JPS6027375A - Tobacco filter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved filter for tobacco smoke, and more particularly to a filter for tobacco smoke that has improved flavor and flavor and contains strongly basic finely powdered activated carbon made from vegetable raw materials. It's about filters.

Generally, the smoke generated by smoking cigarettes is roughly divided into particle phase components and vapor phase components. The particle phase components are tar (including chemical components such as terpenes and phenols),
The vapor phase components include carbon monoxide, methane, acetaldehyde, isoprene, acetone, toluene, etc., and these components contain components that are undesirable in terms of smoking hygiene. .

Cigarette smoke filters remove these components by absorption or adsorption.The above particle-phase components are mainly filtered through filter materials such as acetate MRA and nonwoven fabric, while vapor-phase components are mainly filtered through the filter. It is adsorbed and removed by activated carbon attached or filled inside. for example,
Of the tobacco products currently available on the market from Japan Monopoly Corporation,
Filters under the product names Seven Star, Mild Seven, and Cabin fall under this category, and are called cigarettes with charcoal filters.

However, such charcoal-filtered cigarettes have a unique unpleasant smoking taste called charcoal taste, which is considered to be a major drawback of charcoal filters.

To date, various attempts have been made to improve the aforementioned unfavorable effects of activated carbon-containing cigarette filters on the smoking taste of cigarettes. Means for causing
No. 107489), a means for incorporating a tannin and metal chelate compound into the activated carbon (Japanese Unexamined Patent Publication No. 53-99399)
9), means using nitrogen-containing activated i5 fibers (
Japanese Unexamined Patent Publication No. 53-88400) and the like have been proposed.

However, these technical means cannot be said to be sufficient from the viewpoint of the effect of selectively adsorbing and removing only specific undesirable components in tobacco smoke. That is, these filter-tipped cigarettes have the disadvantage that they also remove desirable flavor components during smoking.

The present inventors were conducting research with the aim of developing an activated carbon filter that can efficiently remove irritating substances in tobacco smoke, such as formaldehyde, acetaldehyde, formic acid, acid resistance, and hydrogen cyanide. Tist is closely related to the abundance ratio of irritating substances in smoke, and surprisingly, by appropriately selecting factors such as raw materials, pore size, particle size, and base preparation of activated carbon to be included in cigarette filters, We have succeeded in obtaining a filter for tobacco smoke that suppresses charcoal tint and has improved aroma and taste, leading to the present invention.

That is, the present invention is made of vegetable raw materials and has a base condition of PH.
9 or more, pore diameter is 20 or less, pore volume is 0, 1
The aroma and taste of the smoker is improved by containing ultrafine powder activated carbon of 0 cc/g or more and 30 μm or more. Regarding tobacco smoke filters.

Although some conventional activated carbons have relatively high surface activity, they have a low basicity and have a low adsorption capacity for irritating 7A gas phase components such as acetaldehyde, and have not been able to improve the problems of conventional filters. According to the invention,
The tobacco smoke rain filter is made of vegetable raw materials, has a base condition of pH 9 or higher, has a pore diameter of 20 Å or less, and has a pore volume of 0. By incorporating ultrafine activated carbon powder with an average particle diameter of 10 cc/g or more and 301 Lm or less, the aroma and taste can be improved. The present invention will be explained in detail below.

First, it is essential that the activated carbon according to the present invention be produced from vegetable raw materials. As such vegetable raw materials, wood (preferably coniferous); South Sea plants such as coconut husk, palm cara, and coir dust; leguminous plants such as Ibir and Takakuchii; wood pulp, cotton, linter pulp, etc. are used. Activated carbon is also produced from other materials such as mineral materials such as coal, petroleum sludge, or synthetic materials such as polyacrylonitrile fibers and phenolic resins.
In order to make ultrafine powdered activated carbon with an average particle size of 30 Bm or less using plant-derived original material, which has a much inferior taste when filtered and is undesirable than the above-mentioned plant materials, the following method is used. ? There are people.

Coniferous wood is crushed to 200-2000 pm using a crusher.
Grind to a particle size of After that, 20-50 in open hearth
Carbonization treatment is carried out by heating from room temperature to 500° C. over a period of time to obtain a carbide having a particle size of 100 to 1000 gm and a carbon content of 70%. The carbide is activated at 1200 to 1300° C. for several seconds in an air-transfer type rotary activation furnace.

This activation treatment involves high temperatures that cannot be reached by ordinary activated carbon activation treatment, and as will be described later, highly reactive wood-based raw materials are treated in active gases such as carbon dioxide and steam, so many It is thought that tl-based F, () is generated on the activated carbon surface. Although the mechanism of formation is not clear, it is assumed that OH group, Quinone 2 (2) is generated by activation of carbon dioxide gas. 900
It can also be obtained by reactivation for a long time at high temperatures above ℃. In addition to water vapor, the reactivation atmosphere includes a high concentration of W.
Acid gas is preferred. Activated carbon is produced by the method described above, but in order to be used as a cigarette filter, if its average particle size (hereinafter referred to as "particle size" means average particle size) exceeds 30 gm, it must be Even if the properties are high, it is difficult to remove or suppress charcoal dust due to the imbalance between adsorbed components. The pulverization process is 50
It is made by pulverizing activated carbon coarsely pulverized to ~100 μm using a ball mill or the like for a long time. It is essential that the activated carbon has a pore diameter of 20 Å or less and a pore volume (hereinafter abbreviated as micropore pore volume) of 0.10 cc/g or more. That is, the microbore pore volume is 0.10
If it is less than cc/g, vapor phase components such as isoprene, acetone, and acetaldehyde will not be effectively adsorbed, which is undesirable in terms of smoking hygiene and flavor. The basicity of the activated carbon thus obtained was determined by a method similar to the Phillips method, in which 1 g of activated L'O was added to 100+ al of a 0.1 NKCI aqueous solution adjusted to pH 7, and left to stand for 24 hours. Determine by measuring the pH of the liquid with a pH meter (for example, Industrial Chemistry Magazine 87.2019 (198
4)). The basicity determined by the above method is C in an aqueous solution.
It is presumed that six OH- ions ion-exchanged by I- ions are being evaluated. In addition, the average particle size can be measured using the Coulter Counter method, which is one of the particle size measurement methods based on the counting principle (e.g., powder optics research synthetic fibers ``Powder Particle Size Measurement Method'').
It was measured by.

Furthermore, the pore diameter and pore volume of activated carbon can be calculated using the Cranston-Inklay (C
ranston -1nkley) (for example, Kei Tominaga, "Adsorption", Kyoritsu Shuppan). However, the ratio of gaseous nitrogen to the amount of nitrogen gas adsorbed at a relative pressure corresponding to a pore diameter of 300 A under standard conditions (1,584 x 10
-3) multiplied by i+fj was regarded as the total pore volume, and the value subtracted from the cumulative pore volume from 300 to 20 pore diameters was defined as the pore diameter volume.

The activated carbon thus obtained can be used as a filter by sprinkling it on a tow of acetate fibers, combining it with another single acetate fiber portion, or by mixing it with wood pulp fibers, acetate fibers, etc. and forming it into a non-woven fabric. Methods include spraying and adhering to non-woven fabrics or tows together with adhesives, methods of dispersing in a dispersion medium containing an adhesive polymer that provides a highly viscous solution such as sodium alginate to create a paste-like impregnating solution, and roller printing, etc. Examples include a method of printing on a nonwoven fabric using a printing method used in printing, dyeing, etc., and a method of making fine particles using a binder such as carboxymethyl cellulose or polyvinyl alcohol and interposing them between acetate fiber tows. At this time, activated carbon is used for filter 1.
A weight of 15 to 100 mg is suitable.

The reason why the activated carbon of the present invention specifically adsorbs and removes acetaldehyde, formaldehyde, cyanide gas, etc. is not clear, but the active carbon increases the active surface area due to the small particle size and the base area with high basicity. The increase in 41L is due to a synergistic effect on the reaction with acetaldehyde, etc. In terms of improving the aroma and flavor, in addition to the high basicity and the removal or suppression of irritating vapor phase components through the selection of ultra-fine powders, the selection of plant-based raw materials as starting materials is also a major plus. .

Activated carbon made from synthetic raw materials such as acrylonitrile-based activated carbon fibers and phenolic resin-based activated carbon fibers has been considered as a cigarette burning filter, but it has the disadvantage of not having a good aroma and taste, so it has not been put to practical use as a cigarette filter. Not done.

As described above, the activated carbon according to the present invention has adsorption properties of imprene and acetone that are on the same level as conventional activated carbon, and has specific multi-liquid adsorption properties for irritating vapor phase components such as acetaldehyde, formaldehyde, and cyanide gas. Since it has the properties of charcoal filters, it is possible to improve the drawbacks of conventional charcoal filters.

Next, experimental examples will be given to clarify the characteristics of the present invention.

Experimental example 1 The activated carbon used was manufactured as follows.

(1) Wood raw materials Coniferous wood waste with a particle size of 200 to 2000 m.

(2) Carbonization treatment By heating the wood chips in an open hearth at temperature A from 200 to 5000C for a day and night, the wood chips are heated to a temperature of A, with a yield of -1130% and a carbon content of 70%.
% of carbide with a particle size of 1100-1000 JL was obtained.

(3) Activation treatment a) The carbide is placed in a fluidized activation furnace for a residence time of 10 seconds and a temperature of 12
Activated carbon having a particle size of 30 to 200 gm was obtained by treatment at 00 to 1300° C. in an atmosphere containing 10% water/nitrogen. By pulverizing the activated carbon in a ball mill for 24 hours, a particle size of 15
Activated carbon with a final micropore volume Q of 38 cc/H was obtained. (Sample name = 1-a) Furthermore, activated carbon having a particle size of 50 JLm, a basic pH of 9.7, and a micropore pore volume Q of 38 cc/H was obtained by sieving the activated carbon before pulverization. (Sample name: 1-b) Residence time 5 seconds, temperature 1200-1300
Treated in an atmosphere containing 10% water and air at °C1, particle size 30-3
00 gm of activated carbon was obtained. The activated carbon was milled in a ball mill for 24 hours.
By time-pulverizing treatment, activated carbon having a particle size of 18 JLm, a basic pH of 9.7, and a micropore volume of 0.32 cc/g was obtained. (Sample name: 1-c) c) Activated carbon having a particle size of 30 to 200 gm was obtained by processing in an atmosphere containing 10% water vapor at a residence time of 20 seconds and a temperature of 1000°C. By pulverizing the activated carbon with a ball mill, activated carbon with a particle size of 15 #Lm, basicity p'H of 8.7, and micropore volume Q of 34 cc/g was obtained.

(Sample name: 1-d) Experimental example 2 Commercially available coconut activated carbon (salt) of 8 to 14 mesh (preparation pH 7, specific surface area 600 m/g) was mixed with 150 to 3'OOJ
Pulverized to Lm and heated at 900° in a rotary kiln.
At C, reactivation treatment was performed for 5 cycles under a combustion gas atmosphere. The activated carbon was pulverized in a ball mill for 100 hours to obtain activated carbon having a particle size of 15 mm, a basicity of PH 9.5, and a micropore volume of 0.4 cc/g. (Sample name: 2-a) In addition, the activated carbon after 5 hours of ball mill pulverization was sieved to have a particle size of 45 g m and a base grade of p.
Activated carbon with H9,3 and micropore volume of 0.39 cc/g was obtained. (Sample name: 2-b) Furthermore, by subjecting the commercially available coconut shell activated carbon to ball mill pulverization treatment, the particle size was 1.
5 lm, basicity pH 7, micropore pore volume 0.35
cc/g of activated carbon was obtained. (Sample name: 2-c) Experimental example 3 200 to 2000 gm of coniferous wood chips were mixed with 50
Mix with aqueous solution of zinc chloride (Tunxing%) and heat at 700℃ in a multi-stage bed furnace.
After performing carbonization and activation treatment by heating at an elevated temperature to
An active tg of cc/g and particle size of 15 pm was obtained. (Sample name: 3-a) In addition, by further treating the activated carbon at 700°C in an air stream containing ammonia gas, the particle size
5μm, basicity pH 9.5, micropore pore volume 1□-
0.08 cc/g of activated carbon was obtained. (Sample name: 3-
b) Experimental Example 4 After subjecting commercially available polyacrylonitrile fibers to flame-retardant treatment in the air at 300°C, activation treatment was performed in an atmosphere containing <1 steam at 850°C to obtain fibrous activated carbon, which was then pulverized in a ball mill. Particle size: 15 pm, base preparation pH: 9.3
, activated carbon with a micropore volume of 0.25 cc was obtained. (Sample name: 4) Experimental example 5 Commercially available novolak type phenolic resin fibers were carbonized in a steam-containing atmosphere at 900°C to obtain fibrous activated carbon, and then pulverized in a ball mill to obtain particles with a particle size of 15 JLm,
T! Basicity pH 9.2, micropore pore volume 0.45c
c/g of activated carbon was obtained. (Sample name: 5) Using the activated carbon obtained in the above experimental example, a cigarette burning filter was produced by the following method. That is, "activated carbon 15
After making a uniform paste by spraying 10 parts of aqueous solution of sodium alginate, a printing process was applied to a dry non-woven fabric made of wood (fabric weight 40 g/rn2, thickness 2.2 ffim) using a roller printing machine. , activated carbon 30
The sheet attached with tng/rr+2 was added.

Four of these sheets are used and fed side by side so that the striped patterns of the four sheets match, and after being folded into an S-shape or a 7-shape, they are twisted by a rotating rotor with a tapered inner diameter, and then By squeezing and rolling it up into a cylindrical shape, a cylinder with a diameter of 8 mm was made. After wrapping a thin paper around the outside of this cylinder, an activated carbon-impregnated filter having a length loa+m was obtained. This filter was joined to an acetate fiber filter having a length of 7 mm, and a cigarette smoke filter having a length of 17 mm was manufactured.

For the various cigarette smoke filters trial-manufactured as described above, the adsorption rates of cyanide gas, acetaldehyde, isoprene, and acetone as components of the incoming gas phase were determined to be All +
The determined results are shown in Table 1. The adsorption rate was determined as follows.

In other words, a test cigarette was prepared by attaching a filter manufactured by the -1-force distribution method to a part of the Japan Monopoly Public Corporation product "Highlight" with a portion of the filter removed, and the same "Highlight" was used as a control to obtain a constant fQ. Using an early type automatic smoker, the subjects smoked under the following conditions.

7Xl: liX: 17.5ml/see smoking l'I
ν interval: 2 sec/times Smoke frequency: 1 time/ll11n Combustion length: 50 mm Number of smokes: 4 pieces/extra-fine glass fiber filter 1.9 out of smoke
5 ml was introduced into a gas chromatography system, the peak height of the control was set as Hs, and the adsorption rate (F) was calculated using the following formula.

F(%) -(H-Hs) /HX I OO Also, the cyanide gas adsorption rate is based on the tar and 0.5N NaOH collected on the ultra-fine glass fiber filter. After distilling the gas absorption liquid absorbed in liquid a, CN-6 was obtained by a colorimetric method.

(For example, Journal of the Japanese Society of Public Health 28,100 (198
1)) From the results in Table 1, the following can be considered.

(+) Sample names (1-b) and (2-b) are both made of plant materials, and have appropriate base preparation and micropore pore volume, but because the particle size is too large, they contain acetaldehyde and cyanide gas. adsorption rate is low.

(2) Sample names (1-d), (2-c) and (3-a
) are all made from plant materials and have appropriate particle sizes and micropore pore volumes, but the base preparation is too low, so (1-d
) and (2-c) have low overall HXf= absorption, and (3
In -a), the adsorption rate of acetaldehyde and cyanide gas is extremely low, and neither of them can achieve the objective.

(3) Sample name (3-b) is made of plant material and has appropriate particle size and base preparation, but the adsorption rate of acetaldehyde and cyanide gas is extremely low because the micropore pore volume is too small.

(4) Sample names (1-a) and (1-c) for these
and (2-b) satisfy all the specified requirements of the present invention, and the adsorption rate of acetaldehyde, isoprene, acetone, and cyanide gases, which are the main components in tobacco smoke, is significantly different from that of conventional products17). It was excellent, and since each adsorbed component was removed well, there was no appearance of charcoal tint. In particular, the adsorption ability of cyanide gas and acetaldehyde, which are involved in smoke irritation, has further improved.
It was found that this greatly contributed to improving the aroma and taste of cigarettes.

Applicant: 11 Monopoly Public Corporation

Claims (1)

[Claims] It is made of vegetable raw materials, and contains ultrafine powder activated carbon with a basicity of PH9 or higher, a pore diameter of 20A or less, a pore volume of 0.10cc/g or less, and an average particle size of 30pLm or less. Cigarette smoke filter with improved flavor