Solid fuel

Abstract

To provide a solid fuel which has sufficiently high hardness even when solidified by cooling under slow cooling conditions, for example.SOLUTION: The solid fuel contains an alcohol (A) and a fatty acid (salt) (B). If the alkali content in the solid fuel or the lacking alkali content for neutralizing the acid content in the solid fuel is converted into sodium hydroxide having the same molarity of alkalinity, and a value expressed as a mass fraction (mg / g) of sodium hydroxide in the solid fuel is from -2.0 to 1.0.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a solid fuel. [Background technology]

[0002] Solid fuels are known as fuels for heating cooked food, etc., in which a cylindrical or prismatic solid fuel body sealed in a resin film is packaged in an exterior material. Solid fuels are mainly used for one-person hotpots, and are widely used not only in tourist inns, but also in beef bowl chain restaurants, Japanese restaurants, etc. in recent years. Solid fuels can also be used as ignition agents, such as charcoal (wood charcoal), for barbecues.

[0003] For example, Patent Document 1 discloses that the volatilization of fuel components can be suppressed by covering the surface of solid fuel with polyethylene. Patent Document 2 discloses that the volatilization of fuel components can be suppressed and storage stability (weight retention of solid fuel during storage) can be improved by blending a fatty acid ester of a polyhydric alcohol without covering the surface of the solid fuel. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 1-267133 [Patent Document 2] Japanese Patent Application Publication No. 8-231970 Summary of the Invention [Problem to be solved by the invention]

[0005] Solid fuel is usually produced by mixing and neutralizing its components while heating in a blending tank, and then cooling and solidifying it, but when it is cooled and solidified under slow cooling conditions, the hardness of the solid fuel decreases, and as a result, the solid fuel may become easily crumbled or may be difficult to cut to adjust the size and shape after solidification. The above Patent Documents 1 and 2 do not particularly disclose how to increase the hardness of the solid fuel.

[0006] The present invention has been made to solve the above-mentioned problems, and has an object to provide a solid fuel that has a sufficiently high hardness even when cooled and solidified under slow cooling conditions, for example. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention (1) is a solid fuel containing an alcohol (A) and a fatty acid (salt) (B), and the amount of alkali content in the solid fuel or a shortage of alkali content for neutralizing the acid content in the solid fuel is converted into the equivalent moles of sodium hydroxide and expressed as a mass ratio (mg / g) of sodium hydroxide in the solid fuel (hereinafter also referred to as alkali index) of -2.0 to 1.0. The alkali content or acid content in the solid fuel is the alkali content or acid content that remains unneutralized when the components of the solid fuel are uniformly mixed. The amount of alkali content in the solid fuel is expressed as a positive value, and the amount of alkali content that is insufficient to neutralize the acid content in the solid fuel is expressed as a negative value. In addition, in the mass ratio (mg / g) of sodium hydroxide in the solid fuel, the mass of the solid fuel, which is the denominator, is the mass of the solid fuel itself, not the alkali content in the solid fuel converted into the same number of moles of sodium hydroxide.

[0008] The solid fuel of the present invention has high hardness, so that it is not easily crumbled, is easy to cut, and can be easily adjusted in size and shape. Although the reason why the solid fuel of the present invention has high hardness is not clear, it is thought that this is because the network structure of the gel formed by the fatty acid becomes strong and stable due to the alkali index being within a specified range.

[0009] In this way, the solid fuel of the present invention has an alkalinity index specified within a predetermined range, and therefore has a high hardness even when produced by solidifying under slow cooling conditions. In this specification, the term "solid" refers to a state of a solid, and is a concept that includes a gel state.

[0010] The present invention (2) relates to the solid fuel of the present invention (1), wherein the fatty acid (salt) (B) comprises a fatty acid (salt) (B-1) having 18 or more carbon atoms and a fatty acid (salt) (B-2) having 17 or less carbon atoms, and the molar ratio of (B-1) / (B-2) is 0.01 or more and 70 or less. This makes the effect of the present invention more pronounced.

[0011] The present invention (3) is the solid fuel according to the present invention (1) or (2), wherein the content of the alcohol (A) is 50 to 99 mass %.

[0012] The present invention (4) is the solid fuel according to any one of the present inventions (1) to (3), wherein the content of the fatty acid (salt) (B) is 3 to 20 mass %.

[0013] The present invention (5) is the solid fuel according to any one of the present inventions (1) to (4), which contains water.

[0014] The present invention (6) relates to the solid fuel according to the present invention (5), wherein the water content is 1 to 40 mass %.

[0015] The present invention (7) is the solid fuel according to any one of the present inventions (1) to (6), the surface of which is covered with paraffin. This more effectively prevents the vaporization of fuel components. In addition, while maintaining the necessary ignition properties as a fuel, the solid fuel is prevented from unintentionally igniting, making it a safer solid fuel.

[0016] The present invention (8) is the solid fuel according to the present invention (7), wherein the paraffin has a thickness of 0.1 to 2.0 mm.

[0017] The present invention (9) is the solid fuel according to any one of the present inventions (1) to (8), which contains a thickener.

[0018] The present invention (10) relates to the solid fuel according to any one of the present inventions (1) to (9), wherein the alcohol (A) contains a monohydric alcohol.

[0019] The present invention (11) relates to the solid fuel according to the present invention (10), wherein the monohydric alcohol is methanol.

[0020] The present invention (12) relates to the solid fuel according to the present invention (10) or (11), wherein the content of the monohydric alcohol is 50% by mass or more and less than 70% by mass.

[0021] The present invention (13) relates to the solid fuel according to the present invention (10) or (11), wherein the content of the monohydric alcohol is 70% by mass or more and less than 85% by mass.

[0022] The present invention (14) relates to the solid fuel according to the present invention (10) or (11), wherein the content of the monohydric alcohol is 85% by mass or more and 95% by mass or less.

[0023] The present invention also relates to a solid fuel comprising an alcohol (A) and a fatty acid (salt) (B), the fatty acid (salt) (B) comprising a fatty acid (salt) (B-1) having 18 or more carbon atoms and a fatty acid (salt) (B-2) having 17 or less carbon atoms, and the molar ratio of (B-1) / (B-2) is 0.01 or more and 70 or less. Effect of the Invention

[0024] The solid fuel of the present invention has basic properties such as ignition ability and flame force, and also has high hardness. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The solid fuel of the present invention contains an alcohol (A) and a fatty acid (salt) (B), and has an alkaline index of -2.0 to 1.0.

[0026] The alkali index is preferably -1.9 or more, more preferably -1.8 or more. The alkali index is preferably 0.9 or less, more preferably 0.8 or less. Such a low alkali index can also reduce shavings during cutting.

[0027] The alkalinity index in this specification is a numerical value which expresses the amount of alkali content in the solid fuel or the shortage of alkali content for neutralizing the acid content in the solid fuel as the mass ratio (mg / g) of sodium hydroxide in the solid fuel by converting the alkali content into the equivalent number of moles of sodium hydroxide, and is calculated by the following method. Approximately 10g of solid fuel was collected and neutralized with ethanol containing phenolphthalein. (※1) Add and heat to completely dissolve. If there is insufficient alkali (phenolphthalein does not turn red), titrate as is with 0.1 mol / L potassium hydroxide-methanol solution. If there is excess alkali (phenolphthalein turns red), add an appropriate amount of 0.1 mol / L hydrochloric acid aqueous solution to make it acidic, then titrate with 0.1 mol / L potassium hydroxide-methanol solution. The end point of the titration is when phenolphthalein turns pale pink. The alkali index is calculated using the following formula. Alkaline index = [(A × fB × f') × 0.1 × 40.00] ÷ C A: Amount (mL) of 0.1 mol / L hydrochloric acid solution (added when excess alkali is present) f: Factor of 0.1 mol / L hydrochloric acid solution B: Amount of 0.1 mol / L potassium hydroxide-methanol solution required for titration (mL) f´: Factor of 0.1 mol / L potassium hydroxide-methanol solution 0.1: Molar concentration of titrant (mol / L) 40.00: Molecular weight of sodium hydroxide C: Weight of collected solid fuel (g) (※1) Neutralized ethanol: Phenolphthalein solution in 1L of ethanol (95v / v%) as specified in JIS K 8102 (※2) Add 10 mL of the above solution, then add 0.1 mol / L potassium hydroxide-methanol solution until the solution turns pale pink. (※2) Phenolphthalein solution: 1.0 g of phenolphthalein as specified in JIS K 8799 is weighed out, dissolved in 90 mL of ethanol (95 v / v%) as specified in JIS K 8102, and then distilled to 100 mL with purified water. The alkalinity index can be appropriately adjusted using known alkali agents such as sodium hydroxide and potassium hydroxide, and known acid agents such as fatty acids, hydrochloric acid, and sulfuric acid. Of these, it is preferable to use sodium hydroxide as the alkali agent. It is preferable to use fatty acids as the acid agent.

[0028] Each component of the solid fuel of the present invention will be described below.

[0029] (Alcohol (A)) Examples of the alcohol (A) include monohydric alcohols such as methanol, ethanol, and propanol, and polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and glycerin, and these can be used alone or in combination of two or more.

[0030] Of these, the solid fuel of the present invention preferably contains a monohydric alcohol. As the monohydric alcohol, from the viewpoints of shape stability of the solid fuel during combustion and suppression of odor, it is preferable to use at least one selected from the group consisting of methanol, ethanol, and propanol, more preferably methanol and / or ethanol, and even more preferably methanol. The monohydric alcohol functions as a combustion component, and the higher the content, the better the ignition ability, flame strength, and shape stability. From the viewpoint of improving the weight retention of the solid fuel during storage, the content is preferably 95% by mass or less, and more preferably 92% by mass or less. The monohydric alcohols may be used alone or in combination of two or more kinds.

[0031] The content of monohydric alcohol (particularly preferably, methanol) is preferably 50 to 95 mass% in 100 mass% of solid fuel in order to achieve a good balance between the fire force, ignition ability, and the weight retention of the solid fuel during storage. For example, from the viewpoint of achieving sufficient fire force and ignition ability while improving the weight retention of the solid fuel during storage, the content is preferably 50 mass% or more and less than 70 mass%. The content is more preferably 55 mass% or more, and even more preferably 60 mass% or more. In addition, from the viewpoint of achieving a good balance between the fire force, ignition ability, the weight retention of the solid fuel during storage, and the shape of the solid fuel during combustion, the content is preferably 70 mass% or more and less than 85 mass%. The content is more preferably 75 mass% or more, and even more preferably 80 mass% or more. Furthermore, from the viewpoint of achieving sufficient weight retention of the solid fuel during storage while improving the fire force and ignition ability, the content is preferably 85 mass% or more and 95 mass% or less. The content is more preferably 88% by mass or more, and further preferably 90% by mass or more.The content is more preferably 92% by mass or less. Here, the content of the monohydric alcohol means the total content when the solid fuel contains two or more kinds of monohydric alcohols. The same applies to the contents of other components. The above-mentioned preferable content range of the monohydric alcohol can be read as the preferable content range of methanol alone.

[0032] The polyhydric alcohol is preferably at least one selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, and glycerin. Polyhydric alcohols have excellent weight retention and can also exhibit appropriate flame strength, storage stability, and ignition properties required for a solid fuel. The polyhydric alcohols may be used alone or in combination of two or more kinds.

[0033] As the polyhydric alcohol, ethylene glycol and / or diethylene glycol are preferred from the viewpoints of ignition ability, continuity of combustion, and maintenance of the shape of the solid fuel during combustion, and ethylene glycol is more preferred from the viewpoint of reducing odor during combustion.

[0034] When the solid fuel of the present invention contains a polyhydric alcohol, the content of the polyhydric alcohol is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 5% by mass or more, and particularly preferably 8% by mass or more, based on 100% by mass of the solid fuel, from the viewpoint of further improving weight retention. The content of the polyhydric alcohol is preferably 40% by mass or less, more preferably 35% by mass or less, even more preferably 30% by mass or less, still more preferably 25% by mass or less, even more preferably 20% by mass or less, and still more preferably 15% by mass or less, from the viewpoint of improving flame force, ignition ability, and continuity of combustion, and is particularly preferably 5% by mass or less, more particularly preferably 3% by mass or less, and even more particularly preferably 1% by mass or less, from the viewpoint of maintaining the shape of the solid fuel during combustion.

[0035] In another preferred embodiment of the present invention, the solid fuel of the present invention contains a monohydric alcohol (particularly preferably, methanol) and a polyhydric alcohol.

[0036] The content of the alcohol (A) is preferably 50 to 99 mass % in 100 mass % of the solid fuel. The content of the alcohol (A) is more preferably 60% by mass or more, further preferably 70% by mass or more, and particularly preferably 75% by mass or more. The content of the alcohol (A) is more preferably 98% by mass or less, further preferably 95% by mass or less, and particularly preferably 93% by mass or less.

[0037] (Fatty Acid (Salt) (B)) The fatty acid (salt) (B) usually has a carbon number of 2 or more, and preferably 8 or more. The carbon number is preferably 22 or less, and more preferably 20 or less. In this specification, the fatty acid (salt) (B) is a fatty acid and / or a fatty acid salt, and is preferably a fatty acid salt. The fatty acid (salt) (B) is preferably a salt formed by, for example, a neutralization reaction between a fatty acid and an alkali. When a fatty acid is neutralized with an alkali to become a fatty acid salt, sufficient solidification properties are exhibited. The fatty acid (salt) (B) may be used alone or in combination of two or more kinds.

[0038] The fatty acid of the fatty acid (salt) (B) is not particularly limited, but examples thereof include saturated fatty acids such as acetic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, pentadecylic acid, and margaric acid; unsaturated fatty acids such as palmitoleic acid, oleic acid, linoleic acid, linolenic acid, and arachidonic acid; and the like. These may be used alone, but it is preferable to use two or more of them in combination. Among them, from the viewpoint of the stability of solidification, saturated fatty acids are preferred, and at least one selected from the group consisting of caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, pentadecylic acid, and margaric acid is more preferred.

[0039] The salt of the fatty acid (salt) (B) is not particularly limited, but examples thereof include sodium salts and potassium salts. These may be used alone or in combination of two or more. Among these, sodium salts are preferred because of their stability in solidification.

[0040] The fatty acid (salt) (B) includes a fatty acid (salt) (B-1) having 18 or more carbon atoms and a fatty acid (salt) (B-2) having 17 or less carbon atoms, and the molar ratio of (B-1) / (B-2) is preferably 0.01 or more and 70 or less. When the molar ratio of (B-1) / (B-2) is within the above range, the hardness of the solid fuel becomes superior. The molar ratio of (B-1) / (B-2) is more preferably 0.1 or more, more preferably 0.2 or more, and particularly preferably 1 or more. In addition, such a large molar ratio can reduce shavings during cutting. The molar ratio is more preferably 20 or less, and even more preferably 10 or less.

[0041] The fatty acid (salt) (B) includes a fatty acid (salt) (B-1') having 18 to 22 carbon atoms and a fatty acid (salt) (B-2') having 2 to 17 carbon atoms, and the molar ratio of (B-1') / (B-2') is more preferably 0.01 or more and 70 or less. When the molar ratio of (B-1') / (B-2') is within the above range, the hardness of the solid fuel becomes superior. The molar ratio of (B-1') / (B-2') is more preferably 0.1 or more, more preferably 0.2 or more, and particularly preferably 1 or more. In addition, such a large molar ratio can reduce shavings during cutting. The molar ratio is more preferably 20 or less, and even more preferably 10 or less.

[0042] The fatty acid (salt) (B) includes a fatty acid (salt) (B-1'') having 18 to 20 carbon atoms and a fatty acid (salt) (B-2'') having 8 to 16 carbon atoms, and the molar ratio of (B-1'') / (B-2'') is more preferably 0.01 or more and 70 or less. When the molar ratio of (B-1'') / (B-2'') is within the above range, the hardness of the solid fuel becomes superior. The molar ratio of (B-1″) / (B-2″) is more preferably 0.1 or more, even more preferably 0.2 or more, and particularly preferably 1 or more. The molar ratio is more preferably 20 or less, and even more preferably 10 or less.

[0043] The content of fatty acid (salt) (B) is 3 to 20% by mass in 100% by mass of solid fuel. If the content of fatty acid (salt) (B) exceeds 20% by mass, the temperature and hardness at which the solid fuel solidifies may become too high, and manufacturability may deteriorate. If the content of fatty acid (salt) (B) is less than 3% by mass, sufficient solidification is not obtained, and the shape of the solid fuel during combustion tends to be poor. The content of fatty acid (salt) (B) is preferably 4% by mass or more, more preferably 5% by mass or more, even more preferably 6% by mass or more, particularly preferably 7% by mass or more, and preferably 18% by mass or less, more preferably 16% by mass or less, even more preferably 14% by mass or less, particularly preferably 12% by mass or less. In this specification, the content of fatty acid (salt) (B) is the total mass ratio of the mass ratio of fatty acid and the mass ratio of fatty acid salt converted into fatty acid in 100% by mass of solid fuel.

[0044] The solid fuel preferably contains a thickener, which tends to suppress scattering of powder particles during combustion and to further improve the stability of solidification. The thickeners may be used alone or in combination of two or more kinds.

[0045] The thickener is not particularly limited, but examples thereof include polysaccharides, polyacrylamides, polyalkylene oxides, polyacrylic acids and their salts, polyvinyl alcohols, etc. Among them, polysaccharides are preferred because they suppress the scattering of powdery fuel during combustion. In other words, it is preferred that the thickener contains a polysaccharide.

[0046] The polysaccharide is not particularly limited, but examples thereof include cellulose derivatives, starch, alginic acid and its salts (e.g., sodium alginate), guar gum, gellan gum, gelatin, pectin, xanthan gum, carrageenan, etc. Among them, cellulose derivatives are preferred because they suppress the scattering of powdery fuel during combustion. In other words, it is preferred that the thickener contains a cellulose derivative.

[0047] The cellulose derivative is not particularly limited, and examples thereof include cellulose ethers such as methyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and hydroxypropyl methyl cellulose. Among them, cellulose ethers are preferred, at least one selected from the group consisting of methyl cellulose and hydroxypropyl methyl cellulose is more preferred, and methyl cellulose is even more preferred, for the reason of suppressing the scattering of powdery fuel during combustion. In other words, it is preferable that the thickener contains methyl cellulose.

[0048] The viscosity of a 2% by mass aqueous solution of the thickener at 20° C. is preferably 100 mPa·s or more and 100,000 mPa·s or less, more preferably 150 mPa·s or more and 50,000 mPa·s or less, and even more preferably 200 mPa·s or more and 10,000 mPa·s or less. In this specification, the viscosity of a 2% by mass aqueous solution of the thickener at 20° C. is measured using a Brookfield type rotational viscometer in accordance with JIS Z8803 (2011).

[0049] When the solid fuel contains a thickener, the content of the thickener is preferably 0.01 mass% or more, more preferably 0.05 mass% or more, even more preferably 0.1 mass% or more, and preferably 1.0 mass% or less, more preferably 0.8 mass% or less, even more preferably 0.5 mass% or less, based on 100 mass% of the solid fuel.

[0050] In addition to the above components, the solid fuel may contain additives that are generally used in solid fuels. Examples of additives include flavorings, coloring powders, stabilizers, etc. Each of these additives may be used alone or in combination of two or more.

[0051] The solid fuel preferably contains water, which provides better weight retention. When the solid fuel contains water, the water content is preferably 1% by mass or more, more preferably 1.5% by mass or more, based on 100% by mass of the solid fuel. The water content is preferably 40% by mass or less, more preferably 35% by mass or less, even more preferably 30% by mass or less, even more preferably 25% by mass or less, and particularly preferably 20% by mass or less. If the water content is less than 1% by mass, sufficient weight retention tends not to be obtained, and if it exceeds 40% by mass, sufficient flame strength, ignition ability, and solidification ability tend not to be obtained. The water content is a value including the amount of water generated by neutralization of the alkaline agent and the acid agent such as fatty acid.

[0052] The solid fuel can be produced by a general method, such as by mixing and neutralizing the above-mentioned components while heating them in a mixing tank, and then cooling and solidifying them. The solid fuel is a solid material containing alcohol. In order to turn the alcohol, which is usually liquid, into a solid material, a fatty acid and an alkali are blended into the solid fuel composition, and the fatty acid is neutralized with the alkali to become a fatty acid salt, thereby obtaining sufficient solidification properties, and the solid fuel composition can be made into a solid material, a solid fuel. Note that the solid fuel in a lump or high cylindrical shape may be formed into a predetermined shape (such as a low cylindrical shape) by cutting or the like.

[0053] The surface of the solid fuel is preferably covered with paraffin. That is, the solid fuel is preferably sealed with paraffin. When the surface of the solid fuel is covered with paraffin, evaporation of the fuel components of the solid fuel can be prevented, and there is a tendency for better weight retention to be obtained. In addition, while having the ignition ability required as a fuel, the solid fuel tends to be prevented from unintentionally igniting, resulting in a solid fuel that takes safety into consideration. In addition, there is a tendency for the shape of the solid fuel during combustion to be superior.

[0054] The paraffin is not particularly limited as long as it is a hydrocarbon, and examples thereof include chain saturated hydrocarbons such as hexadecane, heptadecane, octadecane, nonadecane, icosane, henicosane, docosane, tricosane, tetracosane, pentacosane, hexacosane, heptacosane, octacosane, nonacosane, etc. These may be used alone or in combination of two or more kinds.

[0055] The melting point of paraffin is preferably 40°C or higher, more preferably 45°C or higher, and even more preferably 50°C or higher, and is preferably 80°C or lower, more preferably 78°C or lower, and even more preferably 75°C or lower. In this specification, the melting point of paraffin is measured using a paraffin wax melting point tester in accordance with JIS K2235 (2009).

[0056] The proportion of the surface area of ​​the solid fuel that is covered with paraffin, out of 100%, is preferably 80% or more, more preferably 90% or more, even more preferably 95% or more, particularly preferably 98% or more, and most preferably 100%.

[0057] The lower limit of the thickness of the paraffin is preferably 0.1 mm, more preferably 0.2 mm, and even more preferably 0.3 mm, and the upper limit is preferably 2.0 mm, more preferably 1.5 mm, and even more preferably 1.3 mm. If the thickness of the paraffin is less than 0.1 mm, the weight retention of the solid fuel may not be improved sufficiently, and if the thickness of the paraffin is more than 2.0 mm, the ignition ability may be deteriorated. In this specification, the thickness of paraffin is the average value of measurements taken at five points on the cut surface using a vernier caliper.

[0058] The method for covering the surface of the solid fuel with paraffin is not particularly limited, but can be, for example, a method of spraying liquid paraffin onto the surface of the solid fuel, or a method of immersing the surface in liquid paraffin that has been melted by heating.

[0059] The shape of the solid fuel is not particularly limited, and examples thereof include a cylindrical shape, a prismatic shape, a lump shape, a powder shape, etc. Among these, a cylindrical shape and a prismatic shape are preferred from the viewpoints of ignition ability and flame stability.

[0060] The solid fuel may be filled in a can. For example, a product form is envisaged in which the solid fuel is filled in a can, and the lid is opened while the solid fuel is still in the can, and the solid fuel is ignited to be used as fuel.

[0061] The solid fuel can be used for keeping cooked foods and other foods warm, heating them, cooking them, etc. Among these, it is preferable to use the solid fuel for keeping cooked foods warm and heating them because the flame intensity and burning time are appropriate.

[0062] The weight of the solid fuel is not particularly limited and may be appropriately set according to the purpose of use, etc. If it is used for keeping cooked food warm or heating it, it is preferably 3 to 300 g, more preferably 3 to 60 g, and even more preferably 5 to 50 g. In this specification, when the surface of the solid fuel is covered with paraffin, the weight (mass) of the paraffin is not included in the weight (mass) of the solid fuel.

[0063] When the solid fuel is to be burned, the solid fuel is placed inside the tray and ignited to burn. A solid fuel of this shape is suitable for keeping hot food, for example, in a pot after cooking has already been completed. EXAMPLES

[0064] The present invention will be specifically described based on examples, but the present invention is not limited to these examples.

[0065] Various chemicals used in the examples and comparative examples will be collectively described below. Methanol: Methanol manufactured by Yoneyama Pharmaceutical Co., Ltd. Ethanol: Ethanol (99.5) produced by Yoneyama Pharmaceutical Co., Ltd. Propanol: 1-propanol manufactured by Yoneyama Pharmaceutical Co., Ltd. Ethylene glycol: Ethylene glycol manufactured by Yoneyama Pharmaceutical Co., Ltd. Diethylene glycol: Diethylene glycol manufactured by Yoneyama Pharmaceutical Co., Ltd. Propylene glycol: Propylene glycol manufactured by Yoneyama Pharmaceutical Co., Ltd. Glycerin: Glycerin manufactured by Yoneyama Pharmaceutical Co., Ltd. Sodium hydroxide: Sodium hydroxide manufactured by Yoneyama Pharmaceutical Co., Ltd. Potassium hydroxide: Potassium hydroxide manufactured by Yoneyama Pharmaceutical Co., Ltd. Acetic acid: Acetic acid manufactured by Yoneyama Pharmaceutical Co., Ltd. Caprylic acid: n-caprylic acid manufactured by Yoneyama Pharmaceutical Co., Ltd. Capric acid: Decanoic acid manufactured by Yoneyama Pharmaceutical Co., Ltd. Lauric acid: Lauric acid manufactured by Yoneyama Pharmaceutical Co., Ltd. Myristic acid: Myristic acid manufactured by Yoneyama Pharmaceutical Co., Ltd. Palmitic acid: Palmitic acid manufactured by Yoneyama Pharmaceutical Co., Ltd. Stearic acid: Stearic acid manufactured by Yoneyama Pharmaceutical Co., Ltd. Arachidic acid: Eicosanoic acid manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Methylcellulose: Metrose SM400 manufactured by Shin-Etsu Chemical Co., Ltd. (viscosity of 2% by weight aqueous solution at 20°C: 400 mPa s) Paraffin: Paraffin manufactured by Yoneyama Pharmaceutical Co., Ltd. (melting point: 68-70°C)

[0066] Examples and Comparative Examples <Production of solid fuel> According to the formulations shown in Tables 1 to 3, each chemical was mixed under conditions of 55 to 70°C using a hot stirrer to obtain a solid fuel composition. Here, in each formulation, the fatty acid and sodium hydroxide or potassium hydroxide were mixed so that the fatty acid had the composition shown in Tables 1 to 3 and the alkali index was the value shown in Tables 1 to 3. In Tables 1 to 3, the amount of fatty acid (parts by mass) is the total mass of the mass ratio of the fatty acid and the mass ratio of the fatty acid salt converted to fatty acid in the solid fuel composition. Moreover, the mass (parts by mass) of each component is the mass of the pure content. Moreover, the total amount was set to 100 parts by mass. The resulting solid fuel composition was cooled and solidified, and then cut and molded into a cylindrical shape to obtain a solid fuel. In Examples 7, 20, 30, 33, 37, 41, 43, 56, 66, and 78, the solid fuel was immersed in paraffin that had been heated and melted at 80° C., so that 90% of the surface of the solid fuel was covered with paraffin (thickness of paraffin: 0.5 mm). The obtained solid fuel was used for the following evaluations, and the results are shown in Tables 1 to 3. In Examples 7, 20, 30, 33, 37, 41, 43, 56, 66, and 78, the evaluations of hardness and the resistance to shavings when cut were performed using the solid fuel before it was covered with paraffin, and the other evaluations were performed using the solid fuel covered with paraffin.

[0067] (Hardness (slow cooling)) The solid fuel composition obtained by mixing each chemical under conditions of 55-70°C was filled into a glass tube with a diameter of 40 mm and slowly solidified in a warm bath at 50°C. After solidification, the sample was cut to a height of 25 mm, and compressed horizontally at a speed of 10 mm / min using an autograph AGS-10kNX (manufactured by Shimadzu Corporation) using a jig that covered both the top and bottom surfaces of the sample. The load (N) required to compress the solid fuel by 5 mm was taken as the hardness index. The evaluation was based on the following criteria. ◎: The hardness index is 150 or more and 500 or less. ○: The hardness index is 120 or more and less than 150, or more than 500 and less than 600 △: The hardness index is 100 or more, less than 120, or more than 600 ×: Less than 100 If the hardness is △ or more, the hardness is good, and the hardness is not easily broken and the cutting ability is excellent. The harder the hardness is, the more difficult it is to break down, while the more appropriate the hardness is, the better the cutting ability is. From the viewpoint of achieving a good balance between the hardness and the cutting ability, it is preferable to set the hardness index to the above ◎ or ◯.

[0068] (Less production of shavings when cutting) The degree of shavings produced when cutting solid fuel with a piano wire having a wire diameter of 0.5 mm was checked. Evaluation was made according to the following criteria. ◎: Almost no shavings are produced 〇: Less shavings ×: Too much shavings

[0069] (Shape of solid fuel when burned) The solid fuel was placed in an aluminum cup and ignited, and the state of the solid fuel during burning was visually observed. Evaluation was made according to the following criteria. ◎: No dripping occurs ○: Slight dripping occurs △: Dripping occurs ×: The entire amount is liquefied. If the rating is △ or higher, the shape of the solid fuel during combustion is good.

[0070] (Weight change during storage) 25g of solid fuel was wrapped in polyethylene film and left to stand for 24 hours in an environment of 25℃ and 50% RH. The weight was measured before and after the test, and the amount of weight loss was calculated. Evaluation was based on the following criteria. ◎: Weight loss is 1.00g or less ○: Weight loss is over 1.00g and 1.20g or less ×: Weight loss exceeds 1.20g

[0071] (Ignitability) The flame of a lighter was applied to the top surface of the solid fuel, and the time it took for it to ignite was measured. More highly evaluated. ◎: Ignition time is less than 1 second ○: Ignition time is between 1 and 2 seconds ×: Does not ignite even when exposed to flame for 2 seconds

[0072] (fire force) 25g of solid fuel was placed on the stove and ignited, and an aluminum pot containing 300mL of water (15℃) was placed on the stove. The flame intensity of the solid fuel while it was burning and the state of the water boiling were visually observed. Evaluation was based on the following criteria. ◎: Water takes less than 12 minutes to boil 〇: Water boils in 12 to 15 minutes ×: It takes more than 15 minutes for the water to boil.

[0073] [Table 1] [Table 2] [Table 3]

[0074] From Tables 1 to 3, it can be seen that a solid fuel containing an alcohol (A) and a fatty acid (salt) (B) and having an alkali index of -2.0 to 1.0 has a sufficiently high hardness even when cooled and solidified under slow cooling conditions.

Claims

1. Alcohol (A) and A solid fuel containing fatty acids (salts) (B), The amount of alkali in the solid fuel, or the amount of alkali needed to neutralize the acid in the solid fuel, is expressed as the mass percentage (mg / g) of sodium hydroxide in the solid fuel, converted from the alkali to an equivalent number of moles of sodium hydroxide, and is between -2.0 and 0.

0. The aforementioned fatty acid (salt) (B) includes a fatty acid (salt) (B-1) having 18 or more carbon atoms and a fatty acid (salt) (B-2) having 17 or fewer carbon atoms. A solid fuel in which the molar ratio of (B-1) / (B-2) is 0.01 or higher and 70 or lower.

2. The solid fuel according to claim 1, wherein the content of the alcohol (A) is 50 to 99% by mass.

3. The solid fuel according to claim 1 or 2, wherein the content of the fatty acid (salt) (B) is 3 to 20% by mass.

4. The solid fuel according to claim 1 or 2, comprising water.

5. The solid fuel according to claim 4, wherein the water content is 1 to 40% by mass.

6. The solid fuel according to claim 1 or 2, wherein the surface is covered with paraffin.

7. The solid fuel according to claim 6, wherein the thickness of the paraffin is 0.1 to 2.0 mm.

8. The solid fuel according to claim 1 or 2, comprising a thickening agent.

9. The solid fuel according to claim 1, wherein the alcohol (A) comprises a monohydric alcohol.

10. The solid fuel according to claim 9, wherein the monohydric alcohol is methanol.

11. The solid fuel according to claim 9 or 10, wherein the monohydric alcohol content is 50% by mass or more and less than 70% by mass.

12. The solid fuel according to claim 9 or 10, wherein the monohydric alcohol content is 70% by mass or more and less than 85% by mass.

13. The solid fuel according to claim 9 or 10, wherein the monohydric alcohol content is 85% by mass or more and 95% by mass or less.