JPH06206806A - Skin protecting agent composition - Google Patents

Abstract

PURPOSE:To obtain a skin protecting agent composition having no unpleasant feeling such as greasiness and feeling of tension, showing an excellent feeling in use, improved water repellency and water resistance, being hardly washed off by water flow after application or with a solution of a cleaning agent, having an extremely high remaining ratio on the surface of the skin. CONSTITUTION:A skin protecting agent composition comprises a dimethylpolysiloxane having >=200,000 average molecular weight and an acrylic polymer as essential components. A more preferable skin protecting agent composition is obtained by making the blending ratio of the dimethylpolysiloxane the acrylic polymer of 100:0.5-10:100. The skin can be effective protected from chapped skin by kitchen work and application of agent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skin protectant composition, the object of which is to provide no sticky feeling or sticking feeling even when applied to the skin surface, and to provide a good feeling during use, The present invention provides a skin protectant composition which is hardly washed off with water, detergent solution, etc., has a high residual rate on the skin surface, and can well protect the skin from rough skin caused by water work or drug treatment.

[0002]

BACKGROUND OF THE INVENTION The skin surface of a living body is covered with a sebum film formed by sebum and sweat, and this sebum film physiologically protects the skin from external stimuli and dryness and is flexible to the stratum corneum of the skin. It also plays an emollient effect such as giving elasticity and elasticity. That is, since the sebum film has water repellency and a buffering effect, it prevents the invasion of water and harmful substances into the skin, and when the acid or alkali adheres to the extent that its resistance is not exceeded, the acid or alkali Plays a role in neutralizing and preventing the occurrence of dermatitis due to these stimuli and protecting it. The sebaceous membrane also serves to suppress evaporation of water contained in the outermost stratum corneum of the skin and maintain the flexibility and elasticity of the skin. However, the sebaceous membrane, which has a protective effect on the skin and an emollient effect, is
It is not always well-supplemented and formed, and the secretion of sebum generally decreases as the temperature decreases, and especially in dry skin, the secretion amount of sebum tends to be insufficient in winter. In addition, as the age increases, the amount of sebum secreted gradually decreases, and the formation of a sebum film on the skin surface becomes insufficient.
Therefore, when the temperature is low or as the age increases, the protective action and emollient action by the sebum membrane cannot be expected, the skin surface becomes dry, and the skin is easily cracked, cracked, or cracked. On the other hand, even in everyday life, the formation of the sebum film becomes insufficient due to external stimuli,
Often the sebaceous membrane is destroyed. In other words, housewives at home tend to lose sebum due to the use of detergents during the daily water work, resulting in insufficient formation of the sebum film, which easily causes skin cracks and cracks. In addition, people engaged in occupations such as nurses, barbers, and cosmetologists are liable to cause dermatitis and rough skin due to destruction of the protective function of the sebum membrane due to contact with chemicals. That is, since nurses handle formalin and chemicals on a daily basis, contact with these agents causes hairdressers and barbers to use permanent wave agents or hair dye (oxidative dye) used during perm treatment. Contact with a hair treatment agent (such as a hair agent) causes irritation to the skin surface, which easily causes dermatitis and rough skin.
Therefore, a protective agent such as cream is often applied to the skin surface in order to protect the skin from such a decrease in sebum secretion, exogenous degreasing action on the epidermis, destruction of the sebum membrane, etc. . This protective agent uses a moisturizer to maintain moisture and forms an oily film on the skin surface,
The occlusive action of this film suppresses excessive evaporation of water on the skin surface.

[0003]

2. Description of the Related Art Hand creams are commonly used as a skin protective agent for degreasing the skin surface with a detergent and for protecting the skin. A general hand cream is usually a moisturizer that gives a proper amount of water and oil to the skin and a softening agent that prevents the evaporation of water on the skin surface, and an emulsifier and a fragrance that emulsify and homogenize these ingredients. It consists of additives. As the moisturizer, hydrophilic ones such as glycerin, propylene glycol, polyethylene glycol, soluble collagen, hyaluronic acid and sodium lactate are often used, while as softeners squalane, lanolin, jojoba oil, fatty acid ester, Oils such as orange luffy oil are often used. However, in the hand cream having the above-mentioned constitution, the effect of the moisturizing agent and the softening agent contained is the primary physical effect, the effect is not continuously exerted, and it is easily washed with water or the like. There was a problem of being washed away. In addition, when the amount of the moisturizer or softening agent is sufficiently increased to prescribe a hand cream in order to sufficiently develop the effect, it causes stickiness and hot flashes on the contrary, resulting in poor usability and skin surface There is a problem that the normal metabolism of the skin is hindered by the coating of the softening agent or the like.

In view of such circumstances, instead of the above-mentioned moisturizers and softeners, a component which newly protects the skin from external stimuli and a high water resistance mainly composed of high molecular weight silicone and acrylic polymer are used. Hand creams are also being created. In general, silicones, especially silicones such as dimethylpolysiloxane having a large molecular weight, have excellent water repellency and chemical resistance, so they are easy to repel water, can protect the skin from irritation by chemicals, and are tasteless and odorless. For this reason, it is easy to prescribe as cosmetics and pharmaceuticals, and therefore, attention has been focused on application to a skin protectant that protects the skin from external factors and prevents rough skin. On the other hand, acrylic polymers are also well known as a compound exhibiting better water resistance than before, and attention has been paid to its application to cosmetics that require water resistance.

[0005]

However, although the above-mentioned high molecular weight silicone exhibits good water repellency, it also has a problem that it has a strong sticky feeling, sticks to a contact substance remarkably, and has a bad usability. did. In addition, the film formed by high molecular weight silicone is soft,
There was a problem of poor resistance to friction.
On the other hand, in the case of an acrylic polymer, the film formed on the contrary is too hard, and it is difficult for the film to spread when applied to the surface of the skin, and there is a problem that it is easily peeled off due to body movement or external force. In addition, the acrylic polymer film has a problem in that it has a feeling of tension and pain when applied to the surface of the skin and is not easy to use. So in the industry,
It has a long-lasting effect and shows good water repellency and water resistance that is not easily washed off by washing,
Moreover, it has been desired to create an excellent skin protectant composition which does not cause discomfort such as stickiness or stickiness during use.

[0006]

According to the present invention, the average molecular weight is 20.
By providing a skin protectant composition characterized by containing 10,000 or more of dimethylpolysiloxane and an acrylic polymer as essential components, the above-mentioned conventional problems are solved.

[0007]

[Function] When dimethylpolysiloxane having an average molecular weight of 200,000 or more and an acrylic polymer are combined and blended, excellent water repellency and water resistance are exhibited, and resistance to external stimuli such as water, detergent and chemicals is exerted. Remarkably increases the property, especially against washing off with an aqueous surfactant solution,
Shows excellent residual effect. Further, during use, there is no discomfort such as a feeling of tightness or pain, or a feeling of stickiness, and a good feeling of use that extends well as a refreshing feeling is exhibited.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The constitution of the skin protectant composition according to the present invention will be described in detail below. In this invention, the average molecular weight is 2
More than 100,000, more preferably more than 400,000 dimethylpolysiloxane is added as one of the essential components. The reason for this is that when the average molecular weight of dimethylpolysiloxane is less than 200,000, the water repellency and water resistance are not good, water becomes difficult to repel, and it becomes particularly easy to wash off the aqueous surfactant solution, which is not preferable. Because. On the other hand, the larger the molecular weight of dimethylpolysiloxane, the less sticky it is, and the more refreshing feeling is obtained, which is more preferable.

In the present invention, an acrylic polymer is also included as one of the essential components. Preferred examples of the acrylic polymer include octyl acrylamide / acrylic resin and ethyl acrylate / methacrylic acid resin. In the present invention, the amount of the acrylic polymer blended is preferably 0.5 parts by weight or more, more preferably 2 parts by weight or more, based on 100 parts by weight of the dimethylpolysiloxane having an average molecular weight of 200,000 or more. The reason for this is that if the amount of the acrylic polymer blended is less than 0.5 parts by weight with respect to 100 parts by weight of dimethylpolysiloxane, excellent water resistance, which is the intended purpose of the present invention, will not be exhibited, and water flow or detergent This is because it is not preferable because it is easily washed away by the solution. On the other hand, the amount of dimethylpolysiloxane blended is 10 parts by weight or more, more preferably 50 parts by weight, based on 100 parts by weight of the acrylic polymer.
It is preferable that the amount is at least parts by weight. The reason for this is that the amount of dimethylpolysiloxane blended is 10
When the amount is less than 10 parts by weight with respect to 0 parts by weight, a feeling of tension, which is a drawback of the acrylic polymer, appears, and the usability is significantly deteriorated and the water resistance is deteriorated, which is not preferable.

The skin protectant composition according to the present invention containing the above essential components is applicable to all things used on the skin surface such as cosmetics, pharmaceuticals, quasi drugs, and the like. The type is also optional, but as a preferred example, a lotion or other toner type or an aerosol type can be exemplified. However, in the case of the lotion type, it is necessary to use a solvent capable of dissolving both dimethylpolysiloxane and an acrylic polymer in consideration of compatibility with each other. Specifically, a useful means is, for example, a combined use of a volatile oil represented by light liquid isoparaffin or cyclic silicon and isopropanol. Also, when formulating into an aerosol type, liquefied petroleum gas, dimethyl ether,
Common propellants such as CFCs may be used, and carbon dioxide gas and nitrogen gas may be used in addition to these propellants, and these gases may be used alone or in combination of two or more kinds. Is also good.

In the skin protectant composition according to the present invention, in addition to the above-mentioned essential components, alcohols, water-soluble polymers, antioxidants and pH may be added according to the purpose within the range that does not impair the effects of the present invention. Preparation agent, ultraviolet absorber, sequestering agent, thickener, nonionic surfactant, anionic surfactant, cationic surfactant, amphoteric surfactant, antibacterial agent, preservative, antiphlogistic, vitamin, hormone, Other components used in a usual skin protectant composition such as a refreshing agent, a colorant, and a fragrance can be appropriately mixed appropriately.

(Prescription Example) Specific examples of the skin protectant composition according to the present invention will be given below with reference to prescription examples, but the present invention is not limited to the present formulation. (Prescription example 1: lotion type) Parts by weight Dimethylpolysiloxane 12.5 (Average molecular weight 500,000) Octylacrylamide / acrylic resin 0.5 Light liquid isoparaffin 47.0 Isopropanol 39.8 Perfume 0.1 Tocopherol acetate 0.1 100.0 (Formulation example 2: Aerosol type) Part by weight Dimethylpolysiloxane 2.0 (Average molecular weight 200,000) Octylacrylamide / acrylic resin 0.1 Light liquid isoparaffin 10.0 Isopropanol 9.8 LPG 38.0 Dimethyl ether 40. 0 fragrance 0.1 100.0

[0013]

The effects of the skin protectant composition according to the present invention will be further clarified below with reference to Examples.

(Example 1 and Comparative Examples 1 and 2) Differences in performance between a case where both dimethylpolysiloxane having an average molecular weight of 200,000 or more and an acrylic polymer are mixed and a case where only one of them is mixed are tested. Therefore, the skin protectant compositions of Example 1 and Comparative Examples 1 and 2 were prepared according to the formulations shown in Table 1.

[Table 1]

Example 2 and Comparative Example 3 In order to test the difference in performance when dimethylpolysiloxanes having different average molecular weights were blended, the skin protectant compositions of Example 2 and Comparative Example 3 were prepared according to the formulations shown in Table 2. The thing was prepared.

[Table 2]

(Examples 3 to 4 and Comparative Examples 4 to 5) In order to test the influence of the difference in the blending amount of the acrylic polymer on the performance, Examples 3 to 4 were prepared according to the formulation shown in Table 3.
And the skin protectant compositions of Comparative Examples 4 to 5 were prepared.

[Table 3]

(Examples 5 to 6 and Comparative Examples 6 to 7) In order to test the influence of the difference in the blending amount of dimethylpolysiloxane having an average molecular weight of 200,000 or more on the performance, Example 5 was prepared according to the formulation shown in Table 4. ~ 6 and the skin protectant compositions of Comparative Examples 6 to 7 were prepared.

[Table 4]

(Examples 7 to 8 and Comparative Examples 8 to 9) In order to test the difference in performance when dimethylpolysiloxanes having different average molecular weights were blended, Examples 7 to 8 and Comparative Examples were prepared according to the formulations shown in Table 5. 8-9 skin protectant compositions were prepared.

[Table 5]

[0019]

[Test Example] Using the skin protectants prepared in the above Examples 1 to 8 and Comparative Examples 1 to 9, the following wash-off test with water flow, wash-off test with neutral detergent, sensory feeling on rough skin and feeling of use It was submitted to the test.

(Test Example 1) Washing-off test by water flow Using the skin protecting agents obtained in the above-mentioned Example 1 and Comparative Examples 1 and 2, washing-out test by water flow after application was tested. As the test method, the FT-IR / ATR method was adopted, and after coating, the coated portion was immersed in a water stream, and the amount of remaining silicon was measured. The test procedure is from A to
Shown in C. A. Application of the sample to the forearm part Dirt and sebum on the forearm part to be measured are wiped off well with ethanol, and after the ethanol is evaporated, 0.2 ml of the skin protectant composition obtained in the above Examples and Comparative Examples And spread it well. After this, the applied skin protectant composition was allowed to stand for 20 minutes until it dried. B. Washing off and FT-IR measurement 6 liters of water was placed in a constant temperature water tank, and the water temperature was kept at 37 ° C while circulating water in this water tank. The forearm coated with the skin protectant composition is immersed in the water tank for 5 minutes, and then a dry towel is gently pressed to remove water drops. Air dry for 2 to 3 minutes as it is, and apply A to the forearm
The residual silicon was measured by pressing it against the crystal part of the TR method. C. Numerical treatment The absorbance (A amid) of the peak of amide II (1543.7 cm ^-1 ) was set as an internal standard, and the ratio of this to the absorbance (A sample) at the peak characteristic of the skin residual compound was taken as the absorbance ratio. In this test, a peak at 1012.5 cm ^-1 characteristic of silicon was used to examine the residual silicon.
The absorbance (A base) at 2100 cm ^-1 was defined as the baseline. (However, in the skin protectant of Comparative Example 2 which does not contain silicon, 1150 cm ^-1 which is characteristic of acrylic polymer.
Was used. ) Absorbance ratio = (Asample-Abase) / (Aamid-Abas)
e) Next, as the residual rate, the ratio of the absorbance ratio before the treatment and the absorbance ratio after the treatment was calculated, and this value was used as an index of the residual skin. Residual rate (%) = (Absorbance ratio after treatment / Absorbance ratio before treatment) × 100 In the wash-off test with this water flow, “B. Wash-off and FT-IR measurement” was repeated 7 times for one sample,
The residual rate after the 1st, 3rd, 5th, and 7th washings were measured. The results are shown in Table 6.

[Table 6]

(Test Example 2) Wash-off test with a neutral detergent Using the skin protectants obtained in the above-mentioned Example 1 and Comparative Examples 1 to 2 and Example 2 and Comparative Example 3, neutrality after application A detergent wash-out was tested. As the test method, the same FT-IR / ATR method as in Test Example 1 was adopted, and after application, the applied part was dipped in a neutral detergent, and the amount of residual silicone and acrylic polymer was measured. went. The test procedure is shown in the following AC. A. Application of the sample to the forearm part Dirt and sebum on the forearm part to be measured are wiped off well with ethanol, and after the ethanol is evaporated, 0.2 ml of the skin protectant composition obtained in the above Examples and Comparative Examples And spread it well. After this, the applied skin protectant composition was allowed to stand for 20 minutes until it dried. B. Washing off and FT-IR measurement 10 ml of water is added to about 1 ml of a commercially available neutral detergent and the mixture is whipped.
Using this, the sites to which the skin protectant compositions of Examples and Comparative Examples have been applied are rubbed and washed 20 times. After that, wash the neutral detergent thoroughly with 2 liters (1) of water at 37 ° C and gently press a dry towel to remove water drops. It was air-dried for 2 to 3 minutes as it was, and the applied part of the forearm was pressed against the crystal part of the ATR method to measure the residual silicon. C. Numerical Treatment As in the case of Test Example 1 above, the absorbance (A amid) of the peak of amide II (1543.7 cm ⁻¹ ) was set as an internal standard, and the absorbance at the peak characteristic of this and the residual compound on the skin (A sample)
The ratio with and was taken as the absorbance ratio. In this test, 1012.5 cm ^−1, which is characteristic of silicon, was used to examine the residual silicon.
Peak of 1150cm ^-1 characteristic of acrylic polymers
Was used. The absorbance at 2100 cm ^-1 (A
base) was defined as the baseline. (However, in the skin protectant of Comparative Example 2 containing no silicone, the peak at 1150 cm ⁻¹ characteristic of the acrylic polymer was used.) Absorbance ratio = (A sample −A base) / (A amid −A bas
e) Next, as the residual rate, the ratio of the absorbance ratio before the treatment and the absorbance ratio after the treatment was calculated, and this value was used as an index of the residual skin. Residual rate (%) = (absorbance ratio after treatment / absorbance ratio before treatment) × 100 In the skin protectant compositions of Example 1 and Comparative Examples 1 and 2, washing with a neutral detergent was repeated twice and the first time. Each residual rate of the second time was measured. The results are shown in Table 7.
Further, in the skin protectant compositions of Example 2 and Comparative Example 3,
Washing off with a neutral detergent was performed only once, and the residual rate at that time was measured. The results are shown in Table 8.

[Table 7]

[Table 8]

(Test Example 3) Sensory evaluation of rough skin and feeling of use Examples 3 to 4 and Comparative Examples 4 to 5 and Examples 5 to 5
6 and Comparative Examples 6 to 7, further Examples 7 to 8 and Comparative Example 8
Each of the skin protectant compositions obtained in Examples 1 to 9 was tested for rough skin and feeling of use. As a test method, 20 panelists each suffering from rough skin caused by water work were selected, and a sensory test method by these panelists was adopted. 0.5 ml of the skin protectant composition obtained in each of the Examples and Comparative Examples was applied to each of the panelists before water work.
Each item of feeling of use at the time of application and recovery of rough skin after continuous use for 1 month was evaluated according to the following criteria. Feeling of use For each panel, the overall feeling of use when applying, such as stickiness and tension, was rated as 5 and 4 is fair.
I got a score in 5 levels: 3 points for normal, 2 points for a little bad, and 1 point for bad. The average score in each sensory evaluation was calculated, 1-2 points were x, 2-3 points were △, 3-4 points were ◯, 4
5 points were evaluated as ⊚, and this was used as an index of the feeling of use during application. Rough skin recovery For each panelist, the degree of progress in rough skin recovery should be scored in 4 levels: 4 for those that have remarkably recovered, 3 for those that have recovered, 2 for those that have recovered slightly, and 1 for those that have not recovered. , 1 to 2 for the average score in each sensory evaluation
The point was evaluated as x, the 2-3 point was evaluated as Δ, and the 3-4 point was evaluated as ◯, and this was used as an index of the feeling of use during application. The results of Examples 3 to 4 and Comparative Examples 4 to 5 are shown in Table 9, and Examples 5 to 6 and Comparative Examples 6 to 7 are shown.
The results are shown in Table 10, and the results of Examples 7 to 8 and Comparative Examples 8 to 9 are shown in Table 11.

[Table 9]

[Table 10]

[Table 11]

As is clear from the results of Tables 6 to 7, in the skin protectant composition (Example 1) containing dimethylpolysiloxane having an average molecular weight of 200,000 or more and an acrylic polymer, dimethylpolysiloxane or acrylic was used. It can be seen that, as compared with the skin protectant composition (Comparative Example 1 or 2) in which any one of the base polymers is not blended, the residual rate in the applied portion after washing with water or detergent is extremely high. From the results of Table 8, in the skin protectant composition (Comparative Example 3) containing dimethylpolysiloxane having a small molecular weight, compared to the case of using the polymer (Example 2), the applied portion after washing with detergent was compared. It can be seen that the residual rate of is extremely low. As is clear from the results of Tables 9 and 10, in the skin protectant compositions (Examples 3 to 6) in which dimethylpolysiloxane having an average molecular weight of 200,000 or more and an acrylic polymer were blended, dimethylpolysiloxane and an acrylic polymer were used. The blending ratio with the polymer is 100: 0.5 by weight.
As compared with the skin protectant composition (Comparative Examples 4 to 7) having a range other than 10 to 100, it is found that the composition has an effect on use feeling at the time of application and recovery from rough skin. As is clear from the results of Table 11, it is understood that the one in which dimethylpolysiloxane having a large molecular weight is blended has a better effect on the feeling of use and the recovery of skin swelling.

[0024]

As described above in detail, the present invention is a skin protectant composition comprising dimethylpolysiloxane having an average molecular weight of 200,000 or more and an acrylic polymer as essential components. As is clear from the results of the above Examples and Test Examples, there is no discomfort such as a sticky feeling or a sticking feeling even when applied to the skin surface, and the resistance against external stimuli such as water stream and detergent solution is strong. Since it is not easily washed away by irritation, it has an excellent effect as a skin protector capable of well protecting the skin from rough skin caused by water work or drug treatment. Further, by setting the weight ratio of the dimethylpolysiloxane and the acrylic polymer to be 100: 0.5 to 10: 100, it is possible to more effectively act on the feeling of use and the recovery of skin roughness.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Noriyuki Fujiwara 5-15, 12kencho, Chuo-ku, Osaka City Mandom Central Research Institute, Inc.

Claims (2)

[Claims] 1. A skin protectant composition comprising dimethylpolysiloxane having an average molecular weight of 200,000 or more and an acrylic polymer as essential components. 2. The weight ratio of the dimethyl polysiloxane and the acrylic polymer is 100: 0.5 to 10 :.
The skin protectant composition according to claim 1, wherein the composition is 100.