JPS5846561B2 - disposable diaper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a disposable diaper, and particularly to a disposable diaper using a tape fastener whose adhesive strength decreases as the peeling speed increases.

Conventionally, safety pins were used to secure pair diapers to the wearer, but tape fasteners (adhesive tape) were started to be used for convenience, and convenience was also a factor. diapers have become widely used.

However, known adhesive tapes have a strong adhesive strength, and there is a risk that the diaper will peel off while being worn, and the back sheet may tear when the diaper is removed after wearing, resulting in urine leaking from the tear. The disadvantage is that it is impossible to use tape.

Furthermore, when mothers start wearing the tape, they often tear the adhesive tape from the release paper or release tape in a hurry, which often results in the tape being torn from the boxwood. To improve this, so-called Y-shaped tapes have been devised. We still haven't gotten enough.

The present inventors conducted intensive research to improve the drawbacks of conventional tape fasteners, and as a result, they arrived at the present invention.

That is, the present invention provides a pad assembly comprising a top sheet, a back sheet, and an absorbent layer located between the two sheets; A pair of disposable diapers comprising a tape fastener extending in both directions, characterized in that the tape fastener is coated with a pressure-sensitive adhesive containing an agent for reducing adhesion to speed. This is what we provide.

The top sheet of the disposable diaper of the present invention is the sheet on the side that comes into contact with the wearer's skin, and is a porous liquid-permeable sheet, such as a currently commercially available nonwoven fabric containing a large amount of hydrophobic fibers. Weight per unit area (basis weight) is 20 to 3
0P/m etc. can be used.

In addition, a liquid-impermeable sheet is used as the back sheet of the disposable diaper of the present invention, for example, 3-5% TiO2 is added to low-density polyethylene, and after molding into a film with a thickness of 25-30 μm, For improvement, you can use embossed ones.

Furthermore, a film made of polypropylene or the like can be used instead of polyethylene, and in some cases, a nonwoven fabric can also be used.

Further, as the absorbent layer of the disposable diaper of the present invention, cotton-like pulp, water-absorbing paper, polymeric absorbent material, etc. are used.

In the disposable diaper of the present invention, water-absorbing paper or moisture-resistant paper can be used between the surface absorbent layers.

Is the basis weight 20 for this paper? /m is preferable,
It is also possible to treat with a sizing agent for the purpose of adjusting water absorption.

Furthermore, moisture-resistant paper or water-absorbing paper can also be used between the absorbent layer and the back sheet.

The speed-adhesive strength reducing agent used in the present invention is one that imparts properties such that the adhesive strength decreases as the peeling speed increases, and is preferably a terpene phenol resin.

The pressure-sensitive adhesive used in the present invention includes 100 parts by weight of rubber-based nidistomer and 45 to 57 parts by weight of terpene phenol resin.
Compositions consisting of 0 parts by weight and 8 to 130 parts by weight of liquid rubber are preferred.

The tape fastener according to the present invention is made by applying a pressure-sensitive adhesive as described above to a support such as paper or polyethylene film.
It can be obtained by coating to a thickness of about 300μ.

Next, the present invention will be explained in more detail with reference to the drawings.

1 to 4 are plan views showing embodiments of the disposable diaper of the present invention, and FIG. 5 is a schematic cross-sectional view taken along the line A-A' in FIG. 1.

However, FIG. 5 shows a state in which the tape fastener 3 is folded back toward the topsheet side.

The disposable diaper of the present invention includes a pad assembly 1 consisting of a top sheet 6, a back sheet 2, and an absorbent layer 5 located between these two sheets, and one end fixed to the side of the pad assembly 1. It consists of a tape fastener 3 whose other end extends outward from the side.

The back sheet 2 may be folded back toward the top sheet side to form side flaps as shown in FIGS. 1 and 2, or may not be folded back toward the top sheet side as shown in FIGS. 3 and 4.

The pad assembly 1 may be a rectangular one as shown in Figures 1 and 2, a narrower part corresponding to the wearer's crotch as shown in Figure 3, or a T-shaped pad assembly as shown in Figure 4. There are shapes, etc.

Such a pad assembly is integrally formed by stacking a back sheet 2, an absorbent layer 5, and a top sheet 6.

The tape fastener 3 is most commonly shown in Figure 1, Figures 3-4.
As shown in the figure, the pad assemblies 10 are fixed in pairs facing each other on both sides, but they do not have to face each other as shown in FIG. 2.

The portion of the tape fastener 3 to which the adhesive T is applied is protected with release tape or release paper 4 before use.

This release tape or release paper 4 can be attached to the surface of the pad assembly 10 as shown in FIG. 6, and can be shaped like a Y to sandwich the diaper body, or can be attached to the surface of the pad assembly 10 as shown in FIG. It may be attached on top of the adhesive I on the top surface.

Further, as shown in FIG. 6, it is preferable that the tape fastener 3 is provided with an open end 8 at its tip to make it easier to peel off the tape fastener.

This open end 8 is attached to the tip of the tape fastener 3 with adhesive T.
It can be made by providing a part that is not coated or by partially bending the tip of the tape fastener.

In the disposable diaper of the present invention having a tape fastener as described above, when the adhesive tape is peeled off from the release paper or release tape when worn, the peeling speed is high and the adhesive force is low, so there is no risk of tearing the tape even if you hurry. Also, when peeling off the tape fastener from the backing sheet to check whether the tape sticks out a lot during use, the adhesive strength is similarly reduced, and the backing sheet will not be torn, making it possible to reuse it. .

In addition, since the force applied to the diaper when trying to peel it off during wear is gentle, the adhesive strength is sufficiently large that there is no fear that it will peel off during wear.

Furthermore, when the diaper is about to be thrown away, the used diaper can be rolled up and fixed with tape.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 A polyethylene film (thickness: 170 μm) was coated with an adhesive having the composition shown in Table 1, and dried to produce an adhesive tape.

The thickness of the adhesive layer is 30μ. The relationship between tension speed and adhesive strength of this adhesive tape was investigated, and the results are shown in Table 1.

Adhesive strength was measured by sandwiching a double-sided adhesive tape of the same size between a back sheet (polyethylene thickness 30 μm embossed) cut into 125 mm length and 30 pieces horizontally and a polyacrylic board of the same size. The entire surface of the back seat is adhered to the acrylic plate, and the body is applied to the adhesive tape that is cut into 250 vertical and 25 sideways, and overlapped with the 500S 'roller. After folding the other end 180 degrees and peeling off 25 times by hand, each end of the adhesive tape and adherend is fixed to the upper and lower chucks of a constant speed tensile tester, and a tensile test is performed. 180 degree peeling adhesion measurement By law, 300mm1m1n, 1000z71/mm,
The tensile speed was 4000 MAIL/Ha.

(Refer to JISC2107).

Examples 2 to 6 Adhesive tapes were made in the same manner as in Example 1 using various adhesives shown in Table 1.

However, the thickness of the adhesive layer was 40 μm.

The relationship between the tensile speed and adhesive strength of these tapes was investigated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 1 Using adhesive tape Y-2621 manufactured by Sumitomo 3M Co., Ltd., the relationship between tension speed and adhesive strength was investigated in the same manner as in Example 1, and the results are shown in Table 1.

The analysis results of the adhesive of the adhesive tape Y-2621 were as follows.

Polyterpene 45.4% cysuto 4-ho+)isoprene 41.2% Jitsukijijian
2.7% titanium oxide
10.7% From the results in Table 1, Example 1
It can be seen that the adhesive force decreases as the peeling speed increases in samples 6 to 6.

On the other hand, it can be seen that in Y2621 (Comparative Example 1), which is currently widely used, the adhesive force increases as the tensile speed increases.

Therefore, with Y-2621, the back sheet will be torn if it is not removed carefully and slowly.

Examples 7-8, Comparative Example 2 Adhesive tapes prepared in Examples 1 and 2 and Y-2621
They assembled a huge disposable diaper using the same technology, and actually tested it on babies.

Table 2 shows the results of repeated use of 10 sheets for 10 babies (and 10 housewives).

Further, in practical evaluation, the tape did not peel off during practical use.

[Brief explanation of the drawing]

Figures 1 to 4 are plan views showing embodiments of the disposable diaper of the present invention, Figure 5 is a schematic cross-sectional view taken along line A-A' in Figure 1, and Figures 6 to 7 are tapes according to the present invention, respectively. It is a sectional view showing an example of a fastener. 1...Pad assembly, 2...Back sheet, 3...Tape fastener, 4...
Release paper or release tape, 5... Absorption layer, 6...
...Top sheet, 7...Adhesive, 8...
...Open end.

Claims (1)

[Claims] 1. A pad assembly consisting of a top sheet, a back sheet, and an absorbent layer located between the two sheets, one end of which is fixed to a side of the pad assembly and the other end of which is fixed to a side of the pad assembly. A pair of disposable diapers that prevent tape fasteners from extending outwardly from the tape fasteners, characterized in that the tape fasteners are coated with a pressure-sensitive adhesive containing an agent that reduces adhesion to speed. Diaper. 2. The disposable diaper according to claim 1, wherein the speed adhesion reducing property imparting agent is a terpene phenol resin. 3. The pressure-sensitive adhesive containing the speed-adhesive strength reducing agent is a composition comprising 100 parts by weight of a rubber-based nidistomer, 45 to 570 parts by weight of a terpene phenol resin, and 8 to 130 parts by weight of liquid rubber. Disposable diapers as described in Scope 2.