Cigarette filter which removes carcinogens and toxic chemicals

Abstract

Disclosed herein is a filter for use with tobacco products, such as cigarettes, cigars, and pipes, which selectively absorbs toxic compounds and carcinogenic polynuclear aromatic compounds passing through it, but which permits most low molecular weight species, and in particular nicotine, to pass through. The filter is made from a middle-density polyurethane foam which is pre-treated to increase the number of binding sites for polynuclear aromatic compounds.

Description

[0001] The present application claims priority under 35 U.S.C. .sctn. 120 to U.S. patent application Ser. No. 09 / 252,334, filed Feb. 18, 1999, which in turns claims priority under 35 U.S.C. .sctn. 119(e) to U.S. Provisional Application Ser. No. 60 / 093,330, entitled SAFE CIGARETTE FILTER, filed Jul. 20, 1998.BACKGROUND OF INVENTION[0002] The present invention generally relates to filters for use with tobacco products. In particular, the present invention relates to a filter which selectively removes toxic and carcinogenic compounds from tobacco smoke passing through it, but permits most of the lower molecular weight species, such as nicotine, to pass through.[0003] People begin smoking cigarettes for a variety of reasons. Smoking has been portrayed as being heroic, cool and as enhancing sexual appeal. For some people, smoking also serves to soothe tension, anxiety, or loneliness. However, as is commonly known, cigarette smoke contains the addictive compound nicotine.[0004] Addiction ...

AI Technical Summary

Benefits of technology

[0007] The present invention advantageously provides a filter which selectively removes polynuclear aromatic compounds and cyanide from tobacco smoke, while permitting most of the nicotine and flavor-enhancing molecules in the smoke to pass through. Because of this, people smoking tobacco products who use the filter of the present invention may enjoy the smoking experience, but with less exposure to the dangerous components of tobacco smoke.

[0023] In one embodiment, the benefits of the present invention are achieved by incorporating a filter 35 formed from a polyurethane foam into the body 12 of a tobacco product such as a cigarette 10. As shown in FIG. 1, the filter 35 is incorporated at proximal end 16 by being wrapped with a paper product. Preferably, cigarette 10 also incorporates a portion of conventional filter 25, and PUF filter 35 is positioned proximal to filter 25 at proximal end 16. When this two-filter combination is used, filter 25 will function to protect PUF filter 35 from burning when the tobacco is completely combusted. In this respect, it is preferred that filter 25 have a diameter approximately that of the cigarette body 12, and a length of from about 1 mm to about 4 mm, and more preferably from about 2 mm to about 3 mm.

[0027] To maximize the toxic chemical and carcinogen removing benefits of the present invention, it is preferred that the polyurethane foam first be treated to increase the number of absorption sites for binding polynuclear aromatic compounds and toxic compounds. One method which has been shown useful to achieve this is Soxhlet extraction, which cleans the polyurethane foam and therefore increases the number of absorption sites. In this process, a solvent containing 6% ether in hexane is evaporated from a solvent reservoir. The solvent vapor is then condensed into a chamber containing the polyurethane foam to be treated. The polyurethane foam in the chamber is gradually immersed in the condensed solvent until it is totally immersed. Most of the contaminants on or in the polyurethane foam will be extracted into the solvent. The solvent in the chamber is then siphoned through a tube down to the solvent reservoir at the bottom. The solvent evaporated out of the solvent reservoir is always pure and free from contaminants from the polyurethane foam Therefore, only contaminant-free solvent is condensed into the chamber and all contaminants from the polyurethane foam accumulate in the reservoir. The solvent in the chamber is siphoned approximately once every hour for 16 hours. After the Soxhlet extraction, excess solvent is removed from the polyurethane foam by blowing it to dryness in nitrogen.

[0031] Lumen 60 has a larger inner diameter at distal end 54, and is proportioned to receive the proximal end of a conventional cigarette. Preferably, lumen 60 is dimensioned to snugly fit over a conventional cigarette, such that a cigarette inserted into lumen 60 will be held firmly in place, but may be removed with minimal effort by a person. Incorporated into lumen 60 is a polyurethane foam (PUF) filter 35 of the present invention. Preferably, the PUF filter 35 has been pre-treated to increase the number of polynuclear aromatic compound and cyanide absorption or binding sites, as described above. Filter 35 should have a diameter to fill the entirely of lumen 60, such that any cigarette smoke which passes through lumen 60 to mouthpiece opening 65 must pass through PUF filter 35, This may be accomplished by forming filter 35 to nave an uncompressed diameter slightly greater than that of lumen 60, and then slightly compressing filter 35 so that it fits snugly in lumen 60.

Problems solved by technology

Addiction to nicotine makes it very difficult for smokers to stop smoking cigarettes, even though many realize that smoking will adversely affect their health.

The serious negative health effects of smoking are generally caused by chemicals in tobacco smoke other than nicotine.

The formation of polynuclear aromatic compounds in cigarette smoke is the result of incomplete combustion of the cigarette due to short burning resident time.

Furthermore, polynuclear aromatic compounds harm not only smokers, but also the surrounding environment and people who inhale them as second-hand smoke.

Furthermore, tobacco smoke also contains cyanide, a highly toxic compound which causes adverse health effects in smokers and those inhaling second-hand smoke.

The filters are effective in removing some of the toxic chemicals from tobacco smoke, but a substantial amount still passes through the filter.

Images