JP3537861B2 - Skin protective agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skin protective agent having excellent water resistance and chemical resistance, and more particularly, to protecting the skin from water or chemicals (for example, hair dyes, perm agents, etc.) for a long time. The present invention relates to a skin protective agent having excellent water resistance and chemical resistance.

[0002]

2. Description of the Related Art Ordinary creams and emulsions are effective for daily water work and for the improvement of hand roughness caused by shampooing, hair dyeing and perming, which are tasks of a beauty technician. The skin has not yet been protected from the effects of water and chemicals. In addition, for the purpose of protecting the skin, a composition in which a film agent is added to a cream or an emulsion is also known.
Nothing has been obtained that can completely protect the skin from water and chemicals.

[0003]

SUMMARY OF THE INVENTION In view of such circumstances, the inventors of the present invention have improved the water resistance and chemical resistance of a conventionally used skin protective agent and further improved the skin protective effect. As a result of intensive research, an excellent skin protective agent that combines a film agent with a hydrophobic powder and a volatile oil, and further reduces the content of a humectant to enhance film forming ability and improve water repellency. Were obtained, and the present invention was completed.

[0004]

That is, the skin protective agent according to claim 1 of the present application is selected from polydimethylsiloxane-based polymers, polyvinylpyrrolidone-based polymers, and copolymers of these with other polymers. A skin protective agent excellent in water resistance and chemical resistance, characterized by blending one or two or more filming agents, a hydrophobic powder composed of silicone powder, and a volatile oil component. The skin protective agent according to claim 2 is characterized in that the content of volatile oil in the oil is 30% by weight or more. The skin protective agent according to claim 3 is the skin protective agent according to claim 1 or 2, wherein the content of the humectant is 5% by weight or less. The skin protective agent according to claim 4 is the skin protective agent according to any one of claims 1 to 3, wherein the film agent is a high molecular polymer having a molecular weight of 2,000 to 300,000.

[0005]

The operation of the present invention will be described below together with the knowledge obtained when the present invention is achieved. The present inventors have found that blending a film-forming agent, a hydrophobic powder, and a volatile oil in a skin protective agent significantly improves water resistance (water repellency) and chemical resistance. Unlike a face, a finger frequently makes physical contact with an external object. For example, when washing, two hands or hands and the laundry touch each other. Therefore, even if the skin protective agent is applied, the conventional skin application agent is easily detached from the hand, and the skin protective effect is lost in a short time. As a result, the skin becomes rough. However, the present inventors, in the skin protective agent, a film agent,
When the hydrophobic powder and the volatile oil are used in combination, it has been found that even when the physical contact is large as described above, the surface roughness is reduced. The reason for this is not clear, but it is presumed that the skin protective agent of the present invention has extremely high water repellency, and on the other hand has good adhesion to the skin tissue specific to the hand.

Hereinafter, embodiments of the present invention will be described in detail. (Coating agent) The coating agent used in the present invention has a molecular weight of 20.
Those having a high molecular weight of from 00 to 300,000 are preferred.
As such a coating agent, for example, a polydimethylsiloxane-based polymer, a polyvinylpyrrolidone-based polymer, or a copolymer of these with another polymer is used. Commercial products include Antalon V-220 (GAF). The amount of these film agents is 1
-20%, preferably 5-15%. If it is less than 1%, the skin protection property is not sufficient, and if it is up to 20%, the desired effect is satisfied, so that further addition is not necessary.

(Volatile Oil) The volatile oil used in the present invention includes the following. (1) A volatile cyclic silicone solution having a normal boiling point lower than 250 ° C. and represented by the general formula 1 (a commercially available product such as KF994 (Shin-Etsu Chemical Co., Ltd.)).

[0008]

## STR1 ## [R ₂ SiO] _X [wherein, R is alkyl of 1 to 4 carbon atoms and R may be the same or different, and x is an integer of 4-6]

(2) A polyoxyalkylene-substituted silicone represented by Formula 2.

[0010]

Embedded image in MD _y D ⁰ _z M [wherein, M is an trialkylsiloxy unit having the average formula R ₃ SiO _0.5, D is a dialkylsiloxy unit of the formula R ₂ SiO, D ⁰ is the average formula Is a polyoxyalkylene-substituted alkylsiloxy unit, R is an alkyl group having 1 to 4 carbon atoms, R ⁰ is a terminal group selected from the group consisting of alkyl, aryl and acyl groups, and n is A is an integer of 2 to 8;
12 is a number, b is 2 or 3, y is 10 to 10
0, where the polyoxyalkylene chain is 10
Has a molecular weight of less than 00 and z is a number from 1 to 16]

(3) Light hydrocarbon oil having a normal boiling point lower than 250 ° C. (a commercially available product is Isopar H (Ex
xon).

The amount of the volatile oil is 30% or more of the total amount of the oil incorporated in the skin protective agent, and is 5 to 30%, preferably 10 to 25% based on the total amount of the skin protective agent.
%. If it is less than 30% of the total oil content or less than 5% based on the total amount of the skin protective agent, the film effect and skin protective properties are insufficient.

(Hydrophobic powder) The hydrophobic powder is in contact with its water.
It is preferable to use one having a contact angle of 90 ° to 180 °. If it is less than 90 °, the skin protection is not sufficient. As hydrophobic powder, preferably as a specific example to be used in the sheet re <br/> corn powder (e.g., Tospearl 145A (Toshiba Silicone Co.) and Trefil E-506S (Toray Dow
Corning) ). The blending amount of the hydrophobic powder is 1 to 10%, preferably 2 to 5% in the skin protective agent. If it is less than 1%, the skin protection property is not sufficient, and if it is up to 10%, the desired effect is satisfied, so no further blending is required.

(Other Selective Combination Agents) The skin protective agent of the present invention may contain a humectant, a thickener, an oil, a preservative, an antioxidant, if necessary, as long as the effects of the present invention are not impaired. , A drug, a surfactant, an ultraviolet absorber, and the like.

[0015]

The present invention will be described in more detail with reference to the following examples. The present invention is not limited by this. The compounding amount is% by weight.

(Examples 1 to 4, Comparative Examples 1 to 5) Emulsions having the compositions shown in Tables 1 and 2 were prepared, uniformly applied to a glass plate, dried, and the contact angle with water was measured. The results are shown in Tables 1 and 2. The evaluation criteria for the contact angle are as follows. [Evaluation criteria for contact angle] ×: less than 20 ° Δ: 20 ° or more and less than 50 ° ○: 50 ° or more and less than 80 ° ：: 80 ° or more

[0017]

[Table 1]

[0018]

[Table 2]

As shown in Table 1, when a hydrophobic powder or a film-forming agent is added to a normal emulsion (Comparative Example 1), the contact angle is increased and the water repellency is slightly increased (Comparative Examples 2 to 5).
3). Furthermore, by incorporating a volatile oil content of 30% by weight or more in the oil content, reducing the humectant to 5% by weight or less, and combining the film agent and the hydrophobic powder, the film forming ability is further improved (adhesion to the skin) Good), and a skin protective agent having a high water repellent effect and a high skin protective effect was obtained (Example 1).

(Example 5) Cream type skin protective agent (1) Cetostearyl alcohol 2.0 (2) Squalane 2.0 (3) Beeswax 1.0 (4) Reduced lanolin 1.0 (5) ) Ethyl paraben 0.3 (6) polyoxyethylene (20 mol) sorbitan monopalmitate 2.0 (7) monoglyceride stearate 2.0 (8) sodium N-stearoyl glutamate 0.5 (9) trimethylsiloxysilicate Acid-octamethylcyclotetrasiloxane (50%) 30.0 (10) Decamethylcyclopentasiloxane 10.0 (11) Polyethylene powder 10.0 (12) Vitamin E acetate 0.1 (13) Stearyl glycyrrhetinate 0.1 (14) Ergocalciferol solution (2 million units) 0.1 (15) 1,3-Bu Renguriko - Le 2.0 (16) polyethylene glycol - Le 1500 2.0 (17) Purified water Balance [Preparation] (1), (2), (3), (4), (5),
(6), (7), (8), (9), (10), (1
1), (12), (13), and (14) were dissolved by heating, and
Add to (15), (16) and (17) heated to 0 ° C. with stirring. After homogenizing the emulsion to make the emulsified particles fine, the mixture was rapidly cooled with stirring to obtain a cream-based skin protective agent.

(Example 6) Skin lotion type skin protective agent (1) 1,3-butylene glycol 2.0 (2) ethanol 50.0 (3) trimethylsiloxysilicate-octamethylcyclotetrasiloxane Solution (50%) 20.0 (4) Decamethylcyclopentasiloxane 20.0 (5) Silicone powder 1.0 (6) Polyethylene powder 1.0 (7) Purified water Residue [Production method] ), (3), (4),
(5), (6) and (7) were mixed to obtain a lotion type skin protective agent.

[0022]

According to the present invention, by combining a film agent, a hydrophobic powder, and a volatile oil component, a skin protective agent having enhanced film forming ability, increased water repellency, and a long lasting effect can be obtained. can get.

[Table 1]

[Table 1]

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenzo Ito 1050 Nippa-cho, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture Shiseido First Research Center Co., Ltd. (56) References JP-A-61-65808 (JP, A) JP-A-63-183515 (JP, A) JP-A-4-139106 (JP, A) JP-A-4-210613 (JP, A) JP-A-61-161209 (JP, A) JP-A-63-183516 (JP, A) JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61K ^7/ 00-7/50

Claims (4)

(57) [Claims] 1. One or more coating agents selected from polydimethylsiloxane-based polymers, polyvinylpyrrolidone-based polymers and copolymers of these with other polymers, and a hydrophobic powder comprising silicone powder. And a volatile oil component. A skin protective agent having excellent water resistance and chemical resistance. 2. The skin protective agent according to claim 1, wherein the content of the volatile oil in the oil is 30% by weight or more. 3. The skin protective agent according to claim 1, wherein the content of the humectant is 5% by weight or less. 4. The coating agent has a molecular weight of 2,000 to 300,000.
The skin protective agent according to any one of claims 1 to 3, wherein the skin protective agent is a high molecular weight polymer.