Abstract:
A cigarette or cigar wrapper is disclosed wherein the paper filler consists of two homogeneously intermixed minerals, viz huntite and hydromagnesite, alone, or admixed with calcium carbonate or magnesium hydroxide or calcium carbonate and magnesium hydroxide and carbon.

Description:
SUMMARY OF THE INVENTION 
     This invention relates to smoking articles, such as cigarettes, cigars and the like, and the wrapper for the tobacco column thereof, that provide acceptable burn rates, produce light-colored, well-formed ash which clings tightly without premature flaking, have significantly reduced sidestream smoke generation compared to conventional cigarettes and deliver both mainstream and sidestream smoke with acceptable taste and aroma. These desirable properties are achieved when certain defined levels of ULTRACARB (a mineral additive and a paper filler consisting of two homogeneously intermixed minerals, viz huntite and hydromagnesite). 
     The ULTRACARB may be used as the only filler, or in combination with calcium carbonate co-filler, in combination with magnesium hydroxide and calcium carbonate co-fillers, or in combination with magnesium hydroxide, calcium carbonate and carbon co-fillers, to produce a base cigarette paper or cigar wrapper. The paper may be subjected to treatment with burning chemicals, such as alkali metal salts of carboxylic acids. ULTRACARB wrappers can be employed as a normal cigarette paper or as an inner liner. Organic or inorganic acid treatment of such papers can be utilized to improve the subjective taste properties of the resulting cigarettes. Such papers can also be used in combination with filter dilution and perforation of the base paper to optimize taste and mainstream smoke yields. 
     BACKGROUND OF THE INVENTION 
     The reduced sidestream smoke cigarette paper patents which describe magnesium oxide/magnesium hydroxide as paper fillers, and which define burning chemical types and levels, are U.S. Pat. Nos. 4,231,377; 4,450,847; 4,881,557; and 4,915,118. These patents claim alkali metal acetates, citrates, nitrates, carbonates ad tartrates as burning chemical types at levels in the sheet ranging from 0.5% to 8.0%. 
     Other patents which relate to reduced sidestream smoke cigarette papers are U.S. Pat. Nos. 4,461,311 and 4,805,644. These patents disclose sodium and potassium salts of succinic, carbonic, formic, acetic, propionic, malic, lactic, glycolic, citric, tartaric, fumaric, oxalic, malonic, nitric, and phosphoric acids at levels in the sheet up to 25% weight. U.S. Pat. No. 4,805,644, dealing with reduced sidestream smoke cigarette paper, discloses that various paper fillers with superficial surface areas of at least 20M 2  /g result in a wrapper that provides reduced sidestream smoke when incorporated in paper at 5% to 50% by weight. 
     U.S. Pat. No. 3,744,496 discloses a carbon-filled paper wrapper for cigarettes and/or cigars, preferable used as an inner liner with regular cigarette paper or cigar wrapper as an outer wrap. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     It has been experimentally determined that cigarette paper with ULTRACARB as a filler in the furnish of the paper, by itself, or in combination with a calcium carbonate co-filler, or in combination with calcium carbonate and magnesium hydroxide co-fillers, or in combination with calcium carbonate, magnesium hydroxide and activated carbon co-fillers, provides an enhancement in sidestream smoke reduction compared to that of a conventional calcium carbonate-filled cigarette paper while maintaining acceptable ash quality, static burn rate, mainstream and sidestream taste and aroma. The truly novel feature of this invention is the reduced sidestream smoke obtained with this unique filler. ULTRACARB is a novel mineral based on a unique deposit of two homogeneously intermixed minerals, viz huntite Mg 3  Ca(CO 3 ) 4  and hydromagnesite Mg 4  (CO 3 ) 3  (OH) 2 .3H 2  O. On exposure to heat, the minerals in ULTRACARB decompose presumably as follows: 
     
         Mg.sub.3 Ca(CO.sub.3).sub.4 3 MgO+CaO+4CO.sub.2 
    
     
         Mg.sub.4 (CO.sub.3).sub.3 (OH).sub.2.3H.sub.2 O 4MgO+3CO.sub.2 +4H.sub.2 O 
    
     These reactions are strongly endothermic with a heat change ΔH=1000 J/g and generate non-combustible, non-toxic, non-corrosive gases. ULTRACARB mineral filler is marketed in the U.S. by Anzon Incorporated, 2545 Aramingo Avenue, Philadelphia, Pa. 19125, and is supplied worldwide by Microfine Minerals Limited, Raynesway, Derby, Great Britain. 
     
         ______________________________________PARAMETERS OF THE INVENTION           % of the Basis Weight of Paper______________________________________Basis Weight of Paper:           20 to 100 g/M.sup.2 (preferred 35 to           65 g/M.sub.2)ULTRACARB Content:           5% to 50% (preferred 10% to 35%)Calcium Carbonate Content:           0% to 40% (preferred 10% to 30%)Activated Carbon Content:           0% to 25% (preferred 0% to 15%)Magnesium Hydroxide           0% to 25% (preferred 5% to 15%)Content:Acid Addition:  0% to 10% (preferred 0% to 3%)Porosity Base Sheet:           3 to 50 (cm/min) CORESTA           preferred 5 to 15 (cm/min)           CORESTAULTRACARB Types Untreated and surface modified           (stearate, olefinic treated),           ULTRACARB U5, ULTRACARB           C5, ULTRACARB C5-25           ULTRACARB P5-20 and L5Burning Chemical:           Alkali metal salts of carboxylic           acids selected from a group consist-           ing of citric, malic, lactic, glycolic,           tartaric, fumaric, maleic, malonic,           glutaric, adipic, acetic and succinic,           in combination with or without           sucrose and organic carboxylic           acids named above.Burning Chemical Addition           0.5% to 6%Rate:Smoking Articles:           Cigarettes, Cigars, and the like______________________________________TYPICAL PROPERTIES OF ULTRACARBTYPES U5, L5, C5, C5-25 AND P5-20______________________________________U5Typical ChemicalAnalysis:Magnesium      as MgO          38%Calcium        as CaO          8%Silicon        as SiO.sub.2    0.3%Aluminum       as Al.sub.2 O.sub.3                          0.06%Potassium      as K.sub.2 O    0.01%Iron           as Fe.sub.2 O.sub.3                          0.02%Sulphur        as SO.sub.3     0.02%Titanium       as TiO.sub.2    0.02%Loss on Ignition          (44% CO.sub.2 + 9% H.sub.2 O)                          53%Acid insoluble matter          0.2%Water soluble salts            0.1%Typical PhysicalProperties:Specific Gravity               2.5Oil Absorption g/100 g         40Refractive index          mean            1.56Specific Surface area          m.sup.2 /g      15(nitrogen absorption)Mean spherical diameter          Micron          0.16(nitrogen absorption)Color: Tristimulus Values          X               95(MgO = 100)    Y               95          Z               94Bulk Density - loose          Kg/liter        0.23pH             (10% aqueous    9          suspension)Particle shape                 plateyTypical Particle SizeDistributionPercentage finer as           10 micron      99.9measured by Micromeritics            5 micron      95&#34;Sedigraph&#34;      2 micron      80            1 micron      70          0.5 micron      65          0.2 micron      55L5Typical ChemicalAnalysisMagnesium      as MgO          38%Calcium        as CaO          8Silicon        as SiO.sub.2    0.3%Aluminum       as Al.sub.2 O.sub.3                          0.06%Potassium      as K.sub.2 O    0.01%Iron           as Fe.sub.2 O.sub.3                          0.02%Sulphur        as SO.sub.3     0.02%Titanium       as TiO.sub.2    0.02%Loss on ignition          (44% CO + 9% H.sub.2 O)                          53Acid insoluble matter          0.2%Water soluble salts            0.1%Typical PhysicalPropertiesSpecific Gravity               2.5Oil Absorption g/100 g         40Refractive Index          mean            1.56Specific Surface Area          m.sup.2 /g      15(nitrogen absorption)Mean Spherical Diameter          Micron          0.16(nitrogen absorption)Color: Tristimulus Values          X               95          Y               95          Z               94Bulk Density - loose          kg/liter        0.23pH             (10% aqueous    9          suspension)Particle shape                 plateyThermogravimetricAnalysis                          CumulativeApprox. Decomposition          Weight          WeightTemperature (degree C.)          Loss %          Loss %100 (moisture) 0.5             0.5300            5.5             6400            14              20500            11              31600            16              47700            6               53Thermal decomposition onset temperature 230° C.P5ULTRACARB P5 is a carboxylate-coated, partially hydratedmagnesium calcium carbonate.Technical data for the uncoated product ULTRACARB U5 alsoapplies for the surface-treated P5 version. The only significantdifferences are lower oil absorption (30 g oil per 100 g), slightlyhigher loss on ignition and a slightly lower pH.ULTRACARB P5 offers the same benefits over the standard, un-coated U5 grade that are offered by the stearate-coated C5 range.ULTRACARB P5 is preferred over C5 grades where higherloading levels are desired.The standard product, having a 2% surface coating isULTRACARB P5-20. Coating levels can be varied, e.g.,ULTRACARB P5-10 has a 1.0% coating.C5ULTRACARB C5 is a stearate-coated, hydrated magnesiumcalcium carbonate.Technical data for the uncoated product ULTRACARB U5 alsoapplies for the surface-treated C5 version. The only significantdifferences are lower oil absorption (30 g oil per 100 g), slightlyhigher loss on ignition and a slightly lower pH.The standard product having a 1% stearate coating isULTRACARB C5-10. Stearate coating levels can be varied, asdesired; e.g., ULTRACARB C5-25 has a 2.5% coating.______________________________________ 
    
     
                                           TABLE 1__________________________________________________________________________   Basis                                       StaticCigarette   Weight       CaCO.sub.3           Mg(OH).sub.2                ULTRACARB                        Carbon                             Porosity          Burn                                                     SSDR.sup.1Paper   (g/M.sup.2)       (%).sup.3           (%).sup.2                (%)     (%)  Coresta                                  Fillers      (mg/min)                                                     (mg/min)__________________________________________________________________________Control -   22.5       30.0           0.0  0.0     0.0  25.0 CaCO.sub.3   56.7  2.13Ecusta12556Heavyweight +   45.0       20.0           0.0  0.0     0.0  9.0  CaCO.sub.3   50.7  1.461% CitrateRSS.sup.3   45.0       15.0           0.0  25.0    0.0  6.0  ULTRACARB U5 51.6  0.95                                  CaCO.sub.3RSS.sup.3   45.0       15.0           0.0  25.0    0.0  6.0  ULTRACARB C5-10,                                               49.5  0.90                                  CaCO.sub.3RSS.sup.3   45.0       15.0           10.0 15.0    0.0  7.0  ULTRACARB U5 51.3  0.85                                  CaCO.sub.3, Mg(OH).sub.2RSS.sup.2   45.0       10.0           10.0 20.0    0.0  6.0  ULTRACARB U5 49.7  0.87                                  Mg(OH).sub.2, CaCO.sub.3RSS.sup.2   45.0       5.0 10.0 25.0    0.0  6.0  ULTRACARB U5 45.9  0.84                                  CaCO.sub.3, Mg(OH).sub.2RSS.sup.2   45.0       0.0 10.0 30.0    0.0  7.0  ULTRACARB U5 47.6  0.98                                  Mg(OH).sub.2RSS.sup.2   45.0       0.0 0.0  40.0    0.0  6.0  ULTRACARB U5 52.3  0.99RSS.sup.2   45.0       0.0 10.0 30.0    0.0  6.0  ULTRACARB U5 35.2  0.63                                  Mg(OH).sub.2RSS.sup.2   45.0       0.0 0.0  40.0    0.0  7.0  ULTRACARB U5 49.5  0.93RSS.sup.4   45.0       15.0           25.0 0.0     0.0  10.0 Mg(OH).sub.2, CaCO.sub.3                                               75.3  0.93RSS.sup.4   45.0       25.0           15.0 0.0     0.0  10.0 Mg(OH).sub.2, CaCO.sub.3                                               74.9  1.09RSS.sup.3   45.0       20.0           10.0 0.0     10.0 5.0  Mg(OH).sub.2, Carbon                                               49.5  0.77                                  CaCO.sub.3RSS.sup.3   45.0       5.0 10.0 15.0    10.0 4.0  Mg(OH).sub.2, ULTRACARB                                               44.9  0.65                                  U5, CaCO.sub.3 carbonRSS.sup.3   45.0       0.0 10.0 20.0    10.0 4.0  Mg(OH).sub.2, ULTRACARB                                               44.3  0.65                                  U5, carbon__________________________________________________________________________ .sup.1 SSDR = Sidestream Delivery Rate (mg/min) .sup.2 Burning Chemical Content  8% potassium citrate .sup.3 Burning Chemical Content  6.5% potassium + 3% citric acid + 6% sucrose .sup.4 Burning Chemical Content  4.8% potassium acetate COMMENTS ON TABLE 1 It can be concluded from Table 1 that ULTRACARB fillers are effective in significantly reducing the sidestream smoke delivery rate either as a paper filler by itself, in combination with calcium carbonate and magnesium hydroxide cofillers, or in combination with calcium carbonate, magnesium hydroxide and carbon cofillers. Burn rate control depends upon burning chemical type and level, sheet porosity, filler type and level an sheet density. 
    
     
                       TABLE 2______________________________________Ash PropertiesTest Cigarettes - Commercial &#34;LIGHTS 100&#39;s&#34; with standardpaper removed and replaced with the experimental reducedsidestream smoke cigarette paper.Cigarette Paper        Static Ash   Puffed Ash______________________________________Control.sup.1        Tight shrinkage                     Tight shrinkage        Light Grey   Light Grey        No flake fall off                     No flake fall off        Solid sheath Small adhering flakes45 g/M.sup.2.spsp.2        Tight shrinkage                     Tight shrinkageULTRACARB - 40%        Light Grey   Light Grey        Few loose flakes                     No flake fall off        Small flakes Small flakes45 g/M.sup.2.spsp.3        Tight shrinkage                     Tight shrinkageULTRACARB - 25%        Light Grey   Light GreyCalcium Carbonate -        No flake fall off                     No flake fall off15%          Solid sheath Solid sheath______________________________________ .sup.1 Ecusta 12556 cigarette paper: 30% calcium carbonate; 25 CORESTA porosity; 25 g/m.sup.2 ; 0.55 citrate burning chemicals. .sup.2 40% ULTRACARB U5 filler: 6 CORESTA porosity; 45 g/M.sup.2 ; 6.5% potassium citrate + 3% citric acid + 6% sucrose burning chemical. .sup.3 25% ULTRACARB U5 filler: 15% calcium carbonate filler; 6 CORESTA porosity; 45 g/M.sup.2 ; 8% potassium citrate burning chemical. Comments on Table 2 The data in Table 2 indicate that both ULTRACARB by itself and the ULTRACARB/calcium carbonate combination result in ash properties very similar to that obtained with regular cigarette paper (control). 
    
     
                       TABLE 3______________________________________Particle Size and Surface Area Characteristics ofULTRACARB Filler                         Particle                                 Specific.sup.(2)                         Size.sup.(1)                                 Surface             Chemical    Sedigraph                                 AreaFiller   Vendor   Composition (μm) (M.sup.2 /g)______________________________________ULTRA-   Anzon    Huntite     0.16    15CARB U5           HydromagnesiteULTRA-   Anzon    Huntite     0.16    15CARB C5           Hydromagnesite______________________________________ .sup.(1) Particle Size measured by Micromeritics Sedigraph instrument. .sup.(2) Surface Area measured by B.E.T. Nitrogen Adsorption method. Comments on Table 3 It should be noted that specific surface area for ULTRACARB is only 15 M.sup.2 /g which is less than the minimum 20 M.sup.2 /g filler surface area claimed by Hampl, et al, (U.S. Pat. No. 4,805,644), as being require for effective sidestream smoke reduction. The outstanding sidestream smok reduction demonstrated by cigarettes wrapped in papers containing ULTRACARB fillers contradicts the Hampl, et al, claim that sidestream smoke reduction increases with increasing filler surface area.