JP3996477B2 - Smoking filter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a smoking filter.
[0002]
[Prior art]
In recent years, cigarette smoke has been required to have low tar and low nicotine. Most tar and nicotine reduction techniques in conventional cigarette designs increase the amount of dilution air introduced from the filter section. However, from a different point of view, it is also possible to reduce tar and nicotine by increasing the amount of smoke removed by the cigarette filter (increasing the filtration rate). Paper filters made from wood pulp and formed into filter chips have attracted attention as a material with a high smoke filtration rate. Furthermore, in recent years, decomposability in a natural environment has attracted attention. That is, in the paper filter, filtration performance and degradation rate in the environment are important characteristics.
[0003]
For example, JP-A-9-505473 discloses a paper filter containing fine fibers (riocell fibers) made of regenerated cellulose. This paper filter has been found to exhibit excellent filtration performance.
[0004]
JP-A-8-47385 discloses a sheet-form filter material obtained by making paper by mixing a granular or fine fiber cellulose ester and wood pulp, and a cigarette smoke filter using the same. . It is described that this filter is highly disintegratable when wet.
[0005]
Fine fibers (riocell fibers) made of regenerated cellulose used in the former (Japanese National Publication No. 9-505473) are obtained by dissolving a cellulose raw material in a tertiary amine N-oxide and extruding it into an aqueous coagulation bath. It has been spun. Since the molecular structure of this lyocell fiber does not change from that of the cellulose raw material, the degradation rate in the environment is maintained at the same level as that of the cellulose raw material. Moreover, the cigarette filter made from the paper containing the fully fibrillated lyocell fiber exhibits high filtration performance.
[0006]
However, since a special solvent called tertiary amine N-oxide is used to produce lyocell fiber, a process for removing the solvent remaining in the obtained fiber and a solvent regeneration process are required. Remains.
[0007]
The cellulose ester used in the latter (JP-A-8-47385) has the same problem as the former in that it has a step of dissolving a cellulose raw material in a solvent. In addition, while containing fibrillated fibrous cellulose ester that enhances filtration performance, the fiber is a cellulose derivative in which the OH group of cellulose is substituted with an acetyl group. There is a problem that the structure changes greatly and the filtration performance of the filter does not increase so much. Furthermore, cellulose derivatives exhibit high disintegration properties when wet, but there is a problem that the degradation rate in the environment is slower than that of cellulose raw materials.
[0008]
[Patent Document 1]
Japanese National Patent Publication No. 9-505473
[Patent Document 2]
JP-A-8-47385
[Problems to be solved by the invention]
The object of the present invention is to add a material that does not include a step of dissolving the cellulose raw material to show excellent filtration performance, and to make a smoking filter that maintains the degradation rate in the environment at the same level as the cellulose raw material. Is to provide it.
[0011]
[Means for Solving the Problems]
The smoking filter of the present invention is characterized by being composed of a paper-like material containing 25 to 75% by weight of cellulose fibers refined by viscous beating and 75 to 25% by weight of wood pulp.
[0012]
In the smoking filter of the present invention, the cellulose fiber is preferably a microfibrous cellulose.
[0013]
In the smoking filter of the present invention, the paper-like material preferably has an air permeability of 100 to 10,000 cholesterol.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
First, the cellulose fiber refined by viscous beating used in the present invention will be described.
[0015]
Beating is a treatment performed by applying mechanical friction to the pulp under water. Viscous beating is a process in which the treatment is vigorously promoted. In the pulp after beating, the internal bonds in the fibers are broken and fibrillation occurs. At the same time, the fiber length is shortened, and a high-quality paper-like material with high strength can be realized.
[0016]
Cellulose fibers using cellulose as a raw material are roughly classified into natural fibers and chemical fibers. Natural fibers are classified into those that exist in the form of naturally separated fibers (first type natural fibers) and those that require artificial separation of individual fibers (second type natural fibers) ( Ichiro Sakurada, Textile Chemistry, p.24). Cellulosic artificial fibers made from plant fibers are classified into regenerated fibers, synthetic fibers, and semi-synthetic fibers. Specifically, the regenerated fiber is obtained by once dissolving cellulose contained in wood pulp or cotton with a chemical and regenerating into a slender fiber, such as rayon, polynosic, and cupra. Semi-synthetic fibers are fibers in which natural materials such as cellulose and proteins are made to act on chemicals, and natural products and synthetic products are present in the molecules. For example, diacetate is obtained by reacting cellulose in acetic anhydride to triacetate, adjusting the substitution rate of acetyl groups by hydrolysis, dissolving in acetone, and fiberizing by dry spinning (cellulose ester). One kind).
[0017]
The cellulose fiber refined by viscous beating used in the present invention is obtained by suspending a purified cellulose raw material in water, mechanically treating it at high temperature and high pressure, and beating cellulose to a state close to microfibrils. Yes, it belongs to natural fiber. As an example of such a cellulose fiber, “Cerish (registered trademark)” of Daicel Chemical Industries, Ltd., which is a fine fibrous cellulose, can be mentioned.
[0018]
On the other hand, the lyocell fiber described in the section of the prior art is spun by dissolving a cellulose raw material with a tertiary amine N-oxide and extruding it into an aqueous coagulation bath, and belongs to a regenerated fiber (Haruharu Nomura “ Spinning of cellulose using organic solvent and structural characteristics of purified cellulose fiber ", Fiber and Industry, Vol. 53, No. 2 (1997); edited by Textile Society, Textbook, p.4).
[0019]
As described above, the cellulose fiber refined by viscous beating does not have a step of dissolving cellulose in a solvent in order to fibrillate the fiber. For this reason, the fine fibrous cellulose which is the example is designated as the food additive in Japan. Even when the cellulose fiber refined by viscous beating is applied to a smoking filter as in the present invention, a process for removing the solvent remaining in the fiber and a solvent regeneration process are not required.
[0020]
In addition, the fiber diameter and fiber length of cellulose fibers and lyocell fibers refined by viscous beating differ due to differences in the production method. For example, the fine fibrous cellulose used as the cellulose fiber refined by viscous beating has a fiber diameter of 0.01 to 1.5 μm and a fiber length of 0.1 to 0.7 mm, whereas the lyocell fiber has a fiber diameter of 0. .4-2 μm, fiber length 0.5-12 mm. That is, since the fibrous cellulose refined by viscous beating is obtained by mechanically treating the cellulose raw material, it cannot have a fiber length longer than that of the cellulose raw material. On the other hand, lyocell fibers can be made long because the fiber length is determined depending on the fiber cutting technique after spinning. Here, in terms of dispersibility of fibers as a filter for smoking and degradability in the environment, thin and short fibers are more advantageous. For this reason, the cellulose fiber refined | miniaturized by viscous beating maintains the decomposition rate in an environment at the cellulose original rate.
[0021]
In addition, the smoking filter composed of a paper-like material containing cellulose fibers refined by viscous beating presented in the present invention has excellent filtration performance, so that the amount of material used can be reduced and ventilation can be reduced. There is an advantage that the degree of freedom in designing resistance and filtration performance is increased.
[0022]
In the present invention, the paper-like material constituting the filter for smoking has a blending ratio of 25 to 75% by weight of cellulose fibers refined by viscous beating and 75 to 25% by weight of wood pulp for the following reasons. by. That is, according to electron microscope observation, when the cellulose fiber refined by viscous beating is less than 25% by weight (wood pulp is more than 75% by weight), it is considered that the paper-like material considered that smoke is concentrated and leaks. It was found that a coating with fine fibers was not formed on the porous portion. Thus, if the film by the fine fiber is not formed, filtration performance cannot be improved. On the other hand, when the cellulose fiber refined by viscous beating exceeds 75% by weight (wood pulp is less than 25% by weight), the number of fibers having a short fiber length increases, and it becomes difficult to produce a paper-like material. Further, paper containing a large amount of fibers having a short fiber length has a high fiber filling rate, so that the air flow rate is reduced and the smoke permeability is deteriorated.
[0023]
About the filter for smoking of this invention, the reason which prescribed | regulated the air permeability of the paper-like raw material which is a constituent material as 100 coresta-10000 coresta is as follows. That is, there is a correlation between the air permeability of the paper-like material and the filtration rate of the paper filter, and the range of the air permeability where the filtration rate becomes the highest is in the range of 100 to 10000 Cholesta.
[0024]
Examples of the present invention will be described below.
"Cerish (registered trademark)" of Daicel Chemical Industries, Ltd., which is a microfibrous cellulose, was prepared as a cellulose fiber refined by viscous beating.
[0025]
Adjust the mixing ratio of microfibrous cellulose (Serish) and wood pulp to 0/100 (conventional paper filter) by weight%, 10/90, 25/75, 50/50, 75/25 or 100/0 A paper-like material was manufactured.
[0026]
The produced paper-like material was passed through a grooved roller and then packed into a 25 mm long brass tube to produce a smoking filter. At this time, the pressure loss was adjusted according to the amount of packing.
[0027]
The produced smoking filter was connected to a double-cut cigarette, smoked under standard smoking conditions using an automatic smoking machine, and the outflow of tar and nicotine was determined by gas chromatography. For reference, tar and nicotine spillage was determined in the same manner for double-cut cigarettes not connected to a smoking filter.
[0028]
The filtration rate was determined by comparing the outflow amounts of tar and nicotine between a double-cut cigarette with a paper filter and a double-cut cigarette without a paper filter, and the performance was evaluated.
[0029]
FIG. 1 shows the relationship between the blending ratio of the microfibrous cellulose in the paper material and the nicotine filtration rate. As shown in FIG. 1, when the blending ratio of the microfibrous cellulose is low, the filtration performance does not increase because the formation of the film with the fine fibers is insufficient. On the other hand, when the blending ratio of microfibrous cellulose is high (100% blending), the air permeability of the paper filter is 100 cholesterol or less, and the amount of smoke passing through the paper filter is reduced, so that the filtration performance does not increase. From FIG. 1, it was found that the paper filter containing 25 to 75% by weight of microfibrillar cellulose has high filtration performance.
[0030]
FIG. 2 shows the relationship between the air permeability of the paper material and the nicotine filtration rate. From FIG. 2, it was found that the air permeability range in which the nicotine filtration rate was the highest was 100 to 10,000 cholesterol.
[0031]
Moreover, since the cellulose fiber to be added is a cellulose fiber that does not include a cellulose raw material dissolving step in the processing step, a smoking filter having a decomposition rate in the environment equivalent to that of cellulose can be produced more economically.
[0032]
【The invention's effect】
As described above in detail, according to the present invention, by adding cellulose fibers refined by viscous beating, excellent filtration performance is exhibited, and smoking with the degradation rate in the environment kept at the same level as the cellulose raw material. Filters can be provided more economically.
[Brief description of the drawings]
FIG. 1 is a graph showing the relationship between the mixing ratio of fine fibrous cellulose in a paper-like material and the nicotine filtration rate.
FIG. 2 is a graph showing the relationship between the air permeability of a paper-like material and the nicotine filtration rate.

Claims (3)

A smoking filter comprising a paper-like material containing 25 to 75% by weight of cellulose fibers refined by viscous beating and 75 to 25% by weight of wood pulp. The smoking filter according to claim 1, wherein the cellulose fiber is a microfibrous cellulose. The smoking filter according to claim 1, wherein the paper-like material has an air permeability of 100 to 10,000 cholesterol.

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