JP3901494B2 - Disposable diapers - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a disposable that is less likely to cause wrinkles and twists on a skin contact surface that is in contact with the skin of the wearer or in the vicinity thereof, especially an absorbent body that has a large effect on the skin, and is less likely to cause skin problems such as bed slipping. Regarding diapers.
[0002]
[Prior art and problems to be solved by the invention]
Disposable diapers, especially disposable diapers for adults, tend to cause wrinkles and kinks in the absorbent body on the wearer's back or abdomen, especially on the back side. Applying body pressure to the skin may cause skin problems such as bed slips.
[0003]
Accordingly, the object of the present invention is to prevent skin wrinkles and twists from occurring on a skin contact surface that contacts the skin of the wearer or a member disposed in the vicinity thereof, particularly an absorber that has a large effect on the skin, and skin troubles such as bed slipping. It is in providing the disposable diaper which does not produce easily.
[0004]
[Means for Solving the Problems]
The present inventors have wrinkles on the back sheet due to friction with a sheet or the like when the wearer rolls over or changes his position, and these wrinkles are arranged on or near the skin contact surface that contacts the wearer's skin. It is the main cause of causing skin troubles that are transmitted to the members (surface sheet, etc.) and cause wrinkles and creases, and the bonding between the absorber and the back sheet on the back side and / or the abdomen side It has been found that by making the area ratio lower than the joint area ratio at the crotch, wrinkles and twists of the absorber can be reduced, and skin troubles such as bed slips can be suppressed. The present invention has been completed based on such findings.
[0005]
That is, the present invention includes a liquid-permeable top sheet, a liquid-impermeable back sheet, and a liquid-retaining absorbent interposed between the two sheets, and is formed substantially vertically and sequentially in the longitudinal direction. In a disposable diaper having a back side part, a crotch part and an abdominal side part, wherein the absorbent body and the back sheet are joined, in a belt-like region having a predetermined width extending in the longitudinal direction on both sides in the longitudinal direction, The bonding area ratio between the absorber and the back sheet in the back side and / or the ventral side is lower than the bonding area ratio between the absorber and the back sheet in the crotch, The object described above is achieved by providing a disposable diaper characterized in that an elastic member is disposed in an elongated state along the longitudinal direction in a region located in the crotch part.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on preferred embodiments thereof.
The disposable diaper 1 of the present embodiment is a so-called unfolded diaper, and as shown in FIGS. 1 and 2, a liquid-permeable top sheet 2, a liquid-impermeable back sheet 3, and both the sheets 2, 3 As a fastening means, it is provided with a liquid-retaining absorbent body 4 interposed therebetween and is formed in a substantially vertically long shape on both side edges of the back side portion A disposed on the back side of the wearer when worn. Fastening tape 5 is provided, and a landing zone (not shown) for fastening these fastening tapes 5 is provided on the outer surface of the abdominal side portion B disposed on the abdomen side of the wearer when worn.
[0007]
If it demonstrates further, the disposable diaper 1 of this embodiment has the shape of the hourglass shape in which the external shape narrowed the center part of the longitudinal direction narrowly. The absorbent body 4 has a rectangular shape, a rectangular surface sheet 2 is disposed on the inner surface side, and a back sheet 3 having the same shape as the outer shape of the diaper is disposed on the outer surface side. ing. Both side edges of the surface sheet 2 are located slightly outward along both side edges of the absorbent body 4, and the hydrophobic sheet material 21 is disposed so as to straddle the top sheet 2 and the back sheet 3. Bonded on both sheets. In addition, in FIG. 1, illustration of the boundary line of the surface sheet 2 and the sheet | seat material 21 is abbreviate | omitted.
[0008]
Thus, in the disposable diaper 1 of the present embodiment, as shown in FIG. 3, in the belt-like regions 43 and 43 having a predetermined width extending in the longitudinal direction on both sides in the longitudinal direction, the back side portion A and the ventral side portion B respectively. A region where the bonding area ratio between the absorbent body 4 and the back sheet 3 is lower than the bonding area ratio between the absorber 4 and the back sheet 3 in the crotch part C, and the belt-shaped region 43 is located in the crotch part C. Further, the elastic member 71 is disposed in an extended state along the longitudinal direction.
Hereinafter, the bonding area ratio between the absorber 4 and the back sheet 3 in each part of the belt-like region 43 may be simply referred to as a bonding area ratio.
[0009]
By making the joining area ratio in the back side part A and / or the ventral part B lower than the joining area ratio in the crotch part C, wrinkles generated in the back sheet 3 are arranged on the skin contact surface or in the vicinity thereof. It is possible to suppress the transmission to the member, particularly the absorbent body 4, and to reduce wrinkles and twisting of the absorbent body 4 and the like in the back side portion A and / or the ventral side portion B. Therefore, the occurrence of skin troubles such as bed slips can be reduced. On the other hand, by increasing the joint area ratio in the crotch part C that is disposed opposite to the urination part of the wearer and greatly deforms with the movement of the legs, and firmly fixes both sides of the absorbent body 4 in the crotch part C. , Can stabilize the absorption performance of diapers.
[0010]
From the viewpoint of ensuring such an effect, the bonding area ratio in the dorsal side A and / or ventral side B is preferably 1 to 50%, particularly 5 to 30%, The bonding area ratio in the crotch C is preferably 15 to 85%, particularly preferably 30 to 60%, and the ratio of the bonding area ratio in the dorsal side A and / or ventral side B to the bonding area ratio in the crotch C [A / C (B / C)] is preferably 0.01 to 0.8, particularly preferably 0.1 to 0.5.
It should be noted that wrinkles and twists of the absorbent body are likely to occur when the body position is changed from the supine state to the lateral state, and particularly to the back side part. Therefore, at least the joint area ratio at the back side part A is the joint at the crotch part C. It is preferable that it is lower than the area ratio.
[0011]
Here, as shown in FIG. 1 or FIG. 3, the band-like regions 43 and 43 having a predetermined width absorb the region where the absorber 4 is disposed (the region where the absorber 4 exists in the thickness direction). The width 4 of the body 4 is divided into four equal areas and divided into four areas in the width direction. Each area is one area on both outer sides (a in the figure indicates a quarter length of W). . Moreover, the back side part A, the crotch part C, and the abdomen side part B mean each area | region which divided the longitudinal direction length of the disposable diaper into 3 parts, and divided the crotch part C into the back side. It is an area sandwiched between the part A and the ventral part B.
When the width of the absorbent body is not uniform in the longitudinal direction, for example, when both side edges 41, 41 of the absorbent body are curved in an arc shape, both sides of the absorbent body 4 at the crotch C as shown in FIG. Assuming five parallel straight lines L1, L2, and L3 so that the width W of the portion where the edges 41 and 41 are closest to each other is divided into four, the two outermost straight lines L1 are adjacent to each other. A region sandwiched between the two straight lines L2 is defined as a strip region 43. As shown in FIG. 5, when the absorber 4 is divided in the width direction, the distance W between the outer edges 41 and 41 of the outermost absorber is defined as the width W.
4 and 5, a plurality of elastic members (not shown) are disposed in each band-like region 43 of the disposable diaper as in the disposable diaper 1 shown in FIGS. In the diaper, the innermost elastic member among the plurality of diapers is arranged in the divided region 44.
[0012]
And each junction area rate in the back side part A, the crotch part C, and the abdominal side part B is measured as follows.
<Joint area ratio in back side A>
The total area of the region where the absorber 4 and the back sheet 3 are laminated in the region located in the back side portion A in the band-like region 43 is defined as a region area R, and within the region area R, the absorber 4 The area of the part where the back sheet 3 and the back sheet 3 are joined by a joining means such as an adhesive such as a hot-melt adhesive, heat sealing, or ultrasonic sealing is defined as a joining area S. The bonding area ratio is obtained by the following equation.
Bonding area ratio (%) = (bonding area S / region area R) × 100
[0013]
<Joint area ratio in crotch C or ventral B>
The area and bonding area of each region located in the crotch part C or the abdominal side B in the belt-like region 43 are determined, and the bonding area ratio is determined in the same manner as the bonding area ratio of the back side A.
[0014]
<Measuring method of bonding area>
As shown in FIG. 6 (a), the bonding area when the absorber 4 and the back sheet 3 are bonded by the linear bonding means 82 is the width of the bonding portion W1 as the pattern width, and the pattern width. The average value is multiplied by the length measured along the joint. Moreover, as shown in FIG.6 (b), joining area | regions, such as when the absorber 4 and the back surface sheet 3 are joined by the helical joining means 81, are the maximum width of the diaper width direction of the repetitive pattern. The pattern width W2 is obtained by multiplying the average value of the pattern widths by the pattern length L (see FIG. 1) measured along the longitudinal direction of the diaper. In FIG. 1, the length L of the pattern exceeding the length of the crotch C is illustrated. However, when obtaining the joint area ratio in the crotch C, the length of the portion existing in the crotch C is used. Determine the bonding area. When the linear or spiral joint is provided in the form of a dotted line (in the case of a plurality of dots), the area between the dots is also included in the joint area.
[0015]
When the absorbent body 4 is divided in the width direction and there is a region 44 in which the absorbent body does not exist (hereinafter referred to as a divided region) 44 (see FIG. 5) in the band-like region 43 (see FIG. 5), the surface sheet in the divided region 44 Only when the sheet 2 and the back sheet 3 are bonded directly or indirectly, the divided area is calculated as a part of the area R. In this case, the area of the bonded area 44 in the divided area is the bonded area S. Include in the calculation. This is because the wrinkles and twists of the back sheet 3 are transmitted to the top sheet and cause wrinkles and twists on the skin contact surface.
[0016]
In the disposable diaper 1 of this embodiment, as shown in FIG. 3, in the strip | belt-shaped area | region 43, two types of adhesives (joining means) from which the absorber 4 and the back surface sheet 3 differ, ie, 1st and 1st, are shown. The first adhesive 81 is applied with a pattern width W2 wider than that of the second adhesive 82 (see FIG. 6B). Further, the first adhesive 81 is longer in the longitudinal direction of the diaper than the second adhesive 82 so as not to reach the end edges 4A and 4B of the absorber on the back side A side and the abdominal side B side. It is coated in a narrow area.
Specifically, the first adhesive 81 is applied with a spiral coating pattern, and the second adhesive 82 is applied with a substantially linear coating pattern. The first adhesive 81 is applied over the entire region of the crotch C in the longitudinal direction, and both end portions thereof slightly enter the back side portion A and the ventral side portion B. The second adhesive 82 is applied over the entire area of the absorbent body 4 in the longitudinal direction.
[0017]
The bonding means in the present invention is preferably an adhesive as in the present embodiment from the viewpoint of bondability, productivity, etc., but instead of the adhesive, a bonding means such as heat seal or ultrasonic seal is used. It can also be used. Further, the first and second adhesives (joining means) may have the same factors (for example, physical properties and basis weight of the adhesive) other than the coating pattern (joining pattern).
[0018]
By using an adhesive (joining means) 81 having a wide pattern width for the crotch part C, the position fixability of the absorbent body 4 can be improved. On the other hand, on the back side part A and / or the ventral side part B, By using an adhesive (joining means) having a narrow pattern width, particularly an adhesive 82 having a substantially linear shape (including wavy lines and broken lines), the force in the width direction of the back sheet can be effectively released, and the absorber The occurrence of wrinkles and twists can be further reduced. Especially as in this embodiment, in the crotch station C, a combination of adhesive 81 straight adhesive 82 and the spiral in the rear section A and / or ventral B, one or adjacent the plurality of substantially form using linear adhesive 8 2 took wide spacing between the adhesive that the effect is significant.
[0019]
As described above, the elastic member 71 is disposed in the stretched state along the longitudinal direction in the region located in the crotch part C in the belt-like region 43, and the elastic member 7 contracts in the absorber 4 in the region. As a result, a gather is formed.
By making the absorbent body 4 fit to the wearer's skin with the elastic member 71, the absorbent body is in close contact with the skin, and twisting is less likely to occur. Thereby, the adhesive agent for the absorber 4 fixation in the back side part A and the abdominal side part B can be reduced, and the wrinkle prevention property of an absorber can be improved further.
[0020]
In the present embodiment, as shown in FIG. 1, the emboss line 6 is provided to the absorber 4 located in the band-shaped region 43 so as to extend in the width direction of the band-shaped region 43. The embossed wire 6 has a narrow and long oval shape, and is formed by pressing the surface of the absorbent body 4 on the surface sheet 2 side (surface directed toward the skin side) by embossing.
By providing the embossed wire 6 extending in the width direction, drag acts in the width direction and the twist of the absorber is suppressed. Such effect is particularly prominently expressed in combination with spiral glue 8 1 described above.
From the viewpoint of preventing twisting and improving the strength of the absorbent body, the angle θ (see FIG. 1) formed by the center line CL extending in the length direction of the embossed wire 6 and the straight line WL extending in the width direction of the disposable diaper is 0 to 45 degrees. In particular, it is preferably 0 to 30 degrees.
The embossed line pattern extending in the width direction may be a straight line (including a dotted line) as in the present embodiment, a curved line or a combination thereof, and the absorber can be prevented from twisting and improved in strength. Therefore, the linear shape is preferable.
[0021]
Further, as shown in FIG. 2, the absorbent body 4 in the present embodiment has a structure in which an upper fiber layer 45 and a lower fiber layer 46 as a plurality of absorbent layers are laminated. In the region to which the embossed line 6 is applied, a water-absorbing polymer 47 is disposed between the upper fiber layer 45 and the lower fiber layer 46, and the polymer region P1 is provided in the shape of a vertically long band along the longitudinal direction of the diaper. ing. In particular, it is preferable that the water-absorbing polymer 47 in the region to which the embossed wire 6 is provided is crushed by the application of the emboss, whereby the region is further cured and the twist preventing performance of the absorbent body 4 is further improved.
[0022]
As shown in FIG. 7, the disposable diaper 1 of the present embodiment is configured such that the band-like region 43 in the crotch part C bends downward when worn and is arranged along the inner side of the thigh of the wearer M. . Further, an emboss line 61 (not shown in FIG. 2) having a pattern (lattice pattern) different from the emboss pattern of both the band-like regions 43 is given to the absorber in the central portion 42 located between the belt-like regions 43 and 43. ing. Further, similarly to the two belt-like regions 43, the absorbent body in the central portion 42 is provided with a water-absorbing polymer 47a, and the central polymer region P2 is formed in a vertically long rectangular shape. The absorbent body 4 has a structure in which a water-absorbing polymer 47, 47a is held between the upper and lower fiber layers 45, 46 in a rectangular shape in plan view and covered with two water-permeable sheets 49, 50. Have. Moreover, the 2nd elastic member 72 is distribute | arranged to the wearer's 2nd elastic member 72 in the longitudinal direction in the part located outside the both-sides edges 41 and 41 of the absorber 4 in the crotch part C, and this part closely_contact | adheres to a wearer.
[0023]
The forming material of each part of the disposable diaper 1 of the present embodiment will be described. As the forming material of the top sheet 2, the back sheet 3, the fastening tape 5, the landing zone, and the adhesives 81 and 82, respectively, conventionally used for disposable diapers. Various types can be used without particular limitation. A laminated sheet obtained by laminating and bonding a liquid-impermeable sheet material and another sheet material can also be used for the back sheet 3.
[0024]
As the absorbent body 4, those conventionally used as absorbent bodies in disposable diapers and the like can be used without particular limitation. For example, aggregates of fibers such as pulp fibers, rayon, cellulose, polyethylene, polypropylene, and the like, these fibers Those in which the water-absorbing polymer is held on the whole or a part of the aggregate, those coated with paper or a water-permeable nonwoven fabric, and the like can be used. As the water-absorbing polymer, those conventionally used for absorbent bodies in disposable diapers and the like can be used without particular limitation, but those that can absorb and retain a liquid 20 times or more of their own weight and can be gelled are preferable, for example And polyacrylic acid and salts thereof, and polyacrylate graft polymers such as starch, crosslinked carboxylmethylated cellulose, polymers or copolymers of acrylic acid or alkali metal acrylates, and the like.
[0025]
Examples of the material for forming the elastic member 71 (or 72) include natural rubber, synthetic rubber, spandex, and the like. Examples of the form include a thread shape, a belt shape, and a film shape. The elastic member 71 is preferably a thread rubber or a flat rubber from the viewpoint of shrinkability around the legs, processability, cost, and the like.
[0026]
The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit of the present invention.
For example, the absorber 4 in the ventral part B can be omitted. In this case, the bonding area ratio in the ventral part B is set to zero. Moreover, the elastic member 71 can also be arrange | positioned in any location of thickness direction, such as between the surface sheet 2 and the absorber 4, and the outer surface of the back surface sheet 3.
Moreover, the disposable diaper of this invention is not limited to the cross-sectional shape of an absorber becoming a substantially M shape or reverse U shape, as shown in FIG. The shape may be as follows.
[0027]
【The invention's effect】
The disposable diaper of the present invention is less likely to cause wrinkles and twists on the skin contact surface that contacts the skin of the wearer or a member disposed in the vicinity thereof, particularly an absorbent body that has a large effect on the skin, and skin troubles such as bed slipping are caused. It is hard to occur.
[Brief description of the drawings]
FIG. 1 is a plan view showing an embodiment of a disposable diaper according to the present invention, partly broken away.
FIG. 2 is a cross-sectional view schematically showing an XX cross section of FIG. 1;
FIG. 3 is a rear view showing the back sheet side of the disposable diaper of FIG. 1;
FIG. 4 is a schematic view showing a main part of another embodiment of the present invention.
FIG. 5 is a schematic view showing a main part of still another embodiment of the present invention.
FIG. 6 is an explanatory diagram illustrating a method for measuring a bonding area.
7 is a schematic cross-sectional view showing a cross-section of a crotch part when the disposable diaper of FIG. 1 is worn.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Disposable diaper 2 Top sheet 3 Back sheet 4 Absorbent body 5 Fastening tape 43 Strip | belt-shaped area | region 71 Elastic member 81 1st adhesive agent (joining means)
8 2 Second adhesive (joining means)

Claims (4)

It has a liquid-permeable top sheet, a liquid-impermeable back sheet, and a liquid-retaining absorbent interposed between the two sheets. And in the disposable diaper having the ventral side part, and the absorbent body and the back sheet are joined,
In a belt-like region having a predetermined width extending in the longitudinal direction on both sides in the longitudinal direction, a bonding area ratio between the absorbent body and the back sheet in the back side part and / or the abdominal side part is A disposable diaper characterized in that an elastic member is disposed in a stretched state along the longitudinal direction in a region located in the crotch portion in each belt-like region, which is lower than a bonding area ratio with the back sheet. In the belt-like region, the absorber and the back sheet are joined by at least two kinds of joining means having different joining patterns, and one of these joining means is wider than all the other joining means. It is applied in a narrow pattern in the longitudinal direction of the diaper as compared with the at least one other joining means so that it is applied in a joining pattern having a pattern width and does not reach at least the absorber edge on the back side. The disposable diaper according to claim 1. In the band-shaped region, the absorber and the back sheet are joined by two types of adhesives having different coating patterns, one adhesive is a spiral coating pattern, and the other adhesive is approximately It is a linear coating pattern, and the one adhesive is applied over the entire length of the crotch part so as not to reach the absorber edges on the back side and the abdomen side. The disposable diaper according to claim 1, wherein the disposable diaper is coated over the entire length of the absorbent body. The disposable diaper in any one of Claims 1-3 to which the emboss line is provided so that the absorber located in the said strip | belt-shaped area | region may extend in the width direction of this strip | belt-shaped area | region.

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