Heatable wrapping sheet for heating type aerosol generating product as well as preparation method and application of heatable wrapping sheet

Abstract

The invention relates to a heatable wrapping sheet for a heating type aerosol generating product and a preparation method and application thereof. The heatable wrapping sheet comprises inner-layer paper, a macromolecule cross-linking layer and outer-layer paper from inside to outside, the inner-layer paper is non-water-absorbing paper, and the macromolecule cross-linking layer is formed in the manufacturing process of the heatable wrapping sheet. By the adoption of the wrapping sheet, tobacco shreds or slices can be effectively prevented from generating yellow spots due to chemical substance migration or oxidation reaction in the storage period and the heating process; in addition, the polymer crosslinking layer is adopted for on-site crosslinking, so that the damage to the film in the treatment process of the traditional process is avoided, and the peeling strength is also improved. Besides, the wrapping sheet can provide two-way high barrier property for heated cigarettes and has good processing suitability and heat stability, PPM-level industrial production is achieved, and the effect of preventing yellow spots, the sensory effect and the production efficiency are fully balanced.

Description

Technical Field

[0001] The present invention relates to the technical field of heated cigarettes, and in particular to a heatable wrapping sheet for heated aerosol-generating products, a preparation method thereof, and applications thereof. Background Art

[0002] With the improvement of public health awareness, heated cigarettes, as a product that replaces traditional cigarettes, have gradually received widespread attention in the market. This type of product generates aerosols by heating rather than burning, thereby releasing fragrance, effectively avoiding the large amount of harmful substances produced during the combustion process of traditional cigarettes. It is considered a more environmentally friendly and healthier alternative to smoking. The working principle of heated aerosol-generating products is to heat the atomizer to a certain temperature and release fragrance. Common heated cigarettes are usually composed of tobacco segments and filter segments. The tobacco segments produce aerosol volatile substances during the heating process, and the filter segments are for users to inhale the aerosol. Because this type of product does not rely on combustion, it can significantly reduce the production of harmful substances, thereby reducing the impact on health to a certain extent.

[0003] Accordingly, since heated aerosol-generating products need to be placed in an aerosol-generating device for use, the interior of the aerosol-generating device is relatively closed, reducing the impact of the external atmospheric environment while significantly increasing the impact of the internal environment of the smoking device. This unique usage scenario places higher demands on the structure of heated aerosol-generating products. Typically, their smoke-regulating design is more complex, including one or more segments composed of different materials. Consequently, not only do the individual segments need to be packaged, but they must also be connected by one or more layers of tipping paper. Furthermore, during the heating process of the aerosol-generating product, the physicochemical properties of the tipping paper, such as thermal conductivity, air permeability, and chemical stability, have a direct impact on the heat transfer efficiency and aerosol volatilization of the aerosol-generating product. For example, traditional tipping paper is not heated, while the wrapping sheet of heated cigarettes needs to be heated in the heated smoking device. Using traditional tipping paper directly will affect the overall sensory perception of the smoke due to its uncertain composition. In addition, traditional tipping paper only considers preventing saliva from seeping outward for a short time during contact with the lips. The wrapping sheet of heated cigarettes not only needs to prevent saliva from seeping outward for a short time at the proximal end, but also needs to consider the long-term erosion of smoking agents such as glycerin and propylene glycol at the distal end, which may cause yellow spots. The absorbent tipping paper cannot be used for heated cigarettes.

[0004] In the manufacturing process of heated aerosol-generating products, aluminum foil is usually used as an intermediate barrier layer for the wrapping sheet in order to effectively prevent the yellow spots generated by chemical migration or oxidation reactions during the shelf life of tobacco. The aluminum foil layer can provide certain barrier properties, but it has the following defects: First, the surface of the aluminum foil is smooth, resulting in poor glue adhesion. During the composite process, thick aluminum foil is prone to delamination, or thin aluminum film is prone to partial shedding or uneven deposition to form sand holes. There will still be sporadic yellow spots, which makes production difficult. Second, the aluminum foil itself has high rigidity and low ductility, which makes it easy to break or wrinkle during the high-speed winding process (especially at production line speeds above 2500 cigarettes / minute), affecting the adaptability and stability of the production line. In addition, aluminum foil also has electromagnetic shielding effects and is not suitable for electromagnetic heating smoking devices.

[0005] While prior art attempts have used other barrier materials, such as the anti-seepage coating disclosed in CN114457626B, which can improve the permeation problem, still suffer from drawbacks such as complex processes, high costs, and insufficient temperature resistance. Another example is CN1943456A, which discloses placing a waterproof, moisture-proof, and anti-seepage material layer between the filter plug wrap and the filter element. Before wrapping the filter plug wrap around the filter element, the wrap passes through a laminating machine at a temperature of 70-90°C to laminate the inner wall of the wrap with the waterproof, moisture-proof, and anti-seepage material layer. The waterproof, moisture-proof, and anti-seepage material layer has a thickness of 0.05-0.1 mm and is made of PE (polyethylene) film, PVDC (polyvinylidene chloride) film, or PP (polypropylene) film. However, this process requires a high thickness for the PE film, and both the laminating and laminating processes are prone to perforation.

[0006] Therefore, there is an urgent need for a new wrapping sheet structure for heated cigarettes that can provide high bidirectional barrier properties while having good processing adaptability and thermal stability to balance the effect of preventing yellow spot formation, sensory effects and production efficiency. Summary of the Invention

[0007] In view of the deficiencies of the prior art, the present invention provides a heatable wrapping sheet for heated aerosol-generating products, and a preparation method and application thereof.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a heatable wrapping sheet for a heated aerosol-generating product, the heatable wrapping sheet comprising, from inside to outside, an inner layer of paper, a polymer cross-linked layer, and an outer layer of paper, wherein the inner layer of paper is non-absorbent paper, and the polymer cross-linked layer is formed during the manufacturing process of the heatable wrapping sheet.

[0010] Preferably, the inner paper is non-absorbent paper, and the water absorption of the inner paper is ≤30g / m 2 Preferably, the water absorption of the inner paper is ≤24g / m 2 Preferably, the water absorption of the inner paper is ≤18g / m 2 .

[0011] The water absorption of the inner paper of the present invention can be 2g / m 2 , 4g / m 2 , 8g / m 2 , 10g / m 2 , 12g / m 2 , 14g / m 2 , 16g / m 2 , 18g / m 2 , 20g / m 2 , 22g / m 2 , 24g / m 2 , 26g / m 2 or 28g / m 2 wait.

[0012] Preferably, the basis weight of the inner paper is 15-70 g / m 2 , for example, it can be 20g / m 2 , 25g / m 2 , 30g / m 2 , 35g / m 2 , 40g / m 2 , 45g / m 2 , 50g / m 2 , 55g / m 2 , 60g / m 2 or 65g / m 2 wait.

[0013] Preferably, the thickness of the inner layer of paper is 20-90 μm, for example, it can be 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm or 85 μm.

[0014] Preferably, the outer paper has a basis weight of 15-70 g / m 2 , for example, it can be 20g / m 2 , 25g / m 2 , 30g / m 2 , 35g / m 2 , 40g / m 2 , 45g / m 2 , 50g / m 2 , 55g / m 2, 60g / m 2 or 65g / m 2 wait.

[0015] Preferably, the thickness of the outer paper is 20-60 μm, for example, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm or 55 μm.

[0016] Preferably, the inner paper layer, the polymer cross-linked layer and the outer paper layer are not bonded together by adhesive.

[0017] Preferably, the moisture permeability of the heatable wrapping sheet is ≤6.0g / (m 2 ·d), for example, it can be 0.5g / (m 2 ·d)、1.0g / (m 2 ·d)、1.5g / (m 2 ·d)、2.0g / (m 2 ·d)、2.5g / (m 2 ·d)、3.0g / (m 2 ·d)、3.5g / (m 2 ·d)、4.0g / (m 2 ·d)、4.5g / (m 2 ·d)、5.0g / (m 2 ·d) or 5.5g / (m 2 ·d) etc.

[0018] In a second aspect, the present invention provides a method for preparing the heatable wrapping sheet according to the first aspect, wherein the preparation of the heatable wrapping sheet comprises the following steps:

[0019] (1) preparing a spray liquid for forming a polymer cross-linked layer;

[0020] (2) performing corona pretreatment on the inner layer paper and / or the outer layer paper to form surface grooves and / or concave spots;

[0021] (3) using either the inner or outer paper layer as the first paper layer and the remaining paper layer as the second paper layer, and then spraying the spray liquid of step (1) on one surface of the first paper layer using a laminating device;

[0022] (4) attaching any side of the second paper layer to the spray surface of the first paper layer to form a three-layer composite structure;

[0023] (5) Compacting and cooling the three-layer composite structure to obtain the heatable wrapping sheet.

[0024] Preferably, the peel strength between the polymer cross-linked layer and the inner paper layer is ≥1.5N / mm, for example, it can be 2N / mm, 2.5N / mm, 3N / mm, 3.5N / mm, 4N / mm, 4.5N / mm, 5N / mm, 7N / mm or 10N / mm.

[0025] Preferably, the depth of the grooves or concave spots is controlled at 10-20% of the thickness of the inner paper and / or the outer paper, for example, it can be 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18% or 19%.

[0026] Preferably, the spray liquid contains 0.1-2.0 wt% (for example, 0.3 wt%, 0.5 wt%, 0.8 wt%, 1 wt%, 1.2 wt%, 1.5 wt%, 1.7 wt% or 1.9 wt%) of an antioxidant;

[0027] Preferably, the antioxidant is vitamin E and / or tea polyphenols.

[0028] In a third aspect, the present invention provides a use of the heatable wrapping sheet according to the first aspect in preparing heated cigarettes.

[0029] In a fourth aspect, the present invention provides a heated aerosol-generating article, comprising at least one solid filter plug segment, at least one hollow filter plug segment, and at least one smoking segment;

[0030] The solid filter rod segment, the hollow filter rod segment and the smoking segment are connected by the heatable wrapping sheet material described in the first aspect.

[0031] Preferably, the difference between the maximum and minimum hardness of the solid filter rod segment, the hollow filter rod segment and the smoking segment is ≥8%, for example, it can be 10%, 12%, 15%, 18%, 20%, 25%, 30% or 40%.

[0032] Preferably, the heatable wrapping sheet covers the entire smoking section.

[0033] Any specific point value within the above numerical range can be selected and will not be described in detail here.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] By adopting the wrapping sheet of the present invention, yellow spots can be effectively prevented from forming on tobacco shreds or thin sheets during storage and heating due to chemical migration or oxidation reactions. Due to the on-site cross-linking of the polymer cross-linking layer, damage to the film during traditional processing is avoided and the peel strength is improved. The wrapping sheet of the present invention can provide high bidirectional barrier properties for heated cigarettes while having good processing adaptability and thermal stability, achieving PPM-level industrial production and fully balancing the effect of preventing yellow spot formation, sensory effects and production efficiency. In addition, the wrapping sheet of the present invention can also be used in electromagnetically heated cigarettes, with a wider range of application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic diagram of a heated aerosol-generating article to which the present invention is applied;

[0037] Figure 2 Schematic diagram of the wrapping sheet of the heated aerosol-generating article of the present invention, detailing the layer distribution and interrelationship of the three layers of materials in the present invention;

[0038] Figure 3 A schematic diagram showing the use of the wrapping sheet of the present invention in a heated aerosol-generating article;

[0039] Figure 4 A photo of a cigarette wrapped with tipping paper according to Comparative Example 1 is shown;

[0040] Figure 5 A photo of a cigarette wrapped in the composite forming paper of Comparative Example 2 is shown;

[0041] Figure 6 Shown is a photo of a cigarette wrapped with the wrapping sheet of the present invention.

[0042] Among them, the figure numbers are explained as follows: 1 aerosol generating product (cigarette); 101 tobacco segment; 102 filter segment; 103 sealing segment; 104 support segment; 105 hollow segment; 111 tobacco segment wrapping paper; 113 sealing segment wrapping paper; 114 support segment wrapping paper; 121 wrapping sheet; LO outer layer of paper; LM middle barrier layer; LI inner layer of paper. DETAILED DESCRIPTION

[0043] The detailed features and advantages of the present invention are described below in the specific embodiments, and the content is sufficient to enable those skilled in the art to understand the technical content of the present invention and implement it accordingly. Based on this specification, claims and drawings, those skilled in the art can easily understand the relevant purposes and advantages of the present invention.

[0044] The terms and expressions used herein are for descriptive purposes only, and the present invention is not limited to these terms and expressions. The use of these terms and expressions does not exclude any equivalent features shown and described (or portions thereof), and it should be recognized that various modifications that may exist are also intended to be included within the scope of the claims. Other modifications, variations, and substitutions are also possible. Accordingly, the claims should be deemed to cover all such equivalents.

[0045] See also Figure 1 FIG. 1 shows a specific embodiment of a heated aerosol-generating product 1 of the present invention. In this embodiment, the heated aerosol-generating product 1 is applied to a heated smoking device (not shown) and is heated in the heated smoking device to form an aerosol.

[0046] The aerosol generating article 1 is generally provided with a tobacco section 101 (core) and a filter section 102. As required, the aerosol generating article 1 may further be provided with one or more cooling sections, hollow sections 105, end-sealing sections 103 or support sections 104, etc. Figure 1 The end section 103 (front plug), the support section 104 (small hollow core) and the hollow section 105 (large hollow core) are exemplarily shown in FIG.

[0047] The main function of the sealing section 103 is to prevent tobacco from falling during the heating process, thereby ensuring the integrity of the cigarette and enhancing the user experience. The support section 104 is designed to enhance the overall structural stability of the cigarette, providing the necessary physical support during the heating process, ensuring that the cigarette maintains a stable shape during heating, and avoiding uneven heating or abnormal smoke release caused by a loose structure.

[0048] like Figure 2 As shown, the tobacco segment 101, the end-sealing segment 103, and the support segment 104 are each provided with tobacco segment wrapping paper 111, end-sealing segment wrapping paper 113, and support segment wrapping paper 114. These wrapping papers primarily serve to shape the respective segments and are typically wound around the corresponding segments during separate processing to form independent structural units. Because their primary function is to wrap and secure the cigarette, these wrapping papers are typically relatively thin to ensure overall lightness and good heat transfer performance. Furthermore, since they do not need to withstand the tensile forces generated by relative movement between segments, the strength requirements are relatively low.

[0049] The wrapping sheet 121 is wrapped around the outside of these wrapping papers to connect the segments, enhance the overall structural stability and provide additional protection. The application scope of the present invention is not limited to the packaging of the sealing segment 103, the tobacco segment 101 and the supporting segment 104.

[0050] The wrapping sheet 121 of the heated aerosol generating product of the present invention is made of Figure 3The material shown, this wrapping sheet is composed of an inner paper layer LI, an intermediate barrier layer LM, and an outer paper layer LO, forming a "sandwich" structure, wherein PE film (Polyethylene Terephthalate Film) is used as the intermediate barrier layer LM. The intermediate barrier layer LM of the present invention is a polymer chemical flexible material with high chemical stability, capable of resisting corrosion from a variety of chemical substances. It also has extremely low permeability, effectively preventing the penetration of moisture and liquids, and providing excellent waterproof and moisture-proof properties. In addition, the intermediate barrier layer LM of the present invention has excellent mechanical properties, including high tensile strength, elongation, and tear resistance, and can maintain integrity under certain degrees of deformation. It also has excellent temperature resistance and can be used over a wide temperature range.

[0051] The following examples describe in detail the characteristics of the wrapping sheet of the present invention.

[0052] [Preparation Example 1 of Wrapping Sheet]

[0053] The wrapping sheet of the present invention is completely different from the traditional tipping paper. The outer layer of the paper is made of 40g / m 2 The traditional cigarette paper, the inner paper is made of 100g / m 2 The traditional forming paper is then 2 The high-density PE polymer cross-linked layer is combined together to form a total weight of 170g / m 2 The specific manufacturing process of the new wrapping sheet #1 includes the following steps:

[0054] Step S1 (preparing spray liquid): melt the food-grade PE film raw material in a heating tank, the temperature of the heating tank is controlled at 72-80°C, and form a PE spray liquid;

[0055] Step S2 (corona pretreatment): corona treatment is performed on the inner and outer paper layers respectively to form grooves or pits on the surface of the base paper. The depth of the grooves or pits is controlled to be 10-20% of the thickness of the paper to strengthen the bonding between the inner and outer paper layers and the PE layer.

[0056] Step S3 (external paper laminating process): add spray liquid to the laminating equipment, stir and roll up a layer of spray liquid through the adhesive wheel set above the heating tank, and scraper set on one side of the adhesive wheel scrapes the spray liquid rolled up by the adhesive wheel to a thickness of about 35μm (quantity 30g / m 2 ) Press the paper until it fits with the adhesive wheel. At this time, the spray liquid rolled up by the adhesive wheel will coat the outer paper, forming an intermolecular connection (rather than adhesive bonding). At the same time, the castable coating liquid fully fills the grooves or concave points on the outer paper.

[0057] Step S4 (Inner Paper Lamination Process): The inner paper is immediately attached to the coated outer paper and rolled with rollers to fully fill the grooves or concave spots on the inner paper with the coating liquid, forming a three-layer composite structure.

[0058] Step S5 (Cooling Forming Process): The three-layer composite structure is sequentially conveyed to a hydraulic press for further compaction, and then conveyed to a cooler for cooling at a controlled temperature of 10-15°C. This produces wrapping sheet #1 of the present invention. The final thickness of the middle PE layer is measured to be approximately 30 μm.

[0059] [Preparation Example 2-16 of Wrapping Sheet]

[0060] Referring to the process of Wrapping Sheet Preparation Example 1, wrapping sheets #2-#16 were manufactured according to the materials in Table 1.

[0061] Table 1: Materials used in Preparation Examples 1-16

[0062]

[0063] in:

[0064] In Preparation Example 11, 0.5% vitamin E was mixed into the PE raw material for preparing the cross-linked layer as an antioxidant.

[0065] In Preparation Example 12, 1.0% tea polyphenols was mixed into the PE raw material for preparing the cross-linked layer as an antioxidant.

[0066] The antioxidant is mixed into the raw materials of the polymer cross-linking layer and can be evenly dispersed in the PE film, so that the residual volatile matter under the heating condition of 180° C. is less than or equal to 0.5%.

[0067] In Preparation Example 13, neither the inner paper nor the outer paper was subjected to the corona treatment.

[0068] In Preparation Example 14, the inner paper was not subjected to the corona treatment.

[0069] In Preparation Example 15, the outer paper was not subjected to the corona treatment.

[0070] In Preparation Example 16, the raw material for preparing the cross-linking layer was changed to PLA, and the temperature of the heating tank of the laminating equipment was controlled at 180-210°C.

[0071] [Comparative Examples 1-3]

[0072] Prepared basis weight is 70g / m 2 of traditional tipping paper as comparative example #A.

[0073] According to Chinese invention patent CN107536100B, the total weight is 70g / m2 The composite forming paper of "forming paper-aluminum foil" is used as comparative example #B. Among them, the forming paper has a basis weight of 30g / m 2 , the weight of aluminum foil is 30g / m 2 , and the rest is adhesive.

[0074] According to Chinese invention patent CN1943456A, the total weight is 70g / m 2 The composite forming paper of "forming paper-PE-forming paper" is used as comparative example #C. The basis weights of the two forming papers are 25g / m 2 , the PE film weight is 10g / m 2 The rest is adhesive.

[0075]

Cigarette Preparation Example

[0076] The tobacco cores (central hardness value of 85%), large hollow cores (central hardness value of 93.5%) and small hollow cores (central hardness value of 91.5%) of commercially available UGare heated cigarettes were spliced ​​on a machine (2500 cigarettes / minute production line) using wrapping sheets #1-#16 and papers #A-#C, respectively, to obtain batches of cigarettes #1-#16 and cigarettes #A-#C, respectively.

[0077] [Test Example 1-Moisture Permeability]

[0078] The overall moisture permeability of wrapping sheets #1-#16 and paper #A-#C at 25°C was tested according to the "Test Method for Moisture Permeability of Flexible Packaging Containers (GB / T 6982-2003)". The test results are shown in Table 2.

[0079] [Test Example 2 - Water Absorption of Inner Paper]

[0080] The water absorption of wrapping sheets #1-#8 was tested at 24°C and 50% relative humidity according to the "Determination of Water Absorption of Paper and Paperboard (Cobber Method) (GB / T 1540-2002). The test results are shown in Table 2.

[0081] [Test Example 3 - Cigarette Yellow Spot Test]

[0082] Cigarettes #1-#8, #16, and #C were stored at room temperature and humidity for 2 months. The cigarettes were then visually inspected to see if yellow spots formed on the surface or if the yellow spots within the cigarettes showed through the surface color. The test results are shown in Table 2.

[0083] Table 2

[0084]

[0085]

[0086] [Test Case 1-3 Test Results Discussion]

[0087] First, it can be seen that the moisture permeability of the wrapping sheet of the present invention is mainly determined by the moisture permeability of the PE or PLA cross-linked layer itself, with the outer and inner paper layers having little influence. Although PE film is used as the intermediate layer in Comparative Example 3, small sand holes are easily generated during the lamination process due to factors such as pulling during transportation, affecting the final overall moisture permeability and thus causing yellow spots during long-term storage.

[0088] Secondly, if the inner paper of the present invention has strong water absorption, the smoke generating agent will be absorbed into the inner paper after long-term storage and gradually form dark yellow spots. If the outer paper is relatively thin, the yellow spots will still show through, affecting the appearance of the product.

[0089] [Test Example 4 - Cigarette Appearance Quality Evaluation]

[0090] Manual inspection and evaluation of surface wrinkles, axial bending, and wrapping defects were conducted on cigarettes #1-#16 and #A-#B produced after splicing on the machine. The results are as follows:

[0091] like Figure 4 As shown, due to the large difference in hardness of the cigarette core, large hollow core and small hollow core, directly using a 2500 piece / minute production line on traditional tipping paper will produce very obvious wrinkles and axial bending problems, with an overall defect rate of more than 10%, making large-scale production impossible.

[0092] like Figure 5 As shown in the figure, due to the large difference in hardness between the cigarette core, large hollow core and small hollow core, and the increased difference in tensile strength between the forming paper and the aluminum foil, the aluminum foil is not easy to be coated with glue. Therefore, directly using a 2500 piece / minute production line on traditional tipping paper will result in very obvious wrapping failure problems, with an overall defect rate of more than 10%, making large-scale production impossible.

[0093] like Figure 6 As shown, despite significant differences in the hardness of the cigarette core, large hollow core, and small hollow core, the synergistic stretching of the forming paper and cigarettes through the cross-linking layer resulted in good tensile consistency. Consequently, the aforementioned defects were avoided when the wrapping sheet was used directly on a 2,500 cigarette / minute production line, resulting in an overall defect rate below 1 part per million (PPM), enabling scalable production. Furthermore, in actual production, the five-segment cigarette structure was achieved by simultaneously wrapping a front plug and filter segment with a hardness of 95%. The overall defect rate was also maintained at the PPM level.

[0094] [Test Example 5-Peel Strength Test]

[0095] Wrapping sheets #3, #13-15, and tipping paper #C were tested in accordance with the "Test Method for Peel Strength of Adhesive Tapes (GB / T 2792-2014)" to measure the peel strength between the inner paper layer and the cross-linked layer or PE film. Wrapping sheets #3 and #15, due to their corona pre-treatment of the inner paper, exhibited the highest peel strength, exceeding 3.0 N / mm. Wrapping sheets #13 and #14, without corona pre-treatment, had slightly lower peel strengths, ranging from 2.0 to 2.7 N / mm. Tipping paper #C, due to the use of adhesive to laminate the PE film and paper, lacks direct molecular bonding between the PE film and paper, resulting in a lower peel strength of approximately 1.2 N / mm.

[0096] [Test Example 6-Heating and Puffing Test]

[0097] When cigarettes #1-#9 were placed in UGare's commercially available smoking device for a puff test, it was found that cigarettes #8 and #9 had a noticeably stronger spiciness than cigarettes #1-#7, with #9 being the most pronounced. This suggests that the inner paper layer cannot be too thin, otherwise heat will be quickly transferred to the cross-linking layer during heating, producing unexpected odors.

[0098] In addition, by observing the changes in cigarettes and tipping paper during the heating process, it can be found that the thermal shrinkage rate of these wrapping sheets when heated to 150°C is less than or equal to 1.5%, and they will not burst; and the thermal conductivity coefficient of the wrapping sheets in the range of 100-200°C is between 0.15-0.35W / (m·K), which can meet the technical requirements of heated cigarette smoking.

[0099] Furthermore, measurements of the stiffness of wrapping sheets #1-#9 revealed that they all fell within the range of 50-200 mN·m, meeting relevant technical requirements. Measurements of the hardness of wrapping sheets #1-#9 revealed that they all fell within the range of 80-150 Shore A, also meeting relevant technical requirements.

[0100] The applicant states that the present invention uses the above-described embodiments to illustrate a heatable wrapping sheet for heated aerosol-generating products, its preparation method, and its use. However, the present invention is not limited to the above-described embodiments, nor does it necessarily rely on the above-described embodiments for implementation. Persons skilled in the art should understand that any improvements to the present invention, equivalent substitutions for raw materials in the present invention, addition of auxiliary ingredients, and selection of specific methods, etc., fall within the scope of protection and disclosure of the present invention.

[0101] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0102] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A heatable wrapping sheet for a heated aerosol-generating product, characterized in that The heatable wrapping sheet comprises, from inside to outside, an inner layer of paper, a polymer cross-linking layer and an outer layer of paper; Wherein, the polymer cross-linked layer is formed during the manufacturing process of the heatable wrapping sheet.

2. The heatable wrapping sheet according to claim 1, characterized in that The inner paper is non-absorbent paper, and the water absorption of the inner paper is ≤30g / m 2 .

3. The heatable wrapping sheet according to claim 1, characterized in that The basis weight of the inner paper is 15-70 g / m 2 ; The thickness of the inner layer paper is 20-90 μm.

4. The heatable wrapping sheet according to claim 1, characterized in that The outer paper has a basis weight of 15-70 g / m 2 ; The thickness of the outer paper is 20-60 μm.

5. The heatable wrapping sheet according to claim 1, characterized in that The inner paper layer, the polymer cross-linked layer and the outer paper layer are not bonded together by adhesive.

6. The heatable wrapping sheet according to claim 1, characterized in that The moisture permeability of the heatable wrapping sheet is ≤6.0g / (m 2 ·d).

7. A method for preparing a heatable wrapping sheet according to any one of claims 1 to 6, characterized in that: The preparation of the heatable wrapping sheet comprises the following steps: (1) preparing a spray liquid for forming a polymer cross-linked layer; (2) performing corona pretreatment on the inner layer paper and / or the outer layer paper to form surface grooves and / or concave spots; (3) using either the inner or outer paper layer as the first paper layer and the remaining paper layer as the second paper layer, and then spraying the spray liquid of step (1) on one surface of the first paper layer using a laminating device; (4) attaching any side of the second paper layer to the spray surface of the first paper layer to form a three-layer composite structure; (5) Compacting and cooling the three-layer composite structure to obtain the heatable wrapping sheet.

8. The preparation method according to claim 7, characterized in that The peel strength between the polymer cross-linked layer and the inner paper layer is ≥1.5N / mm; The depth of the grooves or concave points is controlled to be 10-20% of the thickness of the inner paper and / or the outer paper.

9. The preparation method according to claim 7, characterized in that The spray liquid contains 0.1-2.0 wt% of an antioxidant; The antioxidant is vitamin E and / or tea polyphenols.

10. A heated aerosol-generating product, characterized in that: The heated aerosol-generating article comprises at least one solid filter plug segment, at least one hollow filter plug segment, and at least one smoking segment; The solid filter rod segment, the hollow filter rod segment and the smoking segment are connected by the heatable wrapping sheet according to any one of claims 1-6.

11. The heated aerosol-generating product according to claim 10, wherein: The difference between the maximum and minimum hardness values ​​of the solid filter rod segment, the hollow filter rod segment and the smoking segment is greater than or equal to 8%.

12. The heated aerosol-generating product according to claim 10, wherein: The heatable wrapping sheet covers the entire smoking section.

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