JPH08143441A - Skin cosmetic - Google Patents

Abstract

PURPOSE: To obtain a skin cosmetic containing a silicone resin and a volatile silicone oil, capable of effectively protecting skin from scrubbing and washing, having good feeling to user and hardly attaching to the object. CONSTITUTION: This skin cosmetic contains 1-50wt.% of silicone resin containing the formulas R3 SiO1/2 unit (M unit), R2 SiO unit (D unit) and SiO2 unit (Q unit) in a ratio of 0.7/(0.2-1.0)/1.0 and having 10000-30000 weight average molecular weight and 10-99wt.% of at least one kind of a volatile silicone oil of formula I [(n) is 0-3] and/or formula II [(n) is 4-6]. When blend ratio of the volatile silicone oil is high, the cosmetic exhibits solution state and as blend ratio of the silicone resin is increased, the skin cosmetic becomes solid-like state. The skin cosmetic has good slip and is free from stickiness and stretching feeling in applying to skin and has refreshing feeling and protects skin over a long time and is not washed away by water washing, etc., and hardly adheres to the object even if touched with coated hand.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skin cosmetic, and more particularly to a skin cosmetic which protects the skin from rough skin (mainly hand damage) caused by water work.

[0002]

2. Description of the Related Art Conventionally, hand cream has been generally used to protect the skin from rough skin caused by water work.
The hand cream replenishes sebum lost due to water work, etc., and further imparts flexibility to the skin by blending a moisturizer and water.

However, since the hand cream is easily washed off by washing with water, the skin protecting effect is not always satisfactory. Actually, many housewives are troubled by the trouble of repeated water work such as cooking and selection.

[0004] A dentist or the like who often has frequent hand-washing cannot use a hand cream because he / she should not attach it to a treatment instrument or a patient, and his / her hands tend to get rough, and in severe cases, unpleasant skin inflammation often occurs.

In addition, many barbers complain of inflammation caused by hair dyes and perm solutions in addition to rough skin caused by hand washing.

Japanese Patent Publication No. 48-1503 discloses a technique of a skin protectant for a person who is engaged in such a particularly bad profession. This is a relatively high-viscosity trimethylsilyl endblocking agent. Since diorganosiloxane is used and the composition is made of silica or the like, it has a drawback that it has a strong sticky feeling when applied to the skin and is significantly attached to a contact object.

The applicant of the present invention effectively protects the skin from water work (especially the protective effect is not lost even after repeated washing with water), has a refreshing feeling of use, and adheres to a contact object. As a result of various studies aimed at obtaining a small amount of skin cosmetics, when an organic silicone resin composed of MQ units was used together with a volatile silicone oil, it has good elongation and protects the skin, and is easily washed off by washing with water. It was found that a good water-repellent film which does not exist is formed, and a patent application has already been filed as a skin cosmetic (JP-A-61-1580).
No. 8).

However, the MQ resin referred to here has a weight average molecular weight of 1500 to 10,000,
It was difficult to say that the film had cracks as the silicone oil was volatilized and that it did not necessarily have sufficient film-forming properties. Further, when applied to the skin, it had a feeling of tightness and stickiness and was not sufficient as a cosmetic.

That is, these cracks indicate that the film-forming property is not good, which means that they cannot exhibit a sufficient function as cosmetics.

Further, even if the resin is synthesized by changing the composition ratio of the M unit and the Q unit, the weight average molecular weight is at most 10,000.
Below, there is a limit to the further high molecular weight, MQ
The resin did not give a strong, transparent film with a dry feel.

[0011]

DISCLOSURE OF THE INVENTION The present invention is well spreadable and non-greasy when applied to the skin, has no feeling of tightness, protects the skin for a long time with a refreshing feel, and is easily washed off by washing with water. Further, it is an object of the present invention to provide a skin cosmetic which is not adhered to an object even if it is touched by the applied hand and which is not obtained by a conventional MQ resin.

[0012]

DISCLOSURE OF THE INVENTION The present invention relates to skin containing 1 to 50% by weight of an organic silicone resin represented by the following (A) and 10 to 99% by weight of a volatile silicone oil represented by the following (B). It is characterized by being a cosmetic. (A) The ratio of R ₃ SiO _1/2 units (M units), R ₂ SiO units (D units) and SiO ₂ units (Q units) is 0.
An organic silicone resin which is present in the range of 7 / 0.2 to 1.0 / 1.0 and is composed of MDQ units having a weight average molecular weight of 10,000 to 30,000. (However, R is carbon number 1
Represents hydrocarbons up to 6 or phenyl groups. ) (B)
At least one volatile silicone oil represented by the general formula (I) or the general formula (II). Note that R may be the same or different.

[0013]

Embedded image General formula (I)

[0014]

Embedded image General formula (II)

[0015]

In view of the above circumstances, the present inventor has made extensive studies and found that the cracks of the MQ resin are mainly due to the small weight average molecular weight.

Then, by adding D units to the MQ resin composed of M units and Q units and heating and condensing, MDQ resins having a weight average molecular weight of 2500 to 30000 could be obtained. Among them, MDQ resin of 10,000 or less does not crack, but has a sticky feeling and cannot be used as a cosmetic, but M of 10,000 to 30,000 is used.
DQ resin has the property of completely solving the above-mentioned drawbacks,
It was found that the film was a good film, and the present invention was completed based on this finding.

The above-mentioned organosilicone resin (A) used in the present invention can be easily obtained by hydrolysis of the corresponding known silanes. The blending amount is 1 to 50% by weight based on the total amount of the skin cosmetic. Further, both the chain silicone oil and the cyclic silicone oil represented by the general formula (I) or the general formula (II) used in the present invention are volatile and can serve as a solvent for the organic silicone resin.
The blending amount is 10 to 99% by weight in the total amount of the skin cosmetics.

The skin cosmetic containing the above-mentioned essential components is in the form of a solution or a cream depending on the blending amount. That is, when the amount of the volatile silicone oil is large, it takes the form of a solution and becomes solid as the amount of the organic silicone resin increases.

As a matter of course, in addition to the above-mentioned essential components, a water-in-oil type or an oil-in-water type is blended by blending an aqueous component and a suitable surfactant and making full use of the emulsification technique. It is also possible to use the emulsified composition of.

In addition to the above, the skin cosmetics of the present invention may further contain oils and fats, waxes, drugs, fragrances, or other substances, depending on the purpose, within the quantitative and qualitative ranges that do not impair the effects of the present invention. You may mix a volatile component etc.

[0021]

The present invention will be described in more detail with reference to the following examples. The present invention is not limited by these. All compounding amounts are% by weight.

Example 1 Hand Lotion (1) Dimethylsiloxane 1.5 cs (n = 2) 93.0 (2) M / D / Q = 0.7 / 0.8 / 1.0 (R = Me ) Organosilicone resin having a weight average molecular weight of 30,000 2.0 (3) Methylphenylpolysiloxane 5.0 (1) to (3) were dissolved by stirring at 70 to 80 ° C and cooled to obtain a hand lotion.

[0023] In Example 1, it was not sticky, had a refreshing feeling of use, had good water repellency, and had a function of protecting the skin for a long time. Also, I didn't feel tight. Furthermore, the components did not adhere even if the cup or metal was touched with the hand coated with Example 1.

The water repellency test was carried out by repeating the procedure of washing the hand with water and wiping with a towel five times. The contact angles with water were 107 ° (first) and 103 ° (washed 5 times), indicating good water repellency.

(Comparative Example 1) In Example 1, M was added to (2).
A hand lotion was obtained with the same compounding amount and manufacturing method except that Q resin (weight average molecular weight 5500) was used.

In this case, the water repellency was good at first, but when the operation of washing the hand with water and wiping with a towel was repeated 5 times, the water repellency was remarkably reduced. The contact angles with water were 105 ° (first) and 48 ° (wash 5 times).

It is considered that this is because the cleaning film is easily destroyed by physical force, which confirms that the MDQ resin has a characteristic that can be sufficiently differentiated from the MQ resin.

Example 2 Hand Cream (1) Octamethylcyclotetrasiloxane 15.0 (2) M / D / Q = 0.7 / 0.2 / 1.0 (R = Me) Weight average molecular weight 15,000 65.0 (3) Microcrystalline wax 5.0 (4) Liquid paraffin 15.0 Example 2 was obtained according to Example 1.

The hand cream of Example 2 was not sticky,
It had a refreshing feel and had the effect of protecting the skin for a long time. I also didn't feel tight. Furthermore, no adhesion of the components was observed even when holding the cup or metal with the hand coated with Example 2.

Further, Example 2 is also excellent in water resistance,
It had good water repellency even after washing 5 times with soap.
The contact angle with water was actually measured in the same manner as in Example 1. 10
They were 6 ° (first) and 100 ° (soap was washed 5 times).

Example 3 Hand Moisture Lotion (1) Decamethylcyclopentasiloxane 30.0 (2) M / D / Q = 0.7 / 0.5 / 1.0 (R = Me) Weight average molecular weight 19800 organic silicone resin 40.0 (3) sorbitan monooleate 5.0 (4) water 22.0 (5) dipropylene glycol 3.0 (1) to (3) are stirred and mixed at 70 to 80 ° C., What melt | dissolved (5) in (4) was added to this, and it emulsified and obtained the hand moisture lotion.

The hand moisturizing lotion of Example 3 was non-greasy, had a refreshing feeling of use, and had a function of protecting the skin for a long time. Also, I didn't feel tight. Further, even when holding the cup, metal or the like with the hand coated with Example 3, the adhesion of the components was not recognized. Further, Example 3 was also excellent in water resistance and had good water repellency even after being washed 5 times with soap. When the contact angles with water were actually measured in the same manner as in Example 1, they were 110 ° (first) and 106 ° (washed with soap 5 times).

[0033]

EFFECTS OF THE INVENTION According to the present invention, it spreads well, does not become sticky when applied to the skin, has no feeling of tightness, protects the skin for a long time with a refreshing feel, and is not easily washed off by washing with water. Further, it is possible to provide a skin cosmetic which has little adhesion to an object even when it is touched with the applied hand.

Claims (1)

[Claims] 1. A skin cosmetic containing 1 to 50% by weight of an organic silicone resin represented by the following (A) and 10 to 99% by weight of a volatile silicone oil represented by the following (B). (A) The ratio of R ₃ SiO _1/2 units (M units), R ₂ SiO units (D units) and SiO ₂ units (Q units) is 0.7.
/ Organic silicone resin consisting of MDQ units having a weight average molecular weight of 10,000 to 30,000 (wherein R is 1 to 6 carbon atoms).
Represents a hydrocarbon or phenyl group up to). (B) At least one volatile silicone oil represented by the general formula (I) and / or the general formula (II). Embedded image General formula (I) Embedded image General formula (II)