Abstract:
An absorptive article has an absorptive article body, a pair of side flaps, and a pair of waist flaps provided in the rear region so as to extend outward from the side flaps in the lateral direction of the absorptive article body. Each of the pair of waist flaps has formed thereon a waist stretchable region extended so as to reach that edge of the waist flap which is on the belly side. The waist stretchable regions are adapted such that the dimension of the waist stretchable region stretched at the end thereof on the belly side in the lateral direction of the absorptive article body is greater than the dimension of the waist stretchable region stretched at the end thereof on the rear side in the lateral direction of the absorptive article body.

Description:
RELATED APPLICATIONS 
     The present application is a national phase of PCT/JP2009/052646, filed Feb. 17, 2010, and claims priority from, Japanese Application Number 2008-037921, filed Feb. 19, 2008, the disclosure of which is hereby incorporated by reference herein in its entirety. 
     TECHNICAL FIELD 
     The present invention relates to an absorptive article, such as a diaper, providing a snug fit to a wearer. 
     BACKGROUND ART 
     Japanese Patent Application NO. 2004-290400P discloses a conventional diaper of this type. This diaper  100 , as shown in  FIG. 1 , includes absorbent body  101  formed of: a liquid permeable top sheet  101   a , a liquid impermeable back sheet (not shown), and an absorber  101   c . Here, the absorber  101   c  is arranged between the top sheet  101   a  and the back sheet and is configured to absorb and hold fluid. 
     Here, in such diaper  100  a “dorsal side (rear side) Ba” and “ventral side (front side) Fr” are defined. The dorsal side Ba is located on the dorsal side of the wearer when the diaper  100  is put on, and the ventral side Fr is located on the ventral side of the wearer when the diaper  100  is put on. 
     In addition, the diaper  100  includes a dorsal side region  51 , a crotch region S 2 , and a ventral side region S 3 , provided along a longitudinal direction L from the dorsal side Ba toward the ventral side Fr in this order. 
     The absorbent body  101  is configured such that the absorbent body  101  can cover the crotch portion of the wearer as a whole, from a dorsal side toward a ventral side. 
     On both sides of the absorbent body  101  in a width direction W, a side flap portion  110  is formed. Here, the top sheet  101   a  and the back sheet that are stretched so as to form the flap portion  110 . 
     The dorsal side region S 1  of each of the side flap portions  110  is provided with an elastic member  111  in a stretched state in the longitudinal direction. 
     On the dorsal region S 1  of each side flap portion  110 , pair of waist flap portions  120  is formed. 
     Each waist flap portion  120  has a long-and-thin belt like shape while being inclined (approximately 30°) with respect to a direction corresponding to a waistline direction of the wearer (the width direction W of the absorbent body  101 ). 
     A latch portion  130  is attached on an edge portion of each waist flap portion  120 . The diaper  100  is put on the waistline of the wearer when the latch portion attached to one edge portion of one waist flap portion  120  is attached to the other waist flap portion  120 . 
     An attach portion  140  is attached to the ventral region S 3  of the absorber body  101 . 
     When the attach portion  140  is attached from the outer side to the waist flap portion  120  being put on the waistline of the wearer, the absorber body  101  covers the portion around the crotch of the wearer. 
     According to this diaper  100 , when being put on, the pair of waist flap portion  120  can be arranged by inclining to the dorsal side of the wearer with respect to the waistline direction of the wearer. Accordingly, the diaper  100  provides a snug fit to a body. 
     However, this diaper  100  needs to arrange the pair of waist flap portion  120  with inclining to the dorsal side of the wearer with respect to the waistline direction of the wearer (the width direction W of the absorber body  101 ). Accordingly, the manufacturing steps become complex and materials to be used for manufacturing such diaper  100  are increased. 
     SUMMARY 
     In this regard, an object of the present invention is to provide an absorptive article that can provide a snug fit to a body while its manufacturing process is not complex and does not require increased materials for manufacturing this absorptive article. 
     In the aspect of the invention is summarized as an absorptive article in which a dorsal side and a ventral side are defined and a dorsal side region, a crotch region, and a ventral side region are sequentially provided along with a longitudinal direction from the dorsal side toward the ventral side. The absorptive article includes: an absorbent body including a top sheet that is liquid permeable, a back sheet that is liquid impermeable, and an absorber located between the top sheet and the back sheet and being configured to absorb and hold fluid; a pair of side flap portions formed on both sides in a width direction of the absorbent body, in a vicinity of each side edge portions of the absorbent body, along with the longitudinal direction; and a pair of waist flap portions formed in the dorsal side region by extending from the pair of side flap portions toward outside in the width direction of the absorbent body. Each of the pair of side flap portions includes a waistline stretching region. A width size of a ventral side edge in the waistline stretching region becomes larger than a width size of a dorsal side edge in the waistline stretching region, when the absorptive article is stretched in a width direction. Each of the waistline stretching region reaches the ventral side edge of each of the pair of the side flap portions. 
     In the aspect of the invention, each of the waistline stretching region may not reach the dorsal side edge of each of the pair of waist flap portions. 
     In the first aspect of the invention, each of the waistline stretching region may reach the dorsal side edge of each of the pair of waist flap portions. 
     In the aspect of the invention, each of the waistline stretching region may be provided in a basal position in each of the pair of waist flap portions. 
     In the aspect of the invention, each a ventral side edge of each of the waistline stretching region may be stretched in a range of 1.1 to 3.0 times. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view of a conventional diaper. 
         FIG. 2  shows a first embodiment of the present invention and is a plan view showing a diaper in a developed state. 
         FIG. 3  shows the first embodiment of the present invention and is a cross-sectional view taken along A-A line in  FIG. 2 . 
         FIG. 4  shows the first embodiment of the present invention and is a cross-sectional view taken along B-B line in  FIG. 2 . 
         FIG. 5  shows the first embodiment of the present invention and is a cross-sectional view taken along C-C line in  FIG. 2 . 
         FIG. 6  shows the first embodiment of the present invention and is a plan view showing a put on state in a developed manner. 
         FIG. 7  shows the first embodiment of the present invention and is a cross-sectional view of a stretching apparatus. 
         FIG. 8  shows the first embodiment of the present invention and is a side view of a wearing state. 
         FIGS. 9A and 9B  show a second embodiment of the present invention and A is a plan view showing a state before being put on and B is a plan view showing a state after being put on. 
         FIGS. 10A and 10B  show a third embodiment of the present invention and A is a plan view showing a state before being put on and B is a plan view showing a state after being put on. 
         FIG. 11  shows a fourth embodiment of the present invention and is a plan view showing a developed state of a diaper. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present invention will be described below by referring to the drawings. 
       FIG. 2  to  FIG. 8  show a first embodiment of the present invention.  FIG. 2  is a plan view of a diaper in a developed state.  FIG. 3  is a cross-sectional view taken along the A-A line in  FIG. 2 .  FIG. 4  is a cross-sectional view taken along the B-B line in  FIG. 2 .  FIG. 5  is a cross-sectional view taken along the C-C line in  FIG. 2 .  FIG. 6  is a cross-sectional view of an essential part of a stretching apparatus.  FIG. 7  is a plan view of a waistline stretching region in a stretched state.  FIG. 8  is a side view of a diaper being put on. 
     As shown in  FIG. 2  to  FIG. 6 , a diaper  1 A, which is an absorptive article, includes an absorbent body  2 , a pair of side flap portions  10 , which are provided on both sides of the absorbent body  2  in a width direction, a pair of dorsal side waist flap portions (waist flap portions)  20 , and a pair of ventral side waist flap portions  21 . 
     As shown in  FIG. 2 , a dorsal side Ba and the ventral side Fr are defined in the diaper  1 A. Further, the diaper  1 A includes the dorsal region S 1 , the crotch region S 2 , and the ventral side S 3 , along with a longitudinal direction L from the dorsal side toward the ventral side. 
     As shown in  FIG. 2 , the pair of side flap portions  10  is provided on both sides in a width direction W of the absorbent body  2 , along with the longitudinal direction L. 
     Further, the pair of dorsal side waist flap portion  20  is provided in the dorsal side region S 1  by extending from the pair of side flap portions  10  toward outside in the width direction W of the absorbent body  2 . 
     Moreover, the pair of ventral side waist flap portion  21  in the ventral side region S by extending from the pair of side flap portions  10  toward outside in the width direction W of the absorbent body  2 . 
     The absorbent body  2  includes at least a liquid permeable top sheet  3 , a liquid impermeable back sheet  4 , and an absorber  5 . Here, the absorber  5  is located between the top sheet  3  and the back sheet  4 , and absorbs and holds fluid. The absorbent body  2  includes a dorsal region S 1 , a crotch region S 2 , and a ventral region S 3 , and covers the dorsal side, crotch side, and ventral side, when the diaper  1 A is put on. 
     The top sheet  3  is formed of a hydrophilic nonwoven, woven fabric, hydrophobic nonwoven having apertures, or the like. 
     The back sheet  4  is formed of a liquid impermeable nonwoven, liquid impermeable film, a sheet formed by bonding a hydrophilic nonwoven and a liquid impermeable film, or the like. In the present embodiment, a sheet in which a liquid impermeable film  4   a  and a liquid impermeable nonwoven  4   b  are bonded is used for the back sheet  4 . 
     As the absorber  5 , a laminated body in which absorbent pulp and high absorbent polymer are mixed is used. 
     The pair of side flap portions  10  is formed of the top sheet  3  and the back sheet  4 , which are extended in the width direction W from both sides of the absorbent body  2 . 
     An elastic member  12  is provided on at least the crotch region S 2  of the pair of side flap portions  10  in a stretched state along the longitudinal direction L of the side flap portion  10 . 
     As the elastic member  12 , an elastic member in which four polyurethane-based elastic yarns (470 dtex)  12   a - 12   d  are stretched with the magnification of 2.2 times is used. 
     The pair of dorsal side waist flap portions  20  and the pair of ventral side waist flap portions  21  extend in a direction corresponding to a waistline direction (the width direction W of the absorbent body  2 ). 
     That is, the pair of dorsal side waist flap portions  20  is formed so as to extend outwardly in the width direction W from the dorsal region S 1  of the pair of side flap portions  10 . The pair of ventral side waist flap portions  21  is formed so as to extend outwardly in the width direction W form the ventral region S 3  of the pair of side flap portions  10 . 
     In this regard, the dorsal side waist flap portions  20  and the ventral side waist flap portions  21  are formed of a liquid impermeable nonwoven. 
     Among the dorsal side waist flap portions  20  and the ventral side waist flap portions  21 , the dorsal side waist flap portion  20  is particularly formed of a nonwoven that is liquid impermeable and can thermally expand. The dorsal side waist flap portions  20  in the present embodiment are formed by bonding together two sheet materials with SMS of 13 g/m 2  (see,  FIG. 4 ). 
     On tip end sides of the pair of dorsal side waist flap portions  20 , latch portions  22  are provided. 
     The latch portion  22  attaches and is locked on the ventral side waist flap portion  21 . As the latch portion  22 , a hook-and-loop fastener to lock with mechanical locking strength or an adhesive tape to lock with adhesion can be used. 
     When a hook-and-loop fastener is used as the latch portion  22 , a sheet material having at least a surface made of a nonwoven is used as the ventral side waist flap portion  21 . 
     A waistline stretching region  23  is formed on each of the pair of dorsal side waist flap portions  20 . 
     Each of the waistline stretching region  23  is provided in a vicinity of the side flap portion  10 , that is, in a basal portion. 
     Moreover, each of the waistline stretching region  23  is formed while extending outwardly from the ventral side Fr end along with the absorbent body  2  in the longitudinal direction. 
     The extended edge of the waistline stretching region  23  comes up to the verge of the dorsal side edge of the dorsal side waist flap portion  20 , but does not reach the dorsal side edge of the dorsal side waist flap portion  20 . Accordingly, in the dorsal side edge of the dorsal side waist flap portion  20 , a non-stretching region F exists. 
     In the present embodiment, the longitudinal size of the waistline stretching region  23  is set to be 100 mm and the longitudinal size of the non-stretching region F is set to be 10 mm. 
     The waistline stretching region  23  is a region in which a basis weight is lowered than those of other regions by the stretching process. 
     As shown in  FIG. 4 , the waistline stretching region  23  formed by the stretching process has a structure in which a dense portion (reference numeral is not given) whose stretched amount is small and a sparse portion (reference numeral is not given) whose stretched amount is large are alternately provided in the width direction W of the side flap portion  10 . 
     The stretching process is performed so that the size of the edge portion of the ventral side Fr in the waistline stretching region  23  when stretched in the width direction W is to be larger than the size of the edge portion of the dorsal side Ba in the waistline stretching region  23  in the width direction W. 
     By performing such a stretching process, a stretched amount on the dorsal side Ba on the dorsal side waist flap portion  20  can be small, whereas a stretched amount on the crotch side can be large, when the diaper  1 A is put on. Accordingly, the diaper  1 A can fit a crotch portion of a wearer. 
     The waistline stretching region  23  will be described in detail by referring to  FIG. 6 . In  FIG. 6 , X indicates a width size of the width direction W of the waistline stretching region  23  before being stretched (i.e. the stretched amount), and Y is a width size of the width direction W of the waistline stretching region  23  after being stretched (i.e. the stretched amount). 
     As described above, setting is made to be X&lt;Y. It is preferable that Y is set to have a difference of 0.5 to 10 cm in relation to X. 
     If the width size difference made by the stretch is less than 0.5 cm, a gap between circumferential width sizes of waist and hip cannot be covered by the stretched width size of the waistline stretching region  23 , because the difference between the width sizes before and after the stretch is too small for a child whose difference between the circumferential width sizes of waist and hip is 1 cm at the smallest. 
     As a result, a gap is generated in the waist portion, and fitting property is deteriorated, which causes a misalignment of the diaper or excrement leakage while being put on. 
     On the other hand, when the size difference by the stretch exceeds 10 cm, a size difference between the stretched portion and the non-stretched portion becomes too large for an adult whose difference between the circumferential width sizes of waist and hip is approximately 20 cm at maximum. Accordingly, a gap is generated in the hip portion that is stretched by the stretch, and the fitting property is deteriorated, which results in the misalignment of the diaper or the excrement leakage while being put on. 
       FIG. 7  shows a stretching apparatus  30  for performing the stretching process. The stretching apparatus  30  has a pair of stretching blade line portions  31  which are opposite to each other and can be intermeshed to each other. 
     Each stretching blade line portion  31  has a blade depth of 2 mm, a pitch between the pair of blades of 1.25 mm, and the number of the blades  17 . 
     The dorsal side waist flap portion  20  is heated up to a temperature near a melting point, and thereafter is inserted between the stretching blade line portions  31 . Then, the stretching process is performed by setting the temperature of the stretching blade line portions  31  to be 100° C. 
     By heating the stretching blade line portions  31 , the material of the dorsal side waist flap portion  20  comes near to the melting point and becomes easily stretched. Accordingly, the damage of the material caused by the stretching process can be reduced. 
     In addition, if heating to the dorsal side waist flap portion  20  from the blades to the material is insufficient as the process rate is increased, preheating may be performed in front of the stretching blade line portions  31 . 
     With this stretch by such a stretching apparatus  30 , a dense portion in which a stretched amount is small and a sparse portion in which a stretched amount is large are alternately provided in the width direction W of the side flap portion  10  in the dorsal side waist flap portion  20 . 
       FIG. 8  shows a state where the diaper  1 A with the above-described configuration is being put on. The diaper  1 A is in the wearing state when the latch portion  22  on the dorsal side waist flap portion  20  is locked on the front surface of the ventral side waist flap portion  21 . 
     When the wearer puts on the diaper  1 A, the circumference of each side flap portion  10  fits around legs of the wearer with the contraction of each of the elastic members  12   a  to  12   d.    
     In the dorsal side waist flap portion  20 , the non-stretching region F does not stretch in the width direction W of the absorber body  101 , but the waistline stretching region  23  stretches in the width direction W of the absorber body  101 . Accordingly, a size difference between X and Y is caused as described above. 
     As a result, the diaper can preferably fit not only around the waist but also around the hip that is larger than the waist. 
     In this regard, it is preferable that the edge of the ventral side Fr in the waistline stretching region  23  on the dorsal side waist flap portion  20  should be stretched in a range of 1.1 to 3.0 times, on the assumption that the size is large enough for covering the hip portion and that the material damage is not caused. 
     If the stretched amount is less than 1.1 times, the waistline size of the dorsal side waist flap portion  21  may be too small to sufficiently cover the hip portion. If the stretched amount is more than 3.0 times, the damage of the material, such as a torn or a hole, is likely to occur due to the severe damage from the stretch. 
     In addition, it is further preferable that the edge on the ventral side Fr of the waistline stretching region  23  should be stretched in a range of 1.2 to 2.0 times, considering that a fitting property to the hip portion and a prevention of a damage on the material. 
     In addition, each dorsal waist flap  20  can be provided in the direction corresponding to the waistline direction of the wearer (the width direction W of the absorbent body  2 ). Accordingly, increased materials are not required and the manufacturing process is not complex. 
     In this embodiment, the dorsal side waist flap portion  20  stretches only in the waistline stretching region  23  and the entire portion does not stretch. Accordingly, the waistline size before being put on is maintained even during the diaper  1 A is put on, and thus the diaper  1 A is not displaced. 
     In this embodiment, in the longitudinal direction L of the dorsal side waist flap portion  20 , a portion other than the waistline stretching region  23  (non-stretching region F) exists. Accordingly, the deterioration in strength of the dorsal side waist flap portion  21  can be prevented as much as possible. 
     In this embodiment, the waistline stretching region  23  is provided in the basal position of the dorsal side waist flap portion  20  (near the side flap portion  10 ). Accordingly, a displacement amount in relation to the inclination at the tip end in the width direction W of each of the dorsal side waist flap portions  20  can be greatly obtained. Thus, a desired displacement amount can be obtained while keeping the width size of the waistline stretching region  23  small. 
     Note that, the width size in the longitudinal direction L of the dorsal side waist flap portion  20  is determined by the physique of the wearer or the design of the entire diaper, and is not particularly limited. However, it is preferable that an angle formed by an imaginary line in the width direction W of the diaper  1 A, which is made by the stretch of the dorsal side waist flap portion  20  when the diaper is put on, is 0° to 30°. 
     If this angle is less than 0°, a length around the waist becomes longer than a length around the hip. Accordingly, a fitting property cannot be obtained. If this angle is more than 30°, the tension of the dorsal side waist flap portion  20  is hardly applied in the direction around the waist. Accordingly, the fitting property is deteriorated, which is not preferable. 
     It should be noted that, in this embodiment, the dorsal side waist flap portion  20  and the ventral side waist flap portion  21  are configured of a member independent of that of the side flap portion  10 . However, they may be formed as a same member. With such a configuration, the manufacturing the diaper can be simplified. 
       FIG. 9  is a plan view of a diaper  1 B according to a second embodiment of the present invention, and A shows a state before being put on and B shows a state after being put on. 
     A diaper  1 B according to the second embodiment has a waistline stretching region  23  formed up to both edges in the longitudinal direction L of each dorsal side waist flap portion  20 , unlike the first embodiment. 
     That is, the waistline stretching region  23  is formed across the entire length of the dorsal side waist flap portion  20 . 
     In addition, the waistline stretching region  23  has the same width size in which a stretching process is performed across the entire length of the dorsal side waist flap portion  20 . However, in the waistline stretching region  23 , a stretched amount per unit width size is different. 
     Thus, the width size of the waistline stretching region  23  in the ventral side Fr is configured to be larger than the width size of the waistline stretching region  23  in the dorsal side Ba, when the diaper  1 B is stretched (during being put on). 
     That is, as shown in  FIG. 9A , the width size of the waistline stretching region  23  before being put on is a size H, but, as shown in  FIG. 9B , the stretching region  23  on the dorsal side after being put on becomes a size I (H&lt;I). Further, the ventral stretching region  23  on the ventral side Fr after being put on becomes a size J (H&lt;J, and I&lt;J). 
     By setting the stretched amounts in the aforementioned manner, a fitting property similar to that of the first embodiment can be secured. 
     The stretching process in manufacturing the diaper  1 B of this embodiment can be performed by changing a depth of a blade of a stretching blade line portion  31  on the dorsal side Ba and the ventral side Fr. 
     Other configurations are the same as those of the first embodiment, and the duplicated description thereof will be omitted. Also, the same reference numerals are given to denote same portions in the figures for clarification. 
     In this embodiment, even when the stretching width in the longitudinal direction L of the waistline stretching region  23  is the same, the edge portion of the waistline stretching region  23  is restrained by a portion which is not the waistline stretching region  23 . Accordingly, the stretched amount at the edge portion is small, and the stretched amount increases as it recedes from the edge portion. 
     Thus, the waistline stretching region  23  can be obtained without wasting a material when an inclined shape is formed. 
       FIG. 10  is a plan view of a diaper  1 C according to a third embodiment of the present invention.  FIG. 10A  shows a state of the diaper  1 C before being put on, and  FIG. 10B  shows a state of the diaper  1 C after being put on. 
     The diaper  1 C according to the third embodiment has, similar to the second embodiment, a waistline stretching region  23  formed across a dorsal side waist flap portion  20  on its entire length. 
     In this third embodiment, the waistline stretching region  23  has different width sizes in a region having the stretching process performed. Here, the width side of the waistline stretching region  23  in the ventral side Fr is set to be large, whereas the width size of the waistline stretching region  23  in the dorsal side Ba is set to be small. 
     Thus, the width size of the ventral side Fr in the waistline stretching region  23  becomes larger than the width size of the dorsal side Ba in the waistline stretching region  23  when being stretched (during the diaper  1 C is put on). 
     In other words, as shown in  FIG. 10A , the width size of the waistline stretching region  23  before being put on is a width size H, but, as shown in  FIG. 10B , the width size of the dorsal side stretching region  23   b  after being put on becomes a width size I (H&lt;I). Further, the width size of the waistline stretching region  23   a  after being put on becomes a width size J (H&lt;J, and I&lt;J). 
     By setting the stretched amounts having such relationships, a fitting property similar to that of the first embodiment can be secured. 
     Other configurations are same as those of the second embodiment, and the duplicated description thereof will be omitted. Also, same reference numerals are given to denote same portions in the figures for clarification. 
     In the present embodiment, a displacement amount in relation to the inclination at a tip end side in the width direction W of each dorsal side waist flap portions  20  can be largely obtained. Accordingly, the width size or the stretching extent of the waistline stretching region  23  can be minimized as less as possible and a desired displacement amount can be obtained. 
       FIG. 11  is a plan view of a diaper  1 D according to a fourth embodiment of the present invention. 
     A diaper  1 D according to the fourth embodiment is a belt type. In the diaper  1 D, a pair of dorsal side waistline flap portion  20  is provided while extending outwardly in a direction crossing the longitudinal direction L of the absorbent body  2 . 
     A latch portion  22  is provided on one of the dorsal side waist flap portions  20 . 
     A pair of ventral side waist flap portions  21  is also provided in a direction crossing the longitudinal direction L of the absorber body  2 , and a latch portion  24  is provided on the each of the pair of the ventral side waist flap portions  21  so that the diaper  1 D can be put on. 
     In this embodiment, since the waistline stretched portion  23  is provided on the outside in the width direction W of each side flap portion  10 , the fitting property can be improved. 
     As described above, according to the absorptive article of the present invention, a pair of waist flap  20  can be provided in the direction corresponding to the waistline direction of the wearer (the width direction W of the absorbent body  2 ) when the article is manufactured. When being put on, the pair of waist flap  20  can be arranged in the direction inclining to the dorsal side of the wearer with respect to the waistline direction of the wearer in each waistline stretching region  23 . 
     Therefore, according to the present invention, there can be provided an absorptive article that can provide a snug fit to a body while its manufacturing process is not complex and does not require increased materials for manufacturing this absorptive article.