JPH0710725A - Shampoo composition - Google Patents

Abstract

(57) [Summary] [Object] To provide a shampoo composition having an excellent conditioning effect and having less hair damage. [Structure] A shampoo composition comprising polyaspartic acid or a salt thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shampoo composition, and more particularly to a shampoo composition having an excellent conditioning effect and less damage to hair.

[0002]

2. Description of the Related Art In recent years, shampoos having a conditioning property and a rinsing effect have been widely used because of their excellent finish and ease of use.

These shampoos are usually blended with a cationic surfactant, a cationic polymer, a modified silicone or the like in order to impart conditioning and rinsing effects. However, cationic surfactants have the problem of poor compatibility with anionic surfactants that are shampoo bases, and cationic polymers must be used in high concentrations to obtain conditioning effects, Therefore, there is a problem that the hair becomes dry after washing. Further, the modified silicone has a drawback that it is not uniformly dissolved in the shampoo.

On the other hand, an acylated product of an amino acid has been attracting attention as a surfactant having a good feeling of use and a low stimulative property. In combination, the foaming power is improved, and in JP-A-2-160712, a stable conditioning shampoo is prepared by containing N-acyl amino acid or N-acyl taurine or a salt thereof and an amino-modified silicone. It has gained. But,
It is difficult to say that the detergency and foaming power of shampoos containing these acylated amino acids are sufficient, and the conditioning effects such as flexibility and moistness of silicone are reduced by the presence of acylated amino acids. There was a problem.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a shampoo composition which has an excellent conditioning effect and has less hair damage.

[0006]

Means for Solving the Problems As a result of intensive studies for solving the above-mentioned problems, the present inventors have found that addition of polyaspartic acid makes it possible to obtain a shampoo having an excellent conditioning effect. Is completed.

That is, the present invention is a shampoo composition containing polyaspartic acid or a salt thereof.

The polyaspartic acid or a salt thereof of the present invention is a water-soluble polymer used in water treatment agents, pharmaceuticals and agricultural chemicals, and the like. As a synthetic method thereof, aspartic acid is converted to N-carboxylic acid anhydride with phosgene. And a method of obtaining polysuccinimide by heating aspartic acid and then hydrolyzing it with an alkali are known. For example, in Japanese Examined Patent Publication (Kokoku) No. 48-20638, aspartic acid is used under vacuum in the presence of phosphoric acid or other dehydrating agent.
By reacting at 0 to 200 ° C. and performing dehydration polycondensation so that the surface of the bulk reactant is always removed, polysuccinimide is obtained in high yield in a short time. or,
In Japanese Patent Publication No. 52-8873, polyaspartic acid is produced by heating aspartic acid anhydride hydrohalide in an inert organic solvent or without solvent. Further, USP 5,057,597 describes a method for obtaining polysuccinimide by heating aspartic acid at 180 to 250 ° C in a fluidized bed. The polyaspartic acid or a salt thereof used in the present invention may be produced by any method, and may be purified by a conventional method if necessary. Further, examples of the salt include sodium salt, potassium salt, calcium salt, magnesium salt and the like.

The aspartic acid unit in the polyaspartic acid may be either D-form or L-form. There are two polymer chain bonds, an amide bond due to the α-carboxyl group of the aspartic acid unit and an amide bond due to the β-carboxyl group, but preferably those containing a β bond ratio of 10% or more. Good. If the proportion of β-bonds is less than 10%, the conditioning effect of polyaspartic acid itself may be reduced.

The amount of polyaspartic acid or its salt added is 0.1 to 30% by weight of the total composition. If it is less than 0.1% by weight, the conditioning effect of polyaspartic acid may be insufficient, and if it is more than 30% by weight, the finish may be heavy and the slipperiness and combability may be deteriorated.

The shampoo composition of the present invention contains, in addition to polyaspartic acid or a salt thereof, an anionic surfactant, a nonionic surfactant or an amphoteric surfactant in order to exert detergency, water or water. And a suitable solvent are added to prepare a solution. The amount is usually 1 to 3
It is 0% by weight.

In particular, a combination with an anionic surfactant is preferable, and a conditioning effect can be imparted without impairing the foaming power and the detergency. Examples of the anionic surfactant used include sodium polyoxyethylene lauryl ether sulfate, disodium lauryl sulfosuccinate,
Examples include coconut oil fatty acid methyl taurine sodium, sodium N-lauryl glutamate, triethanolamine N-lauroyl glutamate, sodium lauroyl sarcosine, and the like. Further, examples of the nonionic surfactant include lauric acid diethanolamide, coconut oil fatty acid diethanolamide, polyoxyethylene hydrogenated castor oil, sucrose fatty acid ester, and the like, and amphoteric surfactants include, for example, lauryl dimethyl betaine and imidazo. Examples thereof include rhinium betaine.

Further, in addition to these components, additives generally used depending on the purpose of use of the shampoo and the like can be added to the extent that the effects of the present invention are not impaired. For example, methyl cellulose, cationized cellulose, lauric acid diethanolamide, thickeners such as polyethylene glycol, moisturizers such as ethylene glycol and glycerin, pH adjusting agents such as citric acid, antioxidants, ultraviolet absorbers, alcohols, amino acids , Animal and plant extracts, pigments, fragrances and the like. In addition, in order to improve the feeling of finish, cationic surfactants such as cetyltrimethylammonium chloride, polyoxypropylenemethyldiethylammonium chloride, stearyldimethylbenzylammonium chloride and cationic surfactants such as cationized starch and cationic vinyl polymers are used. An appropriate amount of polymer may be added.

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0015]

EXAMPLES Production Example 1 DL-aspartic acid 100 g and 85% by weight phosphoric acid 50
g was mixed, and the mixture was reacted at 180 ° C. for 2.5 hours under reduced pressure by a rotary evaporator. 40 reaction mixture
After dissolving in 0 ml N, N-dimethylformamide,
After reprecipitation with 2 L of water, the obtained precipitate was washed and dried to obtain 68 g of polysuccinimide. Next, water 17
0 g was mixed with 50 g of 50% by weight sodium hydroxide solution, and 65 g of polysuccinimide was added thereto to obtain 30
After stirring for 60 minutes, 60 g of water was added and the pH was adjusted to 9.0 to 10.
While keeping at 0, the solution was stirred at room temperature until clear. The obtained solution was freeze-dried to obtain 70 g of sodium salt of polyaspartic acid. The molecular weight of this polymer was about 10,000, and the proportion of β bonds was 40%. To obtain free polyaspartic acid, this sodium salt may be dissolved in water, acidified to a pH of around 3, and reprecipitated using a suitable solvent.

The molecular weight of the polymer was measured by the LALLS method, and the ratio of α and β bonds was calculated from the ¹³ C-NMR data.

Examples 1 to 3 and Comparative Example 1 Using the sodium polyaspartate or polyaspartic acid produced in Production Example 1, shampoos having the compositions shown in Table 1 (Table 1) were prepared, and their performances were evaluated. did. The results are shown in Table 1. In addition, all the compounding amounts of each component in the table are% by weight. The evaluation method is as follows. A hair bundle of 2 g (about 15 cm in length) was used and washed with 3 g of shampoo of each composition. This washing was repeated 5 times, and 10 panelists evaluated the foaming during washing, the washability, the less squeaking during rinsing, the flexibility of hair after rinsing, the combability and the gloss. The evaluation criteria are 2 points for very excellent ones, 1 point for slightly superior ones, and 0 for equivalents, based on commercially available rinse-less shampoo.
The points were inferior and the inferior one was given a score, and the average was shown.

[0018]

[Table 1]

As is clear from the results shown in Table 1, the shampoo composition to which polyaspartic acid or a salt thereof is added has less foaming, detergency and squeaking than the additive-free one shown in Comparative Example 1. , Excellent in flexibility, combability and luster, and better than commercial shampoo.

Example 4 and Comparative Example 2 A shampoo having the composition shown in Table 2 (Table 2) was prepared and its performance was tested in the same manner as described above. The results are shown in Table 2.

[0021]

[Table 2]

As is clear from the results in Table 2, shampoo compositions containing polyaspartate having a β bond content of 40% were compared with polyaspartate salts having only 1% β bond. Compared to Example 2, foaming, detergency,
It was excellent in all of squeaking, flexibility, combability, and luster, and was superior to commercially available shampoos.

[0023]

INDUSTRIAL APPLICABILITY The shampoo composition containing the polyaspartic acid or its salt according to the present invention is excellent in conditioning effects such as softness and combability on hair without lowering foaming power and detergency. Further, it has an advantage that it is hypoallergenic to hair even if it is repeatedly used.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akihiro Yamaguchi 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd.

Claims (2)

[Claims] 1. A shampoo composition comprising polyaspartic acid or a salt thereof. 2. The shampoo composition according to claim 1, which contains 0.1 to 30% of polyaspartic acid or a salt thereof having a β bond ratio of 10% or more.