US2941907A - Tobacco compositions - Google Patents

Description

June 21, 1960 w. F.1'ouslGNAN-r ErAL 2,941,910? I TOBACCO COMPOSITIONS Filed May 22. 1958 Tobacco /rea/eo/wi//l Fly/ef IIU INVENToRs. W/y//Om 1C.' Tous/'gn n/ W//he/m E. Wa//es WAM United States Patent TOBACCO COMPOSITIONS William F. Tousignant and Wilhelm E. Walles, Midland,

Mich., assignors to The Dow Chemical Company, Midland, Mich., a corporation of Delaware Filed May 22, 1958, Ser. No. 737,002

9 Claims. (Cl.-13117) The chief aim and design of the present invention -is to provide improved tobacco compositions that, when burned for smoking and passed through filters in cigarettes, cigars and pipes, produce smoke having a substantially and materially enhanced propensity to deposit greater portions of the tars and resins from the burning tobacco in and on the lilter medium. It is a corollary purpose of the invention to provide improved tobacco compositions for chewing and other oral usage.

Accordingly, the indicated objective and cognate benefits may advantageously be achieved by preparation of the improved tobacco compositions of the present invention and practice of the method of the invention for their preparation. This involves applying to or treating a tobacco intended for smoking with a minor proportion of between about 0.001 and 2, preferably between about 0.01 and 0.5 weight percent, based on the weight of the tobacco being treated, of an N-vinyl-Z-cyclic carbamate polymer of the type hereinafter more specifically delineated. Tobacco treated in accordance with the invention has excellent burning qualities, equivalent to an identical untreated product, and actually tastes better when smoked than the untreated leaf. Of greater signiiicance, however, is the fact that smoke from the presently contemplated tobacco compositions, upon burning thereof in cigarettes, cigars or pipes and passed through conventional lamentary, brous or cellular filters, has a much greater tendency to deposit the tars and resins produced from the burning leaf than untreated product. Generally, the treated tobacco, upon burning, produces smoke that tends to deposit 20-50 percent or so more resin and tar in any given lter media than an untreated product.

Likewise, chewing tobacco (either plug or cut) and snuif intended for oral and the like internal use may be greatly benefitted by being prepared as compositions according to the invention. In such applications the N- vinyl-2-cyclic carbamate polymers also have an upgrading inuence on the characteristics and properties of the tobacco.

The N-vinyl-Z-cyclic carbamate polymers that are employed so advantageously for treating tobacco in the practice of the present invention are of the structure:

wherein each Q is independently selected from the group consising of hydrogen, methyl, ethyl, propyl, butyl i.e., alkyl radicals containing from 1 to about 4 carbon atoms and aryl radicals containing from 6 to about l0 carbon atoms (i.e., phenyl, alkyl-substituted phenyl, etc); m is an integer from 2 to 3; and n is a plural integer, preferably one whose numerical value is greater than 5 or l0 to 50 or so and Which may be as large as LOGO-2,000 or more. The hydrogen (or other terminal units) which 2,941,907l Patented June 2l, 1960 ICC occur in homopolymeric and other polymeric compositions are not shown in Formula l' since such details are readily understood by the artisan. The N-vinyl-Z-cyclic carbarnate polymers of the Formula I that are employed may advantageously be normally solid, high polymers having an average molecular weight (number average), for example, in the range from 10 to 100-200 thousand and higher (as detenninable from Fikentscher K-values of about 5-10 or more to as high as 75 to 100 or so). Of course, copolymers of various N-vinyl-Z-cyclic carbamate constituents conforming to Formula l can also be employed.

The N-vinyl-Z-cyclic carbamate polymers used in the preparation of the tobacco compositions of the present invention are ordinarily water-soluble, at least moderately hygroscopic polymers, although certain species containing one or more relatively more bulky ring substituents per recurring unit (such as butyl, phenyl, etc.) may not be soluble in water under ordinary conditions. Advantageously, the yspecies that are utilized with most benet in the practice of the present invention (at least from standpoints of both ease of handling and economy) are poly-N-vinyl-2-oxazolidinone (PVO); poly-N-vinyl-S- methyl-Z-oxazolidinone (PVG-M); and poly-N-vinyl-Z- oxazinidinone (PVOZ), which, respectively, are of the structures:

En C=O (PVO-M) .glam

H (PVOZ) Advantageously, particularly rwhen water-soluble poly- N-vinyl-Z-cyclic carbamates are employed for preparations of the tobacco compositions of the present invention (such as PVO, PVO-M and PVOZ), the polymers are applied to the tobacco directly in and from an aqueous solution which can be air or otherwise dried after application of the polymer thereto. While any concentration of solution can be employed, it is generally most practical to utilize one that contains at least about 0.5-l percent of dissolved polymer up to the limit of solubility of the polymer at the temperature o f application. More often, solutions containing between about 5 and l5 weight percent of dissolved polymer may be utilized. These contain elicient quantities of the polymer and tend to avoid certain diiiculties in handling due to excessive viscosity which may be encountered when more concentrated solutions are employed. Of course, equivalent dispersions in water or other suitable solvents of the other N-vinyl-2- cyclic carbamate polymers of the present invention can also be utilized, as well as other suitable dispersions in non-deleterious solvent vehicles of the abovementioned preferred species.

The poly-N-vinyl-Z-cyclic carbamate polymers can b added to the tobacco in the leaf at any stage of its processing or manufacture either before or after it is cut, sliced, ground up, rubbed or otherwise comminuted to prepare the desired compositions for smoking or other use. In this connection, the hygroscopic properties of many ofthe N-vinyl-Z-cyclic carbamate polymers used in practice of the invention (such as PVO, PVD-M and PVOZ) have a most beneficial iniluence on the tobacco with which the polymer is compounded as regards maintaining it in a desirably moist and fresh condition for longer than normal periods. As indicated, any cigarette, pipe or cigar tobacco, or blends of tobaccos intended for smoking may advantageously be treated in accordance with the present invention using any of the herein contemplated N-vinyl-Z-cyclic carbamate polymers, or mixtures thereof, particularly PVO, PVG-M and PVOZ.

Any of the conventional filters or solid porous filtering absorbent media for tobacco smoke can be employed for trapping the greater quantities of tars or resins or other harmful ingredients (which are thought to engender irritating properties in the smoke) from the present tobacco compositions. Thus, the iilters may be comprised of cotton, cellulose acetate and other cellulose esters and ethers (including methyl cellulose, etc.), regenerated celluloses, polyethylene terephthalate and the like and other brous materials (natural, synthetic and artificial, or other mixtures) commonly used for such purpose. The filters may be treated with various chemical and other agents for improving their eiectiveness without disadvantageous consequence when utilized in connection with the smoking of the present tobacco compositions. Advantageously, as apparent, the filters employed, especially on cigarettes, may be an integral part of the article to be smoked, such as a iilter tip for cigarettes. Thus, a filter tip cigarette prepared from a tobacco composition according to the invention is schematically illustrated, partly in broken out section, in Figure 1 of the accompanying drawing. Of course, the compositions may also be smoked with beneiit through accessory filters or iiltering means as lter units having absorbent components for use with cigarettes, cigars and pipes.

In order to further illustrate the invention (with reference to Figure 2 of the hereto annexed drawing which schematically illustrates a test apparatus utilized in the hereinafter described experimentation), a plurality of conventional (regular) cigarettes were made using an ordinary, manually operated, single cigarette rolling device of the Well known type. In each cigarette made there was employed about a one gram quantity of a blend of domestic and imported tobacco (Bugler) cut for use in cigarettes. Prior to preparation of the cigarettes, part of the tobacco was treated by spraying various quantities thereon of PVO-M (having a Fikentscher K-value of 30) from a percent aqueous solution of the polymer. The polymer solutions were sprayed onto the tobacco at room temperature so as to thoroughly and uniformly apply the PVO-M to the tobacco. The treated tobacco was then air dried. A portion of the tobacco (9.0 grams) was treated with one gram total of the 10 percent aqueous solution of the polymer; a second 9 gram portion of the tobacco was treated with 2.0 grams total of the solution; while a third 9 gram portion of the tobacco was treated with a 4.0 gram quantity of the polymer solution.

The cigarettes were then smoked in the apparatus shown in Figure 2 of the drawing, described more fully in the following explanation of the tests:

Each cigarette C was placed in the rubber tube holder l-I and lit therein. Tarred absorbent top and bottom cotton plugs (each weighing about 0.1 gram) P1 and P2, respectively, were used as tilters. These had been placed in the sparge line L Which exhausted in a covered graduated container F (having a height of about l2 inches and a volume of 500 cc.) and which was iilled about two-thirds full with water W. By means of mechanically pressing the rubber squeeze bulb B, air was caused to be passed through the sparge tube L only in the direction of burning of the lit cigarette. The cigarettes C may be (and were) thus puffed and smoked overV any desired length. Each of the test cigarettes were smoked over a length of about two inches, leaving a ve-eighths inch unsmoked butt. As is apparent, the smoke from each burning cigarette was passed through the tarred cotton plugs which removed part of the resins and tar. The amount of tar so taken up for each cigarette that was smoked was then determined by weighing back the used cotton plugs after they had been dried for one hour at C. in an air oven.

Cigarettes from each of the above treated tobaccos were tested along with blank samples of cigarettes made from untreated tobacco for purposes of comparison. The results are set forth in the following tabulation.

CIGARETIES Bottom Total Percent Top Plug, Plug, Top-l- Av. of Tar Pick gm. tar gm. tai Bottom Total up over Blank BLANK PVOM (IC-30) 1.0 gm. (10 percent solntlon)/9.0 gm.

tobacco PvoM (iz-an) V2.o gm. (1o percent summum/9.o gm.

tobacco Thus, as is apparent, treatment of the tobacco with the N-vinyl-Z-cyclic carbamate polymer in accordance with the present invention brought about a condition which permitted the resin or tar entities from the burning tobacco to become more readily xed on the cotton lter. Using such tobacco in iilter cigarettes or in cigarettes, cigars for pipes employed with filtering means', the removed resins and tars are advantageously prevented from passing through the iilter and into the lungs of the smoker. It is signiiicant in the foregoing experimentation to note that the pickup of additional tar b y the iilter was real. As is apparent, if it were merely due to the increased possibility of tar and the adding of polymer to the tobacco, then the experiment in which the greatest quantity of the PVO-M was used would show a greater percent tar pickup. As is also apparent in the foregoing, the use of the higher amount of the PVOv-M (i.e., 4 grams of the 10 percent aqueous solution per 9 grams of tobacco) in the cigarettes did not appear to be necessary, since it did not result in an increased electiveness at such level. In this connection, it is generally preferable for treatment of the tobacco to employ the minimum amount of polymer which is necessary to effect the desired decrease in irritational properties of the tobacco or smoke therefrom. As will be evident to those who are skilled in the art, such quan- 'tity may vary in particular cases with various types of tobacco being treated. In any event, the koptimum quantity can be readily determined by simple preliminary tesis.

Results similar to those described in the foregoing are achieved using the same and varied quantities of PVO,

PVOZ or any of the other N-vinyl-Z-cyclic carbamate polymers of the Formula I contemplated within the scope of the present invention on the same or other types of smoking tobaccos and when the treated tobacco is actually smoked by an individual through a filter tip cigarette or from a cigarette using a tilter, or when treated cigarette, cigar or pipe tobacco is smoked through an absorbent lter of any desired variety, such as cotton, cellulose acetate, and so forth. Likewise, great benefit and improvement in the tobacco is obtained when the same general procedures are repeated on chewing tobacco, snuff, and so forth.

What is claimed is:

1. Tobacco composition comprising tobacco containwherein each Q is independently selected from the group consisting of hydrogen, alkyl radicals containing from 1 to about 4 carbon atoms and aryl radicals containing from 6 to about 10 carbon atoms; m is an integer from 2 to 3; and n is a plural integer having a value of at least about 5, said polymer being substantially uniformly applied to and upon said tobacco.

2. The composition of claim 1, containing between about 0.01 and 0.5 weight percent, based on the Weight of the tobacco, of said polymer of the Formula I.

3. The composition of claim 1, wherein said polymer is poly-N-vinyl-Zoxazolidinone.

4. The composition of claim 1, wherein said polymer is poly-N-vinyl-S-methyl-Z-oxazolidinone.

5. The composition of claim l, wherein said polymer is poly-N-vnyl-2-oxazinidinone.

6. The composition of claim 1 in the form of a cut lead.

7. Method for treating tobacco which comprises apploying thereto a minor proportion of an N-viny1-2- cyclic carbamate polymer of the Formula I.

8. The method of claim 7, wherein between about 0.01 and 0.5 weight percent of said polymer is applied to said tobacco, based on the weight of the tobacco.

9. The method of claim 9, wherein said polymer is selected from the group consisting of poly-N-vinyl-Z- oxazolidinone, poly-N-vinyl-S-methyl-Z-oxazolidinone and poly-N-vinyl-Z-oxazinidinone and is applied to said tobacco from an aqueous solution of said polymer.

References Cited in the le of this patent UNITED STATES PATENTS

Claims (1)

1. TOBACCO COMPOSITION COMPRISING TOBACCO CONTAINING A MINOR PROPORTION OF A NORMALLY SOLID N-VINYL-2CYCLIC CARBAMATE POLYMER OF THE STRUCTURE.

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