Smoking article and smoking article filter

Abstract

Improved filters useful for tobacco products, such as cigarettes, and novel cigarettes having such filters are disclosed. The filters include adsorbents such as activated carbon which reduce amounts of one or more gas phase constituents of mainstream tobacco smoke. The adsorbents are treated with off-taste suppressants which reduce the off-taste associated with adsorbent containing filters and substantially restore the taste normally associated with tobacco smoke.

Description

[0001]This is a divisional application of U.S. Ser. No. 10 / 442,357 filed May 20, 2003 to which priority under 35 U.S.C. § 120 is claimed.FIELD OF THE INVENTION[0002]The present invention relates generally to improved filters useful for tobacco products, particularly cigarettes, and to novel cigarettes having such filters. More specifically, the invention relates to filters containing adsorbents which reduce one or more allegedly undesirable gas phase constituents normally found in mainstream tobacco cigarette smoke.BACKGROUND OF THE INVENTION[0003]Typically, cigarettes are comprised of a paper-wrapped cylindrical rod of cut tobacco filler, alone or combined with other tobacco or non-tobacco substances, and a filter attached at the mouth or buccal end of the rod. On combustion, the smoke passing through the filter, commonly referred to as “mainstream” smoke, contains particulate matter, e.g. tar, and gas or volatile phase constituents. The gas phase of mainstream cigarette smoke cont...

AI Technical Summary

Benefits of technology

[0013]The foregoing and other objectives are achieved according to the invention by providing a filter containing a suitable amount of an adsorbent, preferably activated carbon, and an off-taste suppressant in association with the adsorbent. The adsorbent is capable of trapping and thereby reducing the amount of at least one allegedly undesirable gas phase constituent of mainstream smoke. The off-taste suppressant significantly reduces the characteristic off-taste stemming from the activity of the adsorbent. The composition and amount of off-taste suppressant applied to the adsorbent should be selected to maximize gas phase removal while at the same time minimizing, preferably substantially eliminating, off-taste stemming from adsorbent activity.

[0017]The filters of the present invention are capable of reducing one or more of the allegedly undesirable volatile components of mainstream cigarette smoke including, but not limited to, aldehydes such as formaldehyde, acetaldehyde, acrolein, propionaldehyde and crotonaldehyde.

Problems solved by technology

Most commercially available cigarettes have filters which are designed to reduce particulate matter but are ineffective to remove or reduce gas phase constituents of mainstream smoke.

The commercial acceptance of carbon filters, however, has been limited by the “off-taste” of the mainstream smoke characteristic of such filters.

The smoke from carbon-filtered cigarettes is perceived as having a taste that has been described as unpleasant, astringent, bitter and drying.

However, the presence of flavorants tends to reduce the capacity of the adsorbent to remove the undesirable gas phase constituents.

Flavorants applied as a coating to an adsorbent reduce its gas removal efficiency by decreasing the number of active sites for adsorption.

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