GB1257290A - - Google Patents

Abstract

1,257,290. Tobacco-smoke filters. BRITISHAMERICAN TOBACCO CO. Ltd. 16 April, 1969 [3 May, 1968], No. 32387/71. Divided out of 1,255,657. Heading A2C. A three-component tobacco-smoke filter with two or more filter sections, comprises an absorbent section, an aqueous humidifying means contained in liquid form in an impermeable rupturable enclosure and a poorly absorbent section, a filtration-enhancing additive being included in the said absorbent section and/or aqueous humidifying means. The absorbent section may comprise absorbent paper or paper wadding. The poorly absorbent section may comprise a fibrous or filamentary material, such as cellulose acetate, or a foam material. The filtration-enhancing additive may be polyethylene imine, zinc acetate, sodium carbonate and/or trisodium orthophosphate. The humidifying means, e.g. water, may be contained in one or more capsules which are rupturable by finger pressure exerted on the section containing them, which section is preferably located between the highly and poorly absorbent sections, and which capsules may be surrounded or embedded in absorbent paper or paper wadding. When attached to a cigarette, the poorly absorbent section of the filter forms the mouth end. The aqueous humidifying liquid may be contained in: thin walled tubes of polyvinyl chloride, polystyrene, polyethylene or polypropylene with their ends sealed with a frangible resin, a mixture of paraffin-type waxes blended with polyethylene, or a rupturable adhesive cellulose-type tape; flexible plastics cups with a central aperture closed by a frangible resin or wax; capsules made wholly of resin or wax or, if at least 10% glycerin is included in the aqueous humidifying liquid, of gelatine; cells of a frangible foam or cellular material; or encapsulated smoke-filtering material.