Silicone wax emulsion and preparation method thereof

Abstract

The invention discloses a silicone wax emulsion and a preparation method thereof. The silicone wax emulsion comprises silicone wax, an emulsifier and water, the silicone wax is prepared by hydrosilylation of raw materials containing end-side hydrogen-containing silicone oil and alpha-olefin, the molar ratio of the alpha-olefin to a silicon hydrogen group in the end-side hydrogen-containing silicone oil is 1.1-1.5: 1, and the number of carbon atoms of the alpha-olefin is greater than or equal to 20. The silicone wax emulsion has good high-temperature (60-80 DEG C) stability, and the phenomenon of oil precipitation is not easy to generate.

Description

Technical Field

[0001] The present application relates to the field of organosilicon compounds, and particularly to a silicone wax emulsion and a preparation method thereof. Background Art

[0002] Due to its unique molecular structure, organosilicon silicone wax combines the low surface tension and flexibility of organosilicon with the thickening and film-forming properties of wax substances, showing excellent lubricating, moisturizing and skin-friendly properties in the fields of leather care agents, cosmetic creams, textile coatings, etc. Traditional silicone wax emulsions mostly use mechanical mixing of silicone oil and natural wax or paraffin wax (such as polyethylene wax, beeswax) for co-emulsification, and the hydrophobic phase is forcibly dispersed by surfactants. However, the siloxane chain and the wax molecule are only combined by van der Waals forces, and the poor interfacial compatibility leads to insufficient storage stability of the emulsion. After high temperature or long-term static storage, wax phase precipitation, "coarsening" of silicone oil, and even delamination and demulsification are likely to occur.

[0003] To break through this bottleneck, the industry has developed long-chain alkyl graft-modified silicone oil, which bonds C12 long-chain olefins to the siloxane main chain through hydrosilylation reaction, making the molecule have both the low viscoelasticity of silicone oil and the crystallization characteristics of wax, significantly improving the interfacial strength of emulsion droplets and solving the fundamental problem of poor compatibility of compounded emulsions. However, the silicone wax emulsion prepared from this type of long-chain alkyl silicone oil has stability defects at high temperatures (≥60 °C), resulting in problems such as silicone wax migration and surface oil film precipitation during high-temperature testing of cosmetics or leather finishing and drying processes, affecting the product appearance and performance. Summary of the Invention

[0004] The present application provides a silicone wax emulsion based on long-chain alkyl silicone oil and a preparation method thereof. This silicone wax emulsion has good stability at high temperatures (60 - 80 °C) and is not prone to oil agent precipitation.

[0005] In the first aspect, the present application provides a silicone wax emulsion, which contains silicone wax, emulsifier and water. The silicone wax is prepared by a hydrosilylation reaction from a raw material containing terminal hydrogen-containing silicone oil and α-olefin. The molar ratio of the α-olefin to the silicon hydride group in the terminal hydrogen-containing silicone oil is 1.1 - 1.5:1, and the number of carbon atoms of the α-olefin ≥ 20.

[0006] In any of the above technical solutions, the number of carbon atoms of the α-olefin is 20 - 45, and particularly preferably 20 - 30.

[0007] In any of the above technical solutions, the temperature of the hydrosilylation reaction is 70 - 135 °C.

[0008] In any of the above technical solutions, the dosage of the platinum catalyst for the hydrosilylation reaction is 2 - 100 ppm, and the reaction time is 2 - 8 h.

[0009] In any of the above technical solutions, the hydrogen content of the terminal-side hydrogen-containing silicone oil is 0.3-1.55 wt%.

[0010] It should be noted that terminal-side hydrogen silicone oil refers to a polysiloxane with silicon-hydrogen groups at both ends and side chains of the molecule.

[0011] Traditionally, long-chain alkyl silicone oils are usually prepared by grafting the main chain of silicone oil with active hydrogen at the end groups and C12-C18 α-olefins. Due to the insufficient density of alkyl side chains and the high regularity of short-chain alkyls in the obtained products, the molecular chains are prone to form locally ordered arrangements through van der Waals forces, resulting in the crystallization-melting phase transition of the material during temperature fluctuations, manifested as the exudation of the oil phase in the emulsion system. Therefore, in this application, terminal-side hydrogen-containing silicone oil is introduced as a reaction matrix, and there are reactive Si-H active sites at both the end groups and side chains of its molecular chains, enabling multi-site grafting of C20+ long-chain α-olefins during the hydrosilylation reaction. Its higher steric hindrance significantly interferes with the regular arrangement of molecules, reducing the crystallinity of the material and broadening the melting temperature range, and still maintaining the entangled state of molecular chains at high temperatures, reducing the tendency of oil separation caused by phase separation.

[0012] In addition, long-chain alkyls (C20+) have stronger van der Waals interactions than short-chain alkyls. After grafting, a denser physical cross-linking network is formed through hydrophobic association between alkyl chains. At the same time, side-chain grafting significantly increases the molecular weight and enhances the steric hindrance effect, restricting the movement of molecular chain segments. This helps to increase the cohesive energy of the material, effectively inhibiting the diffusion and migration of small molecular chain segments at high temperatures, thereby reducing the exudation probability of oily components.

[0013] Furthermore, in the silicone wax emulsion, C20+ long chains can penetrate into the core of oil droplets, and shorter chains play a stronger anchoring role, ensuring the firm adsorption of silicone wax molecules. Its comb-shaped molecular configuration can improve the compactness and mechanical strength of the interfacial film, combined with the inhibitory ability of long-chain alkyls on the migration and coalescence of droplets, ultimately achieving high temperature tolerance.

[0014] It should be noted that the α-olefins selected in this application have ≥20 carbon atoms. Due to the high difficulty in obtaining high-purity monomers of long-chain α-olefins, the actual raw materials are usually industrial-grade wide fraction mixtures, whose composition includes α-olefin homologues with different carbon chain lengths. Although this multi-component system introduces molecular weight distribution characteristics, through the multi-site grafting reaction of terminal-side hydrogen-containing silicone oil, the stability of the silicone wax emulsion can still be effectively improved.

[0015] In any of the above technical solutions, the raw materials for the hydrosilylation reaction further include alkenyl sulfonate compounds; the molar ratio of the alkenyl sulfonate compounds to the silicon-hydrogen groups in the hydrogen-containing silicone oil is 0.05-0.1:1.

[0016] In any of the above technical solutions, the alkenyl sulfonate compound is sodium allyloxyhydroxypropyl sulfonate and / or sodium alkyl allyl succinate sulfonate.

[0017] In any of the above technical solutions, the preparation method of the silicone wax emulsion is as follows: Mix the alkenyl sulfonate compound and the hydrogen-containing silicone oil with terminal hydrogen in proportion, add 10-20 wt% of a platinum catalyst, and react at 70-90 °C for 1-2 h under nitrogen protection; then add an α-olefin and the remaining platinum catalyst, raise the temperature to 130-135 °C, and react for 2-6 h to obtain the silicone wax.

[0018] The present application further introduces a small amount of alkenyl sulfonate compound into the hydrosilylation system. The molecule of this compound has both an olefin reaction site and a sulfonate ion group. After the hydrosilylation reaction, the sulfonate group is embedded in the silicone wax molecular chain. When such a modified silicone wax is dispersed in an aqueous system, the sulfonate ions enriched on the surface enhance the stability of the emulsion droplets through electrostatic repulsion and steric hindrance effects, reducing the risk of emulsion stratification and demulsification. More importantly, in the application of cosmetics, the introduction of the sulfonate group breaks the limitation that the traditional silicone wax film layer is completely hydrophobic. Traditional silicone wax emulsions are used as wetting agents in cosmetics. By forming a silicone wax film on the skin surface, they slow down the evaporation of skin moisture and promote the repair of the skin stratum corneum barrier. However, the sealing property of this wax film layer also inhibits the absorption of hydrophilic active ingredients in cosmetics by the skin. The introduction of the sulfonate group can not only reduce the trans-epidermal water loss (TEWL), but also serve as a delivery site to allow the directional diffusion of water molecules and small molecule active ingredients (such as niacinamide and panthenol), solving the problem of inhibited absorption of active substances caused by the too strong sealing property of traditional silicone wax.

[0019] It should be noted that, in addition to having an olefin reaction site and a sulfonate ion group, sodium allyloxyhydroxypropyl sulfonate and sodium alkyl allyl succinate sulfonate also have hydrophilic groups such as hydroxyl groups and ester groups, and their active substance delivery ability is more prominent.

[0020] In any of the above technical solutions, the silicone wax emulsion contains 15-25 wt% of silicone wax, 3-8 wt% of emulsifier, and the balance is water.

[0021] In any of the above technical solutions, the emulsifier is a non-ionic surfactant.

[0022] Exemplarily, the emulsifier is selected from fatty alcohol polyoxyethylene ethers, alkylphenol polyoxyethylene ethers, polyethylene glycol fatty acid esters or polyol esters.

[0023] In a second aspect, the present application provides a method for preparing a silicone wax emulsion, including:

[0024] Put silicone wax and emulsifier into an emulsifying kettle, stir and melt at a constant temperature of 70-80 °C to obtain an oil phase; add deionized water at 70-80 °C dropwise to the oil phase, and stir evenly after adding to obtain an emulsion. Subject the emulsion to high-pressure homogenization until the average particle size of the emulsion is 50-100 nm.

[0025] In any of the above technical solutions, the stirring speed is 4000-6000 rpm.

[0026] In summary, the present application has the following beneficial effects:

[0027] This application uses hydrogen-containing silicone oil at the end side as a reaction matrix, and grafts C20+ long-chain α-olefins at multiple sites to the silicone oxygen main chain through hydrosilylation to construct a comb-like molecular structure. The high hydrophobicity of the long-chain alkyl group and the flexibility of the silicone oxygen chain work together to both reduce the crystallinity and broaden the melting temperature range through physical entanglement, and form a dense network through the van der Waals force between the alkyl chains, so that the emulsion can still inhibit the migration of the oil phase at high temperatures of 60-80 °C, and keep the emulsion homogeneous and stable after long-term storage. At the same time, an alkenyl sulfonate compound is introduced, and its sulfonic acid root group is embedded in the silicone wax molecular chain. On the one hand, the dispersion stability of the emulsion droplets is enhanced through electrostatic repulsion, and on the other hand, the limitation of the completely hydrophobic traditional silicone wax film is broken to form a selective permeation interface, which not only reduces the loss of skin moisture but also promotes the transdermal absorption of hydrophilic active ingredients. Detailed implementation mode

[0028] Preparation example

[0029] Preparation example 1, a kind of silicone wax, the raw material ratio is as follows:

[0030] Hydrogen-containing silicone oil at the end side: 1000 g (hydrogen content 0.36 wt%), model Runhe Materials RH-H536;

[0031] α-olefin: 67.75 g (molar ratio Si-H: olefin = 1:1.3), model Chevron alpha olefin C30+ (molecular weight 420);

[0032] Sodium allyloxyhydroxypropyl sulfonate: 3.72 g (molar ratio Si-H: sulfonate = 1:0.1);

[0033] Platinum catalyst mother liquor (1 wt% Pt): added in two times, the first time 0.2 g, the second time 1.9 g (corresponding to 0.021 g of platinum metal, accounting for 20 ppm of the reaction system).

[0034] The preparation steps are as follows:

[0035] Put the hydrogen-containing silicone oil at the end side, sodium allyloxyhydroxypropyl sulfonate and 0.2 g of platinum catalyst mother liquor into the reaction kettle, heat up to 80 °C under ammonia protection, and stir (300 rpm) for reaction for 1.5 h.

[0036] Add α-olefin and the remaining 1.9 g of platinum catalyst mother liquor, heat up to 132 °C, and continue the reaction for 4 h. Cool to room temperature to obtain a pale yellow transparent silicone wax.

[0037] Preparation Example 2, a silicone wax, with the raw material ratio as follows:

[0038] Hydrogen-containing silicone oil at the end side: 1000 g (hydrogen content 1.0 wt%), model Jiangsu Kexing DSH-100;

[0039] α-olefin: 150.68 g (molar ratio of Si-H:olefin = 1:1.4); model C20-C24 α-olefin (molecular weight 308);

[0040] Sodium alkyl allyl succinate sulfonate: 6.03 g (molar ratio of Si-H:sulfonate = 1:0.05);

[0041] Platinum catalyst mother liquor (1 wt% Pt): added in two portions, 0.2 g for the first time and 1.0 g for the second time (total platinum content of 1.2 g of mother liquor, corresponding to 0.012 g of platinum metal, accounting for 10 ppm of the reaction system).

[0042] The preparation steps are as follows:

[0043] Add the hydrogen-containing silicone oil at the end side, sodium alkyl allyl succinate sulfonate and 0.2 g of platinum catalyst mother liquor to the reaction kettle, heat up to 70 °C under ammonia protection, and stir (300 rpm) for 1 h.

[0044] Add α-olefin and the remaining 1.0 g of platinum catalyst mother liquor, heat up to 130 °C, and continue the reaction for 3 h. Cool to room temperature to obtain a pale yellow transparent silicone wax.

[0045] Preparation Example 3, a silicone wax, with the raw material ratio as follows:

[0046] Hydrogen-containing silicone oil at the end side: 1000 g (hydrogen content 0.36 wt%), model Runhe Materials RH-H536;

[0047] α-olefin: 52.89 g (molar ratio of Si-H:olefin = 1:1.15), model Dow Chemical C24-C28 α-olefin (molecular weight 364);

[0048] Sodium alkyl allyl succinate sulfonate: 4.34 g (molar ratio of Si-H:sulfonate = 1:0.1);

[0049] Platinum catalyst mother liquor (10 wt% Pt): added in two portions, 0.05 g for the first time and 0.48 g for the second time (total platinum content of 0.53 g of mother liquor, corresponding to 0.053 g of platinum metal, accounting for 50 ppm of the reaction system).

[0050] The preparation steps are as follows:

[0051] Add the terminal hydrogen-containing silicone oil, allyl succinic acid alkyl ester sulfonate, and 0.05 g of the platinum catalyst mother liquor into the reaction kettle. Heat up to 90 °C under ammonia protection and stir (300 rpm) for 2 h.

[0052] Add α-olefin and the remaining 0.48 g of the platinum catalyst mother liquor, heat up to 135 °C, and continue to react for 5 h. Cool to room temperature to obtain a pale yellow transparent silicone wax.

[0053] Preparation Example 4, a silicone wax, which is different from Preparation Example 1 in that the molar ratio of allyloxyhydroxypropyl sulfonate to the silicon hydride group in the hydrogen-containing silicone oil is 0.03:1, and the other components and their ratios remain unchanged. The amount of allyloxyhydroxypropyl sulfonate used is 1.12 g.

[0054] Preparation Example 5, a silicone wax, which is different from Preparation Example 1 in that the molar ratio of allyloxyhydroxypropyl sulfonate to the silicon hydride group in the hydrogen-containing silicone oil is 0.15:1, and the other components and their ratios remain unchanged. The amount of allyloxyhydroxypropyl sulfonate used is 5.58 g.

[0055] Preparation Example 6, a silicone wax, which is different from Preparation Example 1 in that allyloxyhydroxypropyl sulfonate is replaced with an equimolar amount of C30+α-olefin, and the other components and their ratios remain unchanged. The amount of α-olefin used is 73.08 g (molar ratio Si-H:olefin = 1:1.4).

[0056] Preparation Example 7, a silicone wax, which is different from Preparation Example 1 in that C30+α-olefin is replaced with an equimolar amount of C18α-olefin (1-octadecene, molecular weight 252), and the other components and their ratios remain unchanged. The amount of 1-octadecene used is 41.18 g (molar ratio Si-H:olefin = 1:1.3).

[0057] Preparation Example 8, a silicone wax, with the following raw material ratios:

[0058] Terminal hydrogen-containing silicone oil: 1000 g (hydrogen content 0.18 wt%), model Runhe Materials RH-H518;

[0059] α-olefin: 33.9 g (molar ratio Si-H:olefin = 1:1.3), model Chevron Alpha Olefin C30+ (molecular weight 420);

[0060] Allyloxyhydroxypropyl sulfonate: 1.86 g (molar ratio Si-H:sulfonate = 1:0.1);

[0061] Platinum catalyst mother liquor (1 wt% Pt): added in two portions, the first portion is 0.21 g, and the second portion is 1.86 g (corresponding to 0.0207 g of platinum metal, accounting for 20 ppm of the reaction system).

[0062] The preparation steps are the same as those in Preparation Example 1.

[0063] Preparation Example 9, a silicone wax, with the following raw material ratio:

[0064] Hydrogen-terminated silicone oil: 1000 g (hydrogen content 0.18 wt%), model Runhe Materials RH-H518;

[0065] α-olefin: 13.25 g (molar ratio Si-H:olefin = 1:1.3), 1-dodecene (molecular weight 168);

[0066] Platinum catalyst mother liquor (10 wt% Pt): 0.2 g (corresponding to 0.02 g of platinum metal, accounting for 20 ppm of the reaction system).

[0067] The preparation steps are as follows: Add the hydrogen-terminated silicone oil, α-olefin, and platinum catalyst mother liquor to the reaction kettle, heat up to 132 °C under ammonia protection, and stir (300 rpm) for 8 h. Cool to room temperature to obtain the silicone wax.

[0068] Examples

[0069] Example 1, a silicone wax emulsion, prepared according to the following steps:

[0070] Add 200 g of the silicone wax from Preparation Example 1 and 50 g of an emulsifier (aliphatic alcohol polyoxyethylene ether, HLB = 12) to the emulsification kettle, melt at a constant temperature of 70 °C, and stir at a speed of 5000 rpm. Slowly add 750 g of deionized water at 75 °C dropwise. After dropping, continue to stir for 30 min to obtain a mixed solution, and perform high-pressure homogenization (600 bar, circulate 3 times) to obtain an emulsion with an average particle size of 80 nm.

[0071] Example 2, a silicone wax emulsion, prepared according to the following steps:

[0072] Add 150 g of the silicone wax from Preparation Example 2 and 30 g of an emulsifier (alkylphenol polyoxyethylene ether, HLB = 14) to the emulsification kettle, melt at a constant temperature of 70 °C, and stir at a speed of 5000 rpm. Slowly add 820 g of deionized water at 80 °C dropwise. After dropping, continue to stir for 30 min to obtain a mixed solution, and perform high-pressure homogenization (800 bar, circulate 4 times) to obtain an emulsion with an average particle size of 50 nm.

[0073] Example 3, a silicone wax emulsion, prepared according to the following steps:

[0074] Add 250 g of the silicone wax from Preparation Example 3 and 80 g of an emulsifier (aliphatic alcohol polyoxyethylene ether, HLB = 12) to the emulsification kettle, melt at a constant temperature of 80 °C, and stir at a speed of 6000 rpm. Slowly add 670 g of deionized water at 80 °C dropwise. After dropping, continue to stir for 30 min to obtain a mixed solution, and perform high-pressure homogenization (1000 bar, circulate 5 times) to obtain an emulsion with an average particle size of 50 nm.

[0075] Example 4, a silicone wax emulsion, which is different from Example 1 in that the silicone wax of Preparation Example 4 is used to replace the silicone wax of Preparation Example 1 in equal amounts.

[0076] Example 5, a silicone wax emulsion, which is different from Example 1 in that the silicone wax of Preparation Example 5 is used to replace the silicone wax of Preparation Example 1 in equal amounts.

[0077] Example 6, a silicone wax emulsion, which is different from Example 1 in that the silicone wax of Preparation Example 6 is used to replace the silicone wax of Preparation Example 1 in equal amounts.

[0078] Comparative Example

[0079] Comparative Example 1, a silicone wax emulsion, which is different from Example 1 in that the silicone wax of Preparation Example 7 is used to replace the silicone wax of Preparation Example 1 in equal amounts.

[0080] Comparative Example 2, a silicone wax emulsion, which is different from Example 1 in that the silicone wax of Preparation Example 8 is used to replace the silicone wax of Preparation Example 1 in equal amounts.

[0081] Performance Detection Test

[0082] Test 1: High-temperature Stability Test

[0083] Sample Preparation: Take 50 mL of the silicone wax emulsions of Examples 1-6 and Comparative Examples 1-3 respectively, and dispense them into transparent glass bottles with stoppers and ground mouths.

[0084] Test Method: Place the samples in an incubator, and let them stand at 60 °C and 80 °C respectively. Observe and record the state of the emulsion every day, and record the number of days when oil separation (appearance of floating oil on the surface) occurs in the emulsion.

[0085] Table 1, High-temperature Stability Test Results

[0086]

[0087] The test results show that the oil separation periods of the silicone wax emulsions prepared in Comparative Example 1 (using short-chain octadecene as the raw material), Comparative Example 2 (using hydrogen-containing silicone oil at the end as the raw material), and Comparative Example 3 (using dodecene and hydrogen-containing silicone oil at the end as the raw material) are significantly shortened at high temperatures. It can be seen that when α-olefins with a carbon chain length less than C20 and / or silicone oils without hydrogen in the side chain are used as raw materials, the high-temperature stability of the obtained silicone wax emulsion decreases.

[0088] Test 2: Cosmetic Performance Test of Silicone Wax Emulsion

[0089] (1) Safety Performance Test

[0090] Samples: The silicone wax emulsions prepared in the above examples and comparative examples.

[0091] Refer to the human skin patch test method in the "2015 Cosmetics Safety and Technology Specifications" to conduct human safety patch tests. Select 30 subjects aged 18 - 60 years old, and use a qualified patch test device with an area not exceeding 50 mm 2 、a depth of about 1 mm. Take 0.02 mL of the above sample and place it in the small chamber of the patch test device. The control hole is a blank control (without placing any substance). Apply the patch test device with the silicone wax emulsion sample to the flexor side of the forearm of the subject with a low-allergy tape, and gently press it with the palm to make it evenly adhere to the skin for 24 h. Observe the skin reaction according to the standard in Table 2 at 30 min, 24 h, and 48 h after removing the patch test device, and record the observation results. The test results are shown in Table 3.

[0092] Table 2 Skin reaction grading standard for skin patch test

[0093]

[0094] Table 3 Results of human skin patch safety test

[0095] Sample 30 min 24h 48h Total result Example 1 0 0 0 None of the 30 people had a positive reaction Example 2 0 0 0 None of the 30 people had a positive reaction Example 3 0 0 0 None of the 30 people had a positive reaction Example 4 0 0 0 None of the 30 people had a positive reaction Example 5 0 0 0 None of the 30 people had a positive reaction Example 6 0 0 0 None of the 30 people had a positive reaction Comparative Example 1 0 0 0 None of the 30 people had a positive reaction Comparative Example 2 0 0 0 None of the 30 people had a positive reaction Comparative Example 3 0 0 0 None of the 30 people had a positive reaction

[0096] The test results show that the silicone wax emulsions prepared in all examples and comparative examples passed the human patch safety test.

[0097] (2) Water retention performance (trans-epidermal water loss rate TEWL) test

[0098] Sample preparation: Prepare 10 g of silicone wax emulsion (Examples 1 - 6 and Comparative Examples 1 - 3), 5 g of glycerin, 2 g of niacinamide, 0.5 g of carbomer, and 82.5 g of deionized water. Mix the silicone wax emulsion, glycerin, and niacinamide, and add carbomer for homogenization and emulsification.

[0099] Test method: Select 50 healthy women (with normal skin barrier) as subjects, aged 35 ± 3 years old, divided into 10 groups (including a blank control group), with 5 people in each group.

[0100] Test steps: 1. Designate a test area (2×2 cm 2 ) on the inner side of the forearm of the subject. After cleaning, measure the initial TEWL value (T O ). Evenly apply the sample (2 mg / cm 2 ) on the test area, and measure the TEWL value (T1) after 8 h. Calculate the trans-epidermal water loss rate: Trans-epidermal water loss rate = (T O - T1) / T O ×100%. Conduct parallel tests 3 times and take the average value.

[0101] Table 4 Test results of trans-epidermal water loss rate

[0102]

[0103] The test results show that the water retention capacity of the silicone wax emulsion prepared by using α-olefins with carbon atoms ≥ 20 and end-side hydrogen-containing silicone oil is significantly better than that of silicone wax prepared by C18 / C12 α-olefins or end-side hydrogen-containing silicone oil.

[0104] Test 3: Directional diffusion ability of active ingredients in silicone wax emulsion

[0105] Sample preparation: Example emulsion containing 0.5% fluorescein sodium (simulating small molecule active ingredient).

[0106] Test method: Franz diffusion cell method was used for testing.

[0107] Diffusion medium: phosphate buffer (pH 7.4), receiving cell volume 5 mL.

[0108] Skin model: pig ear skin (thickness 0.5 mm), fixed in the diffusion cell after pretreatment.

[0109] Experimental conditions: constant temperature of 37°C, magnetic stirring (300 rpm), and determination of the sodium fluorescein concentration in the receiving solution after 24 hours (HPLC method).

[0110] Penetration: Cumulative penetration (ug / cm2) was compared with the control group (no silicone wax emulsion).

[0111] Table 5 Test results of active ingredient directional diffusion ability

[0112]

[0113] The test results show that compared with Examples 1-5, the ability of the silicone wax emulsion of Example 6 (no olefin sulfonate is added to the reaction raw materials) to allow directional diffusion of active ingredients is significantly reduced, indicating that it has a high barrier property for effective hydrophilic active ingredients in cosmetics, which is not conducive to the active ingredients to play the role of moisturizing and repairing the skin.

[0114] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A silicone wax emulsion, characterized in that, It contains silicone wax, emulsifier and water. The silicone wax is prepared by hydrosilylation reaction from raw materials including terminal hydrogen-containing silicone oil and α-olefin. The molar ratio of the α-olefin to the silicon-hydrogen group in the terminal hydrogen-containing silicone oil is 1.1 - 1.5:1, and the number of carbon atoms of the α-olefin is ≥20.

2. The silicone wax emulsion according to claim 1, wherein The temperature of the hydrosilylation reaction is 70 - 135 °C.

3. The silicone wax emulsion according to claim 1, wherein, The dosage of the platinum catalyst in the hydrosilylation reaction is 2 - 100 ppm, and the reaction time is 2 - 8 h.

4. The silicone wax emulsion according to claim 1, wherein The hydrogen content of the terminal hydrogen-containing silicone oil is 0.3 - 1.55 wt%.

5. The silicone wax emulsion according to claim 1, wherein The raw materials for the hydrosilylation reaction further include alkenyl sulfonate compounds; the molar ratio of the alkenyl sulfonate compounds to the silicon-hydrogen group in the hydrogen-containing silicone oil is 0.05 - 0.1:

1.

6. The silicone wax emulsion according to claim 5, wherein, The alkenyl sulfonate compounds are sodium allyloxyhydroxypropyl sulfonate and / or sodium alkyl allyl succinate sulfonate.

7. The silicone wax emulsion according to claim 5, characterized in that, The preparation method of the silicone wax emulsion is as follows: Mix the alkenyl sulfonate compounds and the terminal hydrogen-containing silicone oil in proportion, add 10 - 20 wt% of the platinum catalyst, and react at 70 - 90 °C for 1 - 2 h under nitrogen protection; then add the α-olefin and the remaining platinum catalyst, raise the temperature to 130 - 135 °C, and react for 2 - 6 h to obtain the silicone wax.

8. The silicone wax emulsion according to claim 1, wherein The silicone wax emulsion contains 15 - 25 wt% of silicone wax, 3 - 8 wt% of emulsifier, and the balance is water.

9. The silicone wax emulsion according to claim 1, wherein The emulsifier is a non-ionic surfactant.

10. A method for preparing a silicone wax emulsion, characterized in that, It includes: Put the silicone wax and the emulsifier into an emulsifying kettle, stir and melt at a constant temperature of 70 - 80 °C to obtain an oil phase; drop deionized water at 70 - 80 °C into the oil phase, stir evenly after adding to obtain an emulsion, and perform high-pressure homogenization treatment on the emulsion until the average particle size of the emulsion is 50 - 100 nm.

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