JP2020043872A - Tobacco smoke filter - Google Patents

Abstract

To provide a tobacco smoke filter including a nonwoven fabric which has superior biodegradability and a performance suitable for use as a filter.SOLUTION: A tobacco smoke filter or a filter element includes a nonwoven fabric. The nonwoven fabric comprises a sheet of staple fibers and a water soluble binder, and has a basis weight of 25-42 gsm. The water soluble binder is uniformly applied onto at least one face of the sheet of staple fibers. The nonwoven fabric has dispersibility where 95% or more of the nonwoven fabric passes through 6.3 mm aperture screens after being subjected to EDANA Standard FG511.1 Tier 1 Dispersability Shake Flask Test using screens of 1.6, 3.15, 6.3 and 12.5 mm aperture) in the tobacco smoke filter or the filter element.SELECTED DRAWING: Figure 1

Description

  The present invention relates to filters and filter elements for smoking articles, for example cigarettes.

  It is widely desired to reduce the problems associated with the environmental impact of cigarette butts. Most current cigarette filters are formed using conventional cellulose acetate filamentary tows. Its biodegradation rate is extremely slow. This causes such problems that the filter remains clearly identifiable for a long time when the butt is dumped on the ground. In addition, current cellulose acetate filters do not disperse when discarded in waterways and retain their characteristic size and shape after prolonged flooding. This causes problems in wastewater treatment plants. Within the plant, spent butts must be removed from the water stream during the treatment process. Of course, many butts, which were initially dumped ashore, will also drain into sewers after rainfall and eventually reach the wastewater treatment plant. Therefore, there is a need for a cigarette filter formed from readily biodegradable materials that disperses quickly upon flooding. In addition, the filter material meets a number of other criteria, specifically that it is in a form suitable for high speed processing into cigarette filters, and features suitable for the finished filter (e.g., filtration efficiency, hardness, etc.). Variability, etc.), must be economically feasible, and allow for acceptable subjective properties (especially flavor and appearance) in the final cigarette.

  This is not a new problem, and for decades researchers have attempted to find suitable biodegradable cigarette filter materials. Numerous patent applications have been filed over this period for materials alleged to address these requirements, but none have yet been prominently accepted on the market. Accordingly, there remains a need for a readily biodegradable tobacco smoke filtration material that disintegrates very quickly upon flooding.

  According to the present invention, in a first aspect, there is provided a tobacco smoke filter or filter element comprising a non-woven fabric, wherein the non-woven fabric comprises a staple fiber sheet and a water-soluble binder, wherein the water-soluble binder comprises a staple fiber fiber. A tobacco smoke filter or filter element is provided that is uniformly coated on at least one side of the sheet.

  According to the present invention, in another aspect, a tobacco smoke filter or filter element comprising a non-woven fabric, wherein the non-woven fabric comprises staple fibers (eg, staple fiber sheets) and a water-soluble binder, A tobacco smoke filter or filter element is provided wherein the binder is applied to the staple fibers in an aqueous form.

FIG. 1 is a plot showing the biodegradability of the "viscose 2" and "Tencel 2" filter rods of the present invention over time, as compared to the well known cellulose acetate filter rod "CA". .

  Nonwoven fabric can be defined as a sheet or web structure that is bonded by mechanically, thermally, or chemically entangled fibers (and by forming perforations in a film). Nonwovens can be formed directly from separate fibers (or from molten plastic or plastic film). Here, the term "nonwoven" explicitly indicates that it does not include paper or base paper.

  The nonwoven is preferably a wet laid (wet) nonwoven. The basis weight of the nonwoven fabric may be between 25 and 42 gsm, for example between 27 and 40 gsm.

  The staple fibers are preferably comprised of a biodegradable material. The staple fibers may be regenerated cellulose fibers, such as viscose or Tencel. Both of these are available from Lenzing AG. Other biodegradable fibers such as polyvinyl alcohol (PVOH), polylactic acid (PLA), polyglycolic acid (PGA), or cotton may be used. Low or non-biodegradable fibers such as cellulose acetate fibers, cellulose ester fibers can also be used, but these are not preferred. Preferably, the staple fibers are not cellulose acetate fibers or cellulose ester fibers.

  The filter / filter element and / or non-woven and / or staple fibers are measured for "easy biodegradability" according to the OECD 301B "Ready Biodegradability" method (modified Sturm test) which is well known to those skilled in the art. It preferably has a "degradable" level.

  The staple fiber may be a staple fiber with a cut length of 4 mm to 10 mm, for example, 4 to 6 mm. The diameter of the staple fiber may be between 1.7 dtex and 3.3 dtex. The staple fibers may have any cross-section (eg, circular, trilobal). Of course, staple fibers of any cut length and diameter, as appropriate for use in wet laid nonwovens, can be used without departing from the scope of the present invention, and may vary. A blend of fibers, fiber lengths, or fiber diameters may be used in the nonwoven.

  The amount of water-soluble binder may be 0.1% to 5%, such as 0.5 to 3%, such as 1%, expressed as a percentage of the solids level content in the finished nonwoven. The water-soluble binder may be carboxymethylcellulose (CMC), polyvinyl alcohol (PVOH), hydroxycellulose, polyethylene oxide, natural starch, modified starch, cationic starch, guar gum, or a derivative thereof. The binder can be applied by any known method suitable for applying a liquid binder, such as curtain coating, size pressing, mangle padding, spraying, and the like. The nonwoven fabric preferably does not contain an alkali compound.

  The filters and elements of the present invention include a nonwoven fabric that includes staple fibers (eg, short cut biodegradable) and staple fibers (eg, regenerated cellulose fibers) and a water-soluble binder. The water-soluble binder is preferably applied in an aqueous form (to the fiber). The water-soluble binder is preferably applied in an aqueous form (to the fiber) and subsequently dried.

  Certain nonwoven materials are preferably manufactured by a wet laid process. Nonwoven fabrics can be prepared by various well-known manufacturing routes (eg, dry laid or carded, spunbond, wet laid, air laid, etc.). Applicants have found that wet laid nonwovens are best suited to meet the stringent chip-to-chip pressure drop reproducibility criteria required for cigarette filters. This criterion is an essential requirement for a viable tobacco smoke filtration material (independent of the dispersing properties). The pressure loss is related to the weight of the nonwoven used per chip. The basis weight of the paper and nonwoven is measured using a standard method that quantifies the weight of an area of at least 20 x 25 cm. Since the amount used in a typical cigarette filter uses only about 10% of such amount, data based on such large specimen weight variations will meet the reproducibility criteria for cigarette filters. May be misleading regarding the suitability of By measuring the weight variation of a 2 cm × 30 cm nonwoven strip, Applicants have determined that a wet laid nonwoven is best suited to meet the required weight variation requirements of about ± 1% or less.

  Wet laid nonwovens made from 100% staple fibers are very weak and do not have sufficient mechanical integrity to withstand processing on filter making machines. Therefore, a binder is needed to provide sufficient strength to the nonwoven. Conventional wet laid nonwovens often incorporate thermoplastic binder fibers as part of the fiber furnish. These binder fibers are then activated during the drying stage of the nonwoven production. However, the present applicant has found that the nonwoven fabric containing the binder fiber is not easily dispersed in cold water and is not suitable for the present application (see Comparative Example 3 below). Applicants have found that the use of a water soluble binder (eg, in liquid form) with staple fibers allows for rapid dispersion in cold water.

  The nonwovens were subjected to the EDANA standard FG511.1 Tier 1 Dispersability Shake Flask Test (using screens with 1.6, 3.15, 6.3 and 12.5 mm openings). Thereafter, 95% or more, for example, 96% or more of the nonwoven fabric may be a dispersible nonwoven fabric that passes through a 6.3 mm aperture screen. This test is well known to those skilled in the art, and this dispersibility indicates easy and effective dispersion in cold water (high dispersibility).

  The final appearance and hardness characteristics of the filter according to the invention are also similar to those of cellulose acetate, again increasing commercial acceptability.

  Advantageously, the nonwoven fabric used in the filter according to the invention is treated (eg embossed) using standard equipment used for forming paper-based cigarette filters. Paper filters have higher tar retention than cellulose acetate filters having the same pressure drop. This means that cigarette manufacturers cannot simply replace cellulose acetate with a paper filter. Either the filter length needs to be changed (to maintain the same pressure drop or tar delivery rate) or the cigarette tar delivery rate decreases (if the filter length is constant) This is because the pressure loss increases. Applicants have found that the tar retention of the filters and filter elements according to the invention is much closer to that of cellulose acetate than of paper. Applicants have also found that the higher the openness and intrinsic porosity of the nonwoven structure, the lower the tar retention of the filter incorporating the material. Thus, by controlling the constituent fiber properties, e.g., polymer type, fiber cross-section, fiber crimp, fiber size, to provide a filter and filter element with the desired tar retention and pressure loss, Sex can be designed. This means that the filters / elements of the present invention are more advantageous because they can be used as a simple replacement for cellulose acetate filters.

  The nonwoven may further include wood pulp. As used herein, the term wood pulp includes the pulp that makes up naturally occurring cellulose fibers (e.g., obtained from softwood or hardwood by conventional methods, such as the sulfite or kraft process). The pulp may be beaten (for example, well known to those skilled in the art) using a conventional beater or refiner. Wood pulp can improve the tensile strength of the nonwoven. If wood pulp is included, it is preferably present in an amount of 0.1-20% by weight of the nonwoven, for example 5-10% by weight. In a preferred example, the wood pulp is present in an amount of up to 9.5%, for example 1 to 9%, for example 5 to 9% by weight of the nonwoven. Applicants have surprisingly found that nonwovens containing such very small amounts of wood pulp (in addition to the water-soluble binder) have sufficient strength to form into filters / filter elements. In a different preferred example, the wood pulp is present in an amount of up to 20% by weight of the nonwoven, for example 1 to 20% by weight, and the water-soluble binder is 0%, expressed as a percentage of the solids level content in the finished nonwoven. .1% to 5%.

  Thus, according to the present invention, in one aspect, a tobacco smoke filter or filter element comprising a nonwoven, wherein the nonwoven comprises a staple fiber sheet, wood pulp, and a water-soluble binder, wherein the water-soluble binder comprises: A tobacco smoke filter or filter element is provided that is uniformly coated on at least one side of the staple fiber sheet and wherein up to 9.5% by weight of the nonwoven is wood pulp.

  According to the present invention, in another aspect, a tobacco smoke filter or filter element comprising a nonwoven, wherein the nonwoven comprises a staple fiber sheet, wood pulp, and a water soluble binder, wherein the water soluble binder comprises: The nonwoven is uniformly coated on at least one side of the staple fiber sheet, and the nonwoven comprises wood pulp in an amount of up to 20% by weight of the nonwoven, and the amount of binder is determined by the solids content in the finished nonwoven. A tobacco smoke filter or filter element is provided, expressed as a percentage of the level content, between 0.1% and 5%. Preferably, the staple fibers are not cellulose acetate fibers or cellulose ester fibers.

  The tobacco smoke filter or filter element may further include a flavor enhancing additive. The flavor enhancing additive may be an additive as disclosed in WO 2010/136751 for use in a paper filter. Flavor-enhancing additives include alicyclic lactones, aromatic lactones, aromatic ketones, secondary alcohols or esters thereof, phthalide, χ-valerolactone, χ-hexalactone, δ-hexalactone, χ-heptalactone, χ Octalactone, δ-octalactone, 4-hydroxy-3-pentenoic acid lactone, 5-hydroxy-2-decenoic acid δ-lactone, 4,4-dibutyl-χ-butyrolactone, mintractone, dehydromentofloractone, 3 -Butylidenephthalide, 3-n-butylphthalide, whiskey lactone or sedannolide.

  The tobacco smoke filter or filter element may include a longitudinally extending core of the tobacco smoke filtering material. The tobacco smoke filtration material may include or be a nonwoven. The longitudinally extending core of the tobacco smoke filtration material may be substantially cylindrical.

  The tobacco smoke filter or filter element according to the invention may have a circumference of 14 to 28 mm, for example 16 to 26 mm, for example 16 to 17 mm or 24 to 25 mm. The length of the tobacco smoke filter of the present invention may be 10 to 40 mm, for example 15 to 35 mm, for example 20 to 30 mm. The tobacco smoke filter element of the present invention may be 5-30 mm in length, for example 6-20 mm, for example 8-15 mm, for example 10-12 mm.

  The cigarette smoke filter or filter element of the present invention may further include, for example, a plug wrap wrapper. The wrapper is preferably engaged around a tobacco smoke filter or filter element (eg, around a longitudinally extending core of tobacco smoke filtering material). The wrapper (e.g., plug wrap) is preferably held in place with a water soluble adhesive (e.g., by lap and glue seams as known to those skilled in the art). The water-soluble adhesive exposes the filter material (nonwoven) contained in the filter by facilitating the opening of the filter upon contact with water, thereby facilitating the disintegration of the filter (nonwoven) after use. This is advantageous.

  The filter or filter element of the present invention may be used as a single filter tip, or as a filter rod, or as one or more segments in a multi-segment filter. Thus, the filter element according to the present invention may be used as a two-element, three-element, or other multi-element segment filter. Two-element or other multi-element filters are known to those skilled in the art. Filters according to the present invention may be used in machine cigarettes (eg, mass produced and packaged cigarettes). Filters according to the present invention can be used as filter tips for use with individually wound cigarettes (eg, hand-wound cigarettes) or with Roll Your Own or Make-Your-Own products May be done.

  According to a further aspect according to the present invention there is provided a filter cigarette comprising a tobacco smoke filter or filter element according to the present invention. In a filter cigarette according to the invention, a filter of the invention (or a filter comprising a filter element of the invention) is joined to a wrapped tobacco rod at one end facing the tobacco. The filter may be, for example, by ring chipping (by engaging only around the adjacent ends of the [wrapped] filter and rod, leaving most of the filter wrapper exposed), or full chipping over A wrap (engaging around the entire length of the filter and the adjacent end of the tobacco rod) may be joined to the wrapped tobacco rod. The plug wrap / overlap and / or tipping paper preferably contains a water-soluble lap adhesive. The water-soluble adhesive exposes the filter material (nonwoven) contained in the filter by facilitating the opening of the filter upon contact with water, thereby facilitating the disintegration of the filter (nonwoven) after use. This is advantageous.

  Any of the filters or filter cigarettes according to the invention may be air-impermeable, or by conventional means, for example by using a pre-perforated or air-permeable plug wrap, and / or And may be aerated by laser perforation formation of the tipping overlap.

  The filter or filter element according to the invention may be formed as a continuous rod (by methods well known to those skilled in the art). The continuous rod is cut to a finite length for subsequent use as it continuously exits the manufacturing machine outlet. This cutting can form individual filters or filter elements as defined and described above. Each of these is then attached to a separate wrapped tobacco rod to form a filter cigarette. However, in most cases, successively emerging filter rods are first cut to a length of at least two times (usually four or six times) for subsequent use; If so, they are subsequently cut into double lengths for the filter cigarette assembly. In this case, double length filter rods are assembled and joined (by ring chipping or full chipping overlap) between wrapped tobacco rod pairs. The combination is then split in the middle, resulting in two separate filter cigarettes. As is known to those skilled in the art, similar techniques are used for, for example, double-length filter elements that are combined to form a two-element or multi-element filter. The present invention includes filter rods (and / or filter element rods) that are twice as long or longer.

  In a further aspect according to the present invention, there is provided a nonwoven fabric, wherein the nonwoven fabric comprises a staple fiber sheet and a water soluble binder, wherein the water soluble binder is uniformly distributed on at least one surface of the staple fiber sheet. A coated, non-woven fabric is provided. According to another aspect of the present invention, there is provided a nonwoven fabric, the nonwoven fabric comprising staple fibers (eg, staple fiber sheets) and a water-soluble binder, wherein the water-soluble binder is applied to the staple fibers in an aqueous form. A non-woven fabric is provided. Preferably, the nonwoven is a wet laid nonwoven. The nonwoven fabric of the present invention includes staple fibers (eg, shortcut biodegradable) and a water-soluble binder. The water-soluble binder is preferably applied in an aqueous form (to the fiber). The staple fiber may be a staple fiber with a cut length of 4 mm to 10 mm, for example, 4 to 6 mm. The diameter of the staple fiber may be between 1.7 dtex and 3.3 dtex. The staple fibers may have any cross-section (eg, circular, trilobal). Of course, staple fibers of any cut length and diameter, as appropriate for use in wet laid nonwovens, can be used without departing from the scope of the present invention, and may vary. A blend of fibers, fiber lengths, or fiber diameters may be used in the nonwoven.

  The staple fibers are preferably comprised of a biodegradable material. The staple fibers may be regenerated cellulose fibers, such as viscose or Tencel. Both of these are available from Lenzing AG. Other biodegradable fibers such as polyvinyl alcohol (PVOH), polylactic acid (PLA), polyglycolic acid (PGA), or cotton may be used. Low biodegradable or non-biodegradable cellulose acetate fibers can be used, but these are not preferred.

  The nonwoven may further include wood pulp. Wood pulp can improve the tensile strength of the nonwoven. If wood pulp is included, it is preferably present in an amount of 0.1-20% by weight of the nonwoven, for example 5-10% by weight.

  The amount of water-soluble binder may be 0.1% to 5%, such as 0.5 to 3%, such as 1%, expressed as a percentage of the solids level content in the finished nonwoven. The water soluble binder may be carboxymethyl cellulose (CMC), polyvinyl alcohol (PVOH), hydroxycellulose, polyethylene oxide, or starch. The binder can be applied by any known method suitable for applying a liquid binder, such as curtain coating, size pressing, mangle padding, and the like. The nonwoven fabric preferably does not contain an alkali compound.

  In a preferred example, the wood pulp is present in an amount of up to 9.5%, for example 1 to 9%, for example 5 to 9% by weight of the nonwoven. The inventor has surprisingly found that a nonwoven containing such a very small amount of wood pulp (in addition to the water-soluble binder) has sufficient strength to form into a filter / filter element. Was. In a different preferred example, the wood pulp is present in an amount of up to 20% by weight of the nonwoven, for example 1 to 20% by weight, and the water-soluble binder is 0%, expressed as a percentage of the solids level content in the finished nonwoven. .1% to 5%.

  Preferably, the staple fibers are not cellulose acetate fibers or cellulose ester fibers.

  According to a further aspect according to the invention there is provided a tobacco smoke filter or filter element, the tobacco filter or filter element comprising a filtering material comprising the nonwoven fabric according to the invention.

  The invention will now be described with reference to the following examples and the accompanying drawings.

Example 1
A small wet laid nonwoven fabric of about 40 gsm was prepared using a Handsheet Former according to TAPPI standard T205. A fiber blend of 90% PVOH fiber (2.8 dtex, 4 mm long) and 10% wood pulp was used. The tensile strength of these sheets was below 10 N, ie very weak. The sheets were then coated with a CMC or PVOH water soluble binder using a padding machine. Addition of 4% CMC increased the tensile strength to 65N, while addition of 4.5% PVOH increased the tensile strength to 108N. Thus, the addition of a liquid binder provides sufficient strength to allow such nonwovens to be processed on a high-speed cigarette filter manufacturing facility. These handsheet nonwovens are subjected to EDANA standard FG511.1 Tier 1 Dispersability Shake Flask Test (using screens with 1.6, 3.15, 6.3 and 12.5 mm openings). ) And found to be greater than 99.5% passing through a minimal 1.6 mm screen. This demonstrated a very high level of dispersibility. As measured by this test, it was also observed that the addition of binder to the untreated sheet improved the dispersibility level.

  Example 1 demonstrates that the nonwoven of the invention is suitable for use in tobacco smoke filters or filter elements (according to the invention) and has an excellent level of dispersibility in cold water, ie the nonwoven is highly biodegradable Demonstrate.

Example 2
Two types of wet laid nonwovens (references A and B) according to the present invention were prepared using a pilot scale inclined wire hydroformer. Nonwoven fabric A uses 100% viscose fiber with a length of 6 mm and a linear density of 1.7 dtex (supplied by Kelheim Fibers GmbH), and nonwoven fabric B uses 100% Tencel fiber of a length of 6 mm and a linear density of 1.7 dtex (Lenzing). (Supplied by AG). A 1% solution of a water soluble CMC binder (Finnfix 700, Noviant) was applied to both nonwoven fabrics during manufacturing via curtain coating technology. Cigarette filters were then produced from both types of nonwovens using paper-based cigarette filter production equipment well known to those skilled in the art (see, eg, Example 4). An essential feature of this process is that the nonwoven is longitudinally embossed to facilitate compression into a cylindrical rod form. The bulk, tensile, and stretch properties of the nonwoven are critical in determining if it can withstand embossing, for example, the nonwoven must not break or interfere with the rollers. The inventor has surprisingly found that both nonwovens work well on filter manufacturing equipment. The table below shows the test results for nonwoven fabrics and cigarette filters formed from these nonwoven fabrics.

  The dispersion characteristics of these filters were evaluated by placing them in a beaker containing cold water with the plug wrap removed. Both filters A and B were completely dispersed in less than 1 minute with occasional gentle stirring. This was significantly faster than paper filters showing no sign of dispersion over the same time frame. Samples of nonwoven fabrics A and B were also tested (using screens with 1.6, 3.15, 6.3 and 12.5 mm apertures) for EDANA standard FG511.1 Tier 1 Dispersability Shake Flask Test. Flask test). After so doing, it was found that 99% of nonwoven A and 97% of nonwoven B passed through the 6.3 mm aperture screen. This represents a very high level of dispersibility.

  Example 2 demonstrates that the nonwoven of the invention is suitable for use in tobacco smoke filters or filter elements (according to the invention) and has an excellent level of dispersibility in cold water, ie that the nonwoven is highly biodegradable Demonstrate.

Comparative Example 3 (not of the present invention)
Further testing to prepare a third material ("nonwoven C") using the same equipment and viscose fibers as nonwoven A, but using 5% PVOH binder fibers instead of 1% water soluble liquid binder. Was carried out. That is, nonwoven fabric C was composed of 95% viscose and 5% PVOH fibers. Non-woven fabric C had a weight of 36 gsm, a weight variation of 1.05%, a tensile strength in the machine direction of 47 N, and a tensile strength in the transverse direction of 33 N. These were all close to the values of nonwoven fabrics A and B. However, the dispersion characteristics of the nonwoven fabric C were significantly inferior to those of the nonwoven fabrics A and B. There was no sign of rapid dispersion after placing the chips in water and less than 10% passed through a 6.3 mm aperture screen after the same shake flask test as in Examples 1 and 2.

  Comparative Example 3 demonstrates that for rapid dispersion, the water-soluble binder must be applied to the nonwoven as a uniform layer (eg, by application in an aqueous form) rather than as binder fibers inside the nonwoven. I do.

Example 4
As in Example 2, two types of wet laid nonwoven fabrics (again, A and B) according to the present invention were prepared using a pilot scale inclined wire hydroformer. Nonwoven fabric A uses 100% viscose fiber with a length of 6 mm and a linear density of 1.7 dtex (supplied by Kelheim Fibers GmbH), and nonwoven fabric B uses 100% Tencel fiber of a length of 6 mm and a linear density of 1.7 dtex (Lenzing). (Supplied by AG). A 1% solution of a water soluble CMC binder (Finnfix 700, Noviant) was applied to both nonwoven fabrics during manufacturing via curtain coating technology. The cigarette filters were then produced from both types of nonwovens using paper cigarette filter production equipment well known to those skilled in the art.

  Sample filters were prepared from cylindrical rods (15 mm long and 24.50 mm perimeter) formed from wet laid nonwoven fabrics A or B according to the method described in GB-A-2075328.

  Form a wet laid nonwoven on a graded wire machine as described above. The longitudinally advanced completed nonwoven web is then advanced longitudinally between cooperating rolls having a circumferentially extending corrugated structure (to longitudinally emboss the nonwoven). And then, it is continuously assembled in the lateral direction (while being advanced in the longitudinal direction as a nonwoven web) to form a rod shape. The resulting continuously manufactured rod is then continuously transversely cut to a finite length by a method also known to those skilled in the art to provide a product filter or filter rod.

  The filter / filter rod / filter segment can be included in a filter cigarette by methods well known to those skilled in the art.

Example 5
The fiber biodegradability of the filter of the present invention was compared with a well-known cellulose acetate filter.

  According to the method described in Example 4 above, a sample filter according to the present invention was manufactured. "Viscose 2" filters were formed from fibers using 100% viscose fibers (supplied by Kelheim Fibers GmbH) with a length of 6 mm and a linear density of 1.7 dtex. A "Tencel 2" filter was formed from fibers using 100% Tencel fibers having a length of 6 mm and a linear density of 1.7 dtex (supplied by Lenzing AG). A 1% solution of CMC binder (Finnfix 700, Noviant) was applied to both nonwoven fabrics during manufacture via curtain coating technology. The filters were then produced from both types of nonwovens using paper cigarette filter production equipment well known to those skilled in the art.

  Biodegradability was measured by an independent laboratory according to the OECD 301B “Ready Biodegradability” method (modified Sturm test). This test provides a measure of the biodegradability of the material over 28 days (expressed as a percentage). FIG. 1 shows the results for a viscose 2 and Tencel 2 filter according to the invention compared to CA (standard cellulose acetate filter rod) when tested according to this method.

  It is clear that the viscose 2 and Tencel 2 filters (and materials) according to the invention degrade faster and more extensively than cellulose acetate. In addition, the test allows three biodegradability levels to be assigned to a material as measured by biodegradation over 10 days. The acceptable level of biodegradability is "easy biodegradability" (providing more than 60% biodegradability over a defined 10 day period), but other lower biodegradability levels depending on the performance of the material in the test. For example, "ultimate biodegradability" and "none". All viscose 2 and tencel 2 filters according to the present invention were identified as "easy biodegradable". In contrast, "CA" received a lower certification of "ultimate biodegradability."

  These results confirm that the filters of the present invention exhibit superior biodegradability as compared to cellulose acetate filters (and cellulose ester filters).

Test 6
EP 0709037 mentions the advantages of cellulose ester fibers having a modified cross section, for example a specific X, Y or I cross section. Comparative Examples 1-5 of the above specification refer to fibers having a more standard fiber cross-section, and the disintegration of these fibers is "poor" compared to the "excellent" disintegration of the modified cross-section fiber. ". The EDANA flask shake test (see the method described in Example 1) was performed on multiple handsheets of the present invention formed of viscose fibers having different cross sections. The viscose fibers used were "Danufil" and "Galaxy" from Kelheim Fibers. Each of these fibers has a circular cross section and a modified trilobal cross section. The results are shown in the table below. These results show that there is little difference between the dispersibility of the sheets formed using the circular cross section and the modified trilobal cross section. This result is quite unexpected given the teachings of EP 0709037. The specification states that (cellulose ester) fibers having a modified cross-section, for example a particular X, Y or I-shaped cross-section, have "excellent" disintegration, whereas the more standard fiber cross-section The disintegration of the fibers has "poor". This demonstrates that the biodegradability of the filter of the present invention comprising staple fiber, a small amount of water-soluble binder, and (optionally) a small amount of wood pulp is notable. Furthermore, these results surprisingly show that in the nonwoven fabrics (and filters) of the present invention, the fiber cross-sectional shape is independent of dispersibility.

Claims (25)

  A tobacco smoke filter or filter element comprising a nonwoven fabric, the nonwoven fabric comprising a staple fiber sheet and a water soluble binder, wherein the water soluble binder is on at least one surface of the staple fiber sheet. A uniformly coated tobacco smoke filter or filter element.   A tobacco smoke filter or filter element comprising a nonwoven fabric, the nonwoven fabric comprising staple fibers and a water soluble binder, wherein the water soluble binder is applied to the staple fibers in an aqueous form. Filter or filter element.   3. The cigarette smoke filter or filter element of claim 2, wherein the nonwoven comprises a staple fiber sheet.   The filter or filter element according to any one of claims 1 to 3, wherein the nonwoven is a wet laid nonwoven.   The filter or filter element according to any one of claims 1 to 4, wherein the staple fiber is biodegradable.   6. The staple fiber according to any one of claims 1 to 5, wherein the staple fiber has a "ready biodegradability" level as measured according to the OECD 301B "Ready Biodegradability" method (modified Sturm test). A filter or filter element according to claim 1.   A tobacco smoke filter or filter element according to any one of the preceding claims, wherein the nonwoven fabric comprises wood pulp.   8. A filter or filter element according to any one of the preceding claims, wherein the staple fiber is a staple fiber with a cut length of 4 mm to 10 mm, for example 4 to 6 mm.   9. A filter or filter element according to any one of the preceding claims, wherein the diameter of the staple fibers is between 1.7 dtex and 3.3 dtex.   10. The cigarette smoke filter or filter element according to any one of claims 1 to 9, wherein the staple fibers are regenerated cellulose fibers, viscose, tencel, polyvinyl alcohol, polylactic acid, polyglycolic acid, or cotton. .   11. A tobacco smoke filter or filter element according to any one of the preceding claims, wherein the amount of binder is from 0.1% to 5%, expressed as a percentage of the solids level content in the finished nonwoven fabric. .   The tobacco smoke according to any one of claims 1 to 11, wherein the water-soluble binder is carboxymethylcellulose, polyvinyl alcohol, hydroxycellulose, polyethylene oxide, natural or modified starch, cationic starch, guar gum, or a derivative thereof. Filter or filter element.   13. The filter or filter element according to any of the preceding claims, wherein the basis weight of the nonwoven is 25 to 42 gsm, for example 27 to 40 gsm.   14. A tobacco smoke filter or filter element according to any one of the preceding claims, further comprising a flavor enhancing additive.   15. A tobacco smoke filter or filter element according to any of the preceding claims, wherein the nonwoven is a tobacco smoke filtration material.   After applying the EDANA Standard FG511.1 Tier 1 Dispersability Shake Flask Test (using screens with 1.6, 3.15, 6.3 and 12.5 mm apertures), 16. A tobacco smoke filter or filter element according to any one of the preceding claims, wherein at least 95%, such as at least 96%, of the nonwoven is dispersible through a 6.3 mm aperture screen.   The nonwoven further comprises wood pulp in an amount up to 20% by weight of the nonwoven, and the amount of binder is 0.1% to 5%, expressed as a percentage of the solids level content in the finished nonwoven. 17. A tobacco smoke filter or filter element according to any one of the preceding claims.   A tobacco smoke filter or filter element comprising a nonwoven fabric, the nonwoven fabric comprising a staple fiber sheet, wood pulp, and a water soluble binder, wherein the water soluble binder is at least one of the staple fiber sheets. Cigarette smoke filter or filter element, wherein the filter is uniformly coated on the surface of the nonwoven fabric and up to 9.5% by weight of the nonwoven is wood pulp.   A tobacco smoke filter or filter element comprising a nonwoven fabric, the nonwoven fabric comprising a staple fiber sheet, wood pulp, and a water soluble binder, wherein the water soluble binder is at least one of the staple fiber sheets. And the nonwoven contains wood pulp in an amount of up to 20% by weight of the nonwoven, and the amount of binder is expressed as a percentage of the solids level content in the finished nonwoven. A tobacco smoke filter or filter element that is between 0.1% and 5%.   A cigarette smoke filter or filter element substantially as hereinbefore described with reference to any of Examples 1, 2 or 4.   A filter cigarette comprising a tobacco smoke filter or filter element according to any of the preceding claims.   A nonwoven fabric, comprising: a staple fiber sheet; and a water-soluble binder, wherein the water-soluble binder is uniformly coated on at least one surface of the staple fiber sheet.   A nonwoven fabric, the nonwoven fabric comprising staple fibers (eg, staple fiber sheets) and a water-soluble binder, wherein the water-soluble binder is applied to the staple fibers in an aqueous form.   24. The nonwoven fabric according to claim 22 or 23, wherein the staple fibers are regenerated cellulose fibers, viscose, tencel, polyvinyl alcohol, polylactic acid, polyglycolic acid, or cotton.   25. A tobacco smoke filter or filter element comprising a longitudinally extending rod of tobacco smoke filtering material comprising a nonwoven fabric according to any one of claims 22 to 24.

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