Odor Reductant Body Waste Pad

Abstract

A substantial proportion or all of the total thickness of an unused single use, disposable body waste fluid absorbent pad, such as a sanitary napkin and a baby diaper, combines a water soluble, weakly acidic buffered solid composition having a pH range of 3.5 to 6.0, with a waste fluid absorbent pad. The absorbent pad of wood pulp is impregnated with a dry buffered non-hygroscopic, non-toxic, solid, acid composition having an aqueous pH range of 3.5 to 6.0. The wood pulp pad structure density can range from the macerated loose random fiber of typical density 1.5-2.5 lbs/cu. ft. of the commonly sold commercial fluffed wood pulp absorbent pad sanitary menstrual napkins, to that of a 9-10 pound weight absorbent tissue paper sheet typically embodied in the menstrual napkin of the U.S. Pat. No. 3,532,097, issued Oct. 6, 1970. The controlled acid pH of the buffered absorbent pad, when the pad is wet with body waste fluids, e.g., menstrual fluids or urine of infants, inhibits the rapid formation of free ammonia gas and volatile amine compounds from urea, uric acid, amino acids and peptones by bacterial and enzyme action, and forms nonvolatile salts of the basic compounds. The buffered pH range is not irritating to the user's skin.

Parent Case Text

This application is a continuation of Ser. No. 131,884 filed Apr. 7, 1971 and now abandoned.

Description

BACKGROUND OF THE INVENTION

It is well known that some menstruating females emit odorous menstrual fluids. Emitted fluids can also rapidly form odorous products on further proteolytic reaction. It is established that some of the most perceptible odors are due to chemically basic amine type compounds, which are volatile. The characteristic amine type odors are embarrassing to menstruating females.

The urine impregnated diapers of infants are well known for having and developing an ammonical odor on storage. The widespread use of single use, disposable baby diapers is restricted by the persistent ammonical odor of the discarded, used diapers, prior to their final disposal outside the baby's household. In addition, the ammonical urine products can induce a common rash on the baby's torso, due to the alkaline pH of the urine in persistent contact with the baby's skin.

My buffered acid pH body waste odor prevention pad can inhibit the formation of embarrassing odors by absorbing any free ammonia and amines present in freshly excreted body waste fluids; and also by further inhibiting the rapid formation of ammonia and volatile amine compounds from urea, uric acid, amino acids and the like by bacterial and enzyme action in the waste fluids.

SUMMARY OF THE INVENTION

A substantial portion or all of the total thickness of a single use, disposable body waste fluid absorbent pad, such as a menstrual sanitary napkin or a baby diaper, has a water soluble, weakly acidic, buffered solid composition having an aqueous pH range of 3.5 to 6.0 disposed in the dry reservoir absorbent pad of the napkin and the diaper. The dry, buffered pH reservoir absorbent pad is formed of wood pulp impregnated with a dry, buffered, non-toxic, non-hygroscopic, solid acid composition having a typical pH range of 3.5 to 6.0. The bleached wood pulp pad structure can range from macerated, loose random fiber of typical density 1.5-2.5 lb/cu ft of the commonly sold commercial fluffed wood pulp absorbent pad in sanitary menstrual napkins, to that of a 9-10 pound weight absorbent tissue paper sheet embodied in the menstrual mapkin of the U.S. Pat. No. 3,532,097 issued Oct. 6, 1970, and also in the diaper pad of U.S. Ser. No. 63,749, filed Aug. 14, 1970. The controlled pH range of the buffered pad inhibits the rapid formation of ammonia and volatile amines from the urea, uric acid, amino acids and peptones in the body waste fluids, by bacterial and enzyme action.

The acidic buffers composition also neutralizes and converts to a relatively nonvolatile, nonodorous salt any ammonia or amine which is initially present in the freshly excreted waste fluids or which is formed later by bacterial or enzyme action. The buffered pH of the pad is in the acidic range which is not irritating to the skin.

Included in the objects of this invention are:

To provide a body waste fluid absorbent pad having a dry, solid buffered weakly acidic chemical reservoir composition suitable for inhibiting the formation of ammonia and volatile amine odors from the absorbed waste fluids, and also for neutralizing any basic compounds in the freshly excreted waste fluids.

To provide a dry, body waste fluid absorbent pad having a buffered pH reservoir composition capable of absorbing ammonia and amines contained in waste fluids absorbed on a pad.

To provide a dry, nontoxic, acidic pH reservoir pad, buffered to a pH range of 3.5 to 6.0, and suitable for use in body waste fluid absorbent pads, and which will not irritate the body skin.

To provide a dry body waste fluid absorbent pad suitable for neutralizing and forming non-volatile salts of ammonia and amines and other basic chemical compounds present in the body waste fluids absorbed on the pad.

Further objects and advantages of this invention will become apparent in the following description, to be read in conjunction with the following drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a perspective partial sectional view of a menstrual sanitary napkin containing a buffered acidic pH absorbent pad of this invention.

FIG. 2 is a perspective partial elevational view of another menstrual napkin modification, further illustrating the position of a buffered acidic pH absorbent pad.

FIG. 3 is a perspective view of a disposable single use baby diaper having a buffered acidic pH absorbent pad.

FIG. 4 is a sectional view through 4--4 of FIG. 3, further illustrating the placement of the buffered, acidic pH absorbent diaper pad of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

It is well known that menstruating females can emit odors that are embarrassing to them. The odors can arise as the result of proteolytic decomposition of blood and tissue waste in menstrual fluids, which are further decomposed into products which yield ammonia and volatile amine compounds. The odors of the ammonia and amines are socially unpleasant. Likewise, mothers object to the odor of ammonia in the urine impregnated, single use, disposable infant diaper after they are removed from the infant, and before the diapers are removed from the household.

The waste menstrual fluid and baby urine have a common problem of odor generation. Waste fluid odor generation can be reduced and can be inhibited by preventing bacterial and enzymatic decomposition in the waste products. The urea, creatinine, uric acid in urine are further converted into volatile ammonia in a wet diaper, due to bacterial and enzymatic action. Likewise, the proteins, amino acids, urea and nitrogen containing tissue excreta in menstrual fluids, are converted by proteolytic and enzymatic action into simpler molecules, including some volatile ammonia and amines. The relatively high temperature of the sanitary napkin in use next to the body skin further promotes the microbial incubation process, and the rapid rate of these proteolytic and enzymatic processes.

I have found that the biological conversion processes which lead to the common problem of amine and ammonia formation in these body waste fluids absorbent pads can be inhibited by controlling the pH of the absorbent pads receiving these wastes. By controlling the pH of the absorbent pad structure material to provide a buffered acidic reservoir of pH range 3.5 to 6.0, the formation of substantial amounts of free volatile ammonia and amine compounds is prevented. The buffered pH acidic reservoir functions two-fold. First, it inhibits bacterial growth in the proteolytic degradation of the excretory products, since bacterial growth rate is generally decreased in acid media. Secondly, the the ammonia and amines that form, or which are initially excreted in the waste fluids, are immediately neutralized by the buffer composition, forming nonvolatile salts. The pH of the buffering composition is controlled over a range compatible with the normal human skin.

Human urine normally ranges from pH 5.5-6.5, becoming alkaline or near alkaline after meals. The skin of newborn babies (seven days old) has a pH less than 5.0 (Behrendt and Green The measurement of Anderson (Brit. J. Derm., 63, 283-96) and Martin Beare et al (Brit. J. Derm., 70, 233-41) both show that the skin of normal children is acidic. According to Martin Beare et al, normal children less than three years of age have skin pH values ranging from 5.86 to 6.78. Significantly, the higher pH value of 6.78 was in the perianal area which can be contaminated at that age with traces of urine and feces. The other skin areas of the body were significantly more acidic. Anderson's pH measurements of other skin areas of young children were significantly more acidic, ranging from pH 4.87 to 5.53. The skin of adult females was found to have an average pH of 5.50 by Draize (J. Invest. Derm., 77-85). Thus an acidic pH range of 4.5 to 6 is typically normal for the skin of babies or females.

This invention teaches body waste fluid pads impregnated with nontoxic, water soluble, weakly acidic buffered, dry, solid, acid-salt compositions having a buffered pH range of 3.5 to 6.0, when wet with an aqueous body waste fluid. The waste fluids, urine and menstrual fluid, impregnating the pad will be incubated at substantially body temperature while secured on the person, or at room temperature while awaiting final disposal in the household. The buffered acidic pH of the waste fluid while incubating in the impregnated pad will inhibit the bacterial and enzymatic process leading to formation of the volatile ammonia and amine odors, since acidic pH media generally inhibit bacterial growth processes.

Some of the nontoxic, food type, solid, weak acids useful in the buffered pH compositions of this invention are citric, tartaric, gluconic, glutaric, levulinic, glycolic, succinic, malic, fumaric, and acid phosphate salts. Other similar nontoxic solid, weak acids can be used. Preferably, the buffered acid compositions should not be hygroscopic or deliquescent. The preferred weak acids useful in the buffered compositions should not be the typical short chain aliphatic acids such as acetic or butyric, due to their being liquids, and their volatility and odor. Likewise, the long chain fatty acids such as myristic, palmitic and stearic acids form undesirable surfactant salts or soaps. Obviously toxic acids, such as boric and oxalic, are undesirable.

The buffered acid compositions can typically be simply formed by adding Na OH or Na.sub.2 CO.sub. 3 solutions to the concentration of pure acid solutions in amounts to provide a desired buffered acid solution in the range of pH = 4.5 to 6.0. The lower pH values will provide a greater buffering capacity for the absorbent pad.

The buffered acid compositions can be uniformly dispersed in the absorbent wood pulp, either in the random macerated wet or dry wood pulp form, or on the thin (9-10 lb) absorbent tissue as it is being sheeted out and dried on the paper forming machine. The wood pulp stock can be bleached white stock, for either the macerated pulp or the tissue sheet. The buffered composition can be added to the pulp base for the macerated pulp, as a desired aqueous concentration of the buffered solution. The solution is sprayed on the pulp as it is sheeted into the relatively thick, non-calendared, pulp sheet, which is dried to a sheet stock suitable for storage, and then disintegrated into macerated pulp for absorbent pads.

The buffered composition solution can also be sprayed on the wet tissue stock sheet as it is made on the paper sheeting machine, just prior to final drying of the tissue paper stock. Thus, the dry macerated pulp composition, having a buffered, dry, solid, non-toxic water soluble composition impregnated therein, is suitable for use in absorbent pads for sanitary napkins and diapers. The absorbent pad can also be a menstrual napkin comprised of multiple ply of absorbent tissue sheet stock, as U.S. Pat. No. 3,532,097 and the pending U.S. patent application on diaper pads, Ser. No. 63,749, filed Aug. 14, 1970. In either the macerated wood pulp or the tissue sheet absorbent pad construction, the desired concentration of dry, solid acidic composition can be achieved.

Dry, solid, acidic buffer compositions of sodium citrate and citric acid have been uniformly dispersed in bleached white macerated pulp and bleached white, absorbent tissue paper stock. Typically, 2 wt. percent of a dry citric acid-potassium citrate buffer composition, having an aqueous pH value of 4.0 as a 10 wt. percent solution, was separately sprayed on macerated paper pulp and on 10 lb. weight tissue paper, and dried. The dried buffered paper stock was formed into diapers and napkins in accordance with the earlier reference teachings on diaper and napkin construction.

Blind use tests of both diapers and napkins utilizing the above modified paper stock were made. The female napkin users and the infants' caretakers were unaware of the diaper and napkin modification employed in the respective use tests.

Female napkin users were supplied with buffered napkin modifications and also identical appearing napkins which were not buffered modifications. The napkins supplied to users were numbered in a code unknown to the users, indicating the buffered and non-buffered modifications. The users were asked to indicate the odorous and non-odorous napkins, immediately after the napkin's use and also after incubating the napkin for 24 hours at room temperature in a plastic envelope. Typically, the napkins identified by the user after both time intervals as non-odorous, or less odorous, was the buffered napkin, having the buffer pH controlled composition impregnantly disposed therein.

Likewise, the infant caretakers were asked to indicate the odorous and non-odorous diapers, also supplied as coded buffered and non-buffered modifications. The diapers were examined for odor immediately after use and also after incubating at room temperature, when infant feces did not interfere with the odor test. Typically, the caretaker correctly identified the non-odorous, or less odorous, diapers as the buffered diaper, having the buffer pH controlled composition impregnantly disposed in the diapers.

Typically, the diaper's absorbent pad can be impregnated pregnated with 1. wt percent of a buffer composition, such as NaH.sub.2 PO.sub.4 having an aqueous pH value of 4.1 to 4.5 in a 5 percent aqueous solution. Likewise, sodium dihydrogen phosphate (NaH.sub.2 PO.sub.4) is a suitable buffer composition for for sanitary napkin modifications of this invention.

It is desirable to optimize the concentration of dry, solid acidic buffer composition in the absorbent pad at the lowest concentration value consistent with minimum ammonia and amine odor concentration during the absorbent pad use. The minimum optimal buffer concentration is desirable to provide a low raw material cost, adapting this invention to widespread use. In addition, the low buffer concentration minimizes any potential skin irritation effects. It should be noted that well known and widely used food acids are the preferred acids of choice in the buffer compositions, reducing the toxicity problem to nil.

Referring to FIG. 1 in detail, the menstrual napkin 1 has a menstrual fluid absorptive section 2 and a pair of straps 3 and 4, as disclosed in my copending patent application filed as of this date titled INTEGRAL STRAP TISSUE NAPKIN. The multiple reservoir apertures 5 receive menstrual fluid flow. The adhesive plug securing means 6,6 and 7,7 bond the multiple ply tissue paper sheets of the napkin together. The absorptive section 2 has a total thickness 8, comprising the primary absorptive section thickness 9 and the secondary absorptive section thickness 10. All or a fraction of the total absorptive section thickness 8 comprises multiple ply of tissue paper sheets having the nontoxic, water soluble, weakly acidic, buffered, dry solid composition, having an aqueous pH of 3.5 to 6.0 impregnantly disposed therein. Preferably the buffer impregnated tissue sheets are disposed at least adjacent the surface of the sanitary napkin which first receives the menstrual fluid excreta, as are required to minimize odor.

Referring to the conventional menstrual napkin 20 in FIG. 2, the shaping cover sheet 21, of open gauze or scrim, forms the front strap 23 and the rear strap 22. The partial sectional view discloses the total absorptive section thickness 26 has partial absorptive section thicknesses 24 and 25. The absorptive section thickness 24, which is to be disposed so as to directly receive the menstrual fluid excreta, has the buffered, dry solid composition, whose pH range is 3.5 to 6.0, impregnantly disposed therein. Likewise a portion of the section thickness 25, or all of 25 may also be impregnated with the buffer composition as required to reduce the excreta odor. The relative value of thicknesses 24 and 25 are those values which are required.

Referring to FIGS. 3 and 4 in detail, the infant diaper 30, has the overlying plastic membrane margins 31 and 32, formed by overwrapping and sealing the thin plastic membrane sheet 33 on to the edge margins of absorptive pad 34. The enlarged partial sectional view of FIG. 4 illustrates the porous cover sheet 35, which is disposed directly adjacent the infant in diaper use. The relative thickness values of absorptive sections 36 and 37 can be adapted to provide maximum reduction of ammonia and amine odor, by adjusting the thickness of buffer impregnated absorptive section 36 to the required value. Section 36 can range up to 100 percent of the total absorptive pad thickness 38, thus decreasing section 37 to zero percent.

Other odor reductant body waste pad variations can be made without departing from the scope of this invention. Many modifications and variations of my improvements in an odor reductant waste pad can be made in light of my teachings. It is therefore understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

Claims

I claim:

1. A single use, disposable, human body waste fluid absorbent pad combination comprising:

a waste fluid absorbent pad having cellulose fibers disposed therein, and adapted in size and shape to being externally worn on the human body and to receiving excreted human body waste fluid; and,

a nontoxic, nonvolatile, water soluble, weakly acidic, dry solid buffer composition selected from the solid acids and lithium, sodium, potassium salts of citric, tartaric, gluconic, glutaric, levulinic, glycolic, succinic, malic, fumaric, and phosphoric acids, said buffer composition having an aqueous pH range of 3.5 to 6.0, said buffer composition impregnantly disposed in said cellulose fibers disposed in said absorbent pad in a buffer composition concentration adapted to form salts of all the volatile chemically basic waste fluid excreta products absorbently disposed in said cellulose fibers during use.

2. A single use, disposable, human body waste fluid absorbent pad combination comprising:

a waste fluid absorbent pad having cellulose fibers disposed therein, and adapted in size and shape to being externally worn on the human body and to receiving excreted human body waste fluid; and,

a nontoxic, nonvolatile, water soluble, weakly acidic, dry solid buffer composition selected from the solid acids and solid lithium, sodium and potassium salts of citric, tartaric glycolic, succinic, fumaric, malic acids, and phosphoric acids, said buffer composition having an aqueous pH range of 3.5 to 6.0, said buffer composition impregnantly disposed in said cellulose fibers disposed in said absorbent pad in a buffer composition concentration adapted to form salts of all the volatile chemically basic waste fluid excreta products absorbently disposed in said cellulose fibers during use.

3. A single use, disposable human body waste fluid absorbent pad combination comprising:

a waste fluid absorbent pad having cellulose fibers disposed therein, and adapted in size and shape to external wear on the human body and to receiving excreted human body waste fluid; and,

a nontoxic, nonvolatile, water soluble, weakly acidic, dry solid buffer composition selected from the dry, solid compositions of the acids and lithium, sodium and potassium salts of citric, tartaric, gluconic, glutaric, levulinic, glycolic, succinic, malic, fumaric and phosphoric acids, said buffer composition having an aqueous pH range of 3.5 to 6.0, said buffer composition uniformly impregnantly disposed in said cellulose fibers disposed in said pad and adapted to receive said waste fluid, the concentration of said buffer composition adapted to form non-volatile salts of all the volatile chemically basic waste fluid excreta products disposed on said pad fibers.

4. A single use, disposable human body waste fluid absorbent pad comprising:

a waste fluid absorbent pad having cellulose fibers disposed therein, and adapted in size and shape to external wear on the human body and to receive human body waste fluid excreted on one face of the fiber pad; and,

a nontoxic, nonvolatile, water soluble, weakly acidic, dry, solid buffer composition selected from the solid acids and lithium, sodium and potassium salts of citric, tartaric, glycolic, succinic, fumaric, malic acids, and phosphoric acids, said buffer composition having an aqueous pH range of 3.5 to 6.0, said buffer composition uniformly inpregnantly disposed in said cellulose fibers disposed in said pad and adapted to receive said waste fluid, the concentration of said buffer composition adapted to form nonvolatile salts of all the volatile chemically basic waste fluid excreta products disposed on said pad fibers.

5. A single use, disposable, human body waste fluid absorbent pad comprising:

a waste fluid absorbent pad having cellulose fibers disposed therein and adapted in size and shape to being externally worn on the human body and to receiving excreted human body waste fluid; and

a nontoxic, nonvolatile, water soluble, weakly acidic, dry solid buffer composition, having an aqueous pH range of 3.5 to 6.0, uniformly impregnantly disposed in said cellulose fibers disposed in said absorbent pad in a composite buffer concentration adapted to form salts of all the volatile chemically basic waste fluid excreta products absorbently disposed in said cellulose fibers during use.

6. In the product of claim 5, the modification wherein said waste fluid absorbent pad having cellulose fibers disposed therein is a menstrual waste fluid sanitary napkin pad adapted to external body wear.

7. In the product of claim 5, the modification wherein said waste fluid absorbent pad having cellulose fibers disposed therein is a baby diaper waste fluid absorbent pad adapted to external body wear.

8. In the product of claim 5, the modification wherein said buffered, dry solid composition is uniformly concentrated in said cellulose fibers disposed in the structure of said waste fluid absorbent pad.

9. A single use, disposable human body waste fluid absorbent pad comprising:

a waste fluid absorbent pad having cellulose fibers disposed therein, and adapted in size and shape to external wear on the human body and to receive excreted human body waste fluid on one face of the fiber pad; and

a nontoxic, nonvolatile, water soluble, weakly acidic, dry, solid buffer composition, having an aqueous pH range of 3.5 to 6.0, impregnantly disposed in said cellulose fibers disposed in the pad face to be worn adjacent to said human body, the concentration of said buffer composition adapted to form nonvolatile salts of all the volatile chemically basic waste fluid excreta products disposed on said pad fibers.

10. In the product of claim 9, the modification wherein said waste fluid absorbent pad having cellulose fibers disposed therein is a menstrual sanitary napkin pad and adapted to external body wear.

11. In the product of claim 9, the modification wherein said waste fluid absorbent pad having cellulose fibers disposed therein is a baby diaper absorbent pad adapted to external body wear.