Cigarette tipping paper with flame-retardant effect and preparation method thereof

Abstract

The present application relates to the technical field of cigarette tipping base paper, and particularly discloses cigarette tipping base paper with fire-retardant effect and a preparation method thereof. The cigarette tipping base paper with fire-retardant effect comprises cigarette tipping base paper and a fire-retardant component coated on the cigarette tipping base paper. The cigarette tipping base paper comprises coniferous wood pulp, broadleaf wood pulp, modified composite filler and an additive. The fire-retardant component comprises deionized water, fire-retardant modified hydrotalcite, sodium p-aminobenzenesulfonate and glycerol. By controlling the ratio of coniferous wood pulp and broadleaf wood pulp, the strength of the tipping base paper is ensured, the tipping base paper can effectively bear the fire-retardant coating, has excellent air permeability and printability, and uses a halogen-free fire-retardant system. Organic fire retardant and inorganic hydrotalcite synergistically act, have excellent fire-retardant effect, can be directly coated on the base paper through a conventional coating process, do not change the basic texture of the base paper after coating, do not need complex equipment modification, have high production efficiency, strong process controllability, and are convenient for industrialized production.

Description

Technical Field

[0001] This invention relates to the field of cigarette tipping paper technology, specifically to a cigarette tipping paper with flame-retardant properties and its preparation method. Background Technology

[0002] Cigarette tipping paper is the packaging material that connects the filter to the cigarette and belongs to special industrial paper. Currently, most commercially available cigarette tipping papers primarily focus on their decorative, printable, and basic physical properties, lacking flame-retardant functionality. However, carelessly discarded unextinguished cigarette butts are a major cause of fires, posing a significant safety hazard. With increasing public awareness of safety and environmental health requirements, there is growing concern about the fire hazards and material safety of traditional tipping papers. Since self-extinguishing mechanisms when a cigarette burns to the butt can effectively prevent fires, research is needed to develop flame-retardant tipping papers to reduce the fire safety hazards of cigarettes.

[0003] In existing technologies, flame retardancy is mainly achieved through two methods: locally coating the surface of the tipping paper with flame-retardant tape or directly adding flame retardants into the pulp fibers during the papermaking and pulping process. Locally coating with flame-retardant tape may cause the paper to re-wet and wrinkle, affecting the operational stability of the cigarette machine. Furthermore, some coatings use halogenated flame retardants, which may release toxic gases during combustion, posing potential health and safety hazards. Adding flame retardants directly into the pulp fibers during the papermaking and pulping process requires that the flame retardant in the tipping paper, which comes into direct contact with the mouth, be absolutely non-toxic and harmless. This significantly limits the range of materials that can be selected. Using only inorganic flame retardants often requires extremely high dosages to meet flame retardancy standards, resulting in a decrease in the paper's flexibility and air permeability.

[0004] Chinese patent application CN103031779A discloses a cigarette tipping paper and its production process, which involves pulping, mixing, sand removal, flushing, flow, wire forming, surface sizing, drying, calendering, rolling, slitting, trimming, inspection, finished product, finished product packaging, and finished product warehousing. Calcium carbonate and a flame retardant are added during the pulping process to achieve a flame-retardant effect. However, this process is incomplete, the specific flame retardant is not clearly defined, direct contact with the mouth poses a significant safety hazard, and the addition of large amounts of calcium carbonate affects the printing quality of the paper and the sensory quality of the cigarettes. Chinese patent application CN102535234A discloses a method for producing non-stick lip flame-retardant tipping paper. The method involves pulping and papermaking, drying the wet paper in the pre-drying stage, coating the surface with a mixture of flame retardant and non-stick lip additive using a sizing machine, and then post-drying and calendering to obtain non-stick lip flame-retardant tipping paper with water resistance, moisture resistance and flame retardant properties. However, the flame retardant is not clearly defined, which poses a safety hazard and presents a severe challenge in material selection and performance balance.

[0005] Therefore, it is of great significance to provide a cigarette tipping paper that combines high flame retardancy, excellent comprehensive performance, high safety and environmental protection, and good processing adaptability. Summary of the Invention

[0006] (a) Technical problems to be solved To address the aforementioned technical problems, this invention provides a cigarette tipping paper with flame-retardant properties and its preparation method, thus solving the problem of poor flame-retardant performance of cigarette tipping paper.

[0007] (II) Technical Solution To achieve the above objectives, this invention discloses a cigarette tipping paper with flame-retardant properties, comprising a cigarette tipping paper and a flame-retardant component coated on the cigarette tipping paper, wherein the basis weight of the cigarette tipping paper is 32-40 g / m². 2 The amount of flame-retardant coating on the tipping paper for cigarettes is 1.5-2.0 g / m³ (dry weight). 2 ; The cigarette tipping base paper includes softwood pulp, hardwood pulp, modified composite filler, and additives; The flame-retardant components include deionized water, flame-retardant modified hydrotalcite, sodium p-aminobenzenesulfonate, and glycerin.

[0008] Preferably, the mass ratio of the softwood pulp, hardwood pulp, modified composite filler, and additives is 42-80:100:7-12:0.5-2, and the freeness of the mixed pulp is 58-70°SR.

[0009] Preferably, the additive is composed of a wet strength agent, a dry strength agent, and a sizing agent in a mass ratio of 5:3:2, wherein the wet strength agent is polyamide polyepoxychloropropane resin, the dry strength agent is cationic starch, and the sizing agent is an alkyl ketene dimer.

[0010] Preferably, the preparation method of the modified composite filler includes the following steps: A1. Nanocellulose was ultrasonically dispersed in N,N-dimethylformamide. After uniform dispersion, succinic anhydride and pyridine were added. The mixture was stirred and heated under a nitrogen atmosphere to allow the reaction to proceed. After the reaction was completed, the mixture was centrifuged, washed with anhydrous ethanol, and dried to obtain modified cellulose. A2. Disperse nano-silica in toluene using ultrasound. After uniform dispersion, add γ-aminopropyltriethoxysilane, stir and mix, heat to allow the reaction to occur. After the reaction is complete, wash with anhydrous ethanol, filter, and dry to obtain aminated silica. A3. Modified cellulose was ultrasonically dispersed in N,N-dimethylformamide. After uniform dispersion, aminated silica was added and ultrasonically dispersed. 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide were added. The mixture was stirred and mixed under a nitrogen atmosphere to allow the reaction to occur. After the reaction was completed, the mixture was filtered, washed with anhydrous ethanol, and dried to obtain the modified composite filler.

[0011] Preferably, the mass ratio of nanocellulose, N,N-dimethylformamide, succinic anhydride, and pyridine in A1 is 100:1200-1800:95-150:32-55, the reaction temperature is 80-90℃, and the reaction time is 6-8h.

[0012] Preferably, the mass ratio of nano-silica, toluene, and γ-aminopropyltriethoxysilane in A2 is 100:2100-2500:24-35, the reaction temperature is 95-105℃, and the reaction time is 4-6h.

[0013] Preferably, the mass ratio of modified cellulose, N,N-dimethylformamide, aminated silica, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and N-hydroxysuccinimide in A3 is 100:3200-3600:68-92:58-80:25-40, the reaction temperature is 45-55℃, and the reaction time is 4-8h.

[0014] Preferably, the method for preparing the flame-retardant component includes the following steps: B1. Hydrotalcite was ultrasonically dispersed in an ethanol solution. After uniform dispersion, γ-glycidoxypropyltrimethoxysilane was added. The pH was adjusted to 4-5 with glacial acetic acid. The mixture was stirred and stirred to allow the reaction to occur. After the reaction was completed, the mixture was filtered, washed with deionized water and anhydrous ethanol, and dried to obtain modified hydrotalcite. B2. The modified hydrotalcite was ultrasonically dispersed in N,N-dimethylformamide. After uniform dispersion, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was added, stirred and mixed, heated and reacted. After the reaction was completed, the mixture was filtered, washed with anhydrous ethanol, and dried to obtain flame-retardant modified hydrotalcite. B3. Deionized water, flame-retardant modified hydrotalcite, sodium p-aminobenzenesulfonate, and glycerin are stirred and mixed evenly at 50°C for 2 hours to obtain the flame-retardant component.

[0015] Preferably, the ethanol solution in B1 is composed of deionized water and anhydrous ethanol in a volume ratio of 1:1.

[0016] Preferably, the mass ratio of hydrotalcite, ethanol solution, and γ-glycidyl etheroxypropyltrimethoxysilane in B1 is 100:3500-3800:21-30, the reaction temperature is 25-35℃, and the reaction time is 3-5h.

[0017] Preferably, the mass ratio of modified hydrotalcite, N,N-dimethylformamide, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide in B2 is 100:1200-1500:85-115, the reaction temperature is 105-115℃, and the reaction time is 6-8h.

[0018] Preferably, the mass ratio of deionized water, flame-retardant modified hydrotalcite, sodium p-aminobenzenesulfonate, and glycerol in B3 is 900-1000:100:6-9:3-6.

[0019] A method for preparing cigarette tipping paper with flame-retardant properties includes the following steps: Step 1: Mix softwood pulp and hardwood pulp to obtain mixed pulp, then add modified composite filler and additives, stir and mix, form into paper, and obtain cigarette tipping base paper; Step 2: After coating the flame retardant components onto the cigarette tipping paper, dry it at 60°C, then process it into a finished product by curling, calendering and smoothing, and finally roll it up. Use a high-speed paper machine to slit, rewind, and package it to obtain cigarette tipping paper with flame retardant properties.

[0020] (iii) Beneficial technical effects Compared with the prior art, the beneficial effects of the present invention are as follows: (1) In this invention, nanocellulose is modified by introducing carboxyl groups onto the nanocellulose to obtain modified cellulose. γ-aminopropyltriethoxysilane is used to aminate and modify nano-silica. The carboxyl groups on the modified cellulose react with the amino groups on the aminated silica to obtain a modified composite filler. This effectively improves the dispersibility of nanocellulose and nano-silica, allowing them to be uniformly dispersed in the pulp and effectively preventing agglomeration. The modified composite filler not only fills the fiber gaps, but its surface active groups can also form hydrogen bonds or chemical bonds with the hydroxyl groups on the plant fibers, significantly enhancing the bonding force between fibers, reducing filler shedding during printing and processing, and improving processing performance. Furthermore, the nanocellulose and nano-silica in the modified composite filler have a large specific surface area and active sites, which may have a certain physical or chemical adsorption effect on some harmful components in mainstream flue gas, helping to reduce the potential harm caused by smoking.

[0021] (2) In this invention, γ-glycidyl etheroxypropyltrimethoxysilane is used to modify hydrotalcite, introducing epoxy groups onto the surface of the hydrotalcite. The epoxy groups on the modified hydrotalcite undergo a ring-opening reaction with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, grafting the organic flame retardant onto the hydrotalcite. This avoids the migration and precipitation of the flame retardant during storage and use. When mixed with other components, a flame retardant component is obtained. Sodium p-aminobenzenesulfonate in the flame retardant component not only synergistically retards flames but also improves the dispersion stability of the flame retardant in water due to its sulfonic acid groups. Glycerin, as a moisturizing plasticizer, prevents the coating from drying and ensures that the coating is uniform and firm on the paper. Coating the flame retardant component onto the tipping paper can form a highly efficient flame retardant layer on the paper surface. The phosphaphenanthrene groups in the organic flame retardant can promote the formation of a dense char layer during combustion, isolating oxygen and heat, giving the paper good self-extinguishing properties, and greatly improving the fire safety of the tipping paper for cigarettes. When exposed to fire, the flame-retardant components quickly take effect, effectively inhibiting the spread of flames.

[0022] (3) By controlling the ratio of softwood to hardwood pulp in this invention, the strength of the grafting paper is ensured, which can effectively support the flame-retardant coating and has excellent air permeability and printability. Using a halogen-free flame-retardant system, the organic flame retardant and inorganic hydrotalcite work synergistically, and no toxic or corrosive gases such as dioxins and hydrogen halides are produced during combustion, which meets the requirements of the modern tobacco industry for environmental protection and high safety. The flame-retardant components are prepared as an aqueous dispersion, which can be directly coated onto the base paper through conventional coating processes. After coating, the basic texture of the base paper is not changed, no complicated equipment modification is required, the production efficiency is high, the process is highly controllable, and it is convenient for industrial production. Detailed Implementation

[0023] 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. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0024] In the embodiments and comparative examples of this invention, the nanocellulose was purchased from Funa New Materials Technology (Shanghai) Co., Ltd.; the softwood pulp was bleached sulfate softwood pulp; the hardwood pulp was bleached hardwood pulp; the hydrotalcite was Mg-Al type hydrotalcite, industrial grade, purchased from KSM Advanced Materials Technology Co., Ltd.; the nanosilica was purchased from Jiangsu Lianyungang Pengrui Chemical Co., Ltd., with a particle size of 15nm; other undisclosed raw materials and reagents were all commercially available.

[0025] Example 1 A modified composite filler, the preparation method of which includes the following steps: A1. Nanocellulose was ultrasonically dispersed in N,N-dimethylformamide. After uniform dispersion, succinic anhydride and pyridine were added, wherein the mass ratio of nanocellulose, N,N-dimethylformamide, succinic anhydride and pyridine was 100:1200:95:32. The mixture was stirred and mixed under a nitrogen atmosphere, and the temperature was raised to 80°C for 8 hours. After the reaction was completed, the mixture was centrifuged, washed with anhydrous ethanol, and dried to obtain modified cellulose. A2. Disperse nano-silica in toluene using ultrasound. After uniform dispersion, add γ-aminopropyltriethoxysilane, wherein the mass ratio of nano-silica, toluene, and γ-aminopropyltriethoxysilane is 100:2100:24. Stir and mix, heat to 95℃ and react for 6 hours. After the reaction is complete, wash with anhydrous ethanol, filter, and dry to obtain aminated silica. A3. Modified cellulose was ultrasonically dispersed in N,N-dimethylformamide. After uniform dispersion, aminated silica was added and ultrasonically dispersed again. 1-Ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide were added, wherein the mass ratio of modified cellulose, N,N-dimethylformamide, aminated silica, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and N-hydroxysuccinimide was 100:3200:68:58:25. The mixture was stirred and mixed under a nitrogen atmosphere and reacted at 45°C for 8 hours. After the reaction was completed, the mixture was filtered, washed with anhydrous ethanol, and dried to obtain the modified composite filler.

[0026] Example 2 A modified composite filler, the preparation method of which includes the following steps: A1. Nanocellulose was ultrasonically dispersed in N,N-dimethylformamide. After uniform dispersion, succinic anhydride and pyridine were added. The mass ratio of nanocellulose, N,N-dimethylformamide, succinic anhydride and pyridine was 100:1600:128:45. The mixture was stirred and heated in a nitrogen atmosphere to react at 85°C for 7 hours. After the reaction was completed, the mixture was centrifuged, washed with anhydrous ethanol, and dried to obtain modified cellulose. A2. Disperse nano-silica in toluene using ultrasound. After uniform dispersion, add γ-aminopropyltriethoxysilane, wherein the mass ratio of nano-silica, toluene, and γ-aminopropyltriethoxysilane is 100:2300:31. Stir and mix, heat to 100℃ and react for 5 hours. After the reaction is complete, wash with anhydrous ethanol, filter, and dry to obtain aminated silica. A3. Modified cellulose was ultrasonically dispersed in N,N-dimethylformamide. After uniform dispersion, aminated silica was added and ultrasonically dispersed again. Then, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide were added. The mass ratio of modified cellulose, N,N-dimethylformamide, aminated silica, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and N-hydroxysuccinimide was 100:3400:85:72:32. The mixture was stirred and mixed under a nitrogen atmosphere and reacted at 50°C for 6 hours. After the reaction was completed, the mixture was filtered, washed with anhydrous ethanol, and dried to obtain the modified composite filler.

[0027] Example 3 A modified composite filler, the preparation method of which includes the following steps: A1. Nanocellulose was ultrasonically dispersed in N,N-dimethylformamide. After uniform dispersion, succinic anhydride and pyridine were added, wherein the mass ratio of nanocellulose, N,N-dimethylformamide, succinic anhydride and pyridine was 100:1800:150:55. The mixture was stirred and mixed under a nitrogen atmosphere, and the temperature was raised to 90°C for 6 hours. After the reaction was completed, the mixture was centrifuged, washed with anhydrous ethanol, and dried to obtain modified cellulose. A2. Disperse nano-silica in toluene using ultrasound. After uniform dispersion, add γ-aminopropyltriethoxysilane, wherein the mass ratio of nano-silica, toluene, and γ-aminopropyltriethoxysilane is 100:2500:35. Stir and mix, heat to 105℃ and react for 4 hours. After the reaction is complete, wash with anhydrous ethanol, filter, and dry to obtain aminated silica. A3. Modified cellulose was ultrasonically dispersed in N,N-dimethylformamide. After uniform dispersion, aminated silica was added and ultrasonically dispersed again. Then, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide were added. The mass ratio of modified cellulose, N,N-dimethylformamide, aminated silica, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and N-hydroxysuccinimide was 100:3600:92:80:40. The mixture was stirred and mixed under a nitrogen atmosphere and reacted at 55°C for 4 hours. After the reaction was completed, the mixture was filtered, washed with anhydrous ethanol, and dried to obtain the modified composite filler.

[0028] Example 4 A flame retardant component, the preparation method of which includes the following steps: B1. Hydrotalcite was ultrasonically dispersed in an ethanol solution. After uniform dispersion, γ-glycidoxypropyltrimethoxysilane was added, wherein the mass ratio of hydrotalcite, ethanol solution, and γ-glycidoxypropyltrimethoxysilane was 100:3500:21. The pH was adjusted to 4 using glacial acetic acid, and the mixture was stirred and mixed. The reaction was carried out at 25°C for 5 hours. After the reaction was completed, the mixture was filtered, washed with deionized water and anhydrous ethanol, and dried to obtain modified hydrotalcite. B2. Modified hydrotalcite was ultrasonically dispersed in N,N-dimethylformamide. After uniform dispersion, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was added, wherein the mass ratio of modified hydrotalcite, N,N-dimethylformamide, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was 100:1200:85. The mixture was stirred and heated to 105℃ for 8 hours. After the reaction was completed, the mixture was filtered, washed with anhydrous ethanol, and dried to obtain flame-retardant modified hydrotalcite. B3. Deionized water, flame-retardant modified hydrotalcite, sodium p-aminobenzenesulfonate, and glycerin in a mass ratio of 900:100:6:3 were stirred and mixed evenly at 50°C for 2 hours to obtain the flame-retardant component.

[0029] Example 5 A flame retardant component, the preparation method of which includes the following steps: B1. Hydrotalcite was ultrasonically dispersed in an ethanol solution. After uniform dispersion, γ-glycidoxypropyltrimethoxysilane was added, wherein the mass ratio of hydrotalcite, ethanol solution, and γ-glycidoxypropyltrimethoxysilane was 100:3600:26. The pH was adjusted to 4.5 with glacial acetic acid, and the mixture was stirred and mixed. The reaction was carried out at 30°C for 4 hours. After the reaction was completed, the mixture was filtered, washed with deionized water and anhydrous ethanol, and dried to obtain modified hydrotalcite. B2. Modified hydrotalcite was ultrasonically dispersed in N,N-dimethylformamide. After uniform dispersion, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was added, wherein the mass ratio of modified hydrotalcite, N,N-dimethylformamide, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was 100:1400:105. The mixture was stirred and heated to 110℃ for 7 hours. After the reaction was completed, the mixture was filtered, washed with anhydrous ethanol, and dried to obtain flame-retardant modified hydrotalcite. B3. Deionized water, flame-retardant modified hydrotalcite, sodium p-aminobenzenesulfonate, and glycerin in a mass ratio of 950:100:8:5 were stirred and mixed evenly at 50°C for 2 hours to obtain the flame-retardant component.

[0030] Example 6 A flame retardant component, the preparation method of which includes the following steps: B1. Hydrotalcite was ultrasonically dispersed in an ethanol solution. After uniform dispersion, γ-glycidoxypropyltrimethoxysilane was added, wherein the mass ratio of hydrotalcite, ethanol solution, and γ-glycidoxypropyltrimethoxysilane was 100:3800:30. The pH was adjusted to 5 with glacial acetic acid, and the mixture was stirred and mixed. The reaction was carried out at 35°C for 3 hours. After the reaction was completed, the mixture was filtered, washed with deionized water and anhydrous ethanol, and dried to obtain modified hydrotalcite. B2. Modified hydrotalcite was ultrasonically dispersed in N,N-dimethylformamide. After uniform dispersion, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was added, wherein the mass ratio of modified hydrotalcite, N,N-dimethylformamide, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was 100:1500:115. The mixture was stirred and heated to 115℃ for 6 hours. After the reaction was completed, the mixture was filtered, washed with anhydrous ethanol, and dried to obtain flame-retardant modified hydrotalcite. B3. Deionized water, flame-retardant modified hydrotalcite, sodium p-aminobenzenesulfonate, and glycerin in a mass ratio of 1000:100:9:6 are stirred and mixed evenly at 50°C for 2 hours to obtain the flame-retardant component.

[0031] Example 7 A flame-retardant cigarette tipping paper, the preparation method of which includes the following steps: Step 1: Mix and beat softwood pulp and hardwood pulp to obtain a mixed pulp with a freeness of 58°SR. Then add modified composite filler and additives, wherein the mass ratio of softwood pulp, hardwood pulp, modified composite filler, and additives is 42:100:7:0.5. The additives consist of a wet strength agent (polyamide polyepoxychloropropylene resin), a dry strength agent (cationic starch), and a sizing agent (alkyl ketene dimer) in a mass ratio of 5:3:2. Stir and mix, then form into a sheet to obtain a basis weight of 32 g / m³. 2 Cigarette tipping paper; Step 2: After coating the flame retardant component onto the cigarette tipping paper, dry it at 60℃. The dry weight of the flame retardant component coating is 1.5 g / m³. 2 After processing, the finished product is rolled, calendered and flattened, then rolled up, slit, rewound and packaged using a high-speed paper machine to obtain cigarette tipping paper with flame-retardant properties.

[0032] The preparation method of the modified composite filler in this embodiment is completely the same as that in Example 1, and the preparation method of the flame retardant component is completely the same as that in Example 4.

[0033] Example 8 A flame-retardant cigarette tipping paper, the preparation method of which includes the following steps: Step 1: Mix and beat softwood pulp and hardwood pulp to obtain a mixed pulp with a freeness of 65°SR. Then add modified composite filler and additives. The mass ratio of softwood pulp, hardwood pulp, modified composite filler, and additives is 65:100:9:1. The additives consist of a wet strength agent (polyamide polyepoxychloropropylene resin), a dry strength agent (cationic starch), and a sizing agent (alkyl ketene dimer) in a mass ratio of 5:3:2. Stir and mix, then form into a sheet to obtain a basis weight of 36 g / m³. 2 Cigarette tipping paper; Step 2: After coating the flame retardant component onto the cigarette tipping paper, dry it at 60℃. The dry weight of the flame retardant component coating is 1.6 g / m³. 2 After processing, the finished product is rolled, calendered and flattened, then rolled up, slit, rewound and packaged using a high-speed paper machine to obtain cigarette tipping paper with flame-retardant properties.

[0034] The preparation method of the modified composite filler in this embodiment is completely the same as that in Example 2, and the preparation method of the flame retardant component is completely the same as that in Example 5.

[0035] Example 9 A flame-retardant cigarette tipping paper, the preparation method of which includes the following steps: Step 1: Mix and beat softwood pulp and hardwood pulp to obtain a mixed pulp with a freeness of 68°SR. Then add modified composite filler and additives. The mass ratio of softwood pulp, hardwood pulp, modified composite filler, and additives is 72:100:10:1.5. The additives consist of a wet strength agent (polyamide polyepoxychloropropylene resin), a dry strength agent (cationic starch), and a sizing agent (alkyl ketene dimer) in a mass ratio of 5:3:2. Stir and mix, then form into a sheet to obtain a basis weight of 36 g / m³. 2 Cigarette tipping paper; Step 2: After coating the flame retardant component onto the cigarette tipping paper, dry it at 60℃. The dry weight of the flame retardant component coating is 1.8 g / m³. 2 After processing, the finished product is rolled, calendered and flattened, then rolled up, slit, rewound and packaged using a high-speed paper machine to obtain cigarette tipping paper with flame-retardant properties.

[0036] The preparation method of the modified composite filler in this embodiment is completely the same as that in Example 2, and the preparation method of the flame retardant component is completely the same as that in Example 5.

[0037] Example 10 A flame-retardant cigarette tipping paper, the preparation method of which includes the following steps: Step 1: Mix and beat softwood pulp and hardwood pulp to obtain a mixed pulp with a freeness of 70°SR. Then add modified composite filler and additives, wherein the mass ratio of softwood pulp, hardwood pulp, modified composite filler, and additives is 80:100:12:2. The additives consist of a wet strength agent (polyamide polyepoxychloropropylene resin), a dry strength agent (cationic starch), and a sizing agent (alkyl ketene dimer) in a mass ratio of 5:3:2. Stir and mix, then form into a sheet to obtain a basis weight of 40 g / m³. 2 Cigarette tipping paper; Step 2: After coating the flame-retardant component onto the cigarette tipping paper, dry it at 60℃. The dry weight of the flame-retardant component coating is 2.0 g / m³. 2 After processing, the finished product is rolled, calendered and flattened, then rolled up, slit, rewound and packaged using a high-speed paper machine to obtain cigarette tipping paper with flame-retardant properties.

[0038] The preparation method of the modified composite filler in this embodiment is completely consistent with the preparation method of the modified composite filler in Example 3, and the preparation method of the flame retardant component is completely consistent with the preparation method of the flame retardant component in Example 6.

[0039] Comparative Example 1 A method for preparing cigarette tipping paper, compared with the method for preparing cigarette tipping paper with flame retardant effect in Example 9, differs in that the modified composite filler is replaced with nanocellulose and nanosilica in a mass ratio of 54:46, while the other preparation methods are completely consistent with Example 9.

[0040] Comparative Example 2 A method for preparing cigarette tipping paper, compared with the method for preparing cigarette tipping paper with flame retardant effect in Example 9, differs in that the flame retardant components are replaced with deionized water, hydrotalcite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, sodium p-aminobenzenesulfonate, and glycerol in a mass ratio of 900:48:52:6:3. The other preparation methods are completely consistent with those in Example 9.

[0041] Comparative Example 3 A cigarette tipping paper, the preparation method of which includes the following steps: Step 1: Mix and beat softwood pulp and hardwood pulp to obtain a mixed pulp with a freeness of 68°SR. Then add modified composite filler and additives. The mass ratio of softwood pulp, hardwood pulp, modified composite filler, and additives is 72:100:10:1.5. The additives consist of a wet strength agent (polyamide polyepoxychloropropylene resin), a dry strength agent (cationic starch), and a sizing agent (alkyl ketene dimer) in a mass ratio of 5:3:2. Stir and mix, then form into a sheet to obtain a basis weight of 36 g / m³. 2 Cigarette tipping paper; Step 2: After processing, the cigarette tipping paper is rolled into a finished product, calendered and flattened, then rolled up, slit, rewound and packaged using a high-speed paper machine to obtain the cigarette tipping paper.

[0042] The preparation method of the modified composite filler in this comparative example is completely consistent with the preparation method of the modified composite filler in Example 2.

[0043] The flame-retardant cigarette tipping paper from Examples 7-10 and Comparative Examples 1-3 was subjected to relevant performance tests, as follows: (1) Tensile strength test: The tensile strength test was conducted according to the test standard GB / T 12914-2018 "Determination of tensile strength of paper and paperboard by constant speed tensile test (20 mm / min)". The sample was cut into a standard specimen of 15 mm × 250 mm with a straight cut and no burrs. Under the conditions of 25℃ and relative humidity of 50 ± 5%, the specimen was vertically clamped in the tensile strength tester and stretched at a constant speed of 20 mm / min until it broke. The maximum tensile tension was recorded and the tensile strength was calculated. (2) Flame retardant performance test: The flame retardant performance test shall be conducted in accordance with the test standard GB / T 14656-2009 "Test Method for Burning Performance of Flame Retardant Paper and Paperboard"; (3) Air permeability test: The air permeability test was conducted in accordance with the test standard GB / T 458-2008 "Determination of air permeability of paper and paperboard"; Each sample was tested 5 times, and the average value was taken. The corresponding test data are shown in Table 1: Table 1 According to the test results in Table 1, the samples corresponding to Examples 7-10 have excellent tensile strength, excellent flame retardant properties, and good air permeability. In Comparative Example 1, no modification was made to the nanocellulose and nanosilica. Nanocellulose and nanosilica were used as composite fillers to replace the modified composite fillers. The fillers had poor dispersibility, poor compatibility with the fiber interface, and were prone to agglomeration, resulting in a significant decrease in the reinforcing effect. The agglomeration of the fillers caused excessively large pores in the paper, affecting the stability of use, and reducing the flame retardant effect and air permeability. In Comparative Example 2, the flame-retardant modified hydrotalcite was replaced with hydrotalcite and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, which reduced the dispersibility and greatly reduced the flame retardant effect. In Comparative Example 3, no flame-retardant coating treatment was applied to the bottom-packed paper, resulting in poor flame retardant properties and good air permeability.

[0044] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A cigarette tipping paper with flame-retardant properties, comprising cigarette tipping paper and a flame-retardant component coated on the cigarette tipping paper, characterized in that: The basis weight of the cigarette tipping paper is 32-40 g / m². 2 The amount of flame-retardant coating on the tipping paper for cigarettes is 1.5-2.0 g / m³ (dry weight). 2 ; The cigarette tipping base paper includes softwood pulp, hardwood pulp, modified composite filler, and additives; The flame-retardant components include deionized water, flame-retardant modified hydrotalcite, sodium p-aminobenzenesulfonate, and glycerin.

2. The cigarette tipping paper with flame-retardant properties according to claim 1, characterized in that: The mass ratio of the softwood pulp, hardwood pulp, modified composite filler, and additives is 42-80:100:7-12:0.5-2, and the freeness of the mixed pulp is 58-70°SR.

3. The cigarette tipping paper with flame-retardant properties according to claim 1, characterized in that: The additive is composed of a wet strength agent, a dry strength agent, and a sizing agent in a mass ratio of 5:3:

2. The wet strength agent is polyamide polyepoxychloropropane resin, the dry strength agent is cationic starch, and the sizing agent is an alkyl ketene dimer.

4. The cigarette tipping paper with flame-retardant properties according to claim 1, characterized in that: The preparation method of the modified composite filler includes the following steps: A1. Nanocellulose was ultrasonically dispersed in N,N-dimethylformamide. After uniform dispersion, succinic anhydride and pyridine were added. The mixture was stirred and heated under a nitrogen atmosphere to allow the reaction to proceed. After the reaction was completed, the mixture was centrifuged, washed with anhydrous ethanol, and dried to obtain modified cellulose. A2. Disperse nano-silica in toluene using ultrasound. After uniform dispersion, add γ-aminopropyltriethoxysilane, stir and mix, heat to allow the reaction to occur. After the reaction is complete, wash with anhydrous ethanol, filter, and dry to obtain aminated silica. A3. Modified cellulose was ultrasonically dispersed in N,N-dimethylformamide. After uniform dispersion, aminated silica was added and ultrasonically dispersed. 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide were added. The mixture was stirred and mixed under a nitrogen atmosphere to allow the reaction to occur. After the reaction was completed, the mixture was filtered, washed with anhydrous ethanol, and dried to obtain the modified composite filler.

5. A cigarette tipping paper with flame-retardant properties according to claim 4, characterized in that: The mass ratio of nanocellulose, N,N-dimethylformamide, succinic anhydride, and pyridine in A1 is 100:1200-1800:95-150:32-55, the reaction temperature is 80-90℃, and the reaction time is 6-8h.

6. The cigarette tipping paper with flame-retardant properties according to claim 4, characterized in that: The mass ratio of modified cellulose, N,N-dimethylformamide, aminated silica, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, and N-hydroxysuccinimide in A3 is 100:3200-3600:68-92:58-80:25-40, the reaction temperature is 45-55℃, and the reaction time is 4-8h.

7. The cigarette tipping paper with flame-retardant properties according to claim 1, characterized in that: The preparation method of the flame retardant component includes the following steps: B1. Hydrotalcite was ultrasonically dispersed in an ethanol solution. After uniform dispersion, γ-glycidoxypropyltrimethoxysilane was added. The pH was adjusted to 4-5 with glacial acetic acid. The mixture was stirred and stirred to allow the reaction to occur. After the reaction was completed, the mixture was filtered, washed with deionized water and anhydrous ethanol, and dried to obtain modified hydrotalcite. B2. The modified hydrotalcite was ultrasonically dispersed in N,N-dimethylformamide. After uniform dispersion, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was added, stirred and mixed, heated and reacted. After the reaction was completed, the mixture was filtered, washed with anhydrous ethanol, and dried to obtain flame-retardant modified hydrotalcite. B3. Deionized water, flame-retardant modified hydrotalcite, sodium p-aminobenzenesulfonate, and glycerin are stirred and mixed evenly at 50°C for 2 hours to obtain the flame-retardant component.

8. A cigarette tipping paper with flame-retardant properties according to claim 7, characterized in that: The mass ratio of modified hydrotalcite, N,N-dimethylformamide, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide in B2 is 100:1200-1500:85-115, the reaction temperature is 105-115℃, and the reaction time is 6-8h.

9. A cigarette tipping paper with flame-retardant properties according to claim 7, characterized in that: The mass ratio of deionized water, flame-retardant modified hydrotalcite, sodium p-aminobenzenesulfonate, and glycerol in B3 is 900-1000:100:6-9:3-6.

10. A method for preparing a cigarette tipping paper with flame-retardant properties as described in any one of claims 1-9, characterized in that: Includes the following steps: Step 1: Mix softwood pulp and hardwood pulp to obtain mixed pulp, then add modified composite filler and additives, stir and mix, form into paper, and obtain cigarette tipping base paper; Step 2: After coating the flame retardant components onto the cigarette tipping paper, dry it at 60°C, then process it into a finished product by curling, calendering and smoothing, and finally roll it up. Use a high-speed paper machine to slit, rewind, and package it to obtain cigarette tipping paper with flame retardant properties.

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