PURPOSE: A simple sheet material for cooling having improved durability, consisting of a selective permeability sheet material which has water pressure resistance of ≥ a specific value, does not permeate liquid in at least one direction but has gas permeability.
CONSTITUTION: A cooling sheet material consisting of a selective permeability structure, which comprises (A) a continuous fine porous membrane preferably containing a water-repellent resin, more preferably continuous fine porous membrane of synthetic polymer and a fibrous material reinforcing the membrane or (B) a fibrous structure such as cloth, etc., preferably having a structure of density different in the thickness direction, has at least 30mm H2O/cm2, preferably ≥50mm H2O/cm2 water pressure resistance and does not permeate liquid in at least one direction but has gas permeability. For example, when a canteen is made of this sheet material and water is put in it, water in the canteen can be cooled by latent heat of evaporation of water.
AIYAMA KAZUNORI
TOMITA TADASHI
