US2775970A - Cigarette paper - Google Patents

Description

Unitcd States Patent CIGARETTE PAPER Alexander W. Schoenbaum, Richmond, Va., assignor to The American Tobacco Company, New York, N. Y., a corporation of New Jersey No Drawing. Application June 8, 1954, Serial No. 435,359

4 Claims. (Cl. 131-15) This invention relates to the manufacture of paper and more particularly to the production of a paper that is particularly adapted for use as a cigarette wrapper.

With some of the papers now employed in the manufacture of cigarettes, small particles of partially burned paper, commonly called fly ash, will fall from a burning cigarette at frequent intervals. Sometimes theseparticles are not fully consumed, but are still burning when they land on carpets, upholstered furniture, the smokers clothing, or the like. They are, thus, a fire hazard and also a nuisance.

It has been suggested that paper intended for use in the manufacture of cigarettes be treated or impregnated with various materials to produce a paper which, when used as a cigarette wrapper, will burn with formation of a non-flaking ash. Some impregnants that have been suggested for this purpose have also been alleged to decrease the quantity of irritating gases in the cigarette smoke. However, investigation has established that many of the materials suggested, neither improve the burning characteristics of the paper nor produce a smoother smoke. Many of them actually produce obnoxious fumes not present in cigarette smoke from cigarettes made with other papers.

I have found that a paper particularly suitable as a cigarette paper may be produced by treating the paper with sodium chloride, preferably in combination with a fire retarding compound, such as carboxymethyl cellulose. It has heretofore been proposed to treat cigarette paper with various materials including inorganic salts to decrease the inflammability of the paper. But when the sodium chloride is added to paper in an amount equal to 0.5 to 2% of the weight of the paper, it increases the burning rate of the paper. This increase, while not sufiicient to preclude the use of sodium chloride, might be objectionable and I, therefore, propose to add another material to the paper which will ofiset the acceleration of burning rate proposed by the salt addition without affecting the beneficial efiects of its additions. Various compounds may be used for this purpose. Thus, I propose to add about 0.2% of carboxymethylcellulose with the sodium chloride.

The carboxymethylcellulose may be added in amounts from 0.1% to 1.0% by weight. Other materials which will offset the acceleration of burning rate when sodium chloride is added to the paper in the proportions stated are gum arabic, hydroxyethyl cellulose, locust bean, tragacanth, sodium alginate, Methocel X-2602 (a water soluble hydroxpropyl methylcellulose ether) and carboxymethyl hydroxyethyl cellulose. These may be used in the proportions stated above, that is, 0.1% to 1.0%.

The addition materials may be added to the paper in any suitable manner. Thus, they may be placed on the paper after its manufacture by forming a solution of sodium chloride and the retardent and applying such solution to the paper in any suitable manner. This may be done, for instance, by passing the paper through a bath containing the addition agents. Or the impreg- 'ice nants may be added to the pulp prior to formation of the paper, and the pulp then formed into sheets in the usual way.

In a specific example paper for use in cigarette manufacture was impregnated with substantially 1% of sodium chloride and substantially 0.2% of carboxymethylcellulose by means of rolls arranged approximately midway of the drying section of a paper-making machine. The solution is applied to one of the rolls by passing the roll through a tank in which it is placed, and the paper is then fed between the moistened roll and a second roll. In any of the methods of application the concentration of sodium chloride and the retardent may be controlled by varying the strength of the solution. Where the paper is passed between a pair of rolls, one of the rolls is felt-covered. In this instance the concentration of the addition materials can be further controlled by adjustment of the roll-pressure.

Paper treated as heretofore described forms a white ash as it burns, and this ash shrinks around the tobacco ash forming a solid band. It produces a more pleasing appearance than that produced by the dark gray ash which is formed when the cigarettes are made of untreated paper. The shrinkage of the paper ash strength ens the whole ash on the end of the cigarette and almost completely prevents the dropping of fly ash.

In many instances the slight increase in the burning rate of the paper caused by the addition of sodium chloride is not noticeable. In those instances that it is noticeable, the addition of the retardant shows up the burning rate to substantially that of untreated paper. The proportions of sodium chloride and carboxymethylcellulose given in the specific example have been found to be satisfactory for a certain paper. If other papers are used, the amount of carboxymethylcellulose or other retardant may be adjusted to obtain the desired burning rate.

In the final product, i. e., the cigarette, the better burning qualities are the only noticeable difference between cigarettes made with the paper of the present invention and cigarettes made with other papers. In some instances the sodium chloride additions in amounts of from 0.5% to 2% by weight do not increase the burning rate a suflicient amount to require the retardent. But when it does, one of the retardents may be used in the amount necessary to reduce the burning rate to that of untreated paper. In some instances cigarettes made with sodium chloride impregnated paper produced a milder and more pleasant smoke than that of similar cigarettes made with untreated paper.

I claim:

1. A cigarette paper containing not less than 0.5% and not more than 2% by weight of sodium chloride, and not less than 0.1% and not more than 1.0% of a fire retardent selected from the group consisting of carboxymethylcellulose, gum arabic, hydroxyethyl cellulose, locust bean gum, gum tragacanth, sodium algmate, Methocel X-2602 (a water soluble hydroxypropyl methylcellulose ether) and carboxyrnethyl hydroxyethyl cellulose.

2. A cigarette paper containing not less than 0.5% and not more than 2% by weight of sodium chloride and not less than 0.1% and not more than 1% carboxymethylcellulose.

3. A cigarette paper containing substantially 1% by weight of sodium chloride and 0.2% carboxymethylcellulose.

4. In the production of a cigarette paper which, on burning, produces a white clinging ash, the step which comprises adding not less than 0.5 and not more than 2% by weight of sodium chloride and not less than 0.1% and not more than 1% by Weight of a fire retardent select- 3 ed from the group consisting of carboxy mcthylcellulose, gum arabic, hydroxyethyl cellulose, locust bean gum, gum tragacanth, sodium alginate, Methocel X-2602 (a water soluble hydroxypropyl methylcellulose ether) and carboxymethyl hydroxyethyl cellulose to the paper.

References Cited in the file of this patent UNITED STATES PATENTS 4 Finley Sept. 6, 1927 Morton Sept. 21, 1943 Sartoretto et a1. Oct. 14, 1952 Samfield et a1 May 10, 1955 FOREIGN PATENTS Great Britain June 26, 1930 OTHER REFERENCES Scientific American, July 21, 1894, page 38, Fireproofing Compounds.

Claims (1)

1. A CIGARETTE PAPER CONTAINING NOT LESS THAN 0.5% AND NOT MORE THAN 2% BY WEIGHT OF SODIUM CHLORIDE, AND NOT LESS THAN 0.1% AND NOT MORE THAN 1.0% OF A FIRE RETARDENT SELECTED FROM THE GROUP CONSISTING OF CARBOXYMETHYLCELLULOSE, GUM ARABIC, HYDROXYETHYL CELLULOSE, LOCUST BEAN GUM, GUM TRAGACANTH, SODIUM ALIGINATE, METHOCEL X-2602 (A WATER SOLUBLE HYDROXYPROPYL METHYLCELLULOSE ETHER) AND CARBOXYMETHYL HYDROXYETHYL CELLULOSE.