Classifications

• • 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
  • A24D3/16—Use of materials for tobacco smoke filters of inorganic materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
  • B01J20/0203—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of metals not provided for in B01J20/04
  • B01J20/0222—Compounds of Mn, Re
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
  • B01J20/0203—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of metals not provided for in B01J20/04
  • B01J20/0225—Compounds of Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt
  • B01J20/0229—Compounds of Fe
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
  • B01J20/04—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of alkali metals, alkaline earth metals or magnesium
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
  • B01J20/04—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of alkali metals, alkaline earth metals or magnesium
  • B01J20/041—Oxides or hydroxides
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
  • B01J20/04—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising compounds of alkali metals, alkaline earth metals or magnesium
  • B01J20/043—Carbonates or bicarbonates, e.g. limestone, dolomite, aragonite
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
  • B01J20/06—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising oxides or hydroxides of metals not provided for in group B01J20/04
  • B01J20/08—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising oxides or hydroxides of metals not provided for in group B01J20/04 comprising aluminium oxide or hydroxide; comprising bauxite
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
  • B01J20/10—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising silica or silicate
  • B01J20/16—Alumino-silicates
  • B01J20/18—Synthetic zeolitic molecular sieves
  • B01J20/186—Chemical treatments in view of modifying the properties of the sieve, e.g. increasing the stability or the activity, also decreasing the activity
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
  • B01J20/20—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising free carbon; comprising carbon obtained by carbonising processes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
  • B01J20/28002—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their physical properties
  • B01J20/28004—Sorbent size or size distribution, e.g. particle size
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
  • B01J20/28054—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their surface properties or porosity
  • B01J20/28057—Surface area, e.g. B.E.T specific surface area
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/28—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties
  • B01J20/28054—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof characterised by their form or physical properties characterised by their surface properties or porosity
  • B01J20/28078—Pore diameter
  • B01J20/2808—Pore diameter being less than 2 nm, i.e. micropores or nanopores
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/30—Processes for preparing, regenerating, or reactivating
  • B01J20/3085—Chemical treatments not covered by groups B01J20/3007 - B01J20/3078
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/30—Processes for preparing, regenerating, or reactivating
  • B01J20/3092—Packing of a container, e.g. packing a cartridge or column
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/30—Processes for preparing, regenerating, or reactivating
  • B01J20/32—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating
  • B01J20/3202—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating characterised by the carrier, support or substrate used for impregnation or coating
  • B01J20/3204—Inorganic carriers, supports or substrates
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/30—Processes for preparing, regenerating, or reactivating
  • B01J20/32—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating
  • B01J20/3202—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating characterised by the carrier, support or substrate used for impregnation or coating
  • B01J20/3206—Organic carriers, supports or substrates
  • B01J20/3208—Polymeric carriers, supports or substrates
  • B01J20/321—Polymeric carriers, supports or substrates consisting of a polymer obtained by reactions involving only carbon to carbon unsaturated bonds
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/30—Processes for preparing, regenerating, or reactivating
  • B01J20/32—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating
  • B01J20/3231—Impregnating or coating ; Solid sorbent compositions obtained from processes involving impregnating or coating characterised by the coating or impregnating layer
  • B01J20/3234—Inorganic material layers
  • B01J20/3236—Inorganic material layers containing metal, other than zeolites, e.g. oxides, hydroxides, sulphides or salts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2220/00—Aspects relating to sorbent materials
  • B01J2220/40—Aspects relating to the composition of sorbent or filter aid materials
  • B01J2220/42—Materials comprising a mixture of inorganic materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2220/00—Aspects relating to sorbent materials
  • B01J2220/50—Aspects relating to the use of sorbent or filter aid materials
  • B01J2220/66—Other type of housings or containers not covered by B01J2220/58 - B01J2220/64

Definitions

• compositions of an inorganic metal compound on a support comprise a granular support material impregnated with an alkali ferrate, one or more additives being optionally admixed to the impregnated support material.
• the compositions may be used as general additives, especially structures for treating so as to selectively.remove at least partly some undesirable constituent from a fluid or fluid suspension, for example a gas or hydrogen cyanide containing smoke from which at least part of the hydrogen cyanide may be removed selectively, though the content of one or more other undesirable constituents may likewise be reduced.
• composition of this invention is not limited to such use, one important application thereof is its use in filtration.
• the composition may be employed in manufacturing improved filters for cigarettes, cigars or other smoking articles, which filters are effective in the removal of certain undesirable smoke phase components such as hydrogen cyanide and ammonia.
• undesirable smoke phase components such as hydrogen cyanide and ammonia.
• the background of the invention will be discussed by reference to selective removal of undesirable components from tobacco smoke, but the present invention is not limited to use in filters for tobacco smoke.
• U. S. Patent 3,664,352 discloses alkaline additives such as alkali metal carbonates which may be applied to conventional filter materials to remove any hydrogen cyanide contained in tobacco smoke. Activated carbonaceous material with a surface treatment of copper oxide has also been proposed for hydrogen cyanide removal.
• U. S. Patents 3,251,365, 3,460,543, and 3,355,317 disclose various metal oxides, namely oxides of cobalt, copper, zinc or iron, on a carrier for removal of hydrogen cyanide.
• Patent 3,550,600 discloses zinc acetate in admixture with an organic or inorganic base on a smoke filter paper or cellulose acetate filter support which is described as being effective in the removal of various gaseous components, including hydrogen cyanide, from tobacco smoke.
• U. S. Patent 3,828,800 discloses certain anion exchange resins which have an affinity for volatile aldehydes as well as the capability to filter other components such as hydrogen cyanide.
• U. S. Reissue 28,858 discloses buffered polyalkyleneimines which exhibit an affinity for smoke acids.
• U. S.,Patents 3,946,101, 3,875,949, and 3,842,070 disclose a complex..fluid filter comprising cellulose which has been oxidized by an inorganic metal nitrate. The filter is described as being useful in removing gaseous and particulate components of smoke.
• U. S. Patent 3,618,619 discloses filters fabricated from cellulose acetate which has been impregnated with metal oxides of zinc, iron, copper, etc. and are effective in removing hydrogen cyanide.
• U. S. Patent 3,417,758 discloses filters containing a water-soluble, weak basic inorganic salt, i.e., sodium or potassium phosphite, which are described as effective in neutralizing hydrogen cyanide in tobacco smoke.
• a water-soluble, weak basic inorganic salt i.e., sodium or potassium phosphite
• U. S. Patent 4,022,223 discloses salts of copper and nickel complexed with selected aliphatic or aromatic amines which effectively remove hydrogen cyanide from tobacco smoke.
• the present invention provides an inert fluid-permeable granular support material impregnated with an alkali metal or alkaline earth metal ferrate, said ferrate being present in an amount from about 15 to about 50% by weight of said composition.
• the additives for impregnating the fluid-permeable granular support material are iron compounds in oxidation states of +4, +5, and +6 associated with oxygen in an anion radical. Such compounds are known and are generally referred to as ferrate (IV), ferrate (V), and ferrate (VI).
• the preferred compounds of the invention are the alkali and alkaline earth salts of ferrate (VI).
• the most preferred individual compound is potassium ferrate (K 2 Fe0 4 ), though sodium ferrate (Na 2 Fe0 4 ) is also highly suitable.
• the ferrate compounds of the present invention have been investigated previously for use in water purification systems and specifically for the oxidation of ammonia in water.
• alkaline ferrate* (VI) in combination with a ferrite solution has been used for removing hydrogen sulfide from a low-pressure gas by adsorption.
• the hydrogen sulfide present in the gas is oxidized to sulfur and may be recovered.
• Japan Kokai 74:37,894. The use of ferrates for the removal of gas phase components of tobacco smoke, and specifically, hydrogen cyanide has not been proposed heretofore.
• Granular substances which may be employed in forming a fluid-permeable bed must, of course, be substantially inert to the alkali ferrates; they may consist of (a) inorganic substances, e.g. silica gel, activated alumina, magnesia, calcium sulfate, diatomaceous earth, perlite, and still other inorganic substances; (b) organic substances such as polyethylene, polystyrene, and still other organic substances; and (c) molecular sieve materials such as zeolites.
• the granular substance is preferably porous to the extent of having a pore volume between about 0.1 and 2.5 cc per gram.
• the granules When the granules are utilized as a gas-permeable bed in a cigarette filter, they should be chemically inert, porous and have a size ranging from about 10-100 mesh (U. S. Sieve Series, ASTME-11-61) and preferably a range of 20-80. In expressing granule size by mesh numbers, it is to be understood that each range signifies that granules will pass through the coarser sieve designated (the smaller sieve number) and will be retained on the finer sieve designated (the larger sieve number). Granules having a size finer than about 100 mesh generally impart too high an impedance to gas flow. Granules larger than about 8 mesh provide reduced efficiency of removal of hydrogen cyanide.
• the potassium ferrate (VI) compounds are readily prepared by the method of Thompson et al. (Journal of the American Chemical Society, 73, 1951, page 1379) utilizing the reaction of sodium hypochlorite with ferric nitrate and subsequent conversion to the potassium salt.
• the purified, dried potassium ferrate is obtained in the form of very fine crystalline needles having an average length less than about one millimeter.
• the ferrates (VI) may also be prepared from ferrates (IV) by methods disclosed in U. S. Patent 2,835,553.
• Sodium ferrate (Na 2 FeO 4 ) may be prepared by methods disclosed in German Patent 1,013,272, (8 August 1957).
• the ferra-te-containing granules may be dry-blended with other granular material useful in cigarette filters in a weight ratio of about one part ferrate-containing granules to three parts of other granular materials and preferably at a ratio of about one to one. It has been found that the presence of strongly alkaline compounds in admixture with the ferrates improves storage stability. In the absence of the alkaline compounds, the ferrates will decompose on standing at room temperature. Alkaline compounds suitable as stabilizers for the ferrates include potassium hydroxide,'sodium hydroxide, and the like.
• the ferrate crystals are dissolved in a concentrated aqueous hydroxide solution which is then used to impregnate a granular support, preferably a zeolite molecular sieve.
• the impregnated granules are then treated with a stream of carbon dioxide gas to convert the alkaline hydroxide to its corresponding carbonate salt.
• the impregnated material is then dried at temperatures below about 100°C, and preferably at temperatures from about 0°C to about 50°C:
• the drying step- may be carried out with the aid of a vacuum or a stream of dry inert gas such as nitrogen. The extent of drying is such that the granules will retain from about 2% to about 10% moisture. Overdrying of the ferrate impregnated material may result in loss of storage stability.
• the active ferrate filter materials whether dry-blended or impregnated on various supports may be used alone in a filter element or may be blended with other known granular materials having gas phase activity such as activated carbon, permanganate- impregnated alumina, and the like.
• the activated carbon is a variety generally employed for gas adsorption, having a surface area of at least about 800 m 2 /gm, and ranging as high as about 1600 m 2 /gm.
• the carbon granules are preferably emplpyed in an amount of from about 30 to about 50% by weight of the total mixture.
• permanganate When permanganate is used, it is preferable to employ essentially silica-free activated alumina granules impregnated with an aqueous permanganate solution and a basic sodium compound according to methods disclosed in U. S. Patent 3,957,059 to Rainer et al.
• Basic sodium compounds which may be used include sodium hydroxide, sodium carbonates, sodium phosphates, and sodium borates.
• the permanganate-alumina composition when blended with the ferrate filter material enhances the overall efficiency of the combined filter in that it is especially effective in reducing the amount of nitrogen oxides which may be present in tobacco smoke.
• the filter material can be utilized as a bed in a space between plugs of a standard cellulose acetate filter rod.
• the filter assembly is then abutted against a cylinder of tobacco, and a paper wrapper may be employed to fasten the filter to the tobacco rod.
• the filter material may be separate from the smokable tobacco product, such as a filter unit adaptable for use with a cigarette or cigar holder.
• a filtering device employing the material of this invention can be appropriately packed into the stem of a tobacco pipe.
• the granule-containing filter will have a resistance to draw (RTD) of less than about 127 mm of water when measured at an air flow velocity of 1050 cc/minute.
• Acceptable RTD and hydrogen cyanide removal can be achieved by using from about 50 to 400 mg of the filter material of the invention in the specified mesh size.
• the filter material of this invention is capable of reducing the hydrogen cyanide content of tobacco smoke by about 25 to about 70%.
• K 2 FeO 4 potassium ferrate crystals
• a microporous polyethylene powder having a 40/80 mesh size.
• Sixty milligrams of this mixture were placed in a 10 mm long cigarette filter compartment bounded by two 6 mm long plugs of 8 mm diameter cellulose acetate filter rod comprised. of 8 denier filaments in a bundle having a total denier of 40,000.
• the filter assembly was attached to an end of a Kentucky IRI Reference cigarette described in a research bulletin entitled The Reference Cigarette published by the University of Kentucky, 29 August 1964.
• the overall RTD of the cigarette and filter combination was 127 mm of water when measured at an air flow velocity of 1050 cc/minute.
• Two cigarettes were simultaneously smoked on an electric smoking machine which drew air through the lit cigarette in puffs of 2 seconds duration, 35 cc of air/puff, and permitting 58 seconds cf static burn between puffs.
• the smoke from 8 puffs was passed through a Cambridge filter pad to remove total particulate matter.
• the resultant gas phase of the smoke was combined through a common manifold and collected in a previously evacuated one meter infrared gas cell.
• Potassium ferrate prepared by the aforesaid procedure, is dissolved to saturation in an aqueous 10 molar solution of potassium hydroxide.
• the resultant solution was utilized to impregnate to saturation 20/40 mesh granules of a zeolite molecular sieve material (type SK-40, sold by the Ventron Company of Beverly, MA). .
• the impregnated granules were treated with a stream of C0 2 gas to convert the potassium hydroxide to potassium carbonate, and the resultant product was dried. Two hundred fifty mg of this material was loaded into filters of the same construction utilized in Example 1, and the filters were mounted onto tobacco rods.
• the overall cigarette and filter RTD was 127 mm of water.
• Example 2 Testing of the smoke delivered through the filters was carried out in the same manner described in Example 1. It was found that a 66% reduction in HCN content of the gas phase of the smoke was produced. Little measurable effect was produced on other smoke components, as judged by IR analysis of gas phase. There was no evidence (such as discoloration) to show potassium ferrate emerging into the smoke stream, and the cigarette smoke had acceptable flavor. A control filter, prepared from the granular molecular sieve material without addition of the potassium ferrate solution, produced a 12% reduction in HCN content of the smoke.
• Potassium ferrate-impregnated molecular sieve granules as prepared by the method of Example 2, were blended with an equal weight of 20/40 mesh size granules of alumina impregnated with sodium permanganate/sodium hydroxide in accordance with U. S. Patent 3,957,059 to Rainer et al.
• Example 2 Two hundred fifty mg of the blended granular mixture was loaded into filters of the same construction utilized in Example 1, and the filter assembly was attached to an end of Kentucky IRI Reference cigarettes.
• the overall RTD of the cigarette and filter combination was 127 mm of water when measured at an air flow velocity of 1,050 cc/minute. The cigarettes were smoked and the resultant smoke was analyzed by the methods of Example 1.
• the filter assembly was made to contain solely the alumina granules impregnated with sodium permanganate/sodium hydroxide, the reduction in amount of HCN.in the delivered smoke was only 60%, and the reduction in delivered oxides of nitrogen was only 48%.

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• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Inorganic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Nanotechnology (AREA)
• Cigarettes, Filters, And Manufacturing Of Filters (AREA)

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• 1977
  • 1977-08-01 US US05/820,502 patent/US4246910A/en not_active Expired - Lifetime
• 1978
  • 1978-06-30 DE DE7878300110T patent/DE2860366D1/de not_active Expired
  • 1978-06-30 EP EP78300110A patent/EP0000625B1/de not_active Expired

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