Granular bath composition

Abstract

To provide a formulation with superior formulation stability for granular bath compositions containing magnesium sulfate heptahydrate, effectively suppressing the traditional issue of time-dependent solidification during storage.SOLUTION: A granular bath composition contains (A) magnesium sulfate heptahydrate and (B) water, the content of component (A) is 80 mass% or more, and the content of component (B) is 0.5-20 pts.mass relative to 100 pts.mass of the component (A). The granular bath composition is resistant to time-dependent solidification.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a granular bath composition having excellent anti-caking properties. [Background technology]

[0002] The basic effect of bath additives is to enhance the warming and cleansing effects obtained by bathing itself, and based on this idea, the specific efficacy that can be displayed or advertised on products is stipulated in the Pharmaceuticals and Medical Devices Act. Representative examples of such bath additives include inorganic salts, more specifically, sodium sulfate, magnesium sulfate, sodium carbonate, sodium bicarbonate, calcium carbonate, sodium chloride, etc. Bath additives are also prepared in various dosage forms such as powder, granules, and granular. Inorganic salts, which are commonly used as ingredients of bath additives, combine with proteins on the surface of the skin to form a membrane, and this membrane is said to have a high heat retention effect after bathing and prevent the body from cooling down easily because the membrane prevents the body from losing heat (Non-Patent Document 1).

[0003] In addition, among these inorganic salts, bath additives containing magnesium sulfate have been reported to have the effect of allowing magnesium to be absorbed into the body through the skin and to relieve rheumatic pain (Non-Patent Document 2). [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Effects and mechanisms of bath salts, [online], Japan Bath Salts Industry Association [Searched on May 24, 2023], Internet<URL:https: / / www.jbia.org / knowledge3.html> [Non-Patent Document 2] Dr RH Waring, School of Biosciences, University of Birmingham, Report on Absorption of Magnesium Sulfate (Epsom Salts) across the Skin, [online], [Retrieved May 24, 2023], Internet<URL:https: / / epsomsalt.jp / wp-content / uploads / 2021 / 08 / ReportsofBirmingham.pdf> Summary of the Invention [Problem to be solved by the invention]

[0005] Various inorganic salt bath additives are commercially available, which are essentially granular compositions made of the inorganic salts, and contain trace amounts of fragrances, etc., for the purpose of providing a relaxation effect. Naturally, magnesium sulfate bath additives are also prepared in the same form.

[0006] However, the granular bath composition of magnesium sulfate heptahydrate, which is widely used as a magnesium sulfate bath additive, has the property of caking over time even at room temperature during storage, making it difficult to maintain the granular form, and in this respect, formulation considerations for formulation have not been fully carried out. Furthermore, such caking over time tends to be more noticeable at high temperatures, that is, caking tends to accelerate at high temperatures.

[0007] Therefore, an object of the present invention is to provide a formulation that has good formulation stability in that it suppresses the problem of solidification over time during storage, which has been a problem with granular bath compositions containing magnesium sulfate heptahydrate. [Means for solving the problem]

[0008] After extensive research, the present inventors discovered that by blending a specified amount of water into a granular bath composition containing magnesium sulfate heptahydrate, caking over time during storage can be suppressed.

[0009] That is, the present invention provides the following aspects. Item 1. A granular bath composition comprising (A) magnesium sulfate heptahydrate and (B) water, the content of the component (A) being 80 mass% or more, and the content of the component (B) being 0.5 to 20 mass parts per 100 mass parts of the component (A). Item 2. The granular bath composition according to Item 1, further comprising (C) humidity-regulating particles. Item 3. The granular bath composition according to Item 2, wherein the component (C) is silica. Item 4. The granular bath composition according to Item 2 or 3, wherein the content of the component (C) is 0.1 to 8 parts by mass per part by mass of the component (B). Item 5. The granular bath composition according to any one of Items 1 to 4, wherein the 50% cumulative frequency diameter of the component (A) is 950 to 1300 μm. Item 6. The granular bath composition according to any one of Items 1 to 5, wherein the component (A) has a {(90% cumulative frequency diameter−10% cumulative frequency diameter) / 50% cumulative frequency diameter} value of 0.8 to 2. Item 7. The BET specific surface area of ​​the component (C) is 150 to 250 m 2 Item 7. The granular bath composition according to any one of Items 2 to 6, wherein the composition is in a concentration of 1:1 or more. Item 8. The granular bath composition according to any one of Items 1 to 7, further comprising (D) a fragrance and (E) a nonionic surfactant. Item 9. The granular bath composition according to Item 8, wherein the component (E) is a polyoxyethylene sorbitan fatty acid ester and / or a sorbitan fatty acid ester. Item 10. The granular bath composition according to Item 8 or 9, wherein the content of the component (E) per 1 part by mass of the component (D) is 0.01 to 0.1 part by mass. Effect of the Invention

[0010] The granular bath composition of the present invention exhibits excellent storage stability by preventing solidification over time, and exhibits the remarkably excellent effect of being able to maintain the granular form. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The granular bath composition of the present invention is characterized by comprising (A) magnesium sulfate heptahydrate and (B) water, the content of the component (A) being 80% by mass or more, and the content of the component (B) being 0.5 to 20 parts by mass per 100 parts by mass of the component (A). The granular bath composition of the present invention will be described in detail below. In the present invention, "granular" means having a particle shape such as powder, granules, or pellets.

[0012] (A) Magnesium sulfate heptahydrate The granular bath composition of the present invention contains magnesium sulfate heptahydrate as component (A).

[0013] The particle size of the component (A) used is not particularly limited as long as the desired effect can be achieved, but the 50% cumulative frequency diameter (i.e., D50) may be, for example, in the range of 950 to 1300 μm, and from the viewpoint of maximizing the effect of the present invention, the range of 1000 to 1250 μm is preferable, more preferably 1050 to 1200 μm, and even more preferably 1100 to 1150 μm. Note that D50 indicates the particle size at cumulative 50 volume % of the cumulative particle size distribution measured by a laser diffraction scattering type particle size distribution measurement method.

[0014] The particle size distribution of component (A) is not particularly limited as long as the desired effect can be achieved, but when the 90% cumulative frequency diameter is D90 and the 10% cumulative frequency diameter is D10, {(D90-D10) / D50} may be, for example, in the range of 0.8 to 2, and from the viewpoint of maximizing the effect of the present invention, it is preferably in the range of 0.9 to 1.7, more preferably 1 to 1.5, and even more preferably 1.1 to 1.4. Note that D90 and D10 respectively indicate the particle size at cumulative 90 volume % and cumulative 10 volume % from the small particle diameter side of the cumulative particle size distribution measured by a laser diffraction scattering type particle size distribution measurement method.

[0015] In the present invention, a commercially available product can be used for blending the above component (A). The commercially available product of component (A) may be a single material of magnesium sulfate heptahydrate or a mixed material of magnesium sulfate heptahydrate and other components, as long as the desired effect is exhibited, but is preferably a single material of magnesium sulfate heptahydrate.

[0016] The content of the (A) component in the granular bath composition of the present invention is 80% by mass or more in 100% by mass of the composition. The granular bath composition of the present invention exhibits a remarkably excellent effect in preventing caking during storage by combining with the components described below, so that even in a formulation containing a very large amount of magnesium sulfate heptahydrate, caking can be effectively prevented. From this viewpoint, the content of the (A) component is preferably 85% by mass or more or 88% by mass or more in 100% by mass of the composition, more preferably 90% by mass or more, 92% by mass or more or 94% by mass or more, and even more preferably 95% by mass or more. The content of the (A) component in the bath composition of the present invention is not particularly limited in its upper limit as long as a predetermined amount of the (B) component can be blended, but is, for example, 99.5% by mass or less, 99% by mass or less, or 98% by mass or less in 100% by mass of the composition.

[0017] (B) Water The granular bath composition of the present invention contains water as component (B). The component (B) used is not particularly limited, but is preferably purified water. In the present invention, by combining the component (B) with the component (A), solidification during storage can be suppressed. More specifically, it is believed that the inclusion of the component (B) suppresses the release of bound water in the component (A), thereby suppressing solidification.

[0018] The content of the (B) component in the granular bath composition of the present invention is 0.5 to 20 parts by mass per 100 parts by mass of the (A) component, from the viewpoint of exerting the desired caking inhibition effect and from the viewpoint of forming a granular formulation.

[0019] In the granular bath composition of the present invention, from the viewpoint of improving the caking prevention effect, the content of the above-mentioned (B) component per 100 parts by mass of the above-mentioned (A) component is preferably 0.8 to 20 parts by mass or 0.9 to 20 parts by mass, more preferably 1 to 20 parts by mass, even more preferably 1.5 to 20 parts by mass, 1.8 to 20 parts by mass, 1.9 to 20 parts by mass, or 2 to 20 parts by mass.

[0020] In the present invention, from the viewpoints of reducing the wet feeling of the composition itself and improving usability in addition to the caking suppression effect, it is preferable to adjust the content of the (B) component to 0.5 to 16 parts by mass, preferably 0.5 to 12.5 parts by mass, 0.5 to 7.5 parts by mass, more preferably 0.5 to 4.7 parts by mass, and even more preferably 0.5 to 4 parts by mass, 0.5 to 3.5 parts by mass, 0.5 to 3 parts by mass, 0.5 to 2.3 parts by mass, or 0.5 to 2.2 parts by mass, relative to 100 parts by mass of the (A) component.

[0021] The specific content of component (B) in the bath composition of the present invention depends on the content of component (A) and the content of component (B) per 100 parts by mass of component (A), but is preferably 0.5 to 15 mass% or 0.7 to 10 mass%, more preferably 0.9 to 6 mass%, and even more preferably 1 to 4 mass%, 1.2 to 3 mass%, or 1.5 to 2.5 mass%.

[0022] (C) Humidity-regulating particles The granular bath composition of the present invention preferably further contains humidity-regulating particles as component (C). In the present invention, "humidity-regulating particles" refers to water-insoluble particles that exhibit both the functions of absorbing and releasing moisture, or water and oil. In a preferred embodiment of the present invention, the use of component (C) reduces the moist feeling of the granular bath composition itself.

[0023] Specific examples of the (C) component include silicate minerals such as silica (silicon dioxide), calcium silicate, mica, talc, and sericite; white activated carbon, cyclodextrin, and crystalline cellulose. These (C) components may be used alone or in appropriate combination of two or more. In the present invention, in addition to the above effects, it is preferable to use silicate minerals, and among them, it is more preferable to use silica (silicon dioxide), from the viewpoint of maximizing the unique effects of the present invention.

[0024] The BET specific surface area of ​​the component (C) used is not particularly limited as long as the desired effect can be achieved, but is, for example, 150 to 250 m 2 / g, and from the viewpoint of maximizing the effects of the present invention, the range of 160 to 240 m 2 / g, and more preferably 170 to 230 m 2 / g, more preferably 180 to 220 m 2 / g. The BET specific surface area is measured in accordance with ISO 5794 / 1.

[0025] In the present invention, a commercially available product can be used for blending the above component (C). The commercially available product of component (C) may be a single material of humidity-conditioning particles or a mixed material of humidity-conditioning particles and other components, and is not particularly limited as long as the desired effect is exhibited, but it is preferably a single material of humidity-conditioning particles.

[0026] The content of the (C) component in the granular bath composition of the present invention is not particularly limited, but is, for example, 0.1 to 15% by mass in 100% by mass of the composition. From the viewpoint of further reducing the wet feeling of the composition itself, the content of the (C) component is preferably 0.5 to 15% by mass in 100% by mass of the composition, more preferably 0.7 to 15% by mass, even more preferably 1 to 15% by mass or 1.5 to 15% by mass, and even more preferably 1.8 to 15% by mass. In addition, from the viewpoint of suppressing scattering of the (C) component itself, the content of the (C) component is preferably 0.1 to 10% by mass in 100% by mass of the composition, more preferably 0.1 to 6.5% by mass, even more preferably 0.1 to 6% by mass or less, and even more preferably 0.1 to 5.5% by mass, 0.1 to 4% by mass, 0.1 to 3% by mass, or 0.1 to 2.5% by mass.

[0027] In the granular bath composition of the present invention, the content of the above-mentioned component (C) can be blended so as to be, for example, 0.1 to 8 parts by mass per part by mass of the above-mentioned component (B).

[0028] Furthermore, from the viewpoint of further reducing the wet feeling of the composition itself, or in addition to that viewpoint, from the viewpoint of suppressing thickening of the composition, the content of the (C) component per 1 part by mass of the (B) component can be blended so as to be preferably 0.5 to 8 parts by mass, more preferably 0.67 to 8 parts by mass, or 0.7 to 8 parts by mass, and even more preferably 0.77 to 8 parts by mass, 0.79 to 8 parts by mass, 0.8 to 8 parts by mass, 0.85 to 8 parts by mass, 0.9 to 8 parts by mass, or 0.95 to 8 parts by mass.

[0029] Furthermore, from the viewpoint of suppressing scattering of the (C) component itself, the content of the (C) component relative to 1 part by mass of the (B) component is preferably 0.77 to 6 parts by mass, 0.77 to 4 parts by mass, or 0.77 to 3.5 parts by mass, more preferably 0.77 to 2.3 parts by mass, 0.77 to 2 parts by mass, 0.77 to 1.5 parts by mass, or 0.77 to 1.2 parts by mass. The effect of suppressing scattering of the (C) component itself by satisfying such a ratio between the content of the (B) component and the (C) component can suppress scattering of the (C) component itself during the production and use of the granular bath composition, thereby reducing concerns specific to the granular bath composition. In particular, the scattering suppression effect during use is extremely effective when considering the impact on the human body.

[0030] In a preferred form of the granular bath composition of the present invention, by satisfying the essential components and requirements described above, it is possible to exhibit significantly superior effects in terms of the storage stability of the formulation, suppressing solidification over time, which was a conventional problem, and maintaining the granular form, while also solving various problems and concerns specific to granular bath compositions.

[0031] (D)Fragrance The granular bath composition of the present invention may further contain a fragrance as component (D).

[0032] Examples of (D) include terpene fragrances (e.g., limonene, citral, geraniol, citronellol, nerol, linalool, myrcene, pinene, caryophyllene, terpinene, terpinolene, terpinolene, and carene), ester fragrances (e.g., methyl dihydrojasmonate, linalyl acetate, benzyl benzoate, and neryl acetate), aldehyde fragrances (e.g., p-ethyl-α,α-dimethylhydrocinnamaldehyde, α-hexylcinnamaldehyde, and the like), ketone fragrances (e.g., trans-p-menthan-3-one, and the like), and oxide fragrances (e.g., 1,8-cineole, 4,4a,5,9b-tetrahydroindeno[1,2-d]-1,3-dioxine, and the like). These components (D) may be used alone or in appropriate combination of two or more.

[0033] The content of component (D) in the granular bath composition of the present invention is, for example, 0.1 to 1.5 mass %, preferably 0.3 to 1 mass %, and more preferably 0.45 to 0.8 mass %, based on 100 mass % of the composition.

[0034] (E) Nonionic surfactant The granular bath composition of the present invention may further contain a nonionic surfactant as component (E). In a preferred embodiment of the present invention, the use of component (E) allows the composition containing a fragrance (component (D)) to have a long-lasting fragrance without adversely affecting the storage stability of the formulation (storage stability other than caking inhibition).

[0035] Examples of the (E) component that can be used include polyoxyethylene sorbitan fatty acid esters, sorbitan fatty acid esters, polyoxyethylene hydrogenated castor oil, polyoxyethylene polyoxypropylene alkyl ethers, glycerin fatty acid esters, polyglycerin fatty acid esters, sucrose fatty acid esters, polyethylene glycol fatty acid esters, polyoxyethylene sorbitol fatty acid esters, polyoxyethylene alkyl ethers, etc. These (E) components may be used alone or in appropriate combination of two or more. In the present invention, it is preferable to use polyoxyethylene sorbitan fatty acid esters and sorbitan fatty acid esters from the viewpoint of improving the fragrance durability in a composition containing a fragrance ((D))

[0036] Polyoxyethylene sorbitan fatty acid ester is a compound in which ethylene oxide is condensed with a sorbitan fatty acid ester, which is a monoester, diester, or triester of a fatty acid and sorbitan. The number of carbon atoms of the fatty acid constituting the polyoxyethylene sorbitan fatty acid ester is not particularly limited as long as the desired effect can be exhibited, but is preferably, for example, 8 to 30, more preferably 10 to 22, and even more preferably 16 to 20. The average number of moles of ethylene oxide added condensed to the polyoxyethylene sorbitan fatty acid ester is also not particularly limited, but is preferably, for example, 6 to 160, more preferably 10 to 60, even more preferably 10 to 30, and even more preferably 15 to 25.

[0037] Specific examples of polyoxyethylene sorbitan fatty acid esters include polysorbate 20 (polyoxyethylene (20) sorbitan monopalmitate), polysorbate 40 (polyoxyethylene (20) sorbitan monolaurate), polysorbate 60 (polyoxyethylene (20) sorbitan monostearate), polysorbate 65 (polyoxyethylene (20) sorbitan tristearate), polysorbate 80 (polyoxyethylene (20) sorbitan monooleate), polysorbate 85 (polyoxyethylene (20) sorbitan trioleate), PEG-6 sorbitan stearate, PEG-20 sorbitan isostearate, PEG-6 sorbitan oleate, and polysorbate 85. These polyoxyethylene sorbitan fatty acid esters may be used alone or in appropriate combination of two or more.

[0038] Sorbitan fatty acid esters are monoesters, diesters, or triesters of fatty acids and sorbitan. Specific examples of sorbitan fatty acid esters include sorbitan monostearate, sorbitan monoisostearate, sorbitan sesquiisostearate, sorbitan sesquioleate, sorbitan monooleate, sorbitan trioleate, sorbitan monopalmitate, and sorbitan monolaurate. These sorbitan fatty acid esters may be used alone or in appropriate combination of two or more.

[0039] The content of component (E) in the granular bath composition of the present invention is preferably 0.005 to 0.0 mass%, more preferably 0.008 to 0.02 mass%, and even more preferably 0.01 to 0.015 mass%, based on 100 mass% of the composition, from the viewpoint of sustaining the scent in a composition containing a fragrance (component (D)).

[0040] The content of the (E) component in the granular bath composition of the present invention per 1 part by mass of the (D) component is preferably 0.01 to 0.1 part by mass, more preferably 0.013 to 0.08 parts by mass, even more preferably 0.015 to 0.05 parts by mass, and even more preferably 0.018 to 0.03 parts by mass, from the viewpoint of improving the fragrance persistence of the (D) component.

[0041] Bath additives such as the granular bath composition of the present invention are also required to have a relaxation effect, and various fragrances are used to achieve this effect. However, when fragrance components are added in consideration of the persistence of the scent, there is also the problem that the storage stability (other than the caking inhibition property) of the granular bath composition is adversely affected. A preferred embodiment of the granular bath composition of the present invention is also intended to solve this problem.

[0042] Other Ingredients The granular bath composition of the present invention may contain other components that are typically incorporated into granular bath compositions, in addition to the components (A) and (B), as well as the components (C), (D) and / or (E) that are incorporated as necessary, so long as the effects of the present invention are not impaired.

[0043] Specific examples of other components include inorganic salts such as sodium sulfate, sodium carbonate, sodium bicarbonate, calcium carbonate, magnesium oxide, sodium metaphosphate, sodium chloride, calcium chloride, magnesium chloride, etc.; sugars such as trehalose, erythritol, lactose, reduced starch syrup, glucose, etc.; extracts such as herbal extracts and other plant extracts; oils and fats; alcohols; polyhydric alcohols; surfactants other than component (E); colorants; moisturizers; cooling agents, etc.

[0044] The granular bath composition of the present invention preferably contains fragrance and / or colorant as other ingredients, and more preferably contains fragrance and / or colorant and does not contain any ingredients other than fragrance and colorant.

[0045] Formulation etc. The formulation of the granular bath composition of the present invention is not particularly limited as long as it is a granular composition. In addition, the granular bath composition of the present invention may be one that is not fixed and exhibits fluidity when an external force is applied, and may be wet due to the above-mentioned (B) component. The properties of the granular bath composition of the present invention include, for example, a slightly moist but almost smooth granular form, a not smooth but moist granular form, a state in which viscosity is generated due to moisture, a sleet-like form, etc., and it is desirable that the composition be a slightly moist but almost smooth granular form, or a not smooth but moist granular form.

[0046] The method for producing the granular bath composition of the present invention is not particularly limited, but may be, for example, a known method. Specifically, the above-mentioned components may be mixed and stirred using a ribbon mixer, but the method is not limited to these methods.

[0047] The granular bath composition of the present invention can be stored in any suitable container. The container is not particularly limited, and may be a packaged container that can be opened and closed freely, or a single-use individually packaged container. EXAMPLES

[0048] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The blend amounts are expressed in "mass %" unless otherwise specified.

[0049] <Sample preparation> Bath compositions of Examples 1 to 16 and Comparative Examples 1 to 6 were prepared in a conventional manner according to the compositions shown in Tables 1 and 2, and the resulting bath compositions were used as samples for the following evaluations. The results are shown in Tables 1 and 2.

[0050] The particle size and particle size distribution of component (A) were measured using a laser diffraction scattering type particle size distribution analyzer LA-950 (manufactured by Horiba, Ltd.) and found to be D50 of 1114 μm and {(D90-D10) / D50} of 1.21. The BET specific surface area of ​​component (C) measured in accordance with ISO 5794 / 1 was approximately 200 m 2 / g(180~220m 2 / g). A fragrance composition was used to blend component (D). This fragrance composition contains, as component (D), d-limonene, citral, methyl dihydrojasmonate, p-ethyl-α,α-dimethylhydrocinnamaldehyde, α-hexylcinnamaldehyde, geraniol, citronellol, linalyl acetate, nerol, linalool, benzyl benzoate, myrcene, β-pinene, β-caryophyllene, γ-terpinene, α-pinene, trans-p-menthan-3-one, neryl acetate, 1,8-cineole, terpinolene, 3-carene, and 4,4a,5,9b-tetrahydroindeno[1,2-d]-1,3-dioxine, and contains a total of 65.2 parts by mass or more of component (D) per 100 parts by mass of the fragrance composition.

[0051] <Properties immediately after preparation> 3.0 g of each sample obtained in the Examples and Comparative Examples was placed within a 2 cm radius area at the center of a horizontal glass plate measuring 20 cm square. The glass plate was then tilted in stages from the horizontal position, and the glass tilt angle required for the entire sample to slide off within 3 seconds was measured.

[0052] The degree of free-flowing was evaluated with a number from 1 to 5 according to the classification of glass inclination angle shown below. The smaller the number, the more free-flowing the glass is, and the closer it is to a dry state. On the other hand, the more free-flowing the glass is, the greater the risk of it scattering, so the following classification of 2 to 4 is preferable, 2 to 3 is more preferable, and 2 is the most preferable.

[0053] (Classification of Inclination Angle) 1:30° or less 2: Over 30° and within 45° 3: Over 45° and within 60° 4: Over 60° and within 75° 5: Over 75° (also applies if it does not fall completely within 3 seconds)

[0054] <Evaluation of anti-caking properties> 100 g of each sample obtained in the examples and comparative examples was filled into an aluminum pouch measuring 15 cm long x 11 cm wide, and the pouch was then sealed and left to stand in a thermostatic chamber at 50°C for storage. The time during which caking could be suppressed (i.e., the time required for caking) was measured. Caking was defined as a state in which the entire bath composition lost its fluidity against external forces and became one lump. If the sample did not caking for 3 days or more under the storage conditions, it was determined that the caking suppression property had passed.

[0055] <Evaluation during actual use-1 (condition of the agent)> 100 g of each sample obtained in the Examples and Comparative Examples was packed into an aluminum pouch measuring 15 cm long x 11 cm wide, then the pouch was sealed and left to stand at room temperature for 1 hour. After standing, the pouch was opened and the condition of the packed agent was visually evaluated according to the following criteria.

[0056] (judgment criteria) -: Viscosity increasing effect due to silica is observed +: Slight thickening effect due to silica is observed ++: No thickening effect due to silica is observed

[0057] <Evaluation during actual use-2 (scattering of dust)> After the evaluation in Evaluation-1 during actual use described above, the agent was actually poured into the water bath; specifically, the aluminum pouch was poured while shaking, and the degree of dust scattering upon pouring was visually evaluated according to the following criteria.

[0058] (judgment criteria) ×: A lot of silica dust scatters during use. △: Silica dust scatters during use. 〇: A small amount of silica dust is scattered during use. ◎: No silica dust scattering during use

[0059] [Table 1]

[0060] [Table 2]

[0061] [Table 3]

[0062] Among the bath compositions containing component (A) and Comparative Examples 1 to 6 which do not satisfy the essential constituent requirements of the present invention, those which do not contain component (B) (Comparative Examples 1 and 3, Commercial Products 1 and 2) and those which contain component (B) but whose content does not meet the specified range (Comparative Examples 2, 4, and 5) did not obtain the desired caking inhibition properties and caking occurred in a short time. This is considered to be due to the liberation of bound water in component (A) during storage at high temperatures, causing caking. Moreover, in the case of the composition containing component (B) but whose content exceeded the specified range (Comparative Example 6), granular properties could not be obtained.

[0063] In contrast, the bath compositions containing component (A) and satisfying the essential constituent requirements of the present invention (Examples 1 to 16) exhibited the desired caking inhibition. This is believed to be due to the fact that the release of bound water in component (A) was suppressed during high-temperature storage. Furthermore, among Examples 1 to 11, Examples 3 to 6 and 8 to 16, which contained a more limited ratio of component (B), exhibited particularly excellent caking inhibition.

[0064] Among Examples 1 to 16, those containing the component (C) (Examples 7 to 15) had better properties than those not containing the component (C) (Examples 1 to 6, Example 16) because moisture was absorbed into the component (C) and the moisture was conditioned. Among them, Examples 7 to 14, which contained a limited ratio of the component (C), showed an improved level of moisture conditioning, were more excellent in terms of dryness, and provided an excellent feel when used. Furthermore, among Examples 7 to 14, Examples 9, 11, 12, 13, and 14, which contained a further limited amount and ratio of the component (C), did not scatter dust due to the component (C) and had even more excellent properties both during production and use of the bath composition.

[0065] Furthermore, among Examples 1 to 16, Examples 7 to 16, which contained the components (D) and (E), were excellent in terms of the persistence of the fragrance due to the component (D). However, even when a granular bath composition was prepared that contained the component (D) but not the component (E), such as the compositions of Commercial Products 1 and 2, the persistence of the fragrance was not sufficient.

Claims

1. A granular bath composition comprising (A) magnesium sulfate heptahydrate and (B) water, the content of the (A) component being 80 mass% or more, and the content of the (B) component being 0.5 to 20 mass parts per 100 mass parts of the (A) component.

2. The granular bath composition according to claim 1, further comprising (C) humidity-regulating particles.

3. The granular bath composition according to claim 2, wherein the component (C) is silica.

4. 4. A granular bath composition according to claim 2 or 3, wherein the content of said component (C) per 1 part by mass of said component (B) is 0.1 to 8 parts by mass.

5. The granular bath composition according to claim 1 or 2, wherein the 50% cumulative frequency diameter of the component (A) is 950 to 1,300 μm.

6. 3. The granular bath composition according to claim 1, wherein the (A) component has a value of {(90% cumulative frequency diameter - 10% cumulative frequency diameter) / 50% cumulative frequency diameter} of 0.8 to 2.

7. The BET specific surface area of ​​the component (C) is 150 to 250 m 2 The granular bath composition according to claim 2 or 3, wherein the granular bath composition is 0.01 to 0.1 g.

8. The granular bath composition according to claim 1 or 2, further comprising (D) a fragrance and (E) a nonionic surfactant.

9. The granular bath composition according to claim 8, wherein the component (E) is a polyoxyethylene sorbitan fatty acid ester and / or a sorbitan fatty acid ester.

10. The granular bath composition according to claim 8, wherein the content of the (E) component per 1 part by mass of the (D) component is 0.01 to 0.1 part by mass.

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