Low-toughness aerosol heater, preparation method, application and aerosol generating product

Abstract

The invention relates to a low-toughness aerosol heater, a preparation method, application and an aerosol generating product. The aerosol generating product comprises an aerosol generating substrate and a low-toughness aerosol heater embedded in the aerosol generating substrate, the equivalent resistance critical temperature of the aerosol generating product is 200-500 DEG C, and the aerosol generating product can heat the aerosol generating substrate in a non-combustion mode, so that aerosol generation is achieved. The low-toughness induction heater is made of iron-based heating alloy and comprises, by weight, 70%-97% of iron, 1.6%-6.2% of boron-carbon components, 0%-10.0% of first auxiliary elements and 0%-18% of second auxiliary elements. The heater provided by the invention is low in cost, good in machinability, wide in temperature control interval, high in heating efficiency, wide in aerosol generation matrix applicability and high in 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 herbaceous materials such as licorice, mugwort, agarwood, mosquito coils, tea leaves, mint, cedar, and tobacco. In such aerosol generating articles, a heater (also known as 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, quickly converting electrical energy into heat energy and increasing the temperature, 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 herbaceous-based aerosol generation matrix but higher than the aerosol generation temperature, thus 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] Currently, the induction heaters in heat-not-burn aerosol generating products are all made of 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, namely a nickel alloy layer and a stainless steel layer. 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, plate 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 weight percentage of 40% - 62% and nickel with a weight percentage 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 weight percentage of 77% - 81%, molybdenum with a weight percentage of 3.5% - 6%, and iron with a weight percentage 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 products to achieve heat-not-burn, they have at least the following multiple serious deficiencies that have not been overcome: (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 is punched into a rod-shaped aerosol generating product. 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 product 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.

[0005] (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.

[0006] (3) Poor reliability. Due to the low heating efficiency of the single nickel-based alloy, it can only be used as the 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, and a large amount of heat being generated rapidly in the heating layer, causing the aerosol generation matrix to exceed the ignition point and catch fire, resulting in usage accidents. At the same time, the nickel-based alloy is chemically active and is prone to corrosion failure when embedded in the aerosol generation matrix (usually containing moisture) for a long time.

[0007] (4) High cost. A large amount of expensive and scarce precious 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

[0008] 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, a high coercivity, a high resistivity, and a 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 element.

[0009] The aerosol-generating article proposed by the present invention includes an aerosol-generating matrix and at least one low-toughness aerosol heater embedded therein; the low-toughness 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 composite, roll pressing composite, and papermaking composite; the preparation method of the iron-based heating alloy is one of rapid solidification of melt, melt drawing, melt atomization, and vapor deposition, and includes 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; The iron-based heating alloy after aging treatment is a single-phase structure with a single X-ray diffraction peak: the (110) diffraction peak of iron at 2θ≈44.6°, and the grain size is less than 2 nm.

[0010] 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 with an aging temperature less than 330°C and an aging time of 5 min to 6 h; artificial aging is adopted with an aging 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.

[0011] Preferably, the iron-based heating alloy has a room temperature coercivity greater than 4 A / m, a room temperature magnetic permeability less than 2000, a room temperature resistivity greater than 100 μΩ·cm, and a 50 Hz / 1.3 T power loss greater than 0.4 W / kg.

[0012] Preferably, the low-toughness 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 less than 3%.

[0013] The basic principle of the iron-based alloy heater in the aerosol-generating article of the present invention is as follows: The basic performance requirements of the non-combustion induction heating aerosol-generating article for the iron-based alloy heater are: (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 magnetic hysteresis heating requirements of high coercivity and a suitable Curie temperature.

[0014] Metallic iron, like noble metal nickel, has characteristics such as high plasticity, high toughness, low strength, low elasticity, and low resistivity, which are not desirable 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 radii, which can fully enter the iron atom lattice to break the metallic bonds and tend to form covalent bonds with directionality and electron threshold, thereby achieving the processing properties required by the present invention, such as reducing plasticity and increasing strength, elasticity, and resistivity. However, the solubility of boron or carbon in metallic Fe is very small (weight percentage less than 0.01%), and 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, Fe3C, etc., 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 more boron and carbon to be added 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 chemical 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 to avoid the formation of second phases, thereby obtaining the characteristics of low plasticity, high strength, high elasticity, and high resistivity.

[0015] 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 herbaceous aerosol generation matrix will burn during heating. Surprisingly, by optimizing the addition amounts of boron, carbon, silicon, and phosphorus and the solidification rate, when a single-phase structure of the iron-based heating alloy is formed and the grain size is controlled to be less than 2 nm, the high electronegativity of the above non-ferrous elements can inhibit the electron exchange effect in the metal, thereby reducing the Curie temperature to the range of 200 °C to 500 °C, meeting the requirement of the induction heater equivalent resistance critical temperature for heating non-combustible aerosol generation products. 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 a large amount of internal stress generation. These internal stresses can significantly increase the coercivity and contribute to improving the heat generation efficiency of magnetic hysteresis loss.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] In the present invention, the characteristic dimension of the low-toughness aerosol heater is greater than 50 μm. The so-called characteristic dimension refers to the maximum dimension of the heater 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.

[0020] The shape of the aerosol-generating article is one of rod-shaped, cake-shaped, sheet-shaped, and block-shaped; The shape of the low-toughness aerosol heater is one or more of rectangular thin sheet, thin strip, fragment, and powder: for the rectangular thin sheet, the width is 2 mm to 5 mm, and the length is 5 mm to 20 mm; for the thin strip, the width is 0.1 mm to 2 mm, and the length is 1 mm to 20 mm; for the fragment, the area of a single fragment is 1 mm 2 ~25 mm 2 ; for the powder, the area of a single powder is 0.0025 mm 2 ~1 mm 2 .

[0021] The embedding method includes any one or a combination of mechanical inclusion, coating composite, roll compressing composite, and papermaking composite; The roll compressing composite method includes one of the following steps: 1) Mix the aerosol-generating matrix with the heater, solvent, binder, reinforcing agent, humectant, etc. into a thick slurry mixture. The heater can be one or more of rectangular thin sheet, thin strip, powder, and fragment; roll the obtained mixture into a thin sheet; after drying, cut it into thin sheets, filaments, or fragments of the aerosol-generating matrix embedded with the heater.

[0022] 2) Mix the aerosol-generating matrix with the solvent, binder, reinforcing agent, humectant, etc. into a thick slurry mixture, and roll the obtained mixture into a thin sheet; further roll-compress 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; after drying and cutting the composite body, the aerosol-generating matrix embedded with the heater is obtained.

[0023] The coating composite method includes the following steps: Mix the aerosol-generating matrix with the solvent, binder, reinforcing agent, and humectant into a thick slurry, spread the thick slurry on one or both sides of the iron-based homogeneous heating alloy, and the spreading method is any one of casting, coating, and calendering, with a spreading thickness of 0.05 mm to 3.0 mm. After drying and cutting, the aerosol-generating matrix embedded with the heater is obtained; The described papermaking composite method comprises the following steps: beating the aerosol generation matrix, adding a solvent for extraction 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 making paper on a paper machine to obtain a fiber sheet; roll-compounding the fiber sheet with an 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 drying and slitting to obtain an aerosol generation matrix embedded with a heater.

[0024] In the above two steps of roll-compounding, the solvent is any one or a combination of water, ethanol, glycerol, propylene glycol, polyethylene glycol; the adhesive is any one or a combination of carboxymethyl cellulose, starch, plant gum, protein, polyvinyl alcohol; the reinforcing agent is any one or a combination of fiber-based reinforcing agents, inorganic filler-based reinforcing agents, polymer reinforcing agents, crosslinking agents, bio-based reinforcing agents; the humectant is any one or a combination of polyols, saccharides, natural extracts, polymer humectants.

[0025] The present invention also provides an aerosol generation 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 generation matrix; the strip-shaped heater is any one of the following two: a thin strip-shaped heater with a rectangular or irregular cross-section, 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 major axis to minor axis is 2.5 to 150.

[0026] The present invention also provides a preparation method for a low-ductility aerosol heater, 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 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 a temperature range of 1200 - 1700 °C to obtain a melt; S2. Spray-cast the melt 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. 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; S4. Machine the iron-based heating alloy obtained in S3 into a preset shape to obtain a heater.

[0027] The present invention also provides a low-toughness aerosol heater prepared by the described preparation method.

[0028] The present invention also provides an application of the low-toughness aerosol heater, which is applied to the preparation of aerosol-generating articles.

[0029] The aerosol-generating article proposed by the present invention includes an induction heater made of an iron-based heating alloy and an aerosol-generating substrate, 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 easy to deform, small tool wear, excellent machining performance, and very friendly to large-scale production; the raw material cost can be reduced by up to 90% compared with the existing nickel-based alloy heaters. At the same time, the critical temperature of its equivalent resistance is 200 - 500 °C, and heating without combustion can be achieved; the heater has a low magnetic permeability, high coercivity and resistivity, and high power loss, and has a very high heating efficiency. The purpose of temperature marking and efficient heating can be achieved only with a single-layer configuration; the equivalent resistance changes smoothly with temperature, and distributed heating can be achieved while being compatible with commercial induction heating appliances, improving the heating efficiency. Description of the Drawings

[0030] 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 drawings and examples. The drawings are only used to further describe the present invention as examples.

[0031] In the drawings: Figure 1 is a physical diagram of the iron-based heating alloy described in the present invention; Figure 2 is an X-ray diffraction pattern of the iron-based heating alloy described in the present invention; Figure 3 is a diagram of the change of the magnetic permeability of the iron-based heating alloy described in the present invention with temperature; Figure 4 is the equivalent resistance temperature curve of the heater proposed by the present invention; Figure 5 is a physical diagram of the fracture of the heater proposed by the present invention and the fracture of the traditional heater; Figure 6 is a physical diagram of the bending deformation and recovery effect of the heater proposed by the present invention; Figure 7 is a physical diagram of the bending deformation and recovery effect of the traditional heater; Figure 8 is the X-ray diffraction pattern of the iron-based non-single-phase alloy in Comparative Example 3; Figure 9 is the equivalent resistance temperature curve of the heater made of the iron-based non-single-phase alloy; Figure 10 is the X-ray diffraction pattern of the iron-based non-single-phase alloy in Comparative Example 4; Figure 11 is the equivalent resistance temperature curve of the heater made of the iron-based non-single-phase alloy; Figure 12 is the first specific application effect of the heater proposed by the present invention; Figure 13 is the second specific application effect of the heater proposed by the present invention; Figure 14 is the third specific application effect of the heater proposed by the present invention; Figure 15 is the fourth specific application effect of the heater proposed by the present invention; Figure 16 is the fifth specific application effect of the heater proposed by the present invention; Figure 17 is the sixth specific application effect of the heater proposed by the present invention; Figure 18 is a physical diagram of the composite of the heater proposed by the present invention and the aerosol-forming substrate; Figure 19 is the seventh specific application effect of the heater proposed by the present invention; Figure 20 is a cross-sectional view of an example of an aerosol-generating article proposed by the present invention; Figure 21 is the heating effect of 5 distributed heaters in an example of an aerosol-generating article proposed by the present invention; Figure 22 is the heating effect of the herringbone arrangement of 4 distributed heaters in an example of an aerosol-generating article proposed by the present invention; Figure 23 is the heating effect of the diamond arrangement of 4 distributed heaters in an example of an aerosol-generating article proposed by the present invention; Figure 24This is the heating effect of a herringbone arrangement of three distributed heaters in an aerosol-generating article example proposed by the present invention; Figure 25 This is the heating effect of a triangular arrangement of three distributed heaters in an aerosol-generating article example proposed by the present invention; Figure 26 This is the heating effect of a single heater in a traditional aerosol-generating article. Detailed implementation manners

[0032] To make the above objects, technical solutions and advantages of the present invention clearer, simpler and easier to understand, the following will describe in detail the specific implementation manners of the present invention in conjunction with embodiments and drawings. The following content only makes a general conceptual description and examples of the iron-based heating alloy, heater prepared based on the iron-based heating alloy, composite method of embedding the heater in the aerosol-generating matrix, and actual use effect of the heater in the aerosol-generating article described in the present invention. The described embodiments are part of the embodiments of the present application, not all of the embodiments. The iron-based heating alloy, heater, composite method of embedding the heater in the aerosol-generating matrix, and aerosol-generating article applying the heater of the present invention in the embodiments can be designed and made 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 the present invention, they shall fall within the protection scope of the present invention.

[0033] When the heater proposed by the present invention is in use, it needs to be embedded in the herbaceous aerosol-generating matrix to form a thermal contact. The herbaceous aerosol-generating matrix includes herbaceous materials such as licorice, mugwort, agarwood, mosquito coil, tea leaves, mint, cedar, tobacco, etc. The shape of the aerosol-generating matrix is one or several of filamentous, sheet-like, strip-like, granular, and powdery. The method of embedding the heater in the herbaceous aerosol-generating matrix includes one or several of simple mechanical inclusion method, coating composite method, roll pressing composite method, and papermaking composite method. The heater embedded in the herbaceous aerosol-generating matrix can be one or more.

[0034] Embedding the heater in the herbaceous aerosol-generating matrix by the coating composite method includes the following steps: S1. Mix the aerosol-generating matrix with a solvent, binder, reinforcing agent, humectant, etc. into a thick slurry; 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; S3. Dry and slit the sheet obtained in S2 to obtain the aerosol - forming substrate embedded with the heater.

[0035] When embedding the heater in the herb - based aerosol - forming substrate by the roll - pressing lamination method, it can include one of the following steps: 1) Mix the aerosol - forming substrate with the heater, solvent, binder, reinforcing agent, humectant, etc. into a thick slurry mixture. The heater can be one or several of rectangular sheet - like, thin strip - like, powder - like, or fragment - like; roll the obtained mixture into a sheet; after drying, slit it into sheet - like, filament - like, or fragment - like aerosol - forming substrates embedded with the heater; 2) Mix the aerosol - forming substrate with the solvent, binder, reinforcing agent, humectant, etc. into a thick slurry mixture, and roll the obtained mixture into a sheet; further roll - press and laminate the sheet with the iron - based heating alloy after aging treatment, and the sheet is laminated on one or both sides of the heating alloy; after drying the composite body, slit it to obtain the aerosol - forming substrate embedded with the heater; When embedding the heater in the herb - based aerosol - forming substrate by the papermaking lamination method, it can include the following steps: S1. Pulp the aerosol - forming substrate, then add a solvent for extraction and solid - liquid separation to obtain an extract and fiber pulp, and concentrate the extract to obtain a concentrated extract; S2. Add the above - mentioned reinforcing agent and binder to the fiber pulp obtained in S1, and sheet - making on a paper machine to obtain a fiber sheet; S3. Roll - press and laminate the fiber sheet obtained in S2 with the iron - based heating alloy under high temperature and high pressure to obtain a composite body of fiber sheet / alloy sheet, and the fiber sheet is laminated on one or both sides of the alloy sheet, and the laminated fiber sheet is one or more layers; S4. Spray the concentrated extract onto the composite body of fiber sheet / alloy sheet, and after drying and slitting, obtain the aerosol - forming substrate embedded with the heater.

[0036] In the above practices of embedding the heater in the aerosol - forming substrate by the coating lamination method, roll - pressing lamination method, and 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, and the humectant is one or several of polyols, sugars, natural extracts, and polymer humectants.

[0037] 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, silicon dioxide, diatomaceous earth, talc 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 crosslinking agent is selected from any one or several combinations of the following: aldehyde crosslinking agent, epoxy crosslinking agent, carboxylic acid crosslinking agent, metal ion crosslinking 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 moisturizer is selected from any one or several combinations of the following: sodium hyaluronate, polyethylene glycol.

[0038] By using the above coating composite method, roll pressing composite method, or papermaking composite method to composite the aerosol generating 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 generating substrate (such as reconstituted tobacco sheet, strip, fragment) in the product application embeds a corresponding area of the heater, enabling the heater to have sufficient contact area with the aerosol generating 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 generating substrate using the above method.

[0039] The following describes the preparation method of the heater proposed by the present invention, including the following steps: 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 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 the furnace for smelting within the temperature range of 1200 - 1700 °C. Preferably, carry out melting within the range of 1300 °C - 1500 °C; S2. Spray-cast the molten liquid onto a rotating cooling copper roll through a slit nozzle for continuous casting, with a solidification rate of 10 3 °C / s ~ 105 ℃ / 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; S3. After processing the thin strip obtained in S2 through aging treatment, slitting, slicing, wire cutting, pulverizing, sieving, etc., the heater is obtained; the heater obtained in S2 is mechanically mixed with a filamentous, sheet-like, strip-like, granular, or powdery aerosol-forming substrate to achieve mechanical inclusion and embedding; or the aerosol-forming substrate is compounded with the aged iron-based heating alloy sheet by means of roll pressing, coating, papermaking method, etc., and then processed through slitting, slicing, wire cutting, pulverizing, sieving, etc. to obtain a heater embedded in the herbaceous aerosol-forming substrate.

[0040] The following describes the aerosol-generating article with a distributed heater configuration proposed by the present invention.

[0041] An aerosol-generating article with a distributed heater configuration has two or more long strip-shaped heaters embedded in the aerosol-forming substrate. The long strip-shaped heaters can be thin strip-shaped heaters with a rectangular or irregular cross-section, or filamentous 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 filamentous heaters have a cross-sectional diameter of 0.1 mm to 1 mm and an aspect ratio of 2.5 to 150.

[0042] It should be noted that when preparing the induction heater by using 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.

[0043] The following specifically describes the preparation, performance, and material cost of the low-toughness iron-based alloy heater in the present invention.

[0044] Example 1: Weigh 91.72% iron, 2.96% boron, and 5.32% silicon by weight percentage and place them in a melting furnace. After melting evenly at 1380 °C, spray the molten liquid onto a rotating cooling 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 (as shown in the attachment Figure 1 ). The X-ray diffraction pattern of this iron-based alloy is as shown in the attachment Figure 2As 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 was made into a rectangular heater with dimensions of 4 mm * 11 mm, and its equivalent resistance dropped sharply near the Curie temperature (attached Figure 4 ), demonstrating that it can be used to heat non-combustible aerosol-generating articles.

[0045] Through mechanical testing, the shear toughness of the heater was found to be 50 kJ / m 2 , the tensile strength was 1800 MPa, the strain was less than 2.5%, the cut section of the heater was flat, and there was no curling phenomenon (attached Figure 5 left). After the bending experiment, the heater could 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) had severe edge curling (attached Figure 5 right), and irreversible deformation occurred after the bending experiment (attached Figure 7 ).

[0046] 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 decayed rapidly near 408 °C. However, for the samples after aging, the permeability was more stable at temperatures below the Curie temperature. For the un-aged sample, the permeability increased sharply when the temperature approached the Curie temperature and then dropped suddenly. Attached Figure 4 The equivalent resistance-temperature curves of the heaters made of the above three alloys are given. It can be seen that after aging treatment (shown 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.

[0047] Table 1 compares the properties of the iron-based heating alloy after different aging treatments. It can be seen that the unaged iron-based heating alloy has too high toughness, 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 bears tensile stress) and rapid punching processing (which bears shear force). However, after over-aging (the conditions marked under the line), the toughness is excessively reduced, the strength drops severely, the alloy is extremely easy to break, and stretching operation and shearing processing cannot be carried out. At the same time, over-aging will also lead to too low coercivity and too low power loss, which is not conducive to improving the heating efficiency of the heater.

[0048] Table 1

[0049] 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 roller 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 a size of 4 mm * 11 mm, and its equivalent resistance critical temperature is 340 °C.

[0050] Through mechanical testing, the shear toughness of the heater 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 unaged iron-based heating alloy has too high toughness, 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 under the line), the toughness is excessively reduced, the strength drops severely, and the alloy is extremely easy to break, and stretching operation and shearing processing cannot be carried out.

[0051] Table 2

[0052] 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. The solidification rate is greater than 1200 °C / s, obtaining 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. Make the obtained iron-based heating alloy into a rectangular heater with dimensions 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.

[0053] 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. The solidification rate is greater than 1800 °C / s, obtaining 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. Make the obtained iron-based heating alloy into a rectangular heater with dimensions 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.

[0054] 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. The solidification rate is greater than 2000 °C / s, obtaining 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. Make the obtained iron-based heating alloy into a rectangular heater with dimensions 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.

[0055] 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 through a slit nozzle onto a rotating cooled copper roller. The solidification rate is greater than 1800°C / s, obtaining 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%, the cut section of the heater is flat, and there is no curling phenomenon.

[0056] 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 through a slit nozzle onto a rotating cooled copper roller. The solidification rate is greater than 2100°C / s, obtaining 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%, the cut section of the heater is flat, and there is no curling phenomenon.

[0057] 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 through a slit nozzle onto a rotating cooled copper roller. The solidification rate is greater than 2500°C / s, obtaining 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%, the cut section of the heater is flat, and there is no curling phenomenon.

[0058] 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 cooled 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 coercive force 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.

[0059] 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 cooled 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 coercive force 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. 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.

[0060] 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 formulation is as follows: Weigh 95.15% iron, 1.5% boron, 0.05% carbon, 3.25% silicon, and 0.05% aluminum by weight percentage and place them in a melting furnace. After melting evenly at 1380 °C, the molten liquid was spray-cast onto a rotating cooling copper roll 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 has three diffraction peaks of metallic iron, namely (110), (200), and (211) (attached Figure 10 ), the grain size is ~6 nm, and at the same time, there are also diffraction peaks of the second phase, proving that this alloy is not a single-phase structure. The magnetic permeability of this iron-based alloy is 2100, the coercive force is 3.5 A / m, the resistivity is 98 μΩ·cm, and the power loss at 50 Hz / 1.3 T is 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 sharply near 700 °C (attached Figure 11 ), far exceeding the ignition point of the herbaceous aerosol generation matrix and thus unable to 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 is acceptable, the too large grain size results in too high an equivalent resistance critical temperature and it cannot 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.

[0061] Table 3 lists the composition, magnetic permeability, coercive force, 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 (grade numbers are 1j85 and 1j79 respectively) are compared. It can be seen that the coercive force 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 equivalent resistance critical temperature range, lower toughness, higher strength, and smaller deformation than the heater prepared based on the nickel-based alloy. And because it does not contain nickel elements, the material cost advantage is also very obvious.

[0062] Table 3

[0063] The following specifically describes the actual application effects of the aerosol generation article containing the heater proposed by the present invention.

[0064] The heater proposed by the present invention is used for non-combustion induction heating of herbaceous aerosol generation matrices such as licorice, wormwood, agarwood, mosquito coils, tea leaves, mint, cedar, and tobacco. The heated herbaceous aerosol generation matrix can be one or several of filamentous, strip-shaped, flaky, granular, and powdery. The shape of the heater is any shape that can be made of the aforementioned iron-based heating alloy. Preferably, it can be one or several of rectangular flaky, 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 flaky heater is a width of 2 mm to 5 mm, preferably 2.5 mm to 4.5 mm; a length of 5 mm to 20 mm, preferably 5 mm to 15 mm, and more preferably 8 mm to 12 mm. The size of the strip-shaped heater is a width of 0.1 mm to 2 mm, preferably 0.5 mm to 1 mm; a length of 1 mm to 20 mm, 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 .

[0065] 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 existing mainstream commercial induction heating aerosol generation appliances.

[0066] Figure 21 、 22 、23, 24, and 25 respectively give the technical solutions of: 5 distributed heaters arranged in a cross shape, 4 distributed heaters arranged in a herringbone shape, 4 distributed heaters arranged in a diamond shape, 3 distributed heaters arranged in a herringbone shape, and 3 distributed heaters arranged in a pyramid shape. However, in some aerosol generation articles, a whole sheet 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.

[0067] 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 achieves non-combustion heating of the aerosol generating matrix (attached Figure 12 the black part 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 the single heater also successfully achieves non-combustion heating of the aerosol generating matrix (attached Figure 12 the black part on the right).

[0068] 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.

[0069] 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 achieves non-combustion heating of the aerosol generating matrix (attached Figure 13 the black part on the right). And the automatic recognition, heating time, number of puffs, smoke volume, etc. all reach the level of current nickel-based alloy heaters.

[0070] 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 achieves non-combustion heating of the aerosol generating matrix (attached Figure 14 the black part on the right). And the automatic recognition, heating time, number of puffs, smoke volume, etc. all reach the level of current nickel-based alloy heaters.

[0071] Example 13: In this example, reconstituted tobacco sheet is used as the aerosol - generating 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 device on the market for heating, it can be found that the heater successfully achieves non - combustible heating of the aerosol - generating matrix (attached Figure 15 black part). And the automatic recognition, heating time, number of puffs, smoke volume, 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.

[0072] Example 14: In this example, reconstituted tobacco sheet is used as the aerosol - generating matrix, and heaters made of the alloy in Example 1 after 24 - hour natural aging and over - 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 - generating matrix, and a mainstream induction heating device on the market is used for heating. It can be found that the heater after natural aging achieves non - combustible heating of the aerosol - generating matrix (attached Figure 16 left). And the automatic recognition, heating time, number of puffs, smoke volume, etc. all reach the level of current nickel - based alloy heaters. In contrast, for the heater after over - artificial aging, due to the too - low coercive force and too - small power loss, the heating efficiency is reduced, and although the device can recognize it, the heating effect is very poor (attached Figure 16 right).

[0073] 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 - generating matrix, and a mainstream induction heating device on the market is used for heating. It is found that for the heater without aging treatment, due to the sharp increase of the equivalent resistance with the increase of temperature, the heating device reports an error after heating for 5 s and terminates the heating. While the heaters supported by natural aging and artificial aging can automatically recognize, and the heating time, number of puffs, smoke volume, etc. all reach the level of current nickel - based alloy heaters.

[0074] Example 15: In this example, reconstituted tobacco sheet is used as the aerosol - generating 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 - generating matrix, and a mainstream induction heating device on the market is used for heating. It can be found that the heater successfully achieves non - combustible heating of the aerosol - generating matrix (attached Figure 17 black part). And the automatic recognition, heating time, number of puffs, smoke volume, etc. all reach the level of current nickel - based alloy heaters.

[0075] 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 substrate (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 is laminated with a heater inside, this distributed heating method greatly improves the heating efficiency and enhances the aerosol generation effect, and each tobacco sheet is fully utilized.

[0076] Table 4 compares the aerosol generation effect and heating appliance matching effect of the heaters in Examples 11 to 16 and commercial nickel-based metal heaters when heating non-combustible tobacco products.

[0077] Table 4

[0078] Example 17: This example is an aerosol-generating product with a distributed heater, which consists of an aerosol-generating substrate, distributed iron-based alloy heaters, a support element, a cooling element, and a filtering element (attached Figure 20 ). Among them, the aerosol-generating substrate is a reconstituted tobacco sheet, and the distributed heaters are 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 filtering element is composed of a cellulose acetate tow. The aerosol-generating substrate, distributed heaters, support element, cooling element, and filtering element are rolled into an integral rod shape by a wrapper. Attached Figures 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, and it can be seen that the heating area of the aerosol-generating substrate can be significantly increased. Attached Figure 26 is an aerosol-generating product with a traditional single heater configuration, and it can be seen that a large amount of the aerosol-generating substrate 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 to 500°C and a characteristic size greater than 50 μm; 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 method, melt atomization method, and vapor deposition method, containing 70% - 97% by weight of iron, 1.6% - 6.2% of boron - carbon components, 0% - 10.0% of the first auxiliary element, and 0% - 18% of the 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 has a single - phase structure, with a single X - ray diffraction peak: the (110) diffraction peak of iron at 2θ≈44.6°, and the grain size is less than 2 nm.

2. The aerosol-generating article according to claim 1, wherein, The aging treatment is one or two of the following aging treatments: Using natural aging for at least 24 h; Using artificial aging with an aging temperature less than 330°C and an aging time of 5 min to 6 h; Using artificial aging with an aging 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.

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

4. The aerosol-generating article according to claim 1, wherein, The low-toughness 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%.

5. 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 flake - shaped, thin - strip - shaped, fragment - shaped, and powder - shaped: For the rectangular flake - shaped, the width is 2 mm to 5 mm and the length is 5 mm to 20 mm; For the thin - strip - shaped, the width is 0.1 mm to 2 mm and the length is 1 mm to 20 mm; The fragmentary 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 .

6. The aerosol-generating article according to claim 1, characterized in that, 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 flake - shaped, thin - strip - shaped, powder - shaped, and fragment - shaped; roll - press 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 - forming substrate 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 - forming substrate 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, vegetable gum, protein, and polyvinyl alcohol; the reinforcing agent is any one or a combination of several of fibrous reinforcing agents, inorganic filler - type 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.

7. 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 - shaped low - toughness aerosol heaters are evenly embedded in the aerosol - forming substrate; The long - strip - shaped 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 - 0.08 mm, the width is 0.1 mm - 2 mm, and the aspect ratio of length to width is 2.5 - 150; The cross - sectional diameter of the filament - shaped heater is 0.05 mm - 1 mm, and the aspect ratio of major axis to minor axis is 2.5 - 150.

8. A method for preparing a low-toughness 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. Spray-cast the melt onto a rotating cooled 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; 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 - 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 - 30 min; S4. Mechanically process the iron - based heating alloy obtained in S3 into a preset shape to obtain a heater.

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

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

Images