JP2007519507A - Catalyst containing ultrafine particles - Google Patents

Abstract

  The present invention provides a catalyst composition, a product into which the catalyst composition is introduced, and a method for producing the catalyst composition. The catalyst composition includes a support and ultrafine particles. Disclosed articles of manufacture include filter devices such as those utilized in gas masks or smoking products. Also disclosed is a smoking product comprising the catalyst composition of the present invention.

Description

  The present invention relates generally to catalyst compositions, and more particularly to catalyst compositions comprising ultrafine particles. Embodiments of the present invention are useful in catalyzing reactions in aerosol / gaseous media. In one embodiment, the catalyst composition may be utilized in a smoking product to reduce the amount of gas phase components, such as carbon monoxide, in cigarette smoke.

  The term “catalyst” is commonly used to define a substance that is usually used in small quantities relative to a reactant and that increases the reaction rate without being consumed in the process. Catalysts are widely used in process chemistry and have been used to catalyze reactions that occur in gas streams or aerosols. Catalytic compositions have been used in smoking products to catalyze reactions in aerosol / gas streams flowing through the smoking product.

  Cigarettes are a popular smoking product that uses tobacco in various forms. A description of cigarettes and various components thereof is given in Tobacco Production, Chemistry and Technology, Davis et al. (Eds.) (1999).

  Cigarettes generally comprise a substantially cylindrical rod-shaped structure and include a packing, roll or column of material suitable for smoking, such as chopped tobacco (eg, in cut packing form) surrounded by wrapping paper. To form a so-called “cigarette rod”. Cigarettes typically have a cylindrical filter element aligned with the tobacco rod and end-to-end. Typically, the filter element comprises a cellulose acetate tow surrounded by plug wrap and is attached to the tobacco rod using a surrounding tip material. It has also become desirable to dilute the inhaled mainstream smoke with ambient air by perforating the tip material and plug wrap.

  Cigarettes and cigarette products similar to cigarettes are used by smokers by igniting one end and burning a tobacco rod or igniting a heat source to aerosolize the components in an aerosol generating rod. The The smoker then accepts the mainstream smoke in his mouth by drawing into the opposite end of the cigarette (ie, the filter end).

  Many cigarettes and cigarette-type smoking products that employ carbonaceous components have been proposed. Examples of such smoking products are shown in US patent application Ser. No. 10 / 382,244, entitled “Smoke Articles Completing Ultrafine Particles” (filed on March 5, 2003), which is incorporated herein by reference. Cigarettes having a carbonaceous combustible material component have been sold by RJ Reynolds Tobacco Company under the trademarks Premier and Eclipse. It has also been proposed to introduce catalyst materials into the carbonaceous combustible material component of certain smoking products. See, for example, U.S. Pat. Nos. 5,040,551 (Schlatter et al.); 5,211,684 (Shannon et al.); 5240014 (Devi et al.); And 5,258,340 (Augustine et al.). The disclosure of each of these patents is incorporated herein by reference.

  Catalysts are utilized in cigarettes to alter the chemical composition of cigarette smoke. The use of catalysts in cigarettes is described in US Pat. Nos. 4,182,348 (Seehofer et al.); And 6286516 (Bowen et al.) (Treatment of sidestream smoke). The disclosure of each of these patents is incorporated herein by reference.

  Other attempts have also been made to alter the chemical composition of cigarette smoke. US Patent Publication No. 2003/0188758 (Hajaligol et al.), The disclosure of which is incorporated herein by reference, discloses the use of oxyhydroxide compounds in cigarettes.

  Some cigarettes have a filter element that introduces a material such as carbon. Typical cigarettes and filters are described in U.S. Pat. Nos. 2,881,770 (Tovey); 3,353,543 (Sproll et al.); 3,101,723 (Seligman et al.); And 4,481,958 (Ranier et al.). And in European Patent Applications Nos. 532329 and 608047. Some commercial filters have carbon (eg, activated carbon or activated charcoal material) particles or granules dispersed within a cellulose acetate tow, while other commercial filters have carbon fibers dispersed therein. Yet other commercial filters have a so-called “cavity filter” or “triple filter” design. Typical commercial filters are from American Filtrona Corp. as SCS IV Dual Solid Charcoal Filter; from FIL (FIL International, Ltd.) as Triple Solid Charcoal Filter as Baumgartner as Baumgartner From Holding SA) as a Triple Cavity Filter; and from FIL as ACT. See also Clarke et al., World Tobacco, p. See also 55 (November 1992). A detailed discussion of the properties and composition of cigarettes and filters is provided in US Pat. Nos. 5,366,0023 (Blakeley et al.); 5,404,890 (Gentry et al.); 5,568,819, incorporated herein by reference. (Gentry et al.); And 6537186 (Veluz).

  Various annular arrangements of filters having a carbon retaining annular filter region have been disclosed in the prior art. For example, European Patent Application No. 579410 shows a number of cigarette embodiments having an annular carbon support region surrounding a hollow tubular cavity formed of a porous filtration material or a gas phase porous membrane. Similarly, US Pat. No. 3,894,545 (Crelin et al.) Shows various arrangements of an annular carbon support region surrounding a gas phase porous membrane or a rod of carbon support material surrounded by a gas phase porous membrane. Yes.

  A cigarette filter element incorporating carbon has the ability to change the nature of mainstream smoke passing therethrough. For example, such filter elements have a propensity to reduce the level of certain gas phase components present in mainstream smoke, causing a change in the sensory properties of the smoke. However, such filter elements often incorporate a relatively large amount of carbon (e.g., in particulate form) and / or are configured and arranged longitudinally. Thus, filter elements incorporating carbon require a large number of labor intensive processing steps, and cigarettes incorporating such filter elements are often slightly metallic and bulky It is characterized by having a powdery flavor characteristic.

  US 2002/0014453 (Lilly et al.), The disclosure of which is incorporated herein by reference, describes gaseous components such as 1,3-butadiene, isoprene, and toluene from mainstream smoke. It proposes to remove unsaturated hydrocarbons from mainstream smoke using nanoclusters that selectively remove. Although the nanoclusters described in this publication purposely remove certain classes of gaseous components, such nanoclusters cannot be effective catalysts for other components, for example, cigarettes It may not be possible to catalyze the conversion of carbon monoxide to carbon dioxide in tobacco filters.

  US Patent Publication No. 2003/0131859 (Li et al.), The disclosure of which is incorporated herein by reference, may be used as an oxidant for the conversion of carbon monoxide to carbon dioxide and / or carbon monoxide. Proposed the use of nanoparticle additives that can act as catalysts for the conversion of methane into carbon dioxide and / or as catalysts for the conversion of hydrocarbons, aldehydes, or phenolic compounds to carbon dioxide and water ing. The nanoparticle additive described in this publication is described as acting as a catalyst / oxidant at temperatures above 150 C and effective in the burning and pyrolysis region of cigarettes.

  US Patent Publication No. 2003/0075193 (Li et al.), The disclosure of which is incorporated herein by reference, may be used as an oxidant for the conversion of carbon monoxide to carbon dioxide and / or carbon monoxide. It proposes the use of a nanoparticle additive that can act as a catalyst for the conversion of carbon to carbon dioxide. The nanoparticle additive described in this publication is described as acting as a catalyst / oxidant at temperatures above 150 C and effective in the burning and pyrolysis region of cigarettes. Nanoparticle additives are introduced into the cutting filler used in tobacco rods.

  Despite development to date, there is a need for improved and more effective methods and compositions for changing gas phase components in mainstream smoke of smoking products. It would be desirable for such methods and compositions to catalyze or oxidize carbon monoxide to carbon dioxide in cigarette mainstream smoke at temperatures that do not require excessive heat to drive the conversion process. Like.

  The present invention provides a catalyst composition; a manufactured article including but not limited to a smoking product, a catalyst device, and a filter device comprising the catalyst composition; The catalyst composition is useful in a variety of applications, particularly those involving catalysis of reactions in gas or aerosol media. Embodiments of the catalyst composition of the present invention are advantageous for use in smoking products and may be particularly advantageous for use in filter elements of smoking products. Embodiments of the catalyst composition of the present invention are also advantageous for use in other filter devices.

  In one aspect, the present invention provides a catalyst composition comprising a support and ultrafine particles. The choice of support and / or ultrafine particles, including their size and physical structure, may be based on the chemical reaction being catalyzed and the environment in which the reaction takes place.

  In other embodiments, the present invention provides an article of manufacture comprising a catalyst composition. One embodiment of the present invention is a smoking product comprising a catalyst composition. In certain embodiments, the filter element of the smoking product includes a catalyst composition. In other embodiments, the other component of the smoking product comprises a catalyst composition. Another embodiment of the article of manufacture of the present invention is a filter device comprising a catalyst composition. A further embodiment of the article of manufacture of the present invention is a catalytic device comprising a catalyst composition.

  In a further aspect, the present invention provides a method for producing a catalyst composition. The method of the present invention can be utilized to produce the catalyst composition of the present invention and / or can be utilized to produce other useful catalyst compositions.

  Further details regarding the present invention and its advantages are given in the following sections.

  The present invention provides a catalyst composition comprising ultrafine particles. The present invention also provides an article of manufacture comprising the catalyst composition of the present invention. Among the manufactured products are filter devices and catalyst devices. Smoking products are also included. In one embodiment, the present invention provides a catalyst composition that catalyzes a reaction in and / or within a gas phase component in mainstream smoke from a smoking product, for example, conversion of carbon monoxide to carbon dioxide. Furthermore, this invention provides the manufacturing method of the catalyst composition containing an ultrafine particle.

  Specific embodiments of the invention are referenced below. Each embodiment is provided by way of explanation of the invention, not as a limitation of the invention. In short, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For example, features illustrated or described as part of one embodiment may be introduced into other embodiments to yield further embodiments. Accordingly, the present invention is intended to embrace such modifications and variations that fall within the scope of the appended claims and their equivalents.

  For the purposes of this specification, unless indicated otherwise, all numbers representing the amounts of ingredients, reaction conditions, etc. used herein are altered in all examples by the term “about”. It should be understood to receive. Thus, unless indicated to the contrary, the numerical parameters shown in the following specification are approximations that can be varied according to the desired properties sought to be obtained by the present invention. At a minimum, and not as an attempt to limit the application of doctrine of equivalents to the claims, each numeric parameter should at least take into account the reported significant digits and apply conventional rounding methods. Should be interpreted.

  Although the numerical ranges and parameters representing the broad scope of the present invention are approximate, the numerical values shown in the specific examples are reported as accurately as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Moreover, all ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein and all numbers between the ends. For example, an explicit range of “1-10” means any and all subranges between (and including) a minimum value of 1 and a maximum value of 10, ie, a minimum value of 1 or more, eg 1-6.1 All subranges starting with and ending with a maximum of 10 or less, for example 5.5-10, plus all starting and ending within 2-9, 3-8, 3-9, 4-7 And, finally, should be considered to include each number 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 contained within that range. Further, any reference referred to as “incorporated herein” should be understood to be incorporated in its entirety.

  As used herein, the singular forms include the plural, unless explicitly and explicitly limited to a single object.

  One aspect of the present invention is a catalyst composition comprising a support component and ultrafine particles. The weight ratio of ultrafine particles to the support may vary based on the reaction being catalyzed. Generally, the catalyst composition of the present invention comprises 51 to 99% by weight of support and 1 to 49% by weight of ultrafine particles. In certain embodiments, the catalyst composition of the present invention generally has a support of greater than 50 wt%, often greater than 80 wt% support, or greater than 90 wt% support, or 95 wt% % Of the support and the remainder, or a substantial portion of the remainder comprising ultrafine particles.

  The support component of the catalyst composition of the present invention may comprise metal oxides, ceramics, metals, alloys, zeolites, polymers, carbon-containing materials and / or other materials. The support may be inert with respect to the reaction being catalyzed or, in certain embodiments, may play an active role in catalysis. The purpose of the support in certain embodiments of the present invention is to provide a place for physically immobilizing the ultrafine particles. The support can also aid in catalysis by providing dissociated oxygen for the oxidation reaction.

  The support component of the catalyst composition of the present invention is substantially spherical; oval, polygonal (eg, cubic), and / or amorphous amorphous granules; particles; planar shape / sheet; web; screen / mesh It can take many forms with a porous or non-porous surface, including but not limited to shape and / or fiber shape and the like. In general, it is advantageous to use a physical shape or form that increases the contact surface area between the ultrafine particle component of the catalyst composition and the gas stream.

Supports having a large surface area and a BET surface area of 0.1 to 3000 m ² / g are generally preferred. Methods for determining BET surface area are well known and are described, for example, in US Pat. No. 4,947,874 (Brooks et al.), The disclosure of which is incorporated herein by reference. As used herein, surface area means the nominal surface area determined by known analytical methods.

In embodiments that utilize a granular support, the support may have an average particle diameter of 0.05 mm to 2 mm, preferably 0.2 mm to 1.5 mm, more preferably 0.5 mm to 1 mm. In general, it is advantageous for the support to have a sufficient surface area to facilitate contact between the ultrafine particles disposed on the support and the mainstream smoke. As indicated above, in embodiments of the present invention, nominal surface area of the support, 0.1~3000m ² / g as determined by ASTM Test Procedure C1274-00, preferably, 50~1000m ² / g Range.

  The physical form of the support may be selected based on the intended use of the catalyst composition. For some applications, it is advantageous to maximize the surface area of the support and distribute the ultrafine particles over the largest portion of possible surface area. In one embodiment, the catalyst composition of the present invention comprises a thin layer coating of ultrafine particles spaced substantially uniformly on the surface of the support.

  Several suitable supports can be used in embodiments of the present invention. In choosing the support, various external and thermodynamic considerations can be considered to ensure that oxidation and / or catalysis occurs efficiently. For example, a support useful in embodiments of the present invention can be combined with ultrafine particles, such as gold, and the support can be significantly placed in the filter element without incurring a pressure loss that causes excessive performance degradation. It will be available in a size that can be tightly packed.

Metal oxides are particularly well suited for use as a support in embodiments of the present invention. Examples of metal oxides suitable for use as a support in embodiments of the present invention include alumina (Al ₂ O ₃ ), cerium oxide (CeO ₂ ), iron oxide (Fe ₂ O ₃ ), titania (TiO ₂ ), And many other transition metal oxides, mixtures and alloys thereof. In general, for the support, including at least one of cerium oxide (CeO ₂ ), titanium dioxide (TiO ₂ ), iron oxide (Fe ₂ O ₃ ), alumina (Al ₂ O ₃ ), and mixtures thereof, It has proved advantageous for use in filter devices.

  In one non-limiting embodiment, the support comprises alumina. Alumina can be particularly useful as a support in embodiments of the present invention because it allows alumina to dissociately adsorb oxygen. In general, any phase of alumina is suitable for use in embodiments of the present invention. For certain embodiments, alpha alumina is preferred over gamma alumina in the present invention. The preparation of alumina for use as a support in embodiments of the present invention is discussed in further detail below. An example of an alumina suitable for use in embodiments of the present invention is activated gamma alumina (8-14 mesh), commercially available from Fisher Scientific International under the product number A505-212. For further information regarding the use of alumina in smoking products, U.S. Pat. Nos. 4,771,795 (White et al.); 4,917,128 (Clearman et al.); 4,967,774 (incorporated herein by reference). White); and 5016654 (Bernasek et al.).

  As used herein, the term “ultrafine particles” refers to particles having a size of less than 10,000 nm, including nanoparticles and slightly larger particles. The term “nanoparticle” is generally used to indicate a particle having a size of less than 100 nm (1 nm is one billionth of a meter). Ultrafine particles clearly demonstrate advantageous and unique properties that can be exploited in embodiments of the present invention for various purposes related to catalysis of chemical reactions.

  The size of the ultrafine particles utilized in the catalyst composition of the present invention can vary depending on the reaction being catalyzed. For example, in certain embodiments of the invention, the ultrafine particles may include nanoparticles having a particle size of 10 nm or less.

  Ultrafine particle compositions suitable for use in the present invention include, but are not limited to, ultrafine particles capable of catalyzing chemical reactions, including but not limited to noble metals, alloys, metal oxides, and the like. The ultrafine particles may be doped or coated. Ultrafine particles suitable for use in the present invention include noble metals; metals such as gold, copper, silver, platinum, palladium, rhodium, nickel, zinc, zirconium, and other transition metals; iron; noble metal alloys; metal oxides; And mixtures thereof, including but not limited to.

  To catalyze the conversion of carbon monoxide to carbon dioxide, precious metals such as gold that can catalyze the conversion at temperatures detected in smoking products or smoking product filters are advantageous. Other ultrafine particles having properties similar to gold can also act as catalysts in embodiments of the present invention.

  In embodiments of the invention that utilize gold ultrafine particles, the gold ultrafine particles may have an average particle size of up to about 100 nm. In other embodiments, the gold ultrafine particles may have an average particle size of up to about 10 nm. In still other embodiments, the ultrafine gold particles may have an average particle size of up to about 5 nm.

  The catalytic nature of gold depends mainly on its particle size. Gold ultrafine particles can be particularly effective in converting carbon monoxide to carbon dioxide when the average particle size is from about 2 to about 4 nm. Accordingly, further embodiments of the present invention include gold ultrafine particles having an average particle size of about 2 to about 4 nm.

  The preparation of gold ultrafine particles for use in embodiments of the present invention is discussed in further detail below. An example of a suitable starting material for obtaining gold ultrafine particles is tetrachlorogold (III) acid, which is commercially available from Alfa Aesar under the product number 12325.

  Gold ultrafine particles are particularly effective at particle sizes of about 2 nm to 4 nm, but such small particle sizes are difficult to implement in filter devices such as gas masks or filter elements of smoking products. When placed in a filter, such small particles are very tightly packed so that an unusually high pressure drop occurs.

As used herein, the term “pressure drop” refers to the difference between atmospheric pressure and the pressure at the point where the tip of the cigarette is hit, measured at a given flow rate through the cigarette. means. Typical pressure drop values of cigarettes of the present invention, an air flow rate of 17.5 cc / sec, greater than about 30mm of _{H 2} O, more often, more than about 50mm of _{H 2} O.

  One other potential problem with the use of gold ultrafine particles in filters (eg, gas mask filters or smoking product filters) is that the active catalytic sites of the gold ultrafine particles are inactivated by the aerosol passing through the filter. This is a possible point. Aerosols may include aerosols consisting of water and many other complex chemicals, some of which are complex mixtures of chemicals that rapidly deactivate the active sites of the catalyst.

  The choice of support composition and / or ultrafine particle composition can be made based on the chemical reaction being catalyzed and the environment in which the reaction occurs. A feature of the present invention is that certain embodiments of the present invention act as catalysts at temperatures below 300 ° C., effectively below the operating range of other catalysts. For example, certain embodiments of the present invention catalyze reactions in gas streams at temperatures between 10 ° C and 300 ° C. Other embodiments of the invention act as a catalyst at 80 ° C to 200 ° C, or 130 ° C to 180 ° C.

  In an embodiment of the invention, the support advantageously forms a large structure, resulting in a gentle filling of the filter element. Thus, ultrafine particles of the desired size can be applied to the support and when introduced into the filter device, the high pressure loss is reduced or eliminated. The ultrafine particles supported on the support can also facilitate contact between the aerosol component (eg, CO) and the catalyst.

  The catalyst composition of the present invention may be made by a variety of methods including chemical deposition, precipitation deposition, impregnation, combustion synthesis, vapor deposition, solution chemistry and / or other methods recognized by those skilled in the art. Exemplary methods are described herein, and the disclosure of which is incorporated herein by reference, “The Preparation of High Dispersed Au / Al 2 O 3 by Aqueous Impregnation” by Xu et al., Catalyst Letters V. 85, no. 3-4, February 2003, pages 229 and below.

  In a further aspect, the present invention provides a method for producing a catalyst composition comprising ultrafine particles. The process of the present invention can be utilized to produce the catalyst composition of the present invention. However, the method of the present invention is applicable to other catalyst compositions such as platinum (Pt), palladium (Pd), copper (Cu), rhodium (Rh), gold (Au), silver (Ag), iron (Fe). Nickel (Ni), Zinc (Zn) and Zirconium (Zr) compositions can be used to produce the catalyst composition of the present invention by other methods.

The catalyst composition of the present invention may be prepared by the method of the present invention and / or other methods. One method for producing a catalyst composition containing ultrafine gold particles is a step of dissolving tetrachloroauric (III) acid (HAuCl ₄ ) in water, and acidifying an aqueous solution of tetrachloroauric (III) acid with hydrochloric acid. A step, coating the support with an acidifying solution, washing the coated support, and calcining the washed coated support to form a catalyst composition. Other embodiments may further comprise removing chlorine ions and / or drying the coated support.

One embodiment of the method of the present invention is:
Applying a solution comprising an ultrafine particle precursor and an acid to a particulate support;
Drying the support;
Suspending the support in water;
Mixing a basic solution into the suspension to form a particle precursor solution;
Separating the support and ultrafine particle composite thus created; and treating the composite to produce a catalyst composition comprising the support and ultrafine particles.

  In some cases, the composition may be heat treated in the presence of hydrogen gas to assist in activation. The ultrafine particle composite may be processed by calcination, drying or similar methods depending on the particular end use of the catalyst composition. This method can be used to deposit ultrafine catalyst particles on a single body of various profiles and compositions, as well as on granules of various profiles and compositions.

Suitable ultrafine particle precursors include salts containing the target catalyst composition. Additional ultrafine particle precursors are described in more detail below and in the patents relating to ultrafine particles referenced herein. Suitable acids include organic and / or inorganic acids such as hydrochloric acid (HCl), sulfuric acid (H ₂ SO ₄ ), hydrofluoric acid (HF), nitric acid (HNO ₃ ), and the like.

  The solution comprising the ultrafine particle precursor and acid may be applied to the support using conventional manufacturing methods to bring the physical support into contact with the solution. For example, the support may be immersed in the solution. In general, it is preferred to ensure that the desired catalytically active portion of the support is substantially completely coated with the solution. Alternatively, the solution can be added or sprayed onto the support, or otherwise deposited thereon, to produce a substantially uniform coating.

  Drying of the support after application of the solution may be performed by conventional methods. Drying may be performed at a temperature, generally at least above ambient temperature, for a time sufficient to drive a substantial portion of moisture from the support. As shown in the following description and examples, the support may be dried at 50 ° C. to 150 ° C., usually 80 ° C. to 120 ° C. for 1 to 3 hours, usually 1.5 to 2.5 hours. It was found to be suitable for the support / ultrafine particle precursor solution.

The particle precursor solution may contain water (H ₂ O) or other solvent. The step of suspending the dry support in the aqueous solution may be performed by conventional methods, including mixing the aqueous solution and the dry support with slow stirring to form a suspension of the support.

  Suitable basic solutions include sodium hydroxide, sodium bicarbonate, sodium carbonate, potassium hydroxide, calcium hydroxide, ammonium hydroxide and the like. Generally, basic solutions have a pH greater than 8.

  Mixing the basic solution into the suspension can be done using conventional methods including mixing with stirring. After mixing is complete, the support / ultrafine particle composite particles are separated from the mixture. Separation may be accomplished by physical separation means including sieving, filtration and the like.

  The recovered particles may be calcined using conventional methods. In general, the particles are held at a temperature above ambient temperature for a time sufficient to drive substantially all residual moisture from the particles. In certain embodiments of the method of the present invention, for example, the particles are calcined at a temperature of 100 ° C. to 500 ° C. for 2 to 10 hours, usually at a temperature of 300 ° C. to 400 ° C. for 5 to 7 hours.

  Suitable supports include those listed above and below in the description of the catalyst composition of the present invention. To produce a granular support, the granular high surface area support starting material is ground and has a preferred particle size, for example, 0.1 mm to 2 mm, usually 0.3 mm to 1.7 mm, or some implementation. In the form, it may be sieved to 0.5 to 1.1 mm.

  The particulate catalyst composition produced by the process of the present invention possesses several practical advantages. In particular, they can be free-flowing and substantially free of agglomeration. They can also be substantially free of dust.

In addition to the method of the present invention described above, gold ultrafine particles have been described in “Combination synthesis of nanomaterials supported on α-Al ₂ O ₃ : CO oxidation and NO reduction catalyst,” incorporated herein by reference. Journal of Material Chemistry, Vol. 9, pp. The combustion synthesis shown in 1801-1805 (1999) can be used to place on alpha alumina.

  In another aspect, the present invention provides an article of manufacture comprising the catalyst composition of the present invention. The article of manufacture can include catalytic devices suitable for use in chemical process reactions, such as particles, screens, panels, and the like. In another aspect, the product of the present invention is a filter device comprising the catalyst composition of the present invention. The filter device may further comprise particulate screening media, fillers and / or other inert or active ingredients. The particulate screening medium can include fibrous, granular or other materials that act to remove particulates and / or gaseous substances that poison the catalyst. Examples of this filter device include, but are not limited to, gas mask filters, smoke purification filters, and filters utilized in smoking products.

  In a further aspect, the present invention provides a smoking product. The smoking product of the present invention is desirable in that it provides good aroma, comfort and satisfaction.

  In one embodiment, the present invention provides a smoking product comprising a combustible material for preparing an aerosol and / or for heating an aerosol-forming material. The smoking product includes the catalyst composition of the present invention. For example, an aerosol can be formed by burning to produce smoke or by heating an aerosol-forming material on a suitable support. The placement and location of the catalyst composition can be selected such that the specific functionality of the smoking product is altered. For example, in one embodiment of the invention where it is sought to change the composition of an aerosol, e.g., mainstream smoke, the catalyst composition is within the smoking product such that there is contact between the catalyst composition and mainstream smoke. Placed / positioned. An example of such an embodiment is smoke modification to reduce the level of carbon monoxide in the smoke.

  In one embodiment of the present invention, the filter component of the smoking product comprises the catalyst composition of the present invention. The catalyst composition may be present in an amount sufficient to change the chemical composition of an aerosol, eg, cigarette smoke, that is inhaled through the filter. In one embodiment, the catalyst composition may act to catalyze reactions that occur within an aerosol (eg, cigarette smoke). The catalyzed reaction can be the result of contact between the aerosol and the catalyst composition, contact between the aerosol and the support component of the catalyst composition, or both.

  In an alternative embodiment of the present invention, the catalyst composition of the present invention may be incorporated into other components of the smoking product, for example, aerosol generating component and / or tobacco, in addition to or instead of being introduced into the filter component. As part of and / or surrounding it.

  In embodiments of the invention that use a particulate catalyst composition in a smoking product, the particle size of the composition can range from 0.1 millimeter (mm) to 1.5 mm. In certain embodiments, the particle size can range from 0.5 mm to 1.0 mm, and more particularly, in certain embodiments, a particle size of 0.75 mm to 0.85 mm is preferred. Particle size can be determined by ASTM test procedures B761-02 and E1617-97 (2002).

  Supports and ultrafine particulate materials of the catalyst composition of the present invention for use in smoking products can include any of the materials set forth above. In general, for conversion of carbon monoxide to carbon dioxide in an aerosol, the catalyst composition can serve as a support for promoting oxidation of carbon monoxide to carbon dioxide.

  Embodiments of the present invention include, but are not limited to, embodiments that utilize the catalyst composition of the present invention for modification of smoke components, such as modification by reducing the level of carbon monoxide. The catalyst composition can be introduced into the smoking product, or a component of the smoking product, by a variety of methods, including those detailed below and other methods understood in the art. The catalytic process may exist over a temperature range that includes room temperature or lower.

  The smoking product of the present invention may further comprise a catalyst composition and / or additional materials that enhance the performance of the smoking product. For example, a smoking product filter comprising the catalyst composition of the present invention may further comprise particulate material for filtering out mainstream smoke components that would otherwise impair the catalytic function of the catalyst composition.

  The catalyst composition for use in embodiments of the smoking product of the present invention may comprise a plurality of ultrafine particles located on at least one support. The placement and location of the catalyst composition can be selected such that the specific functionality of the smoking product is altered. For example, in one embodiment of the invention where it is desired to change the composition of mainstream smoke, the catalyst composition comprising ultrafine particles is contained within the filter element such that contact exists between the ultrafine particles and mainstream smoke. Placed / positioned. In such embodiments, the catalyst composition reduces the level of carbon monoxide in the smoke. The ultrafine particles can advantageously act as a catalyst for the conversion of carbon monoxide to carbon dioxide in mainstream smoke.

  Mainstream smoke refers to gas and particulate aerosols created when a smoker inhales through a tobacco rod. Mainstream smoke includes smoke that is inhaled through a lit area of a cigarette, a tobacco rod, and a filter (if the smoking product is fitted).

  In one embodiment of the present invention, the smoking product catalyst composition may comprise 0.01 wt% to 10 wt%, preferably 0.1 wt% to 5 wt% ultrafine particles. The theoretical addition amount corresponding to the weight percent of ultrafine particles can be calculated. The percent added is equal to the amount of ultrafine salt in g multiplied by the fraction of ultrafine particles in the ultrafine salt divided by the total amount of ultrafine salt plus support, and the quotient multiplied by 100. .

  The mainstream smoke temperature is lower when smoke passes through the filter element than when smoke passes through the tobacco rod. In the filter element, the temperature ranges from about room temperature to about 150 ° C. Compared to this, the temperature in the tobacco rod, including the temperature in the so-called combustion and pyrolysis regions, is in the range of 200 ° C to 900 ° C. Thus, when the catalyst composition is disposed in a filter element according to an embodiment of the present invention, the catalyst composition is effective as a catalyst for the conversion of carbon monoxide to carbon dioxide at temperatures below 150 ° C. is there.

  In one embodiment of the invention, the ultrafine particles comprise gold. Although gold cannot be an active catalyst in its bulk form, gold ultrafine particles exhibit excellent catalytic properties, particularly in the conversion of carbon monoxide to carbon dioxide. Furthermore, gold ultrafine particles can advantageously catalyze the conversion of carbon monoxide to carbon dioxide at room temperature.

  A catalyst composition for use in a filter element of a smoking product according to embodiments of the present invention may comprise a plurality of ultrafine particles deposited on at least one support. The filter element can include a plurality of catalyst compositions. In further embodiments, the plurality of catalyst compositions may be disposed in at least one cavity in the filter element. The plurality of catalyst compositions may be placed in a cavity between two filter plugs in one embodiment.

  In one embodiment of the present invention, the catalyst composition includes a plurality of gold ultrafine particles disposed on at least one alumina particle. In a further embodiment, the gold ultrafine particles comprise gold nanoparticles. In further embodiments, the gold nanoparticles have a particle size up to about 10 nm. In other embodiments, the gold nanoparticles have a particle size of up to about 5 nm. In other embodiments, the gold nanoparticles have a particle size of about 2 nm to about 4 nm.

  The size and profile of the alumina support prior to gold deposition is such that, in embodiments of the present invention, the catalyst composition maximizes contact between the catalyst composition and the aerosol without exceeding the allowable pressure loss limit. May be selected to be filled into components of the smoking product. In one embodiment, the alumina support has a particle size of about 12 to about 35 American mesh (about 0.5 to about 1.4 mm). In other embodiments, the alumina support prior to gold deposition has a particle size of about 18 to about 30 American mesh (about 0.6 mm to about 1 mm).

  The catalyst composition in other embodiments of the present invention comprises a plurality having a particle size of about 2 nm to about 4 nm disposed on at least one alumina support having a particle size of about 0.6 mm to about 1.0 mm. Of gold ultrafine particles.

In one embodiment, an untreated gamma alumina support for use in the catalyst composition of the present invention has a surface area of approximately 340 m ² / g as measured by gas adsorption. After the addition of gold, the ultrafine alumina-gold composite has a surface area of approximately 270 m ² / g.

  As will be appreciated by those skilled in the art, the relationship between the support pore size and the ultrafine particle size reflected in the support surface area measurement is to achieve the desired functionality in the catalyst composition of the present invention. Can be optimized.

  Further details regarding embodiments of the catalyst composition of the present invention and products of the present invention comprising this catalyst composition are described below for specific embodiments of the product of the present invention, including embodiments of the catalyst of the present invention. It will be apparent to those skilled in the art from the description.

  Embodiments of the present invention comprising multiple catalyst compositions are illustrated in the accompanying figures.

  1-5 show cross-sectional views of embodiments of the filter elements 10A, 10B, 10C, 10D and 10E of the present invention incorporating the catalyst composition of the present invention. The filter element can be used as a filter element in a smoking product, where the filter element generally has a substantially circular shape. A design similar to the filter element may be used in other applications. For use in the following description, FIGS. 1-5 include arrows indicating the direction of aerosol flow through the filter element. Similar numeric elements are generally described with reference to the first figure in which they appear.

  Referring to FIG. 1, filter element 10 </ b> A includes filter material 11 in filter element portions 12 and 16. Suitable filter materials include cellulose acetate tow and other materials described in detail below.

  Cavity 14 is disposed between portions 12 and 16. In one embodiment of the present invention, the catalyst composition 13 of the present invention is distributed throughout the cavity 14. The cavity 14 includes an air dilution hole 18 for drawing air into the cavity. The air dilution holes are deployed through any outer packaging material that surrounds the filter element when the filter element 10 is placed in the smoking product.

  The catalyst composition of the present invention may be placed in the cavity 14 using methods known to those skilled in the art to place particulate material (eg, carbon) in the filter element. Examples of such methods are shown in US Pat. No. 6,537,186 and US Publication No. 2002/0020420, which are hereby incorporated by reference.

  FIG. 2 illustrates an alternative embodiment of the filter element 10B of the present invention. In one embodiment of the present invention, the cavity 14 comprises a mixture of the catalyst composition 13 of the present invention and granular carbon 15. This mixture may comprise 1 to 80% by weight of the catalyst composition of the present invention and 1 to 80% by weight of granular carbon. This mixture may be placed in the cavity 14 using methods known to those skilled in the art to place particulate material in the filter element.

  FIG. 3 illustrates another alternative embodiment of the filter element 10C of the present invention. In the embodiment shown in FIG. 3, the cavity 14 is subdivided into cavities 14A and 14B. The catalyst composition 13 of the present invention is disposed in a cavity 14A that is a downstream cavity. The granular carbon 15 is disposed in the cavity 14B upstream of the cavity 14A. The relative positions of the catalyst composition and the granular carbon in the cavities may be reversed.

  1-3, the relative lengths of portions 12 and 16 and cavity 14 or 14A and 14B are not drawn on a scale. In general, in embodiments of the invention similar to filter elements 10A and 10B, the ratio of the length of each part to the cavity, 12/14/16, is 30-45 / 10-40 / 30-45. For a filter element having a length of 27 mm, this is a portion 12 having a length of 8.1 to 12.2 mm; a cavity 14 having a length of 2.7 to 10.8 mm; and a length of 8.1 to The portion 16 is 12.2 mm. For the filter element 10C, the relative length ratio of 12 / 14A / 14B / 16 is 30-45 / 5-5-20 / 5-5 / 20-30-45. For a filter element having a length of 27.2 mm, this is 12 with a length of 8.1 to 12.2 mm; a cavity 14A with a length of 1.4 to 5.4 mm; a length of 1.4 to A 5.4 mm cavity 14B and a portion 16 having a length of 8.1 to 12.2 mm are obtained.

  FIG. 4 illustrates another embodiment of the filter element of the present invention. The filter element 10 </ b> D includes a cavity 21 surrounded by a high density filter material 23. Suitable high density filter materials include, but are not limited to, steam bonded cellulose acetate filters available from Filtrona. These steam bonded filters have a filtration efficiency of over 75%. The end of the cavity may be coupled to a region of the filter material 11 that may have a lower filtration efficiency than the filter material 23 to facilitate the passage of the aerosol / gas mixture through the filter element 10D. The filter element includes an air dilution hole 18 for allowing air to pass between the cavity 21 and the external environment.

  The relative dimensions of the cavities can vary depending on the application. In one embodiment, the cavity has a diameter of 10-50% of the diameter of the filter element and a length of 10-80% of the length of the filter element.

  The cavity 21 contains the catalyst composition 13 of the present invention. Alternatively, cavity 21 may be filled with a mixture of catalyst composition 13 and granular carbon.

As mentioned in the preceding description, the embodiment of the present invention shown in FIGS. 1-4 includes a portion of a filter element that includes the catalyst composition of the present invention. The packing density of the catalyst composition in the filter element, or the catalyst composition and other particulate material (eg, particulate carbon) is generally in the range of 0.5 to 2.0 g / cm ³ . A high or low packing density may be desirable for certain embodiments in order to maintain an acceptable pressure drop across the filter.

  FIG. 5 illustrates another possible embodiment of the filter element of the present invention. As shown in FIG. 5, the filter element 10 </ b> E includes a filter material 11 and a cellulose acetate filter portion 12. The filter element 11 includes a filter material in communication with the catalyst composition 13 of the present invention that is distributed throughout the filter element. Filter material 11 may be pretreated with the catalyst composition prior to introduction into the filter element.

  The filter elements 10A-10E shown in FIGS. 1-5 are shown and described with reference to a particular in-line filtration application as found in smoking products. The profile of the filter element may be adapted for use in other applications, eg, gas mask filters, without departing from the invention.

  Further details regarding the use of filter elements 10A-10E in smoking products are given below with reference to the remaining figures. The present invention is described in further detail with reference to a specific smoking product, ie a cigarette that utilizes a catalyst composition comprising ultrafine particles in a filter element. However, as will be appreciated by those skilled in the art, the main part / principle of the present invention applies to other tobacco products and other filter applications.

  FIG. 6 illustrates one embodiment of the smoking product of the present invention. As shown in FIG. 6, the cigarette 30 includes a generally cylindrical rod 35 of a fill or roll of smokable filler material 40 contained in a surrounding wrapping material 45. The rod 35 is commonly referred to as a “smoking rod” or “tobacco rod”. The end of the tobacco rod is open to expose the smokable filler material.

  In one embodiment of the present invention, the cigarette 30 includes a filter element that includes a catalyst composition, such as the filter element 10A shown in FIG. Although filter element 10A is shown in FIG. 6, any of filter elements 10A, 10B, 10C, 10D, 10E, or any other design incorporating the catalyst composition of the present invention may be used in the present invention. May be utilized in other smoking product embodiments.

  The filter element 10A is disposed adjacent to one end of the tobacco rod 35 such that the filter element and the tobacco rod are aligned end-to-end and are preferably axially aligned adjacent to each other. The filter element 10A generally has a cylindrical shape, and this diameter is essentially equal to the diameter of the tobacco rod. The end of the filter element is open to allow the passage of air and smoke therethrough. The filter element 10A includes a filter material 11 that is overwrapped along its surface extending in the longitudinal direction with an enclosing plug wrap material 60. The filter element can have more than one filter portion and / or a fragrance additive introduced therein.

  The filter element 10A may be attached to the tobacco rod 35 by a tip material 65 that surrounds both the entire length of the filter element and the adjacent region of the tobacco rod. The inner surface of the tip material 65 may be secured to the outer surface of the plug wrap 60 and the outer surface of the tobacco rod wrapping material 45 using a suitable adhesive. Smoking products that are ventilated or air diluted include air dilution means such as a series of perforations 18 each extending through the tip material and the plug wrap. The wrapping material 45 has a width equal to the entire circumference of the overlap area of cigarette + adhesive layer (made at the end of cigarette manufacture).

  The catalyst composition 13 is disposed in a cavity in the filter element 10A. The packaging material surrounding the catalyst composition may include dilution holes 18 extending through the tip material.

  FIG. 7 illustrates an embodiment of a smoking product that includes a filter element with a plurality of catalyst compositions disposed therein. Such smoking products can be prepared using the methods described in US Pat. No. 6,537,186.

  As illustrated in FIG. 7, the cigarette 102 includes a combustible material component 110 constrained within a retaining jacket of insulation 112. Located in the longitudinal direction behind the combustible material component 110 is the aerosol generating means 116. Aerosol generating means includes one or more aerosol forming materials (such as glycerin), tobacco form (tobacco powder, extract or dust), and aroma components (volatile by heat generated by combustion of combustible material components) Including. Preferably, the aerosol generating means comprises a support advantageously made of regenerated tobacco cast sheet cut filler material. Such a support is described in US patent application Ser. No. 07/800679 (filed Nov. 27, 1991), incorporated herein by reference. Combustible material component 110 is a co-pending patent application by the same applicant, entitled “Smoking Articulating Ultrafine Particles” (Cooks et al.), US patent application Ser. No. 10 / 382,244, the disclosure of which is incorporated herein by reference. ) May be included.

  The cigarette has a filter element 10A or tobacco element 10A disposed adjacent to one end of the aerosol generating means 116 such that the filter element and tobacco rod are aligned end to end, preferably axially adjacent to each other. Other suitable mouthpieces may further be included. The filter element 10A generally has a cylindrical shape and its diameter is essentially equal to the diameter of the tobacco rod. The end of the filter element is open to allow the passage of air and smoke therethrough. The filter element 10A may include a filter material 11 that is overwrapped along its surface extending longitudinally with an outer plug wrap material. The filter element includes the catalyst composition 13 of the present invention including ultrafine particles. As will be appreciated from the following description, the actual size of typical ultrafine particles may be less than 100 nm. The portion of the filter element that includes the catalyst composition includes air dilution holes 18 in the packaging material adjacent to the filter portion that includes the ultrafine particles.

  Referring again to the cigarette embodiment shown in FIG. 7, the filter element 10 </ b> A includes a cavity disposed between the two filter plugs 11. The two filter plugs may be conventional filter materials such as cellulose acetate filter material. The cavity is filled with a plurality of catalyst compositions 13 of the present invention. The cavity may further include other components such as those described above (eg, granular carbon).

  The particular embodiment of the smoking product of the present invention described with reference to FIGS. 6 and 7 introduces a catalyst composition into the filter element of the smoking product. The same or alternative embodiments of the present invention may include the catalyst composition of the present invention disposed in other components of the smoking product. For example, the catalyst composition may be introduced into, disposed near, or within an aerosol generating material, including introduction into smokable materials, packaging materials, fuel elements and / or other components. Good.

  FIG. 8 illustrates a smoking product of the present invention in which the catalyst composition 13 is disposed adjacent to the fuel element 110 in a smoking product similar to that described with reference to FIG. 7 and US Pat. No. 6,537,186. The embodiment of is shown. As shown in FIG. 8, air dilution holes 18 are provided in the portion of the smoking product that contains the catalyst composition. The filter element 130 in FIG. 8 represents a conventional cigarette filter, but the filter element of the present invention may be utilized.

  As will be appreciated by those skilled in the art, the descriptions in the following sections generally apply to the smoking product embodiments of the present invention, including the smoking products shown in FIGS.

  Smoking products are generally surrounded by packaging material. The wrapping material has a width equal to the entire circumference of the smoking product + adhesive layer overlap area (made at the end of cigarette manufacture). Suitable packaging materials are generally known to those skilled in the art and the above referenced patent applications and the following U.S. Pat. Nos. 4,452,259 (Norman); 5,878,754 (Peterson et al.); Specification (Hayden et al.); 5060675 (Milford et al.); 4998541 (Perfetti et al.); 4805644 (Hampl, Jr. et al.); No. 4450847 (Owens); No. 44420002 (Cline); and No. 4231377 (Cline et al.), Each incorporated herein by reference.

  Paper packaging materials suitable for use in the practice of the present invention are commercially available. Exemplary cigarette paper packaging materials are available from Ecusta Corp. as reference numbers 419, 454, 456, 460 and 473; from Michael, reference numbers Velin 413, Velin 430, VE 825. As C20, VE 825 C30, VE 825 C45, VE 826 C24, VE 826 C30 and 856DL; from Tervakoski, Tercig LK18, Tercig LK24, Tercig LK38, Tercig LK46T (Wattens) from Velin Beige 34, Velin Beige 46, Velin Beige 60, and reference number 454 Available as DL, 454 LV, 553, and 556. Typical hemp-containing cigarette paper packaging materials are available from Schweitzer-Muduit International, brand names 105, 114, 116, 119, 170, 178, 514, 523, 536, 520, 550, 557, 584, Available as 595, 603, 609, 615 and 668. Typical wood pulp-containing cigarette paper packaging materials are available from Schweitzer as brand names 404, 416, 422, 453, 454, 456, 465, 466 and 468.

  In certain embodiments of the present invention, the packaging material for smoking products is the same applicant's co-pending patent application, entitled “Smoking Articulating Wrapping Materials Ultrasizing Particles” (Cooks et al.), US Patent Application No. 10/342618 ( The disclosure may include the ultrafine particles described in (incorporated herein by reference).

  The filter element may be attached to the tobacco-rod / aerosol generating rod by a tip material that surrounds both the entire length of the filter element and the adjacent region of the tobacco rod. The inner surface of the tip material may be fixedly secured to the outer surface of the plug wrap and the outer surface of the tobacco rod packaging material using a suitable adhesive. Smoking products that are ventilated or air diluted include air dilution means such as a series of perforations each extending through the tip material and the plug wrap.

  A conventional automatic cigarette rod making machine useful for producing the smoking product of the present invention is a type commercially available from Morins PLC or Hauni-Werke Korber & Co. KG. belongs to. For example, a cigarette rod making machine of the type known as Mark 8 (commercially available from Molin) or PROTOS (commercially available from Haunibergke Kober) can be used, if appropriate Can be changed. A description of a PROTOS cigarette making machine is provided in US Pat. No. 4,474,190, column 5, lines 48-8, line 3, which is incorporated herein by reference. Suitable types of equipment for the manufacture of cigarettes are also described in US Pat. Nos. 4,844,100 (Holznagel); 5,156,169 (Holmes et al.) And 5,191,906 (Myracle, Jr. et al.); And PCT It is shown in WO 02/19848. The design of the various components of the cigarette making machine and the various materials used to make these components will be readily apparent to those skilled in the cigarette manufacturing industry.

  Smoking products generally have a length in the range of about 50 mm to about 100 mm and a full circumference of about 16 mm to about 28 mm. The aerosol generating means and the resulting smoking product can be manufactured in any known configuration using known cigarette manufacturing methods and equipment. The packaging material is formed in a circular shape so that both ends thereof are adjacent to each other. The ends of the packaging material can be adjacent to each other, substantially adjacent to each other, or slightly overlap each other. A cigarette rod having such a configuration includes a step of supplying paper wrapping paper from a bobbin in a properly equipped cigarette maker, a step of passing the packaging material through a decorative area of the cigarette maker, and a cigarette rod. It can be provided by the forming step.

The tobacco material used for the manufacture of the smoking product of the present invention can vary. Descriptions of various tobaccos, growth methods, harvesting methods and ripening methods are given in Tobacco Production, Chemistry and Technology, Davis et al. (Eds.) (1999). Tobacco is typically in the form of a cut filler (eg, about 1/10 inch to about 1/60 inch, preferably about 1/20 inch to about 1/35 inch wide, and about 1/4 inch to about 3 Used in tobacco filler strips or strands cut to an inch length). The amount of tobacco filler used in the cigarette is typically in the range of about 0.6 g to about 1 g. Tobacco filler, typically, the tobacco rod of about 100 mg / cm ³ ~ about 300 mg / cm ^3, often used to fill in the packing density of about 150 mg / cm ³ ~ about 275 mg / cm ^3. As used herein, “packing density” means the weight of packing material that occupies a unit volume within a smokable rod.

  Tobacco can be processed tobacco stems (eg, cut rolls or cut puff stems), volume expanded tobacco (eg, puff tobacco, propane expanded tobacco and dry ice expanded tobacco (DIET)), or recycled tobacco (eg, paper-making type or cast sheet). Recycled tobacco manufactured using a type method).

In general, cigarette materials for making cigarettes are used in so-called “blend” forms. For example, some common tobacco blends, commonly referred to as “American blends,” include smoke-aged tobacco, valley tobacco and oriental tobacco, and in many cases, certain species such as recycled tobacco and processed tobacco stems. A mixture of processed tobacco. The exact amount of each type of tobacco in the tobacco blend used for the manufacture of a particular cigarette brand varies from brand to brand. For example, Tobacco Encyclopedia, Voges (ed.) P. 44-45 (1984), Browne, The Design of Cigarettes, 3 rd Ed. , P. 43 (1990) and Tobacco Production, Chemistry and Technology, Davis et al. (Ed.) P. 346 (1999). Other representative tobacco blends are also described in US Pat. Nos. 4,924,888 (Perfetti et al.); 5056537 (Brown et al.); And 5220930 (Gentry); and Bombick et al., Fund. Appl. Toxicol. 39, p. 11-17 (1997). See also US Patent Publication No. 2003/0131860 (Ascraft et al.), The disclosure of which is incorporated herein by reference.

  If desired, in addition to the tobacco material described above, the tobacco blend or aerosol generating material of the present invention may further comprise the catalyst composition of the present invention. The catalyst composition may be distributed substantially uniformly throughout the tobacco or aerosol generating material, or may be arranged as a separate component in the smoking product. For example, the catalyst composition may be introduced into processed tobacco utilized in smoking products. Details regarding processed tobacco are disclosed in US patent application Ser. No. 10 / 463,211, filed Jun. 17, 2003, the disclosure of which is incorporated herein by reference.

  The tobacco and / or aerosol generating material can further include other components. Other components include casing materials (eg, sugar, glycerin, cocoa and licorice) and tip decoration materials (eg, fragrance materials such as menthol). The selection of specific casing and tip decoration components will depend on factors such as the sensory characteristics required, and the selection of those components will be readily apparent to those skilled in the art of cigarette design and manufacture. . Gutcho, Tobacco Flavoring Substances and Methods, Noyes Data Corp. (1972) and Leffingwell et al., Tobacco Flavoring for Smoke Products (1972).

  The smoking product can also introduce at least one fragrance component into the side seam adhesive that is applied to the packaging material during the manufacture of the tobacco rod. That is, for example, various fragrances are introduced into adhesives that can be applied to seam lines of packaging materials (such as side seam adhesives such as CS-2201A available from National Starch). Can do. These fragrances are used to mask or ameliorate any unsavory or malodor imparted by the smoke generated by the smoking product. Typical fragrances include methylcyclopentenolone, vanillin, ethyl vanillin, 4-parahydroxyphenyl-2-butanone, γ-undecalactone, 2-methoxy-4-vinylphenol, 2-methoxy-4-methyl. Phenol, 5-ethyl-3-hydroxy-4-methyl-2 (5H) -furanone, methyl salicylate, clary sage oil and sandalwood oil. Generally, this type of fragrance component is used in an amount of about 0.2% to about 6.0%, based on the total weight of the adhesive and the fragrance component.

  In general, the tip material surrounds the filter element and adjacent regions of the tobacco rod such that the tip material develops from about 3 mm to about 6 mm along the length of the tobacco rod. Generally, the tip material is a conventional paper tip material. The tip material can have a porosity that can be varied. For example, the tip material can be essentially air impermeable, air permeable, or treated to have perforations, openings or vent areas that provide air dilution means for the cigarette ( For example, by mechanical or laser drilling methods). The total surface area of the perforations and the location of the perforations along the circumference of the cigarette can be varied to adjust the performance characteristics of the cigarette.

  Embodiments of the present invention include embodiments in which a catalyst composition comprising ultrafine particles is introduced into a filter element of a smoking product. Generally, the filter element has a length in the range of about 5 mm to about 40 mm, preferably about 10 mm to about 35 mm; and a total circumference of about 17 mm to about 27 mm, preferably about 22 mm to about 25 mm. The catalyst compositions of the present invention will be placed in the filter element at a location that maximizes their catalytic activity while maintaining the desired performance characteristics of the smoking products. In one embodiment, the catalyst composition of the present invention is placed between 10-15 mm from the mouth end of the filter.

  The filter element has a wide range of filtration efficiencies. The filter element can have one portion of filter material, two or more longitudinally disposed portions, or other configurations. The filter may also include axially arranged pores to form a hollow filter element.

  The filter material can be any suitable material such as cellulose acetate, polypropylene, tobacco material, and the like. The filter material can further include carbon, eg, carbon particles. Examples of suitable filter materials are (i) a total denier of about 3 denier per filament and about 35,000, and (ii) a tow of cellulose acetate having a total denier of about 3.5 denier per filament and about 35,000 total denier. It is an item. Such tow items provide filter elements that exhibit greater than about 40% by weight of particulate matter removal efficiency from mainstream smoke. The plug wrap is generally a conventional paper plug wrap and can be air permeable or essentially air impermeable. However, if desired, unwrapped cellulose acetate filter elements can be used. Filter elements having two or more parts provided using known plug-tube integration methods can also be used. A variety of filter elements suitable for use in the present invention can be manufactured using known cigarette filter manufacturing methods and apparatus.

  Certain filter elements can provide minimal mainstream smoke removal efficiency while maintaining the desirable suction characteristics of cigarettes. Such minimal smoke removal efficiency is provided by so-called “low efficiency” filters. A low efficiency filter has a minimal ability to remove mainstream smoke particles. In general, low efficiency filters provide mainstream smoke particle removal efficiency of about 40% by weight or less. Low efficiency filters can be used because relatively low “tar” production is obtained primarily as a result of relatively high levels of aeration or air dilution. Such a cigarette configuration provides one means for reducing the production of mainstream gaseous components. An example of a suitable material for obtaining a low efficiency filter element is a cellulose acetate tow item having about 8 denier per filament and a total denier of about 40,000.

  The filter element can be manufactured with a cavity filled with a particulate material such as a carbonaceous material. For example, the filter element can be manufactured with a cavity between two filter plugs, such as those traditionally used in the manufacture of cellulose acetate filters. An apparatus and method for manufacturing such a filter element is described in US Pat. No. 6,537,186, which is incorporated herein by reference. As shown below, the catalyst composition of the present invention can be placed in the cavity of such a filter element. The cavities may also include other suitable active or inert components, including leptite, silica gel, and activated or inert carbon.

  Embodiments of catalyst compositions for use in the smoking products of the present invention are illustrated in the following specific, non-limiting examples.

Catalyst Preparation The catalyst composition of the present invention is prepared in the following manner.

  About 0.5128 g of tetrachloroauric (III) acid (49.5% gold metal, Alfa Aesar) was dissolved in 10 ml of deionized water and the solution was dissolved in 0.0671 g of 6N. Acidify with hydrochloric acid. About 20.0233 g of alumina (18-30 American mesh) is evenly coated with this acidified gold solution. Gold coated alumina particles (which had a pale yellow color) were dried at 95 ° C. for 16 hours. The dried gold coated alumina is added to 750 ml of deionized water containing 35 ml of 5.0N ammonium hydroxide. The suspension is stirred vigorously overnight. Next, the gold-coated alumina is allowed to stand and the liquid is decanted. Approximately 750 ml of deionized water is added and the mixture is stirred for an additional 20 minutes. The gold-coated alumina is allowed to stand for approximately 30 minutes and the supernatant is tested with an aqueous silver nitrate solution for the presence of chloride ions. The gold coated alumina is washed several times with deionized water. Washing is complete when chloride ions are no longer present in the supernatant. The gold coated alumina is dried at 95 ° C. overnight. The dried gold coated alumina is heated to 375 ° C. for about 8 hours. The final catalyst particles are free-flowing granules, dark purple and have a theoretical gold loading value of about 1.2% (weight of ultrafine particles vs. weight of catalyst composition (W / W)). Was. The catalyst is stored in a closed container.

Catalyst Preparation An alternative embodiment of the catalyst composition of the present invention is prepared as follows.

  Granular high surface area activated alumina (8-14 American mesh) is obtained as part number A505-212 from Fisher Scientific International. This alumina is crushed in a pestle mortar to reduce the particle size of the alumina. A set of sieves was used to collect 18-30 American mesh fraction ground alumina (corresponding to a particle size of about 0.6 mm to about 1 mm). The collected alumina is dried at 95 ° C. for 2 hours.

  Gold is obtained from Alpha Aesal Corporation as part number 12325 in the form of tetrachloroauric (III) acid (49.5% gold metal). About 0.5022 g of tetrachloroauric (III) acid is dissolved in 10 ml of deionized water and the solution is acidified with 0.050 g of 6N (6N) hydrochloric acid. Approximately 20.35 g of dry alumina (from above) is evenly coated with this acidified gold solution. Gold-coated alumina particles having a pale yellow color were dried at 95 ° C. for 2 hours. Dry gold-coated alumina is poured into 700 ml of deionized water containing 35 ml of 5N (5N) ammonium hydroxide. The suspension is stirred vigorously overnight. The next day, leave the gold-coated alumina and decant the liquid. Approximately 750 ml of deionized water is added and the mixture is stirred for an additional 5 minutes. The gold coated alumina is allowed to settle and the supernatant is tested with an aqueous silver nitrate solution for the presence of chloride ions. The gold coated alumina is washed several times with deionized water. Washing is considered complete when no more chloride ions are detected in the supernatant using an aqueous silver nitrate solution. The gold coated alumina is dried at 95 ° C. overnight. The dried gold coated alumina is then heated to 375 ° C. for 16 hours. The final catalyst particles were free-flowing granules, dark purple, and had a theoretical gold loading value of 1.2% (W / W). When not in use, the catalyst composition was stored in a closed container.

Catalyst Performance The effectiveness of the catalyst composition of the present invention produced in Examples 1 and 2 is determined by the gas mixture containing 95% air and 5% carbon monoxide and smoking of ECLIPSE® prototype cigarettes. And in the mainstream smoke generated by conventional burned cigarettes.

For the following tests, carbon monoxide / carbon dioxide NDIR (non-dispersive infrared analyzer) is manufactured by Filamatic Smoking Machine, Model DAB-5 (National Instruments Co., Baltimore, Maryland) Attached to one end). The CO / CO ₂ NDIR analyzer used in the following examples is commercially available from Rosemount Analytical Inc.

Reduction of the amount of carbon monoxide in the carbon monoxide-air mixture A gas mixture consisting of 5 wt% carbon monoxide (CO) and 95 wt% air is drawn through a glass tube containing a bed of catalyst composition. The tube is 12 cm long and 1.25 cm in diameter. The catalyst composition used is the catalyst composition prepared in Example 1.

  About 5 g of catalyst composition is filled to approximately tube size and held in place with the glass wool. A bed of this size had a pressure drop of about 70 mm of water, measured at a flow rate of 17.5 cc per second. The gas stream is passed through the bed at a flow rate of 50 cc per second (ie 50/30/2 smoking conditions) in a 30 second interval puff cycle.

The gas leaving the bed is passed through a CO / CO ₂ NDIR analyzer. The control (glass tube without catalyst composition) did not cause any conversion of carbon monoxide to carbon dioxide. However, the catalyst composition is effective in the oxidation of carbon monoxide to carbon dioxide. In the first 50 ml puff, about 85% of carbon monoxide is converted to carbon dioxide. Several puffs of the same gas composition were passed through the bed. The bed of catalyst composition maintained conversion efficiency even after 750 ml of gas passing through it. The average conversion efficiency is approximately 74.4% for each 50 ml 15 puff. There is no catalyst deactivation even after severe exposure to the test gas mixture.

Reduction of carbon monoxide in mainstream smoke of ECLIPSE® type cigarettes A glass tube containing the catalyst composition of Example 1 is prepared as described above. An experimental prototype of ECLIPSE® type cigarette is used for this example. The prototype is the same as the product currently available. The entire smoke from the mouth end of the cigarette is passed directly through the bed of catalyst composition. 50 ml of smoke was passed through the bed every 30 seconds for 2 seconds. The smoke leaving the bed is passed through a Cambridge pad to capture the particulate phase of the smoke. The resulting gas phase without smoke particulates is passed through an NDIR analyzer for CO / CO ₂ analysis. Subsequently, two additional prototype cigarettes were smoked under the same smoking conditions and the smoke passed through the same catalyst composition bed. A total of three cigarette smokes are passed through the catalyst bed.

  The prototype cigarette is smoked without a catalyst composition in a glass tube to determine the amount of carbon monoxide in the prototype cigarette. The prototype cigarette produced 33.5 units of carbon monoxide in 50 ml 15 puffs each. Smoking of the first test cigarette smoked through the catalyst bed resulted in a decrease of 13.9 units / cigarette in carbon monoxide from 33.5 units / cigarette in the control (58.55% in carbon monoxide Reduced). Smoking the second prototype cigarette smoked through the same bed resulted in a 31.6% reduction in 22.9 units of carbon monoxide, carbon monoxide per cigarette. Smoking the third prototype cigarette through the same bed resulted in a 23.5% reduction in 25.6 units of carbon monoxide, carbon monoxide per cigarette.

  Inactivation is seen in the second smoking catalyst composition and the third prototype cigarette is not observed when the catalyst composition is exposed to a mixture of air and carbon monoxide only. Thus, the observed inactivation can be attributed to specific components in smoke or components other than carbon monoxide.

Measurement of Catalytic Activity This example illustrates the catalytic activity of the ultrafine particle catalyst composition produced in Example 2 above.

Catalytic activity is expressed herein in terms of “specific activity” (Turn-Over-Frequency: TOF). For this application, TOF is measured by placing a known amount of test catalyst composition in a glass tube 12 cm long and 1.25 cm in diameter. The catalyst composition is sandwiched between two glass fiber mats. A gas mixture containing 5% carbon monoxide and 95% air at room temperature is passed through the catalyst bed at a rate of 50 cc per second in a 30 second interval puff cycle. This results in an effective flow rate of 1.5 liters / minute. The exit gas is passed through a non-dispersive infrared analyzer where the concentration of CO and CO ₂ is recorded. To measure TOF, 15 50 ml puffs of test gas (5% CO, 95% air) are passed through the bed containing the catalyst composition. The concentration of CO and CO ₂ leaving the bed is recorded in the last 50 ml puff of outlet gas. TOF is expressed as% converted CO / g catalyst per second. Therefore,
TOF = (CO _inlet− CO _outlet ) × 100 / (CO _inlet × catalyst weight × 2)
Table 1 shows the TOF of the catalyst composition produced by the procedure described herein.

  The catalyst composition of Example 2 exhibited about 2.8 times the catalytic activity of the catalyst composition of Example 1.

Reduction of carbon monoxide in mainstream smoke of conventional cigarettes Conventional cigarettes with a cavity filter containing activated carbon can be used to improve the efficiency of catalyst preparation in reducing the amount of CO in cigarette smoke for this study. Used to measure. The smoke exiting the cigarette is passed through the bed of catalyst composition produced in Example 2 contained in a glass tube (length 12 cm, diameter 1.25 cm). Smoke exiting the catalyst bed is filtered through a Cambridge pad. Filtered smoke is fed to an NDIR analyzer.

  This treatment exposes the catalyst composition to the entire (ie, both particulate and gas phase) smoke. Wet Total Particulate Matter (“WTPM”) is measured as an increase in the weight of the Cambridge pad and CO is measured by NDIR.

  As a control, 25 cigarettes were smoked under FTC 35/60/2 smoking conditions. The results for the control cigarette are shown in Table 2. The data represents the average of 25 cigarettes.

  Table 2 shows the FTC smoking production of the control cigarette. The cigarette produced 11.7 mg WTPM, 9.7 mg tar and 9.3 mg CO when smoked under standard FTC conditions.

  For this example, cigarettes were smoked for 8 puffs at 50/30/2 smoking conditions. The control cigarette produced 31 mg WTPM and 11.0 mg CO. Smoking the same cigarette in the presence of catalyst produced 27 mg WTPM and 7.6 mg CO. These results are shown in FIG. The catalyst bed removed 3.4 mg CO and 4 mg WTPM. Thus, CO is reduced by about 31%.

  One possible problem with the use of catalyst compositions in cigarette filter elements is that the active sites of the catalyst can be inactivated by cigarette smoke. Several methods have been tested to reduce the smoke deactivation effect on the catalyst composition. The removal efficiency of the catalyst composition was “doubled” when 1 g of activated carbon (Pica G277, 20 × 50 American mesh) was mixed with 1 g of the catalyst composition of Example 1 and the test described herein was repeated. It became. A mixture containing only half of the amount of catalyst removed the amount of CO from the smoke, similar to 2 g of the catalyst composition of Example 1. The removal efficiency of the mixture is significantly reduced when the activated carbon is replaced with the same amount of high surface area alumina (Fischer). Thus, activated carbon is potentially more effective than alumina in removing smoke components that contaminate the catalyst.

  Although the present invention has been described with reference to preferred embodiments, it should be understood that variations and modifications may be apparent to those skilled in the art. Such variations and modifications are to be considered within the authority and scope of the present invention as defined by the claims appended hereto.

FIG. 3 is a perspective view showing an embodiment of the filter element of the present invention. FIG. 6 is a perspective view showing another embodiment of the filter element of the present invention. FIG. 6 is a perspective view showing a further embodiment of the filter element of the present invention. FIG. 6 is a perspective view showing a further embodiment of the filter element of the present invention. FIG. 6 is a perspective view showing a still further embodiment of the filter element of the present invention. It is a perspective view which shows one Embodiment of the smoking product of this invention. It is a perspective view which shows other embodiment of the smoking product of this invention. FIG. 6 is a perspective view showing a further embodiment of the smoking product of the present invention. 2 is a graphical plot showing the efficiency of the catalyst composition of the present invention in the conversion of carbon monoxide to carbon dioxide.

Claims (24)

  A catalyst composition comprising a support and ultrafine particles.   The catalyst composition of claim 1, wherein the support comprises a metal oxide, a ceramic, a metal, an alloy, a zeolite, a polymer, a carbon-containing material, or a mixture thereof.   The catalyst composition according to claim 1, wherein the ultrafine particles include gold, copper, silver, platinum, palladium, rhodium, nickel and other transition metals, iron, a noble metal alloy, a metal oxide, and a mixture thereof. A rod of aerosol generating material,
A filter element combined with the first end of the rod, and at least one catalyst composition comprising ultrafine particles;
The at least one catalyst composition acts to convert carbon monoxide to carbon dioxide at temperatures below 150C.   The smoking product of claim 4, wherein the catalyst composition is disposed within the filter element.   The smoking product of claim 5, wherein the filter element comprises carbon.   The smoking product of claim 6, wherein the filter element further comprises an adsorbent.   The smoking product of claim 4, wherein the catalyst composition is disposed within a rod of the aerosol generating material.   The smoking product of claim 4 further comprising a heat source.   The smoking product of claim 9, wherein the catalyst composition is disposed adjacent to the heat source.   The smoking product of claim 9, wherein the catalyst composition is disposed in the filter element.   The smoking product of claim 4, wherein the catalyst composition comprises a plurality of ultrafine particles disposed on at least one support. Wherein the at least one support is cerium oxide _(CeO 2), smoking articles according to claim 12 comprising at least one of titanium dioxide _(TiO 2), alumina _(Al 2 _{O 3)} or mixtures thereof. Smoking product according to claim 13 wherein said at least one support, including alumina _(Al 2 _{O 3).}   The smoking product according to claim 13, wherein the ultrafine particles include a noble metal.   The smoking product of claim 15, wherein the noble metal has an average particle size of up to about 100 nm.   The smoking product of claim 16, wherein the noble metal has an average particle size of up to about 10 nm.   The smoking product of claim 17, wherein the noble metal has an average particle size of about 2 to about 4 nm.   Introducing at least one catalyst composition into a filter element of a smoking product, wherein the at least one catalyst composition is disposed on at least one support and the at least one support. A method of promoting the conversion of carbon monoxide to carbon dioxide in the smoking product comprising ultrafine particles. The method of claim 19, wherein the at least one support comprises at least one of cerium oxide (CeO ₂ ), titanium dioxide (TiO ₂ ), alumina (Al ₂ O ₃ ), or a mixture thereof. The method of claim 19, wherein the at least one support comprises alumina (Al ₂ O ₃ ).   The method according to claim 21, wherein the ultrafine particles include gold.   A product comprising the catalyst composition according to claim 1.   A filter element comprising the catalyst composition of claim 1.

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