JP2903247B2 - Water-in-oil emulsion composition - Google Patents

Description

The present invention relates to a water-in-oil type emulsified composition, and more particularly, to a cosmetic film having excellent stability over time and feeling of use and high water resistance. And a water-in-oil emulsion composition suitable for cosmetics and the like.

[Conventional technology and its problems]

Emulsified compositions are generally oil-in-water (O / W) and water-in-oil (W
/ O type), of which water-in-oil type emulsion composition has better affinity for skin than oil-in-water type emulsion composition, and covers the skin surface with an oil film to prevent evaporation of water, Cosmetics such as make-up cosmetics, etc., because of their properties such as protecting the skin from drying and imparting a treatment effect to the skin, and also having excellent water repellency and little breakage of makeup,
It is widely used as a base for medical products.

In a water-in-oil (W / O) emulsified composition, silicone oil is often used as an oil agent in order to obtain a refreshing and less sticky product having good water repellency. When preparing such an emulsified composition, a hydrophilic polyoxyalkylene-modified organopolysiloxane-based interface having good compatibility with silicone oil is usually used as an emulsifier in order to obtain a composition having good stability over time. Activators are widely used. However, it has been difficult to obtain a sufficiently stable surfactant over time simply by blending this surfactant into an emulsified composition containing a large amount of silicone oil. For this reason, it has been attempted to blend a wax or an organically modified clay mineral as a gelling agent (Japanese Patent Application Laid-Open Nos. 61-66752 and 61-218509). It was difficult to obtain a resin having a satisfactory stability over time.

[Means for solving the problem]

Under such circumstances, the present inventors have conducted intensive studies and found that a silicone gel composition comprising a partially crosslinked organopolysiloxane polymer and a low-viscosity silicone oil was contained in an oil phase component, and a specific polymer was used as an emulsifier. By using an oxyalkylene-modified organopolysiloxane surfactant, it is possible to obtain an excellent water-in-oil emulsion composition having excellent stability over time, a good feeling in use, and a high utility as a base material for cosmetics and the like. And completed the present invention.

That is, the present invention provides the following components (A) to (C) (A) (a) and (b) (a) a partially crosslinked organopolysiloxane selected from the following (a-1) and (a-2) Polymer (a-1) An organopolysiloxane polymer (a-2) obtained by crosslinking an organopolysiloxane and partially having a three-dimensional crosslinked structure insoluble in benzene and capable of containing benzene having its own weight or more. A) An organopolysiloxane obtained by addition polymerization of an organohydrogenpolysiloxane and (b) an aliphatic unsaturated group-containing organopolysiloxane and partially having a three-dimensional crosslinked structure which is insoluble but sufficiently swells in silicone oil. Siloxane polymer (b) Oil phase component containing 60 to 100% by weight of a silicone gel composition comprising a silicone oil having a viscosity of 50 cs or less 30 to 60% by weight (B) General formula (I) or (II) [Wherein, G ₁ and G ₂ may be the same or different and each is CH ₃ or (CH ₂ ) _p O (C ₂ H ₄ O) _m (C ₃ H ₆ O) _n R ₁ (p =
X represents a number of 1 to 5, m = 1 to 50, n = 0 to 30, R ₁ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), and X
Is (CH ₂ ) _p O (C ₂ H ₄ O) _m (C ₃ H ₆ O) _n R ₁ (p, m, n and
R ₁ has the same meaning as described above), a = 5-300,
b = 0 to 50. However, both G ₁ and G ₂ are CH ₃
And b = 0. ] Wherein G ₁ , G ₂ and X have the same meaning as described above, and a = 1
~30, b = 0~50, the number of c = 5~300, R ₂ represents an alkyl group having 2 to 20 carbon atoms. However, this excludes the case where both G ₁ and G ₂ are CH ₃ and b = 0. ] A water-in-oil emulsion composition comprising 0.1 to 10% by weight of a polyoxyalkylene-modified organopolysiloxane surfactant represented by the following formula (C): 5 to 69.9% by weight of water. .

The oil phase component as the component (A) of the present invention contains a silicone gel composition comprising (a) a partially crosslinked organopolysiloxane polymer and (b) a low viscosity silicone oil.

Among the partially crosslinked organopolysiloxane polymer (a), a three-dimensional crosslinked structure which is obtained by crosslinking the organopolysiloxane (a-1) and which is insoluble in benzene and can contain benzene having a weight greater than or equal to its own weight. The organopolysiloxane polymer contained in one part has R ₂ SiO units and RSiO _1.5 units, and may contain R ₃ SiO _0.5 units and / or SiO ₂ units. In order to obtain a structure having a three-dimensional cross-linked structure which is insoluble in benzene but may contain benzene of its own weight or more, it is necessary that RSiO _1.5 units and / or S
It is necessary that the ratio between the iO ₂ unit and the R ₂ SiO unit and / or the R ₃ SiO _0.5 unit is in an appropriate range. When the amount of RSiO _1.5 units and / or SiO ₂ units is too small, the organopolysiloxane polymer does not have a sufficient three-dimensional crosslinked structure, becomes soluble in benzene, and cannot be used even if it has an apparent crosslinked structure. In addition, R ₂ SiO units and / or R ₃ SiO _0.5
If there are too many RSiO _1.5 units and / or SiO ₂ units in comparison with the units, the organopolysiloxane polymer has a strong crosslinked structure and is insoluble in benzene, but contains less than the benzene of its own weight. When mixed with a low-viscosity silicone oil, the organopolysiloxane polymer does not sufficiently swell, causing separation and discharge of the silicone oil. For this reason, in order to obtain a soft and stable silicone gel composition, the composition is affected by the molecular weight of the polymer.
In general, (R ₂ SiO unit and / or R ₃ SiO _0.5 unit): (R
It is preferable to use one having an SiO _1.5 unit and / or SiO ₂ unit) in the range of 1: 1 to 30: 1.

In each of the above structural units, R is a hydrogen atom; a methyl group;
Examples thereof include an alkyl group such as an ethyl group and a propyl group; an aryl group such as a phenyl group and a tolyl group; and an aliphatic unsaturated group such as a vinyl group, which may be the same or different.

Such an organopolysiloxane polymer having a three-dimensional crosslinked structure which is insoluble in benzene but may contain benzene having its own weight or more can be synthesized by, for example, the following various methods.

A catalytic amount of an alcoholic aqueous solution of an alkali metal hydroxide is added to an organohydrogenpolysiloxane having a hydrogen atom bonded to at least two silicon atoms in one molecule, and the mixture is heated to perform a dehydrogenation reaction and a condensation reaction. Method.

An organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms in one molecule and an organopolysiloxane having at least two silicon-bonded hydroxyl groups in one molecule are treated with a catalytic amount of alkali. A method of performing a dehydrocondensation reaction by heating in the presence of a metal hydroxide, a platinum compound, or the like.

A method in which an organopolysiloxane having a hydroxyl group bonded to at least two silicon atoms in one molecule is heated in the presence of a catalytic amount of an alkali metal hydroxide, an organotin compound, or the like to perform a dehydration condensation reaction.

An organopolysiloxane having at least two silicon-bonded hydroxyl groups in one molecule and an organopolysiloxane having at least two silicon-bonded alkoxyl groups in one molecule are treated with a catalytic amount of alkali metal water. A method of performing a dealcoholization reaction by heating in the presence of an oxide, an organometallic tin compound, or the like.

In any of these methods, an organopolysiloxane polymer having a three-dimensional crosslinked structure which is insoluble in benzene but can contain benzene having its own weight or more can be easily obtained.

Further, among the partially crosslinked organopolysiloxane polymer (a), the polymer is obtained by addition polymerization of (a-2) (a) an organohydrogenpolysiloxane and (b) an aliphatic unsaturated group-containing organopolysiloxane. The molecular structure of the organopolysiloxanes (a) and (b) used in the production of an organopolysiloxane polymer partially having a three-dimensional crosslinked structure that is insoluble in silicone oil but swells sufficiently is linear. It may be branched, cyclic or cyclic, but is preferably linear in order to control the synthesis reaction of the desired organopolysiloxane polymer.

Here, a hydrogen atom bonded to a silicon atom in the organohydrogenpolysiloxane (a), which is a reactive group, and an aliphatic unsaturated group in the aliphatic unsaturated group-containing organopolysiloxane (b) are each one molecule. The presence of at least two of them is essential for forming a three-dimensional crosslinked structure in a part of the organopolysiloxane polymer obtained by polymerizing both.

The position of each of these reactive groups in the molecule is generally inside the molecular chain, but may be at the end of the molecular chain.

In order to obtain a soft and stable silicone gel composition, the content of each of these reactive groups in the organopolysiloxane is preferably 1% if the molecular structure is linear or branched. It is preferably from 20 to 20 mol%, and in the case of a cyclic one, from 1 to 50 mol%. If the content exceeds the above range, the polymer becomes a hard polymer, and the low-viscosity silicone oil described later tends to be hardly included in the three-dimensional crosslinked structure. Conversely, if the content is less than the above range, the structural viscosity of the silicone gel composition tends to be poor.

The organohydrogenpolysiloxane (a) is
HSiO _1.5 units, RSiO _1.5 units, RHSiO units, R ₂ SiO units, R ₂
HSiO _0.5 units, is made of R ₃ SiO _0.5 units and the like. Here, as R, a methyl group, an ethyl group, a propyl group,
From alkyl groups such as butyl groups, aryl groups such as phenyl groups and tolyl groups, cyclohexyl groups, and groups in which part or all of the hydrogen atoms bonded to carbon atoms of these groups have been substituted with halogen atoms, cyano groups, etc. An unsubstituted or substituted monovalent hydrocarbon group excluding an aliphatic unsaturated group such as a vinyl group is selected.

A typical example of this is (CH ₃ ) ₃ SiO
_{-, (CH 3) 2 SiO} p, CH 3 HSiO q, -Si (CH 3)
₃ (where p = 10 to 500, q = 2 to 50).
It is a suitable material.

Examples of the aliphatic unsaturated group of the aliphatic unsaturated group-containing organopolysiloxane (b) include a vinyl group and an aryl group, and a vinyl group is generally used. As the organovinylpolysiloxane, (CH ₂ = CH) SiO _1.5
Units, RSiO _1.5 units, R (CH = CH ₂ ) SiO units, R ₂ SiO units, R ₂ (CH = CH ₂ ) SiO _0.5 units, R ₃ SiO _0.5 units and the like can be mentioned. Here, R has the same meaning as in (a) above.

A typical example of this is (CH ₂ = CH)
(CH ₃ ) ₂ SiO—, (CH ₃ ) ₂ SiO _r and —Si (CH ₃ ) ₂
(CH = CH ₂ ) (where r = 10 to 100), or (CH ₃ ) ₃ SiO—, (CH ₃ ) ₂ SiO _m , (CH = CH ₂ ) CH ₃
SiO _n and -Si (CH _{3) 3} (where, m = 10~500, n =
Examples thereof include methylvinylpolysiloxane containing units (2 to 50), which may be a mixture and a suitable material.

Such an addition reaction between the organohydrogenpolysiloxane (a) and the organopolysiloxane containing an aliphatic unsaturated group (b) may be performed by a conventionally known general method. For example, the appropriate organohydrogenpolysiloxane and organovinylpolysiloxane are blended so that the molar ratio of the hydrogen group bonded to the silicon atom, which is the reactive group, to the vinyl group is in the range of 1/3 to 3/1. Thereafter, an addition polymerization catalyst such as platinum or palladium is added, and the mixture is heated and stirred to easily obtain a desired organopolysiloxane polymer insoluble in silicone oil. In particular, as the addition polymerization catalyst, it is preferable to use chloroplatinic acid described in JP-B-33-9969.

On the other hand, the reason why the viscosity of the silicone oil (b) is set to 50 cs or less is that, as the viscosity becomes higher, a large amount of the oil becomes tactile and oily, resulting in an unfavorable feeling in use. It is. Examples of the silicone oil having a molecular weight of 50 cs or less include low-polymerization degree chain dimethylpolysiloxane, methylphenylpolysiloxane, cyclic octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and the like. Two or more types can be appropriately selected and used.

(A) The silicone gel composition contained in the component,
It can be easily prepared by sufficiently kneading the partially crosslinked organopolysiloxane polymer (a) obtained as described above and the silicone oil of 50 cs or less in (b) and swelling. In this case, the mixing ratio of (a) and (b) is 10:90 to 50:50, preferably 15:85 to 45 by weight.
It is 55. If (a) is less than this range, a stable and good gel structure cannot be maintained. Conversely, if (a) is too large, weight is felt on the skin and oiliness is generated, resulting in operability and use. Feeling worsens, which is not preferable. The silicone gel composition comprises
It is blended in the component (A) at 60 to 100% by weight (hereinafter simply indicated as%). If it is less than 60%, the feeling of use is poor, and the water resistance is also undesirably reduced.

In addition, in addition to the silicone gel composition, an oil agent used in an ordinary emulsification composition for cosmetics can be blended with the oil phase component of the component (A) within a range that does not lack the uniformity of the oil phase. As such an oil, any of natural and vegetable oils and synthetic oils can be used. Specifically, liquid paraffin,
Examples thereof include liquid, pasty or solid hydrocarbons such as squalane, waxes, higher fatty acids, higher alcohols, esters, glycerides, and silicone oils other than (b).

The component (A) is blended at 30 to 60% in the total composition. 30%
If the amount is less than the above, the satisfactory effect of the present invention cannot be obtained.

The polyoxyalkylene-modified organopolysiloxane-based surfactant which is the component (B) of the present invention is represented by the above general formula (I) or (II), and is called a polyether-modified silicone or an alkyl polyether-modified silicone. It functions as an emulsifier. These are liquid or pasty at room temperature, and are particularly preferably insoluble in water. For example, silicon KF-945A (manufactured by Shin-Etsu Chemical Co., Ltd.), silicon SH-3772C (manufactured by Dow Corning Toray Silicone Co., Ltd.), Abil WE -09 (manufactured by Goldschmidt). These polyoxyalkylene-modified organopolysiloxane-based surfactants have good compatibility with the silicone gel composition in the oil phase component because the main chain is a polysiloxane chain, so that good emulsion stability can be obtained. it can.

Component (B) accounts for 0.1 to 10%, preferably 0.5 to 10% of the total composition.
~ 5% is blended. If it is less than 0.1%, sufficient emulsifying ability cannot be exhibited, and if it exceeds 10%, the water-oil interface becomes too strong, causing weight and stickiness to the touch, which is not preferable.

The water of the component (C) is blended in an amount of 5 to 69.9% in the whole composition.

In the emulsion composition of the present invention, in addition to the above essential components, commonly used aqueous components and oily components such as humectants, preservatives, antioxidants, ultraviolet absorbers, cosmetic components, fragrances, water-soluble polymers, constitution Pigments, coloring pigments, glittering pigments, organic powders, hydrophobized pigments, tar pigments, and the like can be blended within a range that does not impair the effects of the present invention.

The water-in-oil emulsion composition of the present invention can be produced by emulsification according to a usual method except that the silicone gel composition in the component (A) is prepared and used in advance, and is suitably used as a cosmetic base or the like. Can be used.

〔Example〕

Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited to these examples.

Reference Example 1 Synthesis of partially crosslinked organopolysiloxane polymer: trimethylsilyl end-blocked dimethylmethylhydrogenpolysiloxane [molecular weight 2300, CH ₃ HSiO pair (CH ₃ ) ₂ S
iO = 1: 4 (molar ratio)], an appropriate amount of a 1% potassium hydroxide solution (ethanol: water = 2: 1) was added, and the mixture was heated and refluxed to carry out a polymerization reaction to obtain a reaction product. Next, the reaction product is washed with water to remove the alkaline agent, and then naturally dried to be insoluble in benzene.
An organopolysiloxane polymer containing 180% was obtained.

Reference Example 2 Synthesis of Partially Crosslinked Organopolysiloxane Polymer: In a planetary mixer having an internal volume of about 5, 1790 g of dimethylmethylhydrogenpolysiloxane having an end-blocked trimethylsilyl (average molecular weight: 2340, Si-H: 4.5 mol%),
And 710 g of dimethylvinylsilyl-terminal-blocked dimethylpolysiloxane (average molecular weight: 930, vinyl group: 7.7 mol%) were charged and mixed by stirring. Add 2% of chloroplatinic acid to the mixed solution
0.5 g of an isopropanol solution was added, the temperature was raised to 70 to 80 ° C., and stirring was continued for 2 hours. Then, 5-10mm inside the system
The pressure was reduced to Hg, and the stripping was continued for 30 minutes to obtain a colorless, flexible, organopolysiloxane polymer having flexibility.

Example 1 A creamy water-in-oil emulsion composition having the composition shown in Table 1 was prepared and subjected to a stability test with time and a sensory evaluation. The results are shown in Table 2.

(Production Method) A. After dispersing and mixing the components (1) to (3), they are sufficiently kneaded and swelled to prepare a silicone gel composition.

B. Components (7), (8) and a part of the component (12) are gradually added to the components (4) to (6) and mixed with stirring to obtain a gel emulsion.

C. Add B to A and bring to 70 ° C.

D. The remaining components (9), (10) and (12) are mixed and dissolved by heating to 70 ° C.

After D was added to EC and emulsified, the component (11) was added and cooled to obtain a water-in-oil emulsion composition.

(Evaluation method) Stability over time: The emulsified composition was allowed to stand in a constant temperature bath at 50 ° C., 40 ° C., and 5 ° C., and the state was observed on the following day, 1 week, 2 weeks, and 4 weeks. evaluated.

：: Good without change in state △: Slight separation and agglomeration ×: Clear separation and agglomeration Sensory evaluation: Good spreadability during application, no oiliness, no stickiness after application and water resistance Was evaluated according to the following criteria.

◎: Very good ○: Good △: Normal ×: Bad As is clear from Table 2, the water-in-oil emulsion composition of the present invention showed no change in state in any case, and showed good stability over time. On the other hand, in the comparative product, separation of the oil agent was observed particularly at a high temperature, and the storage stability was poor.

In addition, the water-in-oil emulsion composition of the present invention has good spreadability at the time of coating, has no oiliness or stickiness and is refreshing, has an excellent feeling in use, and has high water resistance in a film after application, and has a high cosmetic resistance. It was excellent in sustainability.

Example 2 Face cream (Formulation) (%) (1) Dimethylpolysiloxane (5cs) 12.0 (2) Decamethylcyclopentasiloxane 12.0 (3) Partially crosslinked organopolysiloxane polymer (obtained in Reference Example 2) 8.0 (4) Beeswax 7.0 (5) White petrolatum 1.0 (6) Lanolin 2.0 (7) Glyceryl trioctanoate 2.0 (8) Polyoxyalkylene-modified organopolysiloxane surfactant ^* 0.4 (9) Trisodium phosphate 0.4 (10) ) 1,3-butylene glycol 7.0 (11) perfume suitable amount (12) UV absorber qs (13) xanthan gum 0.05 (14) purified water Balance *: in the general formula _{(II), G 1 = G} 2 = CH 3 , X = (CH ₂ ) _p O (C ₂ H ₄ O) _m (C ₃ H ₆ O) _n R ₁ , a = 2-10, b = 1-10, c = 20-60, p = 3, m = 2-10, n
= 2, R ₁ = H, R ₂ = C 16 alkyl group (Preparation method) A. Components (1) to (3) are dispersed and mixed, kneaded well, and swelled to prepare a silicone gel composition. .

BA and components (4) to (8), (11), and (12) are mixed and uniformly dissolved at 75 ° C.

C. Mix components (9), (10), (13) and (14)
Dissolve uniformly with.

C was added to DB to emulsify and cooled to obtain a face cream.

The face cream of the present invention obtained as described above had a very refreshing feeling in use, had a good feel, was able to form a water-resistant cosmetic film, and had good stability over time.

Example 3 Hand Cream (Formulation) (%) (1) Dimethylpolysiloxane (5cs) 12.5 (2) Decamethylcyclopentasiloxane 15.0 (3) Dimethylpolysiloxane (20cs) 2.5 (4) Partially Crosslinked Organopolysiloxane Polymerization (Obtained in Reference Example 2) 15.0 (5) Liquid paraffin 5.0 (6) Lanolin 2.0 (7) Glyceryl trioctanoate 3.0 (8) Polyoxyalkylene-modified organopolysiloxane surfactant ^* 2.0 (9) Citric acid 0.3 (10) Sodium citrate 1.2 (11) 1,3-butylene glycol 5.0 (12) Preservative trace (13) Flavor trace (14) Tocopherol acetate trace (15) Purified water balance *: General formula (II) Where G ₁ = G ₂ = CH ₃ , X = (CH ₂ ) _p O (C ₂ H ₄ O) _m (C ₃ H ₆ O) _n R ₁ , a = 2-10, b = 1-10, c = 20-60, p = 3, m = 2-10, n
= 2, R ₁ = H, R ₂ = C 16 alkyl group (Preparation method) A. Components (1) to (4) are dispersed and mixed, then sufficiently kneaded and swelled to prepare a silicone gel composition.

BA and components (5) to (8), (13) and (14) are mixed and dissolved at 70 ° C.

C. Components (9) to (12) and (15) are mixed and dissolved at 70 ° C.

The mixture was stirred while adding C to DB, and emulsified, and then cooled to obtain a hand cream.

The hand cream of the present invention obtained as described above,
A cosmetic film having excellent water resistance could be formed, no oiliness or poor spreading was felt, and the feeling of use was good. Further, the stability over time was also good.

〔The invention's effect〕

As described in detail above, the water-in-oil emulsion composition of the present invention shows excellent stability over time even when a large amount of silicone oil is used, has no oiliness or stickiness, and has a good fresh feel when used. In addition, it is excellent in that a cosmetic film having water resistance and good cosmetic durability can be formed.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁶ , DB name) C08L 83/04 C08L 83/05 C08L 83/07 C08L 83/12 C08K 5/54

Claims (1)

(57) [Claims] (1) The following components (A) to (C) (A) (a) and (b) (a) Partially crosslinked organopolysiloxane selected from the following (a-1) and (a-2) Polymer (a-1) An organopolysiloxane polymer (a-2) obtained by crosslinking an organopolysiloxane and partially having a three-dimensional crosslinked structure insoluble in benzene and capable of containing benzene having its own weight or more. A) An organopolysiloxane obtained by addition polymerization of an organohydrogenpolysiloxane and (b) an aliphatic unsaturated group-containing organopolysiloxane and partially having a three-dimensional crosslinked structure which is insoluble but sufficiently swells in silicone oil. Siloxane polymer (b) Oil phase component containing 60 to 100% by weight of a silicone gel composition comprising a silicone oil having a viscosity of 50 cs or less 30 to 60% by weight (B) General formula (I) or (II) [Wherein, G ₁ and G ₂ may be the same or different and each is CH ₃ or (CH ₂ ) _p O (C ₂ H ₄ O) _m (C ₃ H ₆ O) _n R ₁ (p =
X represents a number of 1 to 5, m = 1 to 50, n = 0 to 30, R ₁ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), and X
Is (CH ₂ ) _p O (C ₂ H ₄ O) _m (C ₃ H ₆ O) _n R ₁ (p, m, n and
R ₁ has the same meaning as described above), a = 5-300,
b = 0 to 50. However, both G ₁ and G ₂ are CH ₃
And b = 0. ] Wherein G ₁ , G ₂ and X have the same meaning as described above, and a = 1
~30, b = 0~50, the number of c = 5~300, R ₂ represents an alkyl group having 2 to 20 carbon atoms. However, this excludes the case where both G ₁ and G ₂ are CH ₃ and b = 0. ] A water-in-oil type emulsion composition comprising 0.1 to 10% by weight of a polyoxyalkylene-modified organopolysiloxane surfactant represented by the following formula (C): 5 to 69.9% by weight of water.