MXPA99006200A - Internally heated absorbent article - Google Patents

Abstract

An absorbent article includes a particulate chemical mixture, which is exothermically reactive in the presence of air or moisture, for heating at least a portion of the absorbent article. The heat generated improves the absorption of body fluids by lowering the viscosity of the absorbed fluids.

Description

ABSORBENT ARTICLE INTERNALLY HEATED FIELD OF THE INVENTION The present invention relates generally to an absorbent article and particularly to an absorbent article having a mixture that generates heat when exposed to air or moisture.

BACKGROUND OF THE INVENTION All the ways and varieties of devices or accessories are configured for the absorption of body fluids, just as menstrual fluids are well known. Sanitary napkins are the most frequently used of these devices. The prior art is replete with patents relating to protective pads and sanitary napkins for the absorption of body fluids and to protect underwear from staining. It has been suggested that from 20-25% of all sanitary pads are drained. A factor that contributes to runoff is that menstrual fluids are a viscous fluid that has aqueous and mucosal-type components.

A problem in the operation of the absorbent is that the more viscous the material, the slower the rate of absorption. Basically, low viscous materials easily pass through the sanitary towel cover and are absorbed by the absorbent. Higher viscosity materials in menstrual fluids may not be absorbed and may remain on the cover. Alternatively, the higher viscosity materials can be absorbed per stay at or near the load point clogging the absorption of the lower viscosity materials. This limits the effectiveness of the absorbent and the utilization of the absorbent capacity of the sanitary napkin. In addition, the absorbent may contain superabsorbent materials which preferably absorb the aqueous constituents of lower viscous materials, thereby increasing the viscosity of the remaining material. This exacerbates the problem of the absorbent to absorb the viscous components of menstrual fluids.

So far, surfactants have been used to improve the absorption of body fluids. One or more of the materials used in the construction of the sanitary napkin as the cover and / or the absorbent have been treated to improve the wettability of the material. The problem with using a surfactant is that the surface energy of the coated and modified material but the surfactant does not appreciably change if it does the viscosity of the body fluid at all. Therefore, higher viscosity materials are not yet efficiently absorbed.

Therefore, there is a need for an absorbent article, such as a sanitary napkin, which can modify the viscosity of the viscous material so that it can be absorbed.

SYNTHESIS OF THE INVENTION Briefly, the present invention is an absorbent article adapted to absorb body fluids. The absorbent article has a cover, a separator, or absorbent enclosed between the cover and the separator and a heating means for heating the absorbent. The heating means can, when activated by exposure to air and / or moisture, generate a temperature of from about 22 ° C to about 55 ° C.

It is an object of the invention to provide an absorbent article having heating means for producing heat when activated. It is another object of the invention to provide a sanitary towel that has heating means within the sanitary towel that produce heating when activated.

It is another object of the invention to provide a sanitary napkin having heating means and an improved absorbent utilization.

It is another object of the invention to provide a sanitary towel having a chemical mixture that will generate lime so that the viscosity of the most viscous component of menstrual fluids can be lowered by heating the fluid BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a top view of or incorporation of the absorbent article of the present invention Figure 2 is a cross-sectional view of Figure 1 along lines 2-2.

Figure 3 is a cross-sectional view of an alternate embodiment of the present invention.

Figure 4 is a cross-sectional view of an alternate embodiment of the present invention.

Figure 5 is a cross-sectional view of an alternate embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED INCORPORATIONS Even when the description concludes with a clause that particularly points out and distinguishes what is seen with the invention, it is believed that the invention can be easily understood with reference to the accompanying drawings of the figures in conjunction with the following detailed description of the invention.

Referring to Figures 1-5 of the drawings, in which equal parts are identified with the same reference numerals, Figure 1 illustrates a top view d of a sanitary napkin 10 according to this invention. As shown in these drawings and viewed from the top, for example, is the side that will normally be placed on one side of the user during use, the sanitary pad 10 is composed of a fluid-permeable cover 12; of an absorbent layer 14 which is shorter and narrower than the cover 12; and a separator or backing impermeable to liquid 16. As seen in Figures 2-4, the cover 2 and the separator 16 extend beyond an edge 18 of the absorbent 14 to enclose the absorber 14 and to define the perimeter 20. of the sanitary napkin 10. The term "edge" or the "edge of the absorbent" or equivalent are used herein and encompass the limit at which the absorbent 1 ends, without limitation to the longitudinal sides or transverse ends of the absorbent, to unless that is specifically stated. Although not shown, an expert in the art will understand that the cover 12, and the absorbent 14 and the separate 16 may have a co-term edge, but this is not preferred. The cover 12 and the separator 16 can be sealed together using any suitable means that will not leave an uncomfortable and hard residue that could warn the wearer. As used herein, the term "sealing" encompasses configurations by which the cover 12 is attached directly to the separator 16 or alternatively by attaching the cover 12 to an intermediate member, n shown, which can in turn be attached to the separator. 16. The methods for attaching the cover 12 and the spacer 16 are known to those skilled in the art and include the use of hot melt adhesive, pressure sensitive adhesive, adhesive construction, double sided tape, joined ultrasonic and heat sealing.

As used herein, the term "sanitary napkin" refers to an article which is worn by women on the side of the pudendal region and which is intended to absorb and contain various exudates which are discharged from the body such as the body. blood, menstrual fluids, and urine and which you try to get rid of when it gets dirty, not washed, or reused. Interlabial devices, which reside partially within and partially outside the wearer's vestibule, are also within the scope of this invention.

The sanitary towel 10 further includes heating means 22 placed below the cover 12 preferably on one side of the absorbent 14. The heating means 22 may be composed of one or more cells containing electrochemical or exothermic reagents that will produce heat when activated. with oxygen or humidity or that may comprise a material that will effectively distribute in heat from the user's own body. Desirably, the heating means 22 lower the viscosity of the more viscous components of the menstrual fluids allowing greater fluid mobility and thus obtaining a greater utilization of the absorbent capacity. When electromechanical exothermic reagents are used, the heating means 22 must generate sufficient heat to produce the temperature from about 22 degrees centigrade to about 55 degrees centigrade. More preferably, the heating means 2 generates sufficient heat to produce a temperature from about 27.5 ° C to about 46 ° C and more preferably the heating means 22 generates sufficient heat to produce a temperature of from about 27.5 ° C. at around 37 ° C.

Viewing the sanitary napkin 10 in greater detail said sanitary napkin 10 is illustrated as having a form oval but is not limited thereto. The sanitary napkin 10 may have an hourglass, racetrack shape or any other shape or configuration that will allow the sanitary napkin 1 to come into intimate contact with the wearer. The sanitary towel 10 of the present invention can be of any thickness can cover periods of light and heavy flow and can have a thickness of a few millimeters about 15 millimeters.

Referring to Figure 3, the sanitary towel 10 may further include one or more additional layers 24 which is designed to improve, modify or transfer the fluid in a preferred manner. Such layers include cellulosic and polymeric materials such as tissue, superabsorbents and meltblown materials. Such layers and materials are commercially available from various sources and are well known to those skilled in the construction of disposable absorbent articles, such as sanitary napkins, diapers and incontinent devices. The sanitary napkin 10 may also include shape shaping members adapted to contour shape the sanitary napkin 10 to the anatomy of the wearer during use.

The cover 12 is designed to make contact with the user's body and therefore must be easily penetrated by body fluids. The cover 12 will also be irritating to the user's skin and preferably will absorb an appreciable amount of the fluid insulting the surface. Deck 12 must be constructed of a material • woven or nonwoven, natural or synthetic. Suitable materials include carded and bonded fabrics of polyester, polypropylene, polyethylene, nylon or other heat-bondable fibers. Other polyolefins, such as polypropylene and polyethylene copolymers, low linear density polyethylene, finely perforated film fabrics and network material, also work well. Particularly preferred are materials composed of a polymer and a woven fabric material. Yet another cover material is a polypropylene spunbonded fabric. The fabric may contain about 1 to about 6% titanium dioxide pigment to give it a clean white appearance. A uniformly spunbonded material is desirable because it has sufficient strength in the longitudinal direction even after it has been perforated, to resist being torn or pulled during use. Most preferred polypropylene fabrics have a basis weight of from about 10. and 40 grams per square meter. The optimal base weight is between about 12 and about 3 grams per square meter.

To aid in the penetration of the liquid through the tissue, the cover can also be treated with a surfactant to improve its hydrophilic characteristics. The surfactant may include topical or material additions applied internally as polysiloxanes.

Placed adjacent to the cover 12 is e absorbent 14. The materials used in the absorbent 14 are designed to absorb exudates from the body, including menstrual fluids, blood and urine. Suitable materials include wood pulp fluff, rayon, and cotton and meltblown polymer, such as polyester, polypropylene or coform. The coform is a combination formed by air of meltblown polymers, such as polypropylene and the absorbent fibers. The absorbent 14 can be a composite composed of hydrophilic material that can be formed of several natural or synthetic fibers, of fibers of wood pulp, of cotton fibers or of regenerated cellulose, a tissue placed by air or a mixture of pulp and other fibers. Absorbent 14 can be made from other well-known materials used in absorbent articles, including multiple layers of cellulose wadding, cellulose sponge, hydrophilic synthetic sponge, such as polyurethane, and the like. The capacity of the absorbent 14 can be varied depending on the intended use of the final product.

The separator 16 acts as a barrier between the absorbed body fluids that are contained in the absorbent 14 and the person using the sanitary pad 10. Thus, the separator 16 is non-absorbent and impervious to liquids. The separator 16 should be soft and compliant, since a part of the separator 16 can reside on one side of the thigh region of the wearer. As used here, the term "docile" refers to materials which will easily reshape the general external shape and contours of the human anatomy. In the preferred embodiment, the separator 16 can allow the passage of air or steam out of the sanitary napkin 10 while s blocks the passage of the liquids from the absorbent 14. A material material for the separator 16 is a micro-grained polymeric film, such as polyethylene or polypropylene having a thickness in the range of from about 0.012 millimeters to about 1.0 millimeters. The bicomponent films can also be used as woven or non-woven fabric, which has been treated to render them impermeable to liquids.

Referring to Figures 1 and 2, the heating means 22 are placed in the cover 12 and in the absorbent means 14. The heating means 22 may include a chemical mixture wrapped in an appropriate air permeable material 30. The material 30 can be a woven or non-woven material, natural or synthetic. Desirably, the material 3 is capable of allowing air and moisture to pass while retaining the chemical mixture in particles. Non-limiting examples of such materials 30 include a polyester nonwoven and a polypropylene nonwoven bonded with yarn. The natural materials are also suitable for use containing the chemical mixture. Cotton is an example of a natural material suitable for wrapping the chemical mixture. The exothermic agents, which may be used in the present invention may be a material which readily reacts with oxygen in the air, the water of the absorbed menstrual fluid or both to generate heat at the time of reaction. When the heating means 22 generate heat by an exothermic reaction with oxygen, it is necessary that the reactants have an air exchange. Although not particularly limited to this, the reagents may be a mixture of oxidizable substances such as iron, reduced iron, nickel, sodium, sulfur and / or sodium sulfite; oxidation accelerator and a catalyst such as sodium chloride, calcium chloride, magnesium chloride, activated carbonate, coal dust and a mixture consisting of copper, manganese, as well as water compound retaining the agent such as wood pulp or pulp powder. Other exothermic reagents are described in U.S. Patent No. 4,331,731 and 4,573,447 whose full disclosure of which is incorporated herein by reference.

For example, the chemical mixture of the heating means 22 can include an intermediate having 30% by weight of virmiculite, 55% by weight of an aqueous solution having 10% by weight of sodium chloride and 15% by weight of carbon of the size of fine particle. The intermediate is combined with the fine iron powder at a ratio of about 1: 1. The iron powder due is preferred because it reacts easily with oxygen in the air in the presence of moisture to generate heat. In addition, the material is a good thermal conductor allowing the uniformity of the temperature distribution and avoiding localized areas of sensible heat. The powder fineness can be varied to change the rate of the reaction and so much the amount of heat generated.

As a general rule, the greater the amount of metal powder, the warmer the reaction.

Sodium chloride is used to catalyze the oxidation of iron. It is particularly desirable in the sense that it is readily available and cheap. However, the sodium chlorur can be replaced with other suitable chlorides sulfates, such as potassium chloride, calcium chloride, magnesium chloride, ferric sulfate, potassium sulfate, sodium sulfat and magnesium sulfate.

Those skilled in the art will understand that the proportions of the components, the particle size, and the ingredient quality of the chemical mixture can vary substantially to make either a hotter or colder reaction mixture.

When the heating means 22 used in the present invention is an electrochemical reaction that is active by water, the electrochemical reaction generates heat by using an electrochemically active reducible element and an electrochemically active oxidizable element. The reducible element can be formed from a depolarized cathode on which other material such as oxygen is reduced. The oxidizable element can be a sheet material made of aluminum or d-magnesium or an alloy of both. The reducible element or oxidizable element is separated by a water absorbing material such as felt. Preferably, an electrolyte former is incorporated into a dry granular form with or on the side of the reducible element to thereby avoid the need to impregnate the water absorbent material. This allows the heating means 22 to have an extended storage life. Desirably, the electrolyte salt is uniformly applied to the cathode or reducible element. In the case of a depolarized cathode using an active carbon or manganese dioxide, the table salt is originally mixed in sec uniformly with the manganese dioxide or activated carbon in the range of about 1 to 2 in average grams of salt, about a gram of coal. Preferably the ratio e of from about one and a half grams of salt to one gram of carbon or manganese dioxide.

The heating means 22 may be composed of a material that will effectively distribute the heat from the wearer's body in the absorbent 14. Desirably such materials will have a high thermal conductivity in relation to the absorbent 14. The thermal conductivity of a substance is easily established using the known m techniques.

Referring to Figure 2, a cross-section of an alternate embodiment of the invention is illustrated. The heating means 22 are placed between absorbent 14 and the separator 16 so that the upper part of the heating means 22 is on the side of the absorber. 14 and at the bottom of the heating means is on a separating side 16. The natural means 22 are similar to the one described above for FIGS. 1 and 2, in the sense that the chemical mixture comprising the heating means 22 is surrounded by a envelope material 30.

Referring to Figure 4, there is illustrated cross-section of an alternate embodiment of the invention. The heating means 22 are placed between the separator 16 and a retaining layer 28 placed below the separator 16. Separator 16 and retaining layer 28 are secured together to enclose the heating means 22. At this time, when it is preferred for the chemical mixture to be wrapped the material 30 this is not necessary. The retaining layer may be composed of a material similar to the separator 1 Desirably, the retaining layer 28 is composed of air-permeable material 30 such as that joined with spinning, or perforated film and the like. The retaining layer 28 may include one or more openings or perforations 32 which will increase the oxygen exchange regardless of the air permeability of the composition of the retaining layer 28. Desirably, the apertures of the perforations 32 are placed on the surface of facing the garment of the retaining layer 28. The openings or perforations 32 should be appropriately designed so that the chemical mixture does not escape if it is not used as wrapping material 30 but still allows the exchange of air through the material. 30. Perforations 32 are necessary when material 30 is impermeable to air exchange such as when a polyolefin film is used.

The perforations can be made in many different ways including cutting, sewing and the like. In some cases, the perforations 32 can be arranged in a narrow area or strip of the retaining layer 28 as opposed to having the perforations distributed through the retaining layer 28. By having the perforations 32 arranged along a row , it is possible to decelerate the dissipation through a material 30 and out of the chemical mixture. This can provide moisture conservation within the chemical mix, increasing the life of the chemical mixture.

Referring to Figure 5, a cross section of an alternate embodiment of the invention is illustrated. The chemical mixture of the heating means 22 can be distributed or localized to the orange blossom or distributed evenly located in bags or discrete identifiable areas similar to those described above for Figures 1-4, but with smaller amounts of the chemical mixture contained in each bag. .

Although the invention has been described with reference to several preferred embodiments, and illustrated in relation to the range of optional operations, those skilled in the art will recognize that various substitutions, omissions, modifications and changes can be made without departing from the spirit of the same. Therefore, it is intended that the above description be considered as an example of the preferred scope of the present invention and is not considered a limitation of the same.

Claims (21)

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

1. An absorbent article to absorb body fluids comprising: a) a cover permeable to the fluid; b) a separator impermeable to the fluid; c) an absorbent enclosed between the cover and separator; Y d) heating means for heating the absorbent placed on one side of the absorbent.

2. The absorbent article as claimed in clause 1, characterized in that said heating measures produce a temperature of about 22 ° C around 55 ° C

3. The absorbent article as claimed in clause 1, characterized in that said heating means produce a temperature of about 27.5 ° to about 45 ° C.

4. The absorbent article such and as claimed in clause 1, characterized in that said heating means produce a temperature of about 27.5 ° to about 36 ° C.

5. The absorbent article as claimed in clause 1, characterized in that said heating means is a chemical mixture distributed in absorbent dich.

6. The absorbent article as claimed in clause 5, characterized in that said chemical mixture is distributed substantially uniformly through the absorbent.

7. The absorbent article as claimed in clause 1, characterized in that said heating means comprise a chemical mixture that reacts with oxygen to generate heat.

8. The absorbent article as claimed in clause 7, characterized in that said chemical mixture comprises and includes an oxidizable substance, or oxidation accelerator and a catalyst.

9. The absorbent article as claimed in clause 8, characterized in that the oxidizable substance includes iron.

10. The absorbent article as claimed in clause 1, characterized in that said heating means is an electrochemical heat cell.

11. The absorbent article as claimed in clause 10, characterized in that said electrochemical heat cell reacts with water in said body fluids to generate heat.

12. The absorbent article as claimed in clause 1, characterized in that said heating means have a thermal conductivity in relation to said absorbent.

13. A sanitary towel comprising: a) a cover permeable to the fluid; b) a separator impermeable to the fluid; c) an absorbent enclosed between said cover and said separator; and d) heating means for heating said absorbent placed on one side of absorbent dich.

14. The sanitary napkin as claimed in clause 13, characterized in that said heating means are placed essentially in the absorbent medium.

15. The sanitary napkin as claimed in clause 14, characterized in that the heating means d are placed between the absorbent and the separator.

16. The sanitary napkin as claimed in clause 13, characterized in that said heating means is a chemical mixture distributed essentially uniformly through the absorbent.

17. The sanitary napkin as claimed in clause 16, characterized in that said chemical mixture reacts with oxygen to generate a temperature of about 22 ° C to about 55 ° C.

18. The sanitary napkin as claimed in clause 17, characterized in that said chemical mixture includes iron.

19. A sanitary towel comprising: a) a cover permeable to the fluid; b) a separator impermeable to liquid; c) an absorbent enclosed between said cover and said separator; d) a retaining layer at least partially secured to said separator; e) heating means for heating said absorbent enclosed between the separator and the retaining layer.

20. The sanitary napkin as claimed in clause 19, characterized in that said retention layer includes a perforation.

21. The sanitary napkin as claimed in clause 20, characterized in that the heating means comprise a chemical mixture having iron, and wherein said chemical mixture reacts with oxygen to generate a temperature of about 22 ° C to about 55 °. C. E S U M E N An absorbent article includes a chemical particulate mixture, which is exothermically reactive in the presence of air or moisture, to heat at least a portion of the absorbent article. The heat generated improves the absorption of body fluids by lowering the viscosity of the absorbed fluids.