KR20100107505A - Tobacco smoke filter - Google Patents

Abstract

The present invention relates to a tobacco smoke filter or filter element comprising a cylindrical plug of substantially homogeneous filter material having a circumference of 14.0 to 23.2 mm, the substantially homogeneous filter material comprising a plurality of randomly arranged staple fibers. Include.

Description

Tobacco smoke filter {TOBACCO SMOKE FILTER}

The present invention relates to filters and filter elements for smoking articles such as cigarettes, in particular slim cigarettes.

Typical cigarettes have a circumference of about 24.5 mm, and also known as 'slim' cigarettes (around 21-23.2 mm) and 'superslim' cigarettes (around 16-18 mm). For example, it is possible to produce cigarettes with a narrower circumference, such as in the range of 14-16 mm, but such cigarettes are generally not commercially available. In the text, the term 'slim' should be interpreted to include all cigarette and / or cigarette filters having a circumference of about 14.0 to 23.2 mm.

Selective filtering occurs when the proportion of the selected chemicals in the cigarette smoke is reduced proportionally to a greater degree than the large amount of compounds (eg tar) in the smoke. Phenolic compounds such as phenol, cresol, catechol and resorcinol are known as constituents of cigarette smoke. These are toxic compounds and, in particular, phenol and catechol are included in the so-called "Hoffmann" list of the most harmful compounds detected in cigarette smoke. It is desirable to selectively reduce the amount of such compounds delivered to the smoker as much as possible.

A common filter material used in cigarette filters is a continuous tow of cellulose acetate filaments plasticized with triacetin, which tows aggregate into rods to form a filter or filter element. In such continuous tows (and filters and filter elements formed therefrom), the filaments of cellulose acetate tows are usually aligned longitudinally. Cellulose acetate is known to exhibit selective filtering action for phenolic compounds. “Slim” cigarette filters essentially contain less cellulose acetate filter material than standard filters, and any selective filtering effect can be reduced because of the lower amount of material available for similar amounts of smoke. Accordingly, it is desirable to provide a slim filter that selectively reduces the amount of phenolic compounds delivered to smokers of slim cigarettes.

The specification of the filter tow is described in the form of denier per filament, total denier and fiber cross section. Filament denier is defined as gram weight of a single filament 9000 meters, and total denier is defined as simply multiplying the number of filaments in the tow by dpf. Thus, for example, 5Y30,000 tow means a material comprising a filament having 5 grams of dpf per 9000 meters in the Y shape, which material is 6000 filaments providing a total denier of 30,000 grams per 9000 meters in length. It includes. Due to the limited amount of material that can be filled in slim products, a low total denier tow is used to produce a standard cellulose acetate ("monoacetate") cigarette filter (i.e. slim monoacetate filter) with a narrow perimeter. shall. Tow with low total denier is known to be more expensive (per unit weight) than tow with high total denier, and tow with low total denier on the market is also limited. Accordingly, it is desirable to provide a slim filter that can be made from cellulose acetate tow, which has a wider range of total denier than conventional slim or superslim monoacetate filters.

The present invention provides a tobacco smoke filter or filter element comprising a cylindrical plug of substantially homogeneous filter material having a circumference of 14.0 to 23.2 mm (eg, 16 to 23.2 mm), wherein the substantially homogeneous filter material is random. And a plurality of staple fibers.

As used herein, the term “substantially homogeneous filter material” means a filter material that has substantially uniform physical properties, even through any arbitrary cross section.

As used herein, the term “staple fiber” means a separate, discrete length of fiber. Each of the staple fibers may be arranged randomly. The substantially homogeneous filter material may comprise a plurality of randomly arranged staple fibers, with a portion of the randomly arranged staple fibers generally extending across the long axis of the cylindrical plug. The substantially homogeneous filter material may comprise at least 10% by weight (eg 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90%) of a plurality of randomly arranged staple fibers. And the staple fibers extend substantially across the long axis of the cylindrical plug.

The term “randomly arranged staple fibers” refers to staple fibers that are arranged randomly in three dimensions (within a filter or filter element). As used herein, the term "randomly arranged staple fibers" is not (or does not mean) continuous cellulose acetate tow, and each strand of this staple fiber is usually aligned longitudinally (but not staples). It is understood that the fibers may be formed from the tow as discussed below). As used herein, the term “randomly arranged staple fibers” is formed (eg, from pulp and / or fibers) and then (eg, by wrapping) the entire or substantially entire web. Or does not mean (and does not mean) a web or sheet of filter material in which the sheet is shaped into a rod. The term "randomly arranged staple fibers" does not mean two-dimensional paper artefacts taken in the form of a roll. As used herein, the term “randomly arranged staple fibers” is not to be interpreted to mean a web or sheet of filter material that is formed (eg from pulp and / or fibers), then chopped and shaped into rods. (And does not mean). Sheets or webs may have a two-dimensional random arrangement, but undergo a process (such as embossing) to maintain some formability when drawn through the filter maker . Thus, the fibers in a filter or filter element made from a sheet or web (also chopped sheet or web) are not staple fibers arranged randomly (three-dimensionally) since they are mostly aligned along the long axis of the filter or filter element.

A plurality of randomly arranged staple fibers can form a porous matrix that provides a complicated passage—when used as a cigarette filter, it can act as a passage of smoke. The inventors have found that the performance of a filter or filter element of the present invention is "mono" formed from a continuous tow of filaments arranged in the longitudinal direction of a conventional product (e.g., cellulose acetate tow plasticized with triacetin). Acetate "product, but found that when used in the form of randomly arranged staple fibers, 20-30% less filter material (eg cellulose acetate) is required. In addition to the less filter material required per filter, there is an additional advantage of using cellulose acetate tow with a much higher total denier than conventional super slim products. Thus, according to the present invention, in addition to the cost advantages of saving weight (because less filter material is required), the tow used is no longer required because the total denier no longer requires a low tow (expensive and poorly available). Its unit cost is cheaper.

We unexpectedly found that the tobacco smoke filter or filter element of the present invention is phenol from tobacco smoke (in slim cigarettes), for example, compared to standard monoacetate filter or filter elements (which do not include randomly arranged staple fibers). It has been found to enhance the efficacy of eliminating. Given that the weight of the filter material (cellulose acetate) is lower, the unexpected reduction of the phenolic compound by the filters and filter elements of the present invention is very meaningful. In addition, the inventors have found that the tobacco smoke filter or filter element of the present invention decomposes easier and faster than, for example, standard monoacetate filters or filter elements under environmental conditions. .

Staple fibers may be made of a filament material. Staple fibers can be crimped as is known. Staple fibers can be, for example, cellulose acetate or polypropylene fibers. Staple fibers may be made of (or made from) fiber tow, for example, cellulose acetate tow, polypropylene tow. Staple fibers can be, for example, fibers made from natural and / or synthetic fibers, natural plant material (s), and the like. Staple fibers may be cellulose pulp fibers (eg, fiberized through a hammermill). The staple fibers may be cut herbs (eg, cut tobacco leaves) or may be obtained from reconstituted tobacco sheets. Staple fibers can impart fragrance and / or filter properties to the final product. The staple fibers may be of substantially the same length (substantially uniform length). Staple fibers can have a variety of different lengths. The staple fibers can be, for example, 4 mm to 20 mm long, for example 5 mm to 19 mm long, for example 6 mm to 18 mm long, for example 7 mm to 16 mm long. Staple fibers have, for example, a total denier of 14,000 g to 55,000 g per 9,000 m length, for example 20,000 g to 50,000 g per 9,000 m length, for example 23,000 g to 45,000 g per 9,000 m length, for example For example, it may consist of or be made from fiber tow, such as cellulose acetate tow, from 25,000 g to 40,000 g per 9,000 m length.

The substantially homogeneous filter material may optionally include other materials, for example liquid additives (eg, flavors such as methanol solutions). A substantially homogeneous filter material comprising a plurality of randomly arranged staple fibers may be made from a plurality of staple fibers and may optionally include other materials such as plasticizers, binder materials or other additives. Staple fibers may bind to each other at a plurality of contact point sites (eg, due to the action of a plasticizer).

The substantially homogeneous filter material may optionally include a binder material. The substantially homogeneous filter material may optionally include a water soluble binder material. Examples of water-soluble materials include water-soluble polymer materials such as polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl ether, starch, polyethylene glycol and polypropylene glycol, mixtures of water-soluble binders with plasticizers such as triacetin, and hot in particulate form. Melt water soluble binders are included. By including a water-soluble binder material, it is possible to further improve the ability to easily and quickly disintegrate the filter or filter element, for example under environmental conditions.

The filter or filter element may comprise one or more particulate additives, for example within the body of the filter or filter element. The particulate additive (or each) may be a powder (eg particles having a diameter of 50 to 150 μm) or granules (eg particles having a diameter of 0.15 to 1.0 mm). Examples of suitable particulate additives include, but are not limited to, flavoring or absorbents such as activated carbon, zeolites, ion exchange resins (eg weak base ion exchange resins), sepiolites, silica gels, aluminum, Molecular sieves, carbonaceous polymer resins, diatomaceous earth-.

The filter or filter element may comprise one or more staple fibers. In addition to staple fibers (eg mixed) made from filament tow, staple fibers may be included in the filter, for example, fibers (eg, of cellulose pulp) fibrillated with a hammer mill.

Staple fibers (eg of fiber tow, such as cellulose acetate tow) can be plasticized. That is, the substantially homogeneous filter material may optionally include a plasticizer. Processes for producing plasticized tows are known. The plasticizer (which plasticizes the staple fibers) can be, for example, triacetin, triethylene glycol diacetate (TEGDA) or polyethylene glycol (PEG). The staple fiber may be a fiber of plasticized cellulose acetate tow. The staple fibers can be, for example, cellulose acetate tow plasticized with triacetin.

The circumference of the cylindrical plug is for example 14.0 mm to 23.2 mm, for example 16 to 23.2 mm, for example 16.0 mm to 20 mm, for example 16.2 mm to 20 mm, for example 16.2 mm to 17 mm.

The plurality of randomly arranged staple fibers may be porous matrices that provide complex passages within the filter material. When a complicated passage is used as a cigarette filter, it can function as a passage for smoke.

The tobacco smoke filter or filter element has a substantially uniform physical property over any cross section, rather than the more non-uniform structure caused by being made from a sheet of filter material.

In the filter and filter element according to one aspect of the invention, the filter material of tobacco smoke can be wrapped, for example, in plugwrap wrapping paper, paper wrapping paper, air-permeable paper wrapping paper. Particulate additives such as those described above may be applied, for example, to wrappers or plug wraps surrounding the filter material described in GB 2261152.

An additional aspect of the present invention provides multiple rods comprising a plurality of filters or filter elements described above and / or in end-to-end completely connected to each other in a mirror image relationship. .

The filter element according to the invention can be used as a segment of a multi-segment slim filter, for example as a double, triple or other multi filter. Such filters are known. If the filter element is used as or inside a multi-segment filter, it is used in (or inside) the mouth or ball end segment of the filter or as (or in) any other segment of the filter. Can be used. The filter element according to the invention can be used, for example, as a single segment slim filter itself (for example in the same way as a monoacetate filter). Such filters are known.

In the filter cigarette according to the present invention, the filter end of the cigarette side (or the filter comprising the filter element of the present invention) is connected to a packaged tobacco rod. For example, ring tipping (which is engaged around the filter and the immediate end of the rod (packed) so that much of the filter wrap is exposed) or ring tipping (adjacent of the filter full length and the tobacco rod) The full tipping overwrap, which is engaged around the end, allows the filter to be connected to a packaged tobacco rod. Any filter or filter cigarette according to the invention may not be vented or vented by known methods, for example by pre-perforated or breathable plug wraps and / or laser drilling of plug wraps and tipping overlaps. Can be.

An additional aspect of the present invention provides the use of a tobacco smoke filter or filter element for selectively reducing one or more phenolic compounds in tobacco smoke, the tobacco smoke filter or filter element comprising a plurality of randomly arranged staple fibers. It has a cylindrical plug of substantially homogeneous filter material comprising. An additional aspect of the present invention provides the use of a cylindrical plug of substantially homogeneous filter material comprising a plurality of randomly arranged staple fibers, the plug for selectively reducing one or more phenolic compounds in tobacco smoke. As a filter or filter element, or in the preparation thereof.

An additional aspect of the present invention provides the use of a cylindrical plug of substantially homogeneous filter material comprising a plurality of randomly arranged staple fibers, the plug being or as a filter or filter element having improved degradability. Used for manufacturing.

Hereinafter, the present invention will be described with reference to the following examples, the drawings attached to FIG. 1 is a not to scale plan view of an individual filter as an example of the present invention, Figure 2 is a cross-sectional view of the filter of FIG.

The filter 1 shown in FIG. 1 comprises a porous elongated cylindrical plug 2 having a circumference of 16.9 mm and a length of 27 mm, the plug being made from a 5Y 30,000 cellulose acetate tow plasticized with triacetin. And a plurality of randomly arranged individual or staple filament fibers 3. As shown in FIGS. 1 and 2, staple fibers 3 generally extend across the major axis of the element and are slightly tied back to form a plurality of contact points at the sites where the staple fibers 3 are bonded to each other. The bonded fibers provide a substantially homogeneous filter material forming the plug 2. The substantially homogeneous filter material thus formed can be described as a porous matrix that provides a complex smoke passage when used as a cigarette filter. The filter element 1 has a substantially uniform physical property over all cross sections.

The filter can be produced by known methods, for example by the method disclosed in US Pat. No. 3,552,400. Thus, the tow of raw cellulose acetate passes through a conventional banding device to separate its individual filaments and through additional conventional banding devices that can be used to spread the tow into a relatively thin layer of filament. . The filament layer is then passed through a conventional plasticizer, whereby a suitable plasticizer (triacetin in this embodiment) is sprayed onto one or both sides of the filament layer by a suitable jet to form a plasticized tow. Conventional feeding means, such as a pair of rollers, are used to convey plasticized tow to processing equipment for making staple fibers and forming them into continuous rods. Suitable devices are described in detail in US Pat. No. 3,552,400, which is shown in FIG. 1 of this patent document. The plasticized tow is fed to the chopper through a funnel, which cuts the continuous tow into a plurality of separate staple fibers. The length of the staple fiber then depends on the correlation between the speed of the chopper and the speed at which the continuous toe is fed into the chopper. Staple fibers produced by the chopper are sucked out of the chopper by turbulence, which disperses the staple fibers (also provides or increases the random arrangement of staple fibers) and passes them through a porous frusto-conial screen. The smaller or outlet end of the screen is connected to a moving porous belt. If necessary, particulates or other additives (not shown) may be supplied to the turbulence and dispersed in the filter material at that stage. Porous enclosing means taper and tend to slow the rate of staple fibers passing through them, placing staple fibers such that a portion (length) of the fibers is substantially aligned across the long axis of the filter rod product. Staple fibers are fed onto a porous belt, which carries the fibers to the steam treatment chamber in the longitudinal direction. Since the belt and the fibers on the belt are pulled in the longitudinal direction through the bore, the bore located at the inlet of the vapor-processing chamber constitutes the longitudinal edge of the porous belt relative to the staple fibers. Thus, by pulling the belt around the fiber, the inside of the rod surrounded by the porous belt is made of staple fibers. The vapor is applied to the porous surface of the belt, passing continuously and directly, to treat staple fibers therein. While transporting the fiber within the cylindrical rod-shaped shape enclosed by the belt, the binding component (eg triacetin) of the staple fiber is activated by steam. Such methods are known and are described in the aforementioned US patents. As in known methods, the belt and staple fibers in the belt are conveyed through a cooling station where drying and cooling of the elements (and curing of the bonding components) take place. The cylindrical rod thus produced can be wrapped with plug wrap paper (not shown) and sealed with a lap adhesive by known methods. As a result, a continuous cylindrical rod of dried, cooled, randomly arranged staple fibers is stripped from the belt leaving the cooling station (the belt is substantially flattened, further gathering additional staple fibers from the screen and transferring them into the vapor chamber). Continue to return to the desired location in the screen area for transportation). Initially continuous cylindrical rods of randomly arranged staple fibers are cut to length for subsequent use when produced continuously from the machine outlet. For example, it can be cut by cutting means to form a single filter (eg filter 1 of FIG. 1), each of which is then attached to a separate packaged tobacco rod to form a filter cigarette or a separate Form the filter element. More typically, however, the rods produced in series for subsequent use are first cut into rods of multiple times (typically four or six times) length that are two or more than two times filter 1 (or filter element). The preparation of such multifold length filters (and subsequent bonding with filter cigarettes) is known.

Example  2: reduction of phenol

Table 1 below compares a known monoacetate filter of the same specification as Sample A comprising a filter material made from a plurality of randomly arranged staple fibers of plasticized cellulose acetate as a filter made according to the method of US 3,552,400. will be. Hardness value for the sample (compressed diameter of the filter rod, defined as a percentage of the initial rod diameter, compressing the rod by applying a known weight as a cylindrical foot for a certain time) and pressure drop (PD : mm level gauge (indicated by Water Gauge) was measured. Under ISO conditions, the yield of phenolic compounds was determined for all smoked samples: cresol was the sum of o-, m- and p-cresol, dihydroxyphenol was hydroquinone, resorcinol and catechol. The combined output. Tar yield of cigarettes was also measured to evaluate the change in phenol ratio for tar. The value for sample A is expressed as a% value for the monoacetate filter of the prior art (ie, the monoacetate filter value is 100 and the value for sample A is expressed as that percentage).

As described above, it is desirable to reduce the levels of phenolic compounds in cigarette smoke. Cellulose acetates are known to exhibit selective filter effects on phenols, and the filters according to the invention comprising randomly arranged staple fibers of cellulose acetates are preferred for cellulose acetate as compared to monoacetate filters having similar pressure drop and hardness. For example, since it contains 20 to 30% less, the effect of removing phenol is expected to be lower. Indeed, the results surprisingly showed that Sample A further reduced the yield of all phenolic compounds expressed in absolute standards and per mg of tar, than equivalent monoacetate products. Given that the weight of cellulose acetate in Sample A (including filter material formed from a plurality of randomly arranged staple fibers of plasticized cellulose acetate) is lower than that of monoacetate products (Sample A is a monoacetate filter). Of 77.5% of the total tow weight), the reduction of the phenolic compound in Sample A is more significant.

The results show that the selective reduction effect of the phenolic compounds provided by the filters and filter elements of the present invention is surprising and remarkable.

Example  3: Degradable

Different kinds of cigarette filters were placed in a rooftop wire mesh cage and their weight was periodically observed over 12 months. After 12 months, the weight of the standard monoacetate filter was reduced by 23-30%, while the weight of the filter comprising filter material made from a randomly arranged plurality of staple fibers of similar sized plasticized cellulose acetate was 46 It was found to decrease by%. Contrary to what was expected to result in similar weight loss, the results are surprising.

Example  3: type of tow

Characteristics of two superslim multi-filter rods A and B (including four filters of the invention 27 mm long, in a structure similar to the example of FIGS. 1 and 2) and similar standard monoacetate superslim product "control" Is as follows:

The monoacetate control superslim sample requires a more expensive tow with a lower total denier, while the tow used in Samples A and B is the same as that used in products around any standard (c. 24.5 mm). This example shows that the filter of the present invention provides acceptable properties using cellulose tow with a much higher total denier than conventional superslim products.

Claims (20)

A cylindrical plug of substantially homogeneous filter material having a circumference of 14.0 to 23.2 mm,
Tobacco smoke filter or filter element, wherein the substantially homogeneous filter material comprises a plurality of staple fibers arranged randomly. The method of claim 1,
Tobacco smoke filter or filter element, wherein said plug of said substantially homogeneous filter material is between 16.0 and 23.2 mm. The method according to claim 1 or 2,
Tobacco smoke filter or filter element, wherein the staple fibers are crimped. 4. The method according to any one of claims 1 to 3,
Tobacco smoke filter or filter element, wherein the staple fibers are fibers made from natural and / or synthetic fibers and / or natural plant material (s). The method according to any one of claims 1 to 4,
Tobacco smoke filter or filter element, wherein said staple fibers are cellulose acetate fibers or polypropylene fibers. The method according to any one of claims 1 to 5,
A tobacco smoke filter or filter element comprising at least two staple fibers. The method according to any one of claims 1 to 6,
A tobacco smoke filter or filter element further comprising a liquid additive or particulate additive. The method according to any one of claims 1 to 7,
A tobacco smoke filter or filter element, wherein the staple fibers are from 4 mm to 20 mm in length. The method according to any one of claims 1 to 8,
The staple fiber is made from tow with a total denier of 14,000 g to 55,000 g per 9,000 m length. The method according to any one of claims 1 to 9,
A tobacco smoke filter or filter element comprising plasticized staple fibers. The method according to any one of claims 1 to 10,
A tobacco smoke filter or filter element comprising cellulose acetate staple fibers plasticized with triacetin, triethylene glycol diacetate (TEGDA) or polyethylene glycol (PEG). The method according to any one of claims 1 to 11,
A tobacco smoke filter or filter element having a circumference of the cylindrical plug of 16.2 mm to 23.2 mm. The method according to any one of claims 1 to 12,
Tobacco smoke filter or filter element further comprising a wrapper or plugwrap. The method according to any one of claims 1 to 13,
A tobacco smoke filter or filter element comprising particulate additives on the wrapper or plug wrap. The method according to any one of claims 1 to 14,
A tobacco smoke filter or filter element further comprising a water soluble binder material. The method according to any one of claims 1 to 15,
A tobacco smoke filter or filter element substantially described in the description of the invention and / or in one or more embodiments and / or the attached figures. A filter cigarette comprising a filter according to any one of claims 1 to 16 or a filter containing the filter element according to any one of claims 1 to 16, which is connected to a packaged tobacco rod. 17. A multi-bar, comprising a plurality of filters or filter elements according to any of the preceding claims, wherein the ends and end-to-ends are completely connected to each other. Used to selectively reduce one or more phenolic compounds in tobacco smoke,
Having a cylindrical plug of substantially homogeneous filter material comprising a plurality of randomly arranged staple fibers,
Use of tobacco smoke filter or filter element. Used as or for the manufacture of filters or filter elements with improved resolution,
Use of a cylindrical plug of substantially homogeneous filter material comprising a plurality of randomly arranged staple fibers.

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