Mid Sole Having Layered Structure

摘要

A mid sole arranged on an outsole having a tread surface, the mid sole including: an upper layer and a lower layer, wherein one of the upper layer and the lower layer includes a layer of a first foamed body having a thermoplastic resin component; in another one of the upper layer and the lower layer, one or two or more of a majority of a flat area of a front foot portion, a majority of a flat area of a middle foot portion, and a majority of a flat area of a rear foot portion includes a layer of a second foamed body having a thermoplastic resin component; and the second foamed body has a greater specific gravity than the first foamed body, and is formed by a low-resilience material having a low speed of recovering to its original shape after being deformed.

主权项

1. A mid sole arranged on an outsole having a tread surface,
the mid sole comprising: an upper layer and a lower layer, wherein one of the upper layer and the lower layer includes a layer of a first foamed body having a thermoplastic resin component; in another one of the upper layer and the lower layer, one or two or more of a majority of a flat area of a front foot portion, a majority of a flat area of a middle foot portion, and a majority of a flat area of a rear foot portion includes a layer of a second foamed body having a thermoplastic resin component; and the second foamed body has a greater specific gravity than the first foamed body, and is formed by a low-resilience material having a speed of recovering to its original shape after being deformed lower than that of the first foamed body, wherein a relationship between an asker C hardness Lc of the second foamed body and an asker C hardness Nc of the first foamed body is set to satisfy Expression (1) below:
Lc≦Nc+10  (1).