JPS5856399B2 - Novel shampoo composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shampoo composition in which bis(2-pyridylthio-1-oxide) zinc salt, which is effective as a dandruff inhibitor, is stably dispersed and suspended.

Although it is widely known that bis(2-pyridylthio-1-oxide) zinc salt is effective as an anti-dandruff agent,
This powder is difficult to disperse, and if it is simply added to the shampoo base, it will settle when left to stand, making it impossible to obtain a stable dispersion.

Therefore, in order to stably disperse this material, it is necessary to use a dispersant or a thickener.

Examples of dispersants and thickeners that can be used in shampoos include vinyl polymers, carboxymethylcellulose, alginates, casein, and gelatin, but many of them cannot be used because their dispersing effects are insufficient.

Recently, Japanese Patent Publication No. 49-49117 discloses a method using a polyacrylic acid resin to stably disperse bis(2-pyridylthio-1-oxide) zinc salt.

This method uses bis(2-pyridylthio-1-oxide)
This is an excellent method for dispersing zinc salts well, but its use is limited to around pH 7, and in addition fatty acid alkanolamide, which has a thickening and foam stabilizing effect, and N, which has a texture-improving effect, are
- Addition of long-chain acylamino acid alkali metal salts and the like reduces stability and viscosity, so there is a drawback that they cannot be used.

The purpose of the present invention is to have a wide usable pH range, and to
It is an object of the present invention to provide a shampoo composition that has stable dispersion even under weak acidity close to H and can be stored for a long period of time.

Another object of the present invention is that even when an N long-chain acylamino acid salt, which has a hand-improving effect, is used alone or a fatty acid alkanolamide, which has a thickening effect and a foam-stabilizing effect, is blended, the dispersibility does not deteriorate or the viscosity decreases.

To provide a shampoo composition.

The objects of the present invention can be achieved by dispersing and suspending bis(2-pyridylthio-1-oxide) zinc salt in water using N-long chain acylamino acid alkali metal salt and hydroxyalkyl cellulose as a dispersant. This is based on the knowledge that it is possible.

The hydroxyalkylcelluloses used in the present invention include hydroxyalkylcelluloses such as hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, etc. alone or in combination of two or more.

The N-long chain acylamino acid alkali metal salt used in the present invention has an N-long chain acyl group having 8 carbon atoms such as lauroyl, myristoyl, balmitoyl, stearoyl, oleoyl, coconut oil fatty acid residue, tallow fatty acid residue. The amino acid is a neutral or acidic amino acid such as sarcosine, N-methyl-β-alanine, or glutamic acid, and the alkali metal is sodium or potassium.

These N-long chain acylamino acid alkali metal salts may be used not only singly but also as a mixture of two or more.

The fatty acid alkanolamide used in the present invention includes fatty acids mainly consisting of fatty acids having 8 to 18 carbon atoms such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, and coconut oil fatty acid, monoethanolamine, jetanolamine, Examples include fatty acid alkanolamides having a structure obtained by condensing with alkanolamines such as monoisopropanolamine and diisopropanolamine.

The standard blending ratio of the product of the present invention is 0.1 to 3.0 parts (by weight) of bis(2-pyridylthio-1-oxide) zinc salt.

(same below), N-long chain acylamino acid alkali metal salt 1
0 to 30 parts, 0 to 30 parts of hydroxyalkyl cellulose.
1 to 5 parts of water to make a total amount of 100 parts by weight, and 15 parts or less of fatty acid alkanol □ are added to this composition.

Furthermore, humectants such as glycols, glycerin, sorbitol, and pyrrolidone carboxylic acid salts, fragrances, pigments, and the like can be added to the products of the present invention, if necessary.

The product of the present invention is a shampoo composition in which bis(2-pyridylthio-1-oxide) zinc salt is stably suspended and dispersed in a base of N-long chain acylamino acid alkali metal salt and hydroxyalkylcellulose as a dispersant. p
It has a wide H range and is stable in dispersion even in weakly acidic conditions close to the pH of the skin, making it suitable for long-term storage.

Furthermore, the major feature of the product of the present invention is that even when N-long chain acylamino acid salts, which have a hand-improving effect, are used alone or are mixed with an alkanolamide, which has a thickening effect and a foam-stabilizing effect, the product has good dispersibility.
It can be used without reducing effects such as thickening properties.

This is an excellent feature not seen in conventional products.

The present invention will be described below with reference to Examples, but the present invention is not limited thereto.

The text in the text below indicates parts by weight unless otherwise specified.

Example I N-lauroyl sarcosine sodium (trade name: Neupon SLE, manufactured by Yoken Fine Chemicals, activator purity 30%:
Same below) 15 parts as pure activator, 1 part of bis(2-pyridylthio-1-oxide) zinc salt, and 0.7 parts of hydroxyethyl cellulose (trade name: Natrozol 250 HR manufactured by Cures), 0.7 parts of water was added to bring the total amount to 84 parts, uniformly dissolved, dispersed and suspended, and citric acid was added to adjust the pH to 7 to obtain a shampoo composition with a total amount of 100 parts.

The viscosity of this product was measured at 25° C. using a B-type rotational viscometer (manufactured by Tokyo Keiki Co., Ltd.) and found to be 722 cp.

Further, this composition was left in a constant temperature bath at 50° C. for 15 days to measure the stability of the dispersion, and it was found to be stable.

Examples 2 to 3, Comparative Examples 1 to 7 In the case of Examples 2 to 3, sodium N-lauroyl sarcosine, sodium N-lauroyl-N-methyl β-alanine, sodium N-lauroyl glutamate, and sodium lauryl ethoxylated sulfate 15 parts each and 0.7 parts of hydroxyethyl cellulose as pure surfactants, and as a comparative example, polyacrylic acid (trade name: Carbo, manufactured by Gutdrich) used in place of the above surfactant and hydroxyethyl cellulose. paul 94
027 parts of bis(2-pyridylthio-1)
- Oxide) 1 part of zinc salt was dissolved and dispersed in water according to Example 1, the pH was adjusted to 7, and the total amount was adjusted to 100 parts to obtain a shampoo composition.

However, if the pH of the shampoo composition was 7 or less, it was neutralized with an aqueous sodium hydroxide solution, and if it was 7 or more, it was neutralized with an aqueous citric acid solution.

The viscosity and dispersion stability of these compositions were measured according to Example 1, and the results are shown in Table 1.

The numbers on the far right of the surfactant brands in Table 1 indicate that the following products were used.

(1): Manufactured by Yoken Fine Chemical ■ Activator purity 0% Product name: Alanone ALE (2): Manufactured by Ajinomoto ■ Product name: Amisof 1-LS-11
(3): 30% pure activator made by Shin Nippon Rika, trade name Ginoline 5PE (4): 30% pure activator made by Shin Nippon Rika, trade name Ginoline SP As is clear from the results in Table 1. In the system to which hydroxyethyl cellulose was added, the viscosity was high and the dispersion was stable in the case of NIS acylamino acid salt formulation, whereas the viscosity was low and the dispersion was unstable in the case of higher alcohol sulfate and higher alcohol ethoxylated sulfate.

In addition, in the system in which Carbopol 941 was added, all active agents had low viscosity and unstable dispersion.

Examples 4 to 6, Comparative Examples 8 to 1O 15 parts of N-lauroylsarcosinate sodium as pure activator, 1.0 part of bis(2-pyridylthio-1 oxide) zinc salt, amount added as shown in Table 2 Lauric acid jetanolamide (trade name: Amizol LDE manufactured by Yoken Fine Chemicals ■) 0.7 parts of hydroxyethyl cellulose as a dispersant, and in the case of a comparative example, the same amount of polyacrylic acid resin 0.7 parts. It was treated according to Example 1 using a balanced amount of water to make the total amount 100 parts.

However, the pH was adjusted using an aqueous sodium hydroxide solution if the pH was 7 or less, and by citric acid if the pH was 7 or higher.

The viscosity and dispersion stability of these shampoo compositions obtained were measured according to Example 1.

The results are shown in Table 2.

As is clear from Table 2, hydroxyethylcellulose was added to the shampoo composition based on N-lauroylsarcosine sodium and lauric acid diethanolamide.

In contrast to the examples, the viscosity increased and the dispersion became more stable.
On the contrary, the viscosity decreased and the dispersion became unstable in the comparison side in which polyacrylic acid resin was added.

Furthermore, as shown in the Examples below, shampoo compositions containing various long-chain acylamino acid alkali metal salts, hydroxyalkyl celluloses, and other additives were prepared and their properties were observed.

The numbers on the right end of the surfactants in the Examples below indicate that the following commercial products were used.

Claims (1)

[Scope of Claims] 1. Bis(2-pyridylthio-1-oxide) zinc salt is prepared by using 10 to 30 parts by weight of N-long chain acylamino acid alkali metal salt and 0.1 to 5 parts by weight of hydroxyalkyl cellulose. A shampoo composition prepared by dispersing and suspending 1 to 3.0 parts by weight in water in a total amount of 100 parts by weight. 2. A shampoo composition according to claim 1, which is at least one of the hydroxyalkylcelluloses hydroxyethylcellulose, hydroxyfuropylcellulose, and hydroxypropylmethylcellulose. 3 Bis(2-pyridylthio-1-oxide) using 10 to 30 parts by weight of N-long chain acylamino acid alkali metal salt, 0.1 to 5 parts by weight of hydroxyalkyl cellulose, and 15 parts by weight or less of fatty acid alkanol acid. ) A shampoo composition prepared by dispersing and suspending 0.1 to 3.0 parts by weight of a zinc salt in water in a total amount of 100 parts by weight. 4. A shampoo composition according to claim 3, which is at least one of hydroxyalkylcelluloses, hydroxyethylcellulose, hydroxyfuropylcellulose, and hydroxypropylmethylcellulose.