Wrapper for smoking article, smoking article, and method of making same

Abstract

A wrapper for a smoking article which, when wrapped about a tobacco column, provides improved sidestream smoke reduction, improved ash formation, and acceptable mainstream smoke taste and sidestream smoke odor subjectives. These objectives are attained by forming a single cellulosic sheet containing a filler comprising basic magnesium carbonate and, where desired, a co-filler of calcium carbonate. In addition, the sheet may be treated with a burning chemical such as alkali metal salts of organic carboxylic acids, and compatible acids.

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 is fabricated into a cigarette or cigar with a suitable tobacco column, which provide an acceptable burn rate, produce light-colored, well-formed ash which clings tightly without premature flaking, have significantly reduced sidestream smoke generation compared to a conventional cigarette and deliver both mainstream and sidestream smoke with acceptable taste and aroma. These desirable properties are achieved when certain defined levels of basic magnesium carbonate, by itself, or in combination with calcium carbonate co-filler, are employed to produce a base cigarette paper or cigar wrapper and this paper is subjected to treatment with burning chemicals such as alkali metal carboxylic acid salts.

BACKGROUND OF THE INVENTION

The reduced-sidestream-smoke cigarette paper patents which describe magnesium oxide/magnesium hydroxide as paper fillers, which are assigned to Olin Corporation, Ecusta Corporation, or P. H. Glatfelter Company, 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 disclose alkali metal acetates, citrates, nitrates, carbonates, and tartarates as burning chemical types at levels in the sheet ranging from 0.5% to 8.0%.

The Kimberly-Clark patents dealing with reduced-sidestream-smoke cigarette paper are U.S. Pat. Nos. 4,461,311 and 4,805,644. These patents disclose the sodium and potassium salts of carbonic, formic, acetic, propionic, malic, lactic, glycolic, citric, tartaric, fumaric, oxalic, malonic, nitric and phosphoric acids at levels in the sheet up to 25% by weight. U.S. Pat. No. 4,805,644 dealing with reduced-sidestream-smoke cigarette paper discloses various paper fillers with at least about 20 M.sup.2/ g superficial surface area, when incorporated in paper at 5% to 50% by weight, and results in a wrapper that provides reduced sidestream smoke.

U.S. Pat. No. 3,744,496, assigned to Olin Corporation, discloses a carbon-filled paper to wrap cigarettes and/or cigars preferably 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 by using basic magnesium carbonate as a filler in the furnish of the cellulosic-based paper by itself and in combination with calcium carbonate as a co-filler, provides an enhancement in sidestream smoke reduction compared to that of a conventional calcium carbonate filled cigarette paper or cigar wrapper, while maintaining acceptable ash quality, static burn rate, mainstream and sidestream taste and aroma. The truly novel finding of this invention is the reduced sidestream smoke obtained with a novel filler(s).

PARAMETERS OF THE INVENTION

Basis Weight: 25 to 100 g/M.sup.2 (preferred--35 to 65 g/M.sup.2) Basic Magnesium Carbonate Content: 5% to 50% based on base weight of the paper (preferred 10% to 40%). Calcium Carbonate Content: 0% to 40% (preferred 10% to 40%), based on the base weight of the paper. Porosity: 3 to 25 Coresta (preferred--5 to 15 Coresta) Basic Magnesium Carbonate Type: xMgCO.sub.3.yMg(OH).sub.2.zH.sub.2 O where x, y, and z are integers or fractions. Burning Chemical: Alkali metal salts of organic carboxylic acids selected from a group consisting of citric, malic, lactic, glycolic, tartaric, fumaric, maleic, malonic, glutaric, adipic, acetic and succinic. Addition Rate of Burning Chemical: 0.5% to 6% of the base weight of the paper. Smoking Articles: Cigarettes, cigars and the like. TABLE I__________________________________________________________________________Sidestream Reduction Basic Basis CaCO.sub.3 Magnesium Static Weight Percent Carbonate Porosity Burn Rate SSDR.sup.1Cigarette Paper (g/M.sup.2) (%) (%) Coresta Filler (mg/min) (mg/min)__________________________________________________________________________Control-Ecusta 12556 25.0 30.0 0.0 25 CaCO.sub.3 56.7 2.13Heavyweight + 45.0 20.0 0.0 9 CaCO.sub.3 50.7 1.461% K3 CitrateLSS-Basic MgCO.sub.3.sup.2 45.0 25.0 15.0 12.0 Martin Marietta BMC2 57.5 1.02LSS-Basic MgCO.sub.3.sup.2 45.0 25.0 15.0 17.4 Morton Thiokol Elastocarb 66.6 1.02 HeavyLSS-Basic MgCO.sub.3.sup.2 45.0 25.0 15.0 16.9 Morton Thiokol Elastocarb 59.1 0.96 LightLSS-Basic MgCO.sub.3.sup.2 45.0 0.0 30.0 11.2 Alfa Magnesium Carbonate 55.1c 1.06LSS-Basic MgCO.sub.3.sup.2 55.0 0.0 30.0 11.0 Alfa Magnesium Carbonate 61.6c 0.97LSS-Basic MgCO.sub.3.sup.2 65.0 0.0 30.0 11.2 Alfa Magnesium Carbonate 62.7c 0.85LSS-Basic MgCO.sub.3.sup.2 45.0 0.0 30.0 12.8 Aldrich Magnesium Carbonate 53.9 1.06 BasicLSS-Basic MgCO.sub.3.sup.2 55.0 0.0 30.0 12.4 Aldrich Magnesium Carbonate 54.6 0.95 BasicLSS-Basic MgCO.sub.3.sup.2 65.0 0.0 30.0 12.0 Aldrich Magnesium Carbonate 56.3 0.87 BasicLSS-Basic MgCO.sub.3.sup.3 45.0 15.0 25.0 5.0 Martin Marietta BMC2 55.7 0.92LSS-Basic MgCO.sub.3.sup.2 45.0 15.0 25.0 7.0 Morton Thiokol Elastocarb 55.5 0.94 LightLSS-Basic MgCO.sub.3.sup.2 45.0 15.0 25.0 9.4 Morton Thiokol Elastocarb 58.9 0.89 HeavyLSS-Basic MgCO.sub.3.sup.4 45.0 15.0 25.0 5.0 Martin Marietta BMC2 58.0 0.87LSS-Basic MgCO.sub.3.sup.4 45.0 0.0 40.0 7.5 Martin Marietta BMC2 44.2 0.72LSS-Basic MgCO.sub.3.sup.2 45.0 15.0 25.0 12.4 Marine Magnesium Magcarb 64.1 0.89__________________________________________________________________________ .sup.1 SSDR = Sidestream Delivery Rate (mg/min) .sup.2 Burning Chemical Content 5.1% Potassium Acetate .sup.3 Burning Chemical Content 5.1% Potassium Acetate + 6% Sucrose .sup.4 Burning Chemical Content 5.6% Potassium Citrate + 2% Citric Acid 6% Sucrose

Comments on Table I

It can be concluded from Table I above that all of the basic magnesium carbonates of various compositions evaluated are effective in significantly reducing the sidestream delivery rate in combination with calcium carbonate as a co-filler, or as a filler by itself, in paper. Burn rate control depends upon buring chemical type and level, basis weight, sheet porosity, filler type and level, sheet density and basic magnesium carbonate type and level in paper.

TABLE II______________________________________Ash PropertiesTest cigarettes - Commercial 100 mm "LIGHTS" brand withstandard paper removed and replaced with the experimentalreduced sidestream 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,.sup.2 Some Shrinkage Tight ShrinkageBasic Magnesium Light Grey Light GreyCarbonate = 30% Loose Flakes Few Loose Flakes Small Flakes Small Flakes45 g/M.sup.2,.sup.3 Tight Shrinkage Tight ShrinkageBasic Magnesium Light Grey Light GreyCarbonate - 25% Few Loose Flakes No Flake Fall OffCalcium Small Flakes Solid SheathCarbonate - 10%______________________________________ .sup.1 Ecusta 12556 cigarette paper: 30% Calcium Carbonate; 25 Coresta Porosity; 25 g/M.sup.2 ; 0.55 Citrate Burning Chemicals .sup.2 30% Alfa Basic Magnesium Carbonate; 11.2 Coresta Porosity; 45 g/M.sup.2 ; 5.1% Potassium Acetate Burning Chemical .sup.3 25% Morton Thiokol Elastocarb Light Basic Magnesium Carbonate; 15% Calcium Carbonate Filler; 7 Coresta Porosity; 45 g/M.sup.2 ; 5.1% Potassium Acetate Burning Chemical

Comments on Table II

The ash properties results stated in Table II indicate that combination of basic magnesium carbonate/calcium carbonate-filled cellulosic fiber paper is giving ash properties very similar to that obtained with regular cigarette paper (control) with no significant differences observed between these two papers.

TABLE III__________________________________________________________________________Particle Size and Surface Area Characteristics of Basic MagnesiumCarbonate Fillers Particle.sup.1 Size (um) Surface.sup.2 Chemical Number Number Volume Volume AreaFiller Vendor Composition Median Mode Median Mode (M.sup.2 /g)__________________________________________________________________________BMC-2 Martin Marietta Basic MgCO.sub.3 1.47 1.24 4.83 1.79 11.04Elastocarb Tech heavy Morton Thiokol Basic MgCO.sub.3 2.51 1.41 10.01 9.26 16.90Elastocarb Tech Light Morton Thiokol Basic MgCO.sub.3 2.04 1.28 6.37 7.17 19.01Magcarb L Marine Magnesium Basic MgCO.sub.3 1.74 1.54 6.19 9.88 31.98__________________________________________________________________________ .sup.1 Particle size measured by Coulter Multisizer instrument .sup.2 Surface area by B.E.T. method Comments on Table III The basic magnesium carbonate filler characteristics are presented in terms of particle size and surface area. Based on results presented in Table I on sidestream delivery rate, it is conclusive that filler surface area does not directly correlate with sidestream reduction efficiency. As presented in Table I and III, above, surface area of basic magnesium carbonate fillers ranging from 11 M.sup.2 /g to 32 M.sup.2 /g was evaluated and all fillers were determined to be equivalent in their sidestream reduction activity. This observation is markedly contrary to the claim of Hampl, et al, (U.S. Pat. No. 4,805,644) that as filler surface area increases, the sidestream smoke reduction (%) increases.

Claims

1. A wrapper for smoking articles such as cigarettes, cigars, and the like, comprising a cellulosic fiber sheet containing, as a filler, basic magnesium carbonate.

2. The wrapper, as defined in claim 1, wherein the content of the basic magnesium carbonate is from 5.0% to 50% and further comprising 0% to 40% of a co-filler of calcium carbonate from.

3. The wrapper, as defined in claim 2, wherein the content of basic magnesium carbonate is from 10% to 40% and the content of the calcium carbonate is from 10% to 40%.

4. The wrapper, as defined in claim 3, further including a burning chemical, wherein the addition rate of the burning chemical is 0.5% to 6% of the base weight of the paper.

5. The wrapper, as defined in claim 4, further including 0.5% to 6% alkali metal slats of organic carboxylic acids selected from the group consisting of citric, malic, lactic, glycolic, tartaric, fumaric, maleic, malonic, glutaric, adipic, acetic, and succinic.

6. The wrapper, as defined in claim 3, further including 0.5% to 6% of an appropriately compatible acid.

7. A smoking article such as cigarettes, cigars, and the like, comprising a tobacco charge and a wrapper comprising a cellulosic fiber sheet containing, as a filler, basic magnesium carbonate.

8. The smoking article, as defined in claim 7, wherein the content of the basic magnesium carbonate is from 5.0% to 50% and further including 0% to 40% of a co-filler of calcium carbonate from.

9. The smoking article, as defined in claim 8, wherein the content of basic magnesium carbonate is from 10% to 40% and the content of the calcium carbonate is from 10% to 40%.

10. The smoking article, as defined in claim 9, further including a burning chemical wherein the addition rate of the burning chemical is 0.5% to 6% of the base weight of the paper.

11. The smoking article, as defined in claim 10, further including 0.5% to 6% alkali metal salts of organic carboxylic acids selected from the group consisting of citric, malic, lactic, glycolic, tartaric, fumaric, maleic, malonic, glutaric, adipic, acetic, and succinic.

12. The smoking article, as defined in claim 9, further including 0.5% to 6% of an appropriately compatible acid.

13. A method for reducing the visible sidestream smoke emanating from a smoking article and improving the ash properties comprising wrapping a tobacco charge in a combustible cellulosic sheet containing, as a filler, basic magnesium carbonate.

14. The method, as defined in claim 13, wherein the content of basic magnesium carbonate is from 5.0% to 50% and further comprising 0% to 40% a co-filler of calcium carbonate.

15. The method, as defined in claim 13, wherein the content of basic magnesium carbonate is from 10% to 40% and the content of the calcium carbonate is from 10% to 40%.

16. The method, as defined in claim 15, further including 0.5% to 6% alkali metal salts of organic carboxylic acids selected from the group consisting of citric, malic, lactic, glycolic, tartaric, fumaric, maleic, malonic, glutaric, adipic, acetic, and succinic.

17. The method, as defined in claim 15, further including 0.5% to 6% of an appropriately compatible acid.