WO2018087940A1 - Microemulsion-containing solid soap composition - Google Patents

Abstract

The solid soap composition according to the present invention comprises (A) a soap material and (B) a microemulsion that contains the following components (b1)-(b3): (b1) at least one surfactant selected from the group consisting of nonionic surfactants and anionic surfactants, (b2) at least one kind of an oily component, and (b3) water.

Description

Solid soap composition containing microemulsion

The present invention relates to a solid soap composition, a method for producing the same, and a foam improver for the solid soap composition.

Solid soap compositions mainly composed of fatty acid salts are widely used as detergent compositions for skin such as the face and body. In addition to the detergency, it is also important for the skin cleanser composition to have excellent usability, and it is required to have good foam quality and foam persistence (foam retention). For example, if the foam persists poorly and the foam disappears immediately, the elasticity of the foam cannot be maintained during washing, so the feeling of use is poor and a sufficient washing feeling cannot be obtained. In addition, if the bubbles disappear immediately, a burden is applied to the skin due to friction between the skins (hand and face, etc.). As for the foam quality, a foam having elasticity and stringiness is regarded as a good quality foam, and a solid soap composition is also being studied for improving the foam quality. For example, Patent Document 1 describes a detergent composition including a fatty acid soap part and a granulated product containing a water-soluble polymer having an effect of improving foam quality.

The microemulsion exhibits a transparent or translucent appearance, is stable without being separated, and has a property that a water-soluble component and an oil can be blended simultaneously. Because of these properties, microemulsions are used in the preparation of cosmetics, liquid or gel-like cleaning compositions. Patent Document 2 describes a cosmetic detergent composition containing a microemulsion containing an alkyl (oligo) glycoside, an anionic surfactant, a cationic polymer, and the like.

JP2013-1860A Special table 2014-520770 gazette

In the cleaning composition of patent document 1, in order to improve foam quality, the water-soluble polymer is mix | blended. However, Patent Document 1 does not describe a microemulsion. In patent document 2, it is not examined about improving the foam quality and foam persistence of a solid soap composition. No solid soap composition containing a microemulsion is known.

An object of this invention is to provide the solid soap composition with favorable foam quality and foam persistence, and its manufacturing method.

As a result of intensive studies to solve the above problems, the present inventors improve (improve) the foam quality and foam persistence by blending a microemulsion with a solid soap composition containing a soap base. I found out. It is a surprising finding that microemulsions improve the foam quality and foam persistence of solid soap compositions.

The present invention relates to the following solid soap compositions and the like.
The solid soap composition of the present invention contains (A) a soap base and (B) a microemulsion containing the following components (b1) to (b3).
(B1) At least one surfactant selected from the group consisting of nonionic surfactants and anionic surfactants (b2) At least one oily component (b3) water The solid soap composition of the present invention is a soap base. In addition, by containing the microemulsion, it is possible to form foam with excellent foam quality that has elasticity and stringiness during washing and fine texture. Moreover, since the persistence of foam is good, the elasticity of the foam can be maintained even during washing, and the feeling of use is excellent. Furthermore, a good cleaning feeling can be obtained. In the present specification, the microemulsion containing the components (b1) to (b3) is also simply referred to as a microemulsion.

The blending amount of the (B) microemulsion is preferably 0.15 to 5% by mass in the solid soap composition.
By blending the above amount of the microemulsion, the foam quality of the solid soap composition becomes better, and the foam becomes more excellent in elasticity and stringiness. Moreover, the persistence of foam improves more.
In this specification, the amount (% by mass) of each component of the solid soap composition ((A) soap base, (B) microemulsion and other components blended as required) is solid unless otherwise specified. It is a blending amount in 100% by mass of the soap composition.

In the solid soap composition of the present invention, it is preferable that the (B) microemulsion further contains (b4) a monohydric alcohol having 1 to 4 carbon atoms and / or (b5) a polyhydric alcohol.
The form of the solid soap composition of the present invention is preferably solid, sheet, powder or granule.

In one embodiment of the present invention, the microemulsion is an oil-in-water (O / W type) microemulsion, and the nonionic surfactant has an HLB of 10 to 20, polyoxyethylene alkyl ether, polyoxyethylene It is at least one selected from the group consisting of polyoxypropylene alkyl ether, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene hydrogenated castor oil, polyglycerin fatty acid ester and polyether-modified silicone. It is preferable.
In one embodiment, the microemulsion is an oil-in-water (O / W type) microemulsion, and the anionic surfactant is a polyoxyethylene alkyl ether phosphate salt, N-acyl glutamate, and polyoxy It is preferably at least one selected from the group consisting of ethylene alkyl ether phosphoric acid or a salt thereof.
In one embodiment, the microemulsion is a water-in-oil type (W / O type) microemulsion,
In one embodiment, the nonionic surfactant is a polyoxyethylene difatty acid ester, monoglycerin monofatty acid ester, monoglycerin difatty acid ester, diglycerin monofatty acid ester and polyether-modified, wherein the HLB is 1 to 7. It is preferably at least one selected from the group consisting of silicones.

The method for producing a solid soap composition of the present invention comprises at least (A) a soap base and (B) a microemulsion containing the following components (b1) to (b3) kneaded to obtain a soap base composition. Including the step of preparing.
(B1) At least one surfactant selected from the group consisting of nonionic surfactants and anionic surfactants (b2) At least one oily component (b3) water According to the production method of the present invention, The solid soap composition of the present invention can be produced.
In the production method of the present invention, the blending amount of the (B) microemulsion is preferably 0.15 to 5% by mass in the solid soap composition.

The foam improver of the solid soap composition of the present invention includes the following components (b1) to (b3):
(B1) at least one surfactant selected from the group consisting of a nonionic surfactant and an anionic surfactant;
(B2) at least one oily component, and
(B3) water,
A microemulsion containing is used as an active ingredient.
The foam quality improving agent of the solid soap composition of the present invention can improve the foam quality, for example, by blending it into the solid soap composition. Moreover, the persistence of the foam of a solid soap composition can be improved.
The present invention also includes the use of a microemulsion containing the above components (b1) to (b3) for improving the foam quality of a solid soap composition.

ADVANTAGE OF THE INVENTION According to this invention, the solid soap composition with favorable foam quality and foam persistence and its manufacturing method can be provided.

Hereinafter, the present invention will be specifically described. However, the present invention is not limited to the following embodiments, and can be applied with appropriate modifications without departing from the scope of the present invention.

The solid soap composition of the present invention contains (A) a soap base and (B) a microemulsion containing the following components (b1) to (b3).
(B1) At least one surfactant selected from the group consisting of nonionic surfactants and anionic surfactants (b2) At least one oily component (b3) water The solid soap composition of the present invention is a soap base. And by containing the microemulsion, the foam quality and the persistence of the foam are good. By mix | blending a microemulsion, the foam quality of a solid soap composition improves and the sustainability of foam improves. The solid soap composition of the present invention has elasticity and stringiness when washed, and can form fine foam with fine texture. In addition, since the foam has good durability, the elasticity of the foam can be maintained even during washing. For this reason, when the skin is washed, for example, the feel of the foam is good and the persistence of the foam is good, so that a good feeling of use can be obtained. In addition, good cleaning feeling can be obtained.

<(A) soap base>
The soap base in the present invention may be any soap base used in ordinary solid soap compositions, and fatty acid alkali salts are preferably used. 1 type may be sufficient as a fatty-acid alkali salt, and 2 or more types may be sufficient as it. The fatty acid in the fatty acid alkali salt is preferably a fatty acid having 8 to 22 carbon atoms. The soap base in the present invention is preferably a fatty acid alkali salt having 8 to 22 carbon atoms, and one or more fatty acid alkali salts can be used. The number of carbon atoms in the fatty acid is more preferably 10-20, and still more preferably 12-18. The fatty acid may be linear or branched. The fatty acid may be a saturated fatty acid or an unsaturated fatty acid. As fatty acids, saturated fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid; unsaturated fatty acids such as oleic acid, linoleic acid, linolenic acid, ricinoleic acid; coconut oil fatty acid, which is a mixture thereof, Palm oil fatty acid, palm kernel oil fatty acid, beef tallow fatty acid, hardened beef tallow fatty acid, pork oil fatty acid and the like can be mentioned. Of these, lauric acid, myristic acid, palmitic acid, stearic acid, palm kernel oil fatty acid and the like are preferable.

Examples of the alkali of the fatty acid alkali salt include alkali metals such as sodium and potassium; organic amines such as ethanolamine, among which sodium and potassium are more preferable, and sodium is more preferable. The content of the fatty acid sodium salt in 100% by mass of the fatty acid alkali salt used as the soap base is preferably 50 to 100% by mass, and more preferably 55 to 100% by mass.
The fatty acid alkali salt in the present invention is preferably a sodium salt, potassium salt or triethanolamine salt of a saturated fatty acid such as lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, etc., and lauric acid, myristic acid, palmitic acid Sodium salts and potassium salts are more preferable, and sodium salts of lauric acid, myristic acid and palmitic acid are more preferable. These may be used alone or in combination of two or more.
The fatty acid alkali salt used as the soap base can be prepared by a known method such as a saponification method or a neutralization method using the fatty acid.

<(B) Microemulsion>
The microemulsion in the present invention contains the following components (b1) to (b3).
(B1) at least one surfactant selected from the group consisting of nonionic surfactants and anionic surfactants (b2) at least one oily component (b3) water

The microemulsion in the present invention may be an oil-in-water (O / W type) microemulsion or a water-in-oil (W / O type) microemulsion. O / W type microemulsions and W / O type microemulsions can also be used in combination. As an example, the microemulsion preferably has a pH of 9-11.

<Oil-in-water type (O / W type) microemulsion>
In the O / W type microemulsion, the outer phase is an aqueous phase. As the O / W type microemulsion, 0.1 to 20% by mass of the component (b1), 0.01 to 10% by mass of the component (b2), and 50 to 99% by mass of the component (b3). What is contained is preferable. In the present invention, the content (% by mass) of the components (b1) to (b3) is the content in 100% by mass of the microemulsion.

In the case of an O / W type microemulsion, a nonionic surfactant having an HLB of 10 to 20 is preferred as the nonionic surfactant in the component (b1). In the case of the O / W type microemulsion, the component (b1) is preferably at least one surfactant selected from the group consisting of an anionic surfactant and a nonionic surfactant having an HLB of 10 to 20. Each of the anionic surfactant and the nonionic surfactant having an HLB of 10 to 20 may be used alone, or two or more thereof may be used in combination. In the case of the O / W type microemulsion, the component (b1) preferably contains a nonionic surfactant having an HLB of 10 to 20, and (b1) is a nonionic surfactant having an HLB of 10 to 20, or an HLB Are preferably 10 to 20 nonionic surfactants and anionic surfactants. In the O / W type microemulsion, the component (b1) preferably contains 80% by mass or more of a nonionic surfactant having an HLB of 10 to 20, more preferably 90% by mass or more, for example, 80 to 100% by mass. The content is preferably 90 to 100% by mass. In one embodiment, the upper limit of the content of the nonionic surfactant having an HLB of 10 to 20 may be 99.99% by mass or less, 99.9% by mass or less, or 99% by mass or less in the component (b1). There may be. In one embodiment, the content of the anionic surfactant in the component (b1) is preferably 20% by mass or less, and more preferably 10% by mass or less. When the component (b1) contains an anionic surfactant, the content thereof is preferably 0.01% by mass or more, more preferably 0.1% by mass or more in the component (b1) as an example, for example, 0.01 to 20% by mass is preferable, and 0.1 to 10% by mass is more preferable.
In the present invention, HLB (hydrophilic lipophilic balance) is an HLB value calculated by the Griffin method.

Examples of the nonionic surfactant having an HLB of 10 to 20 include, for example, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene fatty acid ester, polyoxyethylene sorbitan fatty acid ester, Polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, polyoxyethylene sorbitol tetrafatty acid ester, polyglycerin fatty acid ester, sucrose fatty acid ester, alkyl (poly) glucoside, N-alkyldimethylaminooxide, polyoxyethylene glycerin fatty acid Examples thereof include esters and polyether-modified silicones. Each of these may be used alone or in combination of two or more.
The nonionic surfactant used for the component (b1) of the O / W type microemulsion is more preferably a nonionic surfactant having an HLB of 12 to 20.

Nonionic surfactants having an HLB of 10 to 20 include polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene hydrogenated castor oil, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene alkyl ether, Glycerin fatty acid ester, polyether-modified silicone and the like are more preferable. Each of these may be used alone or in combination of two or more. Use of such an O / W type microemulsion containing a nonionic surfactant having an HLB of 10 to 20 is preferable because the foam quality of the solid soap composition becomes better and the persistence of the foam is further improved. Among these, polyoxyethylene alkyl ether, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene hydrogenated castor oil and the like are more preferable. Use of such an O / W type microemulsion containing a nonionic surfactant having an HLB of 10 to 20 is preferable because foaming of the solid soap composition is improved, and quick foaming properties and foaming properties are improved.

As the polyoxyethylene alkyl ether, those having an alkyl group having 8 to 40 carbon atoms and an oxyethylene group (hereinafter also referred to as EO) having a number average addition mole number of 10 to 50 are preferable. Examples include ethylene octyl ether, polyoxyethylene lauryl ether, polyoxyethylene myristyl ether, polyoxyethylene palmityl ether, polyoxyethylene isostearyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene cholesteryl ether It is done. Among these, those having an alkyl group having 12 to 40 carbon atoms and having an EO number average addition mole number of 10 to 30 or 15 to 30 are preferable, for example, polyoxyethylene cholesteryl ether and the like are more preferable.

As the polyoxyethylene alkylphenyl ether, those having an alkyl group having 8 to 22 carbon atoms and a number average addition mole number of EO of 10 to 50 are preferable. For example, polyoxyethylene octylphenyl ether, polyoxyethylene nonyl And phenyl ether. Among these, those having an alkyl group having 12 to 20 carbon atoms and having an EO number average addition mole number of 15 to 30 are preferable.

The polyoxyethylene polyoxypropylene alkyl ether has an alkyl group having 8 to 22 carbon atoms, the number average addition mole number of EO is 10 to 50 (preferably 20 to 40), an oxypropylene group (hereinafter referred to as PO and PO). The number average addition mole number of (described) is preferably 5 to 10, and examples thereof include polyoxyethylene polyoxypropylene octyl ether, polyoxyethylene polyoxypropylene decyl ether, and polyoxyethylene polyoxypropylene decyl tetradecyl ether. It is done.

As the polyoxyethylene fatty acid ester, those having a fatty acid having 8 to 22 carbon atoms and having an EO number average addition mole number of 10 to 50 are preferable. For example, polyoxyethylene octanoic acid ester, polyoxyethylene lauric acid ester , Polyoxyethylene myristic acid ester, polyoxyethylene palmitic acid ester, polyoxyethylene isostearic acid ester, polyoxyethylene stearic acid ester, polyoxyethylene oleic acid ester and the like. Among them, those having a fatty acid having 12 to 20 carbon atoms and an EO number average added mole number of 10 to 30 are preferable, and for example, polyoxyethylene oleyl ether is more preferable.

The polyoxyethylene sorbitan fatty acid ester preferably has a fatty acid having 8 to 22 carbon atoms and a number average added mole number of EO of 10 to 50. For example, polyoxyethylene sorbitan octanoic acid ester, polyoxyethylene sorbitan Lauric acid ester, polyoxyethylene sorbitan myristic acid ester, polyoxyethylene sorbitan palmitic acid ester, polyoxyethylene sorbitan isostearic acid ester, polyoxyethylene sorbitan stearic acid ester, polyoxyethylene sorbitan oleic acid ester (polyoxyethylene sorbitan monoolein Acid ester, or polyoxyethylene sorbitan monooleate). Among them, those having a fatty acid having 12 to 20 carbon atoms and having an EO number average addition mole number of 10 to 30 are preferable. For example, polyoxyethylene sorbitan monooleate (eg, polyoxyethylene (20) sorbitan monoester) Oleate (polysorbate 80)), polyoxyethylene sorbitan monostearate (for example, polyoxyethylene (20) sorbitan monostearate (polysorbate 60)) and the like are more preferable.

The polyoxyethylene castor oil and the polyoxyethylene hydrogenated castor oil preferably have an EO number average added mole number of 10 to 80, more preferably 30 to 70.
The polyoxyethylene sorbitol tetrafatty acid ester is preferably one having a fatty acid having 8 to 22 carbon atoms and a number average addition mole number of EO of 10 to 50, such as polyoxyethylene sorbitol tetraoctanoic acid ester, polyoxyethylene And ethylene sorbitol tetraoleate. Among these, those having a fatty acid having 12 to 20 carbon atoms and having an EO number average added mole number of 10 to 30 are preferable.

As the polyglycerol fatty acid ester, those having a fatty acid having 12 to 22 carbon atoms are preferable. An example is a polyglycerol fatty acid ester having a degree of polymerization of glycerol of 5 to 12. Examples of the polyglycerin fatty acid ester include decaglyceryl monostearate. As the sucrose fatty acid ester, those having a fatty acid having 12 to 22 carbon atoms are preferable, and examples thereof include sucrose stearate ester.
Examples of the alkyl (poly) glucoside include those having an alkyl group having 8 to 22 carbon atoms, such as decyl glucoside and lauryl glucoside. In one aspect, the microemulsion preferably does not contain alkyl (poly) glucoside. When an alkyl (poly) glucoside is contained, for example, a light soap solid soap composition may cause yellowing over time.

The polyoxyethylene glycerin fatty acid ester is preferably a polyoxyethylene glycerin monofatty acid ester having a fatty acid having 8 to 22 carbon atoms and an EO number average added mole number of 10 to 50, such as polyoxyethylene glycerin monooctanoic acid. Esters, polyoxyethylene glycerol monolaurate, polyoxyethylene glycerol monomyristic ester, polyoxyethylene glycerol monopalmitate, polyoxyethylene glycerol monoisostearate (polyoxyethylene glyceryl isostearate), polyoxyethylene glycerol mono Stearic acid ester, polyoxyethylene glycerol monooleic acid ester and the like can be mentioned. Among them, those having a fatty acid having 12 to 18 carbon atoms and a number average addition mole number of EO of 15 to 30 are preferable. For example, polyoxyethylene glycerin monoisostearate is preferable.
The polyether-modified silicone having an HLB of 10 to 20 preferably has a polyoxyethylene group having a number average addition mole number of EO of 10 to 50 as a polyether group. For example, the number average addition mole number of EO is 10 To 50 polyoxyethylene / methylpolysiloxane copolymers (for example, PEG-12 dimethicone, etc.).

Anionic surfactants include fatty acid salts, alkyl ether carboxylates, acyl lactates, N-acyl sarcosine salts, N-acyl glutamates, N-acyl methyl alanine salts, N-acyl methyl taurates, alkane sulfonates, α-olefin sulfonate, α-sulfo fatty acid methyl ester salt, alkyl sulfosuccinate, acyl isethionate, alkyl sulfate ester, alkyl ether sulfate ester, polyoxyethylene alkyl ether sulfate, fatty acid alkanolamide sulfate, Examples thereof include monoacylglycerol sulfate ester salts, monoalkyl phosphate ester salts, polyoxyethylene alkyl ether phosphates or salts thereof, and polyoxyethylene alkyl ether phosphate ester salts. These may be used alone or in combination of two or more.
Examples of the salt include alkali metal salts such as sodium and potassium; organic amine salts such as ethanolamine, etc. Among them, sodium salts and potassium salts are more preferable, and sodium salts are more preferable.

Among the anionic surfactants, polyoxyethylene alkyl ether phosphates, N-acyl glutamates, polyoxyethylene alkyl ether phosphates or salts thereof are preferred, and polyoxyethylene alkyl ether phosphates or salts thereof are more preferred.

Examples of fatty acid salts include fatty acid alkali salts having 8 to 22 carbon atoms, metal soaps, and the like.
Examples of the alkyl ether carboxylate include alkyl ether carboxylates having 8 to 22 carbon atoms in the alkyl group or polyoxyethylene alkyl ether carboxylates.
Acyl lactate, N-acyl sarcosine salt, N-acyl glutamate, N-acyl methyl alanine salt, N-acyl methyl taurate, acyl isethionate, monoacyl glycerol sulfate ester salt, for example, Those of 8 to 22 are preferred.

Alkane sulfonate, α-olefin sulfonate, α-sulfo fatty acid methyl ester salt, alkyl sulfosuccinate, alkyl sulfate ester salt, alkyl ether sulfate ester salt, polyoxyethylene alkyl ether sulfate salt, fatty acid alkanolamide sulfate salt As monoalkyl phosphate ester salts, for example, those having 8 to 22 carbon atoms are preferred. As the polyoxyethylene alkyl ether sulfate, for example, EO having a number average addition mole number of 5 to 50 is preferable.

The polyoxyethylene alkyl ether phosphoric acid or a salt thereof preferably has, for example, an alkyl group having 8 to 22 carbon atoms and a number average addition mole number of EO of 5 to 50, and alkyl having 12 to 20 carbon atoms. More preferably, the EO has a number average added mole number of EO of 5 to 20. Examples thereof include polyoxyethylene lauryl ether phosphoric acid, polyoxyethylene tridecyl ether phosphoric acid, polyoxyethylene myristyl ether phosphoric acid, polyoxyethylene pentadecyl ether phosphoric acid, and salts thereof. As polyoxyethylene alkyl ether phosphoric acid or a salt thereof, dipolyoxyethylene (POE) (8) (C12-15) alkyl ether phosphoric acid or a salt thereof is also preferably used.

The polyoxyethylene alkyl ether phosphate ester salt preferably has an alkyl group having 8 to 22 carbon atoms and has an EO number average addition mole number of 10 to 50. For example, polyoxyethylene decyl ether phosphate ester Salt, polyoxyethylene lauryl ether phosphate ester salt and the like.

The oil component used as the component (b2) is not particularly limited. For example, those generally used in cosmetics can be preferably used. The oil component of component (b2) is preferably at least one oil selected from the group consisting of vegetable oils, animal oils, ester oils, ether oils, higher fatty acids, silicone oils, essential oils and hydrocarbon oils, for example.
One type of oil component may be used, or two or more types may be used in combination.

Examples of vegetable oils include olive oil, argan oil, jojoba oil, linseed oil, camellia oil, sunflower oil, almond oil, rapeseed oil, sesame oil, soybean oil, peanut oil, avocado oil, grape seed oil, castor oil, and shea butter. .
Examples of animal oil include horse oil.

Examples of ester oils include octyldodecyl myristate, isopropyl palmitate, butyl stearate, myristyl myristate, isopropyl myristate, di-2-ethylhexyl adipate, diisopropyl sebacate, neopentyl glycol dicaprate, trioctanoin, ethyl Examples include cetyl hexanoate.

Examples of ether oils include dioctyl ether, cetyl dimethyl butyl ether, ethylene glycol octyl ether, ethylene glycol dioctyl ether, and glycerol monooleyl ether.

Examples of higher fatty acids include eicosenoic acid, isomyristic acid, capric acid and the like.
Examples of silicone oils include dimethylpolysiloxane, cyclic dimethylpolysiloxane, methylphenylpolysiloxane, amino-modified silicone, epoxy-modified silicone, carboxy-modified silicone, alcohol-modified silicone, alkyl-modified silicone, polyether-modified silicone, and fluorine-modified silicone. Can be mentioned.

Examples of essential oils include orange oil and lavender oil.
Examples of the hydrocarbon oil include liquid paraffin, squalane, squalene, n-hexadecane and the like.

In one embodiment, the oil component used for the component (b2) of the O / W type microemulsion preferably has a melting point of 60 ° C. or less, and more preferably 50 ° C. or less.
Moreover, when using the monohydric alcohol of the component (b4) and / or the polyhydric alcohol of the component (b5), which will be described later, in the internal phase (oil phase) of the O / W type microemulsion, It is preferable to select those having a boiling point or lower and soluble in the alcohol. For example, when ethanol is used as the component (b4) and the component (b4) is contained in the internal phase of the O / W type microemulsion, it is preferable to use an oily component having a melting point of 78 ° C. or less.

The oil component to be blended in the microemulsion can be appropriately selected according to the performance desired for the solid soap composition. In one embodiment, the oily component used in component (b2) is preferably vegetable oil, more preferably argan oil, jojoba oil, olive oil or the like. For example, when argan oil or jojoba oil is used, the moisturizing effect of the solid soap composition can be improved. Further, for example, when olive oil is used, the cleaning effect of removing the makeup (make-up) and sebum dirt of the solid soap composition is improved.
In the present invention, by adding an oil component to the microemulsion, the solid soap composition can be provided with a moisturizing action, a cleaning action, etc., which the oil component has.

Water used as the component (b3) can be tap water, ion-exchanged water, distilled water or the like, preferably ion-exchanged water or distilled water.

In the case of the O / W type microemulsion, the content of the component (b1) is more preferably 0.15 to 10% by mass, and further preferably 0.3 to 5% by mass. The content of component (b2) is preferably 0.05 to 5% by mass, more preferably 0.07 to 1% by mass. The content of component (b3) is more preferably 60 to 95% by mass, and further preferably 70 to 90% by mass.
The blending ratio of the component (b1) and the component (b3) is preferably (b1) / (b3) = 1/100 to 1/10, more preferably 1/100 to 1/50, as a mass ratio. The mixing ratio of the component (b2) and the component (b3) is preferably (b2) / (b3) = 1/1000 to 1/50, more preferably 1/900 to 1/100 in terms of mass ratio.

<Water-in-oil type (W / O type) microemulsion>
In the solid soap composition of the present invention, a W / O type microemulsion may be used as the microemulsion. In the O / W type microemulsion, the outer phase is an oily phase. The W / O type microemulsion contains 0.1 to 20% by mass of the component (b1), 50 to 99% by mass of the component (b2), and 0.01 to 10% by mass of the component (b3). It is preferable to do. The content (% by mass) of the components (b1) to (b3) is the content (% by mass) in 100% by mass of the microemulsion. In one embodiment, the content of component (b3) may be 0.001 to 10% by mass.

In the case of the W / O type microemulsion, the nonionic surfactant having an HLB of 1 to 7 is preferable as the nonionic surfactant in the component (b1). One nonionic surfactant having 1 to 7 HLB may be used, or two or more nonionic surfactants may be used. As an example, the content of the nonionic surfactant having an HLB of 1 to 7 in the component (b1) is preferably 90% by mass or more, more preferably 95% by mass or more, for example, 90 to 100% by mass, 100 mass% is more preferable. In the case of the W / O type, a nonionic surfactant having an HLB of 1 to 7 is preferred as the component (b1).
Nonionic surfactants having an HLB of 1 to 7 include, for example, polyoxyethylene difatty acid ester, monoglycerin monofatty acid ester, monoglycerin difatty acid ester, diglycerin monofatty acid ester, monoglycerin monoalkyl ether, diglycerin monoalkyl ether Sorbitan fatty acid ester, polyether-modified silicone and the like. Each of these may be used alone or in combination of two or more.

Monoglycerin monofatty acid ester and monoglycerin difatty acid ester are preferably monoglycerin and mono- or diesters of fatty acids having 8 to 22 carbon atoms, such as monoglycerin octanoic acid ester, monoglycerin 2-ethylhexanoic acid ester, monoglycerin. Decanoic acid ester, monoglycerin lauric acid ester, monoglycerin myristic acid ester, monoglycerin palmitic acid ester and the like are preferable.

The diglycerin monofatty acid ester is preferably an ester of diglycerin and a fatty acid having 8 to 22 carbon atoms, such as diglycerin octanoic acid ester, diglycerin lauric acid ester, diglycerin myristic acid ester, diglycerin palmitic acid ester, etc. Is mentioned.
Monoglycerol monoalkyl ether is preferably glycerol and an ether of an alkyl group having 8 to 22 carbon atoms. For example, monoglycerol octyl ether, monoglycerol decyl ester, monoglycerol lauryl ether, monoglycerol myristyl ether, monoglycerol palmityl ether. Etc.

The diglycerol monoalkyl ether is preferably an ether of diglycerol and an alkyl group having 8 to 22 carbon atoms, and examples thereof include diglycerol octyl ether, diglycerol lauryl ether, diglycerol myristyl ether, and diglycerol palmityl ether. .
The sorbitan fatty acid ester is preferably an ester of a fatty acid having 8 to 22 carbon atoms, such as sorbitan octanoic acid ester, sorbitan caprylic acid ester, sorbitan capric acid ester, sorbitan lauric acid ester, sorbitan myristic acid ester, sorbitan palmitic acid ester, etc. Is mentioned.
The polyether-modified silicone having an HLB of 1 to 7 has a polyoxyethylene polyoxypropylene group having a number average addition mole number of EO of 10 to 20 and a number average addition mole number of PO of 1 to 10 as a polyether group. Preferred are, for example, cetyl dimethicone copolyol (cetyl PEG / PPG-10 / 1 dimethicone) and the like.

Among these, nonionic surfactants having an HLB of 1 to 7 are preferably polyoxyethylene difatty acid ester, monoglycerin monofatty acid ester, monoglycerin difatty acid ester, diglycerin monofatty acid ester, and polyether-modified silicone. Silicone is more preferred. Use of such a microemulsion containing a nonionic surfactant having an HLB of 1 to 7 as the W / O type microemulsion is preferred because the foam quality and foam persistence of the solid soap composition become better. Moreover, since foaming of a solid soap composition improves and quick foaming property and foaming property improve, it is preferable.

The component (b2) in the W / O type microemulsion is the same as the component (b2) used in the O / W type microemulsion described above, and can be appropriately selected. One type of component (b2) may be used, or two or more types may be used in combination. Among them, those having a melting point of 60 ° C. or lower are preferable, those having a melting point of 50 ° C. or lower are more preferable, vegetable oils are more preferable, and olive oil, jojoba oil, argan oil, and the like are still more preferable.

In the case of the W / O type microemulsion, the content of the component (b1) is more preferably 0.15 to 10% by mass, and further preferably 0.5 to 5% by mass. The content of component (b2) is more preferably 60 to 99% by mass, and further preferably 70 to 99% by mass. The content of component (b3) is preferably 0.05 to 5% by mass, more preferably 0.07 to 1% by mass.

In the microemulsion (O / W type and W / O type) in the present invention, optional components other than the above components (b1) to (b3) can be appropriately blended as long as the effects of the present invention are not impaired.
For example, the microemulsion preferably further contains (b4) a monohydric alcohol having 1 to 4 carbon atoms (hereinafter also referred to as component (b4)). Component (b4) is suitably used as a surfactant and a solvent for the oil component. Use of component (b4) is preferred because a microemulsion is more easily formed and becomes stable. Examples of the monohydric alcohol having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, isopropanol, butanol and the like. These may be used alone or in combination of two or more. Of these, ethanol is preferred.
When the microemulsion contains the component (b4), the content thereof is preferably 0.01 to 20% by mass, more preferably 0.1 to 20% by mass, and more preferably 1 to 20% by mass in the microemulsion. It is preferably 2 to 15% by mass.

The microemulsion may further contain (b5) a polyhydric alcohol (hereinafter also referred to as component (b5)). The microemulsion preferably contains components (b4) and / or (b5). The polyhydric alcohol is preferably, for example, a polyhydric alcohol having 2 to 10 carbon atoms, more preferably 2 to 8 carbon atoms, still more preferably 2 to 6 carbon atoms, particularly preferably 2 to 4 carbon atoms. It is a polyhydric alcohol.
The component (b5) is suitably used as a surfactant and a solvent for oily components. Use of component (b5) is preferable because a microemulsion is more easily formed and becomes stable. The polyhydric alcohol is preferably a compound having two or more hydroxyl groups that can be blended in cosmetics, for example, ethylene glycol, 1,2-propanediol (propylene glycol), 1,3-propanediol (propanediol), 1 , 2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 2,3-butylene glycol, dipropylene glycol and other dihydric alcohols; glycerin (glycerol) and other trivalent alcohols; diglycerin And tetravalent alcohols. These may be used alone or in combination of two or more. Of these, divalent or trivalent alcohols are preferable, and 1,3-propanediol, 1,3-butylene glycol, and the like are preferable.
When the microemulsion contains the component (b5), the content thereof is preferably 0.01 to 20% by mass, more preferably 0.1 to 20% by mass, and more preferably 1 to 20% by mass in the microemulsion. It is preferably 2 to 15% by mass.
When the microemulsion contains the component (b4) and / or the component (b5), in one embodiment, the total content of the component (b4) and the component (b5) is preferably 0.01 to 30% by mass in the microemulsion. 0.02 to 30% by mass is preferable, 0.1 to 25% by mass is more preferable, 0.2 to 25% by mass is more preferable, 1 to 25% by mass is further preferable, and 2 to 20% by mass is further preferable. .

In addition to the above-mentioned components, the microemulsion may contain a moisturizer, emollient, cationic surfactant, thickener, pH adjuster, antioxidant, preservative, fragrance, pigment, plant extract, etc. You may contain 1 type, or 2 or more types of arbitrary components. The microemulsion may contain an amphoteric surfactant, but in one aspect, preferably does not contain an amphoteric surfactant. When the amphoteric surfactant is contained, the stability of the microemulsion may be easily lowered.

The microemulsion in the present invention is a thermodynamically stable one-phase composition containing the above-described surfactant, oil component and water. The microemulsion according to the present invention has a transparent or translucent appearance as a property, and is a one-phase solution in which all components to be blended are uniformly dissolved. It can usually be confirmed visually that it is one phase.
In one embodiment, the microemulsion in the present invention preferably has an average particle size of dispersed particles of 10 to 200 nm, more preferably 30 to 150 nm. The average particle diameter here is a value measured by a laser diffraction / scattering method, and means a median particle diameter (D50) by a scattered light intensity distribution. When the average particle size of the dispersed particles is in the above range, it is usually preferable because the microemulsion becomes transparent or translucent.

<Preparation method of microemulsion>
The method for preparing the microemulsion is not particularly limited. For example, the method described below can be used.
(1) The components contained in the inner phase of the microemulsion are weighed, mixed and stirred to prepare a uniform solution of the inner phase components. At this time, heating may be performed as necessary. In particular, when the component corresponding to the inner phase includes a solid component, it is preferable to sufficiently dissolve it by heating.
(2) Weigh the component corresponding to the outer phase. At this time, it may be heated as necessary. When the component corresponding to the outer phase includes a solid component, it is preferably heated and sufficiently dissolved to obtain a uniform solution of the outer phase component.
(3) While stirring the solution of the outer phase component of (2), the solution of the inner phase component prepared in (1) is gradually added.
(4) Stir until it becomes one phase visually.
In the above (4), a microemulsion is usually formed if it is visually one-phase (transparent or translucent, sometimes slightly pale). If desired, a step of preparing the microemulsion to a predetermined pH (preferably 9 to 11) may be performed.
The optional components (component (b4), component (b5), etc.) that can be added as desired are mixed and blended when preparing the solution of the inner phase component, or the solution of the outer phase component is prepared. When mixed, it is blended.

For example, in the case of an O / W type microemulsion, the components (b1) and (b2) are usually used as components corresponding to the inner phase, and the component (b3) is used as a component corresponding to the outer phase.
When preparing an O / W type microemulsion, first, components (b1) and (b2) are mixed to prepare a uniform solution containing components (b1) and (b2). When preparing this solution, you may heat as needed. Next, a homogeneous solution containing the components (b1) and (b2) is gradually added while stirring the component (b3). By stirring after the addition, an O / W type microemulsion can be obtained.
Optional components that can be added as desired (components (b4), (b5), etc.) are mixed and mixed when preparing a solution containing components (b1) and (b2), or component (b3) To be mixed. When an optional component is added to the internal phase (oil phase) in the O / W type microemulsion, when preparing a solution containing the components (b1) and (b2), in addition to the components (b1) and (b2) Any component may be mixed. What is necessary is just to mix an arbitrary component with the water of a component (b3), when mix | blending an arbitrary component with an outer phase (aqueous phase).
In the case of a W / O type microemulsion, components (b1) and (b3) are usually used as components corresponding to the inner phase (aqueous phase), and component (b2) is used as a component corresponding to the outer phase (oil phase). And can be prepared by the methods described above.

<Solid soap composition>
The solid soap composition of the present invention is a solid soap composition containing (A) a soap base and (B) a microemulsion. One type of microemulsion may be used, or two or more types may be used in combination. The solid soap composition of the present invention contains (A) a soap base and (B) a microemulsion, and the microemulsion is preferably uniformly dispersed in the solid soap composition.
The solid soap composition of the present invention can be applied to either mechanical soap (mechanical soap composition) or framed soap (framed soap composition).

The blending amount (blending ratio) of the soap base (A) in the solid soap composition can usually be 20 to 99% by mass, preferably 20 to 95% by mass, more preferably 22 to 90% by mass, The preferred range is 25 to 88% by mass.
As one aspect, for example, in the case of mechanical soap, the blending amount of soap base is preferably 50 to 99% by mass, more preferably 60 to 95% by mass, and further preferably 65 to 90% by mass in the solid soap composition. 70 to 88% by mass is particularly preferable. From the viewpoint of improving foaming, (A) the amount of soap base is better, but if there is a lot of soap base, the detergency that removes sebum etc. will increase, so if the skin is burdened or after washing Skin tightness may be a problem. (A) When the blending amount of the soap base is within the above range, the foaming of the solid soap composition is good and, if desired, a component having a moisturizing action can be blended into the solid soap composition. For this reason, the feeling of use such as washing up can be further improved, which is preferable. As an aspect, in the case of framed soap, the blending amount of soap base is preferably 20 to 70% by mass, more preferably 20 to 65% by mass, and further preferably 20 to 60% by mass in the solid soap composition. 22 to 50% by mass is even more preferable, and 25 to 45% by mass is particularly preferable.

(B) The blending amount of the microemulsion is preferably 0.15% by mass or more, preferably 0.2% by mass or more, or 0.005% or more in the solid soap composition because the foam quality of the solid soap composition is good. 25 mass% or more is more preferable, and 0.3 mass% or more is further more preferable. Moreover, the blending amount of the microemulsion is, for example, preferably 12% by mass or less, more preferably 10% by mass or less, and further preferably 5% by mass, 4% by mass or 3% by mass or less in the solid soap composition. These lower limit values and upper limit values can be arbitrarily combined.

In one embodiment, the blending amount of the (B) microemulsion is preferably 0.15 to 12% by mass, more preferably 0.15 to 10% by mass in the solid soap composition. A blending amount of the microemulsion within the above range is preferable because the foam quality of the solid soap composition is good. Moreover, when manufacturing a solid soap composition, since a moldability is favorable and any method of a mechanical kneading method and a frame kneading method can be employ | adopted, it is preferable. In one embodiment, the upper limit of the amount of the microemulsion is preferably 5% by mass or less in the solid soap composition. When the blending amount of the microemulsion is 5% by mass or less, the moldability becomes better when producing the solid soap composition. The blending amount of the microemulsion is more preferably 0.15 to 5% by mass in the solid soap composition. When the blending amount of the microemulsion is in the above range, the foam quality of the solid soap composition is good, and the foam has elasticity and stringiness. Moreover, the persistence of foam is good. Moreover, the moldability at the time of manufacturing a solid soap composition is also good. In one embodiment, the blending amount of the microemulsion is more preferably 0.15 to 4% by mass, and particularly preferably 0.2 to 3% by mass in the solid soap composition. In one embodiment, the blending amount of the microemulsion is preferably 0.2 to 5% by mass, more preferably 0.25 to 4% by mass, and further preferably 0.25 to 3% by mass. When two or more types of microemulsions are used, the blending amount of the microemulsions is the sum of them.

The blend ratio of (A) soap base to (B) microemulsion in the solid soap composition is (B) / (A), preferably 1/2000 or more, 1/1500 or more, or 1/1000 in mass ratio. More preferably, it is 1/600 or more, 1/500 or more, or 1/400 or more, more preferably 1/350 or more, and particularly preferably 1/300 or more. The mass ratio (B) / (A) is preferably 1/15 or less, more preferably 1/18 or less, 1/20 or less or 1/25 or less, further preferably 1/50 or less, particularly preferably. Is 1/60 or less. These lower limit values and upper limit values can be arbitrarily combined.
As an example, the blending ratio of (A) soap base to (B) microemulsion in the solid soap composition is preferably (B) / (A) of 1/2000 to 1/15 by mass ratio, and 1/1500. To 1/15 is more preferable, 1/1000 to 1/15 is more preferable, 1/1000 to 1/18 is more preferable, 1/1000 to 1/20 is more preferable, and 1/1000 to 1/50 is further More preferably, 1/600 to 1/60, 1/500 to 1/60, 1/400 to 1/60, 1/350 to 1/60, or 1/300 to 1/60 are particularly preferable. In one embodiment, the blending ratio of (A) soap base to (B) microemulsion in the solid soap composition is preferably (B) / (A) 1/600 to 1/15 in terms of mass ratio. 1/500 to 1/15 is preferable, 1/400 to 1/20 is more preferable, 1/350 to 1/25 is more preferable, and 1/300 to 1/25 is particularly preferable.
When the blending ratio of the soap base and the microemulsion in the solid soap composition is in the above range, the foam quality is better, and the foam has elasticity and stringiness. Moreover, since the sustainability of foam is favorable, it is preferable.

As an example of a preferred embodiment in the present invention, for example, (A) the soap base is selected from the group consisting of lauric acid, myristic acid, palmitic acid, stearic acid and isostearic acid (more preferably lauric acid, myristic acid and palmitic acid). Solid soap compositions containing the following O / W type microemulsions and / or W / O type microemulsions as (B) microemulsions are used as the alkali salt of at least one saturated fatty acid.
The nonionic surfactant in (b1) is a nonionic surfactant having an HLB of 10 to 20, and the nonionic surfactant having an HLB of 10 to 20 is a polyoxyethylene alkyl ether or a polyoxyethylene polyoxypropylene alkyl ether. , Polyoxyethylene sorbitan fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene hydrogenated castor oil, polyglycerin fatty acid ester and polyether-modified silicone (more preferably, polyoxyethylene alkyl ether, polyoxyethylene sorbitan fatty acid ester, A polyoxyethylene glycerin fatty acid ester and a polyoxyethylene hydrogenated castor oil).
The anionic surfactant is at least one selected from the group consisting of polyoxyethylene alkyl ether phosphates, N-acyl glutamates, and polyoxyethylene alkyl ether phosphates or salts thereof, more preferably polyoxy O / W type microemulsion which is at least one of ethylene alkyl ether phosphoric acid and its salt;
The nonionic surfactant in (b1) is a nonionic surfactant having an HLB of 1 to 7, and the nonionic surfactant having an HLB of 1 to 7 is a polyoxyethylene difatty acid ester, monoglycerin monofatty acid ester, mono W / O type microemulsion which is at least one selected from the group consisting of glycerin difatty acid ester, diglycerin monofatty acid ester and polyether modified silicone, more preferably polyether modified silicone

The solid soap composition may further contain components (hereinafter also referred to as other components) other than (A) the soap base and (B) the microemulsion unless the effects of the present invention are impaired. For example, moisturizers (wetting agents), emollients, bactericides, chelating agents, surfactants (emulsifiers), inorganic salts, stabilizers (antioxidants, UV absorbers), plant extracts, fragrances, colorants ( 1 type or 2 types or more of components that can be used in solid soap such as water).

Examples of the humectant include hyaluronic acid, collagen, polyhydric alcohol and the like. Examples of the polyhydric alcohol include glycerin, propylene glycol, 1,3-butylene glycol, sorbitol, sucrose, trehalose and the like. When the polyhydric alcohol is blended in the solid soap composition, the blending amount thereof is, for example, mechanical soap, preferably 0.01 to 2% by mass, more preferably 0.1 to 1% in the solid soap composition. % By mass. When polyhydric alcohol is blended with framed soap, the blending amount is preferably 20 to 40% by mass, more preferably 25 to 35% by mass in the solid soap composition.

Examples of the emollient include oily components used as the component (b2) described above. Examples of the disinfectant include trichlorocarbanide, triclosan, isopropylmethylphenol, and the like.

Examples of the chelating agent include pentetate pentasodium salt (pentetate 5Na), etidronate tetrasodium salt (etidronate 4Na), ethylenediaminetetraacetic acid or a salt thereof, citric acid or a salt thereof, and the like. Examples of the salt include sodium salt and potassium salt.
Examples of the surfactant include the above-described anionic surfactants, nonionic surfactants, and cationic surfactants. Examples of the anionic surfactant include alkyl ether sulfates and polyoxyethylene alkyl ether sulfates (sodium laureth sulfate and sodium lauryl sulfate). The fatty acid alkali salt and microemulsion components used as soap base are not included in the surfactant used as other components in the solid soap composition.

Examples of inorganic salts include sodium chloride, potassium chloride, sodium sulfate, sodium carbonate and the like.
Examples of the antioxidant include tocopherol (vitamin E) and ascorbic acid (vitamin C). Examples of plant extracts include tea leaf extract and oolong tea extract. The solid soap composition includes, as other components, fatty acids having 8 to 22 carbon atoms (preferably fatty acids having 12 to 18 carbon atoms such as stearic acid, lauric acid, myristic acid) and monohydric alcohols (for example, (Ethanol, propanol, butanol).

When the solid soap composition contains water, the blending amount thereof is preferably 1 to 30% by mass in the solid soap composition. The water in this case is water contained as other components. In the case of mechanical soap, the amount of water is preferably 1 to 20% by mass, more preferably 1 to 10% by mass in the solid soap composition. In the case of framed soap, the blending amount of water is preferably 10 to 30% by mass, more preferably 15 to 30% by mass in the solid soap composition. As water, the tap water, ion-exchange water, distilled water, etc. which were mentioned above can be used.
1 type, or 2 or more types can be used for another component, respectively. In addition, although an example of the other component was mentioned above, these may be mix | blended for the objectives other than the above according to the effect | action or property. For example, a substance exemplified as a chelating agent may be blended as a bactericidal agent or a stabilizer.

The solid soap composition of the present invention can be produced by using the soap base composition containing the soap base and the microemulsion, and other components blended as desired. The soap base composition can be obtained by kneading the above components.

The form of the solid soap composition of the present invention is not particularly limited. For example, a solid, sheet, powder or granule is preferable.
The solid soap composition of the present invention can be used, for example, for cleaning the face, body skin, and hair. For example, it is suitably used for skin cleaning, and particularly preferably used as a makeup remover composition.

<Method for producing solid soap composition>
The solid soap composition of the present invention comprises a step of preparing a soap base composition by kneading at least (A) a soap base and (B) a microemulsion containing the following components (b1) to (b3): It can manufacture with the manufacturing method containing.
(B1) At least one surfactant selected from the group consisting of nonionic surfactants and anionic surfactants (b2) at least one oily component (b3) water A method for producing a solid soap composition comprising the above steps Is also one aspect of the present invention. The method for producing the solid soap composition of the present invention (hereinafter also simply referred to as the production method of the present invention) is preferable as the method for producing the solid soap composition of the present invention described above.
The production method of the present invention may include a step other than the step of preparing the soap base composition, and may include, for example, a step of preparing a microemulsion.

The soap base and microemulsion in the production method of the present invention and preferred embodiments thereof are the same as those in the above-described solid soap composition of the present invention. The fatty acid alkali salt and microemulsion used as the soap base may be used singly or in combination of two or more. In preparing the soap base composition, at least (A) the soap base and (B) the microemulsion may be kneaded. In addition to these components (A) and (B), the other components described above may be added as desired. You may mix | blend. The blending amount of each component such as soap base and microemulsion should be set appropriately so that the blending amount in the obtained solid soap composition is in the above-mentioned range. Is preferred. For example, the blending amount of the microemulsion is, for example, preferably 0.15 to 12% by mass, more preferably 0.15 to 10% by mass, further preferably 0.15 to 5% by mass in the solid soap composition. 15 to 4% by mass is particularly preferable, and 0.2 to 3% by mass is particularly preferable. In one embodiment, the blending amount of the microemulsion is preferably 0.2 to 5% by mass, more preferably 0.25 to 4% by mass, and further preferably 0.25 to 3% by mass in the solid soap composition.
The blending amount of the microemulsion when producing such a solid soap composition is, for example, preferably 0.15 to 12% by mass, more preferably 0.15 to 10% by mass in the soap base composition, and 0 15 to 5% by mass is more preferable, 0.15 to 4% by mass is particularly preferable, and 0.2 to 3% by mass is particularly preferable. In one embodiment, the blending amount of the microemulsion is preferably 0.2 to 5% by mass, more preferably 0.25 to 4% by mass, and further preferably 0.25 to 3% by mass in the soap base composition.
It is also preferable to appropriately set the blending ratio of (A) the soap base and the microemulsion so that the mass ratio of (B) / (A) in the obtained solid soap composition is in the above-described range.

In the step of preparing the soap base composition, the soap base and the microemulsion, and other components blended as required may be kneaded. Kneading is preferably performed until the components are uniform. The order of kneading these components is not particularly limited. The method of kneading is not particularly limited, and may be kneaded by stirring with a mixer or the like. The raw materials such as soap base and microemulsion may be added all at once, or may be added in a plurality of times. For example, soap base, microemulsion and other ingredients optionally blended may be kneaded at once; after soap base and other ingredients are kneaded, microemulsion may be added and kneaded; After kneading some other ingredients and soap base, the remaining other ingredients and microemulsion may be added and kneaded; after kneading soap base and microemulsion, add other ingredients You may knead. During kneading, heating may be performed as desired.
A solid soap composition can be obtained by applying a general method such as a frame kneading method or a mechanical kneading method to the soap base composition obtained by the above steps.

For example, in the case of a mechanical kneading method, the soap base composition can be used as it is as a solid soap composition. For example, when it is set as a solid soap composition, it can be processed into the shape of solid soap by cutting or stamping the soap base composition. It is also preferable to pulverize the soap base composition and knead it so that it is more uniform. In this case, the solid soap composition can then be obtained by extruding into a rod shape or the like with an extruder and then cutting or stamping to a desired size.
In the case of the frame kneading method, the soap base composition is poured into a frame, solidified, and then cut into a desired size to produce a solid soap composition (frame kneading soap composition). If necessary, it may be cooled during solidification. Before cutting or after cutting, it may be further dried as necessary, and stamping may be performed after cutting.
When the solid soap composition is powdered, it may be powdered by a method such as cutting the solid soap composition.

<Foam improver of solid soap composition>
The foam improver of the solid soap composition of the present invention comprises a microemulsion containing the following components (b1) to (b3) as an active ingredient.
(B1) At least one surfactant selected from the group consisting of nonionic surfactants and anionic surfactants (b2) At least one oily component (b3) water Improvement in foam quality of the solid soap composition of the present invention The foam quality of the solid soap composition can be improved by adding an agent (hereinafter, also simply referred to as a foam quality improving agent) to the solid soap composition. Moreover, the persistence of the foam of a solid soap composition can be improved. Therefore, by blending the foam improver of the present invention into a solid soap composition, a solid soap composition having good foam quality and foam persistence can be obtained. The solid soap foam improver of the present invention is suitably used for a solid soap composition prepared using a soap base. The foam quality improver can also be referred to as a foam quality improver.

The foam improving agent of the present invention contains the microemulsion.
The microemulsion and its preferred embodiment in the foam improver of the present invention are the same as the microemulsion used in the above-described solid soap composition and its preferred embodiment.
In the foam improving agent, the content of the microemulsion may be 100% by mass, but may contain other components as desired as long as the effects of the present invention are not impaired.

In one aspect, when the foam quality of the solid soap composition is improved by the foam quality improver of the present invention, the foam quality improver may be added to the soap base in the production of the solid soap composition. It is preferable to mix the foam improver so that the microemulsion is contained in the solid soap composition in the amount described for the solid soap composition of the present invention. As an example, it is preferable to blend a foam improver in the solid soap composition so as to be 0.15 to 12% by mass as a microemulsion. As an example, the blending amount of the foam improver is preferably 0.15 to 10% by mass, more preferably 0.15 to 5% by mass, and more preferably 0.15 to 4% by mass as a microemulsion in the solid soap composition. % Is particularly preferable, and 0.2 to 3% by mass is particularly preferable. In one embodiment, the blending amount of the foam improver is 0.2 to 5% by mass, 0.25 to 4% by mass, 0.25 to 3% by mass, or the like in the solid soap composition as the microemulsion blending amount. Is also preferable.
In the production of the solid soap composition, a method for improving the foam quality of the solid soap composition in which the microemulsion is added to a soap base is also included in the present invention. Preferably, in the production of the solid soap composition, the soap base and the microemulsion are kneaded. The soap base is not particularly limited, and those described above can be used. By using microemulsions, the foam quality and foam persistence of the solid soap composition can be improved.
Moreover, the foam improvement agent of this invention can also be used, without mix | blending with a solid soap composition. When the solid soap composition is used, for example, by adding a foam improver to the diluted solution of the composition and foaming, the foam quality and the persistence of the foam can be improved. In this case, the amount of the foam improver used is, for example, preferably 0.15 to 12% by mass, more preferably 0.15 to 12% by weight of the microemulsion with respect to the total amount of the solid soap composition and the foam improver. It is preferable to use 10% by mass, more preferably 0.15 to 5% by mass, particularly preferably 0.15 to 4% by mass or 0.2 to 3% by mass. In one embodiment, the amount of the foam improver used is 0.2 to 5% by mass, 0.25 to 4% by mass, or 0.005% as a microemulsion based on the total amount of the solid soap composition and the foam improver. 25 to 3% by mass is also preferable.

The present invention also includes the use of a microemulsion containing the above components (b1) to (b3) for producing a foam improver of a solid soap composition. The present invention also includes the use of a microemulsion containing the above components (b1) to (b3) for improving the foam quality of a solid soap composition. The preferred embodiment of the microemulsion, its method of use, etc. are the same as those described above.

Examples that more specifically describe the present invention are shown below. In addition, this invention is not limited only to these Examples. In Examples,% and part mean mass% and part by mass, respectively, unless otherwise specified.

The surfactants and oily components used below are as follows.
(Surfactant)
Monooleic acid polyoxyethylene sorbitan (20E.O.): trade name Nonion OT-221, manufactured by NOF Corporation, display name polysorbate 80, HLB15.7
Polyoxyethylene glyceryl isostearate: Trade name EMALEX GWIS-120, manufactured by Nippon Emulsion Co., Ltd., display name PEG-20 glyceryl isostearate, HLB13
DiPOE (8) (C12-15) alkyl ether phosphate: trade name NIKKOL DDP-8, manufactured by Nikko Chemicals Co., Ltd., display name di (C12-15) Palace-8 phosphate, HLB11.5
Polyoxyethylene cholesteryl ether: trade name EMALEX CS-10, manufactured by Nippon Emulsion Co., Ltd., display name Colles 10, HLB10
Polyoxyethylene (60) hydrogenated castor oil: trade name NIKKOL HCO-60, manufactured by Nikko Chemicals Co., Ltd., display name PEG60 hydrogenated castor oil, HLB 14.0
Cetyl dimethicone copolyol (cetyl PEG / PPG10-1 dimethicone): trade name ABIL EM 90, manufactured by Evonik, HLB3.5
Polyoxyethylene polyoxypropylene polymer: trade name NIKKOL PEN-4630, manufactured by Nikko Chemicals Co., Ltd., display name PPG-6 decyltetradeces-30 (polyoxyethylene polyoxypropylene decyltetradecyl ether), HLB12.0
Decaglyceryl monostearate: trade name NIKKOL Decaglyn 1-SV, manufactured by Nikko Chemicals Co., Ltd., display name: polyglyceryl stearate-10, HLB 12.0
Polyoxyethylene / methylpolysiloxane copolymer: Trade name DOW CORNING TORAY SS-2804, manufactured by Toray Industries, Inc., display name PEG-12 dimethicone, HLB13

(Oil component)
Argan oil: Trade name Lipofructyl (registered trademark) Argan LS 9779, manufactured by BASF, display name Argania spinosa kernel oil Ethylhexanoate cetyl: Trade name NS-CIO, Nippon Seika Co., Ltd. olive oil: Trade name NIKKOL olive oil, Jojoba oil manufactured by Nikko Chemicals Co., Ltd .: trade name NIKKOL jojoba oil S, manufactured by Nikko Chemicals Co., Ltd., display name jojoba seed oil

(Other)
Propanediol (1,3-propanediol): Trade name Zemea (registered trademark) Select Propanediol, manufactured by DuPont Tate & Lyle Bio Products Butylene glycol: 1,3-butylene glycol citrus extract: Trade names Mandarin, Ichimaru Falcos ( Product name, Mandarin orange peel extract (Ingredients: Purified water, 1,3-butylene glycol, chimpi extract)
The water used for the production of the microemulsion is ion exchange water.

The fast foaming property, foaming property, and drainage time of the solid soap composition were evaluated by the following method using the solid soap composition as a soap sample.
Fast foaming property expresses the speed of foaming. Foamability represents the amount of foam. The drainage time represents the persistence (creaminess) of the foam. The longer the drainage time, the better the foam persistence.
(Evaluation methods)
1) Ion-exchanged water or 300 mL of tap water (water temperature: 25 ° C.) was put into a juice mixer (trade name juice mixer, model number JM-N-88, manufactured by JIK type Nakasa). In addition, in the same test system (For example, when comparing the solid soap composition of Example 1 and Comparative Example 1), it evaluated using the same water (ion-exchange water or tap water).
2) A finely powdered soap sample was added to 1) to prepare a sample.
3) The juice mixer was rotated, and the height of the foam was measured after 10 seconds to make it fast foaming.
4) The rotation was stopped after 60 seconds, and the height of the foam was measured to make it foamable.
5) After 60 seconds, the time required for the amount of foam (volume) to be reduced to 200 mL in the mixer was defined as the drainage time (foam persistence).
Hereafter, the data of the Example to show are the average figures of the measured value of n = 3 (3 times).

<Example 1>
O / W type microemulsions (O / W1-1) containing the components shown in Table 1 were prepared by the following method.
(1) Each component of the inner phase was weighed, mixed and stirred while heating to 60 ° C. to obtain a uniform solution.
(2) Each component of the outer phase was weighed and mixed in a container different from the above (1).
(3) The solution obtained in (1) was gradually added while thoroughly stirring the mixed solution obtained in (2) with a spatula.
(4) After completion of the addition, the mixture was stirred for about 0.5 minutes to obtain a one-phase transparent microemulsion visually.

O / W type microemulsions O / W1-2 to O / containing the components shown in Tables 2 to 3 in the same manner as above except that the components shown in Tables 2 to 3 were used for the internal phase and the external phase. W1-3 was prepared.

A soap base composition is obtained by kneading a composition containing the soap base (hereinafter referred to as composition (I)) and microemulsions O / W1-1 to O / W1-3 until uniform at room temperature. It was. This soap base composition was stamped with a stamping machine to obtain a solid soap composition. This solid soap composition is mechanical soap.

The composition (I) used in the following Examples and Comparative Examples is a composition having the following composition containing soap base (fatty acid alkali salt) and other components (components other than soap base and microemulsion) ( The content (%) of the following soap base and other components is the content (%) in the composition (I). In composition (I), 86.5% of soap base is contained.
Composition of composition (I) (soap base)
Myristic acid Na: 32.7%
Myristic acid K: 21.8%
Lauric acid Na: 14.0%
Lauric acid K: 9.3%
Palmitic acid Na: 5.2%
Palmitic acid K: 3.5%
(Other ingredients)
Water: 9.997%
Lauric acid 2.5%
Glycerin: 0.7%
Citric acid: 0.3%
Tocopherol: 0.003%

The blending amount (%) of the microemulsion (ME) is (1) 0.05%, (2) 0.15%, (3) 0.20%, (4) 0.25% in the solid soap composition. Or (5) 0.30%. The blending amount of this microemulsion is the sum of microemulsions O / W1-1 to O / W1-3 (the same amount is used for each microemulsion). For example, when the blending amount of the microemulsion (2) is 0.15%, 99.85 parts of the composition (I) and 0.05 parts of each of the microemulsions O / W1-1 to O / W1-3 (Total 0.15 parts) was used to prepare a soap base composition.
The blending amounts of the microemulsion (ME) and the soap base in the solid soap compositions (1) to (5) prepared in Example 1 are shown below. The mass ratio of ME / soap base is shown in parentheses.
(1) ME 0.05% and soap base 86.46% (ME / soap base = 1/1729)
(2) ME 0.15% and soap base 86.37% (ME / soap base = 1/576)
(3) ME 0.20% and soap base 86.33% (ME / soap base = 1/432)
(4) ME 0.25% and soap base 86.28% (ME / soap base = 1/345)
(5) ME 0.30% and soap base 86.24% (ME / soap base = 1/287)

<Comparative Example 1>
In Example 1, a solid soap composition was obtained by the same method except that no microemulsion was used. The solid soap composition of Comparative Example 1 is a solid soap composition prepared from the composition (I).

Using 0.5 g of each solid soap composition prepared in Example 1 and Comparative Example 1 as a soap sample, the drainage time was evaluated by the above method (soap sample concentration in the sample: 0.5 g / 300 mL). ). The results are shown in Table 4. The rate of increase in drainage time (%) is the solid soap containing the microemulsion relative to the drainage time (T0) (seconds) of the solid soap composition (solid soap composition not containing the microemulsion) of Comparative Example 1. The rate of increase in drainage time (T1) (seconds) of the composition, which was determined by the following calculation.
Drainage time increase rate (%) = 100 × (T1−T0) / T0

The ME blending amount is 0% in Comparative Example 1. When the microemulsion was blended with the solid soap composition, the drainage time became longer. In particular, when 0.15% by mass or more of the microemulsion was added to the solid soap composition, the drainage time was significantly increased.

<Example 2>
An O / W type microemulsion (O / W2-1) containing each component shown in Table 5 was prepared by the same method as in Example 1 except that each component shown in Table 5 was used for the inner phase and the outer phase. .

A W / O type microemulsion (W / O2-1) containing each component shown in Table 6 was prepared in the same manner as described above except that the components shown in Table 6 were used for the internal phase and the external phase.

Composition (I) (75.6 parts), microemulsion O / W2-1 (0.15 parts), microemulsion W / O2-1 (0.15 parts), and other additive components (emulsifier, emollient) Soap agent, wetting agent, stabilizer, fragrance, colorant, etc. in total 24.1 parts) were kneaded until uniform at room temperature to obtain a soap base composition. This soap base composition was stamped with a stamping machine to obtain a solid soap composition. The blending amount of the microemulsion in the solid soap composition was 0.3%, and the blending amount of the soap base was 65.4% (the mass ratio of ME / soap base was 1/218).
In addition, the other additional component used in the Example and the comparative example does not contain a soap base and a microemulsion.

With the above evaluation methods, the fast foaming property, foaming property and drainage time of each solid soap composition prepared in Example 2 and Comparative Example 1 were evaluated. As a soap sample, 1 g of each solid soap composition was used (soap sample concentration in the sample: 1 g / 300 mL). The results are shown in Table 7. The solid soap composition of Example 2 in which the microemulsion was blended had a longer drainage time than the solid soap composition of Comparative Example 1, and was excellent in foam persistence. Moreover, the solid soap composition of Example 2 was excellent in quick foaming property and foaming property.

<Example 3>
Three types of O / W microemulsions (O / W3) containing the components shown in Tables 8 to 10 were used in the same manner as in Example 1 except that the components shown in Tables 8 to 10 were used for the internal phase and the external phase. −1 to O / W3-3) were prepared. Instead of the microemulsion O / W2-1 (0.15 part) and the microemulsion W / O2-1 (0.15 part), these microemulsions O / W3-1 to O / W3-3 were each set to 0.00. A solid soap composition was obtained in the same manner as in Example 2 except that 1 part (0.3 parts in total) was used. The blending amount of the microemulsion in the solid soap composition was 0.3%, and the blending amount of the soap base was 65.4% (the mass ratio of ME / soap base was 1/218).

With the above evaluation methods, the fast foaming property, foaming property, and drainage time of each solid soap composition prepared in Example 3 and Comparative Example 1 were evaluated. As a soap sample, 1 g of each solid soap composition was used (soap sample concentration in the sample: 1 g / 300 mL). The results are shown in Table 11.

<Example 4>
Three types of O / W type microemulsions (microemulsions O / W1-1 to O / W1-3 containing the components shown in Tables 1 to 3) were prepared in the same manner as in Example 1. For the production of soap base composition, composition (I) (86.0 parts), 0.1 part each of microemulsions O / W1-1 to O / W1-3 (0.3 parts in total) and other additions A solid soap composition was obtained in the same manner as in Example 1 except that the components (13.7 parts in total of emulsifier, emollient, wetting agent, stabilizer, fragrance, colorant and the like) were used. The blending amount of the microemulsion in this solid soap composition was 0.3% in the solid soap composition, and the blending amount of soap base was 74.4% (the mass ratio of ME / soap base was 1/248). .

<Comparative example 2>
Tables 1 to 3 show the composition (I) (86.0 parts) and other additional components (emulsifier, emollient, wetting agent, stabilizer, fragrance, colorant, etc., 13.7 parts in total). In the same manner as in Example 4 except that 0.1 parts (total 0.3 parts) of the components (raw materials) of microemulsions O / W1-1 to O / W1-3 were used without being microemulsified. A solid soap composition was obtained.

With the above evaluation method, the fast foaming property, foaming property, and drainage time of each solid soap composition prepared in Example 4 and Comparative Example 2 were evaluated. As a soap sample, 1 g of each solid soap composition was used (concentration in sample: 1 g / 300 mL). The results are shown in Table 12.
The solid soap composition of Example 4 blended with the microemulsion was faster in foaming and foaming than the solid soap composition of Comparative Example 2 in which the components contained in the microemulsion were blended as they were without the microemulsion. Both properties and foam persistence were excellent.

<Example 5>
Three types of O / W type microemulsions (O / W5) containing the components shown in Tables 13 to 15 were used in the same manner as in Example 1 except that the components shown in Tables 13 to 15 were used for the internal phase and the external phase. -1 to O / W5-3) were prepared. Except for using 0.1 parts (total 0.3 parts) of each of the composition (I) (99.7 parts) and microemulsions O / W5-1 to O / W5-3, the same as in Example 1. A solid soap composition was obtained. The blending amount of the microemulsion in this solid soap composition was 0.3%, and the blending amount of the soap base was 86.2% (ME / soap base mass ratio was 1/287).

With the above evaluation method, the fast foaming property, foaming property, and drainage time of each solid soap composition prepared in Example 5 and Comparative Example 1 were evaluated. As a soap sample, 1 g of each solid soap composition was used (soap sample concentration in the sample: 1 g / 300 mL). The results are shown in Table 16.

<Example 6>
Three types of O / W type microemulsions O / W1-1 to O / W1-3 containing the components shown in Tables 1 to 3 were prepared in the same manner as in Example 1. A soap base composition was prepared using the following composition (II) containing soap base and these microemulsions.
The composition (II) (99.7 parts) and microemulsions O / W1-1 to O / W1-3 (each 0.1 parts, 0.3 parts in total) were kneaded until uniform at room temperature. A soap base composition was obtained. The soap base composition was poured into a 100 mL plastic mold, cooled and solidified at room temperature, and then the solid soap composition was taken out of the mold. The blending amount of the microemulsion in the solid soap composition was 0.3%, and the blending amount of the soap base was 25.8% (the mass ratio of ME / soap base was 1/86). This solid soap composition is framed soap.

The composition (II) is a composition having the following composition containing soap base and other components (the content (%) of the soap base and other components below is the content (%) in the composition (II)). ). In the composition (II), 25.9% of soap base is contained.
Composition of composition (II) (soap base)
Na stearate: 16.0%
Lauric acid Na: 8.0%
Myristic acid Na: 1.9%
(Other ingredients)
Water: 29.9%
Glycerin: 14.0%
Propylene glycol (PG): 14.0%
Sorbitol: 6.0%
Laureth sulfate Na: 6.0%
Lauryl sulfate Na: 2.4%
Na chloride: 0.6%
Stearic acid: 0.6%
Lauric acid: 0.2%
Myristic acid: 0.2%
Penteto acid 5Na: 0.1%
Etidronic acid 4Na: 0.1%

<Comparative Example 3>
In Example 6, a solid soap composition was obtained by the same method except that no microemulsion was used. The solid soap composition of Comparative Example 3 is a solid soap composition prepared from the composition (II).

Using 1.0 g of each solid soap composition prepared in Example 6 and Comparative Example 3 as a soap sample, drainage time was evaluated in the same manner as in Example 1 (soap sample concentration in sample: 1 0.0 g / 300 mL). The results are shown in Table 17. The rate of increase in drainage time (%) is that of Example 6 (solid soap composition containing microemulsion) relative to the drainage time (T0) (seconds) of Comparative Example 3 (solid soap composition not containing microemulsion). This is the rate of increase in the drainage time (T1) (seconds) of the product, and was calculated by the same method as in Example 1.
In Table 17, the ME blending amount is 0% in Comparative Example 3. The ME content is 0.3% in Example 6. By blending the microemulsion, the persistence of the foam was improved.

<Test Example 1>
Three types of O / W type microemulsions O / W1-1 to O / W1-3 containing the components shown in Tables 1 to 3 were prepared in the same manner as in Example 1.
The composition (I) was stamped with a stamping machine to obtain a solid soap base composition.
Fast foaming property and drainage time were evaluated by the following evaluation methods.
1) 100 mL of tap water was added to a juice mixer (trade name juice mixer, model number JM-N-88, manufactured by Naka Institute of JIK) (tap water temperature: 25 ° C.).
2) A finely powdered solid soap base composition and microemulsion were added to 1) to prepare a sample.
3) The juice mixer was rotated, and the height of the foam was measured after 10 seconds to make it fast foaming.
4) After 60 seconds, the rotation was stopped and the height of the foam was measured.
5) After 60 seconds, the time required for the amount of foam (volume) to be reduced to 200 mL in the mixer was defined as the drainage time (foam persistence).
The data on the rapid foaming property and the drainage time are shown as average numbers of actually measured values of n = 3 (three times).

The input amounts of the solid soap base composition and the microemulsion (ME) were the following (1) to (4).
(1) Solid soap base composition 0.5 g, (2) Solid soap base composition 0.4985 g and ME 0.0015 g, (3) Solid soap base composition 0.485 g and ME 0.015 g, (4) Solid soap base Composition 0.475g and ME 0.025g
The amount of ME used is (1) 0%, (2) 0.3%, (3) 3.0%, (4) 5 with respect to the total mass of the solid soap base composition and ME. 0.0%. The same amount of each of the microemulsions O / W1-1 to O / W1-3 was used so that the total amount was the above amount. For example, in (2), the amount of microemulsions O / W1-1 to O / W1-3 used is 0.0005 g.
The amount of the soap base used is 86.5% for (1), 86.2% for (2), 83.9% for (3), and (4) based on the total mass of the solid soap base composition and ME. ) Was 82.2%.
The mass ratio of the use amount of soap base and microemulsion (ME / soap base) was (1) 0, (2) 1/287, (3) 1/28, (4) 1/16. It was.

The results are shown in Table 18.
The drainage time increase rate (%) is the drainage time (T1) when the microemulsion is blended with respect to the drainage time (T0) (seconds) of the sample (1) (sample not blended with ME). The rate of increase in (seconds) was calculated by the same method as in Example 6. It can be seen that the microemulsion improves the foam persistence of the solid soap composition.

<Production Example 1>
Three types of O / W type microemulsions O / W1-1 to O / W1-3 containing the components shown in Tables 1 to 3 were prepared in the same manner as in Example 1.
Composition (I) (88 parts) and microemulsions O / W1-1 to O / W1-3 (4 parts each, 12 parts in total) are kneaded until uniform at room temperature to obtain a soap base composition. It was. This soap base composition was stamped with a stamping machine to obtain a mechanically kneaded solid soap composition. The blending amount of the microemulsion in the solid soap composition was 12%, and the blending amount of the soap base was 76% (ME / soap base mass ratio was 1/6).

<Production Example 2>
Solid soap in the same manner as in Production Example 1 except that 97 parts of the composition (I) and 1 part of each of the microemulsions O / W1-1 to O / W1-3 (3 parts in total) were used in Production Example 1. A composition is produced. The blending amount of the microemulsion in the solid soap composition is 3%, and the blending amount of the soap base is 84% (ME / soap base mass ratio is 1/28).

According to the present invention, it is possible to provide a solid soap composition having good foam quality and foam persistence and excellent usability.

Claims (11)

1. A solid soap composition comprising (A) a soap base and (B) a microemulsion containing the following components (b1) to (b3).
   (B1) at least one surfactant selected from the group consisting of nonionic surfactants and anionic surfactants (b2) at least one oily component (b3) water
2. The solid soap composition according to claim 1, wherein the amount of the (B) microemulsion is 0.15 to 5% by mass in the solid soap composition.
3. The solid soap composition according to claim 1 or 2, wherein the (B) microemulsion further comprises (b4) a monohydric alcohol having 1 to 4 carbon atoms and / or (b5) a polyhydric alcohol.
4. The solid soap composition according to any one of claims 1 to 3, wherein the form of the solid soap composition is solid, sheet, powder or granule.
5. The microemulsion is an oil-in-water (O / W type) microemulsion,
   Polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene hydrogenated castor, wherein the nonionic surfactant has an HLB of 10 to 20 The solid soap composition according to any one of claims 1 to 4, which is at least one selected from the group consisting of oil, polyglycerin fatty acid ester and polyether-modified silicone.
6. The microemulsion is an oil-in-water (O / W type) microemulsion,
   The anionic surfactant is at least one selected from the group consisting of polyoxyethylene alkyl ether phosphates, N-acyl glutamates, and polyoxyethylene alkyl ether phosphates or salts thereof. The solid soap composition according to any one of 1 to 5.
7. The microemulsion is a water-in-oil type (W / O type) microemulsion,
   The nonionic surfactant is selected from the group consisting of polyoxyethylene difatty acid ester, monoglycerin monofatty acid ester, monoglycerin difatty acid ester, diglycerin monofatty acid ester, and polyether-modified silicone having an HLB of 1 to 7. The solid soap composition according to any one of claims 1 to 6, which is at least one kind.
8. A method for producing a solid soap composition comprising a step of preparing a soap base composition by kneading at least (A) a soap base and (B) a microemulsion containing the following components (b1) to (b3): .
   (B1) at least one surfactant selected from the group consisting of nonionic surfactants and anionic surfactants (b2) at least one oily component (b3) water
9. The method for producing a solid soap composition according to claim 8, wherein the blending amount of the (B) microemulsion is 0.15 to 5% by mass in the solid soap composition.
10. The following components (b1) to (b3):
    (B1) at least one surfactant selected from the group consisting of a nonionic surfactant and an anionic surfactant;
    (B2) at least one oily component, and
    (B3) water,
    A foam improver for a solid soap composition, comprising a microemulsion containing
11. The following components (b1) to (b3):
    (B1) at least one surfactant selected from the group consisting of a nonionic surfactant and an anionic surfactant;
    (B2) at least one oily component, and
    (B3) water,
    Use of a microemulsion containing for improving the foam quality of a solid soap composition.