Paper composite filter material for reducing hydrocyanic acid and crotonaldehyde as well as preparation method and application of paper composite filter material

Abstract

The invention discloses a paper composite filter material for reducing hydrocyanic acid and crotonaldehyde and a preparation method and application thereof, and the preparation method comprises the following steps: adding a gelator into a solvent to form a gelator solution; transferring the gelator solution into a liquid storage tank of an intaglio printing device, and printing and coating the gelator solution in the liquid storage tank onto a paper base material by using an anilox roller; the coated paper base material is conveyed to a low-temperature tunnel, so that nanofibers of a three-dimensional network structure are formed inside and on the surface of the paper base material in a self-assembly mode; and transferring the paper base material subjected to low-temperature treatment to a drying cylinder, and drying to obtain the paper composite filter material. According to the prepared paper composite filter material, the specific surface area in contact with smoke can be increased, the paper composite filter material can make full contact with the smoke in the process that the smoke passes through a filter stick, the interception capacity of the paper filter stick on hydrocyanic acid and crotonaldehyde in mainstream smoke of cigarettes is improved through amino and carboxyl groups on the surfaces of the nanofibers, and the sensory quality of the cigarettes with the paper filter stick is improved.

Description

Technical Field

[0001] The present invention relates to the field of cigarette filter rods, and more particularly to a reduced hydrocyanic acid and crotonaldehyde paper composite filter material, and a preparation method and application thereof. Background Art

[0002] In recent years, as consumers have become more aware of the relationship between smoking and health, cigarette manufacturers have been developing new low-tar cigarette products. Compared to acetate filter rods, paper filter rods offer higher tar and nicotine retention efficiencies at the same pressure drop. Furthermore, paper filter media, primarily composed of plant fibers, offers advantages such as low raw material costs and high biodegradability.

[0003] Research has found that paper filter materials have a lower ability to retain components such as hydrocyanic acid and crotonaldehyde in mainstream cigarette smoke than acetate filter rods. Therefore, cigarettes equipped with paper filter rods have sensory quality problems such as spicy smoke and severe choking.

[0004] Therefore, how to improve the sensory quality of paper filter rods is of great significance for the development of low-tar cigarettes and the work of reducing tar and harm of cigarettes. Summary of the Invention

[0005] One object of the present invention is to provide a new technical solution that can effectively improve the retention capacity of a paper filter rod for hydrocyanic acid and crotonaldehyde and improve the sensory quality of the paper filter rod.

[0006] According to a first aspect of the present invention, a method for preparing a hydrocyanic acid-crotonaldehyde paper composite filter material is provided.

[0007] The preparation method of the hydrocyanic acid-crotonaldehyde paper composite filter material comprises the following steps:

[0008] Step (1): adding gelling factor A and gelling factor B to a solvent, heating and stirring at 60-100° C. until completely dissolved, to form a gelling factor solution with a concentration of 0.05 wt % to 0.5 wt %, wherein gelling factor A and gelling factor B are selected from amino acids, small molecule amines, cholesteric acid and anionic polysaccharides;

[0009] Step (2): Transfer the gel factor solution to a liquid reservoir of a gravure printing device, maintain the temperature of the liquid reservoir at 60-100°C, and use an anilox roller with a temperature of 60-100°C, a groove depth of 20-50 μm, and a line count of 100-300 lines / inch to print and coat the gel factor solution in the liquid reservoir onto a paper substrate;

[0010] Step (3): transporting the coated paper substrate to a low-temperature tunnel at a transfer speed of 0.5-1 m / s and allowing it to remain in a 0-10°C environment for 60-600 seconds to self-assemble into nanofibers with a three-dimensional network structure inside and on the surface of the paper substrate, wherein the nanofiber diameter is 10-100 nm;

[0011] Step (4): Transfer the low-temperature treated paper substrate to a drying cylinder and dry it at 70-90°C for 10-60 seconds to obtain a paper composite filter material with a coating amount of 0.05-1 g / m².

[0012] Optionally, the gelling factor A in step (1) is selected from one or more of lysine, arginine, and histidine, and the gelling factor B is selected from one or more of gellan gum, sodium alginate, hyaluronic acid, xanthan gum, carrageenan, and gum arabic, and the mass ratio of gelling factor A to gelling factor B is (5-20):1.

[0013] Optionally, the gelling factor A in step (1) is selected from one or more of glycine, alanine, valine, leucine, and isoleucine, and the gelling factor B is selected from one or more of sodium cholate, sodium deoxycholate, and sodium lithocholic acid, and the molar ratio of the gelling factor A to the gelling factor B is (1-3):1.

[0014] Optionally, the gelling factor A in step (1) is selected from one or more of 1,3-propylenediamine, 3,3'-iminobispropylamine, 3,3'-methyliminobispropylamine, and triethylenetetramine, and the gelling factor B is selected from one or more of cholic acid, deoxycholic acid, and lithocholic acid, and the molar ratio of gelling factor A to gelling factor B is 7.5:1.

[0015] Optionally, the solvent in step (1) is secondary water or 0.05 M KCl aqueous solution.

[0016] Optionally, the anilox roller in step (2) has a pyramid-shaped groove structure, an opening rate of 25% to 40%, and a solution transfer efficiency of ≥85%.

[0017] Optionally, a gradient cooling zone is provided in the low-temperature tunnel in step (3), and the gradient cooling zone is specifically as follows:

[0018] First temperature zone: 5~10℃, residence time is 60-300 seconds;

[0019] The second temperature zone: 0~5℃, residence time is 60-300 seconds.

[0020] Optionally, in step (4), the surface roughness of the drying cylinder Ra≤0.8 μm, and the hot air circulation speed is 2~5 m / s.

[0021] According to a second aspect of the present invention, there is provided a hydrocyanic acid-crotonaldehyde paper composite filter material, which is prepared by the preparation method of the present invention.

[0022] According to the third aspect of the present invention, there is provided an application of the hydrocyanic acid-reducing and crotonaldehyde paper composite filter material of the present invention, which is used for a cigarette filter rod, wherein the cigarette filter rod comprises a fiber acetate segment and a paper segment, the filter material in the paper segment is the hydrocyanic acid-reducing and crotonaldehyde paper composite filter material, and the paper segment is located near the tobacco end of the cigarette filter rod.

[0023] Beneficial effects of the present invention:

[0024] 1. Innovation in Molecular Synergy: Through the synergistic action of two-component gelling factors, nanofibers (10-100 nm in diameter) with a three-dimensional interpenetrating network structure are formed during the low-temperature assembly process. The nanofiber surface is rich in amino and carboxyl groups, significantly enhancing the paper filter material's ability to retain hydrocyanic acid and crotonaldehyde.

[0025] 2. Process breakthrough: Through gravure printing combined with a gradient cooling process, nanofibers can be grown in situ within the pores of the filter material. The coating speed can reach 30-60 m / min, and the solvent residue is ≤0.5 ppm. Compared with the traditional impregnation method, energy consumption is reduced by 40%, and production efficiency is increased by 3 times.

[0026] 3. Cost and environmental advantages: The material coating amount is low (0.05~1g / m²), and the coating liquid can be an aqueous solution or a KCl aqueous solution, which reduces the burden of wastewater treatment during the production process.

[0027] 4. Optimization of the sensory quality of cigarettes: The paper composite filter material prepared by the present invention has a micro-nano composite structure, which can increase the specific surface area in contact with the smoke. During the process of the smoke passing through the filter rod, it can fully contact with the smoke. The amino and carboxyl groups on the surface of the nanofibers are used to improve the paper filter rod's ability to intercept hydrocyanic acid and crotonaldehyde in the mainstream cigarette smoke, thereby improving the sensory quality of the paper filter rod cigarettes. DETAILED DESCRIPTION

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

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

[0030] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

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

[0032] The present invention provides a method for preparing a hydrocyanic acid-crotonaldehyde paper composite filter material, comprising the following steps:

[0033] Step (1): adding gelling factor A and gelling factor B to a solvent, heating and stirring at 60-100° C. until completely dissolved, to form a gelling factor solution with a concentration of 0.05 wt % to 0.5 wt %, wherein gelling factor A and gelling factor B are selected from amino acids, small molecule amines, cholesteric acid and anionic polysaccharides.

[0034] The gelling factor A in step (1) can be selected from one or more of lysine, arginine, and histidine, and the gelling factor B can be selected from one or more of gellan gum, sodium alginate, hyaluronic acid, xanthan gum, carrageenan, and gum arabic, and the mass ratio of gelling factor A to gelling factor B is (5-20):1.

[0035] The gelling factor A in step (1) can be selected from one or more of glycine, alanine, valine, leucine, and isoleucine, and the gelling factor B can be selected from one or more of sodium cholate, sodium deoxycholate, and sodium lithocholic acid, and the molar ratio of the gelling factor A to the gelling factor B is (1-3):1.

[0036] The gelling factor A in step (1) can be selected from one or more of 1,3-propylenediamine, 3,3'-iminobispropylamine, 3,3'-methyliminobispropylamine, and triethylenetetramine, and the gelling factor B can be selected from one or more of cholic acid, deoxycholic acid, and lithocholic acid, and the molar ratio of the gelling factor A to the gelling factor B is 7.5:1.

[0037] The solvent in step (1) can be secondary water or a 0.05 M KCl aqueous solution.

[0038] Step (2): Transfer the gel factor solution to the liquid reservoir of the gravure printing device, maintain the temperature of the liquid reservoir at 60-100°C, use an anilox roller with a temperature of 60-100°C, a groove depth of 20-50 μm, and a line number of 100-300 lines / inch, and print and coat the gel factor solution in the liquid reservoir onto the paper substrate.

[0039] Maintaining the temperature of the reservoir at 60-100°C can prevent the gel factor solution from gelling.

[0040] The anilox roller in step (2) may have a pyramid-shaped groove structure, an opening rate of 25% to 40%, and a solution transfer efficiency of ≥85%.

[0041] Step (3): The coated paper substrate is transported to a low-temperature tunnel at a transfer speed of 0.5-1 m / s and remains in a 0-10°C environment for 60-600 seconds to self-assemble into nanofibers with a three-dimensional network structure inside and on the surface of the paper substrate, wherein the nanofiber diameter is 10-100 nm.

[0042] During the cooling process, electrostatic interactions, hydrogen bonding interactions, π-π stacking interactions, and hydrophilic and hydrophobic interactions drive the gel factors to self-assemble inside and on the surface of the paper filter material to form nanofibers with a three-dimensional network structure.

[0043] The low-temperature tunnel in step (3) is provided with a gradient cooling zone, and the gradient cooling zone is specifically as follows:

[0044] The first temperature zone: 5~10℃, residence time is 60-300 seconds.

[0045] The second temperature zone: 0~5℃, residence time is 60-300 seconds.

[0046] Step (4): Transfer the low-temperature treated paper substrate to a drying cylinder and dry it at 70-90°C for 10-60 seconds to obtain a paper composite filter material with a coating amount of 0.05-1 g / m².

[0047] Drying removes the solvent.

[0048] In step (4), the surface roughness of the drying cylinder Ra≤0.8 μm, and the hot air circulation speed is 2~5 m / s.

[0049] The present invention also provides an application of a hydrocyanic acid-reducing and crotonaldehyde paper composite filter material, which is used for a cigarette filter rod. The cigarette filter rod includes a cellulose acetate segment and a paper segment. The filter material in the paper segment is a hydrocyanic acid-reducing and crotonaldehyde paper composite filter material, and the paper segment is located near the tobacco end of the cigarette filter rod.

[0050] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods. The materials and reagents used are all commercially available unless otherwise specified. The equipment used in the experiments are all well known to those skilled in the art unless otherwise specified.

[0051] Example 1

[0052] (1) Solution preparation: Lysine and gum arabic were added to water and heated at 85°C with stirring until completely dissolved to form a 0.17 wt% gelling factor solution with a mass ratio of lysine to gum arabic of 17:1.

[0053] (2) Solution insulation: Transfer the gel factor solution to a sealed storage tank with insulation function and maintain the solution temperature at 80°C to prevent gelation;

[0054] (3) Gravure printing coating: The gel factor solution in the liquid reservoir is transferred to the surface of the paper substrate using an anilox roller. The anilox roller temperature is 80°C, the anilox roller line count is 300 lines / inch, and the groove depth is 20 μm.

[0055] (4) Low-temperature self-assembly: The coated paper substrate was transported to a low-temperature tunnel at a transfer speed of 0.5 m / s, stayed in the first temperature zone (10°C) for 300 seconds, and stayed in the second temperature zone (3°C) for 240 seconds. During the cooling process, lysine and gum arabic assembled inside and on the surface of the paper substrate to form nanofibers with a three-dimensional network structure. The diameter of the nanofibers was 20 nm.

[0056] (5) High-temperature drying: The low-temperature treated paper substrate is transferred to a drying cylinder for drying (drying cylinder surface roughness Ra = 0.8 μm, hot air circulation speed is 5 m / s), and dried at 90°C for 60 seconds to obtain a paper composite filter material with a coating amount of 0.11 g / m².

[0057] (6) Preparation of paper composite filter rods: The paper composite filter material was cut into 90 mm filter materials, and after embossing and bundling, a paper filter rod with a length of 120 mm and a pressure drop of 4200 Pa was obtained. A 120 mm long acetate filter rod with a pressure drop of 4200 Pa was prepared using a 7.5Y / 16000 tow. The above two filter rods were combined to obtain a composite filter rod S1. The filter rod structure of the composite filter rod was 15 mm acetate segment (near the lip segment) + 15 mm paper segment (near the tobacco end). The pressure drop design value of the composite filter rod S1 was 4600 Pa.

[0058] Example 2

[0059] (1) Solution preparation: Add arginine and carrageenan to water, heat and stir at 90°C until completely dissolved to form a 0.29 wt% gelling factor solution with a mass ratio of arginine to carrageenan of 20:1;

[0060] (2) Solution insulation: Transfer the gel factor solution to a sealed storage tank with insulation function and maintain the solution temperature at 80°C to prevent gelation;

[0061] (3) Gravure printing coating: The gel factor solution in the liquid reservoir is transferred to the surface of the paper substrate using an anilox roller. The anilox roller temperature is 80°C, the anilox roller line count is 300 lines / inch, and the groove depth is 40 μm.

[0062] (4) Low-temperature self-assembly: The coated paper substrate was transported to a low-temperature tunnel at a transfer speed of 1 m / s, stayed in the first temperature zone (10°C) for 200 seconds, and stayed in the second temperature zone (3°C) for 300 seconds. During the cooling process, arginine and carrageenan assembled inside and on the surface of the paper substrate to form nanofibers with a three-dimensional network structure. The diameter of the nanofibers was 10 nm.

[0063] (5) High-temperature drying: The low-temperature treated paper substrate is transferred to a drying cylinder for drying (drying cylinder surface roughness Ra = 0.6 μm, hot air circulation speed is 5 m / s), and dried at 90°C for 60 seconds to obtain a paper composite filter material with a coating amount of 0.26 g / m².

[0064] (6) Preparation of paper composite filter rods: The paper composite filter material was cut into 90 mm filter materials, and after embossing and bundling, a paper filter rod with a length of 120 mm and a pressure drop of 4200 Pa was obtained. A 120 mm long acetate filter rod with a pressure drop of 4200 Pa was prepared using a 7.5Y / 16000 tow. The above two filter rods were combined to obtain a composite filter rod S2. The filter rod structure of the composite filter rod was 15 mm acetate segment (near the lip segment) + 15 mm paper segment (near the tobacco end). The pressure drop design value of the composite filter rod S2 was 4600 Pa.

[0065] Example 3

[0066] (1) Solution preparation: Add glycine and sodium deoxycholate to a 0.05 M KCl solution, heat and stir at 80°C until completely dissolved to form a 0.42 wt% gel factor solution with a molar ratio of glycine to sodium deoxycholate of 1:1;

[0067] (2) Solution insulation: Transfer the gel factor solution to a sealed storage tank with insulation function and maintain the solution temperature at 80°C to prevent gelation;

[0068] (3) Gravure printing coating: The gel factor solution in the liquid reservoir is transferred to the surface of the paper substrate using an anilox roller. The anilox roller temperature is 80°C, the anilox roller line count is 300 lines / inch, and the groove depth is 40 μm.

[0069] (4) Low-temperature self-assembly: The coated paper substrate was transported to a low-temperature tunnel at a transfer speed of 1 m / s, stayed in the first temperature zone (10°C) for 300 seconds, and stayed in the second temperature zone (3°C) for 150 seconds. During the cooling process, glycine and sodium deoxycholate assembled inside and on the surface of the paper substrate to form nanofibers with a three-dimensional network structure. The diameter of the nanofibers was 70 nm.

[0070] (5) High-temperature drying: The low-temperature treated paper substrate is transferred to a drying cylinder for drying (drying cylinder surface roughness Ra = 0.8 μm, hot air circulation speed is 5 m / s), and dried at 90 ° C for 60 seconds to obtain a paper composite filter material with a coating amount of 0.58 g / m².

[0071] (6) Preparation of paper composite filter rods: The paper composite filter material was cut into 90 mm filter materials, and after embossing and bundling, a paper filter rod with a length of 120 mm and a pressure drop of 4200 Pa was obtained. A 120 mm long acetate filter rod with a pressure drop of 4200 Pa was prepared using 7.5Y / 16000 tow. The above two filter rods were combined to obtain a composite filter rod S3. The filter rod structure of the composite filter rod was 15 mm acetate segment (near the lip segment) + 15 mm paper segment (near the tobacco end). The pressure drop design value of the composite filter rod S3 was 4600 Pa.

[0072] Example 4

[0073] (1) Solution preparation: Add valine and sodium lithocholate to a 0.05 M KCl solution, heat and stir at 80°C until completely dissolved to form a 0.35 wt% gel factor solution with a molar ratio of glycine to sodium lithocholate of 2:1.

[0074] (2) Solution insulation: Transfer the gel factor solution to a sealed storage tank with insulation function and maintain the solution temperature at 80°C to prevent gelation;

[0075] (3) Gravure printing coating: The gel factor solution in the liquid reservoir is transferred to the surface of the paper substrate using an anilox roller. The anilox roller temperature is 80°C, the anilox roller line count is 200 lines / inch, and the groove depth is 50 μm.

[0076] (4) Low-temperature self-assembly: The coated paper substrate was transported to a low-temperature tunnel at a transfer speed of 1 m / s, stayed in the first temperature zone (10°C) for 100 seconds, and stayed in the second temperature zone (3°C) for 300 seconds. During the cooling process, valine and sodium lithocholic acid assembled inside and on the surface of the paper substrate to form nanofibers with a three-dimensional network structure. The diameter of the nanofibers was 80 nm.

[0077] (5) High-temperature drying: The low-temperature treated paper substrate was transferred to a drying cylinder for drying (drying cylinder surface roughness Ra = 0.8 μm, hot air circulation speed was 5 m / s), and dried at 90°C for 30 seconds to obtain a paper composite filter material with a coating amount of 0.41 g / m².

[0078] (6) Preparation of paper composite filter rods: The paper composite filter material was cut into 90 mm filter materials, and after embossing and bundling, a paper filter rod with a length of 120 mm and a pressure drop of 4200 Pa was obtained. A 120 mm long acetate filter rod with a pressure drop of 4200 Pa was prepared using a 7.5Y / 16000 tow. The above two filter rods were combined to obtain a composite filter rod S4. The filter rod structure of the composite filter rod was 15 mm acetate segment (near the lip segment) + 15 mm paper segment (near the tobacco end). The pressure drop design value of the composite filter rod S4 was 4600 Pa.

[0079] Example 5

[0080] (1) Solution preparation: Add 1,3-propylenediamine and cholic acid to water, heat and stir at 70°C until completely dissolved to form a 0.25 wt% gel factor solution with a molar ratio of 1,3-propylenediamine to cholic acid of 7.5:1;

[0081] (2) Solution insulation: Transfer the gel factor solution to a sealed storage tank with insulation function and maintain the solution temperature at 80°C to prevent gelation;

[0082] (3) Gravure printing coating: The gel factor solution in the liquid reservoir is transferred to the surface of the paper substrate using an anilox roller. The anilox roller temperature is 80°C, the anilox roller line count is 300 lines / inch, and the groove depth is 40 μm.

[0083] (4) Low-temperature self-assembly: The coated paper substrate was transported to a low-temperature tunnel at a transfer speed of 0.5 m / s, and stayed in the first temperature zone (10°C) for 200 seconds and in the second temperature zone (5°C) for 200 seconds. During the cooling process, 1,3-propylenediamine and bile acid assembled inside and on the surface of the paper substrate to form nanofibers with a three-dimensional network structure. The diameter of the nanofibers was 30 nm.

[0084] (5) High-temperature drying: The low-temperature treated paper substrate is transferred to a drying cylinder for drying (drying cylinder surface roughness Ra = 0.6 μm, hot air circulation speed is 3 m / s), and dried at 80°C for 60 seconds to obtain a paper composite filter material with a coating amount of 0.32 g / m².

[0085] (6) Preparation of paper composite filter rods: The paper composite filter material was cut into 90 mm filter materials, and after embossing and bundling, a paper filter rod with a length of 120 mm and a pressure drop of 4200 Pa was obtained. A 120 mm long acetate filter rod with a pressure drop of 4200 Pa was prepared using 7.5Y / 16000 tow. The above two filter rods were combined to obtain a composite filter rod S5. The filter rod structure of the composite filter rod was 15 mm acetate segment (near the lip segment) + 15 mm paper segment (near the tobacco end). The pressure drop design value of the composite filter rod S5 was 4600 Pa.

[0086] Example 6

[0087] (1) Solution preparation: triethylenetetramine and lithocholic acid were added to water, heated and stirred at 80°C until completely dissolved to form a 0.29 wt% gel factor solution, with a molar ratio of triethylenetetramine to lithocholic acid of 7.5:1;

[0088] (2) Solution insulation: Transfer the gel factor solution to a sealed storage tank with insulation function and maintain the solution temperature at 80°C to prevent gelation;

[0089] (3) Gravure printing coating: The gel factor solution in the liquid reservoir is transferred to the surface of the paper substrate using an anilox roller. The anilox roller temperature is 80°C, the anilox roller line count is 300 lines / inch, and the groove depth is 40 μm.

[0090] (4) Low-temperature self-assembly: The coated paper substrate was transported to a low-temperature tunnel at a transfer speed of 1 m / s, and stayed in the first temperature zone (10°C) for 300 seconds and in the second temperature zone (5°C) for 300 seconds. During the cooling process, triethylenetetramine and lithocholic acid assembled inside and on the surface of the paper substrate to form nanofibers with a three-dimensional network structure. The diameter of the nanofibers was 40 nm.

[0091] (5) High-temperature drying: The low-temperature treated paper substrate is transferred to a drying cylinder for drying (drying cylinder surface roughness Ra = 0.8 μm, hot air circulation speed is 3 m / s), and dried at 90°C for 60 seconds to obtain a paper composite filter material with a coating amount of 0.68 g / m².

[0092] (6) Preparation of paper composite filter rods: The paper composite filter material was cut into 90 mm filter materials, and after embossing and bundling, a paper filter rod with a length of 120 mm and a pressure drop of 4200 Pa was obtained. A 120 mm long acetate filter rod with a pressure drop of 4200 Pa was prepared using a 7.5Y / 16000 tow. The above two filter rods were combined to obtain a composite filter rod S6. The filter rod structure of the composite filter rod was 15 mm acetate segment (near the lip segment) + 15 mm paper segment (near the tobacco end). The pressure drop design value of the composite filter rod S6 was 4600 Pa.

[0093] Comparative Example 1

[0094] Uncoated paper filter rod base paper was embossed and bundled to produce a 120 mm long paper filter rod with a pressure drop of 4200 Pa. A 120 mm long acetate filter rod with a pressure drop of 4600 Pa was prepared using 7.5Y / 16000 tow. The two filter rods were combined to create a composite filter rod S0. The composite filter rod structure consisted of a 15 mm acetate segment (near the lip) and a 15 mm paper segment (near the tobacco end). The design pressure drop of composite filter rod S0 was 4600 Pa.

[0095] The prepared composite filter rods S0-S6 were used to replace the acetate filter rod of a finished cigarette to roll sample cigarettes. The obtained sample cigarettes were marked as T0-T6.

[0096] The release of hydrocyanic acid in the mainstream smoke of the sample cigarettes was determined according to the method specified in "YC / T 253-2008 Determination of Hydrogen Cyanide in Mainstream Cigarette Smoke - Continuous Flow Method", and the release of crotonaldehyde in the sample cigarettes was determined according to the method specified in "YC / T 254-2008 Determination of Major Carbonyl Compounds in Mainstream Cigarette Smoke - High Performance Liquid Chromatography Method". Nine professional sensory quality judges were randomly selected to evaluate and score the sensory quality of the sample cigarettes according to the method specified in "Cigarettes - Part 4: Sensory Technical Requirements".

[0097] The results are shown in Table 1.

[0098] Table 1 Phenol and crotonaldehyde release in mainstream cigarette smoke and sensory quality evaluation results

[0099]

[0100] As shown in Table 1, the paper composite filter material prepared by the present invention can effectively reduce the release of hydrocyanic acid and crotonaldehyde in mainstream cigarette smoke, while improving the smoking quality of cigarettes. The new technology solution of paper filter rods provided by the present disclosure has good application prospects.

[0101] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A method for preparing a hydrocyanic acid-crotonaldehyde paper composite filter material, characterized in that: The steps include: Step (1): adding gelling factor A and gelling factor B to a solvent, heating and stirring at 60-100° C. until completely dissolved, to form a gelling factor solution with a concentration of 0.05 wt % to 0.5 wt %, wherein gelling factor A and gelling factor B are selected from amino acids, small molecule amines, cholesteric acid and anionic polysaccharides; Step (2): Transfer the gel factor solution to a liquid reservoir of a gravure printing device, maintain the temperature of the liquid reservoir at 60-100°C, and use an anilox roller with a temperature of 60-100°C, a groove depth of 20-50 μm, and a line count of 100-300 lines / inch to print and coat the gel factor solution in the liquid reservoir onto a paper substrate; Step (3): transporting the coated paper substrate to a low-temperature tunnel at a transfer speed of 0.5-1 m / s and allowing it to remain in a 0-10°C environment for 60-600 seconds to self-assemble into nanofibers with a three-dimensional network structure inside and on the surface of the paper substrate, wherein the nanofiber diameter is 10-100 nm; Step (4): Transfer the low-temperature treated paper substrate to a drying cylinder and dry it at 70-90°C for 10-60 seconds to obtain a paper composite filter material with a coating amount of 0.05-1 g / m².

2. The method for preparing the hydrocyanic acid-reducing and crotonaldehyde paper composite filter material according to claim 1, wherein: The gelling factor A in step (1) is selected from one or more of lysine, arginine, and histidine, and the gelling factor B is selected from one or more of gellan gum, sodium alginate, hyaluronic acid, xanthan gum, carrageenan, and gum arabic, and the mass ratio of the gelling factor A to the gelling factor B is (5-20):

1.

3. The method for preparing the hydrocyanic acid-reducing and crotonaldehyde paper composite filter material according to claim 1, wherein: The gelling factor A in step (1) is selected from one or more of glycine, alanine, valine, leucine, and isoleucine, and the gelling factor B is selected from one or more of sodium cholate, sodium deoxycholate, and sodium lithocholic acid, and the molar ratio of the gelling factor A to the gelling factor B is (1-3):

1.

4. The method for preparing the hydrocyanic acid-reducing and crotonaldehyde paper composite filter material according to claim 1, wherein: The gelling factor A in step (1) is selected from one or more of 1,3-propylenediamine, 3,3'-iminobispropylamine, 3,3'-methyliminobispropylamine, and triethylenetetramine, and the gelling factor B is selected from one or more of cholic acid, deoxycholic acid, and lithocholic acid, and the molar ratio of the gelling factor A to the gelling factor B is 7.5:

1.

5. The method for preparing the hydrocyanic acid-reducing and crotonaldehyde paper composite filter material according to claim 1, wherein: The solvent in step (1) is secondary water or 0.05 M KCl aqueous solution.

6. The method for preparing the hydrocyanic acid-reducing and crotonaldehyde paper composite filter material according to claim 1, wherein: The anilox roller in step (2) has a pyramid-shaped groove structure, an opening rate of 25% to 40%, and a solution transfer efficiency of ≥85%.

7. The method for preparing the hydrocyanic acid-reducing and crotonaldehyde paper composite filter material according to claim 1, wherein: In step (3), a gradient cooling zone is provided in the low-temperature tunnel, and the gradient cooling zone is specifically as follows: First temperature zone: 5~10℃, residence time is 60-300 seconds; The second temperature zone: 0~5℃, residence time is 60-300 seconds.

8. The method for preparing the hydrocyanic acid-reducing and crotonaldehyde paper composite filter material according to claim 1, wherein: In the step (4), the surface roughness of the drying cylinder Ra≤0.8 μm, and the hot air circulation speed is 2~5 m / s.

9. A hydrocyanic acid-reducing and crotonaldehyde paper composite filter material, characterized in that: Prepared by the preparation method according to any one of claims 1 to 8.

10. An application of the hydrocyanic acid-reducing and crotonaldehyde paper composite filter material according to claim 9, characterized in that: Used for cigarette filter rods, the cigarette filter rods include a fiber acetate segment and a paper segment, the filter material in the paper segment is a composite filter material of hydrocyanic acid reduction and crotonaldehyde paper, and the paper segment is located near the tobacco end of the cigarette filter rod.

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