EP1027023A1 - Article absorbant comprenant un adhesif qui perd avec le temps une quantite controlee de son pouvoir adhesif - Google Patents

Article absorbant comprenant un adhesif qui perd avec le temps une quantite controlee de son pouvoir adhesif

Info

Publication number
EP1027023A1
EP1027023A1 EP98957503A EP98957503A EP1027023A1 EP 1027023 A1 EP1027023 A1 EP 1027023A1 EP 98957503 A EP98957503 A EP 98957503A EP 98957503 A EP98957503 A EP 98957503A EP 1027023 A1 EP1027023 A1 EP 1027023A1
Authority
EP
European Patent Office
Prior art keywords
absorbent article
adhesive
strength
grams
folded
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP98957503A
Other languages
German (de)
English (en)
Inventor
Richard George Coe
Eric Patton Weinberger
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Procter and Gamble Co
Original Assignee
Procter and Gamble Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Procter and Gamble Co filed Critical Procter and Gamble Co
Publication of EP1027023A1 publication Critical patent/EP1027023A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/84—Accessories, not otherwise provided for, for absorbent pads
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/15203—Properties of the article, e.g. stiffness or absorbency
    • A61F2013/15284—Properties of the article, e.g. stiffness or absorbency characterized by quantifiable properties
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F13/00—Bandages or dressings; Absorbent pads
    • A61F13/15—Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body; Supporting or fastening means therefor; Tampon applicators
    • A61F13/15203—Properties of the article, e.g. stiffness or absorbency
    • A61F2013/15284—Properties of the article, e.g. stiffness or absorbency characterized by quantifiable properties
    • A61F2013/15569—Adhesivity

Definitions

  • the present invention relates to absorbent articles such as diapers, sanitary napkins, and incontinence products. More particularly, the present invention relates to absorbent articles of the foregoing type that incorporate an adhesive that loses a controlled amount of strength over time.
  • the adhesive can be useful as an aid in processing, packaging, or otherwise in the production and use of such articles.
  • Absorbent articles such as sanitary napkins, pantiliners, disposable diapers, incontinence products, and bandages are designed to absorb and retain liquid and other discharges from the human body and to prevent body and clothing soiling.
  • the Nakanishi, et al. patent discloses a sanitary napkin having a pair of "fixing elements" that extend outward from the lateral edges of an absorbent body. The fixing elements are provided with adhesive portions which are able to be adhered to and separated from other adhesive coated portions on the back side of the sanitary napkin.
  • U.S. Patent 5,472,437 issued to .Akiyama, et al. discloses still another example of folding portions of an absorbent article over other portions thereof.
  • the Akiyama patent discloses a sanitary napkin having side flaps. The flaps each have a flap adhesive fastener and a release portion disposed thereon. The flaps are folded along a folding line so that the release portion covers the adhesive fasteners on the flaps and is separable therefrom.
  • the flaps are provided with pressure sensitive adhesive fasteners thereon that are intended for later use when the absorbent article is worn.
  • U.S. Patent 5,558,663 issued to Weinberger, et al. on September 24, 1996, discloses a sanitary napkin having undergarment covering components that extend laterally outward beyond the side edges of the main body portion of the sanitary napkin.
  • the undergarment covering components may not have a pressure sensitive adhesive fastener thereon.
  • the garment-facing side of the main body portion typically has a pressure sensitive adhesive thereon, which is covered with a sheet of release paper to prevent the adhesive from sticking to surfaces other than the wearer's undergarments prior to use.
  • a pressure sensitive adhesive thereon
  • the undergarment covering components will be folded over the release wrapper.
  • the undergarment covering components In order to fold the undergarment covering components over the sheet of release paper, and have the undergarment covering components stay folded, it is desirable during manufacture to temporarily adhere the undergarment covering components (which in such a case would be devoid of pressure sensitive adhesive fasteners) to the exposed outside surface of the release paper.
  • the adherence of the undergarment covering components to the release paper should satisfy several requirements. First, the adherence should be sufficiently temporary so that the undergarment covering components will unfold or be capable of readily unfolding for use by the consumer. In this regard, it is often only necessary for the adherence to be present for fifteen minutes or less.
  • the absorbent article will move to a place in the manufacturing process where the undergarment covering components are maintained in a folded configuration, such as by placing the absorbent article into individual packages or grouped packages which maintain the undergarment covering components in a folded configuration.
  • the adhesive should release so that the undergarment covering components will automatically unfold when the package is opened, or the undergarment covering components should be capable of being readily separated from the release paper when the release paper is removed.
  • the adherence should not damage either the undergarment covering components or the release paper.
  • Pressure sensitive adhesives described in the patents discussed above would not lose a controlled amount of strength over the desired relatively short time periods of interest. It is typically undesirable for adhesives to lose strength. If current pressure sensitive adhesives do lose a portion of their strength, this would typically not be their shear strength. .Any loss of strength would generally take several weeks to several months to occur, and will often occur only when the adhesives are exposed to extreme temperatures (e.g. temperatures in excess of about 60°C). Further, adding a pressure sensitive adhesive patch and complementary release coating to an absorbent article would add unnecessary expense to the absorbent article over and above the cost of a small spot of adhesive that is actually necessary to hold the undergarment covering components in a folded configuration.
  • fugitive adhesives Temporary adhesives known as "fugitive” adhesives are known. These adhesives have been used most often to create temporary paper-to-paper bonds. When the adhesive bond is broken, such adhesives are no longer tacky and will not adhere to anything. These temporary adhesives have been used primarily for envelopes, labels, and the like. To the applicants' knowledge, "fugitive adhesives are not known in the art for forming a temporary bond on an absorbent article. This is due to the difference in materials used in absorbent articles (which typically include at least some polymeric materials as opposed to only paper), and to the forces which tend to make the folded portions unfold if the folded portions were adequately restrained from doing so.
  • Known fugitive adhesives typically do not form a strong enough initial bond to make them capable of temporarily holding folded portions of absorbent articles in place during a high speed manufacturing process where the folded portions of the absorbent articles could come in contact with other objects in the manufacturing process. Additionally, there are, to applicant's knowledge, no adhesives that can form a relatively strong temporary bond and lose a controlled amount of strength over a selected time period so that the undergarment covering components would be capable of readily unfolding.
  • fugitive adhesives generally have a peel strength component and a shear strength component. Most conventional fugitive adhesives do not lose strength, either in peel or shear. Conventional fugitive adhesives operate by having a low peel strength. In order to securely hold the folded portions of an absorbent article, an adhesive must have a higher initial shear strength. To release the folded portions, both shear and peel strengths, and in particular, shear strength, must be greatly diminished from the initial strengths.
  • fugitive adhesives lose strength, they frequently require active heating, radiation, or the like to reduce their strength, all of which are impractical for use with absorbent articles. Others are solvent cross-linked materials that are not suitable for use in absorbent articles. Further, water-based fugitive adhesives used in labeling and envelope applications have relatively low bond strengths when wet (that is, when applied). This may be sufficient for use in bonding paper to paper. It is not, however, sufficient for bonding polymeric to paper materials as is necessary in the applications described herein.
  • an object of the present invention to provide an absorbent article that has portions, such as undergarment covering components, that can be folded over another portion of the absorbent article, and maintained in a folded configuration for a finite period of time during processing and/or packaging.
  • the present invention relates to absorbent articles such as diapers, sanitary napkins, and incontinence products. More particularly, the present invention relates to absorbent articles of the foregoing type that incorporate an adhesive that loses a controlled amount of strength over time (or "temporary strength adhesive").
  • the adhesive can be useful as an aid in processing, packaging, or otherwise in the production and use of such articles.
  • the adhesive that loses a controlled amount of strength over time is used on an absorbent article comprising a main body portion and at least one side wrapping element (or "undergarment covering component") extending laterally outward from the main body portion.
  • the main body portion has a body-facing side, a garment-facing side, and an absorbent core positioned between its body-facing side and its garment-facing side.
  • the garment-facing side of the main body portion preferably has an adhesive fastener thereon which is covered by a cover strip.
  • at least one of the side wrapping elements is temporarily adhered to the cover strip with the temporary strength adhesive.
  • the temporary strength adhesive forms an initially relatively strong bond, and then loses a controlled amount of strength over time so that the side wrapping elements are readily separable from the cover strip on garment-facing side of the main body portion for use.
  • the temporary strength adhesive can be used to hold the side panels or flaps of a disposable diaper over the chassis assembly (or main body portion) of the diaper for packaging. Numerous other uses of the present invention are also possible.
  • the present invention is also directed to a method of temporarily joining a first component to a second component during a process of making or packaging an absorbent article.
  • the invention provides a method of folding and retaining a side panel during a process of making or packaging a disposable absorbent article.
  • side panel may include a side wrapping element as described above, a flap, or the portions of a disposable diaper that extend laterally from the end regions of the diaper to form part of a waistband.
  • the method preferably comprises the steps of:
  • an absorbent article comprising a main body portion having a body-facing side, a garment side, an absorbent component between the body-facing side and the garment side, a principal longitudinal centerline, a principal transverse centerline, and two spaced apart longitudinal edges, and a side panel joined to the main body portion of the absorbent article and extending laterally outward beyond at least one of the longitudinal edges;
  • Fig. 1 is a top plan view of a preferred embodiment of a sanitary napkin that uses the present invention.
  • Fig. 2 is an end view of the sanitary napkin shown in Fig. 1 with one of the undergarment covering components folded to overlie the garment-facing side of the main body portion, which is temporarily retained thereon by the adhesive described herein.
  • Fig. 3 is a bottom plan view of the sanitary napkin shown in Figs. 1 and 2 with both of the undergarment covering components folded to overlie the garment- facing side of the main body portion.
  • FIG. 4 is a schematic plan view of the garment-facing side of a diaper that can have its side panels temporarily retained using a temporary strength adhesive according to the present invention.
  • the present invention relates to absorbent articles such as diapers, sanitary napkins, and incontinence products. More particularly, the present invention relates to absorbent articles of the foregoing type that incorporate an adhesive that loses a controlled amount of strength over time (or "temporary strength adhesive").
  • the adhesive can be useful as an aid in processing, packaging, or otherwise in the production and use of such articles.
  • FIGS. 1-3 show one preferred embodiment of a disposable absorbent article that uses the present invention, sanitary napkin 20.
  • the sanitary napkin has a pair of side wrapping elements.
  • the sanitary napkin can be constructed generally in accordance with, or can comprise any of the features described in U.S. Patent 5,558,663 issued to Weinberger, et al. and U.S. patent application Serial No. 08/493,515 entitled "Absorbent Articles Having Undergarment Covering Components Especially Suited For Folding Around The Edges of an Undergarment” filed on June 22, 1995, in the name of Redwine, et al. (PCT Publication No. WO 97/00655 published on January 9, 1997).
  • the sanitary napkin 20, or other absorbent article can be in any suitable configuration, and is not limited to absorbent articles of the type or having the specific configuration shown in the drawings.
  • the sanitary napkin 20 has two surfaces, a liquid pervious body-contacting surface or "body surface” 20 A and a liquid impervious garment surface 20B.
  • the sanitary napkin 20 is shown in FIG. 1 as viewed from its body surface 20A.
  • the body surface 20A is intended to be worn adjacent to the body of the wearer.
  • the garment surface 20B of the sanitary napkin 20 (shown in FIG. 2) is on the opposite side and is intended to be placed adjacent to the wearer's undergarments when the sanitary napkin 20 is worn.
  • the sanitary napkin 20 has two centerlines, a longitudinal centerline L and a transverse centerline T.
  • transverse or “lateral” used herein, are interchangeable, and refer to a line, axis or direction which lies within the plane of the sanitary napkin 20 that is generally perpendicular to the longitudinal direction.
  • FIG. 1 shows that the main body portion 21 of the sanitary napkin 20 comprises the portion of the sanitary napkin without the side wrapping elements.
  • the main body portion 21 has two spaced apart longitudinal edges 22, two spaced apart transverse or end edges (or “ends") 24, which together form the periphery 26 of the main body portion.
  • the main body portion also has two end regions, which are designated first end region 28 and second end region 30.
  • a central region 32 is disposed between the end regions 28 and 30.
  • the end regions 28 and 30 extend outwardly from the edges of the central region 32 about 1/8 to about 1/3 of the length of the main body portion.
  • FIG. 2 shows the individual components of the main body portion 21 of the sanitary napkin 20.
  • the main body portion 21 of the sanitary napkin preferably comprises at least three primary components. These include a liquid pervious topsheet 38, a liquid impervious backsheet 40, and an absorbent core 42 positioned between the topsheet 38 and the backsheet 40.
  • the liquid pervious topsheet, the liquid impervious backsheet, and the absorbent core can comprise any materials described as being suitable for these components in the patents incorporated by reference herein.
  • the topsheet 38 and backsheet 40 will comprise a polymeric material, which may be a fibrous material, or a film.
  • a particularly preferred apertured film for use as the topsheet is described in U.S. Patent 4,342,314 issued to Radel, et al. on August 3, 1982, and U.S. Patent 4,463,045 issued to Ahr, et al. on July 31, 1984.
  • the backsheet 40 preferably comprises a polyethylene film.
  • the garment surface 20B of the sanitary napkin 20 may include, and preferably does include, fasteners for attaching the sanitary napkin to the wearer's undergarment.
  • Figure 3 shows the central pad fastener 44 which is adapted to secure the portion of the sanitary napkin underlying the main body portion 21 to the crotch region of an undergarment. Any types of fasteners known in the art can be used. Fasteners comprising adhesives have been found to work well for this purpose, with pressure-sensitive adhesives being preferred.
  • release paper 46 refers to any material that is suitable for serving as a removable cover for the adhesive fastener.
  • release paper is, therefore, not limited to strips of paper, but may also comprise films, and the like.
  • the release paper 46 has an inside surface 46A that is placed adjacent to the central pad fastener 44, and an exposed outside surface 46B. Suitable release papers are described in the U.S. Patent 4,917,697.
  • the sanitary napkin 20 comprises a pair of undergarment covering components (or “side wrapping elements") 50 that extend laterally outward beyond the longitudinal side edges 22 of the main body portion 21 from their proximal edges 52 to their distal edges 54.
  • the side wrapping elements 50 extend outward at least from the central region 32 of the main body portion 21.
  • the side wrapping elements 50 preferably automatically wrap around the side edges of the wearer's undergarments to keep the undergarments free from being soiled with body fluids.
  • the side wrapping elements 50 comprise an extension of the topsheet 38 and backsheet 40.
  • the body facing surface of the side wrapping elements 50 will comprise an apertured polymeric film
  • the undergarment facing side will comprise a polyethylene film.
  • the side wrapping elements 50 can, as discussed above, be provided with features described in U.S. Patent 5,558,663 issued to Weinberger, et al. and U.S. patent application Serial No. 08/493,515 filed on June 22, 1995 (PCT Publication No. WO 97/00655 published in the name of Redwine, et al. on January 9, 1997).
  • the side wrapping elements 50 comprise a pair of spaced apart zones of extensibility 56 and a stiffened intermediate region 58 between the zones of extensibility.
  • the side wrapping elements 50 are preferably also provided with a hinge 68.
  • the hinge 68 is preferably formed by forming a strainable network region in the desired regions of the side wrapping elements 50. Suitable methods of forming a strainable network region into a material are described in U.S. Patent 5,518,801 issued to Chappell, et al. on May 21, 1996.
  • the side wrapping elements 50 In the manufacture of the sanitary napkin 20 shown in the drawings, it is desirable to fold the side wrapping elements 50 over the garment-facing side 20B of the main body portion 21. This avoids damage to the side wrapping elements 50 during processing and forms a smaller, more conveniently packaged article. In order to fold the side wrapping elements 50 over the garment-facing side of the main body portion, and have the side wrapping elements 50 stay folded, it is desirable to adhere the side wrapping elements 50 to the exposed outside surface 46B of the release paper 46. However, it may only be necessary for the adherence to be present for a relatively short period of time (e.g., fifteen minutes or less).
  • the absorbent article will move to a place in the manufacturing process where the side wrapping elements 50 are maintained in a folded configuration, such as by placing the absorbent article into individual packages or grouped packages which maintain the side wrapping elements 50 in a folded configuration.
  • the side wrapping elements 50 are temporarily adhered to the outside surface 46B of the release paper 46 by an adhesive, temporary strength adhesive 70 that loses a controlled amount of strength over time.
  • the adherence of the side wrapping elements 50 to the release paper 46 should satisfy several requirements. First, the adherence should be temporary so that the side wrapping elements 50 will readily unfold or be capable of readily unfolding for use by the consumer. Second, the adhesive should release so that the undergarment covering components automatically unfold when the package is opened, or they should be capable of being readily separated from the release paper when the release paper is removed. Third, when the side wrapping elements 50 are unfolded, the adherence should not be so strong that the unfolding of the side wrapping elements damages the side wrapping elements 50 or the release paper 46.
  • the bond formed by the temporary strength adhesive 70 is measured in terms of shear strength and peel strength in two directions. These are a direction parallel to the fold line where the side wrapping elements 50 are folded, and a direction perpendicular to this fold line.
  • these directions correspond to the direction that the absorbent article moves through the manufacturing process (the "machine direction” or MD) and the direction perpendicular to the machine direction, the cross-machine direction (or CD), respectively. That is, the machine direction runs in the direction of the longitudinal centerline L of the sanitary napkin, and the cross-machine direction is oriented in the direction of the transverse centerline, T.
  • MD machine direction
  • CD cross-machine direction
  • these directions may be reversed so the sanitary napkin is running in the direction of the transverse centerline. If this is the case, the MD and CD adhesive strength values specified herein will be reversed.
  • the adhesive When used to secure the side wrapping elements 50 to the release paper 46 on the garment-facing side 20B of a sanitary napkin 20 as shown in the drawings, the adhesive preferably has an initial machine direction (MD) shear strength of greater than or equal to about 200 grams, more preferably greater than or equal to about 275 grams, and an initial machine direction peel strength of greater than or equal to about 15 grams, more preferably greater than or equal to about 25 grams.
  • MD machine direction
  • CD cross-machine direction
  • the initial adhesive strength in the cross-machine direction is preferably greater in this embodiment because that is the direction that most of the forces are acting that would tend to unfold the side wrapping elements 50 in the absence of the temporary strength adhesive.
  • the term "initial”, as used herein, refers to the point in time at which the temporary strength adhesive is first used to secure the two components or portions of the absorbent article together.
  • initial bond strengths are needed for up to about 5-10 minutes so that the side wrapping elements 50 can be held in place if the manufacturing line should undergo a temporary shut down.
  • the initial bond strengths needed will, of course, be somewhat dependent on the nature of the materials that are to be temporarily secured, as well as any forces that would tend to unfold the side wrapping elements 50 in the absence of the temporary strength adhesive.
  • the initial bond strength should decay to a second lower bond strength by the time the absorbent article is used by the consumer.
  • the time at which the second lower bond strength occurs may, thus, be referred to as the final bond strength (or the "delivered strength", or as the "consumer bond strength", or simply “consumer strength”).
  • the products will generally take at least 14 days, and more often over 20 days to reach the consumer.
  • a shorter period such as after about five days from the formation of the "initial” bond, can be used. This latter bond strength may, therefore, be referred to as a "five day (or "5 day”) bond strength".
  • the five day bond strength should be sufficiently low that the side wrapping elements can be unadhered and deployed without tearing the release paper or the side wrapping elements.
  • the adhesive should meet these needs throughout the typical temperature/humidity conditions encountered during shipment and storage of the sanitary napkin.
  • both the consumer bond strength and the five day bond strength preferably comprise a machine direction shear strength of less than or equal to 100 grams, more preferably less than or equal to about 65 grams, and a machine direction peel strength of less than or equal to about 25 grams, more preferably less than or equal to about 15 grams.
  • the machine direction consumer and five day bond strength are of interest because the release paper 46 is removed by peeling it away in the longitudinal direction.
  • the initial bond strength will preferably decay completely so that the value of all the specified components of the bond strength (in both MD and CD) will be zero.
  • the lower consumer or five day bond strengths specified above are preferably maintained at the elevated temperatures associated with shipping and storage (e.g., about 140°F (about 60°C)). (Bond strengths will often increase when the adhesive becomes hotter due to a wetting (that is spreading and penetrating) of the adhesive.)
  • One suitable adhesive having these strength characteristics is Fuller HL 1629X obtained from H. B. Fuller Company of St. Paul, MN.
  • the Fuller adhesive was developed at the direction of The Procter & Gamble Company for the purposes described herein. Without wishing to be bound by any particular theory, it is believed that the temporary strength adhesive can operate in at least one of the following manners.
  • the temporary strength adhesive may utilize a delayed crystallization which causes the molecules within the adhesive to come together over a relatively short time period. This causes the adhesive to dry out and take a more solid form. This results in the adhesive losing most or all of its bonding capability.
  • a "poison" can be added to the adhesive to cause the adhesive to lose most or all of its bonding capability.
  • the poison can be used to disrupt the adhesion properties of the adhesive (that is, the stickiness) over time, such as by interfering with the chemical bonding (hydrogen bonding, covalent bonding, or Van der Waals forces) or physical bonding between the adhesive and the surfaces to which it is temporarily attached.
  • the decay of the adhesive properties of the temporary strength adhesive differs from any decay in adhesive properties that might occur over time in known adhesives.
  • the temporary strength adhesive can have relatively high initial bond strengths, such as a machine direction shear strength of about 275 grams, which can be pre-established or designed to decay to less than or equal to about 65 grams (a decay or loss of about 76% of its original strength).
  • Known adhesives do not have such a dramatic reduction in bond strength, particularly shear strength, over the time periods specified herein. In known adhesives, any decay of strength is generally undesirable, and is therefore, not pre-established.
  • the temporary strength adhesive used herein also differs from known types of fugitive adhesives. Most conventional fugitive adhesives do not lose strength, either in peel or shear. Conventional fugitive adhesives operate by having a low peel strength. In order to hold the folded portions of an absorbent article, an adhesive must have a higher initial shear strength. To release the folded portions, both shear and peel strengths, and in particular, shear strength, must be greatly diminished from the initial strengths.
  • fugitive adhesives lose strength, they frequently require active heating, radiation, or the like to reduce the strength, all of which are impractical for use with absorbent articles.
  • Others are solvent cross-linked materials that are not suitable for use in absorbent articles.
  • water-based adhesives used in fugitive adhesives in labeling and envelope applications have relatively low bond strengths when wet (that is, when applied). This may be sufficient for use in bonding paper to paper. It is not, however, sufficient for bonding polymeric to paper materials as is necessary in the applications described herein.
  • the temporary strength adhesives described herein may have a decay in any amount that is suitable for the particular purpose. Suitable decays might involve a loss of greater than or equal to about any of the following amounts of its initial strength (or any component of its initial strength, such as shear strength and/or peel strength): 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100% over the time periods described herein.
  • a sanitary napkin in the form of FIG. 1 will generally be traveling on a conveyor in the machine direction with its longitudinal centerline, L, oriented in the machine direction.
  • the release paper 46 will have already been applied over the central pad fastener 44.
  • the temporary strength adhesive 70 can be applied to the main body portion
  • the temporary strength adhesive 70 is preferably applied to the outwardly facing side 46B of the release paper 46.
  • the temporary strength adhesive 70 can be applied in any shape, and in any amount suitable for temporarily adhering the side wrapping elements 50 to the release paper 46.
  • the sanitary napkin 20 will be traveling rapidly along on the conveyor, so the application of a circular spot of adhesive may take a tear drop shape (or in the shape of an oval with a "tail" thereon).
  • the amount of temporary strength adhesive 70 applied to hold each side wrapping element 50 is preferably in the range of between about 0.002 grams to about 0.015 grams, and more preferably is in the range of between about 0.005 grams to about 0.010 grams. This will result in adhesive covering an area about 2-5 mm wide and about 6-12 mm long.
  • the temporary strength adhesive 70 is applied so that one spot of adhesive will lie under each of the side wrapping elements 50 when they are folded over the release paper 46.
  • the side wrapping elements 50 are then folded over the release paper 46.
  • Any conventional folding means such as folding plows, can be used for this purpose.
  • Each of the folded side wrapping elements 50 then passes between a compression mechanism, such as a pair of belts, rolls, or other means of compression.
  • the compression mechanism applies enough pressure on the folded side wrapping elements 50 to ensure that the temporary strength adhesive 70 holds the same in a folded configuration, but not enough pressure to undesirably compress the absorbent core 42 of the sanitary napkin 20.
  • the sanitary napkins are tri-folded about transversely oriented axes so that one end region, such as the first end region 28, of the sanitary napkin is folded over the body-facing side of main body portion, and the other end region 30 is folded over the first end region 28.
  • Suitable ways of folding sanitary napkins and individual packages for the same are described in U.S. Patent 4,556,146 issued to Swanson, et al.; U.S. Patent 5,181,610 issued to Quick; U.S. Patent 5,462,166 issued to Minton, et al.; and U.S. Patent 5,484,636 issued to Berg, et al.
  • the sanitary napkin 20 can have a separate wrapper (from the release paper 46).
  • the wrapper that is used to form the package for the sanitary napkin can be adhesively joined to a portion of the release paper 46.
  • the side wrapping elements 50 will be temporarily adhered to the release paper 46 as described above.
  • the wrapper can then be joined to those portions of the release paper 46 that are not covered by the side wrapping elements 50.
  • the sanitary napkin 20, release paper 46, and wrapper can then be tri-folded as a unit.
  • panty fastening adhesive 44 will typically be configured so that the side wrapping elements 50 do not contact the panty fastening adhesive 44.
  • the side wrapping elements 50 can then be folded directly over and adhered to the backsheet 40 of the sanitary napkin 20 with the temporary strength adhesive 70.
  • the releasable wrapper 46 can then be applied over the folded side wrapping elements 50 to cover the exposed panty fastening adhesive 44.
  • the sanitary napkin 20 and the release paper 46 can then be tri-folded as a unit to form the package.
  • the sanitary napkin 20 of the present invention is used by opening any individual package and removing the sanitary napkin. Ideally, if the temporary strength adhesive bond strength is low enough, the side wrapping elements 50 will automatically unfold. If the temporary strength adhesive retains some strength, the side wrapping elements 50 can be unfolded by the user by peeling off the release paper 46 to unfold the side wrapping elements 50. The user will then place the sanitary napkin 20 in her panties so that the adhesive (or other fastener) 44 contacts the panty and maintains the sanitary napkin in position within the panty during use. The side wrapping elements 50 automatically wrap around the sides of the wearer's panties by the simple action of the wearer pulling up her panties.
  • the use of the temporary strength adhesive 70 provides a number of advantages. These include, but are not limited to the following. First, the temporary strength adhesive 70 provides a mechanism for holding the side wrapping elements 50 in the desired position for packaging when no separate adhesive fastener is placed on the side wrapping elements 50. Second, the use of a temporary strength adhesive 70 requires fewer steps, and is believed to be less expensive than utilizing a pressure sensitive adhesive fastener on the side wrapping elements in conjunction with a mating release coating for the pressure sensitive adhesive.
  • the amount of temporary strength adhesive 70 used need only cover an area of about 20 mm- * - * to about 30 mm-2, whereas typical pressure sensitive adhesives used on conventional sanitary napkin flaps to secure the flaps in place may range in size from patches about 15 mm x 30 mm to about 15 mm x 60 mm (or about 450 mm-2 to about 900 mm-2). Further, the temporary strength adhesive 70 does not require applying a releasably bondable material to the underlying surface or release coating the underlying surface.
  • the use of the temporary strength adhesive 70 differs from prior releasable adhesive systems in a number of respects. These include, but are not limited to, the following. As discussed in the preceding paragraph, there is no need for the underlying surface to be releasable — the release mechanism is contained entirely within the temporary strength adhesive. In addition, after the side wrapping elements 50 unfold, the temporary strength adhesive 70 need not be, and preferably is not tacky as are pressure sensitive adhesives. As a result, there is no potential problem with the temporary strength adhesive 70 undesirably sticking to a wearer's skin.
  • the temporary strength adhesive 70- used in the present invention differs from the fugitive adhesives used in envelopes (and the like) in that it is substantially stronger in initial strength than that used to merely hold two sheets of paper (as opposed to plastic to paper) together.
  • sheets of paper bonded with known types of fugitive adhesive are not subject to significant forces acting to separate them during production as are the portions of the absorbent article in the present invention.
  • the sanitary napkin 20 can be provided with side flaps.
  • the flaps can be in any suitable configuration. Suitable flaps are described in U.S. Patent No.
  • FIG. 4 shows one preferred embodiment of a diaper that can have its side panels maintained in a folded condition using the temporary strength adhesive described herein.
  • the diaper 520 shown in FIG. 4 has a generally "T-shape".
  • the diaper 520 comprises a chassis assembly 522 that preferably comprises a liquid pervious topsheet 524, a liquid impervious backsheet 526 joined with the topsheet 524, an absorbent core 528 positioned between the topsheet 524 and the backsheet 526.
  • the diaper further comprises extensible leg cuffs 530 each comprising a leg flap panel 531 and one or more elastic members, and elastic strands 554, operatively joined with the leg flap panel 531.
  • the diaper 520 preferably comprises an extensible back waist feature 532 comprising a central waistband panel 534, a pair of side panels 536, and a hip panel 538.
  • the diaper 520 also comprises a closure system for fastening the diaper on the wearer preferably comprising at least a pair of tape tabs 540 and a landing member preferably comprising a reinforcing strip 541; and an extensible front waist feature 542 comprising a front waist panel 543.
  • the side panels 536 of the back waist feature preferably comprise a structural elastic-like film web.
  • the side panels 536 are preferably folded inward toward the longitudinal centerline L over the topsheet 524 in the direction of the arrows.
  • the present invention can involve the use of temporary strength adhesives in many different contexts for temporarily securing one portion or element to another portion or element of an absorbent article. These include, but are not limited to, temporarily securing such portions: in an absorbent article, in a method of making an absorbent article, and/or in a package for an absorbent article.
  • the elements of the absorbent article that are temporarily secured may comprise separate components of the absorbent article, or a component of the absorbent article and a component of another article, such as a package for the absorbent article.
  • the elements of the absorbent article that are temporarily secured can be separate portions of a single component of the absorbent article.
  • the present invention may be described in terms of temporarily securing a "first portion" of an absorbent article to a "second portion".
  • first portion could be the side wrapping elements
  • second portion could be the release paper.
  • Another non-limiting example of a use for the temporary strength adhesive is in the interior of an absorbent article for decoupling of various components of the absorbent article.
  • some types of absorbent articles are designed to be expandable. These include the absorbent articles described in U.S. Patent 5,558,656 entitled “Sanitary Napkin Having an Internal Shaping Component” issued to Bergman on September 24, 1996 and U.S. Patent 5,591,148 entitled “Sanitary Napkin Having an Independently Displaceable Central Core Segment” issued to McFall, et al. on January 7, 1997.
  • the temporary strength adhesive could be used to hold the components of the absorbent article relatively flat for packaging, then the temporary strength adhesive could lose strength and allow the absorbent article to expand for use.
  • Constant Rate of Elongation Tensile Tester such as the EME 599 tensile testing machine obtained from EME, Inc., P.O. Box 187, Newbury, OH, or an Instron Model 1122 tensile testing machine available from the Instron Engineering Corporation of Canton, Mass. Steps
  • the dimensions of the sample should be great enough that when the trimmed sample is oriented in the tensile testing machine in the direction desired to be tested, it will span the one inch (2.54 cm) gauge length between the jaws of the tensile testing machine.
  • the second component at one end of the trimmed sample (e.g., the release paper) so the first component (e.g., the side wrapping element) extends outward beyond the second component (e.g., the release paper) at that end to provide another extending end for gripping in the tensile testing machine.
  • the sample should be cut so that it is long enough in the dimension that will be tested to allow an extension of the first component or portion and the second component or portion beyond the ends of the temporary strength adhesive on the same side (when viewing the sample in plan view) of the temporary strength adhesive to be separated, folded back (as described below), and fit between the jaws of the tensile testing machine.

Abstract

Cette invention concerne des articles absorbants tels que des couches, des serviettes hygiéniques, des produits d'incontinence et autres qui comprennent un adhésif perdant avec le temps une quantité contrôlée de son pouvoir adhésif. L'adhésif peut être appliqué en tant qu'auxiliaire dans le traitement, le conditionnement ou à un autre niveau dans le processus de production et lors de l'utilisation de ces articles.
EP98957503A 1997-10-31 1998-11-02 Article absorbant comprenant un adhesif qui perd avec le temps une quantite controlee de son pouvoir adhesif Withdrawn EP1027023A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US96196097A 1997-10-31 1997-10-31
US961960 1997-10-31
PCT/US1998/023273 WO1999022687A1 (fr) 1997-10-31 1998-11-02 Article absorbant comprenant un adhesif qui perd avec le temps une quantite controlee de son pouvoir adhesif

Publications (1)

Publication Number Publication Date
EP1027023A1 true EP1027023A1 (fr) 2000-08-16

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP98957503A Withdrawn EP1027023A1 (fr) 1997-10-31 1998-11-02 Article absorbant comprenant un adhesif qui perd avec le temps une quantite controlee de son pouvoir adhesif

Country Status (8)

Country Link
EP (1) EP1027023A1 (fr)
JP (1) JP2001521783A (fr)
KR (1) KR20010031631A (fr)
CN (1) CN1274274A (fr)
AU (1) AU728525B2 (fr)
BR (1) BR9815275A (fr)
CA (1) CA2306135A1 (fr)
WO (1) WO1999022687A1 (fr)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6572600B1 (en) 2000-02-15 2003-06-03 The Procter & Gamble Company Disposable article with deactivatable adhesive
DE102004021353A1 (de) 2004-04-23 2005-11-10 Paul Hartmann Ag Absorbierender Inkontinenzartikel
JP6074283B2 (ja) * 2013-02-06 2017-02-01 ユニ・チャーム株式会社 吸収性物品

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5256717A (en) * 1990-12-19 1993-10-26 National Starch And Chemical Investment Holding Corporation Hot melt adhesives useful in temporary bonding operations
FR2716368B1 (fr) * 1994-02-22 1996-03-29 Kaysersberg Sa Article d'hygiène féminine préplié.
JP2899795B2 (ja) * 1996-02-08 1999-06-02 充加 貫名 多層生理用品及びその製造方法並びに多層生理用品用複合吸収シート

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9922687A1 *

Also Published As

Publication number Publication date
AU1374799A (en) 1999-05-24
CN1274274A (zh) 2000-11-22
JP2001521783A (ja) 2001-11-13
AU728525B2 (en) 2001-01-11
KR20010031631A (ko) 2001-04-16
WO1999022687A1 (fr) 1999-05-14
CA2306135A1 (fr) 1999-05-14
BR9815275A (pt) 2001-10-09

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