Underpants-type disposable diaper

Abstract

An underpants-type disposable diaper is of a size and a water absorption capacity suitable for infants 3 to 6 years old, and is capable of preventing the protrusion of the groin portion of the diaper in use so that leakage does not occur. The leakage can be avoided by increasing the size and the water absorption capacity of the diaper main body 110 to a level suitable for infants 3 to 6 year olds still using diaper and at the same time improving the tracks of a plurality of elastic members 170 disposed along the peripheral edges of leg holes 130 so as to reduce the elasticity in the vertical direction of the crotch section and prevent the protrusion of the groin when the diaper is worn.

1 . An underpants-type disposable diaper comprising an underpants-formed diaper main body, wherein said diaper main body comprises an underpants-formed outer cover having a waist opening part to be fixed to a wearer's trunk, a pair of leg holes for the wearer's legs to pass thorough, a front part to be positioned ventral to the wearer, a back part to be positioned dorsal to the wearer and a crotch part jointed to said front part and said back part to be positioned between legs of the wearer, and a substantially belt-like inner member joined to the inner side of said outer cover, said inner member positioned between said leg holes; 
 said front part comprising an elastic member pulling said inner member in the lateral direction of said diaper.    
     
     
         2 . The underpants-type disposable diaper according to  claim 1  wherein said elastic member is a linear elastic member extending from one side edge of said front part to the center of said front part along the peripheral edge of each of said leg holes forming a horizontally elongated arc.  
     
     
         3 . The underpants-type disposable diaper according to  claim 2  wherein the ratio of the minimum dimension of said elastic member from one end positioned near the side edge of said front part to the other end thereof positioned near the center of said front part in the lateral direction to the minimum dimension thereof in the vertical direction is not less than 1.0 and not more than 3.0 in a state that said elastic member is not expanded.  
     
     
         4 . The underpants-type disposable diaper according to  claim 2 , 
 wherein a plurality of the elastic member are provided in both sides of said front part; and    the interval between the ends of the elastic members positioned near the center of said front part is not less than 7 mm and not more than 12 mm in a state prior to its wearing.    
     
     
         5 . The underpants-type disposable diaper according to  claim 3 , 
 wherein a plurality of the elastic member are provided in both sides of said front part; and    the interval between the ends of the elastic members positioned near the center of said front part is not less than 7 mm and not more than 12 mm in a state prior to its wearing.    
     
     
         6 . The underpants-type disposable diaper according to  claim 2 , wherein the maximum dimension of said disposable diaper main body in the vertical direction is not less than 225 mm and not more than 265 mm in a state prior to its wearing, and that in the lateral direction is not less than 180 mm and not more than 215 mm in a state prior to its wearing.  
     
     
         7 . The underpants-type disposable diaper according to  claim 3 , wherein the maximum dimension of said disposable diaper main body in the vertical direction is not less than 225 mm and not more than 265 mm in a state prior to its wearing, and that in the lateral direction is not less than 180 mm and not more than 215 mm in a state prior to its wearing.  
     
     
         8 . The underpants-type disposable diaper according to  claim 4 , wherein the maximum dimension of said disposable diaper main body in the vertical direction is not less than 225 mm and not more than 265 mm in a state prior to its wearing, and that in the lateral direction is not less than 180 mm and not more than 215 mm in a state prior to its wearing.  
     
     
         9 . The underpants-type disposable diaper according to  claim 5 , wherein the maximum dimension of said disposable diaper main body in the vertical direction is not less than 225 mm and not more than 265 mm in a state prior to its wearing, and that in the lateral direction is not less than 180 mm and not more than 215 mm in a state prior to its wearing.  
     
     
         10 . The underpants-type disposable diaper according to  claim 1 , wherein the water absorption capacity of said absorbent body is not less than 800 g and not more than 1000 g, and the water-holding capacity thereof is not less than 500 g and not more than 700 g.  
     
     
         11 . The underpants-type disposable diaper according to  claim 2 , wherein the water absorption capacity of said absorbent body is not less than 800 g and not more than 1000 g, and the water-holding capacity thereof is not less than 500 g and not more than 700 g.  
     
     
         12 . The underpants-type disposable diaper according to  claim 3 , wherein the water absorption capacity of said absorbent body is not less than 800 g and not more than 1000 g, and the water-holding capacity thereof is not less than 500 g and not more than 700 g.  
     
     
         13 . The underpants-type disposable diaper according to  claim 4 , wherein the water absorption capacity of said absorbent body is not less than 800 g and not more than 1000 g, and the water-holding capacity thereof is not less than 500 g and not more than 700 g.  
     
     
         14 . The underpants-type disposable diaper according to  claim 5 , wherein the water absorption capacity of said absorbent body is not less than 800 g and not more than 1000 g, and the water-holding capacity thereof is not less than 500 g and not more than 700 g.  
     
     
         15 . The underpants-type disposable diaper according to  claim 6 , wherein the water absorption capacity of said absorbent body is not less than 800 g and not more than 1000 g, and the water-holding capacity thereof is not less than 500 g and not more than 700 g.  
     
     
         16 . The underpants-type disposable diaper according to  claim 7 , wherein the water absorption capacity of said absorbent body is not less than 800 g and not more than 1000 g, and the water-holding capacity thereof is not less than 500 g and not more than 700 g.  
     
     
         17 . The underpants-type disposable diaper according to  claim 8 , wherein the water absorption capacity of said absorbent body is not less than 800 g and not more than 1000 g, and the water-holding capacity thereof is not less than 500 g and not more than 700 g.  
     
     
         18 . The underpants-type disposable diaper according to  claim 9 , wherein the water absorption capacity of said absorbent body is not less than 800 g and not more than 1000 g, and the water-holding capacity thereof is not less than 500 g and not more than 700 g.