EP1028637B1 - Cigarette with reduced gas phase - Google Patents

Abstract

The invention relates to a cigarette with a filter containing activated carbon. Said cigarette comprises a tobacco string wrapped in cigarette paper, a double filter having a string-side part consisting of a tissue paper containing carbon, and a peripherally extending filter ventilation zone and located in the mouth-side part made of cellulose acetate. The tissue paper of the string-side filter part is a very bulky paper which contains 20 to 50 % wt microfine powdered active carbon. The ratio of condensate retention capacities of the string-side filter part to the mouth-side filter part ranges from 1 to 2. The air permeability of the cigarette paper is comprised between 40 and 100 Coresta units and the filter ventilation grade is comprised between 5 and 60 %.

Description

The invention relates to a cigarette according to the preamble of Claim 1.

It is known that by introducing surface-rich materials into a filter such as B. activated carbon part of the gaseous Components of smoke from which smoke can be retained. A such selective retention leads to undesirable ones changes in taste and thus to reject such Products for smokers. Try this negative side effect to compensate are very complex, see also DE 41 05 500, complicated and expensive.

Conventional gas phase active filters are in the majority Chamber filters, which are divided into three segments and in the middle chamber a surface active material such. B. Activated carbon, meerschaum, silica gel etc. included. These systems are very expensive from the viewpoint and have a serious Disadvantage that the chamber stability with regard to the Squeezing while smoking is unsatisfactory. Other Possible solutions are double filter designs in which the activated carbon in small quantities in the tobacco rod side Filter element can be sprinkled. These constructions only have a limited and not for many applications sufficient gas phase reduction. All known constructions what is common is the negative change in taste that the Smokers articulated as a coal flavor.

A clear but not yet satisfactory improvement showed up when using a carbonaceous tissue paper, that with microfine coal (grain size <15 µm) was offset.

The object of the invention is a cigarette with a gas phase active Develop filters that are very efficient and at the same time is inexpensive to manufacture.

The features of the claim serve to solve this problem 1.

a) einem durch ein Cigarettenpapier umgebenen Tabakstrang;

b) einem Doppelfilter, bei dem der strangseitige Teil aus einem kohlehaltigen Tissuepapier besteht, und mit

c) einer in Umfangsrichtung verlaufenden Filter-Ventilationszone im mundseitigen Teil aus Celluloseacetat;

d) das Tissuepapier des strangseitigen Filterteils ist ein sehr voluminöses Papier, das 20 bis 50 Gew.-% mikrofein gemahlene Aktivkohle enthält;

e) das Verhältnis der Kondensat-Retentionsleistungen von strangseitigem zu mundseitigem Filterteil beträgt zwischen 1 und 2;

f) die Luftdurchlässigkeit des Cigarettenpapiers beträgt 40 bis 100 Coresta-Einheiten; und

g) der Filterventilationsgrad beträgt 5 bis 60 %.

The invention thus relates to a filter cigarette with a filter containing activated carbon with:

a) a tobacco rod surrounded by a cigarette paper;

b) a double filter, in which the strand-side part consists of a carbon-containing tissue paper, and with

c) a circumferential filter ventilation zone in the mouth-side part made of cellulose acetate;

d) the tissue paper of the strand-side filter part is a very voluminous paper which contains 20 to 50% by weight of microfine ground activated carbon;

e) the ratio of the condensate retention performances of the strand-side to the mouth-side filter part is between 1 and 2;

f) the air permeability of the cigarette paper is 40 to 100 Coresta units; and

g) the degree of filter ventilation is 5 to 60%.

Advantageous embodiments of the invention are the subject of Dependent claims.

The cigarette paper porosity lies in the filter cigarette according to the invention 30 to 60% rel. higher than the cigarette paper porosity one made with a conventional filter comparable cigarette and the degree of filter ventilation is 10 up to 60% rel. lower than the filter ventilation level one with conventional filter manufactured comparable cigarette.

The tissue paper has a basis weight of approx. 40 - 60 g / m ² , an activated carbon content of 15 - 50% and a thickness of 150 200 µm. A preferred variant has a weight per unit area of 50 g / m ² and an activated carbon content of 30% by weight with a thickness of 180 μm.

In a special embodiment, the strand side Filter part of the double filter is a core filter according to DE 42 05 658 C2, in which the core of carbon-containing tissue paper as in the first-mentioned embodiment is formed by a Jacket made of almost impermeable to the main current smoke Material is surrounded. This almost smoke-proof material consists, for example, of highly compressed cellulose acetate fibers.

Surprisingly, it has been shown that when using the gas phase-active material not only the gas phase retention, but the specific retention ratios of the individual Filter segments in combination with the ventilation conditions the cigarette are of decisive influence. As special those shown in Table 1 have proved favorable Combinations B, D and F of the retention and ventilation ratios exposed. The combinations A, C and E are known Cigarettes according to the invention by combinations B, D and F were changed.

The sensory comparisons were made by an expert panel carried out and gave the following results: The cigarettes A and B differed only in the point of reactivity, the Variant B significantly less reactive, i. H. for the consumer translated less rough and less sharp.

The cigarettes C and D differed in the same way in the reactivity, whereby the tobacco flavor of variant D is stronger was pronounced.

The experts came to the same result when comparing cigarettes of E and F. The F variant was significantly lower reactive, but had an increased tobacco aroma.

It is striking that the retention quotient of the individual filter segments increases with decreasing condensate and nicotine levels. At the same time, it is necessary to achieve the minimum same tobacco flavor quality the cigarette paper porosity of to increase respective comparison cigarette at the same time Reduction of filter ventilation. A cause of the relative The particle size distribution could improve the aroma quality of the main stream smoke, which is largely due to different flow velocities and therefore different The smoldering temperatures of the tobacco are affected become. Experiments have shown, if you compare the experimental and Comparative flow cigarettes adapts to each other that the so-called coal taste and a decrease in aroma quality occurs.

To set the desired retention ratio of the rod-side to the mouth-side filter part, other known embodiments can be used for the mouth-side filter part in addition to the known acetate monofilter: For example, a coaxial construction of the mouth-side filter part is known to offer the possibility of simultaneously providing the desired retention and the desired open tensile resistance Optimally adjust cigarette independently. Full flavor Lights Ultra low tar A B C D e F Total length [mm] 84 84 84 84 84 84 Length of tobacco rod [mm] 63 63 59 59 59 59 Filter length [mm] 21 21 25 25 25 25 Weight of tobacco rod [mg] 820 820 690 690 620 620 Tensile resistance [daPa] 75 75 140 Filter type Monofilter double filter Monofilter double filter Monofilter double filter filter material cellulose acetate cellulose acetate cellulose acetate Einzeldenier 3.0 y 2.1 y Gesamidenier 35,000 55,000 Manufacturer Rhodia Rhodia strand-side element: Length [mm] 13 13 13 Tensile resistance [daPa] 13 65 97 material carbon paper carbon paper carbon paper mouth-side element: Length [mm] 8th 12 12 Tensile resistance [daPa] 24 28 33 material cellulose acetate cellulose acetate cellulose acetate Einzeldenier 2.5 y 3.04 y 2.54 y total denier 35,000 35,000 35,000 Condensate [mg / cig.] 12.2 12.0 7.2 7.0 2.3 2.0 Nicotine [mg / cig.] 0.80 0.83 0.64 0.66 0.22 0.24 Paper porosity [Coresta] 24 43 60 80 40 80 Filter ventilation [%] 20 17 40 35 70 60 Total retention [%] 38 38 50 50 70 70 Individual retention [%] (Line side) 19 28 45 (Mouth side) 19 22 25 retention coefficient 1 1.27 1.8 (Train / mouth)

Claims (3)

1. A filter cigarette having a filter containing activated carbon, having:

   a) a tobacco string surrounded by a cigarette paper;

   b) a double filter, in which the string-side part is made from a tissue paper containing carbon, and having

   c) a filter ventilation zone extending in the peripheral direction and located in the mouth-side part made from cellulose acetate;

   d) the tissue paper of the string-side filter part is a very bulky paper which contains 20 to 50 % by weight microfine powdered activated carbon;

   e) the ratio of the condensate retention capacities of the string-side filter part to the mouth-side filter part is between 1 and 2;

   f) the air permeability of the cigarette paper is 40 to 100 Coresta units; and

   g) the filter ventilation grade is 5 to 60 %.
2. A filter cigarette according to Claim 1,
   characterised in that the tissue paper of the string-side filter part contains 30 % by weight microfine powdered activated carbon.
3. A filter cigarette according to Claim 1 or 2,
   characterised in that the string-side part of the filter is a core filter having a core made from tissue paper containing carbon in accordance with one of the preceding Claims, which is surrounded by a casing made from material which is virtually impermeable for the main smoke flow.