KR20170060810A - Adsorbent for cigarette filter, preparing method thereof and cigarette filter comprising the same - Google Patents
Adsorbent for cigarette filter, preparing method thereof and cigarette filter comprising the same Download PDFInfo
- Publication number
- KR20170060810A KR20170060810A KR1020150165459A KR20150165459A KR20170060810A KR 20170060810 A KR20170060810 A KR 20170060810A KR 1020150165459 A KR1020150165459 A KR 1020150165459A KR 20150165459 A KR20150165459 A KR 20150165459A KR 20170060810 A KR20170060810 A KR 20170060810A
- Authority
- KR
- South Korea
- Prior art keywords
- hydroxyapatite
- adsorbent
- cigarette
- filter
- cigarette filter
- Prior art date
Links
Images
Classifications
-
- A—HUMAN NECESSITIES
- A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
- A24D—CIGARS; CIGARETTES; TOBACCO SMOKE FILTERS; MOUTHPIECES FOR CIGARS OR CIGARETTES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES
- A24D3/00—Tobacco smoke filters, e.g. filter-tips, filtering inserts; Filters specially adapted for simulated smoking devices; Mouthpieces for cigars or cigarettes
- A24D3/06—Use of materials for tobacco smoke filters
- A24D3/16—Use of materials for tobacco smoke filters of inorganic materials
-
- A—HUMAN NECESSITIES
- A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
- A24D—CIGARS; CIGARETTES; TOBACCO SMOKE FILTERS; MOUTHPIECES FOR CIGARS OR CIGARETTES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES
- A24D3/00—Tobacco smoke filters, e.g. filter-tips, filtering inserts; Filters specially adapted for simulated smoking devices; Mouthpieces for cigars or cigarettes
- A24D3/02—Manufacture of tobacco smoke filters
-
- A—HUMAN NECESSITIES
- A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
- A24D—CIGARS; CIGARETTES; TOBACCO SMOKE FILTERS; MOUTHPIECES FOR CIGARS OR CIGARETTES; MANUFACTURE OF TOBACCO SMOKE FILTERS OR MOUTHPIECES
- A24D3/00—Tobacco smoke filters, e.g. filter-tips, filtering inserts; Filters specially adapted for simulated smoking devices; Mouthpieces for cigars or cigarettes
- A24D3/06—Use of materials for tobacco smoke filters
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Inorganic Chemistry (AREA)
- Cigarettes, Filters, And Manufacturing Of Filters (AREA)
Abstract
The present invention relates to an adsorbent for a cigarette filter, a method for producing the same, and a cigarette filter comprising the same. More particularly, the present invention relates to a cigarette filter comprising hydroxyapatite (HA) having an average particle size of 100 to 400 μm produced by reaction of calcium acetate and phosphoric acid, (Ca 5 (PO 4 ) 3 (OH)), a process for producing the same, and a cigarette filter comprising the same, wherein the adsorbent for a cigarette filter according to the present invention has a phosphate group, Because it is exposed to calcium and possesses amphoteric charge, it exhibits a high selective adsorption characteristic. Therefore, harmful substances such as nicotine in the cigarette smoke are greatly reduced, and the taste of the cigarette as a whole is made mild, It is possible to minimize the negative influence on the cigarette preference, so that it is effectively applied to the cigarette filter. It is good.
Description
The present invention relates to an adsorbent for a cigarette filter, a method for producing the cigarette filter, and a cigarette filter including the cigarette filter. More particularly, the present invention relates to an adsorbent for a cigarette filter which effectively removes a large amount of harmful substances such as nicotine, The present invention relates to an adsorbent for a cigarette filter which does not cause any significant change in taste, a method for producing the same, and a cigarette filter including the same.
It has been reported that about 2500 substances are present in tobacco as a tobacco product, and more than 4000 kinds of substances are reported to be generated in the tobacco smoke depending on the amount of oxygen in air and temperature.
Nicotine, tar, polynuclear aromatic hydrocarbons (PAHs) and carbon monoxide are reported to be determined by tar as a major harmful component of tobacco.
Generally, cigarettes having a high content of nicotine and tar are toxic by themselves, while those having a low content of nicotine and tar are relatively weak in toxicity, but conversely, the cigarette smoke is inhaled more deeply, resulting in an increase in the amount of smoking The harm to health is known to be the same, and the bigger problem is that the mild cigarette is mild and the smoker does not feel the cigarette taste.
Generally, the cigarette smoke component is composed of gaseous substances such as carbon monoxide or hydrogen cyanide, vaporous substances such as acrolein, acetaldehyde, formaldehyde, acetonitrile and the like, and polynuclear aromatic hydrocarbons such as nicotine or tar, It is classified as particulate matter.
As far as it is known, it is known that the removal of particulate matter from cigarette smoke is effective by filtering with a fibrous filter or air dilution method, and air dilution or diffusion adsorption is effective for removal of vapor phase or gaseous material.
Since the cigarette filter has good air permeability, the total amount of the cigarette smoke reaching the smoker is controlled, and the particulate matter classified as the harmful component in the smoke , And adsorbs and reduces the vapor phase or gaseous phase material.
The cigarette filter is classified into a cellulose acetate filter, a paper filter, a pulp filter, and the like depending on raw materials. The filter is classified into a general filter, a perforation filter, a porous filter, a non-wrapped acetate (NWA) A mono filter, a composite filter, and the like.
As a raw material of the most widely used cellulose acetate filter, cellulose acetate tow which leads to a collection of continuous filaments of cellulose acetate as a material for determining the attraction resistance, which is the most important characteristic of the filter, and cellulose acetate tow, A plasticizer, such as triacetin, to form a bond at the point of contact between the fiber bundle and the fiber bundle, and a wrapper to maintain the shape of the filter floc.
In general, the most widely used fibrous filter has a nicotine or tar filtration rate of only about 20 to 40%, and thus has a problem that strong smell inherent in tobacco due to nicotine or tar remains during smoking.
Therefore, in recent years, a dual filter or a triple filter including an adsorbent having a selective adsorption capability for a fibrous filter has been widely used for the purpose of more effectively reducing a gas phase or a vapor phase component.
Examples of the adsorbent for the tobacco filter include hydrophobic activated carbon produced from vegetable raw materials such as palm leaves, oak, and pine as well as lignite as a raw material, hydrophilic zeolite as a mineral adsorbent, or composite adsorbent obtained by suitably combining these two materials Is applied.
In general, activated carbon has a highly developed fine pore structure, and thus has a very large specific surface area and is strong in adsorption to non-polar molecules and is excellent in gas removal, deodorization and decolorizing effect. Zeolite has hydrophilic properties with a pore diameter of about 3-10 Å Carbon monoxide, carbon dioxide, and moisture adsorption characteristics as an adsorbent.
The above-mentioned adsorbent is used as a single filter or a double filter mixed with a fibrous filter in the form of fine particles, or in the form of a triple filter in which a relatively large particle diameter is positioned in the middle of a fibrous filter.
Recently, a DNA filter using a double-stranded DNA structure obtained by extracting from seaweed or salmon and then concentrated has been proposed for effective reduction of polynuclear aromatic hydrocarbons (PAHs).
Examples of typical conventional techniques using an adsorbent include Japanese Patent Application Laid-Open Nos. 59-069146, 04-004039, Korean Patent No. 0131709, and Korean Patent No. 0193377. The adsorption characteristics of activated carbon and zeolite A complex adsorbent using a variety of inorganic and organic binders has been proposed. However, the method using these complex adsorbents has a problem in that the adsorption of the organic and organic binder to the activated carbon and the zeolite results in a lipophilic effect, There is a problem in that the adsorbability to the substance is lowered.
On the other hand, as typical conventional techniques for applying various kinds of additives to filters in order to more effectively reduce specific harmful components of cigarettes, German Patent No. 1300854, German Patent No. 4320348, and Japanese Patent Laid-Open No. 05-023159 And they use an organic acid or an ester compound thereof as a filter additive in order to reduce nicotine. Other typical prior arts include Japanese Patent Laid-Open Nos. 50-125100, 51-032799, and German Patent No. 2527234 , Which add cyclic dextrin directly to the fibrous filter or add granules to reduce nicotine.
Also, U.S. Patent No. 5,409,021 selectively reduces nicotine, benzopyrene, carbon monoxide, metal, and nitroamine by adding lignin to the filter.
In addition, there are various conventional techniques for adding various organic and inorganic compounds to filters or coating them on an adsorbent, but most of them are not sufficiently satisfactory in terms of nicotine removal efficiency and have serious adverse effects on the taste of tobacco In order to solve this problem, early-stage manufacturing companies have raised a suspicion that the harmful effects of other harmful components generated by decomposition of these compounds during combustion are increased rather than unknown additives added at the beginning of the year to enhance the taste of tobacco .
Accordingly, it is a first object of the present invention to provide a method for producing a cigarette having a high adsorption ability due to exposure of a phosphoric acid group, a hydroxyl group and calcium on the crystal surface and possessing an amphoteric charge, thereby significantly reducing harmful substances such as nicotine in cigarette smoke And to provide an adsorbent for an effective tobacco filter which can make the taste of the cigarette as pure as possible.
A second object of the present invention is to provide an adsorbent for a cigarette filter capable of minimizing a negative influence on cigarette preference because it does not give a large change or a large change to the taste of the cigarette in addition to the first object.
A third object of the present invention is to provide an adsorbent for an effective tobacco filter which can maintain a mild taste while retaining the taste of a cigarette even in the case of a particularly toxic cigarette having a high content of nicotine.
A fourth object of the present invention is to provide an effective production method of the adsorbent for the cigarette filter described above.
A fifth object of the present invention is to provide an effective cigarette filter including the adsorbent for the cigarette filter described above.
According to a preferred aspect of the present invention for attaining the first to third objects of the present invention, hydroxyapatite having an average particle size of 100 to 400 탆, preferably 150 to 350 탆 hydroxyapatite (Ca 5 (PO 4 ) 3 (OH)).
Here, the hydroxyapatite may be artificial hydroxyapatite produced by the reaction of calcium acetate and phosphoric acid.
According to a preferred embodiment of the present invention, there is provided a method for preparing a calcium phosphate aqueous solution, comprising the steps of: preparing an aqueous calcium acetate solution; preparing an aqueous phosphoric acid solution; Acetate aqueous solution for 30 minutes to 2 hours to produce and develop crystals of hydroxyapatite and dehydrogenating the hydroxyapatite powder to prepare an adsorbent for a tobacco filter made of hydroxyapatite, do.
The above-mentioned degassing step may be performed at a high speed of 500 to 2000 rpm for 30 minutes to 5 hours in an airtight state.
The degassed hydroxyapatite may be lyophilized and then pulverized to adjust the average particle size to 100 to 400 탆, preferably 150 to 350 탆.
The fifth object of the present invention is achieved by providing a cigarette filter comprising the adsorbent for a cigarette filter made of the hydroxyapatite powder manufactured as described above.
The adsorbent for a hydroxyapatite tobacco filter according to the present invention exhibits a high selective adsorption characteristic because the phosphate surface, hydroxyl group and calcium are exposed on the crystal surface and possesses an amphoteric charge, thereby significantly reducing harmful substances such as nicotine in the cigarette smoke The adsorbent for cigarette filter according to the present invention is effectively applied to the cigarette filter since the negative influence on the cigarette odor can be minimized since the cigarette taste is made mild as a whole, It is possible.
1 is an electron micrograph (X200) of a hydroxyapatite powder as an adsorbent for a cigarette filter according to the present invention.
2 is a scanning electron micrograph (X100,000) of the surface of FIG.
3 is a gas chromatogram and MS spectrum of the nicotine standard solution.
4 is a gas chromatogram and MS spectrum of a commercial tobacco (trade name: Dunhill Light) as a comparative example.
5 to 8 are the gas chromatograms and the MS spectra of Test Examples 1 to 4 according to the present invention, respectively.
9 is a graph showing the results of Test Examples 1 to 4 in comparison with FIG.
Hereinafter, the present invention will be described in detail.
The hydroxyapatite (Ca 5 (PO 4 ) 3 (OH)) used as the adsorbent for the tobacco filter according to the present invention can be classified as calcium-based hydroxyapatite in apatite, bone mineral is a bioceramic material that has no allergic side effects or skin side effects.
The hydroxyapatite crystal as an adsorbent for a cigarette filter according to the present invention exhibits high selective adsorption characteristics because it has a positive charge due to exposure of phosphoric acid group, hydroxyl group and calcium on its surface.
In the present invention, the hydroxyapatite as the adsorbent for the tobacco filter may be artificial hydroxyapatite produced by the reaction of calcium acetate and phosphoric acid, and may have an average particle size of 100 to 400 탆, preferably 150 to 350 탆 If the average particle size is less than 100 탆, the aspiration of the cigarette smoke may become inconvenient, and the preference due to the decrease of the aspiration amount of the cigarette smoke may be lowered. On the other hand, Which is also undesirable.
The hydroxyapatite as the adsorbent for the cigarette filter according to the present invention may be used in the form of a dual compound filter having an adsorbent layer in an amount of 10 to 80 mg in the front part of a conventional cellulose acetate tow filter flock, Can be used independently in the form of a double or triple composite filter in the form of an adsorbent of the type described above on the surface or intermediate layer of a conventional cellulose acetate tow filter flock.
Next, a method for producing hydroxyapatite as an adsorbent for a cigarette filter according to the present invention will be described.
A process for producing hydroxyapatite as an adsorbent for a cigarette filter according to the present invention comprises the following steps.
(A) Calcium acetate aqueous solution preparation step:
Calcium acetate (Ca (CH 3 COO) 2 .H 2 O) is added to distilled water to prepare an aqueous solution of calcium acetate.
(B) Phosphoric acid aqueous solution preparation step:
Phosphoric acid (H 3 PO 4 ) is added to distilled water to prepare an aqueous solution of phosphoric acid.
(C) Production and development steps of hydroxyapatite crystals:
The calcium acetate aqueous solution is added dropwise over a period of 30 minutes to 2 hours, particularly 1 hour while maintaining the pH of the aqueous phosphoric acid solution at 9 to 11, specifically at a pH of 10, to produce and develop crystals of hydroxyapatite .
(D) Degassing step:
The produced and developed hydroxyapatite powder is deaerated.
The degassing step may be performed at a high speed in an airtight state at 500 to 2000 rpm, specifically at 1000 rpm for 30 minutes to 5 hours, particularly for 3 hours with the lid closed.
(E) Average particle size control step:
Alternatively, the degassed hydroxyapatite may be lyophilized and then pulverized to adjust the average particle size to 100 to 400 탆, preferably 150 to 350 탆.
The adjustment of the average particle size can be performed using a spray dryer, and particles having a desired average particle size can be selected by sieving.
The hydroxyapatite powder as an adsorbent for a cigarette filter according to the present invention manufactured as described above and the electron micrograph (X200 and X100,000) showing the surface structure and morphology thereof are shown in Fig. 1 and Fig. 2, respectively.
Meanwhile, the present invention provides a cigarette filter including the hydroxyapatite powder prepared as described above, and can be manufactured in the form of a conventional dual compound filter or a triple compound filter.
Hereinafter, the present invention will be described in more detail with reference to examples and test examples.
Example: Preparation of hydroxyapatite as adsorbent for tobacco filter
5.68 mol of calcium acetate (Ca (CH 3 COO) 2 .H 2 O) was added to distilled water to prepare a 1.42 mL / L aqueous solution of calcium acetate. In addition, 4.38 mol of phosphoric acid (H 3 PO 4 ) / L of a phosphoric acid aqueous solution was prepared, and the aqueous calcium acetate solution was added dropwise over 1 hour while maintaining the pH of the aqueous phosphoric acid solution at 10, to thereby produce and develop crystals of hydroxyapatite.
The resulting and developed hydroxyapatite powders were degassed by high-speed mixing in an air-tight state with lid closed at 1000 rpm for 3 hours.
Subsequently, the degassed hydroxyapatite was lyophilized, pulverized, adjusted to an average particle size of 350 mu m using a spray dryer, and sieved to obtain hydroxyapatite as an adsorbent for a tobacco filter.
Comparative Example: Gas chromatogram and MS spectrum of dunhillite
After putting the dunhill light (tar 6.0 mg, nicotine 0.60 mg) into the syringe, it is lighted and the cigarette smoke is sucked by the syringe and the initial 20 ml is sampled. Then, 0.8 ml is taken by Gastite syringe and gas chromatography and mass And analyzed by a spectrometer.
The gas chromatographic operation conditions were maintained at 20 ° C for 2 minutes, then increased to 8 ° C per minute, and then operated at 200 ° C for 15 minutes.
The results are shown in FIG. 4. As a result of analysis of gas chromatogram, the largest amount of nicotine was detected and other small peaks were detected, and the mass spectrum for each peak was added.
The height of the aboundance of the detected nicotine was 7,447,881 and the area was 425,001,075.
On the other hand, FIG. 3 shows the gas chromatogram and MS spectrum of nicotine standard solution (Dr.Ehrenstorfer GmbH Nicotine 99.5%) as a control, and the retention time of nicotine was about 16 minutes.
Test Example 1:
17.1 mg of hydroxyapatite having an average particle size of 350 mu m prepared in Example 1 was filled in the front portion of the dunhill light cigarette after removing the filter of the dunhill light cigarette and then the original filter was inserted again.
Gas chromatogram and MS spectrum were obtained using the same conditions and method as in the comparative example, and the results are shown in Fig.
From the results of FIG. 5, it can be seen that the first and second peaks were not seen, the area of abundance of the third peak, nicotine peak, was significantly lowered to 206,967,112, and the fourth and fifth peaks were considerably lowered.
Test Example 2:
Gas chromatogram and MS spectrum were obtained using the same conditions and method as in Test Example 1, except that 34.3 mg of hydroxyapatite was used. The results are shown in Fig.
From the results of FIG. 6, it was confirmed that the peak was further lower than that of Test Example 1, and the first, second and fifth peaks were not observed, and the third peak, the abundance area of the nicotine peak was 28,959,257 And the fourth peak was also significantly lowered.
Test Example 3:
Gas chromatogram and MS spectrum were obtained using the same conditions and method as in Test Example 1, except that the amount of hydroxyapatite used was 49.8 mg. The results are shown in Fig.
From the results of FIG. 7, it was confirmed that the peak was further lower than that of Test Example 1, and the first, second and fifth peaks were not observed, and the third peak, the abundance area of the nicotine peak was 19,473,156 And the fourth peak was also significantly lowered.
Test Example 4:
Gas chromatogram and MS spectrum were obtained using the same conditions and method as in Test Example 1, except that the amount of hydroxyapatite used was 69.4 mg. The results are shown in FIG.
From the results of FIG. 8, it was confirmed that the peak was further lower than that of Test Example 1, and the first, second and fifth peaks were not observed, and the third peak, the abundance area of the nicotine peak was 12,250,899 And the fourth peak was also significantly lowered.
Theorem: Comparison between the results of Comparative Example and Test Examples 1 to 4
The results of the comparative example and the test examples 1 to 4 are collectively shown in FIG.
From the results shown in FIG. 9, it was found that the adsorbent for hydroxyapatite tobacco filter according to the present invention has a very excellent effect on the adsorption of harmful components of tobacco smoke including nicotine.
The results are summarized in Tables 1 and 2 below.
(minute)
Test Example 5: Sensory Evaluation Test
Tobacco cigarettes were given to 50 young adults who smoke one to two packs of cigarette per day.
All 50 subjects evaluated that the cigarettes of Test Examples 1 to 4 were smoothed compared to the cigarettes of the Comparative Examples.
Ninety percent of the subjects were asked to smoke again after smok ing the cigarettes of Test Examples 1 and 2 (including initially requested but not required).
75% of the subjects evaluated that the cigarette flavor of Test Examples 2 and 3 was better than that of the comparative example.
In case of Test Example 4, it was evaluated that the taste of the cigarette was mostly poor.
As a result, Test Examples 2 and 3 were evaluated to be the best, followed by Test Example 1 and Test Example 4, respectively.
While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. Various changes and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention Which is also within the scope of the present invention.
Claims (6)
Producing an aqueous phosphoric acid solution;
Maintaining the pH of the aqueous phosphoric acid solution at 9 to 11 while dropping an aqueous solution of calcium acetate over a period of 30 minutes to 2 hours to produce and develop crystals of hydroxyapatite;
And a step of degassing the hydroxyapatite powder
A process for producing an adsorbent for a tobacco filter of hydroxyapatite.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020150165459A KR20170060810A (en) | 2015-11-25 | 2015-11-25 | Adsorbent for cigarette filter, preparing method thereof and cigarette filter comprising the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020150165459A KR20170060810A (en) | 2015-11-25 | 2015-11-25 | Adsorbent for cigarette filter, preparing method thereof and cigarette filter comprising the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| KR20170060810A true KR20170060810A (en) | 2017-06-02 |
Family
ID=59222366
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1020150165459A KR20170060810A (en) | 2015-11-25 | 2015-11-25 | Adsorbent for cigarette filter, preparing method thereof and cigarette filter comprising the same |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR20170060810A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107460776A (en) * | 2017-07-28 | 2017-12-12 | 河南中烟工业有限责任公司 | A kind of preparation method of humectation bag ash cigarette paper |
| CN110754685A (en) * | 2019-11-12 | 2020-02-07 | 广东中烟工业有限责任公司 | Cigarette with low harmful components in smoke and preparation method thereof |
| KR20210112482A (en) | 2020-03-05 | 2021-09-15 | 조영상 | Cigarette filter for toxic gas decomposition |
-
2015
- 2015-11-25 KR KR1020150165459A patent/KR20170060810A/en active Search and Examination
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107460776A (en) * | 2017-07-28 | 2017-12-12 | 河南中烟工业有限责任公司 | A kind of preparation method of humectation bag ash cigarette paper |
| CN107460776B (en) * | 2017-07-28 | 2020-01-10 | 河南中烟工业有限责任公司 | Preparation method of moistening ash-wrapped cigarette paper |
| CN110754685A (en) * | 2019-11-12 | 2020-02-07 | 广东中烟工业有限责任公司 | Cigarette with low harmful components in smoke and preparation method thereof |
| KR20210112482A (en) | 2020-03-05 | 2021-09-15 | 조영상 | Cigarette filter for toxic gas decomposition |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR100908752B1 (en) | Cigarettes and filters with added flavoring downstream | |
| KR101342754B1 (en) | - smoking articles with activated carbon and sodium bicarbonate-treated fibers and method of treating mainstream smoke | |
| RU2572168C2 (en) | Smoking product filter | |
| JP6268289B2 (en) | Adsorbent | |
| ZA200610096B (en) | Application of mesoporous molecular sieves as selective smoke filtration additives | |
| WO2004019709A2 (en) | Cigarette filters comprising unfunctionalized porous polyaromatic resins for removing gas phase constituents from mainstream tobacco smoke | |
| KR20170060810A (en) | Adsorbent for cigarette filter, preparing method thereof and cigarette filter comprising the same | |
| WO2007117115A1 (en) | Cigarette filter using bamboo activated carbon | |
| EP1571934B1 (en) | Tobacco smoke filter | |
| KR100597169B1 (en) | Smoking articles | |
| CN113841922B (en) | Preparation method and application of compound-flavor essence spice for cigarettes | |
| RU2357624C2 (en) | Tobacco smoke filter | |
| JPH08505051A (en) | Filter cigarette | |
| CN1191025C (en) | Method of preparing cigarette containing loess, clay other minerals and cigarette product thereof | |
| EP3003072B1 (en) | Functionalized material for selective removal of smoke constituents | |
| RU2668752C1 (en) | Cigarette filter | |
| KR100588056B1 (en) | Cigarette filter | |
| KR900007006B1 (en) | Method for preparing of cigarette filter | |
| US3842070A (en) | Filtering material | |
| KR101505112B1 (en) | Filtering media for smoking, cigarette filter and cigarette paper using the same | |
| JPH0523159A (en) | Cigarette filter | |
| KR100322201B1 (en) | Charcoal tobacco | |
| RU2330592C1 (en) | Filter for cigarettes | |
| EP2801269A1 (en) | Smoking article | |
| CN113598411A (en) | Composite filter tip for adsorbing crotonaldehyde in cigarette smoke and cigarette |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A201 | Request for examination | ||
| E902 | Notification of reason for refusal | ||
| E601 | Decision to refuse application | ||
| AMND | Amendment |