JPH0442018B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a disposable diaper having a leak-proof structure. [Prior Art] Various leakage prevention mechanisms for disposable diapers have been proposed. One is the special public service in 1972.
40267, JP-A No. 54-115939, and JP-A No. 52-120045, an elastic body is used along the edge in the longitudinal direction of a disposable diaper, gears are provided on the edge in advance, Some diapers have the wearer's crotch area tightly attached to the diaper to prevent leakage. or,
One is as seen in Japanese Patent Application Laid-Open No. 57-35002,
Some disposable diapers have water-absorbing and shrinkable fibers installed along the edges in the longitudinal direction, so that they shrink when leakage occurs, making the wearer's crotch area tightly attached to the diaper to prevent leakage. [Problems to be Solved by the Invention] However, the leakage prevention mechanism described above has various drawbacks. In other words, the former uses the elastic contraction force of an elastic material such as rubber, and in order to prevent urine leakage, it is necessary to firmly press down on the wearer's crotch area. The skin often turns red or hurts, and
It has the disadvantage that it tends to get stuffy because the crotch area is in close contact with each other. In addition, the latter has the disadvantage that the edge of the diaper does not gather until the water-absorbing shrinkable fibers become wet with urine, so it tends to get wet if the wearer has stool, especially diarrhea or loose stool, before urinating. [Means for Solving the Problems] The present inventors have arrived at the present invention as a result of intensive research to solve the above-mentioned drawbacks of the conventional disposable diapers. That is, the present invention provides a disposable diaper comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent layer located between these two sheets.
Water-absorbing shrinkable fibers, which shrink in length and are imparted with elasticity when in contact with water, extend along the longitudinal direction across the longitudinal center of the disposable diaper, and overlap the absorbent layer. The outer surface sheet of the water-absorbing and shrinkable fibers and a part of the surface sheet on the absorbent layer are respectively glued near the middle of the longitudinal direction on both sides. The distance between the two adhesive points on both sides is 50 mm or more, and the length of the adhesive part is 10 mm or more.
50 mm, and furthermore, the elastic force (the elastic part of the diaper is This invention provides a disposable diaper characterized by being equipped with a sheet-like elastic stretchable member having a force of more than 100 g and less than 600 g when stretched over the entire length. Embodiments of the present invention will be described in detail below with reference to the drawings. Fig. 1 is a perspective view showing one embodiment of the disposable diaper of the present invention, Fig. 2 is a sectional view taken along the line A-A, and Fig. 3 shows another embodiment of the disposable diaper of the present invention. FIG. The disposable diaper of the present invention includes a liquid-permeable top sheet 1, a liquid-impermeable back sheet 2, and an absorbent layer 7.
Water-absorbing shrinkable fibers 5 are fixed on both sides of the absorbent layer 7 without overlapping with the absorbent layer, and which contract in length and are imparted with elasticity by contact with water. Further, the outer surface sheet of the water-absorbing shrinkable fibers 5 and the surface sheet on the absorbent layer 7 are partially adhered at two locations near the middle in the longitudinal direction. This adhesive part 4
is hereinafter referred to as leg spot. Further, an elastic elastic member 3' is installed outside the leg spot for the purpose of providing elastic gears 3. The purpose of such disposable diapers is to prevent leakage of urine and feces, and to prevent pressure on the wearer's skin. This point will be explained below. In other words, the leg spots 4 and the elastic gears 3 form a pocket 8 extending from the buttocks to the crotch of the wearer, and this pocket prevents feces from leaking when the wearer is not urinating. Further, regarding urine, the water-absorbing contraction fibers 5 prevent leakage from the thighs. What is important here is to create an effective pocket using the elastic gears 3 and leg spots 4, and for this purpose, the position and length of the elastic member and the length of the leg spots are important issues. In order to form the above-mentioned effective pocket, the distance a between the leg spot 4 and the elastic stretchable member 3' must be 5 mm or more; if it is less than 5 mm, it is difficult to form an effective gear near the leg spot due to the resistance of the leg spot. The formed pockets are shallow and small, making it easy for stool to leak. Also, regarding the length of the elastic stretchable member, if it is too short, it will not be possible to form an effective pocket for fecal leakage, as described above, so the length in the stretched state must be at least 70 mm, preferably 100 mm or more. Another important thing here is the elasticity of the elastic stretchable member. This elasticity needs to balance fecal leakage and skin pressure before the water-absorbing and contracting fibers act. In other words, if this elastic force is too strong, it will put pressure on the skin, and if it is too weak, it will cause leakage. Also, especially in the case of infants, the older the wearer is, the more active they are and the crotch area is larger, which tends to cause leakage. Conversely, smaller wearers, such as newborns, do not have much of a problem with leakage, but their skin is still sensitive. There is a point that it puts too much pressure on the skin. Considering these points, the elastic force when the diaper is stretched to its full length is 100 g.
It must exceed 600g, and
The elastic force at 20% elongation is preferably 20 to 150 g. The elastic and stretchable member forming such gears may be any material as long as it exhibits the above characteristics, but generally urethane, polybutadiene,
Sheet-like materials such as EVA, modified polyethylene, single substances, composites, or composites of these and polyethylene such as films and foams are used. Further, the width of the elastic and stretchable member used in the present invention is preferably wide from the viewpoint of putting pressure on the wearer, and is preferably 4 to 40 mm. In the present invention, thin elastic elastic members such as thread-like rubber tend to leave marks on the skin when the elastic force becomes high. In this case, it is more preferable to use a sheet-like elastic and stretchable member with a width of 15 mm or more. In addition, in order to make the contraction of the water-absorbing shrinkable fibers more effective, it is necessary to keep the water-absorbing shrinkable fibers 5 a certain distance away from the absorbent layer 7, and since the absorbent layer acts as a hindrance in the vicinity of the absorbent layer and prevents the shrinkage, it is not effective. It is more effective to prevent urine leakage if the distance b from the end of the absorbent layer 7 to the water-absorbing shrinkable fibers 5 is at least 10 mm. As the water-absorbing shrinkable fibers used in the present invention, twisted yarns such as carboxymethyl cellulose fibers, acrylic hydrolyzed fibers, and vinylon fibers as disclosed in JP-A-57-35002 are effective.
Further, it is preferable that the water-absorbing shrinkable fibers have a mechanism that allows urine to be introduced from above the absorbent layer. Although the embodiments of the present invention have been described above, the present invention is not limited to this explanation only, and can be arbitrarily modified and implemented within the scope of the spirit thereof. [Example] Hereinafter, the present invention will be explained in more detail with reference to Examples. Examples 1 to 4, Comparative Example 1 As shown in Figure 4, 300 (width) x 430 (length) m/
150 (width) × in the center of the polyethylene sheet 10 of m
Place the absorbent layer 11 with a length of 380 m/m, place the elastic elastic member 12 at a position 22 mm from the end of the polyethylene sheet, place the water-absorbing shrinkable fiber 13 40 mm inside the elastic elastic member, and then remove the polyethylene sheet. The diaper was covered with a nonwoven fabric 14 of the same size as , the nonwoven fabric and polyethylene sheet were bent at a position 68 mm from the edge, and glued at two points 25 mm from the folded position (leg spots 15) to create a diaper. In addition, as the elastic and stretchable members, the following elastic and stretchable members 1 to 5 are used.
An elastic stretchable member was installed with an effective elastic length of 100 mm. Elastic stretchable member 1 (1) Polyethylene composite film 15040 manufactured by Wright Shokai Co., Ltd. (width 15 mm) (2) Elastic force when the diaper is stretched to its maximum (44% elongation) 310g load (3) Diaper stretched by 20% Elastic force when stretched 90g load Elastic stretch member 2 (1) Polyethylene composite film 82035 manufactured by Wright Shokai Co., Ltd. (width 15mm) (2) Elastic force when the diaper is stretched to its maximum (45% stretch) 440g load ( 3) Elastic force when the diaper is stretched 20% 180g load Elastic stretch member 3 (1) Polyethylene composite film 15030 manufactured by Wright Shokai Co., Ltd. (width 10 mm) (2) Elastic force when the diaper is stretched to the maximum ( 42% elongation) 130g load (3) Elastic force when diaper is stretched 20% 45g load Elastic stretchable member 4 (1) Mitsui Petrochemical Co., Ltd. Tafmer P (PE) modified film (width 20mm) (2) Elastic force when the diaper is stretched to the maximum (62% elongation) 640g load (3) Elastic force when the diaper is stretched 20% 120g load The diaper made as above is used for M size infants (weight 5-7kg). The product was worn by 10 people each weighing 7 to 9 kg and 9 to 10 kg, and the effects on the skin were examined. The effect on the skin was measured by the number of people who wore the diaper for 3 hours and left red marks from the elastic on their skin. The results are shown in Table 1. 【table】

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the disposable diaper of the present invention, Fig. 2 is a sectional view taken along the line A-A, and Fig. 3 shows another embodiment of the disposable diaper of the present invention. Cross-sectional view, Figure 4 shows Examples 1 to 4 and Comparative Example 1
FIG. 2 is a cross-sectional view of the diaper used in 1: Top sheet, 2: Back sheet, 3: Elastic gears, 4: Leg spots, 5: Water absorbing shrink fiber, 6: Tape fastener, 7: Absorbent layer, 8: Pocket, 10: Polyethylene sheet, 11: Absorbent layer, 12 : Elastic stretchable member, 13: Water-absorbing shrinkable fiber, 14: Non-woven fabric, 15: Leg spot.

Claims (1)

[Claims] 1. A disposable diaper consisting of a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent layer located between these two sheets, which shrinks in length upon contact with water. and the water-absorbing shrinkable fibers imparting elasticity are fixed along the longitudinal direction across the longitudinal center of the disposable diaper, and on both sides of the absorbent layer in the lateral direction without overlapping the absorbent layer. The outer surface sheet of the water-absorbing and shrinkable fibers and a part of the surface sheet on the absorbent layer are adhered to each other near the middle in the longitudinal direction on both sides, and the distance between the two adhesion points on both sides is is 50 mm or more, and the length of the adhesive part is 10 to 50 mm,
Furthermore, the elastic force (the elastic part of the diaper is the length of the entire length of the diaper) is applied to the middle part of the longitudinal direction at a distance of 5 mm or more from the above two adhesive points toward both ends of the diaper for a length of 70 mm or more along the longitudinal direction. 1. A disposable diaper, characterized in that a sheet-like elastic stretchable member having a force (when stretched) of more than 100 g and less than 600 g is installed. 2. The disposable diaper according to claim 1, wherein the elastic force of the elastic stretch member at 20% elongation is 20 to 150 g. 3. The disposable diaper according to claim 1 or 2, wherein the elastic stretchable member has a width of 4 to 40 mm.