JPH01118604A - Disposable diaper - Google Patents

Abstract

PURPOSE: To provide a disposable diaper without requiring a second pressure sensitive tape and hardly providing stickiness on the surface and an uncomfortable feeling to a user and facilitating the easy attachment thereof by forming a specific self-sticking adhesive layer on the surfaces of a back sheet and a fitting tape. CONSTITUTION: This disposable diaper has coated surfaces of a self-sticking adhesive having 200-1500g/25mm adhesiveness between the self-sticking adhesive layers and <=100g/25mm adhesiveness between the self-sticking adhesive layer and another surface, and formed on an outer surface of a liquid impermeable back sheet 6 and an inner surface of a fitting tape 7. The self-sticking adhesive does not adhere to the surface of another material even if they are pressed, but adhere to the surface of the self-sticking adhesive layer itself, and comprises a natural or a synthetic rubber (preferably, a copolymer comprising a styrene- ethylene block phase having styrene ends and an ethylene-propylene block) and, if necessary, an agent for imparting adhesiveness such as rosin and a factice such as rapeseed oil.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to disposable diapers, and more particularly to disposable diapers that are easy to wear and do not cause discomfort to the wearer.

[Conventional technology]

As a means for fixing the diaper to the wearer, a pressure-sensitive adhesive tape whose surface is coated with an adhesive is used.

Various types of pressure-sensitive adhesive tapes have been proposed in the past. For example, in order to peel off the pressure-bonded tape and re-bond it again (for example, when checking for urination), it is commonly used to removably adhere to the pressure-sensitive adhesive tape and create a strong bond with the back sheet. There are tapes that use a second pressure sensitive tape having a second pressure sensitive tape. Furthermore, instead of the second pressure-sensitive tape, a diaper has been proposed in which a pressure-sensitive adhesive tape and a releasable film are attached to the opposing back sheet surface when the tape is worn, and the film can be attached and peeled off anywhere on the diaper. . Also, diapers have been proposed in which the strength of the backsheet itself is increased so that the backsheet can be attached or removed anywhere on the backsheet.

[Problem that the invention seeks to solve]

However, when using a tape that uses a second pressure-sensitive tape, when actually attaching the pressure-sensitive adhesive tape to the second pressure-sensitive tape, great care must be taken to ensure that it adheres onto the second pressure-sensitive tape. For young children who move a lot, it is quite possible that the pressure-sensitive adhesive tape may be erroneously attached to a part other than the second pressure-sensitive tape. As a result, the diaper was insufficiently fixed, resulting in the disadvantage that the original performance of the diaper could not be fully demonstrated.

In addition, in diapers that use pressure-sensitive adhesive tape and a releasable film instead of the second pressure-sensitive tape, the film must be attached discontinuously to a portion of the backsheet during manufacturing. In addition to being inefficient and expensive, the backsheet where the film is attached is hard and stiff, causing discomfort to the wearer.

In addition, diapers in which pressure-sensitive tape is directly attached to and removed from the backsheet itself have the disadvantage that the backsheet is thicker than necessary and needs to be strengthened, making the entire diaper hard.

[Means for solving problems]

As a result of intensive research to solve the above problems, the inventor of the present invention found that
By providing a self-adhesive adhesive layer on the surface of the adhesive tape base material and one side of the liquid-impermeable backsheet, the adhesive tape can be placed at the correct position on the backsheet without the need for a second pressure-sensitive tape. The present invention was accomplished by discovering a disposable diaper that can be bonded to a diaper without making the backsheet unduly hard.

That is, the present invention provides a disposable diaper that has a liquid-impermeable backsheet constituting one surface of the diaper and fastening tapes provided on both sides of the diaper. A sticky adhesive layer is provided,
The adhesive strength of the self-adhesive adhesive is 100 g/25III width or less, and the adhesive strength between the surfaces coated with the self-adhesive adhesive is 200 to 1
The present invention provides a disposable diaper having a weight of 500 g/25 cm and a width of 25 cm.

In the pair disposable diaper of the present invention, the indigenous tape exhibits adhesive properties only on the area of the back sheet where the self-adhesive adhesive is applied, so even if the tape is accidentally pressed to an area other than the intended area, the tape will It became possible to re-adhere the self-adhesive adhesive in the correct position on the backsheet without having to adhere it. In addition, there is no need to increase the strength of the backsheet by simply applying a self-adhesive adhesive to the backsheet, and it is possible to obtain a fastening tape that can be attached and peeled off anywhere on which the self-adhesive adhesive is applied. Can be done.

The self-adhesive adhesive used in the present invention has the characteristic that it does not adhere to other surfaces even when pressed, but it adheres to surfaces coated with the self-adhesive adhesive with a slight pressure, and - For boat fishing, natural rubber, neoprene rubber, polyisobutylene rubber, polyisoprene rubber, butyl rubber, and styrene-isoprene-styrene block copolymers (S
IS), styrene-butadiene-styrene type block copolymer (SBS), polystyrene-terminated styrene-
Consists of one type of elastomer selected from block copolymers (SEBS) consisting of two layers, an ethylene block layer and an ethylene-butylene rubber layer, or a mixture of two or more elastomers, and if necessary, a tackifier that has good compatibility with the elastomer. A mixture of agents or factice may also be used.

Among them, 5RBS, which can be easily applied and removed and has a large shearing force, is particularly preferred. As a tackifier, rosin, polyterpene resin, terpene/phenol resin, C2
Examples include petroleum resins based on oil, C1 petroleum resins, hydrogenated alicyclic petroleum resins, and the like. Examples of factices include vegetable oil fatty acid glycerides such as rapeseed oil.

In the present invention, the components of the self-adhesive adhesive applied to the back sheet surface and the fastening tape surface of the disposable diaper do not need to be the same.

The self-adhesive physical properties of the self-adhesive adhesive used in the present invention preferably include an adhesive force of 100 g/25 mm width or less, and an adhesive force between surfaces coated with the self-adhesive adhesive of 200 to 1500 g/25 m width. Adhesive strength is 10g/25m width or less,
In addition, it is desirable that the adhesive strength between the surfaces coated with the self-adhesive adhesive (hereinafter referred to as self-adhesive strength) be 200 to 1500 g/25 mm width. If the adhesive force is greater than 100g/25m+width, the coated surface will become sticky, and the self-adhesive adhesive will also adhere to areas other than the coated surfaces, which is not the purpose of zero release.

If the self-adhesion strength is less than 200g/25iun width, it may easily peel off from the coated surface during use;
If the width is larger than 725 μm, problems such as tearing of the back sheet will occur when the tape once bonded is peeled off again, which is not the intention of the present invention.

In addition, in the present invention, the adhesive force of the self-adhesive adhesive refers to the first
As shown in the figure, a self-adhesive tape obtained by applying self-adhesive adhesive 3 to a polypropylene tape base material 2 with a thickness of 60μ and a width of 25mm to a film thickness of 30±5μ is applied to a stainless steel plate (
SOS 304) 1 is pressed with a 1 kg roller, the loose part is folded back 180 degrees against the stainless steel plate, and the force is pulled at a peeling speed of 300 mm/min. Also, the self-adhesive strength of self-adhesive adhesive is as shown in Figure 2.
An axially stretched polyethylene film 4 was pasted on an acrylic plate 5, and a self-adhesive adhesive 3゛ was applied onto the film 4 so that the film thickness was 30±5μ, and the same tape as described above was used for the adhesive force measurement. The self-adhesive tape was pressed onto the film 4 with a 1 kg roller, folded back 180 inches, and peeled at a peeling speed of 300 nu.
It refers to the force when pulled in ++/min.

The self-adhesive strength when the self-adhesive adhesive components applied to the back sheet and the fastening tape are different is shown in Fig. 2. Apply the self-adhesive adhesive on the adhesive tape side and perform the same measurement.

The adhesive tape base material used in the present invention includes, but is not particularly limited to, single or composite materials such as paper, film, nonwoven fabric, and cloth.

Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited thereto.

FIG. 3 is a plan view showing an example of the disposable diaper of the present invention, and FIG. 4 is a perspective view of the disposable diaper when the diaper is worn. The back sheet 6 of the zero-use disposable diaper is made of a uniaxially stretched polyethylene film with a thickness of 40 μm, and a self-adhesive adhesive 8 is applied to the surface thereof. In addition, the indigenous tape 7 has a thickness of 60 mm.
It is made of a polypropylene film of μ, and a self-adhesive adhesive 8 is also applied to its surface. When the adhesive tape 7 is adhered to the back sheet 6 in the state before it is adhered (shape B indicated by the broken line in FIG. 4), the adhesive tape 7 becomes the back sheet coated with the self-adhesive adhesive 8. It becomes like facing the surface.

Regarding the range in which the self-adhesive adhesive 8 is applied to the backsheet 6, at least 18 or more in the longitudinal direction of the backsheet is applied from the short side where the adhesive tape 7 is not provided to the entire surface in the transverse direction. Preferably, it is applied to the site. In this case, the coating may be applied in a pattern, and the area at that time may be 30% or more of the coating range. The coating thickness is preferably 100μ or less. If it exceeds 100μ, the backsheet will feel hard and stiff.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 100 parts by weight of 5EBS (styrene-ethylene/butylene-styrene block copolymer), hydrogenated terpene resin 4
0 parts by weight and dissolved in toluene at a solution concentration of 25% to obtain a self-adhesive adhesive. A disposable diaper was manufactured by applying the coating to a thickness of 60μ.

The adhesive strength, self-adhesive strength, stickiness of the coated surface, and adhesion of the tape to the backsheet surface to which no self-adhesive adhesive was applied were investigated for the obtained adhesive tape for disposable diapers, and the results are shown in Table 1. It was shown to.

Furthermore, the disposable diapers thus obtained were subjected to a wearing test for 10 days on 30 infants, and the ease of putting on the diapers was evaluated according to the following evaluation criteria, and the results are shown in Table 1.

Evaluation criteria> Angry mother'a 15 to less than 20 people Example 2 As a self-adhesive adhesive component, 100 parts by weight of 5EBS and 70 parts by weight of hydrogenated terpene resin were mixed and the solution concentration was 2 in toluene.
Disposable diapers were produced in the same manner as in Example 1, except that a 5% solution was used and the coating was applied so that the film thickness after drying was 80 μm, and the physical properties thereof were evaluated.

The results are shown in Table-1.

Example 3 As self-adhesive adhesive components, 100 parts by weight of 5IS (styrene-isoprene-styrene type block copolymer), styrene-butadiene copolymer (styrene content 85%)
A pair of disposable diapers were produced in the same manner as in Example 1, except that a mixture of 20 parts by weight of polyterpene resin and 20 parts by weight of polyterpene resin dissolved in toluene at a concentration of 25% was used, and its physical properties were evaluated.

The results are shown in Table-1.

Example 4 As a self-adhesive adhesive component, 100 parts by weight of natural rubber, SI
Example 1 except that 60 parts by weight of S and 30 parts by weight of rapeseed oil were mixed and dissolved in toluene at a concentration of 25%.
Disposable diapers for pairs were manufactured according to the method described above, and their physical properties were evaluated.

The results are shown in Table-1.

Example 5 As self-adhesive adhesive components, 100 parts by weight of butyl rubber, 30 parts by weight of natural rubber, 20 parts by weight of polyisobutylene rubber,
Mix 20 parts by weight of polyterpene resin and add 30 parts by weight to toluene.
A disposable diaper was produced in accordance with Example 1 except that the solution dissolved at % concentration was used, and its physical properties were evaluated.

The results are shown in Table-1.

Example 6 A self-adhesive adhesive obtained by mixing 100 parts by weight of SR85 and 100 parts by weight of hydrogenated terpene resin and dissolving the mixture in toluene at a solution concentration of 30% was applied to the adhesive tape surface 7 in FIG. 4 to form a film after drying. Coat it to a thickness of 50μ, and then apply 5EBS100.
A self-adhesive adhesive obtained by mixing 50 parts by weight of hydrogenated terpene resin and dissolving it in toluene at a solution concentration of 25% was applied to the back sheet surface 6 in FIG. 4 to a film thickness of 50 μm after drying.
A disposable diaper was manufactured in accordance with Example 1, except that the coating was applied so as to give the following properties, and its physical properties were evaluated.

The results are shown in Table-1.

Example 7 100 parts by weight of SIS and styrene-butadiene copolymer (styrene content: 85
%) and 20 parts by weight of polyterpene resin were mixed and dissolved in toluene at a solution concentration of 30%, and a self-adhesive adhesive was applied. , and evaluated its physical properties.

The results are shown in Table-1.

Comparative Example 1 A pair diaper was produced according to Example 1 except that a mixture of 199 parts by weight of 5IS, 30 parts by weight of naphthenic oil, and 70 parts by weight of polypentene resin was used, and its physical properties were evaluated.

The results are shown in Table-1.

Comparative Example 2 A disposable diaper was produced in accordance with Example 1 except that a mixture of 1 part of natural rubber 100 ni, 20 parts by weight of naphthene oil, and 80 parts by weight of polypentene resin was used, and its physical properties were evaluated.

The results are shown in Table 1.

Table 1 ■ [Effects of the Invention] The disposable diaper of the present invention does not require a second pressure-sensitive tape by providing a self-adhesive adhesive layer on the surfaces of the backsheet and outerwear tape. Since the adhesive strength is low, the applied surface does not become sticky. Furthermore, since the fastening tape exhibits adhesive properties only on the parts of the backsheet to which the self-adhesive adhesive is applied, it is possible to correctly fix the diaper without adhering the fastening tape to the wrong part during use. Further, the back sheet after applying the self-adhesive adhesive does not feel hard and stiff, and does not cause discomfort to the wearer.

[Brief explanation of the drawing]

Figure 1 is a diagram showing a method for measuring the adhesive strength of a self-tapping tape, Figure 2 is a diagram showing a method for measuring a self-adhesive strength of a self-tapping tape, and Figure 3 is an example of a pair diaper of the present invention. FIG. 4 is a perspective view showing an example of the disposable diaper of the present invention when it is being worn, and the state before the tape is attached is shown by broken lines. 1 Stainless steel plate 2: Polypropylene base material 3.3': Self-adhesive adhesive 4: Uniaxially stretched polyethylene film 5 Niacrylic plate 6: Liquid-permeable back sheet 7: Fastening tape 8: Self-adhesive adhesive coated surface

Claims (1)

[Claims] 1. In a disposable diaper that has a liquid-impermeable backsheet constituting one surface of the diaper and fastening tapes provided on both sides of the diaper, a self-adhesive adhesive layer is provided on the surfaces of the backsheet and the fastening tape. provided, the adhesive strength of the self-adhesive adhesive is 100 g / 25 mm width or less, and the adhesive strength between the self-adhesive adhesive coated surfaces is 200 to 1500 g / 25 m
A disposable diaper characterized by having a width of m.