Solid cleansing agent

Abstract

To provide a solid cleansing agent that is produced by a "machine kneading" method, which is highly productive and has a favorable impact on the environment during packaging and transportation, is used for body cleansing, blends in well with the skin and feels smooth when rubbed directly against the skin, and also blends in well with the skin and feels smooth when lathered with hands, and has excellent moisturizing feel on the skin after drying.SOLUTION: The solid cleansing agent of the present invention contains: a component (A): a non-soap anionic surfactant; a component (B): a clay mineral; a component (C): an amphoteric surfactant; and a component (D): one or more compounds selected from the group consisting of fatty acids, fatty acid triglycerides, and fatty acid triglyceride esters, the content of the component (B) being 20 to 45 mass% based on the total mass of all the components. It may also contain either a component (E): a nonionic surfactant or a component (F): a pH adjuster.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a solid cleansing agent used for washing the body. [Background technology]

[0002] Conventionally, body cleansers have generally been in the form of solid cleansers such as sodium fatty acid or sodium isethionate, or liquid or paste types that contain a large amount of water and are primarily made of anionic surfactants.

[0003] Solid detergents such as sodium fatty acids and sodium isethionate are produced using a highly productive method called "machine kneading," in which the raw materials are mixed, kneaded, bar-formed, and stamped in a continuous process using a kneading machine.

[0004] In addition, for liquid or paste-type body cleansers, for example, cleansers that provide an excellent feel on the skin after use have been proposed (see Patent Documents 1 and 2). However, in recent years, from the perspective of environmental considerations such as reducing plastic waste and saving energy, expectations are growing for new solid body cleansers instead of liquid or paste-type cleansers. This is because solid cleansers can be packaged in paper and are less bulky, allowing for efficient transportation and transfer, and are expected to have a positive impact on the environment.

[0005] Solid cleansing agents such as soap contain anionic soap surfactants, such as sodium fatty acids, and although they are excellent at foaming, they are alkaline, which means that many consumers are dissatisfied with the alkaline nature of the product, as it leaves their skin feeling tight after use and because human skin is naturally slightly acidic.

[0006] In addition, although solid cleansers that use sodium isethionate as the main ingredient can be pH controlled to be slightly acidic, they have a unique base odor that needs to be masked with fragrances or other additives in order to be commercialized.

[0007] Other solid cleansing products disclosed in patent documents include those based on N-acyl glutamic acid, N-acyl amino acid salts, or acylaspartic acid salts, but all of these have formulations that can only be produced by the so-called framing method, in which the raw materials are dissolved and poured into a frame to solidify.

[0008] There are also a number of patents disclosing powdered detergents in powder form or detergents made by compressing these into tablets, but the only solid detergents suitable for the "mechanical kneading" manufacturing method are those proposed in Patent Documents 3 and 4. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 9-183997 [Patent Document 2] JP 2014-193981 A [Patent Document 3] Patent No. 6756562 [Patent Document 4] Patent No. 5923829 Summary of the Invention [Problem to be solved by the invention]

[0010] Liquid or paste-type detergents, including those described in Patent Documents 1 and 2, do not contain ingredients suitable for the manufacture of solid detergents, and the ingredients and ratios of ingredients contained therein cannot be directly applied to solid detergents. In addition, the detergents described in Patent Documents 1 and 2 contain soap-based anionic surfactants such as sodium fatty acids, so they tend not to be used for washing weakly acidic skin or delicate parts of the body. In particular, they are not suitable for solid detergents for washing the bodies of infants, women, the elderly, etc.

[0011] On the other hand, the inventions described in Patent Documents 3 and 4 relate to solid cleansing agents obtained by a "mechanical kneading" method. However, since the main purpose of the invention is to improve moldability such as releasability and the like, and thereby improve the feel when used, they took into consideration pH, usability, reduction of the odor of raw materials, etc., and did not recognize any technical issues such as improving compatibility and smoothness on the skin during use and improving the feel on the skin after use.

[0012] Therefore, there has been a strong demand for a solid cleanser that can be manufactured using the highly productive "machine kneading" method, and that can provide excellent skin feel both during and after use by appropriately mixing common cleansing ingredients to expand the freedom of formulation, such as by adjusting pH, ease of use, and reducing the odor of raw materials.

[0013] To provide a solid cleanser which can be directly rubbed onto the skin or lathered by hand or the like and applied to the skin, has a smooth feel when used, can be arbitrarily adjusted to an optimum pH so as to be compatible with the skin, and is produced by a "machine kneading" method with excellent productivity. [Means for solving the problem]

[0014] As a result of intensive research into solving the above problems, the inventors discovered that by selecting specific ingredients and adjusting their blend ratios within specific ranges, a solid cleanser exhibiting the desired functional effects can be obtained, and thus completed the present invention. That is, the present invention is as follows.

[0015] [1] The present invention provides a solid cleanser comprising: component (A): a non-soap anionic surfactant; component (B): a clay mineral; component (C): an amphoteric surfactant; and component (D): one or more compounds selected from the group consisting of fatty acids, fatty acid triglycerides, and fatty acid triglyceride esters, wherein the content of component (B): the clay mineral is 10 to 45 mass % relative to the total mass of all the components.

[0016] [2] The present invention provides a solid cleanser according to the above item [1], characterized in that it contains component (E): a nonionic surfactant.

[0017] [3] The present invention provides a solid cleanser according to the above item [1], characterized in that one or more compounds selected from the group consisting of component (A): a non-soap anionic surfactant, component (B): a clay mineral, component (C): an amphoteric surfactant, and component (D): a fatty acid, a fatty acid triglyceryl, and a fatty acid triglyceryl ester are contained in amounts of 9 to 40 mass%, 20 to 45 mass%, 1 to 30 mass%, and 1 to 10 mass%, respectively, relative to the total mass of all the components.

[0018] [4] The present invention provides a solid cleanser according to the above item [3], characterized in that it contains (E): a nonionic surfactant, and that the component (E): nonionic surfactant is contained in an amount of 3 to 30 mass % relative to the total mass of all components.

[0019] [5] The present invention provides a solid cleanser as described in [4] above, characterized in that it contains a component (F): a pH adjuster for adjusting the pH of the solid cleanser to a weak acidity of 4.0 to 6.0, and that the component (F): the pH adjuster is contained in an amount of 5 mass % or less based on the total mass of all components.

[0020] [6] The present invention provides a solid cleanser according to any one of [1] to [5], wherein the (B) clay mineral contains bentonite in an amount of 50 mass% or more relative to the total mass of the component (B): clay mineral. Effect of the Invention

[0021] According to the solid cleansing agent of the present invention, by containing the above-mentioned components (A), (B), (C) and (D), it is possible to provide a solid cleansing agent which is familiar to the skin and has a smooth feel when directly rubbed against the skin, and which also has a smooth feel when lathered with the hands to enhance cleaning power, and which also has an excellent moist feeling on the skin after drying. Furthermore, by containing and using the above-mentioned components (E) and (F) in combination, it is possible to improve the ease of lathering and the moist feeling after use, and by adjusting the pH to the same weak acidity as the skin, a good feel on the skin can be obtained.

[0022] In addition, the solid cleansing agent of the present invention optimizes the content of the clay mineral contained as the above component (B), and further contains the above component (D) in a predetermined appropriate range, thereby increasing the dispersibility of the clay mineral and improving the adhesiveness of the solid cleansing agent, which makes it less likely to disintegrate and improves quality, and also makes it easier to manufacture by the "mechanical kneading" method, which has excellent productivity. The solid cleansing agent obtained by the "mechanical kneading" method is easier to package and transport than liquid or paste types, so the impact on the environment during packaging and transportation is reduced, resulting in favorable effects on the environment. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a process flow chart showing an example of a manufacturing process for a solid cleansing agent by "mechanical kneading." DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The term "cleaning agent" broadly refers to products that remove dirt from the face, body, hair, etc., and the solid cleansing agent of the present invention may be used as a "solid cleansing agent" for body washing.

[0025] Hereinafter, an embodiment of the present invention will be described. However, it goes without saying that the present invention is not limited to the embodiment.

[0026] The solid detergent of the present invention contains (A) a non-soap anionic surfactant, (B) a clay mineral, (C) an amphoteric surfactant, and (D) one or more compounds selected from the group consisting of fatty acids, fatty acid triglycerides, and fatty acid triglyceride esters, as components that provide an excellent skin feel both before and after use. The solid detergent of the present invention is characterized in that it does not contain a soap anionic surfactant such as sodium fatty acid as an anionic surfactant, and by containing (A) a non-soap anionic surfactant instead of a soap anionic surfactant, not only can the cleaning power be maintained or improved, but also the combined use of (B) a clay mineral and (C) an amphoteric surfactant can significantly reduce irritation to the skin and provide an excellent skin feel. Here, the content of (B) the clay mineral is set to be higher than that of conventional products in order to correspond to the "machine kneading" manufacturing method, which has excellent productivity as a manufacturing method for solid detergents, in order to suppress the disintegration of the solid detergent.

[0027] The solid cleansing agent of the present invention is specified so that the content of the clay mineral (B) is relatively high, at 20% by weight or more, based on the total mass of all the components, and each component contained in the solid cleansing agent needs to have a higher dispersibility. Therefore, the solid cleansing agent contains (D) one or more compounds selected from the group consisting of fatty acids, fatty acid triglycerides, and fatty acid triglyceride esters, as an oil component that increases the dispersibility of the clay mineral (B) and improves the viscosity of the solid cleansing agent. Furthermore, the content of the clay mineral (B) is specified to be an upper limit of 45% by weight or less in order to maintain a good skin feel after use of the solid cleansing agent.

[0028] In addition, the solid cleanser of the present invention may further contain component (E): a nonionic surfactant as a component that optimizes the ease of dissolving and crumbling of the solid cleanser by improving the affinity between component (B): a clay mineral and component (D): one or more compounds selected from the group consisting of fatty acids, fatty acid triglycerides, and fatty acid triglyceride esters.

[0029] In addition, the solid cleanser of the present invention may contain component (F): a pH adjuster, as a component that adjusts the pH to the weak acidity of the skin (in the range of pH 4.0 to 6.0) in order to further improve the feel on the skin before and after use.

[0030] The above components (A), (B), (C), (D), (E) and (F) may be optimized in their respective contents in order to achieve the object of the present invention of providing a solid cleansing agent that exhibits excellent skin feel (skin compatibility, skin smoothness and moisturizing feel) both during and after use and is manufactured by a "mechanical kneading" method. As described below, the solid cleansing agent of the present invention may contain other components in addition to the above components (A), (B), (C), (D), (E) and (F). In the present invention, the contents of the above components (A), (B), (C), (D), (E) and (F) contained in the solid cleansing agent are each specified relative to the total mass of all components including the other components.

[0031] Each of the components (A), (B), (C), (D) and (F) will be described below. In the present invention, a numerical range defined using the symbol "~" includes the numerical values ​​at both ends of "~" (upper and lower limits). For example, "2-10" means 2 or more and 10 or less. In addition, when there are multiple numerical ranges defined in stages, each numerical value can be arbitrarily combined to form a numerical range. For example, when "2-10, preferably "4-8" is described, the numerical ranges "2-4", "2-8", "4-10" and "8-10" can be formed.

[0032] <Component (A): Non-thermal anionic surfactant> Component (A) used in the present invention is a non-soap anionic surfactant.

[0033] Examples of such non-soap anionic surfactants include alkyl sulfate ester salts, polyoxyethylene alkyl ether sulfate salts, polyoxyethylene alkyl ether acetate salts, α-olefin sulfonate salts, N-acyl amino acid salts, N-acyl methyl taurine salts, alkyl sulfosuccinate salts, and N-acyl sarcosine salts.

[0034] Specific examples of component (A) include sodium lauryl sulfate, sodium POE(3) laureth ether sulfate, sodium α-olefin (C14-16) sulfonate, sodium N-cocoyl-N-methyl taurate, sodium N-lauroyl-N-methyl-β-alanine, sodium N-cocoyl glutamate, and sodium N-lauroyl sarcosine.

[0035] The content of component (A) in the solid cleansing agent of the present invention is 9 to 40% by mass, preferably 15 to 30% by mass, and more preferably 17 to 25% by mass. If the content of component (A) is less than 9% by mass, the ease of lathering and resistance to melting may decrease. On the other hand, if the content of component (A) is more than 40% by mass, the swelling and melting of the product may increase.

[0036] <Component (B): Clay minerals> The component (B) used in the present invention is a clay mineral.

[0037] Examples of such materials include kaolin, bentonite, (Al / Mg) silicate, and montmorillonite. Among these, bentonite is preferred from the viewpoints of resistance to dissolution, moist feeling after use, and smoothness (slipperiness) on the skin. These effects can be sufficiently obtained by including bentonite in an amount of 50% by mass or more, more preferably 70% by mass or more, based on the total amount of the (B) clay mineral, and allowing it to function as the main component of the clay mineral. In addition, when bentonite is used in combination with other clay minerals, (Al / Mg) silicate is a preferred component as the other clay mineral from the viewpoint of resistance to dissolution.

[0038] The content of component (B) in the solid cleansing agent of the present invention is 20-45% by mass, preferably 20-35% by mass, and more preferably 25-35% by mass. If the content of component (B) is less than 20% by mass, the solid cleansing agent is prone to disintegration. In addition, the inclusion of component (B) makes it easier to mold the solid cleansing agent into bars using the "mechanical kneading" manufacturing method. On the other hand, if the content of component (B) exceeds 45% by mass, the resistance to disintegration decreases, and further, the foaming ability, which affects the cleansing power, may be significantly reduced.

[0039] <Component (C): Amphoteric surfactant> The component (C) used in the present invention is an amphoteric surfactant.

[0040] Examples of such surfactants include alkyl betaines, alkyl amido betaines, alkyl hydroxy sulfobetaines, alkyl amido hydroxy sulfobetaines, alkyl carboxymethyl hydroxyethyl imidazolinium betaines, alkyl amido hydroxyethyl amino acid type amphoteric surfactants, and alkyl imino diacetates.

[0041] The content of component (C) in the solid cleansing agent of the present invention is 1 to 30% by mass, preferably 5 to 25% by mass, and more preferably 10 to 20% by mass. Optimizing the content of component (C) in this way can appropriately improve the ease of lathering and moist feeling after use while optimizing the ease of dissolving and crumbling of the solid cleansing agent.

[0042] <Component (D): Fatty acids, fatty acid triglycerides, and fatty acid triglyceride esters> The component (D) used in the present invention is at least one compound selected from the group consisting of fatty acids, fatty acid triglycerides, and fatty acid triglyceride esters.

[0043] Examples of such fatty acids, fatty acid triglycerides and fatty acid triglyceride esters include C12 to C18 fatty acids (containing unsaturated bonds), olive oil, sunflower oil and sunflower oil esters thereof.

[0044] The content of component (D) in the solid cleansing agent of the present invention is 1 to 10% by mass, preferably 4 to 8% by mass, based on the total mass of all the components. The inclusion of component (D) enhances the moisturizing effect on the skin, and also improves the viscosity of the solid body cleansing agent, thereby suppressing disintegration and facilitating bar molding in the "mechanical kneading" manufacturing method.

[0045] <Component (E): Nonionic surfactant> The component (E) used in the present invention may contain, as a nonionic surfactant, a polyoxyethylene alkyl ether or a polyoxyethylene fatty acid ester having an average number of moles of ethylene oxide added of 50 to 200.

[0046] Examples of such include laureth-50, PEG-55 stearate, PEG-75 stearate, PEG-150 stearate, and the like.

[0047] The content of component (E) in the solid cleansing agent of the present invention is 3 to 30% by mass, preferably 5 to 25% by mass, and more preferably 10 to 20% by mass, based on the total mass of all components. The content of component (E) enhances the affinity between the above components (B) and (D), thereby optimizing the ease of dissolving and crumbling of the solid cleansing agent, and can suitably improve the ease of lathering and moist feeling after use.

[0048] <Component (F): pH adjuster> Component (F) used in the present invention is a pH adjuster. Component (F) may be used to adjust the pH of the solid cleansing agent of the present invention to a weak acidity (in the range of pH 4.0 to 6.0) suited to the skin.

[0049] Examples of such acids include citric acid, sodium citrate, lactic acid, tartaric acid, and succinic acid.

[0050] Even when component (F) is blended into the solid body cleanser of the present invention, its content is preferably 5% by mass or less. However, the blending amount is determined in accordance with the blending balance of the above components (A), (B), (C), and (D), as well as the blended component (E), so as to adjust the skin pH as a solid cleanser to the weak acidity of the skin (pH range of 4.0 to 6.0).

[0051] <Other ingredients> In addition to the components (A) to (F) of the present invention, other components generally used in cosmetics may be contained as other components.

[0052] Examples of other ingredients include water, antioxidants, sequestering agents, colorants, fragrances, pigments, etc.

[0053] As the water, water generally used in the production of cosmetics and pharmaceuticals, ion-exchanged water, distilled water, and other purified water are preferably used.

[0054] The water content in the composition of the present invention is preferably 10% by mass, more preferably 5% by mass or less. If the water content exceeds 10% by mass, the entire composition is insufficiently mixed, and mechanical kneading becomes substantially impossible.

[0055] <Manufacturing method of solid cleansing agent> The solid cleansing agent of the present invention is manufactured by the "machine kneading" method, which has excellent productivity. Figure 1 shows an example of a manufacturing process for a solid cleansing agent by the "machine kneading" method as a process flow chart. Figure 1 also shows specific examples of the equipment used in each step.

[0056] As shown in Fig. 1, first, each of the above components (A) to (F) is charged into a container (hopper) (step S1 in the figure), and after the above other components are blended (step S2), they are mixed in a mixing step using a mixer or the like (step S3). Then, the process proceeds to a kneading step, in which the components are kneaded (step S4). Furthermore, in a tight kneading step by vacuum extrusion, the components are thoroughly kneaded using a vacuum extruder or the like so that the mixed state is uniform (step S5).

[0057] The solid cleansing agent vacuum-extruded in step S5 is cut into individual pieces of a desired length (step S6). The solid cleansing agent is then molded into a product shape using a press or the like (step S7). The solid cleansing agent of the present invention is basically manufactured according to steps S1 to S7 shown in Fig. 1, but when the final product is to be shipped, the solid cleansing agent is packaged in a predetermined shape in a packaging step (step S8).

[0058] The method for producing the solid cleansing agent of the present invention is not limited to the steps shown in the example of the production process flow chart in Figure 1. For example, if a large amount of volatile components such as water remains in the solid cleansing agent, a drying step may be added in the middle of the process. The kneading steps S4 and S5 may be performed consecutively, and in order to simplify the production process, kneading may be performed using a normal extruder rather than a vacuum extruder in the intimate kneading step S5. EXAMPLES

[0059] The present invention will now be described more specifically with reference to examples and comparative examples.

[0060] The following raw materials were used: (A) Sodium lauroyl sarcosine: NIKKOL Sarcosinate LN (manufactured by Nikko Chemicals Co., Ltd.) (B) Bentonite: SMFLV (manufactured by Ichinen Chemicals Co., Ltd.) Silicate (Al / Mg): VEEGUM R (Vanderbilt Minerals, LLC) (C) Cocamidopropyl betaine: Tegobetaine CKD (manufactured by Evonik Operations GmbH) (D) (Sunflower seed oil / hydrogenated sunflower seed oil) esters: Sunflower butter (manufactured by Yokoseki Oil Industry Co., Ltd.) Palmitic acid: Palmac98-16 (manufactured by IOI OLEOCHEMICALS) (E) PEG-75 stearate: Nonion S-40 (NOF Corp.) Laureth-50: Emalex 750 (manufactured by Nippon Emulsion Co., Ltd.) (F) Citric acid: Citric acid (manufactured by Komatsuya Co., Ltd.)

[0061] <Production Example: Example 1> Using the above ingredients (A) to (F) and other ingredients, a solid cleansing agent was prepared by simulating the "machine kneading" manufacturing method shown in Figure 1. First, the above ingredients (A) to (F) were blended with the other ingredients and then thoroughly mixed at room temperature. After that, the mixture was kneaded three times using a plodder with a honeycomb-shaped metal fitting attached to the nozzle ("Prototype Mini Plodder J" manufactured by Pelican Soap Co.), extruded into a rod shape using the plodder, and cut into 5 cm widths to obtain a solid cleansing agent.

[0062] <Examples 1 to 9 and Comparative Examples 1 to 6> The solid cleansing agents of Examples 2 to 9 and Comparative Examples 1 to 6 were prepared in the same manufacturing example as Example 1, according to the formulations shown in Tables 1 and 2 below. Here, for the solid cleansing agents of Examples 1 to 3, 5 to 6, and 8 to 9, citric acid was used as component (F) and the content was optimized to adjust the pH so that the pH was in the weakly acidic range of 4.0 to 6.0, close to the pH of skin. On the other hand, for the solid cleansing agents of Examples 4 and 7 and Comparative Examples 1 to 6, it was confirmed in advance that the pH would be 6.0 or less even without the inclusion of citric acid as component (F), so citric acid was not intentionally added.

[0063] The obtained solid cleansing agents of Examples 2 to 9 and Comparative Examples 1 to 6 were evaluated together with the solid cleansing agent of Example 1 above by the following method.

[0064] The evaluation results are shown in the lower part of Tables 1 and 2. "◎" and "◯" were judged as passing, "△" as passing with caution, and "×" as failing. Comparative Examples 1 to 6 shown in Table 2 below are examples of solid cleansers that were rated as "×" in at least one of the evaluation items and therefore failed.

[0065] The examples were judged by the in-house panelists shown below and rated with a score. On the other hand, the comparative examples were judged by two developers on prototypes and use, unlike the examples, so no specific score-based evaluation results were shown.

[0066] <Evaluation Method of the Examples> (1) Ease of whipping The panel consisted of 10 women aged between 22 and 50 years old who were asked to use the solid cleansing products while bathing and were then rated according to the following criteria. 3 points: If you feel that the foam is very good. 2 points: If you feel that it foams well. 1 point: If you feel that the foaming is slightly poor. 0 points: If you feel that the foaming is poor. The total scores of the 10 people were calculated and the evaluation was carried out as follows: ◎: Total score is 25-30 points 〇: Total score is 15 to 24 points △: Total score is 5 to 14 points ×: Total score is 4 points or less

[0067] (2) Smooth feeling on the skin during use The panel consisted of 10 women aged between 22 and 50 years old who were asked to use the solid cleansing products while bathing and were then rated according to the following criteria. 3 points: The cleanser spreads smoothly over the skin and feels very smooth. 2 points: If you feel that the cleanser spreads easily and glides smoothly on the skin. 1 point: If you feel that the cleanser does not glide smoothly on the skin. 0 points: If you feel that the cleanser does not glide smoothly on the skin. The total scores of the 10 people were calculated and the evaluation was carried out as follows: ◎: Total score is 25-30 points 〇: Total score is 15 to 24 points △: Total score is 5 to 14 points ×: Total score is 4 points or less

[0068] (3) Moisturizing feeling after use The panel consisted of 10 women aged between 22 and 50 years old who were asked to use the solid cleansing products while bathing and were then rated according to the following criteria. 3 points: If you feel that your skin feels very moisturized after using the cleanser. 2 points: If you feel that your skin feels moisturized after using the cleanser. 1 point: If you feel that your skin is less moisturized after using the cleanser. 0 points: If you feel that your skin is not moisturized after using the cleanser. The total scores of the 10 people were calculated and the evaluation was carried out as follows: ◎: Total score is 25-30 points 〇: Total score is 15 to 24 points △: Total score is 5 to 14 points ×: Total score is 4 points or less

[0069] (4) Resistant to melting The panel consisted of 10 women aged between 22 and 50 years old who were asked to use the solid cleansing products while bathing and were then rated according to the following criteria. 3 points: The cleanser does not dissolve or fall apart during or after use and is felt to be very good. 2 points: If the cleanser does not dissolve or crumble much during or after use and is felt to be good. 1 point: If you feel that the cleanser does not dissolve well during or after use. 0 points: If the cleanser dissolves or crumbles during or after use and you feel it is not good. The total scores of the 10 people were calculated and the evaluation was carried out as follows: ◎: Total score is 25-30 points 〇: Total score is 15 to 24 points △: Total score is 5 to 14 points ×: Total score is 4 points or less

[0070] (5) Ease of forming into bars When the prototype was actually manufactured, the state of molding into a bar was evaluated and scored. ◎: A good bar was formed (hard enough to be stamped). 3 points 〇: Bar molding was possible (the hardness of the mold is delicate). 2 points △: The bar could be molded, but it was too hard to be stamped. 1 point ×: Hardness that does not allow bar forming. 0 points

[0071] [Table 1]

[0072] [Table 2]

[0073] In the above Tables 1 and 2, Examples 1 to 9 and Comparative Examples 1 to 6 are listed in an order in which the content of component (B) increases in ascending order of numbers.

[0074] The solid detergent of the present invention is not only suitable for the "machine kneading" manufacturing method, but also requires both the properties of "resistance to melting" and "ease of forming into bars" in order to obtain good usability as a solid detergent. Therefore, focusing on Comparative Examples 1 and 2, it can be seen that these two properties cannot be satisfied when the content of component (B): clay mineral is 19% by mass or less with respect to the total mass of all components. On the other hand, in Example 1, in which the content of component (B) is 20% by mass, the properties of "resistance to melting" and "ease of forming into bars" are improved to a level that allows mass production as a solid detergent. It is also inferred from Examples 2 to 9 and Comparative Examples 3 to 6 that these two properties are improved when the content of component (B) is 20% by mass or more. However, these two effects need to be considered together with the effects of the content of components other than component (B), such as component (D), and cannot be obtained by simply increasing the content of component (B). For example, as shown in Comparative Examples 5 and 6, when the content of component (B) exceeds approximately 35-40% by mass, the characteristic of "ease of forming into a bar" is lost. Although not specifically shown in the Comparative Examples in Table 2, when the content of component (B) exceeds 45% by mass, the effect of "resistance to melting and crumbling" is significantly reduced, and it is not possible to form a bar into a solid cleansing agent. Therefore, in the present invention, not only is it necessary to contain the above-mentioned components (A) to (D) listed in the examples in Table 1, but it is also necessary to specify the content of component (B) in the range of 20-45% by mass with respect to the total mass of all components as an essential requirement for producing a solid cleansing agent.

[0075] As shown in Examples 1 to 9 of Table 1, it is preferable to use bentonite as the main component of the clay mineral (B) contained in the solid cleansing agent of the present invention. In this case, the bentonite is contained in an amount of 50 mass% or more, preferably 70 mass% or more, based on the total mass of the clay mineral. As shown in Examples 5 to 9, it is preferable to use silicate (Al / Mg) in combination with bentonite.

[0076] Next, the ranges of the contents of the above-mentioned components (A) to (D) contained in the solid cleanser of the present invention will be described.

[0077] Component (A): A non-soap anionic surfactant fails the "ease of lathering" property, which affects the cleaning power, at 3% by mass as shown in Comparative Example 6. In contrast, at 9% by mass as shown in Example 2, the "ease of lathering" property was improved. Also, as shown in Comparative Examples 1 to 3, the content of component (A) tends to increase as the content of component (A) increases, but conversely, the effects of "resistance to melting" and "ease of bar molding" required for the production of solid detergents are no longer obtained. This is thought to be due to the separation, dispersion, or exudation of component (A), or the effect of the content of component (D) being far beyond 10% by mass, which is specified as the preferred range in the present invention, but the details are unknown. Therefore, the content of component (A) is set within the range of 9 to 45% by mass with respect to the total mass of all components, but 15 to 30% by mass is practical as shown in Examples 1 to 9.

[0078] In addition, in Comparative Examples 4 and 5 in Table 2, the contents of component (A) were 18% by mass and 10% by mass, respectively, but the effect of "ease of whipping" was hardly obtained. This is probably due to the influence of the high content of component (D) as shown in Comparative Examples 4 and 5.

[0079] In the present invention, the content of component (C): amphoteric surfactant can be selected within the range of 1 to 30% by mass, but is preferably within the range of 5 to 20% by mass, as shown in the examples in Table 1. When the content of component (C) exceeds 20% by mass, both the properties of "resistance to melting" and "ease of forming into bars" required for producing a solid cleansing agent are significantly reduced, as shown in Comparative Examples 1 and 2. This is thought to be because, as in the case of component (A), as the content of component (C) increases, separation, dispersion, and exudation of component (C) become more pronounced, but the details are unknown.

[0080] Component (D): As shown in Comparative Examples 4 and 5 in Table 2, if the content of any one or more compounds selected from the group consisting of fatty acids, fatty acid triglycerides, and fatty acid triglyceride esters is 10% by mass or more, the "ease of lathering" that affects the cleaning power is not acceptable, and if it exceeds 10% by mass, the property of "ease of bar molding" is also reduced. Therefore, the content of component (D) contained in the solid cleanser of the present invention is selected within the range of 1 to 10% by mass with respect to the total mass of all components, as can be seen from the evaluation results of the Examples in Table 1 and the Comparative Examples in Table 2. Furthermore, in order to improve the "moist feeling after use (warmth to the skin)", a range of 4 to 8% by mass is practical, as shown in Examples 3 and 6 to 8 in Table 1. In addition, by containing component (D) within the range of 4 to 8% by mass, the dispersibility of the clay mineral of component (B) is increased, and the viscosity of the solid cleanser is improved, so that the effect of improving the property of "resistance to melting and crumbling" is also obtained (Comparison between Examples 3, 6 to 8 and Comparative Example 3).

[0081] The solid cleansing agent of the present invention must contain the above-mentioned components (A), (B), (C) and (D), and further contains component (E) to improve the skin feel (skin compatibility, skin smoothness and moisturizing feel) both during and after use (compare Examples 6 and 7). The content of component (E) in the solid cleansing agent of the present invention is selected within the range of 3 to 30% by mass based on the total mass of all components, but as shown in the examples in Table 1, 5 to 25% by mass is preferred.

[0082] On the other hand, the above-mentioned component (F) does not need to be included as long as the pH of the solid cleanser is in the weak acid range of 6.0 or less. However, as can be seen from the comparison between Examples 3 and 4, the "moist feeling after use" could be improved by including component (F) and setting the pH slightly lower than 6.0 and in the weak acid range close to human skin. This is thought to be because the solid cleanser of Example 4 has a pH close to 6.0, and by including 1 mass % of citric acid of component (F) as a pH adjuster, the effect of lowering the pH to a value close to that of human skin was obtained. Since component (F) basically functions as a pH adjuster, it is practical to limit the content to 5 mass % or less of the total mass of all components, as shown in the examples of Table 1.

[0083] <Comparative Example 7> In Example 2, a soap-based component containing an anionic surfactant of a fatty acid sodium salt was added as component (A), and the content of component (C) was changed from 7% by mass to 8% by mass. Then, a solid cleansing agent was obtained using the same manufacturing method as in Example 2.

[0084] The contents of the components in Comparative Example 7 are as follows: (A) Sodium lauroyl sarcosine: 9% by mass Soap-based ingredients: 23% by weight (B) Bentonite: 26% by mass (C) Cocamidopropyl betaine: 8% by mass (D) (Sunflower seed oil / hydrogenated sunflower seed oil) esters: 2% by mass Palmitic acid: 2% by weight (E) PEG-75 stearate: 8% by mass Laureth 50: 5% by weight (F) Citric acid: 1% by mass Other ingredients: 16% by weight

[0085] The solid detergent of Comparative Example 7 was subjected to pH measurement together with the solid detergent of Example 2. The pH measurement was performed using a pH meter capable of directly measuring the pH of a solid or semi-solid (e.g., HORIBA Canister LAB pH meter, manufactured by Horiba, Ltd.). As a result of the pH measurement, the solid detergent of Example 2 had a pH of 6.0, whereas the solid detergent of Comparative Example 7, even though it contained citric acid as a pH adjuster, had a pH of 8.9, exhibiting alkalinity.

[0086] Comparison Example 7 was evaluated in the same manner as Example 2 for the same items. As a result, the items of "ease of whipping," "resistance to melting and crumbling," and "ease of forming into bars" were each rated (△), and the results for these items were almost the same as those for Example 2.

[0087] However, the evaluation results for the items "smooth feeling on the skin during use" and "moist feeling after use" were "△" and "×", respectively, indicating that the skin feel was inferior to that of Example 2. Thus, the solid cleanser of Comparative Example 7 was judged to be a reject, and it was confirmed that the object of the present invention could not be achieved.

[0088] <Example 10> Based on the evaluation results of Examples 1 to 9 and Comparative Examples 1 to 7 using Pelican Soap's "Prototype Mini Prodder," solid body cleansers were prepared according to the following recipes in accordance with the manufacturing process shown in Figure 1 using actual solid soap manufacturing equipment at Pelican Soap's Saitama factory, and the feasibility of actual manufacturing was evaluated.

[0089] (A) Sodium lauroyl sarcosine 18% by mass (B) Bentonite 27% by mass Silicate (Al / Mg) 7% by mass (C) Cocamidopropyl betaine 18% by mass (D) (Sunflower seed oil / hydrogenated sunflower seed oil) esters 2% by mass Palmitic acid 3.5% by mass (E) PEG-75 stearate 15% by mass Laureth-50 3.5% by weight (F) Citric acid 2.5% by mass (Other ingredients) Silica 0.7% by mass Hydrolyzed guar 1% by mass PEG-90M 0.01% by mass Sodium benzoate 0.25% by mass Gluconomannan 0.2% by mass Oligosaccharides 0.1% by mass Raffinose 0.3% by mass Fragrance 0.6% by mass water remainder Total blending amount 100% by mass

[0090] The solid body cleanser of this Example 10 was judged to be satisfactory in terms of functionality and usability as a cleanser, as it was easy to lather, had a smooth feel on the skin during use, felt moisturized after use, did not easily dissolve and crumble during use and storage, and could be molded into bars and molded using a mechanical kneading stone test manufacturing device.

[0091] As described above, the solid cleansing agent according to the embodiment of the present invention can be manufactured by the highly productive "machine kneading" manufacturing method, and when used by rubbing directly against the skin, it feels good on the skin and has a smooth feel, and when used by lathering with the hands, it also feels good on the skin and has a smooth feel, and leaves the skin feeling excellently moist after drying. It was also confirmed that the solid cleansing agent according to the embodiment of the present invention can be fully mass-produced by the "machine kneading" manufacturing method.

Claims

1. Component (A): a non-soap anionic surfactant; Component (B): clay minerals, Component (C): an amphoteric surfactant, Component (D): one or more compounds selected from the group consisting of fatty acids, fatty acid triglycerides, and fatty acid triglyceride esters, A solid cleansing agent, characterized in that the component (B): clay mineral is contained in an amount of 20 to 45 mass % based on the total mass of all components.

2. 2. The solid cleansing agent according to claim 1, further comprising a nonionic surfactant (E).

3. The solid cleanser according to claim 1, characterized in that one or more compounds selected from the group consisting of component (A): a non-soap anionic surfactant, component (B): a clay mineral, component (C): an amphoteric surfactant, and component (D): a fatty acid, a fatty acid triglyceryl, and a fatty acid triglyceryl ester are contained in amounts of 9 to 40% by mass, 20 to 40% by mass, 1 to 30% by mass, and 1 to 10% by mass, respectively, relative to the total mass of all the components.

4. 4. The solid cleanser according to claim 3, characterized in that it contains component (E): a nonionic surfactant, and that component (E) is contained in an amount of 3 to 30 mass % based on the total mass of all components.

5. The solid cleanser according to claim 4, characterized in that it contains a component (F): a pH adjuster for adjusting the pH of the solid cleanser to a weak acidity of 3.0 to 6.0, and the component (F): the pH adjuster is contained in an amount of 5 mass % or less based on the total mass of all components.

6. The solid cleanser according to any one of claims 1 to 5, characterized in that the component (B): clay mineral contains bentonite in an amount of 50 mass% or more based on the total mass of the component (B): clay mineral.

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