabsorbent material.
For example, in certain preparations, a given layer of absorbent core 30 may comprise a fabric coform comprising a mixture of superabsorbent hydrogel shaped particles and natural fibers, synthetic polymer meltblown fibers, natural fibers and / or synthetic polymer fibers. ) Materials and mixtures thereof. The superabsorbent particles can be substantially homogeneously mixed with the hydrophilic fibers or can be mixed heterogeneously. For example, the concentration of the superabsorbent particles may be lower in the body direction of the absorbent complex and relatively higher in the outward direction of the absorbent structure, with the thickness of each layer of the absorbent structure (z Direction) can be set to a non-step gradient. A suitable z-gradient configuration is described in U.S. Pat. No. 4,699,823 issued Oct. 13, 1987 to Kellenberger et al., The entire disclosure of which is hereby incorporated (without interference) with this description. And incorporated by reference. Alternatively, the concentration of the superabsorbent particles may be higher in the body side direction of the absorbent complex and relatively lower in the outward direction of the absorbent structure, with each layer of the absorbent structure having a relatively lower concentration. Through a substantial part of the thickness (z direction), a non-step gradient can be set. In addition, the superabsorbent particles can be set in a state of a totally discrete layer in the hydrophilic fiber matrix. In addition, two or more different types of superabsorbent particles can be selectively located in or along the fiber matrix at different locations.

The superabsorbent material can include an absorbent gelling material, such as a superabsorbent. The absorbent gelling material can be natural, synthetic, and prepared natural polymer materials. In addition, the absorbent gelling material can be an inorganic material, such as silica gel, or an organic compound, such as a crosslinked polymer. The term "cross-linked" generally refers to any method that renders a water-soluble material substantially sparingly soluble, but retains swellability. Such methods include, for example, physical entanglement, crystal domains, covalent bonds,
Ionic complexes and bonds, hydrophilic bonds such as hydrogen bonds, and hydrophobic bonds
It can include a Van der Waais force.

Examples of synthetic absorbent gelling material polymers include alkali metal and ammonium salts of poly (acrylic acid) and poly (methacrylic acid), poly (acrylamide), poly (vinyl ether), vinyl ether and alpha-olefin. Includes maleic anhydride copolymer, poly (vinyl pyrrolidone), poly (vinyl morpholinone), poly (vinyl alcohol), and mixtures and copolymers thereof. In addition, suitable polymers for use in the absorbent composite are hydrolyzed acrylonitrile conjugated starch, acrylic acid conjugated starch, methylcellulose, chitosan, carboxymethylcellulose, hydroxypropylcellulose, and alginates, xan gum. Includes natural and prepared natural polymers, such as natural rubber, such as carob gum. Also, mixtures of natural absorbent polymers and all or some synthetic absorbent polymers are useful in the present invention. Other suitable absorbent gelling materials are
Asarsson et al., U.S. Patent No. 3,901,236, issued August 26, 1975. The process for preparing synthetic absorbent gelling polymers is described in Masuda et al., February 2, 1978.
U.S. Patent No. 4,076,663, issued on August 8, and Tsubakimoto et al., August 2, 1981
It is disclosed in U.S. Patent No. 4,286,082, issued on the 5th. Synthetic absorbent gelling materials are typically xerogels that form a hydrogel in the event of invasion. However, the term "hydrogel" is commonly used to refer to both wet and non-wet forms of the material.

As mentioned above, the superabsorbent material used for the absorbent core 30 can be a superabsorbent gelling material, which is generally in the form of discrete particles. be able to. The particles can be in any desired shape, for example, helical or semi-helical, cubic, rod, polyhedral, and the like. Shapes with a large maximum / minimum dimension ratio, such as needles, flakes, and fibers, may also be used here. In addition, clumps of particles of the absorbent gelling material can also be used for the absorbent composite 26. Desirable for use are particles having an average size of about 5 microns to about 1 millimeter. As used herein, "particle size" means the weighted average of the smallest dimension of each particle.

In a particular form of the invention, the absorbent gelling material particles have a gram absorption capacity of the liquid absorbed per gram of the absorption material of at least about 20 (g / g). MAUL). Desirably, the superabsorbent material has a MAUL of at least about 24 g / g, more preferably a MAUL of at least about 27 g / g. In other forms, the absorbent material can exhibit a MAUL of up to about 30 g / g or more. MAUL values can be measured using the MAUL test method described in the test procedure described herein. Hydrophilic fibers and high-absorbency particles of all the composite core 30 can be configured such that the average composite basis weight within the range of about ^{400 -900gsm (g / m 2)} . In certain aspects of the invention, the average composite basis weight is in the range of about 500-800 gsm, preferably in the range of about 550-750 gsm to provide the desired performance.

In certain aspects of the invention, the superabsorbent material can include a superabsorbent nonwoven material. Superabsorbent nonwoven materials are nonwoven materials that consist solely of superabsorbent fibers or of a mixture of superabsorbent fibers and other materials. Superabsorbent nonwoven materials have a high maximum storage capacity when immersed in a liquid, especially a 0.9% saline solution, with at least about 10 (grams) of liquid absorbed per gram of absorbent material. g / g). Alternatively, the liquid holding capacity is at least about 20 g / g, and optionally at least about 30 g / g to provide improved performance characteristics. The superabsorbent nonwoven is optionally configured to facilitate liquid uptake, liquid storage, liquid dispersion, or some combination of these functions. In particular, the superabsorbent nonwoven material is designed to perform a specific function or group of functions when the superabsorbent nonwoven material is incorporated as a layer or component in a product having a multi-layered absorbent structure. be able to.

In order to limit the unwanted migration of the superabsorbent material, the article may be, as required, in the immediate vicinity of the entire absorbent core 30, around its individual layers, or one of the absorbent composites An overlapping absorbent composite 26, such as a wrap sheet 28, can be provided around the selected components. In addition, wrap
The sheet can be bonded to the absorbent composite structure and various other components of the article. The wrap sheet is preferably a layer of absorbent material that covers the body-side and exterior major surfaces of the absorbent composite and preferably substantially surrounds the entire perimeter edge of the absorbent composite. And substantially completely seal the periphery. Alternatively, the wrap sheet may be an absorbent wrap covering the body-side and outer major surfaces of the absorbent composite and substantially surrounding only the lateral edges of the absorbent composite. Thus, both the straight and inwardly curved portions of the lateral side edges of the wrap sheet seal around the absorbent composite. However, in such an arrangement, the distal edge of the wrap sheet cannot completely seal around the distal edge of the absorbent composite in the band area of the article. For example, the complete wrap sheet 28, or at least the bodyside layer of the wrap sheet, can include a meltblown web of meltblown fibers, such as meltblown polypropylene fibers. Other examples of the absorber wrap 28 include:
The tissue may comprise a low porosity cellulose web of tissue comprising a hard wood / soft wood fiber blend ratio of about 50/50.

The absorbent wrap 28 can be comprised of a multi-part wrap sheet that includes a separate body side wrap layer and a separate outer wrap layer, each of which comprises an absorbent core 30.
Extends over all or part of the peripheral edge of Such a wrap sheet configuration may facilitate, for example, the formation of a substantially complete seal and occlusion around the peripheral edge of the absorbent core 30. Also, in the illustrated diaper rear belt portion, the absorber wrap increases the opacity at the rear side of the diaper and increases the distance from the periphery of the absorbent core to increase its strength. Can be configured. In the illustrated embodiment, the bodyside and outer layers of the absorbent wrap 28 extend at least about 1/2 inch beyond the perimeter edge of the absorbent core, creating an outwardly projecting flange-type bond area. In this connection zone, the perimeter of the body-side portion of the absorbent wrap is completely or partially connected around the outer part of the absorbent wrap.

The body side and outer layers of the wrap sheet 28 can be composed of substantially the same material or different materials. For example, the outer layer of the wrap sheet can be comprised of a relatively low basis weight material having a relatively high porosity, such as a wet strength cellulose tissue made of soft wood pulp. The bodyside layer of the wrap sheet can be composed of one of the wrap sheet materials described above having a relatively low porosity. The low porosity body-side layer can prevent the highly absorbent particles from migrating to the wearer, and the high porosity and low basis weight outer layer can contribute to cost reduction.

Referring to FIGS. 7, 8 and 9, other absorbent cores of the present invention are provided between layers of liquid permeable material 100 such as tissue open cell porous films, wovens, nonwovens, etc., and combinations thereof. A component may be provided having particles 102 of superabsorbent material held to function in the same manner. In a particular form of the invention, the bottom layer 50 can be comprised of a laminate having superabsorbent particles sandwiched or otherwise held between carrier tissues held by a water-sensitive attachment. . An example of this configuration is shown in U.S. Pat.No. No. 5,593,399 (Attorney Docket No. 10,902.1), the entire disclosure of which is hereby incorporated by reference in its entirety.

Referring again to FIGS. 1 and 2, the diaper 20 may further include a surge control layer 84 to assist in the deceleration and diffusion surge of the liquid directed to the holding and storage of the absorbent article. For example, the surge layer 84 can be provided on the body-side surface facing the inside of the front-side sheet layer 24. In the configuration typically shown, the surge layer 84
It can be provided adjacent to the outer surface of the front side sheet layer. Therefore, the surge layer is inserted between the front side sheet 24 and the absorbent core 30. An example of a suitable surge control layer 84 is C. Ellis and D. Bishop, 1994, issued as U.S. Patent No. 5,486.166.
U.S. Patent Application No. 206,986 entitled "Non-woven Web Surge Layers for Personal Care Absorbent Articles" filed on Mar. 4, 2016 (Attorney Docket No. 11,256), and US Patent No. 5,490,846. As described in US Patent Application No. 206,069 to Ellis and R. Everett, filed Mar. 4, 1994, entitled "Improved Surge Controlled Nonwoven Web for Personal Care Absorbent Articles," filed on Mar. 4, 1994. All of these descriptions are hereby incorporated herein by reference in a consistent manner.

Referring to FIGS. 1 and 2, certain embodiments of the present invention may include an absorbent composite comprising a selected plurality of two or more main layer region components. For example, the configuration of the illustrated multilayer absorbent core 30 includes a first layer region 48 and at least a second layer region 50. A first layer region 48, typically shown, is located on the body side region of the absorbent core 30 and provides a relatively upper layer region relatively closer to the face sheet layer 24. The illustrated second layer region 50 is located on the outer region of the absorbent core and is
Provide a relatively lower layer area, relatively closer to 2.

In a preferred form of the invention, components in various layer regions, such as layer regions 48 and / or 50, can include blends or other matrix high volume fibers. High volume fibers are those that have been provided with improved retention volume and / or resilience from deformation. High volume fibers can provide wet retention volume and / or wet deformation recovery, especially when incorporated into the material to which the fibers are to be wetted. Examples of suitable high volume fibers include synthetic thermoplastic fibers, synthetic fibers composed of natural polymers such as cellulose, natural fibers, and combinations thereof. The elasticity of fibers composed of natural polymers can be increased by chemical crosslinking and / or by imparting kink and / or curl to the fibers.

High volume fibrous materials can exhibit low densities, both in their wet and dry states, thereby increasing permeability and thickness, and increasing flow conductance values.
For example, high volume wood pulp fibers can be embodied by a variety of techniques, such as chemical and / or mechanical preparation of pulp fibers. Examples of suitable high volume fibers include mercerized fibers, cross-linked cellulose fluff pulp fibers, and the like, and combinations thereof.

In another form of the invention, the components in the various layer regions, such as layer regions 48 and / or 50, comprise blends or other matrix high volume fibers, and controlled rate super absorbent material. it can. Controlled-rate superabsorbents are materials such as superabsorbent polymeric materials that exhibit a minimum on-load absorption capacity (MAUL) of at least about 20 g / g.

In a further aspect of the present invention, the desired controlled rate superabsorbent is at least about
A specific absorption rate, such as a tau value of 0.2 min, a tau (τ) value can be indicated. Desirably, the tau value of the superabsorbent is at least about 1 min and can be at least about 2 min to provide improved performance. In yet another form,
Tau values can be up to about 40 minutes or more. In other embodiments, the absorbent core, and in particular the different layer regions of the absorbent core, can advantageously incorporate a combination of selected superabsorbent materials, wherein at least a selected pair of different superabsorbent materials. Is configured to have a tau ratio of about 2: 1 or more. Optionally, the tau value ratio can be up to about 5: 1 or more to provide additional benefits. A superabsorbent material having a relatively large tau value is preferably located relatively close to the bodyside surface of the absorbent core. A suitable technique for measuring the tau value of each superabsorbent is described in the "Flood Absorbency Under Zero Load" procedure set forth in this description.

Certain controlled rate superabsorbents are superabsorbents in which individual superabsorbent particles have been treated with a hydrophobic coating so that each particle has a selected delay in the absorption of aqueous liquids. For example, the superabsorbent can be a coated particulate superabsorbent. The particles have an absorbent core consisting of a partial sodium salt of cross-linked polyproponic acid (prepared by the process described in U.S. Pat. Covered by A typical controlled rate superabsorbent of this type is available from Dow Chemical Company, an office in Midland, Michigan, USA.

[0069] Alternative controlled-rate superabsorbents can be configured with relatively large particle sizes to provide particles having a low surface area / volume ratio, thereby creating the desired absorption. Also, the controlled rate superabsorbent particles can have a substantially spherical or other three-dimensional shape that operatively produces the desired low surface area / volume ratio and delayed absorption. In addition, the chemical volume of the superabsorbent polymer can be adjusted to provide the desired rate of absorption delay. For example, a controlled-rate high absorber can incorporate an anionic polyelectrolyte that is reversibly crosslinked by a polyvalent metal cation. The water-soluble complexing agent can be configured to reverse the crosslinking.

Alternative controlled rate superabsorbents functionally slow the diffusion of liquid into the superabsorbent particles, or are coated by a liquid repellent coating or other treatment, in a form that provides the desired rate of absorption delay can do. The coating or treatment can be elastic or inelastic, and the coating or treatment can be hydrophobic or hydrophilic. The coating can erode, dissolve, or degrade in a controlled manner to provide the desired rate of absorption delay. Optionally, the absorption rate may be adjusted by adjusting the neutralization rate of the selected superabsorbent material or by the chemical mechanism used to create the neutralization of the selected superabsorbent material. It can be limited and / or controlled by adjusting or otherwise controlling.

Another form of determining the absorbency under load of superabsorbents (AUL) is described in J. Qin et al., “Prepared Polysaccharides with Improved Properties and Methods of Preparing the Same,” Aug. 26, 1996. This is described in U.S. Patent No. 5,550,189 issued to Japan and U.S. Patent Application No. 621,390, filed March 25, 1996 (Attorney Docket No. 10,838.2) entitled "Absorbent Complex" by M. Melieus et al. All of these disclosures are incorporated herein by reference in a consistent manner.

Referring to FIGS. 2 and 2A, the first layer region 48, which is typically shown, allows for the controlled rate absorber, and the rapid uptake of liquid, while allowing the liquid to move relatively outside of the absorber. High volume wood pulp or other woven or nonwoven fabrics having a pore size distribution that maintains the liquid in this structure until absorbed by one or more layers in the direction can be included. The components in the first layer region 48 can be arranged to substantially cover a predetermined target area 52 of the product into which liquid such as urine is introduced into the absorbent structure. Therefore,
The first layer region 48 functionally corresponds to a predetermined intake layer region of the absorbent core. The layer area 4
8 can be rectangular, non-rectangular, or irregularly shaped, but is preferably no larger than the underlying region, such as second layer region 50. In a preferred embodiment of the present invention, the first layer region is made smaller than the underlying second layer region. For example, substantially the entirety of the first main layer region starts at a laterally extending line located about 7% of the core length inward from the foremost edge of the absorbent core, and begins at the foremost edge of the absorbent core. From the inside to a laterally extending line located at about 62% of the core length. In addition, the longitudinally extending side edges of the first layer main region can substantially completely overlap the corresponding side edges of the second layer main region.

Further examples of alternative absorbent structures are typically shown in FIGS. In certain aspects of the invention, first layer region 48 may include a composite structure having a plurality of composite sub-layers. FIGS. 3 and 3A show an absorbent core structure having a first front layer region 48 extending over a middle portion of the entire absorbent core 30 and a second bottom layer region 50 extending substantially over the entire absorbent core. A plan view is shown as a representative. The second layer region 50 has a relatively greater basis weight at the longitudinally opposed ends to provide a vertical inversion of the lower second layer region, particularly the target area, to be segmented. It is uneven and has a basis weight distribution by area. Also, the selected intermediate portion of the second layer region 50 has a basis weight that is lower than the basis weight of the adjacent overlapping first layer region 48 to provide a reversed thickness in the target region. be able to. At least in the crotch portion of the absorbent core 30, the surface side layer region 48 substantially completely overlaps the side edge of the second layer region 50. Each of the longitudinal distal edges of the first layer region 48 is inwardly spaced from a corresponding distal edge of the second layer region 50.

FIGS. 4 and 4A show an absorber having a front side layer region 48 that covers the entire front side, ie, the first part, of the bottom side layer region 50 but never covers the entire back side, ie, the second part, of the bottom side layer region. The core is shown representatively. The lateral side edge and at least one longitudinal end edge of the first layer 48 substantially completely overlap the lateral side edge and at least the longitudinal end edge of the second layer region 50. In the illustrated configuration, at least one longitudinal end edge of the first layer region 48 is
It is spaced inwardly from the corresponding distal edge of the two-layer region 50.

FIGS. 5 and 5A exemplarily show an absorbent core structure having a front side layer region that entirely covers the bottom side layer region. The configuration shown has a first layer region 48 and a second layer region 50 having substantially the same thickness and basis weight, but alternatively, the first and second layer regions As with other differences, they have different thicknesses and basis weights.

FIG. 6 shows a plane view of another absorbent core having a lateral dimension smaller and narrower than the bottom layer area and having a shorter longitudinal dimension than the bottom layer area. The figure is shown as a representative. In the configuration shown, for example, substantially the entire outer periphery of the first layer region 48 is spaced inwardly from substantially the entire outer periphery of the second layer region 50. In various configurations of the present invention, the high control absorbent material can be configured to help control the liquid retention in the various bed areas of the absorption system. Controlled-rate superabsorbents can be produced solely as a result of the presence of a controlled-rate superabsorbent material (SAM), or mixed with superabsorbents and other materials to provide a controlled rate superabsorbent composite. It is possible to control the liquid storage rate in the absorbent. High-absorbency composites or high-absorbency composites using high-absorption composites are particularly useful in multi-layer absorbent cores when the high-absorption composites or high-absorption composites are in use. If configured to promote preferential saturation in one or more other layer regions, it can be used as an absorbing layer region in a multi-layer absorbent material. By using a combination of high volume fiber and controlled rate high absorbent material, the saturation in the first layer region 48 can be kept below the saturation level of the other absorbent layer regions, and as a result, the first layer region It produces a high void volume and permeability at 48, and also provides desirable flow conduction values.

Also, composites and superabsorbents composed of high volume fibers, especially pulp fibers, can be prepared by introducing a stabilizer into the composite. Structural stability can be used to maintain or minimize the change of a particular material structure or composite material structure when it is exposed to external or internal forces. Structural stability mechanisms can benefit any layer region within a multi-layer absorbent material when exposed to the forces applied during use to products incorporating the multi-layer absorbent core. . This is due to the intended function of the layer area: liquid intake (generation of void volume),
It will help maintain liquid storage, liquid dispersion, or some combination of the three. Various types of suitable material technologies can be used to stabilize the absorbent structure. For example, stabilization can occur either in the form of chemical stabilization, such as Kymene or other cross-linking agents, or by the introduction of thermoplastic binder fibers and the like.

In various forms of the invention, the upper layer region 48 can be comprised of a fibrous material based on woven or nonwoven technology. As in the previously described aspects of the invention, these materials provide maximum void volume and permeability while controlling the movement of liquids and maintaining sufficient capillary tension to prevent leakage. Will be configured. For example, the absorbent core of the present invention can incorporate a nonwoven material as a functional component of the surface layer region 48. Bonded and carded webs are examples of certain fibrous materials that can be configured to provide an appropriate balance of permeability and capillary action. By selecting the staple fiber option, a composite structure can be created that preferentially saturates the bottom absorbent layer 50. this is,
This can be done by either the physical structure of the surface side layer, the chemistry of the control surface, or both. The porosity of the fiber structure can be determined by the particular fiber and the selected fiber size. Also, the choice of fibers can affect the capillary action of the material.

Suitable card structures have been created from a wide variety of fiber types and various fiber sizes. Fibers can be made from synthetic fibers and naturally occurring materials. The fibers for the first layer 48 are desirably very wettable, and natural cellulose materials such as rayon or cotton can be used. Synthetic fibers such as polyesters and polyamides have limited wettability that can be enhanced by hydrophilic finishes or treatments.
Card nonwovens can have a wide range of fiber diameters, but desirable structures include fibers having a diameter of less than 25 microns. The card material for the first layer 48 can be made at a density of about 0.03 g / cc or less and in a weight range of about 50 to 200 grams / square meter (gsm). The density of the fiber material ultimately depends on the method used to bond or stabilize the fiber.

The card web can be stabilized by various methods. Thermoplastic staple fibers are used in some cases such that their structures are bonded using heat and pressure. Proper application of heat and pressure during thermal bonding can create structures that are stabilized with very specific permeability and capillary action. The card structure can also be stabilized using a chemical resin or an adhesive. In addition, the choice of specific resin and adhesive loadings and cures will facilitate control of the final web properties that affect permeability and capillary action. Wettability can be affected by the choice of chemical resin system for bonding. The card structure can be mechanically stabilized using means such as water, puncture, air, etc. to entangle the fibers. Further, these processes can be controlled in such a way as to make the physical attributes of the material desirable.

Certain aspects of the present invention may incorporate spunbonded fabrics having properties similar to those described above. Still other aspects of the invention include selectively segmenting fiber size, basis weight, or other properties of the material to provide desirable performance attributes. In addition to carded and melt spun fiber webs, airlaid fiber materials can also be used.

The material of the components in the first layer region 48 can be the total amount, the basis weight, the density, and the like described below. A typical basis weight of the absorbent core structure area located in the front half of the article can be from about 750 gsm to about 950 gsm. In the first layer area described above, about 25% to about 7% of the total composite basis weight in those areas where the first layer exists.
It can be set to any value up to 5%. This ratio is strongly governed by the materials used and their relative capabilities. The super absorbent material is made of fluffy fiber and
Materials such as those used in combination with certain staple fibers will typically have an initial density of 0.1 g / cc to 0.3 g / cc. Materials that are synthetic-based card webs or meltspun webs can be about 0.015 g / cc to 0.3 g / cc
And preferably has a density of about 0.2 g / cc. Synthetic fiber webs will typically have a fiber size of less than 3 denier, preferably 1 to 2 denier, and are treated by some wetting agents to exhibit a low contact angle with water. . This treatment desirably does not reduce the surface tension of the liquid passing through the fibrous web.

Other non-woven structures are also suitable for use as the upper layer region 48 in the absorbent system of the present invention. A proper balance of the absorption and capillary action of the underlayer region can ensure preferential saturation of the underlayer region through multiple liquid surges. It is also possible to envisage using other lower layer regions with better dispersion capacity. This will assist in the detachment of the liquid from the nonwoven upper layer region and will improve the performance after the next liquid assault.

A preferred form of the invention is capable of providing a liquid guidance value of at least about 38%.
Wear. Another preferred form has a liquid guidance value of at least about 24% and at least about 4 × 10 ^-6 cm^ThreeCan provide a flow conduction value. In yet another aspect, the present invention provides a method comprising at least about 14 * 10^-6cm^ThreeAnd the combined conduction and guidance value (C).

The desired combined conduction and guidance values can provide an advantageous balance of liquid handling characteristics. In particular, this combination can provide the desired balance between rapid uptake of liquid and rapid transfer of absorbent liquid from the target intake area to a more remote area of the absorbent structure. Conventional structures do not have the desired combination of properties. Therefore,
A structure that provides the desired rapid uptake does not provide a sufficiently rapid transfer of the absorbing liquid far from the intake area, and a structure that provides the desired rapid transfer of the absorbing liquid far from the intake area is liquid. Was not a quick enough take-up. As a result, its ability is to cause excessive saturation early in the absorption target area, i.e., to store excessive liquid on the wearer side.

In certain forms of the invention, the first layer region 48 typically extends across the longitudinal middle of the entire core region, but optionally extends across the entire core region if necessary. It can be a body side layer on the surface side where it can be made. Typically, the frontside layer is a layer that optimizes uptake performance and may or may not have a desired level of liquid guiding or dispersing performance. The first layer region can typically have a minimum basis weight of about 100 gsm or more, and desirably a basis weight of about 300 gsm or more. In a further aspect, the first layer region can typically have a maximum basis weight of about 700 gsm or less, and desirably a basis weight of about 600 gsm or less.

The first layer region typically contains a minimum of about 50% by weight (wt%) or more of fiber material, and desirably about 60% or more by weight of fiber material. In other forms, the first layer portion can typically include up to about 80% by weight or less of fiber material, and desirably
It can include about 70% by weight of fiber material. The fibrous material may be natural or synthetic in nature. The fiber material can have a minimum fiber size of at least about 4 microns, particularly a diameter, and desirably has a fiber size of at least about 10 microns. In a further aspect, the fibrous material can have a fiber size up to about 20 microns or less, and desirably has a fiber size of about 15 microns or less.

The first layer portion may contain a minimum of about 20% by weight or more of the superabsorbent material, and preferably contains about 30% by weight or more of the superabsorbent material. In additional aspects,
One layer portion can include up to about 50% by weight or less of superabsorbent material, and desirably
It may contain 0% by weight of superabsorbent. The superabsorbent material can have a minimum dry particle size of about 110 microns or more, and desirably a dry particle size of about 300 microns or more. In another form, the superabsorbent material can have a maximum dry particle size of about 1000 microns or less, and desirably a dry particle size of about 700 microns or less. In addition, about 20g /
It may have a MAUL value of greater than or equal to g, and may desirably have a MAUL value of greater than or equal to about 25 g / g. In addition, the MAUL value can be up to about 30 g /
It can be up to g or more. In yet another form, the superabsorbent material can have a tau value of at least about 0.8 minutes, and can have a tau value up to about 40 minutes.

The first layer region 48 can typically have a minimum average density of at least about 0.03 g / cc, and desirably has a density of at least about 0.05 g / cc. In another aspect, the first layer region can have a maximum average density of about 0.4 g / cc or less, and desirably has a density of about 0.2 g / cc or less. The first layer region includes a tissue layer used to hold together the materials provided in the first layer region, ie, functioning as a carrier mechanism. For example, several layers of tissue can be used to hold the superabsorbent material laminated between the tissue layers.

Various configurations of the present invention include certain functionalized materials within selected layers of the absorbent structure. An example of a suitable uptake material is R. Anderson et al., Filed Nov. 22, 1996, entitled "Multifunctional Absorbent Materials and Products Made Therefrom" (Attorney Docket No. 12,442
US Patent Application No. 754,414, and LH Sawyer et al., US Provisional Application Number 23,1997, filed December 23, 1997, entitled "Pulps and Super Absorbent Complexes for Improved Uptake Function" (Attorney Docket No. 13,041). Patent Application No. 068,534 including the described materials. This entire disclosure is incorporated herein by reference, consistent with this description.

Referring to FIGS. 2 and 2A, the second layer region 50 comprises a mass or matrix of hydrophilic fibers, such as wood pulp fibers, and a selected amount, such as Coosa 1654 and Stockhausen Favor 800 superabsorbent. High gelling material. These materials are typically blended or otherwise combined such that about 20-80% by weight of the composite is composed of the superabsorbent material. Also, the preparation of this material can be tailored to provide improved product performance. This preparation can include the use of prepared pulp fibers to produce an improvement in the dispersion of the liquid, or the use of stability techniques to control the structure and produce improved guiding performance. Possible methods for stabilization include, but are not limited to, the use of Kymene or other cross-linking agents, or the introduction of thermally activated binder fibers. Structural stabilization is a technique used to maintain or minimize changes in the structure of a material or composite of materials when the material is exposed to external or internal forces. Various approaches such as the incorporation of thermoplastic binder fibers, chemical crosslinkers (such as Kymene), and the like, and combinations thereof, can be used to stabilize the absorbent structure.

A material that is functionally configured to have the ability to provide improved dispersion of the liquid over the target area can provide the desired functional result. These materials can be comprised of a laminate comprising superabsorbent particles and at least one fibrous web specifically configured to exhibit improved guided flow performance. Suitable preparation of the second layer region 50 includes, but is not limited to, laminating a particulate or fibrous superabsorbent web with a cellulosic tissue material or other stabilized fibrous web. Other suitable fiber webs include wet laid
It may include tissues, airlaid materials incorporating synthetic or natural staple fibers, treated meltblown webs, and types of fibrous webs used to construct the first layer region 48. Other types of materials that can be used to provide improved functionality are superabsorbent particles or fibrous webs, and laminates of hydratable open cell foam.

The second layer region 50 can be arranged in various suitable configurations. For example, the second layer region can be in the form of an absorbent pad that is individually provided immediately adjacent to the first layer region 48. Desirably, the second layer region 50 is in substantially direct contact with the first layer region 48, but instead is a selected layer inserted between the first layer region 48 and the second layer region 50. Can be located away from the upper layer area with one or more layer areas of the material. In a particular form of the invention, the second layer region 50 is configured to allow maximum utilization of the absorption for the incoming liquid, while maintaining product attributes that are attractive to the customer.

[0094] In a further aspect, the second main layer region may have a longitudinal extent greater than the longitudinal extent of the first main layer region. Further, the second main layer region can have a lateral extent that substantially completely overlaps the first main layer region. An alternative configuration can include a second main layer region having a lateral extent less than the lateral extent of the first main layer region. For example, the lateral extent of at least a portion of the second main layer region can be about 30% or more of the lateral extent of a corresponding adjacent portion of the first main layer region. Other configurations are
It may include a second main layer region having a lateral extent greater than the lateral extent of one main layer region. For example, the lateral extent of at least a portion of the first main layer region can be about 30% or more of the lateral extent of a corresponding adjacent portion of the second main layer region.

The component materials of the second layer region 50 can be provided in various functional totals, basis weights, densities, and the like. For example, the second main layer region can have a substantially uniform basis weight, or desirably a non-uniform basis weight selected. In addition, the second layer area 50 can comprise about 25% -100% of the total composite basis weight of the absorbent core structure at one location, typically from about 0.1 g / cc to 0.3%. It can have a density in the range of g / cc. In yet other embodiments, the second layer region portion 50 can include a plurality of two or more component sublayer regions, wherein each of the component sublayer regions is a selected physical and sublayer region. Has a combination of functional properties.

In certain embodiments of the invention, at least one layer region of the absorbent core 30 has a thickness of about 16
% Is a dispersed layer that can provide liquid guidance values of at least%. In addition, the dispersion layer
It has a perimeter boundary and area that extends beyond and through a predetermined target area 52 of the absorbent composite. The distribution layer can advantageously provide certain important functions. The first function involves holding and moving the liquid away from the target area, and the second function involves a short enough time (liquid assault) to compensate for the void volume shortfall associated with the fabrication of thin products. ) To provide high absorption capacity. The structural elements of this layer include SAP content, component basis weight, and component density. Examples of materials with high liquid guiding performance include:
This disclosure is described in U.S. Patent No. Incorporated by reference.

The second layer region 50 can include a bottom layer and can typically extend across the entire area of the entire absorbent core 30. The second layer region 50 is typically designed to have a volume of dispersion or guiding capacity of the absorbent core, and thus typically extends beyond the edge of the area covered by the first layer region 48, It is made to extend through. Within the absorbent core target area 52, the second layer region can typically have a basis weight of about 100 gsm or more, and desirably have a basis weight of about 150 gsm or more. In a further aspect, the target area of the second layer region can have a basis weight of about 700 gsm or less, and can desirably have a basis weight of about 250 gsm or less. In the non-target portion outside the target area of the second layer region 50, the second layer region can typically have a basis weight of about 300 gsm or more, and desirably a basis weight of about 450 gsm or more. Can be provided. In a further aspect, the non-target portion of the second layer region outside the target area is the second target.
The layer area can typically have a basis weight of about 800 gsm or less, and desirably
It can have a basis weight of about 550 gsm or less.

The second layer typically comprises at least about 50% by weight of the fibrous material, desirably about 6% by weight.
Contains 0% by weight or more of fiber material. In another form, the second layer portion typically comprises about
It contains no more than 95% by weight of fiber material, desirably no more than about 70% by weight. The fibrous material may be natural or synthetic in nature. The fibrous material can have a fiber size of at least about 4 microns, specifically a fiber diameter, and desirably has a fiber size of at least about 10 microns. In another form, the fiber material can have a fiber size of about 20 microns or less, and desirably has a fiber size of about 15 microns or less. In addition, the fiber material can have a contact angle with water of about 70 degrees or less, and desirably has a contact angle with water of about 50 degrees or less.

Further, the second layer portion can contain about 5% by weight or more of the superabsorbent material, and preferably contains about 15% by weight or more of the superabsorbent material. In an additional aspect, the second layer portion can include up to about 50% by weight of the superabsorbent material, and can desirably include about 40% by weight of the superabsorbent material. Superabsorbent materials can have a dry particle size of about 110 microns or more, and desirably have a dry particle size of about 300 microns or more. In another form, the superabsorbent material can have a dry particle size of about 1000 microns or less, and desirably a dry particle size of about 700 microns or less. In addition, the superabsorbent material can have a MAUL value of about 20 g / g or more, and desirably a MAUL value of about 25 g / g or more. In addition, MAUL values can be up to about 30 g / g or more to provide improved benefits. In yet another form, the superabsorbent material can have a tau value of at least about 0.67 minutes, and desirably a tau value of at least about 2 minutes.

An advantageous configuration of the present invention has a liquid guidance value of at least about 36% and
A second layer region 50 containing a superabsorbent material having a tau value of 0.4 minutes or more can be included.
Other advantageous preparations have a liquid guidance value of at least about 16% and a
A second layer region containing a superabsorbent material having a tau value of at least one minute can be included.

In certain embodiments of the present invention, the superabsorbent material in the first layer region 48 comprises the second layer region
It is configured to have a tau value approximately twice that of the tau value of the superabsorbent provided at 50 (tau value ratio of approximately 2: 1). The tau ratio can alternatively be at least about 2.5: 1, and optionally can be at least about 3: 1 to provide the desired properties. In other embodiments, the combination of superabsorbent materials in the first and second layer regions can be configured to provide a tau ratio of up to about 10: 1; alternatively, the combination of superabsorbent materials may be , Up to about 40: 1, or more.

[0102] The second layer region 50 can typically have an average density of at least about 0.1 g / cc, and desirably has a density of at least about 0.15 g / cc. In another aspect,
The second layer region can have an average density of about 0.3 g / cc or less, and desirably about 0.
It has a density of 25 g / cc or less. For a particular appraisal, the average density can be about 0.2 g / cc. The second layer region includes a tissue layer that is used to hold together the material provided in the second layer region, ie, functions as a carrier mechanism.
For example, several layers of tissue can be used to hold the superabsorbent material laminated between the tissue layers.

In certain aspects of the invention, the at least one main layer region comprises one or more liquid-permeable materials 100, such as an air-dried, non-shrinkable (UCTAD) sheet material, which functions like a dispersing material. Can be included. For example, the sheet material can be a fiber tissue, and in a preferred configuration, the second of the absorbent core.
The selected UCTAD material can be incorporated into the two main layer regions. Suitable UCTAD material, the width of material per inch, a basis weight per 1 g / m ^2, the liquid material per minute is 0.002 grams, comprise a flow characteristics characterized by liquid flow rate at the height 15cm Can be. UCTAD material has at least a basis weight of about 50 g / m ^2, about 0
It has a density in the range of .08-0.5 g / cc. Desirably, the density is in the range of about 0.1-0.3 g / cc. The transmittance of UCTAD is in the range of about 50-1000 Darcys. UCTAD
Material, the force of the material per inch stacked on the total basis weight of 200 g / m ² has a dry tensile strength of at least 5000 grams.

Suitable UCTAD materials are described in US Patent Application No. 08/767, filed December 17, 1996 (Attorney Docket No. 12,267), entitled "Absorptive Structures for Liquid Dispersion" by J. Dutkiewicz et al.
, 645, the entire disclosure of which is incorporated herein by reference, consistent with this description.

Referring to FIG. 8, the second main layer region 50 includes a non-uniform plurality of sub-layer portions 62 assembled.
And 64 can be a complex. In the configuration shown, for example,
The first sub-layer portion 62 can extend substantially throughout the area covered by the absorbent core 30, and a pair of second sub-layer portions 64 includes The absorbent core 30 is disposed adjacent to the body side surface of the first sublayer 62, extending over a selected portion of the entire surface area. The configuration shown has second sub-layer portions 64 spaced longitudinally, and as shown, each sub-layer portion 64 has an associated absorbent core 30 associated therewith.
Substantially completely overlaps the longitudinal ends of the. As a result, the middle portion in the vertical direction has a basis weight lower than the basis weights of the two vertically opposed end portions of the main layer region 50, so that the second main layer region 50 becomes It can have a quantity distribution.

In certain aspects of the invention, at least one of the sublayers comprises a laminate having one or more layers of air-dried, non-shrinkable (UCTAD) sheet material, such as a UCTAD tissue. Can be. For example, a desirable configuration can include a first sub-layer 62 of an absorbent core, wherein at least a pair of cooperating UCTAD sheet materials has a dispersed layer of superabsorbent particles 102 therebetween. Are configured and arranged to sandwich An additional layer of dispersed material, such as an additional layer of UCTAD sheet material, may be used to further sandwich the layer of superabsorbent particles 102 within the first sub-layer 62, as typically shown in FIG. it can.

In another aspect, one or the other of the second sub-layer portions 64 comprises a pair of cooperating UCTAD sheet material layers configured and arranged to sandwich a dispersed layer of superabsorbent particles therebetween. Can be included at least. An additional layer of dispersive material, such as an additional layer of UCTAD sheet material, can be used within the second sub-layer 64 to further sandwich a layer of superabsorbent particles therebetween.

Referring to FIG. 9, the second main layer region 50 may alternatively have a basis weight distribution of the superabsorbent particles,
By being selectively sectioned, it is possible to include a composite whose basis weight can be changed particularly along the longitudinal direction of the second main layer region 50. As a result, in the second main layer region 50, the middle portion in the longitudinal direction of the layer region 50 has a basis weight of the high-absorbent material that is lower than the basis weight of the two vertically opposed end portions of the second main layer region 50. This can have a segmented basis weight distribution of the superabsorbent. A further description of various configurations of the present invention can be found in R. Everett et al., US Patent Application Ser. R. Everett et al., US Patent Application Ser. Filed on June 12, 1998 entitled "Layered Absorbing Structure with Non-uniform Layer Region" (Attorney Docket No. 13,
507) by US patent application Ser. No. 09 / 096,653. This entire disclosure is incorporated herein by reference, consistent with this description.

Referring again to FIG. 1, leg elastic material 34 is provided on the lateral side edges 110 of the diaper and is adapted to attract and hold the diaper 20 against the wearer's legs.
Since the elastic member is fixed to the diaper 20 in a state of being elastically contracted, the elastic member effectively contracts the diaper 20 in a normal stretched configuration. The elastic member can be fixed in an elastically contracted state in at least two ways, for example, the elastic member can be stretched and fixed in a state where the diaper is not contracted. Alternatively, the diaper 20 can be retracted, for example, by crimping, so that the elastic member can be secured and connected to the diaper 20 in a relaxed, ie, uncompressed state. Still other mechanisms, such as heat shrinkable elastic members, can be used to gather the clothing.

In the embodiment shown in FIG. 1, the leg elastic material 34 extends essentially along the entire length of the middle crotch 42 of the diaper 20. Alternatively, the elastic member 34 can extend the entire length of the diaper 20 or other lengths that provide for the adjustment of the elastic shrink line required for a particular diaper design. The elastic member 34 can have various configurations. For example, the width of the individual elastic members can vary from about 0.25 mm (about 0.01 inch) to about 25 mm (about 1.0 inch) or more. The elastic member may be comprised of a single strand of elastic material, or may be provided in a linear or curved arrangement of some elastic material. Where the strands are non-parallel, two or more strands may cross or otherwise interconnect within the elastic member. The elastic member can be fixed to the diaper by any of the known methods. For example, the resilient member can be an ultrasonic bond, a heat and pressure shield using various bond patterns, or a spray of an adhesive such as a hot melt adhesive, an adhesive bond by a swirl pattern.

[0111] In certain embodiments of the present invention, the leg elastic material 34 may comprise a carrier sheet to which a grouped set of elastics comprising a plurality of individual elastic strands is attached. The elastic strands may intersect or intersect each other, or may be completely separated. The carrier sheet can be, for example, a 0.002 cm thick polymer film, such as a film of unembossed polypropylene material. The elastic strands can be composed of, for example, LYCRA elastomer sold by DuPond, an office in Wilmington, Delaware, USA. Each elastic strand is typically in the range of about 470-1500 decitex (dtc) and may be about 940-1050 dtx. In certain embodiments of the invention, for example, three or four strands may be used for the elastic legs.

In addition, the leg elastics 34 may be generally straight or optionally curved. For example, the curved elastic body can be curved in an inward direction toward the longitudinal center line of the diaper. In certain adjustments, the flexure of the elastic body may not be configured or arranged symmetrically with respect to the lateral centerline of the diaper. The curved elastic body may be a reflective type curve that is curved inward and outwardly curved, and the longitudinal center of the elastic body is at a selected distance, either forward or rear of the diaper. Optionally, it may be offset in either direction of the side belt portion to provide a desirable feel and appearance. In certain embodiments of the present invention, the innermost point (apex) of the curved elastic can be offset in either direction of the front or back belt portion of the diaper, and has an outwardly curved bow. The reflector can be located in the direction of the front belt of the diaper.

As typically shown, the diaper 20 may include a waist elastic portion 32 provided on one or both longitudinal edges of the front beltle portion 38 and the rear belt portion 40. The waist elastic may be constructed of a suitable elastic material, such as an elastomeric film, elastic foam, composite elastic strand, elastic cloth, and the like. For example, a suitable elastic waist construction is described in US Pat. No. 4,916,005 to Lippert et al.
, The entire disclosure of which is incorporated herein by reference, consistent with this description.

The diaper 20 can also include a pair of elastic wrap flaps 62 that extend substantially longitudinally along a longitudinal direction 86 of the diaper. The wrap flaps are typically located laterally inward from the leg elastics 34 and are provided substantially symmetrically in the longitudinal direction of the diaper, i.e., on each side of the longitudinal centerline. . In the arrangement shown, each encasement flap 82 has a substantially fixed end 81 and a substantially moveable end 83 so that each encasement flap fits comfortably on the body of the recipient. To give,
Functionally give elasticity. Examples of suitable containment flap structures are described in K. Enloe U.S. Pat.No. 4,704,116 issued Nov. 3, 1987, the entire disclosure of which is incorporated herein by reference. . The wrap flap can be comprised of a wettable or non-wettable material as required. Further, the encapsulating flap material can be liquid impervious, gas only permeable, or both gas and liquid permeable. You can also. Another suitable wrap flap configuration is disclosed in R. Everett et al. U.S. Patent Application No. 206, filed March 4, 1994, entitled "Absorbent Article With Improved Surge Control.
816 (Attorney Docket No. 11,375), now U.S. Pat. No. 5,562,650, the entire disclosure of which is incorporated herein by reference.

In an alternative alternative construction of the present invention, diaper 20 is disclosed in U.S. Pat. Laux et al., U.S. patent application Ser. May be provided with a resilient encased waist flap, such as that disclosed in a patent incorporated herein by reference. Like the structure of the wrap flap,
The encased waist flap can be constructed of a wettable or non-wettable material, as desired. The waist flap material can be liquid impervious, gas only permeable, or both gas and liquid permeable. .

In order to provide a refastenable fastening system, the diaper 20 may include a fastener tab.
A predetermined landing area 78 (eg, FIG. 1A) can be provided that can provide a functional target area for receiving 44 removable fixtures. In certain embodiments of the present invention, the landing area patch can be located on the outer surface of the backing sheet layer 22 and can be provided on the front belt portion 38 of the diaper. The fastening mechanism between the landing area and the fastener tab 44 can be adhesive, cohesive, mechanical, or a combination thereof. Removable,
Structures that use an interlocking mechanical fastening system can be, for example, landing areas 78
Above, a first portion of the mechanical fastener can be provided, and on fastener tab 44, a second cooperating portion of the mechanical fastener. For example, using a hook end loop fastener, hook material 46 can be functionally connected to fastener tab 44 and loop material 80
Can be functionally connected to the landing area 78. Alternatively, the loop material can be operatively connected to the fastener tab 44 and the hook material can be operatively connected to the landing area.

In various embodiments of the present invention, the tape fastener tabs 44 are
One or both lateral distal edges 116 and 118 may be provided on one or both. For example, in the exemplary embodiment shown, one of the fastener tabs 44 is provided on each of the remote side edges of the back belt portion 40. Further, the back sheet layer 22 is
It may have a predetermined fastener landing area 78 located on the outer surface of the backing sheet layer.

Referring to FIG. 1, the article may include a side panel system 90. In a particular form, each side panel 90 has at least one opposed side of the belt portion of the back sheet 22, such as the back band portion 40, as typically shown, to provide a lateral terminal area for the article. Extends laterally from the lateral end. In addition, each side panel may be substantially distanced from the laterally extending terminal belt edge 106 to its associated location only slightly and to the corresponding diaper leg opening area. it can. The diaper 20 has, for example, a pair of laterally opposed leg openings formed by predetermined intermediate sections of the illustrated pair of longitudinally extending side edges 110 (FIG. 1). Each side panel can extend over a longitudinal distance of at least about 4 cm and, optionally, over a longitudinal distance of at least about 5 cm, or alternatively, have improved fit. To provide, it can extend over a distance of at least about 6 cm. In various configurations of the present invention, the side panels can be integrally formed with selected diaper components.
For example, the side panels 90 can be integrally formed from a layer of material that provides the backsheet layer 22 or from the material used to provide the facesheet 24. In an alternative configuration, between the backsheet and the frontsheet, and in various fixedly mounted combinations of such assemblies, the side panel 90 connects to the backsheet 22, the frontsheet 24. And can be provided by one or more separate components assembled.

In certain configurations of the present invention, each of the side panels 90 may be formed from separately prepared pieces of material that are then suitably assembled and attached to predetermined front and / or rear belt portions of the diaper product. it can. In the illustrated embodiment of the invention, for example, each side panel 90 can be attached to the back belt portion of the back sheet 22 along the attachment area 94 of the side panel, and the back sheet and front sheet configuration of the article. It can be functionally attached to one or both parts.
The configuration shown has an inner mounting area area for each side panel that is overlaid and laminated with a corresponding lateral edge area of the belt portion of the article. The side panels extend laterally to form a pair of opposing waist flaps of the diaper and are attached by suitable bonding means such as adhesive bonding, thermal bonding, ultrasonic bonding, clips, staples, stitching, etc. . Desirably, the side panels extend laterally beyond the terminal side edges of the back and front sheet layers at the waist belt portion of the article to which they are attached.

[0120] The side panels 90 can be made of a substantially inelastic material, such as a polymer film, woven fabric, nonwoven fabric, or the like, or a combination thereof. In certain aspects of the invention, the side panels 90 are substantially resilient, such as stretch bonded laminate (SBL) materials, neck bonded laminate (NBL) materials, elastic films, elastic foam materials, and the like. It can be composed of materials. For example, a meltblown elastic fiber web suitable for forming the side panel 90 was produced on May 5, 1987.
No. 4,663,220, issued to T. Wisneki et al., The entire disclosure of which is incorporated herein by reference. An example of a composite fabric consisting of at least one nonwoven fabric secured to a fibrous elastic layer is described by J. Taylor et al.
It is described in European Patent Application EP 0217032 A2, published April 8, 1987, the entire description of which is incorporated herein by reference. An example of an NBL material was Mormon on July 13, 1993.
No. 5,226,992 granted to Ni, the entire description of which is incorporated herein by reference.

As mentioned previously, various suitable structures may be utilized to attach the side panel 90 to a given belt portion of the article. A pair of elastically extensible members is secured to the lateral sides of the article so as to extend laterally outward beyond the laterally opposed side areas of the outer cover and lining components of the article. An example of a suitable structure can be found in U.S. Patent No. 4,983,753 granted to P. Van Gompel et al. I do.

If the side panel 90 is constructed of a material that is elasticized or otherwise configured to be elastically stretchable, the elastic side panel preferably includes an applied load (about 0.58 Assuming a tension of 0.33 pounds per linear inch of sample size measured in the direction perpendicular to the direction of Newtons / cm), it can have an extension at maximum load of at least about 30%. Alternatively, the elastic side panel material may be
It can have at least about 100% elongation, and optionally can have at least about 300% elongation to provide improved performance.

Each of the side panels 90 extends laterally at opposing lateral ends of at least one belt portion of the diaper 20. In the embodiment shown, for example, each side panel extends laterally from the opposite lateral end of the rear belt portion of the backsheet 22. Each side panel includes a relatively outer terminal free end region 92 having a longitudinally extending length dimension. Each side panel also includes a base region mounting area 94 having a laterally extending width dimension and overlapping structural bond mountings for one or both of the front and back sheet layers. The side panel is tapered or curved such that the base length of the side panel mounting area 96 is relatively greater than the length of the outer end region. Optionally, the side panels are
It can be substantially square or substantially trapezoidal.

A stress beam 98 may be formed on each side panel 90 along its outward free end region 92 to more evenly distribute the tension throughout the side panel area. The stress beam portion is configured to have a relatively high stiffness value, and in a desirable configuration, the stress beam portion is formed in a region closer to the outside of the side panel.
It extends over substantially the entire longitudinal length of the 92. Fastener tabs 44 are connected to extend laterally from the stress beams of each side panel 90 to secure the belt portion of the article around the wearer during use of the article.

Each fastener tab 44 connects an inboard end area of a selected fastener component, such as the hook member 46 shown, to its associated outboard end area and corresponding side panel 90. An interconnecting carrier layer 56 can be provided. The carrier layer has a first side region laterally inboard and a second side region laterally outboard. The first side region is laminated or otherwise connected and secured to the side panel by a functional configuration bond. The configuration of the side panel material, the carrier layer material and the structural bond comprises and is disposed on the functional stress beam portion 98. Optionally, an additional layer of reinforcing material can be provided along the stress beam portion to increase the stiffness of the beam and further enhance its ability to distribute stress along the longitudinal dimensions of the side panels. The inner region of the carrier layer 56 has a longitudinal extent that is smaller than the longitudinal dimension of the outer free end 92 of the side panel 90. Alternatively, the carrier layer 56
Can have a longitudinal extent equal to or greater than the longitudinal dimension of the outboard portion of the side panel.

[0126] The members of the hook material 46 are laminated or otherwise connected and secured to the outer region of the carrier layer by functional configuration attachment. Specifically, the illustrated hook member 46 is overlaid on the bodyside surface inside the carrier layer by hook components extending substantially inwardly of the article. With the arrangement shown, the outer lateral terminal edge of the second carrier edge region completely overlaps the outer lateral terminal edge of the hook member 46. Alternatively, the outer lateral distal edge of the second carrier edge region may be spaced laterally inward from the terminal lateral distal edge of the hook member 46. In either configuration, the lateral distal edge of hook member 46 is the lateral terminal edge of the article.

The longitudinally extending relatively outward end of the side panel member 90 may be spaced from the longitudinally extending relatively inwardly extending end of the selected fastening region by the spacing of the carrier. it can. More specifically, the outer end of the side panel member 90 is
An interval from the relatively inner end of the hook member 46 can be provided by the carrier interval. This spacing can optionally have a lateral extent equal to or greater than the lateral extent of the fastening area. In addition, the inwardly facing body side surface of the carrier layer 56 is configured to have limited mechanical interconnection with the hook elements. As a result, the fastener tab 44 is disposed on the body side surface of the carrier layer 56 and selectively places a fastening area in a stowed position with the retained hook element;
It can be folded along a longitudinally extending fold line for construction. The level of bonding between the hook material and the carrier layer need only be sufficient to maintain the stowed position. For example, the bond may have a single maximum peel force value within a force range of about 1-50 grams.

In certain configurations of the present invention, the material of the carrier layer 56 can be comprised of substantially inelastic materials, such as polymer films, wovens, nonwovens, and the like, and combinations thereof. Alternatively, the carrier web material may be a stretch bonded laminate (SBL) material, a neck bonded laminate (NBL) material, an elastic film,
It can be comprised of substantially elastic materials, such as elastic foam materials and the like, and combinations thereof. The elastic material can elastically expand and contract at least along the lateral direction 88. For example, the carrier web material, in order to provide a total composite basis weight in the range of about 50-67g / m ² (about 1.5-2oz / yd ^2), sandwiched between two opposite spunbond fiber layer melt-blown And a spunbond meltblown spunbond (SMS) fiber having a core of According to another example, key Yariawebu material can constitute the entire nonwoven fabric spunbond fibers having a basis weight in the range of about 50-67g / m ² (about 1.5-2oz / yd ^2).

The mechanical fasteners cooperatively leaned by the various structures of the present invention include hooks, buckles, snaps, including cooperating and complementary mating mechanically engaging elements. It may be a mechanical fastener such as a button. In a particular form of the invention, the fastening means may be a hook-end-loop fastening system, a mushroom-end-loop fastening system, etc. (correctly called a hook-end-loop fastener). Such fastening systems generally include a hook or hook-like male element and a cooperating loop or loop-like female element that engages and removably couples with the hook element. It is desirable that the engagement connection be selectively removable and re-attached. For example, conventional systems are available under the VELCRO trademark.

An example of a suitable hook-and-loop fastener system is described in US Pat. No. 5,019,073 issued May 28, 1991 by T. Roessler et al., The contents of which are incorporated herein by reference. . Another example of a suitable hook-and-loop fastener system is G. Zehner et al., US Pat. No. 5,605,735, filed Dec. 28, 1994, application no. 366,080 (attorney docket number 11,571), entitled HIGH-PEEL TAB FASTENER. Application No. 421,640, filed April 13, 1995, by P. VanGompel et al., Name: MULTI-ATTACHMENT FASTENI
This is described in NG SYSTEM, the contents of which are incorporated herein by reference. An example of a fastener tab that constitutes the carrier layer is A. Long et al., Filed on March 6, 1996, filed application number 08 / 603,477 (attorney docket number 12,563), name: MECHNICAL FASHTENI
This is described in NG SYSTEM WITH GRIP TAB, the contents of which are incorporated herein by reference.

With respect to the construction of a typical hook-and-loop fastener system, hook member 46 is operatively connected to fastener tab 44 and loop member 80 is used to define at least one cooperating landing area 78. . For example, the landing area can be suitably located on the exposed outer surface of the backing sheet 22. As mentioned above, another configuration of the hook-and-loop fastener may have a loop material secured to the fastener tab 44 and may have a hook used to form the landing area 78.

For various aspects and configurations of the present invention, hook member 46 may be of the type referred to as a microhook. A suitable microhook material is commercially available under the trade name CS200 from 3M Company of St. Paul, Minn. The microhook material can have mushroom "cap" shaped hooks, with a hook density of about 1600 per square inch, and about 0.033 cm-0.097 cm (about 0.013 to 0.038 inches)
And can be configured to have a cap width in the range of about 0.01 to 0.013 inches (0.025-0.033 cm). The hook is about 0.0075-0.01cm (about 0.003-0.0cm)
04 inches) and attached to a base film fabric having a Gurley stiffness of about 15 mgf.

[0133] Another suitable microhook material is commercially available under the trade name VELCRO CFM-29 1058 from VELCRO, Manchester, NH. The microhook material can have hooks in the form of diagonal hook elements, with a density of about 264 hooks per square centimeter (about 1700 hooks per square inch) and 0.030 cm-0.063 cm (about 0.012 to 0.025 hooks). Inches) in the range, approximately 0.
It can be configured to have a cap width in the range of about 0.003 to 0.009 inches (007-0.022 cm). The hook element has a thickness of about 0.003-0.0035 inches (0.0076-0.008 cm), and the member of the hook material is attached to a base layer fabric having a Gurley stiffness of about 12 mgf (about 12 Gari units).

For the purposes of the present invention, various stiffnesses are measured in terms of bending moment due to a force perpendicular to a plane substantially defined by the length and width of the test material. A suitable technique for measuring stiffness described here is the Gurley stiffness test, an overview of which is TA
It is described in PPI standard test T543 om-94 (bending resistance of paper (Gurry test)). Suitable test equipment is available from Teledyne of Troy, NY
Gurley) Gurley Digital Stiffness Tester: Model 4171-D. For this explanation, the recognized Gurry stiffness values are obtained with standard size samples. as a result,
The gari tester reading is properly converted to the stiffness of a standard size sample,
Recorded in the traditional milligram force (mgf). In general, the standard "Gurry unit" is equal to a stiffness of 1 mgf and can be used equally to record Gurry stiffness.

For various forms and configurations of the present invention, the loop material can be provided by a non-woven, woven or knitted fabric. For example, a suitable loop material knit, as well as other fabrics, is trade name # 3428 from Guildford Mills, Greensblow, NC.
It can be composed of two bar, warp knitted fabric of the type marketed under 85. A suitable loop material is a nylon woven loop sold under the 3M SCOTCHMATATE brand. 3M also sells linerless loop webs with an adhesive on the back of the web and 3M stitch tape.

For certain aspects of the invention, the loop material need not be constrained to individual landing zone patches. Instead, for example, the loop material is provided by a substantially continuous outer fibrous layer that is integrated to extend over substantially all of the exposed surface area of the cloth outer cover used in the diaper 10. Can be As a result, the cloth-like backsheet 22 can provide a loop material for a useful "stay-anywhere" mechanical fastener system.

[0137] The fastener members in the various configurations of the present invention can be implemented using one or more attachment techniques to construct and couple various other components of the article of the present invention. Can be attached to supporting fabric. Desirably, the fastener elements of the various fastening areas can be integrally formed along the associated fabric layer, for example, by molding, co-extrusion, and the like. It is necessary that the fabric layer and its associated mechanical fastening elements are formed from substantially the same polymeric material, and that there is no separate step for first attaching the fastening elements to separate fabric layers. For example, an individual hook element can be co-molded with the base layer of the hook by co-extruding a base layer of substantially the same polymeric material and the hook element. The strength of the attachment or another interconnect between the fabric layer and the attachment fastening element is greater than the maximum force required to remove the fastener tab 44 from its disengageable fixture to the designated landing area of the article. It is easy to see that it needs to be large.

Calculation and Test Procedures <Unsaturated Thickness Procedure> The thickness height (h) of each layer in the unsaturated state can be measured again by using the measured input and the following procedure. Scope of application: The thickness (h) of each layer in an unsaturated state is measured. Equipment and materials: Glass Petri dish (100 × 15 mm, Corning No. 3160-101, Fisher Scientific Catalog No. 08-747C). Blood bank saline, such as Catalog No. 8504 Blood Bank Saline, obtained from Stevenson Scientific, a division of Cornwell, New Jersey. A thickness tester equipped with a 3 inch (7.62 cm) diameter 0.05 psi (0.345 KPa) test bench. Die cutter: 3 inch (7.62 cm) circle diameter. Weight scale. Experiment timer.

Test Procedure: Die cut test material into 3 inch (7.62 cm) samples. Saturation (grams of flow / gram of sample) is calculated based on 0.6 g / cm ² saturation of the absorber and superabsorber using the method discussed in the flow conduction calculations. Weigh the dry sample and record the weight. To increase the weight of the dried sample to the desired saturation level, calculate the amount of liquid saline added to the sample. Distribute the calculated liquid volume to the Petri dish plane to give a uniform liquid distribution to the sample. Place sample flat on Petri dish. Start the timer. After 30 minutes, remove the sample from the Petri dish. Measure the thickness (mm) of the sample under a suppression pressure of 0.05 psi (0.34 KPs) and record the thickness. The unsaturated thickness height (h) value can be used in the equation used to calculate the flow conductance value for the absorbent composite system.

<Flow Conduction Calculation> The flow conduction of the absorbent core at 0.6 g / cm ² liquid holding capacity of the absorbent is used to represent the capacity of the absorbent core in the unsaturated state. Flow conduction can be expressed by the following equation. Flow conduction value = K ₁ h ₁ + K ₂ h ₂ + K ₃ h ₃ +... Here, K is the permeability of each layer at a predetermined saturation, and h is the thickness of each layer at a predetermined saturation. The permeability (K) of each layer of the core can be calculated as follows. Each layer of the absorbent core is a combination of substantially non-water-absorbing expanded fibers and superabsorbent particles, fibers or flakes. The equation for the permeability of an irregularly oriented collection of cylinders and a collection of spheres is: For cylindrical and other regular or irregular, elongated fiber shapes: For spheroids and other regular or irregular, particulate forms: Here, SA / V is the ratio of the surface area to the volume of the solid portion (cm ^-1 ), and the porosity ε is the ratio of the pore volume to the total volume of all media. The above permeability equation is described by Happel and Brenner in "Low Reynolds Number Hydrodynamics", Noordhoff International
This is based on Publishing (1973). The permeability equations for cylinders and spheres obtained in this study fit a simple form to obtain values for exponents and multipliers as described above.

It has been observed that substantially all of the liquid provided during the first liquid raid is absorbed by the superabsorbent prior to the effect of the second liquid raid. Thus, to calculate the permeation value used in flow conduction calculations, all of the above specified liquids (0.6 g / cm ² ) can be considered to be in the superabsorbent. Thus, the liquid volume is included as part of the solid volume to calculate the porosity ε and the ratio of surface area to volume of the superabsorbent. That is, the porosity ε of the material is given by the following equation. ε = 1− [solid volume + liquid volume] / [total volume occupied by wet sample] Here, the total volume occupied by the wet sample is determined by multiplying the area of the sample by the thickness of the sample. Sample thickness can be determined by the unsaturated thickness procedure described herein.

The surface area to volume (SA / V) term used in the permeability equation for the various components is calculated using the surface area to volume equation for fibers or particles to suit the individual component morphology. Is done. For fibers, the ratio of surface area to volume is equal to the ratio of the perimeter to the area of the cross section perpendicular to the longitudinal axis of the cylinder, p / a. For a cylinder with a circular cross section, for example, Where r is the radius (cm) of the cylindrical cross section. For a ribbon-like shape, that is, a substantially rectangular cross section, It is. For fibers with more complex cross-sectional shapes, the ratio of perimeter to area can be determined by well-known micro techniques. For example, "Quan by EE Underwood
titative Stereology ", Addison Wesley Publishing Co. (1970). According to these calculations, the ratio of surface area to volume of a substantially non-water swelling fiber can be determined using the “SA / V” value (ratio of surface area to volume of fiber), which is It is suitable for the cross-sectional shape. For example, fluff fibers are generally ribbon-shaped. For example, about 8 microns (0.00
For a fluff fiber having a thickness of 08 cm) and a width of 40 microns (0.0040 cm), the surface area to volume is:

The form of the superabsorbent may be particulate, fibrous, flat or a combination thereof. Further, the characteristics of the high-absorption non-water-absorbing expansion may be isotropic or anisotropic. Most of the commercially available superabsorbents are particulate and expand substantially isotropically. Such superabsorbent particles can be treated as spheres in this calculation. If the particle sizes are substantially all equal, the ratio of surface area to volume of the sphere can be used to estimate the ratio of surface area to volume of the superabsorbent. The ratio of the surface area to the volume of the sphere is: SA / V = 3 / r where r is the radius (cm) of the sphere.

However, superabsorbents consist of a distribution of multiple particle sizes. If the distribution is substantially single mode, the counterweight surface area to volume can be used. For a given distribution, this value can be calculated by: Here, r _i = _i ^th section center point of the particle size value zone (cm) n _i = _i ^th unit number of particles And m _i = mass of the i ^th part (gram) ρ _SAP = density of the dry superabsorbent (g / cc)

If the particle size distribution is a multimodal mode, eg, two modes, the separate permeability for each mode group is used in the self-consistent calculation of the permeability of the composite material described below. In this case, the counterweight surface area for the capacity needs to be calculated for each mode group as described above. Generally, at least 6 to 8 different particle size portions are used to estimate the particle size distribution of the superabsorbent. The water swelling of the liquid absorbent superabsorbent further complicates the process of incorporating the superabsorbent distribution into the determination of the composite permeability. In particular, the size of the superabsorbent and consequently the surface area to capacity ratio depends on the saturation level of the superabsorbent. The relational expression of the surface area ratio to the volume of the isotropically water-absorbing, high-absorbing particles is expressed by the following equation as a function of the liquid content. Where (SA / V) _wet = surface area ratio of wet superabsorbent to volume (cm ^-1 ) S = saturation of superabsorbent, liquid gram per gram of superabsorbent ρ _SAP = dry height Absorbent density (g / cc) (SA / V) _dry = surface area (cm ^-1 ) relative to dry SAP capacity.

The superabsorbent can be shown in fiber form. Generally, it has been observed that the fibrous superabsorbent has anisotropic water-swelling properties. In particular, the increase in fiber volume with increasing liquid content occurs mainly in the radial direction, and the fiber length remains relatively constant. In such a case, the ratio of the surface area to the volume of the superabsorbent fiber that has been absorbed and expanded is as follows. Using the above relationship for the ratio of surface area to volume as a function of the liquid content of the superabsorbent, the ratio of surface area to volume of the superabsorbent with a particular liquid content can be calculated. Before calculating the ratio of surface area to volume using the above transmission equation, it is necessary to determine the saturation level of each superabsorbent in each layer. In the following, a method for estimating the saturation level of each high absorbent present in the absorbent core will be described.

[0147] It has been observed that the liquid is substantially completely absorbed by the superabsorbent of the system during the time interval during which the product undergoes the first and second liquid assaults. Further, it has been observed that the liquid brought during the first liquid raid is partitioned among the superabsorbents according to their relative volume and liquid recovery. The liquid holding amount of each superabsorbent at the saturation S _j specified by the above (0.6 g / cm ² ), expressed by the liquid amount gram to the superabsorbent gram, can be calculated by the following equation. bw _j = basis weight of the _j -th superabsorbent (grams per square meter) _fpj = liquid distribution factor for the jth superabsorbent The liquid distribution factor _fpj is, for each superabsorbent component, relative to the various superabsorbent components It is calculated based on the ratio and the amount. Where bw _j = basis weight of the _j -th superabsorbent (grams per square meter) f _Rj = relative ratio factor of the j-th superabsorbent

The relative ratio factor f _Rj for each superabsorbent is given by: Where τ _j = time required for the j-th superabsorbent to absorb 60% of the equilibrium force for absorption under the no load (FAUZL) test, as described herein. I have. To illustrate this method exemplarily, consider a two-layer absorber having the following components: Layer Area 1: 120 g / m 2, 400 micron counterweight particle size superabsorbent type 1, τ ₁ = 5 min, 120 gsm wood pulp fluffy with 8 micron × 40 micron fiber cross section, The measured thickness at the saturation level specified below is 0.55 cm. Layer Area 2: 150 g / m 2, 400 micron counterweight particle size superabsorbent type 2, τ ₂ = 10 min, 300 gsm wood pulp fluffy with 8 micron × 40 micron fiber cross section, The measured thickness at the saturation level specified below is 0.51 cm.

With respect to the superabsorbent used in these layers, further, Therefore,

The above calculations are suitable when the total equilibrium FAUZEL high absorption does not exceed a specific retention of 0.6 g / cm ² . Under this circumstance, if the capacity of a particular superabsorbent is exceeded, its degree of saturation is set to an equilibrium value, and the excess liquid is present in another superabsorbent, consistent with the description herein. It is assumed that. Based on the amount of liquid present in the superabsorbent particles, the surface area to volume ratio of the water-swellable particles or fibers of each layer can be calculated using the appropriate surface-to-volume ratio formula described above for the water-swellable particles and / or fibers. The ratio can be calculated. The permeability equation that matches the sphere can be used for particulate superabsorbents, and the permeability equation that matches the cylinder is:
Can be used for fibrous super absorbent materials.

In this particular example, if the superabsorbent is particulate and the core contains 0.6 g / cm ² of liquid, then the ratio of surface area to volume will be: Super absorbent in layer area 1: Super absorbent in layer area 2: The fibrous wood pulp fluffy components used for both layers are: It is.

By using the above equation for the permeability of the aggregate of fibers or aggregates of particles to determine the permeability of each component in the mixed layer region used to construct the absorbent core Appropriate expressions can be set. However, the above equation for the permeability of an aggregate of fibers or aggregates of particles is valid only if the total pore medium consists solely of monodisperse fibers or particles. When both fibers and particles are present as a medium of a particular porosity, the above equations are combined. The way to combine these two equations is
"Perform Permeability Predictions by Se by AL Berdichevsky and Z. Cai
lf-consistent Method and Finite Element Simulation '', Polymer Composites
, 14 (2), (1993) is a self-consistent method.

For this description, a basic assumption underlying a self-consistent method is that the permeability is substantially homogeneous throughout the porous medium. Thus, the local porosity associated with the fibers and particles is determined as having equal permeability. The combination is subject to the constraint that the total porosity (ε _comp ) of the structure is kept at a specific value determined from the sample area and thickness measured as described above. The simplest mixed structure consists of two components. In this case, the two permeability equations require self-consistent calculations for mixed permeability. For the two-layer example above, the permeability equation used to calculate the self-consistent mixed permeability is:

Formula for permeability of layer 1 and layer 2: Layer region 1: For fibers, In the case of super absorbent material, Layer area 2: In case of fiber, In the case of super absorbent material, Here, ε _fiber1 , ε _SAP2 , ε _fiber2 , and ε _SAP2 respectively correspond to the local porosity of the fibers of layer 1 and layer 2 and the high absorbent material. The combination of local porosity must yield the exact full porosity obtained from the thickness dimensions described above. That is, Where bwt _comp = basis weight of the composite (grams per square meter) f _k = mass of the composite provided by the k th fiber f _j = mass of the composite provided by the j th superabsorbent

Therefore, Further, ρ _k = density of _k -th fiber ρ _j = density of _j -th super absorbent ρ _l = density of liquid S _j = saturation level of j th super absorbent (gram of liquid / gram of super absorbent) h _comp = complex thickness at a level where the liquid retention is equal to the total liquid retention of the composite (
cm), where the total liquid retention of the complex is given by:

In the above two-layer example, each layer is provided with only one kind of fiber and one kind of high absorbent material, and the fiber density of both layers is 1.5 g / cc, and the high absorbent material density of both layers Is 1.49 g / cc, and the mass of the superabsorbent, the liquid holding capacity, and the height of the composite in each layer are as specified above. All porosity values are as follows: Layer area 1: Layer area 2: The transmission values of the two layers after performing the calculation without self-contradiction are as follows. Layer area 1: Layer area 2:

This simple two-layer case illustrates the principle of calculating the porosity of a composite. However, the composite used to construct the absorbent core of the present invention includes a composite of two or more layers. In such a case, when performing a composite permeability calculation that is not self-consistent with respect to a layer region, it is necessary to include a permeability equation for each component in a predetermined composite layer region. For example, if the composite layer region includes two types of fibers and two types of superabsorbents, the four permeability equations are used to calculate the composite permeability when using a self-consistent method. Required.

The permeability and thickness (height, h) of the composite, determined for each layer area of the absorbent core in the unsaturated state, allow the flow conduction value of the system to be calculated, as described above. As described above, the flow conduction value = K ₁ h ₁ + K ₂ h ₂ + K ₃ h ₃ +..., And for the two-layer example, the flow conduction value = (1.6 * 10 ⁻⁶ * 0.55) + ( 1.1 * 10 ^-6 * 0.51) = 1.4 * 10 ^-6 cm ³ . The above permeability and flow conduction calculations are illustrated for a two-layer structure where each layer contains one anisotropically water-absorbent expanded particle superabsorbent and one fiber type, but the flow conduction calculation is for two layers. The above-mentioned case can be expanded and applied, and based on the description given here, the calculation of the transmittance K can be easily applied to even more complicated materials.

<Liquid Guide Capability Value> Scope This test is used to measure the ability of the absorbent to remove liquid from the area of interest. Overview The amount of liquid provided to a sample is measured based on a liquid segmentation calculation. The sample can absorb liquid from the reservoir and measure the amount of liquid removed from the area of interest. Equipment and Materials Plexiglas or similar material, 21cm x 21cm piece less than 5mm thick. Suitable liquid reservoir. Laboratory balance. A sample support that vertically supports an absorbing sample while adding liquid to the sample. Caristadt, Medium binder clip N from IDL, NJ
A coupling clip, such as o.10050, for coupling the sample to plexiglass. Laboratory oven at 150 degrees Celsius.

Test Materials Liquids, Saline for Testing; Recommended saline is Catalog No. 85 from Stephens Scientific, a division of Cornwell, Riverdale, NJ.
Blood bank saline, such as 04, or its equivalent. Sample Preparation Remove the sample layer area from the product or prepare a sample having the same shape as the product. Each layer is separated and tested separately. Mark the target position with a permanent ink marker. The target location of the layer to be tested is determined if the layer is present at the intended location of the absorbent core. The target location is the laterally central region, which is located closer to the center from the front end of the absorbent layer of the absorbent core extending furthest forward by a distance equal to 36% of the total length of the absorbent core. Therefore,
The absorbent layer extending farthest forward of the absorbent core need not be the layer to be tested. Mark the area of interest on the sample with a permanent marker. The area of interest of the sample layer to be tested is determined when the layer is present in the intended area of the absorbent core. The target area of the test sample layer is an area of the sample layer located between two lines extending in the lateral direction. The first line is located closer to the center from the front end of the absorbent layer of the absorbent core that extends farthest forward by a distance equal to 24% of the total length of the absorbent core. The second line is located at a distance equal to 59% of the total length of the absorbent core, and is located toward the center from the front end of the absorbent layer of the absorbent core extending farthest forward. Both lines are substantially perpendicular to the center line of the longitudinally extending absorbent core. If the two target area lines both cross the boundary edge of the test absorption sample, the liquid guideability value of the sample is by definition zero.

The amount of liquid absorbed by the sample is calculated using the liquid segmentation calculation described in the description for calculating flow conduction values. However, rather than calculating SAP saturation for each layer, it only determines the expected amount of liquid in each layer. This can be done using the following equation: Layer liquid "j" = (f _pj ) * 1.0 * Object zone surface area (eg, for the example given by the description of determination of flow conductance values; using a target area surface area of 100 cm ² , the liquid 61.6 in layer area 1) Grams, 38.4 grams of liquid in layer area 2.)

Preparation Procedure The sample is attached to the plexiglass sample holder so that the target place is located directly at the bottom of the apparatus. Fill the liquid reservoir to about 1 cm from the top. Place the reservoir on the laboratory balance. Balance the test procedure . Suspend the sample in the reservoir so that the liquid touches the absorption system. Using an experimental balance as a reference, provide an absorbent complex to absorb the fluid volume determined in the previous calculation. If the sample has absorbed an amount equal to that based on the fluid segmentation calculation ± 5 grams, remove the sample from the reservoir. The sample is kept from dispersing in the vertical position for 5 minutes. Cut the sample at the mark in the target area and remove the center. Weigh the remainder. Dry the rest on the oven overnight. The dry sample is weighed and the dry weight is subtracted from the wet weight to determine the amount of liquid removed from the area of interest. Divide the amount of liquid removed from the area of interest by the total amount of liquid added to the layer in the liquid guidance test and multiply by 100. This is the liquid guidance value for the layer region.

<Combination of Conduction Value and Guide Value (C)> The combined conduction value and guide value can be determined by the following equation. Where FCV = flow conduction value per cm ³ , LWV = liquid guide value (%) and (3 · 10 ⁶ ) are units of cm ⁻³ .

Preparation Absorbency Under Load (MAUL) Scope This test measures the ability of particulate superabsorbent polymer (SAP) to absorb saline under a constant load of 0.3 psi (2.07 KPa). It is to be measured. More specifically, 0.3ps
When limited to an area of 5.07 cm ² under a pressure of i (2.07 KPa), the test measures the amount of saline absorbed by 0.160 grams of superabsorbent polymer. The superabsorbent polymer is pre-screened by US Standard # 30 mesh and remains on US Standard # 50 mesh. A suitable test device is shown in FIGS. Equipment and materials Electronic balance, 0.001 gram accuracy (minimum amount of 200 grams) Cylinder group: 1 inch (25.4 mm) ID, resin cylinder (120) with 100 mesh stainless steel screen and mounted on the bottom of the cylinder; 0.995 inch (25.27) 4.4 mm) diameter
Gram resin piston disc (122). The piston disc diameter is 0.005 inch (0.13
mm), which is smaller than the inner diameter of the cylinder. See FIG. 0.984 inch (25mm) diameter 100g weight (124). 0.9% (wt / wt) saline (blood bank saline). Deep dish for saline (126). Timer (140) that can read 200 minutes every second. Measuring paper.

The US Standard Test Sieve (ASTME-11 Standard) group includes one receiver, one US Standard # 30 mesh, one US Standard # 50 mesh, and one lid. As shown in FIGS. 10 and 12, a tapping device is placed on the sample to provide consistent tapping on the support piston disc. This tapping removes any trapped air surrounding the SAP and ensures that the liquid wets the SAP surface. In this installation, a motor (128) rotates a shaft that drives a rod (130) in a vertical direction. As shown in FIG. 12, a rubber foot (132) having a diameter of 13 mm is provided at the lower end of the rod. The shaft stroke is 3 cm, with an upstroke cycle and a downstroke cycle every 0.7 seconds. The maximum impact pressure that the piston disc exerts on SAP is 0.16 psi (0.11 KPa). Referring to FIG. 10, the device (134) has a vacuum port (136) so that interstitial fluid can be evacuated from the sample. The port houses the base of the cylinder group. Placing the cylinders containing the sample in this device removes free liquid from between the sample particles. A suitable pump (138) adds 100 torr (13.3
KPa) or less. FIG. 10 shows the entire test facility. Preferably, an electronic timer (140) is used to control the operating time of the tapping and vacuum device. In this facility, the tapping device is placed on a slide (142) so that it can move between multiple samples.

Procedure 1. The superabsorbent is thoroughly screened using a US standard test sieve to obtain a minimum of 0.160 grams of superabsorbent that passes through # 30 mesh and remains at # 50. 2. Weigh 0.160 grams (± 0.001 grams) of the superabsorbent sieved in step 1 on a pre-measured weighing paper. 3. Slowly pour the superabsorbent into a cylinder with a 100 mesh bottom. Avoid contact of the SAP with the cylinder side walls as particles may be attached. Gently tap the cylinder until the particles are evenly distributed on the screen. 4. Place the resin piston in the cylinder. Measure the weight of the cylinder group, and record the weight as “cylinder group high absorbent amount”. 5. Fill the saline dish with 1 cm of blood bank saline. 6. The cylinder group is placed in the saline dish and directly below the axis of the tapping device, and the timer is started. Tapping device starts and taps for 8 seconds. 7. As shown in FIG. 11, after a beating time of 8 seconds, a 100 gram weight is placed on the top of the group within 5 seconds. 8. After placing the cylinder in the deep dish for 200 minutes, remove the cylinder group and place a weight of 100 grams on the vacuum platform with the cylinder group on the vacuum platform as shown in FIG. Vacuum for 6 seconds. 9. Remove 100 grams of weight from the cylinder group, weigh the cylinder group, and record the weight.

Results and Analysis For each test, the saline (grams) absorbed by SAP is measured. This is the MAUL value of the super absorbent.

<Flood Absorbency Under Zero Load (FAUZL)> Scope This test measures the salt water absorption of a particulate superabsorbent polymer (SAP). 5 as a function of time under a specified nominal pressure of 0.01 psi (0.069 KPa).
When limited to an area of .07 cm ² , the test measures the amount of saline absorbed by 0.160 grams of superabsorbent polymer (either dry or pre-saturated at the start). As a result, the time data for absorption, the indicator time (Tau) reaching 60% of the equilibrium absorption capacity, are measured. Equipment and materials Electronic balance, 0.001 gram accuracy (minimum amount of 200 grams) Cylinder group: 1 inch (25.4 mm) ID, resin cylinder (120) with 100 mesh stainless steel screen and mounted on the bottom of the cylinder; 0.995 inch (25.27) 4.4 mm) diameter
Gram resin piston disc (122). The piston disc diameter is 0.005 inch (0.13
mm), which is smaller than the inner diameter of the cylinder. See FIG. 0.9% (wt / wt) saline (blood bank saline). Deep dish for saline (126). Timer (140) that can read 120 minutes every second. Measuring paper.

As shown in FIGS. 10 and 12, a tapping device is placed on the sample to provide consistent tapping on the support piston disc. This tapping removes any trapped air surrounding the SAP and ensures that the liquid wets the SAP surface. In this installation, a motor (128) rotates a shaft that drives a rod (130) in a vertical direction. As shown in FIG. 12, a rubber foot (132) having a diameter of 13 mm is provided at the lower end of the rod. The shaft stroke is 3 cm, with an upstroke cycle and a downstroke cycle every 0.7 seconds. The maximum impact pressure that the piston disc exerts on SAP is 0.16 psi (0.11 KPa).

Referring to FIG. 10, the device (134) has a vacuum port (136) so that interstitial fluid can be evacuated from the sample. The port houses the base of the cylinder group. Placing the cylinders containing the sample in this device removes free liquid from between the sample particles. A suitable pump (138) adds 100 torr (13.3
Apply a vacuum pressure of KPa) or less. FIG. 10 shows the entire test facility. Preferably, an electronic timer (140) is used to control the operating time of the tapping and vacuum device. In this facility, the tapping device is placed on a slide (142) so that it can move between multiple samples.

Procedure 1. Weigh 0.160 grams (± 0.001 grams) of superabsorbent on pre-measured weighing paper. The particle size distribution is the "accepted" particle size distribution. 2. Slowly pour the superabsorbent into a cylinder with a 100 mesh bottom. Avoid contact of the SAP with the cylinder side walls as particles may be attached. Gently tap the cylinder until the particles are evenly distributed on the screen. 3. Place the resin piston in the cylinder. Measure the weight of the cylinder group, and record the weight as “cylinder group high absorbent amount”. 4. Fill the saline dish with 1 cm of blood bank saline. 5. The cylinder group is placed in the saline dish and directly below the axis of the tapping device, and the timer is started. Tapping device starts and taps for 8 seconds. 6. After placing the cylinder in the bowl for 5 minutes, remove the cylinder, stop the timer and place the cylinder on the vacuum platform as shown in FIG. Vacuum for 6 seconds. 7. Weigh the cylinder group and record the weight. 8. Return the cylinder group to the deep dish just below the tapping device and restart the timer. Note that the time between removing the cylinder group from the saline solution in step 6 and returning the cylinder group to saline solution in step 8 cannot exceed 30 seconds. Repeat the first procedure of soaking, removing, vacuuming and weighing and recording. The recorded data relates to the cumulative immersion time of 1,5,20,15,30,45,60,75,90,120 minutes. 9. The procedure described in step 1-8 is performed three times.

Results and Analysis Grams of saline versus grams of superabsorbent polymer are measured and plotted as a function of cumulative immersion time. Determine the final equilibrium absorbency of SAP: If the change in the average absorbance of SAP (average of three tests) obtained at 90 minutes and 120 minutes is less than 5%, the absorbance of 120 minutes as equilibrium force FAUZL Is used. Change in average absorption power is 5
If it is greater than or equal to%, the test of the sample must be repeated and must include an additional 200 minutes of cumulative immersion time. In the latter situation, an absorption force of 200 minutes is used as the balance force FAUZL.

The interpolation time (Tau) to reach 60% of the equilibrium absorption is determined. This is done by calculating the absorption at 60% of the equilibrium value and then estimating the corresponding time to reach this absorption from the graph. The interpolation time to reach 60% absorption (in this procedure) is obtained by linearly interpolating the data points on either side of the estimation time. Calculate the arithmetic mean interpolation time to reach 60% of the equilibrium force (mean of three tests). This average time is referred to as “Tau”.

Contact Angle with Liquid Fibers A suitable method for measuring the contact angle of liquid fibers is described in US Pat. No. 5,346,382, the entire disclosure of which is incorporated herein by reference. It has been incorporated. In particular, the wettability of a fiber can be measured using the magnitude of the contact angle for the fiber. The size of the contact angle of a single fiber using repeated water and distilled water was determined by Chan Surfa
It can be determined by ce Force Analyzer (SFA222) and WET-TEK data analysis software. SFA222 from Chan Instruments in Cerritos, California
And WET-TEK data analysis software is available from Biomaterial International, Salt Lake City, UT. The fiber is tested in three measurement cycles and the distilled water bath is changed between one and two cycles. The contact angle of the liquid with the fiber is determined by the arithmetic mean of three measurements. The test equipment operates according to the standard operating procedures described in the manufacturer supplied Chan SFA-222 system instructions.

Examples The following examples are provided for a more detailed understanding of the present invention,
It does not limit the scope of the invention. In various examples, the first main layer portion 48 may alternatively be referred to as a front layer or an upper layer, and the second main layer portion 50 may alternatively be referred to as a bottom layer or a lower layer. It is important to note that

Example 1 The body side layer had a basis weight of 500 gsm and consisted of 50% 53C superabsorbent and 50% HPF2 silk pulp. The super absorbent could be Dow Chemical, and the mercerized pulp was Buckeye products can be used. Τ of Dow53C high absorption material is 8.5 minutes, FA
The ULZ force is 33 g / g and the MAUL value at 0.3 psi is 26.2 g / g. As shown in FIG. 2, the body side layer extends to the area of layer 48 and is increased in density to 0.2 g / cc.

The outer layer consisted of three layers of 68 gsm air dried non-shrink tissue,
keye Consists of 50% HPZ fiber available from Cellulose and 50% LL19 available from Kimberly-Clark. A 50gsm layer of SXM880 superabsorbent available from Stockhausen is placed between the outermost layer of tissue and the adjacent tissue using a 10gsm adhesive. The SXM880 superabsorbent has a τ of 4 minutes and a FAULZ force of 3
8 g / g and a MAUL value of 0.3 psi is 29.8 g / g. Two additional sheets, air-dried, non-shrink tissue, as described above, are disposed in an area outside the area occupied by the body side layer 48. Between the two layers is a layer of 100gsm SXM880 superabsorbent, bonded using a 10gsm adhesive as described above. This example has a flow conduction value of 3.56 x 10-6 and a liquid guidance value of 56.2%.

Example 2 The body side layer had a basis weight of 500 gsm and consisted of 50% 53C superabsorbent and 50% HPF2 silk pulp. The super absorbent could be Dow Chemical. Buckeye products can be used. Τ of Dow53C high absorption material is 8.5 minutes, FA
The ULZ force is 33 g / g and the MAUL value at 0.3 psi is 26.2 g / g. As shown in FIG. 2, the body side layer extends to the area of layer 48 and is increased in density to 0.2 g / cc.

The outer layer consisted of four layers of 68 gsm air dried non-shrink tissue,
keye Consists of 50% HPZ fiber available from Cellulose and 50% LL19 available from Kimberly-Clark. The SXM880 superabsorbent available from Stockhausen is distributed to have a basis weight of 50 gsm below the body side layer and a basis weight of 150 gsm in the outer region. The superabsorbent extends over the entire area of the pad (the area of layer 50). The SXM880 superabsorbent has a τ of 4 minutes, a FAULZ force of 38 g / g and a MA of 0.3 psi.
UL value is 29.8 g / g. The superabsorbent is sandwiched between the second and third outermost tissues. This example has a flow conduction value of 3.56 × 10 −6 and a liquid guidance value of 50.0%.

The above data can be summarized as follows. It has been found that some conventional absorption structures require improved dispersion, while other conventional absorption structures require improved uptake. However, such conventional structures are not configured to provide the unique combination of liquid intake and liquid dispersion provided by the various arrangements and features of the present invention. The following Comparative Examples 4-8 were prepared.

[0181] Example ^A shows the structure taught in U.S. Pat. No. 5,356,403 to Faulks et al. In Example 4, the upper layer has a density of 0.2 g / cc and the lower layer has a density of 0.3 g / cc. Examples ^{B to} 5 show the structure taught in EP0631768A1. In these examples, both layers have a density of 0.2 g / cc, and both layers extend over the entire area of the composite pad shape described in EP0631768A1. Example ^C illustrates the structure taught in Cook et al., US Pat. No. 5,360,420. The front layer has a density of 0.07 g / cc and the bottom layer has a density of 0.25 g / cc. Both layers have the shape described in US Pat. No. 5,360,420.

[0182] CCLC is a chemically cross-linked cellulose, for example, as described in US Pat. No. 4,898,642. SXM870 and SXM880 are super absorbents manufactured by Stockhausen under the trade name FAVOR SX. The high absorbent material is sieved at the stated mesh particle size. For example, it is 20/30 mesh (600 to 850 μm) and 60/100 mesh (150 to 250 μm). The SXM880 superabsorbent has a τ of 4 minutes, a FAULT force of 38 g / g, and a 0.3 psi MAUL value of 29.8 g / g. The SXM870 superabsorbent has a τ of 4 minutes, a FAULT force of 32.5 g / g, and a 0.3 psi MAUL value of 27 g / g. 20 / 30SXM870 super absorbent has τ of 6.4 minutes, FAULT force of 34g / g, and 0.3psi MAUL value of 28.8g /
g. The 60 / 100SXM870 superabsorbent has a τ of 3.3 minutes, a FAULT force of 27.5 g / g, and a 0.3 psi MAUL of 25.
3 g / g.

Examples 4-8 exhibited the properties shown in the following table. As can be seen from this table, the structures according to these examples do not provide the combination of properties provided by the structure of the present invention.

The invention has been described in sufficient detail that various changes and modifications can be easily made without departing from the spirit thereof. All such changes and modifications are intended to be within the scope of the present invention.

[Brief description of the drawings]

FIG. 1 typically shows a plan view of an absorbent article incorporating the absorbent system of the present invention.

1A is a representative cross-sectional view of the article of FIG.

FIG. 1B typically illustrates a longitudinal cross-sectional view of the article of FIG.

FIG. 2 typically shows a plan view of the absorbent core structure of the present invention, wherein the absorbent core has a first surface layer region extending over the middle of the total area of the absorbent core, and substantially the entire area of the absorbent core. A second bottom layer region extending therefrom, with opposing vertical edges of the first layer region being spaced from each opposing vertical edge of the second layer region.

FIG. 2A is a representative longitudinal sectional view of the absorbent core of FIG. 2;

FIG. 3 is a plan view of another absorbent core structure according to the present invention, wherein the absorbent core extends over a middle portion of a total area of the absorbent core, and over substantially the entire area of the absorbent core. A second bottom layer region that extends, the second layer region having a relatively greater basis weight at its longitudinally opposite ends to effect a vertical inversion of the lower layer. And has a non-uniform basis weight distribution by area.

FIG. 3A is a representative longitudinal cross-sectional view of the absorbent core of FIG. 3, wherein a selected intermediate portion of the second layer region is to have a basis weight per area that is inverted in the second layer within the target area. And has a basis weight lower than the basis weight of the adjacent longitudinally facing end.

FIG. 4 typically shows a plan view of another absorbent core structure having a front side layer region that covers the entire front side of the bottom layer, but never covers the entire rear side of the bottom layer region.

FIG. 4A is a representative longitudinal sectional view of the absorbent core of FIG. 4;

FIG. 5 is a plan view of another absorbent core having a surface-side layer region that entirely covers the bottom-side layer region.

FIG. 5A is a representative longitudinal sectional view of the absorbent core of FIG. 5;

FIG. 6 represents a plan view of another absorbent core having a lateral dimension smaller and narrower than the bottom layer area and having a shorter longitudinal dimension than the bottom layer area. Is shown.

FIG. 7 typically shows a longitudinal cross-sectional view of an absorbent core of the present invention with a bottom layer region comprising a laminate having superabsorbent particles sandwiched and retained between layer regions of a liquid permeable material.

FIG. 8 illustrates another absorbent core according to the present invention having a bottom layer region comprised of a plurality of heterogeneous sublayer laminates to provide a non-uniform area basis weight within the bottom layer region. A longitudinal sectional view is typically shown.

FIG. 9 is a representative longitudinal cross-sectional view of another absorbent core according to the present invention with a bottom layer region composed of a plurality of heterogeneous sublayer laminates, wherein the distribution of superabsorbent material is It is tuned to provide a non-uniform area basis weight of the superabsorbent material in the layer area.

FIG. 10 shows a schematic diagram of a test apparatus for measuring certain properties of a superabsorbent material.

FIG. 11 shows a representative cross-sectional view of a group of cylinders provided in a basin with weights placed on piston discs.

FIG. 12 shows a representative cross-sectional view of a group of cylinders provided in a basin with a piston rod arranged to strike a piston disk.

FIG. 13 shows a representative cross-sectional view of a group of cylinders provided in a basin with weights placed on a piston disk and placed on a vacuum fixation device.

FIG. 14 shows a representative sectional view of a group of cylinders arranged on a vacuum fixing device.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) // A61F 5/44 (31) Priority claim number 09 / 097,029 (32) Priority date 1998 1998 March 12, 1998 (June 12, 1998) (33) Priority country United States (US) (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AL, AM, AT, AU, AZ, BA, BB , BG, BR, BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, GE, GH, GM, HR, HU, ID, IL, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE , SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, UZ, VN, YU, ZW (72) Inventor Bolwark Thomas Gerald, Wisconsin, USA 54914 Appleton Shawnee Avenue 3410 (72) Inventor Dodge Richard Norris The Second United States 54911 Appleton North Macdonald Street 2717 (72) Inventor Groove Violet May Ame United States of America 54942 Greenville Kaymer Co., Ltd. 1473 (72) Inventor Lee Yon United States of America 54915 Appleton Crestwood Court W 2807 (72) Inventor Melius Shannon Kaslin United States of America 54914 Appleton Blue Ridge Drive 3118 (72) 72) Inventor Langanatan Sridhar, United States of America 54915 Appleton South Nicolet Road 1695- # 2 Appleton North Mauritson Street 3413 (72) Inventor Grisky Wick Stanley Michael United States of America Georgia 30189 Woodstock West Putnam Ferry Road 165 (72) Inventor Little Sylvia Bandy United States Georgia 30064 Marietta Norwood Drive 189 (72) Inventor Matthews Billy Jean United States of America Georgia 30188 Woodstock Julie Ann Way 444 (72) Inventor Macdwar Debra Gene United States Georgia 30075 Roswell Spearfield Trace 245 (72) Inventor Sawyer Lawrence Howell United States Georgia 30075 Roswell Spearfield Trace 245 F-term (reference) 3B029 BA02 BA05 BA12 BA15 BA17 BD01 BD19 4C003 AA03 AA07 AA22 4C098 AA09 CC03 DD05 DD06 DD10 DD23 DD25 DD26 DD27 DD30 [Continuation of summary] As a result, it is not used as a highly saturated guiding layer. It has been used as a put layer. This configuration also allows the intake layer to be in direct contact with the incoming liquid, thus allowing for even more immediate access and enhancement of the intake function. In another aspect, at least one main layer region has a non-uniform, selectively segmented basis weight distribution. The specific structure of at least one main layer region can constitute a target region of this main layer region having a basis weight smaller than that of other non-target regions. Further, at least one main layer region can have a heterogeneous structure. In certain structures, at least one main layer region can include a plurality of two or more sub-layers.

Claims (23)

[Claims] 1. A back sheet layer, a substantially liquid permeable front sheet layer, and a first main layer region and at least a second main layer sandwiched between the back sheet layer and the front sheet layer. An absorbent composite structure including an absorbent core having a region, wherein the second main layer region has a non-uniform basis weight selectively sectioned, and at least one of the first and second main layer regions An absorbent article comprising: a plurality of sub-layers; and at least one of the first and second main layer regions has a liquid guidance value of at least about 38%. 2. The absorbent article according to claim 1, wherein said absorbent core has a dry thickness of about 6 mm or less and a minimum crotch width of about 10 cm or less. 3. The article is configured for use by an adult, and the absorbent core comprises:
2. The absorbent article according to claim 1, wherein the absorbent article has a dry thickness of about 6 mm or less and a minimum crotch width of about 14 cm or less. 4. The absorbent article according to claim 1, wherein said absorbent core has a combined conduction and guidance value of at least about 14 * 10 ^-6 cm ³ . 5. The absorbent article according to claim 4, wherein said absorbent core has a dry thickness of about 6 mm or less and a minimum crotch width of about 10 cm or less. 6. The method according to claim 1, wherein the first main layer region is provided on a body side of the absorbent composite, and the second main layer region is provided relatively outside the first main layer region. 2. The absorbent article according to claim 1, wherein 7. The absorbent article according to claim 1, wherein at least one of said main layer regions comprises a superabsorbent material having a prepared absorbency under load of at least about 20 g / g. 8. The absorbent article according to claim 1, wherein at least one of said main layer regions comprises a superabsorbent material exhibiting a tau value of about 0.8 minutes or more. 9. An absorbent article comprising an absorbent core having a first main layer region and at least a second main layer region, wherein the second main layer region has a selectively partitioned non-uniform basis weight. And a plurality of heterogeneous sub-layers, wherein the absorbent core has a longitudinal length, a lateral width, and a predetermined front edge, and the first main layer region has a length of about 100 g / m ^2. The above has a basis weight of about 700 g / m ² or less, a first main layer area density of about 0.03 g / cm ³ or more, about 0.4 g / cm ³ or less, and about 25% by weight or more And a fiber material having a fiber size of about 4 μm or more and about 20 μm or less, wherein the first main layer region has a fiber size of about 50% by weight or less. A superabsorbent material in an amount of about 80% by weight or less, and the superabsorbent material includes superabsorbent particles having a particle size of about 110 μm or more and about 1000 μm or less. , Absorbent article characterized by having about 20 g / g or more have a MAUL value, and about 0.8 minutes or more Tau values. 10. The first main layer region substantially overlaps a side edge of the second main layer region, and inwardly extends from a leading edge of the absorbent core by about 7% of a length of the core. 10. The method of claim 9, wherein the line extends laterally at a location and extends inwardly from the leading edge of the absorbent core to a laterally extending line at about 62% of the length of the core. The absorbent article according to the above. 11. The absorbent article according to claim 10, wherein the first main layer region contains a binder material. 12. The absorbent article according to claim 9, wherein said second main layer region includes a plurality of sub-layers having an air-dried and non-shrinkable material. 13. The second main layer region has a vertical range that is larger than the vertical range of the first main layer region, and has a horizontal range that substantially overlaps with the first main layer region. 10. The absorbent article according to claim 9, wherein: 14. The second main layer region has a vertical range larger than a vertical range of the first main layer region, and has a horizontal range smaller than a horizontal range of the first main layer region. 10. The method of claim 9, wherein the lateral extent of at least a portion of the second main layer region is about 30% or more of the lateral extent of a corresponding adjacent portion of the first main layer region. Absorbent articles. 15. The second main layer region has a vertical range larger than a vertical range of the first main layer region, and has a horizontal range larger than a horizontal range of the first main layer region. 10. The method of claim 9, wherein the lateral extent of at least a portion of the first main layer region is at least about 30% of the lateral extent of a corresponding adjacent portion of the second main layer region. Absorbent articles. 16. The absorbent article according to claim 9, wherein the target area of the second main layer area has a basis weight lower than that of a non-target portion of the second main layer area. 17. The target area of the second main layer area is about 100 g / m.^TwoAbove, about 250g / m ^Two It has the following grammage, and the non-target portion of the second main layer region is about 450 g / m^TwoAbove, about 550g / m^Two10. The absorbent article according to claim 9, having the following basis weight. 18. The second main layer region has a second layer region density of about 0.1 g / m ³ or more and about 0.3 g / m ³ or less, and about 50% by weight or more and about 95% by weight or more. A fiber material having a fiber diameter of not less than about 4 μm and not more than about 20 μm, and having a water contact angle of not more than about 70 degrees, and further comprising the second main layer. The region includes a superabsorbent material in an amount of about 5 wt% or more and about 50 wt% or less, and the superabsorbent material has a dry particle size of about 110 µm or more and about 1000 µm or less. 18. The absorbent article according to claim 17, comprising particles. 19. The superabsorbent material of the second main layer region may have a MAUL of about 20 g / g or more.
19. The absorbent article according to claim 18, wherein the article has a Tau value of at least about 0.4 min. 20. The superabsorbent material in the second main layer region, wherein the superabsorbent material is formed as a superabsorbent layer laminated between layers of air-dried and non-shrinkable material. The absorbent article according to claim 1. 21. The absorbent article according to claim 20, wherein said article further comprises a backside sheet layer, and a substantially liquid permeable topside sheet layer comprising said absorbent core therebetween. 22. The absorbent core having a flow conduction value of at least about 7 * 10 ^-6 cm ³ , wherein at least one of the first and second main layer regions has a liquid guidance value of at least about 16%. 22. The absorbent article according to claim 21, comprising: 23. The absorbent article according to claim 22, wherein at least one of said first and second main layer regions has a liquid guidance value of at least about 36%.