A cigarette filter rod and its preparation method

Abstract

This invention discloses a cigarette filter rod and its preparation method, belonging to the field of cigarette auxiliary materials technology. Acetate fiber is fed into a molding machine, opened to form an acetate fiber core, and particulate matter is incorporated into the outer side at a concentration of 1.6 mg / mm. The cigarette filter rod adopts a 15mm+15mm binary composite structure, with the 15mm segment being a pure acetate fiber segment and the other 15mm segment incorporating particulate matter. Then, a laminating machine is used to bond the inner wall of the outer paper layer and the inner protective layer together. Finally, the acetate fiber core is rolled, cut, and dried to obtain the cigarette filter rod. The addition of particulate matter in the cigarette filter rod significantly reduces the content of heavy metals in inhaled smoke without affecting the taste. The composite of the hydrophobic and breathable inner protective layer and the outer paper layer improves the hydrophobicity of the cigarette filter rod, making it less prone to cracking. Furthermore, it effectively reduces the content of harmful substances and free radicals in the smoke, making it safer, and also improves the storage stability of the cigarette filter rod in humid and dark environments.

Description

Technical Field

[0001] This invention belongs to the field of cigarette auxiliary materials technology, specifically, it relates to a cigarette filter rod and its preparation method. Background Technology

[0002] Cigarette filters are an indispensable component of cigarettes, significantly impacting smoking quality and reducing tar and harm. Currently, the main type of cigarette filter used is cellulose acetate. Cellulose acetate is a green and environmentally friendly regenerated cellulose fiber; it is non-toxic, odorless, impact-resistant, oil-resistant, static-free, has low draw resistance, strong adsorption capacity, and excellent elasticity and thermal stability. It can selectively adsorb harmful components in cigarette smoke while retaining a certain amount of nicotine without sacrificing the tobacco flavor. However, manufacturing cellulose acetate filters requires opening the cellulose acetate bundles and using plasticizers to bind them into a dense mesh structure. This open structure has relatively large gaps between the fibers, failing to fully utilize the filtering properties of cellulose acetate and thus not fully realizing the filter's tar-reducing and harm-reducing effects.

[0003] As is well known, during cigarette combustion, the breakdown of polyphenolic compounds (chlorogenic acid and rutin) in tobacco leaves produces harmful substances such as phenol and catechol. Simultaneously, heavy metals such as lead, arsenic, cadmium, and chromium contained in tobacco and tobacco products also contribute to the smoke aerosol. Evidence suggests that the presence of phenolic substances significantly increases the carcinogenic activity of polycyclic aromatic hydrocarbons, particularly phenol, ortho-, meta-, and hydroquinones, and ortho-, meta-, and p-methylphenols. Hydroquinone in cigarette smoke condensate has a co-promoting effect on cancer, and some phenols have a strong irritant effect on the skin and respiratory mucosa. Similarly, heavy metals can also lead to various diseases and may even be carcinogenic.

[0004] If conventional cellulose acetate cigarette filter rods are exposed to humid weather, the cellulose acetate will absorb moisture from the air within a certain storage period, affecting the quality of the cigarettes. It may also damage the outer paper layer due to its lack of waterproofness, causing the filter rod to crack. Additionally, it may become moldy and unusable. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a cigarette filter rod and its preparation method.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A method for preparing a cigarette filter rod includes the following steps:

[0008] First, cellulose acetate is fed into a molding machine to loosen it and form a cellulose acetate core. Particles are then added to the outside. Next, at 70-90℃, a laminating machine is used to bond the inner wall of the outer paper layer and the inner protective layer together. Finally, the cellulose acetate core is rolled, cut, and dried to obtain the cigarette filter rod.

[0009] Furthermore, the cigarette filter rod adopts a 15mm+15mm binary composite structure, with the 15mm segment being a pure cellulose acetate segment, and particulate matter being incorporated into the outer side of the cellulose acetate segment at a concentration of 1.6mg / mm.

[0010] Furthermore, the particulate matter is prepared by the following steps:

[0011] Tetrasodium ethylenediaminetetraacetate tetrahydrate was dissolved in deionized water, and mesoporous alumina that had been dried at 150°C for 12 hours was added. The mixture was stirred at room temperature for 48 hours, and then stirred and kept warm in an 80°C water bath for 30 minutes. The resulting solid was filtered and dried. This adsorption-drying process was repeated until the solution was completely adsorbed. Finally, the product was dried at 150°C and granulated to obtain particulate matter. The ratio of alumina, tetrasodium ethylenediaminetetraacetate tetrahydrate, and deionized water was 10 g: 0.6 g: 20 mL.

[0012] Furthermore, the particulate matter has a particle size of 30 mesh and a moisture content of 7-10%.

[0013] Heavy metals in cigarette smoke mainly exist in the form of aerosols or metal oxides, and can enter the human body with the smoke. Tetrasodium ethylenediaminetetraacetate tetrahydrate is an important metal complexing agent that can complex with almost all metals. Therefore, heavy metals in cigarette smoke can be trapped by complexing with it. Alumina has a large specific surface area and contains abundant micropores and mesopores. Extremely fine aerosols and metal oxides can enter its pores. Since heavy metal aerosol particles are generally charged, they are easily adsorbed and trapped by electrostatic effects when passing through the pores or particle surfaces, thereby further reducing the content of heavy metals.

[0014] Furthermore, the inner protective layer comprises the following raw materials in parts by weight: 75-85 parts polypropylene resin, 10-15 parts rice straw fiber, 1-3 parts additives, 0.2-0.3 parts natural antioxidants, 1-4 parts microcapsule fragrance, 2-5 parts nano titanium dioxide, 3-6 parts magnesium hydroxide, 2-5 parts plasticizer, and 0.01-0.03 parts initiator;

[0015] Furthermore, the auxiliary agent is prepared by the following steps:

[0016] S1. Under nitrogen protection, tetradecanoic acid and 1,2-dichloroethane were added to a four-necked flask and stirred at room temperature until homogeneous. While stirring, epoxy butene was slowly added. After the addition was complete, the temperature was raised to 60°C and the reaction was stirred at 60°C for 5 hours. After the reaction was completed, the mixture was cooled to room temperature and distilled under reduced pressure. The crude product was recrystallized from acetone and dried in a vacuum drying oven at 50°C for 24 hours to obtain intermediate 1. The molar ratio of epoxy butene to tetradecanoic acid was 1.3-1.5:1.

[0017] Tetradecanoic acid and glycidene undergo a nucleophilic substitution reaction under heating conditions, as shown below:

[0018]

[0019] S2. Under nitrogen protection, intermediate 1, aluminum trichloride, and DMF (N,N-dimethylformamide) were added to a four-necked flask and stirred thoroughly until homogeneous. The temperature was raised to 40°C, and epichlorohydrin was slowly added while stirring. After the addition was complete, the mixture was stirred at 40°C for 4 hours. After the reaction was completed, the mixture was cooled to room temperature, purified by vacuum distillation, and column chromatography (using a mixed solvent of benzene and acetone as the eluent, with a volume ratio of benzene to diethyl ether of 9:1). Vacuum distillation was then performed to obtain intermediate 2. The molar ratio of epichlorohydrin to intermediate 1 was 1.3-1.5:1.

[0020] Intermediate 1 and epichlorohydrin undergo a nucleophilic substitution reaction under heating and acid catalysis, as shown below:

[0021]

[0022] S3. Under nitrogen protection, chitosan, triethylamine, and DMF were added to a thoroughly dried four-necked flask and stirred until homogeneous. Then, intermediate 2 was added, and the mixture was heated to 80°C and stirred for 4 hours. After the reaction was complete, deionized water was added to the reaction solution, stirred, and allowed to stand. The organic phase was collected, washed three times with saturated brine, dried with anhydrous magnesium sulfate, filtered, and finally distilled under reduced pressure to obtain the auxiliary agent. The ratio of chitosan, intermediate 2, triethylamine, and DMF was 5 g: 0.039 g: 0.01 g: 150 mL.

[0023]

[0024] The additives of this invention contain hydrophobic long alkyl chains, which endow the inner protective layer with excellent hydrophobic properties. Simultaneously, they possess freely extendable and rotatable methylene long chains, thus enhancing the mechanical properties of the inner protective layer. The additives also contain chitosan, a product of chitin deacetylation, containing numerous functional groups such as hydroxyl and amino groups. This allows for the reduction of harmful substances in cigarette smoke through physical and chemical adsorption. Furthermore, chitosan has broad-spectrum antibacterial activity; its addition to the membrane increases the antibacterial properties of the cigarette filter rod in humid environments, extending its service life and storage stability. The additive structure contains double bonds, which, under the action of an initiator, can chemically react with unreacted double bonds at the ends of the matrix resin and some double bonds in natural antioxidants such as squalene, thereby stabilizing the inner protective layer. This ensures the stable presence of natural antioxidants within the inner protective layer, effectively reducing the content of harmful substances and free radicals in the smoke, while also allowing the inner protective layer to fully exert its hydrophobic, breathable, and harmful substance adsorption functions.

[0025] Furthermore, the natural antioxidant is one or more of squalene, beta-carotene, and tea polyphenols.

[0026] Furthermore, the plasticizer is one or more of epoxidized soybean oil and octyl epoxidized stearate.

[0027] Furthermore, the initiator is one or more of dicumyl peroxide, tert-butyl peroctanoate, and azobisisobutyronitrile.

[0028] The present invention also discloses a cigarette filter rod, which is prepared according to the above-described method for preparing a cigarette filter rod.

[0029] The beneficial effects of this invention are as follows: the addition of particulate matter to the cigarette filter rod greatly reduces the content of heavy metals in inhaled smoke without affecting the taste; the composite of the hydrophobic and breathable inner protective layer and the outer paper layer improves the hydrophobicity of the cigarette filter rod, making it less prone to cracking and damage, and effectively reduces the content of harmful substances and free radicals in smoke, making it safer. At the same time, it also improves the storage stability of the cigarette filter rod in humid and dark environments. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1

[0032] The specific steps for preparing particulate matter are as follows:

[0033] Dissolve 0.6 g of tetrasodium ethylenediaminetetraacetate tetrahydrate in 20 mL of deionized water, add 10 g of mesoporous alumina that has been dried at 150 °C for 12 h, stir at room temperature for 48 h, stir and keep warm in an 80 °C water bath for 30 min, filter and dry the obtained solid, repeat the adsorption-drying process until the solution is completely adsorbed, finally dry the product at 150 °C and granulate to obtain particulate matter;

[0034] Example 2

[0035] The specific steps for preparing the auxiliary agent are as follows:

[0036] S1. Under nitrogen protection, 11.4 g of tetradecanoic acid and 120 mL of 1,2-dichloroethane were added to a 250 mL four-necked flask and stirred at room temperature until homogeneous. While stirring, 6 mL of epoxy butene was slowly added. After the addition was completed, the temperature was raised to 60 °C and the reaction was stirred at 60 °C for 5 h. After the reaction was completed, the mixture was cooled to room temperature and distilled under reduced pressure. The crude product was recrystallized from acetone and dried in a vacuum drying oven at 50 °C for 24 h to obtain intermediate 1.

[0037] S2. Under nitrogen protection, 11.9 g of intermediate 1, 0.02 g of aluminum trichloride, and 120 mL of LDMF were added to a 250 mL four-necked flask and stirred thoroughly until homogeneous. The temperature was raised to 40 °C, and 4.7 mL of epichlorohydrin was slowly added while stirring. After the addition was complete, the mixture was stirred at 40 °C for 4 h. After the reaction was completed, the mixture was cooled to room temperature, purified by vacuum distillation, and column chromatography (using a mixed solvent of benzene and acetone as the eluent, with a volume ratio of benzene to diethyl ether of 9:1). Vacuum distillation was then performed to obtain intermediate 2.

[0038] S3. Under nitrogen protection, 5g of chitosan (Mw=50kDa, DD=87%), 0.01g of triethylamine, and 150mL of LDM were added to a thoroughly dried 250mL four-necked flask and stirred until homogeneous. Then, 0.039g of intermediate 2 was added, and the mixture was heated to 80℃ and stirred for 4 hours. After the reaction was completed, deionized water was added to the reaction solution, stirred, and allowed to stand. The organic phase was taken and washed three times with saturated brine, then dried with anhydrous magnesium sulfate. After drying, the mixture was filtered and finally distilled under reduced pressure to obtain the auxiliary agent.

[0039] Example 3

[0040] The specific steps for preparing the inner protective layer are as follows:

[0041] 75 parts of polypropylene resin, 10 parts of rice straw fiber, 1 part of the additive from Example 2, 0.2 parts of squalene, 1 part of microcapsule fragrance, 2 parts of nano titanium dioxide, 3 parts of magnesium hydroxide, 2 parts of epoxidized soybean oil and 0.01 parts of dicumyl peroxide were mixed evenly and then extruded through a twin-screw extruder. The mixture was then cast into a film and stretched to obtain the inner protective layer.

[0042] Example 4

[0043] The specific steps for preparing the inner protective layer are as follows:

[0044] 85 parts of polypropylene resin, 15 parts of rice straw fiber, 3 parts of the additives from Example 2, 0.15 parts of β-carotene, 0.1 parts of tea polyphenols, 4 parts of microcapsule fragrance, 5 parts of nano titanium dioxide, 6 parts of magnesium hydroxide, 5 parts of octyl epoxide stearate, and 0.03 parts of dicumyl peroxide were mixed evenly and then extruded through a twin-screw extruder. The mixture was then cast into a film and stretched to obtain the inner protective layer.

[0045] Example 5

[0046] The specific steps for preparing the inner protective layer are as follows:

[0047] 84 parts of polypropylene resin, 12 parts of rice straw fiber, 2 parts of the additives from Example 2, 0.2 parts of squalene, 0.1 parts of tea polyphenols, 3 parts of microcapsule fragrance, 3 parts of nano titanium dioxide, 5 parts of magnesium hydroxide, 3 parts of epoxidized soybean oil, and 0.02 parts of tert-butyl peroctanoate were mixed evenly and then extruded through a twin-screw extruder. The mixture was then cast into a film and stretched to obtain the inner protective layer.

[0048] Example 6

[0049] The specific steps for preparing a cigarette filter rod are as follows:

[0050] First, cellulose acetate is fed into a molding machine to loosen it and form a cellulose acetate core. The particulate matter prepared in Example 1 is then incorporated into the outer side of the core (the cigarette filter rod adopts a 15mm+15mm binary composite structure, the 15mm segment is a pure cellulose acetate segment, and the 15mm segment has particulate matter incorporated into the outer side of the cellulose acetate at 1.6mg / mm). Then, at 70°C, a laminating machine is used to bond the inner wall of the outer paper layer with the inner protective layer prepared in Example 3. Finally, the cellulose acetate core is rolled, cut, and dried to obtain the cigarette filter rod.

[0051] Example 7

[0052] The specific steps for preparing a cigarette filter rod are as follows:

[0053] First, cellulose acetate is fed into a molding machine to loosen it and form a cellulose acetate core. The particulate matter prepared in Example 1 is then incorporated into the outer side of the core (the cigarette filter rod adopts a 15mm+15mm binary composite structure, the 15mm segment is a pure cellulose acetate segment, and the 15mm segment has particulate matter incorporated into the outer side of the cellulose acetate at 1.6mg / mm). Then, at 80°C, a laminating machine is used to bond the inner wall of the outer paper layer with the inner protective layer prepared in Example 4. Finally, the cellulose acetate core is rolled, cut, and dried to obtain the cigarette filter rod.

[0054] Example 8

[0055] The specific steps for preparing a cigarette filter rod are as follows:

[0056] First, cellulose acetate is fed into a molding machine to loosen it and form a cellulose acetate core. The particulate matter prepared in Example 1 is then incorporated into the outer side of the core (the cigarette filter rod adopts a 15mm+15mm binary composite structure, the 15mm segment is a pure cellulose acetate segment, and the 15mm segment has particulate matter incorporated into the outer side of the cellulose acetate at 1.6mg / mm). Then, at 90°C, the inner wall of the outer paper layer and the inner protective layer prepared in Example 5 are laminated together using a laminating machine. Finally, the cellulose acetate core is rolled, cut, and dried to obtain the cigarette filter rod.

[0057] Comparative Example 1

[0058] The remaining steps remain unchanged, except that the particulate matter incorporated in Example 8 is removed to prepare the cigarette filter rod.

[0059] Comparative Example 2

[0060] The remaining steps remain unchanged, but the inner protective layer of Example 8 is removed to prepare the cigarette filter rod.

[0061] Comparative Example 3

[0062] The remaining steps remain unchanged, except that the particulate matter and inner protective layer incorporated in Example 8 are removed to prepare the cigarette filter rod.

[0063] Performance testing

[0064] The scavenging rates of gaseous and solid-phase free radicals in cigarette smoke were determined according to the standards "Determination of Gas-Phase Free Radical Content in Mainstream Cigarette Smoke by Electron Spin Resonance Spectroscopy (DB45 / T1494-2017)" and "Determination of Solid-Phase Free Radical Content in Mainstream Cigarette Smoke by Electron Spin Resonance Spectroscopy (DB45 / T1495-2017)". The test results are shown in Table 1 below.

[0065] Table 1

[0066] Project Example 6 Example 7 Example 8 Comparative Example 1 Comparative Example 2 Comparative Example 3 Solid-phase clearance rate % 7.31 8.12 8.33 6.02 - - Gas-phase clearance rate % 13.76 14.39 14.92 10.11 - -

[0067] The changes in physical properties of 100 cigarette filter rods from Examples 6-8 and Comparative Examples 1-3 were compared after being soaked in water for 60 minutes. The results are shown in Table 2 below:

[0068] Table 2

[0069] Project Example 6 Example 7 Example 8 Comparative Example 1 Comparative Example 2 Comparative Example 3 Draw resistance (Pa) 4000 4000 4000 4010 Exceed the standard Exceed the standard Blown mouth (number of sticks) None None None None 100 100

[0070] The release amounts of CO, HCN, NNK, NH3, benzo[α]pyrene, phenol, and crotonaldehyde in mainstream cigarette smoke were tested according to standards GB / T23356-2009, YC / T403-2011, GB / T23228-2008, YC / T377-2010, GB / T21130-2007, YC / T255-2008, and YC / T254-2008, respectively. The reduction rates of Cr and Cd in mainstream smoke were determined by graphite furnace atomic absorption spectrometry (YC / T294-2009). Each sample was tested in triplicate, and the average value was taken. The test results are shown in Table 3.

[0071] Table 3

[0072] Project Example 6 Example 7 Example 8 Comparative Example 1 Comparative Example 2 Comparative Example 3 CO (mg / stick) 10.2 10.3 10.1 11.0 10.9 12.3 HCN (μg / stick) 79.5 79.6 79.4 91.5 86.5 120.5 NNK (ng / stick) 4.7 4.7 4.6 4.7 4.7 4.7 <![CDATA[NH3 (μg / branch)]]> 7.5 7.4 7.3 8.2 8.0 9.1 Benzo[a]pyrene (ng / stick) 6.6 6.6 6.5 7.6 7.1 8.1 Phenol (μg / stick) 10.7 10.7 10.6 11.0 10.9 11.3 Crotonaldehyde (μg / stick) 15.6 15.6 15.5 15.7 15.7 15.7 Cr reduction rate (%) 18.1 18.3 18.5 3.5 15.8 - Cd reduction rate (%) 33.9 34.0 34.1 3.7 30.1 -

[0073] Sensory evaluation was conducted according to the standard method GB 5606.4-2005 "Cigarettes Part 4: Sensory Technical Requirements", and the test results are shown in Table 4:

[0074] Table 4

[0075] Project Example 6 Example 7 Example 8 Gloss 5.0 5.0 5.0 Aroma 30.0 30.0 30.1 Harmonious 5.0 5.0 5.1 Off-flavor 11.3 11.4 11.5 Irritation 17.8 17.8 17.9 Aftertaste 23.3 23.3 23.3 Score 92.4 92.5 92.9

[0076] As can be seen from the data in Tables 1-4 above, the cigarette filter rods prepared in Examples 6-8 of the present invention can effectively adsorb harmful substances and heavy metals in the smoke, and the corresponding cigarettes prepared have a good taste.

[0077] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0078] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A method for preparing a cigarette filter rod, characterized in that, Includes the following steps: First, cellulose acetate is fed into a molding machine to loosen it and form a cellulose acetate core. Particles are then added to the outside. Next, at 70-90℃, a laminating machine is used to bond the inner wall of the outer paper layer and the inner protective layer together. Finally, the cellulose acetate core is rolled, cut, and dried to obtain the cigarette filter rod. The inner protective layer comprises the following raw materials in parts by weight: 75-85 parts polypropylene resin, 10-15 parts rice straw fiber, 1-3 parts additives, 0.2-0.3 parts natural antioxidants, 1-4 parts microencapsulated fragrance, 2-5 parts nano titanium dioxide, 3-6 parts magnesium hydroxide, 2-5 parts plasticizer, and 0.01-0.03 parts initiator; The auxiliary agent is prepared by the following steps: S1. Add tetradecanoic acid and 1,2-dichloroethane to a flask, stir, add epoxide butene, react at 60℃ for 5 h, cool, distill under reduced pressure, recrystallize, and dry to obtain intermediate 1; the molar ratio of epoxide butene to tetradecanoic acid is 1.3-1.5:

1. S2. Add intermediate 1, aluminum trichloride, and DMF to a flask, stir, heat to 40°C, add epichlorohydrin, react at 40°C for 4 hours, cool, distill under reduced pressure, purify by column chromatography, and distill under reduced pressure to obtain intermediate 2; the molar ratio of epichlorohydrin to intermediate 1 is 1.3-1.5:

1. S3. Add chitosan, triethylamine, and DMF to a flask, stir, add intermediate 2, react at 80℃ for 4 hours, cool, add deionized water, stir, let stand, take the organic phase, wash the organic phase with saturated brine, dry, filter, and distill under reduced pressure to obtain the auxiliary agent; the ratio of chitosan, intermediate 2, triethylamine, and DMF is 5g:0.039g:0.01g:150mL.

2. The method for preparing a cigarette filter rod according to claim 1, characterized in that, Particulate matter is prepared through the following steps: Dissolve tetrasodium ethylenediaminetetraacetate tetrahydrate in deionized water, add alumina, stir at 80℃ for 30 min, filter, dry, and granulate to obtain particulate matter; the ratio of alumina, tetrasodium ethylenediaminetetraacetate tetrahydrate to deionized water is 10 g: 0.6 g: 20 mL.

3. The method for preparing a cigarette filter rod according to claim 2, characterized in that, The particulate matter has a particle size of 30 mesh and a moisture content of 7-10%.

4. The method for preparing a cigarette filter rod according to claim 1, characterized in that, The cigarette filter rod adopts a 15mm+15mm binary composite structure. The 15mm section is a pure cellulose acetate section, and particulate matter is added to the outside of the cellulose acetate section at a rate of 1.6mg / mm.

5. The method for preparing a cigarette filter rod according to claim 1, characterized in that, Natural antioxidants include one or more of squalene, beta-carotene, and tea polyphenols.

6. The method for preparing a cigarette filter rod according to claim 1, characterized in that, The plasticizer is one or both of epoxidized soybean oil and octyl epoxidized stearate.

7. The method for preparing a cigarette filter rod according to claim 1, characterized in that, The initiator is one or more of dicumyl peroxide, tert-butyl peroctanoate, and azobisisobutyronitrile.

8. A cigarette filter rod, characterized in that, It is prepared by the method of any one of claims 1-7.

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