CA2565112C - Selective filtration of cigarette smoke using chitosan derivatives - Google Patents
Selective filtration of cigarette smoke using chitosan derivatives Download PDFInfo
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- CA2565112C CA2565112C CA2565112A CA2565112A CA2565112C CA 2565112 C CA2565112 C CA 2565112C CA 2565112 A CA2565112 A CA 2565112A CA 2565112 A CA2565112 A CA 2565112A CA 2565112 C CA2565112 C CA 2565112C
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- A—HUMAN NECESSITIES
- A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
- A24D—CIGARS; CIGARETTES; TOBACCO SMOKE FILTERS; MOUTHPIECES FOR CIGARS OR CIGARETTES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES
- A24D3/00—Tobacco smoke filters, e.g. filter-tips, filtering inserts; Filters specially adapted for simulated smoking devices; Mouthpieces for cigars or cigarettes
- A24D3/06—Use of materials for tobacco smoke filters
- A24D3/08—Use of materials for tobacco smoke filters of organic materials as carrier or major constituent
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- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
- Cigarettes, Filters, And Manufacturing Of Filters (AREA)
- Filtering Materials (AREA)
Abstract
A smoking article filter having a porous resin with a high surface area to mass ratio comprised of a chitosan derivative. PreferedPreferred embodiments include chitosan cross-linked with glutaraldehyde and chitosan cross-linked with glyoxal. The chitosan derivative provides for the selective filtration of cigarette smoke, particularly for the removal of aldehydes, hydrogen cyanide, heavy metals and carbonyls.
Description
SELECTIVE FILTRATION OF CIGARETTE SMOKE
USING CHITOSAN DERIVATIVES
FIELD OF INVENTION
This invention concerns improvements relating to tobacco smoke filers. More particularly, the invention relates to a cigarette filter that can selectively remove undesirable constituents from tobacco smoke.
BACKGROUND OF THE INVENTION
A wide variety of materials have been suggested in the prior art as filters for tobacco smoke. Examples of such filter materials include cotton, paper, cellulose acetate, and certain synthetics. Many of these filter materials, however, are only effective in the removal of particulates, tars and condensable components from tobacco smoke. The art is replete with a myriad of filtration techniques and materials for removing undesirable components in smoke and for causing other reactions as the smoke passes through filtration beds or other reactive media. Among the problems encountered with prior filters has been the plugging or clogging with use and the consumption or rendering ineffective of reactive filtering surfaces and materials.
Filters made from filamentary or fibrous material such as cellulose acetate tow or paper are somewhat effective in the removal of particulate phase constituents of tobacco smoke. However, they have little or no effect in removing certain gaseous components in the vapor phase of the tobacco smoke such as hydrogen cyanide, aldehydes, carbonyls, metals and sulphides. These volatile constituents can be removed by adsorption and absorption on a suitable surface or by chemical reaction.
Some known substances which act as absorbents and adsorbents include activated carbon, porous minerals, and ion exchange resins. Ion-exchange resins of porous structure have been found to be somewhat effective, but their efficiency diminishes during smoking, as does that of carbon and porous minerals. This may be due to the material becoming saturated and, therefore, increasingly inactive or it may be due to the release of adsorbed material by thermal desorption of retained substances.
Resins which contain major proportions of tertiary amino or quaternary ammonium groups have been found not to be suitable for removing aldehydes from tobacco smoke.
USING CHITOSAN DERIVATIVES
FIELD OF INVENTION
This invention concerns improvements relating to tobacco smoke filers. More particularly, the invention relates to a cigarette filter that can selectively remove undesirable constituents from tobacco smoke.
BACKGROUND OF THE INVENTION
A wide variety of materials have been suggested in the prior art as filters for tobacco smoke. Examples of such filter materials include cotton, paper, cellulose acetate, and certain synthetics. Many of these filter materials, however, are only effective in the removal of particulates, tars and condensable components from tobacco smoke. The art is replete with a myriad of filtration techniques and materials for removing undesirable components in smoke and for causing other reactions as the smoke passes through filtration beds or other reactive media. Among the problems encountered with prior filters has been the plugging or clogging with use and the consumption or rendering ineffective of reactive filtering surfaces and materials.
Filters made from filamentary or fibrous material such as cellulose acetate tow or paper are somewhat effective in the removal of particulate phase constituents of tobacco smoke. However, they have little or no effect in removing certain gaseous components in the vapor phase of the tobacco smoke such as hydrogen cyanide, aldehydes, carbonyls, metals and sulphides. These volatile constituents can be removed by adsorption and absorption on a suitable surface or by chemical reaction.
Some known substances which act as absorbents and adsorbents include activated carbon, porous minerals, and ion exchange resins. Ion-exchange resins of porous structure have been found to be somewhat effective, but their efficiency diminishes during smoking, as does that of carbon and porous minerals. This may be due to the material becoming saturated and, therefore, increasingly inactive or it may be due to the release of adsorbed material by thermal desorption of retained substances.
Resins which contain major proportions of tertiary amino or quaternary ammonium groups have been found not to be suitable for removing aldehydes from tobacco smoke.
Chitosan and chitosan with a maximum number of amino groups have been found not to be effective. Among the problems encountered with these materials is that they do not provide a filtration media allowing for the continuous flow of smoke at a low pressure differential or gradient. Other problems with selective filtration medias have been found. For example, the use of certain amino acids, such as glycine, have been found effective in removing aldehydes in tobacco smoke. However, it has been discovered that while glycine can reduce the level of formaldehyde in tobacco smoke, it is not stable in the cigarette filter manufacturing process.
Moreover, the use of amino acids causes the release of ammonia odor during storage.
SUMMARY OF THE INVENTION
It has been discovered that chitosan can be chemically modified to have the physical attributes of a filter medium and have a chemical composition capable of effectively adsorbing and absorbing undesirable smoke ingredients, yielding superior performance as a cigarette filter.
Thus, the present invention provides cigarette filter arrangements and, more particularly, cigarette filters that can selectively remove undesirable constituents in the vapor phase of tobacco smoke such as hydrogen cyanide, aldehydes, metals and sulphides without the drawbacks or disadvantages associated with the prior art as previously described.
There is also provided a novel cigarette and smoke filter embodying a porous resin of cross-linked chitosan.
There is also provided cross-linked chitosan reactive materials having a high ratio of surface-to-volume and having a reduced number of reactive amino groups for selective smoke filtration in a smoking article.
According to the present invention, a tobacco-smoke filter includes an adsorbent/ absorbent for removal of undesirable volatile tobacco-smoke constituents such as hydrogen cyanide, aldehydes, carbonyls, metals and sulphides.
Chitosan is cross-linked with glyoxal to form porous resins having a high surface area to mass ratio for the selective filtration of cigarette smoke, particularly for the removal of undesirable smoke constituents such as aldehydes, hydrogen cyanide, carbonyls, sulphides and metals.
Chitosan is a linear polyglucosamine polymer obtained from the deacetylation of chitin, a polysaccharide found in the exoskeleton of crustaceans. Chitin also occurs in insects and in lesser quantities in many other animal and vegetable organisms.
Chitin is a linear polymer of 2-deoxy, 2-acetyl-amino glucose analogous to cellulose in chemical structure. It is insoluble in almost all media except strong mineral acids and due to the acetylated amino group is relatively unreactive.
When chitin is deacetylated by treatment with strong alkalis, the product is chitosan which contains one free amino group for each glucose building unit in the polymer. It is still a long chain linear polymer but is now a highly reactive cationic poly-electrolyte material. It will form salts with simple organic acids, such as formic, acetic, tartaric, citric, etc. and is soluble in dilute aqueous solutions of such substances. Chitosan is nontoxic and biodegradable, and it has found utility in numerous applications, including chromatography, drug delivery, and cosmetics.
A porous chitosan resin may be formed by a phase inversion technique. This is accomplished by dissolving flaked or powdered chitosan in a suitable solvent, such as aqueous acid, and then coacervating in a solution of aqueous base to form water swollen chitosan gel beads. The beads may be cross-linked using glyoxal, to improve the mechanical strength and reduce the solubility of the beads. The wet beads are then freeze dried to yield a porous cross-linked resin. Drying may also be accomplished by vacuum or air drying.
A porous resin may also be prepared using a thermally induced phase separation technique. This is accomplished by dissolving flaked or powdered chitosan in a suitable solvent, such as aqueous acetic acid, and then adding the solution to a non-solvent, such as methanol, and cooling the resulting solution below the freezing point of the chitosan solution which yields frozen beads. These beads may then be neutralized with a base and cross-linked with glutaraldehyde and separately with glyoxal to modify the final properties of the chitosan resin. The resulting beads may then be freeze dried to yield a porous cross-linked chitosan resin. Drying may also be accomplished by vacuum and by air drying.
Moreover, the use of amino acids causes the release of ammonia odor during storage.
SUMMARY OF THE INVENTION
It has been discovered that chitosan can be chemically modified to have the physical attributes of a filter medium and have a chemical composition capable of effectively adsorbing and absorbing undesirable smoke ingredients, yielding superior performance as a cigarette filter.
Thus, the present invention provides cigarette filter arrangements and, more particularly, cigarette filters that can selectively remove undesirable constituents in the vapor phase of tobacco smoke such as hydrogen cyanide, aldehydes, metals and sulphides without the drawbacks or disadvantages associated with the prior art as previously described.
There is also provided a novel cigarette and smoke filter embodying a porous resin of cross-linked chitosan.
There is also provided cross-linked chitosan reactive materials having a high ratio of surface-to-volume and having a reduced number of reactive amino groups for selective smoke filtration in a smoking article.
According to the present invention, a tobacco-smoke filter includes an adsorbent/ absorbent for removal of undesirable volatile tobacco-smoke constituents such as hydrogen cyanide, aldehydes, carbonyls, metals and sulphides.
Chitosan is cross-linked with glyoxal to form porous resins having a high surface area to mass ratio for the selective filtration of cigarette smoke, particularly for the removal of undesirable smoke constituents such as aldehydes, hydrogen cyanide, carbonyls, sulphides and metals.
Chitosan is a linear polyglucosamine polymer obtained from the deacetylation of chitin, a polysaccharide found in the exoskeleton of crustaceans. Chitin also occurs in insects and in lesser quantities in many other animal and vegetable organisms.
Chitin is a linear polymer of 2-deoxy, 2-acetyl-amino glucose analogous to cellulose in chemical structure. It is insoluble in almost all media except strong mineral acids and due to the acetylated amino group is relatively unreactive.
When chitin is deacetylated by treatment with strong alkalis, the product is chitosan which contains one free amino group for each glucose building unit in the polymer. It is still a long chain linear polymer but is now a highly reactive cationic poly-electrolyte material. It will form salts with simple organic acids, such as formic, acetic, tartaric, citric, etc. and is soluble in dilute aqueous solutions of such substances. Chitosan is nontoxic and biodegradable, and it has found utility in numerous applications, including chromatography, drug delivery, and cosmetics.
A porous chitosan resin may be formed by a phase inversion technique. This is accomplished by dissolving flaked or powdered chitosan in a suitable solvent, such as aqueous acid, and then coacervating in a solution of aqueous base to form water swollen chitosan gel beads. The beads may be cross-linked using glyoxal, to improve the mechanical strength and reduce the solubility of the beads. The wet beads are then freeze dried to yield a porous cross-linked resin. Drying may also be accomplished by vacuum or air drying.
A porous resin may also be prepared using a thermally induced phase separation technique. This is accomplished by dissolving flaked or powdered chitosan in a suitable solvent, such as aqueous acetic acid, and then adding the solution to a non-solvent, such as methanol, and cooling the resulting solution below the freezing point of the chitosan solution which yields frozen beads. These beads may then be neutralized with a base and cross-linked with glutaraldehyde and separately with glyoxal to modify the final properties of the chitosan resin. The resulting beads may then be freeze dried to yield a porous cross-linked chitosan resin. Drying may also be accomplished by vacuum and by air drying.
The cross-linked resins produced by both methods have a reduced number of reactive amino groups. The reduced number of reactive amino groups is a result of the cross-linking reaction with glyoxal. It has been surprisingly discovered that the described invention, having a reduced number of reactive amino groups, is selective in removing hydrogen cyanide and formaldehyde from tobacco smoke. It has also been surprisingly found that the cross-linked chitosan resin having a reduced number of reactive amino groups exhibits greater selective removal activity than that associated with the prior art where a maximum number of reactive amino groups have been employed.
The porous resin of the present invention may be incorporated into a cigarette in a variety of ways. The resin may be disposed between filter sections wherein these sections may be comprised of fibrous, filamentary and paper materials. The resin may also be dispersed throughout a filter tow. Alternatively, the resin may be placed within a filter bed in a filter section and the resin may be packed along the filter bed.
The resin may also be incorporated into a part of the cigarette filter such as the tipping paper, a shaped paper insert, a plug, a space, or even a free-flow sleeve.
Additionally, the resin may be incorporated into cigarette filter paper, attached to the tobacco rod with tipping paper or even incorporated within a cavity in the filter.
Accordingly, the present invention provides a tobacco-smoke filter comprising a chitosan resin having chitosan cross-linked with glyoxal.
The present invention also provides a tobacco smoke filtration media obtained by the steps of. dissolving chitosan in a first solution having acetic acid in a range of about 0.1% to about 10% forming a second solution having chitosan in a range of about 0.1% to about 20%; filtering said second solution; adding said second solution drop-wise to a precipitation bath, wherein said precipitation bath has sodium hydroxide in a range of about I molar to about 5 molar, forming gel beads;
rinsing said gel beads; suspending said gel beads in a cross-linking solution containing a solvent and a cross-linking compound glyoxyl for about 1 hour to about 24 hours forming cross-linked beads; rinsing said cross-linked beads; and drying said cross-linked beads forming a porous chitosan crossed-linked resin bead.
The porous resin of the present invention may be incorporated into a cigarette in a variety of ways. The resin may be disposed between filter sections wherein these sections may be comprised of fibrous, filamentary and paper materials. The resin may also be dispersed throughout a filter tow. Alternatively, the resin may be placed within a filter bed in a filter section and the resin may be packed along the filter bed.
The resin may also be incorporated into a part of the cigarette filter such as the tipping paper, a shaped paper insert, a plug, a space, or even a free-flow sleeve.
Additionally, the resin may be incorporated into cigarette filter paper, attached to the tobacco rod with tipping paper or even incorporated within a cavity in the filter.
Accordingly, the present invention provides a tobacco-smoke filter comprising a chitosan resin having chitosan cross-linked with glyoxal.
The present invention also provides a tobacco smoke filtration media obtained by the steps of. dissolving chitosan in a first solution having acetic acid in a range of about 0.1% to about 10% forming a second solution having chitosan in a range of about 0.1% to about 20%; filtering said second solution; adding said second solution drop-wise to a precipitation bath, wherein said precipitation bath has sodium hydroxide in a range of about I molar to about 5 molar, forming gel beads;
rinsing said gel beads; suspending said gel beads in a cross-linking solution containing a solvent and a cross-linking compound glyoxyl for about 1 hour to about 24 hours forming cross-linked beads; rinsing said cross-linked beads; and drying said cross-linked beads forming a porous chitosan crossed-linked resin bead.
The present invention also provides a tobacco-smoke filter comprising in the range of about 10 mg to about 200 mg of a chitosan cross-linked with glyoxal resin, said resin having a size within the range of about 16 mesh to about 70 mesh.
The present invention also provides a tobacco-smoke filter comprising chitosan resin beads cross-linked with glyoxal, said cross-linked chitosan resin beads having a reduced number of reactive amino groups than said chitosan resin beads prior to cross-linking.
In a further aspect the present invention provides a method of smoke filtration comprising providing a smoking article filter having chitosan resin cross-linked with glyoxal, and passing smoke through said filter.
In a further aspect the present invention provides a method of fluid-flow filtration that comprises providing a filtration bed having chitosan resin cross-lined with glyoxal in said bed and passing fluid containing constituents through said filtration bed, wherein said fluid is cigarette smoke and said constituents comprise pyrolysis products of cigarette materials.
In a further aspect the present invention provides a method of removing from cigarette smoke pyrolysis products of cigarette materials comprising providing a filtration region having chitosan resin cross-linked with glyoxal disposed throughout the region and passing said pyrolysis products through said filtration region.
In a further aspect the present invention provides a method of manufacturing a filter which is useful for removing a gaseous component of a gas mixture, comprising steps of. preparing a filter media having a cross-linking compound glyoxal, wherein said cross-linking compound is cross-linked to chitosan forming a bead; and incorporating said filter media in a filter wherein said filter media removes said gaseous component of said gas mixture.
In a further aspect the present invention provides a method of removing a gaseous component of a gas mixture comprising passing said gas mixture in contact with a filter, wherein said filter has a reagent comprising at least one reactive functional group cross-linked to chitosan such that said reagent adsorbs, absorbs, or chemically reacts with said gaseous component of said gas mixture and removes said gaseous component from said gas mixture, wherein said functional group is glyoxal.
The present invention also provides a tobacco-smoke filter comprising chitosan resin beads cross-linked with glyoxal, said cross-linked chitosan resin beads having a reduced number of reactive amino groups than said chitosan resin beads prior to cross-linking.
In a further aspect the present invention provides a method of smoke filtration comprising providing a smoking article filter having chitosan resin cross-linked with glyoxal, and passing smoke through said filter.
In a further aspect the present invention provides a method of fluid-flow filtration that comprises providing a filtration bed having chitosan resin cross-lined with glyoxal in said bed and passing fluid containing constituents through said filtration bed, wherein said fluid is cigarette smoke and said constituents comprise pyrolysis products of cigarette materials.
In a further aspect the present invention provides a method of removing from cigarette smoke pyrolysis products of cigarette materials comprising providing a filtration region having chitosan resin cross-linked with glyoxal disposed throughout the region and passing said pyrolysis products through said filtration region.
In a further aspect the present invention provides a method of manufacturing a filter which is useful for removing a gaseous component of a gas mixture, comprising steps of. preparing a filter media having a cross-linking compound glyoxal, wherein said cross-linking compound is cross-linked to chitosan forming a bead; and incorporating said filter media in a filter wherein said filter media removes said gaseous component of said gas mixture.
In a further aspect the present invention provides a method of removing a gaseous component of a gas mixture comprising passing said gas mixture in contact with a filter, wherein said filter has a reagent comprising at least one reactive functional group cross-linked to chitosan such that said reagent adsorbs, absorbs, or chemically reacts with said gaseous component of said gas mixture and removes said gaseous component from said gas mixture, wherein said functional group is glyoxal.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Examples of the present invention are given below by way of illustration and not by way of limitation. These examples include two distinct methods of preparing chitosan beads as well as several distinct methods of cross-linking the chitosan beads.
All of the following examples yield porous cross-linked chitosan resin beads having a reduced number of reactive amino groups.
EXAMPLES
EXAMPLE 1:
Porous chitosan resin was synthesized according to a phase inversion technique. This was accomplished by preparing a 7% chitosan solution by dissolving approximately 20 grams of chitosan flakes (practical grade) in 3.5% acetic acid. The mixture increased in viscosity and gelled upon the completion of the chitosan addition. Further dilution with acetic acid resulted in a solution having approximately 3% chitosan flake. This provided for a chitosan solution having a more manageable viscosity. The total amount of acetic acid used to dissolve the chitosan flake was approximately 665 milliliters. The solution was then filtered to separate any undissolved materials. This chitosan solution was then added dropwise to a precipitation bath of 2 molar sodium hydroxide to yield water swollen gel beads. The gel beads were then filtered and washed with deionized water until neutral, pH
of the wash water being approximately 7.
6a Heterogeneous cross-linking of the chitosan beads was then accomplished by suspending the beads for several hours in approximately 1 liter of 2.5%
aqueous solution of glutaraldehyde. After cross-linking, the beads were then filtered and washed with warm deionized water to remove any excess glutaraldehyde. Subsequently, the beads were freeze dried which resulted in porous glutaraldehyde cross-linked chitosan resin beads. The BET
surface area of the resin was measured to be approximately 120 m2/g. The beads were then milled and sieved to retain particles having approximately 16 to 70 mesh. A
surface area analysis of the milled resin showed no appreciable change in surface area. The BET surface area of the sieved sample was measured to be approximately 117 m2/g.
EXAMPLE II:
Porous chitosan resin was synthesized according to the phase inversion technique in Example 1. In this example the heterogeneous cross-linking of the chitosan beads was accomplished by suspending the beads for several hours in a 2.5% aqueous solution of glyoxal. After cross-linking, the beads were filtered and washed with warm deionized water to remove any excess glyoxal. The beads were then freeze dried which resulted in porous glyoxal cross-linked chitosan resin beads.
EXAMPLE III:
Porous chitosan resin was prepared according to a thermally induced phase separation procedure. A 4% chitosan solution was prepared by dissolution of chitosan powder (Vansen Chemical; 92% deacetylation) in 3.5% acetic acid. A precipitation bath of sodium hydroxide (2 molar) in 20:80 methanol / water solution was prepared and cooled to 0 C.
The chitosan solution was then added dropwise to the precipitation bath with moderate stirring.
Precipitation of chitosan occurred shortly after addition of the solution to the precipitation bath. The precipitation bath having the chitosan precipitate was then allowed to return to room temperature. The resulting beads were filtered and washed with deionized water until the wash water became neutral, having a pH of approximately 7.
Heterogeneous cross-linking of the chitosan beads was then accomplished by suspending approximately 396 grams of wet beads in approximately 1980 milliliters of 2.5%
aqueous glutaraldehyde solution for several hours. After cross-linking, the beads were filtered and washed with both warm and cold deionized water to remove any excess glutaraldehyde. Subsequent freeze drying of the beads resulted in porous glutaraldehyde cross-linked chitosan resin beads. The beads were then milled and sieved to approximately 16 to 70 mesh. The BET surface area of the resin was measured to be approximately 210 m2/g.
EXAMPLE IV:
Porous chitosan resin was prepared according to the thermally induced phase separation procedure in Example III. In this example, the heterogeneous cross-linking of the chitosan beads was accomplished by suspending approximately 261 grams of wet beads in approximately 1300 milliliters of 2.5% aqueous glyoxal solution for several hours. After cross-linking, the beads were filtered and washed with both warm and cold deionized water to remove any excess glyoxal. Subsequent freeze drying resulted in porous glyoxal cross-linked chitosan resin beads. The beads were then milled and sieved to approximately 16 to 70 mesh. The BET surface area of the cross-linked resin was measured to be approximately 145 m 2/g.
EXAMPLE V :
Examples of the present invention are given below by way of illustration and not by way of limitation. These examples include two distinct methods of preparing chitosan beads as well as several distinct methods of cross-linking the chitosan beads.
All of the following examples yield porous cross-linked chitosan resin beads having a reduced number of reactive amino groups.
EXAMPLES
EXAMPLE 1:
Porous chitosan resin was synthesized according to a phase inversion technique. This was accomplished by preparing a 7% chitosan solution by dissolving approximately 20 grams of chitosan flakes (practical grade) in 3.5% acetic acid. The mixture increased in viscosity and gelled upon the completion of the chitosan addition. Further dilution with acetic acid resulted in a solution having approximately 3% chitosan flake. This provided for a chitosan solution having a more manageable viscosity. The total amount of acetic acid used to dissolve the chitosan flake was approximately 665 milliliters. The solution was then filtered to separate any undissolved materials. This chitosan solution was then added dropwise to a precipitation bath of 2 molar sodium hydroxide to yield water swollen gel beads. The gel beads were then filtered and washed with deionized water until neutral, pH
of the wash water being approximately 7.
6a Heterogeneous cross-linking of the chitosan beads was then accomplished by suspending the beads for several hours in approximately 1 liter of 2.5%
aqueous solution of glutaraldehyde. After cross-linking, the beads were then filtered and washed with warm deionized water to remove any excess glutaraldehyde. Subsequently, the beads were freeze dried which resulted in porous glutaraldehyde cross-linked chitosan resin beads. The BET
surface area of the resin was measured to be approximately 120 m2/g. The beads were then milled and sieved to retain particles having approximately 16 to 70 mesh. A
surface area analysis of the milled resin showed no appreciable change in surface area. The BET surface area of the sieved sample was measured to be approximately 117 m2/g.
EXAMPLE II:
Porous chitosan resin was synthesized according to the phase inversion technique in Example 1. In this example the heterogeneous cross-linking of the chitosan beads was accomplished by suspending the beads for several hours in a 2.5% aqueous solution of glyoxal. After cross-linking, the beads were filtered and washed with warm deionized water to remove any excess glyoxal. The beads were then freeze dried which resulted in porous glyoxal cross-linked chitosan resin beads.
EXAMPLE III:
Porous chitosan resin was prepared according to a thermally induced phase separation procedure. A 4% chitosan solution was prepared by dissolution of chitosan powder (Vansen Chemical; 92% deacetylation) in 3.5% acetic acid. A precipitation bath of sodium hydroxide (2 molar) in 20:80 methanol / water solution was prepared and cooled to 0 C.
The chitosan solution was then added dropwise to the precipitation bath with moderate stirring.
Precipitation of chitosan occurred shortly after addition of the solution to the precipitation bath. The precipitation bath having the chitosan precipitate was then allowed to return to room temperature. The resulting beads were filtered and washed with deionized water until the wash water became neutral, having a pH of approximately 7.
Heterogeneous cross-linking of the chitosan beads was then accomplished by suspending approximately 396 grams of wet beads in approximately 1980 milliliters of 2.5%
aqueous glutaraldehyde solution for several hours. After cross-linking, the beads were filtered and washed with both warm and cold deionized water to remove any excess glutaraldehyde. Subsequent freeze drying of the beads resulted in porous glutaraldehyde cross-linked chitosan resin beads. The beads were then milled and sieved to approximately 16 to 70 mesh. The BET surface area of the resin was measured to be approximately 210 m2/g.
EXAMPLE IV:
Porous chitosan resin was prepared according to the thermally induced phase separation procedure in Example III. In this example, the heterogeneous cross-linking of the chitosan beads was accomplished by suspending approximately 261 grams of wet beads in approximately 1300 milliliters of 2.5% aqueous glyoxal solution for several hours. After cross-linking, the beads were filtered and washed with both warm and cold deionized water to remove any excess glyoxal. Subsequent freeze drying resulted in porous glyoxal cross-linked chitosan resin beads. The beads were then milled and sieved to approximately 16 to 70 mesh. The BET surface area of the cross-linked resin was measured to be approximately 145 m 2/g.
EXAMPLE V :
Porous chitosan resin was prepared according to the thermally induced phase separation procedure in Example III. In this example, the heterogeneous cross-linking of the chitosan beads was accomplished by suspending the beads in a solution of glutaraldehyde and ethanol for several hours. After cross-linking, the beads were filtered and washed with ethanol to remove any excess glutaraldehyde. Subsequent vacuum drying resulted in porous glutaraldehyde cross-linked chitosan resin beads.
EXAMPLE VI:
Porous chitosan resin was prepared according to the thermally induced phase separation procedure in Example III. In this example, the heterogeneous cross-linking of the chitosan beads was accomplished by suspending the beads in a solution of glutaraldehyde and water for several hours. After cross-linking, the beads were filtered and washed with ethanol to remove any excess glutaraldehyde. Subsequent vacuum drying resulted in porous glutaraldehyde cross-linked chitosan resin beads.
Even though these examples specify amounts or concentrations of materials used in making several embodiments of the present invention, a wide range of concentrations and amounts of materials may be used to practice the present invention. For example, the crosslinker solution may be in a range of concentration of about 0.1 % to about 50%, the chitosan solution may be in a range of concentration of about 0.1% to about 20%, the acetic acid solution may be in a range of about 0.1% to about 10%, and the base solution may be in a range of about 1 to about 5 molar sodium hydroxide. Additionally, the range of hours for cross-linking reaction may be from about 1 hour to up to about 24 hours.
EXAMPLES OF USE
EXAMPLE VI:
Porous chitosan resin was prepared according to the thermally induced phase separation procedure in Example III. In this example, the heterogeneous cross-linking of the chitosan beads was accomplished by suspending the beads in a solution of glutaraldehyde and water for several hours. After cross-linking, the beads were filtered and washed with ethanol to remove any excess glutaraldehyde. Subsequent vacuum drying resulted in porous glutaraldehyde cross-linked chitosan resin beads.
Even though these examples specify amounts or concentrations of materials used in making several embodiments of the present invention, a wide range of concentrations and amounts of materials may be used to practice the present invention. For example, the crosslinker solution may be in a range of concentration of about 0.1 % to about 50%, the chitosan solution may be in a range of concentration of about 0.1% to about 20%, the acetic acid solution may be in a range of about 0.1% to about 10%, and the base solution may be in a range of about 1 to about 5 molar sodium hydroxide. Additionally, the range of hours for cross-linking reaction may be from about 1 hour to up to about 24 hours.
EXAMPLES OF USE
A cigarette typically contains two sections, a tobacco-containing portion sometimes referred to as the tobacco or cigarette rod, and a filter portion which may be referred to as the filter tipping. A cigarette sample with a cavity filter was prepared by removing the existing filter on a cigarette made by standard production techniques, and replacing with a filter tipping having a cellulose acetate section at the tobacco end of the filter and a cellulose acetate section at the mouth end of the filter leaving a middle cavity. Sample sets of semolina (an inert filler material), chitosan resin synthesized by phase inversion technique and cross-linked with glutaraldehyde (Ex. I), chitosan resin synthesized by the thermally induced phase separation procedure and cross-linked with glutaraldehyde (Ex. III), chitosan resin synthesized by the thermally induced phase separation procedure and cross-linked with glyoxal (Ex. IV), chitosan resin synthesized by the thermally induced phase separation procedure and cross-linked with glutaraldehyde in ethanol, washed with ethanol, and vacuum dried (Ex. V), and chitosan resin synthesized by the thermally induced phase separation procedure and cross-linked with glutaraldehyde in water, washed with ethanol, and vacuum dried (Ex. VI), were prepared using a 50 mg sample load in the middle cavity of the filter tipping. This loading was consistent for each sample to provide comparable results. Resin loading in a filter of the present invention may be in a range of about 10 mg to about 200 mg.
Each sample was pressure drop selected to minimize smoke delivery variances.
Several tests were conducted to determine the ability of the cigarette filter of the present invention to remove undesirable constituents from tobacco smoke as compared to conventional devices. The tests measured the amount of undesirable constituents removed from the mainstream smoke after the cigarette was fully smoked. The following data sets illustrate the performance achieved in the filtration of volatile constituents of tobacco smoke for each of the preferred embodiments as compared to the control material, semolina.
Analytical results are reported on the vapor phase and whole smoke analyses as indicated in the following tables. Percent reduction refers to the difference, in %, between the amount of the analyte measured in the vapor phase or whole mainstream smoke of cigarettes having filter tipping containing semolina and chitosan resin.
Vapor Phase Smoke Analysis for Chitosan Resin Prepared by Phase Inversion Technique Ex. I
Percent Reduction (%) Analyte Chitosan cross-linked with glutaraldehyde Ex. I
Hydrogen Cyanide 49 Acetaldehyde 10 Acetonitrile 11 Acrolein 15 Propionaldehyde 11 Acetone 7 Methyl Ethyl Ketone + Butyraldehyde 16 Crotonaldehyde 13 Whole Smoke Hydrogen Cyanide Analysis for Chitosan Resin Prepared by Phase Inversion Technique [Ex. I]
Percent Reduction (%) Analyte Chitosan cross-linked with glutaraldehyde Ex. I
Hydrogen Cyanide 41 Whole Smoke Carbonyl Analysis for Chitosan Resin Prepared by Phase Inversion Technique Ex. I
Percent Reduction (%) Chitosan cross-linked with glutaraldehyde Ex. I
Formaldehyde 36 Acetaldehyde 13 Acetone 5 Acrolein 11 Propionaldehyde 16 Crotonaldehyde 9 Butyraldehyde 17 Vapor Phase Smoke Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Exs. III-IVi Percent Reduction (%) Chitosan cross-linked with Chitosan cross-linked with glutaraldehyde glyoxal Ex. III Ex IV
Acetaldehyde 13 31 Acetone 21 30 Acetonitrile 18 26 Acrolein 29 36 Acrylonitrile 21 29 Crotonaldehyde 7 42 Hydrogen cyanide 60 45 Methyl ethyl ketone 21 29 Propionaldehyde 23 36 i-Butyraldehyde 27 35 n-Butyraldehyde 27 40 Whole Smoke Hydrogen Cyanide Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Exs. III-IV]
Percent Reduction (%) Chitosan cross-linked with Chitosan cross-linked with glutaraldehyde glyoxal Ex. III Ex IV
Hydrogen cyanide 54 29 Whole Smoke Carbonyl Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Exs. III-IV]
Percent Reduction (%) Chitosan cross-linked with Chitosan cross-linked with glutaraldehyde glyoxal Ex. III Ex IV
Acetaldehyde 1 2 Acetone 5 0 Acrolein 10 3 Butyraldehyde 14 8 Crotonaldehyde 20 9 Formaldehyde 50 46 Propionaldehyde 17 19 Whole Smoke Trace Metals Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Exs. III-IV]
Percent Reduction (%) Chitosan cross-linked with Chitosan cross-linked with glutaraldehyde glyoxal Ex. III Ex IV
Cadmium 32 38 Vapor Phase Smoke Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Ex. VI
Percent Reduction (%) Chitosan cross-linked with glutaraldehyde Ex. V
Acetaldehyde 9 Acetone 6 Acetonitrile 3 Acrolein 13 Crotonaldehyde 7 Hydrogen Cyanide 36 Methyl Ethyl Ketone 6 Propionaldehyde 11 i-Butyraldehyde 9 n-Butyraldehyde 10 Whole Smoke Hydrogen Cyanide Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Ex. V1 Percent Reduction (%) Chitosan cross-linked with glutaraldehyde Ex. V
Hydrogen Cyanide 27 Whole Smoke Carbonyl Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Ex. V1 Percent Reduction (%) Chitosan cross-linked with glutaraldehyde Ex. V
Acetonitrile 3 Acetaldehyde 27 Acetone 24 Acrolein 32 Butyraldehyde 41 Crotonaldehyde 30 Formaldehyde 58 Propionaldehyde 33 Whole Smoke Trace Metals Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Ex. VI
Percent Reduction (%) Chitosan cross-linked with glutaraldehyde Ex. V
Cadmium 38 Vapor Phase Smoke Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Ex. VIl Percent Reduction (%) Chitosan cross-linked with glutaraldehyde Ex. VI
Acetaldehyde 3 Acetone 4 Acrolein 9 Crotonaldehyde 11 Hydrogen Cyanide 30 Methyl Ethyl Ketone 11 Propionaldehyde 6 i-Butyraldehyde 7 n-Butyraldehyde 11 Whole Smoke Hydrogen Cyanide Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Ex. VI]
Percent Reduction (%) Chitosan cross-linked with glutaraldehyde Ex. VI
Hydrogen Cyanide 30 Whole Smoke Carbonyl Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Ex. VII
Percent Reduction (%) Chitosan cross-linked with glutaraldehyde Ex. VI
Acetaldehyde 0 Acetone 0 Acrolein 0 Butanone 1 Butyraldehyde 14 Crotonaldehyde 36 Formaldehyde 37 Propionaldehyde 0 Whole Smoke Trace Metals Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Ex. VII
Percent Reduction (%) Chitosan cross-linked with glutaraldehyde Ex. VI
Cadmium 26 The data surprisingly showed the cross-linked chitosan resin described in this invention is selective in removing aldehydes and hydrogen cyanide in cigarette smoke compared to the inert semolina control. The glutaraldehyde cross-linked chitosan resin reduced the vapor phase delivery of hydrogen cyanide by 60% versus a control sample (Ex.
III). In a separate test, non-crosslinked ground chitosan particles showed no effect on the vapor phase hydrogen cyanide delivery. The glutaraldehyde cross-linked chitosan resin also decreased whole smoke hydrogen cyanide delivery by 54%, and mainstream whole smoke formaldehyde delivery was decreased by 50% compared to the control sample (Ex.
III).
While the invention has been described with reference to preferred embodiments, it is to be understood that variations and modifications may be resorted to as will be apparent to those skilled in the art. Such variations and modifications are to be considered within the purview and scope of the invention as defined by the claims appended hereto.
Each sample was pressure drop selected to minimize smoke delivery variances.
Several tests were conducted to determine the ability of the cigarette filter of the present invention to remove undesirable constituents from tobacco smoke as compared to conventional devices. The tests measured the amount of undesirable constituents removed from the mainstream smoke after the cigarette was fully smoked. The following data sets illustrate the performance achieved in the filtration of volatile constituents of tobacco smoke for each of the preferred embodiments as compared to the control material, semolina.
Analytical results are reported on the vapor phase and whole smoke analyses as indicated in the following tables. Percent reduction refers to the difference, in %, between the amount of the analyte measured in the vapor phase or whole mainstream smoke of cigarettes having filter tipping containing semolina and chitosan resin.
Vapor Phase Smoke Analysis for Chitosan Resin Prepared by Phase Inversion Technique Ex. I
Percent Reduction (%) Analyte Chitosan cross-linked with glutaraldehyde Ex. I
Hydrogen Cyanide 49 Acetaldehyde 10 Acetonitrile 11 Acrolein 15 Propionaldehyde 11 Acetone 7 Methyl Ethyl Ketone + Butyraldehyde 16 Crotonaldehyde 13 Whole Smoke Hydrogen Cyanide Analysis for Chitosan Resin Prepared by Phase Inversion Technique [Ex. I]
Percent Reduction (%) Analyte Chitosan cross-linked with glutaraldehyde Ex. I
Hydrogen Cyanide 41 Whole Smoke Carbonyl Analysis for Chitosan Resin Prepared by Phase Inversion Technique Ex. I
Percent Reduction (%) Chitosan cross-linked with glutaraldehyde Ex. I
Formaldehyde 36 Acetaldehyde 13 Acetone 5 Acrolein 11 Propionaldehyde 16 Crotonaldehyde 9 Butyraldehyde 17 Vapor Phase Smoke Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Exs. III-IVi Percent Reduction (%) Chitosan cross-linked with Chitosan cross-linked with glutaraldehyde glyoxal Ex. III Ex IV
Acetaldehyde 13 31 Acetone 21 30 Acetonitrile 18 26 Acrolein 29 36 Acrylonitrile 21 29 Crotonaldehyde 7 42 Hydrogen cyanide 60 45 Methyl ethyl ketone 21 29 Propionaldehyde 23 36 i-Butyraldehyde 27 35 n-Butyraldehyde 27 40 Whole Smoke Hydrogen Cyanide Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Exs. III-IV]
Percent Reduction (%) Chitosan cross-linked with Chitosan cross-linked with glutaraldehyde glyoxal Ex. III Ex IV
Hydrogen cyanide 54 29 Whole Smoke Carbonyl Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Exs. III-IV]
Percent Reduction (%) Chitosan cross-linked with Chitosan cross-linked with glutaraldehyde glyoxal Ex. III Ex IV
Acetaldehyde 1 2 Acetone 5 0 Acrolein 10 3 Butyraldehyde 14 8 Crotonaldehyde 20 9 Formaldehyde 50 46 Propionaldehyde 17 19 Whole Smoke Trace Metals Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Exs. III-IV]
Percent Reduction (%) Chitosan cross-linked with Chitosan cross-linked with glutaraldehyde glyoxal Ex. III Ex IV
Cadmium 32 38 Vapor Phase Smoke Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Ex. VI
Percent Reduction (%) Chitosan cross-linked with glutaraldehyde Ex. V
Acetaldehyde 9 Acetone 6 Acetonitrile 3 Acrolein 13 Crotonaldehyde 7 Hydrogen Cyanide 36 Methyl Ethyl Ketone 6 Propionaldehyde 11 i-Butyraldehyde 9 n-Butyraldehyde 10 Whole Smoke Hydrogen Cyanide Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Ex. V1 Percent Reduction (%) Chitosan cross-linked with glutaraldehyde Ex. V
Hydrogen Cyanide 27 Whole Smoke Carbonyl Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Ex. V1 Percent Reduction (%) Chitosan cross-linked with glutaraldehyde Ex. V
Acetonitrile 3 Acetaldehyde 27 Acetone 24 Acrolein 32 Butyraldehyde 41 Crotonaldehyde 30 Formaldehyde 58 Propionaldehyde 33 Whole Smoke Trace Metals Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Ex. VI
Percent Reduction (%) Chitosan cross-linked with glutaraldehyde Ex. V
Cadmium 38 Vapor Phase Smoke Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Ex. VIl Percent Reduction (%) Chitosan cross-linked with glutaraldehyde Ex. VI
Acetaldehyde 3 Acetone 4 Acrolein 9 Crotonaldehyde 11 Hydrogen Cyanide 30 Methyl Ethyl Ketone 11 Propionaldehyde 6 i-Butyraldehyde 7 n-Butyraldehyde 11 Whole Smoke Hydrogen Cyanide Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Ex. VI]
Percent Reduction (%) Chitosan cross-linked with glutaraldehyde Ex. VI
Hydrogen Cyanide 30 Whole Smoke Carbonyl Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Ex. VII
Percent Reduction (%) Chitosan cross-linked with glutaraldehyde Ex. VI
Acetaldehyde 0 Acetone 0 Acrolein 0 Butanone 1 Butyraldehyde 14 Crotonaldehyde 36 Formaldehyde 37 Propionaldehyde 0 Whole Smoke Trace Metals Analysis for Chitosan Resin Prepared by Thermally Induced Phase Separation [Ex. VII
Percent Reduction (%) Chitosan cross-linked with glutaraldehyde Ex. VI
Cadmium 26 The data surprisingly showed the cross-linked chitosan resin described in this invention is selective in removing aldehydes and hydrogen cyanide in cigarette smoke compared to the inert semolina control. The glutaraldehyde cross-linked chitosan resin reduced the vapor phase delivery of hydrogen cyanide by 60% versus a control sample (Ex.
III). In a separate test, non-crosslinked ground chitosan particles showed no effect on the vapor phase hydrogen cyanide delivery. The glutaraldehyde cross-linked chitosan resin also decreased whole smoke hydrogen cyanide delivery by 54%, and mainstream whole smoke formaldehyde delivery was decreased by 50% compared to the control sample (Ex.
III).
While the invention has been described with reference to preferred embodiments, it is to be understood that variations and modifications may be resorted to as will be apparent to those skilled in the art. Such variations and modifications are to be considered within the purview and scope of the invention as defined by the claims appended hereto.
Claims (20)
- Claim 1. A tobacco-smoke filter comprising a chitosan resin having chitosan cross-linked with glyoxal.
- Claim 2. The tobacco-smoke filter according to Claim 1, wherein said resin is in particulate form within a size range of approximately 17 mesh to approximately 70 mesh.
- Claim 3. The tobacco-smoke cigarette filter according to Claim 1, wherein said resin comprises milled particles.
- Claim 4. The tobacco-smoke filter according to Claim 1, wherein said tobacco smoke filter has said resin present in a range from about 10 mg to about 200 mg.
- Claim 5. The tobacco-smoke filter according to Claim 1, wherein said resin is in particulate form and is disposed between filter sections, said filter sections having materials comprising one of a fibrous material, a filamentary material, a paper material, and combinations thereof.
- Claim 6. The tobacco-smoke filter according to Claim 1, wherein said resin is in particulate form and is dispersed in a filter tow.
- Claim 7. A method of smoke filtration comprising providing a smoking article filter having chitosan resin cross-linked with glyoxal, and passing smoke through said filter.
- Claim 8. A method of fluid-flow filtration that comprises providing a filtration bed having chitosan resin cross-lined with glyoxal in said bed and passing fluid containing constituents through said filtration bed, wherein said fluid is cigarette smoke and said constituents comprise pyrolysis products of cigarette materials.
- Claim 9. A method of removing from cigarette smoke pyrolysis products of cigarette materials comprising providing a filtration region having chitosan resin cross-linked with glyoxal disposed throughout the region and passing said pyrolysis products through said filtration region.
- Claim 10. A tobacco smoke filtration media obtained by the steps of.
dissolving chitosan in a first solution having acetic acid in a range of about 0.1 % to about 10% forming a second solution having chitosan in a range of about 0.1 % to about 20%;
filtering said second solution;
adding said second solution drop-wise to a precipitation bath, wherein said precipitation bath has sodium hydroxide in a range of about 1 molar to about 5 molar, forming gel beads;
rinsing said gel beads;
suspending said gel beads in a cross-linking solution containing a solvent and a cross-linking compound glyoxyl for about 1 hour to about 24 hours forming cross-linked beads;
rinsing said cross-linked beads; and drying said cross-linked beads forming a porous chitosan crossed-linked resin bead. - Claim 11. A tobacco-smoke filter comprising in the range of about 10 mg to about 200 mg of a chitosan cross-linked with glyoxal resin, said resin having a size within the range of about 16 mesh to about 70 mesh.
- Claim 12. The tobacco-smoke filter according to Claim 11, wherein said filter is attached to a tobacco rod by tipping paper.
- Claim 13. The tobacco-smoke filter according to Claim 11, wherein said resin is incorporated in at least one cigarette filter part comprising one of a tipping paper, a shaped paper insert, a plug, a space, and a free-flow sleeve.
- Claim 14. The tobacco-smoke filter according to Claim 11, wherein said resin is incorporated in a cigarette filter paper.
- Claim 15. A method of manufacturing a filter which is useful for removing a gaseous component of a gas mixture, comprising steps of:
preparing a filter media having a cross-linking compound glyoxal, wherein said cross-linking compound is cross-linked to chitosan forming a bead; and incorporating said filter media in a filter wherein said filter media removes said gaseous component of said gas mixture. - Claim 16. The method according to Claim 15, further comprising attaching said filter to a tobacco rod with tipping paper.
- Claim 17. The method according to Claim 15, wherein said filter media is incorporated in at least one cigarette filter part comprising one of a tipping paper, a shaped paper insert, a plug, a space, and a free-flow sleeve.
- Claim 18. A method of removing a gaseous component of a gas mixture comprising passing said gas mixture in contact with a filter, wherein said filter has a reagent comprising at least one reactive functional group cross-linked to chitosan such that said reagent adsorbs, absorbs, or chemically reacts with said gaseous component of said gas mixture and removes said gaseous component from said gas mixture, wherein said functional group is glyoxal.
- Claim 19. The method according to claim 18, further comprising steps of generating said gas mixture and directing a gas stream containing said gas mixture through said filter such that said component of said gas mixture to be removed is adsorbed, absorbed, or chemically reacted with said reagent and prevented from reentering said gas stream.
- Claim 20. A tobacco-smoke filter comprising chitosan resin beads cross-linked with glyoxal, said cross-linked chitosan resin beads having a reduced number of reactive amino groups than said chitosan resin beads prior to cross-linking.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US10/842,165 US20050247323A1 (en) | 2004-05-10 | 2004-05-10 | Selective filtration of cigarette smoke using chitosan derivatives |
| US10/842,165 | 2004-05-10 | ||
| PCT/US2005/014476 WO2005112671A1 (en) | 2004-05-10 | 2005-04-27 | Selective filtration of cigarette smoke using chitosan derivatives |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2565112A1 CA2565112A1 (en) | 2005-12-01 |
| CA2565112C true CA2565112C (en) | 2011-11-01 |
Family
ID=34967401
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2565112A Expired - Fee Related CA2565112C (en) | 2004-05-10 | 2005-04-27 | Selective filtration of cigarette smoke using chitosan derivatives |
Country Status (12)
| Country | Link |
|---|---|
| US (2) | US20050247323A1 (en) |
| EP (2) | EP2510815A3 (en) |
| JP (1) | JP4547422B2 (en) |
| CN (1) | CN101043826A (en) |
| AR (1) | AR049048A1 (en) |
| AU (1) | AU2005244774B2 (en) |
| BR (1) | BRPI0510809A (en) |
| CA (1) | CA2565112C (en) |
| MY (1) | MY139894A (en) |
| RU (1) | RU2336790C2 (en) |
| WO (1) | WO2005112671A1 (en) |
| ZA (1) | ZA200609182B (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2411113A4 (en) * | 2009-03-16 | 2014-10-29 | Protista Internat Ab | Cryotropic hydrogels and their use as filters |
| US9226524B2 (en) * | 2010-03-26 | 2016-01-05 | Philip Morris Usa Inc. | Biopolymer foams as filters for smoking articles |
| US9192193B2 (en) | 2011-05-19 | 2015-11-24 | R.J. Reynolds Tobacco Company | Molecularly imprinted polymers for treating tobacco material and filtering smoke from smoking articles |
| CN102336921B (en) * | 2011-06-30 | 2012-09-05 | 哈尔滨工业大学 | Preparation method of vapor-phase crosslinked chitosan/polyoxyethylene composite film |
| GB201112539D0 (en) | 2011-07-21 | 2011-08-31 | British American Tobacco Co | Porous carbon and methods of production thereof |
| WO2013036164A2 (en) * | 2011-09-05 | 2013-03-14 | Общество С Ограниченной Ответственностью "Эфтэк" | Cigarette filter segment |
| MX367027B (en) * | 2012-04-30 | 2019-08-01 | Philip Morris Products Sa | Smoking article mouthpiece including aerogel. |
| CN102793271B (en) * | 2012-08-31 | 2015-04-22 | 福建中烟工业有限责任公司 | Application of cross-linked chitosan porous microspheres in cigarette filter tips |
| CN103190704B (en) * | 2013-04-17 | 2014-06-25 | 江苏中烟工业有限责任公司 | Method for selectively reducing specific nitrosamines in cigarette smoke |
| CN103300477B (en) * | 2013-06-18 | 2015-12-09 | 云南烟草科学研究院 | A kind of novel filter tip material and preparation method thereof and application |
| GB201412752D0 (en) | 2014-07-17 | 2014-09-03 | Nicoventures Holdings Ltd | Electronic vapour provision system |
| CN108433176B (en) * | 2018-03-08 | 2020-12-08 | 武汉力诚生物科技有限公司 | Production device and production method of plant polysaccharide cigarette filter tip or filter tip rod |
| CN108576924B (en) * | 2018-05-17 | 2020-08-11 | 江苏工程职业技术学院 | Cigarette filter tip loaded with molecular sieve and preparation method thereof |
| CN110179155A (en) * | 2019-05-30 | 2019-08-30 | 华侨大学 | A kind of application of polyamino chitosan material in cigarette filter |
| CN113786815A (en) * | 2021-09-26 | 2021-12-14 | 桂林清研皓隆复合材料研究院有限公司 | Adsorbing material for water pollution treatment and preparation method thereof |
| CN117510855B (en) * | 2023-11-09 | 2024-04-23 | 广州雷斯曼新材料科技有限公司 | High-purity dimethyl silicone oil and preparation method and application thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3176004A (en) * | 1961-03-22 | 1965-03-30 | Meiji Seika Kaisha | 6-deoxy-6-mercapto-d-glucosamine and a process for the preparation of this compound |
| GB1509197A (en) * | 1974-06-17 | 1978-05-04 | British American Tobacco Co | Tobacco-smoke filters |
| US4018678A (en) * | 1974-08-09 | 1977-04-19 | Peniston Quintin P | Method of and apparatus for fluid filtration and the like with the aid of chitosan |
| US4038992A (en) * | 1975-09-29 | 1977-08-02 | The Japan Tobacco & Salt Public Corporation | Granular composition for tobacco filter |
| US4125708A (en) * | 1977-02-15 | 1978-11-14 | The United States Of America As Represented By The Secretary Of Agriculture | Chitosan modified with anionic agent and glutaraldehyde |
| JPS624702A (en) * | 1985-06-28 | 1987-01-10 | Lion Corp | Production of water-soluble acrylated chitosan |
| US5021207A (en) * | 1986-12-16 | 1991-06-04 | E. I. Du Pont De Nemours And Company | High strength fibers from chitin derivatives |
| JPH01104305A (en) * | 1987-10-15 | 1989-04-21 | Tadashi Uragami | Membrane for separating liquid |
| JP3576292B2 (en) * | 1995-10-05 | 2004-10-13 | ダイセル化学工業株式会社 | Tobacco filter and method for producing the same |
| US5993661A (en) * | 1997-04-14 | 1999-11-30 | The Research Foundation Of State University Of New York | Macroporous or microporous filtration membrane, method of preparation and use |
| US6209547B1 (en) * | 1998-10-29 | 2001-04-03 | Philip Morris Incorporated | Cigarette filter |
| US20020179106A1 (en) * | 2001-03-28 | 2002-12-05 | Zawadzki Michael A. | Reduced ignition propensity smoking article with a polysaccharide treated wrapper |
| US20030159703A1 (en) * | 2002-02-22 | 2003-08-28 | Zuyin Yang | Flavored carbon useful as filtering material of smoking article |
| US6814786B1 (en) * | 2003-04-02 | 2004-11-09 | Philip Morris Usa Inc. | Filters including segmented monolithic sorbent for gas-phase filtration |
-
2004
- 2004-05-10 US US10/842,165 patent/US20050247323A1/en not_active Abandoned
-
2005
- 2005-04-27 RU RU2006143635/12A patent/RU2336790C2/en not_active IP Right Cessation
- 2005-04-27 WO PCT/US2005/014476 patent/WO2005112671A1/en active Application Filing
- 2005-04-27 AU AU2005244774A patent/AU2005244774B2/en not_active Ceased
- 2005-04-27 CN CNA2005800208649A patent/CN101043826A/en active Pending
- 2005-04-27 EP EP12176082.1A patent/EP2510815A3/en not_active Withdrawn
- 2005-04-27 EP EP05740341A patent/EP1746906A1/en not_active Withdrawn
- 2005-04-27 JP JP2007511421A patent/JP4547422B2/en not_active Expired - Fee Related
- 2005-04-27 CA CA2565112A patent/CA2565112C/en not_active Expired - Fee Related
- 2005-04-27 BR BRPI0510809-8A patent/BRPI0510809A/en not_active IP Right Cessation
- 2005-05-05 MY MYPI20052013A patent/MY139894A/en unknown
- 2005-05-10 AR ARP050101891A patent/AR049048A1/en active IP Right Grant
-
2006
- 2006-11-03 ZA ZA200609182A patent/ZA200609182B/en unknown
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2007
- 2007-09-12 US US11/854,142 patent/US20070295345A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| RU2336790C2 (en) | 2008-10-27 |
| RU2006143635A (en) | 2008-06-20 |
| EP2510815A2 (en) | 2012-10-17 |
| JP4547422B2 (en) | 2010-09-22 |
| CN101043826A (en) | 2007-09-26 |
| US20050247323A1 (en) | 2005-11-10 |
| JP2007535929A (en) | 2007-12-13 |
| WO2005112671A1 (en) | 2005-12-01 |
| CA2565112A1 (en) | 2005-12-01 |
| AU2005244774B2 (en) | 2009-01-29 |
| ZA200609182B (en) | 2008-06-25 |
| BRPI0510809A (en) | 2007-11-06 |
| US20070295345A1 (en) | 2007-12-27 |
| AR049048A1 (en) | 2006-06-21 |
| EP1746906A1 (en) | 2007-01-31 |
| MY139894A (en) | 2009-11-30 |
| AU2005244774A1 (en) | 2005-12-01 |
| EP2510815A3 (en) | 2013-10-30 |
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