WO2013086320A1

WO2013086320A1 - Laminated adhesive tape

Info

Publication number: WO2013086320A1
Application number: PCT/US2012/068447
Authority: WO
Inventors: Tomomi Ito; Yasuhiro Kono
Original assignee: 3M Innovative Properties Company
Priority date: 2011-12-07
Filing date: 2012-12-07
Publication date: 2013-06-13
Also published as: JP2013118923A

Abstract

An extendable laminated adhesive tape including a first tape piece provided with a free end on one of two ends thereof and a first adhesive end on the other end thereof and having a first adhesive part adjacent to the first adhesive end; a second tape piece provided with a first folded-back portion on one of two ends thereof and a second adhesive end on the other end thereof, the first adhesive part and the first folded-back portion being bonded together; and a third tape piece provided with a second folded-back portion on one of two ends thereof and a third adhesive end on the other end thereof, the second adhesive end and the second folded-back portion being bonded together, and the first adhesive end and at least a part of the third adhesive end being bonded together.

Description

LAMINATED ADHESIVE TAPE

FIELD OF THE INVENTION

The present invention relates to an extendable laminated adhesive tape.

BACKGROUND OF THE INVENTION

Disposable diapers, sanitary pads, incontinence pads, and other disposable articles are equipped with a tape for disposal allowing the article to be rolled into a small ball or folded up and discarded. Such tape has a structure in which one or a plurality of pieces of tape are folded up, and is drawn out and applied to the compactly folded-up disposable article, fastening the same in place and thereby preventing the disposable article from returning to the original shape (see, for example, U.S. Patent No. 5182156, Specification; Unexamined Japanese Patent Application Publication No. HI 0-85254; PCT Publication WO 01/13842; Unexamined Japanese Patent Application Publication No. 2003-290276; Unexamined Japanese Patent Application Publication No. 2004-298459; and Unexamined Japanese Patent Application Publication No. 2005-112977).

It is necessary that such disposal tape have adhesive strength sufficient to prevent the folded tape from coming open while the disposable article is being used, and to maintain the shape of the rolled-up or folded-up disposable article after use. It is also demanded that the disposal tape be easily extended without peeling off from the disposable article, as well as that the adhesive surface of the tape not be exposed on the outer surface of the disposable article when the tape has been extended. No disposal tape offering all these required properties has yet been provided, and further development is awaited.

SUMMARY

The present invention relates to an extendable laminated adhesive tape including: a first tape piece having a free end on one of two ends thereof and a first adhesive end on the other end thereof and having a first adhesive part adjacent to the first adhesive end; a second tape piece provided with a first folded-back portion on one of two ends thereof and a second adhesive end on the other end thereof, the first adhesive part and the first folded-back portion being bonded together; and a third tape piece provided with a second folded-back portion on one of two ends thereof and a third adhesive end on the other end thereof, the second adhesive end and the second folded-back portion being bonded together, and the first adhesive end and at least a part of the third adhesive end being bonded together, wherein the first tape piece, second tape piece, and third tape piece are laminated in this order, an area of the first adhesive end of the extendable laminated adhesive tape constitutes from 3 to 25% of the first tape piece as a whole, and a 180° peel force of the laminated adhesive tape being from 1 to 10 mJ.

The present invention also relates to a disposable article provided with the abovementioned laminated adhesive tape. When applied to a disposable article, the laminated adhesive tape according to the present invention prevents the folded tape from coming open while the disposable article is being used, and maintains the shape of the rolled-up or folded-up disposable article after use. The laminated adhesive tape can also easily be extended without peeling off from the disposable article when the laminated adhesive tape is extended.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional schematic view of a laminated adhesive tape according to an embodiment of the present invention in a folded-up state.

FIG. 2 is a cross-sectional view of the laminated adhesive tape shown in FIG. 1 in an extended state.

FIG. 3 is a cross-sectional schematic view of a laminated adhesive tape according to another embodiment of the present invention in a folded-up state.

FIG. 4 is a cross-sectional view of the laminated adhesive tape shown in FIG. 3 in an extended state.

FIG. 5 is a schematic view of a method of measuring the 180° peel force of a laminated adhesive tape.

FIGS. 6a - e are schematic views of changes in a laminated adhesive tape when the laminated adhesive tape is extended in the perpendicular direction.

FIGS. 7a - d are schematic views of changes in a laminated adhesive tape when the laminated adhesive tape is extended in the horizontal direction.

FIG. 8 is a schematic view of a method of manufacturing a laminated adhesive tape.

FIG. 9 is a perspective view of a laminated adhesive tape attached to a disposable diaper.

FIG. 10 is a perspective view of a disposable diaper after having been rolled up using a laminated adhesive tape.

DETAILED DESCRIPTION

Embodiments according to the present invention are described in detail below with reference to the drawings, but the laminated adhesive tape according to the present invention is not limited to the embodiments set forth below. In the following descriptions, identical or similar parts are assigned the same reference number, and redundant descriptions are omitted.

FIG. 1 is a cross-sectional view of a laminated adhesive tape 100 according to an embodiment of the present invention in a folded-up state, and FIG. 2 is a cross-sectional view of the laminated adhesive tape 100 shown in FIG. 1 in an extended state. In FIGS. 1 and 2, the laminated adhesive tape 100 is folded in a Z-shape, and is formed from a first tape piece 1, a second tape piece 2, and a third tape piece 3.

In one aspect, the laminated adhesive tape 100 can be configured to have a total length (L) of from 30 to 70 mm in a folded state. If the total length (L) is less than 30 mm, when the laminated adhesive tape 100 is used as a disposal tape for a diaper which is rolled into a ball using the extended laminated adhesive tape 100 and discarded, the length of the laminated adhesive tape 100 may be insufficient, making it difficult to maintain the diaper in a rolled-up state. On the other hand, if the length is greater than 70 mm, the laminated adhesive tape itself may be too long, impeding peeling or extension; or a printed pattern or the like provided on the surface of the diaper may be blocked from view by the application of such a laminated adhesive tape 100.

From the viewpoint of ease of extending the laminated adhesive tape 100 and dispersing the force generated when the laminated adhesive tape 100 is extended, the respective lengths of the first tape piece 1, second tape piece 2, and third tape piece 3 of the laminated adhesive tape 100, taking the total length (L) of the laminated adhesive tape 100 in the folded state as 1, are preferably from 0.7 to 0.9 for the first tape piece, from 0.9 to 2.3 for the second tape piece, and from 0.8 to 1.3 for the third tape piece.

From the viewpoint of ease of extending the laminated adhesive tape 100, the width (W) of the laminated adhesive tape 100 is preferably in a range from 8 to 20 mm. The first tape piece 1 , second tape piece 2, and third tape piece 3 may all have the same width, or may each have different widths.

There is no particular limitation upon the shape of the first tape piece 1 , the second tape piece 2, and the third tape piece 3. The shape of the first tape piece 1 and the third tape piece 3 may be a rectangle, ellipsoid, circle, parallelogram, or the like, but a rectangular shape is preferable from the perspective of productivity. Examples of the shape of the second tape piece 2, apart from a rectangle, ellipsoid, circle, or parallelogram, include perforated, wavy, crimped, latticed, and the like; but a rectangular shape is preferable from the perspective of productivity.

There is no particular limitation upon the material used for the first tape piece 1, the second tape piece 2, and the third tape piece 3; but polypropylene or another polymeric film with a stable bulk, an elastic or stretchable film, foam, sponge, paper, or a nonwoven fabric is preferable. In one aspect, as described hereafter, the material may be a material whose surface has been pre -treated with a low adhesive substance such as a silicone compound.

The first tape piece 1 is provided with a free end 1 1 on one of two ends thereof and a first adhesive end 12 on the other end thereof and has a first adhesive part 13 adjacent to the first adhesive end 12. The first tape piece is adhered to the second tape piece (that is, is weakly bonded) at a part 14 separate from the free end 1 1, the first adhesive end 12, and the first adhesive part 13. There is no particular limitation upon the method by which the first tape piece 1 and the second tape piece 2 are adhered; any of bonding, pasting, supersonic welding, or fusing performed during the manufacturing of the laminated adhesive tape 100 are acceptable as long as the first tape piece 1 and second tape piece 2 adhere strongly enough to not peel apart when the laminated adhesive tape 100 is in a folded state. In one aspect, an adhesive layer A is provided on the surface of the second tape piece (interior side) of part 14 in the first tape piece 1. The adhesive layer A has a function of adhering the first tape piece 1 to the second tape piece 2; and, when the laminated adhesive tape 100 is attached to a disposable article (not shown), of maintaining the shape of the disposable article after the laminated adhesive tape 100 has been extended and attached to a suitable location on the disposable article, and the article has been fastened in a rolled- up or folded state. Additionally, the entire length of the surface of the first tape piece 1 that is opposite the second tape piece-facing side (that is, on the outer side) may be covered by a coating of a low adhesive substance described hereafter.

The free end 1 1 is the part gripped by a user to pull the first tape piece 1 of the laminated adhesive tape 100 in the horizontal direction, or lift it in the perpendicular direction, when applying the laminated adhesive tape 100 to the disposable article. The surface of the free end 11 is preferably not bonded to the second tape piece by the adhesive layer or the like so that the user can more easily grip and pull the free end 11 up. Thus, it is preferable either to adopt an aspect in which the surface of the free end

11 is not provided with an adhesive layer, or an aspect in which the adhesive layer A provided on the free end 11 is coated or masked with another substance. It is also acceptable to provide a handle part on the tip of the free end 11 in order to make the first tape piece 1 easier to peel off.

The first adhesive end 12 is the end of the first tape piece 1 that is opposite to the free end 11, and is bonded to the third tape piece 3 at the side surface of the third tape piece in the first tape piece 1 so that the first adhesive end 12 can be detached. Bonding the first tape piece 1 and the third tape piece 3 serves to prevent the second tape piece 2 from coming loose before the laminated adhesive tape is extended, and to preserve the shape of the folded laminated adhesive tape.

From the perspective of ease of extending the laminated adhesive tape 100 and maintaining the Z- shape thereof in the folded state prior to being extended, the first adhesive end 12 preferably constitutes from 3 to 25% of the area of the first tape piece 1, more preferably from 6 to 20%. The first adhesive end

12 is provided with an adhesive layer B for bonding with the third tape piece 3.

The first adhesive part 13 is adjacent to the first adhesive end 12, and is the area in which the first tape piece 1 and second tape piece 2 are bonded on the surface of the second tape piece side in the first tape piece 1. The first adhesive part 13 is provided with an adhesive layer C for bonding with a first folded-back portion 21 of the second tape piece 2. Such a configuration allows the first tape piece and the second tape piece to remain bonded together without peeling apart when the laminated adhesive tape 100 is extended.

Identical or different adhesives may be used for the adhesive layers A, B, and C. In one aspect, a rubber-based or acrylic adhesive is generally used as the adhesive, with a rubber-based adhesive being preferred. Specific examples of rubber-based adhesives include synthetic rubbers of a styrene/butadiene block copolymer or a hydrogenated styrene/butadiene block copolymer, or blends of such synthetic rubbers with resin, and the like. For example, a synthetic rubber/resin blend containing 30 parts by weight of a styrene/butadiene/styrene triblock polymer (styrene/isoprene/styrene triblock polymer, product name Kraton® Dl 1 19; Kraton Performance Polymers Inc.), 42 parts by weight of a C-5 hydrocarbon resin (Wingtack® Plus; Cray Valley), and 28 parts by weight of C-5 hydrocarbon resin (Wingtack® 10; Cray Valley) can be used. Examples of patterns in which the adhesive is applied include across the entire surface, in stripes, in a lattice, in dotted lines, or in waves; but the adhesive is preferably applied to the entire surface. If the same adhesive is used for the adhesives layer A, B, and C, a release layer (not shown), to be described in detail later, can be provided on the surface of the first tape piece side of the second tape to make the second tape piece 2 easier to peel off of the adhesive layer of the first tape piece 1.

From the perspective of dispersing the pressure placed upon the first tape piece during peeling and maintaining the strength of the bond of the laminated adhesive tape 100 with the second tape piece when the laminated adhesive tape 100 is extended, the surface area of the first adhesive part 13 preferably constitutes from 10 to 34% of the total surface area of the first tape piece 1, and more preferably from 12 to 25%.

The second tape piece 2 is provided with the first folded-back portion 21 on one end thereof and a second adhesive end 22 on the other end thereof, and the first adhesive part 13 of the first tape piece 1 and the first folded-back portion 21 are bonded together. In one aspect, the second tape piece 2 is bonded to the third tape piece 3 only at the second adhesive end. An aspect in which an adhesive layer is not provided on any surface of the second tape piece 2 is possible. Not providing an adhesive layer on any surface of the second tape piece 2 yields the effects of mitigating the peeling shock generated when the laminated adhesive tape is pulled in the horizontal direction, and keeping the adhesive tape surface from being exposed on the external surface of the disposable article when the tape is extended. Here, "not providing an adhesive layer" on the surface of the second tape piece 2 means that the surface of the second tape piece 2 is left as-is (untreated), or a layer other than an adhesive layer (for example, the release layer described hereafter) is provided.

As described above, a release layer (not shown) can be provided on the surface of the second tape piece 2 facing the first tape piece to make the second tape piece 2 easier to peel off from the adhesive layer of the first tape piece 1. An example of a release layer is a low adhesive substance coating layer, examples of low adhesive substances include a silicone based release agent, a long chain alkyl based release agent, or a fluoride based release agent. Specifically, a silicone compound such as low adhesive polyvinyl siloxane (UV9300; Momentive Performance Materials Inc.) or a low adhesive

organopolysiloxane (XS56-A2982; Momentive Performance Materials Inc.) to which a photoinitiator has been added before being cured via UV irradiation, or an alkylurethane compound such as low adhesive polyurethane (3M) or the like can be used. The low adhesive substance only need be applied to the surface that contacts part 14 of the first tape piece 1 when the laminated adhesive tape 100 is folded. The release layer is preferably applied to the surface of the second tape piece before it is folded into the laminated adhesive tape 100.

Meanwhile, a release layer may also be provided on the surface of the second tape piece 2 facing the third tape piece. If the abovementioned release layer is provided on the surface of the second tape piece 2 facing the third tape piece, it is preferable for a release layer not to be present on the side of the first folded-back portion 21 facing the first tape piece. The surface of the second tape piece 2 facing the third tape piece may also be left untreated.

The first folded-back portion 21 is formed by folding back one end of the second tape piece 2 in the direction of the first tape piece 1 , and the second tape piece 2 and first tape piece 1 are bonded at the first folded-back portion 21. The end of the first folded-back portion 21 preferably extends outward somewhat and has a bonding surface formed, the first tape piece 1 and the first adhesive part 13 being bonded at this part. The abovementioned low adhesive substance may also be applied to the surface opposite of the first adhesive part 13 (inner surface) in the folded-back portion 21.

The second adhesive end 22 is the end of the second tape piece 2 opposite the end on which the first folded-back portion 21 is formed and is bonded with a second folded-back portion 31 of the third tape piece 3 at one surface of the third tape piece side on the second tape piece 2. The surface area of the second end 22 is preferably from 5 to 34% of the total area of the second tape piece 2, and more preferably from 8 to 20%. The surface area of the second end 22 may be the same as or different from that of the first adhesive part 13.

Additionally, the second adhesive end 22 may be directly bonded to the surface of the disposable article to which the laminated adhesive tape has been applied. In one aspect, the second adhesive end 22 is bonded to the surface of the disposable article to which the laminated adhesive tape has been applied in order to enable the user of the disposable article to grasp the free end 11 of the first tape piece more easily.

The second tape piece 2 can be imparted with a folded shape, that is, an accordion structure, by folding the second tape piece 2 in a zigzag shape with respect to an axis perpendicular to the lengthwise direction thereof. FIG. 3 is a cross-sectional view of a laminated adhesive tape in which the second tape piece 2 has been imparted with an accordion shaped structure according to another embodiment of the present invention, and FIG. 4 is a cross-sectional view of the laminated adhesive tape 100 shown in FIG. 3 in an extended state.

If the second tape piece 2 is given an accordion shape, from the perspective of maintaining the Z- folded shape of the tape before the tape is extended, for the surface of the second tape piece 2 facing the third tape piece and the surface of the third tape piece 3 facing the second tape piece to be bonded by an adhesive or the like. There is no limit upon the number of zigzag folds, but typically there will be from two to four. Because the first folded-back portion 21 and the second adhesive end 22 must be positioned not on ends on the same side but on ends on the opposite sides respectively, the number of folds will be an even number. The folded-back portions need not be folded over together evenly, but may be in steps, in a gourd shape, or in ajar shape. The folded-back portions may also be folded in a fan shape, vertically, in a wave shape, or in a cylindrical shape.

In order to increase the length of the laminated adhesive tape 100 after extension, the second tape piece 2 may be folded back a plurality of times to yield an accordion shape, as described above. However, because the obtained thickness of the laminated adhesive tape 100 increases in such instances, hard spots or raised areas may be formed in products to which such a laminated adhesive tape 100 is applied, leading to degradation of visual appearance or a burden upon the user (for example, in the case of a diaper, pressure upon the back).

Thus, if the second tape piece 2 is to be imparted with an accordion shape, the length of the second tape piece 2, taking the total length (L) of the laminated adhesive tape 100 in the folded state as 1, is preferably from 0.3 to 0.8 before extension from the perspective of attractiveness of design. The length after extension is preferably in a range from 1.3 to 2.3 from the perspective of maintaining the shape of the rolled-up disposable article. The thickness of the second tape piece 2 itself is preferably in a range from 40 to 80 μηι from the perspective of molding the laminated adhesive tape without distortions being formed therein (when being taken up in a roll during manufacturing, when being applied to the disposable article, and the like). If the second tape piece 2 is imparted with an accordion shape, the thickness of the obtained laminated adhesive tape 100 as a whole can be kept low by decreasing the thickness of the second tape piece 2 itself (for example, to 70 μηι or less). The thickness of the accordion-shaped second tape piece 2 is preferably roughly uniform with the end of the first folded-back portion 21 and the end of the second adhesive end 22 having roughly the same thickness.

The third tape piece 3 is provided with the second folded-back portion 31 on one of two ends thereof and a third adhesive end 32 on the other end thereof, the second adhesive end 22 and the second folded-back portion 31 being bonded, and the first adhesive end 12 and at least a part of the third adhesive end 32 being bonded. In the aspect shown in FIG. 1, the third adhesive end 32 has a bonded area 32a bonded to the first adhesive end 12 and an unbonded area 32b not bonded to the first adhesive end 12. The third tape piece 3 typically has an adhesive layer D on the surface opposite that facing the second tape piece, that is, the outer surface of the third tape piece of the laminated adhesive tape. The adhesive layer D is used to attach the laminated adhesive tape 100 to the disposable article. The adhesive layer D may cover the entirety of the third tape piece 3, or extend to the end of the second folded-back portion 31. Specifically, in this aspect, the adhesive layer D provided on the third tape piece 3 extends to the end of the second folded-back portion 31 on the bonded surface of the second folded-back portion 31, and the second adhesive end 22 of the second tape piece 2 and the second folded-back portion 31 of the third tape piece 3 are bonded. Such a configuration allows the second tape piece and the third tape piece to remain bonded together without peeling apart when the laminated adhesive tape 100 is extended.

In this way, the adhesive layer D of the third tape piece 3 is not only bonded to the disposable article, but is also used to join the second and third tape pieces. As a result, in this aspect, there is no need for a further step of bonding the second tape piece 2 to the third tape piece 3.

The adhesive used in the adhesive layer D may be selected, as appropriate, according to the adherend (for instance, a disposable article) to which the laminated adhesive tape 100 is applied. The adhesive may be the same as that used for the adhesive layers A, B, and C of the first tape piece 1, or may be different. If the adherend to which the laminated adhesive tape 100 is applied is a soft material, such as a nonwoven fabric, the use of a tacky or soft, highly viscous ("sticky") adhesive is preferred in the adhesive layer D.

From the perspective of reducing the amount of time needed to extend the folded-up laminated adhesive tape 100, the adhesive strength of the adhesive D of the third tape piece 3 is preferably greater than that of the adhesive B of the first tape piece. Thus, if the same adhesive is used for the adhesive B and the adhesive D, the amount of adhesive applied to the third tape piece 3 is greater than the amount of adhesive applied to the first tape piece 1. In one aspect, the amount of adhesive D applied to the third tape piece 3 can be from 35 to 70 g/m², and the amount of adhesive B applied to the first tape piece 1 from 25 to 45 g/m². The third tape piece 3 may have a surface (not shown) to which a low adhesive substance is applied on the side facing the second tape piece 2. The low adhesive substance described above may be used. Providing a surface upon which low adhesive substance is applied in this way allows the tape to be more easily drawn off of a feeder roll during the process of laminating the tape forming the third tape piece 3 when manufacturing the laminated adhesive tape 100.

If the second tape piece 2 is imparted with an accordion shape, as described above, the second tape piece 2 and the third tape piece 3 may bond (that is, weakly bond) to each other using means such as bonding with an adhesive, fusion during the manufacture of the laminated adhesive tape 100, or supersonic welding to the third tape piece 3. Such bonding can prevent lifting of the second tape piece 2 or slipping caused by friction from the folded part of the laminated adhesive tape 100 when the laminated adhesive tape 100 is applied to the disposable article constituting the adherend.

The second folded-back portion 31 is formed by folding back one end of the third tape piece 3 in the direction of the second tape piece 2, and the third tape piece 3 and second tape piece 2 are bonded at the second folded-back portion 31. The end of the second folded-back portion 31 preferably extends somewhat to form a joining surface bonded to the second adhesive end 22 of the second tape piece 1 , forming a support (support point) when the second tape piece 2 is extended. As described above, the second folded-back portion 31 of the third tape piece 3 and the second adhesive end 22 of the second tape piece can be bonded by the adhesive layer provided on the surface of the third tape piece opposite that facing the second tape piece. In this way, the second folded-back portion 31 serves to join the second tape piece 2 and the third tape piece 3 to each other, as well as to mitigate the shock created when the tape is extended so that the third tape piece does not peel off from the disposable article.

The end of the third tape piece 3 towards the third adhesive end 32 may have an area 32c in which the adhesive layer D is not present on the surface opposite that facing the first tape piece. In such cases, the surface of the third tape piece 3 in the area 32c is, for example, untreated; or a coating of the low adhesive substance described above is applied to the surface of the third tape piece 3; or another film (for example, a polyester film or the like) is applied thereto. For this reason, when the laminated adhesive tape 100 is affixed to an adherend, and the free end of the first tape piece of the laminated adhesive tape 100 is pulled in the horizontal direction, it is easier to peel the first adhesive end 13 of the first tape piece off from the third tape piece. In one aspect, the area 32c can constitute from 7 to 24% of the total area of the third tape piece 3, and may have the same area as or a different area from the area of the third adhesive end 32. Typically, the area 32c will be larger than or the same size as the third adhesive end 32. As the area 32c increases in size, the 180° peel force value tends to decrease.

As described above, the third adhesive end 32 is the end of the third tape piece 3 opposite that on which the second folded-back portion 31 is formed, and at least a part of the third adhesive end 32 is bonded to the first adhesive end 12 on the surface of the first tape piece side of the third tape piece 3 in a manner that allows the third adhesive end 32 to be detached.

The 180° peel force of the laminated adhesive tape 100 according to the present invention is from 1 to 10 mJ. A peel force within this range makes the laminated adhesive tape 100 easier to extend, and allows the Z-shape of the laminated adhesive tape 100 to be maintained when the disposable article is used without the first adhesive end 12 and the third adhesive end 32 peeling apart.

The 180° peel force of the laminated adhesive tape 100 can be calculated from the bonding force at the interface of the first adhesive end 12 of the first tape piece 1 and the third adhesive end 32 of the third tape piece 3. In the present invention, the 180° peel force is specifically calculated according to the following method.

A sample of laminated adhesive tape 100 is placed upon a steel panel 4 with the third tape piece 3 facing downward, and a 2 kg roller weight is moved over the top of the sample at a speed of 300 mm/minute, thereby bonding and affixing the outer surface of the sample on the third tape piece side to the steel panel 4. If there is foreign matter (nonwoven fabric, dirt, or the like) adhering to the outer surface of the sample on the third tape piece side (the side bonded/affixed to the steel panel 4), the sample is cooled to a low temperature (°0 C or less) using cold spray or the like before the sample is affixed to the steel panel 4, the foreign matter is removed, and the sample is bonded/affixed to the steel panel 4 after having been confirmed to have returned to room temperature. As shown in FIG. 5, an extension film 5 is inserted between the first tape piece 1 and the second tape piece 2, and affixed to the second tape piece- side surface of the first tape piece 1.

Next, the sample, which has been affixed to the steel panel 4 and has the extension film attached thereto, is left standing for 30 minutes; and the extension film is affixed to an upper chuck 6 and the steel panel 4 is affixed to a lower chuck 7 so as to sandwich the whole therebetween (50 mm from chuck to chuck), as shown in FIG. 5, using a TENSILON RTG-1225 tensile/compression testing apparatus manufactured by A&D Co., Ltd. Pulling the upper chuck 6 in the direction indicated by the arrow at a rate of 300 mm min (the lower chuck 7 being fixed in place), the 180° peel force required for the bond between the first adhesive end and the third adhesive end to be broken before the laminated adhesive tape is extended is measured as the bond force. The 180° peel force (calculated for a laminated adhesive tape width of 15 mm) is found on the basis on the obtained bond force value using the following conversion formula.

180° peel force (mJ) = (bond force (N) x distance (mm) to first adhesive end in the length direction x 0.101972 x (sample width (mm)/15)

From the perspective of allowing the laminated adhesive tape to be extended from the disposable article without peeling off, the surface area ratio of the bonded area bonded to the first adhesive end 12 (32a in FIG. 1) to the area of the unbonded area (32b in FIG. 1) of the third adhesive end 32 is preferably 1 :0.1 to 2.5.

The laminated adhesive tape 100 according to the present invention has a 180° peel force of 1 to 10 mJ, and the area of the first adhesive end constitutes from 3 to 25% of the total area of the first tape piece, thereby enabling the folded state thereof to be maintained, and the tape to be extended by pulling on the free end 1 1 of the first tape piece 1. When the laminated adhesive tape 100 according to the present invention is extended, the free end 1 1 of the first tape piece 1 may be pulled in the perpendicular direction or the horizontal direction with respect to the laminated adhesive tape 100.

FIG. 6 shows changes in the laminated adhesive tape 100 as it extends when it is pulled in the perpendicular direction. Specifically, in FIG. 6a, the free end 1 1 of the first tape piece 1 is lifted upward, thereby causing the first tape piece 1 to peel off of the second tape piece 2 (FIG. 6b). After the first tape piece 1 has peeled off of the second tape piece 2, the free end 1 1 of the first tape piece 1 is lifted in the perpendicular direction and the laminated adhesive tape 100 is extended, thereby breaking the bond between the first adhesive end 12 of the first tape piece 1 and the third adhesive end 32 of the third tape piece 3 (FIG. 6c). When the bond between the first adhesive end 12 of the first tape piece 1 and the third adhesive end 32 of the third tape piece 3 is broken, the first folded-back portion 21 lifts up the second tape piece 2, and the second tape piece 2 peels off of the third tape piece 3 (FIG. 6d).

Next, the second folded-back portion 31 rises up off of the third tape piece 3, and the laminated adhesive tape is extended without the second tape piece 2 and the first tape piece 1 being severed from the third tape piece 3, as shown in FIG. 6e.

As shown in FIGS. 3 and 4, the laminated adhesive tape 100 extends as described above even if the second tape piece has an accordion shape.

If an adhesive layer is not provided on the second tape piece 2, or if the second tape piece 2 has an accordion shape, the free end 1 1 of the laminated adhesive tape 100 is preferably pulled in the horizontal direction. As shown in FIG. 7, when the free end 1 1 of the laminated adhesive tape 100 is grasped and pulled in the horizontal direction with respect to the first tape piece (FIG. 7a), the first adhesive end 13 first peels off of the third tape piece 3 (FIG. 7b), and the second tape piece 2 (or the folded part of the accordion-shaped section if the second tape piece 2 has an accordion shape) is drawn outward while keeping the shape thereof. Next, when the part where the first tape piece 1 and the second tape piece 2 are bonded (the part where the first adhesive part and the second adhesive end are bonded) is pulled apart (FIG. 7c), the laminated adhesive tape 100 can immediately be drawn outward as shown in FIG. 7d due to the lack of an adhesive layer on the second tape piece 2, and the first tape piece 1 can be bonded as-is to the adherend, which has been rolled into a small ball (or folded up) for disposal. This movement allows the amount of time and force needed to pull the tape upward to be reduced.

The following is an example of a method for manufacturing the laminated adhesive tape according to the present invention, but the present invention is not limited to this method. As shown in FIG. 8, three feeder reels 40, 50, and 60 are provided for manufacturing the laminated adhesive tape 100. A film 41 that becomes the first tape piece 1 is wrapped around the feeder reel 40. Likewise, a film 51 that becomes the second tape piece 2 is wrapped around the feeder reel 50, and a film 61 that becomes the third tape piece 3 is wrapped around the feeder reel 60. The films 41, 51 , and 61 are fed from the feeder reels 40, 50, and 60 after the adhesive layers A, B, C, and D and the low adhesive substance coating layer have been provided. In the first tape piece 1, the adhesive layers A, B, and C are provided on the side facing the second tape piece 2; and, if a low adhesive substance is applied, it is applied to the surface opposite that facing the second tape piece 2 (namely, the outer surface). An area equivalent to the free end 11 of the first tape piece 1 is present in part of the area on the upper side of the film 41 shown in FIG. 8, and a surface on which adhesive is not present is preferably formed in this area. In another aspect, a feeder reel (not shown) around which a film that becomes the grip provided on the free end of the first tape piece is provided, and the film can be applied to this area of the tape 41 to act as a grip. As described above, a low adhesive substance may be applied to the surface of the first tape piece 1 side of the second tape piece 2. Additionally, the adhesive layer D need not be provided on the surface of the third adhesive end of the third tape piece 3 opposite that facing the first tape piece 1, for example, a low adhesive substance may be applied.

Next, parts equivalent to the first folded-back portion 21 of the second tape piece 2 and the second folded-back portion 31 of the third tape piece 3 of the laminated adhesive tape 100 are formed on the films 51 and 61 , respectively, at folded parts 70. Folding is performed in a similar manner when the second tape piece 2 has an accordion shape, as well.

Next, after the area of the film 41 equivalent to the first adhesive part 13 of the first tape piece 1 and the area of the film 42 equivalent to the second adhesive end 22 of the second tape piece 2 have been overlapped so that the folded-back parts provided on the films 42 and 43 face each other, the films 41, 51, and 61 are bonded in a laminator device 80, as shown in FIG. 8. Specifically, the first folded-back portion 21 of the second tape piece 2 is bonded to the first adhesive part 13 of the first tape piece 1, and the second folded-back portion 31 of the third tape piece 3 is bonded to the second adhesive end 22 of the second tape piece 2, as shown in FIGS. 1 and 3.

The laminated film obtained from the laminator device 80 is sent to an uptake unit 90 and wound into a roll shape. The rolled-up laminated tape is drawn out to the necessary length and cut in the transverse direction (CD direction) to yield the laminated adhesive tape 100. The area formed in the lengthwise direction (MD direction) on the upper side of the film 41 on the uptake unit 90 is equivalent to the free end 11 of the first tape piece 1. Similarly, the area appearing as the end of the film 61 on the uptake unit 90 is equivalent to the unbonded area 32b of the third adhesive end 32 of the third tape piece not bonded to the first adhesive end 12.

The laminated adhesive tape 100 so obtained stays in a Z-shaped folded state until being extended.

An example of an application for the laminated adhesive tape of the present invention is a disposal tape used when disposing of a disposable diaper, sanitary pad, incontinence pad, or other disposable article. Specifically, as shown in FIG. 9, the tape is attached to the rear surface of a disposable diaper so that the free end of the first tape piece faces upwards (towards the waist). In this application, the laminated adhesive tape is used to maintain the shape of the disposable article after it has been rolled into a ball or folded up, as shown in FIG. 10. Apart from the above application, the tape can also be used as a sealing tape that is attached to a bag for pastries, bread, or the like, allowing the food product to be preserved. Additionally, a design may be put upon the second tape piece of the laminated adhesive tape (for example, on the accordion-shaped part), allowing for use in educational materials such as pop-up books or workbooks, or as a sealing tape for gift products. In addition, the tape can also be used as a tape for bundling together two or more packages or other products (for example, as a display or antitheft tape). EXAMPLES

The present invention will be described in further detail below on the basis of working examples, but the present invention is not limited to these examples.

Working Example 1

First Tape Piece. A 32 mm ^χ 300 mm, 80 μηι-tliick polypropylene film (product name: J-

Allomer® FA 462; SunAllomer Ltd.) was prepared, to one side of which a low adhesive substance A (low adhesive polyvinylsiloxane [UV9300; Momentive Performance Materials Inc.]) and 2.5 weight% with respect to the low adhesive substance A of a photoinitiator (UV-9380C; Momentive Performance Materials Inc.) were added so as to cover the entire surface thereof to a thickness of 5 μηι, then cured to a 100% solid state via UV irradiation. An adhesive X containing a synthetic rubber/resin blend of 30 parts by weight of a styrene/butadiene/styrene triblock polymer (styrene/isoprene/styrene triblock polymer, product name Kraton® Dl 1 19; Kraton Performance Polymers Inc.), 42 parts by weight of a C-5 hydrocarbon resin (Wingtack® Plus; Cray Valley), and 28 parts by weight of C-5 hydrocarbon resin (Wingtack® 10; Cray Valley) was applied to the entirety of the surface opposite the surface to which the low adhesive substance A was applied, so that the thickness of the adhesive X was 35 μηι (35 g/m²).

Second Tape Piece. A 70 mm x 300 mm, 60 μηι-thick polypropylene film (J-Allomer® FA 462; SunAllomer Ltd.) was prepared, and a mixture of 35 parts by weight of low adhesive substance A and 65 parts by weight of a low adhesive substance B (low adhesive organopolysiloxane [XS56-A2982;

Momentive Performance Materials Inc.]) to which 2.5 weight% of a photoinitiator was added was applied to the entirety of one surface thereof to a thickness of 5 μηι, then cured to a 100% solid state via UV irradiation. The opposite surface was left as-is (untreated).

Third Tape Piece. A 42 mm 300 mm, 70 μΓη-thick polypropylene film (J-Allomer® FA 462; SunAllomer Ltd.) was prepared, and the same mixture used on the second tape piece of low adhesive substances A and B to which 2.5 weight% of a photoinitiator was added was applied so as to cover the entirety of one surface thereof to a thickness of 5 μηι, then cured to a 100% solid state via UV irradiation. The same adhesive X that was applied to the first tape piece was applied to a thickness of 50 μπι (50 g/m²) on the surface opposite that to which the mixture of low adhesive substances A and B was applied.

Before being sent to the laminator device, the ends of the second tape piece and the third tape piece were each folded back in the lengthwise direction of the tape piece to form a first folded-back portion and a second folded-back portion each 7 mm in width. This means that 7 mm -wide bonding parts were prepared for the bonds between the first tape piece and the second tape piece and between the second tape piece and the third tape piece. Furthermore, the second tape piece was folded back two times in 17 mm- wide zigzags to form an accordion-shaped folded-back part. In the laminator device, the first tape piece and the second tape piece, the second tape piece, and the third tape piece, and the first adhesive end of the first tape piece and the third adhesive end of the third tape piece were bonded to manufacture a 36 mm ^χ 300 mm three-layered laminated adhesive tape. The tape pieces were bonded so that the surface of the first tape piece to which the adhesive X was applied and the surface of the second tape piece to which the mixture of low adhesive substances A and B was applied, and the untreated surface of the second tape piece and the surface of the third tape piece to which the mixture of low adhesive substances A and B was applied, faced each other. There were no difficulties in manufacturing. The laminated adhesive tape was cut to obtain a laminated adhesive tape of length 36 mm x width 15 mm.

The first adhesive end of the laminated adhesive tape so obtained had a length of 5 mm (the first adhesive end area constituting 15.6% (5 mm / 32 mm = 0.156) of the total area of the first tape piece). The 180° peel force of the laminated adhesive tape was 3.6 mJ. The ratio of the area of the third adhesive end bonded to the first adhesive end and the unbonded area of the third adhesive end was 1 : 1.2. Extensibility Test

Next, the obtained laminated adhesive tape was bonded to a nonwoven diaper, the free end of the first tape piece was grasped, and the laminated adhesive tape was extended in the perpendicular and horizontal directions. In both cases, the tape pieces of the laminated adhesive tape peeled off smoothly, and no resistance was encountered when the tape was being extended.

Peel Test

The waist and crotch areas of the diaper to which the laminated adhesive tape was attached were gripped, and the diaper was folded between the waste and crotch areas, and the portion to which the laminated adhesive tape was attached was rubbed ten times against the nonwoven fabric portion of the crotch area. There was no peeling of the first adhesive end from the third adhesive end. The results of the extensibility and peel tests are shown in Table 2.

Working Examples 2-5. Comparative Examples 1 -3

The tape pieces listed in Table 1 were used to manufacture a laminated adhesive tape according to a method similar as that used for working example 1. For comparative example 1 , an adhesive Y containing a synthetic rubber/resin blend of 30 parts by weight of styrene/butadiene/styrene triblock polymer (styrene/isoprene/styrene triblock polymer, product name Kraton® D 1 119; Kraton Performance Polymers Inc.), 39 parts by weight of C-5 hydrocarbon resin (Wingtack® Plus; Cray Valley), and 31 parts by weight of C-5 hydrocarbon resin (Wingtack® 10; Cray Valley) was applied to the third tape piece side of the second tape piece in contact with the third tape piece to a thickness of 15 μηι. In working examples 2 and 5 and comparative example 3, a 12 μηι-ηι^ polyester film (Emblet®; Unitika Ltd.) of a pre-determined size was attached to the end of the third adhesive end 32 side of the third tape piece 3 to provide an area on the surface opposite that facing the first tape piece on which an adhesive layer X was not provided. Extensibility and peel tests were performed upon the obtained tapes in a manner similar to working example 1. The results are shown in Table 2.

Table 1

Table 2

Claims

What is Claimed is:

1. An extendable laminated adhesive tape comprising:

a first tape piece provided with a free end on one of two ends thereof and a first adhesive end on the other end thereof and having a first adhesive part adjacent to the first adhesive end;

a second tape piece provided with a first folded-back portion on one of two ends thereof and a second adhesive end on the other end thereof, the first adhesive end and the first folded- back portion being bonded together; and

a third tape piece provided with a second folded-back portion on one of two ends thereof and a third adhesive end on the other end thereof, the second adhesive end and the second folded-back portion being bonded together, and the first adhesive end and at least a part of the third adhesive end being bonded together; wherein:

the first tape piece, second tape piece, and third tape piece are laminated in this order; an area of the first adhesive end of the laminated adhesive tape constitutes from 3 to

25% of the first tape piece as a whole; and

a 180° peel force of the laminated adhesive tape is from 1 to 10 mJ.

2. The laminated adhesive tape according to claim 1 , wherein the second tape piece has a folded shape.

3. The laminated adhesive tape according to claim 1 or 2, wherein the second tape piece is bonded to the third tape piece only at the second adhesive end.

4. The laminated adhesive tape according to any one of claims 1 through 3, wherein a low adhesive substance is applied to the surface of the second tape piece in contact with the third tape piece.

5. The laminated adhesive tape according to any one of claims 1 through 4, wherein the surface of the third adhesive end of the third tape piece opposite that facing the first tape piece has an area with no adhesive layer.

6. The laminated adhesive tape according to any one of claims 1 through 5, wherein in the third adhesive end having a bonded area bonded to the first adhesive end and an unbonded area not bonded to the first adhesive end, a surface area ratio of the bonded area to the unbonded area

7. A disposable article comprising the laminated adhesive tape according to any one of claims 1 through 6.