Classifications

• • A—HUMAN NECESSITIES
  • A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
  • A24B—MANUFACTURE OR PREPARATION OF TOBACCO FOR SMOKING OR CHEWING; TOBACCO; SNUFF
  • A24B15/00—Chemical features or treatment of tobacco; Tobacco substitutes, e.g. in liquid form
  • A24B15/18—Treatment of tobacco products or tobacco substitutes
  • A24B15/24—Treatment of tobacco products or tobacco substitutes by extraction; Tobacco extracts
  • A24B15/241—Extraction of specific substances
  • A24B15/246—Polycyclic aromatic compounds
• • A—HUMAN NECESSITIES
  • A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
  • A24B—MANUFACTURE OR PREPARATION OF TOBACCO FOR SMOKING OR CHEWING; TOBACCO; SNUFF
  • A24B15/00—Chemical features or treatment of tobacco; Tobacco substitutes, e.g. in liquid form
  • A24B15/18—Treatment of tobacco products or tobacco substitutes
  • A24B15/28—Treatment of tobacco products or tobacco substitutes by chemical substances
• • A—HUMAN NECESSITIES
  • A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
  • A24B—MANUFACTURE OR PREPARATION OF TOBACCO FOR SMOKING OR CHEWING; TOBACCO; SNUFF
  • A24B15/00—Chemical features or treatment of tobacco; Tobacco substitutes, e.g. in liquid form
  • A24B15/18—Treatment of tobacco products or tobacco substitutes
  • A24B15/28—Treatment of tobacco products or tobacco substitutes by chemical substances
  • A24B15/287—Treatment of tobacco products or tobacco substitutes by chemical substances by inorganic substances only

Definitions

• ABSTRACT concentration of polycyclic aromatic hydrocarbons in tobacco smoke is reduced by incorporating zinc oxide and a nitrate of a Group 11a and 11b metal into tobacco.
• This invention relates to a smoking composition containin g tobacco and having a combination of a catalytic agent and an additive releasing nitric oxide associated with the tobacco for reducing the concentration of polycyclic aromatic hydrocarbons in tobacco smoke. More particularly it relates to such compositions wherein the catalytic agent is zinc oxide and the nitric oxide releasing additive is selected from the group consisting of magnesium, calcium and zinc nitrates.
• nitrates on the composition of cigarette smoke stems from two properties of nitrates: a) their capacity to oxidize, and b) their capacity to form the unpaired electron species, nitric oxide, in the pyrolysis zone of the cigarette that acts as a free radical scavenger.
• nitrates Provided a sufficiently high level is added, all nitrates tend to lower the PCAH yield of cigarettes to some degree, but depending on the particular cation, not necessarily the concentration of PCAl-l in the smoke condensate.
• the nitrates capacity to reduce PCAH concentration is particularly dependent on the ability of the salt to form nitric oxide in the appropriate temperature region of the combustion zone.
• Many of the nitrates and, in particular, nitrates of Group la metals are good combustion promoters. When they are added to tobacco the burn rate of cigarettes is accelerated and the total smoke yield is decreased. The concentration of PCAH within the smoke condensate is, however, not necessarily decreased and is at times increased. The nitric oxide yield from such nitrates is relatively low. Hence, nitrates of Group la metals have to be added at relatively high levels to reduce the concentration of PCAH in tobacco smoke.
• nitrates like zinc oxide, even though being an efficient agent for disrupting some of the pathways of PCAH formation, has not proven to be a universal elminator of PCAH. particularly at levels compatible with acceptable taste and smell of cigarette smoke.
• the concentration of PCAl-l is substantially reduced without adverse organoleptic effect on tobacco smoke by incorporating both zinc oxide and a Group lla or llb nitrate in tobacco.
• the Group lla and llb metal nitrates do not accelerate cigarette burn rate. in addition they yield more nitric oxide per mole under the conditions extant in the cigarette cone. Hence, they effect more efficient reductions in the PCAH concentration in smoke condensate.
• nitrate compound enables reduction of the PCAH concentration to levels below those achieved with zinc oxide alone. This effect is achieved with nitrate concentrations well below the levels having objectionable effects on the organoleptic properties of smoke. in particular, substantial reductions in PCAH concentrations are achieved at nitrate levels below 0.8% nitrate nitrogen, based upon the weight of tobacco.
• the zinc oxide which has been found to be particularly effective in combination with tobacco to provide the smoking composition of this invention is A.C.S. grade zinc oxide which contains (on a weight basis) less than about 0.005% lead, 0.004% sulfate ion, 0.002% nitrate ion and 0.001% chloride ion.
• the particle size of the zinc oxide is finer than about 50 US. mesh. Generally, the particle size is within the range of 60-200 U.S. mesh with the greater portion of the material being preferably finer than 100 US. mesh.
• the catalytic amount of zinc oxide associated with the tobacco in the smoking composition is in the range of between about 0.1% to about by weight of the tobacco used to prepare the smoking composition. Although the reduced yield of polycyclic compounds arising from pyrolytic reactions of the composition have been achieved at these levels, it has been found that the best results are obtained when the zinc oxide is in the preferred range of from about 0.5% to about 8% based upon the weight of the tobacco.
• the nitrates which are employed in accordance with this invention are the Group lla and llb metal nitrates, with calcium, magnesium, and zinc nitrates being preferred.
• a nitrate which has been particularly effective in combination with zinc oxide and tobacco to provide the smoking composition of this invention is A.C.S. grade Mg(NO )2.6H O which contains (on a weight basis) less than about 0.0005% chloride ion, 0.005% sulfate ion and 0.004% heavy metals (calculated as lead).
• the proportion of nitrate associated with zinc oxide and tobacco in the smoking composition is below 0.8%, and preferably is in the range of from about 0.25% to about 0.75%, calculated as nitrate nitrogen.
• the amount of reduction of PCAH yield that is due to the nitrate can be increased as the level of nitrate is increased, the taste and aroma of smoke becomes progressively more obnoxious as the nitrate level is increased.
• in combination with 4 zinc oxide we prefer to operated in the 0.25 to 0.60% nitrate nitrogen range.
• the additives should be well dispersed throughout the tobacco so that they will be uniformly effective during the entire period during which the composition is smoked. Furthermore, it is important to ensure that the dispersion effectively contacts a maximum volume of smoke which is inhaled by the user. Since the catalytic activity of the zinc oxide is most likely a surface phenomenon, the greatest likelihood of maximum contact between the smoke being drawn in by the user and the zinc oxide is obtained when the area/volume ratio of the zinc oxide particles is maximized for a given weight of zinc oxide. For this reason, it is employed as a fine powder of particle size, preferably smaller than about U.S. mesh.
• the calcium, magnesium, and zinc nitrates are very soluble in water and can be applied as a relatively concentrated solution which avoids the excessive wetting of tobacco and yet assures good distribution throughout the tobacco mass.
• Another method of application of the additives to the tobacco is to dry blend the zinc oxide, ground tobacco, a fibrous material and a binder. Dry blending, as in a conventional double cone blender effectively distributes the zinc oxide over the surface of the tobacco, including the pores within the tobacco surface which are large enough to accept the zinc oxide particles.
• dry blending is followed by wet mixing with water and casing materials in proportions sufficient to provide the resulting mixture with the appropriate consistency for conventional reconstituted tobacco sheet manufacturing operations.
• the sheet is then cut into strips and a solution of nitrate compound in water is applied to the strips. This is followed by a drying step if the tobacco moisture level needs to be adjusted.
• This material can be used in cigarette manufacture as such or it can be blended in any desired proportion with regular tobacco.
• the fibrous material which is a constituent of the dry blend can be, for example, oz-cellulose or fibrous tobacco stem material.
• the binder portion of the dry blend may be sodium carboxymethyl cellulose, or a natural gum such as guar gum.
• the casing materials used in the wet mixing step are usually glycerin and propylene glycol. Of course, any other known fibrous material, binder of casing materials known to be useful in combination with tobacco products can be used in combination with or in place of those herein set forth.
• the weight proportions of the additives described above for use in reconstituted tobacco sheets are within the following approximate weight ranges.
• the proportions shown are within the usual range required to provide useful tobacco products.
• the smoking composition may be further processed and formed into any desired shape or used loosely e.g., cigars, cigarettes, and pipe tobacco in a manner wellknown to those skilled in the tobacco art.
• EXAMPLE 30.58 lbs. of ZnO and 28.52 lbs. of Mg(NO;,),'6l-l,O were suspended and dissolved respectively in a mixture of glycerinpropylene glycol casing solution and water and sprayed in a conventional casing applicator onto 294 lbs. of uncut strip tobacco blend.
• the treated tobacco was blended with 38.5 lbs. of reconstituted tobacco sheet and 17.5 lbs. of stems.
• the resulting blend was cut at 32 cuts per inch.
• Blends containing only the zinc oxide and only the magnesium nitrate as well as a control blend containing neither additive were prepared in a similar manner.
• Sample No. 3 illustrative of this invention, afforded materially lower concentrations of PCAH than were obtained with either zinc oxide or magnesium nitrate alone.
• a smoking composition comprising:
• nitrate of calcium, magnesium or zinc in an amount of from about 0.25 to about 0.75 weight percent calculated as nitrate nitrogen. based upon the weight of said tobacco, said amount being sufficient to effect a further reduction in the amount of polycylic aromatic compounds in said smoke.
• composition of claim 1 wherein the concentration of zinc oxide is from about 0.5 to about 8 weight per cent and the concentration of said nitrate is from about 0.25 to about 0.6 weight per cent calculated as nitrate nitrogen, based upon the weight of said tobacco.
• composition of claim 1 wherein said nitrate is magnesium nitrate.
• composition of claim 2 wherein said nitrate is magnesium nitrate.
• composition of claim 1 comprising admixing catalytic quantities of zinc oxide, said nitrate and tobacco to provide a uniform dispersion of said zinc oxide and nitrate throughout said tobacco.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Toxicology (AREA)
• Inorganic Chemistry (AREA)
• Manufacture Of Tobacco Products (AREA)
• Inorganic Insulating Materials (AREA)
• Cigarettes, Filters, And Manufacturing Of Filters (AREA)
• Catalysts (AREA)

Priority Applications (15)

Applications Claiming Priority (1)

Publications (1)

Family

ID=23689354

Family Applications (1)

Country Status (15)

Cited By (5)

Citations (6)

• 1973
  • 1973-12-19 US US426114A patent/US3893464A/en not_active Expired - Lifetime
• 1974
  • 1974-12-10 GB GB53408/74A patent/GB1481718A/en not_active Expired
  • 1974-12-11 IE IE2551/74A patent/IE42111B1/en unknown
  • 1974-12-12 PH PH16613A patent/PH11279A/en unknown
  • 1974-12-12 FR FR7440970A patent/FR2255022B1/fr not_active Expired
  • 1974-12-13 ZA ZA00747967A patent/ZA747967B/xx unknown
  • 1974-12-16 AU AU76484/74A patent/AU466727B2/en not_active Expired
  • 1974-12-17 BR BR10542/74A patent/BR7410542D0/pt unknown
  • 1974-12-17 CA CA216,240A patent/CA1026544A/en not_active Expired
  • 1974-12-18 AR AR256966A patent/AR209288A1/es active
  • 1974-12-18 DE DE19742459891 patent/DE2459891A1/de active Pending
  • 1974-12-18 JP JP49145485A patent/JPS5238118B2/ja not_active Expired
  • 1974-12-18 CH CH1690274A patent/CH595782A5/xx not_active IP Right Cessation
  • 1974-12-19 BE BE151717A patent/BE823595A/xx unknown
  • 1974-12-19 NL NL7416562A patent/NL7416562A/xx not_active Application Discontinuation

Patent Citations (6)

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