TOBACCO PRODUCT FILTERS

Abstract

A tobacco product filter is provided comprising a carrier material which comprises an immobilized ionic liquid. By the term “tobacco product filter” may particularly be meant all sorts of filters which are suitable to remove harmful substances, particles, gases or the like from tobacco smoke. In particular, the tobacco product filter may be suitable to form cigarette, small cigars and smoking pipes.

Description

The invention relates to a tobacco product filter, in particular to a tobacco product filter comprising ionic liquids. Further, the invention relates to a method of reducing harmful substances in the tobacco smoke.

FIELD OF THE INVENTION

A cigarette filter shall reduce the fraction of harmful substances, e.g. condensate, the so called tar, and gases in the smoke of the cigarette. Furthermore, the smoke is getting somewhat milder thus some smokers remove or shorten it for a more intense taste. In case of a classic filter cigarette the filter is wrapped with a cork coloured mouthpiece in order to hide the brown colouring of the filter. Nowadays, most of the cigarettes manufactured in an industrial way are provided with a filter. People rolling cigarettes on their own could buy the same in a tobacco store. The base material for manufacturing of the cigarette filter is mostly cellulose which is obtained from wood. The cellulose is converted into cellulose acetate in a complex chemical process. Subsequently the acetate flocs are solved in acetone and are spun into long fibres from the dope. The diameter of the fibres is about 30 to 50 micrometers. A great deal of fibres is merged to an endless band. For forming the filter, the fibres are punctually glued, e.g. by triacetin, in order to maintain gas permeability. Such a filter can hold back particles as far as about 0.2 micrometers. Thereby, approximately 40% to 70% of the particles and up to 80% of the phenols of the tobacco smoke are hold back. Additional activated charcoal filters hold back up to 85% of the gas phase components.

SUMMARY OF THE INVENTION

However, there may be a need for an alternative tobacco product filter which may have improved filtering effect.

This need is met by the tobacco product filter, the method of removing of harmful substances from the tobacco smoke and the use of a tobacco product filter according to the independent claims. Further, exemplary embodiments are described in the dependent claims.

According to an exemplary aspect of the invention a tobacco product filter is provided comprising a carrier material which comprises an immobilized ionic liquid. By the term “tobacco product filter” may particularly be meant all sorts of filters which are suitable to remove harmful substances, particles, gases or the like from tobacco smoke partially or in total. In particular, the tobacco product filter may be suitable to form cigarette, small cigars and smoking pipes. It should also be noted that the term “tobacco” has to be interpreted in a broad way and shall encompass all smokable materials.

According to an exemplary aspect a method of removing harmful substances from tobacco smoke is provided, wherein the method comprises providing a tobacco product filter according to an exemplary aspect and conducting tobacco product smoke through the tobacco product filter.

In particular, the harmful substances may be removed or extracted from the tobacco smoke in a physical manner. Such a physical extraction may particularly to be distinguished from a chemical extraction, wherein the harmful substances are chemically bonded, e.g. onto the cation of an ionic liquid or of a crystalline structure, e.g. of a zeolite.

According to an exemplary aspect it is provided a use of a filter which comprises a carrier material having an immobilized ionic liquid, for removing of harmful substances out of tobacco product smoke.

The term “immobilize” may here particularly denote an accretion on a carrier substrate or a carrier material. Such an accretion may particularly to be distinguished from an incorporation during the forming of a crystalline structure. Such an incorporation, e.g. as the cation of a zeolite, is typically caused by ionic bonds, while an accretion is possible due to other forces, e.g. van de Waals bonds. Summarizing, the term immobilizing, in the sense of the application, may particularly not denote a firm incorporation in a crystalline structure.

Ionic liquids are—in the sense of the accepted literature (e.g. Wasserscheid, Peter; Welton, Tom (Eds.), “Ionic Liquids in Synthesis”, Verlag Wiley-VCH 2003, ISBN 3527305157; Rogers, Robin D., Seddon, Kenneth R. (Eds.); “Ionic Liquids—Industrial Applications to Green Chemistry”, ACS Symposium Series 818, 2002; ISBN 0841237891) liquid organic salts or salt mixtures consisting of organic cations and organic or anorganic anions having a melting point of less than 100° C. In these salts additionally organic salts and furthermore molecular auxiliary substances may be solved. In the sense of this application we see the arbitrarily defined limit of 100° C. of the melting points of ionic liquids in a broader sense and include as well such liquefied salts having a melting point of above 100° C. but below 200° C. Because they do not differ in their characteristics aside from that.

Ionic liquids exhibit some very interesting characteristics, e.g. having a very low, virtually non measurable, vapor pressure, a high liquidus range, good electrical conductivity, and interesting solvation characteristics. These characteristics predestine ionic liquids for different fields of technical applications. They may be used for example as solvents (for example, during organic or inorganic synthesis in general, transition metal catalysis, in biocatalysis, phase transfer catalysis, multiphase reactions, photochemistry, polymer synthesis, and nanotechnology), as extracting agent (during liquid-liquid or liquid-gaseous extraction in general, sulphur removal in crude oil processing, removal of heavy metals in water processing, and liquid membrane extraction), electrolytes (in batteries, fuel cells, capacitors, solar cells, sensors, in electrochemistry, electroplating, electrochemical metal processing, electrochemical synthesis in general, electro-organic synthesis, nanotechnology), as lubricants, as thermofluids, as gels, as reagents for organic synthesis, in the “green chemistry” (e.g. as replacement for volatile organic compounds), as static inhibitors, during specific applications in chemical analysis (gas chromatography, mass spectroscopy, capillary zone electrophoresis), as liquid crystals, etc. (listing not complete). In this context it is referred to “Rogers, Robin D.; Seddon, Kenneth R. (Eds.); Ionic Liquids—Industrial Applications to Green Chemistry, ACS Symposium Series 818, 2002; ISBN 0841237891” and “Wasserscheid, Peter; Welton, Tom (Eds.); Ionic Liquids in Synthesis, Verlag Wiley-VCH 2003; ISBN 3527305157”, for example.

Furthermore, ionic liquids may have very good characteristic as solvents or extracting agents for polymers, bio-polymers (e.g. cellulose. chitin), biomass (e.g. wood, thus cellulose+lignin, i.e. a polyphenols; proteins), metals, e.g. in aqueous solution, gases, e.g. CO₂, NO_x, polar organic compounds as alcohols, carboxylic acids, ethers, esters, ketones and amines, aromatic carbon hydrides, etc. See for example WO2003029329, “Ionic liquids for aromatic extraction: Are they ready?”; Anjan, Sachin; Chemical Engineering Progress (2006), 102(12), 30-39, Chitin and Chitosan dissolved in ionic liquids as reversible sorbents of CO₂.+ Xie, Haibo; Zhang, Suobo; Li, Shenghai. Green chemistry (2006), 8(7), 630-633, Wood liquefaction by ionic liquids.”, Honglu, Xie; Tiejun, Shi., Holzforschung (2006), 60(5), 509-512 and Ionic liquids as extraction solvents: where do we stand?”, Dietz, Mark L.; Separation Science Technology (2006), 41(10), 2047-2063.

The optimization of the characteristics of ionic liquids for the respective application may be performed, within wide limitations, by varying the structure of anion and cation or the variation of their combination, which, by the way, gained ionic liquids the name “designer solvents” in general (cf. for example Freemantle, M.; Chem. Eng. News, 78, 2000, 37).

Due to these characteristics of ionic liquids it may be possible to provide a filter for tobacco products, which is suitable for effectively removing or at least reducing of unhealthy and often carcinogen ingredients out of tobacco smoke. In particular, such a filter may be suitable to remove or at least reduce one or a plurality of the ingredients, listed in the following. Including in particular:

• • nicotine;
  • tar and tar like condensates;
  • carbon monoxide, hydrogen cyanide, nitrogen oxides, ammonia;
  • hydrazine, coumarin, nitropropane, urethane, vinyl chloride;
  • aldehydes as e.g. formaldehyde, acetaldehyde, acrolein, crotonaldehyde;
  • acids as e.g. acetic acid, formic acid;
  • anhydride as e.g. maleic anhydride, 2,3-dimethyl maleic anhydride, succinic acid anhydride;
  • cetones as e.g. acetone;
  • alcohols as e.g. methanol, propanol;
  • aromatic and hetero aromatic carbon hydrides as e.g. acridine, anthracene, benzimidazole, benzisoxazole, benzo[c]tiophene, benzofuran, benzene, benzothiazole, benzothiophene, benzoxazole, quinazoline, quinoline, quinoxaline, quinoline, furan, imidazole, indazole, indole, isobenzofuran, isoquinoline, isoindole, isoxazole, naphthalene, oxazole, purine, pyrazine, pyrazole, pyridazine, pyridine, pyrimidine, pyrrole, thiazole, thiophene;
  • phenole and quinone as e.g. phenol, hydroquinone, catechol, 3-cresol, 3- and 4-cresol, 3- and 4-guaicol;
  • aromatic amine as e.g. aniline, pyridine, 3-methylpyridine, 4-naphthaleneamine, 4-aminobiphenyle, o-toluidine;
  • polycyclic aromatics (PHA) as e.g. anthanthrene, anthracene, benz[a]anthracene, benzo[b]fluoroanthrene, benzo[a]fluorene, benzo[b]fluoren, benzo[ghi]perylene, benzo[c]phenanthrene, benzo[a]pyrene, benzo[e]pyrene, chrysene, dibenz[a,h]anthracene, Dibenz[a,j]anthracene, fluoroanthrene, indeno[1,2,3]pyrene, 1-methylchrysene, 2-methylchrysene, 3-methylchrysene, perylene, penanthrene, pyrene, triphenylene;
  • polycyclic hetero aromatic as e.g. dibenz[a,h]acridine, dibenz[a,j]acridine, carbazole, 7H-dibenzo[c,g]carbazole, 2-amino-3-methylimidazole[4,5-f]-quinoline [IQ];
  • nitrosamine (TSNA, N-nitroso-compounds) as e.g. N-nitrosodimethylamine, N-nitrosomethylethylamine, N-nitrosodiethylamine, N-nitrosodipropylamine, N-nitrosodibutylamine, N′-nitrosos-nornicotine, N-nitrodiethanolamine, 1-nitrosopyrrolidine and 1-nitrosopiperidine, N-nitrososnornicotine, 4-(methylnitrososamine)-1-(3-pyridyl)-1-butanone, N′-nitrosoanatabine, N′-nitosoanabasine;
  • metals, in particular heavy metals, of which type however (e.g. as vapour, ionic, particles, organically bounded), as e.g. Cr, Mn, Co, Nil, Cu, Ag, Cd, Hg, Pb, As, Sb, Bi, Se, Te, Ra, Th, Po;
  • mechanical effective particles as soot, fibers (e.g. from conventional cellulose acetate filter), in particular such having diameters and/or lengths in the interval of micrometer to nanometer.

In the following embodiments of the tobacco product filter are described. The features of the embodiments however are also valid for the method of removing of harmful substances out of tobacco smoke and the use of filters.

According to an exemplary embodiment the carrier material of the tobacco product filter has a large internal surface. A large internal surface may particularly denote that the internal surface is very large compared to the external surface. For example, the internal surface may be larger than the external surface by a factor of more than 1,000.

Such a large internal surface may in particular support or improve the filtering effect of the tobacco product filter. By a large internal surface may particularly be denoted the collectivity of all surfaces included, for example, in porous or grained solids, that is, also the one which result between the discrete grains or by the pore edges. The specific surface may be seen as a suitable indicator of the internal surface. A suitable internal surface or a suitable specific surface may be defined by that a suitable filter effect, which may be defined by a predetermined criterion, is achievable. Such a predeterminable criterion may be for example that at least 30%, 40%, 50%, 60%, 70%, 80%, 90% or more of the harmful substances to be filtered out are filtered out. In particular, the specific surface of the carrier material may be in the range from approximately 1 m²/g to approximately 2,000 m²/g.

According to an exemplary embodiment of the tobacco product filter the carrier material has a structure selected out of the group consisting of porous structures, sponge like structures, fibrous structures, powdery structures, grained structures, membrane like structures, and foil like structures. In particular, the fibrous structures may be available in form of a fabric, which may be woven, spun, felted or knitted, for example. The powdery structures may be sintered or being sintered, for example. In particular, the membrane like structures and/or the foil like structures may be folded.

In particular, the carrier material may have a structure, which corresponds to a mixture of several of the mentioned structures. For example, a grained structure may be inserted into a fibrous structure or membrane like structure. In particular, all structures may be suitable exhibiting a sufficient permeability for tobacco smoke while having a large internal surface. For that a foil like structure and/or a membrane like structure may form a support structure or external structure into which then a grained structure and/or fibrous structure is inserted.

According to an exemplary embodiment of the tobacco product filter the carrier material comprises at least one material selected out of the group consisting of activated charcoal, charcoal, stone, in particular limestone, coralline rubble or pumice stone, zeolite, silica gel, ceramic, silica gel, aluminum oxide, plastics, in particular polyethylene, glass fibers, mineral wool, paper, cellulose, cellulose acetate, and meerschaum. In particular, the carrier material may comprise a mixture of several of the mentioned materials. All these materials may be materials which are suitable for a carrier material and which can immobilize an ionic liquid. In particular, these materials may also be suitable to form a carrier structure providing a large internal surface.

According to an exemplary embodiment of the tobacco product filter the ionic liquid has a melting point of less than 200° C. In particular, the ionic liquid may have a melting point of less than 100° C.

According to an exemplary embodiment of the tobacco product filter the ionic liquid corresponds to the generic formula ([A]⁺)_a[B]^a−. Here the salts tetramethyl ammonium bromide, tetraethyl ammonium bromide, tetrapropyl ammonium bromide, tetrabutyl ammonium bromide may be excluded as ionic liquids. As well anionic sulfite may be excluded.

According to an exemplary embodiment of the tobacco product filter [A]⁺ stands for a toxicologically harmless cation which is in particular selected from the group which consists of the following cations: cations having short alkyl side chains, cations having polar functional groups in the side chains, and natural cations. In particular, examples for cations having short alkyl side chains may be such cations having one to eight carbon atoms (C₁ to C₈) and preferably one to four carbon atoms (C₁ to C₄). Examples for polar functional groups in the side chains may be alcohol-, ether-, ester-, ceton-, or nitrile-groups. Examples for cations existing in nature may be e.g. choline HOCH₂CH₂N⁺(CH₃)₃, acetylcholine H₃C—CO—CH₂CH₂N⁺(CH₃)₃, anthocyanidinium (cations of the naturally occurring anthocyanidine=aglycone of the anthocyanines) as well as all non toxic, protonated or alkylated natural nitrogen bases (e.g. alkoloides).

According to an exemplary embodiment of the tobacco product filter [B]^a− stands for a toxicologically harmless anion, in particular a natural anion. In particular, a toxicologically harmless anion may be selected from the group consisting of anions which are derived from fruit acid, sugar acid, amino acid, fatty acid, volatile acid and resin acid or are conjugated to these acids. Examples for fruit acids may be in particular, oxalic acids, benzoic acids, salicylic acids, citric acids, tartaric acids, ascorbic acids, lactic acids, and malic acids or the protonated anions of oxalate, benzoate, salicylate, citrate, tartrate, ascorbate, lactate, malate and the like. Examples for sugar acids may be in particular uronic acids and onic acids, like for example linear or cyclic tetronic acids, tetruronic acids, pentonic acids, penturonic acids, hexonic acids, hexuronic acids, in particular, gluconic acids, glucuronic acids or protonated anions of gluconate, glucuronate, mannonate, mannuronate, galactonate, galacturonate, fructonate fructuronate, xylonate or the like. Examples for amino acids or natural amino acids may be in particular alanine, arginine, asparagine, asparaginic acid, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophane, tyrosine, and valine. In particular, the fatty acids may be monocarbonic acids having four to 26 carbon atoms (C4 to C26), wherein the fatty acids may be saturated, unsaturated or mixtures of saturated and unsaturated fatty acids. Examples for fatty acids may be alkyl acids, alkenoic acids, alkanoic acids, alkenylic acids, alcadienylic acids, in particular the protonated anions of caprinate, laurinate, myristate, palmitate, margarinate, arachinate, behenate, myristoleinate, palmitoleinate, petroselinate, oleate, elaidinate, vaccenate, icosenate, cetoleinate, linolenate, linolate and the like. Examples for volatile acids may be in particular the protonated anions of acetate, formates, butyrate or the like.

The term “toxicologically harmless” may particularly denote that the toxicity of the respective substance lies below a predetermined, e.g. statutory, value or that no toxicologically effect of the substance is existing or at least not known. In particular, such substances may have no harmful effects. The term “natural cations” and “natural anions” may in particular denote, which are present already in nature and are thus in contrast to cations respectively anions which are manufactured or produced by man, which can also be denoted as man-made and synthetic cations and anions, respectively.

According to an exemplary embodiment of the tobacco product filter [A]⁺ stands for a quaternary ammonium cation [R^1′R¹R²R³N]⁺, a phosphonium cation [R^1′R¹R²R³P]⁺, sulfonium cation [R^1′R¹R²S]⁺ or a hetero aromatic cation.

In particular, R^1′, R¹, R², R³ may stand for moieties, for example, independently from each other, for hydrogen, and where appropriate substituted alkyl-, alkenyl-, alkinyl-, cycloalkyl-, cycloalkenyl-, aryl- or heteroaryl-moiety; or

two of the moieties R¹, R^1′, R², R³ may form a ring together with the hetero-atom to which they are bound, wherein the ring may be saturated, unsaturated, unsubstitued or substituted and wherein this chain may be interrupted by one or more hetero-atoms selected out of the group consisting of O, S, NH or N—C₁-C₄-alkyl. In particular, the case may be excluded where all moieties are formed by hydrogen or a proton. Organic sulfite as cation may also be excluded.

Further, [B]^a− may be an arbitrary anion having the negative charge a.

The heteroaromate of the formula is typically a 5 or 6 membered heteroaromate comprising at least one nitrogen atom and if necessary one oxygen or sulphur atom and which is unsubstituted or substituted and/or annelated. Preferably, the heteroaromate of the formula IIb is selected from the group consisting of:

wherein the moieties have the following meaning:

R hydrogen, C₁-C₃₀-alkyl, C₃-C₁₂-cycloalkyl, C₂-C₃₀-alkenyl, C₃-C₁₂-cycloalkenyl, C₂-C₃₀-alkinyl, aryl or heteroaryl, wherein the latter 7 moieties may have one or more halogenic moiety and/or 1 to 3 moieties selected from the group consisting of C₁-C₆-alkyl, aryl, heteroaryl, C₃-C₇-cycloalkyl, halogen, OR^c, SR_c, NR^cR^d, COR_c, COOR^c, CO—NR^cR^d, wherein R_c and R^d stand for hydrogen, C₁-C₆-alkyl, C₁-C₆-halogenalkyl, cyclopentyl, cyclohexyl, phenyl, tolyl or benzyl;

R¹, R^1′, R², R³ stand, independently from each other, for hydrogen, where appropriate, substituted alkyl, alkenyl, alkinyl, cycloalkyl, cycloalkenyl, aryl or heteroaryl; or

two of the moieties R¹, R^1′, R², R³ form a ring together with the hetero-atom to which they are bound, wherein the same is saturated or unsaturated, substituted or unsubstitued and wherein the chain may be interrupted by one or more hetero-atoms out of the group of O, S, NH or N—C₁-C₄-alkyl;

R⁴, R⁵, R⁶, R⁷, R⁸ stand, independently of each other, for hydrogen, halogen, nitro, cyano, OR^c, SR^c, NR^cR^d, COR_c, COOR^c, CO—NR^cR^d, C₁-C₃₀-alkyl, C₃-C₁₂-cycloalkyl, C₂-C₃₀-alkenyl, C₃-C₁₂-cycloalkenyl, aryl or heteroaryl, wherein the latter 6 moieties may comprise one or more halogenic moiety and/or 1 to 3 moieties selected out of the group of C₁-C₆-alkyl, aryl, heteroaryl, C₃-C₇-cycloalkyl, halogen, OR^c, SR^c, NR^cR^d, COR^c, COOR^c, CO—NR^cR^d, wherein R^c and R^d R^d stand, independently of each other, hydrogen, C₁-C₆-alkyl, C₁-C₆-halogenalkyl, cyclopentyl, cyclohexyl, phenyl, tolyl or benzyl; or

two of the moieties R, R⁴, R⁵, R⁶, R⁷, R⁸, which are neighbouring, form, together with an atom to which they are bound, a ring wherein the same is unsaturated or aromatic, unsubstituted or substituted, and wherein the chain formed by the respective moieties may be interrupted by one or more hetero-atoms out of the group of O, S, NH or N—C₁-C₄-alkyl;

R^e, R^f, R^g, R^h substituted, independently of each other, for hydrogen, C₁-C₆-alkyl, aryl-, heteroaryl-, C₃-C₇-cycloalkyl, halogen, OR^c, SR^c, NR^cR^d, COOR^c, CO—NR^cR^d or COR^c, wherein R^c, R^d stand, independently of each other, for hydrogen, C₁-C₆-alkyl, C₁-C₆-halogenalkyl, cyclopentyl, cyclohexyl, phenyl, tolyl or benzyl, however preferably for hydrogen, halogen, C₁-C₆-alkyl, in particular, hydrogen or C₁-C₆-alkyl.

[B]^a− is preferably:

fluoride; chloride; bromide; iodide; hexafluorophosphate; nitrite; nitrate; sulfate; hydrogen sulfate; carbonate; hydrogen carbonate; alkyl carbonate; aryl carbonate; phosphate; hydrogen phosphate; dihydrogen phosphate; tetra-substituted borate of the generic formula (Va)[BRⁱR^jR^kR^l]⁻ wherein Rⁱ to R^l stand, independently from each other, for an organic, saturated or unsaturated, acyclic or cyclic, aliphatic, aromatic or araliphatic moiety having 1 to 30 carbon atoms and which can comprise one or more hetero atoms and/or can be substituted by one or several functional groups or halogen, wherein the moiety comprises fluorine or a carbon;

organic sulfonate of the generic formula (Vb)[R^m—SO₃]⁻, wherein R^m stands for an organic, saturated or unsaturated, acyclic or cyclic, aliphatic, aromatic or araliphatic moiety having 1 to 30 carbon atoms and which can comprise one or more hetero atoms and/or can be substituted by one or several functional groups or halogen, wherein the moiety comprises a carbon;

organic sulfate of the generic formula (Vc)[R^m—SO₃]⁻, wherein R^m stands for an organic, saturated or unsaturated, acyclic or cyclic, aliphatic, aromatic or araliphatic moiety having 1 to 30 carbon atoms, and which can comprise one or more hetero atoms and/or can be substituted by one or several functional groups or halogen, wherein the moiety comprises a carbon;

carboxylate of the generic formula (Vd)[Rⁿ—COO]⁻, wherein Rⁿ stands for an organic, saturated or unsaturated, acyclic or cyclic, aliphatic, aromatic or araliphatic moiety having 1 to 30 carbon atoms and which can comprise one or more hetero atoms and/or can be substituted by one or several functional groups or halogen, wherein the moiety comprises hydrogen or a carbon;

(fluoroalkyl)fluorophosphate of the generic formula (Ve)[PF_x(C_yF_2y+1-zH_z)_6-x]⁻¹, wherein 1≦x≦6, 1≦y≦8 and 0≦z≦2y+1; or

imide of the generic formula (Vh)[R^o—SO₂—N—SO₂—R^p]⁻; or (Vg)[R^r—SO₂—N—CO—R^s]⁻; or (Vh)[R^t—CO—N—CO—R^u]⁻, wherein R^o to R^u, independently from each other, stand for an organic, saturated or unsaturated, acyclic or cyclic, aliphatic, aromatic or araliphatic moiety having 1 to 30 carbon atoms and which can comprise one or more hetero atoms and/or can be substituted by one or several functional groups or halogen, wherein the moiety comprises hydrogen or a carbon.

Organic phosphate of the generic formula (Vi)[R^m—OPO₄]²⁻, or (Vj)[R^m—OPO₂—ORⁿ]⁻, wherein R^m stands for an organic, saturated or unsaturated, acyclic or cyclic, aliphatic, aromatic or araliphatic moiety having 1 to 30 carbon atoms and which can comprise one or more hetero atoms and/or can be substituted by one or several functional groups or halogen, wherein the moiety comprises a carbon, and wherein Rⁿ stands for an organic, saturated or unsaturated, acyclic or cyclic, aliphatic, aromatic or araliphatic moiety having 1 to 30 carbon atoms and which can comprise one or more hetero atoms and/or can be substituted by one or several functional groups or halogen, wherein the moiety comprises hydrogen or a carbon.

The charge “a⁻” of the anion [B]^a− is “1-”, “2-”, or “3”. As examples for twofold negatively charged anions sulfate, hydrogen phosphate and carbonate are mentioned. As an example of a threefold negatively charged anion phosphate is mentioned.

As the moieties comprising carbon and being organic, saturated or unsaturated, acyclic or cyclic, aliphatic, aromatic or araliphatic moiety having 1 to 30 carbon atoms

Independently from each other, the moieties comprising carbon and being organic, saturated or unsaturated, acyclic or cyclic, aliphatic, aromatic or araliphatic moiety having 1 to 30 carbon atoms, i.e. the moieties Rⁱ to R^l at the tetrasubstituted borate (Va), the moiety R^m at the organic sulfonate (Vb) and sulphate (Vc), the moiety Rⁿ at the carboxylate (Vd) and the moieties R^o to R^u at the imides (Vf), (Vg) and (Vh), are formed preferably by:

C₁- to C₃₀-alkyl and their aryl-, heteroaryl-, cycloalkyl-, halogen-, hydroxyl-, amino-, carboxy-, formyl-, —O—, —CO—, —CO—O— or —CO—N< substituted components, like methyl, ethyl, 1-propyl, 2-propyl, 1-butyl, 2-butyl, 2-methyl-1-propyl (isobutyl), 2-methyl-2-propyl (tert.-butyl), 1-pentyl, 2-pentyl, 3-pentyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-2-butyl, 3-methyl-2-butyl, 2,2-dimethyl-1-propyl, 1-hexyl, 2-hexyl, 3-hexyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4-methyl-2-pentyl, 2-methyl-3-pentyl, 3-methyl-3-pentyl, 2,2-dimethyl-1-butyl, 2,3-dimethyl-1-butyl, 3,3-dimethyl-1-butyl, 2-ethyl-1-butyl, 2,3-dimethyl-2-butyl, 3,3-dimethyl-2-butyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, icosyl, henicosyl, docosyl, tricosyl, tetracosyl, pentacosyl, hexacosyl, heptacosyl, octacosyl, nonacosyl, triacontyl, phenylmethyl (benzyl), diphenylmethyl, triphenylmethyl, 2-phenylethyl, 3-phenylpropyl, cyclopentylmethyl, 2-cyclopentylethyl, 3-cyclopentylpropyl, cyclohexylmethyl, 2-cyclohexylethyl, 3-cyclohexylpropyl, methoxy, ethoxy, formyl, acetyl or C_nF_2(n-a)+(1-b)H_2a+b wherein n≦30, 0≦a≦n and b=0 or 1 (e.g. CF₃, C₂F₅, CH₂CH₂—C_(n-2)F_2(n-2)F_2(n-2)+1, C₆F₁₃, C₈F₁₇, C₁₀F₂₁, C₁₂F₂₅);

C₃- to C₁₂-cycloalkyl and their aryl-, heteroaryl-, cycloalkyl-, halogen-, hydroxy-, amino-, carboxy-, formyl-, —O—, —CO— or —CO—O-substituted components, e.g. cyclopentyl, 2-methyl-1-cyclopentyl, 3-methyl-1-cyclopentyl, cyclohexyl, 2-methyl-1-cyclohexyl, 3-methyl-1-cyclohexyl, 4-methyl-1-cyclohexyl or C_nF_2(n-a)-(1-b)H_2a-b wherein n≦30, 0≦a≦n and b=0 or 1;

C₂- to C₃₀-alkenyl and their aryl-, heteroaryl-, cycloalkyl-, halogen-, hydroxy-, amino-, carboxy-, formyl-, —O—, —CO— or —CO—O-substituted components, e.g. 2-propenyl, 3-butenyl, cis-2-butenyl, trans-2-butenyl or C_nF_2(n-a)-(1-b)H_2a-b wherein n≦30, 0≦a≦n and b=0 or 1;

C₃- to C₁₂-cycloalkenyl and their aryl-, heteroaryl-, cycloalkyl-, halogen-, hydroxy-, amino-, carboxy-, formyl-, —O—, —CO— or —CO—O— substituted components, e.g. 3-cyclopentenyl, 2-cyclohexenyl, 3-cyclohexenyl, 2,5-cyclohexadienyl or C_nF_{2(n-a)-3(1-b)}H_2a-3b wherein n≦30, 0≦a≦n and b=0 or 1; and

aryl or heteroaryl having 2 to 30 carbon atoms and their alkyl-, aryl-, heteroaryl-, cycloalkyl-, halogen-, hydroxy-, amino-, carboxy-, formyl-, —O—, —CO— or —CO—O-substituted components, e.g. phenyl, 2-methyl-phenyl (2-tolyl), 3-methyl-phenyl (3-tolyl), 4-methyl-phenyl, 2-ethyl-phenyl, 3-ethyl-phenyl, 4-ethyl-phenyl, 2,3-dimethyl-phenyl, 2,4-dimethyl-phenyl, 2,5-dimethyl-phenyl, 2,6-dimethyl-phenyl, 3,4-dimethyl-phenyl, 3,5-dimethyl-phenyl, 4-phenyl-phenyl, 1-naphthyl, 2-naphthyl, 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, 2-pyridinyl, 3-pyridinyl, 4-pyridinyl or C₆F_(5-a)H_a wherein 0≦a≦5.

In case the anion [B]^a− is a tetrasubstituted borate (Va)[BRⁱR^jR^kR^l]⁻ preferably all four moieties Rⁱ to R^l are identical, wherein they stand preferably for fluoride, trifluoromethyl, pentafluoroethyl, phenyl, 3,5-bis(trifluoromethyl)phenyl. Tetrasubstituted borate (Va) which are particularly preferred are tetrafluoroborate, tetraphenylborate and tetra[3,5-bis(trifluoromethyl)phenyl]borate.

In case the anion [B]^a− is an organic sulfonate (Vb)[R^m—SO₃]⁻ or sulfate (Vc)[R^m—OSO₃]⁻ the moiety R^m preferably denotes methyl, trifluoromethyl, pentafluoroethyl, p-tolyl or C₉F₁₉. Organic sulfonates (Vb) which are particularly preferred are trifluoromethansulfonate (triflate), methansulfonate, nonadecafluorononansulfonate (nonaflate) and p-toluolsulfonate; organic sulfates (Vc) which are particularly preferred are methylsulfate, ethylsulfate, n-propylsulfate, i-propylsulfate, butylsulfate, pentylsulfate, hexylsulfate, heptylsulfate, octylsulfate, nonylsulfate, decylsulfate as well as long chained n-alkylsulfates; benzylsulfate, alkylarylsulfate.

In case the anion [B]^a− is a carboxylate (Vd)[Rⁿ—COO]⁻ the moiety Rⁿ preferably stands for hydrogen, trifluoromethyl, pentafluoroethyl, phenyl, hydroxyl-phenyl-methyl, trichloromethyl, dichloromethyl, chloromethyl, trifluoromethyl, difluoromethyl, fluoromethyl or unbranched or branched C₁-C₁₂-alkyl, like methyl, ethyl, 1-propyl, 2-propyl, 1-butyl, 2-butyl, 2-methyl-1-propyl (isobutyl), 2-methyl-2-propyl (tert.-butyl), 1-pentyl, 2-pentyl, 3-pentyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-2-butyl, 3-methyl-2-butyl, 2,2-dimethyl-1-propyl, 1-hexyl, 2-hexyl, 3-hexyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4-methyl-2-pentyl, 2-methyl-3-pentyl, 3-methyl-3-pentyl, 2,2-dimethyl-1-butyl, 2,3-dimethyl-1-butyl, 3,3-dimethyl-1-butyl, 2-ethyl-1-butyl, 2,3-dimethyl-2-butyl, 3,3-dimethyl-2-butyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl. Carboxylates (Vc) which are particularly preferred are formate, acetate, propionate, butyrate, valeriate, benzoate, mandelate, trichloroacetate, dichloroacetate, chloroacetate, trifluoroacetate, difluoroacetate, fluoroacetate.

In case the anion [B]^a− is a (fluoroalkyl)fluorophosphate (Ve)[PF_x(C_yF_2y+1-zH_z)_6-x]⁻ z is preferably 0. (Fluoroalkyl)fluorophosphate (Ve) wherein z=0, x=3 and 1≦x≦4 in practice [PF₃(CF₃)₃]⁻, [PF₃(C₂F₅)₃]⁻, [PF₃(C₃F₇)₃]⁻ and [PF₃(C₄F₇)₃]⁻.

In case the anion [B]^a− is a imide (Vf)[R^o—SO₂—N—SO₂—R^p]⁻, (Vg)[R^r—SO₂—N—CO—R⁵]⁻, or (Vh)[R^t—CO—N—CO—R^u]⁻ the moieties R^o to R^u stand, independently from each other, for hydrogen, trifluoromethyl, pentafluoroethyl, phenyl, trichloromethyl, dichloromethyl, chloromethyl, trifluoromethyl, difluoromethyl, fluoromethyl or unbranched or branched C₁- to C₁₂-alkyl, like methyl, ethyl, 1-propyl, 2-propyl, 1-butyl, 2-butyl, 2-methyl-1-propyl (isobutyl), 2-methyl-2-propyl (tert.-butyl), 1-pentyl, 2-pentyl, 3-pentyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-2-butyl, 3-methyl-2-butyl, 2,2-dimethyl-1-propyl, 1-hexyl, 2-hexyl, 3-hexyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4-methyl-2-pentyl, 2-methyl-3-pentyl, 3-methyl-3-pentyl, 2,2-dimethyl-1-butyl, 2,3-dimethyl-1-butyl, 3,3-dimethyl-1-butyl, 2-ethyl-1-butyl, 2,3-dimethyl-2-butyl, 3,3-dimethyl-2-butyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl. Imides (Vf), (Vg) and (Vh) which are particularly preferred are [F₃C—SO₂—N—SO₂—CF₃]⁻, [F₃C—SO₂—N—CO—CF₃]⁻, F₃C—CO—N—CO—CF₃]⁻ and those wherein the moieties R^o to R^u, independently from each other, stand for, hydrogen, methyl, ethyl, propyl, butyl, trochloromethyl, dichloromethyl, chloromethyl, trifluoremethyl, difluororomethyl or fluoromethyl.

It is pointed out that the embodiments of the invention were described and will be described in the following with reference to different matters of the invention. In particular, some of the embodiments of the invention are described with device claims, and other embodiments are described with method claims or use claims. When studying this application it will immediately become clear that, as long it is not explicitly described to the different, in addition to a combination of features, which belong to one type of the matter of the invention, also arbitrarily combinations of features are possible, which belong to different types of subject-matters of the invention.

Claims

1. A tobacco product filter comprising a carrier material which comprises an immobilized ionic liquid.

2. The tobacco product filter according to claim 1, wherein the carrier material of the tobacco product filter has a large internal surface.

3. The tobacco product filter according to claim 2, wherein the carrier material has a structure selected out of the group consisting of:

porous structures,

sponge like structures,

fibrous structures,

powdery,

grained structures,

membrane like structures, and

foil like structures.

4. The tobacco product filter according to any one of the claim 1, wherein the carrier material comprises at least one material selected out of the group consisting of:

activated charcoal,

charcoal,

stone, in particular limestone, coralline rubble or pumice stone,

zeolite,

silica gel,

ceramic,

aluminum oxide,

plastics, in particular polyethylene,

glass fibers,

mineral wool,

paper,

cellulose,

cellulose acetate, and

meerschaum.

5. The tobacco product filter according to claim 1, wherein the ionic liquid has a melting point of less than 200° C.

6. The tobacco product filter according to claim 1, wherein the ionic liquid corresponds to the generic formula ([A]+)a[B]a−.

7. The tobacco product filter according to claim 6, wherein [A]+ stands for a toxicologically harmless cation which is in particular selected from the group which consists of the following cations:

cations having short alkyl side chains,

cations having polar functional groups in the side chains, and

natural cations.

8. The tobacco product filter according to claim 6, wherein [B]a− stands for a toxicologically harmless anion, in particular a natural anion.

9. The tobacco product filter according to claim 6, wherein [A]+ stands for a quaternary ammonium cation [R1′R1R2R3N]+, a phosphonium cation [R1′R1R2R3P]+, sulfonium cation [R1′R1R2S]+ or a hetero aromatic cation

10. A method of removing harmful substances from tobacco smoke, the method comprising:

providing a tobacco product filter according to claim 1,

conducting tobacco product smoke through the tobacco product filter.

11. Use of a filter, which comprises a substrate having an immobilized ionic liquid, for removing of harmful substances out of tobacco product smoke.