JP7718802B2 - Briquette-type effervescent bath additives - Google Patents

Description

The present invention relates to a briquette-type effervescent bath additive.

Bath additives containing organic acids and carbonates that react in bathwater to generate carbon dioxide gas are known to be effective in promoting blood circulation and preventing chills after a bath (see Patent Document 1). However, to achieve sufficient blood circulation-boosting effects, the foaming bath additives must be fully dissolved before bathing. However, since the above-mentioned bath additives take about five minutes to completely dissolve, many people end up finishing their bath before achieving the full effect.

Therefore, it is known that in order to shorten the dissolution time, it is effective to make the bath additive into a briquette type formulation with a large specific surface area (see Patent Document 2).
One technology related to briquette-type bath additives is known, which increases storage stability while containing more than 2% by mass and not more than 10% by mass of components that are liquid at 25°C by adjusting the average surface area (see Patent Document 3).

Furthermore, briquette-type bath additives are known that increase the size of the briquette particles to improve foaming durability and enable stable production (see Patent Document 4).

Japanese Patent Application Laid-Open No. 2005-97238 JP 2014-43410 A JP 2014-76978 A JP 2013-253056 A

The bath additive compositions described in the above patent documents are based on a blend of organic acids, carbonates, oils, and nonionic surfactants. However, with the composition of Patent Document 2, it is difficult to increase the size of the briquette particles. While a high liquid content, as in Patent Document 3, allows for sufficient molding at low production speeds, the reduced fluidity of the liquid components leads to uneven molding pressure, resulting in the problem of particles cracking and chipping due to the clamshell characteristic of briquettes becoming more likely as production speeds increase. The composition of Patent Document 4 also desired improved storage stability and further suppression of floating bubbles.

The present invention aims to provide a briquette-type effervescent bath additive that is less likely to crack or chip, has good storage stability, and reduces the formation of floating bubbles or particles on the surface of hot water when dissolved therein.

The present invention includes, for example, the following [1] to [5].
[1] Organic acid (A),
Carbonate (B),
(C) at least one selected from the group consisting of silicic anhydride and calcium silicate;
An oil component (D) that is liquid at 25°C, and a nonionic surfactant (E) that is liquid at 25°C
A briquette type effervescent bath additive containing the above components, wherein the total content of component (D) and component (E) in the briquette type effervescent bath additive is 2 mass% or less.
[2] Briquette-type effervescent bath additive of [1], having a major axis of 15 to 25 mm and a thickness of 8 to 13 mm.
[3] The briquette-type foaming bath additive of [1] or [2], wherein component (E) is at least one selected from the group consisting of polyethylene glycol fatty acid esters, polyoxyethylene glycerin fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbit fatty acid esters, polyoxyethylene alkyl ethers, polyoxyethylene polyoxypropylene glycol, ethylenediaminetetrapolyoxyethylene polyoxypropylene, and polyoxyethylene hydrogenated castor oil.
[4] Component (A) contains succinic acid, and the content of succinic acid in the briquette type effervescent bath additive is 10 to 30 mass% [1] to [3].
[5] The briquette-type effervescent bath additive according to any one of [1] to [4], wherein the effervescent duration in 40°C water is 100 seconds or less.

The briquette-type effervescent bath additive of the present invention is less likely to crack or chip, has good storage stability, and when dissolved in hot water, it prevents floating bubbles and particles from appearing on the surface of the water.

The present invention relates to a briquette-type effervescent bath additive containing an organic acid (A), a carbonate (B), at least one component (C) selected from the group consisting of silicic anhydride and calcium silicate, an oil component (D) that is liquid at 25°C, and a nonionic surfactant (E) that is liquid at 25°C, wherein the total content of components (D) and (E) in the briquette-type effervescent bath additive is 2% by mass or less.

(A) Organic Acid The briquette-type effervescent bath additive contains an organic acid (A). Such organic acids are preferably solid at room temperature (25°C), and examples include malic acid, fumaric acid, succinic acid, citric acid, tartaric acid, malonic acid, pyrrolidonecarboxylic acid, monosodium citrate, monosodium succinate, monosodium fumarate, adipic acid, tartaric acid, benzoic acid, salicylic acid, glutaric acid, glycolic acid, lactic acid, glyceric acid, and pyruvic acid. There are no particular limitations on the stereoisomer of malic acid, and any isomer may be used. These may be used alone or in combination of two or more. Among these, from the viewpoints of ensuring the amount of carbon dioxide gas generated and maintaining good storage stability, it is preferable to contain at least one selected from the group consisting of fumaric acid, malic acid, and succinic acid, and it is more preferable to contain succinic acid. It is even more preferable to use a combination of three types of acid: malic acid, fumaric acid, and succinic acid.

The content of organic acid (A) in 100% by mass of the briquette-type effervescent bath additive is preferably 30 to 60% by mass, more preferably 40 to 50% by mass. When the amount of organic acid is within this range, the amount of carbon dioxide gas is sufficient, foaming power is good, storage stability is good, and in the manufacturing process, roll adhesion and leaks are unlikely to occur during compression molding when making into a briquetting agent, burrs and the like are suppressed during crushing, and the problem of formation of insoluble matter during use is also avoided, which is preferable.
When the organic acid contains succinic acid, the content of succinic acid in 100% by mass of the briquette-type effervescent bath additive is preferably 10 to 30% by mass, more preferably 15 to 25% by mass. When the amount of succinic acid is within the above range, it is possible to obtain good effervescence while suppressing the stuffiness that occurs when effervescent bath additives are apt to produce.

(B) Carbonate The briquette-type effervescent bath additive contains a carbonate (B). The carbonate can generate carbon dioxide gas together with the organic acid (A). Examples of carbonates include dialkali metal carbonates such as sodium carbonate and potassium carbonate; monoalkali metal carbonates such as sodium bicarbonate and potassium bicarbonate; carbonates of divalent or higher metals such as magnesium carbonate and calcium carbonate; ammonium carbonate, sodium sesquicarbonate, etc. These may be used alone or in combination of two or more. Among these, from the viewpoint of ease of availability, at least one selected from the group consisting of sodium carbonate and sodium bicarbonate is preferred, and it is more preferred to use a combination of two types of sodium carbonate and sodium bicarbonate.

The content of carbonate (B) in 100% by mass of briquette-type effervescent bath additives is preferably 30 to 65% by mass, and more preferably 35 to 50% by mass. When the amount of carbonate is within this range, the amount of carbon dioxide gas is sufficient, resulting in good effervescent power and good storage stability.

The average particle size of the carbonate (B) is preferably 100 to 450 μm, and more preferably 250 to 400 μm. When the average particle size is within this range, the occurrence of clamshells is suppressed and sufficient crushing strength can be ensured. The average particle size is a value measured using the laser diffraction/scattering method, and if it is listed in the catalog, this value should be used.

(C) At least one kind selected from the group consisting of silicic anhydride and calcium silicate The briquette-type effervescent bath additive contains at least one kind (C) selected from the group consisting of silicic anhydride and calcium silicate. Among these, silicic anhydride is preferred.
The content of at least one kind (C) selected from the group consisting of silicic anhydride and calcium silicate in 100% by mass of the briquette-type effervescent bath additive is preferably 0.05 to 1.5% by mass, more preferably 0.1 to 1% by mass, and even more preferably 0.15 to 0.5% by mass. When the content of at least one kind selected from the group consisting of silicic anhydride and calcium silicate is within the above range, a decrease in the fluidity and binding strength of the raw material powder before molding can be suppressed, and molding properties are good.

(D) Oily Component Liquid at 25° C. Briquette-type foaming bath additives contain an oily component (D) that is liquid at 25° C. The oily component (D) that is liquid at 25° C. is not particularly limited, and examples thereof include hydrocarbons such as liquid paraffin, light liquid isoparaffin, squalane, squalene, and bristan; fatty acid esters such as octyl palmitate, isopropyl palmitate, isostearyl palmitate, isopropyl myristate, myristyl myristate, isocetyl myristate, octyldodecyl myristate, cetyl octanoate, caprylic/capric triglyceride, decyl oleate, isocetyl stearate, and isotridecyl isononanoate; higher alcohols such as lauryl alcohol, oleyl alcohol, and hexyldodecanol; lemon oil, yuzu oil, rose oil, bergamot oil, calamus oil, lavender oil, and orange oil. Natural fragrances such as grapefruit oil, mandarin oil, geranium oil, sage oil, eucalyptus oil, neroli oil, patchouli oil, clove oil, nutmeg oil, cedarwood oil, peppermint oil, spearmint oil, juniper berry oil, almoise oil, chamomile oil, elemi oil, vetiver oil, camphor oil, lime oil, peppermint oil, jasmine oil, cypress oil, turpentine oil, Japanese cypress oil, lavandin oil, clove oil, thyme oil, rosemary oil, and pine oil; terpene fragrances such as α-pinene, β-pinene, d-limonene, camphene, and terpinene; leaf alcohol, sandalwood, evanol, ambrinol, amber core, citronellol, geraniol, nerol, linalool, tetrahydrolinalool, dihydromyrcenol, ethoxycaprylyl glycol, ethylhexyl palmitate ... Alcohol-based fragrances such as lurinalool, isopulegol, menthol, terpineol, dihydroterpineol, farnesol, santalol, vetiverol, β-phenylethyl alcohol, and bacdanol; and other alcohol-based fragrances such as aldehyde C-8, aldehyde C-9, aldehyde C-10, aldehyde C-11, aldehyde C-12, aoba aldehyde, citronellal, citral, α-methylenecitronellal, isocyclocitral, dimethyltetrahydrobenzaldehyde, benzaldehyde, phenylacetaldehyde, α-amylcinnamic aldehyde, α-hexylcinnamic aldehyde, vanillin, ethyl vanillin, heliotropin, helional, cis-jasmone, and dihydrojasmone. Examples of the natural fragrance include synthetic fragrances such as aldehyde-ketone fragrances, such as nectaryl, damascone, ionone, Iso-E-Super, calone, l-carvone, and menthone; blended fragrances that are any combination of the above-mentioned natural fragrances and synthetic fragrances; natural oils and fats, such as soybean oil, jojoba oil, rice bran oil, olive oil, and coconut oil, hardened oils obtained by hydrogenating these natural oils and fats, and glycerides such as myristate glyceride; silicone oils, such as methylpolysiloxane, methylcyclopolysiloxane, methylhydrogenpolysiloxane, methylphenylpolysiloxane, and various modified silicones; and higher fatty acids, such as oleic acid, linoleic acid, linolenic acid, lanolinic acid, and isostearic acid, and these may be used alone or in combination of two or more.

Among these, fatty acid esters and natural oils are preferred, with isopropyl palmitate, isopropyl myristate, octyldodecyl myristate, jojoba oil, and the like being particularly preferred due to their excellent feel on the skin during bathing. It is also preferable to incorporate fragrances, such as the natural fragrances, synthetic fragrances, and blended fragrances mentioned above, as these will impart a fragrant aroma upon foaming.

The content of oily components that are liquid at 25°C in 100% by mass of the briquette-type effervescent bath additive is preferably 0.1 to 5.0% by mass, more preferably 0.3 to 2.0% by mass, and even more preferably 0.5 to 1.3% by mass. When the amount of oily components that are liquid at 25°C is within the above range, there are no problems with storage stability or the feel when used in the bath, and when made into briquettes, there is no decrease in productivity due to insufficient strength.

(E) Nonionic Surfactant Liquid at 25° C. The briquette-type foaming bath additive contains a nonionic surfactant (E) that is liquid at 25° C. Examples of nonionic surfactants (E) that are liquid at 25° C. include polyethylene glycol fatty acid esters such as polyoxyethylene glycol monolaurate and polyoxyethylene glycol monooleate; polyoxyethylene glycerin fatty acid esters such as polyoxyethylene (caprylic/capric acid) glyceryl and polyoxyethylene glyceryl oleate; sorbitan fatty acid esters such as sorbitan monooleate, sorbitan sesquioleate, sorbitan trioleate, sorbitan monoisostearate, sorbitan sesquiisostearate, and sorbitan coconut oil fatty acid; polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan isostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan coconut oil fatty acid esters; Examples of the hydroxybenzoates include polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbit monolaurate and polyoxyethylene sorbit tetraoleate; polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether and polyoxyethylene oleyl ether; polyoxyethylene polyoxypropylene glycol; ethylenediaminetetrapolyoxyethylene polyoxypropylene; and polyoxyethylene hydrogenated castor oil. These may be used alone or in combination of two or more. Among these, polyoxyethylene glycerin fatty acid esters, polyethylene glycol fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and polyoxyethylene alkyl ethers are preferred, polyoxyethylene sorbitan fatty acid esters and polyoxyethylene glycerin fatty acid esters are more preferred, polyoxyethylene sorbitan tetraoleate and polyoxyethylene (caprylic/capric) glyceryl are even more preferred, and polyoxyethylene (caprylic/capric) glyceryl is particularly preferred.

The content of nonionic surfactant (E) that is liquid at 25°C in 100% by mass of the briquette-type effervescent bath additive is preferably 0.1 to 2.0% by mass, more preferably 0.1 to 1.5% by mass, and even more preferably 0.2 to 1.0% by mass. When the amount of surfactant that is liquid at 25°C is within the above range, storage stability is good and floating bubbles and floating matter can be suppressed.

The total amount ((D) + (E)) of the oil component (D) that is liquid at 25°C and the nonionic surfactant (E) that is liquid at 25°C in 100% by mass of the briquette-type effervescent bath additive is 2% by mass or less, preferably 0.5 to 2% by mass, more preferably 1 to 2% by mass, and even more preferably 1.6 to 2% by mass.
If a liquid component is added in excess of the above range, the fluidity of the raw material powder before compaction will decrease, preventing uniform pressure from being applied during compression, resulting in a decrease in compactibility and making it more likely that floating matter will appear on the oil surface.

The mass ratio ((D)/(E)) of the oil component (D) that is liquid at 25°C to the surfactant (E) that is liquid at 25°C contained in the briquette-type effervescent bath additive of the present invention is preferably 0.4 to 10, more preferably 0.5 to 5, and even more preferably 0.7 to 2.
When (D)/(E) is within the above range, floating bubbles are unlikely to form on the oil surface, sufficient moldability can be obtained, and the warming effect of the oil component can be obtained.

<Other ingredients>
(F) Other Inorganic Salts The briquette-type effervescent bath additive may further contain inorganic salts other than silicic acid anhydride and calcium silicate.
Examples of other inorganic salts include sodium sulfate, magnesium sulfate, sodium chloride, ammonium chloride, sodium nitrate, potassium nitrate, calcium nitrate, sodium polyphosphate, sodium phosphate, sodium iron sulfate phosphate, calcium oxide, magnesium oxide, aluminum sulfate, sodium thiosulfate, potassium chloride, potassium sulfide, alum, metasilicic acid, etc. These may be used alone or in combination of two or more. Among these, sodium sulfate, magnesium sulfate, and sodium chloride are preferred, and sodium sulfate is more preferred.

When other inorganic salts are added, the content of inorganic salts (excluding silicic anhydride and calcium silicate) in 100% by mass of the briquette-type effervescent bath additive is preferably 0.1 to 20% by mass, more preferably 1 to 18% by mass, and even more preferably 1 to 15% by mass. When the amount of inorganic salt is within the above range, the bath additive is easy to mold and does not become too hard, which does not interfere with effervescence and does not leave any residue when dissolved in hot water.

Briquette-type effervescent bath additives may optionally contain other known ingredients commonly used in bath additives, provided that the effects of the present invention are not impaired. lubricants such as polyethylene glycol, talc, magnesium stearate; water-soluble polymers such as polyvinylpyrrolidone, methylcellulose, ethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, dextrin, sodium carboxymethylcellulose, starch, cationized cellulose; moisturizers such as sodium glutamate, sodium ascorbate, collagen, sodium hyaluronate, sodium chondroitin sulfate; herbal medicines such as Atractylodes Root, Atractylodes Root, Valerian, Magnolia, Cnidium, Orange Peel, Angelica Root, Powdered Ginger, Carrot, Cinnamon Bark, Peony, Mint Leaf, Scutellaria Root, Chinese Angelica, Poria Coccinea, Poria Root, Calamus, Root, Angelica Root, Saffron, Phellodendron Bark Extract, Citrus Fruit, Fennel, Citrus Fruit Powder, Chamomile, Melissa, Rosemary, Horse Chestnut, Yarrow, Arnica; Examples of ingredients include, but are not limited to, alcohols such as ethanol, stearyl alcohol, isopropyl alcohol, cetyl alcohol, and hexadecyl alcohol; polyhydric alcohols such as glycerin, propylene glycol, and sorbitol; titanium oxide, zinc oxide, talc, sulfur, mineral sand, hot spring deposits, casein, neutral clay, sodium salicylate, sodium carboxymethylcellulose, egg yolk powder, irrigation bran, mica powder, skim milk powder, sterilizing preservatives, metal sequestering agents, pigments, and other ingredients necessary for formulation.

<Manufacturing method>
In producing the briquette-type effervescent bath additive, first, the above-mentioned essential components (A) to (E) and optional components added as needed are mixed and pulverized using a Henschel mixer, high-speed mixer, universal mixer, SV mixer, vertical granulator, Ribocone mixer, or the like to prepare a compounded bulk.

The briquetting agent is then produced by feeding this mixed bulk into a briquetting machine and compressing and molding it to produce a sheet-like primary compact in which multiple briquette particles are molded into a sheet via their connecting parts, and then crushing this to produce the briquetting agent.

The roll rotation speed in the briquetting machine is preferably 5 to 35 rpm, more preferably 15 to 30 rpm. The screw rotation speed in the briquetting machine is preferably 20 to 160 rpm, more preferably 50 to 130 rpm. When the roll rotation speed and screw rotation speed are within the above ranges, it is possible to produce briquettes that have excellent appearance and sufficient strength while maintaining a high production rate.

When the above-mentioned compounded bulk is fed into the briquetting machine, the linear pressure between the rolls is preferably adjusted to 10 to 25 kN/cm by adjusting the size of the clearance between the rolls and the pressure of the feed screw, with a range of 13 to 23 kN/cm being more preferable, and 15 to 20 kN/cm being even more preferable. Within this range, the particles will have an excellent appearance without burrs or chips when crushed, and roll adhesion and leakage during compression molding will be suppressed, improving production efficiency.

<Dosage form>
Briquette-type effervescent bath additives are molded into shapes such as pillow, lens, almond, prism, rod, and finger shapes. Preferably, the major axis is 15 to 25 mm and the thickness is 8 to 13 mm, and more preferably, the major axis is 18 to 23 mm and the thickness is 9 to 11 mm. Here, the major axis of the briquette agent refers to the maximum length of the briquette particles in the horizontal direction of the sheet-like primary compact, and the thickness of the briquette refers to the maximum length of the briquette particles in the vertical direction of the sheet-like primary compact. By achieving these sizes, the amount of dissolved carbon dioxide can be increased, resulting in an excellent hot bath effect when used as a bath additive. Of the above shapes, pillow and almond shapes are preferred from the standpoint of moldability.

(Surface area of briquette-type effervescent bath additive)
Briquette-type effervescent bath additives preferably have a surface area of 350 to 850 mm ² /piece, more preferably 450 to 750 mm ² /piece. When the surface area is within this range, effervescence does not occur suddenly, and gentle, long-lasting effervescence can be obtained.

(Crushing strength of briquette-type bath additives)
Furthermore, the resulting briquette-type effervescent bath additive preferably has a crushing strength of 80 N or more immediately after production, more preferably 90 N or more. Within this range, gentle, long-lasting effervescence can be achieved. This is also advantageous because it reduces the occurrence of chipping during deburring during crushing, improves appearance, and improves production efficiency. In the present invention, the crushing strength is a value determined by the following measurement method.
Using a Kiya hardness tester, place the briquette-type effervescent bath additive on a stand, and lower a rod with a φ5 mm tip vertically from the pocket mating surface while pressing it against the briquette-type effervescent bath additive, and measure the load value when the briquette-type effervescent bath additive breaks.

(Bubble duration of briquette-type bath additives)
The effervescence duration of the briquette-type effervescent bath additive in water at 40°C is preferably 100 seconds or less, more preferably 90 seconds or less, and even more preferably 80 seconds or less. In the present invention, "effervescence duration" refers to the time required from the time 50 g of the briquette-type effervescent bath additive is added to 200 L of hot water at 40°C until the effervescent preparation is completely dissolved. This does not include the time required for the preparation to dissolve after the effervescence has finished. When the effervescent duration is within the above range, effervescence is completed while bathing, and the effects of the briquette-type effervescent bath additive can be fully obtained while bathing.

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 following commercially available components were used in the examples.
Polyethylene glycol 6000: PEG 6000 (manufactured by Toho Chemical Industry Co., Ltd.)
Fragrance: Citrus-based blend fragrance (manufactured by Takasago International Corporation) consisting only of oil-based fragrance ingredients that are liquid at 25°C, including d-limonene
Polyoxyethylene (caprylic/capric acid) glyceryl: Softigen 767 (manufactured by IOI Oleo)
Polyoxyethylene sorbitol tetraoleate: NIKKOL (registered trademark) GO-430NV (manufactured by Nikko Chemicals Co., Ltd.)

[Examples 1 to 6 and Comparative Examples 1 to 4]
A total of 50 kg of the formulation shown in Table 1 was mixed in an SV mixer until uniform, preparing a bulk, which was then fed into a briquetting machine to form briquettes. A roll with round-corner pillow-shaped pockets measuring 20 mm in diameter and 3.5 mm in depth was used, with the roll rotation speed set to 15 rpm and the screw rotation speed set to 60 rpm (assuming 300 kg/h). The clearance between the rolls and the pressure of the feed screw were adjusted to a linear pressure of 20 kN/cm between the rolls. After forming the briquette, it was crushed using a vibrating sieve to obtain a foamable briquette-type bath additive with a diameter of 20 mm and a thickness of 9.4 mm. The surface area of this foamable briquette-type bath additive was 685 ^mm² /piece.

The results of the above evaluations are shown in Table 1. The blend amounts in the table are in mass %.
The average particle size of sodium carbonate was 120 μm, and that of sodium bicarbonate was 300 μm. The average particle sizes were measured by a laser diffraction/scattering method using a HORIBA LA-960 laser diffraction/scattering particle size distribution analyzer.

[evaluation]
The briquette-type effervescent bath additives obtained in the examples and comparative examples were evaluated as follows. Evaluations of "particle state,""storagestability," and "water surface state" were carried out by 20 male and female monitors according to the following evaluation criteria. The evaluation results were decided by discussion among all monitors.
The "grain state" and "crushing strength" are indicators of moldability.

(Grain state)
Briquette-type effervescent bath additives were continuously produced under the conditions described in the examples, and 1 kg of the molded pellets was visually evaluated for cracks, chips, and clamshells according to the following criteria. Note that clamshells refer to a state in which the center of the briquette is cracked due to air entrapment or the like, leaving a shape resembling an open shell.

[Evaluation criteria]
◎: No cracked or chipped grains were observed, and only a small amount of clamshells were formed. ○: Only a small number of cracked or chipped grains were observed, but some clamshells were formed. △: A relatively large number of cracked or chipped grains were observed, and many clamshells were formed.
×: Many grains were cracked or chipped, and many clamshells were also formed.

(Crushing strength)
The crushing strength (unit: N) of the preparation immediately after production was determined using a Kiya hardness tester (product name: KHT-40N, manufacturer: Fujiwara Seisakusho Co., Ltd.) by placing the briquette-type effervescent bath additive on a stand, pressing a rod with a φ5 mm tip vertically against the pocket mating surface while lowering it, and measuring the load value when the briquette-type effervescent bath additive broke.
If the crushing strength is 80N or more, the moldability is good.

(Storage stability)
50 g of the preparation was packaged in an aluminum pillow and placed in a thermostatic chamber at 50° C. After 30 days, the condition of the aluminum pillow was visually evaluated according to the following evaluation criteria.
[Evaluation criteria]
◯: No bulging of the aluminum pillow is observed △: Some bulging of the aluminum pillow is observed ×: Bulging of the aluminum pillow is observed

(Foaming duration)
50 g of the preparation was poured into 200 L of bath water at 40° C., and the time (seconds) required from the time of pouring until the preparation was completely dissolved accompanied by foaming was measured.
The effervescent duration was determined to be good if it was 100 seconds or less, better if it was 90 seconds or less, and even better if it was 80 seconds or less, because ensuring that the bathing time is long enough for the preparation to be completely dissolved and for the carbon dioxide gas to be sufficiently dissolved enhances the effect of the bath.

(Water surface condition)
50 g of the preparation was poured into 200 L of bath water at 40°C, and the state of the water surface immediately after foaming of the preparation was completed was visually observed and evaluated according to the following criteria.
◎: No noticeable bubbles or white floating matter. 〇: No noticeable bubbles or white floating matter. △: Somewhat noticeable bubbles or white floating matter. ×: Somewhat noticeable bubbles or white floating matter.

Examples 1 to 4 have good granular condition and a crushing strength of 80N or more, and therefore have good moldability, good storage stability, and good foaming rate, and are less likely to produce floating bubbles or particles on the surface of the hot water.
Comparison of Example 1 with Comparative Example 1, and Example 2 with Comparative Example 2 shows that if the briquette-type effervescent bath additive does not contain silicic anhydride, the particle condition is poor, the crushing strength is reduced, and moldability is poor.
Comparing Examples 1 to 4 with Comparative Example 3, it can be seen that when the total amount of liquid components, which is the sum of the liquid oil component and the surfactant, exceeds 2 mass%, the particle condition is poor, the crushing strength is reduced, moldability is poor, and the surface condition of the molten metal is also poor.
Comparing Examples 1 to 4 with Comparative Example 4, it can be seen that if the briquette-type foaming bath additive does not contain a liquid surfactant, the granular condition is poor, the crushing strength is reduced, moldability is poor, and the storage stability and water surface condition are also poor.

Claims (4)

organic acid (A),
Carbonate (B),
Silica anhydride (C),
An oil component (D) that is liquid at 25°C, and a nonionic surfactant (E) that is liquid at 25°C
A briquette-type effervescent bath additive containing the component (D) and the component (E), wherein the total content of the component (D) and the component (E) in the briquette-type effervescent bath additive is 2% by mass or less,
The component (A) contains succinic acid, and the succinic acid content in the briquette type effervescent bath additive is 10 to 30 mass %. The briquette-type effervescent bath additive according to claim 1, having a major axis of 15 to 25 mm and a thickness of 8 to 13 mm. 3. The briquette-type effervescent bath additive according to claim 1, wherein component (E) is at least one selected from the group consisting of polyethylene glycol fatty acid esters, polyoxyethylene glycerin fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbit fatty acid esters, polyoxyethylene alkyl ethers , polyoxyethylene polyoxypropylene glycol, ethylenediaminetetrapolyoxyethylene polyoxypropylene, and polyoxyethylene hydrogenated castor oil. The briquette type effervescent bath additive according to any one of claims 1 to 3 , wherein the effervescent duration in water at 40°C is 100 seconds or less.