A filter rod additive, its preparation method and application

Abstract

The application discloses a filter rod additive and a preparation method and application thereof. The preparation method comprises the following steps: uniformly mixing 35-55 parts of raw materials, 0-10 parts of pore-forming agents and 40-65 parts of phase conversion solutions to be stable, and removing bubbles in the mixture under vacuum to obtain a phase conversion slurry; forming the phase conversion slurry into granular or disc-shaped primary embryo materials by adopting a drop pill process or a flow casting process; and drying and calcining the primary embryo materials to obtain granular or disc-shaped filter rod additives. The application forms a through-hole structure by in-situ self-assembly, has excellent connectivity, and has a pore size distribution from the surface to the inside, which can ensure smooth penetration of smoke, realize airflow sweeping and aroma release, and can uniformly load and stably store aroma substances, so that aroma release is stable and uniform during the whole smoking process, and aroma quality and smoking experience are significantly improved.

Description

Technical Field

[0001] This invention relates to the field of cigarette manufacturing, and more specifically, to a filter rod additive, its preparation method, and its application. Background Technology

[0002] Flavor compounds are important components of flavored cigarettes. Currently, the mainstream preparation methods for flavored cigarettes in the industry mainly include spray flavoring, flavoring thread flavoring, flavoring capsule flavoring, and flavoring granule flavoring. Although these processes have been applied on a large scale, they all have inherent defects that are difficult to avoid due to their own technical principles and structural characteristics. They generally suffer from poor flavor stability, weak aroma retention, and insufficient aroma uniformity, making it difficult to meet the uniform, long-lasting, and stable aroma enhancement requirements of high-end cigarettes.

[0003] Currently, mainstream flavored tobacco granules on the market are prepared through processes such as physical blending and mechanical granulation. The internal pores of flavored granules are disordered and chaotic, mostly consisting of closed pores and tortuous channels. Furthermore, their effective aroma-carrying space is limited, the aroma is unevenly distributed, and the lack of interconnected channels prevents the smoke from penetrating, resulting in uneven aroma release and poor layering throughout the process.

[0004] Therefore, how to provide a filter rod additive with continuous pores, high flavor substance loading, and stable release has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] One objective of this invention is to provide a new technical solution for filter rod additives that feature continuous pores, high flavor substance loading, and stable release.

[0006] According to a first aspect of the present invention, a method for preparing a filter rod additive is provided.

[0007] The preparation method of the filter rod additive includes the following steps:

[0008] Preparation of slurry: Mix 35-55 parts by weight of raw material, 0-10 parts by weight of pore-forming agent and 40-65 parts by weight of phase inversion solution until homogeneous and stable, and then degas under vacuum to obtain phase inversion slurry;

[0009] Directional molding: The phase inversion slurry is molded using a drop shot process or a casting process to obtain granular or disc-shaped primary raw materials;

[0010] Drying and calcining: The raw material is dried and calcined to obtain granular filter rod additives or disc filter rod additives.

[0011] Optionally, the raw material is selected from at least one of porous silica, kaolin, porous molecular sieve, calcium silicate, calcium sulfate, sodium silicate, nickel oxide, iron oxide, vermiculite, and montmorillonite;

[0012] The pore-forming agent is selected from at least one of water-soluble starch, graphite, polymethyl methacrylate, sodium chloride, sodium carbonate, urea, and ammonium bicarbonate;

[0013] The phase inversion solution is composed of 70-85 parts by mass of N-methylpyrrolidone, 10-25 parts by mass of polyvinyl butyral and 1-10 parts by mass of polyvinylpyrrolidone.

[0014] Alternatively, the droplet process is as follows:

[0015] The phase inversion slurry is dripped into a coagulation bath at 25℃-35℃ at a rate of 50-200 drops / minute using a pelletizing machine and solidified for 1-4 hours to obtain granular raw material. The coagulation bath consists of 90-100 parts by weight of water and 0-10 parts by weight of ethanol. The stirring speed of the coagulation bath is 200-500 rpm, and the diameter of the pellets is 1-5 mm.

[0016] Optionally, the casting process is as follows:

[0017] The height of the casting squeegee is 2-5mm, the squeegee speed is 25-50mm / min, and it is cured in a coagulation bath at 25℃-35℃ for 1-4h to obtain a disc-shaped virgin blank with a thickness of 1-3mm.

[0018] Optionally, the drying temperature is 60-120℃ and the time is 30-60 minutes.

[0019] Optionally, the calcination process adopts a segmented heating mode, with the heating rate controlled at 1-5℃ / min; the first calcination temperature is 120℃-300℃, and the calcination time is 1-2h; the second calcination temperature is 300℃-800℃, and the calcination time is 1-3h.

[0020] According to a second aspect of the invention, a filter rod additive is provided.

[0021] The filter rod additive is prepared by the filter rod additive preparation method described in this invention, and the filter rod additive is a granular filter rod additive or a disc-shaped filter rod additive.

[0022] Optionally, when the filter rod additive is a granular filter rod additive, the particle size is 2-5 mm, the granular filter rod additive has a straight pore structure, the surface pore size of the straight pore structure is 10 μm-100 μm, the internal pore size is 50 μm-500 μm, and the porosity of the granular filter rod additive is 30%-60%.

[0023] Optionally, when the filter rod additive is a disc-shaped filter rod additive, the outer diameter is 5-7 mm, the thickness is 1-3 mm, the disc-shaped filter rod additive has a columnar pore structure, the pore diameter of the columnar pore structure is 50 μm-200 μm, the pore length is 0.5-3 mm, and the porosity of the disc-shaped filter rod additive is 50%-80%.

[0024] According to a third aspect of the invention, an application of a filter rod additive is provided.

[0025] The application of this filter rod additive includes immersing granular or disc-shaped filter rod additives in a flavor solution using a vacuum impregnation method to obtain a flavor-loaded filter rod additive, and then adding the flavor-loaded filter rod additive into the cavity of a cavity filter rod.

[0026] This invention employs a phase transformation process, which allows for precise control of the pore structure without the need for complex equipment, resulting in good molding consistency and a high yield.

[0027] This invention forms a through-hole structure through in-situ self-assembly, which has excellent connectivity. The pore size is distributed from the surface to the inside, which can not only ensure the smooth penetration of smoke and realize the airflow to sweep and release aroma, but also make the aroma substances evenly loaded and stably sealed. The aroma release is stable and uniform throughout the entire smoking process, and the aroma quality and smoking experience are significantly improved. Detailed Implementation

[0028] Various exemplary embodiments of the present invention will now be described in detail. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0029] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0030] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0031] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0032] The method for preparing filter rod additives provided by the present invention includes the following steps:

[0033] Preparation of slurry: Mix 35-55 parts by weight of raw materials, 0-10 parts by weight of pore-forming agent and 40-65 parts by weight of phase inversion solution until homogeneous and stable, and then degas under vacuum to obtain phase inversion slurry.

[0034] The raw materials can be selected from at least one of porous silica, kaolin, porous molecular sieve, calcium silicate, calcium sulfate, sodium silicate, nickel oxide, iron oxide, vermiculite, and montmorillonite.

[0035] The pore-forming agent can be selected from at least one of water-soluble starch, graphite, polymethyl methacrylate, sodium chloride, sodium carbonate, urea, and ammonium bicarbonate.

[0036] The phase inversion solution is composed of 70-85 parts by mass of N-methylpyrrolidone, 10-25 parts by mass of polyvinyl butyral and 1-10 parts by mass of polyvinylpyrrolidone.

[0037] Directional molding: The phase inversion slurry is molded using a drop shot process or a casting process to obtain granular or disc-shaped primary raw materials.

[0038] The droplet process can be specifically described as follows:

[0039] The phase inversion slurry is dripped into a coagulation bath at 25℃-35℃ at a rate of 50-200 drops / minute using a pelletizing machine and solidified for 1-4 hours to obtain granular raw material. The coagulation bath consists of 90-100 parts by weight of water and 0-10 parts by weight of ethanol. The stirring speed of the coagulation bath is 200-500 rpm, and the diameter of the pellets is 1-5 mm.

[0040] Allowing the pellets to solidify in a coagulation bath facilitates the completion of solvent-induced phase separation through bidirectional diffusion.

[0041] The specific casting process is as follows:

[0042] The height of the casting squeegee is 2-5mm, the squeegee speed is 25-50mm / min, and it is cured in a coagulation bath at 25℃-35℃ for 1-4h to obtain a disc-shaped virgin blank with a thickness of 1-3mm.

[0043] Drying and calcining: The raw material is dried and calcined to obtain granular filter rod additives or disc filter rod additives.

[0044] For the raw material prepared by the casting process, it can also be cut before drying and calcination to obtain the raw material of the target shape.

[0045] The drying temperature is 60-120℃, and the time is 30-60 minutes.

[0046] The roasting process can adopt a segmented heating mode, with the heating rate controlled at 1-5℃ / min; the first roasting temperature is 120℃-300℃, and the roasting time is 1-2h; the second roasting temperature is 300℃-800℃, and the roasting time is 1-3h.

[0047] In addition, a third roasting section can be added, with the temperature of the third roasting up to 1000℃ and the roasting time being 1-2 hours.

[0048] The filter rod additive provided by this invention is a granular filter rod additive or a disc-shaped filter rod additive.

[0049] When the filter rod additive is a granular filter rod additive, the particle size is 2-5 mm. The granular filter rod additive has a straight pore structure with a surface pore size of 10 μm-100 μm and an internal pore size of 50 μm-500 μm. The porosity of the granular filter rod additive is 30%-60%.

[0050] When the filter rod additive is a disc-shaped filter rod additive, the outer diameter is 5-7 mm, the thickness is 1-3 mm, the disc-shaped filter rod additive has a columnar pore structure, the pore diameter of the columnar pore structure is 50 μm-200 μm, the pore length is 0.5-3 mm, and the porosity of the disc-shaped filter rod additive is 50%-80%.

[0051] The application of the filter rod additive of the present invention is as follows: the granular filter rod additive or the disc-shaped filter rod additive is immersed in the flavor solution by vacuum impregnation to obtain the flavor-loaded filter rod additive, and then the flavor-loaded filter rod additive is added to the cavity of the cavity filter rod.

[0052] In practice, the vacuum level can be controlled between -0.05MPa and -0.1MPa, the immersion time is 10min-90min, and after immersion, the surface is air-dried for 5-10min to remove free fragrance substances.

[0053] In addition, the number of immersions can be increased (e.g., 2-3 times) to increase the loading of flavor compounds.

[0054] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, and the materials and reagents used are commercially available. Unless otherwise specified, the equipment used in the experiments is well known to those skilled in the art.

[0055] Example 1

[0056] 1. Weigh 85g of N-methylpyrrolidone, 5g of polyvinylpyrrolidone, and 10g of polyvinyl butyral. Add the three raw materials sequentially to a sealed stirring container and stir magnetically for 24 hours at room temperature to ensure complete dissolution of the polymer additives, full miscibility of the solvent system, elimination of local solute agglomeration and stratification, and finally obtain a clear, homogeneous, and stable phase inversion solution for later use.

[0057] 100g of porous silica powder and 100g of phase inversion solution were mixed in equal amounts. The mixture was then subjected to wet ball milling for 24 hours to achieve ultrafine dispersion and uniform wetting of the powder particles, completely avoiding powder agglomeration and sedimentation. After ball milling, the slurry was transferred to a vacuum degassing device and degassed at room temperature for 1 hour to completely remove the micro-bubbles trapped inside the slurry. This ensured that the subsequent pellet forming particles had smooth surfaces and regular, defect-free internal pores, resulting in a uniform and stable phase inversion slurry.

[0058] 2. The phase inversion slurry is dropped into a 30℃ pure water coagulation bath with a droplet diameter of 3mm. After standing and solidifying for 2 hours, the phase separation reaction is induced by the bidirectional diffusion of solvent and water, which drives the material to spontaneously complete the in-situ ordered assembly and gradually form a through-hole skeleton structure with a gradual change in pore size from the surface to the inside.

[0059] 3. After the green embryo particles have solidified, remove them and drain off any free surface moisture. Place them in a constant temperature drying device, set the drying temperature to 80℃, and dry at that temperature for 2 hours to thoroughly remove any residual coagulation bath moisture and trace amounts of solvent from the particle surface and shallow pores, preventing particle cracking and pore collapse defects during high-temperature calcination. After drying, transfer them to a programmed temperature calcination device, setting the heating rate to a constant 3℃ / min. A segmented gradient calcination regime is adopted: the first stage heats up to 250℃ and holds at that temperature for 2 hours to thoroughly remove any residual organic solvents and polymeric additive impurities inside the particles; the second stage continues to heat up to 550℃ and holds at that temperature for 2 hours to complete the solidification of the particle skeleton crystal form and the shaping of the pores, significantly improving the bonding strength and structural stability of the particle skeleton, ultimately obtaining a self-assembled gradient straight-pore porous particle matrix with regular pores, excellent connectivity, and a stable structure.

[0060] 4. Take 50g of menthol flavoring as the main flavor component and completely dissolve it in a mixed solvent of 50g anhydrous ethanol and 50g pure water. Stir thoroughly until completely dissolved to obtain a uniformly dispersed and stable menthol impregnation solution. Completely immerse the prepared porous particle matrix in the menthol solution and transfer it to a vacuum impregnation device. Control the system vacuum degree to be stable at -0.05MPa and impregnate under negative pressure for 10 minutes. The negative pressure environment thoroughly removes air from the pores inside the particles, allowing the menthol flavor substances to fully penetrate and uniformly adsorb onto the inner walls of the gradient straight pores and the interior of the fine, disordered pores. After a single impregnation, remove the particles and continuously air dry them at room temperature for 10 minutes to completely remove the free menthol and surface solvent adhering to the particle surface, retaining only the flavor substances stably loaded inside the pores.

[0061] Repeat the above vacuum impregnation and cold air drying process multiple times until the menthol loading reaches 15%, and finally prepare menthol-flavored self-assembled filter rod fragrance granules with uniform loading, stable structure, and controllable aroma release.

[0062] Comparative Example 1

[0063] Using the same menthol flavoring as in Example 1, a menthol spray solution of the same concentration was prepared. The same blank filter rod substrate was selected, and a menthol-flavored filter rod was prepared using a traditional uniform surface spraying process. This ensured that the theoretical amount of flavoring sprayed per unit filter rod was consistent with the total amount of flavoring carried by particles in Example 1, resulting in a traditional spray-type menthol-flavored filter rod, which served as a parallel control sample. Corresponding cigarette samples were also prepared.

[0064] Sensory evaluation: As shown in Table 1, traditional spray-type filter cigarettes, due to the exposed and unprotected flavoring, suffer significant loss of mint aroma after high-temperature storage. During smoking, the aroma is weak and lacks depth, with a large difference in aroma between the beginning and end, and a slight off-flavor. The self-assembled granular cigarette of Example 1, relying on a gradient-through straight-pore structure, allows for the uniform release of mint aroma with the smoke flow. Throughout the smoking process, the mint aroma is fresh, pure, and stable, with consistent aroma throughout, without any aroma gaps, pungent odors, or blandness. The smoke is delicate and smooth, exhibiting excellent sensory quality and extremely high stability.

[0065] Table 1 Sensory Evaluation Comparison

[0066]

[0067] Example 2

[0068] 1. Weigh 80g of N-methylpyrrolidone, 10g of polyvinylpyrrolidone and 10g of polyvinyl butyral according to the proportion and mix them. Stir continuously at room temperature for 24 hours to obtain a clear, homogeneous and stable phase inversion solution.

[0069] 70g of calcium silicate powder, 5g of sodium chloride, and 100g of phase inversion solution were mixed and continuously ball-milled for 12 hours to achieve dispersion of the two powders and uniform mixing with the slurry. Then, the mixture was defoamed under vacuum at room temperature for 1 hour at a pressure of -0.05 MPa to remove air bubbles from the slurry, resulting in a uniform and stable phase inversion slurry.

[0070] 2. Drop the phase inversion slurry into a 30°C coagulation bath consisting of 95 parts water and 5 parts alcohol. The droplet diameter is 3 mm. Stir the coagulation bath with a magnetic stirrer at 500 rpm until the droplet is finished, and then let it stand for 2 hours.

[0071] 3. After the solidification is complete, the green pellets are removed, and any residual coagulation bath liquid is drained from the surface. They are then placed in a constant temperature drying device, with the drying temperature set at 100℃ and the drying time at 2 hours. Afterward, they are placed in a muffle furnace for high-temperature calcination, with a constant heating rate of 2℃ / min. The sintering regime is as follows: first calcination temperature 150℃, sintering for 2 hours; second calcination temperature 350℃, sintering for 2 hours; third calcination temperature 1000℃, sintering for 2 hours, finally yielding a porous filter rod additive with columnar pores and micropores.

[0072] The porous filter rod additive obtained in Example 2 was applied to the cavity particulate filter rod at a dosage of 4 rods per rod. The same type of cavity filter rod was used as a control group. Cigarettes were prepared for the detection of draw resistance and tar content. The results are shown in Table 2, indicating that Example 2 has a good filtration effect on smoke.

[0073] Example 3

[0074] 1. Weigh 85g of N-methylpyrrolidone, 2.5g of polyvinylpyrrolidone and 12.5g of polyvinyl butyral according to the proportion and mix them. Stir continuously at room temperature for 24h to obtain a clear, homogeneous and stable phase inversion solution.

[0075] 50g of nickel oxide and 50g of iron oxide powder, 5g of ammonium bicarbonate and 100g of phase inversion solution were mixed and continuously ball-milled for 12 hours to achieve dispersion of the two powders and uniform mixing with the slurry. Then, the mixture was defoamed under vacuum at room temperature for 1 hour at a vacuum pressure of -0.1MPa to remove air bubbles from the slurry and obtain a uniform and stable phase inversion slurry.

[0076] 2. Set the casting squeegee height to 2mm and the squeegee movement speed to 30mm / min. Spread the phase inversion slurry evenly on the PET film tape and transfer the film tape to the coagulation bath (a 30℃ coagulation bath consisting of 100 parts water and 1 part alcohol) and let it stand for 4 hours.

[0077] 3. Drying and roasting

[0078] The solidified elongated green preform was removed from the coagulation bath, and residual coagulation bath liquid was drained from the surface. It was then cut into 5.5mm diameter discs using a punch and placed in a constant-temperature drying device at 120℃ for 2 hours. Afterward, it was placed in a muffle furnace for high-temperature calcination, with a constant heating rate of 1℃ / min. The sintering regime was as follows: first calcination temperature 200℃, sintering for 2 hours; second calcination temperature 400℃, sintering for 2 hours; third calcination temperature 900℃, sintering for 2 hours, ultimately yielding a disc-shaped porous filter rod additive with columnar pores and micropores.

[0079] The porous filter rod additive obtained in Example 3 was placed in the cavity granular filter rod, with an addition amount of 1 piece / stick. The cavity filter rod of the same specification was used as a control group. Cigarettes were prepared for the detection of draw resistance and tar content. The results are shown in Table 2, indicating that Example 3 has a good filtration effect on smoke.

[0080] Table 2. Draw resistance and tar content of different cigarettes

[0081]

[0082] While specific embodiments of the invention have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A method of making a filter rod additive, characterized by, Includes the following steps: Preparation of slurry: Mix 35-55 parts by weight of raw material, 0-10 parts by weight of pore-forming agent and 40-65 parts by weight of phase inversion solution until homogeneous and stable, and then degas under vacuum to obtain phase inversion slurry; Directional molding: The phase inversion slurry is molded using a drop shot process or a casting process to obtain granular or disc-shaped primary raw materials; Drying and calcining: The raw material is dried and calcined to obtain granular filter rod additives or disc filter rod additives.

2. The method for preparing the filter rod additive according to claim 1, characterized in that, The raw materials are selected from at least one of porous silica, kaolin, porous molecular sieve, calcium silicate, calcium sulfate, sodium silicate, nickel oxide, iron oxide, vermiculite, and montmorillonite; The pore-forming agent is selected from at least one of water-soluble starch, graphite, polymethyl methacrylate, sodium chloride, sodium carbonate, urea, and ammonium bicarbonate; The phase inversion solution is composed of 70-85 parts by mass of N-methylpyrrolidone, 10-25 parts by mass of polyvinyl butyral and 1-10 parts by mass of polyvinylpyrrolidone.

3. The method for preparing the filter rod additive according to claim 1, characterized in that, The specific process for producing droplets is as follows: The phase inversion slurry is dripped into a coagulation bath at 25℃-35℃ at a rate of 50-200 drops / minute using a pelletizing machine and solidified for 1-4 hours to obtain granular raw material. The coagulation bath consists of 90-100 parts by weight of water and 0-10 parts by weight of ethanol. The stirring speed of the coagulation bath is 200-500 rpm, and the diameter of the pellets is 1-5 mm.

4. The method for preparing the filter rod additive according to claim 1, characterized in that, The specific casting process is as follows: The height of the casting squeegee is 2-5mm, the squeegee speed is 25-50mm / min, and it is cured in a coagulation bath at 25℃-35℃ for 1-4h to obtain a disc-shaped virgin blank with a thickness of 1-3mm.

5. The method for preparing the filter rod additive according to claim 1, characterized in that, The drying temperature is 60-120℃, and the time is 30-60 minutes.

6. The method for preparing the filter rod additive according to claim 1, characterized in that, The roasting process adopts a segmented heating mode, with the heating rate controlled at 1-5℃ / min; the first roasting temperature is 120℃-300℃, and the roasting time is 1-2h; the second roasting temperature is 300℃-800℃, and the roasting time is 1-3h.

7. A filter rod additive, characterized in that, The filter rod additive is prepared by the method of any one of claims 1 to 6, wherein the filter rod additive is a granular filter rod additive or a disc-shaped filter rod additive.

8. The filter rod additive according to claim 7, characterized in that, When the filter rod additive is a granular filter rod additive, the particle size is 2-5 mm, the granular filter rod additive has a straight pore structure, the surface pore size of the straight pore structure is 10 μm-100 μm, the internal pore size is 50 μm-500 μm, and the porosity of the granular filter rod additive is 30%-60%.

9. The filter rod additive according to claim 7, characterized in that, When the filter rod additive is a disc-shaped filter rod additive, the outer diameter is 5-7 mm, the thickness is 1-3 mm, the disc-shaped filter rod additive has a columnar pore structure, the pore diameter of the columnar pore structure is 50 μm-200 μm, the pore length is 0.5-3 mm, and the porosity of the disc-shaped filter rod additive is 50%-80%.

10. The application of a filter rod additive according to any one of claims 7 to 9, characterized in that, The granular or disc-shaped filter rod additive is immersed in a flavor solution using a vacuum impregnation method to obtain a flavor-loaded filter rod additive, which is then added to the cavity of a hollow filter rod.

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