Low-Ductility Aerosol Heater, Preparation Method, Application, and Aerosol Generation Article

Abstract

The present invention relates to a low-toughness aerosol heater, a preparation method, an application and an aerosol generating article. The aerosol generating article includes an aerosol generating substrate and a low-toughness aerosol heater embedded therein, and the critical temperature of its equivalent resistance is 200°C to 500°C, which can non-combustibly heat the aerosol generating substrate to achieve aerosol generation; the low-toughness induction heater is made of an iron-based heating alloy and contains 70% to 97% by weight of iron, 1.6% to 6.2% of a boron-carbon component, 0% to 10.0% of a first auxiliary element, and 0% to 18% of a second auxiliary element; the heater provided by the present invention has low cost, good processability, a wide temperature control range, high heating efficiency, wide applicability of the aerosol generating substrate and high compatibility.

Description

Technical Field

[0001] The present invention relates to a low-toughness aerosol heater, a preparation method, an application and an aerosol generating article, and belongs to the technical field of electromagnetic induction heating. Background Art

[0002] In recent years, aerosol generation technologies based on electromagnetic induction heating have been applied in fields such as medical treatment, daily chemicals, and tobacco. Heatable aerosol generation matrices include herbal materials such as licorice, mugwort, agarwood, mosquito coils, tea, mint, cedar, and tobacco. In such aerosol generating articles, a heater (also called a susceptor) made of a nickel-based heating alloy is embedded in the aerosol generation matrix. Under the action of an external alternating magnetic field, eddy current loss and magnetic loss will occur, enabling electrical energy to be quickly converted into heat energy and the temperature to rise, thereby heating the aerosol generation matrix and generating aerosol. Since the Curie temperature of nickel is 354 °C, the equivalent resistance of the nickel-based alloy heater will drop sharply near this temperature (this temperature is the critical temperature of the heater's equivalent resistance), and this change can be detected non-contactingly by the control circuit of the heating appliance (WO2015177264). Utilizing this characteristic of the nickel-based metal heater, the heating temperature can be stabilized near 354 °C without additional physical temperature measurement hardware physically connected to the aerosol generating article. This temperature is lower than the ignition point of the herbal-based aerosol generation matrix but higher than the aerosol generation temperature, thereby enabling the generation of aerosol by heating without combustion and avoiding the decomposition of beneficial substances and the generation of harmful substances during high-temperature combustion.

[0003] At present, the induction heaters in heat-not-burn aerosol generating articles are all prepared from nickel-based heating alloys. Since the Curie temperature of nickel is naturally within the heating temperature range required for herb-based aerosol generating matrices (200 - 500°C), the heaters prepared based on such alloys can achieve induction heating between 200°C and 400°C. Document CN105407750B first disclosed a heater composed of two layers of materials, nickel alloy and stainless steel. The nickel alloy layer realizes temperature marking, and the stainless steel layer provides efficient and rapid heating. Document CN115191670A disclosed a heater made by processes such as pulping, casting, laminating, and high-temperature sintering at 1100°C - 1400°C from nickel-based alloy powder and stainless steel powder. Document CN116491712A disclosed a heater made by processes such as melting, sheet casting, heat treatment, and rolling from iron with a weight percentage of 2% - 35% and nickel with a weight percentage of 60% - 90%. Document CN118592686A disclosed a heater made by spin quenching and annealing at 600°C - 800°C from iron with a content of 40% - 62% and nickel with a content of 38% - 60%. Document WO2024234163A1 disclosed a heater made by melting, hot rolling, cold rolling, and hydrogen annealing at 1000°C - 1200°C from nickel with a content of 77% - 81%, molybdenum with a content of 3.5% - 6%, and iron with a content of 11% - 18%. Document CN117652726A disclosed a heater composed of 1j85 or 1j79 alloy, and the mass fraction of nickel metal also exceeds 70%.

[0004] Although the existing heaters prepared based on nickel-based heating alloys can be used in aerosol generating articles to achieve heat-not-burn, there are at least the following multiple serious deficiencies that have not been overcome:

[0005] (1) Poor processing performance. Nickel-based metal heaters need to undergo high-temperature annealing (600°C - 1200°C) to obtain significant temperature indication ability, but high-temperature annealing will result in its high plasticity, high toughness, low strength, and low elasticity. In actual production, the heater is embedded in the continuous aerosol generating matrix in the form of a continuous thin sheet and cut into rod-shaped aerosol generating articles. High plasticity and high toughness will cause serious curling deformation of the heater cut, even leading to serious manufacturing problems such as inability to cut, tool jamming, and the aerosol generating article being scratched; while low strength and low elasticity will also cause problems such as tape breakage and deformation during the automatic feeding of the heater coil, resulting in production interruption.

[0006] (2) Low heating efficiency and poor aerosol generation effect. The nickel-based heating alloy has a high magnetic permeability (>10,000), a low coercivity (<2 A / m), and low magnetic loss, resulting in low hysteresis heating efficiency. At the same time, its resistivity is also very low (~60 μΩ·cm), leading to low eddy current heating efficiency. It can only be used as a temperature marking layer. For commercial heating appliances, existing aerosol generation products can only be equipped with a long strip-shaped nickel-based alloy heater in the center (increasing the number of heaters will cause the system to malfunction), and cannot achieve distributed and uniform heating, resulting in insufficient heating of the aerosol generation matrix, small aerosol generation amount, and poor user experience.

[0007] (3) Poor reliability. Due to the low heating efficiency of a single nickel-based alloy, it can only be used as a temperature gauge base layer. In practical applications, the heater needs to be combined with a heating layer (such as stainless steel) to achieve efficient induction heating (see documents WO2022233988, WO2018178219, WO2015177264, WO2018096000). Due to different magnetostrictive coefficients and thermal expansion coefficients between the temperature marking layer and the heating layer, they are prone to cracking under magnetic fields and high temperatures, resulting in insufficient heat transfer, temperature control failure, a large amount of heat is quickly generated in the heating layer, causing the aerosol generation matrix to exceed the ignition point and burn, resulting in usage accidents. At the same time, nickel-based alloys are chemically active and are prone to corrosion failure when embedded in the aerosol generation matrix (usually containing moisture) for a long time.

[0008] (4) High cost. A large amount of expensive and scarce noble metal nickel is used, and the weight percentage of nickel element is up to 90% at most. This not only results in a very high material cost, but also causes a large waste of precious metal resources because the heater is generally disposable. Summary of the Invention

[0009] Aiming at the defects of existing aerosol generation products containing nickel-based alloy heaters, the technical problem to be solved by the present invention is to provide an aerosol generation product containing an iron-based alloy heater, and its heater has the following advantages: (1) low plasticity, low toughness, high strength, high elasticity, and excellent processing performance; (2) the heater material has a low magnetic permeability, high coercivity, high resistivity, and high power loss, and can simultaneously achieve temperature marking and efficient heating with only a single-layer configuration, with high reliability; (3) multiple heaters can be embedded in the aerosol generation matrix to achieve distributed heating and be compatible with commercial heating appliances; (4) the heater material does not contain nickel and mainly consists of inexpensive iron elements.

[0010] The aerosol-generating article proposed by the present invention includes an aerosol-generating matrix and at least one low-ductility aerosol heater embedded therein; the low-ductility aerosol heater is heated based on the electromagnetic induction effect and is made of an iron-based heating alloy after aging treatment, with an equivalent resistance critical temperature of 200°C to 500°C and a characteristic size greater than 50 μm; the embedding method includes any one or a combination of mechanical inclusion, coating compounding, roll pressing compounding, and papermaking compounding; the preparation method of the iron-based heating alloy is one of rapid melt solidification method, melt drawing method, melt atomization method, and vapor deposition method, and contains 70% to 97% by weight of iron, 1.6% to 6.2% of boron-carbon components, 0% to 10.0% of a first auxiliary element, and 0% to 18% of a second auxiliary element; the boron-carbon components are any one or a combination of boron and carbon; the first auxiliary element is any one or a combination of silicon and phosphorus; the second auxiliary element is any one or a combination of scandium, titanium, vanadium, chromium, manganese, cobalt, copper, zinc, gallium, germanium, indium, tin, antimony, bismuth, lead, aluminum, magnesium, zirconium, niobium, molybdenum, hafnium, tantalum, tungsten, and rare earth elements;

[0011] The iron-based heating alloy after aging treatment has a single-phase structure and has a single X-ray diffraction peak: the (110) diffraction peak of iron when 2θ≈44.6°, and the grain size is less than 2 nm.

[0012] Preferably, the aging treatment is one or two of the following aging treatments: natural aging is adopted for a time of not less than 24 h; artificial aging is adopted, the aging temperature is less than 330°C, and the aging time is 5 min to 6 h; artificial aging is adopted, the aging temperature is the Curie temperature of the iron-based heating alloy or not more than 50°C lower than the Curie temperature, and the aging time is 5 s to 30 min.

[0013] Preferably, the room-temperature coercivity of the iron-based heating alloy is greater than 4 A / m, the room-temperature magnetic permeability is less than 2000, the room-temperature resistivity is greater than 100 μΩ·cm, and the power loss at 50 Hz / 1.3 T is greater than 0.4 W / kg.

[0014] Preferably, the low-ductility aerosol heater is a single-layer structure with a thickness of 0.008 mm to 0.08 mm, a toughness of 10 to 60 kJ / m 2 , a tensile strength of 200 to 2000 MPa, and a shear strain of less than 3%.

[0015] The basic principle of the iron-based alloy heater in the aerosol-generating article of the present invention is as follows:

[0016] The basic performance requirements of a non-combustible induction heating aerosol generating article for an iron-based alloy heater are as follows: (1) The mechanical properties meet the processing requirements of low plasticity, low toughness, high strength, and high elasticity; (2) The electrical properties meet the eddy current heating requirements of high resistance; (3) The magnetic properties meet the hysteresis heating requirements of high coercivity and a suitable Curie temperature.

[0017] Like precious metal nickel, metallic iron has characteristics such as high plasticity, high toughness, low strength, low elasticity, and low resistivity, which are not desired for heaters. This essentially stems from the non-directionality of internal metallic bonds and delocalized electron clouds, enabling atoms to widely slip under low resistance and maintain the deformation ability. Boron and carbon are both atoms with high electronegativity and small atomic radii. They can fully enter the iron atom lattice to break the metallic bonds and tend to form covalent bonds with directionality and electron localization thresholds, thereby achieving the processing properties required by the present invention, such as reducing plasticity, increasing strength, elasticity, and resistivity. However, the solubility of boron or carbon in metallic Fe is very small (less than 0.01% by weight). Excessive boron or carbon is extremely likely to precipitate out during the solidification of the iron melt, forming brittle second phases such as Fe3B, Fe2B, FeB, and Fe3C, resulting in brittle fracture of the heater. The first auxiliary element, silicon or phosphorus, also has relatively high electronegativity, but its atomic radius is relatively large, which can inhibit the formation of the above-mentioned second phases and allow a greater addition amount of boron and carbon at the same solidification rate. The second auxiliary element is used to regulate other properties of the alloy, such as oxidation resistance, resistivity, and temperature stability. By using rapid solidification preparation methods such as melt rapid solidification method, melt drawing method, melt atomization method, and vapor deposition method, the iron, boron or carbon components, the first auxiliary element, and the second auxiliary element can be further mixed evenly, and a single-phase structure with uniform composition can be formed in the solidification state, avoiding the formation of second phases, thereby obtaining the characteristics of low plasticity, high strength, high elasticity, and high resistivity.

[0018] Another problem with the iron-based alloy heater is that the Curie temperature of the iron alloy is generally as high as 700 °C, resulting in too high a critical temperature of the equivalent resistance of the heater, and the herb aerosol generating matrix will burn during heating. Surprisingly, by optimizing the addition amounts of boron, carbon, silicon, and phosphorus and the solidification rate, forming a single-phase structure of the iron-based heating alloy and controlling the grain size to be less than 2 nm, the high electronegativity of the above non-iron elements can inhibit the electron exchange interaction in the metal, thereby reducing the Curie temperature to the range of 200 °C to 500 °C, meeting the requirements of the induction heater equivalent resistance critical temperature for heating non-combustible aerosol generating articles. On the other hand, in the alloy prepared by the rapid solidification method, atoms do not have time to arrange to the lowest energy state, resulting in the generation of a large amount of internal stress. These internal stresses can significantly increase the coercivity and contribute to improving the hysteresis loss heating efficiency.

[0019] Although the iron-based heating alloy prepared by the rapid solidification method has many advantages mentioned above, it also has serious problems: since the atoms do not have time to arrange to the lowest energy state, there is a large amount of free space inside the material, which can absorb the force during mechanical processing, has extremely high toughness, and causes very serious wear on processing tools. On the other hand, in the application of heating without burning, the heater is heated from room temperature to near its Curie temperature and works at the Curie temperature for a long time. In the process of heating from room temperature to the Curie temperature and maintaining it, the inventor found that the magnetic permeability of the iron-based heating alloy has a change characteristic of first rising rapidly and then falling sharply, which causes a similar change in the equivalent resistance. This change process of the equivalent resistance rising rapidly with the increase in temperature will cause the heating device to misjudge the heating process and terminate the heating, so it is necessary to reduce this abnormal change of the equivalent resistance below the Curie temperature as much as possible.

[0020] Therefore, the present invention also proposes an aging treatment for the iron-based heating alloy, through which the atoms inside the material are rearranged to a certain extent, the free space inside the material is reduced, and the purpose of reducing the toughness of the material is achieved. It should be pointed out that the aging temperature is preferably low temperature and short time. Too high aging temperature and too long aging time will eliminate stress and reduce coercive force, thereby weakening the hysteresis heating capacity; at the same time, high temperature will also promote grain growth and second phase precipitation, and the material toughness will be reduced due to transition, resulting in brittle fracture, and will also increase the Curie temperature and reduce the resistivity, which are not conducive to the normal operation of the heater. On the other hand, the inventors found that through aging treatment, especially aging treatment at the Curie temperature or a temperature not more than 50°C below the Curie temperature, the adverse change of the equivalent resistance of the heater during formal operation, which rises rapidly with the increase of temperature, can be suppressed, thereby making the heating process more stable.

[0021] It is particularly important to point out that the high coercivity and high resistivity of the iron-based heating alloy in the present invention will significantly improve the energy utilization rate and heating efficiency of electromagnetic induction heating. In induction heating, the heater material has two heating mechanisms, one is eddy current heating and the other is hysteresis heating. The former requires the material to have a high resistivity, and the latter requires the material to have a high coercivity. However, the resistivity cannot be too high (less than 500μΩ·cm), otherwise the induced eddy current will be too small; the coercivity cannot be too high (less than 500A / m), otherwise the magnetic permeability will be too low, reducing the coupling coefficient between the heater and the heating device, and is not conducive to improving the heating efficiency. The iron-based heating alloy used in the heater in the present invention has a higher resistivity and a higher coercivity than the traditional nickel-based alloy, which can effectively improve the induction heating efficiency of the heater. Therefore, in practical applications, the present invention can achieve an efficient heating effect with only a single-layer alloy heater.

[0022] In the present invention, the characteristic dimension of the low-ductility aerosol heater is greater than 50 μm. The so-called characteristic dimension is the maximum dimension that the heater has when measured in any direction. The iron-based heating alloy proposed in the present invention has a room-temperature magnetic permeability less than 2000, a room-temperature resistivity greater than 100 μΩ·cm, and a skin depth of ~25 μm. Setting the characteristic dimension of the heater in the present invention to be greater than 50 μm can ensure that the heater generates a significant eddy current heating effect. If the size is too small, it will not be sufficient to induce a complete and large enough eddy current, reducing the heating efficiency.

[0023] The shape of the aerosol-generating article is one of rod-shaped, cake-shaped, sheet-shaped, and block-shaped;

[0024] The shape of the low-ductility aerosol heater is one or more of rectangular flake-shaped, strip-shaped, fragmented, and powdery: for the rectangular flake-shaped, the width is 2 mm to 5 mm, and the length is 5 mm to 20 mm; for the strip-shaped, the width is 0.1 mm to 2 mm, and the length is 1 mm to 20 mm; for the fragmented, the area of a single fragment is 1 mm 2 ~25 mm 2 ; for the powdery, the area of a single powder is 0.0025 mm 2 ~1 mm 2 .

[0025] The embedding method includes any one or a combination of mechanical inclusion, coating composite, roll pressing composite, and papermaking composite;

[0026] The roll pressing composite method includes one of the following steps:

[0027] 1) Mix the aerosol-generating matrix with the heater, solvent, adhesive, reinforcing agent, humectant, etc. into a thick slurry mixture. The heater can be one or more of rectangular flake-shaped, strip-shaped, powdery, and fragmented; roll the obtained mixture into a thin sheet; after drying, cut it into thin sheets, filaments, or fragmented aerosol-generating matrices embedded with the heater.

[0028] 2) Mix the aerosol-generating matrix with the solvent, adhesive, reinforcing agent, humectant, etc. into a thick slurry mixture, and roll the obtained mixture into a thin sheet; further roll press and composite the thin sheet with the iron-based heating alloy after aging treatment, and the thin sheet is composite on one or both sides of the heating alloy; cut the composite body after drying to obtain the aerosol-generating matrix embedded with the heater.

[0029] The coating and compounding method described above comprises the following steps: mixing an aerosol generating substrate with a solvent, an adhesive, a reinforcing agent, and a humectant to form a thick paste, spreading the thick paste on one or both sides of the iron-based homogeneous heating alloy, wherein the spreading method is any one of casting, coating, and calendering, and the spreading thickness is 0.05 mm to 3.0 mm. After drying and slitting, an aerosol generating substrate embedded with a heater is obtained.

[0030] The papermaking method for compounding comprises the following steps: beating the aerosol generating substrate, adding a solvent for extraction and concentration and solid-liquid separation to obtain a fiber slurry and a concentrated extract; adding a reinforcing agent and an adhesive to the fiber slurry, and performing papermaking on a paper machine to obtain a fiber sheet; roll-compounding the fiber sheet with the iron-based homogeneous heating alloy to obtain a composite of the fiber sheet / alloy sheet, wherein the fiber sheet is compounded on one or both sides of the alloy sheet, and the compounded fiber sheet is one layer or multiple layers; spraying the concentrated extract onto the composite of the fiber sheet / alloy sheet, and after drying and slitting, an aerosol generating substrate embedded with a heater is obtained.

[0031] In the above two steps of roll-compounding, the solvent is any one or a combination of several of water, ethanol, glycerol, propylene glycol, and polyethylene glycol; the adhesive is any one or a combination of several of carboxymethyl cellulose, starch, vegetable gum, protein, and polyvinyl alcohol; the reinforcing agent is any one or a combination of several of fiber-based reinforcing agents, inorganic filler-based reinforcing agents, polymer reinforcing agents, crosslinking agents, and bio-based reinforcing agents; the humectant is any one or a combination of several of polyols, sugars, natural extracts, and polymer humectants.

[0032] The present invention also provides an aerosol generating article having a distributed induction heater configuration; the distributed induction heater configuration is such that two or more strip-shaped heaters are uniformly embedded in the aerosol generating substrate; the strip-shaped heater is any one of the following two: a thin strip-shaped heater with a rectangular or irregular cross-section, and a filament-shaped heater with a circular cross-section; the thickness of the thin strip-shaped heater is 0.008 mm to 0.08 mm, the width is 0.1 mm to 2 mm, and the aspect ratio of length to width is 2.5 to 150; the cross-sectional diameter of the filament-shaped heater is 0.1 mm to 1 mm, and the aspect ratio of length to diameter is 2.5 to 150.

[0033] The present invention also provides a method for preparing a low-toughness aerosol heater, comprising the following steps:

[0034] S1. Weigh iron, a boron-carbon component, a first auxiliary element, and a second auxiliary element as raw materials according to the following weight percentages:

[0035] 70% to 97% iron, 1.6% to 6.2% boron-carbon component, 0% to 10.0% first auxiliary element, 0% to 18% second auxiliary element; the boron-carbon component is any one or a combination of two of boron and carbon; the first auxiliary element is any one or a combination of two of silicon and phosphorus; the second auxiliary element is any one or a combination of multiple of scandium, titanium, vanadium, chromium, manganese, cobalt, copper, zinc, gallium, germanium, indium, tin, antimony, bismuth, lead, aluminum, magnesium, zirconium, niobium, molybdenum, hafnium, tantalum, tungsten, rare earth elements; melting the raw materials in the temperature range of 1200 - 1700 °C to obtain a melt;

[0036] S2. Spray-casting the melt onto a rotating cooling copper roll through a slit nozzle for continuous casting, with a solidification rate of 10 3 °C / s to 10 5 °C / s, to obtain an iron-based heating alloy, and the thickness of the iron-based heating alloy is 0.008 mm to 0.08 mm;

[0037] S3. Aging the iron-based heating alloy obtained in S2, and the aging treatment is any one or two of the following aging treatment methods: (1) natural aging, with a time of not less than 24 h, (2) artificial aging, with a temperature less than 330 °C and an aging time of 5 min to 6 h, (3) artificial aging, with a temperature being the Curie temperature of the iron-based heating alloy or not exceeding 50 °C below the Curie temperature, and an aging time of 5 s to 30 min;

[0038] S4. Machining the iron-based heating alloy obtained in S3 into a preset shape to obtain a heater.

[0039] The present invention also provides a low-toughness aerosol heater prepared by the described preparation method.

[0040] The present invention also provides an application of the low-toughness aerosol heater, which is applied to the preparation of aerosol generating articles.

[0041] The aerosol generating article proposed by the present invention includes an induction heater made of an iron-based heating alloy and an aerosol generating matrix, and has the following beneficial effects: the heater has the characteristics of low plasticity, low toughness, high strength, and high elasticity, with a flat fracture surface, not easily deformed, small tool wear, excellent machining performance, and is very friendly to large-scale production; the raw material cost can be reduced by up to 90% compared with the existing nickel-based alloy heater, and at the same time, the critical temperature of its equivalent resistance is 200 - 500 °C, which can achieve heating without combustion; the heater has a low magnetic permeability, high coercivity and resistivity, and high power loss, and has a very high heating efficiency, and can achieve the purpose of temperature marking and efficient heating simultaneously with only a single-layer configuration; the equivalent resistance changes smoothly with temperature, and can achieve distributed heating while being compatible with commercial induction heating appliances, improving the heating efficiency. Description of the Drawings

[0042] Features described with respect to one aspect or embodiment may also apply to other aspects and embodiments. Specific embodiments will be described below in conjunction with the accompanying drawings and examples. The accompanying drawings are only used to further describe the present invention as examples.

[0043] In the accompanying drawings:

[0044] Figure 1 is a physical diagram of the iron-based heating alloy described in the present invention;

[0045] Figure 2 is an X-ray diffraction pattern of the iron-based heating alloy described in the present invention;

[0046] Figure 3 is a diagram showing the change of the magnetic permeability of the iron-based heating alloy described in the present invention with temperature;

[0047] Figure 4 is the equivalent resistance temperature curve of the heater proposed by the present invention;

[0048] Figure 5 is a physical diagram of the fracture of the heater proposed by the present invention and the fracture of the traditional heater;

[0049] Figure 6 is a physical diagram of the bending deformation and recovery effect of the heater proposed by the present invention;

[0050] Figure 7 is a physical diagram of the bending deformation and recovery effect of the traditional heater;

[0051] Figure 8 is an X-ray diffraction pattern of the iron-based non-single-phase alloy in Comparative Example 3;

[0052] Figure 9 is the equivalent resistance temperature curve of the heater made of the iron-based non-single-phase alloy;

[0053] Figure 10 is an X-ray diffraction pattern of the iron-based non-single-phase alloy in Comparative Example 4;

[0054] Figure 11 is the equivalent resistance temperature curve of the heater made of the iron-based non-single-phase alloy;

[0055] Figure 12 is the specific application effect 1 of the heater proposed by the present invention;

[0056] Figure 13 is the specific application effect 2 of the heater proposed by the present invention;

[0057] Figure 14 is the specific application effect 3 of the heater proposed by the present invention;

[0058] Figure 15It is the fourth specific application effect of the heater proposed by the present invention;

[0059] Figure 16 It is the fifth specific application effect of the heater proposed by the present invention;

[0060] Figure 17 It is the sixth specific application effect of the heater proposed by the present invention;

[0061] Figure 18 It is a physical diagram of the composite of the heater proposed by the present invention and the aerosol - forming substrate;

[0062] Figure 19 It is the seventh specific application effect of the heater proposed by the present invention;

[0063] Figure 20 It is a cross - sectional view of an example of an aerosol - generating article proposed by the present invention;

[0064] Figure 21 It is the heating effect of 5 distributed heaters in an example of an aerosol - generating article proposed by the present invention;

[0065] Figure 22 It is the heating effect of a herringbone arrangement of 4 distributed heaters in an example of an aerosol - generating article proposed by the present invention;

[0066] Figure 23 It is the heating effect of a diamond arrangement of 4 distributed heaters in an example of an aerosol - generating article proposed by the present invention;

[0067] Figure 24 It is the heating effect of a herringbone arrangement of 3 distributed heaters in an example of an aerosol - generating article proposed by the present invention;

[0068] Figure 25 It is the heating effect of a triangular arrangement of 3 distributed heaters in an example of an aerosol - generating article proposed by the present invention;

[0069] Figure 26 It is the heating effect of a single heater in a traditional aerosol - generating article. Detailed implementation manners

[0070] To make the above objects, technical solutions, and advantages of the present invention clearer, simpler, and easier to understand, the following will provide a detailed description of the specific implementation manners of the present invention in conjunction with embodiments and drawings. The following content only gives a general conceptual description and examples of the iron-based heating alloy described in the present invention, the heater prepared based on the iron-based heating alloy, the composite method of embedding the heater in the aerosol-forming substrate, and the actual use effect of the heater in the aerosol-generating article. The described embodiments are part of the embodiments of this application, not all of them. The iron-based heating alloy, heater, composite method of embedding the heater in the aerosol-forming substrate, and aerosol-generating article applying the heater of the present invention can be designed and fabricated in various different configurations. Those skilled in the art can make various modifications or supplements to the following specific embodiments or use similar methods for substitution, as long as they do not deviate from the conceptual description or examples of the present invention, or exceed the scope defined by the claims of this right, they should all fall within the protection scope of the present invention.

[0071] When the heater proposed by the present invention is in use, it needs to be embedded in the herbaceous aerosol-forming substrate to form thermal contact. The herbaceous aerosol-forming substrate includes herbaceous materials such as licorice, mugwort, agarwood, mosquito coils, tea leaves, mint, cedar, tobacco, etc. The shape of the aerosol-forming substrate is one or several of filamentous, sheet-like, strip-like, granular, and powdery. The method of embedding the heater in the herbaceous aerosol-forming substrate includes one or several of simple mechanical intercalation method, coating composite method, roll pressing composite method, and papermaking composite method. The heater embedded in the herbaceous aerosol-forming substrate can be one or multiple.

[0072] Embedding the heater in the herbaceous aerosol-forming substrate by the coating composite method includes the following steps:

[0073] S1. Mix the aerosol-forming substrate with solvents, adhesives, reinforcing agents, humectants, etc. into a thick slurry;

[0074] S2. Spread the thick slurry on the surface of the iron-based heating alloy. The spreading method includes one of casting, coating, and rolling. The spreading thickness is 0.05 mm to 3.0 mm. It can be spread on one side of the iron-based heating alloy or on both sides to obtain a thin sheet;

[0075] S3. Dry and cut the thin sheet obtained in S2 to obtain the aerosol-forming substrate embedded with the heater.

[0076] Embedding the heater in the herbaceous aerosol-forming substrate by the roll pressing composite method can include one of the following steps:

[0077] 1) Mix the aerosol - forming substrate with a heater, a solvent, a binder, a reinforcing agent, a humectant, etc. to form a thick slurry mixture. The heater can be one or several of rectangular thin - sheet shape, thin - strip shape, powder shape, and fragment shape; roll the obtained mixture into a thin sheet; after drying, cut it into thin sheets, filaments or fragments of the aerosol - forming substrate embedded with the heater;

[0078] 2) Mix the aerosol - forming substrate with a solvent, a binder, a reinforcing agent, a humectant, etc. to form a thick slurry mixture, roll the obtained mixture into a thin sheet; further roll - press and laminate the thin sheet with the aged iron - based heating alloy, and the thin sheet is laminated on one or both sides of the heating alloy; after drying the composite body, cut it to obtain the aerosol - forming substrate embedded with the heater;

[0079] The method of embedding a heater in a herbaceous aerosol - forming substrate by using the papermaking lamination method may include the following steps:

[0080] S1. After beating the aerosol - forming substrate, add a solvent for extraction and solid - liquid separation to obtain an extraction liquid and a fiber slurry, and concentrate the extraction liquid to obtain a concentrated extraction liquid;

[0081] S2. Add the above - mentioned reinforcing agent and binder to the fiber slurry obtained in S1, and carry out papermaking on a paper machine to obtain a fiber thin sheet;

[0082] S3. Roll - press and laminate the fiber thin sheet obtained in S2 with the iron - based heating alloy under high temperature and high pressure to obtain a composite body of fiber thin sheet / alloy thin sheet. The fiber thin sheet is laminated on one or both sides of the alloy thin sheet, and the laminated fiber thin sheet is one or more layers;

[0083] S4. Spray the concentrated extraction liquid onto the composite body of fiber thin sheet / alloy thin sheet, and after drying and cutting, obtain the aerosol - forming substrate embedded with the heater.

[0084] In the above practices of embedding a heater in an aerosol - forming substrate by using the coating lamination method, the roll - press lamination method, and the papermaking lamination method, the solvent is one or several of water, ethanol, glycerol, propylene glycol, polyethylene glycol; the binder is one or several of carboxymethyl cellulose, starch, plant gum, protein, polyvinyl alcohol; the reinforcing agent is one or several of fiber - type reinforcing agents, inorganic filler - type reinforcing agents, polymer reinforcing agents, cross - linkers, and bio - based reinforcing agents; the humectant is one or several of polyols, sugars, natural extracts, and polymer humectants.

[0085] The fiber-based reinforcing agent is selected from any one or several combinations of the following: wood pulp fiber, hemp fiber, cotton fiber; the inorganic filler-based reinforcing agent is selected from any one or several combinations of the following: calcium carbonate, silica, diatomaceous earth, talcum powder, kaolin, magnesium oxide; the polymer reinforcing agent is selected from any one or several combinations of the following: sodium polyacrylate, polyvinylpyrrolidone, vinyl acetate, styrene-acrylic emulsion; the cross-linking agent is selected from any one or several combinations of the following: aldehyde cross-linking agent, epoxy cross-linking agent, carboxylic acid cross-linking agent, metal ion cross-linking agent, and the bio-based reinforcing agent is selected from any one or several combinations of the following: plant polysaccharide, bacterial cellulose, xanthan gum, sodium alginate, genipin, tannic acid; the polyhydric alcohols are selected from any one or several combinations of the following: glycerol, sorbitol; the saccharides are selected from any one or several combinations of the following: glucose, fructose, malt syrup; the natural extracts are selected from any one or several combinations of the following: aloe vera gel, honey; the polymer moisturizing agent is selected from any one or several combinations of the following: sodium hyaluronate, polyethylene glycol.

[0086] By using the above coating composite method, roll pressing composite method, or papermaking composite method to composite the aerosol-forming substrate on the surface of a coiled iron-based heating alloy and then slicing, cutting into strips, or fragmenting, it can achieve the effect that each aerosol-forming substrate (such as a reconstituted tobacco sheet, strip, or fragment) in the product application is embedded with a corresponding area of the heater, enabling the heater to have sufficient contact area with the aerosol-forming substrate. Compared with the traditional mechanical inclusion method of a single heating sheet, distributed heating is achieved, significantly increasing the aerosol generation efficiency. It should be noted that the iron-based heating alloy used to prepare the heater in the present invention can be a continuous thin strip coil with a minimum thickness of 0.008 mm and a maximum width of 300 mm, enabling high-efficiency roll-to-roll production. However, the traditional nickel-based alloy heater is too thick (~0.06 mm) and is only suitable for the composite method of mechanical inclusion embedding, and is not suitable for being composite with the aerosol-forming substrate using the above method.

[0087] The following describes the preparation method of the heater proposed by the present invention, including the following steps:

[0088] S1. Weigh 70% - 97% of iron, one or two of boron and carbon at 1.6% - 6.2%, one or two of the first auxiliary elements phosphorus and silicon at 0% - 10%, and one or several elements of the second auxiliary elements scandium, titanium, vanadium, chromium, manganese, cobalt, copper, zinc, gallium, germanium, indium, tin, antimony, bismuth, lead, aluminum, magnesium, zirconium, niobium, molybdenum, hafnium, tantalum, tungsten, rare earth elements at 0% - 18% by weight percentage, and place the raw material elements into a furnace for smelting within the temperature range of 1200 - 1700 °C. Preferably, carry out melting within the range of 1300 °C - 1500 °C;

[0089] S2. The melt is spray-cast onto a rotating cooled copper roll through a slit nozzle for continuous casting, with a solidification rate of 10 3 ℃ / s to 10 5 ℃ / s, to obtain an iron-based heating alloy sheet with a thickness of 0.008 mm to 0.08 mm, preferably 0.01 mm to 0.04 mm, and more preferably 0.02 mm to 0.03 mm; the width is 0.5 mm to 300 mm, preferably 2 mm to 150 mm, and more preferably 4 mm to 60 mm;

[0090] S3. The thin strip obtained in S2 is subjected to aging treatment, slitting, slicing, wire cutting, pulverizing, sieving and other processes to obtain the heater; the heater obtained in S2 is mechanically mixed with a filamentous, sheet-like, strip-like, granular, powdery aerosol generating substrate to achieve mechanical inclusion and embedding; or the aerosol generating substrate is compounded with the aged iron-based heating alloy sheet by means of roll pressing compounding, coating compounding, papermaking method compounding, etc., and then subjected to slitting, slicing, wire cutting, pulverizing, sieving and other processes to obtain a heater embedded in the herbal aerosol generating substrate.

[0091] The following describes the aerosol generating article with a distributed heater configuration proposed by the present invention.

[0092] An aerosol generating article with a distributed heater configuration has two or more strip-shaped heaters embedded in the aerosol generating substrate. The strip-shaped heaters can be thin strip-shaped heaters with a rectangular or irregular cross-section, or can be fine wire-shaped heaters with a circular cross-section. The thin strip-shaped heaters have a thickness of 0.008 mm to 0.08 mm, a width of 0.1 mm to 2 mm, and an aspect ratio of 2.5 to 150. The fine wire-shaped heaters have a cross-sectional diameter of 0.1 mm to 1 mm and an aspect ratio of 2.5 to 150.

[0093] It should be noted that when preparing the induction heater by the preparation method proposed by the present invention, even if a small amount of nickel element is added, it will not change the use performance of the heater of the present invention, but only increase the cost. Therefore, the induction heater and the aerosol generating article prepared by adding nickel element on the basis of the present invention also fall within the protection scope of the present invention.

[0094] The following makes a specific implementation description of the preparation, performance and material cost of the low-ductility iron-based alloy heater in the present invention.

[0095] Example 1. Weigh 91.72% of iron, 2.96% of boron, and 5.32% of silicon by weight percentage and place them into a melting furnace. After melting evenly at 1380 °C, the melt is spray-cast onto a rotating cooled copper roll through a slit nozzle, with a solidification rate greater than 1300 °C / s, to obtain an iron-based heating alloy with a thickness of 0.025 mm and a width of 4 mm (attachedFigure 1 as shown). The X-ray diffraction pattern of the iron-based alloy is as attached Figure 2 as shown. It can be seen that there is only the (110) diffraction peak of metallic iron, and the corresponding grain size is ~0.5 nm. There are no diffraction peaks of other phases, indicating that the alloy is a single-phase structure. After 24 h of natural aging, the permeability of the iron-based heating alloy is 325, the coercivity is 13 A / m, the resistivity is 128 μΩ·cm, the power loss at 50 Hz / 1.3 T is greater than 0.42 W / kg, and the permeability-temperature curve (attached Figure 3 ) shows that the Curie temperature is 408 °C. The iron-based heating alloy obtained by aging is made into a rectangular heater with dimensions of 4 mm * 11 mm, and its equivalent resistance drops sharply near the Curie temperature (attached Figure 4 ), proving that it can be used to heat non-combustible aerosol-generating articles.

[0096] Through mechanical testing, the shear toughness of the heater is 50 kJ / m 2 , the tensile strength is 1800 MPa, the strain is less than 2.5%, the cut section of the heater is flat, and there is no curling phenomenon (attached Figure 5 on the left). After the bending test, the heater can return to a flat state (attached Figure 6 ). In contrast, the heaters made of traditional nickel-based alloys (Comparative Example 1 and Comparative Example 2) have severely curled edges (attached Figure 5 on the right) and undergo irreversible deformation after the bending test (attached Figure 7 ).

[0097] Attached Figure 3 At the same time, the permeability-temperature curves of different iron-based heating alloys without aging, after 24 h of natural aging, and after aging at 408 °C for 15 s were compared. It can be seen that the permeability of all three alloys rapidly decays near 408 °C. However, for the samples after aging, the permeability is more stable at temperatures below the Curie temperature. For the non-aged sample, the permeability increases sharply when the temperature approaches the Curie temperature and then drops suddenly. Attached Figure 4 shows the equivalent resistance-temperature curves of the heaters made of the above three alloys. It can be seen that after aging treatment (indicated by the two dashed lines), as the temperature increases, the range of change in the equivalent resistance decreases significantly until it drops suddenly at the Curie temperature. This stable equivalent resistance-temperature curve induced by aging treatment is crucial for the stable operation of heating appliances during non-combustible heating applications.

[0098] Table 1 compares the properties of the iron-based heating alloy after different aging treatments. It can be seen that the toughness of the unaged iron-based heating alloy is too high, resulting in difficult shearing and severe tool wear. After natural aging or artificial aging, the toughness can be effectively reduced, and at the same time, the strength decreases, making shearing processing easier. The iron-based heating alloy must have a certain range of toughness and strength to facilitate roll-to-roll processing (which withstands tensile stress) and rapid punching processing (which withstands shear force). However, after over-aging (the conditions marked with an underline), the toughness decreases excessively and the strength drops severely. The alloy is extremely prone to fragmentation and cannot be subjected to stretching operations and shearing processing. At the same time, over-aging also leads to too low coercivity and too low power loss, which is not conducive to improving the heating efficiency of the heater.

[0099] Table 1

[0100]

[0101] Example 2: Weigh 83.5% iron, 1.95% boron, 7.7% silicon, 5.6% niobium, 1.2% copper, and 0.05% chromium by weight percentage and place them into a melting furnace. After melting evenly at 1400 °C, spray the molten liquid onto a rotating cooling copper roll through a slit nozzle, with a solidification rate greater than 1000 °C / s, to obtain an iron-based heating alloy with a thickness of 0.012 mm and a width of 10 mm. After 48 h of natural aging, the coercivity of the iron-based heating alloy is 10 A / m, the magnetic permeability is 600, the resistivity is 135 μΩ·cm, and the power loss at 50 Hz / 1.3 T is greater than 0.45 W / kg. The obtained iron-based heating alloy is made into a rectangular heater with dimensions of 4 mm * 11 mm, and its equivalent resistance critical temperature is 340 °C.

[0102] The shear toughness of the heater obtained through mechanical testing is 59 kJ / m 2 , the tensile strength is 1950 MPa, the strain is less than 3%, and the cut section of the heater is flat without curling. Table 2 compares the toughness reduction effects of the iron-based heating alloy after different aging treatments. It can be seen that the toughness of the unaged iron-based heating alloy is too high, resulting in difficult shearing and severe tool wear. After natural aging or artificial aging, the toughness can be effectively reduced, and at the same time, the strength decreases, making shearing processing easier. Similar to Example 1, after over-aging (the conditions marked with an underline), the toughness decreases excessively and the strength drops severely. The alloy is extremely prone to fragmentation and cannot be subjected to stretching operations and shearing processing.

[0103] Table 2

[0104]

[0105] Example 3: Weigh 95.15% iron, 3.6% boron, 0.05% carbon, 1.15% silicon, and 0.05% aluminum by weight percentage and place them into a melting furnace. After melting evenly at 1350°C, spray the molten liquid onto a rotating cooled copper roller through a slit nozzle, with a solidification rate greater than 1200°C / s, to obtain an iron-based alloy with a thickness of 0.030 mm and a width of 10 mm. After aging at 100°C for 6 h, the magnetic permeability is 280, the coercive force is 18 A / m, the resistivity is 130 μΩ·cm, and the power loss at 50 Hz / 1.3 T is greater than 0.48 W / kg. The obtained iron-based heating alloy is made into a rectangular heater with dimensions of 4 mm * 11 mm, and its equivalent resistance critical temperature is 500°C. Through mechanical testing, the toughness of this heater is 30 kJ / m 2 , the tensile strength is 1200 MPa, the shear strain is less than 2.8%, and the cut section of the heater is flat without curling phenomenon.

[0106] Example 4: Weigh 92.2% iron, 5.7% boron, 1.85% silicon, and 0.25% vanadium by weight percentage and place them into a melting furnace. After melting evenly at 1360°C, spray the molten liquid onto a rotating cooled copper roller through a slit nozzle, with a solidification rate greater than 1800°C / s, to obtain an iron-based alloy with a thickness of 0.032 mm and a width of 10 mm. After aging at 80°C for 10 h, the magnetic permeability is 305, the coercive force is 22 A / m, the resistivity is 131 μΩ·cm, and the power loss at 50 Hz / 1.3 T is greater than 0.51 W / kg. The obtained iron-based heating alloy is made into a rectangular heater with dimensions of 4 mm * 11 mm, and its equivalent resistance critical temperature is 452°C. Through mechanical testing, the shear toughness of this heater is 32 kJ / m 2 , the tensile strength is 1350 MPa, the shear strain is less than 2.1%, and the cut section of the heater is flat without curling phenomenon.

[0107] Example 5: Weigh 82.2% iron, 2.25% boron, 7.05% silicon, 8.4% chromium, and 0.1% zirconium by weight percentage and place them into a melting furnace. After melting evenly at 1360°C, spray the molten liquid onto a rotating cooled copper roller through a slit nozzle, with a solidification rate greater than 2000°C / s, to obtain an iron-based alloy with a thickness of 0.035 mm and a width of 10 mm. After natural aging for 24 h, the magnetic permeability is 420, the coercive force is 18 A / m, the resistivity is 125 μΩ·cm, and the power loss at 50 Hz / 1.3 T is greater than 0.46 W / kg. The obtained iron-based heating alloy is made into a rectangular heater with dimensions of 4 mm * 11 mm, and its equivalent resistance critical temperature is 233°C. Through mechanical testing, the shear toughness of this heater is 28 kJ / m 2 , the tensile strength is 1160 MPa, the shear strain is less than 1.8%, and the cut section of the heater is flat without curling phenomenon.

[0108] Example 6: Weigh 83.2% iron, 1.95% boron, 7.7% silicon, 5.85% molybdenum, and 1.3% copper by weight percentage and place them into a melting furnace. After melting evenly at 1390 °C, spray the molten liquid onto a rotating cooled copper roller through a slit nozzle, with a solidification rate greater than 1800 °C / s, to obtain an iron-based alloy with a thickness of 0.04 mm and a width of 10 mm. After aging at 80 °C for 4 h, the magnetic permeability is 356, the coercive force is 22 A / m, the resistivity is 150 μΩ·cm, and the power loss at 50 Hz / 1.3 T is greater than 0.66 W / kg. The obtained iron-based heating alloy is made into a rectangular heater with dimensions of 4 mm * 11 mm, and its equivalent resistance critical temperature is 320 °C. Through mechanical testing, the shear toughness of this heater is 25 kJ / m 2 , the tensile strength is 1036 MPa, the shear strain is less than 1.6%, and the cut section of the heater is flat without curling.

[0109] Example 7: Weigh 90.2% iron, 1.7% coke, and 8.1% phosphorus by weight percentage and place them into a melting furnace. After melting evenly at 1400 °C, spray the molten liquid onto a rotating cooled copper roller through a slit nozzle, with a solidification rate greater than 2100 °C / s, to obtain an iron-based alloy with a thickness of 0.042 mm and a width of 10 mm. After aging at 120 °C for 1 h, the magnetic permeability is 310, the coercive force is 21 A / m, the resistivity is 133 μΩ·cm, and the power loss at 50 Hz / 1.3 T is greater than 0.54 W / kg. The obtained iron-based heating alloy is made into a rectangular heater with dimensions of 4 mm * 11 mm, and its equivalent resistance critical temperature is 306 °C. Through mechanical testing, the shear toughness of this heater is 20 kJ / m 2 , the tensile strength is 952 MPa, the shear strain is less than 1.8%, and the cut section of the heater is flat without curling.

[0110] Example 8: Weigh 80.6% iron, 3.1% boron, 3.0% phosphorus, and 13.3% lanthanum by weight percentage and place them into a melting furnace. After melting evenly at 1390 °C, spray the molten liquid onto a rotating cooled copper roller through a slit nozzle, with a solidification rate greater than 2500 °C / s, to obtain an iron-based alloy with a thickness of 0.018 mm and a width of 10 mm. After aging at 200 °C for 1 h, the magnetic permeability is 180, the coercive force is 29 A / m, the resistivity is 148 μΩ·cm, and the power loss at 50 Hz / 1.3 T is greater than 0.72 W / kg. The obtained iron-based heating alloy is made into a rectangular heater with dimensions of 4 mm * 11 mm, and its equivalent resistance critical temperature is 200 °C. Through mechanical testing, the shear toughness of this heater is 32 kJ / m 2 , the tensile strength is 1215 MPa, the shear strain is less than 2.2%, and the cut section of the heater is flat without curling.

[0111] Example 9: Weigh 95.4% iron and 4.6% boron by weight percentage and place them into a melting furnace. After melting evenly at 1350°C, spray the molten liquid onto a rotating cooling copper roll through a slit nozzle, with a solidification rate greater than 3000°C / s, to obtain an iron-based alloy with a thickness of 0.012 mm and a width of 10 mm. After aging at 200°C for 1 h, the magnetic permeability is 258, the coercivity is 32 A / m, the resistivity is 140 μΩ·cm, and the power loss at 50 Hz / 1.3 T is greater than 0.68 W / kg. The obtained iron-based heating alloy is made into a rectangular heater with dimensions of 4 mm * 11 mm, and its equivalent resistance critical temperature is 370°C. Through mechanical testing, the shear toughness of this heater is 35 kJ / m 2 , the tensile strength is 1138 MPa, the shear strain is less than 2.3%, and the cut section of the heater is flat without curling phenomenon.

[0112] Comparative Example 3: Using the same elemental formula as in Example 2, after melting evenly at 1400°C, spray the molten liquid onto a rotating cooling copper roll through a slit nozzle, with a solidification rate of 100°C / s, to obtain an iron-based alloy with a thickness of 0.4 mm and a width of 1 mm. The X-ray diffraction pattern of this iron-based alloy has three diffraction peaks of (110), (200), and (211) of metallic iron (attached Figure 8 ), the grain size is ~15 nm, and at the same time, there are also diffraction peaks of the second phase such as Fe3B, proving that this alloy is not a single-phase structure. The magnetic permeability of this iron-based alloy is 3500, the coercivity is 3 A / m, the resistivity is 132 μΩ·cm, and the power loss at 50 Hz / 1.3 T is greater than 0.46 W / kg. The obtained iron-based alloy is made into a rectangular heater with dimensions of 4 mm * 11 mm, and its equivalent resistance drops sharply near 620°C (attached Figure 9 ), far exceeding the ignition point of the herbaceous aerosol generation matrix and cannot be used. Through mechanical testing, the shear toughness of the heater prepared based on this iron-based alloy is 5 kJ / m 2 , the tensile strength is 180 MPa, the shear strain is less than 0.2%, and the cut section of the heater is flat. However, due to the presence of the second phase, the material is too brittle, and the heater is prone to breakage and fracture. This comparative example proves that even with the same formula, if the grain size is too large or the material is not a single-phase alloy, the performance of the induction heater will deteriorate.

[0113] Comparative Example 4: The same types of elements as in Example 3 were used, but the content of the main element boron was reduced. The specific formula is as follows: Weigh 95.15% of iron, 1.5% of boron, 0.05% of carbon, 3.25% of silicon, and 0.05% of aluminum by weight percentage and place them into a melting furnace. After melting evenly at 1380 °C, the molten liquid was spray-cast onto a rotating cooling copper roller through a slit nozzle, and the solidification rate was greater than 1300 °C / s to obtain an iron-based alloy with a thickness of 0.025 mm and a width of 4 mm. The X-ray diffraction pattern of this iron-based alloy had three diffraction peaks of (110), (200), and (211) of metallic iron (attached Figure 10 ), the grain size was ~6 nm, and there were also diffraction peaks of the second phase, indicating that the alloy was not a single-phase structure. The magnetic permeability of this iron-based alloy was 2100, the coercivity was 3.5 A / m, the resistivity was 98 μΩ·cm, and the power loss at 50 Hz / 1.3 T was greater than 0.43 W / kg. The iron-based alloy was made into a rectangular heater with dimensions of 4 mm * 11 mm, and its equivalent resistance dropped suddenly near 700 °C (attached Figure 11 ), far exceeding the ignition point of the herbal aerosol generation matrix and thus could not be used. Through mechanical testing, the shear toughness of the heater prepared based on this iron-based alloy was 6 kJ / m 2 , the tensile strength was 100 MPa, the shear strain was less than 7%, and the cut section of the heater was slightly curled. Although the processing performance of this heater was acceptable, the too large grain size led to too high an equivalent resistance critical temperature, making it unable to be used for heating non-combustible aerosol generation articles. This comparative example proves that too little boron-silicon component is not conducive to controlling the grain size and the equivalent resistance critical temperature, and will also deteriorate the performance of the induction heater.

[0114] Table 3 lists the composition, magnetic permeability, coercivity, power loss, resistivity of the iron-based heating alloy in the above examples, as well as the equivalent resistance critical temperature, toughness, strength, strain, and raw material cost of the corresponding heaters. At the same time, the same type of parameters of commercially available iron-nickel alloy heating materials (grades 1j85 and 1j79 respectively) were compared. It can be seen that the coercivity of the iron-based heating alloy of the present invention is higher than that of the nickel-based alloy, the resistivity is higher than that of the nickel-based alloy, the magnetic permeability is lower than that of the nickel-based alloy, the power loss is greater, and the heater prepared based on the iron-based heating alloy has higher heating efficiency, a wider range of equivalent resistance critical temperature, lower toughness, higher strength, and smaller deformation than the heater prepared based on the nickel-based alloy. And due to the absence of nickel element, the material cost advantage is also very obvious.

[0115] Table 3

[0116]

[0117] The following specifically describes the actual application effects of the aerosol generation article containing the heater proposed by the present invention.

[0118] The heater proposed by the present invention is used for the non-combustion inductive heating of herbaceous aerosol generation matrices such as licorice, wormwood, agarwood, mosquito coils, tea leaves, mint, cedar, and tobacco. The herbaceous aerosol generation matrix to be heated can be one or several of filamentous, strip-shaped, flake-shaped, granular, and powdery. The shape of the heater can be any shape that can be made of the aforementioned iron-based heating alloy. Preferably, it can be one or several of rectangular flake-shaped, strip-shaped, filament fragment-shaped, and powdery. The thickness of the heater is 0.008 mm to 0.08 mm, preferably 0.01 mm to 0.4 mm, and more preferably 0.02 mm to 0.03 mm. The size of the rectangular flake-shaped heater is 2 mm to 5 mm in width, preferably 2.5 mm to 4.5 mm; 5 mm to 20 mm in length, preferably 5 mm to 15 mm, and more preferably 8 mm to 12 mm. The size of the strip-shaped heater is 0.1 mm to 2 mm in width, preferably 0.5 mm to 1 mm; 1 mm to 20 mm in length, preferably 5 mm to 15 mm, and more preferably 8 mm to 12 mm. The fragment-shaped heater can be any non-slender and irregular shape such as square, triangular, and polygonal. The area of a single fragment is 1 mm 2 ~25 mm 2 , preferably 4 mm 2 ~9 mm 2 ; for the powdery heater, a single powder can be any non-slender shape such as rectangular, triangular, circular, and polygonal. The area of a single powder is 0.0025 mm 2 ~1 mm 2 , preferably 0.01 to 0.25 mm 2 .

[0119] It should be noted that multiple strip-shaped, fragment-shaped, and powdery heaters can be embedded in the aerosol generation article of the present invention to be in full contact with the aerosol generation matrix to achieve distributed heating, thereby more fully increasing the contact area between the heater and the aerosol generation matrix and adapting to the existing mainstream commercial inductive heating aerosol generation appliances.

[0120] Figure 21 , 22 Figures 23, 24, and 25 respectively show the technical solutions of the cross arrangement of 5 distributed heaters, the herringbone arrangement of 4 distributed heaters, the diamond arrangement of 4 distributed heaters, the herringbone arrangement of 3 distributed heaters, and the triangular arrangement of 3 distributed heaters. However, in some aerosol generation articles, a whole piece of heater can be embedded in the aerosol generation matrix, such as Figure 26As shown, this type of application does not change the trend of the equivalent resistance of the heater with temperature, and can also make the heater compatible with existing mainstream commercial induction heating aerosol generating devices. This type of implementation does not deviate from the protection scope of the present invention.

[0121] Example Ten: In this example, a mixture of cedar powder and licorice powder for treating pharyngitis is used as the aerosol generating matrix, and 10 heaters with a thickness of 0.015 mm, a width of 0.5 mm, and a length of 11 mm made of the alloy composition after 24 hours of natural aging in Example One are embedded (attached Figure 12 on the left). Using a mainstream induction heating device on the market (model IQOS ILUMA) for heating, it can be found that the heater successfully realizes non-combustion heating of the aerosol generating matrix (the black part in the attachment Figure 12 in the middle). It is also possible to embed 1 heater with a thickness of 0.025 mm, a width of 4 mm, and a length of 11 mm made of the alloy described in Example One in the aerosol generating matrix, and it can be found that a single heater also successfully realizes non-combustion heating of the aerosol generating matrix (the black part in the attachment Figure 12 on the right).

[0122] New tobacco is an important application of the non-combustion induction heating aerosol generation technology. In the following examples, reconstituted tobacco sheets are used as the aerosol generating matrix, and a mainstream induction heating device on the market (model IQOS ILUMA) is used for heating to illustrate the practicality of the present invention.

[0123] Example Eleven: In this example, reconstituted tobacco sheets are used as the aerosol generating matrix, and 5 heaters with a thickness of 0.02 mm, a width of 1 mm, and a length of 11 mm made of the alloy after 24 hours of natural aging in Example One are embedded in the aerosol generating matrix (attached Figure 13 on the left). Using a mainstream induction heating device on the market for heating, it can be found that the heater successfully realizes non-combustion heating of the aerosol generating matrix (the black part in the attachment Figure 13 on the right). And the automatic identification, heating time, number of puffs, smoke volume, etc. all reach the level of current nickel-based alloy heaters.

[0124] Example Twelve: In this example, reconstituted tobacco sheets are used as the aerosol generating matrix, and 1 heater with a thickness of 0.04 mm, a width of 4 mm, and a length of 11 mm made of the alloy after 48 hours of natural aging in Example Two is embedded (attached Figure 14 on the left). Using a mainstream induction heating device on the market for heating, it can be found that the heater successfully realizes non-combustion heating of the aerosol generating matrix (the black part in the attachment Figure 14 on the right). And the automatic identification, heating time, number of puffs, smoke volume, etc. all reach the level of current nickel-based alloy heaters.

[0125] Example 13: In this example, a reconstituted tobacco sheet is used as the aerosol generation matrix, and 1 heater made of the alloy in Example 3 with a thickness of 0.05 mm, a width of 4 mm, and a length of 11 mm is embedded (attached Figure 15 ). Using a mainstream induction heating appliance on the market for heating, it can be found that the heater successfully achieves non-combustion heating of the aerosol generation matrix (attached Figure 15 black part). And the automatic identification, heating time, number of puffs, amount of smoke, etc. all reach the level of current nickel-based alloy heaters. Due to the relatively high critical temperature of the equivalent resistance of this heater (500 °C), the tobacco sheet is carbonized to a relatively high degree.

[0126] Example 14: In this example, a reconstituted tobacco sheet is used as the aerosol generation matrix, and heaters made of the alloy in Example 1 after 24-hour natural aging and transitional artificial aging (360 °C, 40 min) with a thickness of 0.025 mm, a width of 4 mm, and a length of 11 mm are embedded in the aerosol generation matrix, and a mainstream induction heating appliance on the market is used for heating. It can be found that the heater after natural aging achieves non-combustion heating of the aerosol generation matrix (attached Figure 16 left). And the automatic identification, heating time, number of puffs, amount of smoke, etc. all reach the level of current nickel-based alloy heaters. In contrast, the heater after transitional artificial aging has too low coercive force and too small power loss, resulting in a reduction in heating efficiency. Although the appliance can identify it, the heating effect is very poor (attached Figure 16 right).

[0127] On the other hand, heaters made of the alloy in Example 1 after no aging, 24-hour natural aging, and artificial aging (408 °C, 15 s) with a thickness of 0.025 mm, a width of 5 mm, and a length of 12 mm are embedded in the aerosol generation matrix, and a mainstream induction heating appliance on the market is used for heating. It is found that the heater without aging treatment has a sharp increase in equivalent resistance with the rise in temperature, and the heating appliance reports an error after 5 s of heating, terminating the heating. While the heaters supported by natural aging and artificial aging can automatically identify, and the heating time, number of puffs, amount of smoke, etc. all reach the level of current nickel-based alloy heaters.

[0128] Example 15: In this example, a reconstituted tobacco sheet is used as the aerosol generation matrix, and a fragmented heater made of the alloy in Example 1 (thickness 0.02 mm, fragment area 2 mm 2 ) is evenly embedded in the aerosol generation matrix, and a mainstream induction heating appliance on the market is used for heating. It can be found that the heater successfully achieves non-combustion heating of the aerosol generation matrix (attached Figure 17 black part). And the automatic identification, heating time, number of puffs, amount of smoke, etc. all reach the level of current nickel-based alloy heaters.

[0129] Example 16: In this example, the iron-based heating alloy (with a thickness of 0.012 mm) in Example 2 was laminated with two layers of tobacco sheets by roll lamination (attached Figure 18 ). After being cut into filaments with a width of 1 mm and a length of 11 mm, a sol-generating product was formed. Using a mainstream induction heating appliance on the market for heating, it was found that the heater successfully achieved non-combustion heating of the aerosol-generating matrix (attached Figure 19 ). Moreover, the automatic recognition, heating time, number of puffs, amount of smoke, etc. all reached the level of current nickel-based alloy heaters. Since each tobacco sheet was laminated with a heater inside, this distributed heating method greatly improved the heating efficiency and enhanced the aerosol generation effect, and each tobacco sheet was fully utilized.

[0130] Table 4 compares the aerosol generation effect and the heating appliance matching effect of the heaters in Examples 11 to 16 and commercial nickel-based metal heaters when heating non-combustible tobacco products.

[0131] Table 4

[0132]

[0133] Example 17: This example is an aerosol-generating product with a distributed heater, which is composed of an aerosol-generating matrix, a distributed iron-based alloy heater, a support element, a cooling element, and a filter element (attached Figure 20 ). Among them, the aerosol-generating matrix is a reconstituted tobacco sheet, and the distributed heater has 5 heaters made of the alloy based on Example 1 with a shape of 0.02 mm * 0.6 mm * 10 mm. The support element is made of a cellulose acetate hollow tube, the cooling element is made of a polylactic acid sheet, and the filter element is composed of a cellulose acetate tow. The aerosol-generating matrix, the distributed heater, the support element, the cooling element, and the filter element are rolled into an integral rod shape by a wrapper. Attached Figure 21 - 25 is the heating effect diagram of this aerosol-generating product after using the distributed heater. Distributed heating is achieved by using 5, 4, 4, 3, and 3 heaters respectively. It can be seen that the heating area of the aerosol-generating matrix can be significantly increased. Figure 26 is an aerosol-generating product with a traditional single heater configuration. It can be seen that a large amount of the aerosol-generating matrix is not heated.

Claims

1. An aerosol-generating article, characterized in that, Comprising an aerosol - forming substrate and at least one low - toughness aerosol heater embedded therein; The low - toughness aerosol heater is heated based on the electromagnetic induction effect, made of an iron - based heating alloy after aging treatment, with an equivalent resistance critical temperature of 200°C - 500°C and a characteristic size greater than 50μm; The embedding method includes any one or a combination of mechanical inclusion, coating composite, roll - pressing composite, and papermaking composite; The preparation method of the iron - based heating alloy is one of rapid solidification from melt, melt - drawing, melt - atomization, and vapor deposition, containing 70% - 97% by weight of iron, 1.6% - 6.2% of boron - carbon components, 0% - 10.0% of a first auxiliary element, and 0% - 18% of a second auxiliary element; the boron - carbon components are any one or a combination of boron and carbon; the first auxiliary element is any one or a combination of silicon and phosphorus; the second auxiliary element is any one or a combination of scandium, titanium, vanadium, chromium, manganese, cobalt, copper, zinc, gallium, germanium, indium, tin, antimony, bismuth, lead, aluminum, magnesium, zirconium, niobium, molybdenum, hafnium, tantalum, tungsten, and rare earth elements; The iron - based heating alloy after aging treatment is a single - phase structure, having a single X - ray diffraction peak: the (110) diffraction peak of iron at 2θ≈44.6°, and the grain size is less than 2nm; The aging treatment is one or two of the following aging treatments: Using natural aging for at least 24h; Using artificial aging with an aging temperature less than 330°C and an aging time of 5min - 6h; Using artificial aging with an aging temperature being the Curie temperature of the iron - based heating alloy or not exceeding 50°C lower than the Curie temperature, and an aging time of 5s - 30min.

2. The aerosol-generating article according to claim 1, wherein The iron - based heating alloy after aging treatment has a room - temperature coercivity greater than 4A / m, a room - temperature magnetic permeability less than 2000, a room - temperature resistivity greater than 100μΩ·cm, and a 50Hz / 1.3T power loss greater than 0.4W / kg.

3. The aerosol-generating article according to claim 1, characterized in that, The low-ductility aerosol heater has a single-layer structure with a thickness of 0.008 mm to 0.08 mm, a ductility of 10 to 60 kJ / m 2 , a tensile strength of 200 to 2000 MPa, and a shear strain of less than 3%.

4. The aerosol - forming article according to claim 1, wherein, The shape of the aerosol - forming article is one of rod - shaped, cake - shaped, sheet - shaped, and block - shaped; The shape of the low - toughness aerosol heater is one or several of rectangular thin - sheet - shaped, thin - strip - shaped, fragment - shaped, and powder - shaped: For the rectangular thin - sheet - shaped, the width is 2mm - 5mm and the length is 5mm - 20mm; For the thin - strip - shaped, the width is 0.1mm - 2mm and the length is 1mm - 20mm; The fragmented shape, with the area of a single fragment being 1 mm 2 ~ 25 mm 2 ; The powder form, with the area of a single powder being 0.0025 mm 2 ~1 mm 2 .

5. The aerosol-generating article according to claim 1, wherein, The roll - pressing composite includes one of the following steps: 1) Mix the aerosol - forming substrate with the heater, solvent, binder, reinforcing agent, and humectant to form a thick slurry mixture, and the shape of the heater is one or several of rectangular thin - sheet - shaped, thin - strip - shaped, powder - shaped, and fragment - shaped; roll the thick slurry mixture into a thin sheet; after drying, cut it into thin sheets, filaments, or fragment - shaped aerosol - forming substrates embedded with the heater; 2) Mix the aerosol - generating matrix with a solvent, a binder, a reinforcing agent, and a humectant to form a thick slurry mixture, and roll - press the thick slurry mixture into a thin sheet; further roll - press and laminate the thin sheet with the aged iron - based heating alloy so that the thin sheet is laminated on one or both sides of the iron - based heating alloy to obtain a composite; dry the composite and then cut it to obtain an aerosol - generating matrix embedded with a heater. In the above two steps of roll - press lamination, the solvent is any one or a combination of several of water, ethanol, glycerol, propylene glycol, and polyethylene glycol; the binder is any one or a combination of several of carboxymethyl cellulose, starch, plant gum, protein, and polyvinyl alcohol; the reinforcing agent is any one or a combination of several of fibrous reinforcing agents, inorganic filler reinforcing agents, polymer reinforcing agents, cross - linkers, and bio - based reinforcing agents; the humectant is any one or a combination of several of polyols, sugars, natural extracts, and polymer humectants.

6. The aerosol-generating article according to claim 1, wherein, Having a distributed induction heater configuration; The distributed induction heater configuration is such that two or more long - strip low - toughness aerosol heaters are uniformly embedded in the aerosol - generating matrix; The long - strip low - toughness aerosol heater is any one of the following two: a thin - strip heater with a rectangular or irregular cross - section, and a filament - shaped heater with a circular cross - section; The thickness of the thin - strip heater is 0.008 mm to 0.08 mm, the width is 0.1 mm to 2 mm, and the aspect ratio of length to width is 2.5 to 150; The cross - sectional diameter of the filament - shaped heater is 0.05 mm to 1 mm, and the aspect ratio of length to diameter is 2.5 to 150.

7. A method for preparing a low-ductility aerosol heater, characterized in that, Comprising the following steps: S1. Weigh iron, a boron - carbon component, a first auxiliary element, and a second auxiliary element as raw materials according to the following weight percentages: 70% - 97% of iron, 1.6% - 6.2% of the boron - carbon component, 0% - 10.0% of the first auxiliary element, 0% - 18% of the second auxiliary element; the boron - carbon component is any one or a combination of boron and carbon; the first auxiliary element is any one or a combination of silicon and phosphorus; the second auxiliary element is any one or a combination of several of scandium, titanium, vanadium, chromium, manganese, cobalt, copper, zinc, gallium, germanium, indium, tin, antimony, bismuth, lead, aluminum, magnesium, zirconium, niobium, molybdenum, hafnium, tantalum, tungsten, and rare earth elements; Melt the raw materials in the temperature range of 1200 - 1700 °C to obtain a melt; S2. The melt is spray-cast onto a rotating cooled copper roll through a slit nozzle for continuous casting, with a solidification rate of 10 3 ℃ / s to 10 5 ℃ / s to obtain an iron-based heating alloy, and the thickness of the iron-based heating alloy is 0.008 mm to 0.08 mm; S3. Perform aging treatment on the iron - based heating alloy obtained in S2, and the aging treatment is any one or two of the following aging treatment methods: (1) natural aging, with a time of not less than 24 h; (2) artificial aging, with a temperature less than 330 °C and an aging time of 5 min to 6 h; (3) artificial aging, with a temperature being the Curie temperature of the iron - based heating alloy or not exceeding 50 °C below its Curie temperature and an aging time of 5 s to 30 min; S4. Mechanically process the iron - based heating alloy obtained in S3 into a preset shape to obtain a heater.

8. A low - toughness aerosol heater prepared by the preparation method according to claim 7.

9. Use of the low-toughness aerosol heater according to claim 8, characterized in that, Applied to the preparation of aerosol - generating articles.

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