US 2886041 A
Description (OCR text may contain errors)
CIGARETTE PAPER EdgarH. Harwood, Winston-Salem, N.C., assignor to R. J. Reynolds Tobacco Company, Winston-Salem, N.C., a corporation of New Jersey No Drawing. Application June 17, 1957 Serial No. 666,215
4 Claims. (Cl. 131-15) This invention relates to an improved cigarette paper and, more particularly, pertains to an additive therefor which greatly improves the smoking and burning properties thereof.
Cigarette paper as now produced normally comprises essentially a cellulosic sheet having various additives incorporated therein. These additives may be used to add weight, control porosity, influence ash formation, regulate burning properties, provide opacity, and the like. It is apparent that the specific additive and the quantity thereof employed are largely determined by the desired qualities in the cigarette paper utilizing the same.
It is important in the manufacture of cigarettes that the cigarettes will not have a tendency to stop burning during smoking by the average smoker. It has been found that the burning may be controlled or regulated by incorporating additives into the cigarette paper so that the cigarette will not stop burning under ordinary conditions. Also during cigarette smoking it is important that the ash formed by the paper be one which will form a cylindrical ash sheath and not one which will flake. A cigarette paper which flakes during smoking is very undesirable, since the ash flakes drop from the cigarette as formed, which is a source of irritation to the smoker.
It is an object of this invention, therefore, to provide a novel additive intended for incorporation in cigarette paper which will regulate the burning rate of the cigarette paper.
It is another object of this invention to provide an additive for cigarette paper which insures continuous ignition as well as even burning of the cigarette paper.
It is a still further object of this invention to provide a novel additive for incorporation in cigarette paper which upon combustion will release aroma and flavor enhancing compounds, thereby adding to the enjoyment of the smoker.
It is yet another object of this invention to provide an additive for incorporation in cigarette paper which may be processed so as to release a number of specific desired aroma and flavor enhancing compounds.
It is a further object of this invention to provide additives for cigarette paper which are simple in composition and which are easily and readily incorporated in the paper product.
The above and other objects of this invention will appear from the following description and appended claims.
In accordance with the broad principles of the subject invention, a cigarette paper is provided having incorporated therein a small amount of an additive which upon smoking of the cigarette with which it is utilized will release one or more organic flavoring acids having from 3 to 8 carbon atoms. In addition, the cigarette paper additive upon burning of the paper in which incorporated will form an ash which is of substantial strength so as to hold an exceptionally long length of tobacco ash without allowing the ash to break 01f or flake when utilized in a tobacco product. In the course of forming the latter ash, the cigarette paper additive of this invention assures a deditive.
2,886,041 Patented May 12, 1959 sired rate of combustion of the paper and also assures a continuous even burning action. The additive is nonvolatile and is of good stability, so that the cigarette paper or cigarette is capable of being stored for extended periods of timewithout decomposition or other change in the ad- In accordance with this invention, the additive for the cigarette paper comprises a sodium potassium salt of a substituted malonic acid having the formula:
wherein R is an alkyl, alkenyl, aryl, aralkyl, or other hydrocarbon group having from 1 to 6 carbon atoms, and
preferably 2 to 4 carbon atoms. As pointed out in U.S.
- of these substituted malonic acids are incorporated into a cigarette paper, the same flavors and aromas are obtainable, presumably by virtue of a combustion reaction upon burning which involves the decarboxylation of the substituted malonic acid compound. It will be appreciated that since isovaleric and 3-methylvaleric acids impart especially desired flavor and aroma to cigarette smoke, the substituent group or R in the above structural formula is preferably either isopropyl or secondary butyl so that the latter-mentioned acids may be liberated in the course of smoking, as will be understood from a consideration of said Patent No. 2,766,145. However, the R group may be methyl, ethyl, n-propyl, n-butyl, straight or branched chain pentyl or hexyl, aryl, cycloalkyl, or the corresponding unsaturated compounds, all as indicated in said prior patent.
In order to provide for proper control of burning and ashing of the cigarette paper of this invention, the salts of the substituted malonic acids are the sodium and potassium salts either as a mixture of the disoditun and dipotassium salts, a mixture of the monosodium and monopotassium acid salts or the sodium potassium salts. The sodium potassium salts having the formula:
0 0 ONa are preferred. It has been found that both the sodium and potassium are instrumental in preventing ready flaking of the paper ash, that the potassium functions to maintain burning, and the sodium is instrumental .in promoting even burning.
The salts of the substituted malonic acids may be added to the cigarette paper in amounts of from between .1 and 5 percent of the dry weight of the cigarette paper. The salt additive may be incorporated throughout the paper either at the time of paper manufacture or subsequent thereto by impregnating the paper with a solution of the salt and then drying the impregnated paper. The provided salts may be applied to the paper in aqueous solution, or may be dissolved in any other suitable solvent which will leave no characteristic odor or taste and which is preferably of a volatile nature. The latter solvents obviously should not react with the malonic acid salts. The molar ratio of sodium to potassium in the additive is suitably about one to one in order to obtain the desired results. However, this ratio may be varied between about nine to one and one to nine.
A particularly suitable cigarette paper is prepared by impregnating a suitable paper with an aqueous solution of sodium potassium secondary butyl malonate in amounts to provide a paper containing 2 percent by weight (dry basis) of the malonate. The paper is then dried and used in making a cigarette. Upon smoking, the burning and ashing characteristics of the cigarette are satisfactory and the liberated 3-methylvaleric acid produces a desired aroma upon burning.
The substituted malonic acids referred to herein are well known in the art and the sodium and potassium salts thereof may be prepared by treating the acids with a sodium and/or potassium base, such as the hydroxide or carbonate, by well known methods. As is known, the sodium potassium salt may be prepared by treating the free acid with equivalent amounts of a mixture of the sodium and potassium bases.
It is obvious that many modifications of the above-described invention may be made which will still remain within the ambit of the inventive concept disclosed. It is intended, therefore, that this invention be limited only by the scope of the appended claims.
1. A cigarette paper having added thereto sodium and potassium salts of substituted malonic acid having the formula sodium potassium-substituted malonic acid having the formula wherein R is a hydrocarbon radical having from 1 to 6 carbon atoms.
4. The paper recited in claim 3 wherein R is an alkyl group having from 2 to 4 carbon atoms.
References Cited in the file of this patent UNITED STATES PATENTS 2,028,552 Low Jan. 21, 1936 2,766,145 Jones Oct. 9, 1956 2,766,150 Teague Oct. 9, .1956