US3856014A

US3856014A - Sanitary napkin with porous resin powder deodorant

Info

Publication number: US3856014A
Application number: US00317795A
Authority: US
Inventors: A Yamauchi
Original assignee: JEX Co Ltd
Current assignee: Meitec Fielders Inc
Priority date: 1972-10-23
Filing date: 1972-12-22
Publication date: 1974-12-24
Anticipated expiration: 1991-12-24
Also published as: JPS5021793B2; FR2203616B1; JPS4964289A; DE2300871A1; FR2203616A1; GB1351439A; NL7301417A

Abstract

A sanitary napkin containing at least one layer of staple fibers having adhered thereto, as a deodorant, a porous resin powder in the form of its acid salt, the resin having been produced by the condensation of an aromatic amine, with or without a phenol, with formaldehyde. The sanitary napkin containing the layer is particularly effective in deodorizing a malodorous liquid.

Description

[ Dec. 24, 1974 United States Patent 1191 Yamauchi 88R Raw 88 2,634,229 4/1953 (16 Wet 2,643,969 6/1953 Mahon....... 2,837,462 6/1958 M01111 Aklra Yamauchl, y g J p 3,691,271 9/1972 Charle 61 a1. Assignee: Jex Co., Ltd., Osaka-fu, Japan Filed:

T WN A R 0 PD A0 NE D mm m n m NW MPm M 4% U, U

Primary Examiner-Richard A. Gaudet [22] 1972 Assistant ExaminerJ. C. McGowan Appl. No.: 317,795 Attorney, Agent, or FirmStewart and Kolasch, Ltd.

[30] Foreign Application Priority Data Oct. 23, 1972 A sanitary napkin contaimng at least one layer of stal28/290, 424/28 ple fibers having adhered thereto, as a deodorant, a

porous resin powder in the form of its acid salt, the resin having been produced by the condensation of an [51] Int. A6lf 13/16 [58] Field of Search 128/284, 286, 287, 290,

128/296, 285; 424/27 28 aromatic amine, with or without a phenol, with formaldehyde. The sanitary napkin containing the layer is particularly effective in deodorizing a malodorous liquid.

[56] References Cited UNITED STATES PATENTS 2,418,907 4/1947 Schreiber....................... 128/290 R 15 Claims, 1 Drawing Figure SANITARY NAPKIN WITH POROUS RESIN POWDER DEODORANT and retention of the malodorous fluid on sanitary napkins, the conventional sanitary napkins have not been satisfactory. Although some napkins have a thick layer or several layers which function to adsorb the fluid, they still possess the problem of the exudation of the malodorous fluid therefrom.

It is an object of the present invention to provide a sanitary napkin containing a deodorant which is effective in deodorizing a malodorous fluid.

Another object of the present invention is to provide a sanitary napkin which contains at least one layer of staple fibers to which a deodorant powder in the form of its acid salt is adhered, said napkin functioning to absorb the malodorous constituents of a fluid.

A further object of the present invention is to provide a sanitary napkin which is effective in adsorbing and diffusing a malodorous fluid.

Still another object of the present invention is to provide a sanitary napkin which although being thin in thickness and small in size, is nevertheless effective in maintaining the desired deodorizing and adsorbing effects.

Other objects, features and advantages of the present invention will become apparent during the course of the description which follows, and the accompanying drawing wherein The FIGURE is a perspective view of a sanitary napkin according to the present invention.

Referring now more particularly to the FIGURE, element I0 is a non-woven fabric, 11 is a water-adsorbing paper, 12 is a wate r-repellent paper, 13 is a water-proof paper, 14 is a thread, and 15 is a sheet made of staple fibers which contain the deodorant powder of the present invention.

As shown in the FIGURE the non-woven fabric 10 is made in the form of a closed container, which acts as a wrapper to protect the materials contained therein and help them retain their shape. As seen in the FIG- URE two sheets of water-adsorbing paper 11, a sheet of staple fibers 15, another two sheets of wateradsorbing paper 11, another sheet of staple fibers 15, two sheets of water-repellent paper 12 and a sheet of water-proof paper 13 are piled together in this order, and a sheet of water-repellent paper 12 is positioned at both sides of the accumulated materials so as to substantially cover said sides. The materials are arranged in such a way that the upper side of the water-adsorbing paper 11 is next to the inner side of that portion of the wrapper which does not contain the thread, as illustrated in the FIGURE. Both the open sides are sealed at an appropriate length. The side of the napkin containing the thread 14 is the exterior side of the napkin, and as such should not come into contact with the body of the user. Only the opposite or interior side of the napkin should contact the body of the user.

The materials and shapes of the non-woven fabric, the water-adsorbing paper, the water-repellent paper, the water-proof paper and the thread conventionally employed and known in the art may also be used for the sanitary napkin of the present invention, and no limitav tions are placed on these materials and shapes unless undesirable effects can be expected by their use. The essential feature of the present invention is that at least one of the layers or sheets of the napkin is made of staple fibers which contain a specific deodorant powder. Advantageously, the sanitary napkin of the present invention is arranged as shown in the accompanying drawing although some modifications and rearrangements of the materials and shape may be possible without decreasing the desired effects to be attained. For example, a sheet of staple fibers containing activated carbon powder may be used for either of two sheets of staple fibers 15. Alternatively, it is also possible that the deodorant powder of the invention is disposed in the water-adsorbing papers between the two sheets of staple fibers 15. The shape of the wrapper is also not limited to that specifically disclosed in the accompanying drawing, and various modifications and arrangements can be contrived to meet practical needs.

Although the specific embodiment of the present in- The deodorant powder may be used alone or as a mixture with other water-absorbing agents and/0r fillers known in the art. The deodorant of the present invention is a porous resin produced from an aromatic amine, with or without a phenol, by condensation with formaldehyde. The condensation product has as a partial structure the following chemical structure:

NHI NH:

OH OH I i i -CH CH: CH: CH:

NH: NH:

I OH

The resin may be specifically produced from starting materials, such for example, one mole of m-phenylene diamine, one mole of phenol or resorcin, and three moles of formaldehyde, using as a catalyst an acid, such for example, hydrochloric acid or oxalic acid, in substantially the same manner as utilized in conventional processes of manufacturing phenolic resins. As starting materials, m-aminophenol and formaldehyde, may also be used, without the presence of a phenol. A porous structure of the resin may be accomplished by the addition of a conventional aqueous inorganic salt to the reaction system at the beginning of the reaction. The re sulting resin is then heat-treated at above 80C. for about hours in the air and thereafter is washed by a hot alkaline aqueous solution and then by dilute hydrochloric acid, resulting in the removal of intermediate condensates.

The porous resinous powder of the present invention is stable in water, solutes and alkalis, and is not decomposable at temperatures below 100C. Said resin is capable of holding a comparably large amount of water in its structure as will be clear from the hydrophilic property of the amino groups on the aromatic rings and its porous structure. When the resin is employed in the napkin of the present invention, the content of water is preferably about 30 to 50 per cent.

The resin of the present invention is in the form of its acid salt for practical use. The acid salt may be produced by neutralizing the amino groups in the resin with acids. The following is a reaction scheme showing the neutralization reaction.

wherein R is a resin body and X is a residue of an acid.

The acids which can be used for the neutralization of the resin generally are those which are not harmful to human beings, such as tartaric acid. Although the acid used for the neutralization of the resin is liberated in the water in a very small amount, a napkin containing the deodorant of the present invention does not cause any harm to the user because of the presence of the acid liberated in the water contained in the napkin. It should also be noted that no dissolution of other substances such as, for example, formaldehyde occurs.

The functions of deodorizing various malodorous constituents by the deodorant are considered as follows: 1. Basic malodorous constituents such as ammonia, amines, and the like: The malodorous constituents are first dissolved in the water contained in the deodorant and then reacted with acids adhered to the resin to form an odor-free salt. For example, ammonia is converted to a malodor-free salt as follows:

R-N H ,-X* R-NH +HX in which R and X are as given above. The resulting resin is then reacted with the acidic malodorous constituents having the following general formula: HY, in

which Y is a residue of the acid, whose reaction is represented as follows:

This means that the acidic malodorous constituents are adsorbed by the resin, resulting in the formation of the acid salt free from malodor. 3. Neutral malodorous constituents such as aromatic hydrocarbons: The neutral malodorous constituents may be deodorized by intramolecular, physical adsorption because the deodorant is porous and it has a very large surface area.

In accordance with the present invention, said deodorants having the above-mentioned adsorbing properties possess a more effective adsorbing capacity when compared to deodorants conventionally available in the art. As compared with a slightly acidic cationexchange resin, the deodorants of the present invention have the capacity of adsorbing acetic acid about 3 to 4 times more than the cation-exchange resin. Furthermore, the cation-exchange resin has no adsorbing capacity for hydrogen sulfide, as do the deodorants of the present invention. As for strongly basic anion-exchange resins, the deodorants of the present invention adsorb ammonia approximately 30 times more than the basic aninon-exchange resin and they show an adsorbing capacity for trimethylamine, whereas the basic anionexchange resin has no such capacity. Compared with active carbon made from coconuts, the deodorants of the present invention have about 3 to 4 times the adsorbing capacity for ammonia as said activated coconut carbon, and about 4 to 5 times the adsorbing capacity for acetic acid. Furthermore, the ammonia that was adsorbed on the active coconut carbon at 10C. was desorbed in an amount of about to per cent, when the active carbon was heated to 50C. On the other hand, the ammonia adsorbed by the deodorants of the present invention was only slightly desorbed, that is, in an amount of about 1 to 2 per cent under the same conditions.

These characteristics of the deodorants according to the present invention are based upon the following facts; l the resin is an amphoteric ion-exchange resin, not a mere anion-exchange resin; (2) its exchange groups (R-NH and R-OH) act as weak electrolytes; and (3) a gas tends to penetrate into the resin because of its porous structure.

In conventional ion-exchange resins, for example, a cation-exchange resin having strongly acidic exchange groups can easily adsorb basic malodorous constituents, but it does not adsorb acidic malodorous constituents because the repellency of the homogenous electric charges of the strong exchange groups of the cationexchange resin and the acidic malodorous constituents makes it difficult for the constituents to transfer into the liquid phase in the resin. However, the resin of the present invention has weak exchange groups, thereby making it capable of adsorbing both acidic and basic malodorous constituents.

When the deodorants of the present invention were applied to the menstruous discharge, it was confirmed by gas-chromatography that monomethylamine, methyl mercaptan, ethylamine, acetaldehyde, acrolein, diethylamine, ethyl mercaptan, n-butylaldehyde, nbutyl mercaptan, etc. were adsorbed. This shows the removal of a majority of the malodorous constituents of the discharge.

ln accordance with the present invention, the deodorants may be employed alone or as a mixture with unharmful agents, such as diatomaceous earth, conventionally employed in the art as a water-adsorbent or filler.. These additives may be used in an amount of about 10 to 20' parts by weight, preferably 16 parts by weight, with respect to one part by weight of the deodorant.

The layer or sheet of the present invention is made out of staple fibers as a support to which the deodorant powder alone or as a mixture with a water-adsorbent or filler is adhered. The staple fibers may be the same as those employed for conventional sanitary napkins, such as cotton linter and the like. Pulp fiber is particularly preferred. The staple fibers may be used in an amount of about 50 to 500 parts by weight, preferably 200 parts by weight, with respect to a part by weight of the deodorant. Said sheet may be prepared by spreading a ground pulp band with the deodorant powders. However, the deodorant powders tend to peel off or drop from the sheet prepared in this manner causing a decrease in the desired deodorizing effect. The preferred preparation of the sheet is accomplished by a procedure discussed hereinbelow. The procedure enables the deodorants to adhere adhesively to the fiber. The satisfactory adherence effect may be produced by scattering the powder during ventillation of the pulp by a pulp machine following conventional purification procedures. More particularly, the desired sheet of pulp fibers and the deodorant may be prepared from pulp bands in a conventional manner by maintaining the deodorant powders and the ground pulp in a fluidized state in a wind pipe. The deodorant powders are introduced into the wind pipe through a powder supply pipe and the powders are joined in the pipe with the ground pulp which is ventilated into the wind pipe through a crusher. Since the pulp fibers are charged with static electricity created by the friction of the hammers in the crushing device, the deodorant powders adhere to the surface of each fiber while the mixture is fluidized in the wind pipe. Microscopic observations of a sheet manufactured by the above procedures show that particles of an adhering agent, such as diatomaceous earth, and the like, form complex surfaces which adhere to the pulp fibers more strongly than the deodorant powder. Accordingly, the use of an adhering agent prevents the adhering deodorant powder from becoming detached from the fibers during the handling.

The sanitary napkin having the features described above permits a fluid to penetrate through the nonwoven fabric and the water-adsorbing paper into the surface of the sheet of staple fibers containing the deodorant powder. Here the fluid spreads itself into the sheet while being adsorbed and diffused by the combined action of the liquid-adsorbing action of said powder itself and the liquid-adsorbility between the fibers with their effective liquid adsorbing surfaces increased by the adherence of the powder thereon. Accordingly, the fluid is effectively deodorized by contact with the deodorant powder adhered to the surfaces of each of said fibers. In addition, agaseous malodor generated from the fluid is also adsorbed by the deodorant powder. Furthermore, the fluid spreads and distributes itself in the napkin not only in the vertical direction (depth direction) but also in the horizontal direction (the plane direction) resulting in an increase in the amount of liquid which can be adsorbed. Thus the napkin of the present invention can be reduced in size while still maintaining the effective deodorant capacity. Said advantages were confirmed by an organoleptic test using a napkin of normal size (a total weight of 6.5 to 7 grams) having the same shape and structure as shown in the accompanying drawing, and containing 0.02 gram of the deodorant powder, 0.28 gram of diatomaceous earth and 4 grams of pulp staple fibers.

What is claimed is:

1. In a sanitary napkin which comprises at least one layer of staple fibers in the form of a pad, the improvement wherein said pad contains as a deodorant a porous resin powder which is the condensation product of an aromatic amine with fonnaldehyde in the form of its acid salt.

2. The sanitary napkin according to claim 1 wherein a phenol is present in the reaction system.

3. The sanitary napkin according to claim 1 wherein the condensation product is one layer made of a pulp staple fiber containing an aromatic amine selected from the group consisting of m-phenylenediamine and m-aminophenol, with or without phenol or resorcin, and formaldehyde, said reaction product being in the form of the salt of tartaric acid.

4. The sanitary napkin according to claim 3, wherein the deodorant powder is produced from mphenylenediamine and phenol or resorcin by condensation with formaldehyde.

5. The sanitary napkin according to claim 4, wherein one mole of m-phenylenediamine, one mole of phenol or resorcin and three moles of formaldehyde are used.

6. The sanitary napkin according to claim 3, wherein the deodorant powder is produced from maminophenol by condensation with formaldehyde.

7. The sanitary napkin according to claim 3, wherein a pulp staple fiber is used in an amount of about 50 to 500 parts by weight with respect to one part by weight of the deodorant powder.

8. The sanitary napkin according to claim 3, wherein the amount of the pulp staple fiber is about 200 parts by weight with respect to about one part by weight of the deodorant powder.

9. The sanitary napkin according to claim 4, wherein the deodorant powder is used in an amount of about one part by weight with respect to about 10 to 20 parts by weight of diatomaceous earth.

10. The sanitary napkin according to claim 9, wherein the amount of diatomaceous earth is about 16 parts by weight to about one part by weight of the deodorant powder.

11. The sanitary napkin according to claim 1, comprising a composite of two layers of water-adsorbing paper, a layer of staple fibers, another two layers of water-adsorbing paper, another layer of staple fibers, two layers of water-repellent paper and a layer of waterproof paper which are arranged in this order, said composite being provided at both sides thereof with a layer of water-repellent paper.

12. The sanitary napkin according to claim 1 comprising one layer of staple fibers containing said deodorant, said layer being surrounded on one side with at least one layer of water-repellant paper and on the other side with at least one layer of water absorbing paper.

13. The sanitary napkin according to claim 1 comprising two layers of staple fibers containing said deodorant, said layers being separated by at least one layer of water absorbing paper and surrounded on one side with at least one layer of water-repellant paper and on the other side with at least one layer of water absorbing paper.

14. The sanitary napkin of claim 12 housed within a non-woven fabric wrapper.

15. The sanitary napkin of claim 13 housed within a non-woven fabric wrapper.

Claims

1. IN A SANITARY NAPKIN WHICH COMPRISES AT LEAST ONE LAYER OF STAPLE FIBERS IN THE FORM OF A PAD, THE IMPROVEMENT WHEREIN SAID PAD CONTAINS AS A DEODORANT A POROUS RESIN POWDER WHICH IS THE CONDENSATION PRODUCT OF AN AROMATIC AINE WITH FORMALDEHYDE IN THE FORM OF ITS ACID SALT.

4. The sanitary napkin according to claim 3, wherein the deodorant powder is produced from m-phenylenediamine and phenol or resorcin by condensation with formaldehyde.

6. The sanitary napkin according to claim 3, wherein the deodorant powder is produced from m-aminophenol by condensation with formaldehyde.

11. The sanitary napkin according to claim 1, comprising a composite of two layers of water-adsorbing paper, a layer of staple fibers, another two layers of water-adsorbing paper, another layer of staple fibers, two layers of water-repellent paper and a layer of water-proof paper which are arranged in this order, said composite being provided at both sides thereof with a layer of water-repellent paper.

14. The sanitary napkin of claim 12 housed within a non-woven fabric wrapper.

15. The sanitary napkin of claim 13 housed within a non-woven fabric wrapper.