MXPA01009161A - Water dispersible pantiliner - Google Patents

Abstract

Disclosed herein is a water dispersible pantiliner which has a triggerably dispersible body side facing liner, a garment side facing baffle, and, optionally, a triggerably dispersible absorbent core disposed between the liner and baffle. The garment baffle may be biodegradable. In one embodiment, the invention has a peel strip overlaying a garment attachment adhesive layer which adhesively attaches the peel strip to the clothing of a wearer on one side and to one side of a baffle on the other. The baffle is in turn attached on a second side to a body facing side with a construction adhesive. The body facing side may be made from multiple layers such as a body side liner and absorbent layer.

Description

FLUSH FOR DISPERSIBLE BRAGA IN WATER FIELD OF THE INVENTION The present invention relates to a personal care product. More particularly, the present invention relates to a panty liner dispersible in water or a similar product for personal use.

BACKGROUND OF THE INVENTION Discretion, ease and convenience for disposition or disposal are very important characteristics of single-use personal care products such as women's hygiene products. Similarly, there has been progress in the objectives of minimizing odor and reducing solid waste (since such products are typically disposed of in a landfill) by making products, which are disposable with water discharge. The ability to flush out personal care products in a toilet also helps to deliver any waste products from the body contained in the product to the waste treatment facility for proper treatment.

In order to satisfy these consumer wishes, a number of attempts have been made to provide a product which will be dispersed in the water in a toilet. U.S. Patent No. 3,550,592, for example, attempts to provide a disposable sanitary towel with water discharge by the calcium alginate structure and adding sodium carbonate, or some other weak base, to the toilet water. . The base will be provided with the towel at the time of purchase and will be added to the toilet water by the user at the time of disposal. U.S. Patent No. 5,681,299 discloses a product in which the backing is sufficiently dissolved to detach from the rest of the product when placed in a large amount of water (eg, a toilet). The absorbent core then becomes a solution which will pass through a drain pipe. The liner does not dissolve but is small enough to pass through the pipe.

U.S. Patent No. 5,722,966 discloses a product having fibrous upper and lower sheets and an absorbent core, which are dispersible in water. The various materials used in the product are not disparably dispersible.

Other attempts to provide disposable personal care products with water discharge have focused on single use disposable diapers.

Commercially available panty liners can be disposed of with flushing in a toilet. Because they are very small, they will pass through the toilet fixture to the waste system piping. These panty liners do not disperse, however, they remain intact and remove the potential to clog the waste system at any opportunity and probably at a very inaccessible point.

There is still a need for a personal care product in which all the components are docile to disperse by discharging water into a toilet and which are dispersed in a relatively complete toilet with the discharge of water or which are small enough to Pass through the waste pipe system without any incident. Such a process can occur quite easily, without the requirement of agitation by the user and the addition of chemicals by the user. It is an object of this invention to provide a liner for disposable panties and similar articles, which will disperse to a large extent in the toilet water.

SYNTHESIS OF THE INVENTION The present invention is directed to water-dispersible panty liners, which can be successfully transported through a municipal drainage system, and which can pass through the toilet, piping system and pumps without incident (eg example, without a binding). This can be treated in a drainage treatment facility without causing negative effects on the chemical, biological and other methods used in the treatment of waste.

The objects of the invention are satisfied by a water-dispersible panty liner, which has a side-to-body liner that is extensibly dispersible, a garment-side separator, and optionally, an absorbent core dispersible with water. shot placed between the liner and the separator. The garment separator can be biodegradable.

In one embodiment, the invention has a stripping strip lying on a layer of garment fastening adhesive which adhesively bonds the stripping strip to a wearer's clothing on one side and on the other to a spacer. The separator is in turn joined to a side on the side facing the body with an adhesive construction. The face-to-body side can be made of multiple layers, such as a side-to-body liner and an absorbent layer.

All components of the pant liner are essentially water dispersible or, after the release of the article, are so small, that the pant liner can be discarded after use by flushing water in a toilet.

BRIEF DESCRIPTION OF THE DRAWINGS The figure is a schematic side elevation showing a stripping strip 1, which is adhesively held by means of a garment fastening adhesive 2 to a layer of separator or barrier film 3 on one side. The other side of the separator 3 is attached to an absorbent layer 5 with an adhesive construction 4. The absorbent layer 5 is attached to the liner from side to body 6.

DEFINITIONS As used herein and in the claims, the term "comprises" is inclusive or open-ended and does not exclude additional non-recited elements, compositional components, or method steps.

As used herein, the term "non-woven fabric or fabric" means a fabric having a structure of individual threads or fibers, which are interleaved but not in an 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 processes and carded and bonded weaving processes. The basis weight of the non-woven fabrics is usually expressed in ounces of material per square yard (osy) or in grams per square meter (gsm) and the useful fiber diameters are usually expressed in microns (note that to convert ounces into a square yard to grams per square meter multiply ounces per square yard by 33.91).

As used herein, the term "spunbonded fibers" refers to fibers of small diameter which are formed by extruding the melted thermoplastic material or the filaments of a plurality of usually circular fine capillary vessels of a spinner organ having the diameter of the extruded filaments then being rapidly reduced as indicated, for example, in United States of America Patents No. 5,340,563 granted to Appel et al., and 3,692,618 granted to Dorschner, 3,802,817 granted to Matsuki et al., 3,338,992 and 3,341,394 granted. to Kinney, 3,502,763 granted to Hartman and 3,542,615 granted to Dobo and others. Spunbonded fibers are not generally sticky when they are deposited on a collecting surface. Spunbonded fibers with generally continuous and have average diameters (of a sample of at least 10) larger than 7 microns, particularly between about 10 and 20 microns. The fibers may also have many forms such as those described in U.S. Patent Nos. 5,277,976 to Hogle et al., 5,466,410 issued to Hills and 5,069,970 and 5,057,368 to Largman et al. conventional As used herein, the term "meltblown fibers" means fibers formed by extruding a molten thermoplastic material through a plurality of thin, usually circular, capillaries such as filaments or filaments fused into gas streams (eg. air) usually hot, at high speed and converging, which attenuate the filaments of molten thermoplastic material to reduce its diameter which can be to a microfiber diameter. Then, the melt blown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a meltblown fiber fabric dispersed at orange blossom, such a procedure is described, for example, in the United States of America No. 3,849,342 granted to Butin and others. Melt-blown fibers are microfibers which can be continuous or discontinuous, are generally smaller than 20 microns in average diameter and are generally sticky when deposited on a collecting surface.

As used herein, the term "coform" means a process in which at least one meltblown die head is arranged near a conduit through which other materials are added to the fabric while it is being formed. Such other materials may be pulp, superabsorbent particles, natural polymer fibers (eg, rayon or cotton fibers) and / or synthetic polymer fibers. (polypropylene or polyester), for example, wherein the fibers can be of a basic length. The coform processes are shown in the United States of America patents, commonly assigned Nos. 4,818,464 granted to Lau and 4,100,324 granted to Anderson et al. The tissues produced by the coform process are generally mentioned as coform materials.

As used herein, the term "conjugated fibers" refers to fibers, which have been formed from at least two extruded polymers from separate extruders but which have been spun together to form a fiber. Conjugated fibers are also sometimes referred to as multi-component or bicomponent fibers. Polymers are also sometimes referred to as multicomponent or bicomponent fibers. The polymers are usually different from each other even though the conjugated fibers can be monocomponent fibers. The polymers are arranged in different zones placed essentially constant across the cross section of the conjugated fibers and extend continuously along the length of the conjugated fibers. The configuration of such a conjugate fiber can be, for example, a pod / core arrangement in which one polymer is surrounded by another or can be a side-by-side arrangement, a cake arrangement or an arrangement of islands in the sea. Conjugated fibers are taught in U.S. Patent Nos. 5,108,820 issued to Kaneko et al., 4,795,668 issued to Krueger et al., 5,540,992 issued to Marcher et al. And 5,336,552 issued to Strack et al. Conjugated fibers are also shown in U.S. Patent No. 5,382,400 issued to Pike et al. And can be used to produce curl in fibers by employing different rates of expansion and contraction of the two (or more) ) polymers. The crimped fibers can also be produced by mechanical means and by means of the process of the German patent DT 25 13 251 Al. For the bicomponent fibers, the polymers can be present in the proportions of 75/25, 50/50 , 25/75 or any other desired proportions. The fibers may also have shapes such as those described in U.S. Patent Nos. 5,277,976 issued to Hogle et al., 5,466,410 issued to Hills and 5,069,970 and 5,057,368 issued to Largman et al., Which describe fibers with unconventional shapes. .

As used herein, the term "constituent fibers" refers to fibers which have been formed from at least two polymers extruded from the same extruder as a mixture. The term "mixture" is defined below. The biconstituent fibers do not have the various polymer components arranged in different zones placed relatively constant across the cross-sectional area of the fiber and the various polymers are usually not continuous along the entire length of the fiber, in instead of this, they form fibrils or protofibrils which initially and end at orange blossom. Biconstituent fibers are sometimes also referred to as multi-constituent fibers. Fibers of this general type are discussed in, for example, U.S. Patent Nos. 5,108,827 and 5,294,482 issued to Gessner. Bicomponent and biconstituent fibers are also discussed in the text Mixtures and Polymer Compounds by John A. Manson and Leslie H. Sperling, copyright 1976 by Plenum Press, a division of Plenum Publishing Corporation of New York, IBSN 0-306 -30831-1, pages 273 to 277.

The phrase "carded and knitted fabric" refers to fabrics made of basic fibers which are sent through a combing or combing unit, which breaks and separates and aligns the short fibers in the machine direction to form a non-woven fabric. fibrous woven generally oriented in the direction of the machine. Such fibers are usually purchased in bales, which are placed in a collector which separates the fibers before the carding unit. Once the tissue is formed, it is then joined by one or more of the various known joining methods. One such binding method is the binding of powder, wherein a powder adhesive is distributed through the fabric and then activated, usually by heating the fabric and adhesive with hot air. Another suitable joining method is pattern bonding, wherein heated calendering rolls or ultrasonic bonding equipment are used to join the fibers together, usually in a localized bonding pattern, even when the fabric can be bonded through. its full surface if desired. Another well known and suitable joining method, particularly when using bicomponent basic fibers, is the bonding via air.

"Air placement" is a well-known process by which a fibrous non-woven layer can be formed. In the air laying process, bunches of small fibers having typical lengths ranging from about 6 to about 19 millimeters (mm) are separated and carried in a supply stream and then deposited on a forming grid , usually with the help of a vacuum supply. The fibers deposited to the orange blossom are then joined to each other using, for example, the hot air or the sprayed adhesive. Examples of air-laying technology can be found in U.S. Patent Nos. 4,494,278, 5,527,171, 3,375,447 and 4,640,810.

As used here, the binding through air or " " means a process of joining a non-woven fiber bicomponent fiber fabric in which the air is hot enough to melt one of the polymers from which the fibers of the fabric are made, is forced through said fabric. The air speed is 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. The binding through air has a relatively restricted variability and since in the union through air ( ) requires the melting of at least one component to restore the union, this is restricted to fabrics with two components such as conjugated fibers or those which include an adhesive. At the junction through air, air that has a temperature above the melting temperature of one component and below the melting temperature of another component is directed from a surrounding covering, through the fabric, and up to a perforated roller that holds the tissue. Alternatively, the air-binding device can be a flat arrangement in which the air is directed vertically downwards onto the fabric. The operating conditions of the two similar configurations, the primary difference being the geometry of the fabric during the union. The hot air melts the lower melt polymer component and thus forms bonds between the filaments to integrate the fabric.

As used herein, the term "water dispersible" refers to a structure which when placed in an aqueous environment, with sufficient time, will break apart into smaller pieces. As a result of this, the structure once dispersed will be more advantageously processable in the processes of recycling or waste with discharge of water, for example, municipal and septic drainage treatment systems. If desired, such structures may be made dispersible in water or the dispersion may be rushed through the use of agitation and / or certain firing means such as described further below. The actual amount of time will depend on at least part of the particular end-use design criteria.

As used herein, the term "disposable with water discharge" means that an article can be successfully transported through a toilet through the typical main drainage system and pumps without an incident (eg, clogging) .

As used herein, the term "biodegradable" means that a material is degraded by the action of naturally occurring microorganisms such as bacteria, fungi and algae.

As used herein, the term "personal care use" means dressings and articles for wound care, diapers, underpants, swimwear, absorbent undergarments, adult incontinence products, and hygiene products. of the woman.

As used herein, the term "panty liner" means a product for the hygiene of the absorbent woman which is placed in a wearer's panties to absorb body fluids. In addition to the commonly understood meaning, the term "panty lining" is intended to encompass similar products such as bandages and items for wound care and incontinence articles for adults (particularly men). These articles are similar in size and function to panties and are therefore intended to be within the scope of the invention. The term pant lining has been used throughout this document as an abbreviation class for a wider class of similar products, some of which have been mentioned above.

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a composite structure, which has a number of different components, which are disposable with water discharge and / or dispersible with water. The required components are a cover or lining from side to body, which is adjacent to the body of the wearer and which initially accepts the fluids, a separator or lining from side to the garment, which protects the wearer's clothes. stained. Optionally, an absorbent core can be used which accepts and holds fluids from the side-to-body liner and which is positioned between the cover and the spacer. Additional components such as adhesives or strips can be added to particular configurations or construction methods.

The cover or the side facing to the body must allow it to pass through the fluid and, for disposal with water discharge, it must be well dispersed from the rest of the components and preferably should not float. Since the lining facing the side of the body must allow fluids to pass through it and not disintegrate decently from use, it must be made of a fusible polymer. The shape of the trigger polymer is more preferably a fiber, even though it may be a film or a foam ..}. In order to be effective for use in disposable personal care products with water discharge, the trigger liner must be functional in use, maintain its integrity in the presence of body fluids, but dissolve or disperse rapidly in the water found. in the toilets. The main component of the firing liner of the present invention is an ion firing polymer. An ion-releasing polymer is one whose strength and dispersion in water is changed depending on a very slight difference in the concentrations of a salt. More specifically, an ion-releasing polymer loses strength and disperses in tap water, but maintains the strength and is insoluble in the aqueous solution, which maintains no less than 0.5% by weight of a neutral inorganic salt comprising a monovalent ion such as NaCl, KcL and NaBr.

It is well known that the addition of an inorganic salt to an aqueous solution of a water-soluble polymer can force the precipitation of the polymer through a salting-out phenomenon. For example, anionic polymers such as the sodium salts of polyacrylate and carboxymethyl cellulose are rendered insoluble in an aqueous solution of common salt having a concentration of 4 to 5% or more.; nonionic polymers such as hydroxyethyl cellulose and polyvinyl alcohol (PVA) are insoluble in an aqueous solution only when the concentration of the salt is increased to about 10% or higher. This salting out of a water soluble polymer describes the change from a homogeneous polymer solution to a polymer precipitate. Even though an ion triggering polymer is certainly salt sensitive, like the simple water soluble polymers mentioned above, there are several significant differences in the behavior of an ion triggering polymer for disposable applications with water discharge. First, the ion-releasing polymer can be sensitive to changes in ion concentration at low levels, such as 0.5% by weight of a common salt. Secondly, in the typical body fluid aqueous ionic solutions, it is expected that the ion-releasing polymer is not only insoluble but is required to maintain integrity and strength. Finally, the ion-releasing polymer loses sufficient strength or integrity to disperse in the tap water; but note that dispersion does not necessarily require complete dissolution, as would be typical with simple salt-soluble water-soluble polymers.

The characteristic of integrity and resistance in use can be achieved by ensuring an adequate "hydrophobic / hydrophilic" balance through the polymer chain. As used herein, the term "hydrophilic / hydrophobic balance" refers to a balance of the hydrophobic and hydrophilic moieties along the polymer chain, which results in the polymer having a desired firing property. By controlling the hydrophobic / hydrophilic balance in the polymer composition, ion-sensitive polymers having an integrity in use and dispersibility in water are produced. In contrast, for simple water-soluble and salt-sensitive homopolymers, such as polyvinyl alcohol, the hydrophobic / hydrophilic character is fixed by the monomer structure and can not be adjusted.

In a trigger polymer formula, the ion trigger character is provided by a sulfonated polyester condensation polymer. The hydrophobic / hydrophilic balance can be controlled by choosing the monomers involved in the condensation reaction. The preparation of such polyesters is generally described, for example, in United States of America Nos. 4, 910,292 or 4,973,656.

In addition to the sulfonated copolyesters, a variety of other trigger polymers are known in the art. U.S. Patent No. 5,770,528 discloses a methylated hydroxypropyl cellulose as a polymer with a trigger controlled by temperature and ion concentration. The hydroxypropyl cellulose itself has some sensitivity to the ion, but it is more of a trigger material with temperature. Indeed, U.S. Patent No. 5,509,913 lists a variety of polymers, including polyvinyl methyl ether, polyvinyl alcohol, and various cellulose polymers with various temperature triggers modulated by ion concentration. These temperature triggering polymers may have limited utility in a trigger-able fiber.

Water-soluble ion-releasing polymers are also known. For example, U.S. Patent Nos. 5,317,063 and 5,312,883 disclose copolymers of methacrylic acid and acrylic acid that are not ion sensitive. Unfortunately these materials are not melt processable and are not amenable to fiber production. The coating of an aqueous solution of the ion-releasing polymers on a water-insensitive polymer core is also possible.

It is suitable that the face-to-body coating be made of conjugate fibers in a sheath / core configuration so that the core of the fibers resists and sheath bonding. Such fibers may be crimped or crimpable according to U.S. Patent No. 5,382,400 issued to Pike et al. One type of fiber to be used as the conjugate fiber has a polypropylene core and an outer sheath consisting of copolyester NP2068 or NP2074 from HB Fuller, PEBAX MX 1074 from Atochem and Ecomaty AXIOOOO from Nippon Gohsei, 8824-71-1 , 70-4395, 70-4442 from National Starch and the blends of the polymers mentioned above with other biodegradable polymers such as aliphatic polyesters. Suitable aliphatic polyesters include, but are not limited to, polybutylene succinate, polybutylene succinate adipate, polyhydroxybutyrate-co-valerate, polycaprolactone and polylactide and their copolymers, and 80/20 blend of binder fibers conjugated and triprable basic mentioned above. The conjugated fibers can be mixed with other less expensive fibers in a number of known processes in order to reduce the cost. The conjugated fiber can be mixed with less expensive fibers such as polyolefins, polyesters, rayon, etc., in an amount of from about 10/90 to 90/10 or more particularly about 50/50, through any suitable process . Examples of suitable processes include air placement, coformming and bonding and carding, after which the fibers may be joined together such as, for example, by air binding at an appropriate temperature. Liquid binders may also be used such as the ® Kymene 557LX binder available from Hercules, Inc., of Wilmington, Delaware. The least expensive fibers can be the basic fibers which are typically 6 to 12 millimeters in length and about 1.5 deniers so that they will not form long strands in the dispersion which could be trapped in the pipeline projections of the system. waste or other parts of the treatment facility and cause clogging. The finished body side liner 6 can be in the range of from about 10 grams per square meter to 500 grams per square meter in basis weight or more particularly between about 20 grams per square meter and 30 grams per square meter.

The ionically fusible multi-component fibers are provided in U.S. Patent Application No. 08 / 730,951, filed October 16, 1996 and for which the government's rights for the grant have been paid. This provides a polymer fiber in which a component comprises a water dispersible polymer that remains stable in the presence of an aqueous solution having more than about 1.00 parts per million of a cosmotrope and which is dispersed in a period not exceeding of 30 minutes in an aqueous solution having less than about 1,000 parts per million of a cosmotrope. In one example in this application, the film samples formed from National Starch 70-4442 polymer were tested for dispersion in deionized water as compared to a commercially available bath tissue, essentially in accordance with a "Simple Test for Fiber Dispersion of Glass Cut in Wet in Water ", published at the 1996 TAPPI Nonwoven Procedures Conference and incorporated herein by reference. Five film samples of 1.5 inches (38.1 millimeters) long by 1.5 inches (38.1 millimeters) wide (sample 1) that have an average weight of 0.2525 grams were placed in 1,500 ml of deionized water having a strength greater than or equal to 18 megaohms contained in a Kimax beaker of 2.00 ml, No. 14005. A Fisher Scientific stirrer (Magnetic), Catalog No. 11-498-78H, was placed at a speed setting of 7 to agitate the contents of the weeping vessel. Using a standard clock, the period of time from the point at which the agitator was activated to the beginning at which the dispersion occurred was measured, which was defined as at the point at which the first piece of the sample film material was broke from the remaining part of the film sample, and until complete dispersion occurred, which was defined as the point at which the first piece of sample film material was broken into pieces having diameters not exceeding about of 0.25 inches (6.35 millimeters).

® Five unique sheets of Kleenex sanitary tissue Premium (Sample 2) available from Kimberly-Clark Corporation of Dallas, Texas, each measuring 4.0 inches (10.2 centimeters) by 4.5 inches (11.4 centimeters) and having an average weight of 0.3274 grams, underwent the same test procedure and the periods for the start of the dispersion were measured and for the complete dispersion.

Finally this test procedure was repeated by placing a single film sample of 1.5 inches (38.1 millimeters) by 1.5 inches (38.1 millimeters) (Sample 3) made of National Starch 70-4442 polymer which has a weight of 0.2029 grams at 1,500 my blood bank salt water, 0.85% NaCl, catalog No. B3158-1 with 0.1% sulfate anion added. The periods for the beginning of dispersion in the complete dispersion were measured. As can be seen from Table 1 below, no dispersion occurred for a period of 15 minutes, at which time the test was completed.

TABLE 1 Scatter Start No. Displays No, Scatter Full Measurements (seconds) (seconds) 1 5 57.2 84.2 2 5 45.2 122.0 3 1 None Clear After 15 minutes after 15 minutes The results of the test procedures carried out under this example further illustrate that the fibers employing the dispersed water dispersible polymer 70-4442, according to the present invention, will be dispersed in the presence of a particular trigger component, such as the sulfate anion, at a concentration level found in excess water, while remaining essentially unaffected when exposed to the same trigger component at a level concentration typically found in body fluids, such as infant urine or the adult. In addition, the dispersion rate compares favorably with that of commercial bath tissue products, which are generally placed in normal tap water, such as found in toilet bowls.

The absorbent layer, if used, should be able to absorb small loads of menstrual fluids or other vaginal discharge and urine. These amounts are generally between 0.25 and 4 grams. The absorbent layer must be extensibly dispersible since it, like the body-side lining, must be exposed to body fluids while in use and not disintegrate. Particularly suitable materials are made by coform, bonding and carding or air laying processes and include pulp together with water dispersible polymer binder fibers in a range of from about 5/95% by weight to 95/5% by weight, more particularly of about 70/30% by weight and having a basis weight of from 20 to 600 grams per square meter, more particularly from about 190 grams per square meter. Polymers suitable for the coform process include Ecomaty AXIOOOO from Nippon Gohsei, NP2069 and NP2074 from HB Fuller Company, 1200 Wolters Boulevard, Vadnais Heights, Minnesota 55110, PEB.AX MX1074 from Atochem, Inc., 266 Harristown Road, P.O. Box 607, of Glen Rock, New Jersey 07452 and of National Starch 70-4395, a cosmotrope. A desirable binder fiber for an air-laying process is based on a fired resin; a polymer which is stable at temperatures, pH and at ionic concentrations found in body fluids such as urine, menstrual fluids, and blood, but which is still soluble in water at the conditions typically found in a toilet bowl, for example, lower temperatures, a moderate pH and lower ionic concentrations. A preferred binder fiber is a 50/50 core and sheath conjugate fiber with a polyolefin core, typically of polypropylene or polyethylene, and a sheath of a dispersible polymer, which may be a mixture. Successful fusible sheath polymers are mixtures of copolyesters containing one or more ion-sensitive functional groups, such as the sulfonate and carboxylate groups and a biodegradable polymer such as an aliphatic polyester. Suitable aliphatic polyesters include, but are not limited to polybutylene succinate, polybutylene adipate, polybutylene succinate adipate, polyhydroxybutyrate-co-valerate, polycaprolactone and polylactide and their copolymers. One of the particular polymers which may be used is a 80/20 weight mixture of 70-4442 resins from National Starch, with a poly (lactide) copolymer called HeplonE from Chronopol Corporation of Golden, Colorado. Another example is a mixture of 80/20 by weight resin 70-4442 with a polyacid copolymer called CPX5-2 from Chronopol Corporation. Fibers with a denier of about 3 to 6 and a length of less than 6 mm are preferred.

Suitable pulps for the absorbent include Coosa River pulp (CR) 1654 which is a Southern softwood pulp, CR-2054 pulp, and a high volume additive formaldehyde free pulp (HBAFF) which is available from Weyerhaeuser Corporation of Tacoma, WA under the designation NHB-416 and which is a southern softwood pulp fiber cross-linked with an increased wetting modulus. The NBH-416 has a chemical treatment which sits on a curled and twisted, in addition to imparting an added rigidity in dry and wet and an elasticity to the fiber. Another suitable pulp is the soft wood pulp of the south Weyerhaeusr NB-416.

As additional illustrations of the integral triggering behavior for the present invention, tensile tests were carried out on non-woven coform layers and placed by air made with trigger binder fibers. The first example is a structure placed by air made only with binder fiber. In this case the binder fiber was a 50/50 sheath and core of a National Starch sheath 70-4442 around a polypropylene core. These fibers were prepared by Chisso Corporation of Japan, with a denier size of 4 and a length of 6 millimeters. The fibers were then formed into an air-laid structure of about 33 grams per square meter. The tensile strength of the non-woven fabric was then tested dry, after soaking for 5 minutes in distilled water or after soaking for 30 minutes in 1% by weight of a sodium sulfate solution. A sample of 2.5 centimeters x 10.2 centimeters (1 inch x 4 inches) of the air-laid fabric was grasped by the short sides in a Vintrodyne V-1000 mini-tension tester from Chattilone Corporation, of Greensboro, North Carolina, and the peak face For the wet tests, the tissue, the handles and everything was immersed in a beaker of fluid. The results are reported in Table 2 given below in the row marked "Placed by Air".

As a second example of a characteristic trigger behavior, a 65/35 pulp / polymer coform was made at about 150 grams per square meter. The binder polymer was a mixture of 80/20 of NS 70-4442 and Heplon E mentioned above for the sheath of a binder fiber binder. The polymer mixture was not optimized for the coform process, so that the formation was poor, but the triggering behavior is still evident, as seen in the row marked "Coform" in Table 2.

As a final example, a sample of air-laid cover and thermally recorded air-absorber was prepared together. The binder was again a 50/50 sheath / core core fiber prepared by Chisso, with the polypropylene core surrounded by an 80/20 mixture of NS 70-4442 and HeplonE. The cover of 30 grams per square meter was a 50/50 mixture of the binder fiber and a nylon fiber (2.2-dtex polyamide from Novalis), even though the absorber of 120 grams per square meter was a mixture of 70/30 of pulp (Weyerhaeuser NB-416) and binder fiber. In this case the resistance to the peak tension was measured on an Intelect-II machine on a sample of 2.5 centimeters by 15.2 centimeters (1 inch x 6 inches), with the samples for the wet tests soaked in a tray of solution and then removed from the tray for the test. The data for these measurements are reported in the row marked "Laminados Absorbentes / cubierta" in Table 2.

Table 2 Resistance Resistance Resistance Time No dry-weave to Salt soaked in Water Soaked g / inch g / inch in salt g / inch in Water Placed by air 1298 306 30 min. 131 5 minutes Coform 539 66 30 sec. 45 30 sagurrfcs Laminate 295 68 30 sec. 27 30 follow them Absorbent / Cover In contrast to the results of Table 2, the spin-linked polypropylene shell and the coform absorbent with the liner polypropylene binding polymer for ® ® Kotex Lightday panties commercially available from Kimberly-Clark Corporation, did not have a firing behavior , they are insensitive to both the salt and water solution, and they maintained essentially the same level of resistance in dry or wet.

The barrier layer or separator has been a particular problem for waste with discharge of water. Currently the polyethylene films used are not ideal for a disposable product with water discharge since, even when these will disperse or detach from the product, the film itself does not disperse and these have to float in the water. The polyethylene film can pass completely through the modern treatment facilities intact and is in recognizable form in the effluent of the treatment plant. Also suitable for use as separators are foams and non-woven fabrics.

Since it does not absorb fluids from the body or let them pass, the separator layer does not need to be dispersible with a shot. The separator does not contact the body fluids to a degree, however, if it is not dispersible with a shot, it must be protected, for example by a waterproof coating. The preferred structure is a water-dispersible or water-soluble film with a barrier layer or coating to protect it from contact with body fluids.

One such dispersible polymers for the separator layer of the present invention is a mixture of polyethylene oxide (PEO) and ethylene-co-acrylic acid (EAA) in a weight ratio of from about 95/5 to about 20/80, particularly around 80/20. This polymer mixture has a density greater than that of water and therefore will sink and will also be dispersible in water. One source of a suitable polymer blend is Planet Technologies, Inc., of 9985 Business Park Avenue, Suite A, San Diego, California 92131 as the product number PT-P8-200RR9. This particular product number also includes a fragrance capable of surviving the melt extrusion. This mixture can be extruded into a film using either blown bubble or dewatered cooling roll processes which are well known in the art at a thickness range of from 10 to 100 microns. A more particularly suitable thickness is from about 20 to 30 microns. Still another suitable dispersible but non-triggerable polymer is a polyvinyl alcohol such as Ecomaty AX2000 or AX300G supplied by Nippon Gohsei, Higashi Umeda Bldg. 9-6, Nozai-cho, Kita-ku, Osaka 530, Japan.

The separator layer polymer blend can be coextruded with another layer of water impermeable film in the range of about 2 to 4 microns thick. A suitable polymer is ethylene-co-acrylic acid such as those available from the Dow Chemical Company of Midland, Michigan as Primacor 1430. Another suitable polymer is a polycaprolactone such as that available from Union Carbide of Danbury, Connecticut as Tone P787. The water impermeable layer may also be a trigger polymer such as 70-4395 and 8824-71-1 of National Starch. As an alternative to co-extrusion, a water-impermeable layer can be added on the water-soluble part by a coating process. For example, the polyethylene oxide film PTP8200RR9 from Planet Technologies, Inc. can be slot coated with a mixture of 90/10 by weight of RT2730 of polyalphadefine from Rexene Products, of Dallas, Texas and polymer Vybar 253 of Petrolite Poly ers. , of Tulsa, Oklahoma.

If the separator layer is not dispersible, triggerable or otherwise, it should be at least biodegradable. If the separator is biodegradable it can be processed through a waste water facility and eventually disintegrate. Cellulose-based material such as cellulose acetate and aliphatic polyesters such as polybutylene succinate, polybutylene adipate succinate, polyhydroxybutyrate-co-valerate, polycaprolactone and polylactide and their copolymers are suitable candidates. An example of a suitable material is rayon.

A number of means are available to assemble the layers of this invention. The adhesive bond is very satisfactory as is the thermal bond and the engraving. The pant liner of this invention can be etched or bonded using heat and / or pressure. Etching can be accomplished using, for example, ultrasonic bonding and / or mechanical bonding as through the use of pattern and / or smooth bonding rolls which may or may not be heated. In addition, the means of production in which the layers are produced directly on the preceding layer can be used. Such a production technique, such as placement by air, results in the mechanical mixing of the fibers in the boundary area of each layer and thus maintains it together. In short, any means known in the art that successfully increase the integrity of the layers is acceptable to produce a unified product that will remain intact through consumer use.

It is also desired to provide some means for keeping the article in place in the panties while it is worn. Pant liners have traditionally achieved this through the use of peel strips which are removed and discarded to reveal a garment adhesive. The product is then applied to the panties with the side that has the garment adhesive first.

This goal can also be achieved through the use of heat-activated (body) adhesives which remain non-tacky at room temperature but which become adhesive after equilibration at room temperature. It is possible that some small amounts of construction adhesive may be necessary to keep the pant liner in place until the adhesive activated with body heat begins to work. Other mechanical fastening means, such as a patch of micro-hook material which engages the fabric of an undergarment can also provide a fastener that does not require a strip of peel.

In a preferred embodiment of the present invention, as shown in cross-section in the figure, the invention has a strip of peel 1 lying on a garment fastening adhesive 2 which holds the pant liner in place over the panties of the user. The garment adhesive 2 is bonded to a layer or barrier film separator 3 which prohibits the transfer of liquids from the pant liner to the panties. The separator 3 is adhered to the body facing side which includes an absorbent layer 5 and a body facing liner 6 with a layer of construction adhesive 4. The construction adhesive 4 is attached to an absorbent layer 5 to the which joins a liner facing the body 6. Below is a description of each layer.

The disposable stripping strip with water discharge 1 can be made of a paper base sheet with a water-soluble binder (for example polyvinyl alcohol) and a silicone release coating. Such material is available from Sansei E &M Co., Ltd., No. 18-12-3-Chome, Roppongi, Minato-ku, Tokyo 106, Japan and from International Paper, Akrosil Division, 206 Garfield Avenue, P.O. Box 8001, Menasha, Wisconsin 54952-8001. A detachable and disposable strip with water discharge can also be constructed by placing a thin layer of a release coating on a water soluble film.

The garment fastening adhesive 2 must be one which minimizes adhesion and detaches once placed in water. Suitable adhesives may be supplied by National Starch and Chemical Corporation, of Finderne Avenue, of Bridgewater, New Jersey 08807 as product number 7699-67-2 or by Findley Adhesives, Inc., of 11320 from Watertown Plank Road, Wauwatosa, Wisconsin. 53226-3413 as product number H2427 (N2). The garment adhesive 2 must be applied in an effective amount by any effective means. One method is by spraying the adhesive 2 on the separator 3 1 in an amount of about 20 grams per square meter on a strip about 25 millimeters wide. The effective amount of the adhesive 2 can, of course, vary based on the type of adhesive used, the product stiffness, the performance requirements, and the total area of application. It is believed, however, that the effective amount will vary between about 10 grams per square meter and 60 grams per square meter.

Adhesive construction 4 must be one which will be released in water to minimize wet stiffness and to increase waste with water discharge of the product. Suitable polymers include products number 7699-94-1, 7187-119-2, 8328-122-1 from National Starch and number H-9186 from Findley Adhesives. As with the garment adhesive 2, an effective amount of adhesive must be used. This can be an amount between 1 gram per square meter and 50 grams per square meter. The adhesive can be applied by any method known in the art.

Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications to the exemplary embodiments are possible without departing materially from the teachings and novel advantages of this invention. Therefore, all such modifications are intended to be included within the scope of the invention as defined in the following claims. In the claims, said claims of means plus function is intended to cover the structures described herein as carrying out the recited function and not only the structural equivalents but also the equivalent structures. Therefore, even when a screw and a nail may not be structural equivalents in the sense that a nail employs a cylindrical surface to secure the wooden parts together, while a screw employs a helical surface, in the environment of the fastening Wood parts, a screw and a nail can be equivalent structures.

Claims (17)

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

1. A water-dispersible pant liner comprising a side-to-body liner releasably dispersible and a side-to-garment face separator.

2. The water-dispersible panty liner, as claimed in claim 1, characterized in that it comprises a releasably dispersible absorbent core placed between said liner and the separator.

3. The water-dispersible pant liner, as claimed in claim 2, characterized in that said absorbent core, the liner and the separator are joined together by an adhesive.

4. The water-dispersible pant liner, as claimed in claim 2, characterized in that said absorbent core and the liner are joined together by a thermal engraving.

5. The panty liner dispersible in water, as claimed in claim 2, characterized in that said separator facing the side of the garment is biodegradable.

6. The panty liner dispersible in water, as claimed in claim 2, characterized in that it also comprises a strip of peeling.

7. The water-dispersible panty liner, as claimed in claim 6, characterized in that said stripping strip comprises a paper base sheet with a coating of a water-soluble binder and a silicone release agent.

8. The water-dispersible panty liner, as claimed in claim 3, characterized in that said adhesive loses its adhesion essentially when placed in water.

9. The water-dispersible panty liner, as claimed in claim 8, characterized in that said adhesive comprises a binder which loses its adhesion essentially when placed in water.

10. The water-dispersible panty liner, as claimed in claim 1, characterized in that said separator is composed of a film of polyethylene oxide and ethylene-co-acrylic acid.

11. The water dispersible panty liner, as claimed in claim 2, characterized in that said absorbent core comprises pulp and water dispersible polymer fibers in a range of from about 5/95 weight percent to 95/5 percent by weight.

12. The water-dispersible pant liner, as claimed in claim 2, characterized in that said absorbent core comprises basic fibers having average fiber lengths of approximately 18 millimeters or less.

13. The water-dispersible panty liner, as claimed in claim 2, characterized in that it also includes a particulate material within said absorbent core.

14. The panty liner dispersible in water, as claimed in claim 13, characterized in that said particulate material is a superabsorbent.

15. The water dispersible panty liner, as claimed in claim 13, characterized in that said particulate material is an odor reducing agent.

16. The water-dispersible panty liner, as claimed in claim 1, characterized in that said liner comprises multicomponent fibers which are dispersed in a solution having less than 1.00 parts per million of cosmotrope.

17. A panty liner dispersible in water consisting essentially of: a strip of peeling comprising a paper base sheet coated with a polyvinyl alcohol binder and a silicone release agent, and; a water-soluble garment fastening adhesive which adhesively attaches said stripping strip to the first side of a separator, said garment fastening adhesive is present in an amount of between 10 grams per square meter and 60 grams per square meter, and said separator comprises a mixture of polyethylene oxide and ethylene-co-acrylic acid in an amount of between about 20/80 percent by weight and 95/5 percent by weight, and; an adhesive construction which adhesively bonds said separator to an absorbent core which in turn is attached to a body-side liner, said adhesive construction being present in an effective amount, and; said absorbent core comprises pulp and water dispersible polymer fibers in a range of about 5/95 weight percent to 95/5 weight percent, and; said body-side liner comprises crimped water dispersible sheath and core conjugate fibers. SUMMARY Described herein is a water-dispersible panty liner which has a releasably dispersible body-side facing, a garment-side separator, and optionally a releasably dispersible absorbent core positioned between the liner and the separator. The garment separator can be biodegradable. In one embodiment the invention has a stripping strip lying on an adhesive garment securing layer which adhesively bonds the stripping strip to the wearer's clothing on one side and on the other hand to the side of the separator. The separator in turn holds a second side to one side facing the body with an adhesive construction. The face-to-body side can be made of multiple layers such as a side-to-body liner and an absorbent layer.