MXPA01009001A - Articles with odour control - Google Patents

Abstract

The present invention relates to articles, preferably absorbent articles like sanitary napkins and pantiliners, for controlling odours, preferably odours associated with bodily fluids, which comprise a peroxyacid, preferably&egr;-pthalimido peroxyhexanoic acid, as the odour control material. The present invention also discloses the use of such peroxyacids as odour control material.

Description

ARTICLES WITH ODOR CONTROL FIELD OF THE INVENTION This invention relates to articles, such as absorbent articles, for controlling odor, especially odor associated with body fluids, comprising, as the odor control material, the peroxyacids as defined herein, and the use of these peroxyacids as it is defined hereinafter as an odor control material.

BACKGROUND OF THE INVENTION The bad odors can be present in the environment from numerous sources both animate and inanimate. Many products and articles are available that help to avoid or reduce the minimum detection of these odors. In particular, it is particularly desirable to provide odor control materials to resolve odors that are generated by the human body, or from body fluids such as perspiration, urine, feces, menstrual fluids, vaginal fluids and the like. Articles such as absorbent articles are designed to be worn by humans to absorb body fluids, such as urine, menstrual fluid and perspiration, etc. Examples of the absorbent articles include sanitary napkins, pantiliners, disposable diapers, incontinence pads, tampons, perspiration pads, and the like. In use, it is known that these absorbent articles acquire a variety of compounds, for example volatile fatty acids (for example isovaleric acid), ammonia, amines (for example triethylamine), sulfur-containing compounds (for example mercaptans, sulfides), alcohols, ketones and aldheidos (for example, furaldehyde) that release unpleasant odors. These compounds may be present in the body fluid or may be developed by chemical reactions and / or any of the mechanisms of fluid degradation once the body fluid is absorbed in the absorbent article such as a female pad. In addition to body fluids they usually contain microorganisms and / or enzymes that can also generate fetid byproducts as a result of degradation mechanisms such as rotting degradation, acid degradation, protein degradation, fat degradation and the like. The unpleasant odors emanating from the absorbent pads when in use can make the user feel demure. Various odor control materials have been disclosed in the art to combat some of the unpleasant odors referred to above. Actually, solutions have been proposed that employ different technical approaches such as masking, that is, covering the odor with a perfume, or absorbing the odor already present in body fluids and those generated after degradation, or preventing odor formation. The majority of the approach in the prior art is found in the technology of odor absorption. Examples of these types of compounds include activated carbons, clays, zeolites, silicates, gelling absorbent materials, starches, cyclodextrin, ion exchange resins and some mixtures thereof as for example described in European Patents EP-A-348 978, EP-A-510 619, international publications WO 91/12029, WO 91/1 1977, WO 89/02698, and / or WO 91/12030. All of these types of odor control agents are believed to control odor by mechanisms by which the fetid compounds and their precursors are physically absorbed by these agents and thus hide the odor output of the articles as absorbent articles. However, said mechanisms are not completely effective since the formation of the odor itself is not avoided and therefore odor detection is not completely avoided. In this way, although these materials provide some control of the odors associated with body fluids, there is still a need for further improvements in terms of odor control over a wide range of malodorous compounds. It is an object of the present invention to provide effective odor control over a wide range of malodorous compounds. More particularlyIt is an object of the present invention to provide articles, especially disposable absorbent articles, which provide a broader odor control spectrum mainly by preventing odor formation. It has now been found that the above needs can be met using a peroxyacid, preferably an e-phthalimido peroxyhexanoic acid. (PAP) as the odor control material for an article, preferably a disposable absorbent article. By the present invention it has been surprisingly discovered that the use of the peroxyacids of the invention present in an article, such as an absorbent article that is in contact with body fluids, results in the significant decrease of body odor, as compared to the same article without the odor control material according to the present invention. Actually, it is speculated that the peroxyacids according to the present invention have a double mechanism of odor control: these are capable of preventing odor generation by blocking the enzymatic and / or microbial activity as well as combating the odors already present by oxidizing them into molecules not smelling Indeed, in contrast to the use of some inorganic peroxides such as persulfate or perborate, the peroxyacids as described herein are free of deactivation by the enzymes of catalase and peroxidase which are present in body fluids. In this manner, the peroxyacids according to the present invention are capable of maintaining / retaining their oxidation capacity to oxidize oxidizable malodorous compounds in non-odorous compounds. An additional advantage of the peroxyacids described herein is that generation of foul-smelling by-products such as chlorine derivatives and ammonium derivatives, when in contact with body fluids, is avoided. Actually, in contrast to the peroxyacids described here, other oxidants such as persulfate, periodate, percarbonate, and / or perborate oxidize the chlorides usually present in body fluids such as menstruation in chlorine derivatives that are not acceptable to the consumer from one point of view of the smell. Also in contrast to the peroxyacids described herein, other oxidants such as urea peroxides, calcium peroxides, strontium peroxides and / or barium peroxides (ie, compounds having an alkaline pH) promote the formation of fetid ammonia derivatives, one of the byproducts of the degradation of the protein that occurs in body fluids when they are in contact with them. A further advantage associated with the peroxyacid according to the present invention is that it also provides the absorbent article in which it has been incorporated with a better feel and a more acceptable level of cleaning. Actually, the present invention provides an absorbent article capable of changing the color of menstruation (blood red color) to a light red color and even to a whitish color. It is still another advantage of the present invention that the peroxyacid used here as the odor control material ensures the shelf life of the absorbent articles where it is contained compared to other oxidants such as the alkali metal peroxides (e.g. , peroxides of sodium, potassium, lithium, cerium) and / or salts of superoxides (for example, superoxides of sodium, potassium, rubidium, cerium, calcium, strontium, barium). Indeed, it has surprisingly been found that the peroxyacid as described herein present in the present absorbent article of the present invention does not readily react with carbon dioxide or air vapor, and therefore retains its total ability to control odor during a prolonged period of time, until the moment when the absorbent article is used, that is, when in contact with the body fluids. While the present invention is preferably directed to absorbent articles such as pantiliners, feminine pads, incontinence pads, diapers, tampons, interlabial pads, perspiration pads, surgical pads, breast pads, and the like, other articles may include the peroxyacids as described herein also for the purpose of effective control of the odor. Actually, other applications include articles designed to be brought into contact with the body such as garments, bandages, thermal pad, acne pads, cold pads, compresses, surgical pads / bandages and the like, household cleaning items such as towels moist impregnated (for example, btowels, towels for intimate female hygiene), impregnated facial paper, towels, sweat-absorbing articles such as shoe insoles, shirt inserts, mats and the like, and articles for animals such as stretchers and the like . U.S. Patent No. 4,363,322 discloses deodorant and deodorizing liquid absorbent products such as a sanitary napkin, a napkin or a diaper, which comprises a liquid absorbent material and within the product at a distance from its outer edges an substance that releases oxygen in contact with moisture such as peroxides, ozonides, superoxides, oxo-ozonides and the like. This reference does not disclose peroxyacids according to the present invention, without mentioning the benefit of controlling the odor associated therewith.

BRIEF DESCRIPTION OF THE INVENTION The present invention relates to an article, preferably a disposable absorbent article, for controlling odor, preferably the odor associated with body fluids, comprising a peroxyacid according to the formula: R-CO 3 H wherein R is a substituted or unsubstituted, saturated or unsaturated, linear or branched hydrocarbon group, having 1 to 25 carbon atoms or a cyclic group having from 3 to 32 carbon atoms and optionally at least a heteroatom (preferably a heterocyclic group) or a cyclic alkyl group having from 4 to 32 carbon atoms and optionally at least one heteroatom (preferably a heterocyclic alkyl group) or a mixture thereof. The present invention also encompasses the use as a odor control material of a peroxyacid according to the above formula.

DETAILED DESCRIPTION OF THE INVENTION The articles according to the present invention for controlling odors, especially odors associated with body fluids, comprises as an essential element a peroxyacid according to the formula described hereinafter. By "article" is meant herein any three-dimensional solid material that is capable of receiving / carrying a peroxyacid as described hereinafter. Preferred according to the present invention articles are disposable absorbent articles that are designed to be brought into contact with the body of a user and to receive fluids discharged from the body, such as disposable absorbent pantiliners, sanitary napkins, catamenials, inserts / incontinence pads, diapers, tampons, interlabial pads / inserts, breast pads and the like. Other suitable articles according to the present invention also include other articles designed to be worn in contact with the body such as clothing, bandages, thermal pads, pads for acne pads, cold treatment, compresses, pads / surgical dressings and the like sweat-absorbing articles such as shoe insoles, shirt inserts, sweat pads and the like, body and household cleaning articles such as impregnated towels (for example, baby wipes, towels for female intimate hygiene), impregnated facial tissues, towels and the like, and articles for animals such as stretchers and the like. By "body fluid" is meant here any of the fluids produced by the human or animal body occurring naturally or accidentally like for instance in the case of cutting the skin, including for example sweat, urine, menstrual fluids, faeces fecal , vaginal secretions and similar. The peroxyacids to be used herein are according to the following formula; R-CO 3 H wherein R is a substituted or unsubstituted, saturated or unsaturated, linear or branched hydrocarbon group, having 1 to 25 carbon atoms or a cyclic group having 3 to 32 carbon atoms and optionally at least one heteroatom or a cyclic alkyl group having from 4 to 32 carbon atoms and optionally at least one heteroatom. Typically R is an alkyl group or substituted or unsubstituted alkenyl group, linear or branched, having from 1 to 25 carbon atoms, more preferably from 1 to 14 carbon atoms, even more preferably from 3 to 10, and most preferably from 4 to 6. R may also typically be an aryl group having from 3 to 32 carbon atoms, preferably from 3 to 25, more preferably from 6 to 20, even more preferably from 8 to 15 carbon atoms, or an aryl group alkyl having from 4 to 32 total carbon atoms, preferably from 4 to 25, more preferably from 6 to 20 and even more preferably from 8 to 13, or a heterocyclic group containing from 3 to 32 carbon atoms, preferably from 3 to 25, more preferably from 3 to 20 carbon atoms, even more preferably from 5 to 15 and from 1 to 5 heteroatoms, preferably from 1 to 3, wherein the heteroatoms are independently selected from the group consisting of oxygen, nitrogen and sulfur, and is preferably nitrogen or oxygen, or a heterocyclic alkyl group containing from 4 to 32 carbon atoms, preferably from 4 to 25, more preferably from 4 to 22, even more preferably from 6 to 18 and from 1 to 5. heteroatoms, preferably from 1 to 3, wherein the heteroatoms are independently selected from the group consisting of oxygen, nitrogen and sulfur, and is preferably nitrogen or oxygen. Preferred peroxyacids according to the present invention are those wherein R is a cyclic group or a cyclic alkyl group, preferably a heterocyclic group or a heterocyclic alkyl group. Even more preferred herein are peroxyacids according to the following formula: O ° wherein Ra is a substituted or unsubstituted, saturated or unsaturated, linear or branched hydrocarbon group having from 1 to 14 carbon atoms, Y is a heteroatom and X are substituents in the selected ortho or meta position independently of the hydrogen, hydroxy, halogen group, saturated or unsaturated, linear or branched aliphatic hydrocarbon group having from 1 to 10 carbon atoms. Preferably Ra is an alkyl group or a substituted or unsubstituted, linear or branched alkenyl group having from 2 to 12 carbon atoms, preferably from 2 to 10, more preferably from 2 to 8, even more preferably from 3 to 6. and very preferably 5 carbon atoms. Preferably Y is a heteroatom selected from the group consisting of oxygen, nitrogen and sulfur, and more preferably is the nitrogen atom (> N-). Preferably, X are substituents in the ortho or meta position independently selected from the group consisting of hydrogen, hydroxy, alkyl group or straight or branched aliphatic alkenyl group having from 1 to 10 carbon atoms, preferably from 2 to 7 and very preferably from 3 to 5 carbon atoms. Highly preferred here all substituents X are independently hydrogen. Preferred peroxyacids for use in accordance with the present invention are phthalimido and phthalamido peroxyalkane acids. The highly preferred peroxyacids here is e-phthalimido peroxyhexanoic acid which may be commercially available from AUSIMONT under the name PAP®, or EURECO® (in the granulated form), Eureco WKC® (in the form of wet granules) or Eureco HC® (in the active powder form). It has now been surprisingly discovered that the peroxyacids according to the present invention provide the ability to control the significant odor, especially against the odor associated with body fluids. It is speculated that this benefit is due to a dual mechanism: Firstly, these can prevent the generation of odor by for example blocking enzymatic and / or microbial activity. Actually, it is speculated that the peroxyacids as described herein oxidize the sulfhydryl and sulfur sensitive bonds typically present in the enzymes, thus deactivating enzymes which would otherwise have contributed to the normal metabolism of microorganisms as microbes. It is further speculated that these peroxyacids oxidize the double bonds in other metabolites such as for example the nutrients (for example, unsaturated fat) for the microorganisms, thus rendering these nutrients inefficient for microbial growth which would otherwise have resulted in the generation of foul compounds. It is further believed that the peroxyacids described herein break the chemo-osmotic function of the cytoplasmic membrane of the lipoprotein of the microbe / bacteria cells and thus break or disrupt the transport function in the walls of the cells. This latter interruption is especially perceptible with the hydrophobic peroxyacids described herein, such as the cyclic or cyclic alkyl peroxyacids, especially the peroxyacids according to the chemical formulas described herein. Indeed, it is speculated that the heterocyclic group or the heterocyclic alkyl group according to the preferred peroxyacids are capable of reacting better with the lipoproteins of the cell wall of the microorganisms. Second, the peroxyacids as described herein are capable of combating the already present foul-smelling compounds by oxidizing them into compounds that do not smell.

A more important advantage associated with the peroxyacids according to the present invention is that they also provide the absorbent article in which these have been incorporated with a better feeling and more acceptable level of cleaning. Actually, the presence of the peroxyacids according to the present invention provides absorbent articles with controlled odor capacity when the menstruation is put in contact with the article, but also absorbent articles are able to change the color of menstruation (blood red) to a pale red color and even a whitish color. Typically, articles such as disposable absorbent articles comprise the peroxyacid or a mixture thereof at a level of 1 gm "2 to 250 gm" 2, preferably 5 to 150 gm "2, more preferably 10 gm" 2 to 100 gm '2 and most preferably 20 gm "2 to 70 gm'2 Optional accessories The articles according to the present invention preferably further comprise on the peroxyacid described hereinbefore, other conventional agents or their mixtures. For example, additional odor control agents or combinations thereof, known in the art for this purpose can be used here. These agents can typically be classified according to the type of odor that the agent is intended to combat. Odors can be classified chemically as being acidic, basic or neutral. Alternatively, odor control agents can be placed in categories with respect to the mechanism by which odor detection is reduced or prevented. For example, odor control agents that chemically react with the fetid compounds or with compounds that produce malodorous degradation products thereby generating compounds that lack odor or have an odor acceptable to consumers can also be used here. Odor control agents suitable for use herein typically include carbonates (e.g., sodium carbonate), bicarbonates (e.g., sodium bicarbonate), phosphates (e.g., sodium phosphate), sulfates (e.g., zinc sulfates) and copper), carboxylic acids such as citric acid, lauric acid, boric acid, adipic acid, and maleic acid, activated carbons, zeolite clays, silicas, gelling absorbent materials (AGM) and starches. Said agents and odor control systems are disclosed in greater detail hereinafter and for example in European patents EP-A-348 978, EP-A-510 619, WO 91/12029 and international publications WO 91/11977, WO 91 / 12030, WO 81/01643 and WO 96/06589. Suitable odor control agents also include chelating agents and can be selected from amino carboxylates such as for example ethylenediamine tetraacetate, as described for example in U.S. Patent No. 4356190, amino phosphonates such as ethylenediaminetetrakis ( methylene phosphonates), polyfunctionally substituted aromatic chelating agents as described in U.S. Patent No. 3,812,044 and mixtures thereof. Without attempting to be bound by theory, it is believed that the benefit of these materials is in part due to their exceptional ability to remove the iron, copper, calcium, magnesium and manganese ions present in the absorbed fluids and their degradation products through the formation of chelates Another suitable odor control agent to be used herein is a regulatory system, such as citric acid and sodium bicarbonate buffer systems, sodium phosphate and sorbic acid. Also, regulatory systems having a pH of 7 to 10 as described for example in the international publication WO may be useful here. 94/25077.

The alternative odor control agents are ion exchange resins such as those described in U.S. Patent No. 4 289 513 and U.S. Patent No. 3340875. Masking agents such as perfumes may also be used as odor control agents here. Typically, articles such as disposable absorbent articles may comprise the odor control agent or a mixture thereof at a level of 0.5 gm "2 to 600 gm" 2, preferably 5 to 500 gm "2, more preferably 10 gm "2 to 350 gm" 2 and most preferably 20 gm'2 to 200 gm "2.

Qualifying absorbent materials for odor control As is well known from recent commercial practice, gelling absorbent materials (sometimes referred to as "super absorbers") have become widely used in absorbent articles. He AGM are materials that have fluid absorbers. Such materials are highly preferred here as the optional odor control agent because of its dual function of absorbing fluids and odors. These materials form hydrogels when in contact with water (for example, with urine, blood and similar). A highly preferred type of gelling absorbent hydrogel-forming material is based on polyacids, especially polyacrylic acid. Hydrogel-forming polymeric materials of this type are those which, when in contact with fluids (i.e., liquids) such as water or fluids or the body, imbibe said fluids and thus form hydrogels. These preferred gelling absorbent materials will generally comprise substantially insoluble, partially crosslinked, partially neutralized water-insoluble hydrogel-forming polymer materials prepared from polymerizable, unsaturated, acid-containing monomers. In these materials the polymeric component formed from the acid-containing unsaturated monomers may comprise the total gelling agent or may be grafted to other types of polymeric portions such as starch or cellulose. The starch materials grafted with acrylic acid are of this last type. Therefore, the preferred gelling absorbent materials include hydrolyzed starch grafted with acrylonitrile, starch grafted with acrylic acid, polyacrylates, maleic anhydride based copolymers and combinations thereof. Especially preferred gelling absorbent materials are polyacrylates and starch grafted with acrylic acid. Whatever the nature of the polymer components of the preferred gelling absorbent materials, these materials will generally be slightly crosslinked. The crosslinking serves to revert to these preferred hydrogel-forming absorbent materials substantially insoluble in water, and the cross-linking also partly determines the gel volume and the extractable polymer characteristics of the hydrogels formed therefrom. Suitable crosslinking agents are well known in the art and include, for example, (1) compounds that have at least two polymerizable double bonds; (2) compounds having at least one polymerizable double bond and at least one functional group reactive with the acid-containing monomeric material; (3) compounds having at least two functional groups reactive with the acid-containing monomer materials; and (4) polyvalent metal compounds that can form ionic lattices. The crosslinking agents of the above types are described in greater detail in Masuda et al .; U.S. Patent No. 4,076,663 issued February 28, 1978. Preferred crosslinking agents are the di- or polyesters of mono- or polycarboxylic unsaturated acids with polyols, the bisacrylamides and the di-triallyl amines. Especially preferred crosslinking agents are N, N'-methylenebisacrylamide, trimethylol propane triacrylate and triallyl amine. The crosslinking agent will generally comprise from about 0.001 mole percent up to 5 mole percent of the preferred materials. More preferably, the crosslinking agent will comprise from about 0.01 mole percent to 3 mole percent of the gelling materials used herein. Preferred, lightly crosslinked hydrogel-forming gelling absorbers will generally be employed in their partially neutralized form. For the purposes described herein, said materials are considered partially neutralized when at least 25 mole percent, and preferably at least 50 percent, of the monomers used to form the polymer are monomers containing the acid group which has been neutralized with a salt-forming cation. Suitable salt-forming cations include alkali metal, ammonium, substituted ammonium and amines. This percentage of the total monomers used which are monomers containing the neutralized acid group is referred to as the "degree of neutralization". Typically, commercial gelling absorbent materials have a degree of neutralization a little less than 90%. The preferred gelling absorbent materials used herein are those which have a relatively high fluid-absorbing ability found in the absorbent articles; this capacity can be quantified by referring to "gel volume" of said gelling absorbent materials. The gel volume can be defined in terms of the amount of synthetic urine absorbed by any gel-absorbing agent and is specified as grams of synthetic urine per gram of gelling agent. The volume of gel in the synthetic urine (see Brandt, and others below) can be determined by forming a suspension of approximately 0.1 -0.2 parts of dry gelling absorbent material to be tested with approximately 20 parts of synthetic urine. This suspension is maintained at room temperature under gentle agitation for about 1 hour so that the swelling equilibrium is obtained. The gel volume (grams of synthetic urine per gram of gelling absorbent material) is then calculated from the weight fraction of the gelling agent in the suspension and the ratio of the liquid volume excluded from the hydrogel formed to the total volume of the suspension. Preferred gelling absorbent materials useful in this invention will have a gel volume of about 20 to 70 grams, more preferably about 30 to 60 grams, of synthetic urine per gram of gelling absorbent material. Another feature of the very highly preferred gelling absorbent materials relates to the level of the extractable polymeric material present in said materials. The levels of the extractable polymer can be determined by contacting a sample of the preferred gelling absorbent material with a synthetic urine solution over the substantial period of time (eg, at least 16 hours) that is needed to reach the extraction equilibrium, then filtering the hydrogel formed from the supernatant liquid, and finally finally determining the content of the filtrate polymer. The particular procedure used to determine the extractable polymer content of the preferred gelling agent regulators herein is set forth in Brandt, Goldman and Inglin; United States Patent No. 4,654,039, issued March 31, 1987, reissue No. 32,649. The gelling absorbent materials which are especially useful in the absorbent articles herein are those having an equilibrium extractable content in the synthetic urine not greater than about 17%, preferably not more than about 10% by weight of the absorbent material. of gelation.

The gelling absorbent materials hereinbefore described are typically used in the form of discrete particles. Said gelling absorbent materials can be of any desired shape, for example, spherical or hemispherical, cubic, polyhedral type bar, etc. Also contemplated for use here are shapes having a large proportion of larger dimension / smaller dimension such as needles and flakes. Agglomerates of the particles of the gelling absorbent material can also be used. The particle size of the gelling absorbent material can vary over a broad spectrum. For reasons of industrial hygiene, average particle sizes less than about 30 microns are less desirable. Particles having a smaller dimension greater than about 2 mm can cause a feeling of a sandy texture within the absorbent article, which is undesirable from an aesthetic point of view for the consumer. Also, the speed The absorption of fluid can be affected by the particle size. Larger particles have much lower absorption rates. Preferred for use herein are particles of gelling absorbent material all having substantially a particle size of about 30 microns to about 2 mm. "Particle size" as used herein means the weighted average of the smallest dimension of the individual particles. The amount of the particles of absorbent gelling material used in the absorbent article will typically vary from 10 gm "2 to 150 gm" 2, preferably from 30 gm "2 to 110 gm" 2, more preferably from 55 gm'2 to 85 gm'2.

Silica smell control agent Particularly suitable here as an additional odor control agent is silica. Silica, ie silicon dioxide SiO2 exists in a variety of crystalline forms and amorphous modifications, any of which are suitable for use herein. In particular, silicas having a high surface area or in an agglomerated form are preferred. Silica molecular sieves are not considered to be within the definition of silica as used here. Preferably the silica is a highly purified form such that it contains at least 90%, preferably 95%, more preferably 99% silicon oxide. Most preferably the silica is silica gel having a content of 100% silica. Alternatively, the silica can be provided from other sources such as metal silicates including sodium silicate.

Zeolite odor control agent The use and manufacture of zeolite material is well known in the literature and is described in the following reference texts: ZEOLITE SYNTHESIS, ACS Symposium Series 398, Eds. M.L. Occelli and H. E Robson (1989) pages 2-7; ZEOLITE MOLECULAR SIEVES, Structure, Chemistry and Use, by D.W. Breck, John Wiley and Sons (1974) pages 245-250, 313-314 and 348-352; MODERN APPLICATONS OF MOLECULAR SIEVE ZEOLITES; Ph.D. Dissertation of S.M. Kuznicki, U. of Utah (1980), available from the University of Microfilms International, Ann Arbor, Michigan, pages 2-8. The zeolites are crystalline aluminosilicates of the elements of group IA and of the group HA such as Na, K, Mn, Ca and are chemically represented by the empirical formula: M2 / nO. AI2O3. yS¡O2. wH2O where y is 2 or greater, n is the valence of the cation, and w is the water content in the holes of the zeolite. Structurally, zeolites are crystalline, complex inorganic polymers, based on an infinitely extending structure of AIO4 and SiO4 tetra-linked to each other to share the oxygen ions. This system structure contains interconnected channels or gaps that are occupied by cations and water molecules. The structural formula of a zeolite is based on the unit crystalline cell, the smallest unit of the structure, represented by M? / N [(AIO2) x (SiO2) and]. wH2O where n is the valence of the cation M, w is the number of water molecules per cell unit, x and y are the total number of tetrahedra per cell unit, and / x usually having values of 1 -5. The zeolites can be naturally derived or synthetically manufactured. The preferred synthetic zeolites being used here. Suitable zeolites for use herein include zeolite A, zeolite P, zeolite Y, zeolite X, zeolite DAY, zeolite ZSM-5, or mixtures thereof. Zeolite A is very preferred. According to the present invention, the zeolite is preferably hydrophobic. This is typically obtained by increasing the molar ratio of SiO2 to the content of AIO2 such that the ratio of x to y is at least 1, preferably from 1 to 500, most preferably from 1 to 6.

The absorbent article The odor control agents (ie, the peroxyacid as described herein and the optional odor control agent (s), optional) may be incorporated into the absorbent article by any of the methods disclosed in the art, eg, laminate in the core of the absorbent article or mixed within the fibers of the absorbent core. The peroxyacid as described herein and the optional additional odor control agent (s) are preferably incorporated between two layers of cellulose tissue.

Optionally these materials can be joined between two layers of cellulose tissue with, for example, a thermal fusion adhesive or any suitable joining system, as described in international publication WO 94/01069. In one embodiment of the present invention the peroxyacid as described herein and the additional odor control agent, optional, are incorporated into a layered structure according to the disclosure of the international publication WO 94/01069 or the Italian patent application TO 93A 001028. The Italian patent application No. TO 93A 001028 describes a substantially layered structure as described in WO 94/01069 with the exception that the Italian application TO 93A 001028 comprises a much larger amount of gelling absorbent material in the intermediate layer that is between the fibrous layers (120 gm-2) that would be incorporated as a component optional in the present invention. The intermediate layer comprises in particular a polyethylene powder as a thermoplastic material which is mixed with the peroxyacid as described herein. The mixture is then heated so that the polyethylene melts and bonds the laminated layers together. The adhesive lines are preferably also placed on the edges of the laminate to ensure that the edges of the laminate stick and any loose peroxyacid as described herein and the optional, additional, present smell control agent present does not leave the laminate. Alternatively, the polyethylene powder can be replaced by a conventional glue for example those commercially available from ATO Findley under the name H20-31® to bond the layers of the laminates and / or the components together. Advantageously, this step of the method makes it possible to avoid the necessary heating step when the polyethylene powder is used. In a preferred embodiment the peroxyacid as described herein is incorporated between two layers of cellulose tissue separated by another cellulose layer in order to avoid the possible reaction between the peroxyacid and the optional additional odor control agent. The peroxyacid as described herein may be distributed homogeneously or non-homogeneously over the entire absorbent article or in at least one layer of the topsheet or in at least one core layer and any mixture thereof. The peroxyacid as described herein can be distributed homogeneously or non-homogeneously over the total surface of the desired layer or layers, or over one or more areas of the sublayer / surface layers to which it is placed (for example, central area and / or surrounding areas such as the edges of a layer of the absorbent article) or their mixtures. Preferably, the peroxyacid is located towards the topsheet or is located on the topsheet itself (preferably the topsheet). In a preferred embodiment the peroxyacid is positioned so that at least a portion of the fluid discharge contacts the peroxyacid before the additional odor control agent (e.g., AGM) if present. In particular, the peroxyacid is located in a separate layer of the additional odor control agent. Preferably the peroxyacid is located towards the topsheet or is located on the topsheet itself (preferably the topsheet) and the additional odor control agent, if present, is located further away from the topsheet than the peroxyacid. In one embodiment of the present invention, the peroxyacid is placed in at least one of the layers of the topsheet and the additional odor control agent if present is placed inside the core. More preferably, the peroxyacid is located at the point of entry of the fluid discharge of the absorbent article. The peroxyacid as described herein and the optional additional odor control agent, if present, can be inco comoorated as a powder or a granulate within the absorbent article or can be sprayed in the form of for example a solution containing peroxyacid inside. of the absorbent article. When the peroxyacid is used in a granulated or particulate form as described herein and the optional odor control agent can be separately granulated and then blended together or granulated together.

The absorbent core In accordance with the present invention, the absorbent article may include the following components: (a) an optional primary fluid distribution layer preferably together with an optional secondary fluid distribution layer; (b) a fluid storage layer; (c) an optional fibrous layer ("dedusting") underlying the storage layer; (d) other optional components. According to the present invention, the absorber can have any thickness depending on the end use contemplated. a Primary / secondary layer of fluid distribution An optional component of the absorbent according to the present invention is a primary fluid distribution layer and a secondary fluid distribution layer. The primary 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 within the thickness, but also along the length and width directions of the absorbent product. The also optional but preferred secondary distribution layer is typically below the primary distribution layer and is in fluid communication therewith. The purpose of this secondary distribution layer is to easily acquire the fluid from the primary distribution layer and quickly transfer it 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 said distribution layers. In particular, the fibrous layers maintain the capillaries between the fibers even when wetted they are useful as distribution layers. b Fluid storage layer Placed in fluid communication with, and typically underlying the primary or secondary distribution layers is a fluid storage layer. The fluid storage layer may comprise any conventional absorbent material or combinations thereof. It 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 fluff and / or tissue. Suitable carriers can be used together with the gelling absorbent material, however, these can also be used alone or in combinations. Tissues or tissue laminates are very preferred within the context of sanitary napkins and pantiliners. One embodiment of the absorbent structure made in accordance with the present invention may comprise multiple layers comprising a double-layer tissue laminate formed by bending the tissue on itself. These layers can be joined together, for example by adhesive or by internal mechanical locking or by hydrogen bonding bands. 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 orlon), 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 surfaces 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 the retention of the liquid. If the gelling absorbent material is dispersed in an inhomogeneous manner in a carrier, the storage layer can, however, be locally homogeneous, ie have a distribution gradient in one or more directions within the dimensions of the storage layer. The inhomogeneous distribution can also refer to the laminates of carriers that enclose totally or partially the absorbent gelling materials. c Optional fibrous layer ("dust removal") An optional component for inclusion in the absorbent core according to the present invention is a fibrous layer adjacent to, and typically below, 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 instances where the gelling absorbent material is in the form of macrostructures 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 the rapid capillary action of the fluid along the length of the pad. d Other optional components of the absorbent structure The absorbent core according to the present invention may 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. Said reinforcement canvases must be of such configuration so as not to form interfacial barriers to fluid transfer. Given the structural integrity that normally occurs as a result of thermal bonding, reinforcement liners are not usually required for thermally bonded absorbent structures.

The upper sheet According to the present invention, the absorbent article 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 which provides the surface that gives the user 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 can also have elastic characteristics that allow it to be stretched in one or two directions. In accordance with the present invention the top sheet 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 polymer film, with openings, permeable to liquid. Preferably, the upper layer is provided by a film material having openings which are provided to facilitate the transport of liquid from the surface which gives 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 placed in the air.

The back sheet The backsheet mainly prevents the exudates absorbed and contained within the absorbent structure from wetting the articles that are in contact with the absorbent product such as underpants, shorts, pajamas and undergarments.

The backsheet is preferably impermeable to liquids (e.g., 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 easily conform to the general figure and contom 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 throughout the entire absorbent structure and can extend into and form part of all or the preferred side flaps, 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 film-coated nonwoven material.

Preferably, the backsheet is a polyethylene film typically having a thickness of about 0.012 mm to about 0.051 mm. 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 finished in relief and / or dull to provide a more fabric-like appearance. In addition, the backsheet can allow vapors to escape from the absorbent structure, i.e., be breathable, while still preventing exudates from passing through the backsheet. Breathable backsheets comprising several layers can also be used, for example, films plus non-woven structures. The present invention is further illustrated by the following examples.

Examples: Example A The feminine pads used in the following examples were Always (Always is a registered trademark) as sold by The Procter & gamble Company Each female pad was opened by cutting the wrapper around the perforated cover material on its lower surface approximately along the longitudinal edge of the release paper that protects the outer adhesive layer. The side of the absorbent fibrous core was then exposed by slightly separating the lower layer of water-impermeable plastic and subsequently, the fibrous core was divided into two halves, each having approximately the same thickness, along a plane that is parallel to the plane. of the towel itself. The peroxyacid was homogeneously distributed between these two fibrous layers which were then joined together to reconstitute the absorbent core. The inner waterproof backsheet was then put back in its original position and the wrap around the perforated cover material was sealed along the cut by means of for example a double-sided adhesive tape. Samples were produced using the above method, containing the odor control systems as described below.

The peroxy acid (0.8g) used was e-phthalimido peroxyhexanic acid commercially available from Ausimont.

Example B Other pads were prepared following the method of Example A except that the gelling absorbent material (AGM) was added onto the peroxyacid of Example A. Accordingly, the peroxyacid and the AGM were homogeneously distributed between these two fibrous layers which were then joined together to reconstitute the absorbent core. The peroxy acid (0.8g) used was e-phthalimido peroxyhexanic acid commercially available from Ausimont. The AGM (0.8g) used was XZ9589001 commercially available from Dow Chemicals.

Example C Other pads were prepared following the method of Example B except after having divided the fibrous core into two halves, the peroxyacid was homogeneously distributed on the fibrous layer of the upper half (ie, half of the fibrous layer intended to be closer to the top sheet) and the AGM was homogeneously distributed over the fibrous layer of the lower half (ie, the half intended to be closer to the back sheet of the pad once it is reconstituted). Then place a layer of tissue placed with air (19 mm * 70mm of low basis weight) available from Fripa under the code / name NCB Tissue HWS between the two halves of fibrous layers which are then joined together to reconstitute the core absorbent. The presence of the tissue placed with air between the two fibrous layers prevents direct contact between the peroxyacid and the AGM.

These samples were produced using as peroxyacid, 0.8g of e-phthalamido peroxyhexanic acid commercially available from Ausimont and the AGM (0.8g) used is commercially available from Dow Chemicals (XZ 9589001). All the above exemplified pads gave the outstanding benefits of odor control when contacted with for example coforal fluids.

Claims (10)

1. An article comprising an odor control material for controlling odor, preferably the odor associated with coforal fluids, characterized in that the odor control material is a peroxyacid according to the formula: R-CO3H wherein R is a substituted or unsubstituted, saturated or unsaturated, linear or branched hydrocarbon group, having 1 to 25 carbon atoms or a cyclic group having 3 to 32 carbon atoms and optionally at least one heteroatom, or a cyclic alkyl group having from 4 to 32 carbon atoms and optionally at least one heteroatom, or a mixture thereof.

2. An article according to claim 1, wherein the article is a disposable absorbent article, preferably a sanitary napkin, a pantyhose, a tampon, a diaper, an incontinence pad, a breast pad, a pad for Sweat or an interlabial pad. An article according to any one of the preceding claims, wherein the article is a disposable absorbent article comprising a liquid pervious topsheet, a backsheet and an intermediate absorbent core to said backsheet and said topsheet. 4. An article according to any one of the preceding claims, wherein R in the formula of the peroxyacid is an alkyl group or a substituted or unsubstituted alkenyl group, linear or branched, having from 1 to 25 carbon atoms, or a aryl alkyl group having from 4 to 32 total carbon atoms, or an aryl group having from 3 to 32 carbon atoms, or a heterocyclic group having from 3 to 32 carbon atoms and from 1 to 5 heteroatoms, or a heterocyclic alkyl group containing from 4 to 32 total carbon atoms and from 1 to 5 heteroatoms, wherein the heteroatoms are independently selected from the group consisting of oxygen, nitrogen and sulfur, and preferably is nitrogen or oxygen. 5. An article according to any of the preceding claims, wherein the peroxyacid is in accordance with the formulas: or wherein Ra is a substituted or unsubstituted, saturated or unsaturated, linear or branched hydrocarbon group, having 1 to 14 carbon atoms, and is a heteroatom, preferably selected from the group consisting of oxygen, nitrogen and sulfur and is more preferably nitrogen, and X are substituents in the ortho or meta position independently selected from the group of hydrogen, hydroxy, halogen, carboxy, saturated or unsaturated aliphatic hydrocarbon group, linear or branched, having from 1 to 10 atoms of carbon, or a mixture thereof. 6. An article according to any one of the preceding claims, wherein the peroxyacid is a peroxyalkane phthalimido acid, a peroxyalkane phthalamido acid or a mixture thereof, and preferably is the e-phthalimido peroxyalkane acid. An article according to any one of the preceding claims, which comprises from 1 gm "2 to 250 gm" 2, preferably from 5 to 150 gm'2, more preferably from 10 gm "2 to 100 gm" 2, and very preferably from 20 gm "2 to 70 gm" 2 of said peroxyacid or a mixture thereof. 8. An article according to any of the preceding claims, which further comprises at least one additional odor control agent. An article according to claim 8, wherein the additional odor control agent is typically selected from the group consisting of gelling absorbent materials, silica, zeolites, carbons, starches, chelating agents, pH regulating materials, cyclodextrin and its derivatives, chitin, kieselguhr, clays, ion exchange resins, carbonates, bicarbonates, phosphates, sulfates, carboxylic acids and combinations thereof. 10. An article according to claims 8 or 9, wherein the additional odor control agent is a gelling absorbent material. 1 An article according to any of claims 8 to 10, which comprises the additional odor control agent or a mixture thereof at a level of 0.5 gm "2 to 600 gm" 2, preferably 5 to 500 gm'2, more preferably from 10 gm'2 to 350 gm "2 and most preferably from 20 gm'2 to 200 gm" 2. 12. The use, as an odor control material, of a peroxyacid having the following formula R-CO3H, wherein R is a substituted or unsubstituted, saturated or unsaturated, linear or branched hydrocarbon group, having from 1 to 25 carbon atoms or a cyclic group having from 3 to 32 carbon atoms and optionally at least one heteroatom, or a cyclic alkyl group having from 4 to 32 carbon atoms and optionally at least one heteroatom.