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Publication numberUS3702610 A
Publication typeGrant
Publication dateNov 14, 1972
Filing dateApr 29, 1971
Priority dateApr 29, 1971
Also published asCA967088A1
Publication numberUS 3702610 A, US 3702610A, US-A-3702610, US3702610 A, US3702610A
InventorsHenderson William Leland, Sheppard Milton R
Original AssigneeKimberly Clark Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Flushable web containing flushability indicator, and absorbent pads wrapped therewith
US 3702610 A
Abstract
A means for indicating when a sanitary napkin or diaper wrapped with a web bonded with a spaced pattern of water-dispersible adhesive is in condition for flushing away after it is dropped in a toilet for disposal. The indicating means is provided by including a water-soluble coloring agent or dye in the water-dispersible adhesive composition. As the water disperses the adhesive, the dye migrates into the non-bonded area of the web or is diluted in the excess water, and the adhesive pattern substantially disappears, thus indicating that the adhesive has become softened sufficiently to permit the wrapper to be broken up readily by the flushing action of the water.
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United States Patent Sheppard et al.

[54] FLUSHABLE WEB CONTAINING 'FLUSHABILITY INDICATOR,AND ABSORBENT PADS WRAPPED THEREWITH [72] Inventors: Milton R. Sheppard, Appleton; William Leland Henderson, Neenah,

both of Wis.

[73] Assignee: Kimberly-Clark Corporation,

Neenah, Wis.

[22] Filed: April 29, 1971 [21] App]. No.: 138,742

[52] U.S. Cl. ..128/284 [51] Int. Cl. ..A61i 13/16 [58] Field of Search ..128/284, 285, 286, 287, 290,

[56] References Cited UNITED STATES PATENTS 3,004,895 10/1961 Schwartz ..128/287 [4 1 Nov. 14, 1972 3,426,758 2/ 1969 Harautueian ..128/349 8 3,480,016 11/1969 Constanza et al. ..128/284 3,554,788 l/ 1971 Fechillas ..128/284 Primary Examiner-Charles F. Rosenbaum Attomey-Daniel J Hanlon, Jr., William D. Herrick and Raymond J. Miller [57] ABSTRACT A means for indicating when a sanitary napkin or diaper wrapped with a web bonded with a spaced pattern of water-dispersible adhesive is in condition for flushing away after it is dropped in a toilet for disposal. The indicating means is provided by including a water-soluble coloring agent or dye in the waterdispersible adhesive composition. As the water disperses the adhesive, the dye migrates into the non-bonded area of the web or is diluted in the excess water, and the adhesive pattern substantially disappears, thus indicating that the adhesive has become softened sufficiently to permit the wrapper to be broken up readily by the flushing action of the water.

16 Claims, No Drawings FLUSHABLE WEB CONTAINING FLUSHABILITY INDICATOR, AND ABSORBENT PADS WRAPPED THEREWITH BACKGROUND OF THE INVENTION During recent years. much emphasis has been placed upon developing sanitary napkins. and diapers and other single-use absorbent pads with a completely flushable structure, so that they may be disposed of in conventional toilets. The major problem encountered in rendering these absorbent devices flushable has been to develop an outer, fluid-permeable wrap which is strong enough to remain whole while it is subjected to the normal stress, strain, and moist conditions encountered during use, and yet which will break up readily when deposited in the water of a toilet and flushed away. One type of wrapper employed for such purposes is a non-woven web bonded by spaced lines or patterns of water-dispersible adhesive. However, in order to make such webs strong enough to hold together in the moist environment encountered during use, it has been found necessary to apply the adhesive in amounts such that the adhesive will not dissolve in water instantaneously, or to modify the adhesive in some way to slow down its solubility rate. When these practices are used the adhesive disperses readily only after it has been immersed in water for a short period of time. Ideally, therefore, it would be desirable if the person who deposits the product in water could be provided with some easily discernible signal which would inform the user when the adhesive has been immersed in the water for a sufficient time to insure that the wrapper will disperse completely at the first flushing.

The main object of this invention therefore is to provide a water-dispersible wrapper for absorbent pads with a means for indicating when the adhesive binder in the wrapper is dissolved sufficiently to permit ready dispersion of the wrapper in water.

SUMMARY OF THE INVENTION This invention is directed to a means for indicating when a sanitary napkin or diaper wrapped with a nonwoven web bonded with a spaced pattern of waterdispersible adhesive is in condition for disposal by flushing after it is dropped in a toilet. The indicating means is provided by including a small percentage of water-soluble coloring agent or dye in the water-dispersible adhesive which is normally used to bond flushable wrappers. When a pad wrapped in a fluid-permeable web bonded with such a color-containing water'dispersible adhesive is deposited in water, the color or dye gradually diffuses out of the adhesive and spreads to the rest of the web and is diluted by the excess water whereby the adhesive pattern substantially disappears. The change from sharply defined adhesive pattern to an overall faded color in the web is clearly visible to the eye, and as the color fades by diffusing into the surrounding web and by water dilution, the user is made visually aware of the fact that the adhesive is softened by the water to a degree sufficient to destroy its bond ing power and to permit the wrapper to readily disintegrate during the flushing action and thereby release the contained pad so that it, too, will disintegrate and flush away.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In making up a suitable wrapper in accordance with this invention, rayon fibers of 1.5 denier and 1-9/16 inch staple length were carded to form a non-woven fiber web weighing approximately 14 grams per square yard. The carded web was overprinted with a pattern of a water-soluble adhesive containing a compatible water-soluble red dye. The pattern comprised two sets of spaced parallel lines of adhesive. One set extended diagonally of the'web in one direction at an angle of about 45 while the other set extended diagonally in the opposite direction and also at a 45 angle. The sets of adhesive lines intersected to provide an overall closed diamond pattern. This diamond style bonding pattern is one of many commonly used for binding non-woven webs. In this instance, the lines were about one-sixteenth inch wide and spaced about one-quarter inch from each other. The adhesive was applied in the form of a 10' percent solution and in the amount-of about 1 gram per square yard in the finished material.

The water-soluble adhesive used in this example comprised polyvinyl alcohol of a type which was about 79-82 percent hydrolyzed, had a viscosity of 22 cps (4 percent water solution at 20 C.) and was readily soluble in water.

The compatible water soluble dye was present in the polyvinyl alcohol in the amount of about 1.0 percent by weight based on the polyvinyl alcohol. In this instance the dye was of a dark red color sold under the name EASTACRYL dark red LA by Eastman Kodak Company.

The above-described bonded webs were used to construct sanitary napkins by wrapping the webs around conventional absorbent pads made up from layers of cellulose wadding and wood pulp fluff in the conventional manner, leaving the customary fastening tabs extend beyond each end of the pads.

The napkins comprising pads wrapped with the above-described web were then dropped into the water of a toilet bowl. Shortly after the pad immersed itself in the water there was a noticeable migration of the color from the adhesive lines into the adjoining areas of the web. As this migration took place the color in the lines of the adhesive faded rapidly. In about 30 seconds the pattern was no longer discernible, and the coloring matter had distributed itself uniformly throughout the web. When the toilet was flushed at this time, the web broke up immediately, releasing the internal pad components and permitting the entire structure to disintegrate into small pieces and individual fibers which passed through the pipe lines of the disposal system without difficulty. The pipe lines carrying the flushed material were made of transparent material so that the condition of the materials as they were carried therethrough was readily observable.

Another pad of the same structure was dropped in the water and flushed irmnediately without waiting for any color change. In this case when no time was allowed for the adhesive to dissolve, the wrapper did not break up and it was observed that the whole structure traveled down the drain and did not break up to any extent until it had been carried a considerable distance down the transparent pipe-line and around several bendstherein.

As indicated above, the diffusion of the water-soluble dye or coloring matter out of the adhesive and into the water and adjacent areas of the web causes the originally sharp outline of the colored adhesive pattern to substantially disappear. The color itself takes on an overall lighter hue, thus providing a visual signal to the user that the pad is ready for flushing, and also assuring the user that the flushed pad will not travel through the pipe-line for any distance in its bulky, undisintegrated form.

In addition to the dye described in the specific example, any water-soluble dye or coloring agent which is compatible with the particular adhesive employed may be used. It is understood of course that the dye be nontoxic and non-irritating in contact with the skin.

Other specific dyes which were found suitable for use with polyvinyl alcohol are Pontamine Turquoise 8 GLP and Rhodamine B Extra, both sold by the E. I. DuPont Company.

Amounts of coloring agent in the adhesive in the range of from about 0.5 percent to about 1.5 percent by weight have been found useful. A wide range of colors may be employed to identify various types of napkins or the like. The coloring agent should be nonpigmented and may be either an acid, a basic or a direct dye. Vegetable dyes and water-soluble food colors may be used.

In addition to the specific polyvinyl alcohol mentioned above, other cold-water soluble polyvinyl alcohols may be used. For example, polyvinyl alcohols having a percent hydrolysis in the range of about 79 to about 98 are generally cold-water soluble and are suitable for the described use. Viscosities of about 21 to about 28 are preferred. The adhesive pattern used may be in the form of straight or wavy parallel lines which are transversely or diagonally disposed, as well as other patterns including circles, squares, dots and the like. The lines in the patterns may be continuous or discontinuous.

The amount of polyvinyl alcohol used can also vary in the range of about to about 15 percent by weight, but should be regulated to provide a suitable strength as well as softness and drape. Excessive amounts should be avoided as they are inclined to become sticky in use, which is undesirable.

While only polyvinyl alcohol is described in the specific example, and is preferred as the water-soluble binder, other water-soluble adhesives may be used, including such materials as polyvinyl methylether, glycol cellulose, cellulose glycolate, methyl cellulose and the like. The dye or coloring matter used should of course be compatible with the particular adhesive selected.

The binder need not be completely water-soluble, but must be water-dispersible, i.e., sufficiently water sensitive that after a short time immersion in water the binder loses its binding power thus permitting the web to disintegrate. Since the loss of binding power takes longer when the binder is water-dispersible rather than when it is completely water-soluble binder, the use of a dye or coloring agent to serve as a visual dispersibility signal is especially appropriate.

This invention is also applicable to webs in which combinations of water-soluble and water-insoluble binders are employed. One example of such structure may be found in assignees copending application, Ser. No. 9,261 to J. F. Champaigne, Jr. and H. A. Whitehead filed Feb. 6, 1970 and now US. Pat. No. 3,616,797. In that patent the wrapper comprises a non-woven fiber web bonded primarily by a water-soluble adhesive and overprinted with a water-insoluble adhesive, the latter being disposed in a predetermined pattern of spaced segments. In such instances the water-soluble adhesive should comprise the spaced pattern which contains the coloring agent, since it is the eventual dissolution of the water-soluble binder which provides flushability.

It will also be seen that instead of having all the adhesive contain the coloring agent or dye, only certain designated portions may contain it and still serve as the visual signal area. Small spots of the adhesive-dye combination in strategically located areas may be used.

While a carded rayon web is described in the specific example cited above, other fibers including both natural and synthetic may be used in the base web. However, cellulose fibers or fibers of cellulosic derivation are preferred because they are biodegradable. Also, while the fiber lengths in the specific example are 1- 9/16 inch, fiber lengths in the usual staple lengths of k inch to about 3 inches are useful. The longer fibers are, of course, less desirable because they will not disperse as readily.

While a carded web is specified in the examples, other known means of forming the web such as airforrning and drafting of fibrous material may also be employed.

The structure of the absorbent pad itself is not critical as long as it is made up of the usual absorbent materials which break up and disintegrate easily in excess water. Included among these are wood pulp, cotton fibers, absorbent rayon and regenerated cellulose fibers, multiple plies of cellulose wadding and the like or combinations thereof.

While the specific examples described above are directed to sanitary napkins it is understood that the invention is applicable to other absorbent pads such as diapers and the like, and that the entire pad need not be wrapped with the web since in some cases only the body-contacting portion requires a covering web of the nature described.

What is claimed is:

1. In a flushable web comprising a fluid-permeable fibrous web bonded at least in part by a pattern of water-dispersible adhesive, the improvement wherein at least a portion of said adhesive contains a water-activatable flushability indicator, said indicator comprising a water-soluble coloring agent dispersed in said adhesive, said coloring agent being compatible with said adhesive, whereby when said web is immersed in water and as said adhesive is dispersed by said water said coloring agent migrates from said adhesive into said water and adjacent non-bonded portions of said web causing said pattern to substantially disappear.

2. The web of claim 1 in which said adhesive is watersoluble.

3. The web of claim 1, in which said web comprises a non-woven web of staple length fibers.

4. The web of claim 3 wherein the fibers in said web are rayon fibers.

5. The web of claim 1 in which said web is bonded primarily with a water-soluble adhesive and overprinted with a water-insoluble adhesive, and said coloring agent is dispersed in said water-soluble adhesive.

contacting surface covered with a fluid-permeable fibrous web bonded at least in part by a pattern of water-dispersible adhesive, the improvement wherein v at least a portion of said adhesive contains a water-activatable flushability indicator, said indicator comprising a water-soluble coloring agent dispersed in said adhesive, said coloring agent being compatible with said adhesive, whereby when said pad is immersed in water and as said adhesive is dispersed by said water said coloring agent migrates from said adhesive into said water and adjacent non-bonded portions of said web causing said pattern to substantially disappear.

9. The pad of claim 8 in which said web comprises a non-woven web of staple length fibers.

10. The pad ofclaim 8 in which said adhesive binding said web is water-soluble.

1 1. The pad of claim 9 wherein the fibers in said web v are rayon fibers.

12. The pad of claim 8 in which said web is bonded primarily with a water-soluble adhesive and over printed with a water-insoluble adhesive, and said color ing agent is dispersed in said water-soluble adhesive.

13. The pad of claim 12 in which both said adhesives are in the form of spaced adhesive patterns.

14. The pad of claim 8 in which at least a part of said adhesive is selected from the group consisting of polyvinyl alcohol, polyvinyl methylether, glycol cellulose, cellulose glycolate, and methyl cellulose.

15. The pad of claim 8 in which said pad is a sanitary napkin.

16. The pad of claim 8 in which said pad is a diaper.

ilt

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3004895 *Apr 17, 1959Oct 17, 1961Schwartz Samuel MDiaper rash preventative
US3426758 *Oct 10, 1966Feb 11, 1969American Hospital Supply CorpMedical catheter with balloon leakage indicator
US3480016 *Sep 3, 1968Nov 25, 1969Celanese CorpSanitary products
US3554788 *Oct 9, 1968Jan 12, 1971Johnson & JohnsonWater dispersible nonwoven fabric
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3812856 *May 17, 1972May 28, 1974Procter & GambleHydro-dissociative agglomerate tampon
US4022211 *Oct 8, 1975May 10, 1977Kimberly-Clark CorporationWetness indicator for absorbent pads
US4287153 *Nov 30, 1979Sep 1, 1981Towsend Marvin SDisposable article with non-leachable saline water indicator
US6297424Jun 15, 1999Oct 2, 2001Kimberly-Clark Worldwide, Inc.Absorbent articles having wetness indicating graphics providing an interactive training aid
US6307119Jun 15, 1999Oct 23, 2001Kimberly-Clark Worldwide, Inc.Absorbent articles having wetness indicating graphics incorporating a training zone
US6384297Apr 3, 1999May 7, 2002Kimberly-Clark Worldwide, Inc.Peel strip paper, coated with polyvinyl alcohol binder and silicaone release agent; adhesive; baffle blend of polyethylene glycol and acrylic acid-ethylene copolymer; disposable; biodegradable
US6429261May 4, 2000Aug 6, 2002Kimberly-Clark Worldwide, Inc.Copolymer of acrylic acid, acrylates, and sodium 2-acyryl-amido-2-methyl propanesulfonate with ethylene-vinyl acetate copolymer; water solubility changes with ion type and concentration
US6444214May 4, 2000Sep 3, 2002Kimberly-Clark Worldwide, Inc.Ion-sensitive, water-dispersible polymers, a method of making same and items using same
US6530910 *Aug 7, 1998Mar 11, 2003Kimberly-Clark Worldwide, Inc.Flushable release film with combination wiper
US6548592May 4, 2000Apr 15, 2003Kimberly-Clark Worldwide, Inc.Blend of sulfonate ion acrylic acid terpolymer and noncrosslinked ethylene-vinyl acetate copolymer; diapers, sanitary napkins, wipes
US6579570May 4, 2000Jun 17, 2003Kimberly-Clark Worldwide, Inc.Spraying, coating or foaming mixtures of acrylic terpolymers, ethylene-vinyl acetate copolymer binders and wetting agents on natural or synthetic fiber webs to form cleaners or disposable products
US6583722Dec 12, 2000Jun 24, 2003Kimberly-Clark Worldwide, Inc.Wetness signaling device
US6596918Jun 5, 2000Jul 22, 2003Kimberly-Clark Worldwide, Inc.Masking and fading graphics; peripherally disposed adhesive patterns; disposable products
US6599848May 4, 2000Jul 29, 2003Kimberly-Clark Worldwide, Inc.Ion-sensitive, water-dispersible polymers, a method of making same and items using same
US6602955Feb 21, 2002Aug 5, 2003Kimberly-Clark Worldwide, Inc.Water-dispersible or flushable materials, polymers are insoluble in wetting composition comprising ions ofmonovalent salt solutions at a concentration from about 0.3% to 10%, but can be soluble in water or divalent salt solutions
US6603403Dec 12, 2000Aug 5, 2003Kimberly-Clark Worldwide, Inc.Remote, wetness signaling system
US6630558Feb 7, 2002Oct 7, 2003Kimberly-Clark Worldwide, Inc.Ion-sensitive hard water dispersible polymers and applications therefor
US6635797Jul 24, 2001Oct 21, 2003Kimberly-Clark Worldwide, Inc.Absorbent articles having wetness indicating graphics providing an interactive training aid
US6653406May 4, 2000Nov 25, 2003Kimberly Clark Worldwide, Inc.Ion-sensitive, water-dispersible polymers, a method of making same and items using same
US6683143May 4, 2000Jan 27, 2004Kimberly Clark Worldwide, Inc.Copolymer comprising acrylamido- 2-methyl-1-propanesulfonic acid or sodium salt, (meth)acrylic acid, and alkyl acrylate monomers; disposable products; diapers
US6710221Jun 5, 2000Mar 23, 2004Kimberly-Clark Worldwide, Inc.Absorbent articles incorporating color change graphics
US6713414May 4, 2000Mar 30, 2004Kimberly-Clark Worldwide, Inc.Ion-sensitive, water-dispersible polymers, a method of making same and items using same
US6772708Feb 19, 2002Aug 10, 2004The Procter And Gamble CompanyWetness indicator having improved colorant retention
US6814974Jan 28, 2002Nov 9, 2004Kimberly-Clark Worldwide, Inc.The ion-sensitive sulfonate anion modified acrylic acid copolymers
US6815502May 4, 2000Nov 9, 2004Kimberly-Clark Worldwide, Inc.Ion-sensitive, water-dispersable polymers, a method of making same and items using same
US6828014Mar 22, 2001Dec 7, 2004Kimberly-Clark Worldwide, Inc.Water-dispersible, cationic polymers, a method of making same and items using same
US6835678Dec 5, 2001Dec 28, 2004Kimberly-Clark Worldwide, Inc.Fibers with a length of 6-10 mm and a water-soluble binder of sulfonate anion modified acrylic acid terpolymer and a non-crosslinking ethylene-vinyl acetate copolymer
US6855790Mar 29, 2002Feb 15, 2005Kimberly-Clark Worldwide, Inc.Ion-sensitive hard water dispersible polymers and applications therefor
US6897168Mar 22, 2001May 24, 2005Kimberly-Clark Worldwide, Inc.Water-dispersible, cationic polymers, a method of making same and items using same
US6904865Dec 18, 2002Jun 14, 2005The Procter And Gamble CompanyWetness indicator having improved colorant retention and durability
US6908966Mar 22, 2001Jun 21, 2005Kimberly-Clark Worldwide, Inc.A polymer formulation containing a triggerable cationic polymer and a non-crosslinked co-binder polymer dispersed in the triggerable cationic polymer; used as binder for wet wipes
US7070854Mar 22, 2001Jul 4, 2006Kimberly-Clark Worldwide, Inc.Disposable products; containing cationic polymer
US7101612Jul 7, 2001Sep 5, 2006Kimberly Clark Worldwide, Inc.Pre-moistened wipe product
US7159532May 9, 2005Jan 9, 2007The Procter & Gamble CompanyWetness indicator having improved colorant retention and durability
US7276459May 4, 2000Oct 2, 2007Kimberly-Clark Worldwide, Inc.Ion-sensitive, water-dispersible polymers, a method of making same and items using same
US7718844Jun 30, 2004May 18, 2010Kimberly-Clark Worldwide, Inc.Absorbent article having an interior graphic
US7767059Jun 18, 2003Aug 3, 2010Kemira OyjFlushable paper product comprising fibrous substrate having at least one strength region comprising a reacted cationic or reacted nonionic strength agent and at least one dispersibility region; toilet paper; wet strength of at least five percent of dry strength; high wet strength and high dispersibility
US8791317 *Apr 27, 2009Jul 29, 2014Unicharm CorporationAbsorbent article and method of manufacturing absorbent article
US20110144607 *Apr 27, 2009Jun 16, 2011Nahomi SuzukiAbsorbent article and method of manufacturing absorbent article
EP0211524A1 *Jul 7, 1986Feb 25, 1987Willett International LimitedCoding of absorbent materials
WO1983000742A1 *Aug 26, 1981Mar 3, 1983Marvin S TowsendDisposable article with non-leachable saline water indicator
Classifications
U.S. Classification604/361, 604/364, 604/372, 604/368, 604/375
International ClassificationA61F13/42, A61F13/15
Cooperative ClassificationA61F13/15211, A61F13/42
European ClassificationA61F13/15J2