Patent ID: 8053483

Claim:
A gas adsorbent capable of adsorbing gas in a cigarette filter wherein the gas absorbent satisfies the following conditions (I), (II), (IV) and (V): (I) the mean pore radius of the gas adsorbent is at least 330 Å and at most 3,000 Å as measured by a mercury porosimeter; (II) the amine elution amount from the gas adsorbent per unit mass is at most 10 μeq/g; (IV) the neutral salt decomposition capacity of the gas absorbent is at most 0.43 meq/g; and (V) the acid adsorption capacity of the gas adsorbent per unit mass is at least 1.5 meq/g; wherein the gas adsorbent is a weakly basic anion exchange resin having amino groups which has been washed with a strong acid.