JPH02109561A - Disposable diaper - Google Patents

Abstract

PURPOSE:To more effectively absorb the excreta of a body and to decrease back flow and leakage by providing partial parts which are provided with a hydrophobic property by a hydrophobic material to the central region of a surface sheet. CONSTITUTION:The water repelling parts 10 formed by printing a water repellent material, which is formed by adding a slight amt. of a blue pigment to water repellent material paraffin wax to color the wax, to vertical stripe shapes to the central region part l of the surface sheet 1. Namely, the water repellent parts 10 of the patterns such as vertical stripes are provided to the central region of the surface sheet 1 having liquid permeability, by which the discharged urine, etc., are permeated through the parts exclusive of the patterned water repellent parts 10 and are absorbed into an absorptive core 3. Since the backflow is prevented in the patterned water repellent parts 10, the effect of decreasing a wet back is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a disposable diaper that more effectively absorbs body waste and has less relapse and leakage.

[Prior Art] Conventionally, a liquid-permeable top sheet, a liquid-impermeable back sheet, and a liquid-impermeable back sheet are arranged between the two sheets. ,,: Disposable diapers made of absorbent cores are known.

It is also known that the absorbent core mainly consists of an absorbent area N layer, which is covered with an absorbent sheet. Also.

A stretchable elastic body such as an elastic band stretched in at least one place is attached to the flap formed by the top sheet and the η-face sheet on both sides of the disposable diaper in contact with each other in the direction 1). It is glued in between, and also on both ends in the longitudinal direction of the omu'-).
A stretchable elastic body such as an elastic band is embedded in the front sheet and back sheet, and the elastic band on both the side flap and r1 area is stretched while being worn, and the contractile force at the time of GI causes contact. Normally, the diaper is tightened around the MNJ on rainy days, and the diaper is tightly attached from the wearer's abdomen, through the crotch area, and to the back.

The top sheet used in disposable diapers is designed to reduce so-called wet back, where urine and other excreta pass through the top sheet and are absorbed into the absorbent core, and then some of it passes back through the top sheet and returns. , polypropylene (PP
), a nonwoven fabric made of hydrophobic fibers such as polyester (PET) is used, and in order to make it permeable to liquids such as urine, the entire surface area of the top sheet is made hydrophilic using a hydrophilic agent such as a surfactant. It is generally treated with

However, due to the hydrophilic treatment, there is a problem that urine or the like passes through the top sheet layer and reaches both sides of the diaper in the width direction or both ends in the longitudinal direction, and oozes and leaks.

Hydrophilic treatment of the top sheet improves liquid permeability, but
On the other hand, the amount of wet back tends to increase, and it is not preferable to hydrophilize the entire surface of the topsheet because of the aforementioned leakage and increase in the amount of wet back.

Conventionally, in order to eliminate the discomfort of wearing diapers due to leakage and wet back, tightening with elastic bands on both sides of the diaper from the rain printing part to the abdomen and back, or increasing the absorption capacity ω of the absorbent core. Attempts have been made to arrange superabsorbent polymers to prevent leakage, and to place strips of polyethylene film on both sides of the diaper in the longitudinal direction to prevent leakage, but these efforts have not been sufficient.

[Problems to be Solved by the Invention] The present invention has been made to solve the above-mentioned problems by absorbing body excreta more effectively.

Moreover, it is an object of the present invention to provide a disposable diaper that is less likely to relapse and leak.

[Another solution to the problem Vj1 The present invention provides a diaper with an absorbent core between a liquid-permeable top sheet and a liquid-impermeable back sheet. This disposable diaper is characterized by being provided with a partial hydrophobic portion made of a hydrophobic material.

Further, the present invention is a disposable diaper in which the absorbent core is composed of an absorbent sheet and an absorbent 1aH layer.

Furthermore, the present invention provides an absorbent sheet and an absorbent fiber HFr between a liquid-permeable top sheet and a liquid-impermeable back sheet.
In a disposable diaper having an absorbent core consisting of J.
This disposable diaper is characterized in that an absorbent sheet in contact with a top sheet is provided with a partial hydrophobic portion made of a hydrophobic material.

Furthermore, the present invention provides a disposable diaper in which, in addition to the absorbent sheet, a partial hydrophobic portion made of a hydrophobic material is provided in the central region of the top sheet.

Note that there have been proposals for applying hot melt coatings or water repellent treatments to some disposable diapers.

For example, JP-A No. 61-100246 discloses that hot water is heated mainly at both ends in the longitudinal direction of the diaper, that is, at the integrally joined part with the back sheet on the back side (absorbent side) of the top sheet located around the waist when worn. It was proposed to form a melt film to prevent leakage around 1M, and it was published in JP-A-62-22.
Publication No. 3303 proposes that a breathable and waterproof sheet made of a different material from the lower part be provided in the upper part of the side flap, and that the breathable and waterproof sheet be made of 8M nonwoven fabric treated to be water repellent. ing. However, although all of these diapers have a hydrophobic part made of a hydrophobic material in a part of the diaper, the hydrophobic part is embedded in a hot melt film on the back side of the top sheet located around the waist, or in the side flaps. A disposable diaper in which the central region of the top sheet of the present invention or the absorbent sheet in contact with the top sheet is provided with a partial hydrophobic portion made of a hydrophobic material in that the water repellent treatment is applied to the nonwoven fabric made of a special material on the upper side of the portion. It is different from.

The present invention also provides a disposable diaper with a large absorption capacity, which includes a local absorbent AM layer laminated in the center of the absorbent core and highly absorbent granules arranged in a pattern. It is.

Conventionally, highly absorbent granules have been placed in the absorbent fiber layer of an absorbent core, but
It is often arranged uniformly over a surface area, and the present invention is characterized in that it is arranged intensively in the center, and this is done in conjunction with partially providing hydrophobized parts on the top sheet and absorbent sheet. be.

The disposable diaper of the present invention will be explained below with reference to the drawings.

FIG. 12 shows a partially cutaway developed plan view of a conventional disposable diaper. Since the present invention can be applied to general disposable diapers, first, the structure of the membrane-internal diaper will be explained.

The disposable diaper consists of a liquid-permeable top sheet 1, a liquid-impermeable back sheet 2, and an absorbent core 3. FIG. 13 is a partial enlarged cross-sectional view taken along the line A-A in FIG. 12, FIG. 14 is the same <B-B line, and FIG. 15 is the same <C-C line.

The absorbent core 3 may have a structure consisting of an absorbent fiber layer 4 and absorbent sheets 5, 5 covering this from above and below, as shown in FIG. 16, which is a plane view taken along A-Alill 17i in FIG. 12.

In FIG. 12, side flaps 6 on both sides of the diaper are shown.
．． 6, the extended portions of the top sheet 1 and the back sheet 2 are joined by an adhesive (not shown) with one or more elastic bands 7.7° 8.8 in between. This part is called the acid gear, and on the other hand, elastic bands 9, 9 are embedded in the darkness of the top sheet 1 and the back sheet 2 at both longitudinal ends of the diaper to make it fit tightly to the abdomen and back, and it is called the body gear. .

As the liquid-permeable top sheet used in the present invention, a dry non-woven fabric, a perforated film, etc. are used, and as the liquid-impermeable back sheet, a polyethylene film, a water-repellent non-woven fabric, etc. are used.

In addition, the absorbent core placed between the two sheets has absorbent sheets such as tissue φ paper or dry valve nonwoven fabric on the upper and lower surfaces, and absorbent sheets such as fluff pulp and rayon are used between the upper and lower absorbent sheets. It consists of two or more layers of fiber layers.

Superabsorbent granules are placed between the layers in the central region of the absorbent core. The superabsorbent granules used in the present invention include commonly known absorbent polymer particles q1 alone or granules obtained by mixing activated carbon, carboxymethylcellulose, zeolite, etc. therewith.

In addition, as the material for the elastic band for forming the crotch giers and 141' yasers, stretchable elastic bodies such as urethane rubber, urethane thread, thread rubber, and band-shaped rubber are used.

In the present invention, in each central region of the liquid-permeable topsheet 1, the absorbent sheet 5 in contact with the topsheet 1, or both the topsheet 1 and the absorbent sheet 5 in contact with the topsheet 1,
It is characterized in that a hydrophobic portion is partially provided using a hydrophobic material.

The central region of the top sheet as used in the present invention, as shown in FIG. 1, is the area in the longitudinal center of the top sheet centered on the part of the crotch that receives excrement.

In addition, the central area of the absorbent sheet in contact with the top sheet is
This refers to the area of the absorbent sheet that corresponds to the central area of the top sheet.

Further, as the hydrophobic material in the present invention, there is used an oil-based ink commonly used in printing, a water repellent such as paraffin wax, silicone, or a water repellent mixed with a color Ifl material. Further, the water repellent may be mixed with an adhesive between the top sheet of the diaper, the absorbent sheet 1-1, and the absorbent fibers to provide a partial hydrophobic portion.

Further, providing a partial hydrophobized portion using the hydrophobic material of the present invention means providing a hydrophobized portion in a pattern by printing, coating, etc. using a hydrophobic material, which is commonly known as gravure printing. 1 each of printing machines, gravure coaters, etc.! A coating machine can be used.

These printing machines and coating machines can print and coat oil-based ink or water repellent in patterns such as stripes and floral patterns.

- The absorbency of the surface area of the absorbent core in the shell is 18N, and the center of the absorbent core unless the superabsorbent granules have a very large amount of m when the surface area of the superabsorbent particles is evenly distributed. This method concentrates highly absorbent particulate matter in the center of the surface area of the absorbent core, which tends to leak in the groin area before the urine diffuses to the surface of the absorbent core. When urinating, if you just spray it evenly over the central area of the instep, the highly absorbent particles that absorb urine will turn into a gel, and especially when you urinate for the second or third time, the gel layer will become an absorption barrier layer. As a result, the absorption rate is significantly reduced, and the superabsorbent particles leak out of the absorbent core region before being absorbed and diffused, making it impossible to utilize the original properties of the superabsorbent granules. From the above points, in order to effectively increase the absorption capacity in the central area of the absorbent core, that is, at the urination position, and to effectively use a certain amount of absorbent material, it is necessary to increase the absorbent fibers and superabsorbent granules in the area. By concentrating the r1 absorbent granules in the center of Efl and distributing them in a pattern, the absorption rate becomes sufficiently high in the absorbent am parts other than the patterned parts, and I! The absorption capacity of the urine position becomes more favorable. Embodiments of the present invention will be described with reference to the drawings.

Example 1 FIG. 1 shows a water repellent part 10 in which a water repellent colored by adding a small amount of blue pigment to water repellent paraffin wax is printed in vertical stripes on the center Li portion R of the topsheet 1 of the present invention. FIG. 2 is a partially cutaway developed plan view of the diaper. Figure 2 is line A-A in Figure 1, Figure 3 is line B-B11 in Figure 1, Figure 4 is line 1 in Figure 1.
FIG. 6 is a partially enlarged sectional view of c-ctfJ in the figure.

By providing a patterned water-repellent portion 10 in the form of vertical stripes in the central region of the liquid-permeable surface sheet 1, excreted urine, etc. can pass through the portions other than the patterned water-repellent portion 10 and form an absorbent core. 3
Since the patterned water-repellent portion 10 prevents the water from returning, an effect of reducing wet back can be obtained.

Embodiment 2 FIG. 5 shows an example in which the absorbent sheet 5 in contact with the lower surface of the top sheet 1 of the disposable diaper of the present invention is provided with a vertically striped water-repellent portion 10 made of a water-repellent agent. A-A in Figure 5
7 is a partially enlarged cross-sectional view taken along line 8-13 in FIG. 5, and line DD in FIG. 5 from t in FIG. 6 and 7 show that the water-repellent portion 10 is provided in the central region of the absorbent sheet 5 in contact with the lower surface of the top sheet 1 in the cross section of the diaper shown in FIG. The figure is number 5
In the longitudinal cross-section of the diaper shown in the figure, the line D-D indicates that the water-repellent portion 10 is vertically traversed.

By providing water-repellent parts in a pattern with a water-repellent agent on the absorbent sheet, urine, etc. can pass through the parts other than the water-repellent parts 10 of the absorbent sheet 5 from the top sheet 1 and be absorbed into the absorbent tBIlt layer 4. Since the patterned water-repellent portion 10 prevents water from returning, there is an effect of reducing wet back.

Example 3 Example 3 is an example in which the lower surface of the top sheet of the present invention and the upper surface of the absorbent sheet were adhered in a pattern with an adhesive containing a water repellent. FIG. 9 is a partially enlarged sectional view taken along the line A-A of the diaper of the present invention, similar to FIG. 6. The difference from FIG. It is installed as part 11.

In Example 3, a water-repellent paraffin wax ω is added to the adhesive to an extent that does not reduce the adhesive strength, and an adhesive portion that improves water repellency is provided by applying it in vertical stripes to the absorbent sheet.

By providing the absorbent sheet 5 with adhesive portions 11 containing a water-repellent agent in a pattern and adhering them to the lower surface of the top sheet 1, urine, etc. will be absorbed by the portions of the absorbent sheet 5 other than the water-repellent adhesive portions 11. It passes through and is absorbed by the absorbent m14 layer 4, and reverse feeding is prevented by the patterned water-repellent adhesive portion 11, resulting in the effect of reducing wet back.

Example 4 FIG. 10 shows that when producing the diapers of Examples 1, 2.3, an absorbent fiber layer 4 was locally laminated in the center of the absorbent core 3 used as the absorbent core 3 to make it thicker. 2 is a partially cutaway plan view of an absorbent core 3 in which highly absorbent granules 12 are provided in an absorbent m-line layer 4. FIG. Figure 1511 shows the laminated sheets of the absorbent core shown in Figure 10 separated and received. Furthermore, the absorbent IIH layer 4 (c) is formed by locally laminating absorbent fiber layers, and the absorbent fiber layer has recesses formed by embossing in the form of vertical stripes, and superabsorbent granules 12 are arranged in each recess. It shows that it is set up.

(d) is the absorbent fiber layer i layer 5 in contact with the backsheet 2. Absorbent! By arranging the absorbent fiber HD mortar and highly absorbent granules by locally laminating the central part of the 1tIi layer, absorption is achieved in the central part of the diaper, particularly in the crotch area, which directly receives excrement. ability can be increased.

The diaper using the absorbent core 3 shown in FIGS. 10 and 11 is
By centrally concentrating the absorbent am layer 4 and arranging the highly absorbent granules 12 in the central part, urine etc. that have passed through the top sheet 1 centering around the question area are sufficiently absorbed, and the return is prevented as shown in FIGS. This can be prevented by the vertically striped water-repellent portions 10 provided on the topsheet 1 and absorbent sheet 5 shown in Figure 5, thereby passing through the surface of the topsheet 1 and reaching the side flaps on both sides or both ends in the longitudinal direction. Loss of urine etc. is significantly reduced,
Leakage from both ends of the groin area and around the waist can also be improved.

[Effects of the Invention] With the above-described structure, the present invention allows urine, etc. that has passed through the topsheet of the diaper and been absorbed into the absorbent core to be absorbed into the central area of the topsheet or the absorbent sheet in the absorbent core. This disposable diaper is partially treated with hydrophobic material to prevent relapse.

In addition, the present invention adds a hydrophobic material to the adhesive that connects the top sheet and the absorbent sheet or the absorbent sheet and the absorbent AUI layer to give it hydrophobicity. This is a disposable diaper that can prevent the relapse.

Furthermore, the present invention provides a partial hydrophobic portion made of a hydrophobic material in the central region of the topsheet or the absorbent sheet, and also provides absorbency! The absorbent fiber layer in the center of the lems can be applied locally &!
By arranging superabsorbent granules in a pattern in the central part of the absorbent fibers Hm, urine etc. are absorbed intensively in the central area of the absorbent core, and the surface sheet Alternatively, it is a disposable diaper that prevents the absorbent sheet from reversing with a partial hydrophobic portion provided on the absorbent sheet, thereby reducing leakage around the waist and both ends of the crotch area.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway developed plan view showing an embodiment of the disposable diaper of the present invention, Fig. 2 is a partially enlarged sectional view taken along line 8-A in Fig. 1, and Fig. 3 is the same <B-B 4 is a partial enlarged sectional view taken along line C-C, FIG. 5 is a partially cutaway developed plan view showing another embodiment of the present invention, and FIG. - A partial enlarged sectional view, FIG. 7 is a 8-B partial enlarged sectional view, and FIG. 8 is the same <D-DI! i1 partial enlarged cross-sectional view, FIG. 9 is A- in FIG. 5 showing another embodiment of the present invention.
FIG. 10 is a partially cutaway plan view of an absorbent core showing another embodiment of the present invention; FIG. 11 is a diagram showing each layer of the absorbent core shown in FIG. 10 separated. So, (a) and (d) are absorbent sheets, (b) and (c) are absorbent fibers, Ift
Each perspective view of FW, FIG. 12 is a partially cutaway developed plan view of a conventional disposable diaper, and FIGS. 13 and 16 are A-Ali! of FIG. 12! , FIG. 14 is a partially enlarged cross-sectional view taken along the same <[3-B line, and FIG. 15 is a partially enlarged sectional view taken along the same <[C-C line]. DESCRIPTION OF SYMBOLS 1... Top sheet, 2... Back sheet, 3... Absorbent core, 4... Absorbency 1111Fffl, 5... Absorbent sheet 1-. 6...Side flap, 7.8.9.
...Elastic band, 10...Water repellent part, 11.
... Adhesive part, 12 ... Highly absorbent granules, 1 ... Central region of surface sheet and absorbent sheet.

Claims (5)

[Claims] 1. A disposable diaper having an absorbent core between a liquid-permeable top sheet and a liquid-impermeable back sheet, the top sheet having a partially hydrophobized portion made of a hydrophobic material in the central region thereof. Disposable diapers characterized by: 2. The disposable diaper according to claim 1, wherein the absorbent core comprises an absorbent sheet and an absorbent fiber layer. 3. In a disposable diaper that has an absorbent core made of an absorbent sheet and an absorbent fiber layer between a liquid-permeable top sheet and a liquid-impermeable back sheet, a hydrophobic material is added to the absorbent sheet in contact with the top sheet. A disposable diaper characterized by being provided with a partial hydrophobized portion. 4. 4. The disposable diaper according to claim 3, further comprising a partially hydrophobic portion made of a hydrophobic material in the central region of the top sheet. 5. Claim 1.2: A local absorbent fiber layer is laminated in the center of the absorbent core, and highly absorbent granules are arranged in a pattern.
．． Disposable diaper according to 3 or 4.