JP2012201789A - Transparent soap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve foam quality while maintaining transparency in a fatty acid soap-based transparent soap.SOLUTION: The transparent soap includes a fatty acid soap moiety that is a main agent, a sugar and polyol moiety that is a clarifying agent, and an ampholytic polymer, as a component monomer, including acrylic acid, methacrylamidopropyl quaternary ammonium chloride, and methyl acrylate.

Description

  The present invention relates to a transparent soap, in particular to improving its foam quality.

Transparent soap gives a high-class feeling and has high commercial value, so it is used especially for soap for face washing.
By the way, the conventional transparent soap is based on a fatty acid soap, and sugars or polyols such as sucrose, glycerin, sorbitol, and propylene glycol are used as a clarifying agent, and is manufactured by a frame bending method or a mechanical bending method. Is common (Patent Documents 1, 2, etc.).

  The structural mechanism of the transparency of the transparent soap produced in this way is that the fibrous crystallite group of opaque soap, which is optically discontinuous in size with respect to visible light, is mainly perpendicular to the fiber axis. It is considered that the soap is made transparent by being divided to be smaller than the wavelength of visible light.

However, when sugars / polyols are added as described above, the content of the soap component is relatively reduced, and it becomes difficult to obtain foaming properties, particularly fine foam quality.
Therefore, in order to improve the foam quality, the formulation of a cationic polymer or an amphoteric polymer has been studied in the past (Patent Document 3), which is sufficient for improving the foam quality or reducing the feeling of the skin after washing. When the amount is blended, the transparency cannot be maintained, and there is a problem that the freezing point is lowered to prevent solidification.

JP2010-202835 JP-A-10-147800 Japanese Patent No. 3970861

  This invention is made | formed in view of the said prior art, The subject which should be solved is providing the transparent soap by which the improvement of foam quality was aimed at, maintaining transparency.

  As a result of investigations on foam quality improvement of transparent soaps, the present inventors have found that a specific amphoteric polymer has an excellent foam quality improvement effect and does not affect transparency, and the present invention has been completed. It came to do.

That is, the transparent soap according to the present invention is
Fatty acid soap part as the main agent,
A sugar / polyol part as a clarifying agent;
In transparent soap containing
An amphoteric polymer containing acrylic acid, methacrylamidopropyl chloride quaternary ammonium salt and methyl acrylate as a constituent monomer is blended.
In the transparent soap, the amphoteric polymer preferably has the following structural formula.

(In the above structural formulas, R ₁ , R ₂ and R ₃ are the same or different, and are a hydrogen atom, an alkyl group (C 1-18), a phenyl group, an aryl group, a hydroxyalkyl group, an amidoalkyl group, a cyanoalkyl group. A group, an alkoxyalkyl group, and a carboalkoxyalkyl group, X is 30 to 60, Y is 30 to 60, and Z is an integer of 5 to 20.)
In the transparent soap, the molecular weight of the amphoteric polymer is preferably in the range of 1 million to 2 million.

Hereafter, each structure of this invention is explained in full detail.
[Fatty acid soap part]
The fatty acid in the sodium fatty acid or the mixed salt of sodium / potassium fatty acid used in the soap of the present invention is a saturated or unsaturated fatty acid having preferably 8 to 20, more preferably 12 to 18 carbon atoms. Yes, it may be linear or branched. Specific examples include, for example, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, isostearic acid and the like, and beef tallow fatty acid, coconut oil fatty acid, palm kernel oil fatty acid and the like which are mixtures thereof.

  Specific examples of the fatty acid sodium include sodium laurate, sodium myristate, sodium palmitate, sodium stearate, sodium oleate, sodium isostearate, beef tallow fatty acid sodium, coconut oil fatty acid sodium, palm kernel oil fatty acid sodium and the like. These may be used alone or in combination of two or more. Among the above fatty acid sodium, sodium laurate, sodium myristate, sodium palmitate, sodium stearate, sodium oleate, and sodium isostearate can be suitably used.

  Specific examples of sodium / potassium mixed salts of fatty acids include sodium / potassium laurate, sodium / potassium myristate, sodium / potassium palmitate, sodium / potassium stearate, sodium / potassium oleate, sodium / potassium isostearate, Examples include beef tallow fatty acid sodium / potassium, coconut oil fatty acid sodium / potassium, and palm kernel oil fatty acid sodium / potassium. These may be used alone or in combination of two or more. Among the sodium / potassium mixed salts of the above fatty acids, sodium / potassium laurate, sodium / potassium myristate, sodium / potassium palmitate, sodium / potassium stearate, sodium / potassium oleate, and sodium / potassium isostearate are preferred. Can be used for

In the soap of the present invention, the content of the fatty acid sodium or the mixed salt of fatty acid sodium / potassium is preferably 20 to 50% by mass, particularly preferably 30 to 40% by mass. When this content is less than 20% by mass, the transparency is lowered or the freezing point is lowered, so that when stored for a long period of time, the surface melts and the commercial value may be impaired. On the other hand, if it exceeds 50% by mass, the transparency may be lowered, or there may be a feeling of tension after use.
The total amount of lauric acid soap and oleic acid soap is preferably 20% by mass or less in the total composition.

  In the mixed salt of fatty acid sodium / potassium, the molar ratio of sodium and potassium constituting the salt (sodium / potassium ratio) is 100/0 (that is, fatty acid sodium) to 70/30, particularly 90 / It is preferable that it is 10-80 / 20. If the sodium / potassium ratio exceeds 70/30 and the proportion of potassium increases, the freezing point becomes low, and the surface may melt when stored for a long period of time, thereby impairing the commercial value. Moreover, there is a possibility that the hardness decreases, the dissolution during use increases, the sweating occurs under high temperature and high humidity conditions, or the surface becomes clouded during use.

[Sugar / Polyol part]
Examples of the sugar / polyol preferably used in the present invention include maltitol, sorbitol, glycerin, 1,3-butylene glycol, propylene glycol, polyethylene glycol, sugar, pyrrolidone carboxylic acid, sodium pyrrolidone carboxylate, hyaluronic acid, polyoxyethylene An alkyl glucoside ether etc. are illustrated and it is suitable to mix | blend 20-60 mass% in a composition.
In particular, in order to obtain good usability as well as transparency, the ratio of sugar and sugar alcohol to polyol in the sugar / polyol part is preferably 40-60: 60-40.

[Amotropic polymers]
The amphoteric polymer according to the present invention contains acrylic acid, methacrylamidopropyl chloride quaternary ammonium salt, and methyl acrylate as constituent monomers, and specifically has the following structure.

In the above structural formulas, R ₁ , R ₂ , and R ₃ are the same or different, and are a hydrogen atom, an alkyl group (having 1 to 18 carbon atoms), a phenyl group, an aryl group, a hydroxyalkyl group, an amidoalkyl group, a cyanoalkyl group. , An alkoxyalkyl group and a carboalkoxyalkyl group, X is an integer of 30 to 60, Y is 30 to 60, and Z is an integer of 5 to 20.

The molecular weight of the amphoteric polymer is in the range of 600,000 to 3 million, preferably 1 million to 2 million.
Moreover, the compounding quantity of the amphoteric polymer in a composition is 0.2-1.5 mass% as an actual part, Preferably it is 0.4-1.0 mass%.
As a commercial item, Marcoat 2001 (made by Nalco) is mentioned.

[Amphoteric surfactant]
The transparent soap according to the present invention preferably contains the following amphoteric surfactant as a non-fatty acid soap-based surfactant.
Examples of the amphoteric surfactant that can be used in the transparent soap of the present invention include amphoteric surfactants represented by the following chemical formulas (A) to (C).

[Wherein, R ₁ represents an alkyl group or alkenyl group having 7 to 21 carbon atoms, n and m are the same or different and represent an integer of 1 to 3, and Z represents a hydrogen atom or (CH ₂ ) _p COOY (where p is an integer of 1 to 3, and Y is an alkali metal, alkaline earth metal or organic amine). ],

[Wherein R ₂ represents an alkyl group or alkenyl group having 7 to 21 carbon atoms, R ₃ and R ₄ are the same or different and represent a lower alkyl group, and A represents a lower alkylene group. . ],and

[Wherein, R ₅ represents an alkyl group or alkenyl group having 8 to 22 carbon atoms, and R ₆ and R ₇ are the same or different and represent a lower alkyl group. ].

In the chemical formula (A), the “alkyl group having 7 to 21 carbon atoms” of R ₁ may be linear or branched, and the number of carbon atoms is preferably 7 to 17. The “alkenyl group having 7 to 21 carbon atoms” of R ₁ may be linear or branched, and the number of carbon atoms is preferably 7 to 17. Examples of the “alkali metal” of Y include sodium and potassium, examples of the “alkaline earth metal” include calcium and magnesium, and examples of the “organic amine” include monoethanolamine, diethanolamine and trimethylamine. Examples include ethanolamine.

Specific examples of the amphoteric surfactant represented by the chemical formula (A) include imidazolinium betaine type, for example, 2-undecyl-N-carboxymethyl-N-hydroxyethylimidazolium betaine (synthesized from lauric acid) Hereinafter, for convenience, it is also referred to as “lauroiylimidazolinium betaine”), 2-heptadecyl-N-carboxymethyl-N-hydroxyethylimidazolium betaine (synthesized from stearic acid), 2-synthesized from coconut oil fatty acid. Alkyl or alkenyl-N-carboxymethyl-N-hydroxyethylimidazolium betaine (R ₁ is a mixture of C _{7 to} C ₁₇ , hereinafter, also referred to as “cocoyl imidazolinium betaine” for convenience) and the like.

In formula (B), and "alkenyl group having a carbon number of 7 to 21""alkyl group having a carbon number of 7 to 21" of R ₂ is the same as R ₁ of formula (A). The “lower alkyl group” for R ₃ and R ₄ is a linear or branched alkyl group having preferably 1 to 3 carbon atoms. Furthermore, the “lower alkylene group” of A is a linear or branched alkylene group having preferably 3 to 5 carbon atoms.

Specific examples of the amphoteric surfactant (amide alkyl betaine type) represented by the chemical formula (B) include amidopropyl betaine type, for example, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine (R ₂ is C _{7 to} C ₁₇ . Mixture).

In the chemical formula (C), the “alkyl group having 8 to 22 carbon atoms” of R ₅ may be linear or branched, and the number of carbon atoms is preferably 8 to 18. The “alkenyl group having 8 to 22 carbon atoms” of R ₅ may be linear or branched, and the number of carbon atoms is preferably 8 to 18. Furthermore, the “lower alkyl group” of R ₆ and R ₇ is the same as R ₃ and R _{4 in} the chemical formula (B).

Specific examples of the amphoteric surface active agents represented by the chemical formula (C) (alkyl betaine type), lauryl betaine, synthesized from coconut fatty alkyl or alkenyl acid betaine (R ₅ is C ₈ ~ C ₁₈ mixture).

  In the present invention, at least one selected from the group consisting of amphoteric surfactants represented by the above chemical formulas (A) to (C) is used. When a plurality of amphoteric surfactants represented by the chemical formula (A) are used, a plurality of amphoteric surfactants represented by the chemical formula (B) may be used. A plurality of amphoteric surfactants represented by

  Among the amphoteric surfactants described above, imidazolinium betaine type, particularly cocoylimidazolinium betaine, among the amphoteric surfactants represented by the chemical formula (A) is particularly preferably used.

  In the transparent soap of the present invention, fatty acid soap (fatty acid sodium or a mixed salt of fatty acid sodium / potassium) and an amphoteric surfactant form a composite salt by adding the above amphoteric surfactant, thereby improving hardness. The effect of performing is demonstrated.

  The content of the amphoteric surfactant in the transparent soap of the present invention is preferably 2 to 10% by mass, particularly 4 to 8% by mass. If this content is less than 2% by mass, the freezing point will be low, and if stored for a long period of time, the surface will melt and the commercial value may be impaired. Moreover, there exists a possibility that hardness may fall. On the other hand, if it exceeds 10% by mass, a sticky feeling is produced after use, and if stored for a long period of time, the surface may be browned and the commercial value may be impaired.

[Hydroxyalkyl ether carboxylate type surfactant]
It is preferable to add a hydroxyalkyl ether carboxylate type surfactant to the transparent soap according to the present invention, and improvement of foaming is recognized.
A suitable hydroxyalkyl ether carboxylate type surfactant in the present invention has the following structure (D).

(In the formula, R ¹ represents a saturated or unsaturated hydrocarbon group having 4 to 34 carbon atoms; ^one of X ¹ and X ² represents —CH ₂ COOM ¹ and the other represents a hydrogen atom; M ¹ represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium, a lower alkanolamine cation, a lower alkylamine cation, or a basic amino acid cation.)

In the formula, R ¹ may be an aromatic hydrocarbon, a linear or branched aliphatic hydrocarbon, but is preferably an aliphatic hydrocarbon, particularly an alkyl group or an alkenyl group. For example, butyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, docosyl, 2-ethylhexyl, 2-hexyldecyl, 2-octylundecyl, 2-decyltetradecyl , 2-undecylhexadecyl group, decenyl group, dodecenyl group, tetradecenyl group, hexadecenyl group and the like are preferable examples, and among them, decyl group and dodecyl group are excellent in terms of surface active ability.

In the formula, any one of X ¹ and X ² is represented by —CH ₂ COOM ¹ , and as M ¹ , a hydrogen atom, lithium, potassium, sodium, calcium, magnesium, ammonium, monoethanolamine, Examples include diethanolamine and triethanolamine.

Specifically, among the above (A) hydroxyalkyl ether carboxylate type surfactants, dodecane-1, in which H of any OH group of dodecane-1,2-diol is substituted with —CH ₂ COONa, 2-diol sodium ether acetate is most preferred in the present invention.
In the present invention, the hydroxyalkyl ether carboxylate type surfactant may be blended in an amount of 0.5 to 10% by mass, preferably 0.7 to 5% by mass from the viewpoint of improving foaming.

[Nonionic surfactant]
The transparent soap of the present invention may further contain a nonionic surfactant as a non-fatty acid soap-based surfactant. Nonionic surfactants that can be used include polyoxyethylene (hereinafter also referred to as POE) hydrogenated castor oil, polyoxyethylene 2-octyldodecyl ether, polyoxyethylene lauryl ether, propylene oxide ethylene oxide copolymer block polymer, polyoxyethylene Polyoxypropylene cetyl ether, polyoxyethylene polyoxypropylene glycol, polyethylene glycol diisostearate, alkyl glucoside, polyoxyethylene-modified silicon (for example, polyoxyethylene alkyl-modified dimethyl silicon), polyoxyethylene glycerin monostearate, polyoxyethylene Examples include alkyl glucoside. These may be used alone or in combination of two or more. Among the above nonionic surfactants, polyoxyethylene hydrogenated castor oil and propylene oxide ethylene oxide copolymer block polymer can be suitably used.

  In the transparent soap of the present invention, a non-ionic surfactant is added to exert a stimulating lowering effect derived from fatty acid soap.

  The content of the nonionic surfactant in the transparent soap of the present invention is preferably 2 to 15% by mass, particularly preferably 6 to 12% by mass. If this content is less than 2% by mass, a feeling of tension may occur after use. On the other hand, if it exceeds 15% by mass, the freezing point is lowered, so that when stored for a long period of time, the surface may melt and the commercial value may be impaired. Furthermore, a sticky feeling may occur after use.

[Chelating agent]
In addition, it is preferable to add a chelating agent such as edetate trisodium dihydrate to the transparent soap according to the present invention.

  Moreover, as a chelating agent used suitably in this invention, hydroxyethane diphosphonic acid and its salt are mentioned, More preferably, it is hydroxyethane diphosphonic acid. As a compounding quantity, it is 0.001-1.0 mass%, More preferably, it is 0.1-0.5 mass%. When the amount of hydroxyethanediphosphonic acid and its salt is less than 0.001% by mass, the chelate effect is insufficient, causing inconveniences such as yellowing over time. The irritation increases, which is undesirable.

[Others]
As other additives that can be blended in the present invention, the following components can be arbitrarily blended within the range not impairing the above-described action. This optional component includes fungicides such as trichlorocarbanilide and hinokitiol; oils; fragrances; dyes; UV absorbers; antioxidants; Extract; nonionic, cationic or anionic water-soluble polymer; usability improver such as lactic acid ester.

  Moreover, when using a chelating agent for the transparent soap concerning this invention, hydroxyethane diphosphonic acid and its salt are illustrated suitably, More preferably, it is hydroxyethane diphosphonic acid. As a compounding quantity, it is 0.001-1.0 mass%, More preferably, it is 0.1-0.5 mass%. When the amount of hydroxyethanediphosphonic acid and its salt is less than 0.001% by mass, the chelate effect is insufficient, causing inconveniences such as yellowing over time. The irritation increases, which is undesirable.

Regarding the method for producing the soap of the present invention, general methods such as a frame kneading method and a mechanical kneading method can be applied to the mixture of the components described above.
Further, the soap of the present invention is basically transparent, but also includes those whose transparency is lowered by blending pigments and the like.

  As described above, according to the soap according to the present invention, by adding a specific amphoteric polymer, it is possible to improve the foam quality while maintaining good transparency.

Hereinafter, preferred embodiments of the present invention will be described.
In order to examine the improvement in foaming property of fatty acid soap-based transparent soaps, the present inventors have studied using the following basic formulation. In addition, a compounding quantity is shown by the mass%.
In the following embodiments, the number of bubbles was measured by microscopic observation in the 0.55 mm ² region.
The average particle size was calculated by microscopic observation of bubbles.

  First, the present inventors tried to produce a transparent soap using a soap having a basic prescription comprising the following soap part, sugar / sugar / polyol part, and others.

Basic prescription 1
Fatty acid soap part 40.0%
Lauric acid 20 parts Myristic acid 40 parts Palmitic acid 10 parts Stearic acid 20 parts Isostearic acid 5 parts Castor oil 5 parts Sodium hydroxide: Potassium hydroxide = 80:20 (molar ratio) Neutralized sugar / polyol part 30.0%
Sorbitol 77 parts Sucrose 8 parts Oxypropylene (7) Glyceryl ether 15 parts Other 30.0%
Ethyl alcohol 15 parts Dodecane-1,2-diol sodium acetate ether 4 parts Ion-exchanged water remainder

  First, the inventors added a polymer having the following monomer composition (molar ratio) to the basic formulation 1 and studied the properties of soap.

AA: acrylic acid DADMAC: diallyl dimethyl ammonium chloride MAPTAC: methacrylamidopropyl trimethyl ammonium chloride AM: acrylamide MA: methyl acrylate The results are shown in Table 2.

As is apparent from Table 2, when 0.2% (actual amount) of polymer 1 is added, the number of bubbles is slightly increased as compared with the case of no addition, but the average particle diameter of the bubbles is almost unchanged. No, only foam increased, and a creamy foam quality could not be obtained. On the other hand, when 0.4% of polymer 1 is blended, the number of bubbles is about twice that of the case of no addition and the average particle diameter of the bubbles is fine and creamy, but the freezing point is below 40 ° C. , Solidification becomes difficult. In particular, the soap may be used in a bathroom or the like, and if the freezing point falls below 40 ° C., the maintenance of the form may be hindered.
Even when 0.4% of polymer 2 is added, the number of bubbles and the average particle size are improved, but the freezing point is slightly lower than 40 ° C. and becomes opaque.

On the other hand, when the polymer of the present invention (Polymer 3) was used, all of the freezing point, transparency, and foam quality were effectively improved.
Next, the present inventors confirmed the effect of addition of the polymer 3 for other soap formulations.

Basic prescription 2
Fatty acid soap part 30.0%
Lauric acid 23 parts Myristic acid 57 parts Stearic acid 20 parts Sodium hydroxide: Potassium hydroxide = 80:20 (molar ratio) neutralized amphoteric, nonionic surfactant 15.0%
Sodium dodecane-1,2-diol acetate 7.2 parts N-lauroyl-N′-carboxymethyl-N′-hydroxyethylethylenediamine sodium 3.1 parts PEG-60 hydrogenated castor oil 5.0 parts sugar / polyol part 30.0%
Dipropylene glycol 3.5 parts PEG 1500 2.0 parts Concentrated glycerin 13.0 parts Sucrose 11.5 parts Other remainder Ethyl alcohol 10 parts Ion-exchanged water remainder The results are shown in Table 3.

In the system of Basic Formula 2, the same tendency as that of Basic Formula 1 is observed, and the addition of Polymer 1 does not sufficiently improve the foam quality, and the addition of Polymer 2 shows some improvement in the foam quality. However, it becomes opaque.
On the other hand, when the amphoteric polymer 3 according to the present invention is used, the foam quality can be improved without affecting the transparency.
Furthermore, the present inventors examined the addition amount of the polymer 3 using the basic formulation 2.
The results are shown in Table 4 below.

From Table 4, it is understood that the compounding amount (actual part) of the amphoteric polymer 3 is 0.1 to 2.0%, preferably 0.2 to 1.5%.

Claims (4)

Fatty acid soap part as the main agent,
A sugar / polyol part as a clarifying agent;
In transparent soap containing
A transparent soap comprising an amphoteric polymer containing acrylic acid, methacrylamidopropyl chloride quaternary ammonium salt and methyl acrylate as constituent monomers. 2. The transparent soap according to claim 1, wherein the amphoteric polymer has the following structural formula.

(In the above structural formulas, R ₁ , R ₂ , and R ₃ are the same or different, and are a hydrogen atom, an alkyl group (having 1 to 18 carbon atoms), a phenyl group, an aryl group, a hydroxyalkyl group, an amidoalkyl group, a cyanoalkyl group. A group, an alkoxyalkyl group, and a carboalkoxyalkyl group, X is 30 to 60, Y is 30 to 60, and Z is an integer of 5 to 20.)
The molecular weight of the amphoteric polymer is in the range of 600,000 to 3 million, preferably 1 million to 2 million.   The transparent soap according to claim 1 or 2, wherein the amphoteric polymer has a molecular weight in the range of 1,000,000 to 2,000,000.   The transparent soap according to any one of claims 1 to 3, wherein the amphoteric polymer is blended in an amount of 0.2 to 1.5 mass% in the composition.