JPH0118162B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a tape fastener for securing a disposable diaper to an infant. It is well known to use pressure sensitive adhesive tape fasteners to secure the corners of disposable diapers. However, with conventional tape-type fixing devices, when securing a diaper to an infant, the pressure-sensitive tape is crimped to the back sheet, but when the tape is once crimped and then re-pressed (for example, to check whether or not urination has occurred) Since the backsheet is made of a relatively weak material, the backsheet may be severely damaged or a portion of the backsheet may stick to the adhesive tape, making it difficult to repeatedly put on and take off the diaper once it has been secured to the infant. In order to improve the shortcomings of conventional tape fasteners for diapers, a tape fastener that uses two pressure-sensitive tapes and can be repeatedly attached and detached has been considered (Utility Model No. 55-75608).
(see Japanese Patent Application Publication No. 2003-110000), it has the disadvantage of increasing material costs and manufacturing costs. In order to obtain a tape fastener that can be repeatedly put on and taken off using the tape fastener of conventional disposable diapers,
Since the backing sheet is made of a weak material (generally polyethylene film), it is necessary to weaken the adhesive strength, but in this case, there is a risk that it will peel off during use, so the balance between the two must be carefully considered. It's difficult to take. In other words, in the case of diaper tape fasteners, when the wearer puts the diaper on the wearer, they press the tape against the back sheet of the diaper, but the way they press it (the way they apply pressure) is biased toward the center of the tape. It shows a trend. In other words, pressure is not applied uniformly to the entire surface of the tape for adhesion, but pressure is applied intensively to the central portion for adhesion. In other words, the center portion of the tape piece is more strongly adhered than the end portions. For this reason, an adhesive with a weak adhesive strength is likely to peel off during use, whereas a strong adhesive is difficult to peel off from the back sheet, making repeated attachment and detachment impossible. The present inventors have arrived at the present invention as a result of intensive research aimed at improving such conventional tape fasteners and obtaining a tape fastener that is easier to use. An object of the present invention is to provide a tape fastener that has adhesive strength that will not peel off while wearing a disposable diaper, and that can be repeatedly attached and detached without damaging the back sheet. Another object of the present invention is to provide a tape fastener for disposable diapers that is low in cost. The tape fastener of the present invention capable of achieving such an object consists of a piece of pressure-sensitive tape whose one end is fixed to the back side of a disposable diaper and whose other end extends in a direction that allows it to be folded back onto the surface of the diaper. At least a portion of the other end extending in the longitudinal direction of the pressure-sensitive tape piece (lateral direction of the diaper) is coated with an adhesive.
The width of the tape in the longitudinal direction of the applied part is 0.2 to 2.0 mm, and the width of the uncoated part is 0.1 to 2.0 mm. is the adhesive side of the other end of the pressure-sensitive tape piece that extends in the direction that can be folded back onto the diaper surface.
40% or more, the total area of the adhesive-applied parts in the interrupted parts is equal to or greater than the total area of the unapplied parts, and the total area of the adhesive-adherable surface is 5.
cm ² to 15 cm ² . Generally, when using a diaper, when a tape with good adhesive strength that does not peel off is attached to the back sheet and then re-peeled, the tape is peeled off little by little from the back sheet and the back sheet is stretched, and once it stretches to a certain extent, the peeling force increases. I can't stand it and it breaks. On the other hand, in the case of a tape in which adhesive is applied intermittently in the longitudinal direction (peeling direction) of the tape as in the present invention, when re-peeling the tape, if only the coated width is peeled off from the back sheet, the next adhesive will not be removed. As the backsheet appears, new peeling begins, and the backsheet is peeled off one after another, with almost no damage to the backsheet. However, if the uncoated area is large, the adhesive strength will drop significantly and it may peel off during use. In other words, by applying the adhesive intermittently, they were able to minimize the decrease in adhesive strength and successfully obtain a tape that can be used repeatedly. However, the width of the area where this adhesive is applied intermittently (hereinafter referred to as the intermittent area) is 0.2 mm to 2.0 mm,
The width of the uncoated part (hereinafter referred to as uncoated width) is preferably 0.1 mm to 2.0 mm, preferably 0.1 mm to 1.0 mm, and the width of the entire coated part of the interrupted part is preferably 0.3 mm to 1.0 mm. The tape fastener of the present invention is characterized in that the area is equal to or larger than the total area of the non-coated portion. If the coating width exceeds 2.0 mm, it will be difficult to peel off the tape without tearing the back sheet, much the same as when the tape is applied over the entire surface. Also, the uncoated width is 2.0
If it exceeds mm, the adhesive strength will decrease and it will easily peel off during use. Furthermore, if the total area of the coated portion is smaller than the total area of the uncoated portion, the adhesive strength will decrease and the adhesive will be likely to peel off during use. Further, the adhesive in the transverse direction of the tape fastener of the present invention is not particularly limited, and may be continuous or intermittent. In other words, even if the area to which the adhesive is applied is circular, its diameter is considered to be the application width, and any tape that meets the above conditions is included in the present invention. Further, the effect of the present invention will be lost if this interrupted portion does not exceed 40% of the bondable surface extending in the foldable direction. As mentioned above, when putting a disposable diaper on the wearer, pressure is applied mainly to the center of the end of the pressure-sensitive tape that extends in the direction in which it can be folded back, so the center is stronger and the ends are weaker. are doing. When the mother attaches the adhesive to the infant, the pressure is applied at the center.
500g/cm ^2nd place, 100g/cm ^2nd place at the end is common. Therefore, by changing the adhesive application pattern between the center and the edges, the adhesive strength can be adjusted to reduce the difference in adhesive strength between the center and the edges, thereby achieving the object of the present invention more effectively. . In other words, adhesive is applied to the adhesive surface of the end of the pressure-sensitive tape piece that extends in the direction in which it can be folded back to increase the adhesive strength in the range of 10 to 30% on the side closer to the diaper and 10 to 30% on the side farther from the diaper. By setting the width to 2 mm or more and making the total area of the applied area in both areas at least 60% of both areas, the adhesive strength between the center and edges can be adjusted, allowing more effective repeated attachment and detachment of the tape. . In this case, both regions may be discontinuous in the transverse direction of the tape, similar to the discontinuous portion in the center. Further, from the viewpoint of processability, the adhesive used in the present invention is preferably of the hot melt type, but it may also be of the solvent type or emulsion type. Hereinafter, the tape fastener of the present invention will be explained with reference to drawings and examples. FIG. 1 shows a sectional view of an embodiment of the tape fastener of the present invention used in disposable diapers. Further, a plan view thereof is shown in FIG. 2, and FIGS. 3 and 4 show plan views of other embodiments of the tape fastener of the present invention. As can be seen from FIGS. 1 and 2, the pressure-sensitive tape piece 4 of the tape fastener of the present invention consists of a portion 1 fixed to the back of the diaper, an adhesive surface 2, and a portion 3 to which no adhesive is applied, and is adhesive. The surface 2 is provided with an interrupted portion l, which is a feature of the present invention.
The coating width a and the non-coating width b allow the diaper to be repeatedly put on and taken off without peeling off while wearing the diaper. Furthermore, the wide areas m and n of the coating width make the adhesive strength uniform between the center and the ends of the tape when it is put on, making it possible to put it on and take it off more effectively. Further, FIG. 4 shows an example in which the adhesive is applied intermittently in the transverse direction of the tape, and the adhesive is gravure-transferred in a circular shape. This will be explained below using examples. The adhesive used in the examples was TOPCO 535A (trade name, manufactured by Toyo Petrolite Co., Ltd.), which is a hot melt type adhesive, and the adhesive was applied at 35 g/m ² in the pattern illustrated in Figures 2 to 4. , adhesion and removability (tape repeatability test) were tested. Of course, the tape fastener of the present invention is not limited to this embodiment. Example 1 Application pattern: Fig. 2 a = 1 mm, b = 0.5 mm, a' = a'' = 2.5 mm, b' =
b″=1mm, l=18.5mm, m=7mm, n=6mm Tape width 25mm Example 2 Application pattern: Fig. 2 a=1.8mm, b=1.5mm, a′=a″=2.5mm, b′ =
b″=1mm, l=18mm, m=7mm, n=6mm Tape width 25mm Example 3 Application pattern: Fig. 2 a=0.5mm, b=0.2mm, a′=a″=6mm, b′=
b″=0mm, l=19.8mm, m=6mm, n=6mm Tape width 25mm Example 4 Application pattern: Fig. 2 a=0.2mm, b=0.1mm, a′=a″=2mm, b′=
b″=1.5mm, l=19.9mm, m=7mm, n=5.5
mm Tape width 25mm Example 5 Application pattern: Fig. 2 a=0.5mm, b=0.2mm, a′=a″=3.5mm, b′=
b″=0.5mm, l=24mm, m=4.0mm, n=3.5mm Tape width 25mm Example 6 Application pattern: Fig. 2 a=1mm, b=0.5mm, a′=3.0mm, a″=2.5
mm, b′=1mm, b″=1.5mm, l=18.5mm, m=
8mm, n=6.5mm Tape width 25mm Example 7 Coating pattern: Figure 3 A area Coated width 1.5mm Uncoated width 0.5mm B area 〃 1.0mm 〃 0.5mm C area 〃 0.7mm 〃 0.3mm c=c′= 3mm d=d'=2.5mm e=e'=1mm
m = 7.5 mm l = 18.3 mm n = 6.5 mm Tape width 25 mm Example 8 Same pattern as Example 1, tape width 20 mm,
Tape example with l=15mm 9 Application pattern: Fig. 4 a=1.3mm (φ=1.3mm 165 pieces) a′=a″=2.5mm (φ=2.5mm 27 pieces) l=16mm m=8mm n =8mm Tape width 25mm Example 10 Application pattern: Fig. 2 a=1mm b=0.5mm a′=a″=0 b′=b″=
0 l=33mm m=0 n=0 Tape width 25mm Example 11 Application pattern: Fig. 2 a=1mm b=0.5mm a′=a″=1.5mm b′=
b″=1mm l=23.0mm m=5mm n=4mm Tape width 25mm Example 12 Application pattern: Fig. 2 a=1mm b=0.5mm a′=a″=2.5mm b′=
b″=0.5mm l=26mm m=3mm n=2.5mm Tape width 25mm Example 13 Application pattern: Fig. 2 a=1mm b=0.5mm a′=a″=2.1mm b′=
b″=2.8mm l=15.5mm m=9.8mm n=7
mm Tape width 25mm Comparative Example 1 Same as in Example 1, but the entire adhesive surface was coated with adhesive. Comparative Example 2 Application pattern: Fig. 2 a=2.5mm b=1.0mm a′=a″=2.5mm b′=
b″=1mm l=18.5mm m=7mm n=6mm Tape width 25mm Comparative example 3 Application pattern: Fig. 2 a=1mm b=1.2mm a′=a″=0 b′=b″=
0 l=33mm m=0mm n=0mm Tape width 25mm Comparative example 4 Application pattern: Fig. 2 a=1mm b=0.5mm a′=a″=2.5mm b′=
b″=1mm l=11.0mm m=10.5mm n=9.5
mm Tape width 25mm Comparative example 5 Tape with a tape width of 15mm in Example 9. The adhesive strength and removability of the tape fasteners of the above Examples and Comparative Examples were tested and the results are shown in Table 1. Adhesive strength: Use PE film (XP-2102 manufactured by Ethyl Co., Ltd.) as the back sheet, cover the 50 mm x 50 mm absorbent material (cotton-like pulp compressed to 0.1 g/cm ³ ) with the back sheet, and fix it to the absorbent material. and use it as an absorber test piece. Part 1 of the test tape pieces of Examples and Comparative Examples, which is fixed to the back side of the diaper, is strongly adhered to this test piece, and the adhesive side 2 of the test tape pieces of the examples and comparative examples is bonded to another absorbent test piece. 100g of 25% on each end
Glue by making one reciprocation with the roller. 2
Two absorbers are covered with a back sheet and both ends are pulled with Tensilon to measure the adhesive strength. Re-peelability: PE film (XP-2102 manufactured by Ethyl)
The adhesion surface of the test tape piece is adhered to the absorber test piece prepared as above as described above, and the time until it becomes impossible to re-peel it without destroying the PE film is measured. * Both tests are conducted at 20℃ and 60%RH.

【table】

[Table] As is clear from Table 1, the tape fastener of the present invention has adhesive strength and is removable, that is, can be repeatedly attached and detached.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the state in which the tape fastener of the present invention is used and fixed to a diaper, and Fig. 2-
FIG. 4 is a plan view of an embodiment of the tape fastener of the present invention. 1: Part fixed to the back of the diaper, 2: Adhesive surface, 3: Part of the tip of the pressure-sensitive tape that is not coated with adhesive, 4: Pressure-sensitive tape piece (fastening tape), 5: Release tape piece , l: intermittent part,
m, n: wide area of coating width.

Claims (1)

[Scope of Claims] 1. Consisting of a piece of pressure-sensitive tape with one end fixed to the back side of a disposable diaper and the other end extending in a direction that can be folded back onto the diaper surface, and the other end extending in a direction that can be folded back. The adhesive is intermittently applied to at least a portion of the pressure-sensitive tape piece in the longitudinal direction (lateral direction of the diaper), and the width of the applied portion in the longitudinal direction of the tape is 0.2 to 2.0 mm, and the unapplied portion has an interrupted portion with a width of 0.1 to 2.0 mm, and this interrupted portion is 40% or more of the adhesive surface of the other end of the pressure-sensitive tape piece extending in a direction that can be folded back onto the diaper surface; A user characterized in that the total area of the part of the part to which the adhesive is applied is equal to or greater than the total area of the unapplied part, and the total area of the adhesive surface is 5 cm ² to 15 cm ² Tape fastener for disposable diapers. 2. The width of the adhesive-applied part is 2 mm or more on 10-30% of the adhesive side of the end extending in the foldable direction of the pressure-sensitive tape piece, close to the diaper, and 10-30% of the side far from the diaper. The tape fastener for disposable diapers according to claim 1, wherein the total area of the applied portion in both regions is 60% or more of both regions. 3. The tape fastener for disposable diapers according to claim 1 or 2, wherein the pressure-sensitive tape piece has a portion not coated with an adhesive at the tip of the end extending in the foldable direction.