Sole and footwear having the sole

Abstract

A sole includes a first layer, a second layer, a third layer, and a fourth layer stacked from bottom to top. A hardness of the first layer is greater than a hardness of the third layer, the hardness of the third layer is greater than a hardness of the second layer, and the hardness of the second layer is greater than a hardness of the fourth layer. A footwear having the sole is also provided.

What is claimed is: 
     
         1 . A sole comprising:
 a first layer,   a second layer,   a third layer, and   a fourth layer;   wherein the first layer, the second layer, the third layer, and the fourth layer are stacked from bottom to top, a hardness of the first layer is greater than a hardness of the third layer, the hardness of the third layer is greater than a hardness of the second layer, and the hardness of the second layer is greater than a hardness of the fourth layer.   
     
     
         2 . The sole of  claim 1 , wherein the hardness of the first layer is in a range of 51±3 degrees, the hardness of the second layer is in a range of 45±3 degrees, the hardness of the third layer is in a range of 49±3 degrees, and the hardness of the fourth layer is in a range of 35±3 degrees. 
     
     
         3 . The sole of  claim 2 , wherein a difference in hardness between the first layer and the second layer is 10 degrees, and a difference in hardness between the third layer and the fourth layer is 15 degrees. 
     
     
         4 . The sole of  claim 1 , wherein a rebound rate of the second layer is greater than a rebound rate of the fourth layer, the rebound rate of the fourth layer is greater than a rebound rate of the first layer, and the rebound rate of the first layer is greater than a rebound rate of the third layer. 
     
     
         5 . The sole of  claim 4 , wherein the rebound rate of the first layer is in a range of 55%±2%, the rebound rate of the second layer is in a range of 65%±2%, the rebound rate of the third layer is in a range of 50%±2%, and the rebound rate of the fourth layer is in a range of 60%±2%. 
     
     
         6 . The sole of  claim 5 , wherein a difference in rebound rate between any two adjacent layers among the first layer, the second layer, the third layer, and the fourth layer is 10% to 15%. 
     
     
         7 . The sole of  claim 4 , wherein a density of the first layer is greater than a density of the third layer, the density of the third layer is greater than a density of the second layer, and the density of the second layer is greater than or equal to a density of the fourth layer. 
     
     
         8 . The sole of  claim 7 , wherein the density of the first layer is in a range of 200 G/L to 260 G/L, the density of the second layer is in a range of 120 G/L to 160 G/L, the density of the third layer is in a range of 190 G/L to 250 G/L, and the density of the fourth layer is in a range of 120 G/L to 150 G/L. 
     
     
         9 . The sole of  claim 8 , wherein a difference in the density between any two adjacent layers among the first layer, the second layer, the third layer, and the fourth layer is greater than or equal to 50 G/L. 
     
     
         10 . The sole of  claim 1 , wherein each of the first layer, the second layer, the third layer, and the fourth layer is a popcorn layer containing foamed thermoplastic polyurethane elastomer. 
     
     
         11 . The sole of  claim 10 , wherein the third layer is a 4D printed layer. 
     
     
         12 . The sole of  claim 1 , wherein the first layer at least support a rearfoot area and an arch area of the second layer. 
     
     
         13 . The sole of  claim 12 , further comprising an outsole, wherein the outsole is located on a side of the first layer facing away from the second layer and in an area of a side of the second layer facing away from the third layer, the area of the side of the second layer is not supported by the first layer. 
     
     
         14 . A footwear comprising:
 an upper; and   a sole connected to the upper, the sole comprising:
 a first layer, 
 a second layer, 
 a third layer, and 
 a fourth layer; 
 wherein the first layer, the second layer, the third layer, and the fourth layer are stacked from bottom to top, a hardness of the first layer is greater than a hardness of the third layer, the hardness of the third layer is greater than a hardness of the second layer, and the hardness of the second layer is greater than a hardness of the fourth layer. 
   
     
     
         15 . The footwear of  claim 14 , wherein the hardness of the first layer is in a range of 51±3 degrees, the hardness of the second layer is in a range of 45±3 degrees, the hardness of the third layer is in a range of 49±3 degrees, and the hardness of the fourth layer is in a range of 35±3 degrees. 
     
     
         16 . The footwear of  claim 15 , wherein a difference in hardness between the first layer and the second layer is 10 degrees, and a difference in hardness between the third layer and the fourth layer is 15 degrees. 
     
     
         17 . The footwear of  claim 14 , wherein a rebound rate of the second layer is greater than a rebound rate of the fourth layer, the rebound rate of the fourth layer is greater than a rebound rate of the first layer, and the rebound rate of the first layer is greater than a rebound rate of the third layer. 
     
     
         18 . The footwear of  claim 17 , wherein the rebound rate of the first layer is in a range of 55%±2%, the rebound rate of the second layer is in a range of 65%±2%, the rebound rate of the third layer is in a range of 50%±2%, and the rebound rate of the fourth layer is in a range of 60%±2%. 
     
     
         19 . The footwear of  claim 17 , wherein a density of the first layer is greater than a density of the third layer, the density of the third layer is greater than a density of the second layer, and the density of the second layer is greater than or equal to a density of the fourth layer. 
     
     
         20 . The footwear of  claim 19 , wherein the density of the first layer is in a range of 200 G/L to 260 G/L, the density of the second layer is in a range of 120 G/L to 160 G/L, the density of the third layer is in a range of 190 G/L to 250 G/L, and the density of the fourth layer is in a range of 120 G/L to 150 G/L.