Wrapper for Smoking Article, Smoking Article, and Method of Making Same

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.

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 .

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).

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.

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.

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.