Relating to smoking article filters
AssigneeBritish American Tobacco (Investments) Limited
InventorsPeter Branton, Philip Hunt
Life of this patent
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Abstract
The invention describes a filter (1) with a first filter portion (6) comprising an adsorbent, for example carbon, and/or a catalyst, capable of reducing various vapour phase constituents of cigarette smoke. The adsorbent/catalyst is separated from a second filter portion by means of a barrier (2) having pores therein of pore size less than 0.1 μm. The invention also describes a smoking article in which a rod of smoking material, with or without encapsulated flavour, is attached to the above described filter.
Claims36
1-40. (canceled)
A smoke filter comprising a first portion and a second portion, said first portion being closed against particulate material flow and said second portion providing a through path for particulate material flow, said first portion and said second portion being separated by barrier means, said barrier means is formed from a vapour porous polymeric material having pores therein, which pores have a pore size of less than about 0.1 μm.
A smoke filter according to claim 1, wherein the barrier means is porous to the vapour phase of smoke.
A smoke filter according to claims 1, wherein said barrier means is formed from a flexible material.
A smoke filter according to claim 1, wherein said polymeric material is selected from the group consisting of polypropylene, polyethylene, polyvinylidene fluoride, polyvinyl chloride, polycarbonate, nylon, Teflon™ (PTFE), cellulose acetate or nitrocellulose.
A smoke filter according to claim 1, wherein said first portion of the tobacco smoke filter comprises an adsorbent material.
A smoke filter according to claim 5, wherein said adsorbent material is a general adsorbent.
A smoke filter according to claim 6, wherein said general adsorbent is a carbonaceous material.
A smoke filter according to claim 7, wherein said carbonaceous material is in the form of a thread, particles/granules, cloth, paper or a reconstituted carbon-containing paper.
A smoke filter according to claim 6, wherein said general adsorbent is a non-carbonaceous material selected from the group consisting of zeolite, silica, meerschaum, aluminium oxide or combinations thereof.
A smoke filter according to claim 1, wherein said first portion of said smoke filter comprises a catalyst.
A smoke filter according to claim 10, wherein said catalyst facilitates the conversion of carbon monoxide (CO) to carbon dioxide (CO2) in the vapour phase of the smoke.
A smoke filter according to claim 11, wherein said catalyst is selected from the group consisting of transition metal oxides, silica, alumina, zeolites, impregnated carbon.
A smoke filter according to claim 1, wherein said first portion of said smoke filter comprises a selective adsorbent.
A smoke filter according to claim 13, wherein said selective adsorbent material is selected from the group consisting of an ion-exchange resin, zeolite or silica.
A smoke filter according to claim 1, wherein said first portion comprises an adsorbent and a catalyst.
A smoke filter according to claim 1, wherein said filter further comprises a third portion, which third portion comprises an adsorbent.
A smoke filter according to claim 16, wherein said third portion is located upstream of said first portion of the filter.
A smoke filter according to claim 1, wherein said second portion of said filter comprises a conventional smoke filtration material.
A smoke filter according to claim 18, wherein said conventional smoke filtration material is one or more of cellulose acetate, paper and polypropylene.
A smoke filter according to claim 1, wherein said first and said second portions are in co-axial alignment.
A smoke filter according to claim 20, wherein said first portion forms an inner core and said second portion forms an outer annulus of a core-annulus arrangement.
A smoke filter according to claim 20, wherein said second portion forms a core and said first portion forms an outer annulus of a core-annulus arrangement.
A smoke filter according to claim 1, wherein said first portion is formed of a number of discrete, substantially longitudinal segments arranged in co-axial alignment within said second portion of said filter.
A smoke filter according to claim 23, wherein each segment of said first portion is separated from said second portion by barrier means.
A smoke filter according to claim 1, wherein said first portion is closed to the through flow of particulate phase material at the upstream end thereof.
A smoke filter according to claim 25, wherein closure of said first portion is achieved by a plug.
A smoke filter according to claim 26, wherein said plug is formed from a high pressure drop cellulose acetate, plastic, metal or the barrier material described of claim 4.
A smoke filter according to claim 1, wherein said filter further comprises additional portions of conventional smoke filtration material.
A smoke filter according to claim 28, wherein said first, second and third (if present) portions are in co-axial alignment with at least one additional filter portion.
A smoke filter according to claim 29, wherein said additional portion of said filter is in end-to-end abutment with said first, second and third (if present) portions of the filter.
A smoke filter according to claim 1, wherein said additional portion(s) is comprised of cellulose acetate.
A smoking article comprising a smoke filter according to claim 1 in combination with a rod of smoking material wrapped in a wrapper.
A smoking article according to claim 32, wherein said smoking material comprises a flavourant.
A smoking article according to claim 33, wherein said flavourant is in stabilised or encapsulated form.
A smoking article according to claim 33, wherein said flavourant is a non-volatile flavourant.
Dependencies are inferred from the claim text.