Method for producing soap composition containing sodium and potassium higher fatty acids

Abstract

The present invention provides a method for producing a soap composition containing sodium and potassium of higher fatty acids. Mixed saturated fatty acids are heated to 80°C or higher and melted, and then a cooling liquid formed by glycerin and water is added to the mixed saturated fatty acids at once to cool the mixed saturated fatty acids to a temperature at least 20°C lower than the aforementioned heating temperature, and then heated again and maintained at 40-55°C, and a mixed alkali aqueous solution in which potassium hydroxide and / or potassium carbonate and sodium hydroxide and / or sodium carbonate are mixed in a molar ratio of 90 / 10-30 / 70 is added to the heated liquid containing mixed fatty acids at once, and the temperature is raised and maintained at 80-95°C while stirring for neutralization, thereby preparing a liquid soap composition.

Description

Technical Field

[0001] The present invention relates to a method for producing a soap composition containing sodium and potassium higher fatty acids for skin cleansing, and more particularly to a method for producing a soap composition containing sodium and potassium higher fatty acids, which contains sodium higher fatty acid soap at a higher concentration than conventional soap compositions, can maintain a paste or liquid state for a long time even at low temperatures, has good usability, has a high foaming ability, has little irritation to the skin and eyes, and is environmentally friendly. Background Art

[0002] Various technologies have been disclosed for body cleansing soaps such as hair cleansers, skin cleansers, and facial cleansers. As body cleansers, a large number of body cleansers containing chemically synthesized surfactants (hereinafter referred to as "synthetic surfactants") such as alkyl sulfates, alkyl ether sulfates, α-olefin sulfonates, alkyl carboxybetaines, and alkyl methyl taurates are commercially available.

[0003] Methods for producing fatty acid soaps have been put into practical use since ancient times, and generally include a saponification method in which alkaline water is added to oils and fats and heated, and a neutralization method in which alkaline water is added to fatty acids.

[0004] In particular, among liquid body soaps containing fatty acid soap as a main component, fatty acid potassium salts (hereinafter referred to as "potassium soaps") obtained by neutralizing or saponifying fatty acids or oils with potassium hydroxide are widely used as liquid soaps. This liquid potassium soap is sometimes diluted with water to a concentration that does not coagulate or solidify and circulated as liquid soap.

[0005] For example, Japanese Patent Application Laid-Open No. 2006-206525 (Patent Document 1) discloses a paste-like skin cleanser containing 25 to 50% by mass of (a) a higher fatty acid soap, 0.5 to 10% by mass of (b) a lower alcohol, and (c) water.

[0006] Furthermore, Japanese Patent Application Laid-Open No. 2002-322498 (Patent Document 2) proposes a composition containing myristic acid soap, palmitic acid soap and stearic acid soap in a specific weight ratio as fatty acid soaps, and containing propylene glycol, glycerin and water.

[0007] Japanese Patent Application Laid-Open No. 2004-210704 (Patent Document 3) proposes a skin cleansing composition comprising (A) a higher fatty acid salt, (B) an amino acid polymer, and (C) two or more water-soluble polymers having different ionicity (excluding component B).

[0008] Furthermore, Japanese Patent Application Laid-Open No. 2011-121870 (Patent Document 4) proposes a skin cleanser comprising 1 to 10% by mass of (A) an anionic surfactant having a sulfate group, 1 to 25% by mass of (B) a higher fatty acid or a salt thereof, 0.1 to 2% by mass of (C) an acrylic acid / methacrylic acid alkyl copolymer, 0.5 to 10% by mass of (D) a (di)glycerol monofatty acid ester or a (di)glycerol monoalkyl ether, 0.5 to 10% by mass of (E) an alkyl glycoside, and (F) water, wherein the viscosity of the skin cleanser at 30° C. is 150 to 1000 dPa·s.

[0009] Furthermore, Japanese Patent Application Laid-Open No. 2015-196713 (Patent Document 5) discloses a transparent liquid cleaning agent composition, wherein the fatty acid composition comprises: a content of a higher fatty acid potassium salt (A) obtained by reacting 1 to 1.01 mol of potassium hydroxide with respect to 1 mol of a higher fatty acid containing 50% by mass or more of lauric acid, a content of an alkylhydroxysulfobetaine type amphoteric surfactant (B) of 1 to 10% by mass, and a mass ratio of (A):(B) of 1:0.05 to 1.

[0010] On the other hand, sodium salts of saturated fatty acids (hereinafter referred to as "sodium soaps") are mainly used as solid soaps, and their solubility in water is significantly lower than that of potassium soaps, and they are almost insoluble in water. Therefore, sodium soaps are circulated in the form of soap flakes as industrial raw materials, and after heating and mixing additives in a kneading machine, the viscous liquid is poured into a mold to be processed into beauty soaps, etc. The solubility of sodium soap flakes in water is also low, and it is not easy to obtain uniform dissolution even in warm water.

[0011] However, the foaming property and cleaning ability of liquid soap mainly composed of potassium soap are insufficient, and in order to improve the foaming property and cleaning ability, at least one of nonionic surfactants, anionic surfactants, zwitterionic surfactants, etc. synthesized from petrochemical raw materials is used in a mixed formulation. Furthermore, polyols such as sorbitol, glycerin, propylene glycol, butylene glycol, polyalkylene glycol, and water-soluble polymer compounds are added to study the foaming property of the composition.

[0012] Fatty acid soaps are not only safe for the human body, but also safe for the environment, and are highly rated for their feeling of use, such as being able to remove foam and leaving a fresh feeling after washing.

[0013] However, as described above, there are the following problems: potassium soap has a difficulty in foaming and cleaning ability compared to synthetic surfactants; on the other hand, sodium soap has excellent foaming and cleaning ability comparable to synthetic surfactants, but has low solubility in water.

[0014] Regarding the water solubility of sodium soaps, even sodium soaps of lauric acid, which have relatively excellent solubility in water among the sodium salts of saturated fatty acids, need to be set to above about 40°C in order to dissolve more than 10 mass%, and the Krafft point is above 30°C. Even at low concentrations, they lose fluidity. The solubility of sodium soaps with longer carbon chains such as palmitic acid and stearic acid is further reduced (New Edition of Fatty Acid Chemistry, 2nd Edition, edited by Jiro Hirano and Keiichi Inaba, Koushbo) (New Edition of Fatty Acid Chemistry, 2nd Edition, edited by Jiro Hirano and Keiichi Inaba, Koushbo).

[0015] Since the solubility is low, the obtained liquid soap product may separate, the nozzle of the container containing the liquid soap may be clogged, and the like. At present, a liquid fatty acid soap composition containing sodium soap as a main component has not yet been commercialized.

[0016] In addition, although complex potassium soap cleansers blended with synthetic surfactants can make up for the weak cleaning ability and foaming properties, it is pointed out that the unique feel of fatty acid soaps, that is, the good ability to remove foam, is impaired, and there are problems such as skin irritation and sticky feeling.

[0017] Therefore, there is a demand for commercialization of body washes containing saturated fatty acid soap as a main component, which produce rich, mild and sticky foam on the skin, have an excellent cleansing feeling, do not have a sticky feeling, and are refreshing and easy to rinse off.

[0018] Prior art literature

[0019] Patent Literature

[0020] Patent Document 1: Japanese Patent Application Publication No. 2006-206525

[0021] Patent Document 2: Japanese Patent Application Publication No. 2002-322498

[0022] Patent Document 3: Japanese Patent Application Publication No. 2004-210704

[0023] Patent Document 4: Japanese Patent Application Publication No. 2011-121870

[0024] Patent Document 5: Japanese Patent Application Publication No. 2015-196713 Summary of the invention

[0025] Problem that the invention aims to solve

[0026] The present invention aims to provide a method for producing a liquid or paste soap composition with high productivity, wherein the liquid or paste soap composition contains a high concentration of a higher fatty acid sodium soap component and a fatty acid potassium soap component, maintains a liquid or paste state for a long time even at low temperatures, does not separate, has little irritation to the skin and eyes, is environmentally friendly, and has high foaming ability and good cleaning ability. In addition, a method for producing a soap composition containing a higher fatty acid sodium and a higher fatty acid potassium with high productivity is provided, wherein the soap composition is a liquid or paste soap composition that does not contain a synthetic surfactant.

[0027] It should be noted that, in the present invention, "low temperature" means a temperature lower than 10°C.

[0028] Solutions for solving problems

[0029] The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that, instead of using a commonly used synthetic activator, a prescribed mixed fatty acid, in particular a mixed fatty acid containing specific saturated fatty acids in a prescribed ratio, is used, the mixed fatty acid is cooled to a certain temperature difference with water, then heated, and saponified with sodium and potassium alkalis, thereby producing a soap composition containing sodium and potassium higher fatty acids that can solve the above-mentioned problems, thereby completing the present invention.

[0030] That is, the first method for producing a soap composition containing sodium and potassium higher fatty acids of the present invention is the following method: a mixed saturated fatty acid is heated to 80°C or higher to melt, a cooling liquid composed of glycerin and water is added to the mixed saturated fatty acid at once, the mixture is cooled to a temperature at least 20°C lower than the heating temperature, the mixture is heated again and maintained at 40 to 55°C, an aqueous solution of a mixed alkali prepared by mixing potassium hydroxide and / or potassium carbonate with sodium hydroxide and / or sodium carbonate in a molar ratio of 90 / 10 to 30 / 70 is added to the heated liquid containing the mixed fatty acid at once, the mixture is heated and maintained at 80 to 95°C for neutralization, thereby preparing a liquid soap composition, wherein the mixed saturated fatty acid is a mixed fatty acid composed of saturated fatty acids with 12 to 18 carbon atoms including 85 to 100 mol% of saturated fatty acids with 12 and 14 carbon atoms, and does not contain saturated fatty acids with 8 to 10 carbon atoms.

[0031] The first method for producing a soap composition containing sodium and potassium higher fatty acids of the present invention is preferably characterized in that the composition contains more saturated fatty acids having 12 carbon atoms than saturated fatty acids having 14 carbon atoms.

[0032] The second method for producing a soap composition containing sodium and potassium higher fatty acids of the present invention is the following method: a mixture of a mixed saturated fatty acid and 3 to 23 parts by mass of magnesium stearate or magnesium palmitate relative to 100 parts by mass of the mixed saturated fatty acid is heated to 80° C. or above to melt the mixed saturated fatty acid, wherein the mixed saturated fatty acid is a mixed fatty acid formed by saturated fatty acids with carbon numbers of 12 to 18, including 80 to 90 mol % of saturated fatty acids with carbon numbers of 12 and 14, and does not contain saturated fatty acids with carbon numbers of 8 to 10.

[0033] Then, a cooling liquid composed of glycerol and water is added at once to the mixture of the mixed saturated fatty acids and magnesium stearate or magnesium palmitate, and the mixture is cooled to a temperature at least 20°C lower than the aforementioned heating temperature, and the glycerol is mixed in an amount of 30 to 75 parts by mass relative to 100 parts by mass of the mixed saturated fatty acids.

[0034] After the cooling, the mixture was heated again and maintained at 40-55°C.

[0035] An aqueous solution of a mixed alkali mixture of potassium hydroxide and / or potassium carbonate and sodium hydroxide and / or sodium carbonate in a molar ratio of 70 / 30 to 30 / 70 is added all at once to the mixture kept heated, and the temperature is raised and maintained at 80 to 95° C. while stirring for neutralization, thereby preparing a paste soap composition in which talc and sorbitol are blended before or after the neutralization so as to contain 3 to 13 parts by mass of talc and 50 to 180 parts by mass of sorbitol per 100 parts by mass of the mixed saturated fatty acid.

[0036] Preferably, the second method for producing a soap composition containing sodium and potassium higher fatty acids is characterized by further blending sugars and / or fats and oils.

[0037] Effects of the Invention

[0038] The method for producing a liquid soap composition containing sodium and potassium higher fatty acids of the present invention can produce a transparent liquid soap composition or a paste soap composition efficiently and with good productivity. The soap composition can maintain a uniform liquid state or a paste state for a long time even at low temperatures. The obtained soap composition does not separate over time, has excellent stability, has little irritation to the skin and eyes, has high foaming ability, and has excellent feeling during use.

[0039] Furthermore, since the liquid soap composition and the paste soap composition obtained by the production method of the present invention contain a saturated fatty acid soap component as a cleaning component and do not contain a surfactant, they are less irritating to the skin and are also environmentally friendly. DETAILED DESCRIPTION

[0040] The present invention will be described based on the following preferred examples, but the present invention is not limited to these.

[0041] The method for producing a soap composition containing sodium and potassium higher fatty acids of the present invention is a method for producing a soap composition capable of maintaining liquid or paste-like properties for a long time even at low temperatures. In particular, the method for producing a transparent liquid soap composition of the first invention of the present invention is the following method: a mixed saturated fatty acid is heated to 80°C or higher to melt, a cooling liquid composed of glycerin and water is added to the mixed saturated fatty acid at once, the mixture is cooled to a temperature at least 20°C lower than the aforementioned heating temperature, and then the mixture is heated again and maintained at 40 to 55°C, and the cooling liquid is added to the mixture. A mixed alkali aqueous solution prepared by mixing potassium hydroxide and / or potassium carbonate with sodium hydroxide and / or sodium carbonate in a molar ratio of 90 / 10 to 30 / 70 is added at once to a hot liquid containing mixed fatty acids, and the temperature is raised and maintained at 80 to 95° C. while stirring for neutralization, thereby preparing a liquid soap composition, wherein the mixed saturated fatty acid is a mixed fatty acid composed of saturated fatty acids with carbon numbers of 12 to 18 including 85 to 100 mol % of saturated fatty acids with carbon numbers of 12 and 14, and does not contain saturated fatty acids with carbon numbers of 8 to 10.

[0042] Conventionally, when a large amount of sodium soap components is contained, a transparent soap composition having excellent long-term low-temperature performance cannot be obtained. However, by having the above-mentioned configuration, the obtained soap composition is transparent and does not separate for a long time even in a low-temperature range, and can maintain a stable liquid state.

[0043] In the production method of the present invention, no chemically synthesized surfactant or viscosity agent is added.

[0044] The fatty acid used in the method for producing the liquid soap composition of the present invention is a mixed saturated fatty acid composed of saturated fatty acids having 12 to 18 carbon atoms, containing 85 to 100 mol % of saturated fatty acids having 12 and 14 carbon atoms. It should be noted that saturated fatty acids having 8 or 10 carbon atoms are not included. This is because if saturated fatty acids having 8 or 10 carbon atoms are included, the long-term stability of the liquid soap composition at low temperatures to maintain a liquid state for a long time becomes unstable.

[0045] In the present invention, unsaturated fatty acids are not used because, if unsaturated fatty acids are contained, the soap will produce color and odor due to oxidation, and thus is not suitable for skin cleansing.

[0046] As the mixed fatty acid containing saturated fatty acids having 12 to 18 carbon atoms, preferably 12 to 16 carbon atoms, used in the production method of the present invention, lauric acid, myristic acid, palmitic acid and stearic acid are preferably used, and a mixed fatty acid containing a plurality of fatty acids is used.

[0047] From the viewpoint of low odor and temporal stability of color, it is preferable to use a mixed fatty acid of a plurality of saturated fatty acids.

[0048] Furthermore, among all the mixed fatty acids of these saturated fatty acids, 85 to 100 mol % of saturated fatty acids having 12 and 14 carbon atoms are contained, and preferably 88 to 98 mol % are contained.

[0049] By blending the saturated fatty acids having 12 and 14 carbon atoms, lauric acid, and myristic acid in the entire mixed fatty acid at such a high content, the foaming property is improved and a transparent liquid state can be maintained for a long time in a low temperature range.

[0050] Furthermore, it is preferable that the amount of saturated fatty acid having 12 carbon atoms to be compounded is larger than that of saturated fatty acid having 14 carbon atoms, because the effect of the liquid soap composition can be more effectively exhibited.

[0051] In the manufacturing method of the present invention, the mixed saturated fatty acids are heated to a temperature of 80°C or more, preferably 90°C or more, more preferably 80-95°C (heating temperature) while stirring, so that the mixed saturated fatty acids are homogeneously melted. Preferably, the melting is carried out while stirring. Here, the heating temperature refers to the maximum heating temperature at which the mixed saturated fatty acids are heated and homogeneously melted. As long as the mixed fatty acids can be uniformly dissolved, the holding time at the heating temperature is not particularly limited, and for example, it can be exemplified by holding for about 20 to 60 minutes.

[0052] Then, while stirring the heated and melted colorless and transparent mixed fatty acid, a cooling liquid is added to the mixed fatty acid at once to cool the temperature to a temperature (cooling temperature) that is at least 20°C lower than the heating temperature, preferably 25°C lower than the heating temperature. For example, the temperature is cooled to 60°C or less, and more preferably to 50°C or less.

[0053] The mixture of the mixed saturated fatty acid and the cooling liquid to which the cooling liquid is added and cooled is in a state in which small white particles are suspended.

[0054] Regarding the amount of cooling liquid added, the heating temperature of the mixed fatty acid heated to above 80°C, preferably above 90°C and melted can be cooled to below 70°C, preferably below 60°C, more preferably below 50°C by adding the cooling liquid all at once, and a temperature at least 20°C lower than the aforementioned heating temperature, preferably 25°C lower, and a cooling liquid at room temperature, for example, around 20°C, can be added.

[0055] In addition, the coolant contains glycerin and purified water.

[0056] For example, with respect to 100 parts by mass of the mixed fatty acid, the glycerin in the cooling liquid is preferably 15 to 30 parts by mass, more preferably 15 to 22 parts by mass, and the purified water is preferably 100 to 250 parts by mass, more preferably 115 to 200 parts by mass. By adding the cooling liquid which is a mixture of glycerin and purified water in this ratio, it is possible to cool to a cooling temperature which is at least 20°C lower than the above-mentioned heating temperature, and preferably 25°C lower or more.

[0057] Then, the cooled liquid containing mixed saturated fatty acids is heated again and maintained at a heating control temperature of 40 to 55° C. By providing this step, the obtained liquid soap composition can maintain long-term stability (transparency, liquid retention performance) at low temperatures and has excellent foaming properties.

[0058] Then, the mixed alkali is added at once to the liquid containing the mixed fatty acid maintained at the heating control temperature, and the temperature is raised and maintained at 80 to 95° C. while stirring for neutralization, thereby preparing a liquid soap composition. By adding an alkali to the liquid containing the mixed fatty acid which is rapidly cooled by mixing the cooling liquid as described above and then heated again and maintained at the heating control temperature, and raising the temperature to 80 to 95° C. while stirring for neutralization, the obtained liquid soap composition can have liquid retention performance for a long time even at low temperatures and maintain transparency.

[0059] The alkali used to neutralize the mixed saturated fatty acids to obtain fatty acid soaps is a mixed alkali of potassium hydroxide and / or potassium carbonate and sodium hydroxide and / or sodium carbonate, and the mixed molar ratio of potassium hydroxide and / or potassium carbonate to sodium hydroxide and / or sodium carbonate is 90 / 10 to 30 / 70, preferably 80 / 20 to 60 / 40.

[0060] Furthermore, in order to suppress an increase in viscosity and local generation of heat of neutralization during the neutralization reaction, purified water may be preferably added to the mixed alkali.

[0061] The potassium hydroxide and / or potassium carbonate and the sodium hydroxide and / or sodium carbonate may be mixed in advance to prepare a mixed base and then used for neutralization, or may be mixed without mixing in advance and used as individual bases during neutralization.

[0062] If the molar ratio of potassium hydroxide and / or potassium carbonate exceeds 90, the influence of potassium soap becomes strong, and the foaming property, cleaning ability, etc. cannot be satisfied. If the ratio of potassium hydroxide is less than 30, the hardness of the obtained soap may increase and become non-liquid, and it may not dissolve in water quickly during use, and the foaming property may decrease.

[0063] In the neutralization of the mixed fatty acid, the two bases may be prepared in advance as an aqueous alkaline solution (for example, based on an active ingredient concentration of 48%) and used for neutralization, thereby obtaining a uniform solution in a short time.

[0064] Although heat is generated during neutralization, if the temperature rises above the above-mentioned heating temperature, the obtained liquid soap composition may become opaque. Therefore, the temperature is raised to 80 to 90°C (heating temperature).

[0065] Examples of fatty acid soaps obtained by saponifying the above-mentioned mixed fatty acid and mixed alkali include a mixed salt of potassium / sodium laurate, a mixed salt of potassium / sodium myristate, a mixed salt of potassium / sodium palmitate, and a mixed salt of potassium / sodium stearate. From the viewpoint of being able to produce a liquid soap having good foaming properties, it is desirable that a mixed salt of potassium / sodium laurate and a mixed salt of potassium / sodium myristate are necessarily contained, and two or more of the above-mentioned mixed salts are used in combination.

[0066] The reason why the liquid soap composition obtained by the method of the present invention contains, for example, 8 to 35% by mass, preferably 10 to 35% by mass, and more preferably 18 to 28% by mass of a saturated fatty acid soap component is that a more sufficient amount of foam can be obtained during use and a more homogeneous liquid soap composition can be maintained.

[0067] The transparent liquid soap composition obtained by the production method of the present invention contains water, which corresponds to the water used for the cooling, the water contained in each raw material, and the water generated by the neutralization of the saturated fatty acid and the alkali, and the water content in the liquid soap composition is, for example, 92 to 65% by mass, preferably 82 to 72% by mass. If the amount of water contained is adjusted to fall within this range, more satisfactory foaming properties can be obtained during use.

[0068] The liquid soap composition obtained by the production method of the present invention can be measured by the method described in the following Examples and can be a liquid soap composition having excellent long-term liquid retention performance and transparency at low temperatures.

[0069] The transparent liquid soap composition obtained by the production method of the present invention was measured by small angle X-ray scattering (SAXS) using SPring-8 of RIKEN in Hyogo Prefecture. It was confirmed that the average particle size of the soap micelles in the aqueous solution was 50 nm or less and was fine, and the soap solution remained transparent.

[0070] In addition to the above-mentioned essential components, higher alcohols, squalane, various liquid or solid fatty acid esters, oily components such as various purified natural oils and fats such as olive oil and sesame oil, silicone derivatives such as polyoxyethylene alkyl-modified dimethyl silicone, natural water-soluble polymers such as pectin and alginic acid, biodegradable chelating agents such as sodium gluconate, various natural extracts derived from animals and plants, salt for adjusting the freezing point and hardness, inorganic salts such as sodium sulfate, natural antioxidants such as d-tocopherol, natural pigments, natural flavors, and others can be optionally blended as needed within the range not impairing the effects of the present invention.

[0071] The second method for producing a soap composition containing sodium and potassium higher fatty acids of the present invention is the following method: a mixture of a mixed saturated fatty acid and 3 to 23 parts by mass of magnesium stearate or magnesium palmitate relative to 100 parts by mass of the mixed saturated fatty acid is heated to above 80°C to melt the mixed saturated fatty acid, wherein the mixed saturated fatty acid is a mixed fatty acid formed by saturated fatty acids with carbon numbers of 12 to 18 including 80 to 90 mol % of saturated fatty acids with carbon numbers of 12 and 14, and does not contain saturated fatty acids with carbon numbers of 8 to 10.

[0072] Then, a cooling liquid composed of glycerol and water is added at once to the mixture of the mixed saturated fatty acids and magnesium stearate or magnesium palmitate, and the mixture is cooled to a temperature at least 20°C lower than the aforementioned heating temperature, and the glycerol is mixed in an amount of 30 to 75 parts by mass relative to 100 parts by mass of the mixed saturated fatty acids.

[0073] After the cooling, the mixture was heated again and maintained at 40-55°C.

[0074] An aqueous solution of a mixed alkali mixture of potassium hydroxide and / or potassium carbonate and sodium hydroxide and / or sodium carbonate in a molar ratio of 70 / 30 to 30 / 70 is added all at once to the mixture kept heated, and the temperature is raised and maintained at 80 to 95° C. while stirring for neutralization, thereby preparing a paste soap composition in which talc and sorbitol are blended before or after the neutralization so as to contain 3 to 13 parts by mass of talc and 50 to 180 parts by mass of sorbitol per 100 parts by mass of the mixed saturated fatty acid.

[0075] Conventionally, when a large amount of sodium soap is contained, a paste soap composition having excellent long-term low-temperature paste retention performance cannot be obtained. However, by having the above-mentioned configuration of the present invention, even in a low-temperature region and when a larger amount of sodium soap is contained than conventionally, the obtained paste soap composition can have long-term paste retention performance and can maintain a stable paste state without separation for a long time.

[0076] In the second production method of the present invention, similarly to the first production method of the present invention, no chemically synthesized surfactant or tackifier is added.

[0077] The fatty acid used in the method for producing the paste soap composition of the present invention is a mixed saturated fatty acid composed of saturated fatty acids having 12 to 18 carbon atoms, containing 80 to 90 mol % of saturated fatty acids having 12 and 14 carbon atoms. It should be noted that saturated fatty acids having 8 or 10 carbon atoms are not contained because if saturated fatty acids having 8 or 10 carbon atoms are contained, the stability of the paste state retention performance of the paste soap composition at low temperatures becomes unstable for a long time.

[0078] In the present invention, unsaturated fatty acids are not used. If unsaturated fatty acids are contained, the soap will produce color and odor due to oxidation, and is therefore not suitable for skin cleansing.

[0079] As the mixed fatty acid composed of saturated fatty acids having 12 to 18 carbon atoms, preferably 12 to 16 carbon atoms, used in the production method of the present invention, lauric acid, myristic acid, palmitic acid and stearic acid can be used, and a mixed fatty acid composed of a mixture of multiple fatty acids including lauric acid and myristic acid can be used.

[0080] From the viewpoint of low odor and temporal stability of color, it is preferable to use a mixed fatty acid of a plurality of saturated fatty acids.

[0081] Furthermore, among all the mixed fatty acids of these saturated fatty acids, 80 to 90 mol%, preferably 82 to 88 mol% of saturated fatty acids having 12 and 14 carbon atoms are contained.

[0082] By including saturated fatty acids having 12 and 14 carbon atoms, such as lauric acid and myristic acid, in the entire mixed fatty acid at such a high content, the foaming property is good and the paste state can be maintained for a long time in a low temperature range.

[0083] Furthermore, it is preferable that the saturated fatty acid having 14 carbon atoms is contained in a larger amount than the saturated fatty acid having 12 carbon atoms, because the effect of the above-mentioned paste soap composition can be more effectively exhibited.

[0084] In addition, magnesium stearate or magnesium palmitate is blended into the mixed fatty acid. The magnesium stearate or magnesium palmitate is preferably blended into the mixed saturated fatty acid in advance, and is blended in a ratio of 3 to 23 parts by mass, preferably 8 to 16 parts by mass, per 100 parts by mass of the mixed saturated fatty acid.

[0085] If the amount of magnesium stearate or magnesium palmitate is less than 3 parts by mass per 100 parts by mass of the mixed saturated fatty acid, the fluidity of the paste soap composition may become greater. On the other hand, if it exceeds 23 parts by mass, the fluidity of the paste composition decreases, but the texture of the paste becomes rough, which is not preferable.

[0086] By adding magnesium stearate or magnesium palmitate, the obtained paste soap composition can maintain a paste state for a long time even at low temperatures, has an effect of suppressing solidification at low temperatures, and can provide lubricating foam without defoaming during washing, and can provide a good touch such as a moist feeling after washing.

[0087] Here, the paste soap composition prepared by the method of the present invention does not contain calcium stearate or calcium palmitate, and calcium stearate or calcium palmitate cannot be used instead of magnesium stearate or magnesium palmitate. This is because calcium stearate or calcium palmitate has difficulty in maintaining the paste state of the paste soap composition for a long time in a low temperature range.

[0088] Then, the mixture containing the mixed saturated fatty acid and magnesium stearate or magnesium palmitate is heated to a temperature of 80°C or higher, preferably 90°C or higher, more preferably 80-95°C (heating temperature) while stirring, so that the mixed saturated fatty acid is homogeneously melted. Preferably, the melting is carried out while stirring. Here, the heating temperature refers to the maximum heating temperature at which the mixed saturated fatty acid is heated and homogeneously melted. As long as the mixed fatty acid can be uniformly dissolved, the holding time at the heating temperature is not particularly limited, for example, it is kept for about 20 to 60 minutes.

[0089] Furthermore, talc is preferably blended in a ratio of 3 to 13 parts by mass, more preferably 5 to 10 parts by mass, based on 100 parts by mass of the mixed saturated fatty acid.

[0090] Including talc in such a content ratio is preferred because it is possible to more effectively exhibit the paste-state retention performance of the paste soap composition and suppress solidification even in a low temperature region.

[0091] Talc may be mixed in advance when preparing the above-mentioned mixed fatty acid, may be blended with magnesium stearate and the like in the mixed fatty acid, or may be added and blended after the neutralization treatment described below.

[0092] Furthermore, it is preferred to blend sugars in a ratio of 2 to 12 parts by mass, preferably 2 to 8 parts by mass, based on 100 parts by mass of the mixed saturated fatty acid.

[0093] Examples of the sugar include commercially available sugars such as granulated sugar. Inclusion of the sugar is preferred because it can more effectively maintain the paste state of the paste soap composition and inhibit solidification even in low temperature regions.

[0094] The sugars may be mixed in advance when preparing the above-mentioned mixed fatty acids, or may be blended with magnesium stearate and the like in the mixed fatty acids, or may be added and blended after the neutralization treatment described below. It is more ideal to add and blend after the neutralization treatment described below.

[0095] Then, while stirring the heated and molten colorless and transparent mixed fatty acid and magnesium stearate or magnesium palmitate, and the sugar and talc blended as needed, a cooling liquid is added thereto at once to cool the temperature to a temperature (cooling temperature) that is at least 20°C lower than the aforementioned heating temperature, preferably 25°C lower than the aforementioned heating temperature. For example, the temperature is cooled to 60°C or less, and more preferably to 50°C or less.

[0096] The mixture of the mixed saturated fatty acid and the like and the coolant to which the coolant is added and cooled is in a state in which small white particles are suspended.

[0097] Regarding the amount of cooling liquid added for compounding, the temperature of the liquid mixed fatty acid heated to 80°C or higher, preferably 90°C or higher and melted can be cooled to 70°C or lower, preferably 60°C or lower, and at least 20°C or higher, preferably 25°C or higher lower than the aforementioned heating temperature by adding the cooling liquid all at once. The cooling liquid can be a cooling liquid at room temperature, for example, about 20°C, during compounding.

[0098] The coolant contains glycerin and purified water.

[0099] The amount of glycerin in the cooling liquid is preferably 30 to 75 parts by mass, more preferably 45 to 65 parts by mass, and the amount of purified water is preferably 90 to 250 parts by mass, more preferably 90 to 150 parts by mass, relative to 100 parts by mass of the mixed fatty acid. For example, by adding a cooling liquid that is a mixture of glycerin and purified water in this ratio, the cooling can be performed to a cooling temperature that is at least 20° C. lower than the above-mentioned heating temperature.

[0100] In addition, sorbitol is blended in the paste soap composition of the present invention. The sorbitol may be blended in advance in the cooling liquid or partially blended after neutralization. The blending amount of sorbitol is 50 to 200 parts by mass, preferably 50 to 150 parts by mass, relative to 100 parts by mass of the mixed fatty acid. The inclusion of sorbitol is desirable because it can more effectively exhibit the paste state retention performance of the paste soap composition even in a low temperature range and inhibit solidification.

[0101] Then, the cooled liquid containing mixed saturated fatty acids is heated again and maintained at a heating control temperature of 40 to 55° C. By providing this step, the obtained paste soap composition can maintain long-term stability (paste retention performance) at low temperatures.

[0102] Then, a mixed alkali is added at once to the liquid (mixture) containing mixed fatty acids and the like maintained at a heating control temperature, and the mixture is heated and maintained at 80 to 95° C. while stirring for neutralization, thereby preparing a paste soap composition. By adding an alkali to the liquid containing mixed fatty acids that has been rapidly cooled and heated again and maintained at a heating control temperature, and heating and neutralizing the mixture to 80 to 95° C. while stirring, the obtained paste soap composition can have a paste-like retention performance for a long time even at low temperatures.

[0103] The alkali used to neutralize the cooled mixed saturated fatty acids to obtain fatty acid soap is a mixed alkali of potassium hydroxide and / or potassium carbonate and sodium hydroxide and / or sodium carbonate, and the mixed molar ratio of potassium hydroxide and / or potassium carbonate to sodium hydroxide and / or sodium carbonate is 70 / 30 to 30 / 70, preferably 60 / 40 to 50 / 50.

[0104] Furthermore, in order to suppress an increase in viscosity and local generation of heat of neutralization during the neutralization reaction, it is desirable to mix purified water with the mixed alkali.

[0105] The potassium hydroxide and / or potassium carbonate and the sodium hydroxide and / or sodium carbonate may be mixed in advance to prepare a mixed alkali and then used for neutralization, or may be mixed separately during neutralization without being mixed in advance.

[0106] If the molar ratio of potassium hydroxide and / or potassium carbonate exceeds 70, the influence of potassium soap becomes strong, and the foaming property, cleaning ability, etc. cannot be satisfied. If the ratio of potassium hydroxide is less than 30, the hardness of the obtained soap may increase and become non-liquid, and it may not dissolve in water quickly during use, and the foaming property may decrease.

[0107] In the neutralization of the mixed fatty acid, the two bases may be prepared in advance as an aqueous alkaline solution (for example, based on an active ingredient concentration of 48%) and used for neutralization, thereby obtaining a uniform solution in a short time.

[0108] Although heat is generated during neutralization, if the temperature rises above the above-mentioned temperature rise, the obtained paste soap composition may not exhibit the above-mentioned effects. Therefore, the temperature is raised to 80 to 90°C.

[0109] Examples of fatty acid soaps obtained by saponifying the above-mentioned mixed fatty acid and mixed alkali include a mixed salt of potassium / sodium laurate, a mixed salt of potassium / sodium myristate, a mixed salt of potassium / sodium palmitate, and a mixed salt of potassium / sodium stearate. From the viewpoint of being able to produce a paste soap having good foaming properties, it is desirable that a mixed salt of potassium / sodium laurate and a mixed salt of potassium / sodium myristate are necessarily contained, and two or more of the above-mentioned mixed salts are used in combination.

[0110] The paste soap composition obtained by the method of the present invention preferably contains 8 to 35% by mass, preferably 10 to 35% by mass, and more preferably 18 to 28% by mass of a saturated fatty acid soap component. This is because within this range, a more sufficient amount of foam can be obtained during use, and a more homogeneous paste soap composition can be obtained.

[0111] The paste soap composition obtained by the production method of the present invention thus obtained contains water, which corresponds to added water, water contained in each raw material, and water generated by neutralization of fatty acid and alkali, and the amount in the paste soap composition can be 28 to 65% by weight, preferably 35 to 50% by weight.

[0112] As for water content, as the weight ratio of potassium hydroxide / sodium hydroxide becomes 70 / 30 to 30 / 70, more water needs to be contained. This is considered to be because as the usage ratio of sodium hydroxide increases, the concentration of the sodium salt of fatty acid generated by saponification increases, but the solubility of the generated sodium salt of fatty acid in water is low.

[0113] For example, if the water content exceeds 65% by weight, satisfactory foaming properties and foam volume may be difficult to obtain during use, while if the water content is less than 28% by weight, the composition may be easily solidified at low temperatures.

[0114] Adjusting the water content within this range is desirable because it is possible to obtain a paste-like soap composition that is suitable and easy to use even in a low temperature region, has a viscosity within a suitable range, does not have fluidity such as flow-out, and does not harden and solidify.

[0115] In the production method of the present invention, the maximum load of the viscosity of the soap composition finally obtained measured under the following conditions is 200 to 3499 g / cm at 5°C. 2 The ideal paste state is 200~999g / cm 2 It should be noted that in the present invention, the maximum load is 100 to 199 g / cm 2 The soap composition was evaluated as an emulsion, with a value of 99 g / cm 2 The following soap compositions were evaluated as liquids.

[0116] (Conditions) The viscosity is expressed by the following value: a soap composition sample at a predetermined temperature (5° C.) is injected into a 20 ml polypropylene syringe (cosmetic S-Merge container No. 403, sold by Daiso Industries, Ltd., and the syringe outlet diameter is adjusted by cutting to 6.0 mm), a weight is stacked on the injection rod of the syringe, and the maximum load when the soap composition is ejected from the syringe outlet is measured.

[0117] Furthermore, in addition to the above-mentioned essential components, higher alcohols, squalane, various liquid or solid fatty acid esters, various purified natural oils and fats such as olive oil and sesame oil, oily components such as medium-chain fatty acid triglycerides, silicone derivatives such as polyoxyethylene alkyl-modified dimethyl silicone, natural water-soluble polymers such as pectin and alginic acid, biodegradable chelating agents such as sodium gluconate, various natural extracts derived from animals and plants, salt for adjusting the freezing point and hardness, inorganic salts such as sodium sulfate, natural antioxidants such as d-tocopherol, natural pigments, natural flavors, and others may be optionally blended as needed within a range not to impair the effects of the present invention.

[0118] Example

[0119] Hereinafter, the present invention will be described in detail with reference to the following Examples, Comparative Examples, and Test Examples, but the present invention is not limited thereto.

[0120] The raw materials used were the following.

[0121] [raw materials]

[0122] (1) Fatty acids

[0123] ·Lauric acid (carbon number 12: Mw 200.31): trade name NAA122 (manufactured by NOF Corporation)

[0124] ·Myristic acid (14 carbon atoms: Mw 228.36): trade name NAA142 (manufactured by NOF Corporation)

[0125] Palmitic acid (carbon number 16: Mw 256.42): trade name NAA160 (manufactured by NOF Corporation)

[0126] Stearic acid (carbon number 18: Mw 284.44): trade name NAA180 (manufactured by NOF Corporation)

[0127] (2) Alkali

[0128] Sodium hydroxide: 48% sodium hydroxide solution (manufactured by Kanto Chemical Co., Ltd., reagent grade 1)

[0129] Potassium hydroxide: 48% potassium hydroxide solution (manufactured by Kanto Chemical Co., Ltd., reagent grade 1)

[0130] (3) Fatty acid polyvalent metal salts

[0131] ·Magnesium stearate: trade name Daiwax M, manufactured by Dainichi Chemical Industry Co., Ltd.

[0132] (4) Alcohols

[0133] ·Glycerin (Wako Grade 1: Made by Wako Pure Chemical Industries, Ltd.)

[0134] · Sorbitol: Trade name NEOSORB70 / 70 manufactured by Shinko Science Corporation (70% water-soluble liquid)

[0135] (5) Sugar (Mitsui Sugar Co., Ltd. sugar)

[0136] (6) Talc: Trade name: SWA-A TALC, manufactured by Asada Flour Milling Co., Ltd.

[0137] (7) Purified water: Trade name: Japanese Pharmacopoeia Purified Water, manufactured by Kosakai Pharmaceutical Co., Ltd.

[0138] (8) MCT (Medium Chain Triglyceride; Oil): Trade name: Nisshin MCT Oil HC 100% Nisshin OilliO Group Ltd.

[0139] (9) Squalane: manufactured by Kojo Chemicals Co., Ltd.

[0140] A. Liquid Soap Composition

[0141] (Examples 1 to 9, Comparative Examples 1 to 10)

[0142] Each of the above-mentioned fatty acids was blended at the blending ratios shown in the following Tables 1 and 2 to prepare each mixed fatty acid.

[0143] Then, the mixed fatty acid was added to a 1L flask equipped with a stirrer, a thermometer and a dropping funnel, and the mixture was heated while stirring, and the mixture was stirred for 20 to 60 minutes in such a manner that the mixed fatty acid was completely melted and uniformly liquid at each heating temperature (a) shown in Tables 1 and 2. It should be noted that the molten mixed fatty acid was in a transparent state.

[0144] In Comparative Example 5, a liquid obtained by mixing purified water and glycerin was mixed with mixed fatty acids in advance, and the mixed liquid was heated to the temperature shown in Tables 1 and 2 (heating temperature (a)).

[0145] Purified water and glycerin were mixed in the ratios shown in Tables 1 and 2 to prepare respective cooling liquids.

[0146] While stirring the liquid mixed fatty acid at each heating temperature, a coolant at room temperature of about 20°C was added to the mixed fatty acid at once to quench it, and the temperature of the mixed liquid of the mixed fatty acid and the coolant in the flask was cooled to each cooling temperature (b) shown in Tables 1 and 2, and further stirred for about 5 minutes to make it uniform, thereby obtaining a white suspended liquid dispersion. Then, the liquid dispersion was heated to a heating control temperature (c) of 40 to 50°C and maintained.

[0147] It should be noted that, for Comparative Example 5, a mixed solution of 172 (parts by mass / 100 parts by mass of mixed fatty acids) of purified water and 21 (parts by mass / 100 parts by mass of mixed fatty acids) was mixed with mixed fatty acids in advance and was not used as a cooling liquid. Therefore, there was no cooling step, and for convenience, the temperature of the state of stirring for about 5 minutes at the heating temperature was recorded in the columns of the cooling temperature (b) and the heating control temperature (c).

[0148] Then, a mixed alkali aqueous solution prepared by mixing 48% potassium hydroxide aqueous solution and / or 48% sodium hydroxide aqueous solution (Tables 1 and 2) in advance was added all at once to the flask containing the above dispersion, and neutralization (saponification) was performed while stirring.

[0149] The mixed alkali concentration (%) indicates the alkali concentration obtained by dividing ((48% KOH (g) + 48% NAOH (g)) × 0.48) by (48% KOH (g) + 48% NAOH (g) + dilution water (g).

[0150] After neutralization, the neutralized solution (saponified solution) in the flask was heated again while being uniformly stirred so that no bubbles were generated, and was aged while being maintained at the heating temperature (d) shown in Tables 1 and 2 for about 30 minutes.

[0151] After aging, the obtained composition was naturally cooled at room temperature to obtain a soap composition.

[0152] All samples of the examples were in a transparent liquid state at room temperature (evaluation in Table 8). Samples of Comparative Examples 1 to 4 and 7 were transparent liquid soap compositions at room temperature, the sample of Comparative Example 5 was in a semi-solid state at room temperature, and the samples of Comparative Examples 6 and Comparative Examples 8 to 10 were in a solid state at room temperature.

[0153] Test example

[0154] (Test Example 1) Transparency and Liquid Stability at Normal Temperature

[0155] After each liquid soap composition obtained in Examples 1 to 10 and Comparative Examples 1 to 4 and 7 was produced, it was immediately placed in a flat-bottomed test tube F25-100 (model TEST-F25-100, AGC Techno Glass) to a height of 75 mm in a non-foaming manner, and sealed and left to stand in a 25°C constant temperature bath or a 5°C constant temperature bath. The flat-bottomed test tube was visually observed from the vertical direction (upper part) and the horizontal direction when the temperature of the composition was 25°C, and the transparency was evaluated.

[0156] It should be noted that in the evaluation, the case where no white lumps, white precipitates, turbidity, or separated matter were observed visually, and the case where the text in Ming Dynasty font size 8 provided on the bottom of the flat-bottomed test tube could be clearly read by observing from the top (vertical direction) of the test tube was considered to have transparency and was evaluated as "transparent". The results are shown in Tables 1 and 2.

[0157] [Table 1]

[0158]

[0159] [Table 2]

[0160]

[0161] (Preparation of soap water)

[0162] The soap compositions obtained in the above-mentioned Examples and Comparative Examples were used to prepare 5% soap water and 10% soap water using purified water, and the following tests were carried out.

[0163] (Test Example 2) Liquid Retention Performance and Transparency

[0164] The soap water obtained by using the soap compositions obtained in Examples 1 to 9 and Comparative Examples 1 to 10 was placed in a flat-bottomed test tube F25-100 (model TEST-F25-100, AGC Techno Glass) to a height of 75 mm without foaming, and sealed and left to stand in a 5°C constant temperature bath for 1 week. The liquid retention performance after standing for 1 week was visually evaluated, and the transparency of the flat-bottomed test tube in the longitudinal direction (upper part) and the transverse direction was visually evaluated.

[0165] The stability at 5°C (after one week) was evaluated by the following operation.

[0166] · When white solids are precipitated and solidified, the liquid retention performance is not good and the transparency is poor (×)

[0167] No white lumps, white precipitates, turbidity, or separated matter was observed visually, and the text in Ming Dynasty font size 8 provided on the bottom of the flat-bottomed test tube could be clearly read by observing from the top (vertical direction) of the test tube, indicating that the transparency was good, and the test tube was in a liquid state (0) according to the criteria of Test Example 4 described below.

[0168] (Test Example 3) Foaming

[0169] In the above-mentioned Examples and Comparative Examples, the foaming property test at 5° C. was carried out by a simple shaking method for both 5% and 10% soap water samples which were transparent and liquid.

[0170] Specifically, 3 g of each soap solution was weighed and injected into three 25 mm diameter flat-bottom test tubes (TEST-F25-100) manufactured by AGC Techno Glass Co., Ltd. using a dropper, and the test tubes were sealed with vinyl chloride plastic wrap and a rubber ring, immersed in a 5°C constant temperature water bath equipped with a test tube stand, and kept at 5°C for 30 minutes. The test tubes were then shaken by turning upside down 20 times within 20 seconds, and as an immediate foaming test, the height of the liquid surface from the bottom of the test tube (= the bottom of the foam part) and the height of the highest point of the foam part were measured as the height of the foam part.

[0171] Then, each test tube was immersed in a constant temperature water tank again, and after standing for 5 minutes, the height of the liquid surface and the height of the highest position of the foam part were measured as the height of the foam part as a foaming test after 5 minutes. The same operation was performed on all three test tubes, and the average value of the liquid surface and the height of the foam part was calculated to judge the foaming property of each fatty acid soap composition.

[0172] The results are shown in Table 3.

[0173] It should be noted that the evaluation results are as follows.

[0174] When the height of the foam part measured after 5 minutes is 30 mm or more, the foamability is high (○)

[0175] · When the height of the foam part is less than 20 mm, the foaming property is low (×)

[0176] When the height of the foam part is 20 mm or more and less than 30 mm, the foaming property is medium (△)

[0177] Comprehensive evaluation (5℃)

[0178] The case where all the evaluations of Test Example 2 and Test Example 3 were 0 was set as 0.

[0179] The case where any one of the evaluation items of Test Example 2 and Test Example 3 was × was regarded as △.

[0180] The case where all the evaluations of Test Example 2 and Test Example 3 were × was set as ×○.

[0181] The results are shown in Table 3.

[0182] [Table 3]

[0183]

[0184] According to Tables 1 to 3 above, all the liquid soap compositions of Examples were excellent in liquid retention performance and transparency at low temperatures, and also excellent in foaming properties.

[0185] In addition, the above-mentioned Test Examples 2 to 3 were carried out on the samples of the liquid soap compositions of the examples, and the 5% aqueous solutions and 10% aqueous solutions of the respective liquid soap compositions, which were stored at a low temperature of 5° C. for 1 month. As a result, the liquid retention performance, transparency, and foaming properties were also 0, and the same results as those in Table 3 were obtained.

[0186] B. Paste Soap Composition

[0187] (Examples 10 to 20, Comparative Examples 11 to 20)

[0188] Each of the above-mentioned fatty acids was blended at the blending ratios shown in Tables 4 and 6 to prepare each mixed fatty acid. Magnesium stearate and talc (mixture of mixed fatty acids, etc.) were blended into the mixed fatty acid at the blending ratios shown in Tables 4 and 6.

[0189] Then, the above-mentioned mixed fatty acid mixture is added to a 1L flask equipped with a stirrer, a thermometer and a dropping funnel, stirred and heated to a high temperature, and the mixed fatty acid is completely melted at each heating temperature (a) shown in Tables 5 and 7 and stirred for 20 to 60 minutes.

[0190] Glycerin and sorbitol were mixed in purified water at the ratios shown in Tables 4 and 6 (it should be noted that the values ​​of sorbitol in Tables 4 and 6 do not represent the mass parts of the sorbitol aqueous solution but represent the mass parts of substantial sorbitol) to prepare respective cooling liquids.

[0191] While stirring the mixture of the mixed fatty acids, etc. at the above-mentioned heating temperatures, a cooling liquid of about 20°C was added to the mixture of the mixed fatty acids, etc. at once for quenching, so that the temperature of the mixture of the mixed fatty acids, etc. and the cooling liquid in the above-mentioned flask was the cooling temperature (b) shown in Tables 5 and 7, and further stirred for about 5 minutes to make it uniform, thereby obtaining a white suspension state dispersion. Then, the dispersion was heated to the heating control temperature (c) shown in Tables 5 and 7 and maintained.

[0192] Then, a mixed alkali aqueous solution prepared by mixing 48% potassium hydroxide aqueous solution and / or 48% sodium hydroxide aqueous solution (Tables 5 and 7) in advance was added all at once to the flask containing the above-mentioned dispersion liquids under heating and temperature control, and neutralization (saponification) was carried out while stirring.

[0193] The mixed alkali concentration (%) indicates the alkali concentration obtained by dividing ((48% KOH (g) + 48% NAOH (g)) × 0.48) by (48% KOH (g) + 48% NAOH (g) + dilution water (g).

[0194] After neutralization, sugar, MCT, and squalane were blended as needed in the ratios shown in Tables 4 to 7. Then, the neutralized solution (saponified solution) in the flask was heated while being uniformly stirred so that no bubbles were formed, and the solution was aged while being maintained at the heating temperature (d) shown in Tables 5 and 7 for about 30 minutes.

[0195] After aging, the obtained composition was naturally cooled at room temperature to obtain a soap composition.

[0196] All samples of Examples obtained fatty acid soap compositions in a paste state.

[0197] (Test Example 4) Paste Retention Performance

[0198] Each soap composition obtained by Examples 10 to 20 and Comparative Examples 11 to 12, Comparative Examples 14 to 16 and Comparative Examples 18 to 20 was placed in a flat-bottomed test tube F25-100 (Model TEST-F25-100, AGC Techno Glass) to a height of 75 mm without foaming, sealed and placed in a 5°C constant temperature bath for 1 month. The paste retention performance after standing for 1 month was visually evaluated and evaluated by the following viscosity test. It should be noted that for Comparative Examples 13 and 17, solidification occurred at room temperature and was in a solidified state after standing for 1 month at 5°C.

[0199] The soap compositions left to stand at 5°C for one month were subjected to the following viscosity test to test whether they were paste-like at 5°C.

[0200] (Viscosity test)

[0201] A 20 ml polypropylene syringe (cosmetic S-Merge container No. 403, sold by Daiso Industry Co., Ltd.) was cut at its injection port to have a hole with an inner diameter of 6.0 mm and adjusted to a syringe (syringe outlet diameter: 6.00 mm). About 15 ml of each soap composition kept at a constant temperature was injected into the syringe at a predetermined temperature (5° C.), and the outlet was blocked and compressed so that air could not enter. After confirming that each sample was extruded in a cylindrical shape, the sample was fixed vertically to a support table.

[0202] Then, a weight was stacked in a plastic box (13 g) set on the injection rod of the syringe, and the maximum load at the time when each soap composition sample in the syringe began to be ejected was measured to conduct a viscosity test. The evaluation was based on the evaluation criteria shown in the following Table 8. The obtained results are shown in the following Table 9.

[0203] (Test Example 5) Foaming

[0204] For the examples in Test Example 4 in which the paste-like retention performance was maintained, a foaming property test at 5° C. was carried out by a simple shaking method.

[0205] Specifically, 3 g of each of the obtained paste soaps and 5 ml of purified water were weighed and poured into three 25 mm diameter flat-bottom test tubes (TEST-F25-100) manufactured by AGC Techno Glass Co., Ltd. using a dropper, and the mixture was sealed with a vinyl chloride plastic wrap and a rubber ring, immersed in a 5°C constant temperature water bath equipped with a test tube stand, and kept at 5°C for 30 minutes. The test tubes were then shaken by turning upside down 20 times within 20 seconds, and as an immediate foaming test, the height of the liquid surface (= the bottom of the foam part) from the bottom of the test tube and the height of the highest point of the foam part were measured as the height of the foam part.

[0206] Then, each test tube was immersed in a constant temperature water tank again, and after standing for 5 minutes, the height of the liquid surface and the height of the highest position of the foam part were measured as the height of the foam part as a foaming test after 5 minutes. The same operation was performed on all three test tubes, and the average value of the liquid surface and the height of the foam part was calculated to judge the foaming property of each fatty acid soap composition.

[0207] It should be noted that the evaluation results are as follows.

[0208] When the height of the foam part measured after 5 minutes is 30 mm or more, the foamability is high (○)

[0209] · When the height of the foam part is less than 20 mm, the foaming property is low (×)

[0210] When the height of the foam part is 20 mm or more and less than 30 mm, the foamability is medium (△). The obtained results are shown in Table 9 below.

[0211] [Table 4]

[0212]

[0213] [Table 5]

[0214]

[0215] [Table 6]

[0216]

[0217] [Table 7]

[0218]

[0219] [Table 8]

[0220]

[0221] [Table 9]

[0222] example Paste retention performance Foaming Example 10 1 month ○ Embodiment 11 1 month ○ Example 12 1 month ○ Example 13 1 month ○ Embodiment 14 1 month ○ Comparative Example 11 1 week curing - Comparative Example 12 Liquid - Comparative Example 13 Curing - Comparative Example 14 1 week curing - Comparative Example 15 Liquid - Comparative Example 16 1 month curing - Comparative Example 17 Curing - Comparative Example 18 Liquid - Embodiment 15 1 month ○ Example 16 1 month ○ Embodiment 17 1 month ○ Embodiment 18 1 month ○ Embodiment 19 1 month ○ Embodiment 20 1 month ○ Comparative Example 19 1 week curing - Comparative Example 20 ×No paste formation -

[0223] As can be seen from Table 9, all the paste soap compositions of the Examples have excellent paste retention performance at low temperatures and excellent foaming properties. However, when the compounding amount of each component is outside the range of the present invention, the obtained soap has poor long-term paste retention performance at 5°C, cannot maintain the paste state, and flows out or solidifies.

[0224] Industrial Applicability

[0225] The liquid soap composition and the paste soap composition prepared by the method for producing a soap composition containing sodium and potassium higher fatty acids of the present invention can maintain a liquid or paste state even in cold regions or in winter, and therefore have good usability and can be effectively used for facial and body skin cleansing.

Claims

1. A method for producing a soap composition containing sodium and potassium higher fatty acids, in, Mixed saturated fatty acids are heated to 80° C. or higher and melted, and then a cooling liquid composed of glycerol and water is added to the mixed saturated fatty acids at once, and the mixture is cooled to a temperature at least 20° C. lower than the heating temperature, and then heated again and maintained at 40-55° C., and an aqueous solution of a mixed alkali mixture of potassium hydroxide and / or potassium carbonate and sodium hydroxide and / or sodium carbonate in a molar ratio of 90 / 10-30 / 70 is added to the heated liquid containing the mixed fatty acids at once, and the mixture is heated and maintained at 80-95° C. while stirring for neutralization, thereby preparing a liquid soap composition, wherein the mixed saturated fatty acids are mixed fatty acids composed of saturated fatty acids with carbon numbers of 12 to 18, including 85-100 mol % of saturated fatty acids with carbon numbers of 12 and 14, and do not contain saturated fatty acids with carbon numbers of 8 to 10, and the glycerol in the cooling liquid is 15-30 parts by mass relative to 100 parts by mass of the mixed fatty acids.

2. The method for producing a soap composition containing sodium and potassium higher fatty acids according to claim 1, It is characterized in that Contains more saturated fatty acids having 12 carbon atoms than saturated fatty acids having 14 carbon atoms.

3. A method for producing a soap composition containing sodium and potassium of higher fatty acids, in, A mixture of a mixed saturated fatty acid and 3 to 23 parts by mass of magnesium stearate or magnesium palmitate relative to 100 parts by mass of the mixed saturated fatty acid is heated to 80° C. or above to melt the mixed saturated fatty acid, wherein the mixed saturated fatty acid is a mixed fatty acid formed of saturated fatty acids having 12 to 18 carbon atoms and containing 80 to 90 mol % of saturated fatty acids having 12 and 14 carbon atoms, and does not contain saturated fatty acids having 8 to 10 carbon atoms. Then, a cooling liquid composed of glycerin and water is added to the mixture of the mixed saturated fatty acid and magnesium stearate or magnesium palmitate at once, and the mixture is cooled to a temperature at least 20° C. lower than the heating temperature, and 30 to 75 parts by mass of glycerin are added to 100 parts by mass of the mixed saturated fatty acid. After the cooling, the mixture is heated again and maintained at 40-55°C, An aqueous solution of a mixed alkali prepared by mixing potassium hydroxide and / or potassium carbonate with sodium hydroxide and / or sodium carbonate in a molar ratio of 70 / 30 to 30 / 70 is added all at once to the mixture kept heated, and the temperature is raised and maintained at 80 to 95° C. while stirring for neutralization, thereby preparing a paste soap composition, wherein the talc and sorbitol are blended before or after the neutralization so as to contain 3 to 13 parts by mass of talc and 50 to 180 parts by mass of sorbitol per 100 parts by mass of the mixed saturated fatty acid.

4. The method for producing a soap composition containing sodium and potassium higher fatty acids according to claim 3, It is characterized in that Furthermore, higher alcohols and / or squalane and / or MCT and / or sugars and / or purified natural oils and fats are blended.

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