JP4195721B2 - Tobacco smoke filters or filter elements containing additives - Google Patents

Abstract

A tobacco smoking filter is disclosed, with adjunets on the surface in the form of fibres filaments or films and whereby the drawing resistance of the tobacco smoking filter and the mass of the adjuncts in the tobacco smoking filter meet the following equation (I) M<SUB>ad</SUB>/Deltap>1 mg/daPA (I), where Deltap is the drawing resistance [daPA], applied as a value calculated with a 7.8 mm filter diameter and M<SUB>ad </SUB>[mg] is the mass of the adjuncts. The tobacco smoking filter comprises channel structures and the filer material is provided as a planar material. Said tobacco smoking filter has a low draw resistance on smoking with a particularly good filtration effect and is relatively simple to produce.

Description

  The present invention relates to cigarette smoke filters or filter elements, which are constructed in one piece and can be spun or processed into a polymer or polymer mixture based fiber, filament or film and one Or it contains more additives.

  The above types of tobacco smoke filters are known in the art. Here, “integrally” means that the cigarette smoke filter is manufactured uniformly in the long axis direction and can be manufactured without further specifying the filter element. Should. Here, there is an important difference from what is called a “chamber filter”. That is, in the “chamber filter”, a chamber limited in the outer peripheral direction is created by wrapping paper disposed between filter elements from conventional filter materials that are spaced apart from each other in the longitudinal direction. . This chamber may be filled with additives such as granular activated carbon.

  So far, many attempts have been made to design filter structures that can efficiently use porous elements in particular. The structure of the chamber filter is disadvantageous in terms of efficient use of the contained activated carbon. In other words, the degree of filling the chamber is limited, and the activated carbon particles are relatively coarse, so that part of the smoke passes through the unfilled portion of the chamber, and as a result, does not come into direct contact with the activated carbon. Furthermore, activated carbon increases the suction resistance when it is finely divided, and this state is unacceptable for smokers, and therefore cannot be arbitrarily finely divided. In this respect, the filter structure described in EPA-0 014 477 functions more advantageously than this. In this structure, the granular activated carbon is dispersed within the filter element to ensure that the activated carbon particles are approximately uniformly distributed within the fibers or filaments of the filter material, where the fibers or filaments are also uniformly distributed. ing. However, it is still necessary to roughen the additive particles in order to ensure that the aforementioned particles adhere to the cigarette smoke filter even if smoke does not pass through in this way. Therefore, this filter structure also has disadvantages due to coarse activated carbon particles.

  The cigarette smoke filters or their use and the background of the invention are described below. Filtered tobacco has a tobacco smoke filter at its mouth end that blocks at least a portion of the cigarette tobacco combustion products and prevents inhalation of the combustion products during smoking. On the other hand, the impact of cigarette smoke filters on the flavor of cigarette smoke should be such that it is positively evaluated by smokers. Some cigarettes with a filter have a tobacco smoke filter treated with a porous particulate additive. Such tobacco smoke filters or tobacco smoke filter elements have increased filter performance compared to tobacco smoke filters that do not contain particulate additives. This effect is often explained by the fact that porous additives preferentially adsorb gaseous combustion products at their pore inner surface, reducing their concentration in the smoke. The most representative of this type of tobacco smoke filter is the use of activated carbon as a porous particulate additive. Others are tobacco smoke filters as described in DE-A-2 658 479, with oxides, hydroxides and / or oxidations of various metals such as silicon, aluminum, magnesium, iron and / or titanium. Some of them contain hydrates. The accessibility of such porous particulate additives to gaseous smoke components is critical to their effectiveness. For example, the filter performance of finely divided porous materials has been found to be particularly good compared to the filter performance of coarser particulate materials. The disadvantage of this chamber filter is the high manufacturing cost.

In addition, filter structures are known that show that fine particulate additives can be deposited in tobacco smoke filters. The tobacco smoke filters described in U.S. Pat. Nos. 3,043,736 and 2,881,770 consist of a bundle of seamless crimped filaments of cellulose acetate that are incorporated into a filter cylinder by wrapping paper. In addition, individual filaments are coated with finely divided activated carbon. Devices that can be used as a fine particle additive coating apparatus can be classified as follows.
a) A device for applying an additive by suspending it in an aqueous medium or a fluid of a volatile organic color developer or a plasticizer,
b) Spraying device for additives consisting of fine particulate matter (may be pre-wet with adhesive or plasticizer),
c) Equipment for applying additives using latex emulsions d) Equipment for coating by passing a bundle of filaments or yarns previously wetted with an adhesive or plasticizer through a finely divided activated carbon fluidized bed.
In this regard, reference can be made to DE 127 4 946.

  The tobacco smoke filter produced by the above method is characterized in that the additive-attached filaments are preferably arranged longitudinally and bonded to each other at the statistically distributed contact site by the action of an adhesive or plasticizer, It is characterized by the fact that a small space in the longitudinal direction is formed evenly distributed over the entire filter between adjacent filaments by the flow of smoke.

  In the example given in this prior art, even a tobacco smoke filter manufactured in this way and treated with particulate additives has a high suction resistance, as does a comparative filter that does not contain particulate additives. This is clearly shown. In the end, a filter having a large amount of additive evenly and having a low suction resistance cannot be manufactured by the above method.

  Another cigarette smoke filter uses a paper filter to which activated carbon is added. These contained fine particle activated carbons adhere to paper during the paper making process. At the same time, in the manufacture of the filter material, a dough is formed, wound on a bobbin and subsequently sent to a processing device. The filter or tobacco manufacturer takes the dough from the bobbin, wraps it in paper to make a rod-like article, and then compresses it axially across the mold part of the filter rod machine. Cut to final length. Although this dough is not essential, it is usually pleated by a creping device parallel to the flow direction of the dough before it is made into a rod. This fold reduces the material density on the one hand and has an effect on the suction resistance of the filter on the other. A channel structure in which the channel-like regions arranged in the longitudinal direction at a low material density extend over a substantial part of the filter or filter element is a feature of a filter manufactured by pleating such a two-dimensional structural material. These channels are bounded by higher material density filter materials. Further, the suction resistance of this filter is relatively low as a structural characteristic.

  However, if these two-dimensional structure filters are not made of cellulose acetate or only partially made of cellulose acetate, the flavor of smoke is often negatively evaluated. Moreover, as is known for cellulose acetate tobacco filters, such filters cannot specifically keep phenol or nitrosamines in the filter.

  The present invention thus improves the tobacco filter or filter element, constructed in one piece and as described above, to minimize the effect of the adhering finely divided adsorbent as much as possible, nevertheless a large amount of particulate matter. The object is to reduce the suction resistance when the additive is deposited. In particular, cellulose acetate may be used as the filter material.

According to the present invention, the object of the present invention is achieved by the following.
a) an additive is present on the surface of the fiber, filament or film;
b) The suction resistance of the tobacco smoke filter and the additive mass in the tobacco smoke filter are expressed by the following formula (I)
M _ad / ΔP _7.8 > 1 mg / daPa (I)
(Wherein ΔP _7.8 represents the suction resistance [daPa], which is used as a converted value with a filter diameter of mm, and M _ad [mg] represents the mass of the additive),
c) the tobacco smoke filter has a channel structure, and d) the filter material is a two-dimensional structure.

  Within the scope of the present invention, conventional fibers, filaments and films of the polymer or polymer blend system that can be spun or processed into a film can be used. Furthermore, within the scope of the present invention, a two-dimensional structure or film of fibers or filaments is suitable as the filter material, the two-dimensional structure and / or film being smooth, pleated, embossed and / or partially It is in a compressed state.

It is particularly preferred if the filter material is composed of cellulose ester, cellulose acetate, cellulose butyrate, cellulose acetobutyrate, cellulose acetopropionate and / or cellulose propionate, especially cellulose ester filter materials are often used. Particularly preferred cellulose acetates have a degree of substitution of 1.5 to 3.0, especially 2.2 to 2.6, more especially 2.5. In the scope or practice of the present invention, it has been found to be particularly advantageous to use the tobacco smoke filter described in WO 01/28369. If the present invention is slightly modified and further optimized, the ratio S of fiber or filament mass to suction resistance based on filament fineness is preferably greater than 0.7. Where the S value is:
S = (m _A / ΔP _7.8 ) / dpf [10 m / daPa] (II)
(Where m _A is fiber or filament mass [g], ΔP _7.8 is suction resistance [daPa] and dpf is filament fineness (dtex)), and this suction resistance is converted to a filter diameter of 7.8 mm. Use the value. The citronette filter has a Filtrona hardness of over 90%.

Furthermore, it is preferable that the mass of the fiber or filament does not exceed 10 mg / filter length [mm] and / or the residual crimp rate of the filter material does not exceed 1.45. This crimp residual ratio is expressed by the following formula (III)
I _R = 10000 × m _A / (G × l) (III)
(Where m _A is the fiber or filament mass [g], G is the overall fineness [g / 10exp4 × m], and l is the filter length [mm]).

  The optimal crimp residual rate is 1.05 to 1.4, in particular 1.1 to 1.3. More preferably, the ratio S of fibers or filament mass to suction resistance based on filament fineness does not exceed 2, in particular a value of 0.8 to 1.3.

  In the cigarette smoke filter according to the invention, particularly advantageous results are reached when the fiber or filament mass is at least 4 mg / filter length [mm], in particular about 5 to 8 mg / filter length [mm].

  For optimum Filtrona hardness, it should preferably be 90 to 95%, in particular 91 to 93%.

  Within the scope of the present invention, additives are essential to achieve the above objective and are placed on the surface of the fibers, filaments or films. Particularly preferably, these additives are in the form of particles, in particular having a particle size of less than 300 μm, more particularly of less than 100 μm. Even more preferably, a particle size of less than 50 μm, in particular 30 μm, leads to particularly good results. The present invention is not particularly limited in selecting a particulate additive or a porous additive. A person skilled in the art can select suitable additives without problems, these being additives as adsorbents of activated carbon, metal oxide, metal hydroxide and / or metal oxide hydrates In particular, these metals are preferably aluminum, silicon, titanium and / or magnesium. In each case, it is preferred that the porous additive is treated with an active substance, in particular with an active substance as an antioxidant, flavoring and / or antimutagenic substance.

  The method of introducing the particulate additive into the tobacco smoke filter according to the present invention is such that the particulate additive depends on the binder, in particular, polyvinyl acetate, polyvinyl alcohol, polyethylene glycol, water-soluble esters or ethers, starch, starch derivatives. It is preferable that it is fixed to the surface of the filter material with cellulose ester.

  The surface of the fibers, filaments and films may be further optimized as follows. For example, additives on the surface may perform the filter aid function, particularly as a filter aid function as organic acids, acidic carboxylic esters, polyphenols and / or porphyrin derivatives. Fibers, filaments and films, or fibers, filaments and films constituting the film material constituting the tobacco smoke filter or filter element may contain further additives inside to improve the properties. These additives are preferably plasticizers, matting agents, pigments and / or stabilizers. The inclusion of a plasticizer is particularly effective. Preferably 0 to 15% by weight, in particular 5 to 12% by weight, is present in the fiber or filament or film. It should be recommended that the plasticizer is present as triacetin, ethylene glycol diacetate, and / or diethyl citrate. In addition, the tobacco smoke filter of the present invention may contain a photoreactive additive, particularly a photoreactive additive as finely divided anatase-type titanium oxide having an average particle size of less than 2 μm.

The characteristic b) suggested by the present invention described above provides some significant properties. According to this feature, in the present invention, the mass of the additive suction resistance and tobacco smoke in the filter cigarette smoke filter, the following formula (I), the in _{M ad / ΔP 7.8> 1mg /} daPa ( wherein, [Delta] P _7.8 is in the suction resistance [dapA], which is used corresponding value of a filter diameter of 7.8 mm, M _ad it is required according to the a) weight of additives [mg]. Particularly preferably, the ratio of M _ad / ΔP _7.8 is greater than 2 mg / daPa, in particular greater than 3 mg / daPa.

  The integral tobacco smoke filter or filter element channel structure claimed in the present invention is an important feature that further differentiates the present invention. In the channel structure, it is pointed out that the longitudinally arranged channel-like regions have a low material density and extend over a considerable area of the filter or filter element. These channels are bounded by a higher material density filter material. Particularly in the present invention, this channel structure uses a filter material of a two-dimensional structure.

  One skilled in the art can produce the integrated tobacco smoke filter or integrated tobacco smoke filter element of the present invention without problems and without the need for further technical information. In the following, a particularly suitable method is described. In producing the tobacco smoke filter of the present invention, the tow removed from the bale is prepared with a stream of air in accordance with conventional methods of space filters. In an intermediate step before the actual activation step, a non-woven fabric having the highest possible strength in the biaxial direction on the surface is produced, wound around a spool and activated with additives. Any suitable method of manufacturing a tobacco smoke filter can be applied to distribute the powder on the fiber surface. In particular, a) a device in which the additive is suspended in an aqueous liquid or volatile organic colorant or plasticizer liquid and applied to the filament (in each case a binder may be added) and b) microparticles A device for spraying an additive consisting of (which may be pre-moistened with an adhesive or plasticizer) is suitable. Separately or in addition, the particulate additive can be reliably adhered by a melt adhesive (this adhesive is applied with or separately from the particulate additive, or activated by heating for a short time. ).

  The tobacco smoke filter of the present invention is continuously manufactured and cut to a certain length from the initial filter rod. Individual elements with such a limited length can themselves be used as cigarette tobacco smoke filters. However, it is preferably used as part of a combined cigarette filter (double or triple), arranged in the longitudinal direction along with at least another filter element. For example, a single filter element according to the invention is preferably used in combination with a longitudinally arranged mouthpiece element having a normal appearance, such as a uniform rod of cellulose acetate fiber bundles.

  Summarizing the advantages of the present invention, in accordance with the implications of the present invention, finely divided additives can be introduced into tobacco smoke filters, in which the resistance to inhalation during smoking, especially in contrast to prior art comparative products, It has been found that it can be reduced. It was also found that particularly high filtration performance can be achieved with the filter of the present invention.

  Furthermore, in contrast to the corresponding comparative products in the latest state of the art, the integrated tobacco smoke filter of the present invention can be manufactured relatively easily. Furthermore, no expensive manufacturing from several filter elements is required, like the chamber filter described above. Especially when the filter material is composed of cellulose acetate, the smoke flavor is particularly positively evaluated. An effect of selectively delaying phenols was also observed.

  In the following, the invention is described in more detail by means of examples.

(Preparation of the filter of the present invention)
A filter tow of standard 2,1Y48 (filament fineness 2.33 dtex and total fineness 53333 dtex) was prepared on a conventional drawing machine KDF2 by Hauni, Hamburg and sprayed with 8% triacetin. A filter tow web having a minimum width of 250 mm was taken out from the guide roller, introduced into a pair of heated calender rollers, and rolled at an effective linear pressure of 40 kg / cm. The grooved calendar roller has a diameter of 230 cm and a width of 350 mm, and 10 grooves are carved per 1 cm. The other roller is not grooved. These are heated to 150 ° C. with silicone oil. The groove is a trapezoid with an upper width of 0.4 mm and a depth of 0.5 mm.

  The nonwoven fabric thus prepared is taken out from the calendar roller and then wound around a spool. The nonwoven spool is unwound with a conventional Foulard and passed through a bath filled with an aqueous suspension of activated carbon. In this way, the nonwoven fabric is dipped into the suspension down to 5 cm and then turned upward with a guide roller. When leaving the suspension bath, excess suspension is squeezed away by a pair of squeeze rollers. The squeeze roller is driven at a speed of 10 m / min so that the movement of the nonwoven fabric in the suspension is uniform. The nonwoven fabric is passed through a circulating air dryer at a temperature of 150 ° C. after being taken out from the squeeze roller. The dryer has a drying section of 4 meters, which ensures that the suspension is dried and the activated carbon is fixed on the nonwoven fabric.

  The non-woven fabric to which activated carbon is added is taken out of the dryer and introduced into the suction nozzle in the conventional KDF2 handled by Korber, Hamburg, into a strand, wound with wrapping paper and a filter length of 126 mm Disconnected. The filter rod diameter was adjusted to 7.8 mm.

Comparative Example 1

(Preparation of activated carbon filter by spraying carbon particles on filter tow)
A filter tow of standard 2, 1Y48 (filament fineness 2.33 dtex and overall fineness 53333 dtex) was prepared with a conventional drawing machine KDF from Hauni, Hamburg and sprayed with 8% triacetin. A filter tow web having a minimum width of 200 mm was taken out of the guide roller, guided through a spray nozzle, and treated with an activated carbon particulate material having a particle size of 250 μm by an air flow. For this purpose, activated carbon powder was continuously charged into the inlet connection with a weighing scale and sprayed with compressed air through a pipeline to the spray nozzle. The spray nozzle is surrounded by a box with openings for the intake and discharge of the filter tow web by suction, which avoids any discharge of carbon dust to the surrounding environment, which is advantageous Has brought. By adapting the feed rate of the activated carbon to the speed of the filter tow web, the amount of activated carbon on the filter tow web can be adjusted very accurately. The filter tow web was removed from this apparatus and was stranded with a suction nozzle in a conventional KDF2 handled by Korber, Hamburg, at a strand speed of 50 m / min, wound with wrapping paper and cut to a filter length of 126 mm. The filter rod diameter was adjusted to 7.8 mm.

The measurement results of the suction resistance and the mass of the activated carbon are shown in the table.

Claims (23)

Contains a polymer-based or polymer-mixed fiber, filament or film, and one or more additives that can be spun or processed into a film, and is composed of at least one A tobacco smoke filter or filter element, wherein the additive is present on the surface of the fiber, filament or film,
a) at least one said additive is in particulate form,
b) The suction resistance of the tobacco smoke filter and the mass of at least one additive in the tobacco smoke filter are
M _ad / ΔP _7.8 > 1 mg / daPa (I)
According (wherein, [Delta] P _7.8 in suction resistance [dapA], which is used as the corresponding value of a filter diameter of 7.8 mm, M _ad at least one of the mass of the additive [mg]),
c) The filter material exists as a two-dimensional structure ,
d) on the surface of the fibers, filaments or films by means of a binder consisting of polyvinyl acetate, polyvinyl alcohol, polyethylene glycol, water-soluble esters or ethers, starch, starch derivatives and / or cellulose esters. Cigarette smoke filter or filter element, characterized in that it is fixed to   Cigarette smoke according to claim 1, characterized in that the filter material is smooth, pleated, embossed and / or partially compressed as a two-dimensional structure of fibers, filaments or films. filter.   The tobacco smoke filter according to claim 1 or 2, wherein the filter material is composed of cellulose ester.   The tobacco smoke filter according to claim 3, wherein the cellulose ester is cellulose acetate, cellulose butyrate, cellulose acetobutyrate, cellulose acetopropionate, and / or cellulose propionate. The tobacco smoke filter according to claim 4, wherein the cellulose acetate has a substitution degree of 1.5 to 3.0 . The tobacco smoke filter according to any one of claims 1 to 5, characterized in that the ratio of M _ad / ΔP _7.8 exceeds 2 mg / daPa .   The tobacco smoke filter according to any one of claims 1 to 6, characterized in that the particle size of at least one of the particulate additives on the surface of the fiber, filament or film is less than 300 µm. The tobacco smoke filter according to any one of claims 1 to 6, characterized in that the particle size of at least one of the additives is less than 100 µm . At least one of the particulate additives is a porous additive as an adsorbent of activated carbon, metal oxide, metal hydroxide and / or metal oxide hydrate. The tobacco smoke filter according to claim 7 or 8.   The tobacco smoke filter according to claim 9, wherein the metal of the metal oxide, hydroxide and / or metal oxide hydrate is aluminum, silicon, titanium, and / or magnesium. . 11. Tobacco smoke filter according to claim 9 or 10, characterized in that at least one porous additive is treated with an active substance as an antioxidant, a flavor and / or an antimutagenic substance. 2. The at least one additive on the surface of fibers, filaments and films is a filter aid as organic acids , acidic carboxylic esters, polyphenols and / or porphyrin derivatives. 12. The tobacco smoke filter according to at least one of items 1 to 11. The fibers, filaments or films of the film material are characterized in that they contain further additives inside to improve the properties. Tobacco smoke filter according to at least one of claims 1 to 12. 14. The tobacco smoke filter according to claim 13 , characterized in that the further additive is a plasticizer, a marking agent, a pigment and / or a stabilizer. 15. Tobacco smoke filter according to claim 14 , characterized in that the plasticizer in the fiber or filament or film is present from 0 to 15 % by weight. The tobacco smoke filter according to claim 14 or 15 , characterized in that the plasticizer is present as triacetin, ethylene glycol diacetate and / or diethyl citrate. The ratio S of fiber or filament mass to suction resistance based on filament fineness is greater than 0.7 , where the S value is:
S = (m _A / ΔP _7.8 ) / dpf [10 m / daPa] (II)
Where m _A is the mass of the fiber or filament [g], ΔP _7.8 is the suction resistance [daPa] and dpf is the filament fineness (dtex), and this suction resistance is measured at a filter diameter of 7.8 mm. The cigarette smoke filter according to at least one of claims 1 to 16, wherein the cigarette filter has a Filtrona hardness of more than 90% using a converted value. The fiber or filament mass does not exceed 10 mg / filter length [mm] and / or the filter material has a crimped residual rate (Restkrauselung) that does not exceed a value of 1.45, Formula (III)
I _R = 10000 × m _A / (G × l) (III)
Wherein m _A is the fiber or filament mass [g], G is the overall fineness [g / 10exp4 × m] and l is the filter length [mm]. 18. A tobacco smoke filter according to item 17 . The tobacco smoke filter according to claim 18 , wherein the crimp residual ratio is 1.05 to 1.4 . The tobacco smoke filter according to at least one of claims 17 to 19 , characterized in that the ratio S of the fiber or filament mass to the suction resistance based on the filament fineness is a value not exceeding 2 . 21. A tobacco smoke filter according to any one of claims 17 to 20 , characterized in that the fiber or filament mass is at least 4 mg / filter length [mm] . 22. A tobacco smoke filter according to at least one of claims 17 to 21 , characterized in that the Filtrona hardness is 90 to 95% . The photoreactive additive contains a photoreactive additive as finely divided anatase-type titanium oxide having an average particle size of less than 2 μm, according to at least one of claims 1 to 22 . Cigarette smoke filter.