CZ20013565A3 - Adsorption materials intended for treating complex fluids - Google Patents

Abstract

Adsorbent particles exhibiting an efficacy in the handling of complex fluids. Particles of adsorbent material demonstrating an efficacy in the handling of complex fluid are suitable for incorporation into disposable absorbent articles and the like.

Description

ADSORPTION MATERIALS INTENDED FOR USE IN CONNECTION WITH COMPLEX LIQUID PROCESSING

Technical field

The present invention generally relates to the use of adsorbent particles in conjunction with absorbent structures and disposable absorbent articles. In particular, the present invention relates to adsorbent particles having the desired efficacy in treating complex fluids.

BACKGROUND OF THE INVENTION

The use of adsorbent particles in disposable absorbent articles is known in the art. Such adsorbent particles are generally used in a limited amount and are intended to reduce odor in personal protective absorbent articles, such as female hygiene articles and the like.

However, any widespread use of such adsorbent particles in conjunction with absorbent structures and disposable absorbent articles has been limited to some extent by the limited efficacy of adsorbent particles in complex fluid processing. In view of the above, it would be desirable to increase the efficiency of the adsorptive particles in the treatment of complex fluids, which could eventually lead to a much wider range.

utilizing such adsorbent particles contained in absorbent structures and disposable absorbent articles.

SUMMARY OF THE INVENTION

The present inventors have learned in detail the drawbacks and problems encountered in the prior art and, in response to the findings, have conducted an intensive investigation and development of adsorbent particles that exhibit adequate or desirable efficacy in processing complex fluids. During the investigation, it has been found by the present inventors that certain adsorbent materials have some efficacy in processing complex fluids. Furthermore, it has been found that the efficiency of these adsorbent materials can be further enhanced by appropriately selecting for a suitable pore size distribution. Increasing and improving the efficiency of the adsorbent materials of the present invention consequently provides widespread use of adsorbent particles in absorbent structures and disposable absorbent articles.

According to one embodiment of the present invention, the absorbent article comprises retention means, or retention fluid retention means, and particles of at least one adsorbent material. In said retention means, about 20 to about 50 percent of the adsorbent particles exhibit a pore volume provided by pores greater than about 100 microns for the purpose of absorbing complex fluids and for distributing complex fluids. About 80 to about 50 percent of the adsorbent particles exhibit a pore volume provided by pores of less than about 100 microns for retention of complex fluid retention. In addition, the adsorbent particles in the retention means are present in an amount ranging from about 10 to about 100 percent based on the total weight of the retention means and adsorbent particles.

According to another embodiment of the present invention, the absorbent article comprises retention means and particles of at least one adsorbent material. In said retention means, about 10 to about 100 percent of the adsorbent particles exhibit a permeability of 1,000 K. In addition, the adsorbent particles in said retention means are comprised in an amount ranging from about 10 to about 100 percent based on the total weight of the retention means and adsorbent particles. .

According to yet another embodiment of the present invention, the absorbent article comprises retention means and particles of at least one adsorbent material. The adsorbent particles contained in said retention means exhibit a complex fluid retention capacity of at least 2 g / g. In addition, the adsorbent particles in the retention means are present in an amount ranging from about 10 to about 100 percent based on the total weight of the retention means and adsorbent particles.

According to yet another embodiment of the present invention, the absorbent article comprises retention means and particles of at least one adsorbent material. The adsorbent particles contained in said retention means exhibit a minimum average particle size of at least about 200 microns with a standard deviation of at least about 25 percent of the average particle size of the particles. Besides, they are

The compositions of from about 10 to about 100 percent adsorbent particles in the retention particles are present in an amount ranging from about 100 percent. %, based on the total weight of the retention means and adsorbent particles.

And according to yet another embodiment of the present invention, the absorbent article comprises retention means and particles of at least one adsorbent material. The adsorbent particles contained in said retention means exhibit a multi-modal particle size distribution and are present in said retention means. contained in an amount ranging from about 10 to about 100 percent based on the total weight of the retention means and adsorbent particles.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features, aspects and advantages of the present invention will be described and elucidated in the following detailed description of examples of specific embodiments thereof.

design and in the appended claims based on

attached drawings, in which it represents:

Fig. 1 an apparatus suitable for use in measuring the pore size distribution of the adsorbent material using a capillary stress test method; Fig. 2 a piston apparatus suitable for use in determining the permeability value of the gelled layer (GBP) of the adsorbent material; and

Fig. 3

a top view of the piston head of the apparatus of Fig. 2.

DETAILED DESCRIPTION OF THE INVENTION

The adsorbent materials of the present invention include adsorbent particles and adsorptive particles treated with a surface modifying agent. By "particle," "coarse particle," "particulate," and the like, is meant that the adsorbent material typically takes the form of discrete sub-components. Said particles may include grains, granules, finely divided particles, powders, or spherical and globular bodies, respectively. Thus, they may have any desired shape configuration, such as a cubic, rod-like, polyhedral or polyhedral, spherical or globular or hemispherical, rounded or partially rounded, square, irregular, and similar shape configuration. Shape configurations having a large largest / smallest ratio, such as needles, flakes, chips and fibers, are also contemplated as being useful in connection with the present invention. In addition, the terms "particles or" coarse particles may also characterize a group comprising more than one particle, a coarse particle, and the like, and may also consist of more than one type of adsorbent material.

The terms " nonwoven or " nonwoven fabric used in connection with the facts herein refer to a web or fabric that forms a structure in an unidentifiably repetitive manner superimposed on one another and superimposed on each other, substantially

filaments or staple fibers.

The terms "drawn or" drawn fiber, as used herein, refer to molten fibers formed by melt extrusion of thermoplastic material as staple fibers of fine, usually circular, spinneret capillaries with a diameter of melt spinning fibers formed, which are then rapidly reduced.

of quantity

As used herein, the term " composite material " is characterized by a mixture of fibers and cellulosic fibers formed by meltblown molten air into polymeric material by shaping a stream of simultaneously blowing airborne and deposited cellulosic fibers into a stream of meltblown fibers. The blown fibers containing cellulose fibers are collected on the apertured, i. an apertured strip which may have a liquid-permeable material on its surface, for example a non-woven fabric.

The term " meltblown fibers " as used herein refers to fibers formed by spinning molten thermoplastic material by melt extrusion through a plurality of fine, usually circular, extrusion die capillaries (spinnerets) such as molten yarn or staple fibers into a stream of usually heated gas. (e.g., air) of high velocity, which attenuates the formed fibers or molten thermoplastic material to reduce their diameter. Thereafter, the meltblown fibers are entrained by the high velocity gas stream and then deposited on the receiving surface to form a web or sheet

fabrics consisting of randomly divided blown fibers.

The term "complex fluid" as used herein refers to a fluid that is typically characterized as a visco-elastic fluid comprising a plurality of sub-components with inhomogeneous physical and / or chemical properties. By the inhomogeneous properties of the individual components of the complex fluid is meant properties that stimulate the efficiency of the adsorbent material in the processing of the complex fluids. In contrast to complex fluids, "simple fluids" such as urine, saline, water, and the like, mean fluids characterized as relatively low viscosity fluids and fluids comprising one or more sub-components with homogeneous physical and / or chemical properties. Because these fluids exhibit homogeneous properties, the respective one or more single fluid component components behave substantially similarly during absorbent or adsorption absorption.

Although in the above description the complex fluid is characterized generally as a fluid containing specific sub-components and inhomogeneous properties, usually each specific sub-component of the complex fluid exhibits homogeneous properties. For example, suppose, for example, a hypothetical complex fluid containing three specific sub-components: red blood cells, blood protein molecules, and water molecules. In a simple review, one of ordinary skill in the art would be able, by virtue of their generally inhomogeneous properties, to readily distinguish between each of the three specific sub-components. In addition, a simple review would be specific specific

- 8 - 9 9 · 9 • 999 9 9 9 99 9 9 • 9 9 9 • · · · • «· «9 9 • 9 9 · • · ·· · · 9 9 9 · 9 · »9 • · « 9 f · 9 i 9 9 • «« · 8 · sub-components, for example red blood cells, had person familiar state of the art easily recognize her in general homogeneous hair company. Expressions “Superficial flat, respectively “Superficial

As a rule, in the context of the present description, an outer or completely upper boundary of an object, material, structure, particle or the like is meant.

The term " absorbent article " as used herein refers to means for absorbing, absorbing and retaining body fluids, and, more particularly, means that are applied to or in close proximity to the wearer's skin for absorbent absorption. , receiving and retaining body fluids secreted from the body cavities of the user. The term "disposable or intended to be disposed of after waste is used in connection with the facts herein to describe absorbent articles which are not intended to be laundered or cleaned, or any other recovery or restoration, or reuse of such of the absorbent article after its sole functional use. Non-limiting examples of such disposable absorbent articles include: medical protective devices including surgical covers, gowns, and sterile dressings; personal protective absorbent articles, for example female sanitary articles (e.g. sanitary napkins, panty liners and the like), baby diapers, baby diapers, incontinence articles and the like; as well as various cosmetic make-up wipes.

Disposable absorbent articles, such as a variety of personal protective absorbent articles, typically include a liquid-permeable topsheet, a liquid-impermeable backsheet associated with a liquid-permeable topsheet, and an absorbent core conveniently positioned between said topsheet and the backsheet. backing layer. Disposable absorbent articles and components thereof, including a topsheet, a backsheet, an absorbent core, and individual layers of the components, each have a skin-facing surface and a garment-facing surface. For the purposes herein, the term " skin facing the user " refers to the surface area of the article or its component intended to be worn in an arrangement toward or placed directly in close proximity to the user's body or skin, "Garment-facing surface for the purposes herein, means the surface of the article or its respective component, which is disposed on the opposite side and which, when the disposable absorbent article is functional, is intended to be worn in or facing or in close proximity to the user ' s undergarments.

Although a wide variety of adsorbent materials are known in the art, the present invention, in one aspect, relates the correct and satisfactory choice of absorbent material to its ability to be used in the treatment of complex fluids such as blood, menstruation, vaginal discharge, nasal secretions and the like. The required adsorbent materials that are suitable for use in conjunction with complex fluid processing are essentially complex fluids. Ads • · • · · · · · · · · · · · · · · · · Wettable or hydrophilic (or water-retaining), thus allowing complex fluids to spread across the whole surface area of adsorbent materials. In addition, it is desirable that the adsorbent materials of the present invention have a particulate form and are substantially insoluble by complex fluids. Further, it is desirable that the adsorbent materials of the present invention be substantially inert, at the same time not substantially softening, and also not substantially swelling during adsorption. Each such adsorbent material preferably has a very large specific surface area (i.e., surface area) relative to its weight, which is determined using, for example, a gas adsorption method, a cetyltrimethyl ammonium bromide adsorption method, or a mercury porosimetry method. .

Adsorbent materials suitable for use in conjunction with the present invention include, but are not limited to, organic materials, inorganic materials, and mixtures and combinations thereof. Suitable inorganic materials useful herein include, for example, activated carbon, silicates, metal oxides, zeolites, carbonates, phosphates, borates, aerogels, and mixtures thereof and combinations thereof. Suitable organic materials for use herein include, for example, cellulosic materials, starches, chitins, alginates, synthetic polymers, and mixtures and combinations thereof.

The respective adsorbent material may optionally be subjected to treatment with a surfactant or other surface modifying agents prior to incorporation into the retention means. For this intended • ♦ ib * ·

F · · · · · · · · · · · · ·

a variety of materials are applicable, for example, sulfonated alkyl and aryl compounds, ethoxylated alcohols and amines, polyamides and derivatives thereof, polysaccharides and derivatives thereof, polyethylene glycols and derivatives thereof, betaines (trimethylammonioethanoates) and other zwitterionic and silyl compounds. Appropriate application methods are well known to those skilled in the art.

If the adsorbent material of the present invention is used in conjunction with feminine hygiene products, the adsorbent material will have to have the desired pore size distribution guaranteed. In the adsorption particle layer, these pores will consist of interpartial gaps as well as the internal porous structure of the particles themselves. The interstitial gaps are interconnected and form a structure which can be considered a network of interstitial gaps. When permeating a fluid into or through a layer of adsorbent particles, the fluid usually permeates through these interstitial gaps. The interstitial gaps through which the fluid permeates can also be referred to as interstitial pores.

Since the walls of the interstitial pores represent the surfaces of the adsorption particles themselves, the shape and size of the interstitial pores are usually determined on the basis of these particles. Varying the size of the particles by varying their average dimensions or by varying their size distribution ensures that the shape and size of the interstitial pores are varied. The interstitial pores play an important role in the rate of absorption and the ability to retain complex fluid through adsorbent particles.

Adsorbent materials suitable for the desired application exhibit an acceptable absorption rate with respect to the absorption of complex fluids.

This acceptable rate of absorption of complex fluids can be achieved by providing a heterogeneous, or non-uniform, pore size distribution. As mentioned above, an appropriate combination of particle size sizes can provide a satisfactory heterogeneous pore size distribution. Said pore size distribution can be determined by a capillary stress measurement method, a mercury porosimetry method, and indirectly through a permeability test, all of which are adequately explained in the present disclosure. It has been found by the present inventors that a suitable and suitably sized pore size is in the range of about 1,000 to about 0.2 microns, with a pore size in the range of about 1,000 to about 100 microns used primarily in conjunction with by providing rapid absorption and distribution of the complex fluid, and with a pore size range of from about 100 to about 0.2 microns used primarily in conjunction with providing the permeability and retention capability of the complex fluid.

The adsorbent particles are capable of retaining fluid in interstitial pores or interstices between particles, as well as in the internal pores of the particles themselves. In order to adsorb the fluid, it is desirable that the internal pores of the individual particles be accessible from their surface area. The fluid is capable of entering the internal pore volume of the particle through capillary forces.

is individual

The existence of internal pores in addition to the total pore volume allows the retention of liquid or liquid fluid by capillary reality through the pores. Said proportion of the complex force acting in these provides a feeling of dryness to the skin and inner layer reduces the amount of free, unbound adsorbent particles and, consequently, the liquid also reduces the level of rewet after squeezing. Suitable adsorbent materials of the present invention exhibit internal pore sizes ranging from about 100 to about 0.2 microns for adsorption absorption of different sized component components of the complex fluid, which minimizes the level of rewetting by the post-crushed fluid as determined by use. herein described in sufficiently detailed methods for testing the rewet after crushing and the retention retention capacity by centrifugation.

If too many small pores are present in the structure of the adsorbent material, the liquid component of the complex fluid is removed too quickly, while the remaining part of the complex fluid, which in the case of menstruation is largely cellular material, does not adequately spread. The present inventor has found that

whereas it is desirable for those purposes, that pore volume by dimensional smaller than 1 micron was less than 2 percent total pore volume. Based on top listed fact must adsorption materials suitable a compliant for use in conjunction

with the present invention necessarily have at least the following parameters: they must be wettable, they must be stable and resistant to

In order to provide an acceptable absorbency rate, the fluid must exhibit a suitable interstitial pore size distribution, and must have a suitable internal pore size distribution to provide the desired retention retention capability.

In particular different embodiments of the present invention, additional specific parameters may be desirable. For example, where the absorbed complex fluid is menstruation and the adsorbent material is used as part of a feminine hygiene product, it is desirable that the adsorbent materials of the present invention have a particle size range of from about 1,000 to about 100 microns; and preferably in the range of about 850 to about 150 microns. It has been found by the present inventors that adsorbent material particles having a size size greater than about 1,000 microns are usually readily discernible by the user of any retention means containing adsorbent materials according to the present material, whereas adsorbent material particles having a size below 100 microns It is believed that their content in any retention means is problematic since they could allow complex fluids to penetrate the particle volume of the adsorbent materials. Accordingly, it is believed that the adsorbent material particles falling within the above range may comprise porous particles, or may be agglomerated agglomerates of particles comprising a plurality of smaller particles of one or more adsorbent materials.

Another desirable specific parameter of the adsorbent materials is the retention capacity, which is measured as the weight of the complex fluid, in grams, retained by the respective weight of the adsorption material, in grams, using a method for testing the retention capacity of the complex fluids. For example, where the complexing fluid is menstruation and the adsorbent material is used as part of a feminine hygiene article, it is desirable that the retention capacity of the complex fluid of the adsorbent material be in the range of about to about g / g;

alternatively in the range of about 2 to about g / g; and finally, alternatively in the range of about 2 to about 6 g / g. It is believed that in the case of adsorbent materials having a retention capacity of less than 2 g / g, it would be desirable to use such large amounts of adsorbent material that users of absorbent articles containing such adsorbent material would find, for example, feminine hygiene products excessively heavy. The retention capacity of complex fluids can be estimated by adding pore volume sizes ranging from about 100 to about 0.2 microns in diameter, determined, for example, using the capillary strain detection method or the mercury porosimetry method. The retention capacity of complex fluids is limited by the pore wall strength of the adsorbent material.

As mentioned above, it is desirable for the adsorbent material to exhibit a combination of dimensional particle size to improve the absorbency and fluid retention properties. Adequate large interstitial pores between the particles are needed so that menstruation can rapidly enter the layer of adsorbent particles and subsequently be distributed between the particles. This property can be controlled through the particle size distribution of the adsorbent material. Generally, a wide particle size distribution is desired. The term "wide particle size distribution" is used herein to mean a particle size distribution with a standard deviation of greater than 25 percent of the mean.

If a relatively rapid fluid transfer into and through the adsorbent particle layer is desired, it is advantageous to minimize variations in the interstitial pore size and shape configuration along the interstitial pore length. In view of the above, a relatively wide particle size distribution could be provided by interstitial pores, which explicitly allows the fluid to move into and through the adsorbent particle layer relatively quickly. If the size variations and the crowding of the particles were too great, this means that some particles could even move in the interstitial pores, the rate of fluid transfer into and through the adsorbent particle layer decreases, and may even be relatively slow compared to the previous case.

It has further been found by the present inventors that a combination of dimensional pore size is very effective in conjunction with adsorption absorption of a complex fluid. In particular, for the purpose of the pore size combination, a two-modal or multi-modal particle size distribution is desirable, and this pore size combination is desirable for

ability improvement absorption and retention complex fluids. One way to achieve the required dimensional distribution pore size lies in combining

adsorption particles of different size sizes.

Since the fluid-absorbing properties of interest are dimensional size and pore distribution, another method of achieving a pore size distribution is satisfactory to ensure rapid absorption of complex fluids using relatively large globular particles. For example, it is characteristic that relatively large globular particles collect relatively poorly into tight densification. This relatively poor accumulation and shrinkage of relatively large globular particles can result in the formation of relatively complex interstitial pores, which in turn provide rapid permeation through the large fluid bed of relatively large globular particles.

The densification and compacting of the adsorbent particles in the layer is determined using the detailed method of testing the permeability of the gelled layer described herein. It has been found by the present inventors that the permeability values of the layer of relatively large globular particles above the value of at least 1000 K indicate a relatively poor densification of the particles and consequently indicate the assumption of relatively rapid absorption of complex fluids.

From the foregoing, it should be understood that the present invention is not limited to the use of only one of the adsorbent materials herein, but that it may also include mixtures of two or more such adsorbent materials. As mentioned above, the adsorbent material is in particulate form; therefore, the term " adsorbent material as used in the present description and the appended claims represents either one single adsorbent material in particulate form or a combination of more than one adsorbent material in particulate form.

The adsorbent materials of the present material may preferably be contained in absorbent articles by suitable retention means. Whereas

- 18 Dec. any formulations capable of containing the described adsorbent materials are suitable and useful for use in conjunction with the present invention, which means must further be capable of being incorporated and disposed in disposable absorbent articles. A number of such retention means are known to those skilled in the art. Said retention means may comprise, for example, a fibrous matrix, such as by blowing air or wet laid fibrous webs or webs made of cellulose fibers, blown fibrous webs or webs made of synthetic polymeric fibers, under spunbonded fibrous webs or sheets made of synthetic polymeric fibers, a combination matrix comprising cellulosic fibers and fibrous materials formed of synthetic polymeric fibers, air-blown and thermally bonded fibrous webs or sheets of synthetic polymeric fibers, open cell foam, and similar materials.

Alternatively, the retention means may comprise two layers of material that are joined together to form at least one pocket or storage compartment for receiving the adsorbent material. In such a case, at least one of these layers of material should be liquid pervious. The second material layer may then be either a liquid-permeable layer or a liquid-impermeable layer. Said layers of material may be formed from fabric-like woven and nonwoven materials, closed or open-cell foam, apertured film, elastomeric materials, or may be fibrous webs. In the case where the retention means comprise layers 19- >. · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · The material should have a porous structure insignificant in size or indirectly to the extent that it does not impede the bulk of the adsorbent material. The retention means may additionally comprise a laminate material laminated from two layers of material between which the respective adsorbent material is disposed and contained.

The retention means may further comprise a support structure, for example a fiber or polymeric film structure, to which the adsorbent material is bonded, such as by adhesive adhesion. The adsorbent material may be attached to either or both sides of the support structure, which may be either liquid pervious or liquid impervious.

The adsorbent material is contained in the retention means in an amount ranging from about 10 to about 100; alternatively, in the range of about 20 to about 100; alternatively, in the range of about 30 to about 100; alternatively, in the range of about 40 to about 100; alternatively, in the range of about 50 to about 100; alternatively, in the range of about 60 to about 100; alternatively, in the range of about 70 to about 100; alternatively, in the range of about 80 to about 100; and, finally, alternatively in the range of about 90 to about 100 percent by weight based on the total weight of the retention means and adsorbent material.

According to one specific embodiment of the present invention, the retention means comprises two layers of material which are joined together to form a pocket adapted to receive the adsorbent material. The two layers are preferably formed of any material capable of containing and containing an adsorbent material and including woven and nonwoven materials, for example, materials formed from air blown or wet laid fibers, meltblown fibers, drawn fibers, combined fibers , spunbond fibers (e.g. bicomponent fibers), and the like, and are together using fusion welding, ultrasonic bonding, adhesives (e.g., water-soluble or water-sensitive adhesives or adhesives), latex adhesives, thermoplastic adhesives, adhesive or solvent-based adhesives), and similar methods or compositions, combined to form a pocket for accommodating adsorbent materials. It must be clear from the foregoing that an extensive selection of materials can be used to form the two layers and join them together to form a pocket. The adsorbent material is present in the formed pocket in an amount ranging from about 10 to about 100; alternatively, in the range of about 20 to about 100; alternatively, in the range of about 30 to about 100; alternatively, in the range of about 40 to about 100; alternatively, in the range of about 50 to about 100; alternatively, in the range of about 60 to about 100; alternatively, in the range of about 70 to about 100; alternatively, in the range of about 80 to about 100; and, finally, alternatively in the range of about 90 to about 100 percent by weight based on the total weight of the adsorbent material contained in the pocket and the weight of the two pocket-forming layers, or the weight of the retention means including the adsorbent material. In addition to the adsorbent material, said pocket may further comprise fiber or other filler material which in no way unacceptably affects the adsorbent properties of the adsorbent material.

«* • » • • • <· e · • · • • 9 · 9 and • « • • • • • 9 φ · ··· · • · • • · • 9 > · • • • • • • 9 • 4 ·· · « ♦ · t «« 99 9 9

According to another embodiment, the retention means comprises a fibrous matrix. The adsorbent material in this case is mixed with the fibers of the fiber matrix. The adsorbent material is present in an amount of from about 20 to about 95 in admixture with the fibrous matrix; alternatively, in the range of about 30 to about 85; and, finally, alternatively in the range of about 50 to about 75 percent by weight based on the total weight of the composition.

It is believed that any fibers or fibrous materials capable of containing an adsorbent material and forming composites in combination with the adsorbent material are believed to be suitable and suitable for use in connection with the adsorbent material. In many cases, hydrophilic fibers or fibrous materials are preferred for this purpose. In the light of the facts herein, a fiber or fibrous material is considered to be "hydrophilic," or water retention, when it has a wetting angle of water in the air of less than 90 °. For the purposes of the present invention, the measurement of the wetting angle size is performed using the method of Good and Stromberg described in "Surface and Colloid Science", Vol. 11 (Plenum Press, 1979).

Fibers suitable for use in connection with the present invention include cellulosic fibers such as wood pulp, cotton, short ginning cotton, rayon, acetylcellulose, and the like, as well as synthetic polymer fibers. These synthetic polymer fibers may be formed from naturally hydrophilic polymeric materials, or may be formed from naturally hydrophobic polymeric materials (or liquid-repellent materials of

·· * • 'and· • ♦ • • · • • · • · • • · ♦ O • · • * »· • 9 • * · • • » • ·· ♦ ♦ »9 4 · • • t ·

greater than 90 [deg.]), so that at a final wetting angle of the water in the air the fibers are then further processed to provide at least one hydrophilic fiber layer. Such hydrophilic fibers may, for example, be formed from an intrinsically hydrophilic polymer, such as a nylon block copolymer, such as nylon-6, and a polyethylene oxide diamine. Such block copolymers are commercially available, for example, from Allied-Signal Inc under the tradename HYDROFIL. Alternatively, the fibers may be formed from an internally hydrophobic polymer, such as a polyolefin or polyester, which is subjected to a surface treatment to provide a generally stable and durable hydrophilic surface. Such surface-treated or modified polyethylene is commercially available from Dow Chemical Company, under the trade name ASPUN wettable polyethylene.

In the case where the hydrophilic fibers are formed by the application of a hydrophilic surface treatment in order to ensure their hydrophilicity, it is considered desirable to use a generally stable and durable surface treatment in order to achieve the desired quality.

Suitable for use in can be formed after extrusion to form a polymer in order to obtain a polymer

Alternatively, the material is possible

Synthetic polymeric fibers bonded to the present invention using a meltblown spinning process with a desired fiber diameter are extruded and attenuated by stretching, forming the fibers using a spinning spinning process.

Accordingly, it is believed that any person is suitable for use in conjunction with the present invention

A process known in the art for forming fibers or fibrous materials.

Fibers suitable for use in connection with the present invention typically have a length of at least about 1 millimeter. In contrast, these fibers may have a maximum length approaching substantially infinity. This means, in other words, that the fibers may be substantially continuous, such as fibers formed using a meltblown and blow molding process under certain conditions well known to those skilled in the art.

The term "blend of fibers and adsorbent material", as used herein, is intended to mean that the material is in a direct state in which contact with the fibers or fibrous material is not substantially impeded or migrated into direct contact with said fibers. . Thus, for example, in the case of a multi-layered adsorbent core in which the first layer comprises an air-injected blend of fibrous technical pulp and adsorbent material, and the second layer comprises only an air-injected fibrous technical pulp, only the first layer is considered the above-mentioned blend and adsorbent material, however, substantial migration of the adsorbent material between the two layers in the dry state must be prevented.

Methods of preventing such migration are known in the art and include, for example, separating the two layers by a paper overlay, arranging a highly dense fibrous layer, or the like to prevent substantial migration of adsorbent material between the two layers in the dry state. The mixture of fibers and adsorbent material may be substantially homogeneous or substantially inhomogeneous. In the case of a non-homogeneous mixture, the adsorbent material may have a gradient arrangement, that is, with increasing or decreasing concentration, or the adsorbent material may be layered together with the fibers.

In the case where the retention means comprises a mixture of fibers and adsorbent material, the mixture of fibers and adsorbent material may be formed using a wide variety of different methods. This mixture may be formed, for example, by depositing fibers or adsorbent material by air or wet blowing, in accordance with known techniques, to form a web. By injecting the mixture of fibers and adsorbent material by air-blowing, it is intended to include both a process in which the formed fibers are deposited together with the adsorbent material, and a process in which the adsorbent material is mixed with the formed fibers only after formation, e.g. spinning and blowing.

The adsorbent materials of the present invention are particularly suitable for use in disposable absorbent articles. In general, all of these adsorbent materials can be used in the same manner as standard odor control adsorption materials have been used, for example in laminates, in relatively high densified high density absorbent cores (i.e., pressed cores, calendered cores, compacted cores) , and the like), non-densified cores of low density or relatively (i.e., non-compacted, for example, air-blown cores). However, the adsorbent materials of the present invention provide and provide certain advantages over standard adsorption. In general, the odor control materials of the present invention, adsorbent materials according to the invention, exhibit improved efficiency in the treatment of complex fluids compared to standard, commonly used adsorption materials. The adsorption materials of the present invention show improved efficacy especially in the treatment of menstruation. As a result of the improved efficiency, the adsorbent materials of the present invention provide the developers of the absorbent articles with the flexibility to add either an adequate amount of the adsorbent material of the present invention to the adsorbent materials typically contained in disposable absorbent products as a supplement or a certain amount of absorbent material typically contained in disposable absorbent articles with an adequate amount of the adsorbent material of the present invention.

Methods of testing

Test method for soaking and rewetting speed after squeezing

In connection with the facts presented herein, the method of testing the soaking and rewet rate after squeezing is used to measure at least two of the following material characteristics:

A soaking rate - or the amount of time, measured in seconds, that is necessary to soak a multiple action of known amounts of fluid with a known amount of material; and

2. Rewet after squeezing - or the amount of fluid, measured in grams, that is released from the material after placing the absorbent paper on the top surface of the material and applying a known pressure for a predetermined period of time.

Testing carried out according to this method consists of using a stopwatch to determine the amount of time, in seconds, that is required to treat multiple fluid (1 or 2 mL) treatment with 20 mL of absorbent material by soaking. The Harvard Syringe Pump is programmed to dispense fluid at a rate of 2 ml per 20 ml of absorbent material, and at the same time the stopwatch is started to measure the amount of time when the liquid is dosed. After inserting 2 ml of liquid into the absorbent material, the stem is stopped. Subsequently, dosing and measuring the amount of time of the second treatment with 2 ml of fluid. The second treatment is followed by a third treatment, in which case only 1 ml of the applied fluid is used and measured. As a result, a total amount of 5 ml of liquid is used and tripled for a period of time. After a time delay of approximately 60 seconds after the last, third action of the fluid and soaking, pre-weighed blotting paper is deposited on top of the test material, and then applied a pressure of 0.5 psi for 60 seconds. After a period of 60 seconds, the blotting paper is weighed again and the amount of liquid, in grams, absorbed by the blotting paper and determined by appropriate calculation, is taken as the degree or size of rewet after squeezing. Said testing is typically performed in accordance

with conditions standardized by TAPPI Standard

Conditions.

Equipment and materials used:

Harvard Apparatus Programmable Syringe Pump, Model No. 44, marketed by Harvard Apparatus, South Natick, MA 01760, U.S.A .;

the fluid used for this purpose, by way of example and not limitation, is the synthetic menstruation (complex fluid simulation) disclosed in U.S. Patent No. 5,883,231 to Archer et al. , issued March 16, 1999, the disclosure of which is hereby incorporated in its entirety by reference to the present invention and thus becomes (without limiting in any way the claimed scope) a part of the description of the present invention. This complex fluid simulation, which is described and claimed in detail in U.S. Patent No. 5,883,231, is marketed by Cocalico Biologicals Inc., 449 Stevens Rd., P.O. Box 265, Reamstown, PA17567, U.S.A .;

disposable plastic weighing trays (i.e. intended for destruction after use), marketed by NCL of Wisconsin Inc., Birnamwood, WI 54414, U.S.A., Product No. W-D 80055;

Single use disposable syringe

2860 cc (60 cubic centimeters), marketed by Becton Dickinson, Franklin Lakes, NJ 07417, U.S.A .; Tygon plastic tube, size 16, 0.12 inch ID, catalog number 6409-16, commercially available from Cole-Parmer Instrument Company, Chicago, IL 60648, U.S.A .; and plastic tubing, syringe needle tip size, 1/8 inch OD, article number R-3603, also available from Cole-Parmer Instrument Company, Chicago, IL 60648, U.S.A .;

5x5 cm absorbent paper, commercially available from VWR Scientific Products, 1145 Conwell Ave., Willard, OH 44890, U.S.A. Catalog No. 28310-015;

a 100 ml pyrex beaker, filled with a substance of 717.5 grams to give a loading pressure of 0.5 psi with any suitable substance for that purpose;

laboratory scales, accurate to 0,001 g (Note: the standardized conditions applicable for this purpose may, for example, be those specified by the NITS standard, and the scales used may be tested for error rate to ensure the required accuracy);

stopwatches readable to the nearest 0,1 second (Note: the standardized conditions applicable for this purpose may be, for example, those specified by the NITS standard);

cylindrical vessel fitted with a graduation scale of 20 ml;

transparent plexiglass plate (whose dimensional ······· ·:

The size is adjusted so that it can be placed on top of the plastic. disposable weighing trays) provided with a through hole bored approximately in the center thereof and intended to receive a Tygon plastic tube.

Preparation of test samples:

The complex fluid simulation is removed from the cooling device, placed on a turntable and then allowed to slowly rotate for about 30 minutes to thoroughly mix the complex fluid simulation and bring the temperature thereof to room temperature.

At the same time, the graduated cylindrical vessel is placed on the scale and its weight is weighed when empty. 20 ml of the test material is then placed in a graduated cylindrical vessel. After reweighing, the graduated cylindrical vessel is removed from the balance. Then, gently, approximately 10 times, tap the bottom of the cylindrical vessel, after placing it on top of a laboratory bench or similar hardened surface, to settle the test material. A visual inspection is then carried out to ensure that the graduated cylindrical vessel contains 20 ml of material. The 20 ml of material is then poured into a plastic weighing pan and the material is allowed to slowly settle to a horizontal position.

The Harvard Syringe Pump is set to programmed mode. The filling or dispensing velocity of the fluid is set to 12 ml / min with a total dispensing volume set to 2 ml. The appropriate diameter is set to the appropriate size used

- 30 - • 0 00 ·· 0 · Φ · · 0 0 0 0 · • 0 0 0 0 0 0 0 0 0 00 0 · ·· 0 00 04 00 0 0 · • 0 0 0 0 0 · 0 0 0 0 000 0 · ·· injection syringes. Injection molding Pump type Harvard Syringe Pump up filled with complex simulation fluid

in an amount of about 60 ml.

The individual implementation steps of this test method are as follows:

1. One end of the Tygon plastic tube is inserted into and passed through a through hole provided in the Plexiglas plate.

2. Place the Plexiglas plate on top and over a plastic weighing pan containing 20 ml of absorbent material. The Tygon plastic tube should be positioned approximately against the central region of the material.

3. In this state, the timing and initiation of a 2 ml simulation of the complex fluid is simultaneously initiated by actuating the stopwatch to achieve its first action on the material.

4. After soaking the first batch of complex fluid simulation with the test material, the stopwatch is stopped. The measured amount of time, in seconds, read from the stopwatch, is recorded as “1. effect of complex fluid simulation. In the event that the complex fluid simulation is not absorbed by the test material within a five-minute period (ie, when the complex fluid simulation remains on top of the test material), the testing is interrupted and as “1. the value of 300+ seconds is recorded.

5. Again at the same time, by placing the stopwatch in

- 31 - ·· ··. . • »· · · · • · · ·! ! • · ····· · ·· ·· ·· • ··· · · · · · · • · · • · · · · • · · · ··· ·· ··· activities, starts the measurement time and dispensing 2 ml simulation complex Fluid for purpose achieving her second effect on material. 6. Mon soaking this second batch simulation complex

fluid by the test material interrupts the operation of the stopwatch. The measured amount of time, in seconds, read from the stopwatch, is recorded as “2. effect of complex fluid simulation. In the event that the complex fluid simulation is not absorbed by the test material within a five minute period (i.e., when the complex fluid simulation remains on top of the test material), the testing is interrupted and as “2. the value of 300+ seconds is recorded.

7. Thereafter, the timing and the simulation of the complex fluid while it is acting on the material are resumed simultaneously by actuating the stopwatch. In this case, however, the Harvard Syringe Pump is interrupted after dispensing only 1 ml of complex fluid simulation.

8. After soaking a 1 ml dose of complex fluid simulation with the test material, the stopwatch is stopped. The measured amount of time, in seconds, read from the stopwatch, is recorded as' 3. effect of complex fluid simulation. In the event that the simulation of the complex fluid would not be aspirated again and absorbed by the test material within a time interval of five minutes (i.e., when the complex fluid simulation remains on the top of the test material), the test is aborted and as “3. the value of 300+ seconds is recorded.

9. After a third effect of simulating the complex fluid and absorbing it with the test material, a time delay of 60 seconds is allowed.

10. Thereafter, two pieces of blotting paper are weighed and the weight recorded is recorded as the weight of blotting paper in the dry state.

11. After the timeout of 60 seconds mentioned in step 9, the blotting paper is gently placed on the test material, then the blotting paper is gently placed on the blotting paper due to its weight on the test material at 5 psi pressure and the stopwatch is started.

12. After 60 seconds, the weight is removed and the blotting paper is weighed again. The weight obtained is recorded as the wet weight of the absorbent paper.

Steps 3 to 12, described in detail above, are repeated until the test material is no longer capable of receiving and soaking the complex fluid simulation (i.e., in other words, the complex fluid simulation remains on top of the test material and at the said material). time interval of five minutes will no longer be absorbed).

The results of the part of this test method concerning the determination of rewet for crushing, measured in grams, shall be recorded and used for the relevant calculations according to the following equation:

(BP _m ) (BP _SS ) = rewet after crushing;

· ♦

AND

«·«

9 · »99 · <

·· • ·

Where: (BP _M ) = wet weight of absorbent paper, and (BP _SS ) = dry weight of absorbent paper.

Method of determination of retention capacity

In connection with the facts presented herein, the retention capacity determination method is used to measure the amount of test fluid that will be retained in a test sample of the material after the centrifugal force has been applied to the material. The amount of fluid retained, after appropriate calculations, is taken as the fluid retention capacity, or retention capacity, and is reported in grams per gram (g / g). Said test method is typically conducted in accordance with TAPPI Standard Conditions. In the case where the fluid used to test the material is a complex fluid, such as blood, menstruation, synthetic menstruation (complex fluid simulation), vaginal discharge, nasal secretions, and the like, material retention capacity is sometimes also referred to as complex fluid retention capacity (CFRC).

Generally speaking, test testing using this method is carried out by placing 0.5 g of a sample of test material in a conditioned cylindrical container, exposing the sample of test material to the desired fluid for 60 minutes, and then cylindrical containers to remove excess fluid. placed in a centrifuge. The observed and measured values are used to calculate the amount of fluid retained in grams per gram of sample of test material.

Equipment and materials used:

synthetic menstruation (complex fluid simulation) disclosed and described in U.S. Patent No. 5,883,231 to Archer et al. This complex fluid simulation, which is described and claimed in detail in U.S. Patent No. 5,883,231, is marketed by Cocalico Biologicals Inc., 449 Stevens Rd., P.O. Box 265, Reamstown, PA17567, U.S.A .;

Sorvall RT 6000D centrifuge, available from the market

Global Medical Instrumentation Inc., 3874 Bridgewater Dr., St. Paul, MN 55123, U.S.A .;

four 200 ml screw cap centrifuge flasks, available from International Equipment Co., 300 Second Ave, Needham Heights, MA 02494, U.S.A .;

laboratory scales, accurate to 0,001 g (Note: the standardized conditions applicable for this purpose may, for example, be those set by the NITS standard, and the scales used may be tested for frequency to ensure the required accuracy);

four 50-ml pyrex beakers;

a laboratory timekeeper, with a measuring range of 60 minutes, with an accuracy of one second reading, commercialized by VWR Scientific Products, 1145 Conwell Ave., Willard, OH 44890, U.S.A .;

four modified cylindrical containers LEXAN, 9 cm high, with inner diameter 3 1 cm, external diameter 4,8 cm, fitted with a 300 mesh / cm ² sieve attached to the bottom;

US &apos; s 30 & 50 sized screen, 8 inch diameter and 2 inch height, marketed by VWR Scientific Products, 1145 Conwell Ave., Willard, OH 44890, USA, product numbers in the order, respectively, 57334 -456, and 57334-464;

stainless steel grid with four holes per inch, or with perforations large enough to allow passage and flow of complex fluid simulation.

Preparation of test samples:

Using a 30 and 50 size sieve according to the US standard, a sample of the test material is divided into aliquots having a particle size ranging from 300 to 600 microns. This aliquot sample of test material is stored in a substantially airtight container until it is used to prepare a particular sample or samples of test material. Treated cylindrical containers are individually placed on the scales and their empty weight is weighed. 0.5 g ± 0.005 g of the prepared sample of test material is placed in one of the four treated cylindrical containers used. The sample weight is recorded as the sample weight of the test material.

The conditioned cylindrical vessel containing a sample of the test material is weighed and this weight is recorded as the dry weight of the cylindrical vessel.

Additional samples of the test material were placed in the three remaining cylindrical vessels and subjected to the following test method.

The complex fluid simulation is removed from the cooling device, placed on a turntable and then allowed to slowly rotate for about 30 minutes to thoroughly mix the complex fluid simulation and bring the temperature thereof to room temperature.

The individual testing steps are as follows:

of this test method

1. Approximately 10 ml of complex fluid simulation is placed in a 50 ml pyrex beaker.

2. Do pyrexové beakers about volume 50 ml se places a modified cylindrical vessel, in which Yippee occupied sample tested material. 3. Do modified cylindrical containers se nalij e approximately

ml of complex fluid simulation. This ensures access to the sample of the test material from both the top and bottom from the simulation of the complex fluid.

4. The same steps 1 to 3 described above are repeated for the next three required samples of the test material.

5. After step 4 is completed, the laboratory timer is set to a measuring range of 60 minutes and activated.

6. After 60 minutes, the treated cylindrical vessels are removed from the pyrex beakers and placed on a stainless steel grid, where they are left for 60 seconds.

·

9

9

9 ·

♦ · • · · · · ·

99 9

7. After 60 seconds, the conditioned cylindrical vessels from the stainless steel grid are removed and placed in 200 ml centrifuge flasks.

8. The centrifuge flasks are then placed in a centrifuge and subjected to centrifugation for 3 minutes at 1200 rpm.

9. After a period of 3 minutes, the conditioned cylindrical vessels are removed from the centrifuge flasks, and the conditioned cylindrical vessels containing samples of the test material are weighed. The weight obtained is recorded as the wet weight of the cylindrical vessel.

The complex fluid retention capacity (CFRC) of each adsorbent sample tested is then calculated according to the following equation:

CFRC - [(Mvzm M / Ss) / Mrvc where: M _vzm = wet cylinder weight; Mvss = dry weight of the cylindrical vessel; Mvtm = sample mass of test material; and further, in connection with any of the following examples, the reported retention capacity values represent the average obtained from two samples (i.e., n = 2).

Test method for capillary stress testing

The Capillary Stress Test Method (CTT) is a test method that measures the ability of an absorbent material to absorb a liquid (in this case specifically 0.9% sodium chloride solution in distilled water) while applying a load or retention force while exposed to the material. the effect of a vacuum gradient.

Next, referring to FIG. 1 of the accompanying drawings, for determining values, a detailed description of the apparatus and method of capillary stress CTT. The apparatus is shown in a perspective view and in a state when carrying out a trial test.

As can be seen from the figure, a laboratory stand 31 having a scale in centimeters and having an adjustable sleeve 32 to enable lifting and lowering of the support ring 33 can be seen. This support ring 33 carries a funnel 34 having a diameter of 6 centimeters. In this funnel 34 is an aperture provided with a glass plate 35 having a nominal maximum aperture diameter of about 40 microns.

up to 60 plastic

To the bottom of the funnel 34 of the tube 36 which is fixed first by its opposite, second flexible end attached to the one end of the rigid, rigid plastic tube 37 which is held in the corresponding position by the plastic tube 37 is the clamps 38.

coupled with

The other end is rigid with one end of the other flexible plastic tube

39, the other end of which is again attached to the vented fluid reservoir 40.

The vented fluid reservoir 40 is mounted on a scale 41 to which a recording apparatus 42 is attached, which is used to record the weight loss of fluid from the vented fluid reservoir 40 due to its adsorption absorption by the test sample and subsequent evaluation of the test sample.

A plastic beaker 43 for test specimens containing a sample 44 of material to be tested is provided with a liquid-permeable bottom and rests on the holes provided with a glass plate 35 in the funnel 34. On the upper side of the spacer insert 5 that rests on the upper side of the sample of the test material, the weight is stored 46.

The beaker 43 for test samples consists of a plastic cylinder with an internal diameter of 1 inch and an external diameter of 1.25 inch. The bottom of a 100-mesh metal test beaker 43 with a 150 micron diameter aperture is attached to the bottom of said plastic cylinder by heating the metal grid above the melting point of the plastic and pressing the plastic cylinder against the heated grid to melt the plastic and plastic cylinder.

In order to carry out the test, a sample 44 of the test material in a quantity of 10.12 cubic centimeters is placed in a plastic beaker 43. Then, a weight of 100 grams 46 is placed on top of the spacer to provide a load of about 0.3 pounds per square inch. The plastic beaker 43 for the test samples is placed on the openings provided with the glass plate 35.

The vacuum gradient is adjusted by lowering the funnel 34 until the liquid from the vented fluid reservoir 40 flows through the plastic tubes 37, 38 and 39 into the funnel 34 and is brought into contact with the holes provided with the glass plate 35. Then, the funnel 34 rises along a graduated laboratory rack 31 to an appropriate level until a desired vacuum gradient (measured as height difference, in centimeters, between the surface of the liquid in the vented fluid reservoir 40 and the level of the aperture provided with the glass plate 35) is achieved. Thereafter, the recorder is allowed to measure and record the appropriate amount of liquid that has been withdrawn from the vented liquid reservoir 40 and absorbed by the absorbent material, namely the amount of liquid in grams absorbed per gram of material as a function of the vacuum gradient. The vacuum gradient is inversely proportional to the equivalent radius of the interstitial pores according to the following equation:

R = (2-cyclo) / (ω);

wherein: R = equivalent interstitial pore radius; γ = surface tension of the fluid; θ = contact angle; δ - density of the fluid; g = gravitational acceleration; and h = vacuum gradient.

Based on this test method, it is possible to generate a table of total volume and pore size values as a function of the equivalent interstitial pore radius.

Method of testing the permeability of a gelled layer

For the purpose of carrying out the gel-permeability test (GPB) method, a suitable apparatus (i.e., a piston-cylinder device) is shown by way of example in Figures 2 and 3 of the accompanying drawings. Referring to FIG. 2, the apparatus 120 shown here consists of a cylinder 122 and a piston (generally designated 124). As can be seen from the illustration in Fig. 2, the piston 124 consists of a LEXAN tubular shaft 126 with a coaxial cylindrical bore 128 provided in the direction of its longitudinal axis. Both ends of the shank 126 are mounted by machining to form the first end 130 and the second end 132. At the first end 130 of the shank is a weight 134 that is provided with a cylindrical bore 136 drilled in the center thereof. At the other end 132 of the shaft is a circular piston head 140. This piston head 140 is dimensioned such that it can be displaced vertically within the cylinder 122. As can be seen from the illustration in FIG. 3, the piston head 140 is provided with two, internal and external, coaxial circular rings each comprising seven and fourteen cylindrical bores approximately 0.375 inches (0.95 cm) in diameter (designated generally (142 and 144).

The cylindrical holes of each of said coaxially arranged annular rims are drilled in the direction from the upper side of the piston head 140 to its bottom. In addition, the piston head 140 is provided with a cylindrical bore 146 which is drilled in the center thereof and is intended to receive the second end 132 of the tubular shaft 126.

A 400 mesh stainless steel wire mesh 148 is attached to the bottom of the cylinder 122 and is subjected to expansion in two orthogonal axial directions prior to attachment to the tensioned state. Also attached to the lower end (top side) of the piston head 140 is a 400 mesh stainless steel wire mesh 150, which is stretched in two perpendicular axial directions prior to attaching it to the tensioned state. An appropriate sample 152 of test adsorbent material is deposited on the grid 148.

The cylinder 122 is formed by drilling out of a transparent LEXAN round bar or equivalent, and has an inner diameter of 6.00 cm (28.27 cm ² surface area), a wall thickness of approximately 0.5 cm, and a height about 5.0 cm. The piston head 140 is also formed from the LEXAN circular rod. This head has a height of approximately 0.625 inches (1.59 cm) and a diameter that is dimensionally dimensioned to fit and fit into the cylinder 122 with minimal wall clearance, and at the same time in a free, sliding fit. A cylindrical bore 146 formed in the center of the piston head 140 has a diameter of 0.625 inches (1.59 cm) and is threaded (18 turns per inch) to screw the other end 132 of the stem 126.

This shaft 126 is formed by machining and drilling a round bar

LEXAN, and has an outside diameter of size inside diameter of size

0.250 inches

The other end

132 is approximately 0.5 inches (1.27 cm) long for screwing into a cylindrical bore and is threaded

146 formed in the piston head 140. The first end 130, which is approximately 1 inch (2.54 cm) long and exhibits 0.623 inch (1.58 cm) in diameter, forms an annular stainless steel shoulder for supporting and supporting steel weights 134. This stainless steel weight is annular in shape and has an inner diameter of 0.625 inch (1.59 cm) so that it can slidably engage the first end 130 of the stem 126 and rest against the annular shoulder at the first end of the stem . The sum of the weight of the piston 124 and the weight of the weight 134 equals approximately 596 g, which in turn corresponds to a pressure of 0.30 psi (20.685 dynes / cm ² ) on an area of 28.27 cm ² .

As liquids flow through the piston apparatus •

the cylinder 122 is generally supported on a 16 mesh (not shown) rigid stainless steel support grid or equivalent. A piston with a weight is placed in the empty cylinder to determine the appropriate dimension between the underside of the weight and the upper edge of the cylinder. The appropriate dimension is measured using a dividing device with an accuracy of 0.01 mm. The determined dimension will later be used to calculate the height of the sample layer 152 of the adsorbent material. For this purpose, it is important to measure the cylinder empty and maintain the sequence in which the weight piston was used, because the same piston and the same weight should be used to measure a sample of the adsorbed material being swollen.

The layer of adsorbent material used in conjunction with the measurement and permeability measurement of the gelled layer (GBP) is formed by swelling about 0.9 g of a sample of test adsorbent material in a piston apparatus for performing the GPB method (the adsorbent material should be from its dry state firstly evenly distributed over the surface of the entire grid of the cylinder) through the action of a fluid, typically 0.9% aqueous NaCl solution (i.e. 0.9% NaCl based on total weight) for approximately 15 minutes. The sample adsorption material used is taken from the proportion of adsorption material that has passed through a 30 mesh screen (US standard) and has been retained on a 50 mesh screen (US standard). Accordingly, the adsorbent material exhibits a particle size in the range of 300 to 600 microns. The screening of adsorbent material particles on the screen can be carried out manually or mechanically, using, for example, Ro-Tap mechanical screening shakers.

Model B, available from W.S. Tyler, Inc., Mentor, OH, U.S.A.

At the end of the 15 minute period, the cylinder is removed from the fluid and a plunger / weight assembly is placed on a sample of adsorbent material to be tested. The thickness of the swollen sample of the adsorption material to be tested is determined by measuring the dimension between the underside of the weight and the upper edge of the cylinder using a micrometer. Then, the value obtained when measuring the empty cylinder is subtracted from the value obtained after measuring the swollen sample of the adsorbent material to be tested. The resulting value represents the height H of the swollen sample of the test adsorbent material.

The measurement of the permeability of the gelled layer GBP is initiated by adding fluid to the cylinder 122 until the amount of the fluid reaches a height of 4.0 cm from the underside of the sample 152 of the adsorbent material to be tested. This fluid level is maintained throughout testing. The amount of fluid passing through a sample of adsorbent material over time is measured gravimetrically. Individual data are recorded every second for the first two minutes of the test, and every two seconds for the remainder of the test. By plotting this data as a function of the amount of fluid passing through the sample layer of test adsorbent over time, those skilled in the art will be able to appreciate when an even flow rate has been achieved by those skilled in the art. Only the data recorded after the flow rate, which is uniform, is then used to calculate the respective flow rate. Fluid Flow Rate Q, in g / sec, through sample 152 ♦ · ·· ♦ 1 ♦ ♦ • i ·

9 9 9

9

9 9 · 999

9

9 999999

The test adsorption material is determined by direct, at least areal, through the sample of test adsorption material through the fluid passing through the material (in grams) versus time (in seconds).

The permeability of the gelled layer, in cm ² , is calculated using the following equation:

K = [Q * (H * Mu)] / [A * Rho * P] where: K = gel permeability

Q = fluid flow rate (g / sec);

layers

H - height of the sample layer of the test material

Mu - liquid viscosity liquid flow (cm ² );

P = hydrostatic pressure (dyn / cm ² ).

flat

Rho = density

Examples

The following Examples describe particular embodiments of the present invention. Other various embodiments of the present invention, falling within the scope of the appended claims, will be apparent to those skilled in the art from the detailed description of the invention presented herein or its practical implementation only upon consideration. Accordingly, the description, together with the Examples, is intended to be exemplary only and not limiting of the spirit and scope of the present invention as set forth in the following claims.

Example 1

4

This example demonstrates that the use of silica as an adsorbent material is satisfactory for the purposes of processing complex fluids, such as menstruation, and good results are obtained. The adsorbent material used in this Example is a granulated adsorption material with the trade name Zeofree 5157B, commercially available from J.M.Huber Corp. of Havre de Grace, MD, U.S.A. Granulation is achieved by physical means, and this material contains no other ingredients besides the precipitated silica particles. The Zeofree 5157B adsorption material, in an untreated state, was subjected to an assessment of the rate of soaking and rewetting after crushing, based on appropriate test methods. The results are shown in Table 1.

Table 1

Zeofree 5175B 1st action (s) 45, 91 2nd action (s) 62.34 3rd action (s) 63.0 Rewet after crushing (g) 0, 85

The resulting retention capacity of the complex fluid (here, complex fluid simulation) for the above sample of test material is at least about 2.05 g / g.

Example 2

This Example illustrates the effect and effect of particle size and distribution on the absorption capacity of Zeofree 5175B adsorption material, or precipitated silica, supplied by the company to the commercial market.

J.M.Huber

Havre de

Grace, MD, U.S.A. Adsorption material

Zeofree

5175B was screened for finely divided portions of material according to the particle size distribution for the purpose of this Example.

The individual proportions of the material were subjected to an assessment of the rate of soaking and rewetting after crushing as appropriate, and in combination with each other to demonstrate that the rate of soaking was efficiently possible through a suitable combination of particles of varying size . The results obtained in these evaluations are shown in Table 2a and demonstrate that the narrowly defined particle size distribution is not sufficiently effective for the relatively rapid adsorption of fluid.

- 48 Table 2a

Material/ Mesh 1st action (with) 2. effect (with) 3. effect (with) Rewetting (g) Unsorted 45, 91 62.34 63, 0 0, 85 > 20 300+ - - - 20-30 300+ - - - 30-40 300+ - - - 40-50 236 300+ - - 50-60 300 + - - - 60-70 300+ - - - 70-80 268 300+ - - 80-100 300 + - - - 100-140 300+ - - - 140-170 300+ - - - 30-50 178, 8 122 184 0, 74

Table 2b below illustrates, by way of example, that in the case of recombination of narrowly defined particle size distributions into two-modal particle size distributions, some combinations may be capable of soaking up liquid with soaking times of less than 150 seconds, which is considered desirable. Suitable combinations for this purpose include a greater percentage of coarse materials. Adequate proportions of particle size proportions range from fine to coarse particles and include a suitable 10/90 mesh ratio; an even more preferred 20/80 mesh ratio; and the most suitable and most desired 25/75 mesh ratio. Said recombined proportions of particulate material may be characterized as proportions with a standard deviation of greater than 25 percent based on the mean diameter.

··

Table 2b

Percentage of ingredients in the sieve 50:30 (%) 1st action (with) 2. effect (with) 3. effect (with) 10/90 92 110 145 20/80 67 124 134, 5 25/75 60 107 169 50/50 209, 5 260 140 75/25 216 300+ - 80/20 206 146 - 90/10 160 168 185

Table 2c below illustrates, by way of example, a dimensional size distribution of the interstitial pores of Zeofree 5175B adsorbed material screened on sieves ranging from about 30 to about 50 mesh, which was determined using the capillary stress test method. Further Table 2d illustrates, by way of example, a dimensional size distribution of the interstitial pores of Zeofree 5175B adsorber material having a component ratio: 75% of a material ranging from about 20 to about 30 mesh and 25% of a material ranging from about 40 to about 50 mesh, which was determined using the aforementioned capillary stress test method. The pore size distribution obtained by combining the two sized particle size proportions shown in Table 2d contains a smaller percentage of small pore sizes than the sample shown in Table 2c. A relatively larger percentage of pores greater than about 100 microns in the combined particulate mixture correlates with the achievement of improved absorbency, which may be seen from the data in Table 2a and Table 2b.

Table 2c

Pore radius (microns) Total pore volume (g / g) Gap volume (cumulative) (%) 50, 00 2.27 76, 96 100.00 2, 30 77.94 150.00 2.39 81, 15 200.00 2.49 84.56 250.00 2.59 87.86 300.00 2.70 91, 52 350,00 2.78 94.14 400.00 2.79 94.75 450,00 2, 81 95, 20 500.00 2, 82 95, 49 1000,00 2.95 100.00

Table 2d

Pore radius (microns) Total pore volume (g / g) Gap volume (summary) (%) 50.00 2, 08 70.24 100.00 2, 08 70, 34 150.00 2, 09 70.74 200.00 2.15 72, 67 250.00 2.35 79.28 300.00 2.49 84, 14 350,00 2.59 87, 71 400.00 2, 67 90.39 450,00 2.73 92, 27 500.00 2, 75 93, 09 1000,00 2, 96 100.00

Example 3

For the purposes of this Example, vermiculite, or hydrated laminar magnesium aluminum-iron-silicate (commercially available from Strong-Lite Products, POBox 8029, Pine Bluff, AR 71611, USA) is used as the adsorption material, and this Example illustrates that the tested The vermiculite adsorbent material exhibits the desired soaking time, the desired rewet level after crushing, and the desired retention capacity of complex fluids (see Table 3a). Table 3b illustrates, by way of example, that the vermiculite adsorbent material exhibits a satisfactory pore size distribution to provide the desired crush-soaking capability.

and the desired rewet levels after in the Test Table

Dimensional distribution

3b was determined at capillary stress. It has pore sizes indicated by the test method that the laminar and internal porous structure of vermiculite has a significant proportion and provides this adsorbent material with the required capability of soaking rate, rewet level after crushing and retention capacity of complex fluids.

Table 3a

Vermiculite 1st action (s) 29, 03 2nd action (s) 30.56 3rd action (s) 19, 62 Rewet after crushing (g) 0.32

Table 3b

Pore radius (microns) Total pore volume (g / g) Gap volume (cumulative) (%) 50, 00 2, 87 57.93 100.00 2.94 59, 25 150.00 3.13 63.10 200.00 3.55 71, 65 250.00 3.95 79, 58 300.00 4.23 85.26 350,00 4.37 88, 09 400.00 4.54 91, 62 450,00 4, 61 93, 00 500.00 4, 67 94.13 1000,00 4.96 100.00

The vermiculite has a resulting complex fluid retention capacity of at least about 2.17 g / g.

Example 4

For the purposes of this Example, Ryolex 3, or primary aluminosilicate (commercially available from Silbrico Corp., 6300 River Rd., Hodkins, IL 60525-4257, USA), known from the prior art as perlite, was used as the adsorption material. and this Example illustrates that the adsorbent material tested, as can be seen from Table 4a, exhibits the desired soaking time. Further Table 4b illustrates, by way of example, that the Ryolex 3 adsorbent material exhibits a satisfactory distribution of < 0 &gt; 0 &gt; 9 &lt; 9 &gt; 9 &lt; 9 &gt; · 9 * 9 · 9 · 9 · 999 · 9 99 99 · 9 9 9 9 · 9 9 Pore size to provide the required absorbency. The pore size distribution reported in Table 4b was determined using the capillary stress test method.

The Ryolex 3 adsorbent material has a resulting complex fluid retention capacity of at least about 4.4 g / g.

Table 4a

Ryolex 3 1st action (s) 42.45 2nd action (s) 59.88 3rd action (s) 80.27 Rewetting (g) 1.08

Table 4b

Pore radius (microns) Total pore volume (g / g) Gap volume (cumulative) (%) 50, 00 3, 06 72.36 100.00 3.26 77.20 150.00 3, 45 81.60 200.00 3.58 84.79 250.00 3.70 87, 64 300.00 3.76 89, 00 350,00 3, 82 90, 49 400.00 3.88 91.75 450,00 3, 91 92.48 500.00 3, 93 92, 97 1000,00 4.23 100.00

· · · · · · * • • • • • • • • • • • • •

Example 5

For the purposes of this Example, a material designated Celphere CP305, or microcrystalline cellulose in globular form (commercially available from FMC Market St., Philadelphia, PA 19103, USA) was used as the adsorption material, and this Example illustrates that the adsorption material tested shows, as can be seen from Table 5, the required soaking time and rewet level after crushing.

Table 5

Celphere CP305 1st action (s) 31.89 2nd action (s) 56.99 3rd action (s) 47.78 Rewet after crushing (g) 0, 00

Celphere CP305 is an example of a relatively globular adsorption material that exhibits a uniform particle size distribution (i.e., an average mean particle diameter of about 400 microns). Since the material particles are rather large and relatively globular, the permeability of the material is high (i.e., greater than about 1,000 K). This high permeability also explains how to achieve the desired absorbency. However, since the Celphere CP305 has no internal structure, the retention capacity is achieved. · · · · · · · · · · · · · · · · · · · · · · · Complex liquids of about 0.63 g / g, and illustrates, in terms of retention retention capacity of the complex fluid, the necessary securing of pores smaller than about

100 microns.

Example 6 For for the purposes of this Example was like adsorption material used material with business designation LC200 HF, or

material formed from cellulose fibers in a pelletized form (commercially available from J. Rettenmaier & Söhne GmbH & Co., D-73496, Rosenberg, Germany), and this Example illustrates that the adsorption material tested shows how it can be seen from Table 6, required soaking time and rewet level after crushing.

Table 6

LC200 HF 1st action (s) 34 2nd action (s) 38 3rd action (s) 26 Rewet after crushing (g) 0.75

Example 7

For the purposes of this Example, a material designated Csb-O-Sil M5, or unprocessed and untreated disinfected silica (commercially available from Cabot Corp.), was used as the adsorbent material. 9 99 9 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 99 · «· ····

Boston, 02Α 02109, U.S.A.), and this Example illustrates the effect and effect on fluid absorption capacity (in this case complex fluid simulation) caused by dewatering due to the presence of too large a percentage (> 2 percent) of small pores (<1 micron). Table 7a illustrates, by way of example, the effect and effect of the presence of too much pore size of less than about 1 micron on the absorption rate of the complex fluid.

Table 7a

Ca-O-Sil M4 1st action (s) 300 + 2nd action (s) - 3rd action (s) -

Table 7b Table 4b 4 444 444 4 444 4 4 4 4 ·· 444 ·· ····

Pore radius (microns) Total pore volume (g / g) Gap volume (cumulative) (%) 653,512 12.6411 100, 0 378,860 12.4288 98.3 259,830 12,002 94.9 200,326 11.4777 90, 8 162,243 11,0606 87.5 135,774 10.6848 84.5 117,322 10.3533 81, 9 102,620 9.9384 78, 6 90,892 9.6361 76, 2 81,925 9, 3729 74.1 74.171 9,1418 72.3 68,064 8,808 69, 7 62,602 8.58 67, 9 58,144 8.3835 66, 3 54,149 8.0819 63, 9 50,265 7,8929 62.4 47,840 7.7631 61.4 45,261 7.6236 60, 3 39,375 7,2523 57.4 30,661 6, 6537 52, 6 20,600 5.7078 45.2 10,037 4.0636 32.1 8,037 3,621 28, 6 6, 030 3.0944 24.5 4,101 2,5759 20.4 2,007 1,7004 13.5 1,039 1,0323 8.2 0.512 0.4653 3.7 0.251 O o O o

The data presented in Table 7b exemplifies that the Cab-O-Sil dimensional pore size distribution, determined using the mercury porosimetry method, contains 8 percent pore volume in pores less than about 1 micron in diameter. Appropriate mercury porosimetry data was provided by Micromeritics Instrument Corp., One Micromeritics Dr., Norcross, GA 30093, U.S.A. The required test method for this purpose was the Marco and Meso Volume / Size Distribution method for determining the size and distribution of Marco and Meso pore size using mercury porosimetry based on mercury permeability measurement, Test No. 005-65000-31 . A sample of the material was tested on an Auto-Pore Mercury Porosimeter mercury porosimeter, Unit 750, from Micromeritics Instrument Corp., which started on July 28, 1999 at 5:00 pm and ended on July 29, 1999 at 10:00 am.

The examples described above do not in any way limit the claimed scope of the present invention. Accordingly, any other modifications, adaptations and modifications, as well as other embodiments and uses of the proposed and described composites containing superabsorbent materials, apparent to those skilled in the art, are also considered to fall within the claimed scope of the present invention as defined in the appended claims. .

Reference plate laboratory stand adjustable collar thrust ring funnel openings glass plate first flexible plastic tube rigid plastic tube clamp second flexible plastic tube ventilated liquid tank scales recorder plastic beaker for test specimens sample of sample material spacer spacer cylinder piston rod cylinder drilling first end second end weights cylindrical hole circular piston head inner circular rim outer circular rim cylindrical hole stainless steel wire mesh stainless steel wire mesh adsorption material sample

Claims (54)

PATENT CLAIMS An absorbent article comprising retention means and particles of at least one adsorbent material, characterized in that in said retention means about 20 to about 50 percent have a pore volume provided by pores greater than about 100 microns for absorbing complex fluids and distributing complex fluids, and about 80 to about 50 percent of the adsorbent particles have a pore volume provided by pores of less than about 100 microns for retention retention of complex fluids, and that the adsorbent particles are present in said retention means in an amount ranging from about 10 to about 100 percent based on the total the weight of the retention means and adsorbent particles. 2. The absorbent article of claim 1 wherein said retention means comprises a top face layer and a backsheet. 3. The absorbent article of Claim 2 wherein said topsheet is a liquid-permeable nonwoven. 4. The absorbent article of claim 2 wherein said topsheet is an apertured film. 5. The absorbent article of Claim 2 wherein said backsheet is a nonwoven. 6. The absorbent article of Claim 1 wherein said adsorbent material comprises a hydrophilic material. 7. The absorbent article of claim 1 wherein said adsorbent particles are bonded directly to the fibrous material or polymeric film. 8. The absorbent article of Claim 6 wherein said adsorbent material comprises an inorganic material. 9. An absorbent article according to claim 8 wherein said adsorbent material is selected from the group consisting of activated carbon, metal oxides, silicates, zeolites, carbonates, phosphates, borates, and aerogels. 10. An absorbent article according to claim 6 wherein said adsorbent material comprises an organic material. 11. The absorbent article of Claim 10 wherein said adsorbent material is selected from the group consisting of cellulosic materials, starches, chitins, alginates, and synthetic polymers. 12. The absorbent article of Claim 6 wherein said adsorbent material is a mixture of organic and inorganic materials. 13. The absorbent article of claim 1 wherein said adsorbent material has an interstitial gap size in the range of about 100 to about 1,000 microns. G& 6T - 14. The absorbent article of claim 1 wherein said adsorbent material has a pore size between about 100 microns to about 0.2 microns. The absorbent article of claim 1, wherein less than about 2 percent of the pore volume provides pores of less than about 1 micron. 16. An absorbent article comprising retention means and particles of at least one adsorbent material, characterized in that about 10 to about 100 percent of the adsorbent particles exhibit a transmittance of at least about 1,000 K in said retention means, and wherein the adsorbent particles are present in said retention means in an amount ranging from about 10 to about 100 percent based on the total weight of the retention means and adsorbent particles. 17. The absorbent article of claim 16 wherein said adsorbent particles have a permeability in the range of about 1,000 to about 4,000 K. 18. An absorbent article according to claim 16 wherein said retention means comprises an upper facing layer and a lower backing layer. 19. An absorbent article according to claim 16 wherein said adsorbent material comprises a hydrophilic material. • 9 20. An absorbent article according to claim 16 wherein said adsorbent particles are bonded directly to the fibrous material or polymeric film. 21. An absorbent article according to claim 16 wherein said adsorbent material is a mixture of organic and inorganic materials. 22. The absorbent article of Claim 16 wherein said adsorbent material has an interstitial gap size in the range of about 100 to about 1,000 microns. 23. An absorbent article according to claim 16 wherein said adsorbent material has a pore size between about 100 to about 0.2 microns. 24. The absorbent article of claim 16, wherein less than about 2 percent of the pore volume provides less than about 10 pore volume 1 micron. 25. An absorbent article comprising at least one particle retention means wherein the adsorbent material of the complexed particles has a retention fluid of at least about 2 g / g in said retention means, and wherein said adsorbent adsorbent particles are contained in said retention means. an amount ranging from about 10 to about 100 percent, based on the total weight of the retention means and adsorbent particles. · «* * * * * * * * * * * * * * * * * * 26. An absorbent article according to claim 25 wherein said adsorbent particles have a complex fluid retention capacity of from about 1 to about 15 g / g. 27. An absorbent article according to claim 25 wherein said adsorbent particles have a complex fluid retention capacity of from about 2 to about 8 g / g. 28. The absorbent article of Claim 25 wherein said adsorbent particles exhibit complex fluid retention rates of from about 2 to about 6 g / g. 29. An absorbent article according to claim 25 wherein said retention means comprises an upper facing layer and a lower backing layer. 30. The absorbent article of Claim 25 wherein said adsorbent material comprises a hydrophilic material. 31. The absorbent article of claim 25 wherein said adsorbent particles are bonded directly to the fibrous material or polymeric film. 32. An absorbent article according to claim 25 wherein said adsorbent material is a mixture of organic and inorganic materials. - ra - 33. The absorbent article of Claim 25 wherein said adsorbent material has an interstitial gap size in the range of about 100. up to about 1,000 microns. 34. The absorbent article of claim 25, wherein said adsorbent material has a pore size between about 100 microns to about 0.2 microns. The absorbent article of claim 25, wherein less than about 2 percent pore volume provides pores less than about 1 micron. 36. An absorbent article comprising retention means and particles of at least one adsorbent material, characterized in that the adsorbent particles contained therein exhibit a minimum average particle size of at least about 200 microns with a standard deviation of at least about 25 percent of the average particle size of the absorbent article; the adsorbent particles are present in said retention means in an amount ranging from about 10 to about 100 percent based on the total weight of the retention means and adsorbent particles. 37. The absorbent article of claim 36, wherein said adsorbent particles have an average particle size in the range of about 200 to about 800 microns. 65- - 38. The absorbent article of claim 36, wherein said adsorbent particles have an average particle size in the range of from about 300 to about 600 microns. 39. The absorbent article of claim 36, wherein said adsorbent particles have an average particle size in the range of about 400 to about 500 microns. 40. The absorbent article of Claim 36 wherein said retention means comprises a top face layer and a backsheet. 41. The absorbent article of Claim 36 wherein said adsorbent material comprises a hydrophilic material. 42. The absorbent article of Claim 36 wherein said adsorbent particles are bonded directly to the fibrous material or polymeric film. 43. The absorbent article of claim 36, wherein said adsorbent material is a mixture of organic and inorganic materials. 44. The absorbent article of claim 36, wherein said adsorbent material has an interstitial gap size in the range of about 100 to about 1,000 microns. • · 45. The absorbent article of claim 36, wherein said adsorbent material has a pore size between about 100 microns to about 0.2 microns. 46. The absorbent article of claim 36, wherein less than about 2 percent pore volume provides pores less than about 1 micron. 47. Absorbent particles product comprising at least one of the adsorbent material retention means containing the adsorption particles contained in said retention means having a multi-modal particle size distribution, and wherein said adsorbent particles are comprised in said retention means in an amount ranging from about 10 to about 100 percent based on the total weight of the retention means and adsorbent particles. 48. The absorbent article of claim 47, wherein said retaining means comprises an upper facing layer and a lower backing layer. 49. The absorbent article of claim 47, wherein said adsorbent material comprises a hydrophilic material. 50. An absorbent article according to claim 47 wherein said adsorbent particles are bonded directly to the fibrous material or polymeric film. ~ 6 7 * ^- · «« «« «« «* * * * * * * · 6 6 6 6 6 7 6 · · · · · · · · · · · · · 51. The absorbent article of claim 47 wherein said adsorbent material is a mixture of organic and inorganic materials. 52. The absorbent article of claim 47, wherein said adsorbent material has an interstitial gap size in the range of about 100 to about 1,000 microns. 53. The absorbent article of claim 47, wherein said adsorbent material has a pore size between about 100 microns to about 0.2 microns. 54. The absorbent article of claim 47, wherein less than about 2 percent pore volume provides pores less than about 1 micron.