US2652835A - Cigarette paper - Google Patents

Description

Patented Sept. 22, 1953 CIGARETTE PAPER Milton 0. Schur, Asheville, and Robert M. Levy,

Brevard, N. 0., assignors to Eeusta Paper Corporation, a corporation of Delaware No Drawing. Application March 7, 1952, Serial No. 275,462

4 Claims. (Cl. 13115) Our invention relates to cigarette paper and more particularly to improving the ashing properties of cigarette paper when burned as the wrapper on a cigarette.

A desirable paper ash is one that has a minimum of carbonized or incompletely burned residue, has a grayish-white color, adheres to the tobacco ash and thereby avoids dropping of ashes on the smokers clothing, but is nevertheless easily flickable at the will of the smoker.

In U. S. Patent No. 2,580,568, issued January 1, 1952, to Robinson E. Matthews and Ward D. Harrison, there is disclosed a cigarette paper having the above-mentioned desirable ashing properties, which are obtained by incorporating in the paper approximately 0.1% to 1% of ammonium phosphate. An improvement in that connection is disclosed in our U. S. Patent No. 2,580,610, issued January 1, 1952, which comprises incorporating in the cigarette paper, in addition to the ammonium phosphate, a very minute amount of phosphoric acid.

We have now discovered from further research in this field that the above described desired type of ash, and which has even more permanent properties, can be obtained by using in place of the ammonium phosphate, a difierent chemical compound, namely guanylurea phosphate. This compound does not require the addition of phosphoric acid or any other substance to improve the permanency of the desired ashing properties and thus alone fulfllls all of the ashing requirements.

In accordance with the present invention, an aqueous solution of the guanylurea phosphate is prepared and incorporated in the cigarette paper web running on the paper machine, at a point prior to the final drying rolls. A convenient form of application is by means of the conventional size press, located near the middle of the drying section of the paper machine, so that the aqueous composition will be imparted to the partially or completely dried paper sheet.

A typical but non-limiting formula for the aqueous composition, applicable in the size press, is as follows:

Formula Guanylurea phosphate lbs 65 Water to. make gals 1000 2 amount may be varied within the approximate limits of 0.25% to 1.5%.

The above-indicated range is adjusted between two extremes, namely, a maximum or upper limit at which the guanylurea phosphate will begin to fireproof the cigarette paper, which of course, should be avoided to maintain the desired normal burning rate of the paper, and minimum or lower hmit which gives a less desirable ash and a lower degree of stability. Th range indicated falls between these extremes and has been found satisfactory in actual operation. The specific amount given under Formula above is advantageous in certain instances and has given excellent results.

An illustrative commercial procedure for using the present invention in the manufactur of cigarette paper is as follows:

A sheet of cigarette paper was formed in the conventional manner from a furnish comprised of beaten flax pulp and calcium carbonate filler. At a point in the drier where the water content of the paper was about equal in weight to the dry Weight of the fiber and the filler, the paper was run through a size press and impregnated with a solution prepared according to the above formula. A weight of solution about equal to the weight of the dry contents of the paper was imparted to the paper, and the paper was then completely dried by passage over drying cylinders in the conventional manner.

The use of guanylurea phosphate as an ashing chemical is xtraordinary in that cigarette paper treated with this compound when stored at relative humidity for a period of thirty days still retains its fine ashing characteristics.

The stable ashing characteristic of guanylurea phosphate is of special significance when the cigarette paper is on the cigarette, because the cigarette tobacco is moist and that condition accentuates the usual instability of the ashing properties of the paper. Cigarettes rolled in the paper, prepared as above described, burned so as to leave fine, discontinuous flakes of paper ash, which closely adhered to the tobacco ash, and these cigarettes upon storage retained their fine ashing properties, when burned.

The nller commonly used in cigarette paper to regulate the porosity, and hence the rate at which it burns on the cigarette, is calcium carbonate. It is ordinarily added to the flax pulp furnish in an amount sufficient to give a filler content of about 20%25% in the finished paper, and it constitutes the principal ash-forming constituent in the cigarette paper.

Various modifications and changes may be made in the foregoing process, materials and products, without departing from the spirit and scope of our invention as defined in the appended claims.

We claim:

1. A combustible cigarette paper containing cellulosic fibers, calcium carbonate filler, and impregnated throughout with approximately 0.25% to 1.5% guanylurea phosphate, based on the dry weight of the cigarette paper.

2. A combustible cigarette paper containing cellulosic fibers, calcium carbonate filler, and impregnated throughout with approximately 0.75% guanylurea phosphate, based on the dry weight of the cigarette paper.

3. A combustible cigarette paper containing flax fibers, calcium carbonate filler, and impregnated throughout with approximately 0.25% to 1.5% guanylurea phosphate, based on the dry weight of the cigarette paper.

4. A combustible cigarette paper containing flax fibers, calcium carbonate filler, and impregnated throughout with approximately 0.75% guanylurea phosphate, based on the dry weight of 5 the cigarette paper.

MILTON O. SCHUR. ROBERT M. LEVY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,305,035 Rosser Dec. 15, 1942 2,488,034 Pingree et al. Nov. 15, 1949 15 2,580,611 Schur et a1. Jan. 1, 1952 FOREIGN PATENTS Number Country Date 476,043 Great Britain Nov. 29, 1937 638,434 Great Britain June 7, 1950

Claims (1)

1. A COMBUSTIBLE CIGARETTE PAPER CONTAINING CELLULOSIC FIBERS, CALCIUM CARBONATE FILLER, AND IMPREGNATED THROUGHOUT WITH APPROXIMATELY 0.25% TO 1.5% GUANYLUREA PHOSPHATE, BASED ON THE DRY WEIGHT OF THE CIGARETTE PAPER.