Patent Publication Number: US-9888671-B2

Title: Disposable diaper for pets

Description:
RELATED APPLICATIONS 
     The present application is a National Phase of International Application Number PCT/JP2013/080951, filed Nov. 15, 2013, and claims priority of Japanese Patent Application No. 2012-272362 filed on Dec. 13, 2012. 
     TECHNICAL FIELD 
     The present invention relates to a disposable diaper for pets, and more particularly to a disposable diaper for pets that fits well around the legs of the pet. 
     BACKGROUND ART 
     It is common to keep pets, typically dogs and cats, indoors. Therefore, various kinds of disposable diapers for pets are available. For example, a disposable diaper for pets as disclosed in Japanese Unexamined Patent Application Publication JP 2004-159591A is provided. 
     PRIOR ART DOCUMENT 
     Patent Document 
     Patent Document 1: 
     JP 2004-159591A 
     SUMMARY OF THE INVENTION 
     Problem to be Solved by the Invention 
     The disposable diaper for pets (disposable pet diaper) disclosed in JP2004-159591A is now described with reference to  FIGS. 25 and 26 .  FIG. 25  is a plan view showing the disposable pet diaper in its unfolded state, and  FIG. 26  is an explanatory drawing for illustrating a state of the disposable pet diaper worn by a pet. 
     A disposable pet diaper  1000  includes a liquid-permeable sheet  9910 , a liquid-resistant sheet (not shown) and an absorbent core  2000  disposed between the liquid-permeable sheet  9910  and the liquid-resistant sheet. 
     The liquid-permeable sheet  9910  is formed of liquid-permeable nonwoven fabric. The liquid-resistant sheet is formed of liquid-impermeable plastic film. The absorbent core  2000  is formed of a mixture of liquid absorbent fibers such as pulp, and a super absorbent polymer. 
     The disposable pet diaper  1000  has an abdomen-side waist area  1110 , a back-side waist area  1130  and a crotch area  1120  between the abdomen-side waist area  1110  and the back-side waist area  1130 . 
     The disposable pet diaper  1000  has a diaper longitudinal direction in which the abdomen-side waist area  1110 , the crotch area  1120  and the back-side waist area  1130  are contiguously formed, and a diaper transverse direction crossing the diaper longitudinal direction. 
     The abdomen-side waist area  1110  has an end  1110 A and the back-side waist area  1130  has an end  1130 A in the diaper longitudinal direction. 
     An abdomen-side flap  1150  is formed in the abdomen-side waist area  1110  and has a back-side end  1150 B. The back-side end  1150 B is contiguously formed to extend from an end of the abdomen-side flap  1150  in the diaper transverse direction to a region of an end  2220  of the absorbent core  2000  in the diaper transverse direction. 
     When the disposable pet diaper  1000  is put on a pet, a relatively long area of the abdomen-side flap  1150  comes in contact with a leg α 1  of the pet. 
     A fastening part  3000  having a plurality of hooks is provided on the abdomen-side flap  1150 . 
     The absorbent core  2000  is disposed in a prescribed region extending over the abdomen-side waist area  1110  and the crotch area  1120 . A tail insertion opening  1190  is formed in a prescribed position in the crotch area  1120  and the back-side waist area  1130  where the absorbent core  2000  is not provided. 
     A fastening region  9000  comprising a target tape is formed in a prescribed position of the back-side waist area  1130 . In order to put the disposable pet diaper  1000  on a pet, the hooks on the fastening part  3000  are engaged with the fastening region  9000 . 
     A back-side flap  1160  is formed in the back-side waist area  1130 . 
     A leg stretchable elastic member  4000  is provided in the vicinity of an end of the disposable pet diaper  1000  in the diaper transverse direction. Leg gathers  4410  shown in  FIG. 26  are formed by contraction of the leg stretchable elastic member  4000 . The leg stretchable elastic member  4000  is arranged to extend over part of the abdomen-side waist area  1110  and the crotch area  1120 . Therefore, the contraction force of the leg stretchable elastic member  4000  has no influence on the end  1110 A of the abdomen-side waist area  1110  and the end  1130 A of the back-side waist area  1130 . 
     A leakproof sheet  8000  is arranged to extend inward from the end in the diaper transverse direction of the disposable pet diaper  1000 . A leakproof sheet stretchable elastic member  6000  is provided in the leakproof sheet  8000 . Leakproof gathers and a leakproof wall which are not shown are formed by contraction of the leakproof sheet stretchable elastic member  6000 . 
     An end of the leakproof sheet stretchable elastic member  6000  in the abdomen-side waist area does not extend up to the end  1110 A of the disposable pet diaper  1000  in the diaper longitudinal direction. The back-side end of the leakproof sheet stretchable elastic member  6000  is arranged to extend beyond the tail insertion opening  1190 . 
     In order to put the disposable pet diaper  1000  on a pet, the back-side waist area  1130  is placed on a back of the pet and the crotch area  1120  and the abdomen-side waist area  1110  are placed on a crotch and an abdomen of the pet, and then the fastening part  3000  is fastened to the fastening region  9000 . 
     At this time, as described above, the length with which the end  1150 B of the abdomen-side flap  1150  comes in contact with a leg of the pet is relatively long. 
     Therefore, the end  1150 B may be turned up when the diaper is put on the pet. As a result, the pet may dislike wearing the disposable pet diaper  1000 , or excrement may leak out. 
     Accordingly, it is an object of the present invention to provide a disposable diaper for pets which fits well around the legs of the pet. 
     Means for Solving the Problem 
     According to the present invention, a disposable diaper for pets is provided which includes a back-side waist area, an abdomen-side waist area, and a crotch area between the back-side waist area and the abdomen-side waist area, a flap formed in the abdomen-side waist area and having an end on the back side, a diaper longitudinal direction in which the back-side waist area, the crotch area and the abdomen-side waist area contiguously extend when the disposable diaper is not worn by a pet, and a diaper transverse direction crossing the diaper longitudinal direction, both ends in the diaper longitudinal direction, and both ends in the diaper transverse direction, a diaper longitudinal center line extending in the diaper longitudinal direction and passing through a center of the disposable diaper in the diaper transverse direction, a diaper center point which bisects the diaper longitudinal center line on the disposable diaper, a tail insertion opening formed in a prescribed region in the diaper longitudinal direction, an absorbent core formed on one side of the tail insertion opening in the diaper longitudinal direction and disposed in a prescribed region extending over the crotch area and the abdomen-side waist area, a fastening part having a prescribed length and provided on the flap, a fastening part longitudinal direction in which the length of the fastening part extends and a fastening part transverse direction crossing the fastening part longitudinal direction, a fastening part midpoint which bisects a length of the fastening part in the fastening part transverse direction on a boundary between the fastening part and the flap, a fastening region provided in the back-side waist area and configured to receive the fastening part, and a shortest line point located on the diaper longitudinal center line at a shortest straight-line distance from the fastening part midpoint to the diaper longitudinal center line via the back-side end of the flap. 
     Further, the shortest line point is located on an abdomen-side waist area side beyond the diaper center point. 
     When the disposable diaper according to this invention is put on the pet, the crotch area and the abdomen-side waist area cover a crotch and an abdomen of the pet, while the back-side waist area is closely fitted to a back of the pet, and the fastening part is fastened to the fastening region. 
     Further, the weight of the absorbent core after excretion is received in the longitudinal direction of the fastening part while the disposable diaper according to this invention is worn by the pet. 
     In a further aspect of the solution according to the present invention, a straight-line distance between the shortest line point and a diaper end center point at which the end in the diaper longitudinal direction in the abdomen-side waist area and the diaper longitudinal center line intersect is 170 to 250 mm. 
     In a further aspect of the solution according to the present invention, the ratio of the straight-line distance between the shortest line point and the diaper end center point at which the end in the diaper longitudinal direction in the abdomen-side waist area and the diaper longitudinal center line intersect, to the straight-line distance between the abdomen-side end and the back-side end on the diaper longitudinal center line is 45.5 to 50.0%. 
     Effect of the Invention 
     In this invention, the back-side end of the abdomen-side flap is configured to reduce contact with a leg of a pet. Therefore, the disposable diaper for pets fits well around the legs of the pet. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view showing a disposable diaper for pets in its unfolded state according to a first embodiment of the present invention. 
         FIG. 2  is a plan view for showing an absorbent-core non-arrangement region in the unfolded state of the disposable diaper. 
         FIG. 3  is a plan view for showing a structure of an abdomen-side flap. 
         FIG. 4  is an explanatory drawing regarding to measurement for specifying a preferable structure of the abdomen-side flap. 
         FIG. 5  is an explanatory drawing for illustrating the relation between the disposable diaper and legs of the pet  FIG. 6  is a plan view for showing a leakproof sheet fixed part in the unfolded state of the disposable diaper. 
         FIG. 7  is a sectional view taken along line A-A in  FIG. 1 . 
         FIG. 8  is a sectional view taken along line B-B in  FIG. 1 . 
         FIG. 9  is a sectional view taken along line C-C in  FIG. 1 . 
         FIG. 10  is an explanatory drawing for illustrating the structure of a leg stretchable elastic member and a waist stretchable elastic member. 
         FIG. 11  is an explanatory drawing for illustrating the operation of the leg stretchable elastic member and the waist stretchable elastic member. 
         FIG. 12  is an explanatory drawing in a sectional view taken along line D-D in  FIG. 1 . 
         FIG. 13  is an explanatory drawing regarding to a back-side waist area in putting the disposable diaper on a pet. 
         FIG. 14  is an explanatory drawing regarding to an abdomen-side waist area in putting the disposable diaper on a pet. 
         FIG. 15  is an explanatory drawing for illustrating the state of the disposable diaper worn by a pet. 
         FIG. 16  is a plan view showing a disposable diaper for pets in its unfolded state according to a second embodiment of the present invention. 
         FIG. 17  is a plan view showing a disposable diaper for pets in its unfolded state according to a third embodiment of the present invention. 
         FIG. 18  is a plan view showing a disposable diaper for pets in its unfolded state according to a fourth embodiment of the present invention. 
         FIG. 19  is a plan view showing a disposable diaper for pets in its unfolded state according to a fifth embodiment of the present invention. 
         FIG. 20  is a plan view showing a disposable diaper for pets in its unfolded state according to a sixth embodiment of the present invention. 
         FIG. 21  is a plan view showing a disposable diaper for pets in its unfolded state according to a seventh embodiment of the present invention. 
         FIG. 22  is a plan view showing a disposable diaper for pets in its unfolded state according to an seventh embodiment of the present invention. 
         FIG. 23  is a plan view showing a disposable diaper for pets in its unfolded state according to a eighth embodiment of the present invention. 
         FIG. 24  is a plan view showing a disposable diaper for pets in its unfolded state according to a ninth embodiment of the present invention. 
         FIG. 25  is a plan view showing a prior art disposable diaper for pets in its unfolded state. 
         FIG. 26  is an explanatory drawing for illustrating a state of the prior art disposable diaper worn by a pet. 
     
    
    
     BEST MODES FOR CARRYING OUT THE INVENTION 
     First Embodiment 
     A first embodiment of the present invention is now described with reference to  FIGS. 1 to 15 . 
       FIG. 1  is a plan view showing a disposable diaper for pets in its unfolded state. The “pet” in this embodiment widely includes vertebrates (mammals, reptiles, birds and amphibians) and invertebrates, and typically represents pets such as cats, dogs, rabbits, hamsters, horses, cows, pigs and goats. The term “unfolded state” as used in this embodiment refers to the state in which an unused disposable diaper is unfolded or opened and a contraction force of a stretchable elastic member is not developed. 
     A disposable diaper for pets (disposable pet diaper)  100  has an abdomen-side waist area  110 , a back-side waist area  130  and a crotch area  120  between the abdomen-side waist area  110  and the back-side waist area  130 . When the disposable pet diaper  100  is worn by a pet, the abdomen-side waist area  110 , the back-side waist area  130  and the crotch area  120  are in contact with an abdomen, a back and a crotch of the pet, respectively. 
     The abdomen-side waist area  110 , the back-side waist area  130  and the crotch area  120  are example embodiments that correspond to the “abdomen-side waist area, the back-side waist area and the crotch area between the abdomen-side waist area and the back-side waist area”, respectively, according to this invention. 
     In the unfolded state as shown in  FIG. 1 , the disposable pet diaper  100  has a diaper longitudinal direction Y in which the abdomen-side waist area  110 , the crotch area  120  and the back-side waist area  130  contiguously extend, and a diaper transverse direction X crossing the diaper longitudinal direction Y. The term “crossing” as used in this specification means “perpendicularly crossing” unless otherwise specified. 
     The diaper longitudinal direction Y and the diaper transverse direction X are example embodiments that correspond to the “diaper longitudinal direction in which the abdomen-side waist area, the crotch area and the back-side waist area contiguously extend when the disposable diaper is not worn by a pet, and a diaper transverse direction crossing the diaper longitudinal direction”, respectively, according to this invention. 
     The disposable pet diaper  100  has an inside surface  100 Z 1  which faces a pet and an outside surface  100 Z 2  opposite to the inside surface  100 Z 1 . 
     In this embodiment, the inside surface  100 Z 1  may also be referred to as a pet-side surface or a pet wearing surface. 
     The disposable pet diaper  100  has an end  110 A formed in the abdomen-side waist area  110  and an end  130 A formed in the back-side waist area  130  in the diaper longitudinal direction Y. 
     The ends  110 A and  130 A are an example embodiment that corresponds to the “both ends in the diaper longitudinal direction” according to this invention. 
     The disposable pet diaper  100  has a pair of ends  100 A in the diaper transverse direction X. Each of the ends  100 A contiguously extends over an end  150 A in the diaper transverse direction and a back-side end  150 B in each of the abdomen-side flaps  150 , an end  160 A in the diaper transverse direction and an abdomen-side end  160 B in each of the back-side flaps  160 , and a leg-side end  120 A between the back-side end  150 B of the abdomen-side flap  150  and the abdomen-side end  160 B of the back-side flap  160 . 
     The ends  100 A are an example embodiment that corresponds to the “both ends in the diaper transverse direction” according to this invention. 
     The disposable pet diaper  100  has a tail insertion opening  190  formed in a prescribed region in the diaper longitudinal direction Y. The tail insertion opening  190  is formed by an arcuate cut  191  extending through the inside surface  100 Z 1  and the outside surface  100 Z 2 . 
     Although, in the first embodiment, the tail insertion opening  190  is formed by the arcuate cut  191 , it may be a circular opening formed by an annular cut. 
     The tail insertion opening  190  is an example embodiment that corresponds to the “tail insertion opening formed in a prescribed region in the diaper longitudinal direction” according to this invention. 
     The disposable pet diaper  100  has an absorbent core  200  formed on one side of the tail insertion opening  190  in the diaper longitudinal direction Y and disposed in a prescribed region extending over the crotch area  120  and the abdomen-side waist area  110 . The absorbent core  200  has an abdomen-side end  210 , a back-side end  220  and a pair of ends  230  in the diaper transverse direction. 
     The absorbent core  200  is formed of a mixture of a particulate or fibrous super absorbent polymer and fluff pulp or a mixture of a particulate or fibrous super absorbent polymer, fluff pulp and thermoplastic synthetic resin fibers. Preferably, in order to prevent deformation of the absorbent core  200  and falling off of the super absorbent polymer, the absorbent core  200  may be entirely covered with a liquid-permeable sheet such as tissue paper and hydrophilic fiber nonwoven fabric. Further, preferably, the absorbent core  200  may be compressed into a prescribed thickness in the manufacturing process. As the super absorbent polymer, synthetic polymer-based, starch-based or cellulose-based polymer can be appropriately used. 
     The absorbent core  200  is an example embodiment that corresponds to the “absorbent core formed on one side of the tail insertion opening in the diaper longitudinal direction and disposed in a prescribed region extending over the crotch area and the abdomen-side waist area” according to this invention. 
     As shown in  FIG. 2 , a region of the disposable pet diaper  100  in which the absorbent core  200  is not disposed is referred to as an absorbent-core non-arrangement region  170 . 
     In the absorbent-core non-arrangement region  170 , regions adjacent to the abdomen-side end  210  and the back-side end  220  of the absorbent core  200  and to the back-side end  130 A of the disposable pet diaper  100  each form an erected region for forming an erected section  700  which is described below. Specifically, the region adjacent to the abdomen-side end  210  of the absorbent core  200 , the region adjacent to the back-side end  220  of the absorbent core  200 , and the region adjacent to the back-side end  130 A of the disposable pet diaper  100  are referred to as an abdomen-side erected region  171 , a crotch-side erected region  173  and a back-side erected region  172 , respectively. 
     Depending on design of the disposable pet diaper  100 , part of the absorbent core  200  may be arranged within the absorbent-core non-arrangement region  170 , especially in any of the erected regions. Specifically, part of tissue paper, pulp fibers or super absorbent polymer may be disposed in the erected region. Even in such a case, if the erected region maintains its flexibility and forms the erected section  700 , the absorbent-core non-arrangement region  170  is considered as being substantially formed and the erected region is also considered as being formed at the same time. 
     The disposable pet diaper  100  has fastening parts  300  on the both ends  150 A of the abdomen-side flap  150  in the diaper transverse direction. 
     As shown in  FIG. 3 , each of the fastening parts  300  has a fastening part longitudinal direction  300 X and a fastening part transverse direction  300 Y. In the fastening part longitudinal direction  300 X, the fastening part  300  has a fixed part  320  in which the fastening part  300  is fixed to the disposable pet diaper  100 , and a free part  310  provided to be fastened to a fastening region  900 . 
     The fastening part  300  is a fiber nonwoven fabric made of polyolefin thermoplastic synthetic fibers, or a plastic film made of polyolefin thermoplastic synthetic resin. A plurality of hooks (not shown) are provided on the diaper inside surface  100 Z 1  of the free part  310 . The hooks are formed of polyolefin thermoplastic synthetic resin. Although the hooks here are provided and configured to be fastened to the fastening region  900 , other structures such as an adhesive can be selected for use in place of the hooks, depending on the structure of the fastening region  900 . 
     The fastening part  300  is an example embodiment that corresponds to the “fastening part having a prescribed length and provided on the abdomen-side waist area” according to this invention. 
     The fastening part longitudinal direction  300 X is an example embodiment that corresponds to the “fastening part longitudinal direction in which the length of the fastening part extends” according to this invention. 
     The fastening part transverse direction  300 Y is an example embodiment that corresponds to the “fastening part transverse direction crossing the fastening part longitudinal direction” according to this invention. 
     The disposable pet diaper  100  has flaps  140 A. The flaps  140 A include a pair of abdomen-side flaps  150  formed on the both ends  100 A in the diaper transverse direction in the abdomen-side waist area  110 , and a pair of back-side flaps  160  formed on the both ends  100 A in the diaper transverse direction in the back-side waist area  130 . The flaps  140 A are defined by a pair of virtual lines  100 Y 1  extending in the diaper longitudinal direction and passing through a pair of minimum width points  100 AP on the ends  100 A of the disposable pet diaper  100  in the diaper transverse direction between which a line connecting the ends  100 A in the diaper transverse direction is shortest. Specifically, the virtual lines  100 Y 1  are referred to as flap boundary lines, and regions outside a pair of the flap boundary lines  100 Y 1  are referred to as flaps (the abdomen-side flaps  150 , the back-side flaps  160 ), while an inside region between the flap boundary lines is referred to as a body  140 B. 
     As shown in  FIG. 3 , in the abdomen-side flap  150 , the free end  310  of the fastening part  300  protrudes from the end  150 A in the diaper transverse direction. A point which bisects the fastening part  300  in the fastening part transverse direction  300 Y on a boundary between the end  150 A and the fastening part  300  is referred to as a fastening part midpoint  300 P 1 . 
     The back-side end  150 B of the abdomen-side flap  150  is arcuately formed and extends contiguously from the end  150 A of the abdomen-side flap  150  in the diaper transverse direction to the leg-side end  120 A. 
     The abdomen-side flap  150  is an example embodiment that corresponds to the “flap formed in the abdomen-side waist area and having an end on the back side” according to this invention. 
     Further, the fastening part midpoint  300 P 1  is an example embodiment that corresponds to the “fastening part midpoint which bisects a length of the fastening part in the fastening part transverse direction on a boundary between the fastening part and the flap” according to this invention. 
     A preferable structure of the abdomen-side flap  150  is now described with reference to  FIGS. 4 and 5 . 
     In  FIG. 4 , a diaper longitudinal center line  100 Y 2  passes through the center of the disposable pet diaper  100  in the diaper transverse direction X. Specifically, the diaper longitudinal center line  100 Y 2  coincides with a line connecting an abdomen-side end center point  110 AP on the center of the abdomen-side end  110 A and a back-side end center point  130 AP on the center of the back-side end  130 A in the disposable pet diaper  100 . 
     The diaper longitudinal center line  100 Y 2  is an example embodiment that corresponds to the “diaper longitudinal center line extending in the diaper longitudinal direction and passing through a center of the disposable diaper in the diaper transverse direction” according to this invention. 
     The distance between the abdomen-side end  110 A and the back-side end  130 A on the diaper longitudinal center line  100 Y 2  is referred to as a diaper longitudinal length D 1 . 
     The diaper longitudinal length D 1  is an example embodiment that corresponds to the “straight-line distance between the abdomen-side end and the back-side end on the diaper longitudinal center line” according to this invention. 
     Further, a point which bisects the diaper longitudinal length D 1  is referred to as a diaper center point  100 P. 
     The diaper center point  100 P is an example embodiment that corresponds to the “diaper center point which bisects the diaper longitudinal center line on the disposable diaper” according to this invention. 
     In providing the structure of the abdomen-side flap  150 , the inventor focused on the relation between straight lines connecting the fastening part midpoint  300 P 1  of the fastening part  300  and the diaper longitudinal center line  100 Y 2  and the shape of the back-side end  150 B of the abdomen-side flap  150 . 
     Especially, the relation between a shortest straight-line distance  300 L of a straight line passing the back-side end  150 B of the abdomen-side flap  150 , among the straight lines connecting the fastening part midpoint  300 P 1  of the fastening part  300  and the diaper longitudinal center line  100 Y 2 , and a point of intersection of this straight line with the diaper longitudinal center line  100 Y 2  or a shortest line point  300 P 2  was focused on. 
     The shortest line point  300 P 2  is an example embodiment that corresponds to the “shortest line point located on the diaper longitudinal center line at a shortest straight-line distance from the fastening part midpoint to the diaper longitudinal center line via the back-side end of the flap” according to this invention. 
     As a result of keen studies, it was found that the abdomen-side flap  150  has a suitable and advantageous structure when the shortest line point  300 P 2  is located on the abdomen-side end  110 A side of the disposable pet diaper  100  beyond the diaper center point  100 P. 
     This suitable structure of the abdomen-side flap  150  is an example embodiment that corresponds to the structure that “the shortest line point is located on an abdomen-side waist area side beyond the diaper center point” according to this invention. 
     Specifically, the position of the shortest line point  300 P 2  has a great influence on the shape of the back-side end  150 B of the abdomen-side flap  150 . As described above, the back-side end  150 B is arcuate and extends from the end  150 A of the abdomen-side flap  150  in the diaper transverse direction to the leg-side end  120 A of the disposable pet diaper  100 . 
     In this respect, assuming that the shortest line point  300 P 2  is located on the back-side end  130 A side beyond the diaper center point, the position at which the back-side end  150 B of the abdomen-side flap  150  meets the leg-side end  120 A is located closer to the back-side end  130 A than that in the present invention. As a result, the area of the abdomen-side flap  150  is increased. Therefore, when the disposable pet diaper  100  is put on a pet α, a longer area of the abdomen-side flap  150  comes in contact with a leg α 1  of the pet. 
     In the position of the shortest line point  300 P 2  according to this invention, however, as shown in  FIG. 5 , the area of the abdomen-side flap  150  can be reduced, and the length with which the abdomen-side flap  150  comes in contact with the leg α 1  of the pet can be reduced. 
     The disposable pet diaper  100  is available in various sizes corresponding to pets of various sizes. The pets here are limited to cats and dogs. In this case, when a measured length D 2  or a distance between the shortest line point  300 P 2  and the abdomen-side end center point  110 AP of the disposable pet diaper  100 , is set to 170 to 250 mm, the suitable and advantageous abdomen-side flap  150  can be provided in the disposable pet diaper  100  of any size. 
     This is an example embodiment that corresponds to the feature that “a straight-line distance between the shortest line point and a diaper end center point at which the end in the diaper longitudinal direction in the abdomen-side waist area and the diaper longitudinal center line intersect is 170 to 250 mm” according to this invention. 
     Further, the relation between the measured length D 2  and the diaper longitudinal length D 1  of the disposable pet diaper  100  was also considered. As a result, it was found that the suitable and advantageous abdomen-side flap  150  can be provided in the disposable pet diaper  100  of any size when the ratio of the measured length D 2  to the diaper longitudinal length D 1  is 45.5 to 50.0%. 
     This is an example embodiment that corresponds to the feature that “a ratio of a straight-line distance between the shortest line point and the diaper end center point at which the end in the diaper longitudinal direction in the abdomen-side waist area and the diaper longitudinal center line intersect, to a straight-line distance between the abdomen-side end and the back-side end on the diaper longitudinal center line is 45.5 to 50.0%” according to this invention. 
     The disposable pet diaper  100  has the fastening region  900  which is removably fastened to the fastening part  300 . 
     The fastening region  900  is adhered to the outside surface  100 Z 2  in the back-side waist area  130 . The fastening region  900  is formed by a target tape which is a fiber nonwoven fabric made of polyolefin thermoplastic synthetic fibers, or a plastic film made of polyolefin thermoplastic synthetic resin, and having a large number of loops (not shown) made of polyolefin thermoplastic synthetic resin. Depending on the structure of the hooks in the free part  310  of the fastening part  300 , it may be constructed without using the target tape such that the fastening part  300  can be directly fastened to the nonwoven fabric forming the diaper outside surface  100 Z 2 . In this case, the fastening region  900  is provided and configured as a region to which the fastening part  300  can be fastened in the nonwoven fabric forming the diaper outside surface  100 Z 2 . Further, in the case of the structure in which an adhesive is used in the free part  310  of the fastening part  300 , a plastic film is used as the fastening region  900 . 
     The fastening region  900  is an example embodiment that corresponds to the “fastening region provided in the back-side waist area and configured to receive the fastening part” according to this invention. 
     In the disposable pet diaper  100 , a leg stretchable elastic member  400  is provided in the absorbent-core non-arrangement region  170  between the end  100 A in the diaper transverse direction and the absorbent core  200 . 
     The leg stretchable elastic member  400  is arranged in a stretched state, and when using the disposable pet diaper  100 , the leg stretchable elastic member  400  contracts to form leg gathers  410  which are described below. 
     The leg stretchable elastic member  400  is arranged to extend from the abdomen-side end  110 A to the back-side end  130 A of the disposable pet diaper  100  in the diaper longitudinal direction Y. 
     Here, “to extend from the abdomen-side end  110 A to the back-side end  130 A” of the disposable pet diaper  100  does not only mean that the leg stretchable elastic member  400  continuously extends from the abdomen-side end  110 A to the back-side end  130 A. Specifically, the leg stretchable elastic member  400  may be arranged to extend with a distance from the abdomen-side end  110 A or the back-side end  130 A only if the abdomen-side end  110 A or the back-side end  130 A is acted upon by the contraction force of the leg stretchable elastic member  400  and the erected section  700  is formed. 
     The leg stretchable elastic member  400  is formed of synthetic or natural rubber thread. 
     The disposable pet diaper  100  has a waist stretchable elastic member  500 . The waist stretchable elastic member  500  includes an abdomen-side waist stretchable elastic member  510  disposed in the absorbent-core non-arrangement region  170  between the diaper longitudinal end  110 A and the abdomen-side end  210  of the absorbent core  200 , and a back-side waist stretchable elastic member  520  disposed in the absorbent-core non-arrangement region  170  between the diaper longitudinal end  130 A and the back-side end  220  of the absorbent core  200 . 
     The waist stretchable elastic member  500  is arranged in a stretched state, and when using the disposable pet diaper  100 , the waist stretchable elastic member  500  contracts to form waist gathers  530 . 
     The waist stretchable elastic member  500  and the leg stretchable elastic member  400  are arranged to overlap each other. Here, the term “overlap” as used in this embodiment does not only mean that the waist stretchable elastic member  500  and the leg stretchable elastic member  400  are in direct contact with each other. Specifically, the waist stretchable elastic member  500  and the leg stretchable elastic member  400  do not need to be in direct contact with each other only if their contraction forces act upon each other such that a contraction force intersecting region  180  is formed. 
     The waist stretchable elastic member  500  is formed of a urethane foamed sheet material. 
     The disposable pet diaper  100  has a leakproof sheet  800 . 
     A leakproof sheet stretchable elastic member  600  is disposed in a stretched state in the leakproof sheet  800 . 
     The leakproof sheet  800  is disposed in a prescribed region extending from each of the ends  100 A in the diaper transverse direction of the disposable pet diaper  100  to the body  140 B of the disposable pet diaper  100 . 
     The leakproof sheet stretchable elastic member  600  is disposed within a space which is created by a folded part  810  of an inner end of the leakproof sheet  800  and extends in the diaper longitudinal direction Y. 
     As shown in  FIG. 6 , the leakproof sheet  800  has a fixed part  830  which is fixed to other components (a liquid-permeable sheet  910 , a liquid-resistant sheet  920 , an outer sheet  930 ) of the disposable pet diaper  100  by an adhesive (not shown). In  FIG. 6 , the fixed part  830  is shown by hatching. 
     The fixed part  830  is not formed in a region of the leakproof sheet  800  which extends in the diaper longitudinal direction Y and overlaps with the end  230  of the absorbent core  200  in the diaper transverse direction X. This region not having the fixed part  830  is erected by contraction of the leakproof sheet stretchable elastic member  600  and forms a leakproof wall  820  which is described below. Further, leakproof gathers  840  are formed in the leakproof sheet  800  by contraction of the leakproof sheet stretchable elastic member  600 . 
     The leakproof sheet stretchable elastic member  600  does not need to be provided along the whole length of the region (which forms the leakproof wall  820 ) not having the fixed part  830  in the diaper longitudinal direction Y. For example, it is sufficient to provide the leakproof sheet stretchable elastic member  600  only in part of the region of the leakproof wall  820  in the diaper longitudinal direction Y. Specifically, it is sufficient for the contraction force of the leakproof sheet stretchable elastic member  600  to act upon a part of the fixed part  830  on the both ends of the region of the leakproof wall  820  in the diaper longitudinal direction Y. Here, the part of the fixed part  830  on the both ends of the region of the leakproof wall  820  in the diaper longitudinal direction Y is referred to as a contraction force fixing part  610 . 
     The contraction force fixing part  610  includes an abdomen-side contraction force fixing part  620  and a back-side contraction force fixing part  630 . 
     The back-side contraction force fixing part  630  is provided between the back-side end  220  of the absorbent core  200  and the tail insertion opening  190 . Specifically, by provision of this structure, the absorbent-core non-arrangement region  170  between the back-side end  220  of the absorbent core  200  and the tail insertion opening  190  is erected by contraction of the leakproof sheet stretchable elastic member  600  and forms the erected section  700 . 
     Further, the abdomen-side contraction force fixing part  620  is provided between the abdomen-side end  210  of the absorbent core  200  and the abdomen-side end  110 A of the disposable pet diaper  100 . Specifically, by provision of this structure, as described below, the absorbent-core non-arrangement region  170  between the abdomen-side end  210  of the absorbent core  200  and the abdomen-side end  110 A of the disposable pet diaper  100  is erected by contraction of the leakproof sheet stretchable elastic member  600  and forms the erected section  700 . 
     The disposable pet diaper  100  includes the liquid-permeable sheet  910 , the absorbent core  200 , the liquid-resistant sheet  920 , the outer sheet  930  and the leakproof sheet  800 . 
     As shown in  FIGS. 7 to 9 , the liquid-permeable sheet  910  is disposed on the inside surface  100 Z 1  side of the disposable pet diaper  100 . The absorbent core  200  is disposed between the liquid-permeable sheet  910  and the liquid-resistant sheet  920 . The outer sheet  930  is disposed on the outside surface  100 Z 2  side of the liquid-resistant sheet  920 . The leakproof sheet  800  is disposed over the liquid-permeable sheet  910 , the liquid-resistant sheet  920  and the outer sheet  930  in the diaper transverse direction X. As a result, the abdomen-side flap  150  and the back-side flap  160  are formed by the leakproof sheet  800  and the outer sheet  930 . 
     The leg stretchable elastic member  400  is disposed between the leakproof sheet  800  and the liquid-resistant sheet  920 . 
     The leakproof sheet stretchable elastic member  600  is disposed in the space inside the folded part  810  formed on the end of the leakproof sheet  800 . 
     As shown in  FIG. 7 , the fastening part  300  is disposed between the leakproof sheet  800  and the outer sheet  930 . 
     As shown in  FIGS. 7 and 8 , the leakproof sheet  800  not having the fixed part  830  is erected by contraction of the leakproof sheet stretchable elastic member  600  and forms the leakproof wall  820 . At this time, a large number of creases or the leakproof gathers  840  are formed in the leakproof sheet  800 . 
     As shown in  FIG. 9 , the fastening region  900  is provided on the outside surface  100 Z 2  of the outer sheet  930 . 
     The waist stretchable elastic member  500 , not shown, is disposed between the liquid-permeable sheet  910  and the liquid-resistant sheet  920 . 
     The liquid-permeable sheet  910 , the liquid-resistant sheet  920 , the outer sheet  930  and the leakproof sheet  800  are formed of nonwoven fabric. The nonwoven fabric can be selected from those manufactured by spun lacing, needle punching, melt blowing, thermal bonding, spun bonding or chemical bonding. 
     An adhesive, not shown, is used to fix the liquid-permeable sheet  910 , the liquid-resistant sheet  920 , the outer sheet  930  and the leakproof sheet  800  with each other and to fix the leg stretchable elastic member  400 , the leakproof sheet stretchable elastic member  600  and the waist stretchable elastic member  500 . A hot-melt adhesive is preferably used as the adhesive, but other adhesives such as acrylic adhesive and rubber adhesive can also be used. 
     The adhesive is preferably applied in any one of spiral, wave, dot and stripe patterns. 
     Next, the relation between the contraction forces of the leg stretchable elastic member  400  and the waist stretchable elastic member  500  is described with reference to  FIGS. 10 and 11 . In  FIGS. 10 and 11 , for convenience of explanation, the abdomen-side flaps  150  and the back-side flaps  160  are not shown and only the body  140 B is shown. 
     As shown in  FIG. 10 , the leg stretchable elastic member  400  contracts inward from the ends in the diaper longitudinal direction Y. Specifically, contraction force F 1  of the leg stretchable elastic member  400  acts inward in the diaper longitudinal direction Y. 
     The waist stretchable elastic member  500  contracts inward from the ends in the diaper transverse direction X. Specifically, contraction force F 2  of the waist stretchable elastic member  500  acts inward in the diaper transverse direction X. 
     The contraction force intersecting region  180  is a region in which the contraction force F 1  of the leg stretchable elastic member  400  and the contraction force F 2  of the waist stretchable elastic member  500  intersect with each other. Therefore, contraction force F 3  of the contraction force intersecting region  180  acts inward in a direction crossing the diaper longitudinal direction Y and the diaper transverse direction X. 
     The contraction force intersecting region  180  includes a first contraction force intersecting region  181  formed toward the abdomen-side end  110 A of the disposable pet diaper  100  and a second contraction force intersecting region  182  formed toward the back-side end  130 A. 
     As a result, as shown in  FIG. 11 , a first curved part  540  is formed in the abdomen-side end  110 A and the back-side end  130 A of the disposable pet diaper  100  and bulges outward in a direction from the inside surface  100 Z 1  to the outside surface  100 Z 2  of the disposable pet diaper  100  by the contraction force F 2  of the waist stretchable elastic member  500 . 
     The first curved part  540  includes a first abdomen-side curved part  541  formed in the abdomen-side end  110 A of the disposable pet diaper  100  and a first back-side curved part  542  formed in the back-side end  130 A. 
     Further, a second curved part  183  is formed in the contraction force intersecting region  180  and curved in the direction of the inside surface  100 Z 1  of the disposable pet diaper  100  by the contraction force F 3  acting on the contraction force intersecting region  180 . 
     The second curved part  183  includes a second abdomen-side curved part  184  formed in the first contraction force intersecting region  181  and a second back-side curved part  185  formed in the second contraction force intersecting region  182 . 
     Now, the state in which the leg stretchable elastic member  400  and the leakproof sheet stretchable elastic member  600  are contracted is described with reference to  FIG. 12 .  FIG. 12  is a sectional view taken along line D-D in  FIG. 1 , but, for convenience of explanation, part of the liquid-permeable sheet  910 , the liquid-resistant sheet  920  and the outer sheet  930  and the whole of the absorbent core  200  and the fastening region  900  are not shown. 
     In  FIG. 12 , the leg stretchable elastic member  400  and the leakproof sheet stretchable elastic member  600  are contracted. As a result, the erected section  700  is formed by the contraction forces of the leg stretchable elastic member  400  and the leakproof sheet stretchable elastic member  600 . Specifically, each of the abdomen-side erected region  171 , the back-side erected region  172  and the crotch-side erected region  173  in the absorbent-core non-arrangement region  170  is erected and forms the erected section  700 . 
     The erected section  700  includes an abdomen-side erected section  710 , a back-side erected section  720  and a crotch-side erected section  730 . 
     In this invention, as used herein, the term “erect” to form the erected section  700  means that the absorbent-core non-arrangement region  170  deforms by the contraction force of one of the stretchable elastic members or by a combination of the contraction forces of two or more of the stretchable elastic members. 
     The abdomen-side erected region  171  is erected by contraction of the leg stretchable elastic member  400  and forms the abdomen-side erected section  710 . 
     The end of the leg stretchable elastic member  400  is arranged closer to the abdomen-side end  110 A of the disposable pet diaper  100  than the end of the leakproof sheet stretchable elastic member  600 . Therefore, the abdomen-side erected section  710  more strongly receives the influence of the contraction force of the leg stretchable elastic member  400  than the influence of the contraction force of the leakproof sheet stretchable elastic member  600 . Specifically, the abdomen-side fixing part  620  of the contraction force fixing part  610  is moved by the contraction force of the leakproof sheet stretchable elastic member  600 , which causes erection of the abdomen-side erected region  171 . Therefore, the leakproof sheet stretchable elastic member  600  also forms the abdomen-side erected section  710 . 
     The back-side erected region  172  is erected by contraction of the leg stretchable elastic member  400  and forms the back-side erected section  720 . 
     The leg stretchable elastic member  400  is overlapped with the waist stretchable elastic member  500 . Specifically, the both ends of the leg stretchable elastic member  400  are overlapped with the abdomen-side waist stretchable elastic member  510  and the back-side waist stretchable elastic member  520 . 
     The waist stretchable elastic member  500  is arranged having a prescribed length in the diaper transverse direction. Therefore, the abdomen-side erected section  710  and the back-side erected section  720  erect the abdomen-side waist stretchable elastic member  510  and the back-side waist stretchable elastic member  520 , respectively. Thus, the abdomen-side erected region  171  and the back-side erected region  172  are held in the stable erected state. Specifically, the abdomen-side waist stretchable elastic member  510  and the back-side waist stretchable elastic member  520  are provided as an erection sheet  740  to ensure the erected state of the erected section  700 . 
     When the back-side fixing part  630  of the contraction force fixing part  610  is moved by contraction of the leakproof sheet stretchable elastic member  600 , the crotch-side erected region  173  is erected and forms the crotch-side erected section  730 . 
     Further, as described above, the leakproof wall  820  is formed by contraction of the leakproof sheet stretchable elastic member  600 . A space surrounded by the leakproof wall  820 , the abdomen-side erected section  710 , the crotch-side erected section  730  and the absorbent core (not shown in  FIG. 12 ) forms an excrement storage space  850 . 
     A third curved part  640  is formed in a region extending from the abdomen-side end  110 A to the tail insertion opening  190  in the disposable pet diaper  100  and bulges in a direction from the inside surface  100 Z 1  to the outside surface  100 Z 2  of the disposable pet diaper  100  by the contraction force F 1  of the leg stretchable elastic member  400  and the leakproof sheet stretchable elastic member  600 . 
     A fourth curved part  420  is formed in a region extending from the tail insertion opening  190  to the back-side end  130 A in the disposable pet diaper  100  and bulges in a direction from the inside surface  100 Z 1  to the outside surface  100 Z 2  of the disposable pet diaper  100  mainly by the contraction force F 1  of the leg stretchable elastic member  400 . 
     Next, putting the disposable pet diaper  100  on a pet is explained with reference to  FIGS. 13 to 15 . First, a user takes the disposable pet diaper  100  out of a package. In most cases, in the package, the abdomen-side flaps  150  and the back-side flaps  160  of the disposable pet diaper  100  are folded inward, and the disposable pet diaper  100  itself is folded, for example, into two or three. 
     When using the disposable pet diaper  100 , the user unfolds the folded structure. At this time, the leg stretchable elastic member  400 , the waist stretchable elastic member  500  and the leakproof sheet stretchable elastic member  600  contract. As a result, the erected section  700  including the abdomen-side erected section  710 , the back-side erected section  720  and the crotch-side erected section  730  is formed, and the leakproof wall  820  is formed. Further, the first curved part  540 , the second curved part  183 , the third curved part  640  and the fourth curved part  420  are formed, and the leg gathers  410 , the waist gathers  530  and the leakproof gathers  840  are formed. The shape of the disposable pet diaper  100  is stabilized by contraction of the leg stretchable elastic member  400 , the waist stretchable elastic member  500  and the leakproof sheet stretchable elastic member  600 . 
     Next, the user inserts the tail of the pet α through the tail insertion opening  190  of the disposable pet diaper  100 . 
     Then the user covers the crotch and the abdomen of the pet α with the crotch area  120  and the abdomen-side waist area  110 , with the back-side waist area  130  fitted closely to the back of the pet α. Then the free end  310  of the fastening part  300  is fastened to the fastening region  900 . Thus, the disposable pet diaper  100  is put on the pet α. 
     These matters related to putting the disposable pet diaper  100  on the pet α is an example embodiment that corresponds to the feature that “when the disposable diaper is put on the pet, the crotch area and the abdomen-side waist area cover a crotch and an abdomen of the pet, while the back-side waist area is closely fitted to a back of the pet, and the fastening part is fastened to the fastening region” according to this invention. 
     The state of the disposable pet diaper  100  in fitting the back-side waist area  130  to the back of the pet α is explained with reference to  FIG. 13 . 
     The first curved part  540  bulging outward in the direction of the diaper outside surface  100 Z 2  is already formed in the back-side end  130 A. Further, a region extending from the back-side end  130 A to the tail insertion opening  190  is maintained in a stable shape by the fourth curved part  420 . The back-side flap  160  is curved in the direction of the inside surface  100 Z 1  of the disposable pet diaper  100  together with the second contraction force intersecting region  182  by the second curved part  183 . 
     Thus, the user can easily place the back-side end  130 A along a curve of the back of the pet α. 
     Further, the back-side end  130 A has a low possibility of being turned up. 
     The state of the disposable pet diaper  100  in covering the crotch and the abdomen of the pet α with the crotch area  120  and the abdomen-side waist area  110  and fastening the free end  310  of the fastening part  300  to the fastening region  900 , is explained with reference to  FIG. 14 . 
     The first curved part  540  bulging in the direction of the diaper outside surface  100 Z 2  is already formed in the abdomen-side end  110 A. Further, a region extending from the abdomen-side end  110 A to the tail insertion opening  190  is maintained in a stable shape by the third curved part  640 . 
     The abdomen-side flap  150  is curved together with the first contraction force intersecting region  181  in the direction of the inside surface  100 Z 1  of the disposable pet diaper  100  by the second curved part  183 . In the abdomen-side flap  150  having the fastening part  300 , the transverse end  150 A is heavier than a boundary part of the abdomen-side flap  150  with the body  140 B. Therefore, the boundary part of the abdomen-side flap  150  with the body  140 B is curved in the direction of the inside surface  100 Z 1  together with the second curved part  183 , while the transverse end  150 A of the abdomen-side flap  150  is curved in the direction of the outside surface  100 Z 2  by its own weight. As a result, the fastening part  300  is supported on the abdomen-side flap  150  without hanging straight down. 
     Thus, the user can easily set the abdomen-side end  110 A onto a curve of the abdomen of the pet α. 
     Further, the abdomen-side end  110 A has a low possibility of being turned up. 
     Further, the user can easily grab the fastening part  300 . 
     Furthermore, when the user moves the fastening part  300  toward the fastening region  900 , the fastening part  300  receives the influence of the first contraction force intersecting region  181 . Therefore, wherever the user moves the fastening part  300 , the contraction force acts upon the fastening part  300 . As a result, the user can easily move the fastening part  300  onto a desired position of the fastening region  900 . 
       FIG. 15  is a drawing for illustrating the state of the disposable pet diaper  100  worn by the pet α. 
     Even after the disposable pet diaper  100  has been put on the pet, the leg stretchable elastic member  400 , the waist stretchable elastic member  500  and the leakproof sheet stretchable elastic member  600  are maintained in the contracted state. Therefore, the erected section  700  including the abdomen-side erected section  710 , the back-side erected section  720  and the crotch-side erected section  730  is maintained in the erected state. The leakproof wall  820  is also maintained. Further, the first curved part  540 , the second curved part  183 , the third curved part  640  and the fourth curved part  420  are maintained in the curved state. The leg gathers  410 , the waist gathers  530  and the leakproof gathers  840  are maintained. 
     When the pet α excretes, excrement is held within the excrement storage space  850 . When the excrement is urine, it is absorbed by the absorbent core  200 . When the excrement is feces, part of feces is absorbed by the absorbent core  200  and the rest is held within the excrement storage space  850 . 
     Whether the excrement is urine or feces, the weight of the absorbent core  200  is received in the fastening part longitudinal direction  300 X in the free part  310  of the fastening part  300 . 
     This is an example embodiment that corresponds to the feature that “the weight of the absorbent core after excretion is received in the longitudinal direction of the fastening part while the disposable diaper is worn by the pet” according to this invention. 
     In order to remove the disposable pet diaper  100  from the pet α, the fastening part  300  is detached from the fastening region  900 , and then the disposable pet diaper  100  is pulled off through the tail insertion opening  190  and disposed of. 
     In the process of detaching the fastening part  300  from the fastening region  900  and pulling off the disposable pet diaper  100  through the tail insertion opening  190 , the abdomen-side end  110 A is turned obliquely downward from the pet α. Even at this time, the risk of falling of feces can be reduced by the abdomen-side erected section  710 . 
     Second to tenth embodiments of the present invention are now described with reference to  FIGS. 16 to 24 . In the description of the second to tenth embodiments, components which are identical to those in the first embodiment are not described in detail and their reference numerals are omitted. 
     Second Embodiment 
     The second embodiment of the present invention is explained with reference to  FIG. 16 . A disposable pet diaper  101  according to the second embodiment is different from the disposable pet diaper  100  of the first embodiment in that a leg stretchable elastic member  401  includes a plurality of leg stretchable elastic members. Specifically, the leg stretchable elastic member  401  of the second embodiment is configured by continuously arranging a plurality of leg stretchable elastic members with intervals in the diaper longitudinal direction. The number of the continuously arranged leg stretchable elastic members can be appropriately selected according to the disposable pet diaper to be realized. 
     In the second embodiment of this invention, the leg stretchable elastic member  401  extending continuously in the diaper longitudinal direction includes three leg stretchable elastic members, or a leg stretchable elastic member  401 A in the abdomen-side waist area, a leg stretchable elastic member  401 B in the crotch area, and a leg stretchable elastic member  401 C in the back-side waist area. 
     Like in the first embodiment, in the second embodiment, the erected section  700  including the abdomen-side erected section  710 , the back-side erected section  720  and the crotch-side erected section  730  is formed, and the leakproof wall  820  is formed. Further, the first curved part  540  including the first abdomen-side curved part  541  and the first back-side curved part  542 , the second curved part  183  including the second abdomen-side curved part  184  and the second back-side curved part  185 , the third curved part  640  and the fourth curved part  420  are formed. Further, the leg gathers  410 , the waist gathers  530  and the leakproof gathers  840  are formed. 
     Therefore, the disposable pet diaper  101  according to the second embodiment has the same effect as the disposable pet diaper  100  of the first embodiment. 
     Furthermore, by provision of the leg stretchable elastic member  401  including the three leg stretchable elastic members, the stretching forces of the leg stretchable elastic members can be prevented from affecting each other. Therefore, for example, the back-side waist area is little affected by displacement (or slippage) of the abdomen-side waist area, if any, so that the leg stretchable elastic member  401  can be prevented from causing displacement as a whole. 
     Third Embodiment 
     The third embodiment of the present invention is explained with reference to  FIG. 17 . A disposable pet diaper  102  according to the third embodiment is different from the disposable pet diaper  100  of the first embodiment in that a leg stretchable elastic member  402  is not continuously arranged in the diaper longitudinal direction. 
     Specifically, in the third embodiment of this invention, the leg stretchable elastic member  402  includes a leg stretchable elastic member  402 A arranged in the abdomen-side waist area of the disposable pet diaper  102  and a leg stretchable elastic member  402 B arranged in the back-side waist area. 
     The third embodiment is different from the first embodiment in that the leg gathers  410  and the fourth curved part  420  are formed only in the regions of the leg stretchable elastic members  402 A and  402 B in the disposable pet diaper  102 . 
     In this structure, the erected section  700  including the abdomen-side erected section  710 , the back-side erected section  720  and the crotch-side erected section  730  is formed, and the leakproof wall  820  is formed. Further, the first curved part  540  including the first abdomen-side curved part  541  and the first back-side curved part  542 , the second curved part  183  including the second abdomen-side curved part  184  and the second back-side curved part  185 , the third curved part  640  and part of the fourth curved part  420  are formed. Further, part of the leg gathers  410 , the waist gathers  530  and the leakproof gathers  840  are formed. 
     Therefore, the disposable pet diaper  102  according to the third embodiment has all of the effects of the disposable pet diaper  100  of the first embodiment other than those exhibited by the whole leg gathers  410  and the whole fourth curved part  420 . 
     Furthermore, in this structure, the stretchable elastic member is not provided in the crotch area in which the absorbent core is disposed, and nor in the free end of the leakproof gathers. Therefore, the absorbent core does not shrink, so that the area of the absorbent core can be effectively used. 
     Further, a pocket space can be readily formed in both end regions of the absorbent core in the diaper longitudinal direction. 
     Moreover, the stretchable elastic member is not provided in the fastening region. Therefore, the fastening region does not shrink, so that the fastening part can be easily engaged with the fastening region. 
     Fourth Embodiment 
     The fourth embodiment of the present invention is explained with reference to  FIG. 18 . A disposable pet diaper  103  according to the fourth embodiment is different from the disposable pet diaper  100  of the first embodiment in that a leg stretchable elastic member  403  is not provided in the back-side waist area. Further, the contraction force of the leakproof sheet stretchable elastic member exerts no influence on the abdomen-side end of the disposable pet diaper  103 . 
     Compared with the disposable pet diaper  100  of the first embodiment, the disposable pet diaper  103  of the fourth embodiment is different in that the leg gathers  410  and the fourth curved part  420  are formed only in the region of the leg stretchable elastic member  403 . Further, the back-side erected section  720  of the erected section  700  and the second back-side curved part  185  of the second curved part  183  are not formed. 
     In this structure, the erected section  700  including the abdomen-side erected section  710  and the crotch-side erected section  730  is formed, and the leakproof wall  820  is formed. Further, the first curved part  540  including the first abdomen-side curved part  541  and the first back-side curved part  542 , the second curved part  183  including the second abdomen-side curved part  184 , the third curved part  640  and part of the fourth curved part  420  are formed. Further, part of the leg gathers  410 , the waist gathers  530  and the leakproof gathers  840  are formed. 
     Therefore, the disposable pet diaper  103  according to the fourth embodiment has all of the effects of the disposable pet diaper  100  of the first embodiment other than those exhibited by the whole leg gathers  410 , the back-side erected section  720 , the second back-side curved part  185  and the whole fourth curved part  420 . 
     Further, a pocket space can be readily formed in back-side and abdomen-side end regions of the absorbent core. 
     Fifth Embodiment 
     The fifth embodiment of the present invention is explained with reference to  FIG. 19 . A disposable pet diaper  104  according to the fifth embodiment is different from the disposable pet diaper  100  of the first embodiment in that a leg stretchable elastic member  404  is not provided in the abdomen-side waist area. Further, the contraction force of the leakproof sheet stretchable elastic member exerts no influence on the back-side end of the disposable pet diaper  104 . 
     Compared with the disposable pet diaper  100  of the first embodiment, the disposable pet diaper  104  of the fifth embodiment is different in that the leg gathers  410  are formed only in the region of the leg stretchable elastic member  404 . Further, the abdomen-side erected section  710  of the erected section  700  and the second abdomen-side curved part  184  of the second curved part  183  are not formed. 
     In this structure, the erected section  700  including the back-side erected section  720  and the crotch-side erected section  730  is formed, and the leakproof wall  820  is formed. Further, the first curved part  540  including the first abdomen-side curved part  541  and the first back-side curved part  542 , the second curved part  183  including the second back-side curved part  185 , the third curved part  640  and the fourth curved part  420  are formed. Further, part of the leg gathers  410 , the waist gathers  530  and the leakproof gathers  840  are formed. 
     Therefore, the disposable pet diaper  104  according to the fifth embodiment has all of the effects of the disposable pet diaper  100  of the first embodiment other than those exhibited by the whole leg gathers  410 , the abdomen-side erected section  710  and the second abdomen-side curved part  184 . 
     Further, the absorbent core is not subjected to a contraction force, so that the area of the absorbent core can be effectively used. 
     Moreover, by provision of the leg stretchable elastic member only in the back-side area, it is made easier to fit the disposable pet diaper along the back of the pet. As a result, the fastening part can be easily engaged with the fastening region. 
     Sixth Embodiment 
     The sixth embodiment of the present invention is explained with reference to  FIG. 20 . A disposable pet diaper  105  according to the sixth embodiment is different from the disposable pet diaper  100  of the first embodiment in that a leg stretchable elastic member is not provided, and a leakproof sheet stretchable elastic member  601  is arranged to extend from the abdomen-side end to the back-side end of the disposable pet diaper  105 . The abdomen-side fixing part and the back-side fixing part are formed on the abdomen-side end and the back-side end of the disposable pet diaper  105 , respectively, in the fixed part of the leakproof sheet. The leakproof sheet stretchable elastic member  601  is overlapped with the abdomen-side waist stretchable elastic member and the back-side waist stretchable elastic member of the waist stretchable elastic member. 
     A comparison is made between the disposable pet diaper  100  of the first embodiment and the disposable pet diaper  105  of the sixth embodiment. In the disposable pet diaper  105  of the sixth embodiment, the erected section  700  including the abdomen-side erected section  710  and the back-side erected section  720 , the leakproof wall  820 , the leakproof gathers  840 , the third curved part  640  and the fourth curved part  420  are formed by the action of the leakproof sheet stretchable elastic member  601 . 
     The first abdomen-side curved part  541  and the first back-side curved part  542  are formed by the action of the waist stretchable elastic member, or by the actions of the abdomen-side waist stretchable elastic member and the back-side waist stretchable elastic member, respectively. 
     The first contraction force intersecting region  181  is formed by the contraction force of the leakproof sheet stretchable elastic member  601  and the contraction force of the abdomen-side waist stretchable elastic member. As a result, the second abdomen-side curved part  184  is formed. 
     Further, the second contraction force intersecting region  182  is formed by the leakproof sheet stretchable elastic member  601  and the contraction force of the back-side waist stretchable elastic member. As a result, the second back-side curved part  185  is formed. 
     Specifically, in the disposable pet diaper  105  of the sixth embodiment, unlike in the disposable pet diaper  100  of the first embodiment, the crotch-side erected section  730  and the leg gathers  410  are not formed. 
     Therefore, the disposable pet diaper  105  of the sixth embodiment has all of the effects of the disposable pet diaper  100  of the first embodiment other than those exhibited by the leg gathers  410  and the crotch-side erected section  730 . 
     Furthermore, in the disposable pet diaper  105  of the sixth embodiment, due to the absence of the leg stretchable elastic member, the ends of the disposable pet diaper  105  in the diaper transverse direction can be located closer to the absorbent core. As a result, a portion of the disposable pet diaper  105  which comes in contact with the pet&#39;s legs can be further reduced. 
     Further, due to the absence of a sheet forming a portion around legs, the disposable pet diaper when worn can be made neat around legs. 
     Seventh Embodiment 
     The seventh embodiment of the present invention is explained with reference to  FIG. 21 . A disposable pet diaper  106  according to the seventh embodiment is different from the disposable pet diaper  100  of the first embodiment in that a leg stretchable elastic member  404  is not provided in the abdomen-side waist area and the back-side waist area. Further, the contraction force of the leakproof sheet stretchable elastic member exerts no influence on the abdomen-side end of the disposable pet diaper  106 . Further, an abdomen-side waist stretchable elastic member  511  is overlapped with fastening parts  301 . The feature that “an abdomen-side waist stretchable elastic member is overlapped with fastening parts” according to this invention does not mean that the abdomen-side waist stretchable elastic member is in direct contact with the fastening parts. Specifically, it means that the contraction force of the abdomen-side waist stretchable elastic member does not act on the fastening parts via flaps, but it directly act on them. 
     A comparison is made between the disposable pet diaper  100  of the first embodiment and the disposable pet diaper  106  of the seventh embodiment. In the disposable pet diaper  106  of the seventh embodiment, the leg gathers  410  are formed only in a region of the leg stretchable elastic member  401 . Further, the abdomen-side erected section  710  and the back-side erected section  720  of the erected section  700  are not formed. The second abdomen-side curved part  184  and the second back-side curved part  185  of the second curved part  183  are not formed. The fourth curved part  420  is formed only in the region of the leg stretchable elastic member  405 . 
     In this structure, the erected section  700  including the crotch-side erected section  730  is formed, and the leakproof wall  820  is formed. Further, the first curved part  540  including the first abdomen-side curved part  541  and the first back-side curved part  542 , the third curved part  640  and part of the fourth curved part  420  are formed. Part of the leg gathers  410  and the leakproof gathers  840  are formed. 
     Therefore, the disposable pet diaper  106  according to the seventh embodiment has those of the effects of the disposable pet diaper  100  of the first embodiment which are exhibited by the crotch-side erected section  730 , the leakproof wall  820 , the first abdomen-side curved part  541 , the first back-side curved part  542 , the third curved part  640 , part of the fourth curved part  420 , part of the leg gathers  410  and the leakproof gathers  840 . 
     Furthermore, by provision of the abdomen-side waist stretchable elastic member  511  overlapped with the fastening parts  301 , when the abdomen-side waist area is set on the abdomen of the pet in order to put the disposable pet diaper  106  on the pet, the fastening parts  301  are curved inside the disposable pet diaper under the influence of the contraction force of the abdomen-side waist stretchable elastic member  511 . Thus, it is made easier for the user to grab the fastening parts  301 . 
     Eighth Embodiment 
     The eighth embodiment of the present invention is explained with reference to  FIG. 22 . A disposable pet diaper  107  according to the eighth embodiment is different from the disposable pet diaper  100  of the first embodiment in that a leg stretchable elastic member  406  is not provided in the abdomen-side waist area and the back-side waist area of the disposable pet diaper  107 . Further, a leakproof sheet stretchable elastic member  603  is arranged to extend from the abdomen-side end to the back-side end of the disposable pet diaper  107 . The abdomen-side fixing part and the back-side fixing part are formed on the abdomen-side end and the back-side end of the disposable pet diaper  107 , respectively, in the fixed part of the leakproof sheet. The leakproof sheet stretchable elastic member  603  is overlapped with an abdomen-side waist stretchable elastic member  512  and the back-side waist stretchable elastic member of the waist stretchable elastic member. The abdomen-side waist stretchable elastic member  512  is overlapped with the fastening parts  302 . 
     A comparison is made between the disposable pet diaper  100  of the first embodiment and the disposable pet diaper  107  of the eighth embodiment. In the disposable pet diaper  107  of the eighth embodiment, the erected section  700  including the abdomen-side erected section  710  and the back-side erected section  720 , the leakproof wall  820 , the leakproof gathers  840 , the third curved part  640  and the fourth curved part  420  are formed by the action of the leakproof sheet stretchable elastic member  603 . 
     The first abdomen-side curved part  541  and the first back-side curved part  542  are formed by the action of the waist stretchable elastic member, or by the actions of the abdomen-side waist stretchable elastic member  512  and the back-side waist stretchable elastic member, respectively. 
     The first contraction force intersecting region  181  is formed by the contraction force of the leakproof sheet stretchable elastic member  603  and the contraction force of the abdomen-side waist stretchable elastic member. As a result, the second abdomen-side curved part  184  is formed. 
     Further, the second contraction force intersecting region  182  is formed by the contraction force of the leakproof sheet stretchable elastic member  603  and the contraction force of the back-side waist stretchable elastic member. As a result, the second back-side curved part  185  is formed. 
     Specifically, in the disposable pet diaper  107  of the eighth embodiment, unlike in the disposable pet diaper  100  of the first embodiment, the crotch-side erected section  730  and part of the leg gathers  410  are not formed. 
     Therefore, the disposable pet diaper  107  of the eighth embodiment has all of the effects of the disposable pet diaper  100  of the first embodiment other than those exhibited by the whole leg gathers  410  and the crotch-side erected section  730 . 
     Furthermore, due to the absence of the waist stretchable elastic member in the abdomen-side region and the back-side region, the abdomen-side region and the back-side region can be fitted around the waist of the pet while the fastening member is engaged. 
     Further, a pocket can be formed in both end regions of the absorbent core in the diaper longitudinal direction. 
     Furthermore, by provision of the abdomen-side waist stretchable elastic member  512  overlapped with the fastening parts  302 , when the abdomen-side waist area is set on the abdomen of the pet in order to put the disposable pet diaper  107  on the pet, the fastening parts  302  are curved inside the disposable pet diaper under the influence of the contraction force of the abdomen-side waist stretchable elastic member  512 . Thus, it is made easier for the user to grab the fastening parts  302 . 
     Ninth Embodiment 
     The ninth embodiment of the present invention is explained with reference to  FIG. 23 . A disposable pet diaper  108  according to the ninth embodiment is different from the disposable pet diaper  100  of the first embodiment in that a leakproof sheet stretchable elastic member  604  is arranged to extend from the abdomen-side end to the back-side end of the disposable pet diaper  108 . The abdomen-side fixing part and the back-side fixing part are formed on the abdomen-side end and the back-side end of the disposable pet diaper  108 , respectively, in the fixed part of the leakproof sheet. The leakproof sheet stretchable elastic member  604  is overlapped with an abdomen-side waist stretchable elastic member  513  and the back-side waist stretchable elastic member of the waist stretchable elastic member. Further, the abdomen-side waist stretchable elastic member  513  is overlapped with fastening parts  303 . 
     A comparison is made between the disposable pet diaper  100  of the first embodiment and the disposable pet diaper  108  of the ninth embodiment. In the disposable pet diaper  108  of the ninth embodiment, the erected section  700  including the abdomen-side erected section  710  and the back-side erected section  720 , the leg gathers  410 , the leakproof wall  820 , the leakproof gathers  840 , the third curved part  640  and the fourth curved part  420  are formed by the actions of a leg stretchable elastic member  407  and the leakproof sheet stretchable elastic member  604 . 
     The first abdomen-side curved part  541  and the first back-side curved part  542  are formed by the action of the waist stretchable elastic member, or by the actions of the abdomen-side waist stretchable elastic member  513  and the back-side waist stretchable elastic member, respectively. 
     Two structures of the first contraction force intersecting regions  181  are formed. One is formed by intersection of the contraction forces of the leg stretchable elastic member  407  and the abdomen-side waist stretchable elastic member  513 , and the other is formed by the contraction force of the leakproof sheet stretchable elastic member  604  and the contraction force of the abdomen-side waist stretchable elastic member  513 . Accordingly, two structures of the second abdomen-side curved parts  184  are formed by formation of the two first contraction force intersecting regions  181 . 
     Similarly, two structures of the second contraction force intersecting regions  182  are formed. One is formed by intersection of the contraction forces of the leg stretchable elastic member  407  and the back-side waist stretchable elastic member, and the other is formed by the contraction force of the leakproof sheet stretchable elastic member  604  and the contraction force of the back-side waist stretchable elastic member. Accordingly, two structures of the second back-side curved parts  185  are formed by formation of the two second contraction force intersecting regions  182 . 
     Specifically, unlike in the disposable pet diaper  100  of the first embodiment, the crotch-side erected section  730  is not formed in the disposable pet diaper  108  of the ninth embodiment. 
     Therefore, the disposable pet diaper  108  of the ninth embodiment has all of the effects of the disposable pet diaper  100  of the first embodiment other than those exhibited by the crotch-side erected section  730 . 
     Furthermore, by provision of the abdomen-side waist stretchable elastic member  513  overlapped with the fastening parts  303 , when the abdomen-side waist area is set on the abdomen of the pet in order to put the disposable pet diaper  108  on the pet, the fastening parts  303  are curved inside the disposable pet diaper under the influence of the contraction force of the abdomen-side waist stretchable elastic member  513 . Thus, it is made easier for the user to grab the fastening parts  303 . 
     Further, the contraction forces act over the whole diaper in the diaper longitudinal direction, so that leakage of excrement can be prevented. Therefore, this disposable pet diaper is particularly suitable for bedridden pets. 
     Tenth Embodiment 
     The tenth embodiment of the present invention is explained with reference to  FIG. 24 . A disposable pet diaper  109  according to the tenth embodiment is different from the disposable pet diaper  100  of the first embodiment in that a leg stretchable elastic member  408  is not provided in the back-side waist area. Further, a leakproof sheet stretchable elastic member  605  is arranged to extend up to the abdomen-side end of the disposable pet diaper  109 . The abdomen-side fixing part is formed on the abdomen-side end of the disposable pet diaper  109  in the fixed part of the leakproof sheet. The leakproof sheet stretchable elastic member  602  is overlapped with an abdomen-side waist stretchable elastic member  514  of the waist stretchable elastic member. Further, the abdomen-side waist stretchable elastic member  514  is overlapped with fastening parts  304 . 
     A comparison is made between the disposable pet diaper  100  of the first embodiment and the disposable pet diaper  109  of the tenth embodiment. In the disposable pet diaper  109  of the tenth embodiment, the erected section  700  including the abdomen-side erected section  710  and the crotch-side erected section  730 , part of the leg gathers  410 , the leakproof wall  820 , the leakproof gathers  840 , the third curved part  640  and part of the fourth curved part  420  are formed by the actions of the leg stretchable elastic member  408  and the leakproof sheet stretchable elastic member  605 . 
     The first abdomen-side curved part  541  is formed by the action of the waist stretchable elastic member or the abdomen-side waist stretchable elastic member  514 . 
     Two structures of the first contraction force intersecting regions  181  are formed. One is formed by intersection of the contraction forces of the leg stretchable elastic member  408  and the abdomen-side waist stretchable elastic member  514 , and the other is formed by the contraction force of the leakproof sheet stretchable elastic member  605  and the contraction force of the abdomen-side waist stretchable elastic member  514 . Accordingly, two structures of the second abdomen-side curved parts  184  are formed by formation of the two first contraction force intersecting regions  181 . 
     Specifically, unlike in the disposable pet diaper  100  of the first embodiment, the back-side erected section  720 , part of the leg gathers  410 , the first back-side curved part  542 , the second back-side curved part  185  and part of the fourth curved part  420  are not formed in the disposable pet diaper  109  of the tenth embodiment. 
     Therefore, the disposable pet diaper  109  of the tenth embodiment has all of the effects of the disposable pet diaper  100  of the first embodiment other than those exhibited by the back-side erected section  720 , the whole leg gathers  410 , the first back-side curved part  542 , the second back-side curved part  185  and the whole fourth curved part  420 . 
     In this structure, the contraction forces strongly act only on the abdomen-side region, so that a pocket can be readily formed in an abdomen-side region of the absorbent core. Therefore, this disposable pet diaper is suitable as a disposable diaper for male pets. 
     Furthermore, by provision of the abdomen-side waist stretchable elastic member  514  overlapped with the fastening parts  304 , when the abdomen-side waist area is set on the abdomen of the pet in order to put the disposable pet diaper  109  on the pet, the fastening parts  304  are curved inside the disposable pet diaper under the influence of the contraction force of the abdomen-side waist stretchable elastic member  514 . Thus, it is made easier for the user to grab the fastening parts  304 . 
     The structures or features of the disposable pet diaper according to this invention are not limited to those described above. The structures or features of the first to tenth embodiments can be appropriately used in combination. 
     (Correspondences Between the Features of the Embodiments and the Features of the Invention) 
     The disposable pet diaper  100 ,  101 ,  102 ,  103 ,  104 ,  105 ,  106 ,  107 ,  108 ,  109  is an example embodiment that corresponds to the “disposable diaper for pets” according to this invention. The back-side waist area  130  is an example embodiment that corresponds to the “back-side waist area” according to this invention. The abdomen-side waist area  110  is an example embodiment that corresponds to the “abdomen-side waist area” according to this invention. The crotch area  120  is an example embodiment that corresponds to the “crotch area” according to this invention. The abdomen-side flap  150  is an example embodiment that corresponds to the “flap” according to this invention. The diaper longitudinal direction Y and the diaper transverse direction X are example embodiments that correspond to the “diaper longitudinal direction” and the “diaper transverse direction”, respectively, according to this invention. The ends  110 A and  130 A are an example embodiment that corresponds to the “both ends in the diaper longitudinal direction” according to this invention. The ends  100 A are an example embodiment that corresponds to the “both ends in the diaper transverse direction” according to this invention. The diaper longitudinal center line  100 Y 2  is an example embodiment that corresponds to the “diaper longitudinal center line” according to this invention. The diaper center point  100 P is an example embodiment that corresponds to the “diaper center point” according to this invention. The tail insertion opening  190  is an example embodiment that corresponds to the “tail insertion opening” according to this invention. The absorbent core  200  is an example embodiment that corresponds to the “absorbent core” according to this invention. The fastening part  300 ,  301 ,  302 ,  303 ,  304  is an example embodiment that corresponds to the “fastening part” according to this invention. The fastening part longitudinal direction  300 X is an example embodiment that corresponds to the “fastening part longitudinal direction” according to this invention. The fastening part transverse direction  300 Y is an example embodiment that corresponds to the “fastening part transverse direction” according to this invention. The fastening part midpoint  300 P 1  is an example embodiment that corresponds to the “fastening part midpoint” according to this invention. The fastening region  900  is an example embodiment that corresponds to the “fastening region” according to this invention. The shortest line point  300 P 2  is an example embodiment that corresponds to the “shortest line point” according to this invention. The measured length D 2  is an example embodiment that corresponds to the “straight-line distance between the shortest line point and a diaper end center point at which the end in the diaper longitudinal direction in the abdomen-side waist area and the diaper longitudinal center line intersect” according to this invention. The diaper longitudinal length D 1  is an example embodiment that corresponds to the “straight-line distance between the abdomen-side end and the back-side end on the diaper longitudinal center line” according to this invention. 
     In view of the nature of the above-described invention, various features can be provided as follows. 
     (Aspect 1) 
     A disposable diaper for pets, comprising: 
     a back-side waist area, an abdomen-side waist area and a crotch area between the back-side waist area and the abdomen-side waist area, 
     a flap formed in the abdomen-side waist area and having an end on the back side, 
     a diaper longitudinal direction in which the back-side waist area, the crotch area and the abdomen-side waist area contiguously extend when the disposable diaper is not worn by a pet, and a diaper transverse direction crossing the diaper longitudinal direction, 
     both ends in the diaper longitudinal direction, and both ends in the diaper transverse direction, 
     a diaper longitudinal center line extending in the diaper longitudinal direction and passing through a center of the disposable diaper in the diaper transverse direction, 
     a diaper center point which bisects the diaper longitudinal center line on the disposable diaper, 
     a tail insertion opening formed in a prescribed region in the diaper longitudinal direction, 
     an absorbent core formed on one side of the tail insertion opening in the diaper longitudinal direction and disposed in a prescribed region extending over the crotch area and the abdomen-side waist area, 
     a fastening part having a prescribed length and provided on the flap, 
     a fastening part longitudinal direction in which the length of the fastening part extends and a fastening part transverse direction crossing the fastening part longitudinal direction, 
     a fastening part midpoint which bisects a length of the fastening part in the fastening part transverse direction on a boundary between the fastening part and the flap, 
     a fastening region provided in the back-side waist area and configured to receive the fastening part, and 
     a shortest line point located on the diaper longitudinal center line at a shortest straight-line distance from the fastening part midpoint to the diaper longitudinal center line via the back-side end of the flap, wherein: 
     when the disposable diaper is put on the pet, the crotch area and the abdomen-side waist area cover a crotch and an abdomen of the pet, while the back-side waist area is closely fitted to a back of the pet, and the fastening part is fastened to the fastening region, 
     the weight of the absorbent core after excretion is received in the longitudinal direction of the fastening part while the disposable diaper is worn by the pet, and 
     the shortest line point is located on an abdomen-side waist area side beyond the diaper center point. 
     (Aspect 2) 
     The disposable diaper as defined in aspect 1, wherein a straight-line distance between the shortest line point and a diaper end center point at which the end in the diaper longitudinal direction in the abdomen-side waist area and the diaper longitudinal center line intersect is 170 to 250 mm. 
     (Aspect 3) 
     The disposable diaper as defined in aspect 1, wherein a ratio of a straight-line distance between the shortest line point and the diaper end center point at which the end in the diaper longitudinal direction in the abdomen-side waist area and the diaper longitudinal center line intersect, to a straight-line distance between the abdomen-side end and the back-side end on the diaper longitudinal center line is 45.5 to 50.0%. 
     (Aspect 4) 
     The disposable diaper as defined in any one of aspects 1 to 3, comprising: 
     an absorbent-core non-arrangement region in which the absorbent core is not disposed, 
     a first stretchable elastic member disposed in a prescribed region in the diaper longitudinal direction, and 
     an erected section that is formed by the end in the diaper longitudinal direction being erected by contraction of the first stretchable elastic member. 
     (Aspect 5) 
     The disposable diaper as defined in aspect 4, wherein the first stretchable elastic member is disposed in a stretched state between the absorbent core and each of the ends in the diaper transverse direction, and forms leg gathers by contracting. 
     (Aspect 6) 
     The disposable diaper as defined in aspect 4, comprising a leakproof sheet, wherein the first stretchable elastic member is disposed in a stretched state in the leakproof sheet and forms a leakproof wall and leakproof gathers by contracting. 
     (Aspect 7) 
     The disposable diaper as defined in any one of aspects 4 to 6, wherein the erected section is formed on the end in the diaper longitudinal direction in the abdomen-side waist area. 
     (Aspect 8) 
     The disposable diaper as defined in any one of aspects 4 to 6, wherein the erected section is formed on the end in the diaper longitudinal direction in the back-side waist area. 
     (Aspect 9) 
     The disposable diaper as defined in any one of aspects 4 to 6, wherein the erected section comprises a first erected section formed on the end in the diaper longitudinal direction in the abdomen-side waist area and a second erected section formed on the end in the diaper longitudinal direction in the back-side waist area. 
     (Aspect 10) 
     The disposable diaper as defined in any one of aspects 4 to 9, wherein an erection sheet is provided in an end region of the absorbent-core non-arrangement region in the diaper longitudinal direction, and the erection sheet is erected by contraction of the first stretchable elastic member and forms the erected section. 
     (Aspect 11) 
     The disposable diaper as defined in aspect 10, wherein the erection sheet is a second stretchable elastic member. 
     (Aspect 12) 
     The disposable diaper as defined in any one of aspects 4 to 11, wherein, when the disposable diaper is ready to be put on the pet, the first stretchable elastic member is already contracted so that the erected section is already formed. 
     (Aspect 13) 
     The disposable diaper as defined in any one of aspects 4 to 12, wherein, while the disposable diaper is worn by the pet, the first stretchable elastic member is maintained in a contracted state so that the erected section is maintained in an erected state. 
     (Aspect 14) 
     The disposable diaper as defined in any one of aspects 1 to 13, comprising the first stretchable elastic member, the second stretchable elastic member, and a contraction force intersecting region in which contraction force of the first stretchable elastic member and contraction force of the second stretchable elastic member intersect with each other. 
     (Aspect 15) 
     The disposable diaper as defined in aspect 14, wherein the second stretchable elastic member is disposed between the absorbent core and each of the ends in the diaper transverse direction and forms waist gathers by contracting. 
     (Aspect 16) 
     The disposable diaper as defined in aspect 14 or 15, wherein the first stretchable elastic member and the second stretchable elastic member are overlapped with each other. 
     (Aspect 17) 
     The disposable diaper as defined in any one of aspects 14 to 16, wherein a first curved part is formed in the ends in the diaper longitudinal direction and curved outward when the disposable diaper is put on the pet, and a second curved part is formed in the contraction force intersecting region and curved inward when the disposable diaper is put on the pet. 
     (Aspect 18) 
     The disposable diaper as defined in any one of aspects 14 to 17, wherein the contraction force intersecting region is formed in the abdomen-side waist area. 
     (Aspect 19) 
     The disposable diaper as defined in any one of aspects 14 to 17, wherein the contraction force intersecting region is formed in the back-side waist area. 
     (Aspect 20) 
     The disposable diaper as defined in any one of aspects 14 to 17, wherein the contraction force intersecting region includes a first contraction force intersecting region formed in the abdomen-side waist area and a second contraction force intersecting region formed in the back-side waist area. 
     (Aspect 21) 
     The disposable diaper as defined in any one of aspects 14 to 20, wherein, when the disposable diaper is ready to be put on the pet, the first and second stretchable elastic members are already contracted so that the contraction force intersecting region is already formed. 
     (Aspect 22) 
     The disposable diaper as defined in any one of aspects 14 to 21, wherein, while the disposable diaper is worn by the pet, the first and second stretchable elastic members are maintained in a contracted state so that the contraction force intersecting region is maintained. 
     (Aspect 23) 
     The disposable diaper as defined in any one of aspects 1 to 22, comprising: 
     the first stretchable elastic member arranged in the diaper longitudinal direction, 
     a fixed part for fixing contraction force of the stretchable elastic member onto the absorbent-core non-arrangement region, and 
     a crotch-side erected section that is formed by the absorbent-core non-arrangement region being erected between the fixed part and the absorbent core by contraction of the stretchable elastic member. 
     (Aspect 24) 
     The disposable diaper as defined in aspect 23, wherein the erected section is formed between an end of the absorbent core in the diaper longitudinal direction and the tail insertion opening in the crotch area. 
     (Aspect 25) 
     The disposable diaper as defined in aspect 23 or 24, wherein, when the disposable diaper is ready to be put on the pet, the first stretchable elastic member is already contracted so that the crotch-side erected section is already formed. 
     (Aspect 13) 
     The disposable diaper as defined in any one of aspects 23 to 25, wherein, while the disposable diaper is worn by the pet, the first stretchable elastic member is maintained in a contracted state so that the crotch-side erected section is maintained in an erected state. 
     DESCRIPTION OF THE NUMERALS 
     
         
           100 ,  101 ,  102 ,  103 ,  104 ,  105 ,  106 ,  107 ,  108 ,  109 ,  1000  disposable pet diaper 
           100 A end in the diaper transverse direction 
           100 P diaper center point 
           100 Y 1  flap boundary line 
           100 Y 2  diaper longitudinal center line 
           100 Z 1  inside surface 
           100 Z 2  outside surface 
           110 ,  1110  abdomen-side waist area 
           110 A,  1110 A abdomen-side end 
           110 AP abdomen-side end center point 
           120 ,  1120  crotch area 
           120 A leg-side end 
           130 ,  1130  back-side waist area 
           130 A,  1130 A back-side end 
           130 AP back-side end center point 
           140 A flap 
           140 B body 
           150 ,  1150  abdomen-side flap 
           150 A end in the diaper transverse direction 
           150 B,  1150 B back-side end 
           160 ,  1160  back-side flap 
           170  absorbent-core non-arrangement region 
           171  abdomen-side erected region 
           172  back-side erected region 
           173  crotch-side erected region 
           180  contraction force intersecting region 
           181  first contraction force intersecting region 
           182  second contraction force intersecting region 
           183  second curved part 
           184  second abdomen-side curved part 
           185  second back-side curved part 
           190 ,  1190  tail insertion opening 
           191  cut 
           200 ,  2000  absorbent core 
           210  abdomen-side end 
           220  back-side end 
           230  end in the diaper transverse direction 
           300 ,  301 ,  302 ,  303 ,  304 ,  3000  fastening part 
           310  free part 
           320  fixed part 
           300 P 1  fastening part midpoint 
           300 P 2  shortest line point 
           300 L shortest straight-line distance 
           300 X fastening part longitudinal direction 
           300 Y fastening part transverse direction 
           400 ,  401 ,  401 A,  401 B,  401 C,  402 ,  402 A,  402 B,  403 ,  404 ,  405 ,  406 ,  407 ,  408 ,  4000  leg stretchable elastic member 
           410 ,  4410  leg gather 
           420  fourth curved part 
           500  waist stretchable elastic member 
           510 ,  511 ,  512 ,  513 ,  514  abdomen-side waist stretchable elastic member 
           520  back-side waist stretchable elastic member 
           530  waist gather 
           540  first curved part 
           541  first abdomen-side curved part 
           542  first back-side curved part 
           600 ,  601 ,  602 ,  603 ,  604 ,  605 ,  6000  leakproof sheet stretchable elastic member 
           610  contraction force fixing part 
           620  abdomen-side contraction force fixing part 
           630  back-side contraction force fixing part 
           640  third curved part 
           700  erected section 
           710  abdomen-side erected section 
           720  back-side erected section 
           730  crotch-side erected section 
           740  erection sheet 
           800 ,  8000  leakproof sheet 
           810  folded part 
           820  leakproof wall 
           830  leakproof sheet fixed part 
           840  leakproof gather 
           850  excrement storage space 
           900 ,  9000  fastening region 
           910  liquid-permeable sheet 
           920  liquid-resistant sheet 
           930  outer sheet 
         D 1  diaper longitudinal length 
         D 2  measured length 
         F 1  contraction force of the leg stretchable elastic member 
         F 2  contraction force of the waist stretchable elastic member 
         F 3  contraction force acting on the contraction force intersecting region 
         X diaper transverse direction 
         Y diaper longitudinal direction 
         α pet 
         α 1  leg of pet 
         α 2  back of pet 
         α 3  abdomen of pet