JPS6219832B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a tobacco filter. More specifically, 6 is made of wood pulp fiber as the main component.
A sheet formed into a corrugate shape by treating bulky paper with a specific surface area of 0.8 m ² /g or more with a specific volume of cm ³ /g or more and 25 cm ³ /g or less with an organic solvent solution of cellulose ester, This is a new high-performance cigarette filter that is wound around a rod-shaped filter. One of the problems with modern tobacco filters, especially for health reasons, is that particulate matter (hereinafter referred to as tar and nicotine) when smoking is
The key is how to remove TPM (abbreviated as TPM) at a high rate. Most current cigarette filters use cellulose diacetate fiber crimped tow, but in order to remove TPM at a high rate, there are methods of increasing the amount of fibers in the tobacco filter or using tow with a small single fiber fineness. is taken. However, the tobacco filter obtained in this way requires the smoker to apply excessive force to inhale, resulting in a feeling of discomfort when smoking. In view of the above circumstances, the inventors of the present invention have made extensive studies and found that a bulk material with a specific surface area of 0.8 m ² /g or more, which is made of wood pulp as a main component and has a specific volume of 6 cm ³ /g or more and 25 cm ³ /g or less. A cigarette filter, which is made by processing a corrugated sheet of paper with an organic solvent solution of cellulose ester and rolling it up into a rod-shaped filter, has high TPM removal performance and does not require excessive suction force from the smoker. They discovered this and completed the present invention. The feature of the present invention is that a wood pulp sheet having a bulky structure with a high specific surface area is used as a raw material. Wood pulp is chemically composed of cellulose and has a very high specific surface area, so when it is used as a cigarette filter material, it
TPM can be removed at a high rate, but when this kind of wood pulp is molded into a paper-like sheet by the normal wet molding method, the sheet obtained by the hydrogen bonds of the pulp itself is Since the density of the sheet-like material becomes extremely high and its specific surface area decreases greatly, such a sheet-like material has a high rate of
It is not possible to obtain a cigarette filter with a high TPM removal rate, and furthermore, the suction resistance is large, so it is extremely difficult to obtain a cigarette filter with a good smoking feeling. Therefore, in the present invention, the specific volume is 6
The above-mentioned inconveniences were solved by using bulk paper with a density of not less than cm ³ /g and not more than 25 cm ³ /g as a raw material. When the specific volume of the bulky paper is less than 6 cm ³ /g, the bulkiness of the bulky paper is poor and the smoke flow does not pass through the bulky paper, making it impossible to remove TPM efficiently.
Furthermore, if the gap between the bulky papers is made narrower in order to remove TPM, the suction resistance will become too large and it cannot be used as a cigarette filter with an appropriate suction resistance.
If it exceeds cm ³ /g, sufficient gaps between the fibers in the bulky paper will not be formed to trap TMP against the passage of smoke when it is formed into a cigarette filter, resulting in not only poor TPM removal performance but also Inconveniences such as a decrease in the hardness of the cigarette filter are likely to occur. In order to make the paper used in the present invention have the above-mentioned specific volume, there is a method in which wood pulp is formed into paper by mixing other hydrophobic fibers into paper, or a sheet is formed once into paper. can be made by applying crepe processing. Furthermore, the paper used in the present invention has a specific surface area of 0.8
m ² /g or more, and if paper with a specific surface area smaller than this value is used, a filter with good TPM removal efficiency cannot be made. Further, the bulky paper used in the present invention has good winding properties as a tobacco filter, but from this point of view, it is preferable to use a wet forming method for forming the paper. Another major feature of the present invention is that the above-mentioned bulk paper is treated with cellulose ester. When the bulky paper made of wood pulp fiber used in the present invention is used as a tobacco filter, it has high TPM removal efficiency and has moderate suction resistance.
Compared to tobacco filters made from ordinary cellulose diacetate tow, the flavor is inferior to that of tobacco filters, but in order to improve this point, the present invention improves this by treating it with an organic solvent solution of cellulose ester. This solved the problem. When treating bulky paper with the organic solvent solution, it is important to keep in mind that this treatment does not reduce the specific surface area of the bulky paper and that the cellulose ester is uniformly adhered to the surface of the bulky paper. Treatment methods include immersion in an organic solvent solution of cellulose ester, passing over a roll coated with an organic solvent solution of cellulose ester, and spraying a solution of cellulose ester in an organic solvent. The method of spraying a solution of cellulose ester in an organic solvent is
This is preferable because the specific surface area of the bulky paper does not decrease much, and rather has the effect of increasing the specific surface area by attaching the cellulose ester in the form of fibrils, and is moreover uniformly attached to the surface. It is necessary to avoid covering the surface of the bulky paper with a film as much as possible. For this purpose, the amount of cellulose ester attached to the bulky paper used in the present invention is 0.5 to 20% by weight, preferably 1 to 20% by weight.
The proportion is preferably 15% by weight, more preferably 10% by weight or less. In order to obtain bulk paper treated at such a proportion, the cellulose ester concentration of the processing solution is important, and the concentration is 0.5 to 10% by weight. % is preferred. Various esters such as cellulose diacetate, cellulose triacetate, and cellulose propionate can be used as the cellulose ester, but cellulose diacetate is preferably used to provide a good smoking feeling. In cellulose ester, the hydroxyl group in the cellulose molecule is replaced with an acetate group and there is no selective adsorption of tobacco smoke components, so the adhesion of such cellulose ester significantly improves the aroma and taste compared to when it is made only of pulp fibers, and It gives a similar flavor to tobacco filters made from cellulose diacetate tow. It is extremely difficult to wind up the sheet material of the present invention onto a filter plug in a conventional manner, especially at high speed. In addition, the plugs obtained by winding up a sheet-like material through a filter plug using the usual method have non-uniform shapes and large variations in the amount of fiber filling. Although special methods have been used, none of them have satisfactorily solved the above-mentioned inconveniences. Therefore, the present inventors investigated the possibility of winding up the bulky paper of the present invention into a filter plug using a simple method, and found that it was once formed into a corrugated shape using the method shown in US Pat. No. 3,804,695. This made it possible to wind up a filter plug with a uniform structure in a conventional manner, and also to wind it up at high speed. Unlike ordinary wet-formed paper, the bulky paper used in the present invention does not use a binder, so
The TPM removal performance of cellulose can be fully demonstrated. In addition, since this bulky paper is treated with an organic solvent solution of cellulose ester, a plasticizer such as triacetin can be used in conjunction with it when forming it into a corrugate shape, making it extremely easy to form it. Uniform and stable corrugation is possible, and filter plugs can be easily rolled up. The cigarette filter of the present invention is made of extremely unique material, and has a good smoking feeling despite having a high removal rate of TPM from cigarette smoke.
It also has various excellent properties such as moderate hardness. The present invention will be described in more detail with reference to Examples below. Measurements of each measurement item used in the Examples were carried out in accordance with the following methods. Airflow resistance: The filter tip and the U-shaped water column meter were connected in parallel to a vacuum pump to draw air, and the scale of the water column meter was displayed when the flow rate of air passing through the filter tip was 17.5 ml/sec. TPM: Tar and nicotine removal rate: One end of the filter tip was attached to a cigarette from which the filter tip had been removed from a commercially available ``Highlight'' cigarette, and a constant flow type automatic combustor was used to produce a cigarette with a flow rate of 17.5ml/
seconds, smoking time 2 seconds, smoking interval 58 seconds, combustion length 50 mm
Automatic smoking was performed under these conditions, and the mainstream smoke was collected using a Cambridge filter. Collected by filter chips and Cambridge filters
TPM, tar, and nicotine were analyzed to determine their respective removal rates. Flavor: Evaluated on a three-point scale, with the best flavor being rated "3" and the worst flavor being 1, and expressed as the average value of 20 judges. Specific volume: Determined by calculation by cutting a sheet material into squares of 10 cm on a side, and then stacking them together to a height of 10 cm.The weight was measured and calculated. Specific surface area: A mixed gas of nitrogen and helium is adsorbed in a monomolecular layer on a small amount of sample under constant pressure, and the amount of adsorption is quantified by gas chromatography.B.
It was determined according to the adsorption isotherm formula of ET. Example 1 A sheet made by spraying a 1% acetone solution of cellulose diacetate on a binder-free bulk paper obtained by crepe-processing purified long-fiber wood pulp while wet forming it was shaped into a corrugated shape and processed in a conventional manner. I wound up the filter plug. This filter plug was cut into a length of 17 mm to make a filter chip. Table 1 shows a comparison with ordinary wet-formed paper, commercially available tissue paper, and cellulose diacetate tow (4 dpf, Y cross section, 43,000 total denier).

【table】

[Table] Example 2 Bulky paper wet-formed by blending 80 parts of wood pulp with 20 parts of polypropylene fiber was immersed in a 1% acetone solution of cellulose diacetate and then dried. Triacetin was applied to the sheet. The mixture was sprayed at a rate of 3% by weight, passed through a heating roll, shaped into a corrugated shape, and then wound up into a filter plug in the usual manner. This filter plug was cut into a length of 17 mm to form a filter tip (A), and a smoking test was conducted. Also, 85 parts wood pulp and 15 parts polypropylene fiber.
A sheet of bulk paper that has been wet-blended and creped is passed over a roll coated with a 1% solution of cellulose diacetate in acetone. I wound it around the plug. Cut this filter plug to a length of 17 mm and insert the filter chip (B).
A smoking test was conducted.

[Table] As seen in the above examples, the filter of the present invention has almost no difference in ventilation resistance compared to a filter made of ordinary cellulose diacetate fiber tow, and therefore requires excessive suction force from the smoker. Even though there is nothing to do, it is clear that the removal rate of TPM, tar, and nicotine is extremely high, and there is almost no difference in flavor.

[Brief explanation of the drawing]

Figure 1 shows one sheet of bulky paper used in the present invention treated with an organic solvent solution of cellulose diacetate.
This is a cross-sectional view showing an example as a model, in which 1 shows wood pulp fibers and 2 shows cellulose diacetate attached in the form of fibrils. FIG. 2 is a cross-sectional view schematically showing another example of a sheet of bulky paper used in the present invention treated with an organic solvent solution of cellulose diacetate. It shows cellulose diacetate attached in the form of fibrils.

Claims (1)

[Claims] 1. A specific surface area whose main component is wood pulp fiber and has a specific volume of 6 cm ³ /g or more and 25 cm ³ /g or less.
A tobacco filter made by forming a sheet of bulky paper of 0.8 m ² /g or more with an organic solvent solution of cellulose ester into a corrugated shape and rolling it up into a rod-shaped filter. 2. The tobacco filter according to claim 1, characterized in that the bulky paper is made of crepe-processed paper. 3. The bulky paper treated with an organic solvent solution of cellulose ester is prepared by spraying the bulky paper with an organic solvent of cellulose ester. cigarette filter. 4. The tobacco filter according to claim 1, 2, or 3, characterized in that the bulky yarn is made by wet-molding wood pulp fibers. 5. The tobacco filter according to claim 1 or 3, characterized in that cellulose acetate is used as the cellulose ester.