Film selectively permeable to carbon dioxide gas and food packaging film comprising the same

摘要

A film selectively permeable to carbon dioxide gas which includes chitosan having a degree of deacetylation of 70 mol % or higher and in which the ratio of the carbon dioxide gas transmission (CO₂TR) to the oxygen gas transmission (O₂TR), (CO₂TR/O₂TR), is 15 or higher and a food packaging film made from such a film. The films are insoluble in water, are highly safe from the standpoint of food hygiene, and have such selective gas permeability that the ratio of carbon dioxide gas transmission to oxygen gas transmission is high, which can be economically obtained.