Emulsification method
A surfactant-free emulsion using acrylic acid methacrylic acid copolymer and carbomer with ammonia stabilizes oil and water, achieving long-term stability and preserving the skin's barrier function.
Patent Information
- Application Number
- JP2024128245
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-07-18
- Publication Date
- 2026-01-29
AI Technical Summary
Existing cosmetic emulsions that aim to improve wrinkles without surfactants fail to achieve long-term stability and compromise the skin's barrier function due to the use of hydrophilic nanoparticles and surfactants.
A surfactant-free emulsion is created using an acrylic acid methacrylic acid copolymer, carbomer, and ammonia, which are dispersed and mixed to stabilize oil and water, allowing for stable emulsification without skin penetration.
The emulsion maintains stability for three years at room temperature and preserves the skin's barrier function by minimizing skin penetration, ensuring the safety and efficacy of UV-absorbing capsules.
Smart Images
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Figure 2026015113000002
Abstract
Description
[Technical Field]
[0001] This technology relates to a method for stably emulsifying water and oil without using surfactants. [Background technology]
[0002] As the population ages, research is being conducted into wrinkle-fighting technologies, and various cosmetic products have been proposed. Wrinkles are caused by dryness, exposure to ultraviolet rays, and facial expressions. To improve wrinkles, moisturizing with creams and protection from ultraviolet rays by absorbing them are recommended, but repeated and continuous use is required.
[0003] Known ingredients for improving wrinkles include tretinoin, which promotes skin turnover, EGF, which encourages skin growth and regeneration, and hyaluronic acid, which maintains skin firmness and moisture. Anti-wrinkle creams are said to improve wrinkles by repeatedly penetrating these ingredients into the skin. However, it is said that maintaining the skin's barrier function is the most important factor in improving wrinkles.
[0004] To improve wrinkles, high-quality oils and moisture-retaining hydration are necessary to maintain the skin's barrier function, and cream or lotion emulsions are ideal. To produce an emulsion, a surfactant must be used to stably emulsify the water and oil layers. However, surfactants penetrate the skin, causing roughness and impairing the skin's barrier function. The challenge was to find a way to emulsify without using surfactants. In recent years, a technology called three-phase emulsification has been developed, which claims to be surfactant-free. In reality, it claims to use hydrophilic nanoparticles instead of surfactants and utilize van der Waals forces to emulsify. However, hydrophilic nanoparticles contain large amounts of surfactants, so they cannot be considered surfactant-free. [Patent documents]
[0005] [Patent Document 1] Patent No. 3855203 [Patent Document 2] Patent No. 3858230 [Patent Document 3] Patent Publication No. 2013-230266 (Patent Application No. 2013-116786) Summary of the Invention [Problem to be solved by the invention]
[0006] One method of emulsifying without using surfactants is to use polymers, but this is not sufficient to achieve the long-term storage stability (three years at room temperature) required for cosmetics.
[0007] In this invention, a highly safe polymer is used that has little penetration into the skin, and no surfactants are used. TIFF2026015113000001.tif10160Methods to resolve the issue
[0008] As a result of extensive research, the present inventors have discovered that by blending an acrylic acid methacrylic acid copolymer, carbomer, and ammonia, oils such as liquid paraffin and water can be mixed stably at will, and have completed the present invention.
[0009] Acrylic acid methacrylic acid copolymer with a molecular weight of 50,000 to 1,000,000 is pre-dispersed in water. Liquid paraffin is added and emulsified, but sufficient stability is not achieved.
[0010] TIFF2026015113000002.tif7160Effects of the invention
[0011] The emulsion obtained by this invention was stable at room temperature for three years. It is fully marketable as a cosmetic emulsion. Furthermore, because it is a polymer, it hardly penetrates the skin, and the skin's barrier function is not impaired.
[0012] The UV-absorbing capsules of claim 2 were then added and the emulsion was stirred to check for stability, which was also stable for three years. When emulsified using a normal surfactant, the capsules break down due to the surfactant's influence, causing the UV absorber inside to leak out and making the emulsion unsafe for the skin. However, when emulsified using only the polymer of claim 1, the capsules did not break and were stable. (Best Mode for Carrying Out the Invention)
[0013] Disperse acrylic acid copolymer in water. Separately, disperse carbomer and mix. Add oil and stir. Then add ammonia and further stir and emulsify.
[0014] The pH of the resulting emulsion was 6.
[0015] Capsules containing an ultraviolet absorber were added to this emulsion, which was then further stirred to obtain a stable emulsion.
[0016] The effects will be shown in the following examples. Example 1 Ingredients Ingredient name Amount (%) 1 Acrylic acid methacrylic acid crosspolymer 0.2 2 Carbomer 0.2 3 Wednesday 76.3 4 Ammonia water 0.3 5 Liquid paraffin 15.0 6 Encapsulated UV absorber 8.0 Total 100
[0017] Disperse ingredients 1, 2, 4, and 6 evenly in ingredient 3.
[0018] Add ingredient 5 and stir until uniformly mixed.
[0019] After leaving it overnight, fill it into a container. (Measurement of effectiveness)
[0020] The sample filled in the container is observed over time.
[0021] The emulsion was stable after 3 years of observation at room temperature.
Claims
1. A cosmetic emulsion containing acrylic acid methacrylic acid crosspolymer, carbomer, and ammonia, and containing moisture and oil.
2. The emulsion of claim 1 to which an encapsulated ultraviolet absorber has been added.