JPS6211582B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a removing agent that selectively removes carbon monoxide from tobacco smoke generated during smoking without adversely affecting the flavor and aroma of tobacco. In general, carbon monoxide (hereinafter simply referred to as CO), which is generated by the incomplete combustion of carbon and carbon-containing compounds, binds tightly to hemoglobin in the blood.
Since it significantly inhibits the role of oxygen absorption and transport in the blood, it can cause acute poisoning symptoms such as headache and dizziness, and in severe cases can even lead to death. Also, CO
It is said that long-term exposure to can cause chronic heart disease. This CO is contained in a few percent of the so-called mainstream smoke that smokers directly inhale when they smoke cigarettes, and although it is significantly diluted by the air that is simultaneously inhaled before reaching the human lungs. It is believed that this contributes to the chronically elevated concentration of CO-binding hemoglobin in the blood of smokers, and reducing CO from tobacco smoke is an important issue that should be resolved immediately from the health perspective of smokers. has been done. [Prior Art] From this point of view, many attempts have been made to reduce the CO concentration in mainstream cigarette smoke.
Many proposals have been made in patent specifications and the like. These proposals can be broadly classified as follows. (1) A method of selecting and using raw materials that generate less CO. (2) A method of suppressing the generation of CO by creating holes in the filter or using high porosity wrapping paper, or reducing the generated CO by diffusion from the wrapping paper. (3) A method of reducing CO by oxidizing or capturing it by filling or retaining an oxidation catalyst, oxidizing agent, or adsorbent in a filter part or cigarette holder, etc. Among the methods (1) to (3) above, methods (1) and (2) have been extensively studied to date, and some of them have been commercialized. However, as for method (3), no definitively effective method has yet been found. The reason for this is that the contact time between tobacco smoke and the oxidation catalyst and other fillers is extremely short;
There are many problems such as the coexistence of inhibitory components such as moisture and tar in the surrounding environment, the need to take into account the toxicity of the filler itself, and the fact that the aroma and taste of the cigarette is impaired. Examples of substances that have been proposed for the purpose of reducing CO in tobacco smoke by the method (3) above include the so-called hopcalite-based composite oxide catalyst (Japanese Patent Application Laid-open No. 51−
No. 72988, JP-A-53-96399) and metal oxide catalysts such as manganese oxide (Brit.Pat. No. 1315374)
However, all of them are significantly deactivated by moisture, and follow-up tests show almost no removal effect. or,
There are also many disclosures regarding precious metal supported catalysts (Japanese Patent Application Laid-Open No. 1983-1999)
-73344, 53-149192, 55-137039)
However, as a result of further testing, it became clear that sufficient effectiveness could not be expected in removing CO from smoke. However, on the other hand, the so-called Wacker type catalyst, which was developed for the purpose of synthesizing acetaldehyde using ethylene as a raw material and using oxygen in the gas phase, has high activity against CO oxidation.
In addition, a mechanism has been proposed in which water is effectively incorporated into the redox system and CO is oxidized by oxygen in the gas phase (Journal Air
J. Air Pollution Control Assoc. 28, 253
(1978)). This Watzker type catalyst basically uses PdX ₂ or M ₂ PdX ₂ (X is a halogen atom, M is a group A metal in the periodic table) as an active compound for the substrate, and also as a redox pair for the substrate.
CuX ₂ (X is a halogen atom) is used. The presence of moisture, which is generally considered undesirable in low-temperature CO oxidation using metal oxides, works effectively in this type of catalyst, so it can be used under humid conditions such as when reducing CO in cigarette smoke. It can be said that it is an excellent catalyst for the use of Inventions using such Watzker-type catalysts for reducing CO include the addition of copper salts other than copper halides (mainly copper nitrate) to promote reoxidation of palladium salts reduced by CO. A method of increasing activity by adding three components (Japanese Patent Application Laid-open No. 50-33990), an example of adding tin ions, etc. to promote reoxidation (Japanese Patent Application Laid-open No. 110400/1983), 1
There is an example (Japanese Unexamined Patent Publication No. 55-97252) in which a copper salt of 20% is coexisting. The Watzker type catalyst seen in these inventions related to CO oxidation is a homogeneous system as a solution,
Or alumina, silica, aluminosilicate,
It is used as a heterogeneous catalyst supported on various carriers such as molecular sieves and activated carbon. [Problems to be Solved by the Invention] However, the catalyst in which the Watzker type catalyst according to the conventional invention is supported on the above-mentioned carrier, which is known as a catalyst carrier, was used for the purpose of reducing CO in mainstream cigarette smoke. On the other hand, when γ-alumina is used as a carrier, the oxidation activity of CO is high, and the rate of CO reduction in cigarette smoke when filled in the filter part of cigarettes is also extremely low. Although it is expensive, it has the disadvantage of significantly reducing the aroma and taste of tobacco smoke. This is considered to be due to the physical and chemical properties of the γ-alumina surface. Further, when activated carbon alone is used as a carrier, although no adverse effect on tobacco flavor was observed, there is a drawback that a sufficient CO reduction effect cannot be obtained. The present invention was made in view of the above-mentioned problems of conventional CO reduction catalysts, and it
The purpose of the present invention is to provide a CO removal agent that has a high reduction effect and does not adversely affect the aroma and taste of tobacco smoke. [Means for solving the problem] When actually applying a CO remover to cigarettes, mainly cigarettes, it is necessary to
It is necessary to hold the CO oxidation catalyst on a carrier and fill it in the filter or holder of a cigarette. Therefore, the present inventors investigated the relationship between the type of carrier on which the catalyst should be supported and the oxidation activity of CO, and the effect on the aroma and taste of tobacco smoke regarding the Watzker type catalyst consisting of a combination of palladium chloride and cupric chloride. As a result of detailed research, it was discovered that when activated carbon hardened with bentonite is used as a carrier, a highly active CO removal catalyst that does not adversely affect the aroma and taste can be obtained, leading to the present invention. That is, the present invention is a carbon monoxide remover in tobacco smoke, characterized in that a mixture of cupric chloride and palladium chloride is supported on a carrier made of a mixed composition of bentonite and activated carbon. In the present invention, the activated carbon used as a carrier composition is not particularly limited, and vegetable activated carbon or coal-based activated carbon such as coconut shell charcoal, palm charcoal, and softwood charcoal is preferably used. In addition, the specific surface area of these activated carbons is approximately 500 to 1300 according to the BET measurement method.
m ² /g. Next, there are no particular restrictions on bentonite mixed with activated carbon, but there are so-called 2:1 bentonites such as montmorillonite, hectorite, or acid clay.
Preference is given to using clay minerals based on layered silicates of the type. Next, the activated carbon can be solidified with bentonite by any known method. For example, activated carbon powder and bentonite powder are kneaded with an aqueous solution of a water-soluble polymer such as polyvinyl alcohol, formed into particles of about 10 to 30 meshes, and pre-dried. A method such as heat treatment at a temperature of about 100° C. or higher may be adopted. In this case, the amount of bentonite contained in the mixed composition of activated carbon and bentonite is preferably 10 to 90% by weight, more preferably
30-70% by weight is good. Next, the supported amount of the catalytic metal component contained in the CO removal agent of the present invention is as follows for palladium chloride:
A good range is 0.01 to 0.2 mmol/g, and for cupric chloride, 0.1 to 2.0 mmol/g, preferably 0.4
The range of ~1.0 mmol/g is good. In order to support the above-mentioned metal salt catalyst on an activated carbon carrier hardened with bentonite, the pore volume of the carrier is measured in advance by the BET method, etc., and then palladium chloride and dichloromethane are added to a volume of water approximately equal to the pore volume of the carrier. The so-called pore-filling method involves dissolving copper and absorbing the entire amount into the pores of the carrier, or by immersing the carrier in a mixed aqueous solution of palladium chloride and cupric chloride, and then concentrating the solution using a rotary evaporator or the like. Methods such as the so-called impregnation method, in which salts are precipitated on the carrier, can be applied, but the latter impregnation method is simpler and does not require any particular restrictions on the concentration of the active ingredient solution. It is excellent because of The CO remover of the present invention prepared as described above is used by filling it into a cigarette filter or a cigarette holder. [Effects of the Invention] The present invention will be explained in more detail with reference to Examples below. By using the CO remover of the present invention, it is possible not only to significantly reduce CO in tobacco smoke, but also to reduce the amount of CO contained in tobacco smoke. It does not have a negative effect on the aroma and taste of smoke,
In fact, it was found to have excellent effects such as reducing the irritation caused by smoke. [Example] Example 1 Using coconut shell activated carbon and bentonite as carriers
A 10:7 (weight ratio) mixed composition (hereinafter simply referred to as coconut shell activated carbon-bentonite), coconut shell activated carbon, γ-alumina, silica, and bentonite were used, and the amount of palladium chloride supported on these supports was set at a constant value of 0.07 mmol/g. The difference in activity was determined when different ratios of cupric chloride were supported. As for the test conditions, first, palladium chloride
Aqueous solutions of 0.1 mol/copper chloride and 0.1 mol/copper chloride were respectively prepared, and each carrier was impregnated with the above-mentioned impregnation method so as to have a predetermined supported amount. That is, 10 ml of the above palladium chloride aqueous solution was collected for each 10 g of the carrier, and 3 ml, 5 ml, 15 ml and 20 ml of the cupric chloride aqueous solution were collected.
A mixed solution was prepared by adding ml of each. Next, 10 g of each carrier was separately immersed in each mixed solution,
After water was distilled off under reduced pressure, the mixture was air-dried overnight. The amount of supported salts was determined by atomic absorption spectrometry. In addition, to measure the activity, standard gases saturated with water vapor (CO: 3%, O ₂ : 15%, He: 82
%)It was used. In the test, 100 mg of each catalyst supported on each carrier as described above was packed into a glass tube with an inner diameter of 6 mm, and pulsed 10 ml of the above standard gas was applied to the catalyst using helium gas adjusted to a flow rate of 80 ml per minute as a carrier gas. passed through the layers. The CO concentration in the gas after passing through the catalyst layer was measured using a non-dispersive infrared spectrophotometer (ND-
IR). All tests were performed at room temperature (25
The CO removal rate was calculated from the average value of three pulses at one-minute intervals, and the value was plotted against the amount of catalyst supported, and the results were as shown in Figure 1. As is clear from the results shown in FIG. 1, the catalyst of the present invention using coconut shell activated carbon-bentonite as a carrier exhibited a maximum CO removal rate of 90% or more, which was comparable to the catalyst using γ-alumina as a carrier. On the other hand, when coconut shell activated carbon and bentonite were used alone, the activity was 30.
% or less, and it can be seen that when activated carbon and bentonite are mixed, a synergistic effect is exhibited and an excellent carrier can be obtained. Furthermore, when the amount of palladium chloride supported is 0.07 mmol/g, the optimal amount of cupric chloride supported is approximately 0.5 mmol/g for any carrier.
It ranged from mol/g to 0.7 mmol/g. Example 2 Regarding the catalyst of the present invention in which coconut shell activated carbon-bentonite was used as a carrier and a mixture of palladium chloride and cupric chloride was supported on it in the same manner as in Example 1, the amount of supported palladium chloride and cupric chloride was determined. The results of calculating the CO removal rate when each change is shown in the second section.
It was as shown in the figure. The activity was measured under the same conditions as in Example 1, except that the amount of catalyst used was half that of Example 1, ie, 50 mg. From the results shown in FIG. 2, it can be seen that the activity improves as the amount of palladium chloride supported increases. In addition, the optimum amount of cupric chloride supported tends to decrease slightly as the amount of palladium chloride decreases, but the supported amount at which the CO removal rate is maximum is approximately 0.5 m
It can be seen that it is between mol/g and 0.9 mmol/g. Example 3 Table 1 shows the results of measuring CO reduction rates for catalysts prepared by changing the type of activated carbon used as a carrier. Note that the CO reduction rate was measured under the same conditions as in Example 1.

[Table] From the results in Table 1, it can be seen that in all samples, the catalyst of the present invention using bentonite-hardened activated carbon as a carrier was significantly more effective than the catalyst using only activated carbon as a carrier, regardless of the type of activated carbon. It can be seen that this shows a high CO reduction rate. Example 4 Among the sample catalysts shown in Table 1, 1-1, 1-
2 and 1-3 supports and catalysts at 200% each
A glass tube with an inner diameter of 5 mm and a length of 25 mm was filled with the sample, and both ends of the glass tube were pressed with glass wool. One end of this glass tube was connected to the filter part of a product cigarette (trade name Highlight) using cellophane tape. Also, connect the other end of this glass tube to an automatic smoking device and set it under standard smoking conditions (35ml suction/
1 puff, 2 seconds/1 puff, 1 puff/minute, watermelon length
30mm), CO in the obtained mainstream smoke gas
As a result of measuring the concentration using ND-IR, the cigarettes equipped with the glass tube filled with the sample of the present invention of 1-3 had a lower concentration than the samples of 1-1 and 1-2, respectively.
decreased by 28% and 20%. Example 5 Among the samples shown in Table 1 of Example 3, 2-
400 mg each of catalysts 1 and 2-2 were weighed out and filled into a glass tube with an inner diameter of 6 mm and a length of 50 mm, and both ends of the glass tube were pressed with glass wool. A rubber mouthpiece was attached to one end of the glass tube, and the filter part of a cigarette (trade name: Highlight) was inserted. The other end of this glass tube was attached to an automatic smoking device and smoked under the same standard smoking conditions as above. After smoking a single cigarette, the CO concentration in the mainstream smoke gas is determined by ND.
- Measured by IR. After the measurement was completed, a second cigarette was attached, and smoking and measurement were repeated in the same manner, with a total of 10 cigarettes being smoked from each glass tube. Separately, a sample using the same carrier as Sample 2-2 in Table 1 but without supporting palladium chloride and cupric chloride was used as a control. As a result, when looking at the first cigarette, it was found that the mainstream smoke that passed through the sample 2-2 of the present invention
CO was reduced by 24% compared to the 2-1 sample and 52% compared to the control. Also, in the second one, 2-
26% compared to sample 1, 40% compared to control
, and decreased by 2 even in the 10th test.
The -2 sample showed a 14% decrease compared to the 2-1 sample, and a 26% decrease compared to the control. Example 6 A γ-alumina supported catalyst in which a catalyst was supported on γ-alumina at a ratio of 0.07 mmol/g of palladium chloride and 0.7 mmol/g of cupric chloride, and palladium chloride on a coconut shell activated carbon-bentonite carrier. 200 mg of each of the coconut shell activated carbon-bentonite carrier catalyst of the present invention, which supported the same proportions of cupric chloride and cupric chloride, was packed into the filter portion of a product cigarette (trade name Highlight) in a triple filter format. On the other hand, coconut husk charcoal without catalyst support
Table 2 shows the results of an evaluation of the aroma and taste of tobacco smoke by a trained expert panel of 10 people, using a cigarette similarly filled with 200 mg in the filter part as a control product.

[Table] As seen in the evaluation in Table 2, the coconut shell activated carbon-bentonite carrier catalyst of the present invention has almost no adverse effect on the flavor of tobacco smoke, and all the panelists said that it had an excellent flavor and flavor with no difference from the control product. It was evaluated that there is. On the other hand, it can be seen that the γ-alumina supported catalyst has a significant negative influence on the aroma and taste of cigarettes. As explained above in detail including the examples,
The CO remover of the present invention, which comprises a catalyst made of palladium chloride and cupric chloride supported on an activated carbon-bentonite carrier, can significantly reduce CO in smoke without reducing the aroma and taste of tobacco smoke. This invention is extremely useful for the health management of smokers.

[Brief explanation of the drawing]

Figure 1 shows the CO2 emissions when various carriers are used and the ratio of cupric chloride to palladium chloride is varied.
A graph showing the removal rate, Figure 2 is coconut shell activated carbon.
CO when using bentonite as a carrier and varying the supported amounts of palladium chloride and cupric chloride
It is a graph showing a removal rate.

Claims (1)

[Claims] 1. A carbon monoxide remover in tobacco smoke, characterized in that a mixture of cupric chloride and palladium chloride is supported on a carrier made of a mixed composition of bentonite and activated carbon.