An electronic atomizing liquid and a preparation method thereof

Abstract

This invention discloses an electronic atomizing liquid and its preparation method. By weight, the electronic atomizing liquid comprises: 1%–29.5% oil-soluble flavoring agent, 0–10% flavoring agent, 0–5% nicotine or nicotine salt, 0%–4.8% surfactant, 0.2%–14.9% co-surfactant, and 50%–98% carrier, wherein the carrier comprises one or more of propylene glycol, glycerol, and water. Through the action of the surfactant and co-surfactant, the electronic atomizing liquid is stable and does not become cloudy, exhibits good sensory evaluation after atomization, and has a rich and consistent aroma.

Description

Technical Field

[0001] This disclosure belongs to the field of electronic atomization technology, specifically relating to an electronic atomizing liquid and its preparation method. Background Technology

[0002] Electronic atomizing devices convert liquid into aerosol through an atomizer, thus producing a variety of flavors for people to inhale.

[0003] Existing e-liquids typically include flavoring agents, propylene glycol (PG), and glycerol (VG); optionally, they may also include other components such as nicotine, sweeteners, and cooling agents. Among these, flavoring agents are the key source of aroma, and their amount and type significantly affect the final aroma profile. Some oil-soluble flavoring agents are particularly important for enhancing aroma. Propylene glycol, as the main solvent for flavoring agents, has limited solubility for many oil-soluble flavoring agents. When preparing richly flavored e-liquids, the large amount of flavoring agent added easily leads to phenomena such as floating oil, turbidity, and unstable stratification, resulting in low aroma fidelity and poor consistency after atomization, thus failing to meet consumer demands. To improve the solubility of oil-soluble flavoring agents, a higher content of ethanol is usually added. However, on the one hand, the addition of ethanol increases the irritation of the e-liquid, affecting the taste; on the other hand, ethanol has a low flash point of ~13°C, posing a high flammability and explosive safety risk during atomizer storage and transportation. In addition, many countries or regions have regulations that list ethanol as a prohibited substance or restrict its addition.

[0004] Therefore, it is necessary to provide an improved method for preparing a concentrated-fragrance electronic atomizing liquid that is ethanol-free and has high solubility for oil-soluble flavoring agents. Summary of the Invention

[0005] In view of this, the main objective of the present invention is to construct a microemulsion system by adding surfactants and co-surfactants, and to provide an ethanol-free electronic atomizing liquid that can dissolve high concentrations of oil-soluble fragrances. This electronic atomizing liquid is stable and turbid, has good sensory evaluation after atomization, and has a rich and consistent aroma.

[0006] To achieve the above objectives, this disclosure provides the following technical solution.

[0007] The first aspect of this disclosure provides an electronic atomizing liquid, comprising, by weight: 1% to 29.5% oil-soluble flavoring agent, 0% to 10% flavoring agent, 0% to 5% nicotine or nicotine salt, 0% to 4.8% surfactant, 0.2% to 14.9% co-surfactant, and 50% to 98% carrier.

[0008] In some embodiments, the surfactant content in the electronic atomizing fluid is 0.2% to 2% by weight; preferably, the surfactant content is 0.5% to 1%.

[0009] In some embodiments, the content of co-surfactant in the electronic atomizing fluid is 3% to 10% by weight; preferably, the content of co-surfactant is 3% to 6%.

[0010] In some embodiments, the carrier includes at least one of propylene glycol, glycerol, and water, and the carrier content in the electronic atomizing liquid is 50% to 98% by weight; preferably, the carrier content is 50% to 70%.

[0011] In some embodiments, the carrier includes water, with a water content of at least 50% based on the total weight of the electronic atomizing liquid.

[0012] In some embodiments, the surfactant includes at least one of anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants;

[0013] Preferably, the surfactant includes amphoteric surfactants and / or nonionic surfactants;

[0014] Preferably, the surfactant includes at least one of lauryl sulfate, alkyl ether carboxylate, stearoyl lactate, benzalkonium chloride, lecithin, amino acids, polyglycerol fatty acid esters, sucrose fatty acid esters, monoglyceride fatty acid esters, mono- and diglyceride fatty acid esters, polysorbate fatty acid esters, propylene glycol fatty acid esters, polyoxyethylene alkyl ethers, saponins, castor oil, polyoxyethylene sorbitan fatty acid esters 20-80, and dehydrated sorbitan fatty acid esters 20-80; more preferably, the surfactant includes at least one of lecithin, polyglycerol fatty acid esters, sucrose fatty acid esters, polyoxyethylene sorbitan fatty acid esters 20-80, dehydrated sorbitan fatty acid esters 20-80, and monoglyceride fatty acid esters.

[0015] In some embodiments, the co-surfactant includes at least one of alcohol, ester, amine, and amide, and the co-surfactant has 2 to 20 carbon atoms.

[0016] In some embodiments, the e-liquid does not include a surfactant, and the co-surfactant in the e-liquid includes at least one of n-butanol, isopropanol, isobutanol, isoamyl alcohol, n-hexanol, benzyl alcohol, phenylethanol, phenylpropanol, furfuryl alcohol, ethylene glycol, butanediol, tromethamine, N-methylpyrrolidone, and acetylethanolamine.

[0017] In some embodiments, the e-liquid includes a surfactant, and the co-surfactant in the e-liquid includes glyceryl triacetate, triethyl citrate, glyceryl caprylate, ethyl acetate, n-butyl acetate, isoamyl acetate, ethyl propionate, ethyl butyrate, ethyl glycolate, propyl glycolate, butyl glycolate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isoamyl lactate, leaf lactate, lauryl lactate, hexadecyl lactate, and 3-hydroxybutyric acid. Ethyl acetate, monoethyl succinate, ethyl levulinate, methyl 3-hydroxyhexanoate, ethyl 3-hydroxyhexanoate, ethyl 5-hydroxydecanoate, ethyl 12-hydroxystearate, diethyl malate, diethyl tartrate, γ-butyrolactone, γ-valerolactone, γ-butenoic acid γ-lactone, γ-hydroxy-4-methyl-5-hexenoic acid γ-lactone, nicotinamide, isopropanol, benzyl alcohol, n-butanol, triethyl citrate, glyceryl triacetate, and butyl lactate;

[0018] Preferably, the co-surfactant includes at least one of isopropanol, benzyl alcohol, n-butanol, triethyl citrate, glyceryl triacetate, and butyl lactate.

[0019] In some embodiments, the oil-soluble fragrance agent includes at least one of natural essential oils, natural extracts, and synthetic fragrances.

[0020] In some embodiments, the nicotine salt includes at least one of benzoic acid nicotine salt, citrate nicotine salt, lactic acid nicotine salt, levulinic acid nicotine salt, and tartrate nicotine salt.

[0021] In some embodiments, the flavoring agent includes at least one of sweeteners, acidulants, and cooling agents;

[0022] Preferably, the sweetener includes at least one selected from sucralose, neotame, adventitia, neomethylhesperidin dihydrochalcone, D-allulose, aspartame, alitame, sodium saccharin, acesulfame potassium, cyclamate, sugar alcohol sweeteners, steviol glycosides, mogrosides, glycyrrhizin, stevia glycosides, semathymidine, bujnazen, monellin, 4-amino-5,6-dimethylthieno(2,3-D)pyrimidin-2(1H)-one, 3-[(4-amino-2,2-dioxo-1H-2,1,3-benzothiadiazin-5-yl)oxy]-2,2-dimethyl-N-propylpropionamide, 2,4-dihydroxybenzoic acid, and 3-hydroxybenzoic acid;

[0023] Preferably, the acidulant includes at least one of acetic acid, propionic acid, butyric acid, hexanoic acid, octanoic acid, nonanoic acid, decanoic acid, 2-methylbutyric acid, isovaleric acid, oxalic acid, 2-methylvaleric acid, 3-methylvaleric acid, trans-2-hexenoic acid, berry acid, strawberry acid, citric acid, malic acid, L-tartaric acid, and adipic acid.

[0024] Preferably, the cooling agent includes at least one of menthol, menthone, isomenthone, 1-menthol lactate, N,2,3-trimethyl-2-isopropylbutyramide, N-ethyl-p-menthyl-3-carboxamide, N-(ethoxycarbonylmethyl)-p-alkyl-3-carboxamide, N-(4-methoxyphenyl)-p-menthyl-3-carboxamide, N,2-diethyl-2-(isopropyl)-3-methylbutyramide, FEMA4549, and FEMA4496.

[0025] The second aspect of this disclosure provides a method for preparing an electronic atomizing liquid, comprising the following steps: S1, mixing a carrier, a co-surfactant, and a surfactant to obtain a mixture; and S2, mixing the mixture with a flavoring agent to obtain an electronic atomizing liquid.

[0026] In some embodiments, step S2 includes stirring at room temperature to 70°C for 5 to 20 minutes.

[0027] This invention enables the formation of a microemulsion in an electronic atomizing liquid by using a co-surfactant and / or a combination of surfactants, especially in the presence of water as a solvent. This allows for an increase in the amount of flavoring agent that can be added without the use of ethanol. The resulting atomizing liquid is stable and clear, and has good sensory evaluation after atomization, with a rich and consistent aroma. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram showing the changes in the micelle-solvent interface in the microemulsion system after the addition of a co-surfactant.

[0030] Figure 2 The images show the state diagrams of the samples from Example 1-1 and Comparative Examples 1-1 and 2-2.

[0031] Figure 3 The images show the microstructure of samples from Examples 2-4 and Comparative Example 2-2.

[0032] Figure 4 The images show the state of the samples from Examples 3-4 and Comparative Example 3-1 after centrifugation. Detailed Implementation

[0033] The technical solutions of this disclosure will be clearly and completely described below with reference to the embodiments and accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] Except in any operational instance, or where otherwise indicated, all figures used in the specification and claims to represent amounts of components, reaction conditions, etc., should be understood to be modified in all cases by the term "approximately". Unless otherwise indicated, the numerical parameters set forth in the following specification and appended claims are approximate values, which may vary according to the desired properties to be obtained according to the invention. Although the numerical ranges and parameters illustrating a broad scope of the invention are approximate, the values ​​set forth in specific embodiments are reported as precisely as possible. Each numerical parameter should be interpreted at least according to the number of significant figures reported and by applying common rounding techniques.

[0035] The above steps are only for clarity. In practice, they can be combined into one step or some steps can be broken down into multiple steps. As long as they include the same logical relationship, they are all within the scope of protection of this patent.

[0036] Unless otherwise stated, all percentages or % in this disclosure are weight percentages.

[0037] Existing e-liquids mostly use propylene glycol and glycerol as the main solvents. However, due to their high polarity, propylene glycol and glycerol have poor solubility for some less polar flavorings, thus limiting the amount and type of flavorings that can be added. Furthermore, some existing formulations increase the solubility of oil-soluble flavorings by adding large amounts of ethanol to the e-liquid. However, high ethanol levels can negatively impact the taste, pose flammable and explosive safety risks during storage and transportation, and many regulations also restrict the amount of ethanol added.

[0038] In the preparation of highly aromatic electronic atomizing fluids, the large amount of flavoring agent added often leads to poor dispersion, resulting in phenomena such as oil floating, turbidity, and unstable stratification in the atomizing fluid. This, in turn, leads to problems such as low aroma reproduction and poor consistency after atomization. Therefore, it is necessary to provide an improved atomizing fluid that is ethanol-free, produces a stable and turbid atomizing fluid, and provides a rich and consistent aroma after atomization.

[0039] Therefore, this application proposes an electronic atomizing liquid, which, by weight, comprises: 1% to 29.5% oil-soluble flavoring agent, 0% to 10% flavoring agent, 0% to 5% nicotine or nicotine salt, 0.2% to 2% surfactant, 0.2% to 14.9% co-surfactant, and 50% to 98% carrier.

[0040] The electronic atomizing fluid is a microemulsion. A microemulsion is a thermodynamically stable system formed by mixing surfactants and other additives with an aqueous phase and an oil phase, resulting in a transparent or nearly transparent appearance. Phase separation does not easily occur with centrifugation or prolonged storage of the microemulsion. In this application, specific amounts of co-surfactants and surfactants are combined to form a stable microemulsion form of the electronic atomizing fluid, thereby increasing the flavor content and allowing it to be used to prepare a richly flavored atomizing fluid. Furthermore, the electronic atomizing fluid is stable and does not become turbid, exhibiting good sensory evaluation after atomization, with a rich and consistent aroma. An ideal flavor content is obtained without using ethanol, and the taste is not affected.

[0041] surfactants

[0042] The electronic atomizing fluid of this application may or may not contain a surfactant. When a surfactant is added, it is used in combination with a co-surfactant to form micelles, thereby creating a uniform and transparent mixture between the flavoring agent and the carrier phase.

[0043] According to some embodiments, the surfactant includes at least one of the group consisting of anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants.

[0044] Preferably, the surfactant is an amphoteric surfactant and / or a nonionic surfactant. Anionic or cationic surfactants can be harmful to the device (corrosion, etc.), while amphoteric / nonionic surfactants are gentler and safer.

[0045] Preferably, the surfactant includes at least one of lauryl sulfate, alkyl ether carboxylate, stearoyl lactate, benzalkonium chloride, lecithin, amino acids, polyglycerol fatty acid esters, sucrose fatty acid esters, monoglyceride fatty acid esters, mono- and diglyceride fatty acid esters, polysorbate fatty acid esters, propylene glycol fatty acid esters, polyoxyethylene alkyl ethers, saponins, castor oil, polyoxyethylene sorbitan fatty acid esters 20-80, and dehydrated sorbitan fatty acid esters 20-80.

[0046] More preferably, the surfactant includes at least one of lecithin, polyglycerol fatty acid ester, sucrose fatty acid ester, monoglyceride fatty acid ester, polyoxyethylene sorbitan fatty acid ester 20-80 (Tween 20-80), and sorbitan fatty acid ester 20-80 (Span 20-80).

[0047] Among them, lauryl sulfate, alkyl ether carboxylates, and stearoyl lactate are anionic surfactants; benzalkonium chloride is a cationic surfactant; lecithin or amino acid derivatives (e.g., dodecylaminopropionic acid) are amphoteric surfactants; polyglycerol fatty acid esters, sucrose fatty acid esters, monoglycerol fatty acid esters, mono- and diglycerol fatty acid esters, polysorbate fatty acid esters, propylene glycol fatty acid esters, polyoxyethylene alkyl ethers, polyoxyethylene sorbitan fatty acid esters, and dehydrated sorbitan fatty acid esters are nonionic surfactants.

[0048] In the e-liquid, the amount of surfactant, by weight, is 0-4.8%, preferably 0.2%-2%, and more preferably 0.5%-1%. Exemplarily, the amount of surfactant can be 0, 0.2%, 0.5%, 0.8%, 1%, 2%, 4.8%, or any value within a range of two such values. The amount of surfactant is sufficient to form a uniform and transparent mixture between the flavoring agent and the carrier phase without producing undesirable tastes such as a burnt flavor. Excessive surfactant addition may cause burnt, bitter, or coating-like taste problems, especially with heated e-liquids; insufficient surfactant addition makes it difficult to obtain a stable e-liquid with a high content of oil-soluble flavoring agents.

[0049] Co-surfactants

[0050] In microemulsion systems where water is the primary solvent, co-surfactants are used to regulate surface activity and hydrophilic-lipophilic balance, and participate in micelle formation. This increases the distance between the hydrophobic ends of the surfactant, reduces interactions, and results in micelles with smaller particle sizes. Co-surfactants are typically small organic molecules with strong interactions with water, possessing one or more structures including, but not limited to, alcohols, esters, amines, and amides. Compared to adding only a surfactant, the simultaneous addition of a co-surfactant strengthens the interaction between micelles and water molecules, allowing the solvent to penetrate the interlayer of the surfactant layer. This increases the fluidity and disorder of the surfactant layer, prevents micelle aggregation, enhances the stability of the microemulsion, and improves the solubility of the surfactant and low-polarity components. Some co-surfactants have a solubilizing effect when added alone and do not need to be used with the surfactant; others must be used with the surfactant to achieve their solubilizing and stabilizing effects.

[0051] In some embodiments, the co-surfactant includes at least one of alcohols, esters, amines, and amides having 2 to 20 carbon atoms.

[0052] In some embodiments, the co-surfactant is a type that can be used alone and has a certain solubilizing effect, such as an alcohol, amine, or some amides; preferably, the co-surfactant includes at least one of n-butanol, isopropanol, isobutanol, isoamyl alcohol, n-hexanol, benzyl alcohol, phenethyl alcohol, phenylpropanol, furfuryl alcohol, ethylene glycol, butanediol, tromethamine, N-methylpyrrolidone, and acetylethanolamine.

[0053] In some embodiments, a co-surfactant is used in conjunction with a surfactant, and the co-surfactant may be an ester or a partial amide; preferably, the co-surfactant includes glyceryl triacetate, triethyl citrate, glyceryl caprylate, ethyl acetate, n-butyl acetate, isoamyl acetate, ethyl propionate, ethyl butyrate, ethyl hydroxyacetate, propyl glycolate, butyl glycolate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isoamyl lactate, leaf lactate, lauryl lactate, hexadecyl lactate, ethyl 3-hydroxybutyrate, monoethyl succinate, ethyl levulinate, methyl 3-hydroxyhexanoate, ethyl 3-hydroxyhexanoate, ethyl 5-hydroxydecanoate. The surfactant comprises at least one of the following: ethyl 12-hydroxystearate, diethyl malate, diethyl tartrate, γ-butyrolactone, γ-valerolactone, γ-4-hydroxy-2-butenoic acid γ-lactone [also known as 2(5H)-furanone], γ-4-hydroxy-4-methyl-5-hexenoic acid γ-lactone, nicotinamide, isopropanol, benzyl alcohol, n-butanol, triethyl citrate, glyceryl triacetate, and butyl lactate; more preferably, the co-surfactant comprises at least one of isopropanol, benzyl alcohol, n-butanol, triethyl citrate, glyceryl triacetate, and butyl lactate; even more preferably, the co-surfactant comprises at least one of isopropanol, butyl lactate, benzyl alcohol, and triethyl citrate.

[0054] In the e-liquid, the amount of co-surfactant, by weight, is 0.2% to 14.9%, preferably 3% to 10%, and more preferably 3% to 6%. Exemplarily, the amount of co-surfactant can be 0.2%, 1%, 2%, 3%, 4.5%, 6%, 7%, 8%, 9%, 10%, 12%, 13.5%, 14.9%, or any range of two such values. The amount of co-surfactant is sufficient to form a uniform and transparent mixture of flavoring agent and carrier without producing undesirable tastes such as off-flavors. If the amount of co-surfactant added is too high, off-flavors may be generated when using a heated e-liquid; if the amount of co-surfactant added is too low, it is difficult to obtain a stable and uniform e-liquid with a high content of oil-soluble flavoring agent in the e-liquid.

[0055] carrier

[0056] The carrier is the solvent of the electronic atomizing liquid, including one or more of propylene glycol, glycerol, and water.

[0057] In some embodiments, the carrier content in the electronic atomizing liquid is 50% to 98% by weight, preferably 50% to 70%.

[0058] Water is the solvent for most surfactants and combines with surfactants to form O / W microemulsions, which facilitates the formation of stable and transparent mixtures in electronic atomizing liquids.

[0059] In some embodiments, water replaces a portion of propylene glycol and glycerol, reducing the generation of harmful aldehydes and ketones, which is beneficial to health. Preferably, the water content in the e-liquid is at least 50% by weight. Exemplarily, the amount of water added can be 50%, 55%, 60%, 65%, 70%, or any two of these values ​​within a range. The amount of water is necessary for the oil-soluble flavoring agent to form a homogeneous and transparent mixture with the carrier phase. If the amount of water added is too low, the e-liquid cannot form a transparent system, resulting in low aroma concentration and poor aroma consistency in the generated smoke.

[0060] Oil-soluble flavorings

[0061] Fragrance agents are used to provide aroma and may include any component known to provide a pleasant taste to the user. This application does not impose any particular limitation on the types of oil-soluble fragrance agents.

[0062] In some embodiments, the oil-soluble flavoring agent includes at least one of natural essential oils, natural extracts, and synthetic fragrances. For example, the oil-soluble flavoring agent can be fruity, floral, herbal, minty, tobacco, sweet, beverage, or spice flavors. The oil-soluble flavoring agent contains and dissolves the flavor components, producing a rich aroma.

[0063] In some embodiments, the amount of oil-soluble flavoring agent added to the electronic atomizing liquid is 1% to 29.5% by weight; preferably, the amount added is 5% to 25%. Exemplarily, the amount of oil-soluble flavoring agent added can be 1%, 2.5%, 5%, 10%, 15%, 20%, 25%, 29.5%, 30%, etc., or any value within a range of any two of these values.

[0064] Flavorings

[0065] Flavoring agents are used to provide taste and trigeminal nerve sensation, and may include any component that provides the user with taste and tactile sensations such as sweetness, sourness, coolness, and astringency; this application does not impose any particular limitation on the types of flavoring agents.

[0066] In some embodiments, the flavoring agent includes at least one of sweeteners, acidulants, and cooling agents.

[0067] For example, flavoring agents may include sweeteners, including sucralose, neotame, adventitia, neomethylhesperidin dihydrochalcone (NHDC), D-allulose, aspartame, alitame, sodium saccharin, acesulfame potassium, cyclamate, sugar alcohol sweeteners, steviol glycosides, mogrosides, glycyrrhizin, stevia glycosides, semathymidine, bujnazen, monellin, 4-amino-5,6-dimethylthieno(2,3-D)pyrimidin-2(1H)-one, 3-[(4-amino-2,2-dioxo-1H-2,1,3-benzothiadiazin-5-yl)oxy]-2,2-dimethyl-N-propylpropionamide, 2,4-dihydroxybenzoic acid, and 3-hydroxybenzoic acid. Preferably, the sweetener includes at least one of sucralose, neotame, steviol glycoside, and neomethylhesperidin dihydrochalcone (NHDC).

[0068] For example, the flavoring agent may include an acidulant, which may include at least one of acetic acid, propionic acid, butyric acid, hexanoic acid, caprylic acid, nonanoic acid, decanoic acid, 2-methylbutyric acid, isovaleric acid, oxalic acid, 2-methylvaleric acid, 3-methylvaleric acid, trans-2-hexenoic acid, phytic acid, strawberry acid, citric acid, malic acid, L-tartaric acid, and adipic acid. Preferably, the acidulant includes at least one of acetic acid, propionic acid, butyric acid, 2-methylbutyric acid, hexanoic acid, isovaleric acid, oxalic acid, malic acid, citric acid, and adipic acid; preferably, the acidulant may be selected from one or more of acetic acid, propionic acid, and citric acid; preferably, the acetic acid may be glacial acetic acid, i.e., anhydrous acetic acid.

[0069] For example, the flavoring agent may include a cooling agent, which includes at least one of menthol, menthone, isomenthone, 1-menthol lactate, N,2,3-trimethyl-2-isopropylbutyramide (WS-23), N-ethyl-p-menthyl-3-carboxamide (WS-3), N-(ethoxycarbonylmethyl)-p-alkyl-3-carboxamide (WS-5), N-(4-methoxyphenyl)-p-menthyl-3-carboxamide (WS-12), N,2-diethyl-2-(isopropyl)-3-methylbutyramide (WS-27), FEMA4549, and FEMA4496. Preferably, the cooling agent includes at least one of WS-3, WS-23, and menthol.

[0070] In some embodiments, the amount of flavoring agent added to the electronic atomizing liquid is 0-10% by weight; preferably, the amount added is 3%-8%.

[0071] Sensory evaluation of electronic atomizing fluid

[0072] Sensory evaluation of e-liquids is usually divided into five aspects: vapor production, burnt taste, off-flavors, aroma concentration, and aroma uniformity.

[0073] The amount of vapor produced by an e-cigarette is the amount of aerosol that can be perceived visually and in the mouth. Based on experience, the amount of vapor depends primarily on the atomization method, heating element power, airway structure, and the amount of glycerol used. A larger vapor volume results in clearer flavor characteristics and a richer aroma; it also makes the smoke feel fuller and the flavor more intense. A burnt taste is mainly affected by the content of large molecules in the e-liquid and the atomizer's flow rate. A high content of large molecules reduces the flow rate, and localized high temperatures can easily cause burning, resulting in a burnt taste. Off-flavors are caused by small molecules and metal ions produced by corrosion of the e-cigarette. Off-flavors negatively impact the vaping experience. Excessive off-flavors reduce the aroma's fidelity and the enjoyment of vaping, causing discomfort, a strong chemical smell, unpleasant vaping, or even nausea. Aroma concentration depends on the amount of flavoring agent added to the e-liquid, the amount of vapor, and the atomization method. Aroma uniformity depends primarily on the degree and evenness of dispersion. If the atomizing liquid has low stability, high turbidity, and shows layering and floating oil, it indicates that the oil phase is not evenly dispersed, resulting in poor uniformity of aroma perceived subjectively during inhalation. Conversely, if the atomizing liquid is transparent, uniform, and stable, it indicates that the components are evenly dispersed, and the aroma perceived subjectively during inhalation is consistent.

[0074] Preparation method of electronic atomizing fluid

[0075] On the other hand, this application also provides a method for preparing electronic atomizing liquid.

[0076] In some embodiments, the method for preparing the electronic atomizing liquid includes: S1, mixing a carrier, a co-surfactant, and a surfactant to obtain a mixture; S2, mixing the mixture with an oil-soluble flavoring agent, a flavoring agent, nicotine, or a nicotine salt to obtain the electronic atomizing liquid.

[0077] This application does not limit the mixing method in S1, nor does it limit the order of addition of water, glycerol, propylene glycol, co-surfactant, and surfactant. Optionally, heating can be used to promote mixing in S1.

[0078] This application does not limit the mixing method in step S2. In some embodiments, step S2 includes stirring at room temperature to 70°C for 5 to 20 minutes. The mixing step helps to obtain a stable and non-turbid electronic atomizing liquid. Appropriately high temperatures can accelerate the mixing process, but excessively high temperatures can lead to a large amount of volatilization of the flavoring agent and the carrier phase. In other words, the preparation method of this application is simple and can avoid the use of energy-consuming and high-temperature mixing methods such as high-speed shearing or high-pressure homogenization.

[0079] The present disclosure will be further described below with reference to specific embodiments. All raw materials involved were commercially available. Microscopic observation was performed using an optical microscope (VHX7000, Keyence), and stability testing was performed using a centrifuge (Sorvall Legend Micro 21R, Thermo Fisher Scientific).

[0080] Example

[0081] Three sets of electronic atomizing liquid samples for the examples and comparative examples were prepared through the following steps.

[0082] S1: Disperse the surfactant in water, heat and stir to fully dissolve the surfactant, then add the co-surfactant, propylene glycol and glycerol (if the formula contains them), mix well to obtain a mixture.

[0083] S2: Add the oil-soluble flavoring agent to the above mixture, heat and stir to obtain a sample of electronic atomizing liquid.

[0084] In the examples and comparative examples of groups 1, 2, and 3, the S1 temperature was raised to 50°C and stirred for 20 min, and the S2 temperature was raised to 60°C and stirred for 5 min. In the examples and comparative examples of groups 4 and 5, the S1 temperature was raised to 40°C and stirred for 20 min, and the S2 temperature was raised to 45°C and stirred for 5 min. The specific substances of oil-soluble flavoring agents, surfactants, and co-surfactants in the formulations of each group of examples and comparative examples are shown in Table 1. The weight percentage of each component in each sample and the sample state are shown in Table 2.

[0085] Table 1. Flavorings, surfactants, and co-surfactants in the formulations of the examples and comparative samples.

[0086]

[0087]

[0088] Table 2 shows the weight percentage of each component and sample condition in the examples and comparative samples.

[0089]

[0090]

[0091] As shown in Table 2, the sample examples were all homogeneous and clear mixtures, indicating that the oil-soluble flavoring agent was well dispersed in the carrier phase. Specifically, the samples from Example 1-1 and Comparative Examples 1-1 and 2-2 are as follows... Figure 2 As shown.

[0092] Performance testing

[0093] Microscopic observation

[0094] The samples from the examples and comparative examples were spread onto glass slides and observed under an optical microscope. Large oil droplets (micrometer-sized) with uneven size distribution were clearly visible in the turbid samples before centrifugation, which is due to the limited solubility of propylene glycol and glycerol in essential oils. In contrast, the droplets were no longer observable in the clear samples before centrifugation, consistent with their apparent clear and transparent state. The results for the samples from Examples 2-4 and Comparative Example 2-2 are as follows: Figure 3 As shown. Due to the interfacial interaction between the surfactant and co-surfactant, the atomizing liquid in some embodiments of this application is uniform in state, and the oil droplet size is significantly smaller (nanoscale) than that of conventional e-liquids, consistent with the clear and transparent appearance. On the other hand, the reduction in oil droplet size also helps to improve the stability of the e-liquid.

[0095] Stability test

[0096] The samples from the examples and comparative examples were placed into 2 mL centrifuge tubes and centrifuged (3000 rpm, 15 min). The samples that were turbid before centrifugation all showed significant stratification, indicating that the oil-soluble flavoring agent in the samples has limited stability. The samples that were clear before centrifugation did not stratify after centrifugation, significantly improving the stability and shelf life of the atomized liquid. The results for Examples 3-4 and Comparative Example 3-1 are as follows: Figure 4 As shown.

[0097] Sensory evaluation test

[0098] Twelve evaluators were selected, each of whom performed a puff on each of the samples in all embodiments and comparative examples, using a holistic cyclical evaluation method. A blind evaluation scoring method was adopted, and based on the meaning of the five sensory quality evaluation index scores in Table 3, the average score of each evaluator was taken for each item of each e-cigarette liquid sample, and the average scores of each item were summed to obtain the total score. The results are shown in Table 4.

[0099] Table 3 Scoring Criteria for Sensory Evaluation of Electronic Atomizing Fluids

[0100] Score smoke volume burnt smell Mixed gases aroma Uniformity 9 adequate Very small Very light Very strong very good 8 foot Small light powerful good 7 More adequate smaller Lighter Strong better 6 Slightly sufficient Slightly smaller Slightly lighter Slightly heavier Slightly better 5 middle middle middle middle middle 4 Slightly Slightly larger Slightly heavier Slightly weak Slightly worse 3 Lighter Larger heavier Weak Poor 2 light big Heavy weak Difference 1 Very light Very large Very heavy Very weak Very bad

[0101] Table 4 Sensory evaluation of the examples and comparative samples

[0102]

[0103]

[0104] Based on the formulations in Table 2 and the data in Table 4, it can be seen that, except for Comparative Examples 1-2, the first set of examples and comparative examples all used benzyl alcohol, a co-surfactant that can be used alone, while Comparative Examples 1-2 used ethyl acetate, a co-surfactant that cannot be used alone. The first set of examples and comparative examples adjusted the amounts of oil-soluble flavoring agent, co-surfactant, and water. Specifically, Comparative Examples 1-1 and 1-3 added co-surfactants exceeding the recommended range, and Comparative Example 1-3 added too little water, resulting in a cloudy atomized liquid with weak and uneven aroma. Although Comparative Example 1-2 added the same amount of oil-soluble flavoring agent, water, and co-surfactant as Examples 1-2, ethyl acetate cannot be used alone and needs to be used in combination with a surfactant, resulting in a cloudy atomized liquid. Besides the weak and uneven aroma, the excessively high amount of ethyl acetate also produced a lot of off-odors, leading to a poor inhalation experience. In contrast, Examples 1-1 to 1-4 had appropriate amounts of co-surfactant, water, and carrier, all forming stable and non-cloudy atomized liquids with good sensory evaluation after atomization; as the amount of co-surfactant increased, the aroma uniformity first increased and then decreased.

[0105] The second set of examples and comparative examples adjusted the amount of surfactant added. Comparative Example 2-2 added 4.9% surfactant, which was too high, resulting in a heavy off-odor, a strong burnt smell, cloudy and layered atomized liquid, and poor dispersion of the oil-soluble flavoring agent, leading to poor aroma intensity and uniformity. Comparative Example 2-1, although the atomized liquid was clear, had too low an amount of oil-soluble flavoring agent, resulting in a weak aroma. Examples 2-1 to 2-6 had appropriate surfactant addition amounts, forming stable and clear atomized liquids with good sensory evaluation after atomization. As the surfactant addition amount increased, the solubility of the oil-soluble flavoring agent increased, and the aroma intensity and uniformity initially increased and then slightly decreased. Considering factors such as state, smoke volume, and aroma performance, the optimal surfactant addition amount was 0.5%–1%.

[0106] The third set of examples and comparative examples used the same amount of surfactant, but adjusted the amount of co-surfactant. Comparative Example 3-1 used only 0.1% co-surfactant, resulting in a cloudy atomized liquid with poor aroma uniformity. Comparative Example 3-2 used 14.9% co-surfactant, but it could not dissolve 30% of the oil-soluble fragrance, resulting in a cloudy, layered atomized liquid with poor dispersion of the oil-soluble fragrance, leading to poor aroma intensity and uniformity. Comparative Example 3-3 further increased the amount of co-surfactant; although the atomized liquid became clear, it produced severe off-odors. Examples 3-1 to 3-6, however, used appropriate amounts of co-surfactant, all resulting in stable, non-cloudy atomized liquids with good sensory evaluation after atomization.

[0107] In summary, by further controlling the amount of surfactant added to 0.5%–1% and the amount of co-surfactant added to 3%–6%, the atomized liquid can have a strong aroma, good uniformity, and little burnt taste, while the amount of smoke is moderate to high.

[0108] The above descriptions are merely some specific embodiments of this disclosure, intended to illustrate the present invention, and are not intended to limit the scope of protection claimed in this application. Any modifications or substitutions made based on the inventive concept of this invention and the content of this application's specification and drawings, or direct / indirect applications in other related technical fields, are included within the scope of protection claimed in this application.

Claims

1. An electronic atomizing fluid, characterized in that, By weight, it includes: 1% to 29.5% oil-soluble flavoring agent, 0% to 10% flavoring agent, 0% to 5% nicotine or nicotine salt, 0% to 4.8% surfactant, 0.2% to 14.9% co-surfactant and 50% to 98% carrier.

2. The electronic atomizing fluid according to claim 1, characterized in that, The surfactant content is 0.2% to 2% by weight; Preferably, the content of the surfactant is 0.5% to 1%.

3. The electronic atomizing fluid according to claim 1, characterized in that, The content of the co-surfactant is 3% to 10% by weight; Preferably, the content of the co-surfactant is 3% to 6%.

4. The electronic atomizing fluid according to claim 1, characterized in that, The carrier includes at least one of propylene glycol, glycerol and water, and the content of the carrier is 50% to 98% by weight. Preferably, the carrier content is 50% to 70%.

5. The electronic atomizing fluid according to claim 4, characterized in that, The carrier includes water, and the water content is at least 50% based on the total weight of the electronic atomizing liquid.

6. The electronic atomizing fluid according to claim 1, characterized in that, The surfactant includes at least one of anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants; Preferably, the surfactant includes amphoteric surfactants and / or nonionic surfactants; Preferably, the surfactant comprises at least one of lauryl sulfate, alkyl ether carboxylate, stearoyl lactate, benzalkonium chloride, lecithin, amino acids, polyglycerol fatty acid esters, sucrose fatty acid esters, monoglyceride fatty acid esters, mono- and diglyceride fatty acid esters, polysorbate fatty acid esters, propylene glycol fatty acid esters, polyoxyethylene alkyl ethers, saponins, castor oil, polyoxyethylene sorbitan fatty acid esters 20-80, and dehydrated sorbitan fatty acid esters 20-80; more preferably, the surfactant comprises at least one of lecithin, polyglycerol fatty acid esters, sucrose fatty acid esters, polyoxyethylene sorbitan fatty acid esters 20-80, dehydrated sorbitan fatty acid esters 20-80, and monoglyceride fatty acid esters.

7. The electronic atomizing fluid according to any one of claims 1-6, characterized in that, The co-surfactant includes at least one of alcohol, ester, amine, and amide, wherein the alcohol, ester, amine, and amide have 2 to 20 carbon atoms.

8. The electronic atomizing fluid according to claim 1, characterized in that, The electronic atomizing fluid does not include the surfactant, and the co-surfactant includes at least one of n-butanol, isopropanol, isobutanol, isoamyl alcohol, n-hexanol, benzyl alcohol, phenylethanol, phenylpropanol, furfuryl alcohol, ethylene glycol, butanediol, tromethamine, N-methylpyrrolidone, and acetylethanolamine.

9. The electronic atomizing fluid according to claim 7, characterized in that, The co-surfactant comprises at least one of the following: triacetin, triethyl citrate, caprylic / capric triacetin, ethyl acetate, n-butyl acetate, isoamyl acetate, ethyl propionate, ethyl butyrate, ethyl hydroxyacetate, propyl glycolate, butyl glycolate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isoamyl lactate, leaf lactate, lauryl lactate, hexadecyl lactate, ethyl 3-hydroxybutyrate, monoethyl succinate, ethyl acetopropionate, methyl 3-hydroxyhexanoate, ethyl 3-hydroxyhexanoate, ethyl 5-hydroxydecanoate, ethyl 12-hydroxystearate, diethyl malate, diethyl tartrate, γ-butyrolactone, γ-valerolactone, 4-hydroxy-2-butenoic acid γ-lactone, 4-hydroxy-4-methyl-5-hexenoic acid γ-lactone, nicotinamide, isopropanol, benzyl alcohol, n-butanol, triethyl citrate, triacetin, and butyl lactate. Preferably, the co-surfactant includes at least one of isopropanol, benzyl alcohol, n-butanol, triethyl citrate, glyceryl triacetate, and butyl lactate.

10. The electronic atomizing fluid according to claim 1, characterized in that, The oil-soluble fragrance agent includes at least one of natural essential oils, natural extracts, and synthetic fragrances.

11. The electronic atomizing fluid according to claim 1, characterized in that, The nicotine salt includes at least one of benzoic acid nicotine salt, citrate nicotine salt, lactic acid nicotine salt, levulinic acid nicotine salt, and tartrate nicotine salt.

12. The electronic atomizing fluid according to claim 1, characterized in that, The flavoring agent includes at least one of sweeteners, acidulants, and cooling agents; Preferably, the sweetener comprises at least one selected from sucralose, neotame, adventitia, neomethylhesperidin dihydrochalcone, D-allulose, aspartame, alitame, sodium saccharin, acesulfame potassium, cyclamate, sugar alcohol sweeteners, steviol glycosides, mogrosides, glycyrrhizin, stevia glycosides, dihydrochalcone, sematrandrine, bujnazen, monellin, 4-amino-5,6-dimethylthieno(2,3-D)pyrimidin-2(1H)-one, 3-[(4-amino-2,2-dioxo-1H-2,1,3-benzothiadiazin-5-yl)oxy]-2,2-dimethyl-N-propylpropionamide, 2,4-dihydroxybenzoic acid, and 3-hydroxybenzoic acid; Preferably, the acidulant includes at least one of acetic acid, propionic acid, butyric acid, hexanoic acid, octanoic acid, nonanoic acid, decanoic acid, 2-methylbutyric acid, isovaleric acid, oxalic acid, 2-methylvaleric acid, 3-methylvaleric acid, trans-2-hexenoic acid, berry acid, strawberry acid, citric acid, malic acid, L-tartaric acid, and adipic acid. Preferably, the cooling agent comprises at least one of menthol, menthone, isomenthone, 1-menthol lactate, N,2,3-trimethyl-2-isopropylbutyramide, N-ethyl-p-menthyl-3-carboxamide, N-(ethoxycarbonylmethyl)-p-alkyl-3-carboxamide, N-(4-methoxyphenyl)-p-menthyl-3-carboxamide, N,2-diethyl-2-(isopropyl)-3-methylbutyramide, FEMA4549, and FEMA4496.

13. A method for preparing the electronic atomizing fluid according to claims 1-12, comprising the following steps: S1, the carrier, the co-surfactant, and the surfactant are mixed to obtain a mixture; and S2, the mixture is mixed with the oil-soluble flavoring agent, the flavoring agent and the nicotine or nicotine salt to obtain the electronic atomizing liquid.

14. The method according to claim 13, characterized in that, The S2 step includes stirring at room temperature to 70°C for 5 to 20 minutes.

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