CN115192478B - Water-in-oil type physical sun protection emulsion with high stability and preparation method thereof - Google Patents

Abstract

The invention discloses a high-stability water-in-oil type physical sun-screening emulsion and a preparation method thereof, wherein the water-in-oil type physical sun-screening emulsion comprises, by weight percentage in sun-screening emulsion, 3-5.5% of a first emulsion stabilizer, 1-2% of an emulsifying agent, 0.4-0.8% of a thickening agent, 0.8-1.2% of a film forming agent, 19-26% of a sun-screening agent, 41-54% of an emollient, 0.1-0.3% of a second emulsion stabilizer, a solvent and the balance; the first emulsion stabilizer comprises dextrin palmitate, and a cyclopentadimethicone/dimethicone crosspolymer. The stability of the water-in-oil type pure physical sun-screening emulsion is well improved by adding a proper amount of dextrin palmitate and utilizing the structural characteristics of the dextrin palmitate. The invention also adopts the cyclopentadimethicone/dimethicone cross-linked polymer as an emulsion stabilizer, which can form a certain network structure in the oil phase and has certain assistance to the stability of the whole system.

Description

Water-in-oil type physical sun protection emulsion with high stability and preparation method thereof

Technical Field

The invention relates to the technical field of daily chemicals, in particular to a water-in-oil type physical sun protection emulsion with high stability and a preparation method thereof.

Background

In recent years, sun protection products have grown rapidly, and more consumers are aware that photoaging causes greater damage to the skin. Ultraviolet rays are important factors that cause skin aging and melanin production. If the basic sun protection care is not performed, even if other skin care products which claim sun protection effect are smeared, the sun protection effect is very little.

The majority of water-in-oil sunscreen systems on the market are shaking systems (shaking with the front). The great reasons for developing such a system are: high-fold water-in-oil sunscreen systems are formulated to contain high levels of sunscreens (including chemical sunscreens and purely physical sunscreens), which requires the use of a significant portion of the grease to dissolve and disperse the sunscreens. Compared with other skin care products, the oil phase ratio of the water-in-oil type sun-screening product is very high, and most of the grease in the product is polar grease or low-viscosity silicone oil, so that the stability of the formula is very challenging, the product is easy to delaminate, the material body cannot be kept in a uniform state for a long time, and the grease is separated out. Therefore, the water-in-oil type sun-screening product on the market is generally made into a shaking system, and the water-in-oil type sun-screening product after shaking is required to be shaking before use, can be placed for a period of time without layering, but can be maintained for about 3 days generally, the material body is uniform within 3 days, the appearance is unchanged, and the use effect is not affected. However, the layering phenomenon of the material body can occur after a long time, which affects the use.

Disclosure of Invention

In order to overcome the defects of the prior art, one of the purposes of the invention is to provide the water-in-oil type physical sun-screening emulsion with high stability.

The second purpose of the invention is to provide a preparation method of the water-in-oil type physical sun protection emulsion with high stability, which has simple flow and easily controlled quality.

One of the purposes of the invention is realized by adopting the following technical scheme:

the water-in-oil type physical sun protection emulsion with high stability comprises an oil phase and a water phase, wherein the oil phase comprises, by weight percentage in the sun protection emulsion, 3-5.5% of a first emulsion stabilizer, 1-2% of an emulsifier, 0.4-0.8% of a thickener, 0.8-1.2% of a film forming agent, 19-26% of a sun protection agent and 41-54% of an emollient; the water phase comprises 0.1-0.3% of a second emulsion stabilizer, a solvent and the balance; the first emulsion stabilizer comprises dextrin palmitate, and a cyclopentadimethicone/dimethicone crosspolymer.

The stability of the water-in-oil type pure physical sun-screening emulsion is well improved by adding a proper amount of dextrin palmitate and utilizing the structural characteristics of the dextrin palmitate. Cyclodextrin palmitate is a high-molecular oil-soluble thickener with high polymerization degree, and the structure of the thickener is shown in figure 1 (A represents long-chain alkane). The cyclodextrin palmitate is added into the system, long-chain alkane can form a paste thickening system, and hydrogen bonds are formed among residual hydroxyl groups in the dextrin in grease (shown in figure 2). Therefore, the dextrin palmitate can well form a grid structure in the oil phase to support the oil phase, so that the stability of the whole system is remarkably improved. In addition, dextrin palmitate is used as an emulsion stabilizer, is also a thickening stabilizer, is used for thickening oil to form an oil-soluble soft gel, and is different from other oil-phase thickeners to form a hard gel, and the thickening stabilizer can greatly help and improve the spreadability and spreadability of products.

Furthermore, the invention also adopts the cyclopentadimethicone/dimethicone cross-linked polymer as an emulsion stabilizer, which is a cross-linked polymer, can form a certain network structure in an oil phase, and has certain assistance to the stability of the whole system. The cyclopentadimethicone/dimethicone cross-linked polymer is also a filler, is smooth and fresh and is not greasy, is helpful for product coating, and can control oil and hide wrinkles and absorb grease.

In a preferred embodiment of the invention, the oil phase further comprises 1-3% filler; the aqueous phase further comprises one or any combination of the following: 0.01-0.03% of chelating agent, 0.02-0.05% of skin conditioning agent, 0.05-0.2% of surfactant and 0.05-0.2% of preservative. The surfactant can reduce the surface tension of the water phase and further enhance the emulsion stability of the system.

In a preferred embodiment of the invention, in the oil phase, the emulsifier comprises one or any combination selected from the group consisting of: PEG-10 polydimethylsiloxane, cetyl PEG/PPG-10/1 polydimethylsiloxane and lauryl PEG-9 polydimethylsiloxane ethyl polydimethylsiloxane. More preferably, the emulsifier is a combination of PEG-10 polydimethylsiloxane, cetyl PEG/PPG-10/1 polydimethylsiloxane and lauryl PEG-9 polydimethylsiloxane ethyl polydimethylsiloxane, and the 3 emulsifiers are adopted for matching, so that the product is uniformly dispersed and stable in property.

In a preferred embodiment of the invention, the thickener comprises disteardimonium hectorite in the oil phase, which disteardimonium hectorite enhances the emulsion stability of the system.

In a preferred embodiment of the invention, in the oil phase, the film former comprises an acrylic/polydimethylsiloxane copolymer. More preferably, the film former is a complex of cyclopentadimethicone and an acrylic/dimethicone copolymer.

In a preferred embodiment of the invention, the sunscreen agent comprises titanium dioxide, silica and zinc oxide in the oil phase. More preferably, the sunscreen agent comprises a first compound sunscreen agent which is a complex of titanium dioxide, silica and polydimethylsiloxane and a second compound sunscreen agent which is a complex of zinc oxide, silica, aluminum distearate and polydimethylsiloxane. The sun-screening emulsion provided by the invention is pure physical sun-screening emulsion, the sun-screening agent can be fully dispersed in the sun-screening emulsion system, ultraviolet rays can be better shielded and protected, and the performance of the physical sun-screening agent can be fully exerted. Wherein, aluminum distearate can make the viscosity of the sun-screening agent suitable, also prevent the powder from caking.

In a preferred embodiment of the present invention, in the oil phase, the emollient is selected from one or any combination of ethylhexyl palmitate, dimethiconol, dimethicone, isododecane, cyclohexasiloxane, and cyclopentadimethicone.

In a preferred embodiment of the invention, in the oil phase, the filler comprises polymethylsilsesquioxane. The polymethylsilsesquioxane can enhance extensibility and smoothness of the sun block, promote touch feeling, and prevent caking of the sun block.

In a preferred embodiment of the invention, in the aqueous phase, the second emulsion stabilizer comprises sodium chloride.

In a preferred embodiment of the invention, in the aqueous phase, the solvent is water.

In a preferred embodiment of the invention, in the aqueous phase, the chelating agent comprises disodium EDTA.

In a preferred embodiment of the invention, in the aqueous phase, the skin conditioning agent comprises dipotassium glycyrrhizinate.

In a preferred embodiment of the invention, in the aqueous phase, the surfactant comprises PEG/PPG-14/7 dimethyl ether. PEG/PPG-14/7 dimethyl ether can reduce the surface tension of water phase in the formula, and can further enhance the emulsion stability of the system. Whereas PEG/PPG-14/7 dimethyl ether is generally used only as a humectant in other products, the present invention has been found to enhance the emulsion stability of the system by adding it to the system.

In a preferred embodiment of the invention, in the aqueous phase, the preservative comprises phenoxyethanol.

In a preferred embodiment of the present invention, the high stability water-in-oil physical sun protection emulsion comprises an oil phase and a water phase, the oil phase comprising, by weight percent in the sun protection emulsion, 3-5.5% of a first emulsion stabilizer, 1-2% of an emulsifier, 0.4-0.8% of a thickener, 0.8-1.2% of a film former, 19-26% of a sun protection agent, 1-3% of a filler, 41-54% of an emollient; the water phase comprises 0.1-0.3% of a second emulsion stabilizer, 0.01-0.03% of a chelating agent, 0.02-0.05% of a skin conditioning agent, 0.05-0.2% of a surfactant, 0.05-0.2% of a preservative, a solvent and the balance;

the first emulsion stabilizer comprises dextrin palmitate, and a cyclopentadimethicone/dimethicone cross polymer; the emulsifier comprises PEG-10 polydimethylsiloxane, cetyl PEG/PPG-10/1 polydimethylsiloxane and lauryl PEG-9 polydimethylsiloxane ethyl polydimethylsiloxane; the second emulsion stabilizer comprises sodium chloride; the surfactant comprises PEG/PPG-14/7 dimethyl ether.

In a preferred embodiment of the present invention, the highly stable water-in-oil physical sun protection emulsion comprises an oil phase and a water phase, the oil phase comprising, in weight percent in the sun protection emulsion:

first emulsion stabilizer: 1 to 1.5 percent of dextrin palmitate and 2 to 4 percent of cyclopentadimethicone/dimethicone cross-linked polymer;

emulsifying agent: PEG-10 polydimethylsiloxane 0.5-0.8%, cetyl PEG/PPG-10/1 polydimethylsiloxane 0.3-0.6%, lauryl PEG-9 polydimethylsiloxane ethyl polydimethylsiloxane 0.3-0.6%;

and (3) a thickening agent: 0.4 to 0.8 percent of disteardimonium hectorite,

Film forming agent: 0.8 to 1.2 percent of compound formed by cyclopentadimethicone and acrylic acid (ester) or dimethicone copolymer,

Sunscreens: 12-16% of a compound formed by titanium dioxide, silica and polydimethylsiloxane, and 7-10% of a compound formed by zinc oxide, silica, aluminum distearate and polydimethylsiloxane;

filler: 1-3% of polymethyl silsesquioxane;

an emollient: 6-10% of ethylhexyl palmitate, 0.3-0.6% of a complex of polydimethylsiloxane and 5-8% of isododecane; 30-35% of a composite of cyclohexasiloxane and cyclopentadimethicone;

the aqueous phase comprises:

second emulsion stabilizer: sodium chloride 0.1-0.3%,

chelating agent: 0.01 to 0.03 percent of EDTA disodium,

skin conditioning agent: dipotassium glycyrrhizinate 0.02-0.05%,

and (2) a surfactant: PEG/PPG-14/7 dimethyl ether 0.05-0.2%,

preservative: 0.05 to 0.2 percent of phenoxyethanol,

solvent, balance.

The second purpose of the invention is realized by adopting the following technical scheme:

a method for preparing the water-in-oil type physical sun protection emulsion with high stability according to one of the purposes, comprising the following steps:

dividing the emollient in the oil phase raw material into two parts, namely a first part of emollient and a second part of emollient; adding the rest oil phase raw materials except for the emollient and the first part of the emollient into an emulsifying pot, stirring and heating, homogenizing to completely disperse the materials, and preserving heat for later use;

adding the second part of the emollient into an emulsifying pot, uniformly stirring, and preserving heat for later use;

adding the water phase raw materials into a water phase pot, stirring and heating, then starting stirring of the emulsifying pot, pumping the mixed water phase raw materials into the emulsifying pot while stirring, and cooling after coating and emulsifying are completed;

cooling, if the formula comprises preservative, adding the preservative into the emulsifying pot, and stirring uniformly to obtain the product.

In a preferred embodiment of the present invention, the preparation method of the water-in-oil type physical sun protection emulsion with high stability provided by the present invention comprises the following steps:

dividing the emollient in the oil phase raw material into two parts, namely a first part of emollient and a second part of emollient; adding the rest oil phase raw materials except for the emollient and the first part of the emollient into an emulsifying pot, stirring and heating to 80-85 ℃, homogenizing for 5-8min at the speed of 2000-2500R/min to ensure that the materials are completely dispersed, and preserving heat for later use. The operation of this step is critical because the sunscreen emulsion formulation of the present invention contains a large amount of powder (zinc oxide, titanium dioxide, silica), and this step requires sufficient wetting and dispersion of the powder to disperse the agglomerated powder so that the final product can better mask and protect the uv rays and fully exert the properties of the physical sunscreens.

Adding the second part of the emollient into an emulsifying pot, uniformly stirring, and preserving heat for later use;

adding the water phase raw materials into a water phase pot, stirring and heating to 80-85 ℃, then starting stirring of the emulsifying pot, slowly pumping the mixed water phase raw materials into the emulsifying pot while stirring, slowly wrapping, emulsifying completely, and cooling;

cooling to 40-45deg.C, adding antiseptic into the emulsifying pot, and stirring to obtain

Compared with the prior art, the invention has the beneficial effects that:

(1) The water-in-oil type physical sun-proof emulsion with high stability provided by the invention has the advantages that the stability of the water-in-oil type pure physical sun-proof emulsion is well improved by adding a proper amount of dextrin palmitate and utilizing the structural characteristics of the dextrin palmitate; and the cyclopentadimethicone/dimethicone cross-linked polymer is used as an emulsion stabilizer, so that a certain network structure can be formed in the oil phase, certain assistance is provided for the stability of the whole system, the stability of the system is further enhanced, layering is avoided after long-term placement, and grease is not separated out.

(2) The preparation method of the water-in-oil type physical sun protection emulsion with high stability provided by the invention has the advantages of simple flow and easily controlled quality.

Drawings

FIG. 1 is a molecular structure diagram of cyclodextrin palmitate;

FIG. 2 is a network structure diagram of cyclodextrin palmitate formation.

FIG. 3 is a showing that the water-in-oil type physical sun protection milk provided in example 2 of the present invention remains stable after standing for 9 months;

FIG. 4 is a view showing the precipitation of unstable oils of the product after 1 week of the sample of comparative example 1 according to the present invention;

FIG. 5 is a view showing the precipitation of unstable oils of the product after 2 weeks of standing of the sample of comparative example 2 of the present invention;

FIG. 6 is a diagram showing the precipitation of unstable oils of the product after 2 weeks of standing of the sample of comparative example 3 according to the present invention.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and detailed description, wherein it is to be understood that, on the premise of no conflict, the following embodiments or technical features may be arbitrarily combined to form new embodiments.

The raw materials, equipment, etc. used in the following examples are available in a purchase manner except for special restrictions. For example, raw material number 2 can be purchased from Guangzhou Zhengbao chemical company, under the product name SIL ZP-45 SIL-based silicone gel elastomer, which can help the sun-screening emulsion to form a breathable film, effectively improve the water resistance and durability of the color and sun-screening agent, and has strong adhesive force.

The No. 7 raw material can be selected from san Kaiss chemical engineering Co., ltd, is not greasy, has superior smooth silk-like hand feeling and matt effect, plays a role in tackifying, and has excellent thixotropic property.

The No. 8 raw material can be selected from Guangzhou SAKOGHKOGHKOGHKOKOKOKOKOKOKOKOKOKOKO Co, has excellent stability, and can thoroughly ensure no agglomeration of nanoparticles and stable particle size by inorganic surface treatment technology, thereby ensuring sun-screening effect. The all-physical sun-screening agent is non-irritating even if being directly smeared on skin, and is suitable for sensitive skin.

The raw material No. 9 may be selected from products of the company sakumakumakumakumakumakumakumakumakumakumakumakumakumakumakumaku, guangji.

The No. 12 raw material can be selected from Guangzhou Rong Chemicals Inc., and is smooth and light.

The No. 14 raw material can be selected from Guangzhou Rong Chemicals Limited company, and is fresh, not greasy, soft, easy to spread and not irritate.

Examples 1 to 3

A water-in-oil type physical sun protection emulsion with high stability comprises an oil phase raw material and a water phase raw material, wherein the oil phase raw material comprises: a first emulsion stabilizer, an emulsifier, a thickener, a film former, a sunscreen, a filler, and an emollient; the aqueous phase raw materials comprise: a second emulsion stabilizer, a chelating agent, a skin conditioning agent, a surfactant, a preservative, and a solvent. The specific formulation is shown in Table 1 below.

Table 1 formulation tables of examples 1-3

The water-in-oil physical sun block with high stability of examples 1-3 was prepared as follows:

cleaning and sterilizing the emulsifying equipment for later use;

adding the oil phase raw materials of No. 1 to No. 12 into an emulsifying pot, stirring and heating to 83 ℃, homogenizing for 7min at the speed of 2300R/min to ensure that the materials are completely dispersed, and preserving heat for later use;

adding the raw materials No. 13 and No. 14 into an emulsifying pot, uniformly stirring, and preserving heat for later use;

adding water phase raw materials of No. 15-19 into a water phase pot, stirring and heating to 83 ℃, starting stirring by the emulsifying pot, slowly pumping the mixed water phase raw materials into the emulsifying pot while stirring, slowly wrapping, emulsifying completely, and cooling;

cooling to about 43deg.C, adding the No. 20 raw materials into emulsifying pot, and stirring.

Comparative example 1

Comparative example 1 differs from example 2 in that: the raw material No. 1 dextrin palmitate was omitted, and the amount of the raw material No. 2 cyclopentadimethicone/dimethicone crosspolymer was adjusted to 4.2%, the remainder being the same as in example 2.

Comparative example 2

Comparative example 2 is different from example 2 in that: the starting material cyclopentamethylsilicone/dimethicone crosspolymer No. 2 was omitted, the amount of dextrin palmitate No. 1 was adjusted to 4.2%, and the remainder was the same as in example 2.

Comparative example 3

Comparative example 3 is different from example 2 in that: the raw material No. 18 PEG/PPG-14/7 dimethyl ether was omitted, and the amount of raw material No. 19 water was adjusted to 20.95%, and the remainder was the same as in example 2.

Comparative example 4

Comparative example 4 differs from example 2 in that: the starting material No. 4 cetyl PEG/PPG-10/1 polydimethylsiloxane was omitted, and the starting material No. 5 lauryl PEG-9 polydimethylsiloxane ethyl polydimethylsiloxane was adjusted to 0.85% and the remainder was identical to example 2.

Comparative example 5

Comparative example 5 is different from example 2 in that: the No. 10 raw material of polymethylsilsesquioxane is omitted, and the dosage of the No. 2 raw material of cyclopentadimethicone/dimethicone cross-linked polymer is adjusted to be 5%.

Performance testing

1. Stability test

After obtaining the sun protection milk samples of examples 1-3 and comparative examples 1-5, stability tests were performed, respectively. And (3) placing the sample in a room at normal temperature for a corresponding time, and observing whether the sample has layering, precipitation and other phenomena. If appearance phenomenon inconsistent with that before test appears, the stability of the sun-proof milk sample is poor, and the sun-proof milk sample does not pass the stability test and is marked as X; otherwise, the sun protection milk sample is proved to be relatively stable and can pass the stability test and be marked as V. The test results are shown in table 2 below.

Table 2 stability test results record table

Placed for 1 week

Left for 2 weeks

Standing for 1 month

Standing for 3 months

Standing for 6 months

Standing for 9 months

Example 1

√

√

√

√

√

√

Example 2

√

√

√

√

√

√

Example 3

√

√

√

√

√

√

Comparative example 1

√

×

×

×

×

×

Comparative example 2

√

√

×

×

×

×

Comparative example 3

√

√

×

×

×

×

Comparative example 4

√

×

×

×

×

×

Comparative example 5

√

√

√

×

×

×

As can be seen from the records in table 2, the stability of the sun-protection milk of examples 1 to 3 is very good, the sun-protection milk still keeps stable after being placed for 9 months at normal temperature, the sun-protection milk does not delaminate, does not precipitate, and does not separate out grease, and the sun-protection milk of example 1 keeps stable after being placed for 9 months, see fig. 3; the result graphs of examples 2-3 are similar to example 1 and are not repeated here. The existing water-in-oil type pure physical sun protection system (shaking system) in the market can generally keep stability for only a few days.

Comparative example 1 the thickener dextrin palmitate was omitted, which greatly reduced the stability of the sun block, and instability occurred after 2 weeks of storage, see figure 4, oil precipitation. Comparative example 2 the cyclopentadimethicone/dimethicone cross polymer was omitted, and the cyclopentadimethicone/dimethicone cross polymer was synergistic with dextrin palmitate to enhance system stability, and the elimination of one of them would result in a decrease in system stability. An unstable display of comparative example 2 is shown in fig. 5.

Comparative example 3 omits PEG/PPG-14/7 dimethyl ether, and the surface activity of the aqueous phase cannot be modified to be reduced, so that the stability of the system is reduced, as shown in FIG. 6.

The emulsifier formula in the comparative example 4 is changed, so that the stability of the system is reduced, and the invention adopts PEG-10 polydimethylsiloxane, cetyl PEG/PPG-10/1 polydimethylsiloxane and lauryl PEG-9 polydimethylsiloxane ethyl polydimethylsiloxane as the emulsifier combination, so that the sun-screening emulsion system can obtain better stability, and the sun-screening emulsion system can well emulsify grease and disperse the sun-screening agent.

Comparative example 5 the polymethylsilsesquioxane was omitted and the amount of cyclopentadimethicone/dimethicone cross polymer was increased, which also affected the stability of the system.

The embodiment of the invention adopts proper raw materials such as emulsion stabilizer, emulsifier, surfactant, thickener and the like for compounding, and reasonably controls the dosage of the raw materials, so that the water-in-oil type physical sun-proof emulsion can be kept stable for a long time, and the stability is far higher than that of the existing same-series products on the market.

2. Usage sense test

15 testers with healthy facial skin and ages 20-25 were selected, and 15 testers tried the sun protection milk samples of examples 1-3 and comparative examples 1-5 one by one. Prior to the trial, the human subjects all underwent the same skin cleansing procedure. After the trial is finished, the trial staff scores the product, the score is 0-10, the higher the score is, the better the spreadability and the spreadability of the product are, the better the use feeling is, the higher the acceptance degree is, and the score is the average value of 15 trial staff. And the overall evaluation was recorded.

TABLE 3 evaluation and recording Table of Effect of the foundation liquids of examples 1 to 3 and comparative examples 1 to 6

Classification	Example 1	Example 2	Example 3	Comparative example 1	Comparative example 2	Comparative example 3	Comparative example 4	Comparative example 5
									Use feeling score	9.1	9.3	8.8	5.4	7.0	8.5	7.1	6.3

From the record in Table 3, the scores of the test persons for the sun protection emulsions of examples 1-3 were higher, the spreadability of the test persons overall reaction product was good, the application was easy, and the test persons were fresh and not greasy. While the scores of comparative examples 1-5 were all relatively low, the spreadability of the reaction product by the test person was not as good as the sample of the example, the extensibility was relatively poor, and the acceptance was low. In the embodiment of the invention, the dextrin palmitate is used as an emulsion stabilizer and is also a thickening stabilizer, and the thickening stabilizer thickens oil to form an oil-soluble soft gel, so that the spreadability and the spreadability of the product can be greatly improved. The polymethylsilsesquioxane can also enhance the extensibility and smoothness of the sun block and promote the touch feeling.

The above embodiments are only preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, but any insubstantial changes and substitutions made by those skilled in the art on the basis of the present invention are intended to be within the scope of the present invention as claimed.

Claims (4)

1. A highly stable water-in-oil physical sun block comprising an oil phase and a water phase, the oil phase comprising, in weight percent in the sun block:

first emulsion stabilizer: 1 to 1.5 percent of dextrin palmitate and 2 to 4 percent of cyclopentadimethicone/dimethicone cross-linked polymer;

emulsifying agent: PEG-10 polydimethylsiloxane 0.5-0.8%, cetyl PEG/PPG-10/1 polydimethylsiloxane 0.3-0.6%, lauryl PEG-9 polydimethylsiloxane ethyl polydimethylsiloxane 0.3-0.6%;

and (3) a thickening agent: 0.4 to 0.8 percent of disteardimonium hectorite,

Film forming agent: 0.8 to 1.2 percent of compound formed by cyclopentadimethicone and acrylic acid (ester) or dimethicone copolymer,

Sunscreens: 12-16% of a compound formed by titanium dioxide, silica and polydimethylsiloxane, and 7-10% of a compound formed by zinc oxide, silica, aluminum distearate and polydimethylsiloxane;

filler: 1-3% of polymethyl silsesquioxane;

an emollient: 6-10% of ethylhexyl palmitate, 0.3-0.6% of a complex of polydimethylsiloxane and 5-8% of isododecane; 30-35% of a composite of cyclohexasiloxane and cyclopentadimethicone;

the aqueous phase comprises:

second emulsion stabilizer: sodium chloride 0.1-0.3%,

chelating agent: 0.01 to 0.03 percent of EDTA disodium,

skin conditioning agent: dipotassium glycyrrhizinate 0.02-0.05%,

and (2) a surfactant: PEG/PPG-14/7 dimethyl ether 0.05-0.2%,

preservative: 0.05 to 0.2 percent of phenoxyethanol,

solvent, balance.

2. The high stability water-in-oil physical sun block of claim 1 comprising an oil phase and a water phase, said oil phase comprising, in weight percent in said sun block:

first emulsion stabilizer: dextrin palmitate 1.2%, cyclopentamethylsilicone/polydimethylsiloxane cross-linked polymer 3%;

emulsifying agent: PEG-10 polydimethylsiloxane 0.6%, cetyl PEG/PPG-10/1 polydimethylsiloxane 0.4%, lauryl PEG-9 polydimethylsiloxane ethyl polydimethylsiloxane 0.45%;

and (3) a thickening agent: 0.6% distearyldimethylammonium hectorite,

Film forming agent: 1% of a complex formed by cyclopentadimethicone and acrylic/dimethicone copolymer,

Sunscreens: 14% of a composite formed by titanium dioxide, silica and polydimethylsiloxane, 8.5% of a composite formed by zinc oxide, silica, aluminum distearate and polydimethylsiloxane;

filler: 2% of polymethylsilsesquioxane;

an emollient: 8% of ethylhexyl palmitate, 0.45% of a complex of polydimethylsiloxane alcohol and polydimethylsiloxane and 6.5% of isododecane; 32% of a composite of cyclohexasiloxane and cyclopentadimethicone;

the aqueous phase comprises:

second emulsion stabilizer: sodium chloride 0.2%,

chelating agent: 0.02 percent of EDTA disodium,

skin conditioning agent: dipotassium glycyrrhizinate 0.03 percent,

and (2) a surfactant: PEG/PPG-14/7 dimethyl ether 0.1%,

preservative: 0.1 percent of phenoxyethanol,

solvent, balance.

3. A process for the preparation of a highly stable water-in-oil physical sun block according to any one of claims 1 to 2, comprising the steps of:

dividing the emollient in the oil phase raw material into two parts, namely a first part of emollient and a second part of emollient; the first portion of the emollient comprises ethylhexyl palmitate, a complex of dimethiconol and dimethicone; the second portion of the emollient comprises a complex of isododecane, cyclohexasiloxane, and cyclopentadimethicone;

adding the rest oil phase raw materials except for the emollient and the first part of the emollient into an emulsifying pot, stirring and heating, homogenizing to completely disperse the materials, and preserving heat for later use;

adding the second part of the emollient into an emulsifying pot, uniformly stirring, and preserving heat for later use;

adding the water phase raw materials into a water phase pot, stirring and heating, then starting stirring of the emulsifying pot, pumping the mixed water phase raw materials into the emulsifying pot while stirring, and cooling after coating and emulsifying are completed;

cooling, adding the preservative into the emulsifying pot, and stirring uniformly to obtain the product.

4. A method for preparing a high stability water-in-oil physical sun block according to claim 3, comprising the steps of:

dividing the emollient in the oil phase raw material into two parts, namely a first part of emollient and a second part of emollient; the first portion of the emollient comprises ethylhexyl palmitate, a complex of dimethiconol and dimethicone; the second portion of the emollient comprises a complex of isododecane, cyclohexasiloxane, and cyclopentadimethicone;

adding the rest oil phase raw materials except for the emollient and the first part of the emollient into an emulsifying pot, stirring and heating to 80-85 ℃, homogenizing for 5-8min at the speed of 2000-2500R/min to ensure that the materials are completely dispersed, and preserving heat for later use;

adding the second part of the emollient into an emulsifying pot, uniformly stirring, and preserving heat for later use;

adding the water phase raw materials into a water phase pot, stirring and heating to 80-85 ℃, then starting stirring of the emulsifying pot, slowly pumping the mixed water phase raw materials into the emulsifying pot while stirring, slowly wrapping, emulsifying completely, and cooling;

cooling to 40-45deg.C, adding antiseptic into the emulsifying pot, and stirring.