Tobacco and tobacco substitute material including metal chelate compounds

Abstract

In a smokable product comprising a cellulose-based combustible material, the improvement which comprises incorporating therein at least one chelate compound of the stoichiometric formula. K.sub.z [Me.sub.x R.sub.y ].sub.w In which K is an alkaline earth metal or divalent manganese, Me is trivalent iron or aluminum, R is the radical of a chelate-forming organic carboxylic acid, and w, x, y, and z are integers up to about 5, The chelate compound being incorporated in an amount ranging from about 0.5 to 70% by weight of the combustible material. Preferably R is the radical of an organic dicarboxylic acid containing 2 to 8 carbon atoms or a hydroxy- or keto-substituted carboxylic acid. The product may also contain fillers, compounds which split off ammonia, oxidizing agents, ammonium salts of polymeric acids, low sulfur-content proteins and/or tobacco extracts. The product may be used as such or in blends with tobacco as cigarettes, cigars or pipe tobacco.

Description

This invention relates to smoking products which contain combustible materials based on cellulose together with other constituents, in particular metal chelates, and to a process for producing them.

It is known how to produce a smokable material, which is not natural tobacco, from tobacco waste products or mixtures thereof with other plant materials, as well as from natural or synthetic non-tobacco products, which are made up into paper-like webs or foils or fibres. According to DOS No. 1,900,491, for example, smoking materials can be produced from cellulose, cellulose derivatives or starch using certain inorganic fillers which keep the material glowing. According to U.S. Pat. No. 3,461,879, hydrated magnesium citrate and calcium tartrate may be added to certain cellulose derivatives to assist the combustion process.

The non-tobacco smokable products produced by the previously known processes do not have satisfactory organoleptic properties but on the contrary organoleptic properties which are unpleasant to a greater or lesser degree, e.g. sharpness and poor aroma in the main and side streams. For example, even tobacco substitute products with only a low sulphur content, e.g. in the form of sulfates, are found to produce a smoke with an unpleasant sulfidic flavor. Tobacco substitute products with a high cellulose content which contain the alkali metal, alkaline earth metal and iron salts normally present in smokable products give rise, when allowed to glow, to a sharp and biting smoke with a cellulosic flavor and leave behind a persisting astringent effect in the mouth. Moreover, the known non-tobacco smoking products generally manifest an organoleptic incompatibility with numerous sorts of tobacco when blended with them.

For example, the addition of substances such as magnesium citrate or calcium tartrate which, according to the prior art, may be added to a smoking material to improve its glowing properties, results in smoking products which are completely unsatisfactory in their organoleptic properties. The sharpness of the smoking products is not sufficiently reduced. A particularly disturbing feature of such a product is that the burning of the cellulosic material in it gives rise to an unpleasant flavor (cellulosic flavor) and to a smell of burnt paper, which are practically the same as the smell and flavor of burning pure cellulose. These products are therefore not economically utilizable as smokable products or as additions to smokable products.

Other disadvantages of the known non-tobacco smokable products are their low bulk volume, their generally insufficient wet strength and their low mechanical strength, which leads to an excessive production of dust in processing.

It is accordingly an object of the present invention to provide a smokable product which has desirable organoleptic properties and a relatively low content of undesired condensible materials in its smoke and which is free of the disadvantages noted hereinabove.

These and other objects and advantages are realized in accordance with the present invention pursuant to which there is provided a cellulose-based combustible material having incorporated therein trivalent metal chelate compounds of alkaline earth metals and/or of manganese, the trivalent metal chelate compounds being complex anions which contain trivalent iron or aluminum as the central atom and the anions of chelate-forming organic carboxylic acids as ligands.

A smokable product comprising a combustible material based on cellulose has now been found characterised in that the smokable product contains metal (III) chelate of alkaline earth metals and/or of manganese (II), the "metal (III) chelate compounds" being complex anions which contain trivalent iron or aluminium as the central atom and the anions of chelate-forming organic carboxylic acids as ligands.

The alkaline earth metal-metal (III)-chelate compounds used in the products according to the invention may be, for example, the calcium or magnesium compounds.

The chelate compounds used in the products according to the invention will hereinafter be referred to simply as "chelates."

The term chelate is therefore used to denote complex salts with a chelate structure which contain alkaline earth metal ions or manganese (II) ions as the cation, and as the anion, a chelate complex consisting of iron (III) ions or aluminium ions as the central atom and chelate-forming organic carboxylic acids as ligands (see, e.g., A. E. Martell, M. Calvin, Die Chemie der Metall-Chelat-Verbindungen, page 204, Verlag Chemie, Weinheim (1958)).

Smokable products according to the invention may preferably contain at least one chelate compound of the stoichiometric formula I

K.sub.z [Me.sub.x R.sub.y ].sub.w (I)

in which:

K is an alkaline earth metal or divalent manganese,

Me is trivalent iron or aluminum,

R is the radical of a chelate-forming organic carboxylic acid, and

w, x, y and z are integers up to about 5,

In general, x denotes 1 or 2 and y denotes integers of from 1 to 4, and z resp. w denote the number of divalent cations K resp. anions and depend on the number of free negative valencies remaining in the anion complex.

The cations of the chelates contained in the products according to the invention may be calcium, magnesium or manganese (II), preferably magnesium or manganese (II).

In some cases, it has been found advantageous partly to replace the cations of the chelates by hydrogen so that the corresponding acid salts are formed. Acid chelates which contain one hydrogen ion are preferred.

Chelate-forming organic carboxylic acids, hereinafter referred to as "Chelate formers" (see A. E. Martell, M. Calvin, Die Chemie der Metallchelatverbindungen (pages 462-517) Verlag Chemie, Weinheim (1958), are, for example, organic carboxylic acids which contain 2 to 8 carbon atoms and in addition to the carboxylic group contain at least one hydroxyl group, keto group or additional carboxyl group.

Chelate formers may therefore for example be dicarboxylic acids. The following are mentioned as examples of dicarboxylic acids: oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid and itaconic acid. Particularly preferred dicarboxylic acids are oxalic acid, malonic acid and succinic acid. Hydroxy acids such as hydroxymonocarboxylic acids, hydroxydicarboxylic acids and hydroxytricarboxylic acids may also be chelate formers. Examples of such hydroxymonocarboxylic acids are: lactic acid, glycolic acid, .beta.-hydroxypropionic acid, glyceric acid and hydroxypivalic acid. Glycolic acid and glyceric acid are particularly preferred hydroxymonocarboxylic acids. The following are mentioned as examples of hydroxydicarboxylic acids and hydroxytricarboxylic acids: hydroxymalonic acid, malic acid, tartaric acid, 2-hydroxglutaric acid, 3-hydroxyglutaric acid, 3-methylmalic acid, 2,5-dihydroxyadipic acid, 2,4-dihydroxyadipic acid and citric acid, among which malic acid, tartaric acid and citric acid are preferred.

Mono- and dicarboxylic acids derived from pentoses and hexoses, for example, may also be chelate formers. Examples of these chelate formers are the isomeric monocarboxylic acids known as uronic acids, for example, glucuronic acid, galacturonic acid and mannuronic acid, the compounds known as saccharic acids, e.g. saccharic acid itself, manosaccharic acid and idosaccharic acid, as well as the isomeric mucic acids (galactaric acids). The pentaric acids derived from pentoses, ribotrihydroxyglutaric acid and xylotrihydroxyglutaric acid may also be mentioned as examples. Ketocarboxylic acids containing 3 to 8 carbon atoms may be used as chelate formers which contain a keto group. Examples of keto carboxylic acids are: pyroracemic acid, acetoacetic acid. laevulinic acid and mesoxalic acid.

The preferred chelate formers used are dicarboxylic acids and hydroxycarboxylic acids, in particular oxalic acid, glyceric acid, glycolic acid, malic acid, tartaric acid, galactaric acid, saccharic acid and citric acid.

It has been found particularly advantageous, for example, to use chelates of the general formula (I) which have the following composition: magnesium-iron(III)-glycolate, magnesium-iron-(III)-oxalate, magnesium-iron-(III)-citrate, magnesium-iron-III)-tartrate, magnesium-iron-(III)-galactarate, magnesium-iron-(III)-saccharate, magnesium-aluminum glycolate, magnesium- aluminum oxalate, magnesium-aluminum citrate, magnesium- aluminum tartrate, magnesium-aluminum galactarate, magnesium-aluminum saccharate, manganese-iron-(III)-glycolate, manganese-iron-(III)-oxalate, manganese-iron-(III)-citrate, manganese-iron-(III)-tartrate, manganese-iron-(III)-galactarate, manganese-iron-(III)-saccharate, manganese-aluminum glycolate, manganese- aluminum oxalate, manganese-aluminum citrate, manganese-aluminum tartrate, manganese-aluminum galactarate, manganese-aluminum saccharate.

The chelates used in the smokable products according to the invention may, for example, have the composition indicated in Table (I). The compounds shown in Table (I) correspond to the general formula (I) (K.sub.z [Me.sub.x R.sub.y ].sub.w), in which K represents magnesium, calcium or manganese (II), Me represents iron (III) or aluminum and R represents the chelate-forming carboxylic acid. The values indicated for x, y, w and z are substituted in the general formula (I) in each case to give the summation formula of the given example of chelate.

Table I ______________________________________ R x y free negative z w valences ______________________________________ citrate 1 2 3 3 2 citrate 1 2 6 3 1 citrate 1 3 6 3 1 citrate 2 3 6 3 1 tartrate 1 1 1 1 2 tartrate 1 2 3 3 2 tartrate 1 3 3 3 2 tartrate 2 3 4 2 1 oxalate 1 2 1 1 2 oxalate 1 3 3 3 2 oxalate 1 4 4 2 1 glycolate 1 2 1 1 2 glycolate 1 3 3 3 2 galactarate 1 1 1 1 2 galactarate 1 1 2 1 1 galactarate 1 2 3 3 2 galactarate 1 3 3 3 2 ______________________________________

Particularly preferred chelate formers are tartaric acid, citric acid and galactaric acid.

Particularly preferred chelates are magnesium-iron-(III)-tartrate, magnesium-iron-(III) citrate, magnesium-aluminium tartrate, magnesium-aluminum citrate, manganese-iron-(III)-galactarate and manganese-iron-(III)-citrate.

The chelates contained in the smokable products according to the invention may be prepared in known manner in aqueous solution, e.g. by reacting the iron or aluminum salts of the desired chelate-forming carboxylic acids with calcium magnesium or manganese salts, which may be added as hydroxides, carbonates or salts of the corresponding chelate-forming carboxylic acids (see DRP 514,504; Hanus and Quadrate Z Anorg. Chem. 63, page 314 (1909) and W. Franke, Liebig Ann. Chem. 486, page 248 (1931)).

Examples of combustible materials based on cellulose are: cellulose-containing plant materials, particularly tobacco, tobacco waste products, e.g. stalks, ribs or fragments, decomposed cellulose-containing plant material such as for example hay, straw, lupins or fern, as well as cellulose or wood pulp or cellulose derivatives, alone or as mixtures. The cellulose derivatives used may be, for example, carboxymethyl cellulose, hydroxyethylcellulose or methyl cellulose.

The combustible materials used may also be polymerlike lower molecular weight fragments of cellulose obtained by thermal degradation of cellulose, or they may be cellulose derivatives prepared by chemical processes, particularly by alkaline or acid oxidation.

Particularly satisfactory results are obtained by the use of tobacco or of paper-like webs composed of tobacco waste products or of cellulose or wood pulp.

The smokable products according to the invention generally contain about 0.5 to 70% by weight of chelate, based on the total weight of combustible material used in the products. It has been found advantageous to adjust the quantity of chelate according to the cellulose content of the combustible material used. If, for example, the cellulose content of the combustible material is about 10% by weight, then the quantity of chelate used is preferably about 1 to 15% by weight, based on the total weight, and in particular about 5 to 10% by weight. If the cellulose content of the combustible material is higher than 70% by weight, the quantity of chelate used, based on the total weight, is about 10 to 70% by weight, preferably 25 to 50% by weight.

According to a preferred embodiment of the invention, the smokable products contain a filler. By fillers are meant minerals, inorganic salts and oxides which have no effect on the flavor under smoking conditions, for example silica, silicates, mica, alumina, dolomite, magnesite and chalk or carbonates, phosphates and oxides of aluminum iron, magnesium and calcium. Inert fillers which split off water under smoking conditions may also be used. This elimination of water may be due to the presence of a large quantity of water of crystallization in the filler or it may be due to chemical decomposition, e.g. from metal hydroxides. Fillers which have been found to be particularly advantageous are the hydroxides and hydrated oxides of aluminum and iron, natural silicates such as vermiculite and kaolin, precipitated silicates such as silicic acid, silica gel, silica sol and alkaline earth metal and alkali metal silicates, the hydrated oxides of aluminum and/or silicic acid being preferred. It is generally suitable to use about 1 to 70% by weight of fillers, based on the total quantity of smokable product. The quantity used is preferably about 15 to 50% by weight.

It has been found particularly advantageous to use the fillers in ratios within the range of about 9:1 to 1:9, inclusive, based on the quantity of chelate used.

According to another preferred embodiment of this invention, the smokable products contain compounds which split off ammonia under smoking conditions, in particular, ammonium salts of inorganic acids and organic carboxylic acids, salts of amino acids and acid amides.

The preferred compounds which split off ammonia under smoking conditions are the acid and neutral ammonium salts of inorganic acids such as carbonic acid, nitric acid and phosphoric acid, particularly the ammonium salts of phosphoric acid.

Good results are also obtained with the acid and neutral ammonium salts of organic carboxylic acids which have a carbon to oxygen ratio in the overall formula within the range of about 2:1 to 1:2, inclusive, preferably about 1:1 to 1:2, inclusive. Suitable ammonium salts are therefore, for example the ammonium of monocarboxylic acids such as formic acid and acetic acid, ammonium salts of dicarboxylic acids such as oxalic acid, malonic acid and succinic acid, ammonium salts of hydroxymono-, hydroxydi- and hydroxytricarboxylic acids such as glycolic acid, lactic acid, .beta.-hydroxypropionic acid, glyceric acid, malic acid, tartaric acid and citric acid, and the ammonium salts of mono- and di-carboxylic acids derived from pentoses and hexoses, such as glucuronic acid, galacturonic acid and mannuronic acid, saccharic acid and the isomeric mucic acids. Ammonium tartrate and ammonium citrate are preferred.

The ammonium salts corresponding to the chelates according to the invention ("K" representing ammonium in the general formula (I) are also very advantageous to use as compounds which split off ammonia. The following ammonium chelate compounds are preferably used: ammonium-iron-(III)-glycolate, ammonium-iron-(III)-oxalate, ammonium-iron-(III)-citrate, ammonium-iron-(III)-tartrate, ammonium-iron (III)-galactarate and ammonium-iron-(III)-saccharate as well as ammonium-aluminum glycolate, ammonium-aluminum oxalate, ammonium-aluminum citrate, ammonium-aluminum tartrate, ammonium-aluminum galactarate and ammonium-aluminum saccharate.

Ammonium-iron-(III)-citrate, ammonium-iron-(III)-tartrate, ammonium-iron-(III)-galactarate, ammonium-aluminium citrate and ammonium-aluminum tartrate are particularly preferred.

It has also been found advantageous to use acid amides as compounds which split off ammonia, for example acetamide, propionamide, succinic acid monoamide and diamide and particularly urea. Ammonium, magnesium or manganese (II) salts of aminoacids may also be used as compounds which split off ammonia, the aminoacids being preferably glycine, serine, lysine, arginine, leucine, proline, valine, aspartic acid or glutamic acid. Magnesium glutamate and manganese glutamate are particularly preferred as compounds which split off ammonia.

The compounds which split off ammonia are used, for example, in quantities of about 1 to 25% by weight, based on the smokable product, preferably about 5 to 15% by weight.

It has been found suitable to adjust the quantity of compounds which split off ammonia under smoking conditions so that the acids which are formed in the smoke when the smokable product smolders are neutralized. This can easily be controlled by pH measurements in the main stream smoke. The compounds which split off ammonia are advantageously added in such quantities that the pH of the main stream smoke is adjusted to about 5 to 8, preferably 6 to 7.5.

According to another special embodiment of the invention, the smokable products contain about 0.01 to 7% by weight, preferably about 1 to 5% by weight based on the total weight of the smoking product, of an oxidizing agent. By oxidizing agent is meant a substance which improves the glowing of the smoking product.

The oxidizing agents used may be, for example, salts of nitric acid, particularly alkali metal or alkaline earth metal nitrates. The nitrates preferably used are potassium nitrate and/or sodium nitrate.

Oxidizing agents which have been found to be particularly advantageous in the smokable products according to the invention are compounds of manganese (VII), in particular alkali metal permanganates, e.g. potassium permanganate.

According to another preferred embodiment of the invention, the smokable products contain about 0.01 to 10% by weight, preferably about 0.1 to 5% by weight, based on the smokable product, of ammonium salts of polygalacturonic acids such as pectin, alginic acid or gum arabic and/or ammonium salts of carboxymethyl cellulose.

Satisfactory organoleptic properties are also obtained when using about 0.01 to 5% by weight, preferably about 0.1 to 3% by weight, based on the smokable product, of proteins which have a low sulfur content, e.g. zein, hordein or gliadin, as well as the alcoholic extracts of these proteins, e.g. the ethanol extracts. Apart from liberating ammonia in the smokable products, these compounds impart a pleasant plant flavor with a tobacco-like note. The smokable products obtained by this method are completely compatible in their aroma with any tobacco with which they may be blended.

According to another preferred embodiment, the smokable products contain about 0.1 to 50% by weight, based on the total weight of smokable product, of tobacco constituents. Tobacco constituents are substances or groups of substances which can be obtained from tobacco by known processes, e.g. by pressing, distillation or extraction. It is preferred to use tobacco constituents which have been obtained by extraction carried out, for example, with water or organic solvents.

The combustible material which forms the basis of the smokable products according to the invention may be in the form of a paper-like-web, a fleece, a foil or a thread or strand, cut or uncut. The paper-like webs, fleeces or the like may be produced by known technical processes (see Ullmanns Enzyklopadie der techn. Chemie, 3rd Edition, Volume 13, pages 122-130 (1962) and ibid. Volume 17, pages 288 to 296 (1966)).

It has been found particularly advantageous to produce the product according to the invention in the form of paper-like webs with a surface weight of about 10 to 250g/m.sup.2, preferably about 15 to 60 g/m.sup.2 and thicknesses generally in the region of about 10 to 120 .mu., preferably about 20 to 60 .mu., and particularly about 30 to 45 .mu..

The smokable products according to the invention may be produced, for example, by applying the chelates used according to the invention in the form of a solution, preferably an aqueous solution, to the combustible material based on cellulose which is in the form of a paper-like web, a fleece, a foil or a thread or strand, cut or uncut. Application of the chelate solution may be carried out, for example, by immersing the combustible material in a bath of the solution of chelate compounds and then drying it, advantageously at temperatures of about 50.degree. to 120.degree.C. Alternatively, the material may be sprayed or painted with the solution of chelates. Furthermore, the chelates may be introduced directly into the starting mixture from which the combustible material is produced, e.g. in the form of paper-like webs, fleeces, foils, threads or strands.

The chelates may, for example, be introduced directly into a casting solution containing the combustible material. These casting solutions may advantageously contain about 0.1 to 20% by weight of a binder, in addition to optional fillers compounds which split off ammonia, oxidizing agents and tobacco constituents. The binders may be for example polysaccharides or their derivatives, gum arabic, starch, carboxymethylcellulose with a low alkaline content and/or ammonium-carboxymethylcellulose. If the binder comprises a combustible material based on cellulose, it may, of course, take over the function of combustible material in the products according to the invention. The products according to the invention may be produced, for example, by pouring the casting solution on to an endless band and by drying at 50.degree.C to 120.degree.C.

The smokable products according to the invention are preferably produced using paper-like webs or fleeces.

The amount of chelates taken up by the foil or fleece may be controlled not only by the various operating conditions but also by the structure of the foil and the viscosity and concentration of the chelate solution. Adjustment of the viscosity can be achieved for example by varying the concentration of the solution of chelates or by adding thickeners such as a carboxymethylcellulose which has a low alkaline content, a hydroxyethyl, cellulose, pectins, gum arabic, alginates, galactomanan, starch and derivatives thereof. A high uptake of salts into the smokable product is possible, for example, by using concentrated, highly viscous solutions.

The fillers which may be used according to a preferred embodiment of the invention may be incorporated into the combustible material at the same time as the chelates. Alternatively, they may be incorporated partly or completely in a separate stage of the process before or after the treatment with chelates. Incorporation of the fillers may be carried out by known technical methods employed for producing paper-like webs, fleeces or foils which contain fillers.

The compounds which split off ammonia, which may also be used according to a preferred embodiment of the invention, may be introduced into the combustible material either together with the chelates or in a separate stage of the process before or after incorporation of the chelates. Introduction of the compounds which split off ammonia is carried out e.g. by spraying or painting the combustible material with aqueous solutions of the compounds which split off ammonia, or by immersing the material in such solutions, and then drying the material.

The oxidizing agents used according to a preferred embodiment of the invention may be introduced into the combustible material at the same time as the chelates or before or after their incorporation into the material.

Introduction of the oxidizing agents is carried out e.g. by spraying or painting the combustible material with an aqueous, alcoholic or acetonic solution of the oxidizing agent or by immersing the material in such a solution.

The ammonium salts of polygalacturonic acids used according to another preferred embodiment of the invention, as well as the proteins with a low sulfur content and their alcoholic extracts, and the tobacco constituents which are used according to a further embodiment of the invention, may be introduced together with the chelates or before or after the latter are incorporated into the combustible material. They are preferably incorporated into the combustible material together with or after the chelates.

In all the embodiments, the usual additives employed in tobacco processing, e.g. moisturizing agents, "flavor" and nicotine, may be introduced in the same or separate process steps.

The preferred embodiments of the process for producing the smokable products according to the invention may, of course, be applied in any combination.

When the products according to the invention are compared with smokable products produced from the same combustible material to which the combustion modifying substances of the prior art have been added, it is found that when smoked, the products of the invention are organoleptically less acrid, they have a pleasant, mild flavor without any astringent effect the aroma is improved. For example, when the smokable products according to the invention are added to tobaccos which have a cellulosic sharpness or when such tobaccos are treated by the process according to the invention, then not only is the sharpness reduced but the aroma of these tobaccos is greatly enhanced. The smokable products according to the invention are not only distinguished by their exceptionally low condensate value but also have excellent glowing properties. The smokable products according to the invention are particularly distinctive in producing a smoke which has no cellulose flavor and therefore no organoleptically irritating components.

Smoke analyses of smokable products according to the invention show in part a considerable reduction in physiologically harmful substances as compared with those found in tobacco. Thus, a cigarette containing the products according to the invention is found to have a substantially lower phenol content and hydrocyanic acid content as well as substantially lower condensate values than a cigarette comprising tobacco. For example, when comparing cigarettes produced from cellulose foils containing a filler and treated with chelates with cigarettes produced from tobacco, the phenol content in each cigarette was found to be reduced by more than 90%, the hydrocyanic acid content by about 40% and benzpyrene content by about 25%. The quantity of dry condensate could be reduced by about 80 to 90% compared with that in tobacco.

The addition of the smokable products according to the invention to tobacco can have an advantageous influence on the burning properties of tobacco, especially in that the amount of physiologically harmful substances in the smoke is substantially reduced, as was to be expected from the individual components of these mixtures.

The aroma and flavor of the smokable products can be varied and if desired, for example, the flavor can be neutralized, by varying the chelates used as well as the other components which are added according to various preferred embodiments of the invention, e.g. by adjusting the ratios of the quantity of chelate compounds to the quantity of compounds which split off ammonia under smoking conditions. By means of the process according to the invention therefore, the characteristics of the smokable products can easily be adjusted to those of various synthetic aromatic components or aromatic components obtained by extraction from tobacco as well as to those of various kinds of tobacco such as Burley, Virginia or Oriental with which the smokable products may be blended. A harmonious blend of tobacco aromas and flavors can therefore be obtained in every case and constantly reproduced. Application of the chelates contained in the products according to the invention is found to be particularly advantageous because these compounds are generally readily soluble in water. Homogeneous distribution of the chelates in the smokable products can therefore easily be achieved in one step. Due to their low tendency to crystallization and their hygroscopic properties, the products obtained by the process according to the invention are smooth and elastic and therefore particularly easy to work with.

They have a tobacco-like texture and in their processing properties, such as the ease with which they can be cut and mixed, they are comparable with natural tobacco. The bulk volume can be increased to a value higher than that of an equal quantity of tobacco by adjusting the surface weight of the support, for example to a value of about 15 to 60 g/m.sup.2, so that, by blending tobacco with such smokable products, the individual smokable article, such as a cigarette, cigar or pipeful of tobacco, is reduced in weight, and consequently the total quantity of substance smoked, and hence the quantity of condensate produced, is still further reduced.

The smokable products according to the invention may be used alone or as components of blends of cigarette tobacco, cigar tobacco and pipe tobacco. They are also suitable for use as cigar wrappers or binders or as cigarette paper.

The invention will be further described with reference to the following examples wherein all parts are by weight unless otherwise expressed.

EXAMPLES

The smokable products produced according to the Examples were made up into filter cigarettes with cellulose acetate filters. The filter cigarettes had a length of 82 mm, a diameter of 8 mm and a butt length of 15 mm. They were smoked down to an average butt length of 23 mm.

The density of packing of the cigarettes was measured in terms of the draft resistance. The draft resistance was determined for individual cigarettes by using a draft resistance measuring instrument supplied by Filtrona, London, which indicated the pressure drop in "mm H.sub.2 O."

The filter cigarettes produced from the smokable products generally had draft resistances of from 100 to 125 mm H.sub.2 O.

The quantities of condensate given in the examples were quantities of dry condensate in mg/cig.. They were determined in accordance with Coresta Standard No. 10. The test cigarettes were smoked with a puff volume of 35 ml a puff time of 2 seconds and a puff frequence of 60 seconds. The condensate formed was deposited on a Cambridge filter and weighed. The water content was determined by titration using the Karl-Fischer method and was subtracted from the total condensate.

The smokable products obtained in the examples were assessed for their organoleptic properties which were graded as follows:

a. Sharpness:

(++) usual sharpness of cellulose

(+) light sharpness, especially when lighting up the cigarette

(-) hardly any sharpness, similar to that of tobacco material

(--) completely free from sharpness

b. Smoking flavor:

(++) usual pronounced taste of cellulose, burning paper, strongly astringent

(+) light taste of cellulose, not astringent

(-) no taste of cellulose, slight impairment of flavor

(--) mild, no impairment of flavor.

Example 1a

100 g of a paper-like foil of bleached sulfate cellulose having a surface weight of 58 g/m.sup.2, a thickness of 60 .mu. and an ash content of 0.06% were sprayed with a 25% aqueous solution of magnesium-aluminum citrate, Mg.sub.3 [Al.sub.2 (citrate).sub.3 ] and dried so that the resulting dry foil contained 20% by weight of the chelate. The foil was cut up into strips of various lengths about 0.9 mm in width (fine cigarette cut), and made up into cigarettes with an average draft resistance of 113 mm H.sub.2 O using ordinary commercial cigarette paper tubes with cellulose acetate filters.

When smoked, the cigarettes glowed uniformly without ignition of the smoking product,, and the ash was gray white and self-supporting.

Organoleptic assessment:

Sharpness (+)

Smoking flavor: (-)

Condensate; 7.3 mg

Example 1b

100 g of a paper-like foil of bleached sulfate cellulose with a surface weight of 25 g/m.sup.2, a thickness of 32 .mu. and an ash content of 0.08% were sprayed with a 25% aqueous solution of magnesium-aluminum citrate Mg.sub.3 [Al.sub.2 (citrate).sub.3 ], and dried so that the resulting dry foil contained 20% by weight of the chelate. The treated foil was cut up into strips of various lengths about 0.9 mm in width (fine cigarette cut) and made up into cigarettes with an average draft resistance of 102 mm H.sub.2 O using ordinary commercial cigarette paper tubes with cellulose acetate filters.

When smoked, the cigarettes glowed uniformly without ignition of the smoking product. The ash was self-supporting.

Organoleptic assessment:

Sharpness (+)

Smoking flavor (-)

Condensate: 5.0 mg.

Example 1c

100 g of a paper-like foil produced in known manner on a Fourdrinier machine from about 60% by weight of ground tobacco ribs, 30% by weight of tobacco leaf waste (fragments and dust) and 10% by weight of unground sulfate cellulose and having a surface weight of 70 g/m.sup.2 and a thickness of 60 .mu., were sprayed with a 25% solution of magnesium-aluminum citrate, Mg.sub.3 [Al.sub.2 (citrate).sub.3 ], and dried so that the impregnated foil contained 5% by weight of the chelate. The resulting product was cut up and made into filter cigarettes as in Example 1a. The cigarettes had an average draft resistance of 109 mm H.sub.2 O.

The cigarettes glowed uniformly. The main stream smoke and subsidiary stream smoke were assessed as being distinctly aromatic.

Organoleptic assessment:

Sharpness: (-)

Smoking flavor (-)

Condensate: 6.2 mg

Example 2

A product was produced as described in Example 1a but with the addition of magnesium citrate instead of magnesium-aluminium citrate. This was obtained as follows:

100 g of a paper-like foil as described in Example 1a consisting of bleached sulfate cellulose, having a surface weight of 58 g/m.sup.2 and a thickness of 60 .mu. and containing 11.3% by weight of magnesium carbonate as a filler, were immersed in a 10% aqueous citric acid solution at 30.degree.C. so that the product contained magnesium citrate produced in situ. When the excess citric acid had been washed out and the foil dried, the weight increase of the foil was found to be 19 g, which corresponds to a magnesium citrate content of 22% by weight. The resulting product was cut up and made into filter cigarettes as in Example 1a. The cigarettes had an average draft resistance of 102 mm H.sub.2 O.

Organoleptic assessment:

Sharpness: (++)

Smoking flavor: (++)

Condensate: 9.3 mg/Cig.

Example 3a

100 g of a paper-like foil according to Example 1b were sprayed with a 25% aqueous solution of magnesium-iron-(III)-citrate, Mg.sub.3 [Fe(citrate).sub.2 ].sub.2, and dried so that the dried foil contained 20% by weight of chelate. The resulting product was cut up into strips of various lengths about 0.9 mm in width and made up into cigarettes with a draft resistance of 115 mm H.sub.2 O by the method described in Example 1a.

When smoked, the cigarettes glowed like tobacco without ignition of the smoking product. The ash was brownish gray and self-supporting.

Organoleptic assessment:

Sharpness: (+)

Smoking flavor (+)

Condensate: 4.5 mg

EXAMPLE 3b

300 g of dried, cut stalks of shield fern (Dryopteris filix-mas) were heated to 105.degree.C. with 6 litres of a 5percent aluminum sulfate solution for 4 hours in a 10 1 pressure vessel. The decomposed plant material was then filtered and washed free from sulphate with water. It was then pulped up in a Hollander and made up into a web with a surface weight of 68 g/m.sup.2 and a thickness of 60 .mu. on a Fourdrinier machine. 90 g of the resulting foil were sprayed with a 10percent magnesium-iron citrate solution and dried so that the foil contained 10percent by weight of chelate. The resulting product was then cut up and made into filter cigarettes as in Example 1a. The cigarettes had an average draft resistance of 120 mm H.sub.2 O. They were mild in the main stream smoke and had a pleasant, plant-like flavor.

Organoleptic assessment:

Sharpness: (-)

Smoking flavor (-)

Condensate: 5.2 mg/Cig

EXAMPLE 3c

100 g of a paper-like foil produced in known manner on a Fourdrinier machine from about 60percent by weight of ground tobacco ribs, 30percent by weight of tobacco waste (fragments and dust) and 10percent by weight of unground sulfate cellulose, and having a surface weight of 70 g/m.sup.2 and a thickness of 60 .mu., were sprayed with a 5% aqueous solution of magnesium-iron-(III)-citrate, Mg.sub.3 [Fe(citrate).sub.2 ].sub.2, and dried so that the weight increase after drying was 5percent, i.e. the chelate content was 5percent by weight. The cigarettes produced in accordance with Example 1a, which had a draft resistance of 115 mm H.sub.2 O, glowed uniformly. The ash was brownish red and self-supporting.

When smoked, the product had a light, aromatic flavor without cellulosic sharpness.

Organoleptic assessment:

Sharpness: (-)

Smoking flavor: (--)

Condensate: 4.4 mg/Cig.

Example 4

A paper-like foil similar to that described in Example 1b was repeatedly dipped alternately into a saturated calcium hydroxide solution and then into a 10percent tartaric acid solution and then washed and dried until the weight increase was 25.3percent by weight, i.e. the foil contained about 20percent by weight of calcium tartrate. The product produced in this way was cut up as in Example 1 (fine cigarette cut), and made up into filter cigarettes with a draft resistance of 117 mm H.sub.2 O.

The cigarettes had a dull, musty after-taste and very pronounced cellulosic sharpness.

Organoleptic assessment:

Sharpness: (++)

Smoking flavor: (++)

Condensate: 8.4 mg/Cig.

EXAMPLE 5

A paper-like foil according to Example 1a was treated in an aqueous immersion bath containing 12.6percent by weight of magnesium-aluminum tartrate Mg.sub.3 [A1(tartrate).sub.3 ].sub.2, squeezed off between steel rollers and dried so that the impregnated web showed a weight increase of 24.8percent, which corresponded to a chelate content of 20percent by weight. The resulting product was cut up as in Example 1a and made up into filter cigarettes which had an average draft resistance of 115 mm H.sub.2 O. The cigarettes glowed slowly and constantly and formed a pale, self-supporting ash.

Organoleptic assessment:

Sharpness: (+)

Smoking flavor: (-)

Condensate: 6.8 mg/Cig.

Example 6

100 g of a paper-like foil according to Example 1a were sprayed with a 25percent manganese-iron-(III) oxalate solution, Mn.sub.3 [Fe(oxalate).sub.3 ].sub.2, and dried so that the treated foil contained 20percent by weight of the chelate. The resulting product was cut up and made up into filter cigarettes in a manner analogous to Example 1a. Draft resistance: 123 mm H.sub.2 O. The cigarettes glowed very uniformly and formed a brown, self-supporting ash.

Organoleptic assessment:

Sharpness: (-)

Smoking flavor: (+)

Condensate: 4.2 mg/Cig.

EXAMPLE 7

100 g of a paper-like foil according to Example 1a were sprayed several times with a total of 250 m1 of a 10percent magnesium-aluminum glycolate solution, Mg.sub.3 [A1(glycolate).sub.3].sub.2, and dried so that the chelate content was 20percent by weight.

The resulting product was made up into filter cigarettes as in Example 1a. The cigarettes had a draft resistance of 122 mm H.sub.2 O. They glowed uniformly and formed a light white ash.

Organoleptic assessment:

Sharpness: (+)

Smoking flavor: (+)

Condensate: 7.0 mg/Cig.

EXAMPLE 8

100 g of a paper-like foil according to Example 1bwere sprayed with a 12percent solution of manganese-iron galactarate, Mn.sub.3 [Fe(galactarate).sub.3 ].sub.2, and dried. The foil contained 19.5percent by weight of the chelate.

The material cut up as in Example 1a and made up into filter cigarettes having a draft resistance of 121 mm H.sub.2 O glowed uniformly and formed a brownish gray ash.

Organoleptic assessment:

Sharpness: (-)

Smoking flavor: (+)

Condensate: 4.9 mg/Cig.

EXAMPLE 9

A mixture of 30percent weight of the impregnated foil from Example 1a, and 70percent by weight of an American Virginia tobacco having a condensate of 28 mg/Cig. was made up into filter cigarettes with a draft resistance of 126 mm H.sub.2 O. The aromatic substances and the characteristic sweetness of Virginia tobacco were found to be completely preserved when the mixture was smoked. The nicotine reaction on the respiratory tract was considerably attenuated;

Organoleptic assessment:

Sharpness: (-)

Smoking flavor: (--)

Condensate: 15 mg/Cig.

EXAMPLE 10

A mixture of 30percent by weight of the foil from Example 3aand 70percent by weight of an Italian Burley tobacco having a condensate of 22 mg/Cig. was made up into filter cigarettes with an average draft resistance of 121 mm H.sub.2 O. The cigarettes were found when smoked to have the complete characteristic cigar-like flavour of Burley tobacco.

Organoleptic assessment:

Sharpness: (-)

Smoking flavor: (--)

Condensate: 12 mg/Cig.

EXAMPLE 11

A mixture of 30percent by weight of the foil from Example 6 and 70percent by weight of a commercial tobacco mixture with a light note (American blend type flavor ) having a condensate of 15 mg/Cig. was made up into filter cigarettes. The cigarettes were found when smoked to have a pleasant, mild flavor. The smoke appeared much thinner than that produced by the tobacco mixture alone. The glowing process was similar to that of natural tobacco in its uniformity and rate. Draft resistance: 118 mm H.sub.2 O

Organoleptic assessment:

Sharpness: (-)

Smoking flavor: (-)

Condensate: 9.3 mg / Cig.

EXAMPLE 12

The combustible material used as a tobacco which was characterized as rough Burley with a strong cigar note. This tobacco was sprayed with a solution of ammonium-iron (III) citrate, (NH.sub.4).sub.3 [Fe(citrate).sub.2 ], and acid magnesium-aluminum tartarate, Mg H [A1 (tart).sub.3 ], in a ratio by weight of 1:1, so that the amount of dry substance taken up was 2.5percent by weight, i.e. the amount of each compound present in the treated tobacco material is 1.25percent by weight.

Compared with this material, the Burley tobacco which has been treated by the process according to the invention was less sharp when smoked but with an overall spicy aromatic flavor. The Burley note was completely preserved.

Assessment:

Sharpness: (--)

Smoking flavor: (--)

Example 13

The combusticle material used was a paper-like foil produced from a 1:1 mixture of ground tobacco ribs and sulfate cellulose and having a surface weight of 45 g/m.sup.2 and a thickness of 55 .mu.. This material was treated in an immersion bath containing 15 parts by weight of magnesium-aluminum citrate, Mg.sub.3 [Al (citrate).sub.2 ].sub.2, 6 parts of ammonium aluminum citrate, (NH.sub.4).sub.3 [Al (citrate).sub.2 ], 4 parts of aluminum hydroxide, 4 parts of silicic acid, 11 parts of tobacco extract and 60 parts of water. The treated foil was squeezed off and dried in a stream of air at 95.degree.C. A weight increase of 55% by weight was obtained. The components dissolved in the immersion bath were incorporated in the foil at the same concentration ratio, i.e. the foil contained 13.6% by weight of Mg.sub.3 [Al (citrate).sub.2 ].sub.2 and 5% by weight of (NH.sub.4).sub.3 [Al (citrate).sub.2 ].

Compared with a product obtained without the addition of chelate, the smokable product obtained had no astringent effect, was free from sharpness and produced a light, aromatic smell. It was found to be completely compatible with commercial cigarette tobaccos with which it was blended.

Assessment:

Sharpness: (--)

Smoking flavor: (-)

Examples 14-22

Chelate complexes on Cellulose webs

Paper-like foils or webs with and without fillers were produced on a paper-machine to be used as starting materials for the smoking products. A description of the foils obtained is summarized in Table II.

Table II ______________________________________ Foil Surface Thick- Constituents Filler % Ash weight ness after (g/m.sup.2) (.mu.) glowing ______________________________________ A 45 38 bleached -- 0.07 sulfate cellulose B 16 20 do. -- 0.09 C 50 52 do. Al(OH).sub.3 29 D 68 60 do. Vermic- 34 ulite ______________________________________

Foils A to D were prepared in an immersion bath consisting of the aqueous solution of the chelate together with the compound which splits off ammonia when smoked. In Examples 15, 17, 18 and 19, the immersion bath contains in addition a filler and a binder. The immersed foil was squeezed off in its passage through rollers and dried on an endless band in an air stream at 95.degree.C.

Table III summarizes for Examples 14 to 22 the nature of the foil used as combustible material, the composition of the immersion bath, the increase in dry weight of the treated foil (total weight increase and increase due to chelate content) and the assessment of the organoleptic properties of the resulting smokable products as well as the condensate values. The quantity of solids taken up by the foil (compounds which split off ammonia, fillers) is obtained from the weight increase, the individual constituents being taken up into the foil in the same ratio by weight as that found in the immersion bath. The quantity of chelates taken up is indicated separately.

Table III __________________________________________________________________________ Ex. Composition of the immersion bath Solids Assessment taken up* (Foil) Chelate Compound which Filler Binder Total Chelate Sharp- Cellulose Condensate (g/l) splits off (g/l) (g/l) ness flavor ammonia (g/l) __________________________________________________________________________ 14 200 g of magnes- 100 g of -- -- 29.6 20.0 (-) (+) 9.7 (A) ium-aluminum ammonium citrate tartrate Mg.sub.3 [Al.sub.2 (citrate).sub.3 ] 15 100 g of magnes- 100 g of 250 g 10 g 25 5.7 (-) (-) 8.3 (A) ium-aluminum ammonium Al(OH).sub.3 of gum citrate tartrate arabic Mg.sub.3 [Al(citrate).sub.2 ].sub.2 16 200 g of magnes- 50 g of -- -- 36.4 29.1 (-) (-) 9.6 (A) ium-aluminum urea citrate Mg.sub.3 [Al(citrate.sub.2 ].sub.2 17 190 g of acid 30 g of urea 200 g 30 g 56 20.0 (--) (-) 6.3 (B) magnesium-alum- 84 g of ammonium- of of inum tartrate aluminum Al(OH).sub.3 corn MgH[Al(tar- tartrate starch trate).sub.2 ] NH.sub.4 [Al(tartrate)] 18 100 g of magnesium 50 g of urea 200 g 10 g 60 15 (--) (--) 4.8 (B) iron (III) citrate 50 g of magnesium Al(OH).sub.3 gum Mg.sub.3 [Fe(citrate).sub.2 ].sub.2 glutamate arabic 19 100 g of magnesium 200 g of ammon- -- -- 24 8.1 (-) (-) 8.5 (C) aluminum citrate ium citrate Mg.sub.3 [Al(citrate).sub.2 ].sub.2 20 100 g of magnesium 200 g of ammonium 250 g 8 g 40 7.3 (-) (--) 7.8 (C) aluminum citrate citrate Al(OH).sub.3 of gum Mg.sub.3 [Al(citrate).sub.2 ].sub.2 arabic 21 120 g of magnesium 50 g of urea -- -- 19.5 13.1 (-) (--) 5.5 (C) iron-(III) citrate 10 g of magnes- Mg.sub.3 [Fe(citrate).sub.2 ].sub.2 ium glutamate 22 60 g of magnesium 100 g of -- -- 16 6.0 (-) (+) 7.3 (D) aluminum citrate ammonium Mg.sub.3 [Al.sub.2 (citrate).sub.3 ] tartrate __________________________________________________________________________ *Increase in % by weight after drying, based on the original foil.

Examples 23-25

Tobacco mixtures

The cut foils from Examples 15, 16 and 18 were mixed with a commercial cigarette tobacco with a light note and made up into filter cigarettes.

Example 23

A 30% mixture of the foil from Example 15 and a commercial cigarette tobacco with a light note resalted in a round, soft aroma without any cellulosic sharpness. The only effect of the low nicotine content in the total mixture was an attenuation of the reaction to inhalation of the main stream smoke.

Assessment:

Sharpness: (--)

Smoking flavor: (-)

Condensate: 13.6 mg

Example 24

A 30% mixture of the foil from Example 16 resulted in a slightly attenuated aromatic impression in the tobacco mixture with a low residual sharpness (-). The nicotine reaction on inhalation of the main stream smoke was the same as in Example 13.

Assessment:

Sharpness: (-)

Smoking flavor: (-)

Condensate: 14.1 mg

Example 25

A 30% by weight mixture of foil from Example 18 was assessed to be organoleptically weaker as regards its aroma but to be completely inert as regards its sharpness. No cellulose after-taste was found either in the main stream smoke or in the side-stream smoke. The nicotine reaction on inhalation of the main stream smoke was even weaker than in Examples 23 and 24.

Assessment:

Sharpness: (--)

Smoking flavor: (--)

Condensate: 15.0 mg

Examples 26-31 Foils from Examples 14-22 were immersed in accordance with the following Examples 26-31 in a solution of aqueous tobacco extract containing about 30% by weight of soluble tobacco constituents or sprayed with this solution so that the dry weight increase was up to 50% by weight. Drying was carried out using hot air at 60.degree.C. to 100.degree.C.

Example 26

20% of the constituents of commercial tobacco mixture with an "American Blend" type flavor were extracted using a cold methanol/water solution (70 vol/30 vol). This aqueous-methanolic extract was sprayed on the smoking product produced according to Example 17 so that the dry weight increase was 30% by weight. The resulting product was made up into filter cigarettes which gave an aromatic overall impression without sharpness in the main stream (assessment (--)) and no cellulosic after-taste (assessment: (-) ) on inhalation, with a distinctly perceptible nicotine reaction and a fully aromatic side stream. The resulting smokable product was compatible when mixed in any proportion with Virginia, Burley and Orient type tobaccos and mixtures of such tobaccos (Condensate: 9.8 mg).

Example 27

The foil obtained according to Example 19 was treated with the same extract of tobacco constituents as in Example 26 to result in a dry weight increase of 29% by weight. The flavor of the product made up into filter cigarettes was assessed as inert with little aroma and with only a slight sharpness (assessment: (-) ) when the cigarette was lit up. The side stream smoke was aromatic and mild (assessment of smoking flavor: (-), condensate: 10.7 mg).

Example 28

The foil obtained according to Example 20 was treated with the same extract of tobacco constituents as in Example 26 so that the increase in dry weight was about 25% by weight. Compared with Example 27, a fuller flavor was obtained with a good reaction, and even when lighting up the cigarette no sharpness (assessment: (-)) and no cellulosic after-taste (assessment: (--) ) were experienced. The side stream smoke was pleasantly aromatic. (Condensate: 9.0 mg).

Example 29

The constituents of American Virginia tobacco were completely extracted with hot water. The aqueous extract was sprayed onto the smokable product produced according to Example 20 so that the increase in dry weight was 31%. When this cigarette was smoked, it was found to have an unmistakable, typical Virginia flavor the spiciness of which was not impaired by the foil.

Assessment:

Sharpness: (--)

Smoking flavor: (--)

Condensate: 11.0 mg

Example 30

The soluble constituents were completely extracted from Italian Burley tobacco by means of a cold methanol/water solution (60 vol/40 vol). The extract was sprayed onto the smokable product obtained according to Example 22 so that the weight increase was 20%. The flavor was that of a good quality, characteristic Burley tobacco with a sweetish note. The smokable product was less sharp than the Burley tobacco used for extraction. The smokable product obtained was compatible in any proportions with Virginia, Burley and Orient type tobaccos and mixtures thereof.

Assessment:

Sharpness: (-)

Smoking flavor: (--)

Condensate: 11.3 mg

Example 31

Foil C indicated in Table II was treated in an immersion bath which contained 160 g of ammonium citrate, 80 g of magnesium-aluminum citrate, Mg.sub.3 [Al.sub. 2 (citrate).sub.3 ], and 280 g of the tobacco constituents obtained by extraction with water in accordance with Example 19 and which had been adjusted to pH 7 with ammonia. The increase in dry weight of the foil was 50% and the resulting smokable product contained 5.1% by weight of chelate. When smoked, the product was light, aromatic and practically free from any after-taste or sharpness. It was compatible with all the usual sorts of tobacco in any proportions.

Assessment:

Sharpness: (-)

Smoking flavor: (-)

Condensate: 9.9 mg

Example 32

15 parts of ground, pure linters (99.8% .alpha.-cellulose), 15 parts of aluminum hydroxide, 5 parts of magnesium-aluminum citrate, Mg.sub.3 [Al (citrate).sub.2 ].sub.2, and 5 parts of magnesium-iron citrate, Mg.sub.3 [Fe(citrate).sub.2 ].sub.2, were added to a 5% aqueous casting solution of sodium carboxymethylcellulose/ammonium carboxymethylcellulose (3:1).

The solution was cast onto a polytetrafluorethylene-coated band using a pressure casting tool and dried at 130.degree.C. The cast foil weighed 15 g/m.sup.2. A 30% by weight mixture of this product with a Virginia-Burley mixture (proportion by weight: 3:1) had a slightly weaker aroma than the Virginia Burley mixture without the product but there was no adulteration of the aroma and no sharpness (--). (Condensate: 12.4 mg).

Example 33

A commercial cigarette paper was sprayed with a 6% by weight solution of 2 parts of magnesium-aluminum citrate, Mg.sub.3 [Al.sub. 2 (citrate).sub.3 ], and 1 part of ammonium-aluminum citrate, (NH.sub.4).sub.3 [Al (citrate).sub.2 ]and dried at 90.degree.C. The amount of salt taken up was 9% by weight. Cigarettes produced using this paper were improved in flavor and aroma compared with cigarettes produced with untreated paper because the treated paper was free from sharpness and had no unpleasant cellulosic after-taste.

Examples 34-49

The combustible materials used were paper webs of bleached sulfate cellulose with different filler contents and surface weights. The compositions of the foils used as combustible starting material are shown in Table IV.

Table V shows examples of the preparation of smokable products by the process according to the invention and quantities of condensate formed by these products.

Table VI shows the production of smokable products according to Table V which in addition contain potassium permanganate as an oxidizing agent and the quantities of condensate formed by these products.

Table IV ______________________________________ Foil Cellulose Fillers Surface Thickness material weight .mu. g/m.sup.2 ______________________________________ A bleached 43.5% by weight 42 55 sulfate Al (OH).sub.3 cellulose 10.2% by weight SiO.sub.2 B do. 44.6% by weight 50 62 Al (OH).sub.3 C do. 40.2% by weight 54 70 Al (OH).sub.3 10.0% by weight SiO.sub.2 D do. 31.1% by weight 38 45 Al (OH).sub.3 12.4% by weight SiO.sub.2 E do. 16.1% by weight 32 40 Al (OH).sub.3 F do. 18% by weight 25 35 Al (OH).sub.3 ______________________________________

Table V __________________________________________________________________________ Example Foil from Composition of immersion bath (g/l) Solids taken Condensate Table III up* Total/Chelate __________________________________________________________________________ 34 A 80 Magnesium-iron citrate Mg.sub.3 [Fe(citrate).sub.2 ].sub.2 20.2 10.6 3.8 30 amminium-iron citrate (NH.sub.4).sub.3 [Fe(citrate).sub.2 ] 20 urea 20 ammonium citrate 35 B as in Example 34 16.8 8.9 3.7 36 C as in Example 34 17.4 9.3 4.1 37 D as in Example 34 26.6 14.0 4.3 38 E 120 Magnesium-iron citrate Mg.sub.3 [Fe(citrate).sub.2 ].sub.2 27.5 18.7 6.6 50 urea 10 magnesium glutamate 39 F 160 Magnesium-iron citrate Mg.sub.3 [Fe(citrate).sub.2 [.sub.2 44.0 23.0 4.8 30 ammonium-iron citrate (NH.sub.4).sub.3 [Fe(citrate).sub.2 ] 20 urea 20 ammonium citrate 75 water-soluble tobacco constituents** __________________________________________________________________________ *Increase in % by weight after drying, based on the foil used as startin material **Obtained by complete extraction of Burley tobacco with hot water

Table VI __________________________________________________________________________ Example Production Application of potassium permanganate Potassium Condensate of the foil permanganate as in Example content of foil (% by weight) __________________________________________________________________________ 40 34 Addition of 10 g/l into the immersion bath 2.8 1.2 41 35 after drying, the foil treated with complex 3.0 1.9 salts is passed through an aqueous-acetonic bath of KMnO.sub.4 42 36 after drying of the complex salt solution, 2.6 1.8 the foil is passed through an aqueous KMnO.sub.4 bath 43 36 sprayed from solution in acetone 3.0 1.7 44 37 foil was treated with aqueous KMnO.sub.4 solution 3.0 3.0 before application of the complex salts and dried 45 38 before application of the complex salts, the 2.9 2.7 foil was treated with aqueous KMnO.sub.4 solution and dried 46 39 as in Example 44 2.1 2.6 46a 39 as in Example 45 2.1 2.6 __________________________________________________________________________

Example 47a

A 1% solution of citrus pectin in the form of the ammonium salt was sprayed onto the product produced according to Example 34 so that the dry weight of citrus pectin taken up by the product was 1.3% by weight.

The material made up into cigarettes and smoked was found when compared with the product according to Example 34 to have an improved, pleasantly fresh and slightly plant-like flavor and the same condensate value.

Example 47b

A mixture of 30% by weight of the product according to Example 47a and 70% by weight of a commercial fine cut tobacco mixture with the type of flavor of an American blend was made up into cigarettes. The flavor produced by the pectin in the main stream smoke was completely compatible with the tobacco aroma and rounded off the aroma bouquet.

Example 48

A 2% solution of zein in ethanol was sprayed onto the product produced according to Example 35 so that the weight increase due to the zein was 1.7% after drying.

The product made up into cigarettes was found when smoked to produce an improved aroma in the main stream and subsidiary stream smoke compared with the product according to Example 35 and had the same condensate value.

Example 49

A 2% ethanolic solution of zein was sprayed onto the product made according to Example 39 so that the weight increase due to the zein was 1.5% by weight after drying.

The product made up into cigarettes had a much more intense tobacco aroma and a rounder flavor than the product according to Example 39 and the same condensate value.

Example 50

Mixtures were prepared as indicated in Table VII from the smoking products according to Example 39 and 46 and a commercial tobacco mixture which had a nicotine content of 0.86 mg and a condensate of 14.8 mg/filter cigarette. Table VII shows the expected and found condensate contents and nicotine contents for various mixtures. When calculating the expected values, the bulk volumes of the various mixtures were taken into consideration.

Table VII __________________________________________________________________________ Smokable product Tobacco Calculated condensate Condensate Nicotine Nicotine from Example 29 (% by content (tobacco content found calculated found (% by weight) weight) + smokable product (mg/Cig.) (mg/Cig) content) __________________________________________________________________________ 20 80 10.7 + 1.3 = 12.0 9.9 0.62 0.45 40 60 6.7 + 2.1 = 8.8 7.4 0.39 0.28 60 40 3.5 + 2.4 = 5.9 4.4 0.22 0.17 Smokable product from Example 36 (% by weight) 20 80 10.5 + 0.7 = 11.2 10.0 0.61 0.39 40 60 7.6 + 1.3 = 8.9 6.7 0.44 0.26 60 40 3.9 + 1.5 = 5.4 3.8 0.22 0.14 __________________________________________________________________________

EXAMPLE 51

The foil produced according to Example 36 was sprayed with an aqueous alcoholic solution of potassium nitrate and dried, the increase in dry weight being 1%. Condensate: 3.1 mg/Cig.

Example 52

The foil produced according to Example 36 was sprayed with an aqueous potassium nitrate solution and dried, the increase in dry weight being 2%. Condensate: 2.5 mg/Cig.

Example 53

A foil produced according to Example 38 was sprayed with an aqueous potassium nitrate solution and dried, the increase in dry weight being 2%. Condensate: 3.2 mg/Cig.

Example 54

A combustible material in the form of a paper web of bleached sulfate cellulose containing 45% by weight of aluminum hydroxide as a filler and having a surface weight of 50 g/m.sup.2 and a thickness of 38 .mu. was treated in an immersion bath containing:

10 parts of manganese-iron citrate, Mn.sub.3 [Fe(citrate).sub.2 ].sub.2

6 parts of ammonium-iron citrate, (NH.sub.4).sub.3 [Fe(citrate).sub.2 ]

5 parts of urea

12 parts of tobacco constituents obtained buy complete extraction of Burley tobacco with hot water

100 parts of water,

so that, after drying at temperatures constantly increasing from 55.degree.C to 95.degree.C, the increase in dry weight was 34%. The resulting smokable product contained 7.6% by weight of the chelate. It was made up into filter cigarettes. The product was assessed organoleptically as neutral in flavor with a marked impression of tobacco. Condensate: 3.1 mg/Cig.

Example 55

A combustible material as in Example 54 consisting of a foil of bleached sulfate cellulose which contained 45% by weight of aluminum hydroxide as a filler and which had been pretreated with a 2% aqueous potassium permanganate solution was treated in an immersion bath which consisted of:

8 parts of manganese-iron galactarate, Mn.sub.3 [Fe(galactarate).sub.3 ].sub.2

8 parts of magnesium-aluminum citrate, Mg.sub.3 [Al (citrate.sub.2 ].sub.2

6 parts of ammonium iron galactarate, NH.sub.4 [Fe(galactarate)]

6 parts of urea

12 parts of tobacco constituents (which had been obtained according to Example 29)

100 parts of water

so that, after drying at 55.degree.C. to 95.degree.C with constantly increasing temperature, the increase in dry weight was 41%. The resulting smokable product contained 11.4% by weight of the chelate. It was made up into filter cigarettes. The product was assessed organoleptically as exceptionally mild and tobacco-like. Condensate: 2.8 mg/Cig.

The product obtained by this Example was exceptionally compatible with a commercial tobacco mixture which had a light note.

It will be appreciated that the instant specification and examples are set forth by way of illustration and not limitation and that various modifications and changes may be made without departing from the spirit and scope of the present invention.

Claims

What is claimed is:

1. In a smokable product comprising a cellulose-based combustible material, the improvement which comprises incorporating therein at least one chelate compound of the stoichiometric formula.

K.sub.z [Me.sub.x R.sub.y ].sub.w

in which

K is an alkaline earth metal or divalent manganese,

Me is trivalent iron or aluminum,

R is the radical of a chelate-forming organic carboxylic acid, and

w, x, y and z are integers up to about 5,

the chelate compound being incorporated in an amount ranging from about 0.5 to 70% by weight of the combustible material.

2. A smokable product according to claim 1, wherein K is magnesium.

3. A smokable product according to claim 1, wherein the organic carboxylic acid has from 2 to 8 carbon atoms and is substituted with at least one hydroxy or keto group or has at least two carboxylic acid groups.

4. A smokable product according to claim 3, wherein the organic carboxylic acid is a material selected from the group consisting of oxalic, glyceric, glycolic, malic, tartaric, citric, galactaric and saccharic acids.

5. A smokable product according to claim 1, wherein x is 1 or 2 and y is from 1 to 4.

6. A smokable product according to claim 1, wherein the chelate compound is incorporated in an amount ranging from about 5 to 50% by weight of the combustible material.

7. A smokable product according to claim 1, wherein the chelate compound is a material selected from the group consisting of magnesium-iron (III) glycolate, magnesium-iron (III)-oxalate, magnesium-iron (III) citrate, magnesium-iron (III) tartrate, magnesium-iron (III) galactarate, magnesium-iron (III) saccharate, magnesium-aluminum glycolate, magnesium-aluminum oxalate, magnesium-aluminum citrate, magnesium-aluminum tartrate, magnesium-aluminum galactarate, magnesium-aluminum-saccharate, manganese-iron (III) glycolate, manganese-iron (III) oxalate, manganese-iron (III) citrate, manganese-iron (III) tartrate, manganese-iron (III) galactarate, manganese-iron (III) saccharate, manganese-aluminum glycolate, manganese-aluminum oxalate, manganese-aluminum citrate, manganese-aluminum tartrate, manganese-aluminum galactarate and manganese-aluminum saccharate.

8. A smokable product according to claim 1, containing about 1 to 70% by weight of at least one filler selected from the group consisting of minerals and salts which are inert under conditions of smoking, and hydroxides and hydrated oxides which split off water under conditions of smoking.

9. A smokable product according to claim 8, wherein the filler is at least one material selected from the group consisting of hydrated oxides of aluminum and silicic acid.

10. A smokable product according to claim 1, containing at least one compound which splits off ammonia under conditions of smoking and which is present in an amount such that the smoke has a pH of about 5 to 8.

11. A smokable product according to claim 10, wherein the compound which splits off ammonia is at least one material selected from the group consisting of ammonium salts of inorganic acids, ammonium salts of organic acids, salts of amino acids and acid amides.

12. A smokable product according to claim 10, wherein the compound which splits off ammonia is at least one material selected from the group consisting of acid or neutral ammonium carbonate, nitrate or phosphate, ammonium citrate, ammonium tartrate, ammonium or magnesium glutamate, urea, ammonium-iron (III) glycolate, ammonium-iron (III) oxalate, ammonium-iron (III) citrate, ammonium-iron (III) tartrate, ammonium-iron-(III) galactarate, ammonium-iron (III) saccharate, ammonium-aluminum glycolate, ammonium-aluminum oxalate, ammonium-aluminum citrate, ammonium-aluminum tartrate, ammonium-aluminum galactarate and ammonium-aluminum saccharate.

13. A smokable product according to claim 1, containing about 0.01 to 7% by weight of at least one oxidizing agent selected from the group consisting of alkali metal or alkaline earth metal nitrates and alkali metal permanganates.

14. A smokable product according to claim 1, containing about 0.01 to 10% by weight of the ammonium salt of at least one polymeric acid selected from the group consisting of pectin, alginic acid, gum arabic or carboxymethylcellulose.

15. A smokable product according to claim 1, containing about 0.01 to 5% by weight of at least one low sulfur-content protein selected from the group consisting of zein, hordein and gliadin.

16. A smokable product according to claim 1, containing about 0.1 to 50% by weight of a tobacco extract.

17. A smokable product according to claim 7, wherein x is 1 or 2 and y is from 1 to 4 and the chelate compound is incorporated in an amount ranging from about 5 to 50% by weight of the product; said product optionally containing about 1 to 70% by weight of at least one material selected from the group consisting of hydrated oxides of aluminum and silicic acid; at least one compound which splits off ammonia under conditions of smoking and which is present in an amount such that the smoke has a pH of about 5 to 8, said compound being selected from the group consisting of acid or neutral ammonium carbonate, nitrate and phosphate, ammonium citrate, ammonium tartrate, ammonium or magnesium glutamate, urea, ammonium-iron (III) glycolate, ammonium-iron (III) oxalate, ammonium-iron (III) citrate, ammonium-iron (III) tartrate, ammonium-iron-(III) galactarate, ammonium-iron (III) saccharate, ammonium-aluminum glycolate, ammonium-aluminum oxalate, ammonium-aluminum citrate, ammonium-aluminum tartrate, ammonium-aluminum galactarate and ammonium-aluminum saccharate; about 1 to 5% by weight of at least one oxidizing agent selected from the group consisting of alkali metal or alkaline earth metal nitrates and alkali metal permanganates; about 0.01 to 10% by weight of the ammonium salt of at least one polymeric acid selected from the group consisting of pectin, alginic acid, gum arabic or carboxymethylcellulose; about 0.01 to 5% by weight of at least one low sulfur-content protein selected from the group consisting of zein, hordein and gliadin; and about 0.1 to 50% by weight of a tobacco extract; said cellulose-based combustible material being in the form of a paper-like web of about 10 to 120 .mu. in thickness and weighing about 10 to 250 grams per square meter.

18. A smokable product according to claim 17, blended with tobacco.

19. A smokable product according to claim 1, in the form of a cigarette or cigar.

20. The process for making a smoking product according to claim 17 which comprises applying to a paper-like web of said cellulose-based combustible material of about 10 to 120 .mu. in thickness an aqueous solution containing said chelate compound, said filler, said compound which splits off ammonia, said oxidizing agent, said ammonium salt of polymeric acid, said protein and said tobacco extract, and drying, application being effected by spraying or painting said solution onto said web or by immersing said web in said solution, the impregnated web on a solvent-free basis weighing about 10 to 250 grams per square meter.

21. The process for making a smoking product according to claim 17, which comprises forming a solution containing said cellulose-based combustible material, said chelate compound, said filler, said compound which splits off ammonia, said oxidizing agent, said ammonium salt of polymeric acid, said protein and said tobacco extract, casting said solution to form a sheet having a solvent-free weight of about 10 to 250 grams per square meter, and drying said sheet to remove the solvent and leave the sheet with a thickness of about 10 to 120 .mu..

22. A smokable product according to claim 1, wherein the combustible material is selected from the group consisting of tobacco, tobacco waste products, hay, straw, lupins, fern, cellulose, wood pulp, carboxymethyl cellulose, hydroxyethyl cellulose and methyl cellulose.