Liquid composition for liquid heating type flavor inhaler

Abstract

To provide a liquid composition for a liquid heating type heating type flavor aspirator.SOLUTION: A liquid composition for a liquid heating type heating type flavor aspirator contains (1) propylene glycol and glycerol, (2) nicotine, (3) benzoic acid and (4) organic acid other than benzoic acid. The liquid composition for a liquid heating type heating type flavor aspirator further contains (1) propylene glycol and glycerol, (2) nicotine and (4) organic acid other than benzoic acid.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a liquid composition for a liquid-heating type heated flavor inhaler and a preparation method thereof. The present invention also relates to a liquid-heating type heated flavor inhaler, comprising a liquid composition for a liquid-heating type heated flavor inhaler. The present invention further relates to a method for reducing the gunpowder-like odor of benzoic acid in a liquid composition for a liquid-heating type heated flavor inhaler. [Background technology]

[0002] A liquid heating type heated flavor inhaler is a flavor inhaler that generates an aerosol by directly or indirectly heating a liquid composition for the liquid heating type heated flavor inhaler with an electrical heat source or a heat source by chemical reaction, and delivers the aerosol into the oral cavity through a mouthpiece. A typical liquid composition for a liquid heating type heated flavor inhaler (liquid for electronic cigarettes (commonly known as e-liquid or e-juice)) is composed of propylene glycol (PG), glycerin (GL), nicotine, and flavoring.

[0003] JP2018-532377 describes a liquid formulation for an e-vaping device. The liquid formulation in the document contains propylene glycol and is substantially free of glycerol. JP2016-520061 describes a nicotine salt formulation for an aerosol device and a method thereof. The document specifies the acid for forming the nicotine salt of the nicotine salt formulation in terms of vapor pressure, melting point, boiling point, etc.

[0004] The role of nicotine in e-liquid is said to be to give a satisfying taste when inhaled. On the other hand, the higher the nicotine concentration in e-liquid, the more irritation it causes to the oral cavity and throat when inhaled (sometimes referred to as "flavor-inhibiting sensation" in this specification), and users often find it difficult to inhale the aerosol. As a method for solving such problems, products containing benzoic acid (BA) in e-liquid have become widespread in recent years. This mechanism involves the neutralization of nicotine, which is a basic substance, by benzoic acid, which is an acidic substance, and the action on the gas-liquid equilibrium of nicotine when heated reduces the flavor-inhibiting sensation caused by nicotine. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special table 2018-532377 [Patent Document 2] Special table 2016-520061 Summary of the Invention [Problem to be solved by the invention]

[0006] The inventors have found that, in the case of products containing benzoic acid in e-liquid to reduce the nicotine-induced flavor inhibition (nicotine impact), when heated, the product expresses a characteristic odor of benzoic acid (gunpowder-like, sometimes referred to as "gunpowder-like odor" or "benzoic acid odor" in this specification), which inhibits the expression of flavors in the e-liquid and impairs the flavor and taste. In addition, since benzoic acid has low solubility in PG and GL, a long stirring process or heating process is required to dissolve benzoic acid during e-liquid production, there are concerns about adverse effects on product quality such as volatilization / deterioration of the content ingredients, as well as effects on production efficiency.

[0007] The inventors of the present invention realized that e-liquids containing only benzoic acid have various problems such as sensory characteristics, product quality, and manufacturing efficiency, and conducted research to solve these problems. They then developed the present invention from the following perspectives:

[0008] -Reducing the amount of benzoic acid to reduce the benzoic acid odor; -Other organic acids are substituted for the reduced amount of benzoic acid, but the effect of reducing the unpleasant aroma and taste caused by nicotine and the sensory characteristics are guaranteed to be at the same level as products using benzoic acid alone; -Establish a formulation procedure to efficiently formulate e-liquid containing organic acids with the developed composition.

[0009] The inventors have also found that in a liquid composition for a heated flavor inhaler containing nicotine, even when benzoic acid is not used and only an organic acid is used, the sense of inhibition of flavor and taste caused by nicotine (nicotine impact) is reduced, and have conceived the present invention relating to a liquid composition that does not contain benzoic acid. [Means for solving the problem]

[0010] The present invention includes, but is not limited to, the following aspects. [Aspect 1] A liquid composition for a liquid heating type flavor inhaler, comprising: (1) propylene glycol and glycerin, (2) Nicotine, (3) Benzoic acid, and (4) Organic acids other than benzoic acid, The liquid composition comprising: [Aspect 2] The liquid composition according to aspect 1, wherein a molar ratio of (2) nicotine to the sum of (3) benzoic acid and (4) the organic acid other than benzoic acid is in the range of 1:0.85 to 1:1.15. [Aspect 3] (4) The liquid composition according to aspect 1 or 2, further comprising lactic acid as the organic acid other than benzoic acid. [Aspect 4] (4) The liquid composition according to aspect 3, wherein the organic acid other than benzoic acid includes, in addition to lactic acid, any one selected from the group consisting of tartaric acid, fumaric acid, levulinic acid, malonic acid, acetic acid, adipic acid, citric acid, malic acid, pyruvic acid, sorbic acid, and mixtures thereof. [Aspect 5] (4) The liquid composition according to aspect 3, further comprising, as the organic acid other than benzoic acid, in addition to lactic acid, any one selected from the group consisting of tartaric acid, fumaric acid, levulinic acid, malonic acid, and mixtures thereof. [Aspect 6] (4) The liquid composition according to aspect 3, comprising, as the organic acid other than benzoic acid, tartaric acid in addition to lactic acid. [Aspect 7] The liquid composition according to any one of aspects 1 to 6, wherein the molar ratio of (2) nicotine to (3) benzoic acid is in the range of 1:0.7 to 1:0.15. [Aspect 8] The liquid composition according to any one of aspects 1 to 7, wherein the molar ratio of (2) nicotine to (4) the organic acid other than benzoic acid is in the range of 1:0.9 to 1:0.3. [Aspect 9] (4) The liquid composition according to any one of aspects 1 to 8, wherein the organic acid other than benzoic acid has a solubility in glycerin of 0.32 mol / kg or more in terms of molar concentration. [Aspect 10] Aspects 1-9, wherein the liquid composition is substantially free of water. [Aspect 11] Aspect 10. The composition of any one of aspects 1-10, further comprising a fragrance. [Aspect 12] (i) Prepare a preparation solution (A) by dissolving nicotine and benzoic acid in propylene glycol; (ii) Dissolve lactic acid in glycerin to prepare preparation solution (B); (iii) preparing a preparation solution (C) by dissolving, as desired, one or more organic acids other than benzoic acid and lactic acid in propylene glycol or glycerin; and (iv) mixing preparation solution (A), preparation solution (B), and preparation solution (C); A method for preparing a liquid composition for a liquid heating type flavor inhaler, comprising the steps of: [Aspect 13] (i) Prepare a preparation solution (A) by dissolving nicotine and benzoic acid in propylene glycol; (v) dissolving glycerin, lactic acid, and optionally one or more organic acids other than benzoic acid and lactic acid in the preparation liquid (A); A method for preparing a liquid composition for a liquid heating type flavor inhaler, comprising the steps of: [Aspect 14] 14. The method according to claim 12 or 13, further comprising adding a flavoring in a step subsequent to step (i). [Aspect 15] A liquid heating type flavor inhaler comprising the liquid composition according to any one of Aspects 1 to 14. [Aspect 16] A method for reducing the gunpowder-like odor of benzoic acid in a liquid composition for a heated flavor inhaler, comprising: The liquid composition for the heated flavor inhaler comprises: (1) propylene glycol and glycerin; (2) nicotine; and (3) benzoic acid. The liquid composition for the heating type flavor inhaler further contains (4) an organic acid other than benzoic acid. The method comprising: [Aspect 17] (4) The method according to aspect 16, wherein the organic acid other than benzoic acid comprises lactic acid. [Aspect 18] (4) The method according to aspect 17, wherein the organic acid other than benzoic acid includes, in addition to lactic acid, any one selected from the group consisting of tartaric acid, fumaric acid, levulinic acid, malonic acid, acetic acid, adipic acid, citric acid, malic acid, pyruvic acid, sorbic acid, and mixtures thereof. [Aspect 19] A liquid composition for a liquid heating type flavor inhaler, comprising: (1) propylene glycol and glycerin, (2) Nicotine, and (4) Organic acids other than benzoic acid, The liquid composition comprising: [Aspect 20] The liquid composition according to aspect 19, wherein a molar ratio of (2) nicotine to (4) the organic acid other than benzoic acid is in the range of 1:0.85 to 1:1.15. [Aspect 21] (4) The liquid composition according to aspect 19 or 20, comprising lactic acid as the organic acid other than benzoic acid. [Aspect 22] (4) The liquid composition according to aspect 21, comprising, as the organic acid other than benzoic acid, in addition to lactic acid, any one selected from the group consisting of tartaric acid, fumaric acid, levulinic acid, malonic acid, acetic acid, adipic acid, citric acid, malic acid, pyruvic acid, sorbic acid, and mixtures thereof. [Aspect 23] (4) The liquid composition according to any one of aspects 19 to 22, wherein the organic acid other than benzoic acid has a solubility in glycerin of 0.32 mol / kg or more in terms of molar concentration. [Aspect 24] (i') Prepare a preparation solution (B) by dissolving lactic acid in glycerin; (ii') preparing a preparation solution (C) by dissolving, as desired, one or more organic acids other than benzoic acid and lactic acid in propylene glycol or glycerin; and (iii') mixing nicotine with preparation solution (B) and preparation solution (C); A method for preparing a liquid composition for a liquid heating type flavor inhaler, comprising the steps of: [Aspect 25] 25. The method of preparing according to embodiment 24, further comprising adding a flavoring. [Aspect 26] A liquid heating type flavor inhaler comprising the liquid composition according to any one of aspects 19 to 25. Effect of the Invention

[0011] The liquid composition (I) for a liquid-heating type heating flavor inhaler of the present invention has the excellent features that the mixture of benzoic acid and other organic acids reduces the nicotine flavor and aroma inhibition feeling, and also reduces the gunpowder-like odor of benzoic acid generated when heated.

[0012] In addition, the method for preparing the liquid composition described above involves first dissolving benzoic acid in propylene glycol in the presence of nicotine, and then mixing it with glycerin, thereby making it possible to efficiently prepare a liquid composition for a liquid-heating type heated flavor inhaler containing benzoic acid, which is difficult to dissolve in glycerin, efficiently and in a short period of time without heat treatment.

[0013] The liquid composition (II) for the liquid heating type flavor inhaler of the present invention also has the effect of mitigating the nicotine flavor taste inhibition feeling by only organic acids other than benzoic acid without using benzoic acid.Since the liquid composition does not use benzoic acid, the preparation method does not require the step of first dissolving benzoic acid in propylene glycol in the presence of nicotine.Nicotine can be mixed after dissolving the organic acid used in propylene glycol or glycerin as appropriate, for example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Without being limited thereto, the present invention includes the following aspects. 1. Liquid composition for liquid heating type flavor inhaler (I) The present invention relates to a liquid composition for a liquid heating type flavor inhaler.

[0015] In one embodiment, a liquid composition for a liquid heating type flavor inhaler comprises: (1) propylene glycol and glycerin, (2) Nicotine, (3) Benzoic acid, and (4) Organic acids other than benzoic acid, Includes.

[0016] The non-combustion type flavor inhaler is a flavor inhaler that allows the inhalation of flavors without combustion. The non-combustion type flavor inhaler includes a heating type flavor inhaler with an electrical heat source or a heat source by a chemical reaction, and a non-heating type flavor inhaler without a heat source.

[0017] A "liquid heating type heated flavor inhaler," which is one type of non-combustion type flavor inhaler, is a flavor inhaler that has a cartridge containing a liquid composition (aerosol source) containing nicotine, and directly or indirectly heats the aerosol source (liquid) with an electrical heat source or a heat source generated by a chemical reaction, generating an aerosol containing nicotine and flavor, which is then delivered to the oral cavity through a mouthpiece member.

[0018] In one embodiment, the liquid heating type heated flavor inhaler is a porous or fibrous object impregnated with an aerosol source, which is a liquid such as glycerin, propylene glycol, or a mixed solution thereof, and the gas containing the vapor and particulate matter generated by electrically heating the porous or fibrous object is mixed into the air drawn in through the flavor inhaler. Usually, the consumer inhales the mixed gas by drawing it in through the end (the mouth end, the filter end, or the mouthpiece end) of the flavor inhaler.

[0019] In one embodiment, the liquid composition for a liquid heating type heated flavor inhaler contains (2) nicotine, (3) benzoic acid, and (4) an organic acid other than benzoic acid dissolved in a solvent such as propylene glycol and glycerin. In this specification, the liquid composition for a liquid heating type heated flavor inhaler may be referred to as "e-liquid". Without limitation, benzoic acid reduces the sense of inhibition of flavor caused by nicotine, and the organic acid other than the organic acid reduces the gunpowder-like odor caused by benzoic acid.

[0020] In one embodiment, in the liquid composition for a liquid heating type flavor inhaler, the molar ratio of (2) nicotine to the sum of (3) benzoic acid and (4) organic acid other than benzoic acid is in the range of 3:0.1 to 0.1:3, 2:0.5 to 0.5:2, or 1:0.85 to 1:1.15. In a preferred embodiment, the molar ratio of (2) nicotine to the sum of (3) benzoic acid and (4) organic acid other than benzoic acid is in the range of 1:0.85 to 1:1.15.

[0021] In one embodiment, the liquid composition for a liquid heating type heating flavor inhaler contains (4) an organic acid other than benzoic acid. "Organic acid" is a general term for the acid of an organic compound. Most organic acids are carboxylic acids having a carboxyl group or sulfonic acids having a sulfo group. The type of (4) organic acid other than benzoic acid used in the liquid composition of the present invention is not particularly limited. The number of types of organic acids other than (4) benzoic acid is also not particularly limited, and two or more types of (4) organic acids other than benzoic acid may be contained. In one embodiment, the organic acid other than (4) benzoic acid includes lactic acid, but is not limited thereto.

[0022] Furthermore, in one embodiment, the liquid composition for the liquid heating type heated flavor inhaler may contain, in addition to lactic acid, any one selected from tartaric acid, fumaric acid, levulinic acid, malonic acid, acetic acid, adipic acid, citric acid, malic acid, pyruvic acid, sorbic acid, and mixtures thereof, as an organic acid other than benzoic acid (4). Non-limitingly, in addition to lactic acid, any one selected from tartaric acid, fumaric acid, levulinic acid, malonic acid, and mixtures thereof, as an organic acid other than benzoic acid (4). Non-limitingly, in addition to lactic acid, any one selected from tartaric acid, levulinic acid, malonic acid, and mixtures thereof, as an organic acid other than benzoic acid (4). The organic acid contained in the liquid composition for the liquid heating type heated flavor inhaler is preferably an organic acid that is recognized as a food additive and is recognized as safe for living organisms.

[0023] In the liquid composition for a liquid heating type flavor inhaler, (4) as an organic acid other than benzoic acid, the molar ratio of lactic acid to the organic acid other than lactic acid is not particularly limited. In one embodiment, the molar ratio of lactic acid to the organic acid other than lactic acid is 10:1 to 1:2, 5:1 to 1:1, or 4:1: to 2:1. In one embodiment, the molar ratio of lactic acid to the organic acid other than lactic acid is about 3:1.

[0024] In order to prepare a liquid composition, the "organic acid other than benzoic acid" is preferably an organic acid that can be dissolved in glycerin and / or propylene glycol. In one embodiment, but not limited to, the organic acid other than benzoic acid has a solubility in glycerin of 0.32 mol / kg or more in terms of molar concentration. Lactic acid has a property that it is relatively soluble in glycerin and propylene glycol compared to benzoic acid and other organic acids. Some other organic acids, such as tartaric acid and malic acid, show a higher dissolution rate in propylene glycol than in glycerin (Example 8).

[0025] In one embodiment, in the liquid composition for a liquid heating type flavor inhaler, the molar ratio of (2) nicotine to (3) benzoic acid is in the range of 1:0.9 to 1:0.1, or 1:0.7 to 1:0.15. In a preferred embodiment, in the liquid composition for a liquid heating type flavor inhaler, the molar ratio of (3) benzoic acid to (2) nicotine is 60% or less.

[0026] In one embodiment, in the liquid composition for a liquid heating type flavor inhaler, the molar ratio of (2) nicotine to (4) an organic acid other than benzoic acid is in the range of 2:1 to 1:0.1, or 1:0.9 to 1:0.3. In one embodiment, in the liquid composition for a liquid heating type flavor inhaler, the molar ratio of (2) nicotine to (4) an organic acid other than benzoic acid is in the range of 1:0.9 to 1:0.3.

[0027] Non-limiting examples of the ratio of propylene glycol to glycerin include 1:1 to 1:3, more preferably 1:1 to 1:2.5, and more preferably 1:about 2.4. In one embodiment, the water content in the liquid composition for a liquid heating type heating type flavor inhaler is 10% by weight or less, 5% by weight or less, 3% by weight or less, or 1.5% by weight or less. In one embodiment, the liquid composition for a liquid heating type heating type flavor inhaler is substantially free of water. "Substantially free of water" means that "water" is not added in the process of preparing the liquid composition.

[0028] The liquid composition for a liquid-heating type heated flavor inhaler may further contain a component for constituting an aerosol source of the liquid-heating type heated flavor inhaler in addition to the components (1) to (4). In one embodiment, the liquid composition contains a flavor.

[0029] 2. Method for preparing liquid composition for liquid heating type flavor inhaler (I) The present invention relates to a method for preparing a liquid composition for a liquid heating type flavor inhaler. In one embodiment, a method for preparing a liquid composition for a liquid heating type flavor inhaler includes the steps of: (i) Prepare a preparation solution (A) by dissolving nicotine and benzoic acid in propylene glycol; (ii) Dissolve lactic acid in glycerin to prepare preparation solution (B); (iii) preparing a preparation solution (C) by dissolving, as desired, one or more organic acids other than benzoic acid and lactic acid in propylene glycol or glycerin; and (iv) mixing preparation solution (A), preparation solution (B), and preparation solution (C); The process includes:

[0030] Matters relating to the liquid composition for a liquid heating type heating flavor inhaler are as described in "1. Liquid composition for a liquid heating type heating flavor inhaler." Benzoic acid has a property of being difficult to dissolve in glycerin. Lactic acid has a property of being relatively good in solubility in glycerin and propylene glycol compared to benzoic acid and other organic acids. For example, some other organic acids, such as tartaric acid and malic acid, show a higher dissolution rate in propylene glycol than in glycerin. In the preparation method of the present invention, first, nicotine and benzoic acid are dissolved in propylene glycol (preparation liquid (A)) (step (i)), separately, lactic acid is dissolved in glycerin (preparation liquid (B)) (step (ii)), and further, one or more organic acids other than benzoic acid and lactic acid are dissolved in propylene glycol or glycerin as desired (preparation liquid (C)) (step (iii)), and after each organic acid is dissolved, the preparation liquid (A), the preparation liquid (B), and the preparation liquid (C) are mixed. This makes it possible to efficiently prepare, in a short time, a liquid composition for a liquid heating type heated flavor inhaler, which contains benzoic acid that is difficult to dissolve in glycerin.

[0031] In one embodiment, when the organic acid other than benzoic acid is an acid that is easily soluble in glycerin and propylene glycol, such as lactic acid, the glycerin and the organic acid may be added directly to the preparation liquid after preparation liquid (A) is prepared without preparing preparation liquid (B) separately from preparation liquid (A). In one embodiment, the method for preparing a liquid composition for a liquid heating type flavor inhaler includes the following steps: (i) Prepare a preparation solution (A) by dissolving nicotine and benzoic acid in propylene glycol; (v) dissolving glycerin, lactic acid, and optionally one or more organic acids other than benzoic acid and lactic acid in the preparation liquid (A); The process includes:

[0032] The method for preparing a liquid composition for a liquid heating type flavor inhaler further includes, but is not limited to, adding a flavoring in a step subsequent to step (i). By adding the flavoring after dissolving nicotine and benzoic acid in propylene glycol to prepare preparation liquid (A) in step (i), the stirring time after the flavoring is mixed is shortened, and loss of the flavoring component can be prevented or reduced. The addition of the flavoring or other component may be performed after step (i) before, at the same time, or after step (iv) of mixing preparation liquid (A), preparation liquid (B), and preparation liquid (C), or step (v) of dissolving glycerin, lactic acid, or the like in preparation liquid (A).

[0033] 3. Liquid heating type flavor inhaler (I) The present invention relates to a liquid heating type flavor inhaler. The liquid heating type flavor inhaler contains the liquid composition for the liquid heating type flavor inhaler of the present invention.

[0034] The liquid composition for a liquid-heating type heated flavor inhaler and matters relating to the liquid-heating type heated flavor inhaler are as described in "1. Liquid composition for a liquid-heating type heated flavor inhaler."

[0035] 4. Method for reducing the gunpowder-like odor of benzoic acid in a liquid composition for a liquid-heating type heated flavor inhaler The present invention relates to a method for reducing the gunpowder-like odor of benzoic acid in a liquid composition for a liquid-heating type heated flavor inhaler.

[0036] A method for reducing the gunpowder-like odor of benzoic acid in a liquid composition for a liquid heating type flavor inhaler, comprising: The liquid composition for the liquid heating type heated flavor inhaler contains (1) propylene glycol and glycerin, (2) nicotine, and (3) benzoic acid; The liquid composition for the liquid heating type heating flavor inhaler further contains (4) an organic acid other than benzoic acid. This includes:

[0037] (4) Lactic acid may be included as an organic acid other than benzoic acid. In one aspect, a method for reducing a gunpowder-like odor of benzoic acid in a liquid composition for a liquid-heating type heated flavor inhaler includes: Matters relating to the liquid composition for a liquid-heating type heated flavor inhaler and the heated flavor inhaler are as described in "1. Liquid composition for a liquid-heating type heated flavor inhaler."

[0038] In the method for reducing the gunpowder-like odor of benzoic acid in a liquid composition for a liquid-heating type heated flavor inhaler, it is important that the liquid composition for a liquid-heating type heated flavor inhaler contains (4) an organic acid other than benzoic acid, and the order in which (1) propylene glycol and glycerin, (2) nicotine and (3) benzoic acid, and (4) an organic acid other than benzoic acid are contained in the liquid composition for a liquid-heating type heated flavor inhaler is not particularly limited.

[0039] In one embodiment, the liquid composition for a liquid heating type heating flavor inhaler may be prepared according to the method described in "2. Method for preparing a liquid composition for a liquid heating type heating flavor inhaler". In one embodiment, the method for preparing a liquid composition for a liquid heating type heating flavor inhaler is as follows: (i) Prepare a preparation solution (A) by dissolving nicotine and benzoic acid in propylene glycol; (ii) Dissolve lactic acid in glycerin to prepare preparation solution (B); (iii) preparing a preparation solution (C) by dissolving, as desired, one or more organic acids other than benzoic acid and lactic acid in propylene glycol or glycerin; and (iv) mixing preparation solution (A), preparation solution (B), and preparation solution (C); The process includes:

[0040] In one embodiment, a method for preparing a liquid composition for a liquid heating type flavor inhaler includes the steps of: (i) Prepare a preparation solution (A) by dissolving nicotine and benzoic acid in propylene glycol; (v) dissolving glycerin, lactic acid, and optionally one or more organic acids other than benzoic acid and lactic acid in the preparation liquid (A); The process includes:

[0041] "Reducing the gunpowder-like odor of benzoic acid" means that (4) the gunpowder-like odor of benzoic acid is perceived as weaker than when benzoic acid and an organic acid are not included. In one embodiment, but not limited to, for example, χ 2 Test (Pearson's χ 2 This means that when the odor of benzoic acid is judged to be "weak" at a significance level of 1% or 5% in a randomized controlled trial (NCT) or binomial test, the gunpowder-like odor of benzoic acid is reduced.

[0042] 5. Liquid composition for liquid heating type flavor inhaler (II) The present invention relates to a liquid composition for a liquid heating type flavor inhaler. In one embodiment, a liquid composition for a liquid heating type flavor inhaler comprises: (1) propylene glycol and glycerin, (2) Nicotine, and (4) Organic acids other than benzoic acid, Includes.

[0043] Matters relating to the "non-combustion type flavor inhaler" are as described in "1. Liquid composition (I) for liquid heating type flavor inhaler." As shown in Example 6 of the present specification, it was found that a plurality of organic acids exhibit the same degree of reduction effect as benzoic acid in terms of the reduction effect of the nicotine-induced flavor inhibition (nicotine impact). Among the organic acids tested in this Example, lactic acid in particular exhibited a strong effect. Therefore, the liquid composition (II) for the liquid heating type heating flavor inhaler does not contain benzoic acid, and contains (only) an organic acid other than benzoic acid as the organic acid.

[0044] In one embodiment, a liquid composition for a liquid-heating type heated flavor inhaler contains (2) nicotine and (4) an organic acid other than benzoic acid dissolved in a solvent such as propylene glycol or glycerin.

[0045] In one embodiment, in the liquid composition for a liquid heating type flavor inhaler, the molar ratio of (2) nicotine to (4) organic acid other than benzoic acid is in the range of 3:0.1 to 0.1:3, 2:0.5 to 0.5:2, or 1:0.85 to 1:1.15. In a preferred embodiment, the molar ratio of (2) nicotine to (4) organic acid other than benzoic acid is in the range of 1:0.85 to 1:1.15.

[0046] In one embodiment, the liquid composition for a liquid heating type heating flavor inhaler contains (4) an organic acid other than benzoic acid. "Organic acid" is a general term for the acid of an organic compound. Most organic acids are carboxylic acids having a carboxyl group or sulfonic acids having a sulfo group. The type of (4) organic acid other than benzoic acid used in the liquid composition of the present invention is not particularly limited. The number of types of organic acids other than (4) benzoic acid is also not particularly limited, and two or more types of (4) organic acids other than benzoic acid may be contained. In one embodiment, the organic acid other than (4) benzoic acid includes lactic acid, but is not limited thereto.

[0047] (4) By adding other organic acids in addition to lactic acid as organic acids other than benzoic acid, slight negative sensory elements due to lactic acid (slight acidic odor, slight oiliness) can be reduced. In one embodiment, (4) organic acids other than benzoic acid may include, in addition to lactic acid, any one selected from tartaric acid, fumaric acid, levulinic acid, malonic acid, acetic acid, adipic acid, citric acid, malic acid, pyruvic acid, sorbic acid, and mixtures thereof.

[0048] In one non-limiting embodiment, the organic acid other than benzoic acid has a solubility in glycerin of 0.32 mol / kg or more in terms of molar weight concentration. Matters regarding "(4) Organic acids other than benzoic acid" are as described in "1. Liquid composition for liquid-heating type heating flavor inhaler" unless otherwise specified in this section.

[0049] Non-limiting examples of the ratio of propylene glycol to glycerin include 1:1 to 1:3, more preferably 1:1 to 1:2.5, and more preferably 1:about 2.4. In one embodiment, the water content in the liquid composition for a liquid heating type heating type flavor inhaler is 10% by weight or less, 5% by weight or less, 3% by weight or less, or 1.5% by weight or less. In one embodiment, the liquid composition for a liquid heating type heating type flavor inhaler is substantially free of water. "Substantially free of water" means that "water" is not added in the process of preparing the liquid composition.

[0050] The liquid composition for a liquid-heating type heated flavor inhaler may further contain a component for constituting an aerosol source of the liquid-heating type heated flavor inhaler in addition to the components (1), (2), and (4). In one embodiment, the liquid composition contains a flavor.

[0051] 6. Method for preparing liquid composition for liquid heating type flavor inhaler (II) The present invention relates to a method for preparing a liquid composition for a liquid heating type flavor inhaler. In one embodiment, a method for preparing a liquid composition for a liquid heating type flavor inhaler includes the steps of: (i') Prepare a preparation solution (B) by dissolving lactic acid in glycerin; (ii') preparing a preparation solution (C) by dissolving, as desired, one or more organic acids other than benzoic acid and lactic acid in propylene glycol or glycerin; and (iii') mixing nicotine with preparation solution (B) and preparation solution (C); The process includes:

[0052] Matters relating to the liquid composition for a liquid-heating type heating type flavor inhaler are as described in "5. Liquid composition for a liquid-heating type heating type flavor inhaler (II)". Lactic acid has a property that it is relatively soluble in glycerin and propylene glycol compared to benzoic acid and other organic acids. For example, tartaric acid and malic acid are other organic acids that show a higher dissolution rate in propylene glycol than in glycerin. In the preparation method of the present invention, first, lactic acid is dissolved in glycerin (preparation liquid (B)) (step (i')), and further, one or more organic acids other than benzoic acid and lactic acid are dissolved in propylene glycol or glycerin as desired (preparation liquid (C)) (step (ii')), and after each organic acid is dissolved, nicotine, preparation liquid (B) and preparation liquid (C) are mixed. Since the liquid composition (II) for a liquid heating type heated flavor inhaler does not use benzoic acid, the preparation method does not require a step of first dissolving benzoic acid in propylene glycol in the presence of nicotine. Nicotine can be mixed, for example, after dissolving the organic acid used in propylene glycol or glycerin, as appropriate.

[0053] The method for preparing a liquid composition for a liquid heating type flavor inhaler further includes, but is not limited to, adding a flavor. The preparation method (II) does not include a step of dissolving benzoic acid in propylene glycol, which takes a relatively long time, so the timing of adding the flavor is not particularly limited, and may be before, at the same time as, or after the step (i'), step (ii'), or step (iii').

[0054] 7. Liquid heating type flavor inhaler (II) The present invention relates to a liquid heating type flavor inhaler. The liquid heating type flavor inhaler contains the liquid composition for the liquid heating type flavor inhaler of the present invention.

[0055] The liquid composition for a liquid-heating type heated flavor inhaler and matters relating to the liquid-heating type heated flavor inhaler are as described in "1. Liquid composition for a liquid-heating type heated flavor inhaler (I)" and "5. Liquid composition for a liquid-heating type heated flavor inhaler (II)". EXAMPLES

[0056] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Those skilled in the art can easily modify and alter the present invention based on the description in this specification, and such modifications and alterations are within the technical scope of the present invention.

[0057] Example 1: Study on reducing benzoic acid odor 1-1 Experimental Overview In this embodiment, as an approach to reduce the benzoic acid odor, the amount of benzoic acid used was reduced. Specifically, two approaches were examined: 1) simply reducing the amount of benzoic acid used (no longer equimolar with nicotine), or 2) replacing the amount of benzoic acid reduced with a single other organic acid to supplement the acid deficiency. In addition, the prerequisite for development was that the reduction function of the flavor and taste inhibition caused by nicotine, which is expected as the original function of benzoic acid, was guaranteed to be at the same level as that of a product in which benzoic acid was mixed in an equimolar amount with nicotine.

[0058] In addition, when selecting organic acids other than benzoic acid in 2), the following two points were taken into consideration. (i) It is a common acid that is widely accepted as a food additive, preferably one that is widely contained in foods and that poses very little health concern; and (ii) Good solubility in PG and GL We decided to use two acids that fulfill these conditions: acetic acid (AA) and citric acid (CA). Note that we used citric acid monohydrate (CA·H2O), which is more commonly used as a food additive, rather than anhydrous citric acid, in our experiments.

[0059] 1-2 Experimental procedure An e-liquid (liquid composition for a liquid-heating type heated flavor inhaler) was prepared with the composition in Table 1, and 1.5 mL of the liquid was filled into capsules for a liquid-heating type heated flavor inhaler that heats at 200 to 300°C. A sensory evaluation was conducted by a seven-member expert panel (a panel that is engaged in flavor development work on a daily basis and has high sensory evaluation capabilities) using a device for a liquid-heating type heated flavor inhaler that heats at 200 to 300°C.

[0060] As a comparative example, an e-liquid containing only benzoic acid as an acid in an equimolar amount with nicotine was used. Table 1 shows the composition of the e-liquid samples used in the sensory evaluation. Table 1 E-liquid composition

[0061] [Table 1]

[0062] The sensory evaluation comments obtained are shown in Table 2. Table 2. Sensory evaluation comments

[0063] [Table 2]

[0064] 1-3 Results and Discussion As shown in the results in Table 2, Lot 1-1, which simply reduces the amount of benzoic acid, is clearly not effective in reducing the unpleasant aroma and taste caused by nicotine, and is therefore unsuitable because it does not meet the prerequisites for development.

[0065] It was determined that Lot 1-3, which used citric acid, had a weak effect on reducing the benzoic acid odor and did not fully exert the desired function of reducing the benzoic acid odor. In Lot 1-2, which used acetic acid, there were no comments about the strong benzoic acid odor or the strong aroma and taste inhibition caused by nicotine, so there is a possibility that the initial objectives and prerequisites for development are met. Although there were comments about the acetic acid odor and sourness, it is possible that the coexistence of easily detectable aromas such as the acetic acid odor with benzoic acid can mask the gunpowder odor derived from benzoic acid.

[0066] Here, when comparing the physical / chemical properties of acetic acid with other organic acids such as citric acid, it has the following advantages: -The pKa, an indicator of acidity, is close to that of benzoic acid (benzoic acid: 4.21, acetic acid: 4.76), so it may behave similarly to benzoic acid in terms of the neutralization reaction with nicotine; -It has extremely high solubility in PG and GL (dissolves in any ratio), which is advantageous in manufacturing; and -Its molecular weight is small, so a relatively small amount is required when calculated by weight.

[0067] Taking all of the above into consideration, acetic acid (AA) was selected as the most promising organic acid to replace benzoic acid and was used in the subsequent studies. Example 2: Examination of the range in which acetic acid exerts its function of reducing benzoic acid odor 2-1 Experimental Overview In this example, a composition that exhibits the effect of reducing the benzoic acid odor by acetic acid was examined. Specifically, an e-liquid containing acetic acid and benzoic acid was prepared, and the effect was confirmed by sensory evaluation.

[0068] 2-2 Experimental procedure An e-liquid with the composition shown in Table 3 was prepared and filled into capsules for a liquid heating type heated flavor inhaler that heats at 200° C. to 300° C., 1.5 mL each, and a sensory evaluation was carried out by a panel of 14 experts using a device for a liquid heating type heated flavor inhaler that heats at 200° C. to 300° C. As a comparative example, an e-liquid containing only benzoic acid as an acid in an equimolar amount to nicotine was used.

[0069] Table 3. E-liquid composition for consideration of reducing benzoic acid content

[0070] [Table 3]

[0071] According to the definition of each evaluation item in Table 4, the strength of each sensory evaluation item in each lot compared with the comparative example was evaluated and judged as "strong," "same," or "weak." Table 4. Sensory evaluation items and definitions of each item

[0072] [Table 4]

[0073] 2-3 Results and Discussion If no difference from the comparative example is observed, i.e., if acetic acid does not exert its function of reducing the benzoic acid odor, the sensory evaluation is expected to be dominated by votes for "the same" or the votes for "strong," "the same," and "weak" are expected to be distributed in the order of N / 3 = 4.67.

[0074] In this example, in order to confirm whether there is a difference between the comparative example and the use of acetic acid, a commonly used χ 2 Test (Pearson's χ 2 Test) (Reference: Statistical Analysis Handbook, 2nd edition, October 1, 1996, Shinsuke Muto, Asakura Publishing Co., Ltd.) was used. 2 If the probability value calculated in the test does not exceed the set statistical significance level, it is determined that the panel is randomly distributed among the items "strong", "same", and "weak", i.e., there is no significant difference. This does not mean that the panel has difficulty in judging the difference between "strong", "same", and "weak" through evaluation, but rather that the panel chose that item consciously, and so the number of people gathered there. In this embodiment, the commonly used statistical significance level α = 0.05 (significance level 5%) is set. If the value p calculated for the occurrence probability of the panel distribution result is 0.05 or less, it is determined that the statistical significance level is exceeded, i.e., it is significant.

[0075] Tables 5, 7, 9, 11, and 13 (Analysis Result A) show the results of whether the distribution of votes for each lot is significantly biased compared to the expected value. In Analysis Result A, the values ​​for "Strong," "Same," and "Weak" for each evaluation item of "Benzoic Acid Odor," "Acetic Acid Odor," and "Sourness" indicate the number of people who selected each evaluation (14 people in total). The expected value indicates the expected value when the number of votes for "Strong," "Same," and "Weak" in the three groups is evenly distributed at N / 3 = 4.67. The probability (p) indicates the probability of such a bias for each evaluation item of "Benzoic Acid Odor," "Acetic Acid Odor," and "Sourness." The greater the degree of bias, the smaller the probability (p). When the probability (p) is 0.05 or less, it means that the distribution of the number of people in the panel is particularly biased toward that item, that is, the bias is significant.

[0076] Furthermore, if analysis result A shows a significantly biased distribution, is the number of votes for "strong," "same," and "weak" significantly biased from the expected value? 2 The probabilities obtained from the test are shown in Tables 6, 8, 10, 12, and 14 (Analysis Result B). Each value in these tables indicates the probability that the number of people who chose "strong," "same," or "weak" for each of the ratings of "benzoic acid odor," "acetic acid odor," and "sourness" will be "strong." For example, the value of "0.001" for "acetic acid odor" and "strong" in Table 6 is the chi-square for the fact that 11 out of 14 panelists selected "strong" (from Table 5). 2 This indicates the probability of the test. When the probability is 0.05 or less, it means that the distribution of the panel members is particularly biased towards that item, in other words, the selection is significant. The value "0.001" for "Acetic acid odor" and "Strong" in Table 6 is less than 0.05, which means that the selection made by 11 out of 14 panel members is significant.

[0077] Table 5 Lot2-1 analysis result A

[0078] [Table 5]

[0079] Table 6 Lot2-1 analysis result B

[0080]

Table 6

[0081] Table 7 Analysis Results of Lot2-2 A

[0082]

Table 7

[0083] Table 8 Analysis Results of Lot2-2 B

[0084]

Table 8

[0085] Table 9 Analysis Results of Lot2-3 A

[0086]

Table 9

[0087] Table 10 Analysis Results of Lot2-3 B

[0088]

Table 10

[0089] Table 11 Analysis Results of Lot2-4 A

[0090]

Table 11

[0091] Table 12 Analysis Results of Lot2-4 B

[0092]

Table 12

[0093] Table 13 Lot2-5 analysis results A

[0094] [Table 13]

[0095] Table 14 Lot2-5 analysis result B

[0096] [Table 14]

[0097] From the results of Table 5-14, it can be said that the benzoic acid odor is "weak" at a significance level of 5% in Lots 2-3, 2-4, and 2-5, i.e., in the range of 3:7 to 5:5 (i.e., 1:1) of the molar ratio of acetic acid to benzoic acid, compared to the comparative example. From this, it can be concluded that the effect of reducing the benzoic acid odor by replacing a part of benzoic acid with acetic acid is confirmed, and that this effect is manifested when more than 30% of the benzoic acid in equimolar amounts to nicotine is replaced with acetic acid.

[0098] On the other hand, the comparative example did not contain acetic acid, so the acetic acid odor and sour taste were found to be "stronger" than the comparative example at a significance level of 5% for all lots, which was to be expected. Example 3: Examination of reduction in acetic acid odor / acidity 3-1 Experimental Overview In Example 2, the effect of reducing the benzoic acid odor by replacing a part of benzoic acid with acetic acid was confirmed. However, too strong acetic acid odor or sourness may inhibit the expression of fragrance in e-liquid containing fragrance, and the acetic acid odor or sourness itself may be recognized as off-note or off-taste, which may impair the acceptability / preference of the e-liquid itself. In this example, we investigated how to reduce the acetic acid odor and sourness as much as possible while maintaining the function of reducing the gunpowder odor of benzoic acid.

[0099] Specifically, in order to examine the extent to which the amount of acetic acid needs to be reduced to produce the effect of reducing the acetic acid odor / sourness, an e-liquid was prepared with a composition that combined acetic acid, benzoic acid, and citric acid, and the effect was confirmed by sensory evaluation. In addition, a flavoring was added to the e-liquid of this embodiment in order to reproduce a state close to the actual use state of a liquid heating type heated flavor inhaler. However, in order to prevent the acetic acid odor and benzoic acid odor themselves from being masked by the fragrance derived from the fragrance, a tobacco-type flavoring that is empirically considered to be less likely to produce such an effect was used. Therefore, the sensory evaluation of the acetic acid odor, benzoic acid odor, and sourness in this embodiment was not affected by the flavoring.

[0100] 3-2 Experimental procedure An e-liquid was prepared with the composition shown in Table 15. At this time, citric acid monohydrate (CA·H2O) was dissolved in GL in advance and used as liquid C. In addition, the flavoring was added last after mixing liquids A and B.

[0101] The preparation of the evaluation samples and the method of the sensory evaluation were the same as in "2-2 Experimental Procedure" in Example 2, and the sensory evaluation was carried out by a panel of 16 experts. As a comparative example, the same organic acid blend as Lot 2-3, in which the effect of reducing the benzoic acid odor was confirmed in Example 2, that is, the molar ratio of acetic acid to benzoic acid was 3:7, was used.

[0102] Table 15. E-liquid composition for acetic acid odor / acidity reduction study

[0103] [Table 15]

[0104] 3-3 Results and Discussion The same χ as in "2-3 Results and Discussion" in Example 2 2 Analysis was performed using statistical methods with statistical tests.

[0105] Analysis result A: Analysis of whether the vote distribution of each lot is significantly biased compared to the expected value (analysis of the significance of bias), Analysis result B: Analysis of the significance of each evaluation (number of votes) for each item Analysis results A are shown in Tables 16, 18, 20, 22 and 24, and analysis results B are shown in Tables 17, 19, 21, 23 and 25.

[0106] Table 16 Lot3-1 analysis result A

[0107] [Table 16]

[0108] Table 17 Lot3-1 analysis result B

[0109] [Table 17]

[0110] Table 18 Lot3-2 analysis result A

[0111] [Table 18]

[0112] Table 19 Lot3-2 analysis result B

[0113] [Table 19]

[0114] Table 20 Lot3-3 analysis results A

[0115] [Table 20]

[0116] Table 21 Lot3-3 analysis result B

[0117] [Table 21]

[0118] Table 22 Lot3-4 analysis results A

[0119] [Table 22]

[0120] Table 23 Lot3-4 analysis result B

[0121] [Table 23]

[0122] Table 24 Lot3-5 analysis result A

[0123] [Table 24]

[0124] Table 25 Lot3-5 analysis result B

[0125] [Table 25]

[0126] First, no significant difference was observed in the intensity of the benzoic acid odor in any lot compared to the comparative example. From this, it can be said that the function of reducing the benzoic acid odor is guaranteed even if a part of the acetic acid is replaced with an equimolar amount of citric acid monohydrate.

[0127] Next, from the results of Lot 3-1 and 3-2, when the molar ratio of acetic acid, benzoic acid, and citric acid is in the range of 0.05:0.70:0.25 to 0.10:0.70:0.20, the acetic acid odor and sourness are "weak" at a significance level of 5% compared to the comparative example. From this, it was confirmed that the acetic acid odor and sourness reduction effect is achieved by replacing a part of the acetic acid with citric acid. And, it is concluded that the effect is expressed when the molar ratio of acetic acid is within a certain range, for example, when the molar ratio of acetic acid to nicotine is within a range of 10% or less, and when the molar ratio of acetic acid to benzoic acid is within a range of 1 / 7 or less.

[0128] Example 4: Examination of the blending procedure in the preparation method of e-liquid 4-1 Experimental Overview Benzoic acid is a relatively hydrophobic substance with low solubility in water. The main solvents for e-liquids are PG and GL, but the solubility of benzoic acid in these solvents is also not very high, and long periods of stirring or heating are often required to dissolve benzoic acid alone in these solvents.

[0129] In order to solve the above problems and to devise a more efficient method for preparing e-liquid, the inventors have focused on the fact that hydrophilicity is improved when benzoic acid is neutralized with nicotine to form nicotine benzoate, and that when the structures of PG and GL are compared, PG has two hydrophilic hydroxyl groups, while GL has three, so that PG is considered to be a more suitable solvent for dissolving hydrophobic substances than GL. Specifically, in this embodiment, based on the above consideration, the hypothesis is made that the conditions for efficiently dissolving benzoic acid are (a) dissolving benzoic acid in a solvent in the presence of nicotine, and (b) dissolving in PG alone, and the blending procedure in the preparation method of e-liquid is examined.

[0130] 4-2 Experimental procedure The e-liquids having the compositions shown in Table 26 were prepared using the following two blending procedures, I. and II., and the time required for benzoic acid to completely dissolve was compared.

[0131] Table 26. E-liquid composition for blending tests

[0132] [Table 26]

[0133] I. PG, GL, nicotine, and benzoic acid are all added at first, and then stirred and mixed at room temperature. II. After adding only PG, nicotine, and benzoic acid, stir and mix at room temperature. After confirming that the benzoic acid has completely dissolved (liquid A), add GL (liquid B) and stir and mix again at room temperature. The weighed materials were placed in a beaker, a stirrer was placed in the beaker, and the materials were stirred at 1000 rpm using a magnetic stirrer. After stirring was completed, the presence or absence of undissolved materials was confirmed by visual inspection.

[0134] 4-3 Results and Discussion In the case of procedure I, even after stirring for more than 6 hours, benzoic acid powder was observed and the solution did not completely dissolve.

[0135] On the other hand, in the case of procedure II, when only PG, nicotine, and benzoic acid were mixed, the benzoic acid powder disappeared 30 minutes after the initial stirring, and complete dissolution was confirmed. GL was then added and mixed again, and after 10 minutes it was confirmed that the mixture had become a homogeneous liquid.

[0136] From the above results, it was confirmed that by using only PG, nicotine, and benzoic acid and then completely dissolving the benzoic acid using the blending procedure shown in II, in which GL is then added, benzoic acid can be dissolved in a short time even at room temperature.

[0137] Example 5: Examination of the use of acids other than acetic acid and benzoic acid 5-1 Experimental Overview When preparing an e-liquid using an organic acid (third organic acid) other than benzoic acid and acetic acid (citric acid in Example 3), if it is added to PG (liquid A) together with nicotine and benzoic acid, it is considered that the neutralization reaction between benzoic acid and nicotine will be antagonized and the solubility of benzoic acid will be inhibited. Therefore, it is assumed that it is more appropriate to pre-dissolve organic acids other than benzoic acid and acetic acid in a GL solvent separately from liquid A. Alternatively, if a liquid organic acid such as acetic acid has high solubility in PG and GL, it is assumed that it may be directly added to the system (liquid A) without pre-dissolving in GL.

[0138] In Example 3, citric acid was used as an organic acid (third organic acid) other than benzoic acid and acetic acid, but any acid capable of completely dissolving the required amount in GL may be used instead of citric acid. Assuming an embodiment in which the third organic acid is pre-dissolved in GL within the scope of the present invention, the following conditions are satisfied.

[0139] - Nicotine content is 5% by weight -Fragrance content is 5% by weight -The weight ratio of the solvent is 50:50 -One third organic acid -Mole ratio of nicotine:acetic acid:benzoic acid:third organic acid is 1.00:0.05:0.50:0.45 As for the organic acids that can be used as the third organic acid, those that are recognized as food additives as listed in Example 1-1 and that are expected to have a certain degree of solubility in PG or GL (=those with a large proportion of polar functional groups in the molecule) will be candidates. For example, long-chain fatty acids such as stearic acid and palmitic acid are obviously highly hydrophobic and have low solubility in PG or GL, and are therefore considered to be unsuitable. On the other hand, organic acids with short carbon chains or multiple polar functional groups are expected to be soluble in PG or GL, and therefore may be candidates. Examples of such organic acids include adipic acid, citric acid, fumaric acid, lactic acid, malic acid, malonic acid, pyruvic acid, sorbic acid, succinic acid, and tartaric acid. In this example, we investigated whether these organic acids that are candidates for the third organic acid can be used under the above conditions.

[0140] 5-2 Experimental procedure The e-liquid composition under the above conditions was simulated, and the molar concentration of the third organic acid was calculated assuming that the third organic acid was pre-dissolved in only the prescribed amount of GL. The results are shown in Table 27.

[0141] Table 27. Simulation results of the third organic acid candidate e-liquid composition

[0142] [Table 27]

[0143] As can be seen from the simulation of the formulation shown in Table 27, "solubility in GL of 0.32 mol / kg or more in terms of weight molar concentration" can be one guideline for selecting a third organic acid that can realize the e-liquid composition and formulation method envisioned within the scope of the present invention.

[0144] Next, a solubility test for GL was carried out to verify whether this composition could actually be realized by the blending method of the present invention. The amounts of GL and acid shown in Table 28 were weighed into a beaker, a stirrer was placed in the beaker, and the mixture was stirred at 500 rpm for 12 hours at room temperature using a magnetic stirrer. After stirring, the presence or absence of undissolved matter was confirmed by visual inspection, and any solid matter found to remain was deemed to have not dissolved.

[0145] Table 28. Solubility confirmation level and results for the third organic acid candidate in GL

[0146] [Table 28]

[0147] 5-3 Results and Discussion Six organic acids, citric acid, lactic acid, malic acid, malonic acid, pyruvic acid, and tartaric acid, showed a solubility in GL of 0.32 mol / kg or more. In other words, it was found that the third organic acid, which is used in the highest concentration within the scope of the present invention, can be used in the e-liquid of the present invention.

[0148] Example 6 Effect of each organic acid on the inhibition of flavor and taste caused by nicotine In this example, the effect of each organic acid alone in reducing the unpleasant aroma and taste caused by nicotine (nicotine impact) was examined.

[0149] An e-liquid (liquid composition for a liquid-heating type heated flavor inhaler) was prepared with the composition in Table 29, and 1.5 mL of the liquid was filled into capsules for a liquid-heating type heated flavor inhaler that heats at 200°C to 300°C. A sensory evaluation was conducted by an eight-member expert panel (a panel that is engaged in flavor development work on a daily basis and has high sensory evaluation capabilities) using a device for a liquid-heating type heated flavor inhaler that heats at 200°C to 300°C.

[0150] As a negative comparison example, an e-liquid containing only nicotine and no organic acid was used. As a positive comparison example, an e-liquid containing benzoic acid as an organic acid in an equimolar amount with nicotine was used. Table 29 shows the composition of the e-liquid of each sample subjected to the sensory evaluation and the results of the sensory evaluation.

[0151] Table 29. Effect of each organic acid on the inhibition of flavor and aroma caused by nicotine (sensory evaluation)

[0152] [Table 29]

[0153] The sensory evaluation items are as follows. Table 30. Sensory evaluation items

[0154] [Table 30]

[0155] As shown in Table 29, several organic acids were found to have the same level of reducing effect as benzoic acid on the nicotine-induced flavor inhibition (nicotine impact). Among the organic acids tested in this example, lactic acid in particular had a strong effect. Lactic acid is liquid and has good solubility in PG and GL, so it has the great advantage of being easy to handle in manufacturing. However, lactic acid had some negative sensory elements (slight acidic odor, slight oiliness). Therefore, it is considered more desirable to combine it with other organic acids.

[0156] Example 7: Examination of liquid compositions containing benzoic acid, lactic acid, and other organic acids In this example, the composition of a liquid composition containing benzoic acid, lactic acid, and other organic acids was examined. The benzoic acid to nicotine ratio was maintained at 0.6 or less.

[0157] As candidates for combination with lactic acid, tartaric acid, fumaric acid, levulinic acid, and malonic acid were examined, which show a strong nicotine impact reduction effect in Example 6 and have no strong negative factors. The ratio of lactic acid to benzoic acid and organic acids other than lactic acid was 3:1. As a comparative example, an e-liquid containing only benzoic acid and no lactic acid or other organic acids was used.

[0158] Table 31 shows the composition of the e-liquid of each sample subjected to the sensory evaluation, and the results of the sensory evaluation (by a panel of 14 experts). Table 31 Reduction effect of combinations of benzoic acid, lactic acid, and other organic acids (sensory evaluation)

[0159] [Table 31]

[0160] The results of analyzing the sensory evaluation in Table 31 using a binomial test are shown below. Table 32. Binomial test results for the reduction effect (sensory evaluation) of combinations of benzoic acid, lactic acid, and other organic acids

[0161] [Table 32]

[0162] In a binomial test, the p-value of the number of times "strong" or "weak" was selected means the statistical probability of the number of times "strong" was selected out of the total number of n. For example, let's take the gunpowder odor (benzoic acid odor) sample with fumarole of 0.10. Of n=14, "weak" was selected 11 times, and the p-value in this case is 0.006, or 0.6%. This means that if "strong" and "weak" are selected randomly 14 times with a 50% probability each, the statistical probability of "weak" being selected 11 times by chance is 0.6%. This value of 0.6% is smaller than the 1% commonly used significance level, so it can be concluded that the bias of "weak" being selected 11 times out of 14 times is a significant bias at the significance level of 1%.

[0163] In all lots in which lactic acid was combined with fumaric acid, levulinic acid, malonic acid, or tartaric acid in various ratios, the nicotine impact was equal to or weaker than that of the comparative example (Ref). Therefore, it was confirmed that the effect of reducing the nicotine impact was guaranteed even when a part of the benzoic acid was replaced with a combination of lactic acid and other organic acids. The gunpowder odor was weaker than that of the comparative example (even in lots where there was no significant difference, the number of people selecting "weak" was higher). It was confirmed that by replacing a part of the benzoic acid with a combination of lactic acid and other organic acids, the gunpowder odor could be reduced more than in a composition containing only benzoic acid as an organic acid.

[0164] Example 8 Solubility of Malic Acid and Tartaric Acid in Propylene Glycol and Glycerin In this example, the dissolution rate of malic acid and tartaric acid in propylene glycol and glycerin was investigated. (1) Organic acid, PG or GL was weighed into a glass screw tube; (2) Stirring was continued at room temperature at a stirring speed of 500 rpm using a magnetic stirrer; and (3) visual confirmation was made as to whether the organic acid was completely dissolved. The results are shown in Table 33.

[0165] Table 33. Dissolution rate test results of malic acid and tartaric acid in propylene glycol and glycerin

[0166] [Table 33]

[0167] In Table 33, OK indicates that the solid matter had disappeared and was confirmed to be completely dissolved, and NG indicates that the solid matter remained and it was determined that it was not yet dissolved. Both malic acid and tartaric acid dissolved faster in propylene glycol than in glycerin.

Claims

1. (i) preparing a preparation solution (A) by dissolving nicotine and benzoic acid in propylene glycol; (ii) preparing a preparation solution (B) by dissolving lactic acid in glycerin; (iii) preparing a preparation solution (C) by dissolving one or more organic acids other than benzoic acid and lactic acid in propylene glycol or glycerin; and (iv) mixing the preparation liquid (A), the preparation liquid (B) and the preparation liquid (C); A method for preparing a liquid composition for a liquid heating type flavor inhaler, comprising the steps of:

2. (i) preparing a preparation solution (A) by dissolving nicotine and benzoic acid in propylene glycol; (v) dissolving glycerin, lactic acid, and one or more organic acids other than benzoic acid and lactic acid in the preparation liquid (A); A method for preparing a liquid composition for a liquid heating type flavor inhaler, comprising the steps of:

3. 3. The method of claim 1 or 2, further comprising adding a flavoring agent in a step subsequent to step (i).

4. (i') preparing a preparation solution (B) by dissolving lactic acid in glycerin; (ii') preparing a preparation solution (C) by dissolving one or more organic acids other than benzoic acid and lactic acid in propylene glycol or glycerin; and (iii') mixing nicotine, the preparation solution (B) and the preparation solution (C); A method for preparing a liquid composition for a liquid heating type flavor inhaler, comprising the steps of:

5. 5. The method of claim 4, further comprising adding a flavoring.

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