JPH04169521A - Skin detergent - Google Patents

Abstract

PURPOSE:To obtain a skin detergent, having a reduced amount of residual adsorption on the skin with a small amount thereof remaining on the skin and excellent in safety and feeling of use by blending a specific amount of polyethylene glycol having a specific value or above of molecular weight with a soap type detergent containing a fatty acid at a specified concentration. CONSTITUTION:A skin detergent is obtained by blending (A) 10-40wt.% fatty acid with (B) polyethylene glycol having >=400 molecular weight in a soap type detergent as essential ingredients in an equal amount or more to the ingredient (A). The aforementioned detergent has the above-mentioned effects without impairing foaming and fouling removal and further causing tenseness, dryness and skin roughening. Furthermore, the polyethylene glycol is a polyhydric alcohol normally used as a solidifying stabilizer and a wetting agent in soap with excellent safety and can simply be blended in the skin detergent without impairing detergency, stability and safety of the formulation, etc.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a skin cleansing agent, and its purpose is to provide a skin cleansing agent that does not leave much residue on the skin and is safe and easy to use. be.

In addition, fatty acids in this specification refer to natural animal and vegetable fats and oils such as beef tallow, palm oil, coconut oil, and palm kernel oil that are directly saponified, or
Alternatively, it refers to fatty acids derived from them, or fatty acids such as synthetic fatty acids that can be used in soaps.

Furthermore, in this specification, a soap-type detergent refers to a detergent whose main component is soap, which is an alkali salt of fatty acid.

(Background of the Invention) Soaps, which are alkaline salts of fatty acids, are widely used as skin cleansers.

The origin of this soap is very old, dating back to before the B.C. Since then, soap has continued to evolve and is still used as a typical skin cleansing agent.

In addition to the bar soaps that have been used since ancient times, recently there has been a remarkable spread of skin cleansers in the form of liquids and creams. It is a soap that is an alkaline salt of fatty acids.

Soap, which is an alkaline salt of this fatty acid, has excellent cleaning power.
Moreover, it has the excellent feature of providing a relatively refreshing feeling after use.

However, when using this soap as a skin cleansing agent, if rinsing is insufficient, fatty acids and the like remain and are adsorbed on the skin, which tends to cause skin irritation, rough skin, and a tight feeling.

Problems related to safety and usability that arise from residual adsorption to the skin can be avoided if thorough cleaning is performed, but in reality, users do not fully understand the concept. This was a drawback of soap.

In particular, lauric acid, which is often used in liquid and cream detergents, has a large amount of residual adsorption on the skin and is relatively irritating to the skin, so there was a need for a technology to improve it.

(Prior Art and its Problems) Synthetic detergents containing various surfactants as main ingredients are conventionally used as cleaning agents other than soap.

These synthetic detergents are detergents that use various surfactants as their main ingredients, and they have problems such as stronger degreasing power from the skin than soaps, poor usability, and high prices. It was insufficient for use as a skin cleansing agent.

For these reasons, the inventors have made extensive studies to overcome the drawback of soaps that they tend to be adsorbed onto the skin.

As a result, it has been found that this drawback is due to the fact that fatty acids form insoluble fatty acid calcium salts with calcium ions contained in tap water, especially during rinsing. (Collection of lecture abstracts from the 26th Japanese Cosmetic Engineers Financial Policy Research Conference) Therefore, we thought that the above drawbacks could be solved by utilizing the various effects of bilgu, such as the chelating effect, and we investigated using various builders.

However, the results showed that only a slight effect was obtained for carbonate builders, and some builders even showed an increasing trend.

However, carbonate salts, which had some effect, also had the disadvantage of irritating the skin during washing.

Therefore, a skin cleansing agent containing this builder to suppress residual adsorption of fatty acids has not been a technology that can be put to practical use.

(Problems to be Solved by the Invention) In view of the above-mentioned circumstances, it has been desired to create a skin cleansing agent that does not remain on the skin, does not cause skin irritation, and is safe and easy to use.

(Means for Solving the Invention) The skin cleansing agent according to the present invention is a soap-type cleansing agent that contains fatty acids and polyethylene glycol as essential components, and this fatty acid is blended in an amount of 10 to 40% by weight, and This skin cleansing agent is characterized by containing more than the same amount of polyethylene glycol with a molecular weight of 400 or more, so it solves all of the above problems.

(Structure of the invention) The configuration of the present invention will be described in detail below.

The skin cleansing agent according to the present invention is a soap-type cleansing agent obtained using a fatty acid, and is characterized in that it contains polyethylene glycol.

In this invention, it is desirable that 10 to 40 times by weight of the fatty acid used for preparing the detergent be blended into the soap-type detergent.

The reason for this is that if it is less than 10% by weight, the amount is too small to exhibit the detergency effect, and if it is more than 40% by weight, it is necessary to mix at least the same amount of polyethylene glycol as detailed below. This is because, if blended, the fatty acid and polyethylene glycol will be 80% by weight, and as a result, the effective skin cleansing ingredients cannot be blended and the skin cleansing agent will not function.

In this skin cleansing agent, all fatty acids that can be used in soap can be suitably used, and there are no particular limitations. Specific examples include direct saponification of natural animal and vegetable oils such as beef tallow, palm oil, coconut oil, and palm kernel oil. , fatty acids derived therefrom, or synthetic fatty acids, such as lauric acid, myristic acid, palmitic acid, and stearic acid.

As the alkali for neutralizing the fatty acid in this invention, all commonly used alkalis such as sodium hydroxide, potassium hydroxide, and triethanolamine can be suitably used.

The formulation of the soap-type detergent in the present invention is not particularly limited, and can suitably be used in solid, cream, and liquid forms.

The reason for using polyethylene glycol in this invention is
As shown in the examples and test examples below, polyethylene glycol is a highly safe polyhydric alcohol that is effective in reducing the residual adsorption amount of skin cleansers and is widely used in soaps as a solidification stabilizer and wetting agent. This is because it can be easily incorporated into skin cleansers without impairing the cleansing power, stability of the formulation, safety, etc.

The polyethylene glycol preferably has a molecular weight of 400 or more.

The reason for this is as shown in the examples and test examples below.
This is because if it is less than that, the effect of suppressing residual adsorption of fatty acids etc. cannot be expected to be very effective.

The amount of polyethylene glycol to be added to the fatty acid can be preferably equal to or greater than the amount of the fatty acid.

The reason for this is that the effect cannot be expected sufficiently if the magnification is less than the same size.

The skin cleansing agent according to the present invention can be easily produced by a conventional method,
There is no need to use a specific manufacturing method.

In addition, fragrances, surfactants, emulsifiers, humectants, preservatives, solidification stabilizers, and the like can be used in this skin cleansing agent as appropriate.

Therefore, the dosage form of the skin cleansing agent according to the present invention is solid,
Cream, liquid, etc. may be selected as appropriate.

Hereinafter, the effects of this invention will be clarified by showing Examples, Comparative Examples, and Test Examples.

(Example 1, Comparative Examples 1 to 4) Skin cleanser consisting of the composition shown in Table 1, molecular weight 400
A skin cleanser containing polyethylene glycol (hereinafter referred to as PEG) (Example 1)), a skin cleanser containing glycerin with a molecular weight of 92 (Comparative Example 1), and propylene glycol with a molecular weight of 76 (hereinafter referred to as PG). A skin cleansing agent formulated with the compound (Comparative Example 1), a skin cleanser containing 1.3 butylene glycol (hereinafter referred to as 1.3BG) with a molecular weight of 90 (Comparative Example 3), and a skin cleanser containing no polyhydric alcohol. (Comparative Example 4) were prepared.

Test Example 1) 50% each of the skin cleansers obtained in Example 1 and Comparative Examples 1 to 4
0g was adjusted with hard water (containing 60 ppm of Ca ions) to prepare a cleaning solution of No. 101. (37°C, reflux) In this washing solution, the flexor side of the forearm of a man and a woman (23 to 30 years old) with healthy skin was wiped with absorbent cotton containing ethanol, thoroughly washed with ion-exchanged water, and air-dried. Soaked for minutes.

Note that commercially available cleaning agents were not used on this test area for 3 days before the experiment, and when the test area was to be used again for testing, the test was conducted after an interval of one week or more.

After immersion, it was quickly rinsed with water (37°C, 2F) and air-dried.

The amount of the skin cleansing agent remaining on the skin surface of these test areas was measured by the total reflection absorption (ATR) method using a Fourier transform infrared spectrometer (FT-IR).

As a measurement device, N1colet FTIR Model
Skin analyzer (Spectra) on 20DXG
(manufactured by Tech) was attached directly to the skin surface so that the skin surface could be directly analyzed.

As a detector, triglycine sulfide (TGS),
The internal reflective surface (IRE) was 70× IOX 3 mm Zn5e (60° angle of incidence).

The spectrum was obtained under the conditions of a resolution of 4 cm-' and 100 integrations (measurement time: about 3 minutes).

The measurement method uses H to improve contact between the skin and the IRE.
, M, Kl 1m1rch et al.'s method ()1. M,Kl
1m1sch and G.

Chandra, J., Soc., Cosmet,
Chem, 37.73-87 (1986)), a towel soaked in ion-exchanged water (37°C) was applied to the test area for 1 minute to soften the skin surface.

Thereafter, the skin was quickly pressed lightly against the IRE and measured.

This measurement was carried out at a room temperature of 23° C. and a humidity of 50±10%.

The results are summarized in Table 1.

(Margin below) Table 1 (Examples 2 to 4, Comparative Example 5) In order to investigate the relationship between the molecular weight of polyethylene glycol (PEG) and the amount remaining on the skin, the skin cleansers of Examples 2 to 4 and Comparative Example 5 were used. It was prepared according to the recipe shown in Table 2.

(Test Example 2) Examples 2 to 4 and Comparative Example 5 were conducted in the same manner as in Test Example 1.
The amount of skin cleanser remaining on the skin was measured.

The results are also summarized in Table 2.

Table 2 shows Example 1 and Comparative Example 4 tested in Test Example 1.
The results are also summarized.

(Margins below) Table 2 (Any + Kadomori) (Examples 5 to 7, Comparative Example 6) Examples 5 to 7 and A skin cleansing agent of Comparative Example 6 was prepared according to the formulation shown in Table 3.

(Test Example 3) Examples 5 to 7 and Comparative Example 6 were conducted in the same manner as in Test Example 1.
The amount of skin cleanser remaining on the skin was measured.

The results are summarized in Table 3.

Table 3 shows Example 1 and Comparative Example 4 tested in Test Example 1.
The results are also summarized.

(Margins below) Table 3 (Test Example 4) In order to investigate the relationship between Ca ion concentration and skin residual amount, hard water with a Ca concentration of 60 ppm and Ca
The skin cleansers of Example 1 and Comparative Example 4 were used to compare and measure the amount of residual skin on the skin in the same manner as Test Example 1 except that hard water with a concentration of 10 ppm was used.

The results are summarized in Table 4.

(Margins below) Table 4 (Examples 8 to 11, Comparative Examples 7 to 10) In order to investigate the relationship between skin cleansers using various fatty acids and the amount of skin residue, the compositions shown in Table 5-1 were used. Skin cleansers of Examples 8 to 11 were prepared, and skin cleansers of Comparative Examples 7 to 10 were prepared from the compositions shown in Table 5-2.

(Test Example 5) In the same manner as in Test Example 1, the amounts of the skin cleansers of Examples 8 to 11 and Comparative Examples 7 to 10 remaining on the skin were measured.

In this Test Example 5, each fatty acid was blended in the same number of moles.

The results are shown in Tables 5-1 and 5-2.

(The following are blank spaces) Table 5-1 Table 5-2 Table *Ave±5D (n=5) (Test Example 6) Skin cleansing agent A according to the present invention consisting of the composition shown in Table 6 and conventional skin cleansing Agent B (both cream-like) was prepared.

2 with healthy skin using these skin cleansers A and B
Twenty-three men and women (8 men, 15 women) between the ages of 3 and 30 were interviewed about their usability.

Regarding foaming and stain removal, 0 points are given for bad, 1 point is slightly bad, 2 points are average, and 3 points are good.
× for 0.5, △ for 0.6 to 1.5, 1.6
- 2.5 was rated ○, and 2.6-3 was rated ◎.

Regarding tightness, dryness, and rough skin, score 0 for not feeling it, 1 point for feeling it a little, 2 points for feeling it, and 3 points for feeling it strongly.
If the average score is 0-0.5, ◎, 0.6~
○ for 1.5, △ for 1.6 to 2.5, 2.6
-3 was marked as x.

These results are summarized in Table 7.

(Hereinafter in the margin) Table 6 (Hereinafter in the margin) Table 7 (Effects of the invention) The skin cleansing agent according to the present invention is a soap-type cleansing agent containing a fatty acid and polyethylene glycol as essential components, and the fatty acid is Since it is a skin cleansing agent characterized by containing 10 to 40% by weight of polyethylene glycol with a molecular weight of 400 or more relative to the fatty acid, it does not cause foaming and staining, as is clear from the above test examples. This is a skin cleansing agent that does not impair the skin's cleansing properties and does not cause tightness, dryness, or roughness.

That is, this skin cleansing agent has little residual property on the skin, and is excellent in safety and usability.

Agent: Patent attorney Yoshihiro Kiyohara

Claims (1)

[Claims] (1) A soap-type detergent that contains fatty acids and polyethylene glycol as essential ingredients, and this fatty acid contains 10
A skin cleanser characterized by containing polyethylene glycol in an amount of ~40% by weight and having a molecular weight of 400 or more based on the fatty acid.