Breathing sheet materials

摘要

Sheet material capable of absorbing and evaporating water vapour is obtained by treating vapour-permeable substrate, e.g. textiles with copolymers containing at least 5 wt.% 3-4C carboxylic acid esters with 4-8C tert alcohols and 0.1-10 equivalent % unsaturated acid with dissociation constant above 10-4 (e.g. unsatd. sulphonic acid) and heating. Polymers cleave off gaseous olefins when heated and form foam, creating carboxyl groups which impart hydrophilic character to sheet material.