MXPA98010309A - Absorbent article comprising an aromatic chelatation agent polifunctionally replaced by the control of the or - Google Patents

Abstract

The present invention relates to absorbent articles in particular sanitary napkins and panty liners having an odor control system comprising a polyfunctionally substituted aromatic chelating agent for odor control improvement

Description

ABSORBENT ARTICLE THAT COMPRISES AN AROMATIC CHELATATION AGENT POL1FUNCTIONALLY REPLACED FOR THE CONTROL OF ODOR FIELD OF THE INVENTION The present invention relates to absorbent articles, in particular sanitary napkins and panty liners comprising compositions that provide odor control benefits.

BACKGROUND OF THE INVENTION Although the primary focus of absorbent articles remains on these items absorbing and retaining fluids, another important area of development in this field is the control of the odorous compounds contained within the absorbed fluids or their degradation products. There is a wide range of compounds that can be present in an absorbent article during use, which results in the formation of bad odors. These compounds include fatty acids, ammonium, amines, sulfur-containing compounds and ketones and aldehydes. The art is replete with descriptions of various odor control agents for use in absorbent articles in order to address the problem of malodour formation. These agents can typically be classified according to the type of odor that the agent tries to combat. Odors can be classified as being acidic, basic or neutral. Acid odor control agents have a pH greater than 7 and typically include carbonates, bicarbonates, phosphates and inorganic sulfates. The basic odor control agents have a pH less than 7 and include compounds such as citric acid, boric acid and maleic acid. Neutral odor control agents have a pH of about 7. Examples of these types of compounds include activated carbons, clays, zeolites, silicas and starches, for example as described in European patents EPO 348 978, EPO 510 619, international publications WO 91/12029, WO 91/11977 and WO 91/12030. All of these types of odor control agents are believed to control odor by a mechanism with which malodorous compounds and their precursors are J 10 absorbed by the agent. However, these mechanisms are not completely effective as the same odor formation is not avoided and in this way odor detection is not completely eliminated. U.S. Patent No. 4,356,190 discloses the use of aminopolycarboxylic compounds and aminophosphonates to inhibit the production of undesirable products on the surface of the body and their use in catamenial products. The European patent EPO 524 581 discloses the removal of odors by the formation of an insoluble complex with cations that cause odor. Suitable compounds include fluorides, phosphates and oxalates. The compositions find application in catamenial products, diapers and incontinence products. However, there is still a need to provide an odor control agent or system that provides effective odor control over a wide range of malodorous compounds. In particular, there is a need to provide a system that prevents and preferably prevents the formation of odorous compounds by itself and that absorbs any residual odor. It has now surprisingly been found that the above needs can be met by the use of an odor control system comprising a polyfunctionally substituted aromatic chelating agent.

BRIEF DESCRIPTION OF THE INVENTION The present invention relates to an absorbent article comprising a liquid permeable topsheet, an absorbent core and a backsheet. The absorbent core is intermediate to the top sheet. The absorbent article comprises an odor control system comprising a polyfunctionally substituted aromatic chelating agent.

DETAILED DESCRIPTION OF THE INVENTION In accordance with the present invention, the absorbent article thus comprises as an essential component an odor control system comprising a polyfunctionally substituted aromatic chelating agent. The polyfunctionally substituted aromatic chelating agents useful herein are disclosed in U.S. Pat. No. 3, 812.044, issued May 21, 1974 to Connor and others, included herein by reference. Of the agents disclosed therein, it has been found that the action of the optimal chelating agent is achieved with those in which the functional groups are positioned close to each other, more preferably where the functional groups are attached to adjacent carbon atoms in the aromatic nucleus. Preferred compounds of this type in the acid form are dihydroxydisulfobenzenes such as 1,2-dihydroxy-3,5-disulfobenzene. Absorbent articles of the present invention preferably comprise from 5 g / m2 to 300 g / m2, more preferably from 10 g / m2 to 180 g / m2, most preferably from 35 g / m2 to 65 g / m2 of said control system of the smell. In addition to the polyfunctionally substituted aromatic chelating agents, the odor control system may comprise additional chelating agents known in the art. In addition, the system may comprise additional odor control agents such as zeolites, silica, activated carbon, gelling absorbent material, antimicrobials or mixtures thereof, all of which are well known to those skilled in the art. Preferably, the polyfunctionally substituted aromatic chelating agents are present in combination with an additional agent for odor control in a weight ratio of 1: 5 to 5: 1, preferably 1: 3 to 3: 1. According to the present invention, the weight of the odor control system that can be used in absorbent articles, can be easily determined by the skilled person having in mind the dimensions of the absorbent article. For example, the absorbent article may comprise from 0.5 to 5g, preferably from 1 to 3g, most preferably from 1.5g to 2.5g of said odor control system. The chelating agent and any of the optional odor control agents can be incorporated into the articles by any of the methods disclosed in the art, for example in layers on the core of the absorbent article, or mixed within the fibers of the absorbent core. The chelating agent is preferably incorporated between the two layers of the cellulose tissue. Optionally, the system may be joined between two layers of cellulose tissue with, for example hot melt adhesive or any suitable bonding system. More preferably, the chelating agent is incorporated in a layered structure according to the disclosure of WO 94/01069 or Italian patent application TO 93A 001028. Document TO 93A 001028, describes a substantially layered structure, is described in WO 94/01069, with the exception that TO 93A 001028 comprises a much larger amount of gelling absorbent material in the intermediate layer, which is between the fibrous layers (120 g / m2) that would be incorporated as an additional component in the present invention . The intermediate layer comprises a polyethylene powder in particular as the thermoplastic material, which is mixed with the pre-mixed odor control system of the present invention. The mixture is then heated such that the polyethylene melts and bonds the layers and components of the laminate together. The bridges that form the junction points between the fibrous layers involve MAG particles, also as particles of thermoplastic material. (MAG absorbent capacity is not affected by bonding.) Adhesive lines are also preferably placed on the edges of the laminate to ensure that the edges of the laminate stick and that any loss of odor control material or chelating agent does not occur. fall out of the laminate. The chelating agent can be incorporated as a powder or a granulate within the absorbent article. The chelating agent can be distributed homogeneously over the entire absorbent article, in the secondary topsheet, in at least one core layer or any mixture thereof. In a preferred embodiment, the chelating agent is positioned in such a way that at least a part of the fluid discharge comes into contact with the chelating agent before the odor control agent. In particular, said chelating agent is located in a separate layer of the odor control agent. More preferably, the chelating agent is located towards the topsheet or is located on the same topsheet, and the odor control agent is located further away from the topsheet than the chelating agent. Most preferably, the chelating agent is placed in at least one of the layers of the topsheet and the odor control material is placed in the core. In particular, the chelating agent is located at the point of entry of the fluid discharge of the absorbent article. The chelating agent and the odor control agent can be homogeneously distributed throughout the absorbent article or in any of the layers thereof, or it can be distributed substantially in the center of the absorbent article or substantially on the edges of the absorbent article. .

ABSORBENT NUCLEUS In accordance with the present invention, the absorbent core may include the following components: (a) an optional primary fluid distribution layer, preferably joined with a secondary optional fluid distribution layer; (b) a fluid storage layer; (c) optionally a fibrous layer ("dedusting"), which is below the storage layer; and (d) other optional components. According to the present invention, the absorbent core can have any thickness depending on the end use contemplated.

A Primary / secondary fluid distribution layer An optional component of the absorbent core according to the present invention is a primary fluid distribution layer and a secondary fluid distribution layer. The primary fluid distribution layer is typically below the top sheet and is in fluid communication with it. The top sheet transfers the acquired fluid to this primary distribution layer for final distribution to the storage layer. This transfer of fluid through the primary distribution layer occurs not only in the thickness, but also along the longitudinal and wide directions of the absorbent product. The also optional but preferred secondary distribution layer is typically below the primary distribution layer and is fluid communication with it. The purpose of this secondary distribution layer is to rapidly acquire the fluids from the primary distribution layer and transfer them rapidly to the underlying storage layer. This helps the fluid capacity of the underlying storage layer to be fully utilized. The fluid distribution layers may be composed of any typical material for such distribution layers. In particular, the fibrous layers to which the capillaries maintain between the fibers, even when wetted, are useful as distribution layers. b Fluid storage layer Located in fluid communication with, and typically being below, the primary or secondary distribution layers, is a fluid storage layer. The fluid storage layer may comprise any conventional absorbent material or combinations thereof. This preferably comprises gelling absorbent materials in combination with suitable carriers. Suitable carriers include materials that are conventionally used in absorbent structures such as natural, modified or synthetic fibers, particularly modified or unmodified cellulose fibers, in the form of foams or tissue. Suitable carriers can be used together with the gelling absorbent material, however, they can also be used alone or in combinations. More preferably they are tissue or tissue laminates in the context of sanitary napkins and panty liners. One embodiment of the absorbent structure made in accordance with the present invention may comprise multiple layers comprising double-layer tissue laminates formed by folding the tissue onto itself. These layers can be bonded together, for example, by means of an adhesive or by mechanical interlacing or by bands of hydrogen bridges. The gelling absorbent material or other optional material may be comprised between the layers. Modified cellulose fibers such as hardened cellulose fibers can also be used. Synthetic fibers can also be used and include those made from cellulose acetate, polyvinyl fluoride, polyvinylidene chloride, acrylics (such as Orion), polyvinyl acetate, non-soluble polyvinyl alcohol, polyethylene, polypropylene, polyamides (such as nylon) , polyesters, two-component fibers, three-component fibers, mixtures thereof and the like. Preferably, the surface of the fiber are hydrophilic or are treated to be hydrophilic. The storage layer can also include filling materials, such as Perlite, diatomaceous earth, Vermiculite, etc., to improve liquid retention. If the gelling absorbent material is dispersed in an inhomogeneous manner in a carrier, the storage layer can nevertheless be locally homogeneous, i.e., have a distribution gradient in one or several directions within the dimensions of the storage layer . The inhomogeneous distribution can also refer to the laminates of the carriers that partially or completely enclose the gelling absorbent material. c Optional fibrous layer (dedusting) An optional component for inclusion within the absorbent core according to the present invention is a fibrous layer adjacent to, and typically underlying the storage layer. This underlying fibrous layer is typically referred to as a "dedusting" layer as it provides a substrate on which the absorbent gelling material is deposited in the storage layer during the manufacture of the absorbent core. Indeed, in those examples where the gelling absorbent material is in the form of macro structures such as fibers, sheets or strips, this fibrous "dedusting" layer need not be included. However, this dedusting layer provides some of the additional fluid handling capabilities, such as capillary action or fast wicking effect of the fluid along the length of the pad. d Other optional components of the absorbent core The absorbent core according to the present invention can include other optional components normally present in the absorbent webs. For example, a reinforcing fabric may be placed within the respective layers, or between the respective layers, of the absorbent core. These reinforcement canvases should be of such configuration as they do not form interfacial barriers to fluid transfer. Given the structural integrity that usually occurs as a result of thermal bonding, reinforcing canvases are not usually required for thermally bonded absorbent structures.

TOP SHEET According to the present invention, the absorbent ale comprises as an essential component an upper sheet. The top sheet may comprise a single layer or a multiplicity of layers. In a preferred embodiment, the top sheet comprises a first layer providing the user facing surface of the top sheet and a second layer between the first layer and the absorbent structure / core. The upper sheet as a whole and therefore each layer individually needs to be docile, soft feeling and non-irritating to the user's skin. This must also have elastic characteristics that allow it to be stretched in one or two directions. In accordance with the present invention, the topsheet can be formed from any of the materials available for this purpose and known in the art, such as woven and non-woven fabrics and films. In a preferred embodiment of the present invention, at least one of the layers, preferably the top layer, of the top sheet comprises a hydrophobic, liquid permeable, liquid-permeable polymeric films. Preferably, the top layer is provided by a film material having openings that are provided to facilitate the transport of liquid from the surface facing the user towards the absorbent structure. If present, the lower layer preferably comprises a non-woven layer, a film formed with openings or a tissue laid with air.

BACK SHEET The backsheet fundamentally prevents the exudates absorbed and contained within the absorbent core from moistening the ales that come into contact with the absorbent product such as underpants, pajamas and undergarments. The backsheet is preferably impermeable to liquids (eg, menstruation and / or urine) and is preferably manufactured from a thin plastic film, although other flexible liquid impervious materials may also be used. As used herein, the term "flexible" refers to materials that are docile and that will readily conform to the shape and general contour of the human body. The back sheet can also have elastic characteristics that allow it to stretch in one or two directions. The backsheet typically extends through the entire absorbent structure and may extend into and form part of all or of the lateral fins, preferred side wrapping elements or wings. The backsheet may comprise a woven or non-woven material, polymeric films such as polyethylene or polypropylene thermoplastic films, or composite materials such as a nonwoven film-coated material. Preferably, the backsheet is a polyethylene film. Exemplary polyethylene films are manufactured by Clopay Corporation of Cincinnati, Ohio, under the designation P18-0401 and by Ethyl Corporation, Visqueen Division, of Terre Haute, Indiana under the designation XP-39385. The backsheet is preferably embossed and / or finished without gloss to provide a more fabric-like appearance. In addition, the backsheet can allow the vapors to escape from the absorbent core, i.e., be breathable, while still preventing the passage of exudates through the backsheet. Breathable backsheets comprising several layers can also be used, for example, microporous film or with openings plus non-woven structures. According to the present invention, the absorbent article can find utility in sanitary napkins, pantyliners, adult incontinence products and baby diapers. In particular, the present invention finds application in sanitary napkins and linings for panties.

Claims (7)

1. CLAIMS 1. An absorbent article comprising a liquid permeable upper sheet, a back sheet and an absorbent core, said core being intermediate the upper sheet and the rear sheet, and said absorbent article comprising an odor control system, said system comprising a polyfunctionally substituted aromatic chelating agent.
2. 2. An absorbent article according to claim 1, wherein the absorbent article comprises from 5 g / m2 to 300 g / m2 of the polyfunctionally substituted aromatic chelating agent.
3. 3. An absorbent article according to any of the preceding claims, wherein the aromatic chelating agent is selected from those in which the polyfunctional groups are placed close to each other.
4. 4. An absorbent article according to claim 1, wherein the odor control system further comprises an odor control agent selected from silica, zeolites, activated carbon, gelling absorbent material or mixtures thereof.
5. 5. An absorbent article according to claim 4, wherein the ratio of the aromatic chelating agent to the odor control agent is from 1: 5 to 5: 1.
6. 6. An absorbent article according to claim 4, wherein the odor control agent is located more from the top sheet than the aromatic chelating agent.
7. 7. An absorbent article according to any of the preceding claims, wherein the article is a sanitary napkin or a panty liner.