JP2002153505A - Throwaway diaper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably wet an indicator in a throwaway diaper provided with the indicator informing mother of urination by getting tangible when wetted with urine. SOLUTION: The indicator 18 of this throwaway diaper comprises a hydrophilic foundation sheet 21, a first coating material layer 19 formed on one side of the foundation sheet, the color of which turns bright when wetted with urine, a second coating material layer 22 formed on the other side, concealing the first coating material layer 19 and becoming transparent when wetted with urine, and the second coating material layer 22 intermittently joins with the inside of the rear sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disposable diaper, and more particularly, to a disposable diaper having an indicator capable of notifying a mother of urination.

[0002]

2. Description of the Related Art A disposable diaper disclosed in Japanese Utility Model Laid-Open Publication No. 3-58416 has a discoloration layer formed on the inner surface of a polyethylene back sheet, and a discoloration layer formed so as to cover the discoloration layer and colored. An indicator means comprising a transparent layer formed is employed. According to this means, the excreted urine penetrates the permeable layer to reach the discolored layer, and the discolored layer is made transparent to make the color tone of the permeable layer visible, so that the color tone is visually recognized from the outside of the diaper. be able to. The mother sees the color and knows that the diaper is ready for change.

[0003]

In the above-mentioned prior art, the indicator means is provided with a mechanism which can be made apparent, but the diaper does not have a mechanism for surely allowing excreted urine to penetrate into the indicator means. Since the indicator means composed of the color changing layer and the transmission layer is formed on a hydrophobic polyethylene film, the indicator means and its surroundings may not be easily wetted. In addition, it is conceivable that the absorbent core and the indicator means are joined with a hydrophilic adhesive, and urine penetrates to the indicator means via the adhesive, but it is necessary to match the high production rate of the diaper. No such adhesive is found that sets in a short time. Therefore, it is difficult to say that the indicator means of the related art is surely exposed when urination occurs.
In addition, since the polyethylene backsheet does not absorb any paints used to form the discoloration layer and the permeable layer, in the diaper production process, if each layer is not sufficiently dried over time, Can not proceed to the step. Therefore, the production rate of diapers is significantly restricted.

Accordingly, an object of the present invention is to facilitate the penetration of urine into the indicator means without disturbing the productivity of disposable diapers.

[0005]

In order to solve the above problems, the present invention is based on the premise that a liquid-absorbing core is interposed between a liquid-permeable top sheet and a liquid-impermeable back sheet, This is a disposable diaper having an indicator means that becomes apparent when the body fluid gets wet in any of the side trunk regions and makes it possible to identify from the outside that the body fluid has been excreted.

[0006] On this assumption, the present invention is characterized by: a. The back sheet is light-transmitting,
b. The indicator means is formed on one side of a hydrophilic base sheet and the base sheet, a first paint layer having a different color tone from that of the base sheet, and formed on the other side of the base sheet, and the second base sheet in a dry state. A first paint layer which substantially conceals the color tone of the paint layer, becomes transparent in a wet state, and is capable of revealing the color tone, and c. The first coating layer contains at least one of silica and alumina particles, a water-absorbing binder, and a colorant; d. The second paint layer contains at least one of silica and alumina particles and a hydrophilic binder, and e. The second
The indicator means is attached to the diaper by a paint layer being intermittently joined to the inner surface of the back sheet.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the disposable diaper according to the present invention will be described below with reference to the accompanying drawings.

A pants-type diaper 1 shown in a partially broken perspective view in FIG. 1 has a liquid-permeable top sheet 2 and a liquid-impermeable back sheet 3.
And the liquid-absorbent core 4 interposed between the sheets 2 and 3, and the front and back sheets 2 and 3 are joined in a water-tight manner at a portion extending from the periphery of the core 4. Diaper 1
It has a front torso region (front body) 6, a rear torso region (rear body) 7, and a crotch region 8 located between the two torso regions 6, 7. The portions overlap each other with the topsheet 2 inside, and are integrally joined at a joining portion 10 intermittently arranged in the vertical direction to form a waist opening 12 and a pair of left and right leg openings 13. ing. Around the periphery of each of the openings 12 and 13, there are a waist elastic member 15 and a leg elastic member 16. These elastic members 15 and 16 are located between the front and back sheets 2 and 3 and extend in the extended state.
3 is attached to at least one inner surface. A non-woven fabric or a perforated plastic film is used for the top sheet 2, and a light-transmitting plastic film having a light transmittance of 20 to 80%, more preferably titanium oxide, barium sulfate, calcium carbonate, or the like is used for the back sheet 3. A white or milky white air-permeable and liquid-impermeable film having a light transmittance of 30 to 70%, which is obtained by stretching a plastic film containing the above inorganic particles. The core 4 includes a core portion 4A in which a mixture of ground pulp and superabsorbent polymer particles is shaped into an hourglass shape, and a tissue paper covering portion 4B for the core portion 4A. In the front waist region 6,
A strip-shaped sheet piece extending in the waist direction, and an indicator 18 for notifying the mother that urine has been excreted is interposed between the back sheet 3 and the core 4. When the indicator 18 gets wet with excreted urine, the illustrated floral pattern 19 printed on the indicator 18 becomes visible so as to be visible through the back sheet 3. Thereby, the mother can identify that urination has occurred, and can know that the diaper 1 is at the time of changing.

FIG. 2 is a partial end view taken along the line II-II of FIG. In the drawing, the indicator 18 is printed so as to cover at least the floral pattern 19 on the hydrophilic substrate sheet 21, the floral pattern 19 printed on the inner surface thereof, and the outer surface thereof.
When the diaper 1 is in a dry state, the floral pattern 19 is hidden from the outside so that the masking section 2 conceals the floral pattern 19 from being substantially invisible.
And 2. Such indicator 18
The masking portion 22 corresponding to the floral pattern 19 is coated with the hot-melt adhesive 23 intermittently applied so that at least the portion of the base material sheet 21 on which the floral pattern 19 is printed adheres to the back sheet 3. It is joined to the inner surface of the back sheet 3 through the interposition. However, the band-shaped indicator 18 may not be joined to the back sheet 3 in the range of the length L of the end portion. In the figure, the floral pattern 19 is in close contact with the core 4.

The base sheet 2 constituting the indicator 18
1 uses a printable hydrophilic paper having a basis weight of 15 to 40 g / m ² . The floral pattern 19 is made of, for example, 5 to 20% by weight of a pigment having a color tone different from that of the base sheet 21 and the masking portion 22, silica (SiO ₂ ) or alumina (A).
l ₂ O ₃₎ 5~35 wt% light scattering inorganic particles such as 5-25 wt% hydrophilic acrylic binder, water 30 to 75
This is a colored first paint layer obtained by printing or applying an aqueous ink or paint consisting of, for example, weight% on one surface of the base sheet 21 by an appropriate means. Such a floral pattern 19
When dry, the inorganic particles scatter light and take on a white tint,
In a wet state wet with urine, the scattering is reduced, and the color of the floral pattern 19 becomes vivid. The masking part 22 is composed of, for example, 10 to 40% by weight of inorganic particles such as silica and alumina, 5 to 25% by weight of a hydrophilic acrylic binder, and 40 to 85% by weight of water.
The second paint layer is obtained by printing or applying a water-based ink or paint composed of the same on one surface of the base sheet 21 so as to cover the floral pattern 19. When the masking portion 22 is in a dry state, it scatters light and exhibits a white or milky white color, and makes it difficult to visually recognize the floral pattern 19 through the portion 22. When wet with urine, the scattering is reduced and it becomes transparent, while the floral pattern 19 different in color from the part 22 and the base sheet 21 becomes vivid.
9 can be visually recognized. At the time of such visual recognition, the base sheet 21 exhibits a masking portion 22 and a hiding effect on the floral pattern 19 when in a dry state, and the effect is reduced in a wet state, and the visual recognition of the floral pattern 19 is facilitated. I do.

The back sheet 3 conceals the core 4 and usually has
It has a white or milky white color, but may have other colors if necessary. Indicator 18 inside back sheet 3
Is wet with the flower pattern 1 when it is separated from the sheet 3.
Even if 9 becomes a vivid color,
It may be difficult to see through the image. However, since the indicator 18 is in close contact with the back sheet 3, there is no such fear. In addition, the indicator 1 between the intermittently applied adhesives 23 is used.
When urine is present at the non-joining portion 25 between the back sheet 8 and the back sheet 3 (see FIG. 2), the visual recognition becomes easier. The hot-melt adhesive 23 that joins the indicator 18 to the back sheet 3 sometimes penetrates into the masking part 22,
The concealing effect may be lost by making the portion 22 transparent as when wet. In order to eliminate such an adverse effect, the adhesive 23 is applied intermittently at least at a portion corresponding to the floral pattern 19, and is preferably applied so as not to exceed 70% of the area of the floral pattern 19. ing. Further, as the adhesive 23, an adhesive which does not contain an oil component and has no possibility of penetrating into the masking portion 22 is used.

Indicator 18 bonded to back sheet 3
The end portion L is in a freely deformable state without being joined to the back sheet 3 in a range of the length L, and the possibility of contact with the core 4 is increased. Urine can penetrate from the core 4 to the site of the floral pattern 19 joined to the back sheet 3 via this end. The length L of the end acting in this manner is preferably 10 mm or more. The indicator 18 and the covering portion 4B of the core 4 are intermittently joined so that the indicator 18 is more reliably wetted, or the back sheet 3 and the covering portion 4B are intermittently joined in the vicinity of the indicator 18. May be.

FIG. 3 is a view similar to FIG. 2 showing one embodiment of the indicator 18. The indicator 18 repeats undulation in the longitudinal direction, and has a waveform having a top portion 30 and a bottom portion 31. Indicator 18 is on top 3
0 is in contact with the core 4, and the bottom 31 is joined to the back sheet 3 via the adhesive 23. The floral pattern 19 is at the bottom 31, and the masking portion 22 is formed on the entire outer surface of the base sheet 21. Urine flows from the core 4 through the top 30 to the floral pattern 1
9 permeate. Since the indicator 18 has a waveform, the indicator 18 can reliably contact the core 4 even when the back sheet 3 and the core 4 are separated from each other.

FIGS. 4 and 5 show one embodiment of the diaper 1. FIG.
FIG. 5 is a view similar to FIG. In the diaper 1, a plurality of grooves 40 extending from the front waist region 6 to the crotch region 8 are formed on the inner surface 43 of the core portion 4A.
Is in a state where the groove 40 and the indicator 18 cross each other on the outer surface 44 side. The groove 40 is a portion where the core portion 4A is locally squeezed, and the bottom portion 40A of the groove 40 is in a state where the crushed pulp is closer to and denser than the remaining portion, and the crotch region 8 Urine excreted into the bottom portion 40A quickly spreads in the length direction thereof, so that the indicator 18 can be wetted. In the core 4 made of the pulverized pulp or the superabsorbent polymer particles, the body fluid is generally difficult to diffuse, but the presence of the high-density bottom portion 40A as shown in the drawing indicates that the indicator 18 is separated from the crotch region 8. Easily wets and manifests.

In the present invention, the material used for the indicator 18 is preferably hydrophilic so as to be easily wetted by urine. For example, pulp fiber or rayon fiber is used for the base sheet 21. The color tone of the base sheet 21, the floral pattern 19, and the masking portion 22 of the indicator 18 together with the color tone of the back sheet 3 and the floral pattern 1 when wet become wet.
9 can be selected so as to be easily recognized. The masking portion 22 can be formed by applying ink or paint on and near the floral pattern 19 in addition to the illustrated example. In this case as well, the indicator 18 has the masking portion 22 formed thereon. Is bonded to the back sheet 3. The base sheet 21 is not limited to the strip shape as shown in the illustrated example, but may be formed in an appropriate shape. For example, if it is rectangular, a non-joining area with the back sheet 3 having a width of 10 mm or more can be formed on the four sides thereof, and the possibility of contact with the core 4 can be increased. The floral pattern 19 can be replaced with an appropriate pattern or a paint layer formed on one entire surface of the base sheet 21. In the present invention, the material for forming the paint layer may be a paint or ink, and a common application technique including a printing technique can be used for the means. To these materials, a component such as polyacryl ether for promoting the penetration of urine into the paint layer can be added. The back sheet 3 made of a plastic film may be a sheet in which a non-woven fabric is stuck on the outer surface to make the feel of the back sheet 3 like a cloth.

[0016]

In the disposable diaper according to the present invention,
On a hydrophilic substrate sheet, an indicator is formed by forming a first paint layer of an appropriate pattern that becomes bright when wet,
Since this indicator is intermittently bonded to the inner surface of the back sheet, excreted urine penetrates and diffuses from the absorbent core to the base sheet to reach the first paint layer, and this layer is securely formed. Wet and can make colors brighter. The indicator that is bonded to the back sheet is in a state where its edge and peripheral edge are free to deform without being bonded to the back sheet,
When it has a corrugation, contact with the absorbent core is ensured. A groove having a high-density bottom formed by locally squeezing the absorbent core containing pulp fibers extends between the waist region and the crotch region, and the indicator crosses the groove. In some diapers, even when the indicator is separated from the inseam area, the urine is excreted and becomes apparent as soon as urine is excreted. According to the present invention, since the indicator can be manufactured in a process different from the diaper production process, the adoption of the indicator does not hinder the diaper productivity.

[Brief description of the drawings]

FIG. 1 is a partially broken perspective view of a diaper.

FIG. 2 is an end view taken along line II-II of FIG.

FIG. 3 is a drawing similar to FIG. 2, showing one mode of a diaper.

FIG. 4 is a drawing similar to FIG. 1 showing another aspect of the diaper.

FIG. 5 is an end view taken along line VV of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Diaper 2 Top sheet 3 Back sheet 4 Core 18 Indicator 19 Flower pattern (1st paint layer) 21 Base sheet 22 Masking part (2nd paint layer) 23 Hot melt adhesive 40A Bottom of groove

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) G01N 31/22 121 F term (reference) 2G042 AA01 CA10 FA11 FB05 3B029 BA01 BA03 BA12 BC06 BE02 4C098 AA09 CC03 CC05 CC07 CC12 CC14 CD07 CD09 CE05 DD03 DD10 DD12 DD16 DD20 DD21 DD23

Claims (10)

[Claims] 1. A liquid-absorbent core is interposed between a liquid-permeable top sheet and a liquid-impervious back sheet, and when a body fluid gets wet in any of the front and rear trunk regions, it becomes apparent that the body fluid is excreted. A disposable diaper having indicator means for making it externally identifiable, comprising: a. Said back sheet is light transmissive; b. The indicator means is formed on one side of a hydrophilic base sheet and the base sheet, a first paint layer having a different color tone from that of the base sheet, and formed on the other side of the base sheet, and the second base sheet in a dry state. A second paint layer capable of substantially concealing the color tone of one paint layer and being transparent in a wet state to make the color tone visible; c. The first paint layer contains at least one of silica and alumina particles, a water-absorbing binder, and a colorant; d. The second coating layer contains at least one of silica and alumina particles and a hydrophilic binder; e. The diaper, wherein the indicator means is attached to the diaper by intermittently joining the second paint layer to an inner surface of the back sheet. 2. The back sheet has a light transmittance of 20 to 80%.
The diaper according to claim 1, which is a plastic film having the following. 3. The diaper according to claim 1, wherein said indicator means is joined to said back sheet by an intermittently applied hot melt adhesive. 4. The diaper according to claim 3, wherein said hot melt type adhesive is a non-oil type. 5. The method according to claim 1, wherein said indicator means comprises:
The diaper according to claim 1, wherein a paint layer is intermittently provided on the base sheet. 6. The diaper according to claim 1, wherein the first paint layer and the second paint layer are both intermittently arranged in the base sheet of the indicator means. 7. The diaper according to claim 1, wherein the base sheet of the indicator means is free to deform in a range of 10 mm or more in a peripheral edge without being joined to the back sheet. 8. The diaper according to claim 1, wherein the base sheet is a strip which is long in one direction, and the length of both ends of the strip is not less than 10 mm without being bonded to the back sheet. . 9. The core sheet, wherein the base sheet forms a wave that repeats undulation in one direction and is intermittently joined to the back sheet at the bottom of the wave, while the top of the wave is separated from the back sheet to form the core. The diaper according to claim 1, wherein the first paint layer is formed on the bottom of the wave. 10. A core comprising ground pulp, wherein the pulp is locally squeezed to form a plurality of grooves having a relatively high bottom portion between one of the front and rear waist regions and the crotch region. 2. The diaper according to claim 1, wherein the indicator means provided in the region crosses the groove in any of the trunk regions.