MXPA01008662A - Water-absorbent materials treated with surfactant-modified cyclodextrins - Google Patents

Abstract

A thermoplastic porous water-permeable layer material has at least one odor-reducing surface which is wettable to aqueous liquids and capable of controlling a wide variety of malodors. The thermoplastic water-permeable layer material is treated with a surfactant-modified cyclodextrin prepared by mixing or chemically reacting a cyclodextrin-based odor absorbing material with a surfactant-producing compound. The layer material thus treated can be used in awide variety of personal care and medical absorbent products, as well as other applications.

Description

ABSORBENT WATER MATERIALS TREATED WITH MODIFIED CYLINDEXTRINS WITH SURFACTANT Field of the Invention This invention relates to compounds and chemical mixtures which control odor and impart surface wetting properties to porous water permeable layer materials. In particular, the invention relates to water-permeable porous layer materials treated with these compounds and dual-purpose chemical mixtures.

Background of the Invention Water-permeable non-woven fabrics, porous films, open cell foams, and other layer materials and their manufacture have been the subject of extensive development which has resulted in a wide variety of materials for numerous applications. For example, lightweight, open-weighted nonwovens are used in personal care articles such as disposable diapers such as lining fabrics that provide dry skin contact but which readily transmit fluids to more absorbent materials. which may also be non-woven of a different composition and / or structure. Heavier-weight nonwovens can be designed with pore structures that make them suitable for filtration, absorbent and barrier applications such as wrappers for articles to be sterilized, wipes or protective garments for medical, veterinary or other uses. industrial Even heavier weight non-woven materials have been developed for recreational, agricultural and construction uses. Porous water-permeable thermoplastic films are also used in some of these applications and can be combined with non-woven fabrics. Open cell foams are also useful in some applications.

It is not always possible to efficiently produce a water permeable layer material having all the desired properties upon being formed, and it is often necessary to treat the material with a surfactant to improve or alter the surface properties such as wettability by one or more fluids, repellency to one or more fluids, electrostatic characteristics, conductivity and softness to name only a few examples. Conventional surfactant treatments involve steps such as embedding the substrate in a treatment bath, coating or spraying the substrate with the treatment composition, and printing the substrate with the treatment composition. For cost and other reasons it is usually desired to use the minimum amount of treatment composition that will produce the desired effect with an acceptable degree of uniformity.

For many end-use applications of thermoplastic layer material, it is desirable to reduce, eliminate or avoid odors. For diapers and other incontinence products, it is desirable to reduce or eliminate the ammonia odor which is present in the urine. For women's hygiene products, it is desirable to reduce or eliminate the odor of triethylamine. Other common odor-producing substances include isovaleric acid, dimethyl disulfide, and dimethyl trisulfide.

Odor control agents include odor inhibitors, odor absorbers, and other compounds which reduce, prevent or eliminate odors. Odor inhibitors prevent odor from forming. For example, U.S. Patent No. 4,273,786 issued to Kraskin teaches the use of an aminopolycarboxylic acid compound to inhibit the formation of ammonia from urea in the urine. Odor absorbers and adsorbers remove the odor after it has formed. Examples of odor control agents that remove odor by absorption or adsorption include activated carbon, silica and cyclodextrins.

Typical odor control agents based on cyclodextrins can not easily be applied from aqueous solutions to water-permeable thermoplastic substrates such as non-woven polyolefin fabrics, porous films, and open cell foams because the surface tension of these solutions is too high to wet the hydrophobic substrate. Personal care products such as diapers and pads for women's care typically contain polyolefin non-woven fabrics and / or other porous thermoplastic cover layers. Therefore, typical odor control agents can not usually be applied to the porous thermoplastic components of personal care products. Instead, these odor control agents are usually introduced as powders to the product, which has several disadvantages. For example, placement and containment of the powder in the product can be problematic. More importantly, the powders do not have an optimum surface area for odor absorption due to a fairly low surface to volume ratio. Therefore, more of the odor control agent will be required if it is in the powder form.

There is therefore a need or desire for odor absorbing compounds and blends which can be applied to a water permeable hydrophobic substrate (eg thermoplastic) in a liquid or solvent form, and which have sufficient surface wetting properties. to facilitate a distribution of fluid and durability pairs.

Synthesis of the Invention The present invention is directed to a porous water permeable layer material which has been treated with a surfactant modified odor control agent. The surfactant modified odor control agent can be prepared by mixing a cyclodextrin-based odor control agent with a surfactant, or by chemically reacting a cyclodextrin-based odor control agent with a surfactant-producing compound. . The surfactant-producing compounds include both surfactants, and other compounds which behave as surfactants after the chemical reaction. The surfactant modified odor control agent can be applied to the water permeable porous layer material using conventional internal or external application techniques for the surfactants, and is preferably applied using an external application technique. The resulting treated substrate is more humid to aqueous liquids and absorbs odors from its surfaces.

The water-permeable porous layer material can be a hydrophobic material, made using one or more thermoplastic polymers. For example, the porous substrate can be a thermoplastic nonwoven filament fabric, a porous thermoplastic film, an open cell foam material, or a combination thereof. A non-woven thermoplastic filament fabric is preferred. The water permeable and treated porous layer material can be used in a wide variety of products for personal care and medical products and in other applications.

Surfactant modified odor control agents can be applied to hydrophobic substrates (eg, polyolefin-based porous films, open cell foam layers, and non-woven fabrics) from an aqueous solution, because the surface tension of the solution is sufficiently low to wet the low surface energy substrate. For example, the coating of the surfactant modified odor control agent on the polyolefin fibers of a polyolefin nonwoven fabric will optimize the surface to volume ratio of the odor control chemistry, and thus provide better odor control (for example, odor absorption, adsorption or inhibition). In addition, fibers coated with a surfactant-modified odor control agent will be in direct contact with body fluids as fluids enter and transmitted through the fabric components of the personal care product. This will provide optimal odor control since the odors are believed to emanate from body fluids.

It is therefore a feature and an advantage of the invention to provide a treated water-permeable porous layer material having at least one surface which is more wettable to aqueous liquids than the untreated layer material, and which absorbs the common smells.

It is also a feature and an advantage of the invention to provide a personal care product or fabric which utilizes a treated water-permeable porous layer material that is more moistenable and absorbs odors on at least one exterior surface.

It is also a feature and an advantage of the invention to provide a medical product or fabric which utilizes a treated, water-permeable, porous layer material that is more moistenable and absorbs odors on at least one exterior surface.

Definitions The term "porous water permeable layer material" refers to a material present in one or more layers, such as a film, a nonwoven fabric or an open cell foam, which is porous, and which is permeable to water due to the flow of water and other aqueous liquids, through the pores. The pores in the film or foam, or the spaces between the fibers or filaments in a non-woven fabric, are sufficiently large and often allow runoff and flow of liquid water through the material. The term does not include films and other materials that block the transfer of water, or which allow the transfer only by molecular diffusion.

The term "nonwoven fabric or fabric" means a fabric having a structure of individual fibers or threads which are interleaved but not in a regular or identifiable manner as in a woven fabric. Fabrics or non-woven fabrics have been formed from many processes such as, for example, meltblowing processes, spinning bonding processes, air laying processes, and carded and bonded tissue processes. The basis weight of the non-woven fabrics is usually expressed in ounces of material per square yard (osy) or grams per square meter (gsm) and the useful fiber diameters are usually expressed in microns (note that to convert ounces per square yard to grams per square meter, multiply ounces per square yard by 33.91).

The term "microfibers" means small diameter fibers having an average diameter of no more than about 75 microns, for example, having an average diameter of from about 1 micron to about 50 microns, or more particularly, microfibers can have an average diameter of from about 1 miera to about 30 micras. Another frequently used expression of fiber diameter is denier, which is defined by grams per 9,000 meters of a fiber. For a fiber having a circular cross section, the denier can be calculated as fiber diameter in square microns, multiplied by the density in grams / cubic centimeter, multiplied by 0.00707. A lower denier indicates a finer fiber and a higher denier indicates a heavier or thicker fiber. For example, the diameter of a polypropylene fiber given as 15 microns can be converted to denier by placing the square, multiplying the result by .89 g / c3 and multiplying by 0.00707. Therefore, a polypropylene fiber of 15 microns has a denier of about 1.42 (152 x 0.89 x .00707 = 1.415). Outside the United States of America, the unit of measurement is more commonly the "tex" which is defined as grams per kilometer of fiber. The tex can be calculated as denier / 9.

The term "spunbonded fibers" refers to fibers of small diameter which are formed by extruding the molten thermoplastic material as filaments from a plurality of fine capillary vessels of a spinner member having a circular configuration or other configuration, with the diameter of the extruded filaments then being rapidly reduced as indicated for example in U.S. Patent No. 4,340,563 issued to Appel et al., and in U.S. Patent No. 3,692,618 issued to Dorschner et al. , in the patent of the United States of America No. 3,802,817 granted to Matsuki and others, in the patents of the United States of America Nos. 3,338,992 and 3,341,394 granted to Kinney, patent of the United States of America No. 3,502,763 granted to Hartmann , United States of America Patent No. 3,502,538 granted to Petersen and United States of America Patent No. 3,542,615 granted to Dobo and others, each of which is incorporated herein in its entirety by reference. Spunbonded fibers are cooled and are generally non-tacky when deposited on a collector surface. Spunbonded fibers are generally continuous and frequently have average diameters greater than about 7 microns, more particularly between about 10 and 30 microns.

The term "meltblown fibers" means fibers formed by extruding a molten thermoplastic material through a plurality of thin, usually circular, capillaries, such as melted threads or filaments into heated gas (eg air) streams. at high speed which attenuate the filaments of the molten thermoplastic material to reduce its diameter, which can be to a microfiber diameter. After, the meltblown fibers are carried by the gas stream at high speed and are deposited on a collecting surface to form a fabric of melt blown fibers and randomly dispersed. Such a process is described, for example, in United States of America Patent No. 3,849,241 issued to Butin et al. The melt blown fibers are microfibers which may be continuous or discontinuous, are generally smaller than 10 microns in diameter, and are generally self-supporting when deposited on a collecting surface. The meltblown fibers used in the present invention are preferably and essentially continuous in length.

The term "monocomponent" fiber refers to a fiber formed from one or more extruders using only one polymer. This does not mean that fibers formed from a polymer to which small amounts of additives have been added for color, antistatic properties, lubrication, hydrophilicity, repellency, etc. are excluded. These additives (for example titanium dioxide for color) are generally present in an amount of less than 5% by weight and more typically of about 2% by weight or less.

The term "coform" material refers to a product containing about 10% by weight to 90% by weight of thermoplastic meltblown fibers and about 10% by weight to 90% by weight of basic length pulp fibers dispersed inside the fiber matrix blown with fusion. Most commonly, coform materials contain about 20% by weight to 70% by weight of thermoplastic melt blown fibers and about 30% by weight to 80% by weight pulp fibers.

The term "film" refers to a thermoplastic film made using a film extrusion process, such as a set film or a blown film extrusion process.

The term "water permeable porous film" includes films, such as films containing thermoplastic polymer, which allow water to flow through open or interconnected pores. The term includes films made porous by perforation or perforation, and films that are made porous by mixing a polymer with a filler, forming a film of the mixture, and stretching the film sufficiently to form conduits for liquid through the film. the movie.

The term "open cell foam material" refers to a layer material made with the aid of a forming process, in which the cells in the foam create open pores from one surface of the layer to the opposite surface. The term does not include foams which essentially block the flow of liquid water, such as closed cell foam materials.

The term "polymer" includes, but is not limited to homopolymers, copolymers, such as for example block, graft, random and alternating copolymers, terpolymers, et cetera, and mixtures and modifications thereof. In addition, unless specifically limited in another way, the term "polymer" should include all possible geometric configurations of the material. These configurations include, but are not limited to, isotactic, syndiotactic and atactic symmetries.

The term "bicomponent fibers or filaments" refers to the fibers which have been formed from at least two extruded polymers from separate extruders but which have been spun together to form a fiber. The polymers that are arranged in different areas placed essentially constant across the cross section of the bicomponent fibers and that extend continuously along the length of the bicomponent fibers. The configuration of such bicomponent fiber can be, for example, a pod / core arrangement where one polymer is surrounded by another or can be a side-by-side arrangement or an arrangement of "islands in the sea". The bicomponent fibers are taught in U.S. Patent No. 5,108,820 issued to Kaneko et al., In U.S. Patent No. 5,336,552 issued to Strack et al., And in the U.S. Patent. of America No. 5,382,400 granted to Pike et al., each of which is hereby incorporated by reference in its entirety. For the two component fibers, the polymers may be present in proportions of 75/25, 50/50, 25/75 or any other desired proportions. Conventional additives, such as pigments and surfactants, can be incorporated into one or both polymer streams, or they can be applied to the filament surfaces.

The term "pulp fibers" refers to fibers from natural sources such as woody and non-woody plants. Woody plants include, for example, deciduous and coniferous trees. Non-woody plants include, for example, cotton, flax, esparto, benzene, straw, jute and bagasse.

The term "average pulp fiber length" refers to a heavy average length of pulp determined using a Kajaani fiber analyzer model No. FS-100 available from Kajaani Oy Electronics in Kajaani, Finland. Under the test procedure, a sample of fiber is treated with a macerator liquid to ensure that no bunches or pieces of fibers are present. Each sample of fiber is dispersed in hot water and diluted to around a concentration of 0.001%.

Individual test samples are drawn in portions of approximately 50 milliliters to 500 milliliters from the diluted solution and tested using the standard Kajaani Fiber Analysis procedure. The average heavy fiber lengths can be expressed by the following equation: k S (XX * nA / n Xi> O where k = maximum fiber length, Xi = individual fiber length, nx = number of fibers that have the length X ± and n = total number of fibers measured The term "superabsorbent material" refers to an organic or inorganic material insoluble in water and swellable in water, capable, under the most favorable conditions, of absorbing at least 20 times its weight, preferably at least about 30 times its weight in an aqueous solution containing 0.9% by weight of sodium chloride.

The term "air binding" or " " means a process for joining a nonwoven material, for example, a two-component fiber fabric in which the air which is hot enough to melt one of the polymers of the which fibers are made of the tissue is forced through said tissue. The air speed is often between 100 and 500 feet per minute and the dwell time can be as long as 6 seconds. The melting and resolidification of the polymer provides the bond. Bonding through air has a restricted variability and is generally seen as a second step joining process. Since air binding requires the melting of at least one component to achieve bonding, it is restricted to two-component fabrics such as bicomponent fiber fabrics or fabrics containing a fiber or adhesive powder.

The term "thermal point union" involves passing a fabric or fabric of fibers to be joined between a heated calender roll and an anvil roll. The calendering roller usually has, although not always, some pattern in some way so that the entire fabric is not bonded through its entire surface. As a result of this, several patterns have been developed for calendering rolls for functional as well as aesthetic reasons. An example of a pattern has points and is the Hansen Pennings pattern or "H &P" with a bound area of about 30% with about 200 joints / square inch as taught in the United States of America patent No. 3,855,046 awarded to Hansen and Pennings. The H &P pattern has bolt or square point joining areas where each bolt has a side dimension of 0.038 inches (0.965 millimeters), a spacing of 0.070 inches (1,778 millimeters) between the bolts, and a joint depth of 0.023 inches (0.584 millimeters). The resulting pattern has a bound area of about 29.5%. Another typical point binding pattern is the Hansen & Expanded Pennings or "EHP" which produces a 15% joint area with a square bolt that has a side dimension of 0.037 inches (0.94 millimeters), a bolt spacing of 0.097 inches (2.464 millimeters) and a depth of 0.039 inches ( 0.991 millimeters). Another typical point union pattern designated "714" has square bolt joint areas where each bolt has a side dimension of 0.023 inches, a spacing of 0.062 inches (1,575 millimeters) between the bolts, and a joint depth of 0.033 inches (0.838 millimeters). The resulting pattern has a bound area of about 15%. Yet another common pattern is the star-C pattern which has a bound area of about 16.0%, the star-C pattern has a bar in the transverse direction or a "corduroy" pattern interrupted by shooting stars. Other common patterns include a diamond pattern with slightly off-center and repetitive diamonds and a woven wire pattern that looks like the name suggests (like a window grid). Typically, the percent bond area varies from about 10% to about 30% of the area of the fabric laminated fabric. As is well known in the art, point bonding holds the laminated layers together as well as imparting integrity to each individual layer by joining the filaments and / or fibers within each layer.

The term "personal care product" includes, without limitation, diapers, underpants, swimwear, absorbent underwear, baby wipes, adult incontinence products, and women's hygiene products.

The term "medical product" includes without limitation garments, undergarments, bandages, absorbent covers, and medical drapes.

The term "hydrophilic" or "wettable" means that the polymeric material has an apparent surface free energy such that the polymeric material is wettable by an aqueous medium (eg, a liquid medium of which water is a major component). That is, an aqueous medium moistens the non-woven fabric. The term "apparent surface free energy" refers to the highest surface tension of an aqueous liquid which moistens the polymeric material. For example, the apparent surface free energy of a polymeric material that is wetted by an aqueous liquid having a surface tension of 72 dynes / centimeter is at least 72 dynes / centimeter and possibly higher. In the fabrics of the invention, a surface of the non-woven fabric has been treated with a surfactant-modified odor control agent using internal or external application techniques as described below.

The term "surfactant" refers to a compound or mixture which, when applied to a surface of a substrate, causes the surface to become more "wettable" as defined above. In one case, the substrate is not wettable independently and the surfactant causes it to become wettable. In another case, the substrate is somewhat humid and the surfactant makes it more wettable or moistens more easily.

The term "surfactant-producing moiety" or "Surfactant producing compound" refers to a chemical group or compound which, when reacted or mixed with another compound (e.g., an odor control agent) causes the reacted compound or mixture to behave as a surfactant. The surfactant-producing compound or moiety may or may not behave as a surfactant prior to the chemical reaction or mixing.

The term "odor control agent" includes compounds and mixtures which inhibit the formation of at least one undesirable odor, as well as the compounds and mixtures which absorb an undesirable odor that has already been formed.

The term "surfactant modified odor control agent" refers to a mixture and / or a reaction product, between an odor control agent and a surfactant or surfactant producing moiety, which both act as a surfactant and an odor control agent.

Detailed Description of Current Preferred Incorporations The invention relates to a water permeable layer material having at least one odor reducing surface. The starting material for the invention is a water permeable layer material. For example, the starting material for the invention can be a multilayer or porous thermoplastic layer capable of transmitting water (and other aqueous liquids) through the pores. Examples of suitable starting materials include thermoplastic nonwoven fabrics, open cell foam layers, and films containing thermoplastic polymers which are perforated or otherwise made porous, such as by stretching a film made of a mixture of thermoplastic material and a particulate filler.

The starting material is treated with a surfactant modified odor control agent. The surfactant modified odor control agent is produced by mixing a cyclodextrin-based odor control agent with a surfactant compound, and / or by chemically reacting a cyclodextrin-based odor control agent with a compound surfactant producer. The surfactant modified odor control agent is applied to the starting material using conventional techniques to apply surfactants externally or internally. Preferably, the surfactant modified odor control agent is applied externally in the form of a liquid, using techniques such as embedding, spraying, brushing and other liquid coating techniques. The odor control agent modified with surfactant can be mixed with water or another solvent to facilitate its application.

The preferred starting material for the invention is a nonwoven fabric that includes a plurality of filaments made of one or more polymers. The non-woven fabric may be a spunbonded fabric, a meltblown fabric, a bonded and bonded fabric, or another type of non-woven fabric, and may be present in a single layer or in a multilayer composite including one or more layers of non-woven fabric and, in some cases, one or more layers of film or foam. The fabric may include monocomponent or bicomponent filaments, or a combination that includes one or both types of filament. The non-woven fabric can have a variety of basis weights, preferably ranging from about 0.1 grams per square meter to 200 grams per square meter (gsm). A preferred nonwoven fabric is a coform material which includes a polyolefin meltblown fiber matrix and a large percentage (frequently 30% by weight to 80% by weight) of pulp fibers dispersed in the fiber matrix blown with fusion. Another preferred nonwoven fabric is an air-laid fabric of polyolefin fibers and pulp fibers.

A wide variety of thermoplastic polymers can be used to construct the starting porous layer material, including without limitation polyamides, polyesters, polyolefins, ethylene and propylene copolymers, ethylene or propylene copolymers with a C4 alpha olefin -C20, the terpolymers of ethylene with propylene and a C4-C20 alpha olefin, the ethylene vinyl acetate copolymers, the propylene vinyl acetate copolymers, the styrene-poly (ethylene-alpha olefin) elastomers, the polyurethanes, the copolymers of block AB wherein A is formed of poly (vinyl arene) moieties, such as polystyrene and B is an elastomeric middle block such as a conjugated diene or a lower alkene, polyethers, polyether esters, polyacrylates, ethylene alkyl acrylates, polyisobutylene, poly-1-butene, poly-1-butene copolymers including copolymers of ethylene-1-butene, polybutadiene, isobutylene-isoprene copolymers, and combinations of any of the above. Polyolefins are preferred. Most preferred are polyethylene and polypropylene homopolymers and copolymers.

The odor control agent, which can be mixed or chemically reacted with a surfactant to make the odor control agent modified with surfactant, includes a compound selected from cyclodextrins. Suitable cyclodextrins include any of the known cyclodextrins containing from six to twelve glucose units, including without limitation alpha-cyclodextrins (six glucose units arranged in a ring), beta-cyclodextrins (seven glucose units arranged in a ring ), and gamma-cyclodextrins (eight glucose units arranged in a ring). The configuration and coupling of the glucose units makes the cyclodextrins have a conical molecular structure with a hollow interior lined by hydrogen atoms and glycoid bridge oxygen atoms. When the cyclodextrins alone are applied to the starting substrate material, the material does not have sufficient wettability to the aqueous liquids.

According to the invention, the precursor odor control agent is mixed with a surfactant, and / or chemically reacted with a surfactant-producing compound, to give the modified odor control agent with surfactant which can serve both functions . As indicated above, the term "surfactant producing compound" includes surfactants and other compounds which behave as surfactants following the chemical reaction. The surfactant and / or the surfactant-producing compound must include at least one functional group which is compatible with the thermoplastic polymer used to make the non-woven fabric. Functional groups include alkyl groups having about 3 carbon atoms to 20 carbon atoms, including but not limited to propyl, benzyl, isopropyl, butyl, tertiary butyl, allyl, alkyl benzyl, hexyl, octyl, decyl, lauryl, myristyl, palmityl, coyl, oleyl, stearyl and other common alkyl groups. Alkyl groups can be combined with cyclodextrins by mixing an alkyl-containing surfactant with a cyclodextrin odor control agent (for example in a solvent such as water) or by reacting a hydroxyl group on the cyclodextrin under appropriate conditions with an alkyl compound producing a surfactant such as an alkyl-containing surfactant, an alkyl halide, an alkyl alkylating sulfate reagent, or another suitable alkylating compound. Mixing and / or chemical reaction can be achieved using conventional techniques.

Other suitable functional groups include acyl groups having about three carbon atoms to twenty carbon atoms including without limitation propionyl, butyryl, trifluoroacetyl, benzoyl, caproyl, caprylyl, capryl, lauroyl, myristoyl, palmitoyl, stearoyl, cocoyl, oleyl , and other common acyl groups. The acyl groups can be combined with the cyclodextrins by mixing an acyl-containing surfactant with a cyclodextrin control agent (for example using a solvent such as water). The acyl groups can be formed on cyclodextrins by reacting a hydroxyl group on the cyclodextrin under appropriate conditions with an acyl surfactant producing compound such as a surfactant containing acyl, acid anhydride, acid chloride or other suitable acylating compound. Mixing and / or chemical reaction can be achieved using conventional techniques.

Other suitable functional groups include those which contain an aliphatic hydrocarbon group or a derivative thereof which can be mixed or reacted with a cyclodextrin to make it surfactant. Suitable aliphatic hydrocarbon compounds include the compounds containing the 2-ethylhexylglycidyl group, which can be mixed with a cyclodextrin, and / or linked to a cyclodextrin to form an ether, ester or other derivative compound. Other suitable functional groups may also be employed including the perfluoro and siloxane groups and the compounds containing them. Examples include the compounds that contain the following groups: (-CF2-X-CF3 where x = 2 to 11, CH, CH, I "4 yes or x- Yes CH, CH, CH, where x = 2 to 20 CH3 CH, CH, CH3 CH, Si O - 4 Si O y- Si O -x-- Si CH, I CH3 CH3 CH3 where x = 2 to 20.

The resulting odor control agent modified with surfactant can be applied using internal or external application techniques known in the art. Some compounds and mixtures operate more favorably when applied internally and are called "internal additives". Others operate more favorably when they are applied externally and are called "external additives". Still other compounds and mixtures operate properly as both internal and external additives.

As is generally known, an internal additive is typically mixed with the polymer used to make the porous film, the nonwoven fabric, or other porous thermoplastic material, and migrates to the surfaces of the porous film, the nonwoven fabric filaments or other layer material during and / or after its formation. Frequently, the emigration results from a stimulus, such as heat applied to the thermoplastic material. An external additive is applied externally to the surfaces of the layer material after it is formed. An external additive can be applied by soaking, soaking, spraying, or by otherwise coating the porous thermoplastic layer material with a solvent or other medium containing the additive.

External application methods are currently preferred for the surfactant modified odor control agents used with the treated materials of the invention. The surfactant modified odor control agent (either formed by mixing or chemical reaction) can be mixed with water or other suitable solvent in a concentration of about 0.1% by weight to 30% by weight of the agent, preferably about 0.5. % by weight to 15% by weight of the agent, more preferably from about 1% by weight to 5% by weight of the agent. The solution can then be applied to a porous and water permeable thermoplastic substrate by dipping, spraying, brush coating, printing, or other suitable technique. The treated layer material can then be dried using heat, forced air convection, vacuum induced evaporation, or other conventional drying technique.

The treated layer material thus formed has wettability to aqueous liquids, and odor resistance to a wide variety of odor-producing compounds. The terms "odor resistance" and "odor control" refer to the ability of the treated materials to react, neutralize, form complexes or otherwise reduce or eliminate the odors produced by these compounds. Examples of the odor-producing compounds which the treated layer materials of the invention can reduce or eliminate include, without limitation, ammonia, triethylamine, isovaleric acid, dimethyl disulfide, dimethyl trisulfide, indole, skatole and similar.

The amount of surfactant modified odor control agent necessary to provide sufficient wetting and sufficient odor absorption may vary depending on the surfactant producing compound and the odor control agent mixed or reacted together, the type of base polymer, and if the odor control agent modified with surfactant is added internally or externally. On a solvent free weight basis, the surfactant modified odor control agent should generally constitute about 0.1% to 10% by weight of the water permeable and porous substrate layer to which it is applied, preferably around from 0.5% by weight to 8% by weight, more preferably around 2% by weight to 7% by weight.

The treated water permeable layer materials thus formed can be used in a wide variety of absorbent product applications including, in particular, absorbent personal care products. Absorbent personal care products include diapers, underpants, swimwear, absorbent underwear, baby wipes, adult incontinence products, women's hygiene products, and Similar. In most absorbent products, the treated water-permeable layer material is used as a cover sheet or a containment matrix for an absorbent medium capable of absorbing aqueous liquids. An absorbent medium may include, for example, pulp fibers alone or in combination with a superabsorbent material. The treated water-permeable layer material can be used in medical absorbent products, including without limitation garments, undergarments, absorbent covers, bandages and medical cleansing wipes.

The pulp fibers may be any high average fiber length pulp, low average fiber length pulp, or mixtures thereof. Preferred pulp fibers include cellulose fibers. The term "high average fiber length pulp" refers to a pulp that contains a relatively small amount of short fibers and non-fiber particles. The high fiber length pulps typically have an average fiber length greater than about 1.5 millimeters, preferably about 1.5 millimeters to 6 millimeters as determined by a fiber optic analyzer, such as the Kajaani tester mentioned above. The sources generally include the non-secondary (virgin) fibers as well as the secondary pulp fiber which has been screened. Examples of high average fiber length pulps include virgin softwood pulp bleached and unbleached.

The term "low average fiber length pulp" refers to pulp that contains a significant amount of short fibers and non-fiber particles. The low average fiber length pulps have an average fiber length of less than 1.5 millimeters, preferably from about 0.7 millimeters to 1.2 millimeters, as determined by a fiber optic analyzer such as the Kajaani tester that has been made mention above. Examples of low fiber length pulps include virgin hardwood pulp, as well as secondary fiber pulp from sources such as office waste, newsprint, and cardboard trimming.

Examples of high average fiber length wood pulps include those available from U.S.

Alliance Coosa Pines Corporation, under the trade designations Longlac 19, Coosa River 56, and Coosa River 57. Low average fiber length pulps may include some virgin hardwood pulp and secondary fiber pulp (eg, recycled) from sources that include newspaper, reclaimed cardboard, and office waste. Mixtures of high average fiber length and low average fiber length pulps may contain a predominance of low average fiber length pulps. For example, blends can contain more than about 50% by weight of pulp of low average fiber length and less than about 50% by weight of high average length of fiber pulp.

The term "superabsorbent" or "superabsorbent material" refers to an organic or inorganic material insoluble in water, and swellable in water capable, under the most favorable conditions, of absorbing at least about 20 times its weight and, more desirably, of at least about 30 times its weight in an aqueous solution containing 0.9 percent by weight of sodium chloride.

The superabsorbent materials can be polymers and natural, synthetic and modified natural materials. In addition, the superabsorbent materials may be inorganic materials such as silica gels, or organic compounds such as crosslinked polymers. The term "cross-linked" refers to any means for effectively making the materials normally water-soluble essentially insoluble, but swellable in water. Such media may include, for example, physical entanglement, crystalline domains, covalent bonds, complexes and ionic associations, hydrophilic associations, such as hydrogen bonding, and hydrophobic associations or Van der aals forces.

Examples of the polymers of synthetic superabsorbent material include the alkali metal and ammonium salts of poly (acrylic acid) and poly (methacrylic acid), poly (acrylamide), poly (vinyl ethers), copolymers of maleic anhydride with ethers of vinyl and alpha olefins, poly (vinyl pyrrolidone), poly (vinyl morpholinone), poly (vinyl alcohol), and mixtures and copolymers thereof. Additional superabsorbent materials include natural and modified natural polymers such as hydrolyzed acrylonitrile grafted starch, acrylic acid grafted starch, methylcellulose, chitosan, carboxymethylcellulose, hydroxypropylcellulose, and natural gums such as alginates, gum xanthan, locust bean gum and the like. Mixtures of natural and fully or partially synthetic superabsorbent polymers may also be useful in the present invention. Other suitable absorbent gelation materials are described by Assarsson et al. In U.S. Patent No. 3,901,236 issued Aug. 26, 1975. Processes for preparing synthetic absorbent gelation polymers are described in the US Pat. United States No. 4,076,663 granted on February 28, 1978 to Asuda and others, and in United States of America No. 4,286,082 issued August 25, 1981 to Tsubakimoto et al.

The superabsorbent materials can be xerogels which form hydrogels when wetted. The term "hydrogel", however, has been commonly used to also refer to both wet and unmoistened forms of the superabsorbent polymer material. The superabsorbent materials can be in many forms such as flakes, powders, particles, fibers, continuous fibers, networks, spun filaments of solution and fabrics. The particles can be of any desired shape, for example, spiral or semi-spiral, cubic, rod-type, polyhydric, etc. Needles, flakes, fibers and combinations can also be used.

The superabsorbents are generally available in particle sizes ranging from about 20 to about 1,000 microns. Examples of the commercially available particulate superabsorbents include SAN ET® IM-3900 and SAN ET® IM-5000P, available from Hoescht Celanese located in Portsmouth, Virginia, DRYTECH® 2035LD available from the Dow Chemical Company, located in Midland, Michigan, and FAVOR® SXM880, available from Stockhausen, located in Greensboro, North Carolina. An example of a fibrous superabsorbent is OASIS® 101, available from Technical Absorbents, located in Grimsby, United Kingdom.

As indicated above, the treated water-permeable layer material may be a cover sheet or a matrix for an absorbent medium. The non-woven filaments can be used as a matrix, and can be combined with the pulp fibers and (optionally) a superabsorbent material using processes well known in the art. For example, a coform process may be employed, in which at least one meltblown die head is arranged near a conduit through which other materials are aggregated while the tissue is being formed. The coform processes are described in U.S. Patents Nos. 4,818,464 to Lau and 4,100,324 to Anderson et al., Whose descriptions are incorporated by reference. Thermoplastic non-woven filaments and pulp fibers can also be combined using hydraulic entanglement or mechanical entanglement. A hydraulic entangling process is described in U.S. Patent No. 3,485,706 issued to Evans, the disclosure of which is incorporated herein by reference.

When the treated thermoplastic nonwoven filaments are used as a matrix for an absorbent nonwoven fabric composite, the composite should contain about 5% by weight to 97% by weight pulp fibers, preferably about 35% by weight to 95% by weight. % by weight of pulp fibers, more preferably from about 50% by weight to 95% by weight of the pulp fibers. When a superabsorbent material is present, it should constitute about 5% by weight to 90% by weight of the compound, preferably about 10% by weight to 60% by weight, more preferably about 20% by weight to 50% by weight . In either case, the thermoplastic nonwoven matrix should constitute about 3% by weight to about 95% by weight of the compound, preferably about 5% by weight to 65% by weight, more preferably about 5% by weight to 50% by weight.

After combining the ingredients together, the absorbent nonwoven composites can be joined together using the thermal bond or air bonding techniques described above, to provide a high coherent integrity structure.

The following examples were prepared and tested for wettability to water and for odor absorption properties.

Example 1 A nonwoven coform fabric was prepared with 30% by weight of melt blown polypropylene fibers and 70% by weight pulp fibers. The fabric had a basis weight of 170 grams / square meter. The coform fabric was not wettable to deionized water.

Example 2 The coform fabric described as Example 1 was treated with 1.0% by weight of beta-cyclodextrin (Cerestar USA, Inc.) as follows. Three grams of beta-cyclodextrin were dissolved in deionized water, and the solution was diluted with deionized water to a total weight of 750 grams. The surface tension of this solution of 0.4% by weight of beta-cyclodextrin was measured at 74.6 dynes / centimeter, around the same pure deionized water (75.2 dynes / centimeter). The beta-cyclodextrin can not be applied to the coform fabric of this solution because the solution would not moisten the fabric due to the high surface tension. Therefore, 3.8 grams of hexanol was added to the solution to give 0.4% by weight of beta-cyclodextrin / 0.5% by weight of hexanol / 99.1% by weight of deionized water. The surface tension of this new solution was measured at 36 dynes / centimeter, low enough to moisten the coform fabric and apply the beta-cyclodextrin treatment to the surface of the fabric. The coform fabric was soaked in the solution for about 1 minute, squeezed with a pressure point to remove excess solution, and dried on a cover. This procedure yielded an added level of 0.1% by weight of beta-cyclodextrin, which was determined from the moisture content of the fabric and the concentration of solution, calculated as follows:% by weight of treatment = [(wet weight of the fabric less dry weight of the fabric), divided by the dry weight of the fabric], multiplied by the% by weight of the treatment in the solution. The dried cloth with 1.0% by weight of the beta-cyclodextrin treatment was tested for wettability to deionized water. The fabric was only slightly wettable to water, and therefore, it was not preferred for use in personal care products, which must absorb liquids.

Example 3 The coform fabric described as in Example 1 was treated with 1.0% by weight of 2-ethylhexylglycidyl ether beta-cyclodextrin (EHGE Beta-CD) as follows. Three grams of ethylhexylglycidyl ether beta-cyclodextrin (Cerestar USA, Inc.) was mixed with 750 grams of deionized water. The mixture was heated to about 60 ° C for a period of 1 to 2 hours in order to disperse and dissolve the ethylhexylglycidyl ether beta-cyclodextrin. This 0.4% by weight solution of ethylhexylglycidyl ether beta-cyclodextrin / deionized water was cooled to less than 30 ° C before being used to soak the coform fabric. The surface tension of the solution was measured at 34 dynes / centimeter low enough to easily moisten the coform fabric without the need for hexanol. The coform fabric was soaked in 0.4% by weight of ethylhexylglycidyl ether beta-cyclodextrin solution for about 1 minute, squeezed with a pressure point to remove the excess solution and dried on a cover. The percent of treatment aggregate for the fabric was determined to be 1.05 by weight of ethylhexylglycidyl ether beta-cyclodextrin, using the procedure described for sample 2. The coform fabric treated with the dried ethylhexylglycidyl ether beta-cyclodextrin was tested for of wettability to deionized water. The fabric was highly humid to water, as water droplets completely penetrated the fabric in less than a second. Therefore, the coform fabric treated with ethylhexylglycidyl ether beta-cyclodextrin will be preferred for use in a personal care product since both properties of wettability to fluids and odor absorption are provided.

The results for these samples clearly teach the benefit of using the surfactant-modified cyclodextrins as treatments for porous water-permeable layer materials. These materials provide the materials with both the wettability to the fluids and the odor absorption properties.

Although the embodiments of the invention described herein are presently preferred, various modifications and improvements can be made without departing from the spirit and scope of the invention. The scope of the invention is indicated by the appended claims, and all changes that fall within the meaning and range of equivalents are intended to be encompassed here.

Claims (46)

R E I V I N D I C A C I O N S

1. A disposable personal care absorbent garment incorporating therein a treated water permeable layer material comprising a thermoplastic and porous water permeable substrate layer treated with a surfactant modified odor control agent selected from the group consisting of ) a mixture of a surfactant with a cyclodextrin control agent, b) a reaction product of a surfactant producing compound with a cyclodextrin odor control agent and c) combinations of the above, with the modified odor control agent with surfactant not being attached to the layer material.

2. The water permeable layer material treated as claimed in clause 1, characterized in that the substrate layer comprises a non-woven thermoplastic filament fabric.

3. The water permeable layer material treated as claimed in clause 1, characterized in that the substrate layer comprises a porous film.

4. The water permeable layer material treated as claimed in clause 1, characterized in that the substrate comprises an open cell foam layer.

5. The water permeable layer material treated as claimed in clause 1, characterized in that the cyclodextrin odor control agent comprises a compound selected from alpha-cyclodextrins, beta-cyclodextrins, gamma-cyclodextrins, and combinations, of the same.

6. The water permeable layer material treated as claimed in clause 5, characterized in that the cyclodextrin odor control agent comprises a beta-cyclodextrin.

7. The water permeable layer material treated as claimed in clause 5, characterized in that the cyclodextrin odor control agent comprises an alpha-cyclodextrin.

8. The water permeable layer material treated as claimed in clause 5, characterized in that the cyclodextrin odor control agent comprises a gamma-cyclodextrin.

9. The water-permeable layer material treated as claimed in clause 1, characterized in that the surfactant or the surfactant-producing compound comprises an alkyl group.

10. The water permeable layer material treated as claimed in clause 9, characterized in that the alkyl group comprises about 3 carbon atoms to 20 carbon atoms.

11. The water-permeable layer material treated as claimed in clause 1, characterized in that the surfactant or the surfactant-producing compound comprises an acyl group.

12. The water permeable layer material treated as claimed in clause 11, characterized in that the acyl group comprises about 3 carbon atoms to 20 carbon atoms.

13. The water-permeable layer material treated as claimed in clause 1, characterized in that the surfactant-producing compound or the surfactant comprises an aliphatic hydrocarbon group.

14. The water permeable layer material treated as claimed in clause 13, characterized in that the aliphatic hydrocarbon group comprises a group of 2-ethylhexylglycidyl.

15. The water-permeable layer material treated as claimed in clause 1, characterized in that the surfactant or the surfactant-producing compound comprises a perfluoro group.

16. The water-permeable layer material treated as claimed in clause 1, characterized in that the surfactant or the surfactant-producing compound comprises a siloxane group.

17. The water permeable layer material treated as claimed in clause 1, characterized in that the odor control agent modified with surfactant is applied externally.

18. The water permeable layer material treated as claimed in clause 1, characterized in that the odor control agent modified with surfactant is applied internally.

19. The water permeable layer material treated as claimed in clause 1, characterized in that it comprises about 0.05% by weight to 10% by weight of the surfactant modified odor control agent.

20. The water permeable layer material treated as claimed in clause 1, characterized in that it comprises about 0.1% by weight to 5% by weight of the surfactant modified odor control agent.

21. The water permeable layer material treated as claimed in clause 1, characterized in that it comprises about 1% by weight to 3% by weight of the surfactant modified odor control agent.

22. The water permeable layer material treated as claimed in clause 1, characterized in that the layer material comprises a polymer selected from the group consisting of polyamides, polyolefins, polyesters, ethylene and propylene copolymers, ethylene or ethylene copolymers. of propylene with a high-olefin C4-C20, terpolymers of ethylene with propylene and a C4-C20 alpha-olefin, copolymers of ethylene vinyl acetate, copolymers of propylene vinyl acetate, elastomers of styrene-poly (ethylene-alpha-olefin), polyurethanes, AB block copolymers, wherein A is formed of poly (vinyl arene) moieties such as polystyrene and B is an elastomeric middle block such as a conjugated diene or a lower alkene, polyethers, polyether esters, polyacrylates, ethylene alkyl acrylates , polyisobutylene, polybutadiene, isobutylene-isoprene copolymers, and combinations of any of the foregoing.

23. The water permeable layer material treated as claimed in clause 1, characterized in that the layer material comprises a polyolefin.

24. The water permeable layer material treated as claimed in clause 1, characterized in that the layer material comprises a polyethylene homopolymer or copolymer.

25. The water permeable layer material treated as claimed in clause 1, characterized in that the layer material comprises a polypropylene copolymer homopolymer.

26. A disposable absorbent personal care garment incorporating therein a treated water permeable layer material comprising a thermoplastic nonwoven filament fabric treated with a surfactant modified with cyclodextrin; the treated non-woven fabric having better wettability and better odor control than the non-woven fabric without the surfactant modified with cyclodextrin; wherein the absorbent personal care garment exhibits effective odor control with respect to selected malodors of ammonia, triethylamine, isovaleric acid, dimethyldisulfide, dimethyltrisulfide, indole, skatole, and combinations thereof.

27. The water permeable layer material treated as claimed in clause 26, characterized in that the cyclodextrin modified with surfactant comprises a cyclodextrin reacted or mixed with an alkyl compound.

28. The water permeable layer material treated as claimed in clause 26, characterized in that the cyclodextrin modified with surfactant comprises a cyclodextrin reacted or mixed with an acyl compound.

29. The water permeable layer material treated as claimed in clause 26, characterized in that the cyclodextrin modified with surfactant comprises a cyclodextrin reacted with an aliphatic hydrocarbon.

30. The treated non-woven fabric as claimed in clause 29, characterized in that the aliphatic hydrocarbon comprises 2-ethylhexylglycidyl ether.

31. An absorbent product for personal care, comprising: an absorbent medium capable of absorbing aqueous liquids; Y a thermoplastic water permeable layer material having a treated surface capable of reducing at least one selected odor of ammonia, triethylamine, isovaleric acid, dimethyldisulfide, dimethyltrisulfide, indole, skatole, and combinations thereof; wherein the treated surface comprises a surfactant-modified cyclodextrin compound for malodour control within the absorbent personal care product when the absorbent product for personal care contains bodily fluids.

32. The absorbent product as claimed in clause 31, characterized in that it comprises a diaper.

33. The absorbent product as claimed in clause 31, characterized in that it comprises training underpants.

34. The absorbent product as claimed in clause 31, characterized in that it comprises swimming clothing.

35. The absorbent product as claimed in clause 31, characterized in that it comprises absorbent undergarments.

36. The absorbent product as claimed in clause 31, characterized in that it comprises a cleaning cloth for a baby.

37. The absorbent product as claimed in clause 31, characterized in that it comprises a product for adult incontinence.

38. The absorbent product as claimed in clause 31, characterized in that it comprises a product for the hygiene of women.

39. The absorbent product as claimed in clause 31, characterized in that it comprises a medical garment.

40. The absorbent product as claimed in clause 31, characterized in that it comprises an inner pad.

41. The absorbent product as claimed in clause 31, characterized in that it comprises an absorbent cover.

42. The absorbent product as claimed in clause 31, characterized in that it comprises a bandage.

43. The absorbent product for personal care as claimed in clause 31, characterized in that it comprises a medical absorbent cloth.

44. A treated water-permeable layer material comprising a porous water permeable thermoplastic substrate layer treated with a modified surfactant odor control agent selected from the group consisting of (a) a mixture of a surfactant with a control agent of cyclodextrin odor, b) a reaction product of a surfactant producing compound with a cyclodextrin odor control agent, and c) combinations of the above and d) wherein the surfactant or surfactant producing compound comprises an acyl group.

45. A treated water-permeable layer material comprising a porous water-permeable thermoplastic substrate layer treated with a modified surfactant odor control agent selected from the group consisting of (a) a mixture of a surfactant with a control agent of cyclodextrin odor, b) a reaction product of a surfactant-producing compound with a cyclodextrin odor control agent, and c) combinations of the above and d) wherein the surfactant or surfactant-producing compound comprises a perfluoro group.

46. A treated water-permeable layer material comprising a porous water-permeable thermoplastic substrate layer treated with a modified surfactant odor control agent selected from the group consisting of (a) a mixture of a surfactant with a control agent of cyclodextrin odor, b) a reaction product of a surfactant-producing compound with a cyclodextrin odor control agent, and c) combinations of the above and d) wherein the surfactant or surfactant-producing compound comprises a siloxane group. SUMMARY A porous thermoplastic water permeable layer material having at least one odor reducing surface which is wettable with aqueous liquids and is capable of controlling a wide variety of malodors. The thermoplastic water permeable layer material is treated with a surfactant-modified cyclodextrin prepared by mixing or chemically reacting a cyclodextrin-based odor absorbing material with a surfactant producing compound. The coating material thus treated can be used in a wide variety of personal care and medical products, as well as in other applications.