| 摘要 |
To provide a gas adsorbent which has sufficient gas adsorptivity for noxious gas components in a cigarette when brought into contact with a gas stream having a high flow rate as that when it passes through a cigarette filter, and which releases a small amount of bad odor components such as amine impurities and free noxious components which adversely affect health such as aromatic compounds derived from the gas adsorbent itself. A gas adsorbent which satisfies the following conditions (I), (II), (IV) and (V) or the following conditions (I), (III), (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;
(III) the content of a monocyclic aromatic compound represented by the following formula 1 in the gas adsorbent per unit mass is at most 4 mg/g:
wherein R is a substituent selected from the group consisting of a hydroxyl group, a C 1-3 alkyl group and a C 2-3 alkenyl group, and n is an integer of from 1 to 6 and represents the number of the substituent R, provided that when there are a plurality of R's, the respective R's may be the same or different;
(IV) the neutral salt decomposition capacity 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. |
