JPH0317499B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to paper diapers, and particularly to paper diapers that have improved water absorption performance and are capable of efficiently absorbing water over a wide area of the diaper.

Conventionally, various paper diapers have been provided not only for infants but also for adults, but normal paper diapers are made of a water-absorbent layer made of a band-shaped layer of water-absorbing materials such as paper cotton or crushed pulp laminated to an appropriate thickness. The lower surface is wrapped in a water-impermeable sheet such as a vinyl sheet, the upper surface is covered with a water-permeable sheet such as a nonwoven fabric, and both sides and ends of the sheets are welded together.

However, in the case of paper diapers with the above structure, when urinating, water is concentrated in the central part, so especially for adults, the water absorption effect is sufficient unless the thickness of the water absorption layer is increased. was something that could not be obtained.

However, if the water-absorbing layer is made thicker, it does not come in close contact with the body when applied, causing leakage, has an unpleasant feel when worn, and is expensive.

Conventionally, paper diapers have been made so that only the longitudinal central part of the water-absorbing layer is made thicker and the other parts are made thinner to increase the water-absorbing ability in the central part, or when the water-absorbing layer absorbs water. There have been provided products in which a water-absorbing and coagulating substance that gels and coagulates is mixed in, and the amount of water absorbed is increased by allowing the water-absorbing and coagulating substance to absorb water.

However, in the case where only the central part of the water absorbing layer is medium height, another narrow water absorbing layer is placed over the longitudinal center of one water absorbing layer, and this is combined with a water impermeable sheet and a water permeable sheet. Because it is a wrap-around configuration,
Although the amount of water absorbed in the central part certainly increases,
The permeability to other parts of the diaper is not improved, and because another narrow absorbent layer is layered on top of the paper diaper's absorbent layer, the diaper becomes extremely stepped and feels uncomfortable when in use. Shortcomings are inevitable.

In addition, if a water absorption coagulation substance is mixed into the water absorption layer, the amount of water absorbed increases, but this kind of water absorption and coagulation substance is expensive, and mixing it into the entire surface of the water absorption layer reduces the cost of the paper diaper itself. Not only does this water-absorbing and coagulating material absorb water during urination and becomes a gel, it gives the wearer an extremely unpleasant sticky feeling, and especially when worn by adults, water absorption increases due to the weight of the wearer. The water-absorbing solidified substance that has become a gel moves and protrudes from the water-absorbing layer,
The sensation of touching the skin through the non-woven fabric causes a truly unpleasant feeling. Furthermore, in paper diapers that have a structure in which water-absorbing layers are laminated in layers and a water-absorbing and coagulating material is sprinkled between the layers, when the water-absorbing layer becomes a water-absorbing gel, the upper and lower parts of the water-absorbing layer separate and shift, and the coagulating material that has become a water-absorbing gel becomes There is an inconvenience that it protrudes and causes discomfort.

Although conventional paper diapers each have their own advantages, they also have many drawbacks, and paper diapers that are comfortable to use, have high water absorption capacity, and are economical are still available. Currently, this is not the case.

In view of this, the present invention drastically improves the structure of the water absorption layer in conventional paper diapers, provides excellent usability,
This was done with the aim of providing paper diapers that have a large water absorption capacity and are economically obtainable.

In order to achieve the above object, in the present invention,
Both ends of a water-absorbing material formed into a band of a desired thickness by laminating paper cotton, crushed pulp, etc. are folded back over the required width to form a first folded part, and moisture is absorbed within the range between the folded surfaces. A water-absorbing and coagulating substance that gels by being interposed in a linear manner in the longitudinal direction, and the folded pieces of the first folded part are on the inside, and the folded parts of the first folded part touch each other over a wider width. Fold back to the second
By forming the folded portions, a water absorbing layer that exhibits a mid-to-height shape is formed with a gentle slope, and a water-impermeable sheet such as vinyl is placed on the bottom surface of this water-absorbing layer, and a diffused water-permeable sheet such as non-woven fabric is placed on the top surface. This is because the sides and ends of these sheets are joined by welding or the like.

The present invention will be explained below with reference to embodiments shown in the drawings.

The paper diaper 1 according to the present invention includes a water absorbent layer 2, a water impermeable sheet 3 such as a vinyl sheet that covers the lower surface of the water absorbent layer 2, and a diffusion water permeable sheet 4 such as a nonwoven fabric that covers the upper surface of the water absorbent layer 2. The water-impermeable sheet 3 and the water-permeable sheet 4 are sealed by welding at both longitudinal sides 5, 5 and at both ends 6, 6.

The present invention has a main feature in the structure of the water absorbing layer 2.

This water-absorbing layer 2 is made of a water-absorbing material made by mixing old pulp with thermoplastic fibers and heating it to form a strip of the desired thickness, as shown in the cross-sectional shape of Figure 2.
Both sides in the longitudinal direction are folded back over a required width (approximately 1/10 of the total width of the water-absorbing material) to the upper side to form first folded parts 7, 7, and folded pieces 8, 8 of the first folded parts 7, 7. A water-absorbing and coagulating substance 9, 9 that absorbs water and turns into a gel is interposed in a linear manner in the longitudinal direction between the upper surface and the upper surface where these are joined. The linear width on which the water-absorbing and coagulating substances 9, 9 are deposited is preferably a narrow width of 20 m/m or less, and the deposition may be not only continuous but also intermittent.
In addition to direct attachment, it is also possible to impregnate a string-like material or a band-like material with water-absorbing and coagulating substances 9, and sandwich the material between them.

After forming the first folded parts 7, 7 as described above, the folded pieces 8, 8 are turned inside again, and the folded parts 10, 10 of the first folded parts 7, 7 touch or are close to each other. The second folded portions 11, 11 are formed by folding back the water absorbing layer 2 as shown in FIG. is formed.

The water absorption layer 2 configured as described above is covered with a water impermeable sheet 3 and a water permeable sheet 4,
As shown in the first figure, the paper diaper 1 is shaped like a medium-high shape with a gently sloped slope from both sides and a raised central portion, and the folded portions 10, 10 of the first folded portions 7, 7 are facing toward the central portion of the medium-high portion. By aligning them, a joining line 12 is formed.

The water-absorbing and coagulating substance 9 is, for example, an alkali metal carboxylate obtained by saponifying a fusion copolymer containing starch and acrylonitrile or methacrylnitrile in a ratio of 1:4 with an ethanolic potassium hydroxide aqueous solution. A material containing about 14% carboxy pigment (commonly known as Polymer 35.A-100) is used, but is not necessarily limited thereto.

Further, as a manufacturing procedure of a paper diaper including the intervention of the water-absorbing and coagulating substance 9, as shown in FIGS. , 10 in a line, and then folded back at the bent portions 10, 10 as shown in FIG. be able to. Next, the paper is folded back as shown in FIG. A paper diaper 1 is obtained by cutting it to a length as a diaper and then sealing both ends 6, 6.

Since the paper diaper 1 according to the present invention has the water absorption layer 2 configured as described above, when it is used, the first folded portions 7, 7, which are rounded with gentle slopes, will contact the body. The upper surface is brought into contact with the water-permeable sheet 4, and since the water-absorbing material 2a has a three-layer structure, this part has an extremely large amount of water absorption, and the area between the layers of the first folded parts 7, 7 Since the water-absorbing and coagulating substance 9 is interposed within, the water-absorbing and coagulating substance 9 absorbs water and coagulates, thereby significantly increasing the amount of water absorbed in this part.

Moreover, the water absorption into the first folded parts 7, 7 is limited to the bent parts 10, 10 of the first folded parts 7, 7.
This joint line 12 has the shape of a narrow groove, so that water during urination does not stay locally but diffuses, and together with this, the entire three-layer part containing the water-absorbing and coagulating substance 9. It is possible to improve the water absorbency of the first folded portions 7, 7 and make the first folded portions 7, 7 evenly absorb water.

In addition to the above points, the water-absorbing solidified material 9 absorbs water and becomes a gel, and then flows due to the weight of the body.As shown in FIG. As a result, since one side is sealed by the folded parts 10, 10, it flows only to the other direction as shown by arrow A, and the water absorbed and solidified flows out from between the first folded parts 7, 7. The substances 9, 9 are the second folded portion 11,
Therefore, the water absorbed in the first folded portions 7, 7 is absorbed into the upper and lower portions of the water absorption layer 2 of the second folded portions 11, 11 as shown by arrow B. The water absorption area is also expanded in the width direction of the layer 2, resulting in water absorption being spread over the entire area of the water absorption layer 2 without waste, and these effects work together to significantly increase the water absorption capacity of the water absorption layer 2. Furthermore, since the ends of the second folded parts 11, 11 are sealed, the gel-like water absorbing and coagulating substance 9 that has flowed out into the second folded parts 11, 11 can be transferred to the lower side of the water-permeable sheet 4 or the water-impermeable material. It does not protrude from the inner surface of the sheet 3, thereby preventing the wearer from feeling sticky and uncomfortable.

As explained above, the paper diaper according to the present invention has a three-layer structure in which the water-absorbing material in the central part, which absorbs the most water during urination, has a three-layer structure, and the presence of the bending part joining line of the first folded part constituting this makes the paper diaper absorb more water. Of course, it is possible to increase the water absorption function and water absorption amount in the part, and since the water absorption and coagulation substance is built in the first folded part that makes up the middle and high part, the water absorption capacity is even greater. Since it is sufficient to use the substance in a line that is extremely narrow relative to the width of the paper diaper within the range between the first folded parts, the amount used is different from the conventional method of spreading the substance over the entire surface or mixing it in. In comparison, the amount required is extremely small, and there is an advantage that there is almost no need to consider the increase in cost due to the use of the above-mentioned expensive substances.

In addition, since the above-mentioned water-absorbing and coagulating substance is narrowly interposed between the first folded part that is folded back to the inside, the water-absorbing layer does not shift even if it absorbs water and becomes a gel. Due to the formation of gentle slopes,
Rather, it actively utilizes the flow caused by body weight to transport moisture to both sides of the water absorption layer, and has the effect of allowing moisture to be absorbed over a wide area of the water absorption layer, leaving areas that were previously abandoned without absorbing water. The entire water-absorbing layer can be effectively used to absorb water. As a result, the thickness of the water absorbing layer itself can be made considerably thinner than conventional products, which can also be useful for reducing costs.

Even if water is carried to the sides by the flow of the gelled water-absorbing and coagulating material as described above, the side edges are
Since it is sealed by the folded part of the folded part, the gelled water-absorbing and coagulating substance does not enter the water-permeable sheet, and the wearer does not feel uncomfortable as if a gel-like substance was felt on his body. You can get the effect that you don't have.

Therefore, according to the present invention, the water absorbing ability can be significantly increased even though the thickness of the water absorbing material and the amount of the water absorbing coagulating substance can be extremely reduced, and the material is inexpensive and comfortable to wear. It has excellent effects and can be used as paper diapers.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view of a paper diaper according to the present invention;
FIG. 2 is an enlarged sectional view along the line shown in FIG. 1, FIG. 3 is an explanatory diagram showing the flow state of the gelled water absorbing and coagulating substance, and FIGS. It is an explanatory view showing an example of the process. 1...Paper diaper, 2...Water absorbing layer, 3...Water impermeable sheet, 4...Diffusion water permeable sheet, 7...First
Folded portion, 8...Folded piece, 9...Water-absorbing solidified material, 10...Folded portion, 11...Second folded portion, 12... Joining line.

Claims (1)

[Claims] 1. Both ends of a water-absorbing material formed into a strip of the required thickness by laminating paper cotton, crushed pulp, etc. are folded back over the required width to form a first folded part, and moisture is absorbed within the range between the folded surfaces. A water-absorbing and coagulating substance that is gelled and interposed in a linear manner in the longitudinal direction is arranged so that the folded pieces of the first folded part are on the inside, and the folded parts of the first folded part touch each other over a wider width. Fold each back and make the second
By forming the folded portions, a water absorbing layer that exhibits a mid-to-height shape is formed with a gentle slope, and a water-impermeable sheet such as vinyl is placed on the bottom surface of this water-absorbing layer, and a diffused water-permeable sheet such as non-woven fabric is placed on the top surface. A paper diaper made by joining the sides and ends of these sheets by welding or the like.