TW201306874A - Oil-in-water emulsified sunscreen cosmetic - Google Patents

Abstract

Provided is a low viscosity oil-in-water emulsified sunscreen cosmetic, which is blended with an ultraviolet absorbent with a high concentration thereby having a sufficient ultraviolet resistance effect, and also has good accessibility. The oil-in-water emulsified sunscreen cosmetic of this invention includes (A) alkyl phosphate, and (B) oil drops containing an ultraviolet absorbent and having a number average particle diameter less than 130nm due to a high shear treatment, the viscosity at 30 DEG C of the emulsion is 20mPa.S or less.

Description

Oil-type emulsified sunscreen lotion in water

The present invention relates to a low-viscosity sunscreen cosmetic which has high ultraviolet protection effect and is excellent in stability and usability.

In the case of sunscreen cosmetics, in order to satisfy various conditions such as sufficient anti-ultraviolet effect, safety, feeling of use, water resistance, migration resistance, etc., emulsification type, lotion type, oil type, gel are known. A product in the form of a spray or a spray.

Among the emulsified types, since the oil-in-water emulsion can be formulated with a small amount of ultraviolet absorber in the oil phase (dispersed phase), it can be formulated into a low SPF to high SPF product, and a refreshing feeling can be obtained. Therefore, it is widely used as a base for sunscreen cosmetics.

However, the oil-in-water emulsion has a problem of poor water resistance. For example, Patent Document 1 describes that a phosphate surfactant is combined with a sulfopolyester to reduce the amount of the phosphate surfactant, and as a result, water resistance is obtained. Sexual improvement.

On the other hand, in the sunscreen cosmetic, an inorganic ultraviolet ray scattering agent such as fine particle titanium oxide or fine particle zinc oxide is blended in addition to the organic ultraviolet absorbing agent to impart ultraviolet ray shielding ability. However, when a large amount of inorganic ultraviolet shielding powder such as fine particle titanium oxide or fine particle zinc oxide is blended, the finished makeup becomes white, and a feeling of stagnation or powderiness is generated.

Patent Document 2 describes a solar shading composition including an inorganic sunshade agent, a specific anionic emulsifier, and an oil component, and describes that by using such a combination, the inorganic sunlight is reduced while maintaining a high SPF. The amount of masking agent is adjusted and the usability is improved.

However, it has been found that when the viscosity of the oil-in-water emulsion in which the ultraviolet absorber is blended at a high concentration (for example, 5% by mass or more) is lowered in order to maintain high SPF, stability problems such as separation/sedimentation may occur. In addition, since the ultraviolet absorber and the surfactant are formulated, there is also a problem of greasy or sticky use.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 2009-536948

[Patent Document 2] Japanese Patent Publication No. 2002-515851

Therefore, an object of the present invention is to provide a low-viscosity water-based sunscreen cosmetic which has a high-concentration ultraviolet-absorbing agent and has a sufficient ultraviolet protection effect and is also excellent in usability.

The inventors of the present invention have continually reviewed the above-mentioned problems, and as a result, it has been found that even a low-force machine is used to emulsify a raw material containing a specific surfactant and a UV absorber into a nanoemulsion. The present invention has been completed in that the viscosity is still stable and the useability is excellent, and the cosmetic having sufficient ultraviolet defense power is used.

That is, the present invention provides an oil-based emulsified sunscreen cosmetic which is characterized by containing (A) an alkyl phosphate, and (B) an ultraviolet absorber, and by a high shear High-shear processing consists of an oil-in-water emulsion having oil droplets having an average number of particles of less than 130 nm, and the viscosity of the emulsion at 30 ° C is 20 mPa ‧ s or less.

The sunscreen cosmetic of the present invention is composed of a low-viscosity oil-based emulsion in water, which not only imparts a tender touch when applied, but also is non-sticky or non-greasy, and is excellent in use feeling. Further, even if it is formulated with an ultraviolet absorber in an amount sufficient to obtain a sufficient ultraviolet protection effect, the stability is excellent.

The cosmetic of the present invention contains an alkyl phosphate (ingredient A) as an essential component. The alkyl phosphate used in the present invention may be any conventionally known as an anionic surfactant, and includes an alkali metal such as a monoalkylphosphoric acid, a dialkylphosphoric acid or a trialkylphosphoric acid (for example, sodium, Potassium, etc.) salt. In the present invention, it is preferred to use a potassium alkyl phosphate salt, and particularly preferably a potassium cetyl phosphate.

The compounding amount of the alkyl phosphate of the cosmetic of the present invention is preferably from 0.2 to 2.1% by mass, more preferably from 0.5 to 1.5% by mass. When the blending amount is less than 0.2% by mass, there is a case where a stable emulsion cannot be obtained, and if the blending amount exceeds 2.1% by mass, there is a problem that the usability such as sticking occurs.

The other essential component of the cosmetic of the present invention is an ultraviolet absorber (ingredient B). The ultraviolet absorber used in the present invention is not particularly limited, but is preferably an organic ultraviolet absorber which is liquid at normal temperature.

The organic ultraviolet absorber which is liquid at normal temperature may be used as a cosmetic or the like. Specific examples include ethyl hexyl cinnamate, Octocrylene, and ethylhexyl The third butyl methoxy benzhydryl methane or the like is preferably one or more selected from the above.

The blending amount of the ultraviolet absorber of the cosmetic of the present invention is preferably 4 to 15% by mass, more preferably 6 to 10% by mass. If the amount is less than 4% by mass, sufficient ultraviolet protection (SPF) cannot be obtained, and if it is more than 15% by mass, there is a problem that sticking occurs when applied to the skin.

The cosmetic of the present invention is a sunscreen cosmetic, and may contain an organic ultraviolet absorber which is solid at normal temperature, in addition to the ultraviolet absorber (component B) described above, insofar as the effects of the invention are not impaired. In the case of a solid organic ultraviolet absorber, exemplified by bisethylhexyloxyphenol methoxyphenyl three (Bis-ethylhexyloxyphenol methoxyphenyl triazine) (chemical name: 2,4-bis{[4-(2-ethylhexyloxy)2-hydroxy]-phenyl}-6-(4-methoxyphenyl)- (1,3,5)-three Methylene bisbenzotriazolyl tetramethylbutyl phenol (chemical name: 2,2'-methylenebis[6-(2H-benzotriazol-2-) Base)-4-(1,1,3,3-tetramethylbutyl)phenol]). However, when problems occur in the use properties of the cosmetic material due to such blending, it is preferred that the organic ultraviolet absorber is not blended at a normal temperature.

In addition to the above-mentioned essential components and any solid ultraviolet absorbing agent and/or inorganic ultraviolet ray scattering agent, the cosmetic of the present invention can be formulated into a cosmetic material within a range that does not inhibit the effects of the present invention, and in particular, can be generally used for blending sunscreen cosmetic materials. . Specific examples thereof include an oil component, a chelating agent, a neutralizing agent, a pH adjuster, an antioxidant, an antibacterial agent, various chemicals, and the like.

Further, the cosmetic of the present invention is characterized in that the aqueous phase component containing the alkyl phosphate (component A) and the oil phase component containing the ultraviolet absorber (component B) are separately carried out as needed. The mixture is heated and dissolved, and the oil phase is homogeneously dispersed in the aqueous phase by high shear treatment to form an oil-in-water emulsion having oil droplets having an average number of particles of less than 130 nm.

The "high shear treatment" in the present specification is not particularly limited, but means that a high-shear force of at least 40 MPa, preferably 55 MPa, is applied to perform homogeneous dispersion (homogenization).

For such a high shearing treatment, for example, 15MR manufactured by SPX Corporation APV, a nano-sized homogenizer LPN60 (Nanogenizer LPN60) manufactured by Serendip, and H-20 (Homogenizer H-20) manufactured by Sanwa Engineering Co., Ltd., etc. can be used. Commercially available devices are implemented.

The oil droplets constituting the emulsion of the cosmetic of the present invention have a number average particle diameter of less than 130 nm by the high shear treatment as described above. The number average particle diameter can be calculated from a particle size distribution measured by a Zetasizer (for example, a high-concentration particle size analyzer FPR-1000; manufactured by Otsuka Electronics Co., Ltd.). By dispersing the oil phase in such fine particles, the cosmetic of the present invention can be extremely stable.

Further, the cosmetic of the present invention is characterized in that the emulsion has a viscosity at 30 ° C of 20 mPa ‧ (B type viscometer) or less. As far as sunscreen cosmetics are concerned, there is still almost no such low viscosity. The cosmetic of the present invention is made into a transparent preparation by a low viscosity such as a lotion, so that the feeling of use is soft and refreshed. Therefore, the cosmetic of the present invention is most suitably provided in the form of, for example, a sunscreen cosmetic which is sprayed into a mist after being placed in a dispenser.

(Example)

Hereinafter, the present invention will be described in more detail by way of specific examples, but the invention is not limited to the following examples. In addition, the blending amount of the following examples and the like means mass% unless otherwise specified.

The oil-in-water emulsion compositions (Examples and Comparative Examples) of the compositions disclosed in Table 1 below were prepared, and the following items were evaluated. The evaluation results are shown together in Table 1.

Emulsification stability

After the composition was allowed to stand at room temperature or elevated temperature (50 ° C) for 1 month, it was evaluated by visual observation.

○: No oil slick or Creaming was observed.

×: Oil slick or condensed was observed.

2. Emulsified particles

The particle size distribution of the composition was measured by a particle size analyzer (high-concentration particle size analyzer FPR-1000), and the average particle diameter was calculated.

3. Use feeling (sticky)

Each composition was applied to the wrist or face of a female investigator (N=20), and the adhesion after penetration into the skin was evaluated on the following basis.

○: 16 or more were evaluated as no stickiness.

△: 6 to 15 were evaluated as no stickiness.

×: Five or less were evaluated as no stickiness.

4. Use feeling (transparency)

Each composition was filled in a spray container, and applied to the wrist or face of a female investigator (N=20), and the transparency was evaluated on the following basis.

○: More than 16 evaluations were transparent.

△: 6 to 15 were evaluated as transparent.

×: The following five evaluations are transparent.

5. Emulsified particle stability (aggregation)

After the composition was allowed to stand at room temperature or cold temperature (below 0 ° C) for 1 month, it was evaluated by visual observation.

○: No aggregation or precipitate was observed.

×: Aggregation or sediment was observed.

1) 15MR manufactured by SPX Corporation APV

2) General homogenizer

a) Uvinul N539T (BASF Japan Co., Ltd.)

b) Uvinul T150 (BASF Japan Co., Ltd.)

c) Parsol MCX (DSM Nutrition Japan, Inc.)

d) Parsol 1789 (DSM Nutrition Japan, Inc.)

e) Amphisol K (DSM Nutrition Japan, Inc.)

As is clear from Table 1, the composition of Example 1 which was subjected to high shear treatment using a high-pressure apparatus was excellent in transparency and emulsion stability, but Comparative Example 1-1 which was emulsified by a general homomixer was not Good emulsification, insufficient transparency and stability. Further, when a homomixer was used, a stable emulsion could not be obtained even if a water-soluble tackifier was added (Comparative Example 1-2).

According to the compositions disclosed in the following Tables 2 and 3, the above-described respective items were evaluated by preparing the oil-in-water emulsion composition having the same high shearing treatment as in Example 1. The results of the assessment are shown together in the tables.

According to the results of Table 2, by applying high shear treatment using an alkyl phosphate as an emulsifier, even if the emulsifier amount is increased to 2.1% by mass, no sticking occurs, and not only can be formulated as A low-viscosity preparation of an ultraviolet absorber having an SPF of up to 31 is excellent in transparency and stability (Examples 1 to 3).

On the other hand, as shown in Table 3, when the emulsifier is replaced with another anionic surfactant, the transparency becomes insufficient, and oil slick or condensate is generated, and aggregation or precipitation occurs, and stability is achieved. For the poor (Comparative Examples 2-1 to 3).

Claims (4)

An oil-based emulsified sunscreen cosmetic characterized by having an oil having a number average particle diameter of less than 130 nm by containing (A) an alkyl phosphate, and (B) an ultraviolet absorber and treating by high shear force It is composed of an oily emulsion in water, and the viscosity of the emulsion at 30 ° C is 20 mPa ‧ or less. The cosmetic according to claim 1, wherein the high shear treatment is a treatment of uniformly dispersing by applying a shear force of at least 40 MPa. The cosmetic according to claim 1 or 2, wherein the alkyl phosphate is potassium cetyl phosphate. The cosmetic according to any one of claims 1 to 3, wherein the ultraviolet absorber is selected from the group consisting of ethylhexyl methoxycinnamate, outoquilla, and ethylhexyl And one or more of the group consisting of the third butyl methoxy benzhydryl methane.