JP7516000B2 - Transparent shampoo composition - Google Patents

Description

The present invention relates to a transparent shampoo composition that is less likely to drip when applied to the hands, has good finger combability when rinsing, and has excellent stability over time at low temperatures.

Acylamino acid surfactants are used as a major component of body cleansers, such as scalp, hair and body cleansers, because they are less irritating to the skin and hair and have a superior feel when used, with high foaming properties. Among these acylamino acid surfactants, acylmethyltaurine salts are preferably used because, when used in shampoos, they produce good foam when washing hair and a smooth finish. For this reason, attempts have been made to further improve foaming and the smooth feel when washing hair by incorporating a high amount of acylmethyltaurine salts into shampoos.

In recent years, in addition to performance aspects such as foaming and usability, there has been a demand for shampoos with even higher added value. For example, there is a demand for transparent shampoos that do not contain silicones or pearlizing agents in order to create a luxurious feel. Acylamino acid surfactants contain small amounts of sodium chloride derived from fatty acid chlorides used as acylating agents, and therefore, when used in high concentrations, the sodium chloride contained in the shampoo can cause the shampoo to become dull at low temperatures, which could be problematic for products intended as transparent shampoos.

Patent Document 1 proposes a cleaning agent composition containing a polyhydric alcohol, such as a dihydric alcohol such as 1,3-butylene glycol or dipropylene glycol, as a formula for improving stability over time at low temperatures (hereinafter also referred to as "low-temperature stability"). However, when a polyhydric alcohol is added in an amount that can improve low-temperature stability in a shampoo containing a high amount of acyl methyl taurine salt, the viscosity of the shampoo composition is significantly reduced, making it difficult to prepare a shampoo with the appropriate viscosity.

Patent Document 2 describes a shampoo that has good finger-combing properties when rinsing and excellent stability over time at low temperatures, achieved by blending specific amounts of acyl methyl taurine salt, amphoteric surfactant, and cationic polymer. Although low-temperature stability can be improved to a certain extent by devising the blending formula, it may be difficult to obtain the appropriate viscosity in shampoos that contain a high amount of acyl methyl taurine salt. In such cases, a small amount of sodium chloride is added to improve the viscosity and a formula is adopted that prevents dripping when the shampoo is applied to the hands, but the shampoo may become dull at low temperatures and transparency may not be maintained.

There was thus a demand for a transparent shampoo composition that contains a high amount of acylmethyl taurine salt, has good finger-combing properties when rinsing, and has excellent stability over time at low temperatures even when sodium chloride is added to give the formula a viscosity that does not drip.

Japanese Patent Application Publication No. 10-218744 Japanese Patent Application Publication No. 5-246829

The present invention was made based on the above circumstances, and its purpose is to provide a transparent shampoo composition that is less likely to drip when applied to the hands, has good finger-combing properties when rinsing, and has excellent stability over time at low temperatures.

As a result of intensive research conducted by the present inventors to solve the above problems, they discovered that a clear shampoo composition containing an acylmethyl taurine salt, an amphoteric surfactant, and a cationic cellulose of a specific molecular weight and a specific amount of sodium chloride has good finger combability when rinsing the shampoo and excellent stability over time at low temperatures, even when a high amount of acylmethyl taurine salt is included, and thus completed the present invention.

（式（１）中、ＲＣＯは炭素数８～１８の脂肪族アシル基を示し、Ｍ^１はアルカリ金属原子、アルカノールアミン、タウリンのアルカリ金属塩を示す。）
（ｉ）成分：平均分子量１０，０００～３５，０００のポリエチレングリコールに、繰り返し数が５～７０であるジメチル鎖を有するシリコーン基を導入したトリブロックポリマー
（ｉｉ）成分：シリコーン化された繰り返し数が６０～１００００である多糖類 That is, the present invention provides a transparent shampoo composition comprising: component (a): 1 to 20 mass% of a surfactant represented by formula (1); component (b): 1 to 12 mass% of an amphoteric surfactant; component (c): 0.05 to 2 mass% of a cationized cellulose having a weight-average molecular weight of 5 x 10 ⁵ to 30 x 10 ⁵ ; component (d): 0.75 to 2.1 mass% of sodium chloride; and component (e): 1.5 to 3 mass% of lauric acid ethanolamide or coconut fatty acid ethanolamide, wherein the mass ratio (a)/(b) of component (a) to component (b) is 1 to 6.0 and {(a)/(b)}/(d) is 1.0 to 3.6 (provided that when the following component (i) or (ii) is contained, In this case, the cases excluding those containing cationized guar gum , those containing 14% by mass or more of sugar and/or sugar alcohol , and those containing 3 to 15% by mass of sodium PEG (2) lauryl ether sulfate, 3 to 5% by mass of coconut oil fatty acid amidopropyl betaine, 0.5% by mass of cationized cellulose (Leoguard MGP, degree of cationization 1.8% by mass, weight average molecular weight 1.7 million), 1% by mass of sodium chloride, and 1.0% by mass of coconut oil fatty acid monoethanolamide are excluded.

(In formula (1), RCO represents an aliphatic acyl group having 8 to 18 carbon atoms, and ^M1 represents an alkali metal atom, an alkanolamine, or an alkali metal salt of taurine.)
Component (i): A triblock polymer in which a silicone group having a dimethyl chain with a repeat number of 5 to 70 is introduced into polyethylene glycol with an average molecular weight of 10,000 to 35,000. Component (ii): A polysaccharide with a silicone-modified repeat number of 60 to 10,000.

The transparent shampoo composition of the present invention, even when it contains a high amount of acylmethyl taurine salt, is less likely to drip when applied to the hands, has good finger combability when rinsing, and has excellent stability over time at low temperatures.

Hereinafter, an embodiment of the present invention will be described.
The transparent shampoo composition of the present invention contains the components (a), (b), (c) and (d). Each component will be described below.

[Component (a)]
The component (a) used in the present invention is a surfactant represented by formula (1) and is an acylmethyltaurine salt.
RCO in formula (1) represents an aliphatic acyl group having 8 to 22 carbon atoms, preferably 8 to 18 carbon atoms. The aliphatic acyl group includes not only acyl groups derived from saturated or unsaturated fatty acids having 8 to 22 carbon atoms, but also acyl groups derived from mixed fatty acids containing two or more of these fatty acids. Examples of such aliphatic acyl groups include coconut oil fatty acid acyl groups, palm kernel oil fatty acid acyl groups, capryloyl groups, caprinoyl groups, lauroyl groups, myristoyl groups, palmitoyl groups, stearoyl groups, oleoyl groups, and behenoyl groups. Preferred are lauroyl groups, myristoyl groups, coconut oil fatty acid acyl groups, and palm kernel oil fatty acid acyl groups, and particularly preferred are lauroyl groups, coconut oil fatty acid acyl groups, and palm kernel oil fatty acid acyl groups.

M ¹ in formula (1) represents an alkali metal atom, an alkanolamine, or an alkali metal salt of taurine. Examples of the alkali metal atom include sodium and potassium. Examples of the alkanolamine include monoethanolamine, diethanolamine, and triethanolamine. Examples of the alkali metal salt of taurine include sodium taurate and potassium taurate. Of these, sodium, potassium, triethanolamine, and sodium taurate are preferred.

Specific examples of acyl methyl taurine salts represented by formula (1) include sodium lauroyl methyl taurine, potassium lauroyl methyl taurine, sodium myristoyl methyl taurine, potassium myristoyl methyl taurine, sodium coconut oil fatty acid methyl taurine, potassium coconut oil fatty acid methyl taurine, sodium lauroyl methyl taurine taurine, and sodium coconut oil fatty acid methyl taurine taurine.

In the present invention, component (a) can be one or more of the compounds included in formula (1) above.

[Component (b)]
The component (b) used in the present invention is an amphoteric surfactant, for example, a surfactant having a structure having an N-acyl group or an N-alkyl group, a cationic group, and an anionic group in combination. Specific examples include alkyl betaines, alkyl amido betaines, alkyl hydroxysulfobetaines, alkyl amido hydroxysulfobetaines, alkyl carboxymethyl hydroxyethyl imidazolinium betaines, alkyl amido hydroxyethyl amino acid type amphoteric surfactants, alkyl imino diacetates, etc.

The N-acyl group contained in the amphoteric surfactant is, for example, a straight-chain or branched fatty acid residue having 8 to 18 carbon atoms. Examples of fatty acids in such fatty acid residues include saturated fatty acids such as caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and isostearic acid; unsaturated fatty acids such as palmitoleic acid, oleic acid, elaidic acid, linoleic acid, and linolenic acid; and mixtures thereof such as coconut oil fatty acid, palm kernel oil fatty acid, beef tallow fatty acid, and hardened beef tallow fatty acid. Of these, preferred are lauric acid, myristic acid, palmitic acid, oleic acid, coconut oil fatty acid, and palm kernel oil fatty acid. Particularly preferred are lauric acid, coconut oil fatty acid, and palm kernel oil fatty acid.

The alkyl group contained in the above amphoteric surfactant is, for example, a hydrocarbon group having 8 to 18 carbon atoms, and also includes alkyl groups derived from mixed fatty acids. Examples include alkyl groups such as caprylyl, capryl, lauryl, myristyl, palmityl, stearyl, and oleyl groups; and mixed alkyl groups such as coconut oil alkyl groups, palm kernel oil alkyl groups, and beef tallow alkyl groups. Of these, preferred are lauryl, myristyl, palmityl, coconut oil alkyl groups, and palm kernel oil alkyl groups. Particularly preferred are lauryl, coconut oil alkyl groups, and palm kernel oil alkyl groups.

Specific examples of the amphoteric surfactant (b) include lauryl betaine, coconut oil fatty acid amidopropyl betaine, palm kernel oil fatty acid amidopropyl betaine, lauryl dimethylaminoacetate betaine, and lauryl hydroxysulfobetaine.

In the present invention, the component (b) can be one or more of the above amphoteric surfactants selected appropriately.

[Component (c)]
The component (c) used in the present invention is a cationic cellulose having a weight average molecular weight of 5×10 ⁵ to 30×10 ^5. The weight average molecular weight of the cationic cellulose of the component (c) is preferably 7×10 ⁵ to 25×10 ⁵ , and particularly preferably 9×10 ⁵ to 20×10 ⁵ .
Component (c) has the function of forming a complex with the mixed micelles of components (a) and (b). This complex precipitates (coacervation phenomenon) during hair rinsing and is adsorbed to the hair, thereby imparting a conditioning effect that improves the combability of the hair during washing and rinsing.
Examples of component (c) include O-[2-hydroxy-3-(trimethylammonio)propyl]hydroxyethylcellulose chloride, which is a polymer of a quaternary ammonium salt obtained by adding glycidyltrimethylammonium chloride to hydroxyethylcellulose. Examples of commercially available cationized cellulose having a weight average molecular weight of 5×10 ⁵ to 30×10 ⁵ include "Leoguard MGP" from Lion Corporation, "Catinal HC-200" and "Catinal LC-200" from Toho Chemical Industry Co., Ltd., and "Poise C-150L" from Kao Corporation.

In the present invention, the weight average molecular weight is measured by static light scattering measurement. That is, the concentration-differential refractive index curve of a diluted polymer aqueous solution is measured using a differential refractometer, and the concentration-angle dependence of scattering intensity is measured using a scattering intensity measurement device, and the weight average molecular weight can be measured by extrapolating to a concentration of 0 and an angle of 0 on the Zimm plot.

In the present invention, one or more of these cationic celluloses can be appropriately selected and used as component (c).

[Component (d)]
The component (d) used in the present invention is sodium chloride. For example, the sodium chloride contained in the component (a) used can be utilized as the component (d), and sodium chloride can also be used separately as necessary.

[Transparent Shampoo Composition]
Next, the content of each component in the transparent shampoo composition of the present invention will be described.
The content of component (a) in the transparent shampoo composition of the present invention is 1 to 20% by mass, preferably 2 to 16% by mass, and particularly preferably 3 to 12% by mass. If the content of component (a) is too low, poor lathering during washing may occur and sufficient smoothness may not be obtained for hair after drying, whereas if the content is too high, problems such as precipitation of the surfactant at low temperatures may occur.

The content of component (b) in the transparent shampoo composition of the present invention is 1 to 20% by mass, preferably 2 to 16% by mass, and particularly preferably 3 to 12% by mass. If the content of component (b) is too low, the foam quality during hair washing may be reduced, and finger-combability during rinsing may be reduced, while if the content is too high, problems such as precipitation of the surfactant at low temperatures may occur.

The content of component (c) in the clear shampoo composition of the present invention is 0.01 to 2 mass%, preferably 0.05 to 1.5 mass%, and particularly preferably 0.1 to 1.0 mass%. If the content of component (c) is too low, only a small amount of coacervate is formed, and good finger-combing properties may not be obtained during rinsing, whereas if the content is too high, the low-temperature stability of the shampoo composition may be impaired.

The content of component (d) in the transparent shampoo composition of the present invention is 0.5 to 2.5% by mass, preferably 0.75 to 2.1% by mass, and particularly preferably 1.0 to 1.7% by mass. If the content of component (d) is too low, the shampoo composition is likely to drip when taken in the hands, and if the content is too high, the low temperature stability of the shampoo composition may be impaired.
The content of component (d) in the clear shampoo composition can be calculated from the content of sodium chloride contained in component (a) used, and the content can be adjusted, if necessary, by separately adding sodium chloride, for example.

In the transparent shampoo composition of the present invention, the mass ratio of component (a) to component (b) ((a)/(b)) is from 1 to 9, preferably from 1.1 to 6.0, particularly preferably from 1.2 to 4.5, and even more preferably from 1.3 to 3.0. If the mass ratio ((a)/(b)) is too large or too small, the low temperature stability of the shampoo composition may be impaired.

In addition, in the transparent shampoo composition of the present invention, particularly when the mass ratio (a)/(b) is 3 or more, from the viewpoint of achieving both resistance to dripping when the shampoo composition is applied to the hands and low-temperature stability, it is preferable that the mass ratio of the mass ratio (a)/(b) to the (d) component, {(a)/(b)}/(d), is 1.9 to 2.4, and more preferably 2.0 to 2.2.

The transparent shampoo composition of the present invention can be produced according to a conventional method. The transparent shampoo composition of the present invention may further contain a solvent. Examples of the solvent include water, lower alcohols such as ethanol, and aqueous solutions of lower alcohols, and water is particularly preferred.
In the transparent shampoo composition of the present invention, the total content of each of the components (a) to (d) and solvents such as water is 100% by mass or less.

The transparent shampoo composition of the present invention may be in any form, such as liquid or gel, so long as it is intended for washing hair, and may be used, for example, as a shampoo or a rinse-in shampoo.
Furthermore, the transparent shampoo composition of the present invention may contain, as necessary, various ingredients that are generally used in hair and body cleansers, such as other surfactants, moisturizers, oils, water-soluble polymers, preservatives, bactericides, pH adjusters, sequestering agents, antioxidants, animal and plant extracts, colorants, and fragrances, within the range that does not impair the effects of the present invention.

[Examples 1 to 11 and Comparative Examples 1 to 11]
The present invention will be specifically described below with reference to examples and comparative examples.
Based on the formulations shown in Tables 1 and 2, shampoo compositions were prepared according to a conventional method.
In addition, the following was used as component (c) in the table.
(c)-1 Cationic cellulose A: Leoguard MGP (manufactured by Lion Corporation, weight average molecular weight 17×10 ⁵ )
(c)-2 Cationic cellulose B: Catinal HC-200 (manufactured by Toho Chemical Industry Co., Ltd., weight average molecular weight 20×10 ⁵ )
(c)-3 Cationic cellulose C: Poise C-150L (manufactured by Kao Corporation, weight average molecular weight 15×10 ⁵ )

The shampoo compositions obtained in the Examples and Comparative Examples were used as samples and evaluated as described below, and the results are summarized in Tables 1 and 2.

(1) Resistance to Dripping Each composition was applied to the palm of the hand and the degree of dripping was evaluated. Twenty men and women (aged 24 to 47) were used as panelists, and the total score of the 20 panelists was calculated based on the following criteria: if dripping from the palm of the hand was not bothersome, the score was 2; if dripping from the palm of the hand was slightly bothersome but did not pose a problem in use, the score was 1; if dripping from the palm of the hand was bothersome, the score was 0. The results were evaluated as follows:
⊚: Total score of 35 points or more; when placed on the palm of the hand, the liquid hardly drips and can be sufficiently applied to the hair.
◯: Total score is 20 points or more and less than 35 points; when placed on the palm, the liquid drips slightly, but can be applied to hair.
Δ: Total score is 10 or more and less than 20 points; when taken on the palm, the liquid drips and is difficult to apply to the hair.
×: Total score less than 10 points; when the liquid was taken on the palm, it dripped violently and could not be applied to the hair.

(2) Finger-combability during rinsing
A panel of 20 men and women (aged 24-47) who dye their hair evaluated the ease of running their fingers through their hair after washing and rinsing with 5 mL of the sample (shampoo composition) using water at 40° C. If the hair felt smooth and did not catch on the fingers, a score of 2 was given, if the hair felt slightly caught on the fingers, a score of 1 was given, and if the hair felt very difficult to run their fingers through, a score of 0 was given. The total score given by the 20 panelists was calculated and rated as follows:
⊚: A total score of 35 points or more; the feel of the fingers running through the skin is very good.
A: The total score is 30 points or more and less than 35 points; finger combability is excellent.
Δ: Total score is 20 or more and less than 30 points; finger combability is somewhat poor.
×: Total score is less than 20 points; poor finger combability.

(3) Stability over Time Each composition was sealed in a transparent glass container and stored at 0° C. and 5° C. for one week, respectively, and then its appearance was observed and evaluated according to the three-level scale shown below.
◯: No change in appearance at either 0° C. or 5° C.
Δ: There is no change in appearance at 5°C, but the composition becomes cloudy at 0°C.
×: The composition turns cloudy at both 0°C and 5°C.

Examples 1 to 11 were evaluated as being good in all items.
On the other hand, since Comparative Example 1 did not contain component (a), the composition dripped significantly when placed on the palm of the hand, and the composition did not easily run fingers through the palm during rinsing.
Since Comparative Example 2 did not contain component (b), the composition dripped significantly when placed on the palm of the hand, did not run smoothly over the fingers when rinsing, and had problems with stability over time at low temperatures.
Since Comparative Example 3 did not contain component (c), the composition was prone to dripping when placed on the palm of the hand, had poor finger-combability during rinsing, and had poor stability over time at low temperatures.
In Comparative Example 4, the content of component (a) was large, and therefore there was a problem with stability over time at low temperatures.
In Comparative Example 5, the content of component (b) was high and the mass ratio ((a)/(b)) was outside the range specified by the present invention, and therefore there was a problem with the long-term stability at low temperatures.
In Comparative Example 6, the content of sodium chloride (d) component was low, so that when the composition was placed on the palm of the hand, it dripped violently and could not be applied to the hair.
In Comparative Example 7, the content of sodium chloride as component (d) was high, and therefore the stability over time at low temperatures was poor.
In Comparative Examples 8, 9, and 10, cationic guar gum, polydimethylmethylene piperidinium chloride, and dimethyldiallylammonium chloride-acrylamide copolymer were contained instead of component (c), respectively, and therefore there was a problem with stability over time at low temperatures.
In Comparative Example 11, since 1,3-butylene glycol was contained, the composition was prone to dripping when placed on the palm of the hand, and the shampoo composition could not be applied sufficiently to the hair.

Furthermore, specific formulation examples of the transparent shampoo composition of the present invention are shown below. Note that in all formulation examples, the total amount was adjusted to 100% by mass using water.

The effects of the present invention were confirmed in the clear shampoo compositions of these formulation examples, which are less likely to drip when taken into the hands, have good finger-combing properties when rinsing, and have excellent stability over time at low temperatures. The present invention provides a clear shampoo composition that is less likely to drip when taken into the hands, has good finger-combing properties when rinsing, and has excellent stability over time at low temperatures.

Claims (1)

Component (a): 1 to 20% by mass of a surfactant represented by formula (1),
(b) component: 1 to 12% by mass of an amphoteric surfactant,
(c) component: 0.05 to 2 mass% of cationic cellulose having a weight average molecular weight of 5×10 ⁵ to 30×10 ⁵ ,
(d) component: 0.75 to 2.1 mass% sodium chloride,
(e) component: containing 1.5 to 3 mass% of lauric acid ethanolamide or coconut fatty acid ethanolamide,
1. A clear shampoo composition, characterized in that the mass ratio (a)/(b) of component (a) to component (b) is 1 to 6.0 and {(a)/(b)}/(d) is 1.0 to 3.6 (however, excluding the cases where the composition contains the following component (i) or (ii), where the composition contains cationized guar gum , where the composition contains 14% by mass or more of sugar and/or sugar alcohol , and where the composition contains 3 to 15% by mass of sodium PEG (2) lauryl ether sulfate, 3 to 5% by mass of coconut oil fatty acid amidopropyl betaine, 0.5% by mass of cationized cellulose (Leoguard MGP, degree of cationization 1.8% by mass, weight average molecular weight 1,700,000), 1% by mass of sodium chloride, and 1.0% by mass of coconut oil fatty acid monoethanolamide ).

(In formula (1), RCO represents an aliphatic acyl group having 8 to 18 carbon atoms, and ^M1 represents an alkali metal atom, an alkanolamine, or an alkali metal salt of taurine.)
Component (i): A triblock polymer in which a silicone group having a dimethyl chain with a repeat number of 5 to 70 is introduced into polyethylene glycol with an average molecular weight of 10,000 to 35,000. Component (ii): A polysaccharide with a silicone-modified repeat number of 60 to 10,000.