US20070246055A1

US20070246055A1 - Smoking articles and wrapping materials therefor

Info

Publication number: US20070246055A1
Application number: US11/408,625
Authority: US
Inventors: Robert Oglesby
Original assignee: Individual
Current assignee: RJ Reynolds Tobacco Co
Priority date: 2006-04-21
Filing date: 2006-04-21
Publication date: 2007-10-25

Abstract

A smoking article includes a smokable rod manufactured using a paper wrapping material having an additive material applied thereto as a pattern. The additive material is applied as coating formulation (e.g., an aqueous coating formulation) incorporating (i) inulin and guar gum, (ii) inulin and a polymeric material such as hydroxypropylcellulose or an alginate, or (ii) guar gum and a polymeric material such as hydroxypropylcellulose.

Description

FIELD OF THE INVENTION

The present invention relates to smoking articles, and in particular, to wrapping materials associated with those smoking articles. More specifically, the present invention relates to cigarettes, and in particular, to the positioning of additive material to desired locations of wrapping materials of cigarette rods.

BACKGROUND OF THE INVENTION

Smoking articles, such as cigarettes, have a substantially cylindrical rod-shaped structure and include a charge, roll, or column of smokable material, such as shredded tobacco, surrounded by a paper wrapper, to form a “cigarette rod,” “smokable rod” or a “tobacco rod.” Normally, a cigarette has a cylindrical filter element aligned in an end-to-end relationship with the tobacco rod. Typically, a filter element comprises plasticized cellulose acetate tow circumscribed by a paper material known as “plug wrap.” Certain cigarettes incorporate filter elements comprising, for example, activated charcoal particles. Typically, the filter element is attached to one end of the tobacco rod using a circumscribing wrapping material known as “tipping paper.”
A cigarette is used by a smoker by lighting one end of that cigarette, and burning the tobacco rod. The smoker then receives mainstream smoke into his or her mouth by drawing on the opposite end of the cigarette. During the time that the cigarette is not being drawn upon by the smoker, the cigarette remains burning.
Numerous attempts have been made to control the manner that a cigarette burns when the cigarette is not being drawn upon. For example, cigarette papers have been treated with various materials to cause cigarettes incorporating those papers to self extinguish during periods when those cigarettes are lit but are not being actively puffed. Certain treatment methods have involved applying materials to the paper in circumferential bands or longitudinal stripes, creating areas that affect the burn rate of cigarettes incorporating that type of cigarette paper. See, for example, U.S. Pat. Nos. 3,030,963 to Cohn; 4,146,040 to Cohn; 4,489,738 to Simon; 4,480,650 to Weinert; 4,615,345 to Durocher; 6,606,999 to Crooks et al; 6,827,087 to Wanna et al; and 6,848,449 to Kitao et al.; 6,904,917 to Kitao et al.; and U.S. Patent Application Pub. Nos. 2004/0231685 to Patel et al.; 2005/0016556 to Ashcraft et al.; and 2005/0076929 to Fitzgerald et al.; each of which is incorporated herein by reference. In addition, numerous references disclose applying films to the paper wrapping materials of tobacco rods. See, for example, U.S. Pat. Nos. 1,909,924 to Schweitzer; 4,607,647 to Dashley; and 5,060,675 to Milford et al., each of which is incorporated herein by reference.
“Banded” paper wrapping materials that are used for cigarette manufacture possess segments defined by the composition, location, and properties of the various materials within those wrapping materials. Numerous references contain disclosures suggesting various banded wrapping material configurations. See, for example, U.S. Pat. Nos. 1,996,002 to Seaman; 2,013,508 to Seaman; 4,452,259 to Norman et al.; 5,417,228 to Baldwin et al.; 5,878,753 to Peterson et al.; 5,878,754 to Peterson et al.; 6,198,537 to Bokelman et al.; 6,779,530 to Kraker; 6,837,248 to Zawadzki et al; and 6,725,867 to Peterson et al.; and U.S. Patent Application Pub. Nos. 2005/0016556 to Ashcraft et al. and 2005/0229941 to Minami et al.; each of which is incorporated herein by reference. Methods for manufacturing banded-type wrapping materials also have been disclosed. See, for example, U.S. Pat. Nos. 4,739,775 to Hampl, Jr. et al.; and 5,474,095 to Allen et al.; and PCT Application Pub. Nos. WO 02/44700 to Watkins and WO 02/055294 to Hammersmith et al. Some of those references describe banded papers having segments of paper, fibrous cellulosic material, or particulate material adhered to a paper web. See, U.S. Pat. Nos. 5,263,999 to Baldwin et al.; 5,417,228 to Baldwin et al.; 5,450,863 to Collins et al.; and 6,502,613 to Suzuki; and U.S. Patent Application Pub. No. 2005/0045297 to Garg et al. A representative method for manufacturing cigarettes having treated wrapping materials is set forth in U.S. Pat. No. 5,191,906 to Myracle, Jr. et al. Additive materials can be applied to cigarette paper wrapping materials while those wrapping materials are being used for cigarette manufacture (i.e., in a so-called “on-line” fashion). See, for example, U.S. Pat. Nos. 1,999,223 to Weinberger; 1,999,224 to Miles; and 6,848,449 to Kitao et al.; 6,904,917 to Kitao et al.; and U.S. Patent Application Pub. Nos. 2004/0129281 to Hancock et al; 2004/0261805 to Wanna et al; 2005/0039764 to Barnes et al.; and 2005/0076929 to Fitzgerald et al.; each of which is incorporated herein by reference.
It would be desirable to apply additive material in a controlled manner as a predetermined pattern (e.g., as bands) to wrapping material of the type that is used for the manufacture of smokable rods for cigarettes. It also would be desirable to provide an additive material formulation that is capable of being applied to the wrapping material in an efficient and effective manner. It also would be desirable to ensure that the wrapping material so treated with additive material, when employed for the manufacture of a cigarette rod, yields a cigarette that meets standards of quality and behavior desired by the manufacturer of that cigarette.

SUMMARY OF THE INVENTION

The present invention provides manners and methods for manufacturing smoking articles, such as cigarettes. In a preferred aspect of the present invention, a suitable additive material is applied to the wrapping material of a cigarette rod, and that additive material includes at least one type of polymeric component. Typical additive materials incorporate a mixture of polymeric components. The additive material is applied to at least one major surface of the wrapping material, and most preferably, to one major surface of the wrapping material.
The present invention also relates to wrapping materials having additive material formulations applied thereto (most preferably in a controlled manner), and to cigarettes manufactured from those wrapping materials. For example, additive material is applied to a wrapping material as a formulation of the present invention; and that formulation incorporates at least one type of polymeric agent, and most preferably, a polymeric agent mixture.
A representative additive material formulation, and in particular, a representative polymeric agent mixture, most preferably incorporates a polymeric agent that can be characterized as a low viscosity material; that is, a material that can be used to reduce the amount of solvent or liquid carrier within the formulation, without acting to increase the viscosity of that formulation to any significant degree. Exemplary preferred polymeric agents of this type are relatively low molecular weight inulin-type materials, which include inulins and modified inulins.
A representative additive material formulation, and in particular, a representative polymeric agent mixture, most preferably incorporates a polymeric material that can be characterized as providing a thickening property to the formulation; that is, an agent that provides desirable rheological properties to the formulation. Representative thickening agents are polymeric materials that because of character or behavior, because of viscosities that they exhibit, and because of factors such as their molecular weight, have the ability to provide an increased viscosity to a formulation into which they are incorporated.
A representative additive material formulation, and in particular, a representative polymeric agent mixture, most preferably incorporates a polymeric material that can be characterized as providing film-forming properties to the formulation; that is, an agent that provides desirable functional effects or properties to the formulation. That is, film-forming agents act to provide a formulation that can allow the formulation to be applied to the wrapping material in a desired manner (e.g., as a pre-determined pattern), and can provide a treated wrapping material that exhibits desired functional behaviors. Representative film-forming agents are polymeric materials of varying molecular weights. The thickening agent and the film-forming agent can be provided by one particular type of polymeric material, or one type of polymeric material that is provided in at least two forms, or at least two ranges of molecular weights. That is, certain polymeric materials can have the ability to act as both film-forming and thickening agents. Alternatively, the thickening agent can be provided by one type of polymeric material, and the film-forming agent can be provided by a different type of polymeric material.
One representative type of additive material formulation incorporates a mixture of (i) a material such as an inulin-type material, and (ii) at least one polymeric film-forming agent (e.g., which can include a polymeric material such as guar gum or a relatively low molecular weight alginate). Such a formulation preferably includes a polymeric agent that can be characterized as a thickening agent.
Another representative type of additive material formulation incorporates a mixture of (i) guar gum, and (ii) at least one other polymeric material. Such a formulation can further include a material such as an inulin-type material.
Representative formulations of additive materials are most preferably water-based formulations; but may alternatively be formulations containing water-miscible components (e.g., one or more alcohols), or that are non-aqueous based (e.g., organic solvent) in nature.
Optional ingredients, such as flavoring agents, preservatives, pigments and/or colorants, also can be incorporated into the aforementioned formulations. Ingredients such as water soluble and/or water insoluble filler materials (e.g., sodium chloride, calcium chloride, potassium citrate and/or calcium carbonate) also can be incorporated into those formulations.
Certain aspects of the present invention involve transferring additive material to, and retaining additive material on, desired locations of a wrapping material (e.g., paper wrapping web). For example, wrapping material having a formulation incorporating a polymeric agent mixture (e.g., a formulation having an adhesive-type of character or nature) disposed thereon or otherwise applied thereto (e.g., by printing) can have liquid solvent or carrier removed (e.g., the treated wrapping material can be dried to remove significant amounts of water, when the formulation is a water-based formulation) and wound onto a roll that is adapted for later use for smoking article manufacture.
Other aspects of the present invention involve transferring the polymeric agent mixture, and retaining that mixture on, desired locations of, a wrapping material suitable for use for smoking article manufacture (e.g., paper wrapping web) when manufacturing smoking articles from those materials using a cigarette making machine. That is, a formulation of additive material is applied to a continuous advancing strip of a paper web within a region of an automated cigarette making machine system (e.g., a machine designed to produce a continuous cigarette rod) in a desired amount, in a desired configuration and in a desired location.
For a wrapping material of the present invention, the region thereof coated with coating formulation of the present invention most preferably exhibits a diffusion capacity in that coated region, when measured at ambient temperature, that is relatively low; but exhibits a higher diffusion capacity in that coated region when measured after being subjected to exposure to a temperature significantly above ambient temperature. That is, the amount of polymeric agent and other additive material components, and the total amount of those components applied to the wrapping material (e.g., as a coated film), are such that the wrapping material exhibits the foregoing diffusion capacity-related behavior.
In another aspect of the invention, a smoking article incorporating a tobacco rod manufactured from wrapping material treated with the additive material formulation of the present invention can possess at least one band of additive material located in a region of its tobacco rod such that the band is capable of providing that smoking article with the ability to meet certain smoking article extinction criteria. Certain smoking articles of the present invention possessing tobacco rods manufactured using certain appropriately treated wrapping materials, when tested using the methodology set forth in the Cigarette Extinction Test Method by the National Institute of Standards and Technology (NIST), Publication 851 (1993) using 10 layers of Whatman No. 2 filter paper, meet criteria requiring extinction of greater than about 50 percent, preferably greater than about 75 percent, more preferably greater than about 90 percent, and most preferably about 100 percent, of cigarettes tested. Certain cigarettes of the present invention possessing tobacco rods manufactured using certain appropriately treated wrapping materials, when tested using the methodology set forth in the methodology set forth in ASTM Designation: E 2187-02b using 10 layers of Whatman No. 2 filter paper, meet criteria requiring extinction of greater than about 50 percent, preferably greater than about 75 percent, more preferably greater than about 90 percent, and most preferably about 100 percent, of cigarettes tested.

BRIEF DESCRIPTION OF THE DRAWINGS

The FIGURE is an exploded perspective of smoking article, showing the smokable material, the wrapping material components, and the filter element.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the FIGURE, there are shown the components of a smoking article 174 in the form of a cigarette. The cigarette 174 includes a generally cylindrical rod 186 of a charge or roll of smokable filler material 188 contained in a circumscribing wrapping material 190 of the present invention. The rod 186 is conventionally referred to as a “tobacco rod”. The ends of the tobacco rod are open to expose the smokable filler material. At one end of the tobacco rod 186 is the lighting end 195, and at the other end is shown a filter element 200. The cigarette 174 is shown as having one printed band 202 printed on wrapping material 190, and that band entirely circumscribes the cigarette rod in a direction transverse to the longitudinal axis of the cigarette. That is, the band 202 provides a cross-directional region relative to the longitudinal axis of the cigarette 174. The band 202 most preferably is applied to the inner surface of the wrapping material 190 (i.e., facing the smokable filler material), but can be, in a much less preferred embodiment, applied to the outer surface of the wrapping material 190. Although the cigarette 174 shown in The FIGURE has wrapping material having one band, the cigarette also can possess wrapping material having two, three, or more spaced bands. The band 202 comprises additive materials of a water-based coating formulation that incorporates a polymeric agent mixture of the present invention.
The cigarette 174 normally includes a filter element 200 or other suitable mouthpiece positioned adjacent one end of the tobacco rod 186 such that the filter element and tobacco rod are axially aligned in an end-to-end relationship, preferably abutting one another. Filter element 200 has a generally cylindrical shape, and the diameter thereof is essentially equal to the diameter of the tobacco rod. The ends of the filter element are open to permit the passage of air and smoke therethrough. The filter element 200 includes filter material 205 (e.g., plasticized cellulose acetate tow) that is overwrapped along the longitudinally extending surface thereof with circumscribing plug wrap material 206. The filter element 200 can have two or more filter segments, and/or flavor additives incorporated therein.
The filter element 200 is attached to the tobacco rod 186 by tipping material 208 which circumscribes both the entire length of the filter element and an adjacent region of the tobacco rod. The inner surface of the tipping material 208 preferably is secured to the outer surface of the plug wrap 206 and the outer surface of the wrapping material 190 of the tobacco rod using a suitable adhesive. A ventilated or air-diluted smoking article is provided with an air-dilution means, such as a series of perforations 210, each of which extend through the tipping material and plug wrap.
Various representative types of cigarette components are set forth in U.S. Pat. No. 5,220,930 to Gentry and U.S. Patent Application Pub. Nos. 2004/0255965 to Perfetti et al.; 2004/0261807 to Dube et al.; 2005/0066982 to Clark et al. and 2005/0066986 to Nestor et al., which are incorporated herein by reference. See, also, Johnson, Development of Cigarette Components to Meet Industry Needs, 52^ndT.S.R.C. (September, 1998). In addition, representative cigarette components and methods for manufacturing cigarettes from those components are set forth in U.S. patent application Ser. No. 11/375,700, filed Mar. 14, 2006, to Thomas et al., which is incorporated herein by reference.
Various types of equipment and methods for manufacturing cigarettes, and for applying additive material formulation to smoking article wrapping material, are known. For example, representative types of equipment and the operation thereof are set forth in U.S. Pat. No. 6,848,449 to Kitao et al.; 6,904,917 to Kitao et al.; U.S. Patent Application Pub. Nos. 2004/0129281 to Hancock et al.; 2004/0231685 to Patel et al; and 2005/0039764 to Barnes et al.; and 2005/0076929 to Fitzgerald et al.; which are incorporated herein by reference. Other representative techniques for applying additive material formulation to wrapping material are set forth in U.S. Pat. No. 6,779,530 to Kraker; U.S. Patent Application Pub. Nos. 2005/0016556 to Ashcraft et al.; 2005/0103355 to Holmes and 2005/0194014 to Read, Jr.; and PCT WO 04/095957 to Bray et al., which are incorporated herein by reference. As such, there are various known manners and methods for applying additive material formulations in a desired manner (e.g., as a coating or film) to desired locations and/or in desired patterns on wrapping materials, such as paper wrapping materials suitable for use for the manufacture of tobacco rods for cigarettes.
Coating formulation incorporating the additive material typically is applied to wrapping material that is supplied from a roll. In one regard, the formulation can be applied to wrapping material supplied from a bobbin. The amount of wrapping material on a bobbin can vary, but the length of continuous strip of wrapping material on a bobbin typically is more than about 6,000 meters; and generally, the length of continuous strip of wrapping material on a bobbin typically is less than about 7,000 meters. The width of the wrapping material can vary, depending upon factors such as the circumference of the smokable rod that is manufactured and the width of the overlap region zone that provides for the sideseam. Typically, the width of a representative continuous strip of wrapping material useful for cigarette rod manufacture is about 24 mm to about 30 mm.
Paper wrapping materials of the present invention are useful as components of smoking articles such as cigarettes. Preferably, one layer of the wrapping material of the present invention is used as the wrapping material circumscribing the smokable material, and thereby forming the tobacco rod of a cigarette. Most preferably, the wrapping material has the coated regions located on the “wire” side thereof; and the “wire” side of that wrapping material forms the inner surface of the circumscribing wrapping material of the tobacco rod. That is, when the wrapping material is used to manufacture a smokable rod, the “wire side” major surface of the wrapping material that circumscribes the smokable material faces that smokable material. Typically, the “felt” side of the wrapping material is used as the visible outer surface of the tobacco rod. The terms “wire side” and “felt side” in referring to the major surfaces of paper sheet are readily understood as terms of art to those skilled in the art of paper and cigarette manufacture.
The selection of a particular wrapping material will be readily apparent to those skilled in the art of cigarette design and manufacture. Typical paper wrapping materials are manufactured from fibrous materials (e.g., a cellulosic materials, such as wood pulp), and optional filler materials (e.g., calcium carbonate), to form so-called “base sheets.” Such wrapping material base sheets have basis weights that can vary, and exhibit porosities that can vary. See, for example, the representative wrapping materials, including those commercially available paper wrapping materials that are set forth in U.S. Pat. Application Pub. Nos. 2004/0129281 to Hancock et al.; 2005/0016556 to Ashcraft et al.; and 2005/0076929 to Fitzgerald et al. Other types of wrapping materials, and components thereof, are set forth in U.S. Pat. No. 6,868,855 to Shafer et al. and U.S. Pat. Application Pub. Nos. 2004/0134631 to Crooks et al. and 2006/0027243 to Matsufuji et al.; and EP 1234514 to Grider et al.; which are incorporated herein by reference.
The base sheets can be treated so as to impart a change to the overall physical characteristics thereof and/or so as to introduce a change in the overall chemical compositions thereof. For example, a base sheet can be electrostatically perforated, coated with a film, treated with burn chemicals, or treated with flavoring agents or aroma precursors. Various additives can be added to, or otherwise incorporated into, the wrapping material simultaneously to, or at different stages during or after, the paper manufacturing process. See, for example, U.S. Pat. Application Pub. Nos. 2005/0016556 to Ashcraft et al. and 2005/0076929 to Fitzgerald et al.
The base sheet can be pre-treated, prior to application of an additive material formulation over discrete regions (e.g., as bands or so as to provide banded regions) to provide distinct coated areas. That is, the base sheet most preferably is treated with an appropriate coating formulation pursuant to the present invention such that virtually the entire base sheet is treated with a polymeric material (e.g., as a coating), and discrete coated areas of additive formulation may subsequently be applied over the treated base sheet. For example, virtually the entire major surface of the base sheet can be treated with a coating formulation incorporating a polymeric material, such as an alginate. The coating formulation can be applied to either or both major surfaces of the wrapping material, or the coating can be applied so as to be dispersed throughout the base web. Different application techniques may be used for the base coating formulation. For example, a liquid formulation incorporating polymeric material can be sprayed on to the base sheet, printed onto the base sheet, applied using a size press, or using other suitable application and drying techniques. Preferably, the amount of polymeric material (e.g., an alginate) applied to virtually the entire base sheet is less than about 2.5 g/m², often less than about 1 g/m², and frequently less than about 0.5 g/m², on a dry weight basis. See, for example, U.S. Pat. Application Pub. Nos. 2005/0016556 to Ashcraft et al. and 2005/0076929 to Fitzgerald et al.
Preferably, the amount of polymeric material that is applied to virtually the entire surface of the base sheet is not sufficient on its own to provide self extinction properties to a cigarette using the base sheet. That is, the diffusion capacity of such a treated base sheet preferably is less than about 2.5 cm/sec., but typically is greater than about 1 cm/sec., and often is greater than about 0.5 cm/sec., when measured at 25° C. This range may vary depending upon the initial, untreated properties of the base sheet. A base sheet treated in such a manner (e.g., with an alginate) so as to provide a thin but porous pre-layer thereto can be further treated with additive material to provide a pattern (e.g., bands) thereon. A representative base sheet treated with a pre-layer of alginate can, in some instances, (i) exhibit a controlled porosity and/or diffusivity, (ii) provide for control of subsequent additive material application, (iii) provide for improved drying and reduced blocking of base sheet that is subsequently treated with additive material, and (iv) provide a means for alternating to some extent the smoke chemistry of a cigarette manufactured from that treated base sheet.
Diffusion, with respect to a cigarette wrapping material having a coated region of additive material, is the amount of gas transported through the wrapping material when a gas concentration gradient is present. See, Baker et al., The Diffusion of Carbon Monoxide out of Cigarettes, Beitr. Tabakforsch., Vol. 9(3), 131-140 (1977); Drake et al., On a Cell to Measure Diffusion Coefficients of Gases through Cigarette Papers, Int. J Heat Mass Transfer, Vol. 23, 127-134 (1980); Baker, The Viscous and Inertial Flow of Air through Perforated Papers, Beitr. Tabakforsch., Vol. 14(5), 253-260 (1989); Miura, Oxygen Diffusion through Cigarette Paper, Beitr. Tabakforsch., Vol. 19(4), 205-208 (2001); Miura et al., Heat Emission from a Burning Cigarette, Beitr. Tabakforsch., Vol. 19(5), 245-249 (2001); Rostami et al., Modeling the Diffusion of Carbon Monoxide and Other Gases from the Paper Wrapper of a Cigarette During Puffing, J. Anal. Pyrolysis, Vol. 66, 263-280 (2003); Rostami et al., Modeling of a Smoldering Cigarette, J. Anal. Pyrolysis, Vol. 66, 281-301 (2003). An apparatus suitable for measuring the diffusion capacity of a wrapping material, including coated regions thereof, is set forth in U.S. Patent Application Pub. No. 2005/0087202 to Norman et al., which is incorporated herein by reference. See, also, Norman et al., Measurement of Gas Diffusion Capacity of Cigarette Papers, Beitr. Tabakforsch. Int. Vol. 21 (2205) 425-434 (2005), which is incorporated herein by reference.
A coating formulation of the present invention may incorporate a low viscosity polymeric material. Such an ingredient preferably is used in an amount that is effective for providing, or at least sufficient to provide a formulation having a relatively low liquid solvent or carrier (e.g., water) content. That is, the polymeric ingredient preferably is used primarily for the purpose of significantly decreasing the moisture content of the formulation. As such, the ingredient can assist in providing a coating formulation exhibiting improved drying and reduced blocking of base sheet that is subsequently treated with additive material. However, the ingredient preferably exhibits characteristics, and is employed in an amount, such that the use of the ingredient will not result in significantly increasing the viscosity of the coating formulation.
Exemplary low viscosity polymeric materials include inulins and modified inulins. Inulin is a fructo-oligosaccharide. Exemplary forms of inulin and partially hydrolyzed forms of inulin are available Ticaloid LC-CSR-2 and Inulin LV 110 from T.I.C. Gums; as Oliggo-Fiber LC/HT and Oliggo-Fiber F97 from Cargill, Incorporated; and as Beneo HP from Orafti Group.
The amount of low-viscosity polymeric material within the coating formulation can vary. Typically, for a representative ingredient such as an inulin or modified inulin, the amount can be as much as up to about 50 percent, and can range from about 5 percent to about 30 percent, often from about 10 percent to about 25 percent, based on the total weight of the coating formulation prior to use (i.e., including the liquid solvent or carrier of the formulation). Although the viscosity of the formulation may vary, the amount of inulin-type material that is incorporated into the formulation may be dependent upon factors such as specific type and amount of other polymeric material present within the formulation. For example, for formulations incorporating relatively high levels of polymeric materials that have the ability to thicken the formulation, the addition of relatively small amounts of inulin may have the effect of causing substantial thickening of the formulation.
The coating formulation that is applied to the wrapping material includes at least one film-forming agent. The film-forming agent is a polymeric material that can be applied to the wrapping material to form a pattern (e.g., spaced bands), sufficiently adhere to the wrapping material, and provide a decrease in the air permeability of the wrapping material in the area where the coating formulation is applied.
The coating formulation may also incorporate a thickening agent. Such a material preferably provides desirable rheological properties to the formulation. Such a material may be selected, and employed in a manner, such that the coating formulation has the form of a paste that can be readily applied in a desired fashion to the wrapping material. It is preferred that rheology of the coating formulation is not overly thick or overly thin, but that the paste is of such consistency that it can be applied to a wrapping material without damaging the material. Preferred coating formulations may also function as adhesives, as it is desirable for those coatings to remain in intimate contact with (e.g., to adhere to or otherwise remain secured to) desired locations on the wrapping material where those formulations are applied, and preferred thickening agents assist in facilitating such behaviors. Typically, thickening agents are polymeric materials that are selected on the basis of possessing relatively high molecular weights, and hence exhibiting relatively high viscosities when incorporated within a liquid formulation.
The thickening agent and the film-forming agent can be provided by one particular type of polymeric material, or one type of polymeric material that is provided in at least two forms, or in more than one range of molecular weights. That is, certain polymeric materials can have the ability to act as both film-forming and thickening agents. Alternatively, the thickening agent can be provided by one type of polymeric material, and the film-forming agent can be provided by a different type of polymeric material.
Exemplary preferred polymeric agents include alginates, such as sodium alginate, potassium alginate, ammonium alginate, and the like. Exemplary alginates are available as Kelgin RL, Manucol LD, Manucol LB, Manugel LBA, and Keltone LVCR NF from ISP Corporation. Particularly preferred alginates are relatively low molecular weight alginates. See, for example, the types of alginates set forth in U.S. Pat. No. 6,779,530 to Kraker and U.S. patent application Ser. No. 11/251,632 to Oglesby, filed Oct. 14, 2005; each of which is incorporated herein by reference. Relatively low molecular weight alginates may act as film-forming agents, while relatively high molecular weight alginates may act as thickening agents as well as film-forming agents. If desired, mixtures of alginates, such as mixtures of relatively high molecular weight alginates and relatively low molecular weight alginates, may be employed. Preferably, the amount of a representative ingredient, such as alginate, is at least about 1 percent, may be at least about 5 percent, and often at least about 10 percent; and typically does not exceed about 30 percent, generally does not exceed about 25 percent, and often does not exceed about 20 percent; based on the total weight of the coating formulation prior to use.
Another representative polymeric agent is hydroxypropylcellulose. An exemplary hydroxypropylcellulose is available as Klucel EF from Hercules, Inc. See, also, for example, the types of polymeric agents set forth in U.S. patent application Ser. No. 11/109,404 to Oglesby et al., filed Apr. 19, 2005, which is incorporated herein by reference. Hydroxypropylcellulose can act as a film-forming agent as well as a thickening agent. Preferably, the amount of a representative ingredient, such as hydroxypropylmethylcellulose or hydroxypropylcellulose, is at least about 1 percent, generally at least about 5 percent, and often at least about 10 percent; and typically does not exceed about 30 percent, generally does not exceed about 25 percent, and often does not exceed about 20 percent; based on the total weight of the coating formulation prior to use.
Another representative polymeric agent is guar gum. Guar gum is a polysaccharide composed of galactose and mannose units. Exemplary forms of guar gum that are suitable as thickening agents are available as GG30, GG40, GG50 and GG60 from The Procell Company; and Nutriloid 010 and Nutriloid LUC from T.I.C. Gums. Preferably, the amount of a representative ingredient, such as guar gum, is at least about 1 percent, generally at least about 5 percent, and often at least about 10 percent; and typically does not exceed about 30 percent, generally does not exceed about 25 percent, and often does not exceed about 20 percent; based on the total weight of the coating formulation prior to use.
Another representative polymeric agent is pullulan. Pullulan can act as a film-forming agent as well as a thickening agent. Exemplary types and forms of pullulan have been set forth in U.S. patent application Ser. No. 11/304,991 to Borschke et al., filed Dec. 15, 2005, which is incorporated herein by reference.
Other exemplary polymeric agents include starches and starch-based materials. Starches and starch-based materials can be used as thickening agents as well as film-forming agents. See, for example, the types of starches and starch-based materials set forth in U.S. Pat. Application Pub. No. 2005/0076929 to Fitzgerald et al.; which is incorporated herein by reference.
Other exemplary polymeric agents, which can act as film-forming agents and/or thickening agents, include carrageenans, polyvinylacetate, methylcellulose, xanthan gum, polyvinylalcohol, polyvinylacetate, polyvinylacetate copolymers, chitosan, pectins, hydroxypropylmethylcellulose, gum arabic, and the like, as well as combinations of these with each other or any other polymeric agents described herein.
The amount of film-forming agent within the coating formulation may vary. Preferably, the amount of film-forming agent is at least about 1 percent, generally at least about 5 percent, and often at least about 10 percent; and typically does not exceed about 30 percent, generally does not exceed about 25 percent, and often does not exceed about 20 percent; based on the total weight of the coating formulation prior to use (i.e., including the liquid solvent or carrier of the formulation). However, for certain polymeric materials, such as polyvinylacetate, polyvinylacetate copolymers, or gum arabic, the amount of polymeric material may exceed about 30 percent, often can exceed about 50 percent, but typically does not exceed about 75 percent, based of the weight of that polymeric material and the solvent or liquid carrier of coating formulation prior to use. Although the viscosity of the formulation can vary, preferably, the film-forming agent preferably acts to thicken the formulation to a viscosity of less than about 100,000 centipoise, often about less than about 50,000 centipoise, when measured as a Brookfield viscosity (No. 6 spindle, 10 rpm, 25° C.).
When employed, the amount of thickening agent within the coating formulation may vary. The amount of thickening agent that can be employed can be selected based upon factors such as the desired rheological properties of the coating formulation, the characteristics and properties of the other components of the coating formulation (e.g., the thickening properties of the film-forming agent components), the compatibility of the thickening agent with the other components of the formulation, and the thickening properties of the thickening agent that is selected. Preferably, the amount of thickening agent is at least about 1 percent, generally at least about 5 percent, and often at least about 10 percent; and typically does not exceed about 30 percent, generally does not exceed about 25 percent, and often does not exceed about 20 percent; based on the total weight of the coating formulation prior to use (i.e., including the liquid solvent or carrier of the formulation). Although the viscosity of the formulation can vary, preferably, the thickening agent acts to thicken the formulation to a viscosity of about 15,000 centipoise to about 100,000 centipoise, preferably about 20,000 centipoise to about 30,000 centipoise, as measured as a Brookfield viscosity (No. 6 spindle, 10 rpm, 25° C.).
The relative amounts of the various polymeric agents within the coating formulation can vary. For example, the amount of optional thickening agent within the coating formulation may make up about 5 percent to about 40 percent, of the combined weight of thickening, low viscosity polymeric and film-forming agents within the formulation; the amount of low viscosity polymeric agent within the coating formulation can make up about 10 percent to about 60 percent of the combined weight of thickening, low viscosity polymeric and film-forming agents within the formulation; and the amount of film-forming agent within the coating formulation can make up about 20 percent to about 75 percent of the combined weight of thickening, low viscosity polymeric and film-forming agents within the formulation.
The coating formulation may incorporate other ingredients, in addition to the aforementioned polymeric materials. Those other ingredients can be dissolved within the liquid carrier of the coating formulation, dispersed on, or suspended within that coating formulation. Those other ingredients can be employed in order to provide specific properties or characteristics to the wrapping material. For example, the coating formulation can incorporate flavoring agents, humectants, sugars and sugar-type compounds (e.g., sucrose, glucose, fructose, maltose, melezitose, dextrose, lactose, galactose and mannose), syrups (e.g., high fructose corn syrup and honey), wetting agents, preservatives, colorants or pigments, and the like. Though not necessarily preferred, the coating formulation can incorporate water soluble (e.g., sodium chloride, calcium chloride, potassium citrate or potassium chloride) and/or water insoluble (e.g., calcium carbonate or magnesium oxide) fillers. Certain salts can act to enhance the ability to remove liquid solvent or carrier of the additive material formulation during drying operations. Other ingredients can include catalytic materials (e.g., ultrafine particles or nanoparticle types of materials), metals or metal oxides (e.g., iron oxide powder), ammonium salts or ammonia generating compounds, or other types of ingredients that have the ability to alter the chemical nature or character of tobacco smoke generated by the cigarette. Preferably, the optional ingredients are essentially chemically non-reactive with other components of the formulation, at least under those conditions at which the formulation is employed. Preferably, the optional ingredients are employed in amounts that do not result in introduction of undesirable rheology to the coating formulation (e.g., introducing an undesirably high viscosity to the formulation). See, also, for example, the types of ingredients, and amounts of those ingredients, set forth in U.S. Pat. Application Pub. Nos. 2005/0016556 to Ashcraft et al. and 2005/0076929 to Fitzgerald et al.; and U.S. patent application Ser. No. 11/251,632, filed Oct. 14, 2005, to Oglesby, each of which is incorporated by reference.
The coating formulation preferably is incorporated within a suitable solvent, such as an aqueous liquid, to produce a coating formulation that is considered to be a thickened mixture. Preferred coating formulations can be considered to have a “paste-like” consistency. A representative water-based coating formulation having a solvent or carrier content of about 65 weight percent to about 80 weight percent exhibits a Brookfield viscosity (No. 6 spindle, 10 rpm, 25° C.) that is typically greater than about 10,000 centipoise, often greater than about 20,000 centipoise, but usually less than about 800,000 centipoise, often less than about 400,000 centipoise, and frequently less than about 200,000 centipoise; and preferably about 30,000 centipoise to about 100,000 centipoise.
The suitable solvent or liquid carrier of the coating formulation most preferably is a liquid having an aqueous character, and can include relatively pure water (e.g., tap water or de-ionized water). If desired, organic solvents or liquid carriers, such as alcohols, can be employed. Although not all components of the coating formulation are necessarily soluble in the liquid carrier, it is most preferable that the film-forming components be soluble (or at least highly dispersible) in that liquid. By “soluble” in referring to the components of the coating formulation with respect to the liquid solvent, it is meant that the components for a thermodynamically stable mixture when combined with the solvent, have a significant ability to dissolve in that solvent, and do not form precipitates to any significant degree when present in that solvent.
Representative coating formulations typically incorporate about 50 to about 90, generally about 65 to about 80, weight percent liquid carrier (e.g., an aqueous solution such as relatively pure water, or a non-aqueous solution); about 10 to about 50, generally about 15 to about 30, weight percent of the polymeric agent mixture (e.g., the combined weight of the polymeric thickening, low viscosity polymeric, and film-forming polymeric components); based on the total weight of liquid carrier and polymeric agent mixture. Preferably, other optional ingredients, such as the previously described salts, preservatives, sugars, flavoring agents, and the like, typically are incorporated within the coating formulation in total amounts that are less than about 15, and usually less than about 10 weight percent, based on the total weight of the coating formulation prior to use.
The relative amounts of the various other optional components of the coating formulation can vary. In many preferred embodiments, the combined amounts of ingredients such as flavorings, colorants, preservatives, fillers, and the like, preferably do not exceed about 50 percent, often do not exceed 40 percent, and frequently do not exceed about 30 percent, of the total combined weight of the film-forming agent components and optional components.
Coating formulations, such as the types of water-based coating formulations described hereinbefore, are subjected to drying conditions after those formulations have been applied to the wrapping material, such as a continuous strip of paper web of wrapping material. Preferably, sufficient solvent is removed from the formulation after that formulation has been applied to the wrapping material such that the additive material that remains in contact with the wrapping material does not exhibit a sticky or tacky character or nature. Preferably, sufficient solvent (e.g., water or a non-aqueous solvent) is removed from the formulation after it has been applied to the wrapping material such that the additive material that remains in contact with the wrapping material exhibits a solvent (e.g., moisture) content of less than about 10 percent, more preferably less than about 8 percent, based on the weight of the coating formulation that remains in contact with the wrapping material. Preferably, sufficient solvent (e.g., water or a non-aqueous solvent) is removed from the formulation after that formulation has been applied to the wrapping material such that the formulation that remains in contact with the wrapping material exhibits a solvent (e.g., moisture) content of about 4 percent to about 6 percent, based on the weight of the coating formulation that remains in contact with the wrapping material.
A representative coating formulation may incorporate both an alginate and an inulin-type of material. Representative coating formulations can incorporate about 10 percent to about 40 percent alginate, about 2 percent to about 30 percent inulin-type material, and solvent or liquid carrier (e.g., water) in an amount of about 60 percent to about 90 percent, often about 70 percent to about 85 percent, based on the total weight of the formulation prior to application to a wrapping material. One representative coating formulation can incorporate about 59.6 weight parts water, about 20 weight parts alginate (e.g., an alginate available as Manucol LD or Manucol LB from ISP Corporation), about 20 weight parts inulin-type material (e.g., a material available as TIC Pretested Ticaloid LC-CSR-2), about 0.2 weight parts of a preservative (e.g., potassium sorbate) and about 0.2 weight parts colorant.
The amount of coating formulation that is applied to the wrapping material may vary. The coating formulation preferably is applied to the wrapping material such that the dry weight of the additive material on the wrapping material is least about 1 g/m², often at least about 2 g/m², and frequently at least about 3 g/m². The coating formulation may be applied to the wrapping material such that the dry weight of the additive material on the wrapping material is less than about 10 g/m², often is less than about 7 g/m², and frequently is less than about 4 g/m². For example, a paper wrapping material having a dry basis weight of about 25 g/m²can be coated with coating formulation and dried to have a resulting overall dry basis weight in the coated regions of about 27 g/m²to about 28.5 g/m².
Coated regions of the wrapping material useful as the circumscribing wrapper of tobacco rods for cigarettes are produced using additive materials that are effective in reducing the porosity of the wrapping material in those regions. Film-forming materials coated onto the wrapping material have a tendency to reduce the porosity of the wrapping material. Typical coated regions of the wrapping materials have porosities that can vary. Preferably, the porosities of the coated regions of the wrapping materials are less than about 9 CORESTA units, and usually are less than about 8 CORESTA units. Preferably, the porosities of the coated regions of the wrapping materials are at least about 0.1 CORESTA units, usually are at least about 1 CORESTA unit, often are at least about 3 CORESTA units. Preferably, the porosities of the coated regions of the wrapping materials, particularly those wrapping materials that are used for the manufacture of cigarettes designed to meet certain cigarette extinction test criteria, are from about 3 CORESTA units to about 6 CORESTA units.
The wrapping material can possess patterns of predetermined shapes and sizes positioned at predetermined locations, and hence, cigarettes appropriately manufactured from that wrapping material can possess coated patterns of predetermined shapes and sizes positioned at predetermined locations on their smokable rods. Representative patterns are set forth in U.S. Pat. Application Pub. Nos. 2005/0016556 to Ashcraft et al.; and 2005/0076929 to Fitzgerald et al. For example, shapes of coated regions, compositions of the coating formulations, or amounts or concentrations of coating materials, can change over the length of the wrapping material. The relative positioning of the printed regions can be selected as desired. For example, wrapping materials that are used for the production of cigarettes designed to meet certain cigarette extinction test criteria, the pattern most preferably has the form of spaced continuous bands that are aligned transversely or cross directionally to the longitudinal axis of the wrapping material. Cross-directional lines or bands that are essentially perpendicular to the longitudinal axis of the wrapping material preferably extend sufficiently across the wrapping material such that smokable rods manufactured from that wrapping material have bands that completely or nearly completely circumscribe the smokable rods. A cigarette also can be manufactured from a wrapping material possessing discontinuous bands positioned in a spaced apart relationship. For a wrapping material of such a cigarette, it is most preferred that discontinuous bands (e.g., bands that include a pattern, such as a series of dots, grids or stripes) cover at least about 70 percent of the surface of the band area or region of the wrapping material. A cigarette also can be manufactured from a wrapping material possessing at least one longitudinally extending stripe, which stripe is provided by a coating formulation, such as a coating formulation of the present invention.
Preferred wrapping materials possess coatings in the form of bands that extend across the wrapping material, generally perpendicular to the longitudinal axis of the wrapping material. The widths of the individual bands can vary, as well as the spacing between those bands. Preferably, those bands have widths of at least about 2 mm, usually at least about 3 mm, frequently at least about 4 mm. However, the bands may have widths of up to about 8 mm. Preferred bands have widths of about 4 mm to about 7 mm, and often have widths of about 6 mm to about 7 mm. Such bands can be spaced apart such that the spacing between the bands (i.e., as measured from the inside adjacent edges of the bands) is at least about 10 mm; but which may be about 15 mm, 20 mm, or 25 mm, in certain instances at least about 30 mm, and on occasion at least about 35 mm; but such spacing preferably does not exceed about 50 mm. For certain preferred wrapping materials, the bands are spaced apart such that the spacing between the bands is about 15 mm to about 25 mm, more preferably about 18 mm to about 24 mm.
Preferably, the coating formulation has an overall composition, and is applied in a manner and in an amount, such that the physical integrity of the wrapping material is not adversely affected when the coating formulation is applied to selected regions of the wrapping material. It is desirable that the components of the coating formulation applied to wrapping materials not adversely affect to any significant degree (i) the appearance of cigarettes manufactured from those wrapping materials, (ii) the nature or quality of the smoke generated by those cigarettes, (iii) the desirable burn characteristics of those cigarettes, or (iv) the desirable performance characteristics of those cigarettes. Specifically, it desirable that components of the coating formulation not introduce undesirable sensory characteristics to the smoke generated by a smoke article incorporating a wrapping material treated with that coating formulation. For preferred cigarettes, it is desirable that the coating formulation applied to the wrapping material provide the desirable extinction performance characteristics to the cigarettes manufactured using that wrapping material at relatively low coating or application levels. For example, for cigarettes evaluated for self-extinction properties using the type to test method set forth in ASTM Designation: E 2187-02b using 10 layers of Whatman No. 2 filter paper, extinction criteria most preferably are met for 100 percent of the cigarettes tested when about 2.5 g/m²to about 3.5 g/m²of preferred dry coating is applied as bands that extend around the cigarette rod and are spaced along the length of the cigarette rod.
A preferred wrapping material includes a coated region exhibiting a diffusion capacity in that coated region when measured at ambient temperature that is relatively low, but exhibits a diffusion capacity in the coated region—when measured after being subjected to exposure to a temperature significantly above ambient temperature—that is relatively high. For example, ratios of diffusion capacities for an uncoated region to a coated region of a wrapping material (e.g., for a wrapping material heated at about 230° C. for an effective period of time and cooled to ambient for measurement, relative to a wrapping material maintained and measured at ambient temperature) can be greater than about 3:1, and often can be greater than about 5:1. See, U.S. Patent Application Pub. No. 2005/0087202 to Norman et al. and Norman et al., Beitr. Tabakforsch. Int. 21 (2205) 425-434, each of which is incorporated by reference.
A preferred embodiment of a wrapping material includes one or more bands of a coating formulation of the present invention. When measured at ambient temperature, each portion of the wrapping material that is a coated region or a region occupied by a band of the coating formulation preferably exhibits a diffusion capacity of less than about 0.2 cm/sec, and more preferably less than about 0.1 cm/sec. After being heated substantially above ambient temperature, (preferably at about 230° C.) for about 15 minutes, and cooled to ambient temperature for measurement, each coated region or region occupied by a band of the coating formulation preferably exhibits, for certain preferred formulations, a diffusion capacity of at least about 0.5 cm/sec, and more preferably at least about 0.7 cm/sec.
A preferred smoking article in the form of cigarette incorporating a tobacco rod manufactured from wrapping material treated with the additive material formulation of the present invention meets extinction criteria while also exhibiting a propensity to avoid self-extinction during normal smoking conditions. That is, a preferred cigarette, while being capable of meeting the certain extinction criteria, does not experience free air self-extinction to a significant degree, and most preferably there is a low rate of occurrence free air self-extinction. For example, a preferred cigarette does not have a tendency to undergo premature extinction, such as when lit cigarettes are held in the smoker's hand or when placed in an ashtray for a brief period of time. Preferred cigarettes undergo free air self-extinction for less than about 30 percent, preferably for less than about 15 percent, and most preferably for 0 percent, of cigarettes tested. Free air self-extinction with regards to a cigarette having a tobacco rod incorporating a wrapping material possessing circumscribing bands of additive material relates to those burning cigarette rods that extinguish when left to burn in air (and not in contact with a substrate).
The following examples are provided in order to further illustrate the present invention, but should not be construed as limiting the scope thereof. Unless otherwise noted, all parts and percentages are by weight.

EXAMPLE 1

A water-based additive formulation that may be applied as a patterned coating to a cigarette paper wrapping material is prepared in the following manner. The additive material incorporates guar gum, inulin and another polymeric material (e.g., pullulan).
Tap water is heated to and maintained at about 60° C. Potassium sorbate is added to the water in a manner such that the potassium sorbate dissolves in the water. Colorant in the form of a water-based dye also is added. Potassium citrate also is added. Guar gum, inulin, and pullulan are added to the water. The polymeric materials are added in a fashion that avoids the formation of lumps. An exemplary guar gum is TCI Pretested Gum Guar VLV Powder from T.I.C. Gums. An exemplary inulin is Inulin LV110 from T.I.C. Gums. An exemplary pullulan is available as PI-20 from Hayashibara Biochemical Laboratories, Inc.
During addition of the various components to the water, the water is rapidly stirred using a high speed electric mixer. The resulting mixture has a relatively uniform consistency. The resulting mixture comprises about 77.2 parts water, about 12 parts guar gum, about 4 parts inulin, about 4 parts pullulan, about 2.4 parts potassium citrate, about 0.2 parts colorant, and about 0.2 parts potassium sorbate.
The resulting aqueous mixture is cooled to room temperature. The mixture at room temperature has a relatively uniform consistency and resembles a paste. After being allowed to sit for about 24 hours at ambient temperature, the mixture exhibits a Brookfield viscosity (No. 6 spindle, 10 rpm, 25° C.) of about 350,000 centipoise.

EXAMPLE 2

A water-based additive formulation incorporating an inulin-type of material and another polymeric material (e.g., hydroxypropylcellulose) is provided as follows, and is applied as a pattern to a cigarette paper wrapper in the following manner.
Tap water is heated to, and maintained at, about 60° C. Potassium sorbate is added to the water in a manner such that the potassium sorbate dissolves in the water. Colorant in the form of a water-based dye also is added. Calcium chloride also is added. Hydroxypropylcellulose and inulin are added to the water. The polymeric materials preferably are added in a fashion that avoids the formation of lumps. For this formulation, which incorporates a relatively large ratio of inulin to hydroxypropylcellulose, the polymeric ingredients initially may not be soluble in solution with one another. However, after standing for a period of time (e.g., about 4 hours to about 8 hours), and re-stirring, a stable, homogeneous aqueous polymeric dispersion is formed. A preferred hydroxypropylcellulose is available as Klucel EF from Hercules, Inc. A preferred inulin material is available as TIC Pretested Ticaloid LC-CSR-2.
During addition of the various components to the water, the water is rapidly stirred using a high speed electric mixer. The resulting mixture has a relatively uniform consistency. The resulting mixture comprises about 62.4 parts water, about 18 parts hydroxypropylcellulose, about 18 parts of the inulin material, about 1.2 parts calcium chloride, about 0.2 parts colorant, and about 0.2 parts potassium sorbate.
The resulting aqueous mixture is cooled to room temperature. The mixture at room temperature has a relatively uniform consistency and resembles a paste. After being allowed to sit for about 24 hours at ambient temperature, the mixture exhibits a Brookfield viscosity (No. 6 spindle, 10 rpm, 25° C.) of about 60,000 centipoise.
An application apparatus of the type generally as described with reference to FIG. 29 of U.S. Patent Pub. No. 2005/0076929 to Fitzgerald et al. is provided. The apparatus is equipped with a bobbin of cigarette rod wrapping paper having an inherent porosity of 46 CORESTA units that is available as LK 46 from Tervakoski. The apparatus has an applicator system having a 20 head applicator roller that has a maximum outer diameter of about 152.8 mm, and a width of about 23 mm. Each head is about 5 mm wide, and the heads are equally spaced on at a pitch of about 19 mm. The heads of the applicator roller are fed with coating formulation from a grooved roller having an outer diameter of about 103.5 mm, and a width of about 70.5 mm. A groove of about 31 mm wide is ground in the roll face of the roller so as to extend around the peripheral face of that roller. The rollers and wrapping material are configured so as to provide a series of spaced bands extending transversely to the longitudinal axis of the web of wrapping material fed from the bobbin. The groove grind depth is fixed for a series of rollers, one roller having a groove grind depth of about 1.25 mil, another roller having a groove grind depth of about 1.5 mil, and another roller having a groove grind depth of about 2.0 mil.
The application apparatus is operated so as to feed a web of wrapping material from the bobbin through the applicator system at a rate of 300 meters per minute. In this manner, the coating formulation is applied to the web while the coating formulation is maintained at a temperature slightly above ambient. The coated web is dried and collected. The dried film can be characterized as brittle, and can be dried in a time-frame consistent with providing good drying properties on the previously described machine. The band weight of the coating applied using the roller with a groove grind depth of about 1.25 mil is about 1.8 g/m². The band weight of the coating applied using the roller with a groove grind depth of about 1.5 mil is about 2.1 g/m². The band weight of the coating applied using the roller with a groove grind depth of about 2.0 mil is about 2.7 g/m².
Diffusion capacities of the wrapping materials in the regions of the bands provided by the coating formulation preferably are determined using the apparatus and methodologies set forth in U.S. Patent Application Pub. No. 2005/0087202 to Norman et al. See, also, Norman et al., Beitr. Tabakforsch. Int. 21 (2205) 425-434.
For a coating applied using the roller that has a groove grind depth of about 1.25 mil, the web has bands with average diffusion capacities (measured at 25° C.) of about 0.21 cm/sec. For a coating applied using the roller with a groove grind depth of about 1.5 mil, the web has bands with average diffusion capacities (measured at 25° C.) of about 0.19 cm/sec. For a coating applied using the roller with a groove grind depth of about 2.0 mil, the web has bands having average diffusion capacities (measured at 25° C.) of about 0.10 cm/sec.
Diffusion capacities of the wrapping materials in the regions of the bands provided by the coating formulation preferably are determined at 25° C. after heating the band region of wrapping material substantially above ambient temperature in, for example, a radiant oven at about 230° C. for about 15 minutes, and then cooling the band region to about 25° C. Diffusion capacities measured after heating typically are expected to be as follows. For web with coating applied using the roller with a groove grind depth of about 1.25 mil, the spaced bands have average diffusion capacities (measured at 25° C.) of about 0.92 cm/sec. For web with coating applied using the roller with a groove grind depth of about 1.5 mil, the spaced bands have average diffusion capacities (measured at 25° C.) of about 0.89 cm/sec. For web with coating applied using the roller with a groove grind depth of about 2.0 mil, the spaced bands have average diffusion capacities (measured at 25° C.) of about 0.81 cm/sec.
This example demonstrates the production of an additive formulation of manageable viscosity, an additive formulation that can be dried, and a formulation exhibiting an increase in the diffusivity coefficient of the band formed using that formulation after the cigarette paper wrapper coated with that formulation is heated at about 230° C.

EXAMPLE 3

A water-based additive formulation incorporating guar gum and inulin is provided as follows, and is applied as a pattern to a cigarette paper wrapper in the following manner.
A liquid additive formulation is provided in the general manner set forth previously in Example 1. The resulting mixture comprises about 71.6 parts water, about 8 parts guar gum, about 20 parts inulin, about 0.2 parts colorant, and about 0.2 parts potassium sorbate. An exemplary guar gum is TCI Pretested Gum Guar VLV Powder from T.I.C. Gums. An exemplary inulin is Inulin LV110 from T.I.C. Gums.
The resulting aqueous mixture is cooled to room temperature. The mixture at room temperature has a relatively uniform consistency and resembles a paste. After being allowed to sit for about 24 hours at ambient temperature, the mixture exhibits a Brookfield viscosity (No. 6 spindle, 10 rpm, 25° C.) of about 50,000 centipoise.
Paper of the type set forth in Example 2 is coated using equipment of the general type set forth in Example 2. The roller that is employed has a groove depth of about 2.0 mil, and the formulation is applied to the paper web running at a speed of about 300 meters per minute. The paper so coated can be collected, and the dry weight coating is applied in an amount of about 3.4 g/m².
The resulting web having spaced bands applied thereto has bands with average diffusion capacities (measured at 25° C.) of about 0.14 cm/sec. Diffusion capacities in the regions of the bands provided by the coating formulation is determined at 25° C. after heating the band region of wrapping material substantially above ambient temperature in, for example, a radiant oven at about 230° C. for about 15 minutes, and then cooling the band region to about 25° C. A heated and cooled web after this process has bands with average diffusion capacities, measured at 25° C., of about 0.17 cm/sec.

EXAMPLE 4

A water-based additive formulation incorporating guar gum, inulin and another polymeric material (e.g., hydroxypropylcellulose) is provided as follows, and is applied as a pattern to a cigarette paper wrapper in the following manner.
A liquid additive formulation is provided in the general manner set forth previously in Example 1. The resulting mixture comprises about 77.2 parts water, about 10 parts guar gum, about 4 parts inulin, about 6 parts hydroxypropylcellulose, about 2.4 parts potassium citrate, about 0.2 parts colorant, and about 0.2 parts potassium sorbate. An exemplary guar gum is TCI Pretested Gum Guar VLV Powder from T.I.C. Gums. An exemplary inulin is Inulin LV110 from T.I.C. Gums. An exemplary hydroxypropylcellulose is available as Klucel EF from Hercules, Inc.
Paper of the type set forth in Example 2 may be coated with the additive formulation using equipment of the general type set forth in Example 2. The roller that is employed may have a groove depth of about 2.5 mil, and the formulation can be applied to the paper web running at a speed of about 300 meters per minute. The paper so coated can be collected, and the dry weight coating preferably is applied in an amount of greater than about 2.5 g/m².

EXAMPLE 5

A water-based additive formulation suitable for application as a patterned coating to a cigarette paper wrapping material may be prepared in the following manner. The additive material incorporates guar gum and inulin.
A liquid additive formulation is provided in the general manner set forth previously in Example 1. The resulting mixture comprises about 76.8 parts water, about 14.4 parts guar gum, about 6 parts inulin, about 2.4 parts potassium citrate, about 0.2 parts colorant, and about 0.2 parts potassium sorbate. The guar gum and inulin are described above in Example 4.
The resulting aqueous mixture is cooled to room temperature. The mixture at room temperature has a relatively uniform consistency and resembles a paste. After being allowed to sit for about 24 hours at ambient temperature, the mixture exhibits a Brookfield viscosity (No. 6 spindle, 10 rpm, 25° C.) of about 830,000 centipoise.

EXAMPLE 6

A water-based additive suitable for application as a patterned coating to a cigarette paper wrapping material may be prepared in the following manner. The additive material incorporates guar gum and another polymeric material (e.g., hydroxypropylcellulose).
A liquid additive formulation is provided in the general manner set forth previously in Example 1. The resulting mixture comprises about 76.8 parts water, about 14.4 parts guar gum, about 6 parts hydroxypropylcellulose, about 2.4 parts calcium chloride, about 0.2 parts colorant, and about 0.2 parts potassium sorbate. The guar gum and hydroxypropylcellulose are described above in Example 4.
The resulting aqueous mixture is cooled to room temperature. The mixture at room temperature has a relatively uniform consistency and resembles a paste. After being allowed to sit for about 24 hours at ambient temperature, the mixture exhibits a Brookfield viscosity (No. 6 spindle, 10 rpm, 25° C.) of about 800,000 centipoise.

EXAMPLE 7

A water-based additive formulation suitable for application as a patterned coating to a cigarette paper wrapping material may be prepared in the following manner. The additive material incorporates guar gum and another polymeric material (e.g., hydroxypropylcellulose).
A liquid additive formulation is provided in the general manner set forth previously in Example 1. The resulting mixture comprises about 76.8 parts water, about 14.4 parts guar gum, about 6 parts hydroxypropylcellulose, about 2.4 parts potassium citrate, about 0.2 parts colorant, and about 0.2 parts potassium sorbate. The guar gum and hydroxypropylcellulose are described previously in Example 4.
The resulting aqueous mixture is cooled to room temperature. The mixture at room temperature has a relatively uniform consistency and resembles a paste. After being allowed to sit for about 24 hours at ambient temperature, the mixture exhibits a Brookfield viscosity (No. 6 spindle, 10 rpm, 25° C.) of about 890,000 centipoise.

EXAMPLE 8

A water-based additive formulation suitable for application as a patterned coating to a cigarette paper wrapping material may be prepared in the following manner. The additive material incorporates guar gum and two other polymeric materials (e.g., hydroxypropylcellulose and pullulan).
A liquid additive formulation is provided in the general manner set forth previously in Example 1. The resulting mixture comprises about 77.2 parts water, about 7 parts guar gum, about 6 parts hydroxypropylcellulose, about 7 parts pullulan, about 2.4 parts potassium citrate, about 0.2 parts colorant, and about 0.2 parts potassium sorbate. An exemplary guar gum is TCI Pretested Gum Guar VLV Powder from T.I.C. Gums. An exemplary hydroxypropylcellulose is available as Klucel EF from Hercules, Inc. An exemplary pullulan is available as PI-20 from Hayashibara Biochemical Laboratories, Inc.
The resulting aqueous mixture is cooled to room temperature. The mixture at room temperature has a relatively uniform consistency and resembles a paste. After being allowed to sit for about 24 hours at ambient temperature, the mixture exhibits a Brookfield viscosity (No. 6 spindle, 10 rpm, 25° C.) of about 60,000 centipoise.

EXAMPLE 9

A water-based additive formulation suitable for application as a patterned coating to a cigarette paper wrapping material is prepared in the following manner. The additive material incorporates guar gum and another polymeric material (e.g., gum arabic).
A liquid additive formulation is provided in the general manner set forth previously in Example 1. The resulting mixture comprises about 83.2 parts water, about 9.1 parts guar gum, about 6.2 parts gum arabic, about 1.1 parts calcium chloride, about 0.15 parts colorant, and about 0.15 parts potassium sorbate.

EXAMPLE 10

A liquid additive formulation incorporating hydroxypropylcellulose and an inulin-type of material is provided as follows, and is applied as a pattern to a cigarette paper wrapper in the following manner.
A liquid additive formulation is provided in the general manner set forth previously in Example 1. The resulting mixture comprises about 32 parts water, about 32 parts denatured ethanol, about 17 parts hydroxypropylcellulose, about 17 parts of an inulin material, about 1.4 parts calcium chloride, about 0.2 parts colorant, and about 0.1 parts potassium sorbate. An exemplary inulin is Inulin LV 110 from T.I.C. Gums. An exemplary hydroxypropylcellulose is available as Klucel EF from Hercules, Inc.
The aqueous mixture is cooled to room temperature. The mixture at room temperature has a relatively uniform consistency and resembles a paste. After being allowed to sit for about 24 hours at ambient temperature, the mixture exhibits a Brookfield viscosity (No. 6 spindle, 10 rpm, 25° C.) of about 65,000 centipoise.
Paper of the type set forth in Example 2 is coated using equipment of the general type set forth in Example 2. The roller that is employed has a groove depth of about 1.5 mil, and the formulation is applied to the paper web running at a speed of about 300 meters per minute. The paper so coated can be collected, and the dry weight coating is applied in an amount of about 3.8 g/m².
The resulting web having spaced bands applied thereto has bands having average diffusion capacities, measured at 25° C., of about 0.04 cm/sec. Diffusion capacities in the regions of the bands provided by the coating formulation is determined at 25° C. after heating the band region of wrapping material substantially above ambient temperature in, for example, a radiant oven at about 230° C. for about 15 minutes, and then cooling the band region to about 25° C. The resulting web having spaced bands applied thereto has bands having average diffusion capacities, measured at 25° C., of about 0.47 cm/sec.

EXAMPLE 11

A water-based additive formulation that is suitable for application as a patterned coating to a cigarette paper wrapping material may be prepared in the following manner. The additive material incorporates guar gum and an inulin-type of material.
A liquid additive formulation is provided in the general manner set forth previously in Example 1. The resulting mixture comprises about 74.4 parts water, about 8 parts guar gum, about 16 parts of inulin-type material, about 1.2 parts calcium chloride, about 0.2 parts colorant, and about 0.2 parts potassium sorbate. An exemplary guar gum is TCI Pretested Gum Guar VLV Powder from T.I.C. Gums. An exemplary inulin-type material is available as Ticaloid LC-CSR-2 from T.I.C. Gums. The resulting aqueous mixture is cooled to room temperature. The mixture at room temperature has a relatively uniform consistency and resembles a paste. After being allowed to sit for about 24 hours at ambient temperature, the mixture exhibits a Brookfield viscosity (No. 6 spindle, 10 rpm, 25° C.) of about 50,000 centipoise.

EXAMPLE 12

A water-based additive formulation that is suitable for application as a patterned coating to a cigarette paper wrapping material may be prepared in the following manner. The additive material incorporates an alginate and an inulin-type material.
A liquid additive formulation is provided in the general manner set forth previously in Example 1. The resulting mixture comprises about 79.6 parts water, about 15 parts ammonium alginate, about 5 parts inulin-type material, about 0.2 parts colorant, and about 0.2 parts potassium sorbate. An exemplary ammonium alginate is available as Collatex A/RE from ISP Corporation, and an exemplary inulin-type material is available as TIC Pretested Ticaloid LC-CSR-2.
The resulting aqueous mixture is cooled to room temperature. The mixture at room temperature has a relatively uniform consistency and resembles a paste. After being allowed to sit for about 8 hours at ambient temperature, the mixture exhibits a Brookfield viscosity (No. 6 spindle, 5 rpm, 25° C.) of about 152,000 centipoise.
For comparison purposes, a similar formulation not incorporating inulin-type material, but incorporating 84.6 parts water, exhibits a Brookfield viscosity after sitting for about 8 hours (No. 6 spindle, 5 rpm, 25° C.) of about 104,000 centipoise.
It is intended that the foregoing detailed description be regarded as illustrative rather than limiting. It should be understood that the following claims, including all equivalents, are intended to define the spirit and scope of this invention.

Claims

1. A wrapping material for a smoking article, the wrapping material comprising a base sheet and an additive material disposed on at least one major surface thereof, the additive material comprising (i) an inulin-type material, and (ii) at least one polymeric film-forming agent.

2. The wrapping material of claim 1, wherein the additive material further comprises a non-polymeric filler.

3. A smoking article incorporating the wrapping material of claim 1.

4. The wrapping material of claim 1, wherein the additive material is applied to the wrapping material such that its dry weight application is at least 1 g/m².

5. The wrapping material of claim 1, wherein the additive material is applied to the wrapping material such that its dry weight application is about 3 g/m²to about 4 g/m².

6. The wrapping material of claim 1, wherein the additive material comprises guar gum.

7. The wrapping material of claim 6, wherein the additive material comprises a liquid carrier and the guar gum comprises about 1 percent to about 30 percent by combined weight of the additive material and the liquid carrier.

8. The wrapping material of claim 6, wherein the additive material comprises a liquid carrier and the guar gum comprises about 10 percent to about 20 percent by combined weight of the additive material and the liquid carrier.

9. The wrapping material of claim 1, wherein the additive material comprises an alginate.

10. The wrapping material of claim 9, wherein the additive material comprises a liquid carrier and the alginate comprises about 1 percent to about 30 percent by combined weight of the additive material and the liquid carrier.

11. The wrapping material of claim 9, wherein the additive material comprises a liquid carrier and the alginate comprises about 10 percent to about 20 percent by combined weight of the additive material and the liquid carrier.

12. The wrapping material of claim 1, wherein the additive material comprises hydroxypropylcellulose.

13. The wrapping material of claim 12, wherein the additive material comprises a liquid carrier and the hydroxypropylcellulose comprises about 1 percent to about 30 percent by combined weight of the additive material and the liquid carrier.

14. The wrapping material of claim 12, wherein the additive material comprises a liquid carrier and the hydroxypropylcellulose comprises about 10 percent to about 20 percent by combined weight of the additive material and the liquid carrier.

15. The wrapping material of claim 1, wherein the additive material comprises pullulan.

16. The wrapping material of claim 15, wherein the additive material comprises a liquid carrier and the pullulan comprises about 1 percent to about 30 percent by combined weight of the additive material and the liquid carrier.

17. The wrapping material of claim 15, wherein the additive material comprises a liquid carrier and the pullulan comprises about 10 percent to about 20 percent by combined weight of the additive material and the liquid carrier.

18. The wrapping material of claim 1, wherein the at least one polymeric film-forming agent is selected from the group consisting of hydroxypropylcellulose, alginates, guar gum, pullulan, starches, carrageenans, methylcellulose, xanthan gum, polyvinylalcohol, polyvinylacetate, polyvinylacetate copolymers, chitosan, pectins, hydroxypropylmethylcellulose, gum arabic, and any combination thereof.

19. The wrapping material of claim 1, wherein the additive material further comprises at least one thickening agent.

20. The wrapping material of claim 19, wherein the at least one thickening agent is selected from the group consisting of inulin, hydroxypropylcellulose, alginates, guar gum, pullulan, starches, carrageenans, methylcellulose, xanthan gum, polyvinylalcohol, polyvinylacetate, polyvinylacetate copolymers, chitosan, pectins, hydroxypropylmethylcellulose, gum arabic, and any combination thereof.

21. A wrapping material for a smoking article, the wrapping material comprising a base sheet and an additive material disposed on at least one major surface thereof, the additive material comprising (i) guar gum, and (ii) at least one polymeric material.

22. The wrapping material of claim 21, wherein the additive material further comprises a non-polymeric filler.

23. The wrapping material of claim 21, wherein the additive material further comprises at least one thickening agent.

24. The wrapping material of claim 23, wherein the at least one thickening agent is selected from the group consisting of inulin hydroxypropylcellulose, alginates, guar gum, pullulan, starches, carrageenans, methylcellulose, xanthan gum, polyvinylalcohol, polyvinylacetate, polyvinylacetate copolymers, chitosan, pectins, hydroxypropylmethylcellulose, gum arabic, and any combination thereof.

25. The wrapping material of claim 21, wherein the additive material is applied to the wrapping material such that its dry weight application is at least 1 g/m².

26. The wrapping material of claim 21, wherein the at least one polymeric material is selected from the group consisting of inulin, hydroxypropylcellulose, alginates, pullulan, starches, carrageenans, methylcellulose, xanthan gum, polyvinylalcohol, polyvinylacetate, polyvinylacetate copolymers, chitosan, pectins, hydroxypropylmethylcellulose, gum arabic, and any combination thereof.

27. A smoking article incorporating the wrapping material of claim 21.

28. A wrapping material for a smoking article, the wrapping material comprising a base sheet and an additive material disposed on at least one major surface thereof, the additive material comprising (i) inulin, (ii) guar gum, and (iii) at least one polymeric material.

29. The wrapping material of claim 28, wherein the additive material further comprises a non-polymeric filler.

30. The wrapping material of claim 28, wherein the additive material further comprises at least one thickening agent.

31. The wrapping material of claim 28, wherein the at least one thickening agent is selected from the group consisting of inulin, hydroxypropylcellulose, alginates, guar gum, pullulan, starches, carrageenans, methylcellulose, xanthan gum, polyvinylalcohol, polyvinylacetate, polyvinylacetate copolymers, chitosan, pectins, hydroxypropylmethylcellulose, gum arabic, and any combination thereof.

32. The wrapping material of claim 28, wherein the additive material is applied to the wrapping material such that its dry weight application is least 1 g/m².

33. The wrapping material of claim 28, wherein the at least one polymeric material is selected from the group consisting of hydroxypropylcellulose, alginates, pullulan, starches, carrageenans, polyvinylacetate, methylcellulose, xanthan gum, polyvinylalcohol, polyvinylacetate, polyvinylacetate copolymers, chitosan, pectins, hydroxypropylmethylcellulose, gum arabic, and any combination thereof.

34. A smoking article incorporating the wrapping material of claim 28.

35. A method of treating a wrapping material for a smoking article, said method comprising the steps of:

providing a base sheet;

applying a polymeric coating to substantially all of at least one major surface of the base sheet; and

applying an additive material in a pattern on a major surface of the base sheet, wherein the additive material comprises a polymeric material that is selected from the group consisting of inulin, guar gum, gum arabic, and any combination thereof.

36. The method of claim 35, wherein the additive material further comprises a polymeric material is selected from the group consisting of hydroxypropylcellulose, alginates, pullulan, starches, carrageenans, methylcellulose, xanthan gum, polyvinylalcohol, polyvinylacetate, polyvinylacetate copolymers, chitosan, pectins, hydroxypropylmethylcellulose, and any combination thereof.

37. The method of claim 35, wherein the step of applying additive material in a pattern comprises printing the additive material onto the base sheet from a grooved surface.

38. The method of claim 35, wherein the step of applying a polymeric coating comprises providing between about 1 g/m²and about 2.5 g/m²on a dry weight basis.

39. The method of claim 35, wherein the step of applying a polymeric coating provides the wrapping material with a diffusion capacity less than 2.5 cm/sec, when measured at 25° C.

40. The method of claim 35, wherein after the steps of applying the polymeric coating and applying the pattern of additive material, the diffusion capacity in a region with polymeric coating only is at least three times the diffusion capacity in a region with polymeric coating and additive material.

41. The method of claim 35, further comprising the step of heating the wrapping material at about 230° C. for about 15 minutes and then cooling it to ambient temperature.

42. The method of claim 32, wherein after the step of heating and cooling, a portion of the wrapping material comprising the additive material pattern exhibits a diffusion capacity of at least about 0.5 cm/sec, when measured at 25° C.

43. The method of claim 35, wherein the additive material further comprises at least one thickening agent.

44. The method of claim 43, wherein the at least one thickening agent is selected from the group consisting of inulin, hydroxypropylcellulose, alginates, guar gum, pullulan, starches, carrageenans, methylcellulose, xanthan gum, polyvinylalcohol, polyvinylacetate, polyvinylacetate copolymers, chitosan, pectins, hydroxypropylmethylcellulose, gum arabic, and any combination thereof.

45. The method of claim 35, wherein the additive material comprises a liquid carrier.

46. A coating formulation for coating a wrapping material for a smoking article, the coating formulation comprising a liquid carrier and an additive material, wherein the additive material comprises (i) an inulin-type material, and (ii) at least one polymeric film-forming agent.

47. The coating formulation of claim 46, wherein the at least one polymeric film-forming agent is selected from the group consisting of hydroxypropylcellulose, alginates, guar gum, pullulan, starches, carrageenans, methylcellulose, xanthan gum, polyvinylalcohol, polyvinylacetate, polyvinylacetate copolymers, chitosan, pectins, hydroxypropylmethylcellulose, gum arabic, and any combination thereof.

48. The coating formulation of claim 46, comprising by weight about 50 percent to about 90 percent of the liquid carrier, about 10 percent to about 50 percent, combined, of the inulin-type material and the at least one polymeric film-forming agent.

49. The coating formulation of claim 46, comprising by weight about 65 percent to about 80 percent of the liquid carrier, about 15 percent to about 30 percent, combined, of the inulin-type material and the at least one polymeric film-forming agent.

50. A coating formulation for coating a wrapping material for a smoking article, the coating formulation comprising a liquid carrier and an additive material, wherein the additive material comprises (i) at least one thickening agent selected from the group consisting of hydroxypropylcellulose, alginates, guar gum, pullulan, starches, carrageenans, methylcellulose, xanthan gum, polyvinylalcohol, polyvinylacetate, polyvinylacetate copolymers, inulin-type material, chitosan, pectins, hydroxypropylmethylcellulose, gum arabic, and any combination thereof, and (ii) at least one polymeric film-forming agent selected from the group consisting of hydroxypropylcellulose, alginates, guar gum, pullulan, starches, carrageenans, methylcellulose, xanthan gum, polyvinylalcohol, polyvinylacetate, polyvinylacetate copolymers, inulin-type material, chitosan, pectins, hydroxypropylmethylcellulose, gum arabic, and any combination thereof.

51. A smoking article comprising a wrapping material, wherein the wrapping material comprises the coating formulation of claim 51.