US 2580610 A
Description (OCR text may contain errors)
Patented Jan. 1, 1952 CIGARETTE PAPER Milton 0. Schur, Asheville, and Robert M. Levy,
Brevard, N. 0., assignors to Ecusta Paper Corporation, a corporation of Delaware No Drawing. Application May 29, 1951, Serial No. 228,982
2 Claims. 1
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 resi due, 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. The usual cigarette produces black, curling ashes that fall from the cigarette onto the smokers clothing.
In the application of Robinson E. Matthews and Ward D. Harrison, Serial No. 162,402, filed May 16, 1950, there is disclosed a cigarette paper having the above-mentioned desirable ashing properties, which are obtained by-incorporating in the paper approximately 0.2% to 1% of ammonium phosphate. Under certain storage conditions of the cigarette paper, particularly those involving an atmosphere of high humidity, we have found it desirable to increase the permanency of these ashing properties and we have discovered that this can be done by incorporating in the paper, in addition to the ammonium phosphate, a, small amount of phosphoric acid.
The amount of phosphoric acid required for efiecting this stabilization of the ashing properties is minutely small in relationship to the weight of the cigarette paper or even to the weight of the ammonium phosphate. For example, we have found a good practical percentage range for the phosphoric acid is about 0.002% to 0.05% based upon the dry weight of the paper, where the amount of ammonium phosphate is within the range of about 0.1% to 1.0%. A commercially advantageous amount of phosphoric acid is about 0.02% when the ammonium phosphate, used as mono-ammonium phosphate, is present to the extent of about 0.4% based upon the dry weight of the paper. This minute amount of phosphoric acid greatly improves the stability, over a long period, of the initially excellent ashing properties of the above-mentioned type of cigarette paper.
The incorporation of the stabilizing, free, i. e., uncombined, phosphoric acid may be efiected. in aqueous solution, by addition to the dry cigarette paper, although it may be more expeditious to apply it to the partially dried paper web running on the paper machine prior to the final drying rolls. A convenient form of application is bymeans of the conventional sizepress, located near the middle of thedrying sec- 2 tion onthe paper machine, so that the aqueous phophoric acid solution will be imparted to the dry or partially dried paper sheet.
A typical but non-restrictive formula for the liquid compositiomcontaining both the ammonium phosphate and the phosphoric acid, applicable in the size-press, is as follows:
Formula I Monoammonium phosphate lbs 38 Phosphoric acid -gals 0.15 Water gals..- 1,000
Formula II Monoammonium phosphate --lbs 36 Phosphoric acid (85%).. gals 0.15 Urea formaldehyde wet-strengthening agent lbs. (dry basis) 4 Water gals..- 1,000
An illustrative commercial procedure for using the present invention in the manufacture of cigarette paper,is as follows:
Asheet of cigarette paper was formed in the conventional manner from afurnish 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 Formula I above. 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. H
The filler 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 flaxpulp furnish in an amount suflici'ent to give a filler content of about,20%-25% in the finished paper,
. 3 and it constitutes the principal ash-tannin: constituent in the cigarette paper.
This stabilizing eiiect of the phosphoric acid 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. Cigarette rolled in the paper, prepared as abovedescribed, 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. to a much better extent than when the phosphoric acid was not used.
This application is a continuation-in-part of our application Serial No. 4,924 filed January 28, 1948, now abandoned.
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. a
1. A combustible, cellulose ciaarette paper containing cellulosic fibers, calcium carbonate filler, and impregnated throughout with approximately 0.1% to 1% ammonium phosphate (expressed as P04) and approximately 0.002% to 0.05% phosphoric acid based on the dry weight 01 the cigarette paper.
2. A combustible, cellulose cigarette paper containing predominantly cellulose fibers, approximately 20% to calcium carbonate illler, and impregnated throughout with 0.1% to 1% am-" monium phosphate (expressed at PO), and approximately 0.002% to 0.05% phosphoric acid based on the dry weight of the cigarette paper.
MILTON 0. 868173,. ROBERT MLLEVY.
No references cited.